医院环境中肺炎克雷伯菌分子特征及高风险抗菌药物耐药基因识别OA

Objective To investigate the high-risk molecular characteristics of Klebsiella pneumoniae(KP)isolates from hospital environments,and to identify high-risk antimicrobial resistance genes(ARGs)with potential transmission risks along with their associated genetic structures.Methods A total of 20 environmental KP isolates and 112 clinical KP isolates were collected from two hospitals in Shanghai between 2023 and 2025.Whole genome sequencing(WGS),multilocus sequence typing(MLST),phylogenetic analysis,and analyses of antimicrobial resistance and virulence genes were performed.High-risk ARGs were screened based on evidence of their associations with mobile genetic elements(MGEs),and their local genetic structures were further analyzed.Results The 132 KP isolates were classified into 18 sequence types(STs),with ST11 being predominant,accounting for 53.79％(71 isolates).The environmental isolates did not form an independent phylogenetic clade,but were scattered across clades predominantly composing clinical isolates.The positivity rate of core hypervirulence-associated genes among environmental isolates was 40.00％,and the co-occurrence rate of antimicrobial resistance and hypervirulence-asso-ciated characteristics was 25.00％.Four major high-risk ARGs groups were identified:blaKPC,blaCTX-M,rmtB,and blaNDM.These ARGs showed varying degrees of association with MGEs,and blaKPC and rmtB exhibited relatively recurrent local genetic structural patterns in some environmental isolates.Conclusion KP isolates from the hospital environment exhibited certain high-risk molecular characteristics.Some high-risk ARGs were associated with MGEs,suggesting the potential for horizontal transfer and further dissemination of these resistance genes.