Random Amplification of Polymorphic DNA (RAPD) analysis of Croatian and Irish isolates of Mycoplasma bovis

A RAPD technique was employed for molecular typing of Mycoplasma bovis strains isolated from bovine milk, nasal discharge and lungs. In addition, for the first time strains caused diverse clinical signs: pneumonia, arthritis and mastitis were compared. Also, strains isolated from Croatian cattle were compared to strains from Northern Ireland to see if there is any genetic relationship between them. 150 strains including the type strain PG45 were analyzed. The majority of Croatian strains were placed in a single group (A). Strains isolated from mastitic milk, pneumonic lungs and nasal cavities from the same farm sometimes had identical but sometimes markedly different patterns. A small portion of Croatian strains from a single herd, mainly from the years 2007-2008, clustered within the group C of Irish strains, and were more closely related to them than to other Croatian strains, possibly because of importation of animals from Western Europe. Irish strains were divided in two different groups, B and C, with isolates from the early nineties in group B, and from the years 2005 to 2010 in group C. Although no obvious relationship between geographical and/or temporal origin of strains and RAPD profiles was observed, in our study the majority of strains from different years of isolation were clearly distinguishable from each other. However, strains with identical RAPD patterns were found in different geographical locations and from distant temporal origins so for better understanding of M. bovis epidemiology further testing on greater number of strains from various locations is needed.