目的  调查成都市龙泉驿区第一人民医院维持性血液透析患者反复发生蜡样芽孢杆菌血流感染的原因，探讨分离株的生物膜形成能力和预防院内感染的重要性。 方法 收集蜡样芽孢杆菌临床菌株(11株)及环境菌株(4株)共15株，完成细菌鉴定、药敏、生物膜形成实验，按照不同抗生素使用节点，选取3个临床菌株、3个环境菌株进行细菌的系统发育分析和生物膜基因检测。 结果 15个菌株全部经质谱鉴定为蜡样芽孢杆菌。药敏试验显示所有的临床菌株(11/11，100%)对左氧氟沙星、美罗培南、红霉素、利福平、四环素、万古霉素敏感，对青霉素耐药；对复方新诺明表现为耐药的菌株占63.6%(7/11)，对克林霉素表现为中介的菌株占72.7%(8/11)。3个临床菌株与血液净化室工作人员手表面分离株在进化上的亲缘关系较近，携带calY、cdgD、cdgF、sinl、sinR、spoOA、tasA共7个生物膜形成相关基因。从患者血培养中分离到的11个菌株中，9株(81.8%)均为生物膜形成阳性菌株，在应用莫西沙星、万古霉素治疗时出现短暂的生物膜形成能力抑制状态。 结论 蜡样芽孢杆菌会导致血液透析患者发生导管相关血流感染，生物膜的形成使感染难以清除，临床上应重视手卫生，避免院内感染的发生。

Objective To investigate the causes of recurrent bloodstream infections by Bacillus cereus in maintenance hemodialysis patients in the First People's Hospital of Longquanyi District Chengdu, and to explore the biofilm-forming ability of the isolates and the importance of preventing nosocomial infection.  Methods A total of 15 strains of Bacillus cereus including 11 clinical and 4 environmental strains were collected. Bacterial identification, antimicrobial susceptibility test and biofilm formation experiments were conducted. Three clinical strains selected at the clinical stage of different antibiotic therapies and 3 environmental strains were subjected to phylogenetic analysis and biofilm formation-associated genes detection.  Results All the 15 strains were identified as Bacillus cereus by matrix assisted laser desorption ionization time of flight mass spectrometry (MALDI-TOF MS). Antimicrobial susceptibility test showed that all of the clinical strains (11/11, 100%) were sensitive to levofloxacin, meropenem, erythromycin, rifampicin, tetracycline and vancomycin and resistant to penicillin, 63.6% (7/11) were resistant to cotrimoxazole, and 72.7% (8/11) were intermediately resistant to clindamycin. Three of the clinical strains phylogenetically resemble the strains isolated from hands of the staff working in the blood purification room, and carried 7 biofilm-forming genes, including calY, cdgD, cdgF, sinl, sinR, spoOA and tasA. Biofilm-forming ability was found in 9 (81.8%) of the 11 clinical strains, and this ability could be transiently inhibited in the presence of moxifloxacin or vancomycin.  Conclusions Bacillus cereus can cause catheter-associated bloodstream infection in hemodialysis patients. The formation of biofilm causes the difficulties to eradicate the infection. Hand hygiene should be emphasized to avoid nosocomial infection.