[PCR amplification of the leptospiral DNAs from different genus and species with the variable sequences of 16S rRNA gene].

We designed a pair of primers from the variable regions (V2 and V4) of 16S rRNA gene of Leptospira interrogans, i. e. PI: 5'GGG AAC CTA ATA CTG GAT GG; PII: 5' ACA TAG TTT CAA GTG GAG GC, and amplified the leptospiral DNAs from different genus and species. When denaturing with 55 degrees C, all DNAs of L. interrogans had the same products not only in length but also with Kpn I-digested pattern. The DNA of L. biflexa could be amplified with a c. a. 280 bp-band but not digested by Kpn I, while the DNAs of Leptonema and other control bacteria had no amplification. In addition, the products of L. interrogans spp. could be hybridized with the PCR product of L. interrogans serovar lai strain Lai labelled with 32P, while the product of L. biflexa had no hybridization. It proved that the 16S rRNA gene primers is useful for the classification and detection of leptospires.