Randomly amplified polymorphic DNA (RAPD) fingerprinting of 14 laboratoiy strains of leptospiral serovars (serovars australis, autumnalis, ballum, bataviae, canicola, grippotyphosa, hardjoprajitno, hebdomadis, icterohaemorrhagiae, javanica, pomona, pyrogenes, panama, and tarassovi) was carried out by using a pair of primers. Each serovar had a unique and distinct fingerprint pattern. DNAs of other bacterial species, including Escherichia coli, Pasteurella multocida, Salmonella spp., Pseudomoms spp., and Klebsiella spp., did not show any amplification. RAPD fingerprinting was found to be a rapid and sensitive method for serovar identification when it was compared to DNA restriction enzyme analysis, which produced a larger number of bands that made it more difficult to compare serovars.Leptospirosis, which is caused by one of the nine or more species of pathogenic leptospires, is an important disease that affects livestock and humans. At present, there are more than 212 recognized serovars of leptospires divided into 23 serogroups (4). Conventionally, leptospirosis is diagnosed by detecting serum antibodies by the microscopic agglutination test or enzyme immunoassays. Direct demonstration of the presence of leptospires in biological samples is a definitive method of diagnosis, but large numbers of organisms need to be in a sample for direct demonstration. Isolation of leptospires from clinical specimens by culturing is labor-intensive and slow (too slow for clinical diagnosis), and samples may be from contaminated sources. Recently, tests based on DNA restriction enzyme analysis (5,7) and DNA-DNA hybridization (6) and PCR assays (8) have been used to detect leptospires in clinical samples. Although DNA restriction enzyme analysis with different restriction enzymes is useful for identifying the leptospiral serovars, the large number of DNA fragments obtained makes differentiation between serovars difficult when only a few enzymes are used. Pulsed-field gel electrophoresis of Not1 digests of leptospiral DNA (3) has facilitated comparisons between serovars because there are fewer DNA fragments. Recently, randomly amplified polymorphic DNA (RAPD) fingerprinting, which produces fewer DNA fragments, has been used for rapid identification of leptospires (1, 2). This method makes it easy to compare different serovars.The goal of this work was to adapt the RAPD fingerprinting method so that it could be used to differentiate various leptospiral laboratory strains.Bacterial strains and media. A total of 14 laboratory strains of leptospiral serovars were grown in EMJH media. The serovars represented were serovars autumnalis (strain Akiyami A), australis (strain Ballico), ballum (strain Mus 127), bataviae (strain Swart), canicola (strain Hond Utrecht IV), grippotyphosa (strain Moskva V), hardjo (strain Hardjoprajitno), hebdomadis (strain Hebdomadis), icterohaemarrhagiae (strain RGA), javanica (strain Veldrat Bat.46), pomona (strain Pomona), pyrogenes (strain Salinem), panama (strain CZ 214), and tarassovi (strain Perepelicin)....
