Emergence of High Levels of Extended-Spectrum--Lactamase-Producing Gram-Negative Bacilli in the Asia-Pacific Region: Data from the Study for Monitoring Antimicrobial Resistance Trends

Of 3,004 gram-negative bacilli collected from intra-abdominal infections in the Asia-Pacific region during 2007, 42.2 % and 35.8 % of Escherichia coli and Klebsiella spp., respectively, were extended-spectrum -lactamase (ESBL) positive. Moreover ESBL rates in India for E. coli, Klebsiella pneumoniae, and Klebsiella oxytoca were 79.0%, 69.4%, and 100%, respectively. ESBL-positive E. coli rates were also relatively high in China (55.0%) and Thailand (50.8%). Ertapenem and imipenem were the most active drugs tested, inhibiting over 90 % of all species, including ESBL-positive isolates with the exception of Pseudomonas aeruginosa isolates (<90 % sus-ceptible to all study drugs) and ESBL-positive Klebsiella pneumoniae isolates (<90 % susceptible to all study drugs except imipenem). Quinolones achieved 90 % inhibition levels only against ESBL-negative K. pneumoniae and ESBL-negative K. oxytoca. A decline in ampicillin-sulbactam activity was noted, with only 34.5 % of all Enterobacteriaceae inhibited in this study. Gram-negative bacilli (GNB) continue to be an important cause of health care-associated infections (8, 15). They are a common cause of sepsis, pneumonia, urinary tract infection, postsurgical infections in acute care hospitals, and intra-ab-dominal infections (16). Antimicrobial resistance among thes