Gut multidrug-resistant organism colonization (Gut MDRO colonization)

Gut multidrug-resistant organism (MDRO) colonization refers to the establishment and expansion of antibiotic-resistant bacteria within the gastrointestinal tract, often following the disruption of the commensal microbiota by broad-spectrum antibiotics (Donskey, 2004). This ecological state serves as a significant reservoir for healthcare-associated infections, as these organisms can translocate into the bloodstream or be transmitted to other patients (Pamer, 2016). Unlike traditional drug targets that involve a single protein or receptor, this target represents a complex microbial ecosystem where the therapeutic goal is to restore colonization resistance (Buffie & Pamer, 2013). This is achieved through the reintroduction of diverse microbial communities or specific commensal strains that compete with MDROs for nutrients and niche space (Woodworth et al., 2018). Current therapeutic strategies include fecal microbiota transplantation (FMT) and defined microbial consortia, which aim to shift the gut environment from a state of dysbiosis to one that suppresses the growth of pathogens like Carbapenem-resistant Enterobacteriaceae (CRE) and Vancomycin-resistant Enterococci (VRE) (Seres Therapeutics, 2023). By restoring the metabolic landscape, such as the production of secondary bile acids, these interventions effectively decolonize the host and reduce the risk of clinical infection (Buffie et al., 2015). This approach represents a paradigm shift from killing pathogens with antibiotics to managing the ecological balance of the gut microbiome.

Other names

Intestinal MDRO carriageGut MDRO reservoirMicrobiota-mediated colonization resistanceDysbiosis-associated MDRO expansionGastrointestinal MDRO colonization

Restoration of colonization resistance through competitive exclusion for nutrients, production of inhibitory metabolites like secondary bile acids and bacteriocins, and stimulation of host mucosal immunity (Buffie & Pamer, 2013; Pamer, 2016).