调查1例免疫缺陷患者出现耐碳青霉烯类肺炎克雷伯菌肺部感染的原因，探讨其发病机制并评价治疗措施。

该患者为中年男性、58岁，肝移植术后，为免疫功能缺陷宿主（ICH），出现快速进展性碳青霉烯类耐药肺炎克雷伯菌（CRKP）肺部感染。以患者诊疗过程为主线，结合宿主危险因素、时间及空间交叉医疗环境分析及发病机制探索，通过院感诊断分析思路判断病原菌来源，二代基因测序检测耐药基因，行抗菌药物精准治疗。

以追溯影像学初始病灶为突破点，判断该患者为术后CRKP院内感染。对本次住院病区前后1个月肺炎克雷伯菌（KP）检出患者进行汇总，筛选出5例患者（4例来自痰液，1例来自尿液）。筛选10例高危病例进行肛拭子筛查，1例CRKP阳性，考虑定植。采集50份环境卫生标本，1份RICU床栏表面标本检出CRKP，综合分析排除外源性感染因素，判断为医院CRKP内源性感染。耐药基因含产KPC酶，无金属酶，应用头孢他啶/阿维巴坦等药物，加强院感防控管理，取得良好疗效。

ICH出现院内耐药菌感染的风险较高，预后较差，应将院感分析思维带入临床诊疗工作中，对ICH医院获得性肺炎（HAP）行精准治疗，防范CRKP的水平或垂直播散。

To investigate the cause of carbapenem-resistant Klebsiella pneumonia (KP) infection in a patient with immunodeficiency, and explore its pathogenesis and evaluate the efficacy.

The patient was a middle-aged man, 58 years old, who was an immunodeficiency host (ICH) after liver transplantation, and developed a rapidly progressive carbapenem-resistant Klebsiella pneumonia (CRKP) lung infection. Taking the diagnosis and treatment process as the main line, host risk factors, time and space cross medical environment analysis and pathogenesis analysis, the source of pathogens were enrolled to distinguish the infection origin. The second-generation gene sequencing was applied to detect drug-resistant genes in order to conduct precise antibiotic treatment.

To trace the initial lesion of imaging as a breakthrough point, the patient was diagnosed as postoperative CRKP nosocomial infection. Five patients (4 strains from sputum and 1 strain from urine) with KP were screened out. Ten high-risk cases were screened for anal swab, and one case was positive for CRKP and considered to be colonized bacteria. Total of 50 samples of environmental hygiene were collected, and one CRKP sample was detected in bed bar surface in RICU. This patient was judged as endogenous infection of hospital CRKP. The drug-resistant genes contained KPC enzymes and metalloenzymes was not detected. Zavicefta was selected to control CRKP infection and various prevention measures were carried out and achieved good clinical effects.

ICHs have a high risk of nosocomial infection of drug-resistant bacteria and poor prognosis. The nosocomial analysis should be brought into clinical practice, and accurate treatment of ICH hospital-acquired pneumonia should be performed to prevent horizontal or vertical spread of CRKP.