Colibactinproducing

Colibactin-producing bacteria are a group of enteric pathogens, primarily associated with *Escherichia coli* strains, that synthesize colibactin, a potent genotoxin. Colibactin is a polyketide compound produced by certain *E. coli* strains, particularly those belonging to the sequence type (ST) 38, ST648, and ST131, which are often linked to urinary tract infections (UTIs), traveler’s diarrhea, and extraintestinal infections. This toxin is known for its ability to induce DNA damage, leading to chromosomal aberrations and cell cycle arrest, which can contribute to tumor development in animal models.

The production of colibactin is regulated by the *cytR* gene cluster, which encodes enzymes responsible for its biosynthesis. This cluster is often found in mobile genetic elements, such as integrative and conjugative elements (ICEs) or plasmids, allowing horizontal gene transfer among bacterial populations. The toxin’s genotoxic effects are particularly concerning in the gastrointestinal tract, where chronic exposure may increase the risk of colorectal cancer.

Clinical significance of colibactin-producing *E. coli* includes severe infections, particularly in immunocompromised individuals. Research suggests that colibactin may play a role in the pathogenesis of inflammatory bowel diseases and colorectal neoplasia. Further studies are needed to fully understand its mechanisms and potential therapeutic interventions.