In vitro susceptibilities of aerobic and facultative gram-negative bacilli isolated from patients with intra-abdominal infections worldwide: the 2002 Study for Monitoring Antimicrobial Resistance Trends (SMART).

BACKGROUND

The Study for Monitoring Antimicrobial Resistance Trends (SMART) was begun in 2002 to monitor international drug-resistance patterns among aerobic and facultative gram-negative bacilli isolated from patients with intra-abdominal infections.

METHODS

In 2002, 40 medical centers from 17 countries collected consecutive non-duplicate isolates from intra-abdominal infections for susceptibility testing against 12 antimicrobial agents using the broth microdilution methods recommended by the Clinical and Laboratory Standards Institute (formerly the National Committee for Clinical Laboratory Standards).

RESULTS

A total of 3,134 aerobic and facultative gram-negative bacilli were isolated. Enterobacteriaceae accounted for 82% of the total and were most consistently susceptible to amikacin and the carbapenems. Escherichia coli (45%) and Klebsiella spp. (17%) were the most common species. The susceptibility rates of these organisms to the 12 antimicrobial agents differed among geographic regions, with isolates from the Asia/Pacific and Latin American regions usually having the highest rates of resistance. Ampicillin/sulbactam was the agent least frequently active against E. coli (56% susceptible) and Klebsiella spp. (73% susceptible). Extended-spectrum beta-lactamases (ESBLs) were detected phenotypically in 7% of E. coli, 13% of Klebsiella spp., and 18% of Enterobacter spp. Producers of ESBL overall had a more antibiotic-resistant profile than non-producers but were usually susceptible to carbapenems.

CONCLUSIONS

Antimicrobial resistance rates among gram-negative bacilli isolated from intra-abdominal infections differed among geographic regions. The carbapenems were consistently active in vitro against Enterobacteriaceae worldwide, including ESBL producers.