Enterobacteriaceae의 Extended - Spectrum ß - Lactamase 생성율

Abstract

Extended-spectrum ß -lactarnases(ESBL) are enzymes that confer resistance to extended spectrum cephalosporins, such as ceftazidime and cefotaxime, and related oxyimino-ß -lactarns as well as to older penicillins and cephalosporins. In recent years, bacterial resistance to β -lactam antibiotics has risen dramatically, contributing to this increase has been the spread of extended-spectrum ß -lactamases. In this study, we determined the occurrence of ESBL among all genera of the family Enterobacteriaceae lsolated at the Kangnam St. Mary’s hospital, during April 1997 and October 1997. A total of 430 clinical is이ates of members of the family Enterobacteriaceae were tested forproduction of extended-spectrum ß -lactamases by the double disk synergy test using ceftazidime, cefotaxime, ceftriaxone and amoxicillin/clavulanic acid disks. Of the 430 lsolates tested by the double disk method, enhanced zones of inhibition were observed with 50(11.6%) isolates. The 50 ESBL-producing is이ates were composed of Klebsiella pneumoniae(21), Escherichia coli(12), Enterobacter clcαcae(11),Citrobacter freundii (2) , Klebsiella oxytoca(1). Morganella morlganii(1). Proteus vulgaris(1) and Serratia marcescens (1). The highest occurrence rates of ESBL within each species that produced ESBL was E. cloacae(25.6%), otherwise K. pneumoniae and E. coli, known as relatively high ESBL producing organisms, were 23.3% and 5.4%, respectively. Among the members of family Enterobacteriaceae other than K. pneumoniae and E. coli, the ESBL producing rates of these isolates that reduced susceptibility with third generation cephalosporins(ceftazidime, ceftizoxime) or aztreonam were 38.1%. Therefore, all members of the family Enterobacteriaceae with reduced susceptibility to third generation cephalosporins or monobactams by disk diffusion antimicrobial susceptibility test should be determined whether they are ESBL producing-strains or not.