Genotypes of β-lactamase in ESBLs-producing Klebsiella pneumoniae

Objective To understand the genotypes of ESBLs and AmpC β-lactamases in ESBLs-producing Klebsiella pneumoniae isolates from Shenzhen People's Hospital.Methods 64 ESBLs-producing Klebsiella pneumoniae strains were selected from clinical isolates of Shenzhen People's Hospital.TEM,SHV and CTX-M genes in these isolates were respectively amplified by PCR and multiple PCR was used for AmpC gene.DNA sequencing was performed for the genotyping of these genes.Results Of 64 ESBLs-producing strains,61(95.3%) were found carrying at least one of ESBLs genes.51.6%(33/64) and 46.9%(30/64) was detected carring SHV-12 and CTX-M-14 gene,respectively.11(17.2%) strains showed the existence of AmpC genes,including 10 with CYM-2 and one with DHA1.And moreover,19(29.7%) strains produced at least two type of ESBLs or both ESBLs and AmpC.Conclusion For ESBLs-producing Klebsiella pneumoniae isolates in this hospital,the common genotypes of ESBLs were SHV-12 and CTX-M-14;and DHA-1 was the main type of AmpC.It was often that a single Strain produced more than one ESBLs or AmpC enzyme.