Trends in the frequency of multiple drug-resistant Enterobacteriaceae and their susceptibility to ertapenem, imipenem, and other antimicrobial agents: data from the Study for Monitoring Antimicrobial Resistance Trends 2002 to 2007.

The management of patients with complicated intra-abdominal infections has increased in complexity because of the evolution of antibiotic resistance and the development of multidrug-resistant (MDR) Enterobacteriaceae implicated in this clinical infectious process. The Study for Monitoring Antimicrobial Resistance Trends study 2002 to 2007 monitored the susceptibility of Enterobacteriaceae from intra-abdominal infections to a panel of appropriate antimicrobials. During 2002 to 2007, 6644 MDR (resistant to 2 or more antimicrobial classes) Enterobacteriaceae species were isolated and tested against selected antimicrobials from varying classes. The carbapenems were the most consistently active agents. Escherichia coli was the most commonly isolated MDR pathogen. The susceptibility of E. coli to the quinolone (8-21.6%), cephalosporin (30.2-70.7%), aminoglycoside (81.0-92.1%), and carbapenem (91.9-99.3%) agents varied by year. Susceptibilities of other Enterobacteriaceae were similar to those of E. coli. Surveillance of pathogens responsible for intra-abdominal infections is useful in the monitoring of changing susceptibility patterns and in the formulation of more effective treatment modalities.