MRSA and <i>P. aeruginosa</i> infection and colonisation after ICU admission.

Significant isolates (SI) in patients admitted for more than 48 h (n = 1194;) compared with commensal isolates (CI) from those admitted to ICU within 48 h of hospital arrival and received only cefepime or APP-β, or no antibiotics at all, by the end of their first week in ICU (n = 286). FEP, cefepime; APP-β, antipseudomonal penicillin/β-lactamase inhibitor combinations; *indicates significance (p-value <0.05) relative to the previous cycle, by Chi-Squared analysis. Rate: patients positive per 100 admissions; % SI: rate per 100 significant isolates.