Development of a Multiplex PCR Assay for Detection and Discrimination of Pathogenic and Saprophytic Leptospira in Water

Abstract

Leptospirosis is a zoonosis prevalent in tropical countries and affects animals and humans alike. Leptospira interrogans, the causative organism for this waterborne infection, spreads through the urine of infected animals. There is a direct link between contaminated water and Leptospira outbreaks. This study reports a rapid assay to detect and differentiate pathogenic Leptospira from non-pathogenic in environmental water using multiplex PCR. The assay uses primers targeting the Lipl32 and Lipl21 gene. The multiplex PCR has been standardized using 11 pathogenic and one saprophytic serovar of Leptospira. The analytical sensitivity of the developed method was evaluated with different concentrations of template DNA. This method was used to screen water samples collected from 20 different sources from Chengalpattu town in Kancheepuram District, Tamil Nadu, India. Of the 20 water samples screened, 13 samples tested positive for pathogenic Leptospira, and seven samples tested negative. Four water samples were found to carry both pathogenic and saprophytic species. The developed multiplex PCR assay is highly useful for detecting and distinguishing pathogenic and saprophytic leptospires in water.