[Show abstract][Hide abstract] ABSTRACT: Anaplasma phagocytophilum is an emerging pathogen of humans, dogs and other animals, and it is transmitted by ixodid ticks. The objective of the current study was a) detect A. phagocytophilum in dogs and ixodid ticks using real-time Polymerase Chain Reaction (qPCR); and b) Determine important variables associated to host, environment and potential tick vectors that are related to the presence of A. phagocytophilum in dogs domiciled in Rio de Janeiro, Brazil.
We tested blood samples from 398 dogs and samples from 235 ticks, including 194 Rhipicephalus sanguineus sensu lato, 15 Amblyomma cajennense, 8 Amblyomma ovale and 18 pools of Amblyomma sp. nymphs. A semi-structured questionnaire was applied by interviewing each dog owner. Deoxyribonucleic acid obtained from ticks and dog buffy coat samples were amplified by qPCR (msp2 gene). The sequencing of 16S rRNA and groESL heat shock operon genes and a phylogenetic analysis was performed. The multiple logistic regression model was created as a function of testing positive dogs for A. phagocytophilum.
Among the 398 blood samples from dogs, 6.03% were positive for A. phagocytophilum. Anaplasma phagocytophilum was detected in one A. cajennense female tick and in five R. sanguineus sensu lato ticks (four males and one female). The partial sequences of the 16S rRNA, and groESL genes obtained were highly similar to strains of A. phagocytophilum isolated from wild birds from Brazil and human pathogenic strains. The tick species collected in positive dogs were R. sanguineus sensu lato and A. cajennense, with A.cajennense being predominant. Tick infestation history (OR = 2.86, CI = 1.98-14.87), dog size (OR = 2.41, IC: 1.51-12.67), the access to forest areas (OR = 3:51, CI: 1.52-16.32), hygiene conditions of the environment in which the dogs lived (OR = 4.35, CI: 1.86-18.63) and Amblyomma sp. infestation (OR = 6.12; CI: 2.11-28.15) were associated with A. phagocytophilum infection in dogs.
This is the first report of A. phagocytophilum in ixodid ticks from Brazil. The detection of A. phagocitophylum in A. cajennense, an aggressive feeder on a wide variety of hosts, including humans, is considered a public health concern.
[Show abstract][Hide abstract] ABSTRACT: The objective of this study was to evaluate factors associated with infestation by Amblyomma cajennense on horses in two microregions of the state of Rio de Janeiro. Horses on 62 farms in the municipalities of the Itaguaí and Serrana microregions were evaluated between January and May 2009. The animals were examined to determine the presence of ticks and infestation level. The animals' rearing and management were assessed on each farm property using an epidemiological questionnaire. Out of the 635 horses evaluated, 41.6% were infested with A. cajennense. It was observed that farms in low-altitude regions (OR=3.69; CI: 2.3-5.8), with unsatisfactory zootechnical and sanitary management (OR=5.92; CI: 3.8-9.2) and an extensive rearing system (OR=4.25; CI: 2.1-8.5) were factors associated with tick infestation (p < 0.05) and also with cases of high infestation on horses. Use of chemical acaricides on horses was also associated with infestation (p < 0.05); the owners described different therapeutic approaches with different treatment intervals. From the present study, low altitudes, unsatisfactory management, extensive rearing and inappropriate use of acaricide products were factors associated with occurrences of A. cajennense at different infestation levels on horses in these municipalities.
Revista brasileira de parasitologia veterinaria = Brazilian journal of veterinary parasitology: Orgao Oficial do Colegio Brasileiro de Parasitologia Veterinaria 06/2013; · 0.72 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The aim of this study was to detect Theileria equi (Laveran 1901) DNA in horses and ticks using real-time PCR and to list the factors associated with infection in animals located in the Seropedica and Petropolis municipalities of the state of Rio de Janeiro. We tested blood samples from 314 horses and samples from 300 ticks, including 191 Amblyomma cajennense, 104 Dermacentor nitens, and 5 Ixodida larvae. Factors inherent to the horse, the ownership, and animal management were obtained from an epidemiological questionnaire and were evaluated in association with the presence of T. equi DNA in the animals. Among the horses in the study, 81 % (n = 253/314) presented T. equi DNA, and the animals of the Seropedica municipality had the highest infection frequency (91 %, n = 128/141, p < 0.001). The factors that had significantly different infection frequencies by chi-squared or Fisher's exact tests (p < 0.2) were included in a logistic regression model using the R programming package. Work and walking activity (odds ratio [OR] = 5.7, CI = 2.3-14.4), reproductive activity (OR = 3.8, CI = 1.3-11.5), and tick infestation (OR = 2.6, CI = 1.1-6.2) were factors that favored the presence of T. equi DNA in the animals (p < 0.05). Among the tick samples, A. cajennense and D. nitens were the identified species. The presence of T. equi DNA was observed in 9.9 % (n = 19/191) of the A. cajennense samples and 3.8 % (n = 4/104) of the D. nitens samples. A multivariate analysis revealed that the presence of A. cajennense on the animals (OR = 4.1, CI = 1.8-9.1) was associated with the presence of T. equi DNA in the horses. In the studied municipalities, activities related to work, walking, and reproduction and the presence of ticks on the horses, particularly an intense infestation of A. cajennense, are factors that lead to infection with T. equi in the horses.
Parasitology Research 03/2013; · 2.85 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: This study evaluated factors associated with the frequency of Leishmania spp. antibodies in dogs residing in the Itaguai micro-region, State of Rio de Janeiro, Brazil. Blood samples were collected from 524 dogs. The serum samples were submitted to indirect fluorescent antibody test (IFAT) and enzyme-linked immunosorbent assay (ELISA) for Leishmania spp. The frequency of seropositive dogs was 28.24% (n = 148) in the micro-region, and among the three municipalities within that region, the highest frequency (p < 0.05) was observed in Seropedica (59.46%), followed by Itaguai (29.05%) and Mangaratiba (11.49%). Regarding factors associated with the host, mongrel dogs and those over the age of two presented higher frequency of antibodies to Leishmania spp. (p < 0.05). Concerning factors related to the environment and habits of the animal, dogs residing in rural areas (FR = 1.67, p = 0.0002), living outside the residence (FR = 1.42, p = 0.0197), with access to forest, streams and pastures (FR = 2.81, p = 0.0007), remaining loose (FR = 1.66, p = 0.0073), and those that had no shelter (FR = 2.16, p < 0.0001) were more likely to be seropositive. Canine leishmaniasis is a disease with high occurrence in the Itaguai micro-region, and aspects such as the definition of breed, age, habits and care by owners showed significant association in this micro-region.
Revista brasileira de parasitologia veterinaria = Brazilian journal of veterinary parasitology: Orgao Oficial do Colegio Brasileiro de Parasitologia Veterinaria 03/2013; 22(1):39-45. · 0.72 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Rangelia vitalii is a protozoon described from dogs in the south and southeast regions of Brazil. It is phylogenetically related to Babesia spp. that infects dogs, but data on this enigmatic parasite is still limited. The aim of this work was to detect piroplasm species in dogs in the state of Rio de Janeiro, Brazil, by 18S rRNA gene-based PCR assay, restriction fragment length polymorphism (RFLP) and sequence analyses. Of 103 dogs examined, seven (6.8%) were positive for Babesia spp. by PCR. The amplified products were digested by restriction enzymes to differentiate the Babesia species, and one sample was identified as Babesia vogeli. The pattern observed for the other six amplification products did not match with pattern described for large Babesia infecting dogs. Sequencing analysis confirmed these six samples as R. vitalii, with high homologies (99-100%) with a sequence from south Brazil. This study confirms the presence of Babesia vogeli and Rangelia vitalii circulate in domestic dogs in Teresópolis, Rio de Janeiro, Brazil.
Revista brasileira de parasitologia veterinaria = Brazilian journal of veterinary parasitology: Orgao Oficial do Colegio Brasileiro de Parasitologia Veterinaria 06/2012; 21(2):137-42. · 0.72 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The current study aimed to investigate the seroprevalence of IgG antibodies to Anaplasma marginale in cattle from Maputo, Gaza and Inhambane provinces, south Mozambique. A total of 809 serum samples from cattle were obtained and tested by indirect enzyme-linked immunosorbent assay (i-ELISA). The chi-square test at 5% significance was used to assess the association between seroprevalence and the variables gender, age and geographic origin of animals. The overall seropositivity was 76.5% (n = 619) and anti-A. marginale antibodies were detected in 89.1% (n = 156), 68.4% (n = 308) and 84.2% (n = 155) of the animals in the provinces of Maputo, Gaza and Inhambane, respectively. A significant association (p < 0.05) was found with the geographic origin of the animals, while sex had no significant relationship. The frequencies of seropositive in the age groups were 63.2% (n = 72), 80.0% (n = 92), 83.1% (n = 98) and 77.3% (n = 357) for animals <12; >12 and ≤24; >24 and ≤36; >36 months, respectively. These results indicate that in southern Mozambique there are areas of enzootic stability to A. marginale. Thus, epidemiological monitoring is required to monitor the immune status of animals in the region.
Revista brasileira de parasitologia veterinaria = Brazilian journal of veterinary parasitology: Orgao Oficial do Colegio Brasileiro de Parasitologia Veterinaria 10/2011; 20(4):318-24. · 0.72 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Neosporosis and toxoplasmosis are parasitic diseases which can cause reproductive problems in goats and sheep. The current study aimed to determine the occurrence of anti-Neospora caninum and anti-Toxoplasma gondii IgG antibodies in goats and sheep from the districts of Amarante do Maranhão and Buritirana, Imperatriz microregion, western area of Maranhão State, northeastern Brazil, and to assess factors associated to infection by these etiologic agents. Blood samples from 110 animals (46 goats and 64 sheep) from five herds were collected, and indirect immunofluorescence assay was used for serological testing. Of 46 goat samples, 17.39% (n = 8) showed anti-N. caninum antibodies and 4.35% (n = 2) anti-T. gondii, while of 64 sheep samples 4.69% (n = 3) and 18.75% (n = 12) showed anti-N. caninum and anti-T. gondii antibodies, respectively. No significant difference regarding the presence of domestic cats and/or dogs on the property and veterinary care was seen for both etiologic agents studied. However, food supplementation and animal reproductive failure were significantly (p < 0.05) for N. caninum among sheep and goats, respectively. The current study showed that goats and sheep in western Maranhão are exposed to N. caninum and T. gondii. It is the first evidence of these agents in small ruminants in this region.
Revista brasileira de parasitologia veterinaria = Brazilian journal of veterinary parasitology: Orgao Oficial do Colegio Brasileiro de Parasitologia Veterinaria 10/2011; 20(4):312-7. · 0.72 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Anaplasma phagocytophilum was detected in dogs from Brazil in the municipalities of Seropédica and Itaguaí, Rio de Janeiro state, by real-time polymerase chain reaction (PCR) using SYBR Green to detect the amplification. Of 253 samples, 18 (7.11%) were positive, with a threshold cycle (Ct) ranging from 31 to 35 cycles. The PCR product from a positive sample was cloned and sequenced. The sequence obtained demonstrated 100% identity with other A. phagocytophilum sequences published in the GenBank database. The analytical sensitivity of RT-PCR using SYBR Green system was able to detect 3 plasmid copies when defined numbers of plasmid copies containing 122 base pairs from the msp2 gene were used. The assay was considered specific when DNA from bacteria (Anaplasma platys, Anaplasma marginale, Ehrlichia canis, Neorickettsia risticii, Rickettsia rickettsii) closely related to A. phagocytophilum was placed in the reaction. These results demonstrate that the canine granulocytic anaplasmosis agent is present in regions in which dogs could be a source of infection for tick vectors. The current study reports the detection of A. phagocytophilum, a zoonotic agent responsible for Human granulocytic anaplasmosis, in Brazilian dogs.
Journal of veterinary diagnostic investigation: official publication of the American Association of Veterinary Laboratory Diagnosticians, Inc 07/2011; 23(4):770-4. · 1.18 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Serum samples from 714 equids of Itaguaí and Serrana microregions, Rio de Janeiro, southeastern Brazil, were examined by indirect fluorescent antibody test (titer 1:80) for Theileria equi. The prevalence in the microregions and factors associated with seropositivity were evaluated and the prevalence ratio (PR) calculated. The overall prevalence of T. equi infection was 81.09% (n = 579), with higher prevalence (p < 0.05) in the Itaguaí (85.43%) when compared to Serrana microregion (76.92%). The geographic area, altitude, farming condition and area of origin of equids were associated (p < 0.05) with seropositivity for T. equi. Equids reared in the Itaguaí microregion (PR = 1.11, p = 0.003) and at altitudes below 500 m (PR = 1.10; p = 0,014) were more likely to be seropositive for T. equi. Furthermore, when equids were born in the farm (PR = 1.10, p = 0.008) and reared with poor farming conditions (PR = 1.13, p = 0.018) they were more likely to be exposed to T. equi. The main ticks found on equids were Amblyomma cajennense and Dermacentor (Anocentor) nitens. The microregions studied are endemic areas for equine theileriosis and there exists enzootic stability for T. equi. Only factors related to the collection area of serum samples influenced the seropositivity of equids for T. equi in that region.
Revista brasileira de parasitologia veterinaria = Brazilian journal of veterinary parasitology: Orgao Oficial do Colegio Brasileiro de Parasitologia Veterinaria 07/2011; 20(3):235-41. · 0.72 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The life cycle of Argas (Persicargas) miniatus in adult stage was studied in controlled conditions (27±1°C and 80±10% RH) and uncontrolled temperature and humidity conditions (room conditions during wet and dry season). Males originated preferentially from N2 and females from N3. Females in controlled conditions laid eggs up to 18 times, while females in uncontrolled room conditions, during wet and dry seasons, laid eggs 9 to 12 times, respectively. In controlled conditions, females laid 1350 eggs, whereas in uncontrolled conditions females laid 443 eggs during the wet season and 894 eggs during the dry season. Male ticks survived without feeding for 165 days in controlled conditions and 135 days in uncontrolled conditions, while females survived for 300 days in controlled conditions and 240 days in uncontrolled conditions. In ambient conditions, biological parameters of Argas (Persicargas) miniatus adult stage were negatively affected especially during the wet season when compared with adult stage kept in controlled condition.
[Show abstract][Hide abstract] ABSTRACT: One of the species that causes avian malaria is Plasmodium juxtanucleare. It is commonly found in poultry, especially when the birds receive food free of coccidiostats. Since industrial and organic poultry breeding is increasing in the world and few studies have been conducted examining the clinical parameters of both healthy and infected birds, this work evaluated whether the infection caused by P. juxtanucleare in Gallus gallus provokes alterations in the birds' hepatic profile. We analyzed the activity of ALT and AST and carried out histological analyses of liver sections of infected fowls by intracelomic inoculation with infected blood from a donor fowl with a parasite load of around 7%. The infected birds' parasite load was evaluated during 45 days by means of blood smears. There was a positive correlation between the increase in parasite load and higher ALT activity in the infected fowls, but there was no significant variation of the AST activity between the control and infected groups, possibly because of the non-specificity of this enzyme as an indicator of hepatic lesion. The results show that infection caused by P. juxtanucleare in G. gallus provokes hepatic alterations, indicated by the increase in the ALT enzyme activity and by the inflammatory infiltrates found in the liver sections of the infected fowls.
[Show abstract][Hide abstract] ABSTRACT: The current study investigated the biology of nymphs of the first and second instars of Argas (Persicargas) miniatus. Nymphs were deprived of food for 15, 30 or 60 days and held at 27 ± 1 °C and 80 ± 10% relative humidity (controlled conditions) or at room conditions of temperature and relative humidity. Nymphs of first instar deprived of food for 15 or 30 days molted to second and third instars in both controlled and room conditions. Nymphs of the first instar deprived of food for 60 days had 28 and 37% mortality in controlled and room conditions, respectively; and survivors did not attach to the host. Nymphs of the second instar, deprived of food for 60 days, molted either to the third instar or to males after feeding on Gallus gallus, and the nymphs of the third instar developed to adults (42.42% males and 36.36% females when nymphs were held in controlled temperature and humidity conditions, and 40.54% males and 48.65% females when nymphs were held in room conditions). The remainder of the nymphs molted to the fourth instar and then molted to females. In conclusion, the nymphal starvation period of 60 days determined the number of nymph instars in the life cycle of A. miniatus under the experimental conditions studied.
Revista brasileira de parasitologia veterinaria = Brazilian journal of veterinary parasitology: Orgao Oficial do Colegio Brasileiro de Parasitologia Veterinaria 01/2010; 19(3):164-8. · 0.72 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: This study describes biological characteristics of Rhipicephalus (Boophilus) microplus in the parasitic phase from equines experimentally infested. Four equine were experimentally infested, initially with 20,000 and then, in a sequence of three times with 40,000 larvae each. In all infestations the animals developed intense cutaneous reaction on the larvae fixation area. This reaction was characterized by intense local itch and hair elevation, followed by alopecic areas, with bounded ulcerated lesions. Larvae and nymphs mortality was nearly 90% and 60%, respectively. From the initial infestation, none engorged or semi-engorged female was recovered. After infestations accomplished with 40,000 larvae of R. microplus, two equines were considered resistant to the infestation, because none engorged or semi-engorged female was recovered. One equine was considered moderately resistant, since a few semi-engorged female were recovered. One equine was considered susceptible. In this last one, R. microplus completed its parasitic cycle with 30% of adult mortality. The average period of parasitic phase were 33.3; 36.9 and 38.5 days, respectively, to three infestations accomplished with 40,000 larvae. Recovery rates of engorged female ranged from 0.9% to 1.8%. This research shows that it is possible to study the R. microplus biology from experimental infestations in equine. However, the number of larvae used for infestation, as well as the existence of susceptible and resistant equines should be considered.
[Show abstract][Hide abstract] ABSTRACT: This study reports the experimental transmission of Borrelia anserina to domestic chickens by infected Argas (Persicargas) miniatus. Clinical alterations as well as prepatent and patent periods were evaluated. Twenty-seven 67-day-old birds were divided into three groups in a randomized experimental design. The first group was exposed to ticks infected with B. anserina, the second group was exposed to noninfected ticks, and the third group was not exposed to ticks. Blood smears from each bird of groups 1 and 2 were prepared daily and examined for 25 days postexposure (PE). Examination of the blood smears from birds in group 1 revealed large numbers of spirochetes from days 5 to 12 PE. In this group the prepatent and patent periods were 5-7 and 4-7 days, respectively. Birds from group 1 presented ruffled feathers, pale combs, drowsiness, inappetence, loss of weight, and greenish diarrhea after day 6 PE. The current study confirms the viability of experimental transmission of B. anserina to domestic chickens by A. (P.) miniatus.
[Show abstract][Hide abstract] ABSTRACT: The Brazilian Spotted Fever (BSF) is a zoonotic disease caused by Rickettsia rickettsii and transmitted by ticks of the genus Amblyomma, more frequently, Amblyomma cajennense. The aim of this paper was to report the first molecular detection of R. rickettsii on R. sanguineus naturally infected in Rio de Janeiro, Brazil. Ticks were collected from dogs in a rural region of Resende municipality, Rio de Janeiro State, Brazil (22º30'9.46"S, 44º42'44.29"WO), where occurred five human cases of BSF in 2006. The ticks were identified under a stereoscopic microscope and separated in pools by stages, species and sex. DNA extraction was carried out using QIAamp DNA Mini Kit (QIAGEN®). The DNA was submitted to PCR amplification using 04 set of primers: Rr190.70p/Rr190.602n (OmpA, 532bp), BG1-21/BG2-20 (OmpB, 650bp), Tz15/Tz16 (17 kDa protein-encoding gene, 246bp) and RpCS.877p/RpCS.1258n (gltA, 381bp). PCR products were separated by electrophoresis on 1% agarose gels and visualized under ultraviolet light with ethidium bromide. PCR products of the expected sizes were purified by QIAquick® and sequenced by ABI PRISM®. The generated nucleotide sequences were edited with using Bioedit® software and compared with the corresponding homologous sequences available through GenBank, using Discontiguous Mega Blast (http://www.ncbi.nlm.nih.gov). It was confirmed R. rickettsii by sequencing of the material (GenBank FJ356230). The molecular characterization of R. rickettsii in the tick R. sanguineus emphasizes the role of dogs as carriers of ticks from the environment to home. Moreover, this result suggests that there is a considerable chance for active participation of R. sanguineus as one of tick species in the transmission of R. ricketsii to human being in the Brazilian territory.
[Show abstract][Hide abstract] ABSTRACT: This research was performed to study the prevalence of antibodies against Babesia equi in horses of the northern region of Rio Grande do Sul state, using ELISA and indirect immunofluorescence antibody test (IFA). The total sera sample was 380, this number was considered as statistically representative of the population, as determined by mathematical model. The prevalence of B. equi was 31.6% and 35.8% by ELISA and IFA, respectively. The concordance between the assays was 0.87 (indices kappa), which is considered an optimal result. The results did not show any significant statistical difference (P < 0.05) between sex, age and horses breed. The results of this study allowed the characterization of the northern region of Rio Grande do Sul as an instable enzootic area for B. equi, which indicates a potential risk of economic losses caused by babesiosis outbreaks, especially for sensible horses from non enzootic areas or even born is the studied region.
Revista brasileira de parasitologia veterinaria = Brazilian journal of veterinary parasitology: Orgao Oficial do Colegio Brasileiro de Parasitologia Veterinaria 09/2008; 17 Suppl 1:317-21. · 0.72 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The aim of this study was to demonstrate, through nested PCR (nPCR) method, the occurrence of congenital babesiosis in two foals born of carrier mares. All mares were positive for T. equi based in visualization of intraerytrocytic parasites in blood smears, in indirect fluorescent antibody test (IFAT) and nPCR reactions. Just one mare was nPCR-positive for B. caballi. After the birth, all foals presented nPCR-positive for T. equi, while just one foal presented nPCR-positive for B. caballi. The present study prove the occurrence of congenital babesiosis in new-born foals, however, new studies are necessary to elucidate if the infection occur for transplacental transmission or in parturition moment.
Revista brasileira de parasitologia veterinaria = Brazilian journal of veterinary parasitology: Orgao Oficial do Colegio Brasileiro de Parasitologia Veterinaria 09/2008; 17 Suppl 1:348-50. · 0.72 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: To characterize phylogenetically the species which causes canine hepatozoonosis at two rural areas of Rio de Janeiro State, Brazil, we used universal or Hepatozoon spp. primer sets for the 18S SSU rRNA coding region. DNA extracts were obtained from blood samples of thirteen dogs naturally infected, from four experimentally infected, and from five puppies infected by vertical transmission from a dam, that was experimentally infected. DNA of sporozoites of Hepatozoon americanum was used as positive control. The amplification of DNA extracts from blood of dogs infected with sporozoites of Hepatozoon spp. was observed in the presence of primers to 18S SSU rRNA gene of Hepatozoon spp., whereas DNA of H. americanum sporozoites was amplified in the presence of either universal or Hepatozoon spp.-specific primer sets; the amplified products were approximately 600bp in size. Cloned PCR products obtained from DNA extracts of blood from two dogs experimentally infected with Hepatozoon sp. were sequenced. The consensus sequence, derived from six sequence data sets, were blasted against sequences of 18S SSU rRNA of Hepatozoon spp. available at GenBank and aligned to homologous sequences to perform the phylogenetic analysis. This analysis clearly showed that our sequence clustered, independently of H. americanum sequences, within a group comprising other Hepatozoon canis sequences. Our results confirmed the hypothesis that the agent causing hepatozoonosis in the areas studied in Brazil is H. canis, supporting previous reports that were based on morphological and morphometric analyses.