Objective·To analyze the molecular epidemiological characteristics of Klebsiella pneumoniae isolated from children,including the distribution of serotypes,resistance genes,and virulence genes,to provide a scientific basis for the prevention and treatment strategies of Klebsiella pneumoniae infections in children.Methods·A total of 133 non-duplicate strains of Klebsiella pneumoniae clinically isolated from Shanghai Children's Hospital,Shanghai Jiao Tong University School of Medicine,from April 2023 to April 2024,were collected.Antimicrobial susceptibility testing was performed by using the Vitek-2 Compact system.Capsular polysaccharide K antigen serotypes(K types)were determined by wzy-dependent initiator(wzi)gene sequencing.Resistance genes were detected by the colloidal gold method.Virulence genes and lipopolysaccharide O antigen serotypes(O types)were identified by PCR method.Results·Among the 133 strains of Klebsiella pneumoniae,a total of 50 strains of carbapenem-resistant Klebsiella pneumoniae(CRKP)were detected,mainly distributed in the neonatal ward and intensive care unit(ICU).CRKP exhibited high resistance to most antimicrobial agents,and the main type of carbapenemase gene was blaNDM(34/50,68.00%),followed by co-carriage of blaNDM+blaOXA-48(10/50,20.00%)and blaKPC(6/50,12.00%).Serotype analysis revealed that the 50 CRKP strains could be divided into 8 K types and 6 O types.The most common K type was KL17(30/50,60.00%),followed by KL105(10/50,20.00%)and KL47(5/50,10.00%).The most common O type was O4(30/50,60.00%),followed by O3b(7/50,14.00%,),O3/O3a(6/50,12.00%),and OL101(5/50,10.00%).Significant correlations were identified between KL47 and OL101 serotypes(KL47:OL101),between KL17 and O4 serotypes(KL17:O4),and between KL1/KL2 and O1 serotypes(KL1/KL2:O1).Conclusion·The CRKP strains infecting children primarily carry blaNDM-type carbapenemase genes,showing a significant difference compared to CRKP-infected adults.The detection rate of CRKP in the neonatal ward is significantly higher than those in other departments,suggesting that infection prevention and control measures in this ward need to be strengthened.

Objective·To analyze the molecular epidemiological characteristics of Klebsiella pneumoniae isolated from children,including the distribution of serotypes,resistance genes,and virulence genes,to provide a scientific basis for the prevention and treatment strategies of Klebsiella pneumoniae infections in children.Methods·A total of 133 non-duplicate strains of Klebsiella pneumoniae clinically isolated from Shanghai Children's Hospital,Shanghai Jiao Tong University School of Medicine,from April 2023 to April 2024,were collected.Antimicrobial susceptibility testing was performed by using the Vitek-2 Compact system.Capsular polysaccharide K antigen serotypes(K types)were determined by wzy-dependent initiator(wzi)gene sequencing.Resistance genes were detected by the colloidal gold method.Virulence genes and lipopolysaccharide O antigen serotypes(O types)were identified by PCR method.Results·Among the 133 strains of Klebsiella pneumoniae,a total of 50 strains of carbapenem-resistant Klebsiella pneumoniae(CRKP)were detected,mainly distributed in the neonatal ward and intensive care unit(ICU).CRKP exhibited high resistance to most antimicrobial agents,and the main type of carbapenemase gene was blaNDM(34/50,68.00%),followed by co-carriage of blaNDM+blaOXA-48(10/50,20.00%)and blaKPC(6/50,12.00%).Serotype analysis revealed that the 50 CRKP strains could be divided into 8 K types and 6 O types.The most common K type was KL17(30/50,60.00%),followed by KL105(10/50,20.00%)and KL47(5/50,10.00%).The most common O type was O4(30/50,60.00%),followed by O3b(7/50,14.00%,),O3/O3a(6/50,12.00%),and OL101(5/50,10.00%).Significant correlations were identified between KL47 and OL101 serotypes(KL47:OL101),between KL17 and O4 serotypes(KL17:O4),and between KL1/KL2 and O1 serotypes(KL1/KL2:O1).Conclusion·The CRKP strains infecting children primarily carry blaNDM-type carbapenemase genes,showing a significant difference compared to CRKP-infected adults.The detection rate of CRKP in the neonatal ward is significantly higher than those in other departments,suggesting that infection prevention and control measures in this ward need to be strengthened.