Isolation and identification of leptospira hardjo from cattle in Argentina.

A serological evaluation was done on the prevalence of bovine leptospirosis in Argentina. In 1,857 serum samples obtained from the major cattle raising areas of the country, 59.1 percent showed leptospiral agglutinins in the microscopic-agglutination test. The most frequent leptospiral antigens showing antibody reactions were the hebdomadis group serotypes, of which 45.8 per cent of the sera reacted to Leptospira hardjo with titres ranging from 1:100 to 1:25,600. Six Leptospira isolations were made from 161 bovine kidneys collected at local abattoirs. Their isolation and subsequent identification as serotype L. hardjo is described. This study reports on L. hardjo in cattle of Argentina for the first time and confirms the need for improved cultural methodology for its isolation.