The Epidemicfeatures Of ESBLs In PMQR Genes Positive Escherichia Coli And Klebsiella Pneumoniae

Objective: To investigate the drug resistance and distribution of Extended-spectrumβ-lactamases (ESBLs) producers in plasmid-mediated quinolone resistance(PMQR)-positive strains. It is also investigated the epidemiology by genotyping amongisolates.Isolates: In2008-2009,40plasmid-mediated quinolone resistance (PMQR)-positive strainswere collected from the first affiliated hospital of AnHui medical university.Methods: Antibiotic susceptibility test was performed using the agar dilutionmethod.ESBL production was determined by the Clinical and Laboratory StandardInstitute（CLSI) ESBL confirmatory test.Conjugation experiments were performed todetermine whether the PMQR and blaESBLs genes were self-transferable.Results:The data showed that, in addition to resistance quinolone,40clinicallyisolated strains containing PMQR gene showed a multidrug resistance phenotype,including resistance to penicillin (piperacillin), the first-generation cephalosporins (cefazolin), second generation cephalosporins (cefuroxime),third-generation cephalosporins cefotaxime and ceftazidime resistance. Thephenotypic tests revealed that the40clinical isolates produced ESBLs.The strains displayed high rates of resistance both to β-lactams and fluoroquinolones.The Susceptibility of donor strains and transconjugants of40isolates for Piperacillin,Piperacillin/tazobactam, Cefazolin, Cefuroxime, Cefotaxime, Ceftazidime, Cefepime,Gentamicin, Amikacin, Meropenem, Ciprofloxacin, Levofloxacin, Chloramphenicol andAztreonam are shown Table2.Conclusions: Our study shows that PMQR gene showed a multidrug resistance phenotypefrom Anhui Province, China. PMQR gene was therefore present in bothquinolone-resistant and-susceptible isolates and some of them could be transferredby conjugation experiments. Objective: This study was designed to evaluate the occurrence and genotypicdistribution of ESBL producing in plasmid-mediated quinolone resistance(PMQR)-positive strains as well as to investigate the genetic relationship of thePMQR genes and blaESBLs E. coli and K. pneumoniae clinical isolates in Anhui,China. Methods:The presence and type of ESBL in PMQR positive strains were determined bypolymerase chain reaction (PCR) and nucleotide sequencing. The epidemiologicalrelationship between positive isolates was studied by ERIC-PCR.Results: The distribution of blaESBLs in the PMQR-positive strins in this study isreported in Table3. PMQR-positive strains showed high positive rates ofblaESBLs(24/40,60%), such as CTX-M, TEM and SHV.The most frequent β-lactamase typewas cefotaximase (CTX-M,55%), which generally hydrolyzes cefotaxime more than itdoes ceftazidime; followed by sulfhydryl variable (SHV,5%). The result of ERIC-PCRand reaction of enzyme cutting showed that these electrophoretic bands were distinctfrom each other.Conclusion: A high prevalence of CTX-M type β-lactamase was detected in PMQR positiveE. coli and K. pneumoniae strains. This study also identified the co-expression ofPMQR genes and blaESBLs. The co-existence of PMQR genes with blaESBLs may lead toa serious public health problem.