Detection of Pathogenic Leptospira in Rats and Phylogenetic Analysis Using Outer Membrane Lipoprotein Lipl32 Gene at Two Major Public Markets

@#Introduction: Limited studies have been documented on the presence of pathogenic Leptospira in public markets serving the community in sub-districts of Selangor. The aim of this study was to detect the presence of pathogenic Leptospira in rats using a gene encoding an outer membrane lipoprotein LipL32. Methods: Polymerase chain reaction (PCR) was performed using LipL32 primers on sixty kidney samples of rats trapped at two locations of study; Pasar Borong Selangor in Seri Kembangan and Pasar Basah Bandar Baru Bangi in Bangi. Results: Out of 60 samples analysed, 36.7% were positive for the presence of LipL32. All positive samples highly matched (>94%) nucleotide sequence for LipL32 of pathogenic Leptospira and related to the pathogens through phylogenetic analysis. Conclusion: The detection of LipL32 indicates the potential presence of pathogenic Leptospira species at public markets. Although only 60 rats were successfully trapped, the rats are mobile and might further transmit the pathogenic organisms to other areas.

Evaluation of an in-house LipL32 polymerase chain reaction for diagnosis of leptospirosis and its correlation with various serological diagnostic techniques

Background: Leptospirosis is a zoonotic disease of ubiquitous distribution. During rainy seasons, in spring and summer and also during harvest times, the risk of leptospirosis increases as there are chances of frequent contact with infected rat population which is common in Karnataka as farming is a main source of income to the people here. There is a paucity of data regarding the prevalent serovars from Karnataka. This study was undertaken as an attempt to compare a battery of tools such as immunochromatographic test (ICT), microscopic agglutination test (MAT), immunoglobulin M (IgM) enzyme-linked immunosorbent assay (ELISA) and in-house polymerase chain reaction (PCR) to detect leptospirosis. Settings and Design: This study using consecutive sampling technique was conducted in a tertiary care centre, Mysore, Karnataka. Subjects and Methods: Samples from 783 suspected cases of leptospirosis in and around Mysore between April 2013 and April 2016 were processed. Samples from 783 patients suspected of leptospirosis were subjected to ICT, IgM ELISA, MAT and in-house PCR. Statistical Analysis Used: The statistical analysis was carried out using SPSS software version. Results: Among 783 samples tested, only 14 (1.7%) were positive by ICT, 341 (44%) were positive by IgM ELISA, 368 (47%) were positive by MAT and 393 (50.2%) were positive by in-house PCR. Conclusions: Mysore can be considered endemic for leptospirosis. The in-house PCR based on LipL32 gene proved to be useful in the early diagnosis of leptospirosis.