Bryce E A, Smith J A, Tweeddale M, Andruschak B J, Maxwell M R
Division of Medical Microbiology, Vancouver General Hospital, British Columbia, Canada.
Infect Control Hosp Epidemiol. 1993 Aug;14(8):459-62. doi: 10.1086/646779.
To report the contamination of ventilator equipment with Bacillus cereus and to outline the measures taken to trace the source of the organism.
A prospective survey of all intensive care unit patients who were culture-positive for B cereus and obtaining of environmental cultures of the cleaning and assembly area of the respiratory services division between October 1991 and September 1992.
Ventilated patients from a 16-bed medical and surgical intensive care unit (ICU) in a 1,000-bed adult tertiary care hospital.
From October 1991 to April 1992, B cereus colonized the ventilator circuitry of patients in the ICU. One of two washer/decontaminators in the cleaning and assembly area of the respiratory services division was found to yield the microorganism consistently from the water intake port. The design of the machine precluded easy decontamination of the port with 2% glutaraldehyde and a second outbreak occurred. Following the second outbreak, aqueous chlorhexidine in a final concentration of 0.05% was added to the first of two pasteurization cycles in an attempt to achieve sporicidal activity. This ended the outbreak. Sixty-two patients became colonized with the organism including two with nonfatal Bacillus sepsis and one death due to pneumonia associated with the organism.
This experience emphasizes the importance of obtaining cultures of machine parts to identify the source of contamination and thereby direct control measures. Use of chlorhexidine gluconate at high temperatures effectively eradicated B cereus from ventilator circuitry in a practical and cost-effective manner.
报告呼吸机设备被蜡样芽孢杆菌污染的情况，并概述为追踪该生物体来源所采取的措施。
对1991年10月至1992年9月间所有蜡样芽孢杆菌培养呈阳性的重症监护病房患者进行前瞻性调查，并对呼吸服务部门清洁和组装区域进行环境培养。
来自一家拥有1000张床位的成人三级护理医院中一个有16张床位的内科和外科重症监护病房（ICU）的使用呼吸机的患者。
1991年10月至1992年4月，蜡样芽孢杆菌在ICU患者的呼吸机回路中定殖。呼吸服务部门清洁和组装区域的两台清洗/消毒器中有一台被发现从进水口持续产生该微生物。该机器的设计使得用2%戊二醛难以对进水口进行消毒，于是发生了第二次暴发。在第二次暴发后，在两个巴氏消毒循环中的第一个循环中加入终浓度为0.05%的洗必泰水溶液，试图达到杀孢子活性。这结束了暴发。共有62名患者被该生物体定殖，其中2例发生非致命性蜡样芽孢杆菌败血症，1例因与该生物体相关的肺炎死亡。
该经验强调了获取机器部件培养物以识别污染源从而指导控制措施的重要性。在高温下使用葡萄糖酸洗必泰以实用且经济有效的方式有效根除了呼吸机回路中的蜡样芽孢杆菌。
