Multiple locus variable number tandem repeat analysis of Mycoplasma bovis isolated from local and imported cattle.

Mycoplasma bovis is an important and emerging pathogen of cattle. In this study, multiple locus variable number tandem repeat (VNTR) analysis was used to differentiate M. bovis type strain PG45 and 68 M. bovis field isolates, including 34 isolates from calves imported to Israel from Australia, Lithuania and Hungary in the period 2006-2011, 32 isolates from mastitic dairy cows in Israel in the period 2000-2011, one isolate from the pneumonic lungs of a calf in Israel in 2010 and one isolate from frozen bull semen in Israel in 2008. A total of 35 VNTR types were distinguished, including three, eight and 10 different VNTR types among isolates from calves imported from Australia, Hungary and Lithuania, respectively, and 17 VNTR types among isolates from dairy cows in Israel. The VNTR types in isolates from Lithuanian calves were not identified among isolates from Israeli dairy cows. VNTR type XX, present in the Hungarian group, was identified in one Israeli mastitis-associated isolate. A cluster of 16 M. bovis isolates from Israeli dairy cows possessed the same VNTR type III as three Australian isolates from a single shipment of calves in 2006. The other cluster of isolates contained M. bovis strain 883, isolated from a mastitic cow, strain 72236, isolated from a calf with pneumonia, two isolates from calves imported from Australia to the same farm 3 months previously and four isolates from calves in quarantine imported to Israel from Australia in 2009-2010. Multiple locus VNTR analysis is a useful tool for understanding the movement and spread of strains of M. bovis within and across international boundaries.