Heldtander M, Wesonga H, Bölske G, Pettersson B, Johansson K E
Department of Bacteriology, National Veterinary Institute, SE-751 89, Uppsala, Sweden.
Vet Microbiol. 2001 Jan 5;78(1):13-28. doi: 10.1016/s0378-1135(00)00290-x.
Mycoplasma capricolum subsp. capripneumoniae (M. capripneumoniae), the causal agent of contagious caprine pleuropneumonia (CCPP), is a member of the so-called Mycoplasma mycoides cluster. These mycoplasmas have two rRNA operons in which intraspecific variations have been demonstrated. The sequences of the 16S rRNA genes of both operons from 13 field strains of M. capripneumoniae from three neighbouring African countries (Kenya, Ethiopia, and Tanzania) were determined. Four new and unique polymorphism patterns reflecting the intraspecific variations were found. Two of these patterns included length differences between the rrnA and rrnB operons. The length difference in one of the patterns was caused by a two-nucleotide insert (TG) in the rrnB operon and the length difference in the other pattern was due to a three-nucleotide deletion, also in the rrnB operon. Another pattern was characterised by a polymorphic position caused by a mutation that is known to cause streptomycin resistance in other bacterial species. The strain with this pattern was also found to be resistant to streptomycin. Streptomycin resistant clones were selected from four M. capripneumoniae strains to further investigate the correlation of this mutation to streptomycin resistance. Mutations in the 16S rRNA genes had occurred in two of these strains. The fourth pattern 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 evolution of this species.
山羊支原体山羊肺炎亚种（M. capripneumoniae）是山羊传染性胸膜肺炎（CCPP）的病原体，属于所谓的丝状支原体簇成员。这些支原体有两个rRNA操纵子，已证明存在种内变异。测定了来自三个相邻非洲国家（肯尼亚、埃塞俄比亚和坦桑尼亚）的13株山羊支原体野毒株两个操纵子的16S rRNA基因序列。发现了四种反映种内变异的新的独特多态性模式。其中两种模式包括rrnA和rrnB操纵子之间的长度差异。其中一种模式的长度差异是由rrnB操纵子中的两个核苷酸插入（TG）引起的，另一种模式的长度差异也是由于rrnB操纵子中的三个核苷酸缺失。另一种模式的特征是由一个多态性位点引起的，该位点的突变在其他细菌物种中已知会导致链霉素抗性。具有这种模式的菌株也被发现对链霉素耐药。从四株山羊支原体菌株中筛选出链霉素抗性克隆，以进一步研究这种突变与链霉素抗性的相关性。其中两株菌株的16S rRNA基因发生了突变。第四种模式在第1059位包含一个新的多态性。结果表明，山羊支原体菌株中的多态性可作为较小地理区域内CCPP的流行病学标记，并用于研究该物种的分子进化。
