[Reclassification of the four China isolated strains of the pathogen for contagious caprine pleuropneumonia].

Contagious caprine pleuropneumonia (CCPP) is caused by Mycoplasma capricolum subsp. capripneumoniae (Mccp). The aims of this study were to identify 4 Chinese isolated strains employing molecular methods and to determine the appropriate subspecies classification of these strains. Three genome fragments (A, B and C) from each strain were amplified and then transformed into plasmids. The inserted fragments were sequenced and analyzed by comparison with six members of the Mycoplasma mycoides cluster. Cleavage of the PCR products of the 4 strains with PstI yielded three fragments 548, 420 and 128bp in length, just like strain F38. The other M. mycoides cluster members had only 2 fragments of 428 and 128bp. Homology analysis of fragment B indicated that the 4 strains exhibited 99.5% homology with Mccp reference strain F38, 98.9% with M. capricolum subsp. Capricolum (Mcc) strain California Kid, and only 95.4% with Mmc strain ZZ. In fragment C, the 4 strains had 67.4% - 67.6% homology with Mmc PG3, 95.1% -98.6% with Mcc strains 8601-50 and California Kid, 99.6% - 99.8% with Mccp strains 97097ET, Gabes and F38. The analysis revealed that 4 pathogeny strains, 87001, 87002, 367, 1653, isolated from China are more closely related to Mccp than to Mcc. Therefore the pathogeny of CCPP in China should be reclassified as Mccp.