Overview
Enterobacter cloacae is a Gram-negative, facultatively anaerobic member of the Enterobacteriaceae. Ubiquitous in soil, water, and the mammalian gut, it is a leading cause of nosocomial infections and carries clinically significant antibiotic resistance through inducible AmpC beta-lactamases.
Metal Dependencies
E. cloacae relies heavily on iron for growth and virulence. It produces multiple siderophore types — enterobactin and aerobactin — that compete directly with host lactoferrin and transferrin. Zinc and manganese serve as cofactors for its beta-lactamase enzymes and oxidative stress defense systems, linking metal availability to antibiotic resistance expression.
Ecological Role
In healthy adults, E. cloacae persists at low abundance. It expands during antibiotic-induced dysbiosis, exploiting the vacated niche and elevated luminal iron that follows inflammation. Its capacity for biofilm formation on mucosal surfaces and medical devices makes it particularly persistent once established.
Conditions Associated
E. cloacae is enriched in neonatal intensive care settings, where it contributes to necrotizing enterocolitis and bloodstream infections. In adults, it appears in complicated urinary tract infections and post-surgical wound infections. Its AmpC-mediated resistance limits treatment to carbapenems in severe cases.
Cross-References
- iron — siderophore-dependent acquisition
- zinc — beta-lactamase cofactor
- biofilm — persistence mechanism
- antimicrobial resistance — AmpC beta-lactamase