Acquisition of vancomycin-resistant enterococci during scheduled antimicrobial rotation in an intensive care unit

Scheduled rotation of treatment of gram-negative antimicrobial agents has b een associated with reduction of serious gram-negative infections. The impa ct of this practice on other nosocomial infections has not been assessed. T he purpose of this study was to determine if scheduled antimicrobial rotati on reduced rates of acquisition of enteric vancomycin-resistant enterococci (VRE) among 740 patients admitted to an intensive care unit (ICU). The pre ferred gram-negative agent was ceftazidime during rotation 1 and ciprofloxa cin during rotation 2. Unadjusted VRE acquisition rates were 8.5 cases per 1000 ICU days and 11.7 cases per 1000 ICU days during rotations 1 and 2, re spectively (P<.01). However, scheduled antimicrobial rotation of ceftazidim e with ciprofloxacin had no effect on the risk of acquiring VRE in the ICU after adjustment for known risk factors. Independent predictors of acquisit ion of VRE were enteral feedings, higher colonization pressure, and increas ed duration of anaerobic therapy. Our findings can confirm no additional be neficial or adverse effect on VRE acquisition among ICU patients as a resul t of this practice.