论文部分内容阅读
目的了解某地区肿瘤患者医院感染产超广谱β-内酰胺酶(ESBLs)大肠埃希菌的基因型及耐药性。方法用CLSI推荐的双纸片扩散法表型确证试验确定临床标本中产ESBLs大肠埃希菌251株,随机抽取其中50株应用聚合酶链反应(PCR)方法分别扩增产ESBLs大肠埃希菌常见的β-内酰胺酶基因:TEM、SHV和CTX-M;微量稀释法测定产与非产ESBLs菌株对18种抗菌药物的耐药率并进行比较。结果 PCR扩增显示,50株产ESBLs大肠埃希菌中,TEM 48株(96.00%)、CTX-M1 36株(72.00%)、CTX-M13 36株(72.00%)和SHV 20株(40.00%);45株(90.00%)携带2种或2种以上耐药基因。微量稀释法测定产与非产ESBLs大肠埃希菌对亚胺培南及美罗培南的耐药率均为0,但产ESBLs大肠埃希菌的耐药率除哌拉西林/他唑巴坦、阿莫西林/克拉维酸以外的其余14种抗菌药物均高于非产ESBLs菌株,多种抗菌药物两者差异均有统计学意义(P<0.05)。结论该地区肿瘤患者医院感染产ESBLs大肠埃希菌基因型以TEM、CTX-M1、CTX-M13型为主。产ESBLs大肠埃希菌呈现多重耐药趋势。
Objective To understand the genotype and drug resistance of extended-spectrum β-lactamases (ESBLs) -producing Escherichia coli in nosocomial patients with cancer in a certain area. Methods A total of 251 ESBLs-producing Escherichia coli strains from clinical specimens were identified by CLSI recommended double-disk diffusion method phenotypic confirmatory test. Among them, 50 strains were randomly selected for polymerase chain reaction (PCR) amplification of ESBLs-producing Escherichia coli strains Β-lactamase genes: TEM, SHV and CTX-M. The drug resistance rates of 18 kinds of antibacterials against non-producing ESBLs strains were determined by microdilution method and compared. Results PCR amplification showed that 50 strains of ESBLs-producing Escherichia coli were identified as TEM 48 (96.00%), CTX-M1 36 (72.00%), CTX-M13 36 (72.00%) and SHV 20 ); 45 strains (90.00%) carry two or more resistant genes. Microdilution method was used to determine the resistance rates of Escherichia coli producing and non-producing ESBLs to imipenem and meropenem. All of the drug resistance rates of Escherichia coli producing ESBLs except piperacillin / tazobactam, The other 14 kinds of antibacterial drugs except amoxicillin / clavulanic acid were higher than non-ESBLs-producing strains. The differences of various antimicrobial agents were statistically significant (P <0.05). Conclusion The genotypes of ESBLs-producing Escherichia coli producing in hospital were mainly TEM, CTX-M1 and CTX-M13. ESBLs-producing Escherichia coli showed a multi-drug resistance trend.