Shift in the dominant sequence type of carbapenem-resistant Klebsiella pneumonia infection from ST278-NDM-1 to ST11-KPC-2 in neonatal patients in a children’s hospital in Shanghai, China, 2017–2021

Objectives To investigate the clinical characteristics and molecular epidemiology of CRKP infection in neonatal patients in a children’s hospital in China from 2017 to 2021. Methods Species identification and antibiotic susceptibilities were tested with matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) and VITEK 2 systems. The clinical data were collected from medical records. Carbapenem-resistant Klebsiella pneumoniae (CRKP) isolates were investigated by antimicrobial susceptibility testing, carbapenemase genes and multilocus sequence typing. Results Six kinds of resistant genes and 23 STs were detected. Bla NDM-1 ( n =83, 55.3%) was the predominant carbapenemase gene, followed by bla KPC-2 ( n =45, 30.0%), bla NDM-5 ( n =7, 4.7%), bla IMP-38 ( n =6, 4.0%). Bla NDM-1 was predominant in 2017 and 2018, whereas bla KPC-2 increased in 2019 and became the predominant gene from 2020 to 2021. ST11 accounted for most infections ( n =35, 23.3%), followed by ST278 ( n =23, 15.3%), ST17 ( n =17, 11. 3%) and ST2735 ( n =16, 10.7%). ST278 and ST17 were predominant in 2017 and 2018, whereas ST11 increased in 2019 and became the predominant sequence type from 2020 to 2021. Compared with bla NDM-1 , the CRKP strains producing bla KPC-2 were characterized by high resistance to gentamicin, amikacin and levofloxacin and the change trend of drug resistance rate before and after COVID-19 was consistent with that of bla NDM-1 and bla KPC-2 . Conclusions The main sequence type of CRKP infection changed dynamically from ST278-NDM-1 to ST11-KPC-2 during the years 2017–2021 in the newborns. Antibiotic exposure and the prevalence of COVID-19 since 2020 may have led to changes in hospital population and lead to the changes.