Arbitrarily primed PCR- a rapid and simple method for typing of leptospiral serovars.

PURPOSE: To investigate the use of arbitrarily primed polymerase chain reaction (AP-PCR) for typing of leptospiral serovars.

METHODS

AP-PCR was adopted for identification of laboratory strains of leptospires and leptospiral cultures at serovar level. A primer of 12 bp was used for amplifying DNA of 13 laboratory strains of leptospires as well as culture pellets of leptospires.

RESULTS

Each serovar produced distinct DNA fingerprint which was characteristic for each serovar. These patterns were used for typing of 81 serum culture samples obtained from human leptospiral cases. Of these samples, 39 could be typed based on AP-PCR fingerprints belonging to serovars autumnalis, pomona, canicola, javanica, icterohaemorrhagiae, patoc and pyrogenes. These results were confirmed by RAPD fingerprinting of the DNA samples of the respective leptospiral serovars after culturing -*them in EMJH media. One of the important findings of this work was that straight culture sample could be used for AP-PCR assay, without purification of DNA. By having more number of AP-PCR reference fingerprints, more serovars could be typed.

CONCLUSIONS

AP-PCR technique provides great potential for simple and rapid identification of leptospires at serovar level, which could be useful in molecular epidemiological studies of leptospirosis.