Abstract：
Background: Carbapenem-resistant Klebsiella pneumoniae (CRKP), a significant worldwide public health threat, is common in patients in intensive care units. Methods: A retrospective study was conducted over a period of 22 months to assess the risk factors associated with infection caused by CRKP isolates. Strain identification was performed using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS), and antimicrobial sensitivity was assessed using the micro broth dilution method and Kirby-Bauer test. The genes blaKPC, blaOXA-48, blaNDM, blaVIM, and blaGES were amplified using polymerase chain reaction (PCR), followed by sequencing of the PCR products. The polymerase hypermucoviscosity phenotype was determined using the string test. Capsular serotypes (K1, K2) and presence of the virulence gene (rmpA) in positive isolates were investigated using phenotypic tests followed by PCR. Results: Length of hospitalization and use of carbapenems were associated with CRKP infection. CRKP isolates exhibited extensive drug resistance, but retained sensitivity to colistin and ceftazidime-avibactam (CZA). The main gene detected in 35 CRKP isolates was blaKPC-2. In addition, 11 strains were positive in the string test, and two of these strains carried rmpA. Conclusions: Prolonged hospitalization and carbapenem exposure increased the risk of CRKP infection in intensive care unit (ICU) patients. The prevalence of CRKP carrying the blaKPC-2 gene was high, and suspected hypervirulent carbapenem-resistant K. pneumoniae isolates were scattered.
摘要：
背景：耐碳青霉烯类肺炎克雷伯菌（CRKP），一个重大的全球公共卫生威胁，在重症监护病房的患者中很常见。方法：进行了22个月的回顾性研究，以评估与CRKP分离株感染相关的危险因素。使用基质辅助激光解吸/电离飞行时间质谱（MALDI-TOFMS）进行应变鉴定，抗菌敏感性采用微量肉汤稀释法和Kirby-Bauer试验进行评估。BlaKPC基因,blaOXA-48,blaNDM,BlaVIM,使用聚合酶链反应（PCR）扩增blaGES，然后对PCR产物进行测序。使用字符串测试确定聚合酶高粘膜粘度表型。使用表型测试，然后进行PCR，研究了阳性分离株中的荚膜血清型（K1，K2）和毒力基因（rmpA）的存在。结果：住院时间和碳青霉烯类抗生素的使用与CRKP感染相关。CRKP分离株表现出广泛的耐药性，但保留了对粘菌素和头孢他啶-阿维巴坦（CZA）的敏感性。在35个CRKP分离株中检测到的主要基因是blaKPC-2。此外,11株菌株在字符串试验中呈阳性，其中两个菌株携带rmpA。结论：长期住院和碳青霉烯暴露会增加重症监护病房（ICU）患者CRKP感染的风险。携带blaKPC-2基因的CRKP患病率较高,和疑似高毒力耐碳青霉烯类肺炎克雷伯菌分离株散落。
