Study On Resistance And SHV-type Beta-lactamases In Escherichia Coli Isolates

PartⅠExtended-spectrumβ-lactamases producers and resistance in Escherichia coli isolates from Anhui province hospitalsBackground:Soon after introducing the clinical use of extended-spectrum cephalosporins,such as cefetaxime,ceftriaxone,aztreonam and ceftazidime, SHV-2-type-extended-spectrumβ-lactamases(ESBLs) were firstly isolated from Enterobacteriaceae in Germany in 1983.Then,reports about new ESBLs spread around the world.Extended spectrum beta-lactamases were plasmid-mediated,which made bacteria resistance to many beta-lactams.ESBLs were produced by Gram-negative bacteria,and the resistance of ESBLs-producing strains has currently become one of the most important nosocomial resistance problems in hospitals around the world.ESBLs have spread around the world from they were reported.The partly reason is the fact that we lack dependable test method.After third generation cephalosporin treatment failed,the people began to be aware of ESBLs existence.In order to control its epidemic,early detection of ESBLs is very important,and genetype diversity everywhere lead to distinction of resistance and detecting substrates.We studied on the drug-resistance of ESBLs-producing E.coli isolates in the part of Anhui Province,So that we could prevent regional prevalence of ESBLs producers and guide clinical therapy in order to avoid delaying therapy and wasting drugs.In view of lacking wide-ranging investigation about the prevalence of ESBLs in Anhui,we studied the resistance and resistant genotypes of ESBLs-producing E.coli isolates in the part hospital of Anhui Province.Objective:To study ESBLs-producers and resistance in E.coli isolates from in the part hospital of Anhui Province.Methods:361 clinical isolates of E.coli were collected from different hospitals in Anhui Province.Their resistance to antimicrobial agents was also tested by agar dilution method and ESBLs producers were screened by CLSI phenotype confirmatory test.Results:The incidence of ESBLs producers in E.coli were 33.8%and they were resistant to most antimicrobial agents.Compared with the resistance rates of non-ESBLs producing strains,ESBLs producers were more resistant to cefotaxime,ampicillin, cefuroxime,cephazolin,levofloxacin and ciprofloxacin.Conclusions:The incidence of ESBLs producers was high in E.coli isolates in Anhui Province hospitals.ESBLs producers were multi-resistance and we should enhance to detect and survey those isolates.PartⅡStudy on SHV-type beta-lactamase in Escherichia coli isolatesBackground:Since plasmid mediated ESBLs was first reported in1983 by German, many new ESBLs types have been detected around the world.By now,there have been many types of ESBL,including TEM,SHV,CTX-M,OXA and undefined ESBLs.SHVβ-lactmase was mainly produced by E.coli.The spreading type of it was different in countries and areas.Infection caused by ESBL producers increased year by year,and has been reported to cause epidemic outbreak in some hospitals.Resistance of ESBLs was the most important problem of hospital-acquired drug resistance in the world.SHV ESBLs have been reported all around the world,including Europe,South America,Middle East and Far East,as well as China.Owning to different favorite drug and drug selection stress,the spreading type of SHV ESBLs was then different in countries and areas.So,understanding the best detection substrate,drug resistance profile and type distribution of ESBL producing strains can help us preventing regional spreading of ESBL and guiding clinical therapy.Because cefotaxime was widely used in our country,so it caused the spreading of SHV ESBLs.To understand the genotype distribution of SHV ESBLs and drug resistance profile in Anhui province,we perform a series of molecular biology study on E.coli isolates collected from in the part hospitals of Anhui province.Objective:To study the SHV beta-lactamases genotype and molecular epidemiology in E.coli isolates.Method:The SHV beta-lactamases genotype of 122 strains produing E.coli was determined by PCR and sequenceing.Molecular typing was analyzed by ERIC-PCR.Results:4 isolates produced SHV beta-lactamases and molecular typing was different in those isolates.3 isolates carried SHV-1 and 1 carried SHV-5(ESBLs).Conclusion:The SHV-1-type genes of ESBLs are predominate.At the same time SHV-5 have spreaded.