Sha Li1, Yan Qu2, Dan Hu2, Yong-Xin Shi3. 1. Department of Nursing, Qingdao University Medical College, Qingdao 266021, China. 2. ICU, Qingdao Municipal Hospital, Qingdao 266071, China. 3. Department of Clinical Laboratory, Qingdao Municipal Hospital, Qingdao 266071, China.
Abstract
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, qacEΔ1-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, qacEΔ1-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 strains, the positive rates of multiple drug-resistant strain, qacEΔ1-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 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.
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, qacEΔ1-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, qacEΔ1-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 strains, the positive rates of multiple drug-resistant strain, qacEΔ1-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 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.
Authors: S Chakraborty; J S Deokule; P Garg; S K Bhattacharya; R K Nandy; G B Nair; S Yamasaki; Y Takeda; T Ramamurthy Journal: J Clin Microbiol Date: 2001-09 Impact factor: 5.948