[Analysis of genomic polymorphism in leptospira by polymerase chain reaction with random primers]

A test system for genetic typing of Leptospirae is developed, based on the polymerase chain reaction (PCR) with arbitrary primers. Thirteen strains of 4 Leptospira species were examined: L. interrogans, L. parva, L. illini, and L. inadai. Analysis of polymorphism of amplicon length (PAL) by the PCR with short Sh1 and Sh2 primers revealed genotypical differences at the inter- and intraspecias levels, as well as at the subserovar level. PAL of L. interrogans strains Rga and M-20, serovars icterohaemorrhagiae and copenhageni, were identical both with Sh1 and Sh2 primers. Moreover, PCR with Sh2 primer showed genotypical similarity between strains Moscow V and M. oeconomus, serovar grippotyphosa of the same serogroup. Analysis of PAL by the PCR with long Lgn1 and Lgn2 primers showed similar results. Analysis of the PAL values obtained by the PCR with all primers permitted us to differentiate 9 L. interrogans strains into 8 PAL genotypes and identify a different degree of genotypical relation between strains of different serovars of this species. Complete genotypical relationship between strains L. inadai N 10 and EMJH 86 (serovar lyme) was confirmed by the new test system. Therefore, PCR-based test system with different primers can be used to differentiate between closely related Leptospira strains and to investigate the genotypical relationships between the strains at the intra- and interspecies and inter- and subserovar levels.