Genetic diversity and evolution of Mycoplasma capricolum subsp capripneumoniae strains from eastern Africa assessed by 16S rDNA sequence analysis

Mycoplasma capricolum subsp. capripneumoniae (M. capripneumoniae), the caus al agent of contagious caprine pleuropneumonia (CCPP), is a member of the s o-called Mycoplasma mycoides cluster. These mycoplasmas have two rRNA opero ns in which intraspecific variations have been demonstrated. The sequences of the 16S rRNA genes of both operons from 13 field strains of M. capripneu moniae from three neighbouring African countries (Kenya, Ethiopia, and Tanz ania) were determined, Four new and unique polymorphism patterns reflecting the intraspecific variations were found. Two of these patterns included le ngth differences between the rrnA and rrnB operons. The length difference i n one of the patterns was caused by a two-nucleotide insert (TG) in the rrn B operon and the length difference in the other pattern was due to a three- nucleotide deletion, also in the rrnB operon. Another pattern was character ised by a polymorphic position caused by a mutation that is known to cause streptomycin resistance in other bacterial species. The strain with this pa ttern was also found to be resistant to streptomycin. Streptomycin resistan t clones were selected from four M. caprineumoniae strains to further inves tigate the correlation of this mutation to streptomycin resistance. Mutatio ns in the 16S rRNA genes had occurred in two of these strains. The fourth p attern included a new polymorphism in position 1059. The results show that polymorphisms in M. capripneumoniae strains can be used as epidemiological markers for CCPP in smaller geographical areas and to study the molecular e volution of this species. (C) 2001 Elsevier Science B.V. All rights reserve d.