Genotype Distribution Of OXA-type Extended-spectrum β-lactmases In Clinical Isolates Of Klebsiella Pneumoniae And Escherichia Coli In Hefei

OBJECTIVE To study the drug resistance of Klebsiella pneumoniae (K. pneumoniae ) and Escherichia coli(E. coli) and the genotype distribution of OXA-type ESBLs gene in extended-spectrum P-lactamases(ESBLs)-producing K. pneumoniae and E. coli clinical isolates in Hefei.METHODS 299 strains of K. pneumoniae and E. coli conserved by Anhui Center for Surveillance of Antimicrobial Resistance, were collected from 4 general hospitals, such as the First Affiliated Hospital of Anhui Medical University, Anhui Provincial Hospital, the First People's Hospital of Hefei and the 105 Hospital of PLA, in Hefei, from September 1999 to September 2000. These strains were all reidentificated by automatic microorganism analysator. The drug resistance of 98 strains of ESBLs-producing K. pneumoniae and E.coli were tested by agar plate dilution method with 14 antibiotics. The OXA-type ESBLs genes were amplified by polymerase chain reaction (PCR), then sequenced by Sanger's dideoxy chain termination composition method. RESULTS The detection rates of ESBLs are 50.5% and 24.3% in K.pneumoniae and E.coli respectively. The total detection rate of ESBLs is 32.8%. Results of resistance test indicated that ESBLs-producing strains showed high resistance to 13 kinds of antibiotics except for Imipenem.The electrophoresis of PCR products of 98 ESBLs-producing K. pneumoniae and E.coli isolates indicated that 15 strains were consistent with OXA-1 type ESBLs gene, 1 sample was consistent with OXA-2 gene, and 3 samples were consistent with OXA-10 gene. We sequenced one strain of each...