No full-text available
To read the full-text of this research,
you can request a copy directly from the authors.
Molecular detection of brucellosis in dromedary camels of Qatar by real-time PCR technique
ResearchGate has not been able to resolve any citations for this publication.
Background:
Brucellosis is an emerging yet neglected zoonosis that has been reported in Kenya. Epidemiological data on brucellosis in ruminants is readily accessible; however, reports on brucellosis in pigs remain limited. This study sought to detect Brucella infection in pig serum by both serological and molecular techniques. Serum from 700 pigs randomly collected at a centralized abattoir in Nairobi region, Kenya were screened in parallel, using both Rose Bengal Test (RBT) and competitive Enzyme-Linked Immuno-sorbent Assay (cELISA) for antibodies against Brucella spp. All sera positive by RBT and 16 randomly selected negative samples were further tested using conventional PCR targeting bcsp31 gene and real-time PCR (RT-PCR) assays targeting IS711 and bcsp31 genes.
Results:
A prevalence of 0.57% (n = 4/700) was estimated using RBT; none of these samples was positive on cELISA. All RBT positive sera were also positive by both PCRs, while two sero-negative samples also tested positive on RT-PCR (n = 6/20). Brucella abortus was detected in four out of the six PCR positive samples through a real-time multiplex PCR.
Conclusion:
The detection of antibodies against Brucella spp. and DNA in serum from slaughterhouse pigs confirm the presence of Brucella in pigs. Therefore, investigation of the epidemiology and role of pigs in the transmission of brucellosis in Kenya is needed. Further targeted studies would be useful to systematically quantify and identify the spp. of Brucella in pigs.
Background Occupational hazards are the leading cause of morbidity and mortality among abattoirs personnel and animal workers. These hazards result from direct or indirect exposure to potential infection and several distressing events during routine procedures.
Objectives To serologically investigate the potential occupational brucellosis hazard at Egyptian abattoirs. To provide an insight on the needed biosafety practices that should be implemented to mitigate the spread of occupational brucellosis among abattoir workers.
Methods Two hundred and thirty (n = 230) blood samples were collected from animals in two Egyptian abattoirs. The rose Bengal test was used to evaluate the seroprevalence of Brucella in abattoir animals. A questionnaire was distributed among abattoir personnel to address biosafety gaps and deficiencies as a cause of occupational brucellosis.
Results The overall seroprevalence of Brucella using the rose Bengal test was 75.2% in the two targeted abattoirs. It was obvious that there are gaps of malpractices and inconvenient behavior among individuals of the targeted community.
Conclusions The current findings reveal the missing role of concerned authorities and lack of written safety policy. The data highlights the need for further research, including isolation and characterization of the causative agents, and reliable epidemiological studies.
Background
In Argentina, vaccination with Brucella abortus Strain 19 vaccine is mandatory. The objective of the study was to develop and test a method for evaluating, in an innovative way, some farmers’ and veterinarians’ management practices in relation to brucellosis and to assess the vaccination campaign and coverage. The work took place in Brandsen and Navarro districts. Four questionnaires were designed (for officials from Local Sanitary Entities, vaccinators, vet practitioners and farmers). Responses were coded as “ideal” (0) and “not ideal” (1). To assess the relative weight of each question (“item”), experts ranked the items according to their impact on management practices and vaccination. A weighted score was then calculated. A higher weighted score was assigned to the worse practices. Farmers obtaining a global weighted score above the third quartile were classified as “inappropriately managed farms”, to be compared per type of production system and district. To assess the immunization coverage, female calves were sampled 30 to 50 days post vaccination; they were expected to react positively to serological diagnostic tests (DT+).
Results
There were significantly more inappropriately managed farms and higher global scores among beef farmers and in Brandsen. Eighty three percent (83%) of female calves were DT+, significantly under the ideal immunization coverage (95%). Only 48% of farms were considered well vaccinated. DT+ results were positively associated with the Brandsen district (OR = 25.94 [4.60–1146.21] and with the farms having more than 200 cow heads ((OR = 78.34 [4.09–1500.00]). On the contrary, DT+ were less associated with vaccinators being veterinary practitioners (OR = 0.07 [0.006–0.78]). Farmers are well advised by their veterinary practitioners but they should improve some management practices.
Conclusions
The vaccination campaign is globally well implemented, but the immunization coverage and some vaccinators’ practices should be improved.
This study leads to a better understanding of the most common used management and control practices regarding brucellosis, which affect its epidemiology. Any vaccination campaign should be periodically assessed to highlight possible fails. The described methodology can be extrapolated to other countries and different contexts.
Background
Brucellosis is a zoonotic pathogen responsible for great economic losses in most sub-Saharan nations. Although Ghana has successfully implemented the “One Health” initiative for the control of some emerging infectious zoonotic diseases with pandemic potential like Avian Influenza, there is very limited data available on brucellosis especially human brucellosis prevalence. He objective of his study is to determine the seroprevalence of human and bovine brucellosis as well as the predisposing factors at the community level in the North Tongu District of Ghana.
Materials and Methods
Rose Bengal Plate test (RBPT) was used to analyze blood samples from 178 cattle farmers, and 315 cattle. The positive samples were further confirmed with cELISA. Predisposing factors were determined by questionnaires administered to cattle farmers. All sample sites were geo-referenced.
Results
Human and bovine brucellosis seroprevalence using RBPT were 10.1% and 22.9% respectively. Eighty six percent (62/72) of bovine cases were confirmed with ELISA. Delivery assistants were more likely to be infected (p=0.043) with odds ratio of 2.7. Out of the human cases (18), males constituted 88.9%. Ages 11-20 years recorded 77.7% seropositivity whilst cattle drovers represented 44.5% (8/18) of positives. Significant risk factors in cattle were herd size (p=0.037), history of retained placenta (0.000) and abortion (0.005).
Conclusion
Bovine and human brucellosis is prevalent in North Tongu district, Ghana. Close contact with parturient cows was a major predisposing factor for human infection. Early referral of positive persons to the Hospital for confirmation and treatment is required to comply with the “One Health” initiative on brucellosis and other zoonoses.
Brucellosis is the most frequent zoonosis reported in Qatar, mainly related to exposure to infected camels. An outbreak of human brucellosis in 14 members of a family living in a rural area in Qatar is reported herein. Clinical, epidemiological and laboratory results from all 14 patients with Brucella and 12 non-confirmed family members were collected from files. All patients reported fever for a maximum of 14 days, associated with arthralgia (6 patients), weakness (4 patients), headache (4 patients), diarrhea (2 patients) and abdominal pain (2 patients). The median age of the patients was 10 years and that of non-cases was 16 years, with a predominance of males (92.9%). Elevated levels of transaminases were observed in patients. A mixed infection caused by Brucella abortus and Brucella melitensis was identified by blood culture and serology. The source of the infection was the milk of an infected camel. The outbreak of brucellosis melitensis/abortus related to the consumption of camel milk constitutes a gap in the prevention and control of the potential sources of brucellosis in animal farms. Proper control and education of the population are required.
During the years 2001 and 2002 on seven localities in Croatia a survey on the prevalence of brucellosis in wild boar was carried out. The survey included 271 (52.7%) female and 243 (47.3%) male animals between 7 months and 4 years of age and weighing from 14 to 135 kg. On that occasion 514 blood samples of wild boar were serologically analysed. For serological analysis indirect enzyme immunoassay (iELISA), Rose Bengal test (RBT), complement fixation test (CFT) and slow agglutination test (SAT) were used. In all of the wild boar from all of the localities investigated positive reactions to brucellosis were established. Most of the positive reactions were established by iELISA (13.6%), then by RBT (11.5%), CFT (10.5%) and SAT (8.9%). Tissue samples of 106 animals: testes samples from 67 animals, uterus tissue from 38 animals and 5 fetuses of piglets from 1 mother were analysed bacteriologically. Brucella suis biovar 2 was isolated from 18 (17.0%) animals that originated from all of the localities investigated. Isolates were identified by PCR using BRU-UP and BRU-LOW primers specific for genus Brucella and primers specific for IS711. Based on our results it could be concluded that in Croatia wild boar are natural vector and/or reservoirs of B. suis biovar 2. This permanent risk factor is hazardious for domestic and wild animals in the Republic of Croatia.
Brucellosis is a zoonosis of economic importance that reduces productivity in livestock enterprises as it induces abortion in infected animals. A study was designed aimed at detecting Brucella in blood and lymph node specimens from camels by the use of real-time PCR in Iran. Sample collection and DNA extraction were done on blood (n = 135) and lymph node (n = 135) samples collected from 135 camels (abattoir survey) from both sexes at various ages in different seasons. The real-time PCR for species differentiation was based on unique genetic loci of B. melitensis and B. abortus. The regions were chosen for the construction of primers and TaqMan® probes for species differentiation: BMEII0466 gene for B. melitensis and Bru-Ab2-0168 gene for B. abortus. Brucella spp. were identified in 18 (13.33%) blood samples and 4 (2.97%) lymph node samples. This method showed to be effective in detecting B. abortus and B. melitensis in blood and lymph samples respectively. Brucella abortus was detected in 3 (2.22%) blood samples but was however, not detected in the lymph node samples. Brucella melitensis was only observed in 4 (2.97%) lymph node samples. Significant differences were observed on the blood prevalence of unknown Brucella spp. in different age groups and seasons (P < 0.05). However, there were no significant differences observed on the prevalence of B. abortus, B. melitensis, unknown Brucella spp. in different age groups, sex and seasons (P > 0.05). Therefore, Brucella was detected in apparent healthy camels slaughtered at an abattoir in Iran and this recommends the significance of the detection of Brucella in camels, since the infected camels appear to be healthy.
Background
Brucellosis is one of the most common zoonotic diseases worldwide. It can cause acute febrile illness in human and is a major health problem. Studies in human brucellosis in Malaysia is limited and so far no genotyping studies has been done on Brucella isolates. The aim of the study was to determine the genetic diversity among Brucella species isolated from human brucellosis, obtained over a 6-year period (2009–2014).
Methods
In this study, the genotypic characteristics of 43 human Brucella melitensis isolates were analysed using multiple-locus variable-number tandem-repeat analysis (MLVA) which consisted of eight minisatellite loci (panel 1) and eight microsatellite loci; panels 2A (3 microsatellite loci) and panel 2B (5 microsatellite loci). Two human Brucella suis isolates were also investigated using the MLVA assay.
Results
Using panel 1 (MLVA8), two genotypes namely genotype 43 and 44 were obtained from the 43 B. melitensis isolates. Using the combination of panels 1 and 2A loci (MLVA11), two genotypes were obtained while using the complete panels 1, 2A and 2B, nine genotypes were obtained. The polymorphisms in using the complete panels (MLVA16) were observed in three loci from panel 2B, which showed a diversity index higher than 0.17. All B. melitensis isolates were closely related to the East Mediterranean group. For B. suis isolates, only genotype 6 and genotype 33 were obtained using panel 1 and MLVA11 respectively.
Conclusion
In conclusion, the results of the present study showed a low genetic diversity among B. melitensis and B. suis isolates from human patients. Based on the MLVA16 assay, B. melitensis belonging to the East Mediterranean group is responsible for the vast majority of Brucella infections in our Malaysian patients. To our knowledge, this is the first genotyping study of human Brucella isolates in Malaysia.
Brucellosis is considered as endemic zoonotic disease in the country of Georgia. However, the burden of the disease on a household level is not known. Therefore, this study sought to determine the benefits of active surveillance coupled to serological screening for the early detection of brucellosis among close contacts of brucellosis cases.
We used an active surveillance approach to estimate the rate of seropositivity among household family members and neighboring community members of brucellosis index cases. All participants were screened using the serum tube agglutination test (SAT). Blood cultures were performed, obtained isolates were identified by a bacteriological algorithm, and confirmed as Brucella spp. using real-time PCR. Further confirmation of Brucella species was done using the AMOS PCR assay.
A total of 141 participants enrolled. Of these, 27 were brucellosis index cases, 86 were household family members, and 28 were neighboring community members. The serological evidence of brucellosis in the household member group was 7% and the rate at the household level was 21%. No screened community members were Brucella seropositive. Majority of brucellosis cases were caused by B. melitensis; only one index case was linked to B. abortus.
We found evidence of brucellosis infection among household family members of brucellosis index cases. B. melitensis was the most common species obtained. Findings of this active surveillance study highlight the importance of screening household family members of brucellosis cases and of the use of culture methods to identify Brucella species in the country of Georgia.
Brucellosis is a zoonosis that disseminated by a variety of ways between animals and humans. The effective disinfection of contaminated environments, soil, feces, and animal bodies plays an irreplaceable role in the prevention and control of brucellosis. To kill Brucella effectively, the bactericidal effects of frequently used disinfectants (including aldehydes, halogens, quaternary ammonium compound, phenolics, and alkalines) and the potential factors that influence disinfection effects were determined in the present study. The results revealed that the minimum bactericidal concentrations (MBCs) of the six disinfectants were all significantly lower than the routinely used concentrations, and all the tested disinfectants were effective against B. melitensis NI. The results of quantitative determination showed that the bactericidal effects of the disinfectants were influenced by their concentration, exposure time, dirty condition and the temperature. Under dirty conditions and a low temperatures, sodium hypochlorite and sodium hydroxide showed better bactericidal effect, while benzalkonium chloride was almost without bactericidal ability. In addition, increasing the disinfectant concentration at low temperatures can improve the bactericidal effect. The present study suggested that Brucella is sensitive to commonly used disinfectants. However, the bactericidal effect is vulnerable to dirty conditions and low temperatures. Thus, it is necessary to test the in vitro sensitivity of disinfectants that are commonly used on farms or the new disinfectant formulations periodically, with the aim of improving the efficacy of animal and human brucellosis prevention programs.
In this study, we determined the seroprevalence of Brucella in the blood of bovine and ovine animals and in the blood of the people who raise these animals to produce cheese in two rural counties that use two different methods of cheese production in Erzurum Province in Turkey.
Samples are taken from 100 bovine animals, 100 ovine animals, 100 young people between the ages of 10-20 years and 100 adults between the ages of 20-60 years. The samples were tested with the Rose Bengal Plate Test (RBPT), the Serum Agglutination Test (SAT), the Coombs' Test and a micro-ELISA.
We found the following rates of Brucella in the province that makes cheese with raw milk: bovine (3.00%), ovine (5.00%), people between 10-20 years of age (2.00%) and people between 20-60 years of age (10.00%). However, the corresponding rates in the region that makes cheese with boiling milk were 2%, 4%, 1% and 5%, respectively.
The results were analyzed descriptively and in comparison to the results from the other region. There was a significant difference found between the two regions among the Hinis and Oltu individuals aged 10-20 and 20-60 (z=0.6<1.96 with a 95% confidence interval).
Introduction: Brucellosis in Egypt is an endemic disease among animals and humans. In endemic developing countries, dairy products produced from untreated milk are a potential threat to public health. The aim of this study was to detect brucellae in milk and milk products produced from apparently healthy animals to estimate the prevalence of contamination.
Methodology: Two hundred and fifteen unpasteurized milk samples were collected from apparently healthy cattle (n = 72) and buffaloes (n = 128) reared on small farms, and from milk shops (n = 15) producing dairy products for human consumption. All milk samples were examined by indirect enzyme-linked immunosorbent assay (iELISA) and real-time PCR (RT-PCR) to detect Brucella antibodies and Brucella-specific DNA, respectively.
Results: Using iELISA, anti-Brucella antibodies were detected in 34 samples (16%), while RT-PCR amplified Brucella-specific DNA from 17 milk samples (7.9%). Species-specific IS711 RT-PCR identified 16 of the RT-PCR-positive samples as containing B. melitensis DNA; 1 RT-PCR-positive sample was identified as containing B. abortus DNA.
Conclusions: The detection of Brucella DNA in milk or milk products sold for human consumption, especially the highly pathogenic species B. melitensis, is of obvious concern. The shedding of Brucella spp. in milk poses an increasing threat to consumers in Egypt. Consumption of dairy products produced from non-pasteurized milk by individual farmers operating under poor hygienic conditions represents an unacceptable risk to public health.
Laboratory diagnosis of brucellosis is generally performed by microbiological and serological methods. PCR assay is a specific and sensitive choice for the detection of different bacterial agents. An evaluation of this test was carried out for the detection of Brucella melitensis DNA in sheep milk. 102 milk samples from sheep after abortion were taken and studied using bacteriological culture, PCR and milk ring test (MRT). PCR found B. melitensis DNA in 24 (23.5%) out of 102 milk samples, while only 8 (7.8%) of the samples were positive to B. melitensis through direct culture. MRT found 28 (27.4%) positive milk samples. The detection limit for PCR in sheep milk inoculated with B. melitensis strain 16 M was 1.7 x 10(3) - 1.7 x 10(4) cfu/ml. PCR and MRT coincidence was 96%. The diagnostic sensitivity and specificity were determined as 100% and 81.3% respectively for PCR assay and 75% and 75% for MRT. PCR is a useful tool for a fast diagnosis of B. melitensis in sheep milk.
Brucellosis in livestock causes enormous losses for economies of developing countries and poses a severe health risk to consumers of dairy products. Little information is known especially on camel brucellosis and its impact on human health. For surveillance and control of the disease, sensitive and reliable detection methods are needed. Although serological tests are the mainstay of diagnosis in camel brucellosis, these tests have been directly transposed from cattle without adequate validation. To date, little information on application of real-time PCR for detection of Brucella in camel serum is available. Therefore, this study was performed to compare the diagnostic efficiency of different serological tests and real-time PCR in order to identify the most sensitive, rapid and simple combination of tests for detecting Brucella infection in camels.
A total of 895 serum samples collected from apparently healthy Sudanese camels was investigated. Sudan is a well documented endemic region for brucellosis with cases in humans, ruminants, and camels. Rose Bengal Test (RBT), Complement Fixation Test (CFT), Slow Agglutination Test (SAT), Competitive Enzyme Linked Immunosorbant Assay (cELISA) and Fluorescence Polarization Assay (FPA) as well as real-time PCR were used. Our findings revealed that bcsp31 kDa real-time PCR detected Brucella DNA in 84.8% (759/895) of the examined samples, of which 15.5% (118/759) were serologically negative. Our results show no relevant difference in sensitivity between the different serological tests. FPA detected the highest number of positive cases (79.3%) followed by CFT (71.4%), RBT (70.7%), SAT (70.6%) and cELISA (68.8%). A combination of real-time PCR with one of the used serological tests identified brucellosis in more than 99% of the infected animals. 59.7% of the examined samples were positive in all serological tests and real-time PCR. A subpopulation of 6.8% of animals was positive in all serological tests but negative in real-time PCR assays. The high percentage of positive cases in this study does not necessarily reflect the seroprevalence of the disease in the country but might be caused by the fact that the camels were imported from brucellosis infected herds of Sudan, accidentally. Seroprevalence of brucellosis in camels should be examined in confirmatory studies to evaluate the importance of brucellosis in this animal species.
We suggest combining bcsp31 real-time PCR with either FPA, CFT, RBT or SAT to screen camels for brucellosis.
Human brucellosis has been found to be prevalent in the urban areas of Kampala, the capital city of Uganda. A cross-sectional study was designed to generate precise information on the prevalence of brucellosis in cattle and risk factors for the disease in its urban and peri-urban dairy farming systems.
The adjusted herd prevalence of brucellosis was 6.5% (11/177, 95% CI: 3.6%-10.0%) and the adjusted individual animal prevalence was 5.0% (21/423, 95% CI: 2.7%-9.3%) based on diagnosis using commercial kits of the competitive enzyme-linked immunosorbent assay (CELISA) for Brucella abortus antibodies. Mean within-herd prevalence was found to be 25.9% (95% CI: 9.7%-53.1%) and brucellosis prevalence in an infected herd ranged from 9.1% to 50%. A risk factor could not be identified at the animal level but two risk factors were identified at the herd level: large herd size and history of abortion. The mean number of milking cows in a free-grazing herd (5.0) was significantly larger than a herd with a movement restricted (1.7, p < 0.001).
Vaccination should be targeted at commercial large-scale farms with free-grazing farming to control brucellosis in cattle in and around Kampala city.
A seroepidemiological study of Brucella infections in multiple livestock species in the Borana pastoral system of Ethiopia was performed between December 2007 and October 2008. A cross-sectional multi-stage sampling technique was employed to select 575 cattle, 1073 camels and 1248 goats from the target populations. Sera were collected from the animals, and serially tested using Rose Bengal test and complement fixation test. Overall prevalence and prevalence with respect to explanatory variables were established, and potential risk factors for seropositivity were analysed using a multivariable logistic regression. The results showed that 8·0% (95% CI 6·0-10·6), 1·8% (95% CI 1·1-2·8) and 1·6% (95% CI 1·0-2·5) of the tested cattle, camels and goats, respectively, had antibodies to Brucella antigen. Positive reactors were found in 93·8% of the villages with more frequent detection of positive cattle (93·3%) than camels (56·3%) and goats (37·5%). Risk factors identified for cattle were: keeping more livestock species at household level (OR 4·1, 95% CI 1·9-8·9), increasing age of the animal (OR 2·8, 95% CI 1·3-6·0) and wet season (OR 3·3, 95% CI 1·6-6·9). Increase in household-level species composition (OR 4·1, 95% CI 1·2-14·2) and wet season (OR 3·7, 95% CI 1·5-9·1) were found to be risk factors for seropositivity in camels and goats, respectively. Existence of more than one seroreactor animal species in most villages and association of increased livestock species composition with seropositivity may add more credence to the possibility of cross-species transmission of Brucella infections. Although no attempt to isolate Brucella spp. was made, our results suggest that cattle are more likely maintenance hosts of Brucella abortus which has spread to goats and camels. This should be substantiated by further isolation and identification of Brucella organisms to trace the source of infection and transmission dynamics in various hosts kept under mixed conditions. In conclusion, the present study suggests the need for investigating a feasible control intervention and raising public awareness on prevention methods of human exposure to brucellosis.
Meta-analysis of diagnostic test accuracy presents many challenges. Even in the simplest case, when the data are summarized by a 2 × 2 table from each study, a statistically rigorous analysis requires hierarchical (multilevel) models that respect the binomial data structure, such as hierarchical logistic regression. We present a Stata package, metandi, to facilitate the fitting of such models in Stata. The commands display the results in two alternative parameterizations and produce a customizable plot. metandi requires either Stata 10 or above (which has the new command xtmelogit), or Stata 8.2 or above with gllamm installed. Copyright 2009 by StataCorp LP.
To gain deeper insight into the seroprevalence of brucellosis, which remains a zoonotic disease of worldwide public health concern, by reviewing studies from countries including North Africa, the Middle East, and India.
Studies on brucellosis performed in countries that are neighbors or important trading partners of the European Union and on trade animals and their products were analyzed. We reviewed 37 seroprevalence studies on brucellosis published from 1948 to 2009 retrieved from Pubmed, Google, and ScienceDirect.
The set of studies was heterogeneous in the number of samples and laboratory tests used. We included studies from Algeria (n=1), Egypt (n=7), India (n=3), Iran (n=3), Iraq (n=1), Jordan (n=5), Libya (n=3), Saudi Arabia (n=3), Syria (n=1), Turkey (n=5), and Yemen (n=2). The total number of animals in these studies was 116317 (cattle 75375; buffalo 9644; sheep 10550; goats 14447; camels 6301). The prevalence of brucellosis in different animal species varied widely. Representative surveillance data have not recently been published in any of the countries.
Wars in the Middle East, insufficient preventive measures, the lack of adequate control programs in some countries, as well as uncontrolled animal transportation through "open" borders increased the risk that brucellosis will spread in some regions. New seroprevalence data are needed urgently to evaluate the current situation and for continuous monitoring of necessary control programs.
Brucellosis is a zoonosis caused by facultative intracellular bacteria of the genus Brucella, which are widely distributed in both humans and animals, especially in the developing world. The diagnosis of human brucellosis requires isolation of the bacteria or confirmation through serologic tests. However, culture sampling sensitivity is often low, depending on the disease stage, Brucella species, culture medium, quantity of circulating bacteria and blood culture technique employed. The development of the PCR has offered a new dimension in the diagnosis of different microorganisms, which is possible in just a few hours. Over the past decade, there have been major advancements in all aspects of molecular diagnostics with regard to human brucellosis. PCR-based tests are proving to be faster and more sensitive than traditional methods. However, the sensitivity and specificity of the PCR for Brucella vary between laboratories and no standardization of sample preparation, target genes and detection methods have been established yet. Therefore, in this study, all the important aspects of the PCR for Brucella DNA detection and its utility in the diagnosis and follow-up of patients with brucellosis are reviewed.
Human brucellosis is an important animal transmitted disease of man. Although, the cases have been recorded all over the world, the prevalence is higher in developing countries. Lack of sufficient knowledge about the disease among the physicians, its under-diagnosis or misdiagnosis and absence of effective prevention and management strategies are attributed to the widespread of the disease. Increase in the occurrence of animal brucellosis has also resulted indirectly in an increase in the prevalence of human infection. Absence of characteristic clinical symptoms, chronic nature of the infection and difficulty in isolation of the causal agent from the patients make the diagnosis of the disease more difficult. The serological tests employed for diagnosing human brucellosis vary in terms of their sensitivity and specificity. Therefore, a combination of serological tests is desirable. Currently no vaccine is available against human brucellosis, which could check the spread of the disease effectively. It is suggested that clinicians investigate the cases of pyrexia of unknown origin (PUO) for brucellosis. It is desirable that specimens from cases of tuberculosis, typhoid, rheumatoid arthritis, urogenital infections, kala-azar, cirrhosis, bacterial endocarditis, leukemia and filariasis should also be screened for brucellosis in man. The cases of meningitis of unestablished etiology as the cases of human brucellosis are often misdiagnosed as cases of typhoid or tuberculosis.
The identification of Brucella can be a time-consuming and labor-intensive process that places personnel at risk for laboratory-acquired infection. Here,
we describe a real-time PCR assay for confirmation of presumptive Brucella isolates. The assay was designed in a multiplex format that will allow the rapid identification of Brucella spp., B. abortus, and B. melitensis in a single test.
Objectives: Brucellosis is a zoonosis with severe complications for both humans and animals. In this work, we intended to examine the Brucella infection in dromedary camels in Qatar by using different analysis. Materials and Methods: A total of 203 samples of dromedary camels were randomly collected from the nearby farms in Qatar. Real-time PCR for the genus specific Brucella cell surface salt extractable bcsp31 kDa protein gene were performed on DNA extracted from camel samples. Rose Bengal and rivenol tests were performed to detect the Brucella species. The milk samples were collected from the camels and utilized for the milk ring test. Results: The outcomes of RT-PCR analysis illustrate the presence of Brucella spp. in 170 samples (83.74%) out of 203 samples. The findings of immunological assays also proved the presence of Brucella spp. such as Rose Bengal (67.14%), ELISA (71.42%), and precipitation assay (65.71) in both serum and blood samples of the dromedary camels, which were collected from the Qatar. Conclusions: In conclusion, it was clear that the incidence of the brucellosis in camels is significantly rising in Qatar region and there is a need to control the spread of the disease from camels to camels as well as from camels to humans.
Brucellosis is a natural epidemic zoonotic disease. Liaoning province, northeast of China, has been among the top ten provinces with highest brucellosis incidence. In this study, the spatial and temporal distribution of brucellosis in Liaoning province from 2006 through 2017 was analyzed using the Bayesian theory of space‐time modeling. The study found that in Liaoning province: (1) All regions of the entire study area were stable counties; (2) the risk of brucellosis declined slowly with time without an obvious trend; (3) the declining trend of disease risk in three sub‐hot‐spot counties was faster than the overall trend, whereas in other counties the trend was similar to the overall trend. Furthermore, the time and spatial trends of brucellosis incidence in Liaoning province were calculated and analyzed. These results may provide a theoretical and scientific basis for the public health department to develop targeted effective prevention and control measures for the disease.
Camel brucellosis is a widespread zoonotic disease in camel-rearing countries caused by Brucella melitensis and Brucella abortus. The aim of this study was the first genetic analysis of B. melitensis strains isolated from dromedary camels (Camelus dromedarius) using multiple-locus variable-number tandem repeat analysis (MLVA). MLVA 16 and its MLVA 8 and MLVA11 subsets were used to determine the genotypes of 15 B. melitensis isolates from dromedary camels (11 strains) and other host species (4 strains) from the United Arab Emirates and the results were then compared to B. melitensis MLVA genotypes from other parts of the world. Five, including two novel genotypes were identified with MLVA 8. MLVA 16 further discriminated these five genotypes to ten variants. The eleven camel isolates clustered into four main genetic groups within the East-Mediterranean and African clades and this clustering correlated with the geographic origin of the hosts (United Arab Emirates, Kingdom of Saudi Arabia and Sudan) and the date of their isolation. The camel strains were also genetically related to strains isolated from wild and domestic ruminants from their close habitat or from other parts of the world. Although limited number of strains were analysed, based on our data imported animals from foreign countries, local small ruminants and wildlife species are hypothesized to be the main sources of camel brucellosis in the United Arab Emirates. MLVA was successfully applied to determine the epidemiological links between the different camel B. melitensis infections in the United Arab Emirates and it can be a beneficial tool in future disease control programs.
Brucellosis is an important re-emerging zoonosis with a worldwide distribution. It is still an uncontrolled serious public health problem in many developing countries including India. Brucellosis in India is yet a very common but often neglected disease. Currently, Brucella melitensis accounts for most recorded cases globally with cattle emerging as a important reservoir with the few cases of B. suis. Isolated cases of non-terrestrial brucellosis and continuing transmission from wild animals have raised important epidemiological issues. Routine serological surveillance along with high clinical suspicion and screening of family members of index cases would be essential in delineating the real magnitude of human brucellosis in endemic countries. Increased business and leisure travel to endemic countries have led to diagnostic challenge in non-endemic areas. Laboratory testing is indispensable for diagnosis. Advances in newer rapid, sensitive, and specific testing methodologies and alternate treatment strategies are urgently needed. A safe and effective vaccine in human is not yet available. Prevention is dependent upon increasing public awareness through health education programmes and safe livestock practices. Active co-operation between health and veterinary services should be promoted. This review collates world literature and its impact to the discovery, isolation and diagnosis and epidemiology along with the control measures adapted in the Indian scenario.
The application of two synthetic oligonucleotides as probes and as primers in the polymerase chain reaction is presented for a specific, sensitive, and quick identification of Brucella spp. The specific oligonucleotide sequences were chosen on the basis of a 16S rRNA sequence alignment between Brucella abortus and Agrobacterium tumefaciens.
Six camels were experimentally infected with two strains of Brucella abortus, four with S19 and two with a field bovine strain. In all cases antibody titres were detected within 6 to 11 days. Serum agglutination titres peaked between days 11 and 32 and complement fixation titres between days 11 and 52; both titres then declined steadily. No clinical signs were observed in the four camels inoculated with S19. Slight non-specific symptoms were seen in the two camels infected with the field bovine strain. On post mortem examination no gross lesions were observed although histopathological sections showed focal granulomata in the liver and a generalized lymphadenitis. The organism was recovered mainly from the lymph nodes of the head and genital tract.
The epidemiology of human brucellosis, the commonest zoonotic infection worldwide, has drastically changed over the past decade because of various sanitary, socioeconomic, and political reasons, together with the evolution of international travel. Several areas traditionally considered to be endemic--eg, France, Israel, and most of Latin America--have achieved control of the disease. On the other hand, new foci of human brucellosis have emerged, particularly in central Asia, while the situation in certain countries of the Near East (eg, Syria) is rapidly worsening. Furthermore, the disease is still present, in varying trends, both in European countries and in the USA. Awareness of this new global map of human brucellosis will allow for proper interventions from international public-health organisations.
Brucellosis is a highly infectious disease which is diagnosed using serological and microbiological methods. The objective of this study was to assess the viability of using conventional and real-time PCR assays as potential diagnostic tools for the detection of Brucella abortus in naturally infected cows. PCR assays that amplify various regions of the Brucella genome, IS711 genetic element, 31kDa outer membrane protein and 16S rRNA, were optimised using nine known Brucella strains. Real-time PCR was used to examine the detection efficiency of the IS711 assay which was estimated at 10 gene copies. Milk, blood and lymph tissue samples were collected from naturally infected animals. B. abortus was not detected in blood samples collected from naturally infected cows by conventional or real-time PCR, but was detected in a proportion of the culture-positive milk (44%) and lymph tissue (66% - retropharyngeal, 75% - supramammary) samples by the same methods. There was no difference between PCR and bacteriological detection methods. It is unlikely that conventional or real-time PCR will supersede current diagnostic methods for detection of B. abortus in clinical samples.
The objective was to evaluate a PCR assay for the detection of Brucella canis in canine semen, comparing its performance with that of bacterial isolation, serological tests and PCR assay of blood. Fifty-two male dogs were examined clinically to detect reproductive abnormalities and their serum was tested by the rapid slide agglutination test, with and without 2-mercaptoethanol (2ME-RSAT and RSAT, respectively). In addition, microbiological culture and PCR assays were performed on blood and semen samples. The findings of the semen PCR were compared (Kappa coefficient and McNemar test) to those of blood PCR, culture of blood and semen, RSAT, and 2ME-RSAT. Nucleic acid extracts from semen collected from dogs not infected with B. canis were spiked with decreasing amounts of B. canis RM6/66 DNA and the resulting samples subjected to PCR. In addition, semen samples of non-infected dogs were spiked with decreasing amounts of B. canis CFU and the resulting suspensions were used for DNA extraction and amplification. Of the 52 dogs that were examined, the following tests were positive: RSAT, 16 (30.7%); 2ME-RSAT, 5 (9.6%); blood culture, 14 (26.9%); semen culture, 11 (21.1%); blood PCR, 18 (34.6%); semen PCR, 18 (34.6%). The PCR assay detected as few as 3.8 fg of B. canis DNA experimentally diluted in 444.9 ng of canine DNA (extracted from semen samples of non-infected dogs). In addition, the PCR assay amplified B. canis genetic sequences from semen samples containing as little as 1.0 x 10(0) cfu/mL. We concluded that PCR assay of semen was a good candidate as a confirmatory test for the diagnosis of brucellosis in dogs; its diagnostic performance was similar to blood culture or blood PCR. Furthermore, the PCR assay of semen was more sensitive than the 2ME-RSAT or semen culture. Examination of semen by PCR should be included for diagnosis of brucellosis prior to natural mating or AI; in that regard, some dogs that were negative on serological and microbiological examinations as well as blood PCR were positive on PCR of semen.
- M Gwida
- A El-Gohary
- F Melzer
- I Khan
- U Rösler
- H Neubauer
M. Gwida, A. El-Gohary, F. Melzer, I. Khan, U. Rösler, H. Neubauer, Brucellosis in
camels, Res. Vet. Sci. (2011).
- U Salisu
- C Kudi
- J Bale
- M Babashani
- B Kaltungo
- S Saidu
- A Asambe
- A Baba
U. Salisu, C. Kudi, J. Bale, M. Babashani, B. Kaltungo, S. Saidu, A. Asambe, A. Baba,
Seroprevalence of Brucella antibodies in camels in Katsina State, Nigeria, Trop.
Anim. Health Prod. 49 (2017) 1041-1046.
Manual of Diagnostic Tests and Vaccines for Terrestrial Animals Office International Des Epizooties
- Bovine Oie
- Brucellosis
OIE, Bovine brucellosis. Manual of Diagnostic Tests and Vaccines for Terrestrial
Animals Office International Des Epizooties, Paris, 2009.
- A M Al-Majali
- K M Al-Qudah
- Y H Al-Tarazi
- O F Al-Rawashdeh
A.M. Al-Majali, K.M. Al-Qudah, Y.H. Al-Tarazi, O.F. Al-Rawashdeh, Risk factors
associated with camel brucellosis in Jordan, Trop. Anim. Health Prod. 40 (2008)
193-200.
- S Ali
- S Akthar
- H Neubauer
- F Melzer
- I Khan
- E N Abatih
- H E Adawy
- M Irfan
- A Muhammad
- M W Akbar
S. Ali, S. Akthar, H. Neubauer, F. Melzer, I. Khan, E.N. Abatih, H.E. Adawy,
M. Irfan, A. Muhammad, M.W. Akbar, et al., Seroprevalence and risk factors
associated with bovine brucellosis in the Potohar Plateau, Pakistan, BMC Res.
Notes 10 (2017) 1-11.