Characterisation of leptospires isolated from cattle and man in Plateau State, Nigeria

Summary: Six leptospiral strains isolated from bovine kidneys and one other strain isolated from midstream urine of a butcher were characterised. All the bovine isolates shared serological and biological properties characteristic of Leptospira interrogans but the human isolate had some characteristics of pathogenic and some of saprophytic leptospires. Although the human isolate was not recovered in culture, all six bovine isolates were recovered. Five of the bovine isolates belonged to a new serovar in the Pyrogenes serogroup and the remaining two isolates belonged to serovar hardjo. Further tests using the restriction endonuclease analysis confirmed that the restriction patterns of the five bovine isolates were identical, but differed from other serovars within the Pyrogenes serogroup. The sixth bovine isolate, vvlJA and the human isolate vv7JH, were identified as genotypes Hardjobovis and Hardjoprajitno respectively. Since serovar hardjo is increasingly being recognised as the commonest cause of bovine and human leptospirosis in many parts of the world, the isolation of the two genotypes in Nigeria is of public health significance.