Resistance mechanism and molecular epidemiological characteristics of carbapenem-resistant Klebsiella pneumoniae analyzed based on whole-genome sequencing / 中华微生物学和免疫学杂志

ABSTRACT

Objective:To elucidate the drug resistance characteristics and molecular epidemiological features of carbapenem-resistant Klebsiella pneumoniae (CRKP) in this region, and to provide a basis for clinical anti-infective therapy. Methods:A total of 92 CRKP isolates were collected from the First Affiliated Hospital of Ningbo University and Ningbo No.2 Hospital. Antimicrobial susceptibility testing was performed using the VITEK2 Compact analyzer. Whole-genome sequencing was used to analyze their molecular characteristics including capsular serotypes, sequence types (multilocus sequencing typing) and resistance genes. Plasmid replicon types were identified using PlasmidFinder, and core genome phylogenetic analysis was performed with Parsnp.Results:The CRKP isolates were mainly isolated from critically ill elderly patients, with sputum (51.09%, 47/92) and urine (13.04%, 12/92) as the major specimen sources, followed by blood (8.70%, 8/92). Most of the infections were reported in the intensive care unit (33.70%, 31/92). All isolates showed high resistance to commonly used antibiotics, but lower resistance to polymyxin B (6.52%, 6/92). The predominant resistance gene, capsule serotype and ST were blaKPC-2 (78.26%, 72/92), KL64 (48.91%, 45/92), and ST11 (54.35%, 50/92), respectively. ST11-KL64 was the predominant clone, accounting for 46.74%(43/92) and carried multiple plasmids with IncR and IncFⅡ as the major types. Conclusions:CRKP in this region mainly harbored the blaKPC-2 resistance gene and showed high resistance to commonly used antibiotics. The ST11-KL64 clone spread widely in this region and the strains circulating in the two hospitals were similar. Thus, the surveillance should be strengthened.