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

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.