| Objective:Esrcherichia is a common opportunistic pathogen which can cause urinary tract,blood stream infection and meningitis.In recent years,the sensitivity of Escherichia coli to commonly used clinical antibiotics has decreased,which increased the difficulty of clinical anti-infection treatment.Therefore,the purpose of this study was to investigate the epidemiology of Escherichia coli in urinary tract infections,to determine the distribution of integrons in Escherichia coli isolated from community patients with urinary tract infections and their relationship with the phylogenetic groups and antimicrobial resistance,and the ESBL and PMQR genes carried by Escherichia coli were analyzed.Methods:From November 2015 to December 2018,152 isolates of Escherichia coli that collected without repetition from the urine samples of outpatients in nephrology of Fengxian Hospital affiliated of Anhui University of Science and Technology,were studied retrospectively.Bacterial identification and antimicrobial susceptibility analysis was carried out by Phoenix 100 automatic microbiological analyzer.Integron integrase genes of class 1,2,3 and the phylogenetic groups were screened by PCR,and variable regions of integron were amplified by long-fragment PCR.The type of promoters and gene cassette arrays of variable regions were determined by sequencing.At the same time,PCR screened the ESBL gene and PMQR gene produced by Escherichia coli.The relationship between Class 1 integron,ESBL and PMQR genes and phylogeny groups and bacterial resistance was also analysed.Results:The resistance rate of 152 Escherichia coli to ampicillin was 70.39%,and the resistance rates to other antibacterial drugs were all less than 40.00%.The phylogeny groups of 152 isolates were mainly belonged to group B2 and D.Among the 152 Escherichia coli isolates,class 1 integron integrase gene intI1 was detected in 65 isolates(42.76%),8 gene cassette arrays and 14 antimicrobial resistance gene cassettes were detected in 68 class 1 integrons.The most popular gene cassette array was dfrA17-aadA5(35/68),while the variable regions of class 1 integrons were failed to detected in 12 intI1-positive isolates.Five variable region promoters were detected in 68 class 1 integrons,with the relative weak promoter PcHl to be the most popular type(53/68).The gene cassette array arr-2-cmlA5-blaOXA-10-aadA1 was also detected in this study.65 intI1-positive isolates were mainly belonged to group B2 and D.The class 2 integron integrase gene intI2 was detected in 4 isolates(2.63%),and their variable region gene cassette arrays were all No intI3 was detected in all isolates.The commonly used clinical antibiotics resistance rate of intI1 positive isoaltes was higher than that of intI1 negative isolates.Among a total of 152 isolates of Escherichia coli,102 carried ESBL genes,including blaTEM-1,blaCTX-M-55,blaCTX-M-14,blacTX-M-27,blacTX-M-65 and blaOXA-1.At the same time,7 out of 152 isolates of Escherichia coli carried blaTEM-1 and blaCTX-M-27,9 isolates carried blaTEM-1 and blaCTX-M-14,1 isolates carried both blaTEM-1 and blaCTX-M-65.The ESBL genotypes of blacTX-M-2,blacTX-M-8,blaCTX-M-25 and blaSHV were not detected.23 out of 152 isolates of Escherichia coli carried PMQR genes,including qnrD,qnrS,oqxA,oqxB,aac(6')-1b and aac(6')-1b-cr,no qnrA,qnrB,qnrC,qepA were detected.Among the 152 isolates of Escherichia coli,6 isolates carried multiple(?2)PMQR resistance genes,17 isolates carried both ESBL and PMQR resistance genes,and 44 isolates did not detect ESBL and PMQR resistance genes.Conclusion:Escherichia coli isolated from community urinary tract infections had low resistance to antibiotics,and phylogenetic groups B2 and D were dominant groups.Class 1 integrons were closely related to antimicrobial resistance in Escherichia coli isolated from community patients with urinary tract infection.Most of the variable region promoters of class 1 integrons were relatively weak promoters.The gene cassette array arr-2-cmlA5-blaOXA-10-aadAl was detected in Escherichia coli.blaTEM-1 and blaCTX-M-14 were the main types of ESBL gene of Escherichia coli in this study.PMQR gene has a low prevalence in community urinary tract infection of Escherichia coli.Figure[4]table[14]reference[59]... |
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