Surveillance on Drug Resistance Genes Associated with Extended-spectrum Beta-lactamases in Escherichia coli and Klebsiella neumoniae

Objective To investigate the distribution of resistance genes associated with ESBLs in Escherichia coli and Klebsiella pneumoniae. Methods Polymerase chain reaction(PCR) was used to detect three kinds of β-lactamase genes(TEM,SHV,and CTX-M) in 77 ESBLs producing strains,including Escherichia coli and Klebsiella pneumoniae.The PCR products were sequenced by DNA sequencer. Results Among 50 strains producing ESBLs in Escherichia coli,there were 41 strains positive for the TEM gene positive for the(82.0%),7 strains positive for the SHV gene(14.0%),and 16 strains positive for the CTX-M gene(32.0%).Two or more genotypes were simultaneously isolated from 21 strains.Among 27 strains producing ESBLs in Klebsiella pneumoniae, TEM gene was positive in 21 strains(77.8%),SHV gene was positive in 24 strains(88.9%),and CTX-M gene was positive in 3 strains(11.1%).Two or more genotypes were simultaneously isolated from 16 strains. Conclusions ESBLs producing strains in Escherichia coli and Klebsiella pneumoniae have carried out various kinds of beta-lactamase resistance genes,however,TEM and SHV genotypes are prevalent.