African 2, a Clonal Complex of Mycobacterium bovis Epidemiologically Important in East Africa

VLA Weybridge, New Haw, Surrey KT15 3NB, United Kingdom.
Journal of bacteriology (Impact Factor: 2.81). 02/2011; 193(3):670-8. DOI: 10.1128/JB.00750-10
Source: PubMed


We have identified a clonal complex of Mycobacterium bovis isolated at high frequency from cattle in Uganda, Burundi, Tanzania, and Ethiopia. We have named this related group of M. bovis strains the African 2 (Af2) clonal complex of M. bovis. Af2 strains are defined by a specific chromosomal deletion (RDAf2) and can be identified by the absence of spacers 3 to 7 in their spoligotype patterns. Deletion analysis of M. bovis isolates from Algeria, Mali, Chad, Nigeria, Cameroon, South Africa, and Mozambique did not identify any strains of the Af2 clonal complex, suggesting that this clonal complex of M. bovis is localized in East Africa. The specific spoligotype pattern of the Af2 clonal complex was rarely identified among isolates from outside Africa, and the few isolates that were found and tested were intact at the RDAf2 locus. We conclude that the Af2 clonal complex is localized to cattle in East Africa. We found that strains of the Af2 clonal complex of M. bovis have, in general, four or more copies of the insertion sequence IS6110, in contrast to the majority of M. bovis strains isolated from cattle, which are thought to carry only one or a few copies.

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    • "This study further shows that in cases where potentially pathogenic NTM are isolated from mycobacteria cultures of tuberculosis –like lesions and human sputum, the non –use of additional selective culture techniques could lead to misinterpretations of the diagnostic test results. This is in view of the fact that tuberculosis like lesions in wildlife and livestock is highly associated with Mycobacterium bovis [26] and human tuberculosis is also associated with Mycobacterium tuberculosis [27]. This hypothesis is supported by a study done in Chad which suggested that 72% of the tuberculosis lesions in cattle carcasses detected through standard meat inspection were caused by pathogens other than M. bovis [28]. "
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    BMC Research Notes 09/2014; 7(1):622. DOI:10.1186/1756-0500-7-622
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    • "The isolated spoligotype SB 0120 belongs to the BCG family but has not undergone chromosomal deletion (RDAf1) as the one observed in some parts of Africa, which is identified by the absence of spacer 30 in the standard spoligotyping scheme [41]. It is also different from the other observed in East Africa which has undergone a chromosomal deletion of RDAf2 and identified by the absence of spacers 3 to 7 [42]. However, combining spoligotyping with MIRU-VNTR results, it has been established that the observed profiles could be unique to Zambia. "
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    • "Recent work has characterised M. bovis isolates and reported that regional clonal complexes predominating in specific areas occur, for example Af1 M. bovis complex in westcentral Africa (Muller et al. 2009), Af2 prevalent in East Africa (Berg et al. 2011) as well as European 1 with European origin (Smith et al. 2011). Thus we do not yet know for certain whether M. bovis is an endemic or alien disease to Africa, or whether it is endemic to some areas (e.g. "
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