Researchers tackle threatening ‘superbug’ that kills at least 29,000 people a year

Biologist Joseph Sorg is leading a team to analyze C. difficile, which kills at least 29,000 people a year.

Scientists around the world have been working hard to improve our understanding of an increasingly virulent superbug, Clostridium difficile. The highly contagious nosocomial pathogen, named by the Centers for Disease Control and Prevention as one of the five most urgent threats to the American health system, causes more than 500,000 infections and 29,000 deaths each year at societal cost total exceeding $ 5 billion.

Biologists from Texas A&M University and Baylor College of Medicine have teamed up in a new National Institutes of Health-funded systems biology study to tackle the problem at its source – the initial point of infection – in hoping to find out what makes patients susceptible to it. in the first place.

Previous studies have shown It’s hard infection is strongly correlated with a high abundance of secondary bile acids which are toxic to It’s hard in a laboratory setting. These small molecules are generated by a healthy gut microbiome from primary bile acids synthesized in the liver.

Texas A&M biologist and Chancellor’s EDGES 2020 member Joseph Sorg says scientists have long viewed these small molecules as a key protector in prevention It’s hard infection. The research was first presented by Sorg Laboratory graduate student Andrea Martinez Aguirre in an article published earlier this fall in the journal. PLOS pathogens with help from Tor Savidge’s group at Baylor College of Medicine.

“There are many ongoing efforts developing probiotic treatment options for C. diff-infected patients – efforts that focus on restoring secondary bile acids in patients, ”Sorg said. “Our results show that these treatments should instead focus on microbes that consume nutrients important to C. diff growth and that secondary bile acids are a red herring for protection.

As the basis for their study, the team used germless-derived mice from Baylor College of Medicine that were colonized with a single species of bacteria known to be involved in secondary bile. acid generation and strongly correlated with protection It’s hard environment. As an additional control measure, they selected a mutant mouse strain purchased as part of the NIH Knockout Mouse Project, bred at Texas A&M and distinct for its inability to synthesize a major class of bile acids, thereby further limiting the pool of bile acids. secondary bile acids.

“Surprisingly, we found that mice colonized by these microbes (C. scindens, C. hiranonis, Where C. leptum) protected against C. diff disease but did not produce secondary bile acids, ”Sorg said.

Sorg joined the Texas A&M Department of Biology in 2010 and has been working since his postdoctoral days to unlock It’s hard fundamental science, from its physiology to its virulence. He obtained his doctorate in microbiology at the University of Chicago in 2006, the same year, the It’s hard genome was sequenced, and has since become one of the pioneers of It’s hard to study.

Reference: “Independent protection of bile acids against Clostridioides difficile infection ”by Andrea Martinez Aguirre, Nazli Yalcinkaya, Qinglong Wu, Alton Swennes, Mary Elizabeth Tessier, Paul Roberts, Fabio Miyajima, Tor Savidge and Joseph A. Sorg, October 19, 2021, PLOS pathogens.
DOI: 10.1371 / journal.ppat.1010015