Molecular Epidemiology of Contagious Bovine Pleuropneumonia in Tanzania Based on Amplified Fragment Length Polymorphism and Pulsed‐field Gel Electrophoresis Analysis

Abstract

The genetic diversity of 60 field strains of Mycoplasma mycoides ssp. mycoides, small colony type (M. mycoides SC), comprising 56 isolates from cattle in Tanzania, one from Kenya, two from Botswana and one from Portugal, as well as the type (PG1T) and vaccine (T1-SR49) strains, was investigated. The strains were analyzed for 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 pulsed-field gel electrophoresis (PFGE). Six AFLP types were detected among the analysed strains. The AFLP profiles of the type and vaccine strains were indistinguishable from each other. Indistinguishable AFLP profiles were found for 55 Tanzanian field 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 field strains displaying indistinguishable PFGE profiles. Strains from different countries revealed different PFGE profiles, and so did the type and 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 by 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.

Prevalence and genotype of Mycoplasma bovis in beef cattle after arrival at a feedlot

“…This finding differs from that of a recent study 30 in which isolates obtained 4 weeks after an episode of respiratory tract disease had no change in M bovis genotype as determined on the basis of PFGE analysis. This is consistent with reported discrepancies between AFLP analysis and PFGE analysis, 15,32 perhaps because of the number of fragments analyzed (mean of 65 fragments in the present AFLP analysis, compared with 6 to 10 fragments in the PFGE analysis in other studies 15,33 ) or differences in the restriction enzymes used (BglII and MfeI vs KpnI, MluI, and SmaI), although the discrepancy may also reflect differences in the interval between sample collections (44 to 50 days in the present study vs 3 weeks) and differences in the nature of the disease in Canadian beef feedlots and French veal feedlots. We considered the following 3 possible explanations for the reason that different samples from the same calf had differences in M bovis AFLP profiles: recombination of the M bovis genome might change the AFLP profile over time, concurrent infection with multiple strains might artifactually lead to identification of different AFLP profiles at the different times, or a calf might eliminate 1 strain of M bovis but become reinfected with another strain.…”

Isolates of Ureplasma diversum genotyped by single-enzyme amplified length polymorphism

“…In contrast, isolates of M. mycoides spp mycoides recovered from cattle in Tanzania (16) and in isolates of M. bovis recovered in Denmark (15) presented a genomic stability, allow for establishing an epidemiological relationship. Isolates of M. capricolum subsp.…”

A novel MLSA allelic profile ‘A15’ of Mycoplasma mycoides subsp mycoides in Niger

“…The distribution of this profile could be explained by transboundary movement only if it was circulating in Mali or in the lake Chad region which share borders with Niger. The profile ‘E’ was also identified in Botswana but the study did not differentiate whether it was E01 or E02 (Kusiluka et al, 2001). This situation could be explained by the techniques used during this study (Amplified fragment length polymorphism: AFLP, and Pulsed‐field gel electrophoresis: PFGE) which have weaker discriminating power than MLSA (Kusiluka et al, 2001).…”