Link between geographical origin and occurrence of Brucella abortus biovars in cattle and water buffalo herds.

Istituto Zooprofilattico Sperimentale del Mezzogiorno, Portici, Italy.
Applied and Environmental Microbiology (Impact Factor: 3.95). 11/2012; DOI: 10.1128/AEM.02887-12
Source: PubMed

ABSTRACT Sixty-three Brucella isolates from water buffaloes and cattle slaughtered within the Italian National plan for brucellosis control were characterized by MLVA. Genotyping indicated a strong influence of geographic origin on B. abortus biovars distribution in areas where brucellosis is endemic and highlighted the importance of rigorous management procedures aiming at avoiding inter- and intra-herd pathogen spreading.

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    ABSTRACT: Brucellosis is considered the world's most widespread zoonotic infection. It causes abortion and sterility in livestock leading to serious economic losses and has even more serious medical impact in humans, since it can be a trigger to more than 500,000 infections per year worldwide. The aim of this study was to evaluate the role of Haematopinus tuberculatus, a louse that can parasitize several ruminants, as a new host of brucellosis. Louse specimens were collected from seropositive and seronegative water buffaloes and divided in 3 developmental stages: adults, nymphs and nits. All samples were separately screened for Brucella spp. DNA and RNA detection by Real Time PCR. In particular, primers and probes potentially targeting the 16S rRNA and the Brucella Cell Surface 31kDalton Protein (bcsp31) genes were used for Real Time PCR and buffalo beta actin was used as a housekeeping gene to quantify host DNA in the sample. A known amount of B. abortus purified DNA was utilized for standard curve preparation and the target DNA amount was divided by the housekeeping gene amount to obtain a normalized target value. A further molecular characterization was performed for Brucella strain typing and genotyping by the Bruce-ladder, AMOS-PCR and MLVA assays. Data were statistically analysed by ANOVA. Brucella abortus DNA and RNA were detected in all developmental stages of the louse, suggesting the presence of viable bacteria. Data obtained by MLVA characterization support this finding, since the strains present in animals and the relative parasites were not always identical, suggesting bacterial replication. Furthermore, the detection of Brucella DNA and RNA in nits samples demonstrate, for the first time, a trans-ovarial transmission of the bacterium into the louse. These findings identified H. tuberculatus as a new host of brucellosis. Further studies are needed to establish the role of this louse in the epidemiology of the disease, such as vector or reservoir.
    BMC Veterinary Research 12/2013; 9(1):236. DOI:10.1186/1746-6148-9-236 · 1.74 Impact Factor
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    ABSTRACT: An isolate of Brucella spp. from an aborted water buffalo (Bubalus bubalis) fetus was characterized based on its pheno- and genotype. The phenotype was defined by carbon dioxide requirement, hydrogen sulfide production, sensitivity to thionin and basic fuchsin and agglutination with Brucella A and M monospecific antisera. The genotype was based on the amplification of the following genes: bcsp31, omp2ab, and eri and the species-specific localization of the insertion sequence IS711 in the Brucella chromosome via B. abortus-B. melitensis-B. ovis-B. suis (AMOS)-PCR. Unexpectedly, the isolate showed a phenotype different from B. abortus bv1, the most prevalent strain in cattle in Argentina, and from vaccine strain 19, currently used in bovines and water buffaloes. Genotyping supported the phenotypic results, as the analysis of the omp2ab gene sequence showed an identical pattern to either B. abortus bv 5 or B. melitensis. Finally, the AMOS PCR generated a 1,700-bp fragment from the isolate, different than those amplified from B. abortus bv 1 (498 bp) and B. melitensis (731 bp), confirming the presence of B. abortus bv 5. The OIE/FAO Reference Laboratory for Brucellosis confirmed this typing. This is the first report of B. abortus bv 5 from a water buffalo in the Americas.
    Veterinary Microbiology 09/2014; 173(1-2). DOI:10.1016/j.vetmic.2014.07.011 · 2.73 Impact Factor
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    ABSTRACT: Brucellosis is endemic in livestock and humans in Uganda and its transmission involves a multitude of risk factors like consumption of milk from infected cattle. To shed new light on the epidemiology of brucellosis in Uganda the present study used phenotypic and molecular approaches to delineate the Brucella species, biovars, and genotypes shed in cattle milk. Brucella abortus without a biovar designation was isolated from eleven out of 207 milk samples from cattle in Uganda. These isolates had a genomic monomorphism at 16 variable number tandem repeat (VNTR) loci and showed in turn high levels of genetic variation when compared with other African strains or other B. abortus biovars from other parts of the world. This study further highlights the usefulness of MLVA as an epidemiological tool for investigation of Brucella infections.
    BioMed Research International 10/2014; Article ID 720413. DOI:10.1155/2015/720413 · 2.71 Impact Factor

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