郑州市健康人群携带耐碳青霉烯大肠埃希菌的特征分析OA

This study analyzed the positivity rates,antimicrobial resistance,and genomic characteristics of carbapenem resistant Escherichia coli(CREC)in the feces of healthy individuals in Zhengzhou city.Fecal samples were collected from healthy individuals.CREC strains were obtained through isolation,culture,and identification.The antimicrobial resistance profiles,resistance genes,virulence genes,plasmids,and multi-locus sequence typing(MLST)of the CREC strains were analyzed.A total of 12 CREC strains were isolated from 108 fecal samples,with a detection rate of 11.11%.The positivity rate was significantly higher in middle-aged indi-viduals(41-65 years,20.51%)than in young adults(18-40 years,5.80%)(χ2=5.46,P<0.05).The resistance rated to 16 antibiotics exceeded 80%.All strains were resistant to carbapenems,cephalosporins,ampicillin/sulbactam,and ampicillin/clavulanic acid.The resistance rates to minocycline(8.33%),fosfomycin w/G6P(16.67%),and norfloxacin(16.67%)were relatively low.All isolates were susceptible to tigecycline,nitrofurantoin,and amikacin.All strains were multidrug-resistant and carried one carbapenemase gene(11 carried blaNDM-5,and one carried blaNDM-1).The high-frequency co-occurring resistance genes were mdf(A)(100%),floR(83.33%),and qnrS1(75.00%).The main virulence genes carried were associated with pili,the iron transport system,and the type II/III secretion system.The plasmids IncX3 and IncF were detected in eight CREC strains.MLST analysis revealed that all 12 CREC strains belonged to different sequence types(STs).Therefore,healthy middle-aged individuals in Zhengzhou constitute a major CREC reservoir.All isolated CREC strains were highly resistant to most antibiotics and carried multiple resistance and virulence genes.CREC monitoring efforts in healthy people should be strengthened.