Studies on the drug-resistance genes and its epidemiology of the strains produced extended spectrum β-lactamases of Klebsiella neumonia in Pediatric Intensive Care Unit

Abstract

Objective To explore the antimicrobial resistance genotypes and molecular epidemic features of Klebsiella neumonia (K.pneumoniae) producing extended spectrum β-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, Ceftriaxone, 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) (χ2=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 respectively: 93.1% 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 presented: 14 (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. Key words: Intensive Care Unit; Extended spectrum β-lactamase; Klebsiella pneumoniae; Genotype; Child