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BACKGROUND:The virulent factors of Escherichia coli(E.coli) play an important role in the process of pathopoiesis.The study aimed to compare drug-resistant genes and virulence genes between extended spectrum β-lactamases(ESBLs)-producing E.coli and non-ESBLs-producing E.coli to provide a reference for physicians in management of hospital infection.METHODS:From October 2010 to August 2011,96 drug-resistant strains of E.coli isolated were collected from the specimens in Qingdao Municipal Hospital,Qingdao,China.These bacteria strains were divided into a ESBLs-producing group and a non-ESBLs-producing group.Drug sensitivity tests were performed using the Kirby-Bauer(K-B) method.Disinfectant gene,qacEA1-sull and 8 virulence genes(CNF2,hlyA,eaeA,VT1,est,bfpA,elt,and CNF1) were tested by polymerase chain reaction(PCR).RESULTS:Among the 96 E.coli isolates,the ESBLs-producing E.coli comprised 46(47.9%)strains and the non-ESBLs-producing E.coli consisted of 50(52.1%) strains.The detection rates of multiple drug-resistant strain,qacEA1-sull,CNF2,hlyA,eaeA,VT1,est,bfpA,elt,and CNF1 in 46ESBLs-producing E.coli isolates were 89.1%,76.1%,6.5%,69.6%,69.6%,89.1%,10.9%,26.1%,8.7%,and 19.6%,respectively.In the non-ESBLs-producing E.coli strains,the positive rates of multiple drug-resistant strain,qacEA1-sull,CNF2,hlyA,eaeA,VT1,est,bfpA,elt,and CNF1 were 62.0%,80.0%,16.0%,28.0%,64.0%,38.0%,6.0%,34.0%,10.0%,and 24.0%,respectively.The difference in the detection rates of multiple drug-resistant strain,hlyA and VT1 between the ESBLs-producing E.coli strains and the non-ESBLs-producing E.coli strains was statistically significant(P<0.05).CONCLUSION:The positive rate of multiple drug-resistant strains is higher in the ESBLsproducing strains than in the non-ESBLs-producing strains.The expression of some virulence genes hlyA and VT1 varies between the ESBLs-producing strains and the non-ESBLs-producing strains.Increased awareness of clinicians and enhanced testing by laboratories are required to reduce treatment failures and prevent the spread of multiple drug-resistant strains.
BACKGROUND: The virulent factors of Escherichia coli (E. coli) play an important role in the process of pathopoiesis. The study aimed to compare drug-resistant genes and virulence genes between extended spectrum β-lactamases (ESBLs) -producing E. coli and non-ESBLs-producing E. coli to provide a reference for physicians in management of hospital infection. METHODS: From October 2010 to August 2011, 96 drug-resistant strains of E. coli isolated were collected from the specimens in Qingdao Municipal Hospital, Qingdao , China.These bacteria were were divided into ESBLs-producing group and a non-ESBLs-producing group. Drug sensitivity tests were performed using the Kirby-Bauer (KB) method. Disinfectant gene, qacEA1-sull and 8 virulence genes , hlyA, eaeA, VT1, est, bfpA, elt, and CNF1) were tested by polymerase chain reaction (PCR) .RESULTS: Among the 96 E.coli isolates, the ESBLs- and the non-ESBLs-producing E. coli consisted of 50 (52.1%) of the detection rates of multiple drug-resistant strains, qacEA1-sull, CNF2, hlyA, eaeA, VT1, est, bfpA, elt, and CNF1 in 46 ESBLs- producing E. coli isolates were 89.1%, 76.1%, 6.5%, 69.6%, 69.6% , 89.1%, 10.9%, 26.1%, 8.7%, and 19.6% respectively.In the non-ESBLs-producing E. coli strain, the positive rates of multiple drug-resistant strain, qacEA1- sull, CNF2, hlyA, eaeA , VT1, est, bfpA, elt, and CNF1 were 62.0%, 80.0%, 16.0%, 28.0%, 64.0%, 38.0%, 6.0%, 34.0%, 10.0%, and 24.0% respectively. rates of multiple drug-resistant strain, hlyA and VT1 between the ESBLs-producing E. coli strains and the non-ESBLs-producing E. coli strains were significantly (P <0.05) .CONCLUSION: The positive rate of multiple drug-resistant strain The expression of some virulence genes hlyA and VT1 varies between the ESBLs-producing strains and the non-ESBLs-producing strains. Increased awareness of clinicians and enhanced testing by laboratories are require dto reduce treatment failures and prevent the spread of multiple drug-resistant strains.