Glutamine from plasma-like medium fuels nitrogen metabolism and influences proliferation in Leptospira interrogans
4 affiliations
- 1Department of Chemistry, Washington University in St. Louis, St. Louis, Missouri, United States of America.
- 2Department of Genetics, Washington University in St. Louis, St. Louis, Missouri, United States of America.
- 3Department of Medicine, Washington University in St. Louis, St. Louis, Missouri, United States of America.
- 4Center for Mass Spectrometry and Metabolic Tracing, United States of America.
Abstract
Leptospirosis, caused by pathogenic Leptospira spp. such as L. interrogans, is a bacterial zoonosis of increasing prevalence with no consistently effective treatments in severe cases. We sought to characterize metabolic mechanisms that support L. interrogans infection, with the ultimate goal of revealing unexplored therapeutic opportunities. We first established and validated a culture medium, which we refer to as supplemented Human Plasma-Like Medium (sHPLM). sHPLM more closely resembles the physiological environment of the human host than standard culture media, such as the EMJH (Ellinghausen-McCullough-Johnson-Harris) medium typically used for Leptospira culture. We also pioneered metabolomics approaches to study sHPLM-cultured Leptospira. Specifically, we developed a liquid chromatography/mass spectrometry (LC/MS) workflow for both medium metabolomics and stable isotope tracing with L. interrogans cultures. The application of these technologies in L. interrogans revealed that the amino acid glutamine is a major nitrogen source among the many available in sHPLM. Subsequent growth studies in three pathogenic Leptospira strains and the nonpathogenic strain L. biflexa Patoc-1 showed robust proliferation when only glutamine-derived nitrogen was available. Further, a small-molecule inhibitor designed to target glutamine utilization, JHU-083, effectively impaired the proliferation of L. interrogans cultures. Adding glutamine to non-physiological EMJH medium also rapidly induced a short-term proliferative boost in L. interrogans and increased biofilm formation. RNA-sequencing after glutamine exposure revealed transcriptional trends for increases in biosynthesis to support these phenotypes. Although ammonium has long been thought to be the sole nitrogen source for Leptospira spp., our results demonstrate that glutamine provides a second source of nitrogen for biosynthesis in multiple strains and may act as a metabolite signal to alter L. interrogans physiology in ways that could influence infection. This work highlights that studying L. interrogans under physiological conditions is key to understanding mechanisms supporting infection and points to nitrogen assimilation as a potential target for therapies. Author summary: Leptospirosis is a potentially fatal disease transmitted through water and soil contaminated with pathogenic Leptospira bacteria. Much research is currently focused on the idea that an improved understanding of how Leptospira infects hosts and causes disease may inspire the development of improved therapeutics, which are urgently needed. Focusing on Leptospira interrogans, a clinically important species, we determined that conventional growth media are inadequate for understanding how the bacterium behaves when inside hosts. Instead, we designed an optimized formulation to mimic human blood, and we applied an underutilized technique for measuring the biochemical reactions that enable pathogen survival. These two innovations revealed that L. interrogans uses glutamine, an abundant nutrient in host blood and tissues, as a source of nitrogen for the production of biomolecules that are required for replication and infection. Our discovery is notable because nitrogen demands were previously thought to be met with ammonium. Treating L. interrogans with inhibitors of both glutamine and ammonium metabolism blocked bacterial replication. We also discovered that L. interrogans increases its growth rate, upregulates its expression of biosynthetic pathways, and increases its formation of biofilm when exposed to glutamine. Our results reveal the importance of glutamine in supporting the lifecycle of leptospirosis-causing bacteria.
Related
- Terminal hydroxylation of eIF5A hypusination influences mitochondrial protein expression and cellular metabolism in fission yeast
- Salidroside Regulates Energy Metabolism Reprogramming to Suppress Tumor Proliferation: Mechanisms and Therapeutic Implications
- Wolbachia outcompetes mosquito-borne viruses by reprogramming host ATPSβ1-driven ATP metabolism toward symbiotic proliferation
- Core–sheath coupling controls flagellar curvature and motility in Leptospira
- Leptospira infection in European hedgehogs (Erinaceus europaeus): occurrence, diversity and associated risk factors in Greater Paris, France.
BibTeX
@article{ward2026glutamine,
title = {{Glutamine from plasma-like medium fuels nitrogen metabolism and influences proliferation in Leptospira interrogans}},
author = {Matthew H Ward and Nathan Scherer and Leah P Shriver and Gary J Patti},
journal = {PLOS Pathogens},
year = {2026},
month = oct,
doi = {10.1371/journal.ppat.1014534},
url = {https://journals.plos.org/plospathogens/article?id=10.1371/journal.ppat.1014534},
note = {CC BY},
}
RIS
TY - JOUR
TI - Glutamine from plasma-like medium fuels nitrogen metabolism and influences proliferation in Leptospira interrogans
AU - Matthew H Ward
AU - Nathan Scherer
AU - Leah P Shriver
AU - Gary J Patti
PY - 2026
DA - 2026/10/08
JO - PLOS Pathogens
DO - 10.1371/journal.ppat.1014534
UR - https://journals.plos.org/plospathogens/article?id=10.1371/journal.ppat.1014534
AB - Leptospirosis, caused by pathogenic Leptospira spp. such as L. interrogans, is a bacterial zoonosis of increasing prevalence with no consistently effective treatments in severe cases. We sought to characterize metabolic mechanisms that support L. interrogans infection, with the ultimate goal of revealing unexplored therapeutic opportunities. We first established and validated a culture medium, which we refer to as supplemented Human Plasma-Like Medium (sHPLM). sHPLM more closely resembles the physiological environment of the human host than standard culture media, such as the EMJH (Ellinghausen-McCullough-Johnson-Harris) medium typically used for Leptospira culture. We also pioneered metabolomics approaches to study sHPLM-cultured Leptospira. Specifically, we developed a liquid chromatography/mass spectrometry (LC/MS) workflow for both medium metabolomics and stable isotope tracing with L. interrogans cultures. The application of these technologies in L. interrogans revealed that the amino acid glutamine is a major nitrogen source among the many available in sHPLM. Subsequent growth studies in three pathogenic Leptospira strains and the nonpathogenic strain L. biflexa Patoc-1 showed robust proliferation when only glutamine-derived nitrogen was available. Further, a small-molecule inhibitor designed to target glutamine utilization, JHU-083, effectively impaired the proliferation of L. interrogans cultures. Adding glutamine to non-physiological EMJH medium also rapidly induced a short-term proliferative boost in L. interrogans and increased biofilm formation. RNA-sequencing after glutamine exposure revealed transcriptional trends for increases in biosynthesis to support these phenotypes. Although ammonium has long been thought to be the sole nitrogen source for Leptospira spp., our results demonstrate that glutamine provides a second source of nitrogen for biosynthesis in multiple strains and may act as a metabolite signal to alter L. interrogans physiology in ways that could influence infection. This work highlights that studying L. interrogans under physiological conditions is key to understanding mechanisms supporting infection and points to nitrogen assimilation as a potential target for therapies. Author summary: Leptospirosis is a potentially fatal disease transmitted through water and soil contaminated with pathogenic Leptospira bacteria. Much research is currently focused on the idea that an improved understanding of how Leptospira infects hosts and causes disease may inspire the development of improved therapeutics, which are urgently needed. Focusing on Leptospira interrogans, a clinically important species, we determined that conventional growth media are inadequate for understanding how the bacterium behaves when inside hosts. Instead, we designed an optimized formulation to mimic human blood, and we applied an underutilized technique for measuring the biochemical reactions that enable pathogen survival. These two innovations revealed that L. interrogans uses glutamine, an abundant nutrient in host blood and tissues, as a source of nitrogen for the production of biomolecules that are required for replication and infection. Our discovery is notable because nitrogen demands were previously thought to be met with ammonium. Treating L. interrogans with inhibitors of both glutamine and ammonium metabolism blocked bacterial replication. We also discovered that L. interrogans increases its growth rate, upregulates its expression of biosynthetic pathways, and increases its formation of biofilm when exposed to glutamine. Our results reveal the importance of glutamine in supporting the lifecycle of leptospirosis-causing bacteria.
SN - 1553-7374
SN - 1553-7366
ER -