Emergence of High Levels of Extended-Spectrum-β-Lactamase-Producing Gram-Negative Bacilli in the Asia-Pacific Region: Data from the Study for Monitoring Antimicrobial Resistance Trends (SMART) Program, 2007

Of 3,004 gram-negative bacilli collected from intra-abdominal infections in the Asia-Pacific region during 2007, 42.2% and 35.8% ofEscherichia coli andKlebsiella spp., respectively, were extended-spectrum β-lactamase (ESBL) positive. Moreover ESBL rates in India forE. coli ,Klebsiella pneumoniae , andKlebsiella oxytoca were 79.0%, 69.4%, and 100%, respectively. ESBL-positiveE. 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 ofPseudomonas aeruginosa isolates (<90% susceptible to all study drugs) and ESBL-positiveKlebsiella pneumoniae isolates (<90% susceptible to all study drugs except imipenem). Quinolones achieved 90% inhibition levels only against ESBL-negativeK. pneumoniae and ESBL-negativeK. oxytoca . A decline in ampicillin-sulbactam activity was noted, with only 34.5% of allEnterobacteriaceae inhibited in this study.