Relationship between genotype of extended spectrum -lactamases (ESBLs) and virulence factors of ESBLs producing E. coli strains

Objective To understand the drug resistance of extended spectrum -lactamases (ESBLs) producing Escherichia coli strains isolated in our hospital and the relationship between genotype of ESBLs and the virulence factors of ESBLs producing E coli strains Methods PCR was conducted to amplify virulence factors such as papC, sfa/foc, afa/dra, hly, cnf1, iutA, aer, fimH, kpsMTⅡ, fyuA in 188E. coli strains isolated from inpatients in our hospital. ESBLs was detected with K-B disc diffusion method, the genotype of ESBLs and their distribution were detected by PCR. Results The detection rates of virulence factors iutA and fyuA were all 50%, the detection rats of fimH and aer were 20%-40%,but the detection rate of papC, sfa/foc, afa/dra and kpsMTⅡ were all 20%. There was no significant differences (P0.05) in virulence factor distribution between ESBLs producing E. coli strains and non ESBLs producing. E. colistrains. Among the 92 ESBLs producing E. coli clinical isolates, the positive rate of papC in CTX-M-9 was higher than that in CTX-M-1 and TEM, the difference was statistical significant (P0.05) and the positive rate of aer was higher in CTX-M-1 than in TEM and CTX-M-9, the difference was statistical significant (P0.05). Conclusion The detection rate of virulence factor was not associated with ESBLs producing or not in E. coli, but ESBLs genotype was associated with virulence factor. Virulence factor might be associated with the drug resistance of CTX-M producing E. coli.