Brucella Abortus Biovar Research Articles

The prevalence of camel brucellosis and associated risk factors

Camel brucellosis is a widespread and critical zoonotic infection caused by Brucella abortus and Brucella melitensis that negatively impact dairy and meat products. The current meta-analysis covers studies published over a course of 40 years, between 1 January 1980 and 1 April 2021, aiming to investigate the global prevalence of Brucella spp. in camels and related risk factors in different camel-keeping areas. Chi-squared test (I2 index) was applied to evaluate the heterogeneity of studies. A random-effect model (REM) estimated the pooled prevalence among subgroups. The literature search on camel brucellosis was performed among the available databases, including CABI, PubMed, Embase, Web of Science, Cochrane, Scielo, Scopus, and Science Direct. A total of 56 publications, comprising 205 data reports, were evaluated. Our results showed that the overall prevalence of camel brucellosis in the world was 9.23%. The lowest and highest prevalence rates of Brucella spp. infections among camels were reported in Oman (0.34%, 95%CI: 0.18–0.55) and Sudan (37.41%, 95%CI: 25.27–50.31), respectively. According to different risk factors, subgroup analysis showed that the location, sex, herd size, age, and mixed rearing with other animals could be considered the main risk factors impacting the occurrence of brucellosis in camels. The reported Brucella spp. in dromedary camel was Brucella melitensis (Biovar 1, 2, and 3), Brucella abortus (Biovar 3, 5, and 6), and Brucella suis. Our study represented remarkable differences between the prevalence of Brucella spp. in male (6.83% in 41 studies) and female (9.64% among 62 studies) camels. However, the present meta-epidemiological study would help improve control and surveillance approaches to prevent the spread of camel brucellosis among herds.

In Vitro Evaluation of Immunogenicity of Recombinant OMP25 Protein Obtained from Endemic Brucella abortus Biovar 3 as Vaccine Candidate Molecule Against Animal Brucellosis.

Brucellosis is a zoonotic disease that causes serious economic losses due to factors, such as miscarriages and decreased milk yield in animals. Existing live vaccines have some disadvantages, so effective vaccines need to be developed with new technological approaches. The primary objectives of this study were the expression and purification of recombinant Omp25 fusion protein from B. abortus, and the evaluation of the effect of the Omp25 protein on cell viability and inflammatory response. The omp25 gene region was amplified by a polymerase chain reaction and cloned into a Pet102/D-TOPO expression vector. The protein expression was carried out using the prokaryotic expression system. The recombinant Omp25 protein was purified with affinity chromatography followed by GPC (Gel Permeation Chromatography). The MTS assay and cytokine-release measurements were carried out to evaluate cell viability and inflammatory response, respectively. It was determined that doses of the recombinant Omp25 protein greater than 0.1 μg/mL are toxic to RAW cells. Doses of 1 μg/mL and lower significantly increased inflammation due to Nitric Oxide (NO) levels. ELISA results showed that IFN-γ was produced in stimulated RAW 264.7 cells at a dose that did not affect the viability (0.05 μg/mL). However, IL-12, which is known to have a dual role in the activation of macrophages, did not show a statistically significant difference at the same dose. Studies on cell viability and Th1-related cytokine release suggest Omp25 protein to be a promising candidate molecule for vaccine development.

Role of Brucella abortus Biovar 3 in the Outbreak of Abortion in a Dairy Cattle Herd Immunized with Brucella abortus Iriba Vaccine.

Bovine brucellosis is a widespread zoonosis caused by Brucella abortus. The disease is prevalent nationwide in Iran and is on an increasing trend among humans and livestock. The eradication of brucellosis is challenging and requires control policies at both national and regional levels. Regarding this, the aim of the current study was to evaluate if Brucella is implicated in an abortion outbreak that occurred in a dairy cattle herd, in Shahre Rey, Tehran province, Iran, after vaccination with B. abortus Iriba vaccine. The research context was a dairy cattle farm with 2,000 animals located in Shahre Rey. This farm was Brucella-free based on the results of two serological tests performed one month before vaccination. After the incidence of the first case of abortion following vaccination, serodiagnosis revealed a seropositive reaction in 30 non-pregnant cows and 19 pregnant cows that aborted later. Bacteriology and molecular typing facilitated the identification of 16 isolates of B. abortus biovar 3 from the aborted animals. None of the isolates were confirmed as B. abortus Iribavaccine strain. The results confirmed that B. abortus biovar 3 was the most prevalent biovar in the cattle of Iran. The source and time of infection in the current study were not detected most likely due to the low biosecurity level in the farm (e.g., uncontrolled introduction of the agents via humans, infected animals, semen, and vectors). In endemic countries, the serodiagnosis of brucellosis alone is not sufficient and has to be accompanied by isolation and molecular diagnosis. In addition, it is important to evaluate the presence of B. abortus in bovine semen and vectors.

First identification of a Brucella abortus biovar 4 strain from yak in Tibet, China

Brucellosis is one of the major zoonotic diseases in the world. In China, understanding on its causative agent Brucella is still limited. Recently, we isolated a Brucella strain XZ19-1 from yak in Lhasa, Tibet. Phenotypical characterization proved that it belongs to B. abortus biovar 4, a biotype that has never been reported in China. MLVA-16 genotyping revealed a novel profile (4-5-3-12-2-2-3-3-8-32-8-5-4-3-3-3) in this strain, while MLST sequence typing demonstrated that it belongs to ST 71. Furthermore, the whole genome of XZ19-1 strain was sequenced. Subsequent phylogenetic analysis demonstrated that XZ19-1was genetically more closely related to B. abortus strains originated from European countries rather than to those collected from China previously. Isolation and identification of XZ19-1 strain may thus indicate a unique Brucella lineage existing in Qing-Tibet plateau. These findings will help to improve the diagnosis and epidemiological studies of brucellosis in animals and human in this part of China.

Investigating selective media for optimal isolation of Brucella spp. in South Africa.

Bovine brucellosis in South Africa is caused mainly by Brucella abortus biovar (bv.) 1 and less frequently by B. abortus bv. 2. Bacterial isolation is regarded as the gold standard for diagnosis of Brucella species; however, it is not very sensitive. The aim of this study was to determine the selective medium with optimum antibiotic composition that will allow the growth of Brucella species (spp.) while inhibiting moulds, yeast and most, if not all, Gram-negative contaminants in South Africa. In the controlled experiment, modified Agrifood Research and Technology Center of Aragon (CITA) medium (mCITA) seemed to be the optimum selective medium for isolation of Brucella spp. as compared with Farrell’s medium (FM) and modified Thayer Martin (mTM), while FM inhibited the growth of most fungal and bacterial contaminants. Mean comparison between the three media used to culture B. abortus resulted in lower mean difference ranging from 0 to 2.33. In case of Brucella ovis, high mean difference was obtained when comparing FM with mCITA (10.33) and mTM (12). However, the mean differences of 0.67 and 1.67 were obtained when comparing mCITA and mTM media used to, respectively, culture pasteurised and raw milk spiked with B. ovis. Further optimisation at the Agricultural Research Council – Onderstepoort Veterinary Research Institute resulted in a comparable performance between FM and mCITA; however, mCITA allowed optimal growth of the fastidious B. ovis, which is generally inhibited on FM. Generally, mCITA seemed to be the optimum selective medium for isolation of Brucella spp., while FM inhibits the growth of most fungal and bacterial contaminants. Thus, veterinary laboratories can use mCITA and/or FM but should take into consideration the detection of factious Brucella isolated in the country or region.

COMPARISON OF HUMORAL IMMUNE RESPONSES BETWEEN HEAT-INACTIVATED BRUCELLA ABORTUS BIOVAR 3 AND STRAIN RB51 VACCINES IN INDIGENOUS CATTLE OF BANGLADESH

Background: Live attenuated Brucella abortus strains 19 and RB51 vaccines have been used as a key method for the control and eradication of brucellosis in cattle worldwide for decades. Due to certain limitations of these live vaccines, research has been undertaken for the development of an ideal more effective and safer vaccine for animals and human brucellosis. Objective: The main objective of this study was to compare the humoral immune responses (HIR) between the heat-inactivated Brucella abortus biovar 3 and attenuated live RB51 vaccines in native cattle of Bangladesh. Materials and Methods: The methods of isolation, identification, preparation of inoculum dose (10 × 1010 cfu/5 ml) and heat inactivation of B. abortus biovar 3 was followed as described earlier. Each of the three B. abortus sero-negative native cows was inoculated with heat-inactivated B. abortus vaccine @ 5.0 ml (10 × 1010 cfu /5 ml)/ cow SC single injection. Similarly, each of five native calves of 6 to 9 months old was inoculated with live attenuated RB51 vaccine (CZ Veterinaria, SA, Spain) @ 2.0 ml (10-34×109) SC as single dose. The sera of cows were collected at 0, 7, 14, 21, 28, 40, 60 and 90 days post vaccination, whereas the sera of the calves were collected at 0, 7, 14, 21, 28, 60, 90, 120, 150 and 180 days post-vaccination. All the collected sera of both the groups were tested to evaluate antibody titer by RBT followed by ELISA with commercial tests kits. Results: The HIR of the cows inoculated with heat-inactivated vaccine showed antibody (Ab) titer started to rise significantly (p < 0.05) from the 14 days (OD 0.2116 ± 0.0397, Ab titer 1:120) and reached a peak level at 28 days (OD 0.319 ± 0.172, Ab titer 1:800) and then started to decline significantly (p < 0.05) from 40 days (OD 0.234 ± 0.0415, Ab titer 1:35) to 60 days (OD 0.094 ± 0.0075, Ab titer 0). The mean Ab titer in calves inoculated with RB51 vaccine showed that Ab titer started to appears insignificantly (p ˃ 0.05) from day 7 (OD 0.094 ± 0.01603) and reached peak level at day 60 days (OD 0.592 ± 0.398), changes are very significant from day 0 (p < 0.05), after 60 days Ab level start to decrease and reach at lowest level at day 150 (OD 0.112 ± 0.0188), Ab level found similar to day 0 (OD 0.0826 ± 0.00517) at 180 days (OD 0.0822 ± 0.00249). Conclusions: The S19 and RB51 are the approved B. abortus vaccine strains have been widely and successfully used with some limitations to prevent bovine brucellosis worldwide. In addition to live attenuated and inactivated vaccines, recombinant genes, proteins, vectors, DNA and recombinant mutant vaccines have also been evaluated for the prevention of brucellosis but further research would be required to develop an ideal vaccine for both the humans and animals.

Correction for Islam et al., "First Genome Sequence of Brucella abortus Biovar 3 Strain BAU21/S4023, Isolated from a Dairy Cow in Bangladesh".

Volume 8, no. 24, e00446-19, 2019, [https://doi.org/10.1128/MRA.00446-19][1]. Page 3: The following should be added to Acknowledgments. “M.E.E.Z., M.A.I., S.T., and A.H.M.V.V. contributed to writing the initial draft, M.A.I. submitted the strain for sequencing, and M.E.E.Z. analyzed the sequences

First Genome Sequence of Brucella abortus Biovar 3 Strain BAU21/S4023, Isolated from a Dairy Cow in Bangladesh

We report the genome sequence of Brucella abortus biovar 3 strain BAU21/S4023, isolated from a dairy cow that suffered an abortion in Savar, Dhaka, Bangladesh. The genome sequence length is 3,244,234 bp with a 57.2% GC content, 3,147 coding DNA sequences (CDSs), 51 tRNAs, 1 transfer messenger RNA (tmRNA), and 3 rRNA genes.

Association of Brucellosis with Abortion Prevalence in Humans and Animals in Africa: A Review.

Brucellosis is a worldwide zoonotic disease suspected to be the cause of abortions which remain largely undiagnosed in both humans and animals. A review of literature was performed to elucidate the contribution of brucellosis to abortions in humans, livestock and wildlife in Africa. A total number of 18 published articles associated brucellosis to abortions observed in humans and livestock in some parts of Africa. The contribution of brucellosis to abortions in humans was less reported in the literature compared to livestock; and no report was done in wildlife in Africa. The association of brucellosis to abortions in Africa was mostly based on bacteriologic, serologic or molecular techniques and Brucella abortus biovar 3 seemed more associated to abortions in cattle. The isolation and molecular characterization of Brucella species could advance the assessment of the contribution of brucellosis to abortions in Africa, focusing much in humans. The epidemiologic approach based on case-control comparisons could elucidate more about the contribution of brucellosis to abortions in Africa. The economic impact evaluation of abortions due to brucellosis could justify implementation of eradication programs of this disease in Africa, such as occupational and food hygiene in humans; with a vaccination and culling in animals.

Complete Genome Sequencing of 10 Brucella abortus Biovar 3 Strains Isolated from Water Buffalo.

ABSTRACTBrucellosis is a zoonotic disease that affects both humans and animals. Its distribution is global, concentrated in the Mediterranean area, India, Central Asia, and Latin America. Here, we present a complete genome assembly of 10 Brucella abortus strains isolated from water buffaloes farmed in the Campania region of Italy.

Complete Genome Sequencing of Eight Brucella abortus Biovar 1 Strains Isolated from Water Buffalo.

ABSTRACTBrucellosis is a zoonotic disease caused by bacteria of the genus Brucella. The disease is endemic in many areas, causing chronic infections responsible for reproductive disorders in infected animals. Here, we present eight complete genome assemblies of eight Brucella abortus strains isolated from water buffaloes farmed in the Campania region.

Exploring the Diversity of Field Strains of Brucella abortus Biovar 3 Isolated in West Africa.

Brucellosis is one of the most widespread bacterial zoonotic diseases in the world, affecting both humans and domestic and wild animals. Identification and biotyping of field strains of Brucella are of key importance for a better knowledge of the epidemiology of brucellosis, for identifying appropriate antigens, for managing disease outbreaks and for setting up efficient preventive and control programmes. Such data are required both at national and regional level to assess potential threats for public health. Highly discriminative genotyping methods such as the multiple locus variable number of tandem repeats analysis (MLVA) allow the comparison and assessment of genetic relatedness between field strains of Brucella within the same geographical area. In this study, MLVA biotyping data retrieved from the literature using a systematic review were compared using a clustering analysis and the Hunter-Gaston diversity index (HGDI). Thus, the analysis of the 42 MLVA genotyping results found in the literature on West Africa [i.e., from Ivory Coast (1), Niger (1), Nigeria (34), The Gambia (3), and Togo (3)] did not allow a complete assessment of the actual diversity among field strains of Brucella. However, it provided some preliminary indications on the co-existence of 25 distinct genotypes of Brucella abortus biovar 3 in this region with 19 genotypes from Nigeria, three from Togo and one from Ivory Coast, The Gambia, and Niger. The strong and urgent need for more sustainable molecular data on prevailing strains of Brucella in this sub-region of Africa and also on all susceptible species including humans is therefore highlighted. This remains a necessary stage to allow a comprehensive understanding of the relatedness between field strains of Brucella and the epidemiology of brucellosis within West Africa countries.

Brucella abortusΔcydCΔcydD and ΔcydCΔpurD double-mutants are highly attenuated and confer long-term protective immunity against virulent Brucella abortus

We constructed double deletion (ΔcydCΔcydD and ΔcydCΔpurD) mutants from virulent Brucella abortus biovar 1 field isolate (BA15) by deleting the genes encoding an ATP-binding cassette-type transporter (cydC and cydD genes) and a phosphoribosylamine–glycine ligase (purD). Both BA15ΔcydCΔcydD and BA15ΔcydCΔpurD double-mutants exhibited significant attenuation of virulence when assayed in murine macrophages or in BALB/c mice. Both double-mutants were readily cleared from spleens by 4 weeks post-inoculation even when inoculated at the dose of 108 CFU per mouse. Moreover, the inoculated mice showed no splenomegaly, which indicates that the mutants are highly attenuated. Importantly, the attenuation of in vitro and in vivo growth did not impair the ability of these mutants to confer long-term protective immunity in mice against challenge with B. abortus strain 2308. Vaccination of mice with either mutant induced humoral and cell-mediated immune responses, and provided significantly better protection than commercial B. abortus strain RB51 vaccine. These results suggest that highly attenuated BA15ΔcydCΔcydD and BA15ΔcydCΔpurD mutants can be used effectively as potential live vaccine candidates against bovine brucellosis.

Epidemiology of Brucella infection in the human, livestock and wildlife interface in the Katavi-Rukwa ecosystem, Tanzania

BackgroundBrucellosis is a zoonosis of public health importance worldwide. In Tanzania, the disease is underreported due to insufficient awareness, inadequate diagnostic protocols, including lack of appropriate reagents for diagnosis. Livestock and wildlife are considered potential sources of infection to humans; however, the role played by these carriers in the epidemiology of the disease in the ecosystems in Tanzania is not fully understood. The objective of this study was to establish the prevalence of anti-Brucella antibodies in humans, wildlife and livestock; and molecular prevalence of Brucella spp in cattle and goats in the Katavi- Rukwa ecosystem.ResultsAnti-Brucella antibodies were detected in humans at 0.6 % (95 % CI: 0.1, 2.1 %); cattle at 6.8 % (95 % CI: 5.4, 8.5 %), goats at 1.6 % (95 % CI: 0.4, 4.1 %) and buffaloes at 7.9 % (95 % CI: 1.7, 21.4 %). One of the two sampled lions tested positive. Cattle had a significantly higher prevalence of anti-Brucella antibodies as compared to goats (P < 0.05). A significantly higher seroprevalence was found in female than in male cattle and in adult than in young cattle (P < 0.05). There was an agreement of 95 and 89 % in cattle and goats, respectively, for the Rose Bengal plate Test (RBPT) and Competitive Enzyme Linked Immunosorbent Assay (c-ELISA) in detecting Brucella infection. Eight (3.5 %) out of 231 milk samples tested were positive for Brucella spp on Polymerase Chain Reaction (PCR), and Brucella abortus biovar 1 was detected in cattle milk. However, no Brucella spp were detected in goat milk.ConclusionThis study has shown the presence of anti- Brucella antibodies in humans, livestock, and wildlife in the Katavi- Rukwa ecosystem. Transmission of the infection between wildlife, livestock and humans is likely to continue due to increasing human activities in the human wildlife interface. This information is an important contribution to public health policy development in the human wildlife interface of the Katavi- Rukwa ecosystem.Electronic supplementary materialThe online version of this article (doi:10.1186/s12917-015-0504-8) contains supplementary material, which is available to authorized users.

국내 가축에서 브루셀라병에 대한 혈청학적 모니터링

(Received: July 23, 2014; Revised: September 16, 2014; Accepted: October 13, 2014)Abstract : In Korea, brucellosis has been reported periodically in cattle and rarely in dogs; however, it has not previouslybeen screened in domestic animals such as elk, pigs and goats. To investigate the serological prevalence, serum sampleswere taken from the aforementioned animals annually during 2007-2013 and screened by the rose-bengal test (RBT)or modified RBT, after which positive sera were evaluated by the standard tube agglutination test (STAT). Finally,RBT and STAT-positive sera were confirmed by competitive-ELISA. Brucella abortus biovar 1 was isolated from threeelk that were shown to be positive serologically in 2008. There was no evidence of brucellosis in pigs. Based onserological monitoring and investigation of etiological agents, there is no evidence of outbreak of brucellosis in elk,pigs or goats of Korea since 2008. However, the possibility for brucellosis from cattle to affect these other livestockexists; therefore, extensive and continuous serological monitoring is required to maintain their brucellosis-free status.Keywords : brucellosis, competitive-ELISA, rose-Bengal test, serological test, standard tube agglutination test

140 EFFECTIVENESS OF WASHING PROCEDURES FOR REMOVING BRUCELLA ABORTUS FROM IN VIVO-DERIVED WOOD BISON EMBRYOS

Endemic brucellosis threatens wild herds of wood bison (Bison bison athabascae) in and around Wood Buffalo National Park, the largest genetic reserve of wood bison in the world. The overall goal of our project was to produce and preserve disease-free embryos for the purpose of conserving the genetic diversity of this species. The aim of the present experiment was to determine the effectiveness of washing procedures for removing Brucella bacteria from in vivo-derived wood bison embryos exposed in vitro to the pathogen. Wood bison cows were given 300 mg im of Folltropin diluted in 0.5% hyaluronan on the day of follicle wave emergence (Day 0) and 100 mg im of hyaluronan on Day 2, and then given 2500 IU im of hCG on Day 5 and inseminated 12 and 24 h later. Embryos were collected on Day 13. The experiment was done in 6 replicates (n = 4 bison/replicate) and an average of 9 embryos/replicate were collected. Zona pellucida-intact embryos were kept in holding medium (PBS + 2% fetal calf serum) and transported to a Biosafety Level 3 laboratory at the International Vaccine Centre, University of Saskatchewan. Embryos were transferred through 5 aliquots of holding medium to remove any contaminant before exposure to Brucella. Embryos were divided equally into 2 Petri dishes (representing later wash groups with v. without antibiotics) containing 2.7 mL of holding medium (n = 2 to 7 embryos per dish/replicate). In a Class II biosafety cabinet, Brucella abortus biovar 1 (1 × 107 to 1 × 109 CFU mL–1 in 0.3 mL) was added to each Petri dish and incubated for 2 h at 37°C in 8% CO2. A sample of holding medium was taken before exposure and after incubation for culture as negative and positive controls, respectively. After incubation, embryos in each Petri dish were subjected to a 10-step washing procedure (according to the IETS Manual, 2010) using wash medium (PBS + 0.4% BSA) without antibiotics or with antibiotics (100 IU mL–1 of penicillin + 100 μg mL–1 of streptomycin). The embryo wash medium was cultured at wash steps 1, 3, 6, and 9. After the tenth wash, the zona pellucida of each embryo was ruptured mechanically using a glass pipette and embryos were cultured individually. Culturing of samples was done on sheep blood agar and specific identification of Brucella organisms was done by PCR. Brucella abortus was detected in 3 embryos from the group washed in medium without antibiotics (3/27), whereas all embryos washed in medium with antibiotics were culture negative (0/27). Brucella abortus was not detected in wash media after the third wash in either group (with or without antibiotics). In summary, Brucella abortus was removed from 89% of in vitro-exposed wood bison embryos using the washing procedure without antibiotics, and from 100% using the washing procedure with antibiotics. Results validate the embryo washing technique for producing Brucella-free wood bison embryos. Thanks to the Canadian Food Inspection Agency for the field strain of Brucella abortus, Bioniche AH for Folltropin and embryo collection supplies, Merck AH for hCG (Chorulon), and Intervac/VIDO for technical and logistical support.

Seroprevalence of brucellosis in sheep and isolation of Brucella abortus biovar 6 in Kassala State, Eastern Sudan.

Brucellosis is one of the important zoonotic diseases among livestock. This study was carried out to estimate the prevalence of brucellosis and isolate Brucella spp. in sheep in Kassala State in the east of Sudan. Two thousand and five serum samples were randomly collected from nine different localities. All serum samples were examined by the Rose Bengal plate test (RBPT) and the modified RBPT (mRBPT). Forty-three (2.15%, 95% confidence interval [CI]: 1.6,3.0) and 68 (3.4%, 95% CI: 2.6, 4.2) samples were positive with the RBPT and the mRBPT, respectively. According to a known diagnostic sensitivity of 86.6% and a known diagnostic specificity of 97.6% for the mRBPT, the true prevalence was estimated to be 1.2% (95% CI: 0.3, 2.2). Different tissue samples were collected from 41 mRBPT seropositive animals. Brucella abortus biovar 6 was isolated from a pyometra of a seropositive ewe. It is important to note that B. abortus biovar 6 cannot be differentiated from Brucella melitensis biovar 2 by routine bacteriology. Only phage typing performed in reference laboratories will allow accurate identification of the strain. The fact that B. abortus biovar 6 does not require CO2 for growth, combined with the fact that it has been isolated from a small ruminant in this study, could easily have led to misidentification (as B. melitensis biovar 2), to wrong epidemiological inferences and to the implementation of inappropriate control measures. The results presented here suggest that sheep are spillover hosts, as previously described for camels, and that the actual reservoir of B. abortus biovar 6 is cattle in Kassala State, Eastern Sudan. This study highlights the importance of isolating and identifying Brucella spp. in different livestock species in order to accurately decipher brucellosis epidemiology in sub-Saharan Africa.

Seroprevalence and potential risk factors for Brucella spp. infection in traditional cattle, sheep and goats reared in urban, periurban and rural areas of Niger.

IntroductionIn Niamey, Niger, interactions within the interface between animals, humans and the environment induce a potential risk of brucellosis transmission between animals and from animals to humans. Currently, little is known about the transmission of Brucella in this context.Results5,192 animals from 681 herds were included in the study. Serum samples and hygroma fluids were collected. A household survey enabled to identify the risk factors for transmission of brucellosis. The true adjusted herd-level prevalence of brucellosis ranged between 11.2% and 17.2% and the true adjusted animal-population level prevalence was 1.3% (95% CI: 0.9–1.8%) based on indirect ELISA test for Brucella antibodies. Animals aged of 1–4 years were found to be more susceptible than animals less than 1 year old (Odds ratio [OR] of 2.7; 95% CI: 1.43–5.28). For cattle, the odds of brucellosis seropositivity were higher in rural compared to the periurban areas (OR of 2.8; 95% CI: 1.48–5.17) whereas for small ruminants the risk of seropositivity appeared to be higher in urban compared to periurban areas (OR of 5.5; 95% CI: 1.48–20.38). At herd level, the risk of transmission was increased by transhumance (OR of 5.4; 95% CI: 2.84–10.41), the occurrence of abortions (OR of 3.0; 95% CI: 1.40–6.41), and for herds having more than 50 animals (OR of 11.0; 95% CI: 3.75–32.46). Brucella abortus biovar 3 was isolated from the hygromas.Conclusionbrucellosis in Niger is a serious problem among cattle especially in the rural areas around Niamey and among sheep in the urban areas of Niamey. The seroprevalence varies across strata and animal species with important risk factors including herd size, abortion and transhumance at herd level and age at animal population level. For effective control of brucellosis, an integrated approach seems appropriate involving all stakeholders working in public and animal health.

UnexpectedBrucella suisBiovar 2 Infection in a Dairy Cow, Belgium

To the Editor: Belgium was declared free of bovine brucellosis by the European Union in 2003 (http://eur-lex.europa.eu/LexUriServ/LexUriServ.do?uri=OJ:L:2003:156:0074:0078:EN:PDF). To maintain this status, the Federal Agency for the Safety of the Food Chain implemented a monitoring program, approved by the European Union, that consists of random serologic surveys and mandatory reporting of spontaneous abortion. This reporting enabled the detection of 2 outbreaks of bovine brucellosis in cattle caused by Brucella abortus biovar 3, in 2010 and 2012, but the origin of these outbreaks has not been identified.

Brucellosis seroprevalence in Bali cattle with reproductive failure in South Sulawesi and Brucella abortus biovar 1 genotypes in the Eastern Indonesian archipelago

BackgroundBrucellosis is a major cause of infertility and reproductive failure in livestock. While cattle in the Eastern Indonesian archipelago suffers from reproductive problems information on bovine brucellosis in the region is fragmentary. The control of brucellosis requires a major and prolonged effort and confirmation of the infection by isolation with detailed knowledge of the spread of the infection is essential when planning a control program.ResultsSerological investigation of Brucella infection in beef cattle tended under extensive farming conditions revealed a high seroprevalence (19.3%; 95% CI, 17–22) in the compliment fixation tests. The results of a rapid and simple field test correlated well with the Rose Bengal test (kappa, 0.917) and indicated an acceptable sensitivity (87.5%) and specificity (98.1%) compared with the complement fixation test. Reproductive failure was reported for 39.0% of the cows with a loss of calves due to abortion or early death amounting to 19.3%. Past reproductive failure did not, however, correlate with seropositivity in the complement fixation test (RP = 1.21; P = 0.847). B. abortus biovar 1 was freshly isolated from the hygromas of two cows and together with thirty banked isolates collected since 1990 from different parts of Sulawesi and Timor eight related genotypes could be distinguished with one genotype being identical to that of an isolate (BfR91) from Switzerland. The Indonesian genotypes formed together with BfR91 and one African and one North American isolate a distinct branch on the B. abortus biovar 1 dendogram.ConclusionsBovine brucellosis appears to be widespread in the Eastern Indonesian archipelago and calls for urgent intervention. The fresh isolation of the pathogen together with the observed high seroprevalence demonstrates the presence and frequent exposure of cattle in the area to the pathogen. The application of a rapid and simple field test for brucellosis could be very useful for the quick screening of cattle at the pen side.