Effects of efflux pump inhibitor on resistance phenotype of Enterobacter cloacae

Objective To explore the role of efflux systerm in multidrug resistance to antibiotics of clinical isolated Enterobacter cloacae. Method Enterobacter cloacae were collected,separated and identified.The agar dilution method was used to detect the changes of minimum inhibitory concentration(MIC) against Ceftazidime,Amikacin,Azithromycin,Levofloxacin and Tetracycline,with and without carbonyl cyanldem-chlorophenylhydrazone(CCCP). Result Of the 83 isolates,at least four fold decrease in MIC was observed in 30,36,19,32 and 28 isolates to the five antibiotics with 10 μg/mL CCCP.19 strains were found to have an evident efflux effect against three or more antibiotics.Positive efflux pump existed in resistant strains and susceptible strains.Compared with susceptible strains,the effect on resistant strains was more significant. Conclusion Active efflux systerm exist in clinical islated Enterobacter cloacae widely,which is an important mechanism leading to multidrug resistance to antibiotics of clinical isolated Enterobacter cloacae.The inhibitor CCCP can increase the susceptibilty of Enterobacter cloacae to antibiotics.