下呼吸道产超广谱β-内酰胺酶肺炎克雷伯菌及大肠埃希菌的耐药性基因型分析

    Detecting drug-resistant bacteria and their genotype of extended-spectrum β-lactamases in K. pneumoniae and E. coli

    • 摘要: 目的:观察下呼吸道产超广谱β-内酰胺酶(extended spectrumβ-lactamases,ESBLs)肺炎克雷伯菌及大肠埃希菌耐药菌株耐药基因分型,并探讨耐药菌株的流行状况及发生耐药的机制。方法:按常规方法进行细菌分离、培养和菌种鉴定。采用微量液体稀释与K-B法,分别对常用抗生素和头孢哌酮/舒巴坦的耐药性进行检测。采用纸片法确证产超广谱β-内酰胺酶菌株,并应用PCR技术进一步扩增TEM型、SHV型β-内酰胺酶的基因型。结果:产ESBLs肺炎克雷伯菌和大肠埃希菌对AMP、AMP/SB、PIP、CF、CFZ、CRM、CPD、CAX、CAZ、CTX、CPE和AZT的耐药率高达90%以上。产ESBLs肺炎克雷伯菌中产TEM型、SHV型、TEM和SHV型β-内酰胺酶基因的百分率分别为26.92%、30.76%、7.69%,大肠埃希菌百分率分别为46.15%、5.12%、10.25%。结论:产ESBLs肺炎克雷伯菌和大肠埃希菌对多种不同种类抗生素耐药,且具有多重耐药的特点。产ESBLs肺炎克雷伯菌和大肠埃希菌携带TEM或SHV型β-内酰胺酶基因,其中肺炎克雷伯菌以产SHV型β-内酰胺酶为主,大肠埃希菌则以产TEM型β-内酰胺酶为主。

       

      Abstract: Objective: To observe resistant-drug bacteria and their genotype of ESBLs in K.pneumoniae and E.coli from clinical specimens and to understand their epidemiological status and the mechanisms of drug-resistant to antibiotics.Methods: The isolation,cultivation and identification of bacteria were performed by the traditional procedures.Microdilution and K-B method were applied to detect the resistance of ESBL-producing in K.pneumoniae and E.coli to cefoperazone/sulbactam.ESBLs were confirmed by double disk test.Polymerase chain reaction(PCR) was applied to amplify the TEM and SHV genotype of beta-lactamase.Results: The resistance rates to common antibiotics were up to 90% in K.pneumoniae and E.coli,including to AMP,AMP/SB,PIP,CF,CFZ,CRM,CPD,CAX,CAZ,CTX,CPE and AZT.Furthermore,the resistance was multiple resistant-drug bacteria except for sensitive to imipenem.There-fore,the carbopenems was main antibiotics to bacteria producing ESBLs.The percentage of the genotype of TEM or SHV or TEM and SHV of the bacteria-producing ESBLs in K.pneumoniae were 26.92%,30.76%,7.69%,respectively,and were 46.15%,5.12%,10.25% in E.coli,respectively.Conclusions: The resistance rates are high to lots of common antibiotics in K.pneumoniae and E.coli,especially to penicillin and cephalosporin except for sensitive to imipenem,the carbopenems are main antibiotics to bacteria-producing ESBLs.Most of ESBLs-producting bacteria carry the genotype of TEM or SHV.The SHV genotype of β-lactamase is mainly in K.pneumoniae,TEM genotype of β-lactamase is found mainly in E.coli.

       

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