Detection of CHBls,ESBLs and AmpC in 112 strains of Enterobacter cloacae and analysis of the drug resistance

OBJECTIVE To evaluate the production of CHBls,ESBLs and AmpC in clinical specimens-derived Enterobacter cloacae from the affiliated hospital of jining medical college and analyze the drug resistance to 17 common antibiotics,so as to guide rational use of antibiotics in clinical practice.METHODS A total of 112 non-repeated strains of E.cloacae were isolated in our hospital from May 2009 to May 2010.Modified Hodge test was applied to detect CHBls.AmpC was checked by cefoxitin three-dimensional test.Phenotypic confirmatory test was used to detect ESBLs.The drug susceptibility test was performed by Kirby-auer method.RESULTS The 112 strains of E.cloacae were mainly isolated from sputum,accounting for 60.7%,followed by secretions and urine,accounting for 16.1% and 13.4% respectively.Positive rates of CHBls,AmpC and ESBLs in the 112 strains of E.cloacae were 1.8%(2 strains),53.6%(60 strains) and 41.1%(46 strains),respectively.In these strains,28 strains(25.0%) only had ESBLs,42 strains(37.5%) only had AmpC,and 18 strains(16.07%) had both ESBLs and AmpC.CONCLUSION We should enhance the detection and control of E.cloacae producing CHBls.There are very high positive rates of ESBLs and AmpC produced by E.cloacae.Clinical therapy should based on drug susceptibility test and antibacterials are rationally selected according to different enzyme-producing E.cloacae.