Generation of Mammalian Host-adapted by Cultivation in Peritoneal Dialysis Membrane Chamber Implantation in Rats.

can infect a myriad of mammalian hosts, including humans (Bharti , 2003; Ko , 2009). Following acquisition by a suitable host, leptospires disseminate the bloodstream to multiple tissues, including the kidneys, where they adhere to and colonize the proximal convoluted renal tubules (Athanazio , 2008). Infected hosts shed large number of spirochetes in their urine and the leptospires can survive in different environmental conditions before transmission to another host. Differential gene expression by spp. permits adaption to these new conditions. Here we describe a protocol for the cultivation of within Dialysis Membrane Chambers (DMCs) implanted into the peritoneal cavities of Sprague-Dawley rats (Caimano , 2014). This technique was originally developed to study mammalian adaption by the Lyme disease spirochete, (Akins , 1998; Caimano, 2005). The small pore size (8,000 MWCO) of the dialysis membrane tubing used for this procedure permits access to host nutrients but excludes host antibodies and immune effector cells. Given the physiological and environmental similarities between DMCs and the proximal convoluted renal tubule, we reasoned that the DMC model would be suitable for studying gene expression by . In a 20 to 30 min procedure, DMCs containing virulent leptospires are surgically-implanted into the rat peritoneal cavity. Nine to 11 days post-implantation, DMCs are explanted and organisms recovered. Typically, a single DMC yields ~10 mammalian host-adapted leptospires (Caimano , 2014). In addition to providing a facile system for studying the transcriptional and physiologic changes pathogenic undergo within the mammal, the DMC model also provides a rationale basis for selecting new targets for mutagenesis and the identification of novel virulence determinants. Caution: Leptospira interrogans is a BSL-2 level pathogen and known to be excreted in the urine of infected animals. Animals should be handled and disposed of using recommended Animal Biosafety Levels (ABSL) for infectious agents using vertebrate animal guidelines. Note: All protocols using live animals must conform to governmental regulations regarding the care and use of laboratory animals. The success of this protocol is dependent on the proper use of aseptic techniques during all stages of both dialysis membrane chamber preparation and animal surgery.