The Expression of AmpC and MBL(metallo-β-lactamase) among Clinical Isolates of Enterobacter Cloacae and Its Impact on Antibiotics Susceptibility

Objective To study the expression of MBL among clinical isolates of enterobacter cloacae and its impact on antibiotic susceptibility.Methods MBL was detected by comparing the inhibition zones using imipenem containing EDTA,AmpC was detected by three-dimensional test methods.Antimicrobial resistance was detected by Kirby-Bauen methods.Results AmpC and MBL enzyme positive rates of 120 strains of enterobacter cloacae were 5% and 22.5% respectively.Antimicrobial resistant rates of AmpC-producing strains to ceftriaxone,cefotaxime,cefoxitin were higher than non-AmpC-producing strains(P0.05),resistant rates of MBL-producing strains to ceftazidime,cefotaxime,ceftazidime,piperacillin-sulbactam,imipenem were higher than non-MBL-producing ones(P0.05).Conclusion Resistance to expanded-spectrum cephalosporins and cephalomycin in enterobacter cloacae was mediated by AmpC,and to carbopenems was mediated by MBL.In order to reduce the emergence and prevalence of antimicrobial resistant strains,antimicrobial agents should be choosed carefully according to the antimicrobial resistance experiment.