Metabolites from plasma-like medium fuel nitrogen metabolism and influence proliferation in Leptospira interrogans

The pathogen Leptospira interrogans expands from a small inoculum to reach high bloodstream titers before colonizing host kidneys; however the supporting metabolic programs and the role of the host environment are largely unknown, and tools to investigate these host-pathogen metabolic interactions in a controlled in vitro setting are in their infancy.

Here, we built upon the concept of human plasma-like medium (HPLM) to develop a more physiological system for L. interrogans culture. This supplemented HPLM (sHPLM) supported robust growth, and we used RNA-sequencing analyses to demonstrate the fidelity of the transcriptome of sHPLM cultures to in vivo models. Through the use of sHPLM, we identified the amino acid glutamine as a major nitrogen source supplying the biosynthetic activities of L. interrogans.