A comparative study of genotyping and antimicrobial resistance between carbapenem-resistant and isolates at a tertiary pediatric hospital in China.

Background: Carbapenem-resistant (CRKP) clinical isolations have rapidly increased in pediatric patients. To investigate a possible health care-associated infections of CRKP in a tertiary pediatric hospital, the circulating clones and carbapenem-resistant pattern between CRKP and carbapenem-resistant (CRAB) isolates were compared to classify their epidemiological characteristics. The results will help to identify the epidemic pattern of the CRKP transmission in the hospital.

Methods: Ninety-six CRKP and forty-eight CRAB isolates were collected in Kunming Children's Hospital from 2019 through 2022. These isolates were genotyped using repetitive extragenic palindromic-PCR (REP-PCR). Carbapenemase phenotypic and genetic characterization were investigated using a disk diffusion test and singleplex PCR, respectively. In addition, these characteristics of the two pathogens were compared.

Results: The rates of CRKP and CRAB ranged from 15.8% to 37.0% at the hospital. Forty-nine and sixteen REP genotypes were identified among the 96 and 48 CRKP and CRAB isolates tested, respectively. The CRKP isolates showed more genetic diversity than the CRAB isolates. Of the 96 CRKP isolates, 69 (72%) produced Class B carbapenemases. However, all 48 CRAB isolates produced Class D carbapenemase or extended-spectrum β-lactamases (ESBL) combined with the downregulation of membrane pore proteins. Furthermore, the carbapenemase genes , , and were detected in CRKP isolates. However, CRAB isolates were all positive for the , , and genes.

Conclusions: These CRKP isolates exhibited different biological and genetic characteristics with dynamic changes, suggesting widespread communities. Continuous epidemiological surveillance and multicenter research should be carried out to strengthen the prevention and control of infections.