Molecular epidemiology of contagious bovine pleuropneumonia in Tanzania based on amplified fragment length polymorphism and pulsed-field gel electrophoresis analysis

The genetic diversity of 60 field strains of Mycoplasma mycoides ssp. mycoides, small colony type (M,. mycoides), comprising 56 isolates from cattle in Tanzania, one from Kenya, two from Botswana and one from Portugal, as well as the type (PG1(T)) and vaccine (T-1-SR49) strains, was ivestigated. The strains were analysed fur variations in the EcoRI and Csp6I restriction sites in the genomic DNA using the amplified fragment length polymorphism (AFLP) technique, and variations in the BamHI restriction sites using pulscd-field gel electrophoresis (PFGE).

Six AFLP I) pes were detected among the analysed strains. The AFLP profiles of the type and vaccine strains were indistingiuishable from each other. Indistinguishable AFLP profiles were found for 55 Tanzanian held strains, one of them isolated in 1990 and the other 54 isolated in 1998/1999), although one strain isolated in 1999 showed a different profile.

Strains from different countries revealed different AFLP profiles. Six PFGE types were detected among the analysed strains, with all the 56 Tanzanian held strains displaying indistinguishable PFGE profiles. Strains from different countries revealed different PFGE profiles, and so did the type anti vaccine strains.

The strong genomic homogeneity among, M. mycoides SC strains associated with outbreaks of contagious bovine pleuropneumonia in different regions of Tanzania suggests that the outbreaks of the disease in the 1990-99 period might have been caused Ly a single epidemic clone. Moreover, this study; has demonstrated that AFLP and PFGE are potential tools for molecular epidemiological studies of M. mycoides SC infections.