Detection and Analysis of Bacteria Producing Extended Spectrum β-Lactamases in Children with Lower Respiratory Tract Infection

Objective To understand the status and drug resistant patterns of strains of extended spectrum β-lactamase(ESBLs) in children with lower respiratory tract infection,and to give clinical suggestions for rational treatment.Methods Escherichia coli and klebsiella pneumoniae were isolated from the 2 969 nasopharyngeal secretions which collected from lower respiratory tract of children in our hospital from Jan.2006 to Dec. 2007.Dual-sheets and sheets-diffusing method (K-B method) were used to determine the ESBLs and antibiotic susceptibility was tested by K-B method which included 18 kinds of antibiotics,the results were marked by resistant,intermedial and sensitive.Chi-square test was used to analyze the data.Results Total 135 strains were detected,73 strains were escherichia coli,of which 54 strains(74.0%)produced ESBLs,62 strains were klebsiella pneumoniae,of which 33 strains(53.2%)produced ESBLs.The 2 bacterias were found more in children with 1-6 months old than those in other age groups,the ratio of which were 50 strains and 41 strains,respectively (Pa0.05).There were no statistical differences of the ratio of 2 ESBLs-producing strains between 2 years,neither among each age groups (Pa0.05).The resistant rate of ESBLs-producing strains to penicillins,cephalosporins,quinolones,aminoglycosides and sulfamido was higher than that of non ESBLs-producing strains respectively.And the resistant rates to beta-lactam antibiotics of ESBLs strains were located on a high level.Whether producing ESBLs or not,the 2 bacterias were still sensitive to amikacin,cefoxitin,cefoperazone/sulbactam and imipenem.Conclusions The prevalences of ESBLs-producing escherichia and klebsiella pneumonia were high.There was a multi-drug resistance to the varied antibiotics.It is very important to make sputum culture and use sensitive antibiotics in treatment according to drug sensitivity test to control the occurrence and conveying of the ESBLs.