Toxoplasmosis of animals and humans, second edition
Abstract
Found worldwide from Alaska to Australasia, Toxoplasma gondii knows no geographic boundaries. The protozoan is the source of one of the most common parasitic infections in humans, livestock, companion animals, and wildlife, and has gained notoriety with its inclusion on the list of potential bioterrorism microbes. In the two decades since the publication of the first edition of Toxoplasmosis of Animals and Humans there has been an explosion of knowledge concerning T. gondii and toxoplasmosis. Still used extensively as a cell model, its genome has recently been published making it a subject of even greater scientific interest. Keeping the organizational style that made the previous edition so popular and usable, this second edition has been completely revised and updated. New in the Second Edition: Expanded information on the cultivation, maintenance, and preservation of T. gondii Expanded information on the cell biology and molecular biology of the parasite Reviews all literature from the past 20 years for each domestic animal Summarizes information on the worldwide prevalence of toxoplasmosis in pregnant women and the devastating disease it can cause in newborn Written by one of the pioneers of the field, the book provides unique information on all known host types for this parasite. It distills the voluminous and potentially confusing scientific literature that has grown geometrically in the 20 years since the publication of the first edition into a comprehensive resource. The single author approach ensures a strong foundation in the biology and a seamless integration of topics. The new edition of this groundbreaking work is the only volume to cover toxoplasmosis of animals and humans thoroughly in one source. It supplies an entry point to further research by cutting through the morass of literature to identify the most relevant references.
... T. gondii infection can be transmitted through several routes to different hosts. Water or food contaminated with oocysts, undercooked meat, are the main sources of T. gondii infection in humans (Dubey, 2021). In Indonesia, the seroprevalence of toxoplasmosis in humans is 58.13% (Perdana, 2024). ...
... Toxoplasmosis is one of the important zoonotic diseases in the world because it causes birth defects of 2-8 million babies by the year (Smith et al., 2021). Felidae, especially cats, are the definitive hosts of T. gondii (Dubey, 2021). Oocysts in feces are intermediaries for the transmission of the T. gondii parasite, where water is a good medium for the existence of oocysts from T. gondii. ...
... In Morocco, Toxoplasma contamination in water sources was 17.3% and combined contamination of Toxoplasma with Giardia was 16.3% (Berrouch et al., 2023). Toxoplasmosis has been reported to be transmitted through drinking water from 1960 to 2020, around 34 acute toxoplasmosis outbreaks were reported worldwide, of which 21% were waterborne (Dubey, 2021). Outbreaks in water sources in Brazil were 931 confirmed cases in 2018, India had 248 cases in 2004 and Canada had 100 cases in 1995 (Arquilella et al., 2019), in China 1.9% through PCR testing (Lass et al., 2022) and in 15% of water sources in Serbia (Cirkovic et al., 2020). ...
Toxoplasmosis is one of the zoonotic diseases caused by the protozoa Toxoplasma gondii. The disease infects warm-blooded animals including humans. The purpose of this study was to determine the contamination of Toxoplasma oocysts in water sources in goat-sheep farms in Sidoarjo Regency. A total of 63 water samples were used for the study. Water samples were taken from 5 sub-districts that have many goat-sheep farms, each sub-district has 2 villages, with each village having 6-7 samples. The examination used the floating method and was examined under a microscope with a magnification of 400x. The results of the examination found 21 samples of Toxoplasma gondii oocysts or 33.33% (21/63). The morphology of T.gondii oocysts is round, ovoid or ellipsoid with sizes varying between 8.02 - 12.72 micrometers. Preventive measures are needed by treating water before giving it to livestock.
... These tissue cysts survive throughout the host's lifetime and can infect any human or animal that consumes them. Thus, the consumption of undercooked or raw meat from infected meat-producing animals may pose a risk to public health [6,7]. Oocysts are shed with the faeces of infected felids, particularly kittens, sporulate and may contaminate food, fresh produce, shellfish, and water leading to human infection following consumption [7][8][9]. ...
... Thus, the consumption of undercooked or raw meat from infected meat-producing animals may pose a risk to public health [6,7]. Oocysts are shed with the faeces of infected felids, particularly kittens, sporulate and may contaminate food, fresh produce, shellfish, and water leading to human infection following consumption [7][8][9]. In addition, humans acquire T. gondii by ingesting undercooked meat containing viable tissue cysts or unpasteurised milk and dairy products containing tachyzoites [10,11]. ...
... It should be noted that consumers prefer "ready-to-eat" products and favour meat from animals raised in organic farms, i.e., with access to outdoor grazing. On top of that, the tendency to consume rare or raw meat not previously frozen may also increase the risk of ingesting infective T. gondii tissue cysts [7]. ...
Simple Summary
Toxoplasma gondii is a parasite that can infect humans and animals, mainly through meat consumption. It is also the second most important pathogen transmitted with food in Europe. However, detecting the presence of T. gondii in animal meat differs on a country basis since there are no mandatory controls along the food chain in the European Union. Underreporting of cases is still a problem in many countries like Greece. The current review examines the prevalence of T. gondii in animals in Greece and identifies the risks associated with meat transmission. Certain animals like sows, wild boars, hares, equines, and cats had lower levels of infection, while sheep and goats generally had higher levels compared to other European countries and to the global averages. The level of infection in chickens was similar between Greece and Europe, while there was high variation in cattle studies, with no data regarding dairy products. Until now, Greece has not implemented a comprehensive system to ensure meat safety, particularly regarding T. gondii. This review highlights the preventive measures that the state should implement to ensure food safety and protect public health, as well as the various control measures that should be adopted by consumers to reduce the infection risk.
Abstract
Toxoplasma gondii is a zoonotic protozoon with a complex life cycle and the second most important foodborne pathogen in Europe. Surveillance of toxoplasmosis is based on national considerations since there are no mandatory controls along the food chain in the European Union, and underreporting of meat is still a problem in many countries like Greece. The current review provides an overview of T. gondii prevalence, associated risk factors, and surveillance in animals in Greece, focusing on the transmission role of meat and highlighting the control measures that should be adopted by consumers. Sows, wild boars, hares, equines, and cats had lower, while sheep and goats generally had higher seroprevalence than their respective pooled European and global values. Seroprevalence in chickens was similar between Greece and Europe, while there was high variation in cattle studies, with no data regarding dairy products. Though a comprehensive meat safety assurance system is the most effective approach to control the principal biological hazards associated with meat, such as T. gondii, the prerequisite risk categorisation of farms and abattoirs based on EFSA’s proposed harmonised epidemiological indicators has not materialised as yet in Greece. Therefore, comprehensive control strategies are still required to ensure food safety and safeguard public health.
... A toxoplasmose é uma infecção comumente transmitida por alimentos e água contaminados pelo protozoário Toxoplasma gondii. Mundialmente, é considerada uma das zoonoses mais amplamente propagadas, tanto entre humanos quanto em animais [1,2]. A infecção pode ocorrer pela ingestão de alimentos ou água contaminados com oocistos que são excretados nas fezes de felinos domésticos ou selvagens, durante curto período, e apenas na primoinfecção. ...
... O período de incubação é de 10 a 23 dias quando ingeridos cistos teciduais e, de 5 a 20 dias, no caso de ingestão de oocistos. [1,2] A sintomatologia e patogênese da infecção por T. gondii são variáveis e associadas ao estágio da infecção e à via de exposição. A infecção por T. gondii, na maioria das pessoas primoinfectadas, resulta majoritariamente em quadros assintomáticos ou oligossintomáticos, sem a necessidade de tratamentos específicos. ...
... A infecção por T. gondii, na maioria das pessoas primoinfectadas, resulta majoritariamente em quadros assintomáticos ou oligossintomáticos, sem a necessidade de tratamentos específicos. Quando sintomático, o quadro mais característico da fase aguda é a linfadenopatia localizada, com presença de nódulos linfáticos cervicais posteriores, podendo haver também presença de febre, com duração entre uma semana e um mês [1,2,6,7]. ...
Antecedentes: Um surto de toxoplasmose ocorreu entre trabalhadores de uma indústria madeireira do município de Lages,
Santa Catarina, Brasil, entre março e agosto de 2022. População e métodos: Foi realizado um estudo do tipo coorte
retrospectiva entre todos os trabalhadores ativos da sede da indústria madeireira. Como instrumento de coleta de dados, foi
utilizado um questionário semiestruturado. Foi coletada amostra de sangue para processamento de anticorpos imunoglobulina
M (IgM), G (IgG) e avidez de IgG de cada trabalhador. Os casos confirmados foram aqueles com IgM+ e IgG- ou IgM+ e IgG+
com baixa avidez. Foram utilizadas medidas de frequência absoluta e relativa, de tendência central e dispersão. Foi calculado
a razão de risco (RR) para as fontes de exposição, e coletadas amostras de água, alimentos e lodo para pesquisa de DNA de
Toxoplasma gondii. Resultados: A taxa de ataque foi 39.3%. A curva epidêmica sugeriu a ocorrência de um surto contínuo de
fonte comum. Dos casos de toxoplasmose aguda, 47 (73.4%) eram do sexo masculino, 38 (59.4%) da raça/cor não branca. A
ingestão de água via bebedouros apresentou RR de 3.7 (IC 95%: 1.1 - 14.4). Não foi encontrada a presença de T. gondii em
amostras de água, alimentos o lodo.. Discusión: Foi confirmado um surto de toxoplasmose entre trabalhadores da indústria
madeireira local, por fonte comum e exposição contínua, associada à ingestão de água via bebedouros da empresa.
Recomendou-se intensificar as ações de vigilância da água potável do estado e do município.
... Tissue cysts can range in size (5-70 mm) and can contain a few to hundreds of bradyzoites [11]. Toxoplasmosis is diagnosed using a variety of techniques, most frequently serological ones. ...
... Common symptoms of T. gondii infection in cats can include fever, ocular inflammation, anorexia, lethargy, abdominal discomfort and neurologic abnormalities [16]. Most infected cats are asymptomatic, whereas clinical toxoplasmosis is mostly manifested in pneumonia, and in cats that subsequently died the most common signs were sensory depression and anorexia [11]. Other consequences of the infection are hepatitis, pancreatic necrosis, myositis, myocarditis, uveitis, dermatitis, and encephalitis with the worst lesions being in kittens with congenital infections [90,91]. ...
... Generally, in immunocompetent patients' treatment is usually unnecessary since the infection is subclinical and the immune response is able to control it. However, in immunocompromised patients (including HIV and other risk groups), the patients need to be treated and monitored since toxoplasmosis is a major cause of death among AIDS patients [11]. In these patients, the recommended treatment is a combination of two drugs, pyrimethamine (25-100 mg daily) and trisulfapyrimidines (2-6 g daily), administered for 1 month where this combination acts by inhibiting the enzyme, dihydrofolatereductase, of T. gondii preventing the synthesis of DNA and proteins. ...
Toxoplasmosis is an obligate intracellular protozoon that infects warm-blooded animals and humans, causing multiple manifestations. It can cause serious ocular disease, even in immune competent people, as well as abortions and encephalitis in domestic and wild animals. It can also result in fatal encephalitis in immunosuppressed individuals; if first contracted during pregnancy, it can result in miscarriage or congenital defects in the newborn. The parasite then penetrates the intestinal epithelial barrier and spreads from the lamina propria to a wide range of other organs in the body. The disease has a complex epidemiology and is spread by consumption of oocysts that are shed in the faeces of definitive feline hosts and contaminate water, soil, and crops, or by consumption of intracellular cysts in undercooked meat from intermediate hosts. Congenital infection is mostly diagnosed through laboratory testing, such as PCR and serologic assays, which also helps with the confirmation diagnosis of toxoplasmic encephalitis and ocular toxoplasmosis. For prevention and control, programs on the parasite and avoiding contact with infectious stages; biosecurity and sanitation to ensure the safety of food and water; chemo-and immunotherapeutic to control active infections and disease; prophylactic measures to prevent the infection of livestock and the formation of cysts in meat; and vaccines to prevent oocyst shedding by permanent feline hosts.
... The present study used an ELISA technique for the detection of both parasites, which is considered to have higher specificity and sensitivity compared to other serological methods [47]. Cross-reactions between T. gondii and N. caninum have been demonstrated to occur when IFAT was used given that a high concentration of fluorescent antibodies against apical organelles antigens of numerous apicomplexan parasites is common [48]. Notably, the majority of goats seropositive for T. gondii and N. caninum were adult animals. ...
... In Malaysian ruminant farms, semi-intensive management systems provide opportunities for livestock to graze externally in contrast to intensive systems where the animals are confined. Such practices heighten the exposure to oocysts, which are widely distributed in the environment, thereby increasing the risk of T. gondii infection [48]. ...
... Such animals are more likely to be exposed to these infections from various sources since they have lived longer. Therefore, older goats are less resistant to T. gondii infection as a result of lower defense mechanisms associated with aging [3,48]. ...
Simple Summary
Toxoplasma gondii, Neospora caninum, and Besnoitia besnoiti are important causes of production losses in small and large ruminants. These parasites could result in severe economic losses to farmers if they are not effectively controlled. The prevalence of these parasites in smallholder farms in Malaysia is underreported. Thus, this study attempted to determine the level of exposure of cattle and goat population from 19 farms in Selangor, Malaysia to T. gondii, N. caninum, and B. besnoiti using ELISA test kits. Results revealed that the prevalence of T. gondii, N. caninum, and B. besnoiti antibodies in the sampled cattle was 5.3%, 2.5%, and 5.7%, respectively. The corresponding seroprevalence in the sampled goats was 69.8% for T. gondii and 3.9% for N. caninum antibodies. Further analyses demonstrated that older animals, semi-intensive management systems, the presence of dogs or cats on farms, a large herd size (>100 animals), and the source of replacement stock increased the risk of exposure to T. gondii. These findings reflect the extent of T. gondii, N. caninum, and B. besnoiti infections in smallholder farms in Selangor. More research is required to develop effective measures to control these important parasites at the national level.
Abstract
Apicomplexan parasites such as Toxoplasma gondii, Neospora caninum, and Besnoitia besnoiti are widely recognized as causes of production diseases in ruminants. This study aimed to investigate the serological occurrence of T. gondii, N. caninum, and B. besnoiti in cattle and goats from smallholder farms in Selangor, Malaysia. A cross-sectional study was conducted on 19 farms by collecting 404 bovine (n = 225) and caprine (n = 179) serum samples, which were then essayed for T. gondii, N. caninum, and B. besnoiti antibodies using commercially available ELISA test kits. Farm data and animal characteristics were documented, and the data were analyzed using descriptive statistics and logistic regression models. The seroprevalence of T. gondii at animal and farm levels in cattle was 5.3% (95% CI 1.2–7.4%) and 36.8% (95% CI 22.4–58.0%), respectively. Animal-level seropositivity for N. caninum was 2.7% (95% CI 0.4–4.2%) and 5.7% for B. besnoiti (95% CI 1.3–9.4%) with corresponding farm-level seropositivity of 21.0% and 31.5%, respectively. For the goat samples, a high animal- (69.8%; 95% CI 34.1–82.0%) and farm-level (92.3%) seropositivity was recorded for T. gondii, but was relatively lower for N. caninum antibodies, at 3.9% (95% CI 1.5–6.2%) and 38.4% (5/13). The factors associated with T. gondii seropositivity were older animals (above 12 months) (OR = 5.3; 95% CI 1.7–16.6), semi-intensive farms (OR = 2.2; 95% CI 1.3–6.2), the presence of either dogs or cats (OR = 3.6; 95% CI 1.1–12.3), a large herd size (>100 animals) (OR = 3.7; 95% CI 1.4–10.0), and a single source of replacement animals (OR = 3.9; 95% CI 1.6–9.6). These findings are vital in developing effective control measures against these parasites in ruminant farms in Selangor, Malaysia. More national epidemiological research is required to elucidate the spatial distribution of these infections and their potential impact on Malaysia’s livestock industry.
... Toxoplasma gondii is a protozoan parasite that can cause severe disease in humans and many species of animals (Dubey, 2022). Felids are the definitive hosts of this parasite, while other warm-blooded animals serve as intermediate hosts. ...
... Felids are the definitive hosts of this parasite, while other warm-blooded animals serve as intermediate hosts. The infections can be acquired through the ingestion of raw/undercooked meat or vegetables containing oocysts or drinking water contaminated with the feces of the infected felids (Dubey, 2010;2022). ...
... There are numerous surveys of T. gondii infection in domestic and wild animals worldwide, but little is known of its infection in Siberian tigers (Panthera tigris altaica) and giant pandas (Ailuropoda melanoleuca) (Loeffler et al. 2007;Dubey, 2010;2022). Heilongjiang Siberian Tiger Park and Dujiangyan Panda Park are two popular scenic spots in China. ...
Toxoplasmosis, caused by Toxoplasma gondii, is a worldwide zoonosis. The aim of the present study was to detect the seroprevalence of T. gondii infection and associated risk factors among Siberian tigers (Panthera tigris altaica) and giant pandas (Ailuropoda melanoleuca) in China. Blood samples from 112 Siberian tigers and 22 giant pandas were tested for immunoglobulin G (IgG) against T. gondii by enzyme-linked immunosorbent assay (ELISA). The seroprevalence of T. gondii infection was 7.14% among Siberian tigers and 9.09% among giant pandas. No risk factors were found to be significantly associated with seroprevalence (P > 0.05). This is the first study to evaluate T. gondii infection in Siberian tigers on a large scale in China, and it also updates the information regarding the positivity rate of T. gondii infection among giant pandas in China.
... Toxoplasma gondii is one of the intracellular protozoan parasites that could infect mammals and birds, including humans and felines (Dubey, 2010;Pappas et al., 2009;Waldman et al., 2020). Generally, felines serve as the definitive host of T. gondii; they specifically excrete millions of environmentally resistant oocysts. ...
... Furthermore, cats could re-shed oocysts after secondary or tertiary T. gondii infection (Dubey, 1995;Zulpo et al., 2018). Under the mild environmental condition, the infectious sporulated oocysts could survive more than 1 year (Dubey, 2010). Hence, captive felids (e.g., in zoos) infected with T. gondii can be a possible contamination source for other animals and humans. ...
... Tissue samples (50 g: namely heart, tongue, skeletal muscle, diaphragm, or brain) from the four tigers were homogenized and digested in pepsin solution, respectively (Dubey, 2010). The homogenates were injected subcutaneously into Swiss mice (n = 3-5) and IFN-γ − /− mice (n = 1). ...
Toxoplasmosis is one of the most common zoonotic diseases in the world. Felines excrete Toxoplasma gondii oocysts, which play a key role in the transmission of this protozoon. Pathological diagnoses were performed on four carcasses of captive tigers collected from 2019 to 2021 in China, and T. gondii was surveyed using serology, molecular analysis, and aetiology. Striated muscle samples of the tigers (n = 4) were bioassayed in mice. DNA derived from T. gondii tachyzoites was isolated and characterized using PCR–RFLP. The pathological diagnoses revealed that ageing, declined immune function, liver, and kidney failures caused the deaths in the tigers examined. A modified agglutination test (cut–off: 1:25) revealed that IgG antibodies to T. gondii were 100% (4/4) in the captive tigers. Two viable T. gondii strains (TgTigerCHn3 and TgTigerCHn4) were isolated from tiger striated muscles and seeded on the Vero cell culture for further propagation. The genotypes of TgTigerCHn3 and TgTigerCHn4 were ToxoDB#20 and ToxoDB#2, respectively. The two strains were avirulent for Swiss mice, which matched the ROP18 and ROP5 gene alleles of TgtigerCHn3 (3/4) and TgtigerCHn4 (3/3). Few brain tissue cysts (0–213) were observed in the mice after inoculation with TgTigerCHn3 and TgTigerCHn4. This is the first documented isolation of T. gondii ToxoDB#20 and ToxoDB#2 from tigers. The results provide additional direct evidence of tiger as intermediate hosts for Toxoplasma gondii. Tigers in the zoos may potentially transmit T. gondii to other animals and humans.
... Toxoplasma gondii (T. gondii), the etiological agent of toxoplasmosis, is an intracellular protozoan parasite (Dubey, 2010a) with a worldwide distribution with the exception of Artactica (Li et al., 2020;Al-Malki et al., 2021). The definitive hosts for T. gondii are cats and other felids (Dubey, 2010a). ...
... gondii), the etiological agent of toxoplasmosis, is an intracellular protozoan parasite (Dubey, 2010a) with a worldwide distribution with the exception of Artactica (Li et al., 2020;Al-Malki et al., 2021). The definitive hosts for T. gondii are cats and other felids (Dubey, 2010a). The parasite has a broad range of intermediate hosts (Markovic et al.,2014) comprising mammals including humans and birds which harbor the cysts stage in their tissues (Foroutan et al., 2019;Opsteegh et al., 2016). ...
... In humans, infection with T. gondii occurs through ingestion of oocysts shed by cats (Wang et al., 2017), consumption of bradyzoites in raw or undercooked meat from intermediate hosts (Tenter et al., 2000;Weiss and Dubey, 2009), congenital infection, blood transfusion, and organ transplant (Morris et al., 2010). The main sources of T. gondii infection for domestic animals including donkeys are water or feed contaminated with sporulated oocysts and probably from mother to fetus (Dubey, 2010a). In livestock, especially small ruminants, T. gondii is mainly involved in abortions (Hussein et al., 2011), reproductive failure (Fernández-Escobar et al., 2020), loss of milk production (Ali et al., 2021), and production of weaker offsprings (Khan and Noordin, 2020). ...
Toxoplasma gondii is an intracellular parasite of zoonotic concern and economic importance in humans and animals, respectively. This study was conducted to determine the occurrence of T. gondii and associated risk factors in domestic donkeys from Kirinyaga and Meru counties in Kenya. Blood samples were collected from 363 randomly selected donkeys for detection of antibodies to T. gondii using a commercial kit ID Screen® Toxoplasmosis Multi-species indirect enzyme-linked immunosorbent assay (ELISA). The data on risk factors were collected by interviewing donkey owners using epidemiological questionnaire. Serum antibodies to T. gondii were detected in 26.4% (95% CI: 22.2–31.3) of the donkeys. The analysis showed that age of donkeys (OR = 2.484, 95% CI: 1.315–4.693; p = 0.005) was associated with increased risk for T. gondii seroprevalence while county of origin of donkeys (OR = 0.182, 95% CI: 0.083–0.400; p = 0.000), residential place of donkeys (OR = 0.301, 95% CI: 0.136–0.665; p = 0.003), rearing chicken (OR = 0.203, 95% CI: 0.064–0.644; p = 0.007), and donkey production system (OR = 0.644, 95% CI: 0.456–0.909; p = 0.012) were associated with reduced risk of T. gondii seroprevalence. This is the first report to provide epidemiological information on T. gondii infection among donkeys in Kenya. The presence of antibodies to T. gondii in donkeys suggests the high potential of transmission to other animals and humans. Regular monitoring and control of T. gondii infection in donkeys were recommended in the study area.
... In most cases, the immune system can control T. gondii infection, and hosts remain asymptomatic (Weiss and Dubey 2009). However, the parasite could cause severe disease in immunocompromised individuals, such as patients with AIDS (Dubey 2010(Dubey , 2022. ...
... Once the host ingests T. gondii tissue cysts or oocysts, the parasites penetrate the intestine and rapidly disseminate through all the organs (Dubey 2010). The T. gondii (Me 49 strain) can promote strong Th1 responses and result in the loss of Paneth cells and their secreted antibacterial substances in C57BL/6 mice; owing to the lack of antibacterial substances, the abundance of E. coli expanded dramatically, thereby accelerating the development of toxoplasmosis (Raetz et al. 2013;Burger et al. 2018). ...
Oral infection of mice with several strains of Toxoplasma gondii results in intestinal pathological lesions, which contributes to the invasion of this parasite. However, the exact mechanism is unclear, and only a few strains have been explored. Here, T. gondii TgSheepCHn5 and TgRedpandaCHn1 strains from sheep and red panda were evaluated. The TgSheepCHn5 and TgRedpandaCHn1 strains induced intestinal lesions, loss of Paneth cells, and gut commensal bacteria dysbiosis in Swiss Webster mice. The lesions and loss of Paneth cells were dependent on IFN-γ and gut commensal bacteria during T. gondii infection. Deleting IFN-γ or gut commensal bacteria suppressed the Th1 immune response, alleviated the lesions and parasite loading, and upregulated the number of Paneth cells. Loss of IFN-γ production accelerated mice death, whereas the deletion of gut commensal bacteria enhanced the survival time of the host. The Th1 cell immune responses have positive and negative effects on toxoplasmosis, resistance to T. gondii infection, and acceleration intestine lesions. Adjustment of Th1 cell responses and gut commensal bacteria may be effective treatments for toxoplasmosis.
... This scenario in raccoons is different from the related protozoan infection, toxoplasmosis. In most of the Order Carnivora, clinical toxoplasmosis in dogs and other canids occurs during dual CDV and T. gondii infection (Dubey, 2010(Dubey, , 2022b. Unlike Sarcocystis, bradyzoites released from the ruptured cyst can initiate remultiplication of T. gondii. ...
... Apparently, raccoons are resistant to clinical toxoplasmosis, and we are not aware of documentation of clinical toxoplasmosis in raccoon, despite CDV infection outbreaks. Many factors including differences in virulence of strains affect clinical outcome of toxoplasmosis (Dubey, 2022b). Whether the strain SN-39R is more virulent than other strains remains to be further evaluated. ...
Here, we report the first known outbreak of clinical protozoal myeloencephalitis in naturally infected raccoons by the parasite Sarcocystis neurona. The North American opossum (Didelphis virginiana) and the South American opossum (Didelphis albiventris) are its known definitive hosts. Several other animal species are its intermediate or aberrant hosts. The raccoon (Procyon lotor) is considered the most important intermediate host for S. neurona in the USA. More than 50% of raccoons in the USA have sarcocysts in their muscles, however clinical sarcocystosis in raccoons is rare. In 2014, 38 free-living raccoons were found dead or moribund on the grounds of the Saint Louis Zoo, Missouri, USA. Moribund individuals were weak, lethargic, and mildly ataxic; several with oculo-nasal discharge. Seven raccoons were found dead and 31 were humanely euthanized. Postmortem examinations were conducted on nine raccoons. Neural lesions compatible with acute sarcocystosis were detected in eight raccoons. The predominant lesions were meningoencephalitis and perivascular mononuclear cells. Histologic evidence for the Canine Distemper Virus was found in one raccoon. Schizonts and merozoites were present in the encephalitic lesions of four raccoons. Mature sarcocysts were present within myocytes of five raccoons. In six raccoons, S. neurona schizonts and merozoites were confirmed by immunohistochemical staining with S. neurona-specific polyclonal antibodies. Viable S. neurona was isolated from the brains of two raccoons by bioassay in interferon gamma gene knockout mice and in cell cultures seeded directly with raccoon brain homogenate. Molecular characterization was based on raccoon no. 68. Molecular characterization based on multi-locus typing at five surface antigens (SnSAG1-5-6, SnSAG3 and SnSAG4) and the ITS-1 marker within the ssrRNA locus, using DNA isolated from bradyzoites released from sarcocysts in a naturally infected raccoon (no. 68), confirmed the presence of S. neurona antigen type I, the same genotype that caused a mass mortality event in which 40 southern sea otters stranded dead or dying within a 3 week period in April 2004 with S. neurona-associated disease. An expanded set of genotyping markers was next applied. This study reports the following new genotyping markers at 18S rRNA, 28S rRNA, COX1, ITS-1, RON1, RON2, GAPDH1, ROP20, SAG2, SnSRS21 and TUBA1 markers. The identity of Sarcocystis spp. infecting raccoons is discussed.
... The conduct control theory recommends that parasites can modify in such a way that helps the parasite rather than the host (1,2). The proliferation of the parasite in the host stimulates the immune system on the protozoan, leading to the formation of cysts that contain a slow-growing form (bradyzoite) in the nerve tissue and skeletal muscle and cause infection (3). This parasite is a significant illustration of parasites that control the behavior of their hosts, and it has been found that rodents infected with this parasite are less sensitive to felines as the definitive host, which is important in the spread and epidemiology of the disease (4,5). ...
... Infection with T. gondii is often asymptomatic; however, in immunocompromised individuals, cysts containing bradyzoites can rupture, leading to the reactivation of the latent infection (3). Immune responses to T. gondii infection vary depending on the clinical signs of the disease. ...
Parkinson's disease (PD) is a psychiatric neurological infection of the focal sensory system and is accepted as a multifactorial disease. Chronic Toxoplasmosis is sometimes associated with the proliferation of bradyzoites in the nervous system. The measurement of interleukin-5 (IL-5) as an inflammatory mediator in patients with PD and Toxoplasmosis infection may be helpful in determining the correlation between these diseases. In the present study, 80 examples were collected, including 35 patients diagnosed with idiopathic PD and 45 samples from healthy people from Najaf, Babylon, and Baghdad provinces, Iraq. After measuring the immunoglobulin G (IgG) antibody of Toxoplasma gondii, the level of IL-5 was evaluated in different groups. Serological examination showed that the IgG antibody of Toxoplasmosis increased (P
... Em animais domésticos de produção, a infecção por T. gondii geralmente é assintomática, porém em algumas espécies, como os ovinos, a toxoplasmose pode causar surtos de aborto, morte neonatal e fetos macerados ou mumificados nos rebanhos (6). Por outro lado, os cavalos são resistentes à infecção toxoplásmica e raramente manifestam a doença (7). A soroprevalência global da infecção por T. gondii é de 11,3% em equinos e de 56% em ovinos que apresentaram episódios de aborto (8,9). ...
... No presente estudo, foram avaliados animais criados com a finalidade de desenvolvimento de pesquisas em diferentes áreas do conhecimento. A interferência da exposição dos ovinos e equinos criados na Fazenda Nhumirim ao protozoário deve ser considerada e melhor investigada, principalmente nos estudos de desempenho reprodutivo na espécie ovina, tendo em vista uma maior suscetibilidade à ocorrência de abortos (7). ...
RESUMO A toxoplasmose é uma zoonose de distribuição mundial que acomete vertebrados homeotérmicos, incluindo o ser humano e animais de produção. É causada pelo protozoário Toxoplasma gondii (T. gondii) e pode ser transmitida pela ingestão de cistos teciduais, presente na carne crua ou mal-cozida, pela ingestão de oocistos esporulados, presentes na água e alimentos contaminados, ou até mesmo ingestão de taquizoítos presentes no leite. Dentre estes, a contaminação ambiental com oocistos esporulados apresenta-se como um importante fator de risco para a infecção toxoplásmica em animais herbívoros, como equinos e ovinos. O presente estudo teve como objetivo pesquisar a presença de anticorpos para T. gondii em equinos e ovinos criados na Fazenda Experimental Nhumirim, propriedade da Embrapa Pantanal, Mato Grosso do Sul, Brasil, em amostras de soro de 101 equinos e 99 ovinos coletadas entre março de 2011 e maio de 2015. Os soros foram submetidos à reação de imunofluorescência indireta (RIFI), sendo consideradas positivas a partir da diluição 1:64. Anticorpos para T. gondii foram detectados em 15,2% (15/99) dos ovinos e 9,9% (10/101) dos equinos. A ocorrência observada aponta contaminação ambiental da propriedade, onde, possivelmente, felídeos silvestres estariam atuando como dispersores do parasita. A exposição dos animais estudados ao parasita deve ser considerada ao avaliar resultados dos estudos de desempenho nos quais estes animais são utilizados, em especial os ovinos, devido à sua alta sensibilidade à infecção toxoplásmica. O presente estudo corrobora outros estudos sobre o risco de infecção de animais domésticos e a presença de T. gondii no ambiente do Pantanal brasileiro. Diante das dificuldades de se aplicarem medidas de prevenção e controle nos sistemas produtivos agropecuários praticados, sugere-se aplicá-las com foco na saúde humana. Palavras-chave: Toxoplasmose, Sorologia, Ovinos, Equinos, Pantanal.
... As amostras foram testadas para o Teste de Aglutinação Modificado (MAT), no ponto de corte de 1:25 (Dubey, 2010). O mix com antígeno de T. gondii foi preparado juntamente com Tampão Borato, 2-mercaptoetanol e azul de Evans. ...
... Cerca de um terço da população mundial humana está infectada com T. gondii, revelando ligação intrínseca com seus hábitos culturais e alimentares, representando risco real aos consumidores, inclusive gerando episódios de surtos de toxoplasmose ligados a esse costume. Outra fonte de preocupação está ligada aos derivados cárneos, tais como curados, maturados, salgados, embutidos e outros produtos de origem animal, que, se não empregadas corretamente técnicas de higiene, conservação e inativação do parasita, tornam-se outra fonte de preocupação para a disseminação da doença, representando risco na segurança alimentar(Dubey, 2010).O presente trabalho objetiva detectar anticorpos anti-Toxoplasma gondii em produtos cárneos comercializados em feiras livres da região sul da Bahia, gerando dados para comprovação ou não de emprego de técnicas adequadas na fabricação dos produtos, seu armazenamento e se estes procedimentos são eficientes em inviabilizar o protozoário.Foram coletadas 70 amostras de derivados cárneos, sendo 45 carnes de sol (bovina e suína), 23 linguiças curadas (suína) e duas amostras de linguiça frescal (frango), entre Dezembro de 2020 a Março de 2021. As amostras foram coletadas nos municípios de Ilhéus (26), Itabuna Figura 01: Feira livre visitada, mostrando cortes de carne disponíveis para consumo humano.Durante a aquisição, foram coletados dados acerca dos procedimentos tecnológicos aos quais os produtos foram expostos, tais como temperatura de cozimento, concentração de sal, tempo de cura, tipo de defumação (a frio ou a quente), entre outros aspectos relevantes.Após a coleta, as amostras foram encaminhadas ao Laboratório de Parasitologia Veterinária da Universidade Estadual de Santa Cruz, onde fragmentos foram macerados com o mínimo de PBS (Solução Fosfato Salina) para obtenção do soro e em seguida armazenados a -20ºC até a realização do teste. ...
... As amostras foram testadas para o Teste de Aglutinação Modificado (MAT), no ponto de corte de 1:25 (Dubey, 2010). O mix com antígeno de T. gondii foi preparado juntamente com Tampão Borato, 2-mercaptoetanol e azul de Evans. ...
... Cerca de um terço da população mundial humana está infectada com T. gondii, revelando ligação intrínseca com seus hábitos culturais e alimentares, representando risco real aos consumidores, inclusive gerando episódios de surtos de toxoplasmose ligados a esse costume. Outra fonte de preocupação está ligada aos derivados cárneos, tais como curados, maturados, salgados, embutidos e outros produtos de origem animal, que, se não empregadas corretamente técnicas de higiene, conservação e inativação do parasita, tornam-se outra fonte de preocupação para a disseminação da doença, representando risco na segurança alimentar(Dubey, 2010).O presente trabalho objetiva detectar anticorpos anti-Toxoplasma gondii em produtos cárneos comercializados em feiras livres da região sul da Bahia, gerando dados para comprovação ou não de emprego de técnicas adequadas na fabricação dos produtos, seu armazenamento e se estes procedimentos são eficientes em inviabilizar o protozoário.Foram coletadas 70 amostras de derivados cárneos, sendo 45 carnes de sol (bovina e suína), 23 linguiças curadas (suína) e duas amostras de linguiça frescal (frango), entre Dezembro de 2020 a Março de 2021. As amostras foram coletadas nos municípios de Ilhéus (26), Itabuna Figura 01: Feira livre visitada, mostrando cortes de carne disponíveis para consumo humano.Durante a aquisição, foram coletados dados acerca dos procedimentos tecnológicos aos quais os produtos foram expostos, tais como temperatura de cozimento, concentração de sal, tempo de cura, tipo de defumação (a frio ou a quente), entre outros aspectos relevantes.Após a coleta, as amostras foram encaminhadas ao Laboratório de Parasitologia Veterinária da Universidade Estadual de Santa Cruz, onde fragmentos foram macerados com o mínimo de PBS (Solução Fosfato Salina) para obtenção do soro e em seguida armazenados a -20ºC até a realização do teste. ...
... Toxoplasma gondii is a widespread parasite of animals that causes zoonotic infections in humans 32 1 . Serological studies suggest that ~ 1/3 of humans are chronically infected with T. gondii 33 worldwide, although prevalence rates vary widely by geographic region 2 . ...
Toxoplasma gondii causes widespread chronic infections that are not cured by current treatments due to inability to affect semi-dormant bradyzoite stages within tissue cysts. To identify compounds to eliminate chronic infection, we developed a HTS using a recently characterized strain of T. gondii that undergoes efficient conversion to bradyzoites in intro. Stage-specific expression of luciferase was used to selectively monitor growth inhibition of bradyzoites by the Library of Pharmacological Active Compounds, consisting of 1280 drug-like compounds. We identified 44 compounds with >50% inhibitory effects against bradyzoites, including several new highly potent compounds several of which have precedent for antimicrobial activity. Subsequent characterization of the compound Sanguinarine sulfate revealed potent and rapid killing against in vitro produced bradyzoites and bradyzoites harvested from chronically infected mice. These findings provide a platform for expanded screening and identify promising compounds for further preclinical development against T. gondii bradyzoites responsible for chronic infection.
... Toxoplasma gondii is a unicellular spore-forming organism that is an obligate endoparasite in virtually all warm-blooded animals. It is estimated that one-third of people across the world are exposed to T. gondii, mainly through consuming raw and contaminated foodstuffs or accidentally swallowing the parasite after coming in contact with cat feces (Dubey, 2010;Lourido, 2019). Toxoplasmosis is typically asymptomatic but is a prevalent foodborne disease that leads to mortality because of the development of severe clinical symptoms in immunocompromised individuals, such as AIDS patients, those undergoing chemotherapy, organ transplantation recipients, or infants born to mothers who were recently infected with T. gondii during or just before pregnancy (Ajzenberg et al., 2009;Centers for Disease Control and Prevention, 2023). ...
Toxoplasmosis, while often asymptomatic and prevalent as a foodborne disease, poses a considerable mortality risk for immunocompromised individuals during pregnancy. Point-of-care serological tests that detect specific IgG and IgM in patient sera are critical for disease management under limited resources. Despite many efforts to replace the T. gondii total lysate antigens (TLAs) by recombinant antigens (rAgs) in commercial kits, while IgG detection provides significant specificity and sensitivity, IgM detection remains comparatively low in sensitivity. In this study, we attempted to identify novel antigens targeting IgM in early infection, thereby establishing an IgM on-site detection kit. Using two-dimensional gel electrophoresis (2DE) and mouse serum immunoblotting, three novel antigens, including EF1γ, PGKI, and GAP50, were indicated to target T. gondii IgM. However, rAg EF1γ was undetectable by IgM of mice sera in Western blotting verification experiments, and ELISA coated with PGKI did not eliminate cross-reactivity, in contrast to GAP50. Subsequently, the lateral flow reaction employing a strip coated with 0.3 mg/mL purified rAg GAP50 and exhibited remarkable sensitivity compared with the conventional ELISA based on tachyzoite TLA, which successfully identified IgM in mouse sera infected with tachyzoites, ranging from 10³ to 10⁴ at 5 dpi and 10⁴ at 7 dpi, respectively. Furthermore, by using standard T. gondii-infected human sera from WHO, the limit of detection (LOD) for the rapid fluorescence immunochromatographic test (FICT) using GAP50 was observed at 0.65 IU (international unit). These findings underline the particular immunoreactivity of GAP50, suggesting its potential as a specific biomarker for increasing the sensitivity of the FICT in IgM detection.
... Toxoplasma gondii is a common intracellular parasite of companion, agricultural, and wild animals that also infects up to one-third of the world's human population. 1 Following initial expansion and dissemination of actively replicating tachyzoites, a vigorous immune response controls parasite replication. 2 In response to stress, the parasite differentiates into a slow growing, semi dormant stage called the bradyzoite, which resides in cysts in the brain and other tissue. ...
Previous studies have shown that bicyclic azetidines are potent and selective inhibitors of apicomplexan phenylalanine tRNA synthetase (PheRS), leading to parasite growth inhibition in vitro and in vivo , including in models of Toxoplasma infection. Despite these useful properties, additional optimization is required for the development of efficacious treatments of toxoplasmosis from this inhibitor series, in particular to achieve sufficient exposure in the brain. Here, we describe a series of PheRS inhibitors built on a new bicyclic pyrrolidine core scaffold designed to retain the exit-vector geometry of the isomeric bicyclic azetidine core scaffold while offering avenues to sample diverse chemical space. Relative to the parent series, bicyclic pyrrolidines retain reasonable potency and target selectivity for parasite PheRS vs. host. Further structure-activity relationship studies revealed that the introduction of aliphatic groups improved potency, ADME and PK properties, including brain exposure. The identification of this new scaffold provides potential opportunities to extend the analog series to further improve selectivity and potency and ultimately deliver a novel, efficacious treatment of toxoplasmosis.
Lay abstract
The inhibition of protein synthesis in parasites has emerged as an attractive strategy to target parasitic diseases such as malaria, cryptosporidiosis, and toxoplasmosis. In this study, we report a new series of small molecules that inhibit the enzyme responsible for loading the amino acid phenylalanine onto its cognate tRNA in the parasite species Toxoplasma , directly upstream of protein synthesis. We show that small molecules in this new series inhibit Toxoplasma parasite growth at low concentrations, and that, orally administered to mice, these molecules achieve high concentrations in the brain, which hold promise for the treatment of forms of toxoplasmosis that result from parasitic brain infection.
... Toxoplasmosis is a zoonotic infection caused by the intracellular protozoan Toxoplasma gondii (Dubey 2016). An estimated one-third of the world's population is infected with this parasite (Duffy et al. 2019). ...
This study aimed to investigate the effect of rosuvastatin treatment on anxiety-related behavior and short- and long-term memory impairment in mice infected with acute RH and BRI strains of Toxoplasma gondii. Balb/C mice were infected intraperitoneally and after 2 h, oral treatment with rosuvastatin (40 mg/kg/day) was initiated for 4 days. Behaviors related to anxiety and locomotion were evaluated in the open field (OF), and short- and long-term memory through the novel object recognition test (NOR). At the end of the experiments, peritoneal fluid, brain, liver, and lung were collected for T. gondii DNA quantification and histopathological analysis. Infection with BRI strain reduced the dwell time and central locomotion in the OF (p < 0.05), indicating anxiogenic type behavior, while treatment with rosuvastatin reversed this response (p < 0.05). RH strain infection did not alter any behavior in the OF (p > 0.05) and both strains impaired short- and long-term memory (NOR test), but with no significant treatment effect (p > 0.05). The BRI strain was shown to be more damaging in relation to anxiogenic type behavior when compared to the RH strain (p < 0.05), whereas rosuvastatin reduced this damaging effect in BRI. The treatment reduced the parasite load in the peritoneal lavage, liver, and lung of animals infected with both acute strains; however, it significantly (p < 0.05) attenuated the inflammatory process only in BRI-infected and treated animals, showing that non-archetypal genotypes are more damaging in rodents. This suggests that rosuvastatin may be a drug with great therapeutic potential against T. gondii mainly to reduce damage from virulent strains.
... Toxoplasmosis is considered one of the global zoonotic diseases, it caused by a "successful" parasite called Toxoplasma gondii [1]. This coccidian parasite has a wide variety of intermediate hosts such as humans and a great majority of homoeothermic animals [2][3][4], and the family felidae is considered a definitive host [5]. The disease is transmitted mainly by the consumption of food and water contaminated by sporulated oocysts or tissue cysts, mainly from undercooked meat [6][7][8]. ...
TOXOPLASMA gondii, an obligatory intracellular protozoan parasite, that has the ability to
causes toxoplasmosis in wide range of host, including humans and various warm-blooded
animals as intermediate hosts. The parasite has a complex life cycle include sexual and asexual
replication in members of the cat family (Felidae).
In this study, 45 blood samples were collected from stray cats that caught with special traps
from Mosul’s residential neighbour hoods, during the period extended from September 2022
to February 2023, the results of the current study showed that all cat serums gave positive to
Direct Latex agglutination test, While, the percentage of infection with the parasite by ELISA
was (26.6) .According to gender the percentage of infection in females was (15.5%) more than
males (11.1%). In order to confirm the infection, the blood samples collected during the study
were subjected to polymerase chain reaction (PCR) detection using primers targeting B1 gene.
Molecular results showed that the infection rate was 22% (10 out of 45). Bioinformatics and
phylogenetic analysis revealed the presence of SNPs in the sequence of the nitrogenous bases of
the two isolates that were recorded during this study for the first time in the city of Mosul. It was
registered in the name of the two researchers in the International Gene Bank with serial number
LC749846.1 RK1 and the second isolate LC749847.1 RK2.By comparing the sequences of the
two isolates, it was noted that there is a single nucleotide polymorphism (SNP), as well as some
mutations (inversion and insertion mutations).
Keywords: Toxoplasma gondii, B1 Gene, Elisa, Mosul city, Stray cats
... Human toxoplasmosis, caused by the apicomplexan parasite Toxoplasma gondii is one of the most prevalent parasitic diseases with one-third of the human population on planet earth being chronically infected [1]. In Europe and North America, three main genotypes (I-III) prevail [2], but new and atypical genotypes, distinct from I-III, have been discovered, most notably in South America [3]. ...
In T. gondii, as well as in other model organisms, gene knock-out using CRISPR-Cas9 is a suitable tool to identify the role of specific genes. The general consensus implies that only the gene of interest is affected by the knock-out. Is this really the case? In a previous study, we have generated knock-out (KO) clones of TgRH88_077450 (SRS29B; SAG1) which differed in the numbers of integrated dihydrofolate-reductase-thymidylate-synthase (MDHFR-TS) drug-selectable marker. Clones 18 and 33 had a single insertion of MDHFR-TS within SRS29B. Clone 6 was disrupted by the insertion of a short unrelated DNA-sequence, but the marker was integrated elsewhere. In clone 30, the marker was inserted into SRS29B and several other MDHFR-TS copies were found in the genome. KO and wild-type (WT) tachyzoites had similar shape, dimensions and vitality. This prompted us to investigate the impact of the genetic engineering as such on the overall proteome patterns of the four clones as compared to the respective WT. Comparative shotgun proteomics of the five strains was performed. Overall, 3236 proteins were identified. Principal component analysis of the proteomes revealed five distinct clusters corresponding to the five strains by both iTop3 and iLFQ algorithms. Detailed analysis of the differentially expressed proteins revealed that the target of the KO, srs29B, was lacking in all KO clones. Besides this protein, twenty other proteins were differentially expressed between KO clones and WT or between different KO clones. The protein exhibiting the highest variation between the five strains was srs36D encoded by TgRH_016110. The deregulated expression of SRS36D was further validated by quantitative PCR. Moreover, the transcript levels of three other selected SRS genes, namely SRS36B, SRS46, and SRS57 exhibited significant differences between individual strains. These results indicate that knocking out a given gene may affect the expression of other genes. Therefore, care must be taken when specific phenotypes are regarded as a direct consequence of the KO of a given gene.
... The sexual cycle of T. gondii initiates in the intestine of the definitive host (cat) when they eat birds or rodents infected with T. gondii (Dubey et al.,2010). After ingestion, bradyzoites are released from the cysts, penetrate the epithelial cells of the small intestine and replicates via several rounds of merogony during 3 to7 days (Dubey et al.,2017). ...
... The identification of protozoa within the plastisphere is likely to be hindered by the lack of sensitivity of current methods. As few as 10 oocysts of Cryptosporidium or G. duodenalis can cause infection in humans (Teunis et al., 2002) (Erickson and Ortega, 2006), while a single oocyst of T. gondii can cause infection in rodent models (Dubey, 2016). With current methodologies it is difficult to detect such low concentrations of protozoa in environmental samples. ...
Plastic waste is ubiquitous in the environment and can become colonised by distinct microbial biofilm communities, known collectively as the 'plastisphere.' The plastisphere can facilitate the increased survival and dissemination of human pathogenic prokaryotes (e.g., bacteria); however, our understanding of the potential for plastics to harbour and disseminate eukaryotic pathogens is lacking. Eukaryotes are abundant in natural environments and represent some of the most important disease-causing agents, collectively responsible for tens of millions of infections, and millions of deaths worldwide. While prokaryotic plastisphere communities in terrestrial, freshwater, and marine environments are relatively well characterised, such biofilms will also contain eukaryotic species. Here, we critically review the potential for fungal, protozoan, and helminth pathogens to associate with the plastisphere, and consider the regulation and mechanisms of this interaction. As the volume of plastics in the environment continues to rise there is an urgent need to understand the role of the plastisphere for the survival, virulence, dissemination, and transfer of eukaryotic pathogens, and the effect this can have on environmental and human health.
... But small mammals play an important role in the life cycle of several parasites as definitive hosts, but also can be paratenic host, connecting the parasite with the final host as in T. gondii infection. After getting infected in the environment for the ingestion of sporulate oocysts (Horta et al., 2018), the small mammal can act as one of the main sources of infection of domestic and wild cats through the trophic network (Dubey, 2010;Gennari et al., 2015). An isolated duo of host-parasite was Oecomys cleberi ( =1), that showed infection only by Trypanosoma dionisii ( =1) and vice-versa (this parasite was described only in this host), highlighting as the highest specialization value in the complete network. ...
... Toxoplasma gondii --T.gondii (the main cause of toxoplasmosis) is an intracellular protozoan parasite, highly distributed worldwide, T.gondii can infect all warm-blooded animals and humans virtually which include mammals, rodents and birds [1,2]. In almost hosts, the latent infection with parasite establishes a lifelong in different tissues such as cardiac muscle, skeletal muscle, cardiac muscle, retina, brain, central nervous system-CNS and spinal cord [3]. ...
The current study was carried out to evaluate the incidence of Toxoplasma gondii –T.gondii among blood donors individuals in Samarra city. One hundred blood sample were randomly collected from blood donor male (aged 20-57year) attendance to blood bank in Samarra general hospital. The results indicate that the total ratio for infection with T. gondii was 58% (58 from 100 person).While the incidence of infection according to the type of blood group were 37.5% for A blood group, 70% for B blood group, 71.42% for AB blood group and 46.66% for O. In addition to that the incidence of infection with parasite in Rh blood group were 60%(54 form 90) in positive Rh and 40%(4from 10) in negative Rh. Otherwise the incidence of infection with T. gondii between age group were 63.33% in age group(20-29)year,28.57% in age group(30-39)year,78.57% between blood donor with age group(40-49) year and 85.71% in age group(50-59) year. The incidence of infection with T. gondii according to the residence area were 58.13% (50 from86) in urban and 57.14%(8from 14) in Rural. The study also include determination of serum sex hormones (testosterone, follicular stimulating hormone-FSH and luteinizing hormone-LH). The concentration of LH were 3.15±1.156mU/ml in infected group and 2.722±0.942mU/ml in non-infected group, and the concentration of FSH were 3.16±1.35mU/ml, 2.156±0.809 mU/ml in infected and non-infected respectively, while the concentration of testosterone were 3.187±0.995mU/ml, 4.653±1.66 mU/ml in infected and non-infected respectively. From all the results we can conclude that the infection with T. gondii was high incidence between blood donor, so its importance to add this investigation acts one factor of strategies for blood safety.
... The seropositivity of T. gondii antibodies in cats, although not an indicator for the current shedding of the parasite, is a useful indicator of infection in a cat population and can be used to evaluate the infection risk in both the definitive and intermediate hosts in the same area [6]. The seroprevalence for T. gondii in cats was reported to vary between 30% and 40% worldwide [5,7]. Although previous studies have reported the prevalence of toxoplasmosis in cats in some areas of China [8,9], related information is still lacking in many provinces. ...
Background
Toxoplasma gondii infects almost all warm-blooded animals, and cats play a crucial role in the epidemiology of T. gondii as the definitive host. Despite sporadic reports on the seroprevalence of T. gondii in domestic cats, systematic surveys are lacking and some regions remain in China uninvestigated.
Methods
A total of 1,521 serum samples were collected from 10 regions of China and analyzed by antibodies against T. gondii by ELISA with the purpose of identifying risk factors of T. gondii infection in cats across China and obtaining seroprevalence data from some previously uninvestigated areas.
Results
Antibodies to T. gondii were detected in 62 of 1,478 (4.2%) urban pet cats and in 9 of 43 (20.9%) stray cats. Among the regions examined, the prevalence was 13% in Sichuan, 12.8% in Chongqing, 6.4% in Hunan, 2.5% in Hubei and 0.9% in Guangdong. Additionally, this is the first report on the seroprevalence of T. gondii in urban pet cats from Qinghai (6.2%), Anhui (3.1%), Jiangxi (2.5%), Shaanxi (2.4%) and Ningxia (1.6%). The age and lifestyle (stray or pet) of cats were identified as the risk factors for seropositivity by multivariate analysis of the data.
Conclusions
Our findings improve our understanding of seroprevalence and risk factors of T. gondii infection in cats across China, and provide useful information for the formulating of preventive and control measures against this widespread zoonotic parasite.
... Different species of warm-blooded mammals, birds, as well as human [14,67] comprise the wide range of hosts that have been found exposed to T.gondii. Several studies have shown the occurrence of antibodies against T.gondii in rabbits, mainly the European rabbit (O. ...
Wild rabbits (Oryctolagus cuniculus) can be important sentinel species for the presence of zoonotic pathogens. Therefore, we collected blood samples from wild rabbits harvested by hunters during the hunting season 2019–2020 on the island of Lemnos, to determine exposure of wild rabbits to the zoonotic pathogens Leishmania infantum, Toxoplasma gondii, Anaplasma phagocytophilum and Babesia caballi, as well as aqueous humor to assess its diagnostic performance in terms of sensitivity, specificity, positive and negative likelihood ratios. Antibodies against these pathogens were detected by Indirect Immunofluorescence Antibody (IFA) assay. Out of the 72 wild rabbits included in the study, 4.2%, 5.5%, 18% and 9.7% were seropositive to L. infantum, T. gondii, A. phagocytophilum and B. caballi, respectively. Although less frequently, antibodies were also detected in aqueous humor of wild rabbits. The antibody detection in aqueous humor presented 100% specificity but decreased sensitivity compared to serum suggesting that aqueous humor could be successfully used in epidemiological studies to confirm exposure at the population level but has little diagnostic value at the individual level. This is the first report on the seropositivity of wild rabbits to A. phagocytophilum and B. caballi and the detection of antibodies against A. phagocytopylum, L. infantum, T. gondii and B. caballi in the aqueous humor.
... gondii) is a protozoan parasite that, like Cryptosporidium spp., belongs to the phylum Apicomplexa. The parasite has a complex life cycle for which usually domestic cats are the definitive hosts [163]. Intermediate hosts are all warm-blooded animals, including livestock and humans. ...
This book, Proteomics and Food Analysis: Principles, Techniques, and Applications, edited by Dr. Mónica Carrera and published by MDPI, is an excellent collection of a wide range of proteomics approaches applied in food analysis.
Proteomics methodologies are an advantageous strategy for food science studies, where research institutions, agencies, food industries, and regulatory laboratories are combining efforts to acquire necessary knowledge on food composition, quality and safety.
The potential of proteomics in food analysis is highlighted in this book, which contains
one editorial article and six scientific manuscripts covering different applications of proteomics methodologies to ensure food quality and safety. This book is an ideal and up-to-date guide for researchers seeking to understand the proteomics methodologies applied to different foods.
Finally, the editor wants to express her gratitude to all the coauthors for their assistance in the preparation of this book.
... Each gram of infected cat feces may contain between 1 million and 13 million oocysts; assuming a mean of 6 million oocysts per gram for the 56 million grams of infected cat feces would produce a total of 336 trillion (336,000,000,000) T. gondii oocysts each day. Although it is not known how many oocysts are needed to infect a human, studies have been done in pigs which weigh about the same as humans, and it only took one oocyst to infect them [3,4]. ...
This chapter examines some additional implications of the Toxoplasma gondii problem. Especially impressive is evidence suggesting that this parasite is contaminating our land and waterways. The infection of marine mammals by this parasite is little known but disturbing. The chapter then proposes various solutions to the problem: specifically by better control of feral cats to decrease the distribution of T. gondii oocysts; by research, including the development of vaccines for cats; by improving the treatment of toxoplasmosis in humans; and by educating the public regarding these issues.
... Toxoplasma gondii; Phylogenic analysis; Genetics polymorphisms evaluation Introduction oxoplasma gondii is an obligate intracellular parasite and the causative agent of toxoplasmosis that considered as an important public health concern not only for humans but also in veterinary field and animal husbandry worldwide (1,2). The definitive host of T. gondii is feline species and other animals as intermediate hosts could be infected by ingesting oocysts from food or water sources (3). ...
Background:
A high correlation is observed between specific clonal lineages and host types in toxoplasmosis. The main objectives of this study were comparing polymorphism and evolutionary analysis of the B1 and ROP8 genes, as well as the evaluation of phylogenic and Toxoplasma gondii isolates obtained from different hosts and regions.
Methods:
Overall 96 brain/diaphragm tissue samples of livestock and poultry from three provinces of Iran (cows: 9 from Yazd, 9 from Qom; sheep: 19 from Yazd, 7 from Qom; goats: 7 from Yazd, 4 from Qom; one camel from Yazd and 37 chickens, 2 roosters and one duck from Golestan) were tested during 2018-19. A nested PCR and PCR-PCR methods were developed with the B1 and ROP8 genes. Evaluation of genetic proximity, genetic diversity and evolutionary analysis were done using MEGA-X and DnaSP5 software. Thirty samples of both genes were sequenced (18 B1 and 12 ROP8 genes), and submitted to the GenBank (MN275903-MN275932).
Results:
Tajima's D index analyses showed that both genes were in the negative direction of evolution. The B1 gene was more sensitive than the ROP8 gene. The ROP8 gene showed better and more acceptable results in terms of the relationship between the host and the genotyping of the samples.
Conclusion:
The B1 gene was only an attractive target for rapid detection of T. gondii parasites, whereas the ROP8 gene due to a high level of polymorphism was able to isolate the three clonal lineages (type I, II and III), intertypes and even atypical strains from different isolates of T. gondii.
... Introduction oxoplasma gondii, a pervasive coccidian parasite is an obligatory single-celled intracellular protozoan that can infect a wide range of warm-blooded animals as well as humans. Approximately 30%-80% of the world's human population harbor infection and due to the bulk of the burden disease, it was ranked as the second most important food-borne parasitic disease in Europe (1,2). T. gondii has a heteroxenous life cycle in which a member of the Felidae family (particularly cats) acts as a definitive host wherein sexual reproduction happens and oocysts shed in the feces result in parasite dissemination into the environment. ...
Background:
Toxoplasma gondii is a neuroinvasive protozoa pathogen that could manipulate its intermediate host's behavior. However, the possible link between T. gondii infection and the development of neurodegenerative disorders such as Parkinson's disease (PD) has been proposed, we tested the hypothesis that in chronic toxoplasmosis neuroinflammation, and molecular mediators potentiate behavioral-cognitive impairments in BALB/c mice with PD.
Methods:
To establish chronic toxoplasmosis by Tehran strain, cysts of T. gondii were injected intraperitoneally into BALB/c mice in Kerman, Iran in 2019. To induce the PD model, mice (BALB/c) were treated with Methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP). The behavioral experiments such as anxiety and motor coordination were performed using the Open field and Rotarod tests. Additionally, we investigated the contribution of Toxoplasma-induced neuroinflammation, and behavioral-cognitive impairments in the PD mice model.
Results:
Chronic toxoplasmosis caused PD-like symptoms and induced various behavioral changes in infected BALB/c mice. In T. gondii infected+MPTP treated group, T. gondii infection could potentiate PD in infected mice receiving MPTP and caused remarkable dysfunction in motor coordination and change in anxiety and depression-like behaviors similar or more severe than PD group.
Conclusion:
Chronic T. gondii infection exacerbates pathological progression of PD in BALB/c mice brain by promoting neuroinflammation, and behavioral changes establishing.
... Infection caused by T. gondii is widespread among homeothermic animals including birds, wild animals, domestic animals and humans (Dubey, 2009). According to Dubey (2010), domestic and wild felids are the only definitive hosts, with production and release of oocysts occurs in the feces, and thus contaminate the environment. After sporulation, these oocysts can maintain their infectivity for several months in water and soil and are responsible for infestation of intermediate hosts, including humans and other animals (Buxton et al., 2007). ...
A serological, molecular and histopathological study was carried out in order to investigate occurrences of Toxoplasma gondii in pigs slaughtered with and without inspection service. Serum samples were collected from 60 pigs to detect anti-T. gondii antibody by indirect fluorescent antibody (IFAT). Tongue, masseter and diaphragm fragments were also collected for parasite DNA detection by means of the polymerase chain reaction (PCR) and histopathological analysis. The serological results showed that 77% (44/60) of the pigs were positive. Regarding PCR, 66.67% (40/60) were positive for T. gondii. Among the tissues evaluated, the diaphragm was the one with the highest frequency of positivity (40%; 24/60), followed by the masseter (38.33%; 23/60) and tongue (33.3%; 20/60). Histopathological changes were only observed in the diaphragm, which presented inflammatory infiltrates of lymphohistiocytic and neutrophilic types. These results not only show the potential threat of T. gondii to human health, but also demonstrate the dynamic epidemiological situation of toxoplasmosis in pigs in the city of São Luís, providing support for food security regarding pigs and for T. gondii control programs in Brazil.
Quercetin (QUE) is a natural polyphenol known to have numerous pharmacological properties against infectious and non-infectious diseases. Azithromycin (AZ) is an antibiotic that belongs to the azalide class of antimicrobials and an antiparasitic that is known to be effective in combination with clindamycin against pyrimethamine/sulfadiazine-resistant Toxoplasma gondii tachyzoites in clinical settings. Both compounds are known to target protein synthesis and have anti-inflammatory properties. However, little is known about QUE and AZ synergistic interaction against T. gondii growth. Here, we report for the first time the effects of the combination of QUE and AZ on T. gondii growth. The 50% inhibitory concentration (IC 50 ) for QUE at 72 h of interaction was determined to be 0.50 µM, whereas AZ gave an IC 50 value of 0.66 µM at 72 h of interaction with parasites. Combination testing of QUE and AZ in a ratio of 2:1 (QUE:AZ) showed an IC 50 value of 0.081 µM. Interestingly, a fractional inhibitory index value of 0.28 was observed, indicating a strong synergy. QUE was also found to upregulate the generation of reactive oxygen species and cause dysfunction of the mitochondria membrane of both intracellular and extracellular T. gondii tachyzoites. Overall, the results indicate that QUE is a novel lead capable of synergizing with AZ for inhibiting T. gondii growth and may merit future investigation in vivo for possible combination drug development.
Graphical Abstract
Toxoplasma gondii is an important protozoan parasite of humans and animals throughout the world. Black bears are among the animals with the highest seroprevalence of T. gondii in the United States. A rapid point of care (POC) test is commercially available to detect antibodies to T. gondii in humans. We evaluated the utility of the POC test to detect anti-T. gondii antibodies in 100 wild black bears from North Carolina (n = 50) and Pennsylvania (n = 50). In a blind study, sera were tested by the POC test, and results were compared to the modified agglutination test (MAT). Overall, anti-T. gondii antibodies were detected in 76% (76/100) black bears by both MAT and POC tests. One false positive and one false negative result in the POC test were obtained in bears from Pennsylvania. The sensitivity and specificity of the POC test were both 99% when compared to the MAT. Results from our study indicate the POC test could be a useful screening tool for serological surveillance of T. gondii in black bears.
A ring trial among five European laboratories was organized to reach consistency in microsatellite (MS) typing of the zoonotic parasite Toxoplasma gondii. Three sample sets were circulated and analyzed by each laboratory following a previously published method that is based on fragment length polymorphism of 15 MS markers. The first sample set compared typing results in general and focused on effects of DNA concentration; the second sample set focused on the polymorphic fingerprinting markers that can differentiate T. gondii strains within the same archetypal lineage; and the third set focused on non-archetypal genotypes. Methodological variations between laboratories, including the software programs used to determine MS fragment length, were collated using a questionnaire. Overall, lineage-level typing results reached a high level of agreement, especially in samples with the highest DNA concentrations. However, laboratory-specific differences were observed for particular markers. Major median differences in fragment length, of up to 6 base pairs, were related to the fluorophore used to label fragment-specific primers. In addition, primer pairs with identical sequences obtained from different suppliers resulted in fragments of differing length. Furthermore, differences in the way the sequencing profiles were assessed and interpreted may have led to deviating results in fragment length determination. Harmonization of MS typing, for example, by using the same fluorophores or by numerical adjustments applied to the fragment-lengths determined, could improve the uniformity of the results across laboratories. This is the first interlaboratory comparison, providing guidelines (added as a supplement) for the optimization of this technique.
Rats
serve as carriers of Toxoplasma gondii, an obligate intracellular protozoan parasite that causes a global zoonotic disease referred to as toxoplasmosis, and thus play a very important role in the epidemiology of the disease. This study evaluated the occurrence of anti-Toxoplasma gondii antibodies, haematology and serum biochemistry in wild rats and humans in Nigeria where wild rats are consumed by humans as source of animal protein. Indirect enzyme-linked immunosorbent assay (iELISA) was used to detect anti-Toxoplasma gondii antibodies in serum of 33 wild rats (Zyzomys pedunculatus) caught in the villages and 20 consenting humans in the study area. Blood samples collected from the rats and humans were further subjected to haematological and biochemical evaluations. Out of the 33 rats sampled, three (9.09%) were positive for T. gondii antibodies, while three out of the 20 persons sampled (15%) were positive. Rats seropositive for T. gondii antibodies had significantly (p < 0.05) lower platelet count, higher granulocyte/lymphocyte ratio (GLR) and lymphocyte/monocyte ratio (LMR) than those seronegative for T. gondii antibodies. Mean corpuscular haemoglobin concentration (MCHC) was significantly (p < 0.05) lower while LMR was significantly (p < 0.05) higher in humans that were seropositive for T. gondii. It was concluded that anti-Toxoplasma gondii antibodies is moderately prevalent (9–15%) in rats and humans who consume rats as source of animal protein in the study area. High GLR in rats and high LMR in both rats and humans may be good pointers to toxoplasmosis.
O Toxoplasma gondii (T. gondii) é um parasita eurixeno, do qual os felinos são os hospedeiros definitivos e os demais animais de sangue quente, os hospedeiros intermediários. Há, nesses casos, importância clínica, principalmente em indivíduos imunocomprometidos, dado que pode causar alterações comportamentais em roedores. Entre os mecanismos neurofisiológicos utilizados para se explicar tal fenômeno, está a influência da resposta imunológica no sistema nervoso central (SNC). Uma vez que a neuroimunologia vem ganhando espaço na ciência nos últimos anos, o objetivo deste artigo foi avaliar as abordagens da literatura atual do processo neuroinflamatório em modelo animal infectado pelo T. gondii, valendo-se de uma revisão integrativa da literatura. Consideraram-se artigos indexados nas bases de dados PubMed e Scopus que atendessem aos critérios de inclusão e que realizaram pesquisa experimental com roedores no período de janeiro de 2012 a fevereiro de 2022. Ao todo, foram encontrados 42 artigos, desses, selecionaram-se 18 para a leitura na íntegra e excluíram-se 24. As abordagens avaliadas foram: a) correlação entre estado físico ou comportamento animal e neuroinflamação; b) influência dos astrócitos, micróglias e neurônios no processo neuroinflamatório; c) influência da resposta imune nas alterações de neurotransmissores; e d) outros fatores imunológicos e sua influência no SNC. A revisão integrativa permitiu a discussão das principais abordagens da literatura sobre o tema, formando um panorama geral, a partir do qual realizaram-se algumas considerações que podem contribuir para o desenvolvimento de novas pesquisas experimentais, a fim de avaliar a influência da resposta imune no SNC de animais parasitados.
The use of apitherapy and natural herbal medicines for combating toxoplasmosis has garnered major attention from many researchers. However, there is no available information regarding the potential use of a combination of propolis and wheat germ oil (WGO) in the treatment of toxoplasmosis. In the present study, the potential effects of propolis, WGO, and their combination in the treatment of chronic toxoplasmosis in Swiss albino mice were investigated. Following induction of chronic toxoplasmosis, the potential antiparasitic effects of these substances were evaluated by parasitological assessment and by counting of Toxoplasma cysts. Additionally, the effects of the treatments on parasite loads were analyzed using TaqMan real-time quantitative PCR targeting the Toxoplasma P29 gene followed by investigation of the major histopathological changes in the brain, uterus, and kidney. Interestingly, the combination of propolis and WGO significantly (P ≤ 0.05) decreased the parasite burden in experimental animals compared with burdens seen in groups treated with propolis or WGO alone. Furthermore, the quantification of the DNA concentrations of Toxoplasma P29 gene after the treatment with propolis and WGO revealed a reduction in parasite load in treated groups versus the control group (infected untreated animals). Importantly, the severity of histopathological lesions was significantly (P ≤ 0.05) improved following treatment with propolis and WGO. Collectively, the present study indicated a potential novel role for propolis and WGO as an active apitherapy and natural herbal medication for treating chronic toxoplasmosis, combat the disease, and which could also help overcome the side effects of chemical drugs.
Toxoplasmosis is a zoonotic, parasitic infection caused by the intracellular, apicomplexan parasite Toxoplasma gondii, which infects all homeothermic animals including humans. The parasite has a major economic impact on the livestock industry. This is especially true for small ruminants (sheep, goats) as it is one of the most likely reasons for reproductive disorders in these animals. Primary infection in sheep and goats can result in a fetus that is mummified or macerated, fetal embryonic death, abortion, stillbirth, or the postnatal death of neonates, all of which threaten sheep and goat rearing globally. Humans can also become infected by ingesting bradyzoite-containing chevon or mutton, or the contaminated milk of sheep or goats, highlighting the zoonotic significance of this parasite. This article reviews the advances in vaccine development over recent decades and our current understanding of the immune response to toxoplasmosis in small ruminants (sheep, and goats).
The influence of climate on parasite distribution has been demonstrated in different regions worldwide. Despite its small size, Gran Canaria (Canary Islands, Spain) constitutes a ‘biodiversity laboratory’ due to the huge climatic differences between municipalities. Feral cats may represent a threat to biodiversity due to their predatory behaviour. In addition, they may be a source of pathogens zoonotic to humans. To study the climatic/seasonal influence and prevalence of feral cat parasites throughout the island, a total of 290 stool samples from 29 feral cat colonies were analysed following standard concentration protocols (sodium chloride, formol-ether and zinc sulphate). In total, 13 feline parasitic taxa were found, with the most common species being Ancylostoma spp., which, together with Toxocara spp., Toxoplasma gondii and Giardia spp., are considered a concern for human health. Nematodes were the most common parasites in all areas. Nematodes and protozoans were significantly more prevalent in temperate mild (75.0% and 30.0%) than in dry desert areas (29.3% and 18.7%). In contrast, cestodes were significantly more prevalent in dry desert than in temperate mild areas (26.0% and 13.3%). Only protozoans exhibited statistically significant seasonal patterns, mostly in the wet season. Data reported in this study endorse the usage of small and diverse islands such as Gran Canaria to study the climatic influence on parasitic communities in wild/feral animals. Cat colonies require better management to reduce their threat to endemic wildlife, domestic animals and public health, being invasive species that harbour zoonotic parasites.
The aim of this study was to assess the agreement between anti-Toxoplasma gondii IgG antibody detection in serum and filter paper (FP) blood spots using the indirect immunofluorescence antibody assay (IFA) and to evaluate the potential impact of the packed cell volume (PCV) on antibody detection in FPs. A pair of a serum and an FP sample was collected from 96 sows at various farms in Greece, with previously identified high seropositivity and/or risk factors associated with high seropositivity against T. gondii. The PCV value was determined using the microhematocrit method. IFA was used for the detection of antibodies against T. gondii. T. gondii-specific antibodies were detected in 45.8% serum samples and 41.6% FP samples showing almost perfect agreement. Detection in FP samples presented high sensitivity (87.1-92.8%) and excellent specificity (100%) when compared with detection in serum, regardless of the PCV values. The findings of this study support the reliability of FPs for the evaluation of the serological status of swine against T. gondii. FPs could be a good alternative sample type compared with serum for large-scale epidemiological studies.
Sarcocystis neurona , Neospora spp. and Toxoplasma gondii are related protozoans; they were considered the same parasite until 1970s. Two of these parasites, S. neurona and Neospora spp. are associated with a neurological syndrome in horses, called equine protozoal myeloencephalitis (EPM). The diagnosis and treatment of EPM are difficult. Most cases of EPM are related to S. neurona while only a few are due to Neospora spp. infections. There are two species of Neospora , Neospora caninum that has a wide host range and Neospora hughesi that has been found only in horses. Currently, T. gondii is not considered as a cause of EPM in horses, although it causes neurological illness in many other hosts, including humans. The present review provides an update on history, life cycle, diagnosis and treatment of these three infections in horses.
Despite public concern on the role of free-roaming cats as reservoirs of zoonotic agents, little is known about the influence of urban and peri-urban landscapes on the exposure risk. We evaluated the seroprevalence of three zoonotic agents (Chlamydia felis, Coxiella burnetii and Toxoplasma gondii) in domestic cats (Felis catus). Two hundred and ninety-one free-roaming cats were trapped in Murcia municipality (Southeast Spain), and their sera were tested for specific antibodies against T. gondii using a modified agglutination test (MAT), and for C. felis, C. burnetii and feline immunode-ficiency virus (FIV) antibodies with ELISA technique. Pathogen seroprevalence at 95% CI was calculated for each sex and age category (up to and over 12 months) and compared with a chi-squared test. The role of human population density and urban landscape characteristics on the risk of pathogen exposure in the cat population was explored using generalized linear models. Seropositivity against a single pathogen was found in 60% of the cats, while 19% was seropositive for two or three pathogens. Seroprevalence of C. felis was 8% (CI 95% : 5-11), 37% (CI 95% : 31-42) for C. burnetii and 42% (CI 95% : 36-47) for T. gondii. In addition to these three pathogens, FIV seropositiv-ity was low (1%, CI 95% : −0.1 to 2) and adult cats were more likely to be seropositive to C. burnetii than young individuals (OR: 2.3, CI 95% : 1.2-4.2). No sex or age class differences in seroprevalence were observed for the rest of the pathogens. Seropositivity was correlated with water surface areas for C. felis, and not with crop areas. Coxiella burnetii seropositivity was correlated with the percentage of urban areas (continuous with only buildings and discontinuous, that include buildings, parks, and pedestrian and urban green areas), human population size and peri-urban areas with shrubs, and not correlated with other agricultural landscapes (orchards and crop areas). However, the seroprevalence of T. gondii was only associated with agricultural landscapes such as orchards. The detection of hotspot areas of high pathogen exposure risk is the basis for municipal services to implement surveillance and risk factor control campaigns in specific-risk areas, including (a) efficient health management of urban cat colonies by geographical location, population census and health status monitoring of the components of each cat colony, (b) improvement of hygiene and sanitary conditions
Dihydroquinine (DHQ), is a quinine-based compound with anti-malarial properties. However, little is known about its mechanism of action against T. gondii inhibition, which shares similar biology with Plasmodium spp. In order to explore DHQ activity as an inhibitor of T. gondii using in vitro assays, we first used an in silico approach to decipher its mechanisms of action based on previous knowledge about its disruption of nucleic acid and protein synthesis. An in silico study was performed on T. gondii parasite replication, transcriptional and translational machinery to decipher the binding potentials of DHQ to some top selected enzymes. We report for the first time, using an in silico analysis that showed that DHQ binds strongly to DNA gyrase, Calcium Dependent Protein Kinase 1 (CDPK 1), and prolyl tRNA synthetase and thus could affect DNA replication, transcriptional and translational activities in T. gondii. Also, we found DHQ to effectively bind to mitochondria detoxifying enzymes (i.e., superoxide dismutase (SOD), peroxidoxin, and Catalase (CAT)). In conclusion, DHQ could be a lead compound for the treatment of toxoplasmosis when successfully evaluated using in vitro and in vivo models to confirm its effectiveness and safety.
This open access book analyzes the evidence linking Toxoplasma gondii to the increasing incidence of schizophrenia and bipolar disorder in the United States. Initially establishing that infectious agents are regularly transmitted from animals to humans, lead to human disease, and that infectious agents can cause psychosis, it then examines the protozoan parasite Toxoplasma gondii in detail. Infecting 40 million Americans, Toxoplasma gondii is known to cause congenital infections, eye disease, and encephalitis for individuals who are immunosuppressed. It has also been shown to change the behavior of nonhuman mammals, as well as to alter some personality traits in humans. After discussing the clinical evidence linking Toxoplasma gondii to human psychosis, the book elucidates the epidemiological evidence further supporting this linkage; including the proportional increase in incidence of human psychosis as cats transitioned to domestication over 800 years. Finally, the book assesses the magnitude of the problem and suggests solutions.
Parasites, Pussycats and Psychosis: The Unknown Dangers of Human Toxoplasmosis provides a comprehensive review of the evidence linking human psychosis in the United States to infections of Toxoplasma gondii. It will be of interest to infectious disease specialists, general practitioners, scientists, historians, and cat-lovers.
A toxoplasmose é uma zoonose de distribuição mundial que acomete vertebrados homeotérmicos, incluindo o ser humano. Toxoplasma gondii, seu agente etiológico, é capaz de infectar seus hospedeiros por diversas vias de transmissão, dentre elas a ingestão de cistos teciduais, presente na carne crua ou malcozida, e a ingestão de oocistos, presentes na água e alimentos contaminados, sendo essas as principais rotas de infecção na cadeia epidemiológica da toxoplasmose. Neste sentido, a contaminação ambiental com oocistos esporulados apresenta-se como um importante fator de risco para a infecção toxoplásmica em animais herbívoros, como os equinos e ovinos. Enquanto os equinos mostram resistência à infecção e a manifestações de sinais clínicos da doença, em ovinos, a toxoplasmose pode ser responsável por importantes distúrbios reprodutivos como aborto e morte neonatal. Sendo assim, este estudo teve como objetivo pesquisar a presença de anticorpos específicos anti- T. gondii em equinos e ovinos criados na Fazenda Experimental Nhumirim, propriedade da Embrapa Pantanal, Mato Grosso do Sul, Brasil. Para tanto foram coletadas amostras de soro de 101 equinos e 99 ovinos entre março de 2011 e maio de 2015. As amostras de soro foram enviadas para o Laboratório de Toxoplasmose e outras Protozooses, do Instituto Oswaldo Cruz, na Fundação Oswaldo Cruz/RJ. Os soros foram submetidos à reação de imunofluorescência indireta, sendo consideradas positivas as amostras sororreagentes a partir da diluição de 1:64 para ambas as espécies. Anticorpos anti-T. gondii foram detectados em 15% (15/99) dos ovinos e 10% (10/101) dos equinos. A ocorrência de anticorpos específicos anti-T. gondii nas amostras de soro desses animais, aponta para uma contaminação ambiental da propriedade, onde possivelmente, felídeos silvestres estariam atuando como dispersores do parasito. A exposição dos animais estudados ao T. gondii deve ser considerada ao avaliar resultados dos estudos de desempenho nos quais estes animais são utilizados, em especial os ovinos devido à sua alta sensibilidade à infecção toxoplásmica. Corroborando com outros autores, sobre o risco de infecção de animais domésticos e a presença de T. gondii no ambiente do Pantanal brasileiro, e diante das dificuldades de se aplicarem medidas de prevenção e controle nos sistemas produtivos agropecuários praticados, sugere-se aplicá-las com foco na saúde humana.
Toxoplasma gondii has evolved different developmental stages for disseminating during acute infection (i.e. tachyzoites) and for establishing chronic infection (i.e. bradyzoites). Calcium ion (Ca ²⁺ ) signaling tightly regulates the lytic cycle of tachyzoites by controlling microneme secretion and motility to drive egress and cell invasion. However, the roles of Ca ²⁺ signaling pathways in bradyzoites remain largely unexplored. Here we show that Ca ²⁺ responses are highly restricted in bradyzoites and that they fail to egress in response to agonists. Development of dual-reporter parasites revealed dampened Ca ²⁺ responses and minimal microneme secretion by bradyzoites induced in vitro or harvested from infected mice and tested ex vivo. Ratiometric Ca ²⁺ imaging demonstrated lower Ca ²⁺ basal levels, reduced magnitude, and slower Ca ²⁺ kinetics in bradyzoites compared with tachyzoites stimulated with agonists. Diminished responses in bradyzoites were associated with down-regulation of Ca ²⁺ -ATPases involved in intracellular Ca ²⁺ storage in the endoplasmic reticulum (ER) and acidocalcisomes. Once liberated from cysts by trypsin digestion, bradyzoites incubated in glucose plus Ca ²⁺ rapidly restored their intracellular Ca ²⁺ and ATP stores leading to enhanced gliding. Collectively, our findings indicate that intracellular bradyzoites exhibit dampened Ca ²⁺ signaling and lower energy levels that restrict egress, and yet upon release they rapidly respond to changes in the environment to regain motility.
Toxoplasma gondii is a common parasite that infects warm-blooded animals and influences host physiology. T. gondii is known to target the host's central nervous system, affecting circulating levels of steroid hormones, fear-related behaviors, and health, although these effects appear to vary among host taxa. Here, we investigated the relationship between T. gondii infection and levels of plasma testosterone and cortisol within a wild population of spotted hyenas (Crocuta crocuta, n = 109). In our analyses, we accounted for age and sex via stratified regression analyses. We detected a negative association between circulating plasma testosterone and T. gondii infection among female cubs and subadults as well as adult male hyenas. We found no associations between T. gondii infection and cortisol in any age class or sex group of hyenas. Our work adds to a growing body of literature by characterizing the relationship between T. gondii infection and physiology in a novel host in its natural habitat. In a broader context, our findings indicate that responses to infection vary with characteristics of the host and point to a clear need for additional studies and priorities for future work that include diverse taxa and ecological settings.
Background: Toxoplasma gondii (T. gondii) is a pathogenic and zoonotic parasite, which felines implicate as
definitive hosts; intermediate hosts are warm-blooded vertebrates. The protozoa can cause serious symptoms in
humans, while in poultry is usually asymptomatic. The prevalence of Toxoplasma gondii in poultry due to the
way poultry are fed is an important indicator of the distribution of oocysts in the environment; in addition,
consumption of raw or under cooked meat of chickens can cause infection in human and other animals.
Therefore, in this study, the prevalence rate of infection to toxoplasma gondii in domestic and industrial breeding
poultry in Isfahan City, Iran, was assessed.
Methods: From three groups of domestic breeding, broiler, and laying eggs poultry, 60 blood clot samples were
collected. On collected serums, serological modified agglutination test (MAT) was performed. Toxoplasma
gondii-specific antibodies were assayed by this test. Then, the obtained results were analyzed.
Findings: By performing the MAT serological test, 20, 15, and 30 samples were positive in domestic breeding,
industrial broiler, and in laying eggs samples, respectively. Therefore, relative frequency was 33.3, 25.0, and
50.0 percent in domestic breeding, industrial broiler, and industrial laying eggs, respectively, which by
performing chi-square test and calculating the P < 0.050 between the three groups, a significant difference was
observed serologically.
Conclusion: A considerable percent of domestic and industrial poultry was infected with Toxoplasma gondii.
Therefore, preventive measures should be conducted to provide safe foods for vertebrate animals and human.
Keywords: Agglutination; Poultry; Prevalence; Serology; Toxoplasma gondii
This is the only book to cover toxoplasmosis of animals and humans thoroughly in one single source. Found worldwide from Alaska to Australasia, Toxoplasma gondii is the cause of one of the most common parasitic infections in humans, livestock, companion animals, and wildlife, and is included on the list of potential bioterrorism microbes. Furthermore, T. gondii has been and continues to be used extensively as a model for the cell biology of apicomplexan parasites. In the decade since the second edition of this book was published, there has been an explosion of knowledge concerning the parasite Toxoplasma gondii and toxoplasmosis. This update provides unique information on all known host types for this parasite, with an additional chapter on history, substantial updates throughout, and a detailed focus on the biology of the parasite in Chapter 2. The third edition is compiled by author JP Dubey, an authority on T. gondii who has worked with virtually all hosts of the protozoan during the last 55 years, including humans, all livestock species, wildlife, and zoo animals. The book distills the voluminous and potentially confusing scientific literature, that has grown geometrically in the 30+ years since the publication of the first edition, into a comprehensive resource for all professionals, graduate students and researchers working in this field.
Modified agglutination test (MAT) was applied to 150 chicken sera (90 were farm-bred and 60 house-bred chickens). The prevalence of Toxoplasma antibodies was 18.7%. In house-bred chickens positive cases were 18 out of 60 (30.0%), while in farm-bred chickens positive cases were 10 out of 90 (11.1%). Histopathological sections of the seropositive chickens showed tissue lesions which were most likely to be induced by T. gondii. Tissue cysts of T. gondii were demonstrated in the liver, brain, heart and skeletal muscles of 22 (78.6%) out of 28 positive chickens. These tissue cysts were found mostly in the brain of seropositive chickens. Epidemiological implications of these data for public health significance were discussed.