Comparison of extended spectrum β-lactamases-producing Escherichia coli with non-ESBLs-producing E.coli: drug-resistance and virulence / 世界急诊医学杂志（英文）

ABSTRACT

@#BACKGROUND: The virulent factors ofEscherichia 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)-producingE.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 ofE.coli isolated were colected 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, qacE&Delta;1-sull and 8 virulence genes (CNF2, hlyA, eaeA, VT1, est, bfpA, elt, and CNF1) were tested by polymerase chain reaction (PCR). RESULTS: Among the 96E.coli isolates, the ESBLs-producingE.coli comprised 46 (47.9％) strains and the non-ESBLs-producingE.coli consisted of 50 (52.1％) strains. The detection rates of multiple drug-resistant strain, qacE&Delta;1-sull, CNF2, hlyA, eaeA,VT1, est, bfpA, elt, and CNF1 in 46 ESBLs-producingE.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-producingE.coli strains, the positive rates of multiple drug-resistant strain, qacE&Delta;1-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-producingE.coli strains and the non-ESBLs-producingE.coli strains was statistically significant (P<0.05). CONCLUSION: The positive rate of multiple drug-resistant strains is higher in the ESBLs-producing 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.