genomic insights into molecular characteristics and phylogenetic linkage between the cases of carbapenem-resistant klebsiella pneumoniae from a non-tertiary hospital in china: a cohort study

Background: carbapenem-resistant klebsiella pneumoniae (crkp) strains have been listed as one of the major clinical concerns. objectives: we investigated cpkp isolates from non-tertiary hospitals to find disseminated clones and analyze extensive phenotypic and genetic diversity in this study. methods: in this cohort study, a total of 49 crkp isolates from 3 hospitals in the same region were collected in 2021. the prevalence and antimicrobial susceptibility patterns were analyzed. clinical data were retrieved from electronic medical record systems. the molecular types, antimicrobial resistance (amr) profiles, plasmid replicons, and virulence factors were analyzed. the maximumlikelihood phylogenetic tree and transmission networks were constructed using single-nucleotide polymorphisms (snps). results: the median age of patients (n = 49) was 66.0 years, and 85.7% were male. the mostcommoncrkp infection was nosocomial pneumonia (75.5%), followed by bacteremia (10.2%). more than 53% of isolates were resistant to ceftazidime-avibactam (caz/avi). forty-five isolates were successfully sequenced; the predominant carbapenem-resistant gene was blakpc-2 (93.3%). the 30-day mortality in our cohort was 24.5%. the most dominant sequence type (st) was st11 (60.0%), followed by st15 (13.3%). whole genome sequencing (wgs) analysis exhibited dissemination of st11 strain clones, st420, and st15 clones, both within and outside the given hospital. conclusions: in this surveillance study, several dissemination chains of crkp were discovered in the hospital and the region, as st11 was the main epidemic clone. our findings suggest that effective infection control practices and antimicrobial stewardship are needed in non-tertiary hospitals in china.