In vitro susceptibilities of aerobic and facultative anaerobic Gram-negative bacilli from patients with intra-abdominal infections worldwide from 2005-2007: results from the SMART study.

SMART (Study for Monitoring Antimicrobial Resistance Trends) is an ongoing multiyear surveillance study to monitor worldwide antimicrobial resistance trends among aerobic and facultative anaerobic Gram-negative bacilli (GNB) isolated from intra-abdominal infections. During 2005-2007, a total of 255 laboratories from 37 countries in five global regions collected intra-abdominal GNB for antimicrobial susceptibility testing using broth microdilution according to Clinical and Laboratory Standards Institute guidelines. A total of 19703 GNB were isolated from intra-abdominal infections, comprising 5476, 6633 and 7594 GNB were isolated in the years 2005, 2006 and 2007 from 75, 84 and 96 medical centres, respectively. The most frequently isolated organisms were Escherichiacoli, Klebsiella pneumoniae and Enterobacter cloacae, of which 18.0% of E. coli and 26.2% of K. pneumoniae were positive for extended-spectrum beta-lactamase (ESBL). Overall, resistance among GNB increased during 2005-2007 and resistance rates in 2007 were generally higher than data from previous years. Ertapenem and imipenem were the only agents that maintained consistent activity against GNB, including most ESBL-producing isolates.