Department of Environmental Science, University of Eastern Finland, Kuopio, Finland.
APMIS. 2014 Apr;122(4):353-8. doi: 10.1111/apm.12153. Epub 2013 Aug 13.
Evaporative cooling towers are water systems used in, e.g., industry and telecommunication to remove excess heat by evaporation of water. Temperatures of cooling waters are usually optimal for mesophilic microbial growth and cooling towers may liberate massive amounts of bacterial aerosols. Outbreaks of legionellosis associated with cooling towers have been known since the 1980's, but occurrences of other potentially pathogenic bacteria in cooling waters are mostly unknown. We examined the occurrence of mycobacteria, which are common bacteria in different water systems and may cause pulmonary and other soft tissue infections, in cooling waters containing different numbers of legionellae. Mycobacteria were isolated from all twelve cooling systems and from 92% of the 24 samples studied. Their numbers in the positive samples varied from 10 to 7.3 × 10(4) cfu/L. The isolated species included M. chelonae/abscessus, M. fortuitum, M. mucogenicum, M. peregrinum, M. intracellulare, M. lentiflavum, M. avium/nebraskense/scrofulaceum and many non-pathogenic species. The numbers of mycobacteria correlated negatively with the numbers of legionellae and the concentration of copper. The results show that cooling towers are suitable environments for potentially pathogenic mycobacteria. Further transmission of mycobacteria from the towers to the environment needs examination.
蒸发冷却塔是一种水系统，例如在工业和电信中使用，通过水的蒸发来去除多余的热量。冷却水的温度通常最适合中温微生物的生长，并且冷却塔可能会释放大量的细菌气溶胶。自 20 世纪 80 年代以来，已经知道与冷却塔有关的军团病爆发，但冷却水中其他潜在致病细菌的发生情况大多未知。我们检查了在含有不同数量军团菌的冷却水中常见于不同水系统并可能引起肺部和其他软组织感染的分枝杆菌的发生情况。分枝杆菌从所有 12 个冷却系统和所研究的 24 个样本中的 92%中分离出来。在阳性样本中，它们的数量从 10 到 7.3×10(4)cfu/L 不等。分离出的物种包括 M. chelonae/abscessus、M. fortuitum、M. mucogenicum、M. peregrinum、M. intracellulare、M. lentiflavum、M. avium/nebraskense/scrofulaceum 和许多非致病性物种。分枝杆菌的数量与军团菌的数量和铜的浓度呈负相关。结果表明，冷却塔是潜在致病性分枝杆菌的适宜环境。需要进一步检查从塔到环境的分枝杆菌的传播。
