Study of the Epidemiological and Mechanistic Differences Between Carbapenem-Resistant Klebsiella pneumoniae Infections in Children and Adults

Background: The emergence of carbapenem-resistant Klebsiella pneumoniae (CRKP) has garnered international concern due to its significant antibiotic resistance. Notably, children exhibit distinct resistance mechanisms compared to adults, necessitating a differential approach to antibiotic selection. A thorough analysis of CRKP's epidemiology and drug resistance mechanisms is essential for establishing a robust foundation for clinical anti -infection strategies and precise prevention and control measures. Methods: This study involved the collection of 31 non-repetitive strains from pediatric and adult patients at a tertiary hospital in China, spanning from July 2016 to July 2022, testing for resistance genes, antimicrobial susceptibility, and homology analysis. Results: Infants (0-1 year) were the largest pediatric CRKP group, with 61.3% of cases. The neonatal intensive care unit (NICU) and pediatrics were the main departments affected. Adults with CRKP had a mean age of 67 years, with the highest prevalence in neurology and emergency ICU. Antimicrobial susceptibility testing revealed that adult CRKP strains exhibited higher resistance to amikacin, ciprofloxacin, cotrimoxazole, and aztreonam compared to pediatric strains. Conversely, pediatric strains showed a higher rate of resistance to ceftazidime/avibactam. The predominant resistance genes identified were blaNDM-5 in children (58.1%) and blaKPC-2 in adults (87.1%), with over 93% of both groups testing positive for extended-spectrum beta-lactamase (ESBL) genes. Multilocus Sequence Typing (MLST) indicated ST2735 and ST11 as the predominant types in children and adults, respectively. Pulsed-field gel electrophoresis (PFGE) identified clonal transmission patterns of ST11 blaKPC-2 and ST15 blaOXA-232 across both age groups. Notably, this study reports the first instance of ST1114-type CRKP co-producing blaNDM-5 and blaOXA-181 in the NICU. Conclusion: This study reveals distinct resistance mechanisms and epidemiology in CRKP from children and adults. The identified clonal transmission patterns emphasize the need for improved infection control to prevent the spread of resistant strains.