Analysis Of The Resistance And Molecular Biology Property Of CTX-M-Type ESBLs-Producing Strains Isolated From Several Hospitals In Hefei

ObjectiveTo study the resistance of the CTX-M-producing Escherichia coli and Klebsiella pneumoniae strains against 14 antibiotics, and offer the resistance data to clinical therapy.To investigate the genotypes and epidemiology of CTX-M enzyme carrier, Escherichia coli and Klebsiella pneumoniae isolates, in several hospitals of Hefei.To study the biochemical properties of the 6 novel CTX-M enzymes and the resistance of the novel enzyme producing strains. Materials and Methods IsolatesTotally 98 strains of ESBLs-producing Escherichia coli and Klebsiella pneumoniae were collected between 1999 and 2000 from four hospitals in Hefei. MethodAdopting PCR methods, universal primers of bla_CTX-M were used for CTX-M⁺ isolates screening; matting method was used between CTX-M⁺ isolates and E.coli C600 to transfer resistance plasmid; agar dilution method was used to determine MICs of 14 antibiotics against wild-type isolates and the transconjugants.According to the universal primers PCR results, two pairs of entire coding gene primers were designed, and to convenient the consequence experiments, endonucleotide cleavage site of EcoRI and BamHI were added at 5' terminal of the upstream and downstream of the two groups of primers.The sequence was determined by direct sequencing of PCR products, carried out by the dideoxy chain termination procedure of Sanger on an ABI377 automatic sequencer (Invotrigen Biocompany, Shanghai, China). Then blastn program was used to ascertain the genotype at Genbank.After digestion by EcoRI and BamHI, the whole ORF amplicon was linked into the vector pHSG398 by T₄DNA lingase. And then, the recombinant plasmid was introduced into the...