60株鲍曼不动杆菌耐药基因携带情况分析

目的研究临床分离的60株鲍曼不动杆菌耐药谱及Ⅰ型整合子和β-内酰胺酶等基因携带情况。方法用微量肉汤稀释法测定16种临床常用抗菌药物的最小抑菌浓度;PCR检测β-内酰胺酶、Ⅰ型整合子和外排泵基因,对阳性基因进行序列分析。结果60株菌中,多重耐药株53株,占88.3%;6株携带OXA-23基因,均对包括碳青霉烯在内的5类以上抗菌药耐药,并具有高耐药特性;38株携带PER-1基因,对头孢菌素类耐药率显著高于PER-1基因阴性菌株(P<0.01);45株检出Ⅰ型整合子结构基因,多重耐药率明显高于Ⅰ型整合子阴性菌株(P<0.01);Ⅰ型整合子和PER-1基因同时阳性25株,与7株两者同为阴性菌株相比,多重耐药率增高(P<0.01),但耐药程度无显著差别。结论Ⅰ型整合子基因及β-内酰胺酶类基因的作用是导致鲍曼不动杆菌多重耐药的重要原因;OXA-23基因阳性菌株多为泛耐药和高耐药株,有必要采取有效措施控制其传播。

Analysis of drug-resistant genes of 60 Acinetobacter baumannii isolates

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.