Detected and Analyzed AmpC Genotypes of Plasmid-mediated AmpC Beta-lactamases in Escherichia coli and Klebsiella pneumoniae / 中华医院感染学杂志

ABSTRACT

OBJECTIVE To realize AmpC genotypes of plasmid-mediated AmpC beta-lactamases in Escherichia coli and Klebsiella pneumoniae in Taizhou and Wenzhou,Zhejiang Province of China.METHODS Twenty strains of E.coli and 20 strains of K.pneumoniae which plasmid mediated AmpC beta-lactamases were detected by three methods such as three-dimensional-test of enzyme-extract,cefoxitin-triphase-test,cloxacillin-double-slips-synergia-test and detected ampC genotypes.RESULTS Five DHA genotypes,2 MIR and 2 FOX genotypes were found in 20 strains of E.coli with plasmid-mediated AmpC beta-lactamases.Seven DHA genotypes and 1 MIR genotype were found in 20 strains of K.pneumoniae with plasmid-mediated AmpC beta-lactamases.DHA and MIR genotypes were found in a strain of E.coli that ESBLs were positive but AmpC was suspicious.CONCLUSIONS The ampC genotypes of E.coli in Taizhou and Wenzhou are DHA genotypes mainly and then MIR and FOX genotypes;the ampC genotypes of K.pneumoniae in Taizhou and Wenzhou are DHA gene mainly and then MIR gene;their positive rates of DHA genes are 25%(E.coli) and 35%(K.pneumoniae),their positive rates of MIR genes are 10%(E.coli) and 5%(K.pneumoniae),and the positive rate of FOX is 10%(E.coli),no other genotypes were found.