Infections Caused by Enterobacter cloacae:Clinical Distribution and Antimicrobial Resistance

OBJECTIVE To investigate the clinical distribution and antimicrobial resistance of infections caused by Enterobacter cloacae in our hospital,for guiding the prophylaxis and treatment of these infections in clinical practice. METHODS Antimicrobial susceptibility tests were done by Kirby-Bauer disk diffusions method,the phenotypes of E.cloacae strains harboring AmpC β-lactamases and extended-spectrum β-lactamases(ESBLs) were detected by modified three-dimensional extract test. RESULTS A total of 162 strains of E.cloacae were isolated between Jan 2002 and Dec 2004,the percentages of these strains isolated from sputum,urine and wound secretion were 62.3%,11.7% and 9.9%,respectively.73.5% of all strains isolated from intensive care unit(ICU) in every endemic area.AmpC β-lactamases,AmpC β-lactamases combined with ESBLs and ESBLs producing strains were detected in 19.1%,11.7% and 14.2% of E.cloacae,respectively.The resistance of AmpC β-lactamases or ESBLs producer was obviously higher than that of non-AmpC β-lactamases and ESBLs producer,while the phenomenon of resistance was serious especially in AmpC β-lactamases combined with ESBLs producer,but all strains were sensitive to imipenem. CONCLUSIONS E.cloacae causes infections of respiratory tract,urinary tract and wound principally in clinic,the most of which occurred in ICU.AmpC β-lactamases and ESBLs are popular in E.cloacae,the restricted use of β-lactams is a considerable measure which reduces prevalence of AmpC(β-lactamases) and ESBLs producing strains.The antimicrobial agents for treating infections caused by E.cloacae should be chosen according to the results of the antimicrobial susceptibility tests,imipenem is the first choice for severe infections.