The Detection Of Drug-resistance And Resistance Gene Of E.coli

Objective:1.to investigate the drug-resistance produced by Escherichia coli(E. coli) from our hospital and the difference of drug-resistance between extended-spectrumβ-lactamases(ESBLs) positive and extended-spectrumβ-lactamases(ESBLs) negative groups. 2. to investigate the genotypes distribution of ESBLs produced by E. coli. 3. to investigate the drug-resistance rate and drug-resistance gene in E. coli of aminoglycosides and quinolones. 4. to investigate the disinfectant-resistance gene(qacE△1-sul1) in E. coli and the difference between the two groups.Method:1. 27 strains of ESBLs positive and 27 strains of ESBLs negative E. coli from YanTaiYuHuangDing Hospital from September 2005 to June 2006 were collected(54 strains nonrepetitive E. coli in total). 2.K-B test was used to detect drug-resistance of E. coli to 22 antibiotics, the resistant rate(R%),intermediate rate(I%) and sensitive rate(S%) were calculated according to the criteria in guidelines of CLSI/NCCLS(2005). 3. PCR was used to amplify ESBLs gene,aminoglycosides- resistance gene,quinolones- resistance gene and qacE△1-sul1 gene to indentify their genotypes.Results: 1.the susceptibility of ESBLs positive E. coli to Ceftazidime and Cefotaxime were 66.7%(18/27) and 3.7%(1/27) respectively. 2.the relativity between the two groups to aminoglycosides and nitrofurantoin resistance,P<0.05,and to the others,P>0.05. 3.among 27 strains of ESBLs positive E. coli,CTX-M-1 were amplified from 9 isolates, ,SHV were amplified from 5 isolates ,TEM were amplified from 16 isolates, and OXA were amplified from 8 isolates..More than two types of ESBLs gene were produced by ten of them.PER,VEB,GES,CARB were not found among 27 strains. 4. 44 strains were resistant to aminoglycosides of 54, drug-resistancerate 81.5 %. 4 strains of aac(3)-Ⅰ, 38 of aac(3)-Ⅱ, 17 of aac(6′)-Ⅰ, 11 of aac(6′)-Ⅱ, 8 of ant(2″)-Ⅰ, 12 of ant(3″)-Ⅰ. 5. 41 strains were resistant to quinolones of 54, drug-resistance rate 75.9%(41/54),the detection rate of qnr gene was 7.3%(3/41).6. ,the detection rate of qacE△1-sul1 was 70.4%(38/54). 7. 20 strains carried qacE△1-sul1 gene in ESBLs positive group, and 18 in ESBLs negative group.Conclusion:1. ESBLs hydrolyzed Cefotaxime better than Ceftazidime. 2.the drug- resistance of ESBLs positive group was higher than ESBLs negative group.,except aminoglycosides and nitrofurantoin. 3.TEM is the most common genotype in ESBLs. 4. aac(3)-Ⅱand aac(6′)-Ⅰwere the most capital genotypes in aminoglycosides. 5.the drug-resistance rate of quinolones was high. 6. qacE△1-sul1 gene was high detected. 7.there was no relationship between whether the E.coli carried qacE△1-sul1 or not and whether it produced ESBLs or not.