Differentiation of pathogenic and saprophytic leptospires by polymerase chain reaction.

PURPOSE: To study the diferences between pathogenic and saprophytic leptospires. METHOD: A total of 275 samples were collected from different sources out of which 107 were subjected to PCR and bacteriological culturing. Two sets of primers were used for detection of leptospiral DNA and differentiation of pathogenic and saprophytic leptospires. Differentiation was also carried out by conventional methods. RESULTS: Twenty seven samples were found positive by PCR ut of which 26 were pathogenic and one was saprophytic. Culturing in EMJH medium yielded four isolates, of which isolates from sera were found to be pathogenic and isolate from water was found to be saprophytic. CONCLUSION: From the present study, it was concluded that PCR is simple, specific and rapid method for detection as well as differentiation of leptospires when compared to conventional methods.

Identification of leptospiral isolates by bacterial restriction endonuclease analysis (Brenda).

DNA samples from 19 reference serovars belonging to 19 different serogroups of Leptospira interrogans and two serovars belonging to Leptospira biflexa were examined by bacterial restriction endonuclease analysis using EcoR I and Hae III enzymes. All the serovars gave unique restriction patterns that differed from each other. DNA from 10 local isolates digested with these enzymes produced patterns which on comparison with the standard patterns produced by reference strains could be identified to serovar level.