Isolation studies of Leptospira from rats in Andhra Pradesh

Abstract

Isolation studies were carried out from reservoir hosts rats, and the rats were trapped from different geo-graphical areas of Andhra Pradesh. The rats were ethunized and kidneys (cortical part) were processed for isolation. A total of 299 kidney processed samples were inoculated into a selective EMJH liquid medium containing 5-flurouracil (100µg/ml). Out of 299 samples processed for isolation studies, only 5 isolates (1.67%) were recovered. Further, the recovered isolates were purified and maintained in EMJH liquid medium. Physio-chemical characterization of isolates revealed the absence of growth at 130C, absence of the growth in the presence of 8-azaguanine and lipase activity on egg yolk agar medium indicated the pathogenecity of the isolates. On dark field microscopy, three of the isolates shown characteristic flexion, extension and rotational movements suggestive of leptospira where as the other two isolates shown sluggish motility. On Molecular characterization two of the isolates sent for sequencing were identified as Leptospira nagouchi & L. illini on 16SrRNA PCR. This is the first report of isolation studies in rats from Andhra Pradesh and isolation studies from rats help in finding epidemiological link between animals, humans and rats (reservoir hosts).