产超广谱β-内酰胺酶肠杆菌科细菌耐药性及基因型检测

Detection of drug resistance and genotype of extended-spectrum β-lactamase producing Enterobacteriaceae bacteria

目的 调查我院产超广谱 β 内酰胺酶 (ESBL)菌株对临床常用抗生素的耐药情况及其ESBLs基因型。方法 对 2 0 0 1年 4月～ 2 0 0 2年 5月我院临床分离的 40株产ESBL肠杆菌科细菌采用NCCLS推荐的琼脂平皿对倍稀释法测定对不同抗生素的MIC值 ,用针对TEM、SHV、CTX M基因的特异性引物进行PCR扩增确定ESBL基因型。结果 40株产ESBL菌株对第三代头孢菌素耐药率高 ,对头孢噻肟的耐药程度高于头孢他啶。对头孢哌酮 /舒巴坦、头孢吡肟、环丙沙星、阿米卡星的耐药率分别为 37 5 %、5 7 5 %、90 %、5 2 5 %。除 2株菌外 ,其它 38株菌对亚胺培南敏感。 40株菌中携带SHV、TEM、CTX M型ESBLs的比率分别为 87 5 %、5 0 %、40 %。结论 我院产ESBL菌多重耐药现象严重 ,临床上需慎用酶抑制剂复合物及第四代头孢菌素 ,亚胺培南仍是治疗产ESBL菌感染的首选药物。我院存在CTX M酶的流行 ,产ESBL菌绝大多数产SHV型酶 ,有 2 4株菌同时产 2种或 3种酶。

To study the drug resistance and genotypes of extended-spectrum β-lactamases (ESBLs)-producing Enterobacteriaceae in our hospital. Methods ESBL-producing Enterobacteriacea were isolated from clinical specimens in our hospital from April 2001 to May 2002. The MICs of ten kinds of antibiotics against the ESBLs-producing strains were detected by agar dilution. The TEM-type, SHV-type and CTX-M-type encoding genes were amplified by PCR. Results The MIC value of cefotaxime was much higher than that of ceftazidime. The resistant rates of ESBLs pruducing strain to cefoperazone/sulbactam, cefepime, ciprofloxacin, amikacin were 37.5%, 57.5%, 90%, 52.5%. Except 2 strains of Escherichia coli, all of the 40 strains were susceptible to imipenem. The rates of Eterobacteriaceue carrying TEM-type, SHV-type, CTX-M-type ESBLs were 87.5%, 50%, 40% respectively. Conclusion Most of the ESBLs-producing strains in our hospital were multidrug resistance. Cefoperazone/sulbatam and cefepime should be used carefully, and impenem was still the best choice for treatment of the infections caused by ESBLs-producing bacteria. CTX-M-type β-lactamase existed prevalently in our hospital, and most of the ESBL-producing strains carried SHV-type ESBLs and 24 strains produced 2 or 3 kinds of ESBLs.