Genotype analysis of ESBLs-producing Klebsiella pneumoniae isolates

Objective To identify the genotypes of ESBLs-producing Klebsiella pneumoniae isolates from the First Affiliated Hospital,Shantou University Medical College.Methods The MICs of 10 antibiotics were determined by agar-dilution against the clinical isolates of ESBLs-producing K.pneumoniae.PCR were performed with specific primers for blaTEM,blaSHV, blaCTX-M and blaOXA respectively.PCR products were cloned and sequenced.Results The results of PCR showed that a- mong the 83 strains of ESBLs-producing K.pneumoniae,75 were positive for blaTEM,41 positive for blaSHV,25 poitive for blaCTX-M,9 positive for hlaOXA.Three genotypes were found in 13 strains(15.7%),2 genotypes in 59 strains (71.1%) and single genotype in only 11 strains(13.2%).The genes of CTX-M-3,TEM-1 and SHV were found co-existent in 9 strains. The strains carrying 2 or 3 ESBL genes were more resistant to antibiotics than those carrying only 1 ESBL gene.Conclusions The genotypes of ESBLs-producing Klebsiella pneumoniae in this hospital are blaTEM,blaSHV,blaCTX-M and blaOXA. Most strains carry 2 or 3 ESBL genes.