Bile acid fitness determinants of a isolate from a human pouchitis patient.

The Gram-negative bacterium is a common member of the human gut microbiota that colonizes multiple host niches and can influence human physiology through a variety of mechanisms. Identification of genes that enable to grow across a range of host environments has been impeded in part by the relatively limited genetic tractability of this species. We have developed a high-throughput genetic resource for a strain isolated from a UC pouchitis patient.

Bile acid fitness determinants of a isolate from a human pouchitis patient.

comprises 1-5% of the gut microbiota in healthy humans but can expand to >50% of the population in ulcerative colitis (UC) patients experiencing inflammation. The mechanisms underlying such microbial blooms are poorly understood, but the gut of UC patients has physicochemical features that differ from healthy patients and likely impact microbial physiology. For example, levels of the secondary bile acid deoxycholate (DC) are highly reduced in the ileoanal J-pouch of UC colectomy patients.

Phage-resistant mutations impact bacteria susceptibility to future phage infections and antibiotic response.

Bacteriophage (phage) therapy in combination with antibiotic treatment serves as a potential strategy to overcome the continued rise in antibiotic resistance across bacterial pathogens. Understanding the impacts of evolutionary and ecological processes to the phage-antibiotic-resistance dynamic could advance the development of such combinatorial therapy. We tested whether the acquisition of mutations conferring phage resistance may have antagonistically pleiotropic consequences for antibiotic resistance.