Drug resistance genes and homology of Klebsiella pneumoniae in the pediatric intensive care unit of Guiyang area

Abstract

Objective To investigate the genetic characteristics of drug resistance and homology of extended-spectrum β-lactamase (ESBLs)-producing Klebsiella pneumoniae (Kpn) in hospitalized children in the pediatric intensive care unit (PICU) in Guiyang area. Methods The Kpn strains were collected from hospitalized children at 3 PICU from the Affiliated Hospital of Guizhou Medical University, Guizhou Provincial People′s Hospital and Guiyang Children′s Hospital from September 2014 to December 2016.Automatic bacteria identification instrument and Kirby-Bauer method were used to identify Kpn strains and confirm ESBLs phenotype respectively.The drug resistance genes were detected by using polymerase chain reaction (PCR), and their homology was analyzed by means of pulsed field gel electrophoresis (PFGE) and cluster analysis. Results (1) A total of 207 non-repetitive Kpn strains were isolated, of which 128 strains produced ESBLs (61.8%). There was no significant difference in the ESBLs detection rates among the different hospitals, years and types of samples(χ2=0.40, 5.19, 4.68, all P>0.05). (2) Among those 128 ESBLs-producing Kpn strains, 123 strains (96.1%) were found to have drug-resistant genes, of which the detection rate of SHV type was the highest, accounting for 87.5%.These 3 drug resistance genotypes were distributed in 7 modes, of which 85.2% were carrying more than 2 genotypes.(3) PFGE genotypic assay showed that there were 109 genotypes and 5 dominant clones.The PICU at 3 hospitals were all prevalent with type A strain, accounting for 14.8%.In 2015, there was a short-term outbreak of type A strain in Guiyang Children′s Hospital.While, the resistance phenotypes of Kpn and the genotype of PFGE could both be consistent or different. Conclusions The ESBLs-producing Kpn at PICU in Guiyang area has the characteristics of multi-drug resistance, its drug-resistant genotypes have diversified, and there is a small-scale short-term outbreak epidemic, which poses a serious threat to clinical anti-infection treatment.It is necessary to strengthen clinical drug resistance monitoring and adopt effective infection control measures to prevent and control the spread of nosocomial infections. Key words: Pediatric intensive care unit; Klebsiella pneumoniae; Extended-spectrum β-lactamase; Homogeneity; Pulsed field gel electrophoresis