Applicability of Polymerase Chain Reaction to Diagnosis of Leptospirosis

Abstract

Abstract

Polymerase chain reaction was developed for the rapid detection of leptospires. The PCR amplification of Leptospira spp using primers of 16SrRNA and flaB gene gave products of 300 and 790 bp, respectively. To test the ability of 16SrRNA primer and flaB gene primer with other bacteria, the positive PCR products amplified for 16SrRNA primers were Streptococcus pyrogenes, Salmonella group E and Staphylococcus epidermidis. No amplification products of other bacteria were amplified with flaB primer. In this study, a PCR method for the clinical diagnosis of leptospires was evaluated. The mean detection limit was 10 leptospires per ml of EDTA blood, the critical threshold for vital patient prognosis. EDTA blood test results of 93 patients from Buriram Hospital were compared using PCR and culture/MAT methods. The sensitivity, specificity and efficacy (accuracy) of the PCR method using culture/MAT method as a gold standard were 80.0, 96.2 and 93.5%, respectively. The method is also suitable for diagnosis of leptospirosis, and appears to have advantages in terms of yield and time.

Keywords: Leptospira; PCR; 16SrRNA; flaB gene