Use of luminescent Leptospira interrogans for enumeration in biological assays

Abstract

Rapid and reliable in vitro methods for the detection of pathogenic leptospires, such as Leptospira interrogans, are lacking. The present study investigated the use of luminescence to replace the existing enumeration techniques. Transposon TnSC189 was modified to incorporate the luxCDABE cassette from Photorhabdus luminescens and was used to construct luminescent Leptospira spp. There was a linear relationship between luminescence and cell number, with the theoretical detection limit being less than 104 leptospires. A comparison of enumeration by a standard method (counting by dark-field microscopy) and enumeration by luminescence was conducted with luminescent L. interrogans. There was a go..