| Objective: To understand the distribution and and the drug resistance of extended spectrum β-lactamases(ESBLs)-producing Escherichia coli(E.coli)in a hospital in recent 3 years,and to determine the genotypes of ESBLs,so as to provide guidance for reasonable clinical use of antibiotics for treatment of E.coli infection.Methods: A total of 316 E.coli strains were collected from various clinical specimens from Jan 2014 to Oct 2016 in this hospital.The drug sensitivity was tested and the ESBLs-producing strains were screened by Biomerieux VITEK-COMPACT automatic bacterial analyzer.The ESBLs-producing strains were further confirmed by double disk agar diffusion method.PCR amplification was used to detect the CTX-M,TEM,SHV and OXA genotypes of ESBLs in ESBLs-producing strains.Results:(1)The detection rate of ESBLs-producing E.coli was 41.5% in all the 316 E.coli strains,with relative high detection rate in strains isolated from secretion and urine specimens(47.5% and 45.8%),but there was no significant difference in detection rate among different specimens(P>0.05).The positive rates of ESBLs-producing strains were 44.8%(43/96),39.6%(44/111)and 40.4%(44/109),respectively,in 2014,2015 and 2016,and also there was no significant difference among them(P> 0.05).(2)The resistant rates of E.coli to Penicillins,Quinolones and some Cephalosporins were high(47.7%-81.4%)and those for ESBLs-producing strains were more higher(67.9%-100%),while the resistance rates to Amikacin,Otapenem,Piperacillin/Tazobactam,Cefotetan and Imipenem were less than 5%.ESBLs-producing strains showed highly resistant to most of the antimicrobial drugs than non-ESBLs-producing strains,with significant differences(P<0.05).The resistant rates of E.coli or ESBLs-producing strains in different years showed some differences,but the differences were not obvious.(3)There were 24 strains carrying CTX-M gene(55.8%)and 2 strains carrying TEM gene(7.0%)in 43 ESBLs-producing strains.SHV gene and OXA gene were not detected.Conclusions:(1)ESBLs-producing strains are found in various clinical specimens of specimens in our hospital.The positive rate of ESBLs-producing strains has no obvious changes in recent 3 years.(2)E.coli is resistant to multiple antibacterial drugs and the drug resistance of ESBLs-producing strains is more serious.It is necessary for the hospital to strengthen the detection of pathogens and reasonably use antibiotics based on the results of drug susceptibility testing.(3)The predominant ESBLs genotype of ESBLs-producing E.coli is CTX-M in this hospital. |
