Detection of AmpC and extended-spectrum beta-lactamases in Klebsiella pneumoniae isolated from children.

Objective To investigate the prevalence of AmpC beta-lactamases and extended-spectrum beta-lactamases (ESBLs) produced by Klebsiella pneumoniae isolated from children living in Guangzhou and to evaluate the extent of antibiotic resistance of the isolates. Method Antibiotic susceptibility of K.pneumoniae was determined by the Kirby-Bauer methods. AmpC beta-lactamases was detected by three-dimensional extract test. ESBLs was confirmed by dish diffusion test. Result Among the 248 isolates, the prevalence of AmpC and ESBLs producing K.pneumoniae was 18.5% and 63.3%, respectively. 18.1% of the isolates produced both AmpC and ESBL. The percentage of cephalosporins and cefepime, cefoperazone / sulbactam resistant AmpC-producing strains was 56.5%～ 100%, respectively. However, the percentage of Amikacin and ciprofloxacin resistant strains was lower than 30%. The resistant rate of ESBLs producers to cephalosporins, cefoperazone / sulbactam was in the ranged of 50% to 91.7% , to Amikacin and ciprofloxacin was 11.5% and 10.3% , respectively. Imipenem-resistant strain was not detected. The antibiotics sensitivity of ESBLs negative isolates was in the range of 81.2% to 100%. Conclusion The incidence of AmpC and ESBLs-producing K.pneumoniae isolated from children was relatively high in Guangzhou. The beta-lactamases producing strains were highly resistant to the commonly used antibiotics. Carbopenems may be used in the treatment of infections caused by AmpC and / or ESBLs-producing K.pneumoniae.