Studies on the drug-resistance genes and its epidemiology of the strains produced extended spectrum β-lactamases of Klebsiella pneumoniae in Pediatric Intensive Care Unit / 中华实用儿科临床杂志

ABSTRACT

Obgective To explore the antimicrobial resistance genotypes and molecular epidemic features of Klebsiella pneumoniae (K.pneumoniae) producing extended spectrum 3-lactamases (ESBLs) in the Pediatric Intensive Care Unit (PICU) of Guiyang Children' s Hospital.Methods Disc diffusion technique (Kirby-Bauer method) and automatic microbiology analysis system were employed to determine the antimicrobial resistance,and Double-disk Diffusion was adopted in the phenotype confirmatory test of ESBLs,and PCR was used to determine the antimicrobial resistance genotypes.Results Among 44 straits of non-repetitive-K.pneumoniae,isolated from the children during hospitalization since April to December of 2013,29 straits (65.9％) were detected.The findings of sensitivity tests showed that 29 strains of ESBLs-producing K.pneumoniae presented a higher rate of sensitivity to carbapenems,cephamycin and quinolones,100％ resistance to penicillin and cephalosporins of the first and the second generations.Fifteen non-ESBLs-producing K.pneumoniae presented 100％ resistance to penicillin.The rate of resistance to 9 kinds of antibiotics (Ampicillin/Sulbactam,Cefazolin,Cefuroxime,Cefamandole,Cefiriaxone,Ceftazidime,Cefepime,Gentamicin,Aztreonam) in ESBLs-producing K.pneumoniae strains(79.3％,100.0％,100.0％,100.0％,100.0％,79.3％,65.5％,41.4％,79.3％) was significantly higher than that of non-ESBLs-producing K.pneumoniae trains (13.3％,6.7％,20.0％,20.0％,0,0,0,6.7％,0) (x2 =17.54,35.51,28.00,28.00,44.00,24.93,17.30,4.18,24.93,all P ＜ 0.05).In 29 strains of ESBLs-producing K.pneumoniae,3 genotypes were detected respectively93.1％ of SHV (27/29 strains),51.7 ％ of TEM (15/29 strains) and 37.9 ％ of CTX-M (11/29 strains).Five forms of genotype distribution were presented14 (43.8％) strains carrying single ESBLs gene,5 (17.2％) strains carrying 2 types,19 (31.0％) strains carrying 3 types,and 1 strain had not been genotyped.Conclusions ESBLs-producing K.pneumoniae had been epidemic in PICU of Guiyang Children's Hospital,with multiple antimicrobial resistances and diversification of antimicrobial resistance genotypes.