Repetitive sequence element cloned from Leptospira interrogans serovar hardjo type hardjo-bovis provides a sensitive diagnostic probe for bovine leptospirosis.

A repetitive sequence element was cloned from the primary etiological agent causing bovine leptospirosis in North America, Leptospira interrogans serovar hardjo type hardjo-bovis. This element was used to design a sensitive diagnostic probe which distinguishes hardjo-bovis from other pathogenic leptospires which commonly infect domestic animals in North America and discriminates between hardjo-bovis and the reference strain for serovar hardjo, hardjoprajitno. By using this probe, it was possible to identify infected cattle shedding hardjo-bovis in their urine. This is the first practical demonstration of a cloned DNA probe for leptospirosis, and it provides a sensitive method for studying the transmission and pathogenesis of L. interrogans infections. Control measures for L. interrogans infections may now be improved by rapidly and efficiently identifying infected animals.