[Molecular epidemiological characterization of hypervirulent carbapenem-resistant Klebsiella pneumoniae in a hospital in Henan Province from 2020 to 2022].

Objective: The study investigated the clinical distribution, antimicrobial resistance and epidemiologic characteristics of hypervirulent Carbapenem-resistant Klebsiella pneumoniae (hv-CRKP) in a hospital in Henan Province to provide a scientific basis for antibiotic use and nosocomial infection prevention and control. Methods: A retrospective analysis of the clinical data from the cases was carried out in this study. Clinical data of patients infected with the CRKP strain isolated from the clinical microbiology laboratory of Henan Provincial Hospital of Traditional Chinese Medicine from January 2020 to December 2022 were retrospectively analyzed. A string test, virulence gene screening, serum killing, and a G. mellonella infection model were used to screen hv-CRKP isolates. The clinical characteristics of hv-CRKP and the drug resistance rate of hv-CRKP to twenty-five antibiotics were analyzed using WHONET 5.6. Carbapenemase phenotypic characterization of the hv-CRKP was performed by colloidal gold immunochromatographic assay, and Carbapenemase genotyping, multi-locus sequence typing (MLST) and capsular serotyping of hv-CRKP isolates were performed by PCR and Sanger sequencing. Results: A total of non-duplicate 264 CRKP clinical isolates were detected in the hospital from 2020 to 2022, and 23 hv-CRKP isolates were detected, so the corresponding detection rate of hv-CRKP was 8.71% (23/264). The hv-CRKP isolates in this study were mainly from the intensive care unit (10/23) and neurosurgery department (8/23), and the main sources of hv-CRKP isolates were sputum (10/23) and bronchoalveolar lavage fluid (6/23). The hv-CRKP isolates in this study were highly resistant to β-lactam antibiotics, fluoroquinolones and aminoglycosides, and were only susceptible to colistin, tigecycline and ceftazidime/avibactam. The detection rate of the blaKPC-2 among 23 hv-CRKP isolates was 91.30% (21/23) and none of the class B and class D carbapenemases were detected. Results of MLST and capsular serotypes showed that ST11 type hv-CRKP was the dominant strain in the hospital, accounting for 56.52% (13/23), and K64 (9/13) and KL47 (4/13) were the major capsular serotypes. Conclusion: The hv-CRKP isolates from the hospital are mainly from lower respiratory tract specimens from patients admitted to the intensive care department and the drug resistance is relatively severe. The predominant strains with certain polymorphisms are mainly composed of the KPC-2-producing ST11-K64 and ST11-KL47 hv-CRKP isolates in the hospital.目的： 探讨河南省某医院高毒力耐碳青霉烯类肺炎克雷伯菌（hv-CRKP）的临床分布、耐药特征和分子流行病学特征，为临床治疗用药和院内感染防控提供科学依据。 方法： 采用临床资料回顾性研究。回顾性分析2020年1月至2022年12月河南省中医院临床微生物实验室分离的CRKP菌株相关患者的临床资料。利用挑丝试验、毒力基因检测、血清杀伤试验和大蜡螟幼虫毒力试验联合检测筛选出hv-CRKP菌株；WHONET 5.6分析hv-CRKP临床特征及25种抗菌药物耐药率；胶体金法检测hv-CRKP的碳青霉烯酶表型，多聚酶链式反应（PCR）技术和桑格测序技术检测hv-CRKP检测碳青霉烯酶耐药基因、多位点序列分型（MLST）和荚膜血清型。 结果： 2020—2022年本院共检出非重复CRKP临床分离株264株，其中hv-CRKP 23株，hv-CRKP的检出率为8.71%（23/264），主要分布在重症医学科（10/23）和神经外科（8/23），标本来源主要为痰液（10/23）和支气管肺泡灌洗液（6/23）；hv-CRKP对β-内酰胺类、氟喹诺酮类和氨基糖甙类抗菌药物高度耐药，仅对多黏菌素B、替加环素和头孢他啶/阿维巴坦保持较好的敏感性；23株hv-CRKP中KPC-2型碳青霉烯酶的检出率为91.30%（21/23），未检出B类和D类碳青霉烯酶；MLST和荚膜血清分型结果显示，本院hv-CRKP主要为ST11型，占比56.52%（13/23），荚膜血清型以K64（9/13）和KL47（4/13）为主。 结论： hv-CRKP主要来自重症科室的下呼吸道标本，耐药情况较为严重，流行株具有一定的多态性，主要为产KPC-2型碳青霉烯酶的ST11-K64型和ST11-KL47型。.