Detection of antibodies to Leptospira interrogans serovar hardjo by the microscopic agglutination test and enzyme-linked immunosorbent assay in cattle sera

Abstract

Leptospirosis is an important zoonotic disease of food-producing animals caused by infection with pathogenic serovars of Leptospira spp. Bovine leptospirosis is most commonly caused by infection with Leptospira interrogans serovar hardjo (Thiermann, 1983). This serovar has been associated with abortions, stillbirths, the birth of weak calves, mastitis, decreased milk production and infertility in cattle (Ellis et al., 1986). The diagnosis of leptospirosis can be done with bacteriological, serological and DNA-related methods. Routine diagnosis by bacterial culture is difficult and impractical due to the fastidious nutritional requirements of the organism, the amount of time and skill involved, the high cost of reagents and the low success rates. DNA-related methods require well established laboratory facilities and highly skilled personnel. Hence, may workers prefer to use serological methods for routine diagnosis of bovine leptospirosis (Cousins et al., 1985; Cho et al., 1989; Surujballi et al., 1997). Though the microscopic agglutination test (MAT) using live antigen is considered the international standard methodology for the diagnosis of leptospirosis (Faine et al., 1999), Enzyme Linked Immunosorbent (ELISA) has been increasingly used as a suitable test system for non-specialized routine laboratories which do not keep a battery of live leptospira strains in recent years. This communication describes the application of commercially available ELISA for the detection of bovine antibodies to L. interrogans serovar hardjo, and measures the performance of the test in terms of its diagnostic sensitivity and specificity, compared with the standard MAT used by The Reference Leptospira Laboratory of The Ministry of Agriculture and Rural Affairs of Turkey.