Drug resistance and genotype of Klebsiella pneumonia in children with respiratory tract infection

Objective To investigate the resistance and resistant genotype distribution of Klebsiella pneumoniae producing ultra-β-lactamases(ESBLs and AmpC enzymes) in children with respiratory tract infections in Linhai.Method VITEK-60 Automatic bacterial identification instrument was used to identify the ESBLs bacteria according to the CLSI-recommended confirmatory test detected,and K-B disk method was used to determine the susceptibility;Cefoxitin disk diffusion method was used to screen AmpC-producing strains,and PCR was used to detect AmpC enzyme gene;the products were sequenced for genotypes.Result Of the 113 strains of Klebsiella pneumonia,the total detection rates of ESBLs and AmpC were 29.20% and 18.58% respectively,in which the rates of ESBLs,AmpC enzymes and AmpC enzyme+ESBLs were 23.01%,12.39% and 6.19%,respectively.The resistant genotypes of AmpC-positive strains were DHA-1(16 strains) and ACT-1(5 strains).All the Klebsiella pneumoniae isolated were sensitive to imipenem;The resistance was very low to quinolones,while higher to most β-lactam antibiotics,and the enzyme-producing strains were significantly more resistant than non-enzyme producing strains.The drug resistance of the strains producing both ESBLs and AmpC was the highest.Conclusion The detection rate of ESBLs and/or AmpC enzyme producing Klebsiella pneumonia isolated from pediatric respiratory,tracts was high in Linhai region.DHA-1 was the main genotype among AmpC enzyme,and the enzyme producing strains showed a high degree of multi-drug resistance.