ABSTRACT
Objective To investigate β-lactamase gene and class 1 integron gene from 60 clinical Acinetobacter baumannii isolates.Methods The minimal inhibitory concentrations (MICs) for 16 antibiotics widely used were determined using the standard broth microdilution method.The β-lactamase gene,class 1 integron gene and adeB gene were determined by PCR and then sequenced.Results Fifty-three strains of the 60 A.baumanii isolates were multi-drug resistant.OXA-23 gene was detected positive in six A.baumanii isolates,which were all resistant to more than five antimicrobial agents including carbapenem and showed high resistance to many antibiotics.Thirtyeight strains earring PER-1 gene showed higher resistance to cephalosporins than those without this gene (P＜0.01).Class 1 integron gene was positive in 45 strains,which exhibited significantly higher multiple resistance than those without this gene (P＜0.01).Twenty-five strains carrying both class 1 integron and PER-1 genes had a markedly higher multiple resistance (P＜0.01),but not in resistant level,compared to the 7 strains without these two genes.Conclusion Class 1 integron and β-lactamase gene may be the causes of muhidrug-resistance of A.baumanii.The strains carrying OXA-23 gene always showed multiple and high resistance to several antibiotics,so effective measures must be taken to control the epidemic of these strains.