DIFFERENTIATION OF LEPTOSPIRA SPECIES AND SEROVARS BY PCR-RESTRICTIONENDONUCLEASE ANALYSIS, ARBITRARILY PRIMED PCR AND LOW-STRINGENCY PCR

Reference strains from 30 serovars representing seven species of Lepto spira and 48 recent isolates from human patients, dogs and rats, were characterised by polymerase chain reaction-restriction endonuclease an alysis (PCR-REA), arbitrarily primed PCR (AP-PCR) and low stringency P CR (LS-PCR), PCR-REA analysis yielded seven groups among 29 serovars o f pathogenic Leptospira; the non-pathogenic L. biflexa serovar patoc w as not amplified with the primer pairs studied, AP-PCR and LS-PCR fing erprinting resulted in 25 and 21 distinct profiles, respectively, amon g the 30 reference strains. The results of the three PCR-based techniq ues were highly concordant and were in general agreement with those fr om previous DNA studies, confirming the high level of polymorphism amo ng Leptospira species and serovars, and supported the concept of the s erovar as the basic taxonomic unit of leptospiral classification. Resu lts of the PCR-based typing methods for 11 randomised leptospiral stra ins, 36 clinical isolates from human patients and dogs and 12 survey i solates from trapped rats agreed with those from serological identific ation. With one exception, isolates of the same serovar gave identical profiles irrespective of the source. AP-PCR and LS-PCR are simple to pet-form and interpret, and appear to be useful for characterising iso lates of Leptospira spp. for diagnostic and epidemiological purposes.