Abstract
We surveyed the detection patterns of extended spectrum β-lactamase (ESBL)-producing enteric bacteria isolated from blood cultures between January 2006 and March 2011 in our hospital. One hundred and eighty-four strains of enteric bacteria were detected in 163 (5.8%) of 3,019 patients whose blood samples were available for culture. Among those, 16 strains (8.7%) of ESBL-producing bacteria were detected: 13 strains of Escherichia coli and 1 strain each of Klebsiella pneumoniae, Enterobacter cloacae, and Proteus mirabilis. The genotype was analyzed in 14 strains: CTX-M 1 in 3, CTX-M 2 in 1, and CTX-M 9 in 10. We conducted an epidemiological analysis of E. coli using the random amplified polymorphic DNA (RAPD) technique, which showed no transmission of the same strains and dominant plasmid transmission. Nine of eleven strains had the phylogenetic group (PG) B 2 of E. coli, with potentially high pathogenicity. A microbial sensitivity test revealed a significantly higher rate of resistance to levofloxacin or amikacin for ESBL-producing compared to non-ESBL-producing strains (p<0.05). For antimicrobial therapies, carbapenems were used in 11 of 16 patients, 8 of whom showed a favorable effect. In this survey, we identified the detection patterns of ESBL-producing enteric bacteria in blood cultures obtained over the last five years.
