Antibiotic usage and risk of colonization and infection with antibiotic-resistant bacteria: a hospital population-based study

Accurate assessment of risk factors for nosocomial acquisition of colonization by antibiotic-resistant bacteria (ARB) is often confounded by scarce data on antibiotic use. A 12-month, nested, multicenter cohort study was conducted. Target ARB were methicillin (meticillin)-resistant Staphylococcus aureus (MRSA), vancomycin-resistant enterococci (VRE), and ciprofloxacin-resistant Pseudomonas aeruginosa (CR-PA). Identifying ARB colonization early during antibiotic therapy could target a high-risk hospitalized population that may benefit from intervention to decrease the risk of subsequent nosocomial infections.