Molecular studies on European equine isolates of Leptospira interrogans serovars Bratislava and Muenchen

Strains of Leptospira interrogans belonging to two very closely related serovars – Bratislava and Muenchen – are known to cause widespread infection of the horse population in many parts of the world. Conventional serological typing of isolates has been unable to differentiate between wildlife, pig, dog and possibly horse maintained isolates and therefore has been unable to provide further insight into their diversity and the relationship between them. Twenty-one such European isolates of serovar Bratislava and Muenchen were examined by restriction endonuclease analysis and multiple-locus variable-number tandem repeat analysis in an attempt to elucidate their epidemiology. The restriction pattern types were identified and fell into one of four REA designed pattern types, B1, B2a, M1, M2a. Nine strains from Northern Ireland and two from Germany belonged to B2a, which is a ubiquitous strain being originally isolated from a large number of wild and domestic animal species in the UK. Five strains were identified as B1 and they came from Portugal, The Netherlands, Germany and Northern Ireland; three strains isolated in Germany belong to M1; two strains belonged to M2a. Genotypes B1 and M1 have, with the exception of one hedgehog isolate, been recovered only from horses and it may indicate their adaptation to this species.