Blapidly rising prevalence of nosocomial multidrug-resistant, gram-negative bacilli: A 9-year surveillance study

OBJECTIVE: To examine and quantify the temporal trends of nosocomial multidrug-resistant, gram-negative bacilli. DESIGN: A 9-year surveillance study was conducted. Multidrug resistance was defined as resistance to 3 or more antimicrobial classes. SETTING: Tertiary-care institution. RESULTS: From 1994 to 2002, multi drug-resistant, gram-negative bacilli increased from 1% to 16% for multidrug-resistant Pseudomonas aeruginosa, 4% to 13% for multidrug-resistant Enterobacter species, 0.5% to 17% for multidrug-resistant Klebsiella species, 0% to 9% for multidrug-resistant Proteus species, and 0.2% to 4% for multidrug-resistant Escherichia coli (P less than or equal to .05). The most common pattern of multidrug resistance was co-resistance to quinolones, third-generation cephalosporins, and aminoglycosides. CONCLUSION: The rapid rise of multidrug-resistant, gram-negative bacilli may warrant infection control programs to include these pathogens in strategies aimed at limiting the emergence and spread of antimicrobial-resistant pathogens.