Resistance Phenotype and Molecular Epidemiology of Carbapenem-Resistant Klebsiella pneumoniae Isolated from Nanjing Children’s Hospital in Jiangsu Province, China

OBJECTIVE: The drug resistance phenotype and molecular epidemiological characteristics of carbapenem-resistant Klebsiella pneumoniae (CRKP) were identified among children in Jiangsu Province, China. METHODS: CRKP strains were collected from the Children’s Hospital of Nanjing Medical University from December 2020 to March 2022. CRKP strains were characterized for further study: antimicrobial susceptibility testing, carbapenem resistance genes and homology analysis. RESULTS: Among 86 strains of CRKP, 85 carried carbapenemase genes; the dominant gene was bla(KPC-2) (88.2%, 75/85), followed by bla(NDM-1) (4.7%, 4/85), bla(NDM-5) (4.7%, 4/85), bla(IMP-8) (2.3%, 2/85), and bla(OXA-181) (1.2%, 1/85). Among the 86 strains of CRKP, one isolate contained both the bla(NDM-5) and bla(OXA-181) genes, which is the first time that Klebsiella pneumoniae has been shown to jointly carry these genes in China. Another CRKP strain did not carry any carbapenemase gene. MLST analysis identified a total of 10 different sequence types, among which sequence type (ST) 11 was the most common. PFGE analysis identified 75 bla(KPC-2)-producing CRKP ST11 strains, of which 68 were dominant clusters distributed among 11 different wards, mainly the neonatal medical centre (18 strains), neonatal surgery (17 strains) and cardiac care unit (CCU) (8 strains) wards. CONCLUSION: Clonal dissemination of KPC-2-producing CRKP ST11 was observed in multiple departments. Additionally, non-ST11 strains showed high polymorphism based on molecular typing, indicating increasing diversity in CRKP strains. To our knowledge, this is the first report of NDM-5 and OXA-181-coproducing Klebsiella pneumoniae causing infection in children in China, which poses a significant health risk for paediatric patients. Active surveillance and effective control measures are urgently needed to prevent further transmission of these strains among children.