Characterization of some Brucella species from Zimbabwe by biochemical profiling and AMOS-PCR

Gift Matope,Berit Djønne,John Muma,Evison Bhebhe,Eystein Skjerve

doi:10.1186/1756-0500-2-261

Abstract

BackgroundBovine brucellosis caused by Brucella abortus is endemic in most large commercial and smallholder cattle farms of Zimbabwe, while brucellosis in other domestic animals is rare. The diagnosis of brucellosis is mainly accomplished using serological tests. However, some Brucella spp. have been isolated from clinical cases in the field and kept in culture collection but their biochemical profiles were not documented. We report biochemical profiling and AMOS-PCR characterization of some of these field isolates of Brucella originating from both commercial and smallholder cattle farming sectors of Zimbabwe.FindingsFourteen isolates of Brucella from culture collection were typed using biochemical profiles, agglutination by monospecific antisera, susceptibility to Brucella-specific bacteriophages and by AMOS-PCR that amplifies species- specific IS711. The results of the biochemical profiles for B. abortus biovar 1 (11 isolates) and biovar 2 (2 isolates) were consistent with those of reference strains. A single isolate from a goat originating from a smallholder mixed animal farm was identified as B. melitensis biovar 1. The AMOS-PCR produced DNA products of sizes 498 bp and 731 bp for B. abortus (biovar 1 and 2) and B. melitensis biovar 1, respectively.ConclusionWe concluded that the biochemical profiles and AMOS-PCR characterization were consistent with their respective species and biovars. B. abortus biovar 1 is likely to be the predominant cause of brucellosis in both commercial and smallholder cattle farms in Zimbabwe.

Highlights

Bovine brucellosis caused by Brucella abortus is endemic in most large commercial and smallholder cattle farms of Zimbabwe, while brucellosis in other domestic animals is rare
We concluded that the biochemical profiles and AMOS-PCR characterization were consistent with their respective species and biovars
B. abortus biovar 1 is likely to be the predominant cause of brucellosis in both commercial and smallholder cattle farms in Zimbabwe

Summary

Introduction

Bovine brucellosis caused by Brucella abortus is endemic in most large commercial and smallholder cattle farms of Zimbabwe, while brucellosis in other domestic animals is rare. Some Brucella spp. have been isolated from clinical cases in the field and kept in culture collection but their biochemical profiles were not documented. We report biochemical profiling and AMOS-PCR characterization of some of these field isolates of Brucella originating from both commercial and smallholder cattle farming sectors of Zimbabwe. On the basis of phenotypic profiles, some Brucella spp. are further divided into biovars [3]. The traditional classification into nine different species is still used This has been further supported by the recent discovery of B. ceti and B. pinnipedialis from marine mammals [5], or B. microti from a common vole Microtus arvalis [4]. The genomic similarity makes the differentiation of Brucella spp. difficult, and often a study of biological and physiological characteristics is required [3]

Objectives

Methods

Results

Conclusion