Isolation of Leptospira interrogans serovar muenchen from a sow with a history of abortion.

The isolation of Leptospira interrogans serovar muenchen from a sow which aborted in the first third of pregnancy is described. Isolation was achieved only in media containing a rabbit serum additive and identification was determined by cross-agglutination absorption. A high degree of cross-reactivity was found with reference antisera of the Australis serogroup. Serovar muenchen has not previously been reported in animals and may be responsible for a proportion of the titres to antigens of the Australis serogroup that have recently been reported in pigs in England.