Reinhardt D J, Kennedy C, Malecka-Griggs B
J Clin Microbiol. 1980 Aug;12(2):199-204. doi: 10.1128/jcm.12.2.199-204.1980.
Effluent aerosols and liquid reservoir samples from 255 in-use hospital nebulization devices were analyzed by Aero-Test samplers (Olympic Corp.) and direct dilution procedures (0.1-, 0.01-, and 0.001-ml plated samples). Thirty-five percent (89 of 255) of the in-use hospital reservoir samples were positive by direct dilution, and 24% (61 of 255) were positive by Aero- Test samplers. Acinetobacter calcoaceticus var. anitratus was found either alone or in association with Pseudomonas spp. in 50% of all the contaminated in-use reservoirs. This indicates a high endemicity for Acinetobacter in the environment studied. Viable microbes in the reservoirs of contaminated nebulizers ranged from as few as 20 to >2 x 10(5) colony-forming units/ml. Microbial contamination at moderate to heavy levels (1 x 10(4) to >2 x 10(5)) was regularly detected by both procedures. Microbial densities of 10(3) colony-forming units/ml and less in contaminated reservoirs often were negative in the Aero- Test but positive by direct dilution techniques. These hospital-based results were similar to laboratory data obtained with sterile nebulizers intentionally contaminated in graduated densities with either Staphylococcus aureus or Pseudomonas aeruginosa. Sensitivity of the Aero- Test system was best when >/=10(4) colony-forming units/ml were present in the reservoirs of operating nebulizers. The manufacturer suggests that five or less colonies appearing after sampling on Aero- Test plates upon 48-h incubation does not indicate contamination of the reservoir. Our data show that even a single colony, particularly if it is typical, water-associated, gram-negative bacterial species, may well indicate low levels of reservoir contamination. Both the Aero- Test and direct dilution methods indicated the need for more rigorous management of the in-use respiratory therapy equipment in the hospital surveyed. These studies demonstrate the value of selective nonroutine surveillance for identifying potential or actual contamination problems of in-use nebulizing equipment, particularly when recommended care guidelines are not followed due to choice or unawareness. Ameliorative-corrective measures, which included routine 24-h substitution of old units with new sterile units, were initiated as a result of this surveillance program.
使用Aero-Test采样器（奥林匹克公司）和直接稀释程序（0.1毫升、0.01毫升和0.001毫升接种样本）对255台使用中的医院雾化设备的流出气溶胶和储液器样本进行了分析。通过直接稀释，35%（255份中的89份）使用中的医院储液器样本呈阳性，通过Aero-Test采样器检测，24%（255份中的61份）呈阳性。在所有受污染的使用中的储液器中，50%发现了醋酸钙不动杆菌脱硝亚种单独存在或与假单胞菌属共同存在。这表明在所研究的环境中不动杆菌的高流行率。受污染雾化器储液器中的活菌数量少至20个/毫升，多至>2×10⁵个菌落形成单位/毫升。两种程序均定期检测到中度至重度（1×10⁴至>2×10⁵）的微生物污染。受污染储液器中微生物密度为10³个菌落形成单位/毫升及以下时，Aero-Test检测结果常为阴性，但直接稀释技术检测结果为阳性。这些基于医院的结果与在实验室中用金黄色葡萄球菌或铜绿假单胞菌以分级密度故意污染的无菌雾化器获得的数据相似。当运行中的雾化器储液器中存在≥10⁴个菌落形成单位/毫升时，Aero-Test系统的灵敏度最佳。制造商建议，在Aero-Test平板上培养48小时后采样出现五个或更少菌落并不表明储液器受到污染。我们的数据表明，即使是单个菌落，特别是如果它是典型的、与水相关的革兰氏阴性细菌物种，很可能表明储液器受到低水平污染。Aero-Test和直接稀释方法均表明，在所调查的医院中，需要对使用中的呼吸治疗设备进行更严格的管理。这些研究证明了选择性非例行监测对于识别使用中的雾化设备潜在或实际污染问题的价值，特别是当由于选择或意识不足而未遵循推荐的护理指南时。作为该监测计划的结果，启动了包括每天24小时用新的无菌设备替换旧设备的改善纠正措施。
