Angenent Largus T, Kelley Scott T, St Amand Allison, Pace Norman R, Hernandez Mark T
Department of Chemical Engineering and Environmental Engineering Science Program, Washington University, St. Louis, MO 63130, USA.
Proc Natl Acad Sci U S A. 2005 Mar 29;102(13):4860-5. doi: 10.1073/pnas.0501235102. Epub 2005 Mar 15.
Indoor warm-water therapy pool workers in a Midwestern regional hospital were diagnosed with non-tuberculosis pulmonary hypersensitive pneumonitis and Mycobacterium avium infections. In response, we conducted a multiseason survey of microorganisms present in this therapy pool water, in biofilms associated with the pool containment walls, and in air immediately above the pool. The survey used culture, microscopy, and culture-independent molecular phylogenetic analyses. Although outfitted with a state-of-the-art UV-peroxide disinfection system, the numbers of bacteria in the therapy pool water were relatively high compared with the potable water used to fill the pool. Regardless of the source, direct microscopic counts of microbes were routinely approximately 1,000 times greater than conventional plate counts. Analysis of clone libraries of small subunit rRNA genes from environmental DNA provided phylogenetic diversity estimates of the microorganisms collected in and above the pool. A survey of >1,300 rRNA genes yielded a total of 628 unique sequences, the most common of which was nearly identical to that of M. avium strains. The high proportion of clones with different Mycobacterium spp. rRNA genes suggested that such organisms comprised a significant fraction of microbes in the pool water (to >30%) and preferentially partition into aerosols (to >80%) relative to other waterborne bacteria present. The results of the study strongly validate aerosol partitioning as a mechanism for disease transfer in these environments. The results also show that culture protocols currently used by public health facilities and agencies are seriously inadequate for the detection and enumeration of potential pathogens.
一家中西部地区医院的室内温水治疗池工作人员被诊断出患有非结核性肺过敏性肺炎和鸟分枝杆菌感染。作为应对措施，我们对该治疗池水中、与池壁相关的生物膜以及池上方空气中存在的微生物进行了多季节调查。该调查采用了培养、显微镜检查和非培养分子系统发育分析方法。尽管配备了最先进的紫外线 - 过氧化物消毒系统，但与用于填充水池的饮用水相比，治疗池水中的细菌数量相对较高。无论来源如何，微生物的直接显微镜计数通常比传统平板计数大约高1000倍。对环境DNA中的小亚基rRNA基因克隆文库进行分析，提供了对水池内和上方收集的微生物的系统发育多样性估计。对1300多个rRNA基因的调查共产生了628个独特序列，其中最常见的序列与鸟分枝杆菌菌株的序列几乎相同。具有不同分枝杆菌属rRNA基因的克隆比例很高，这表明此类生物体在池水中占微生物的很大一部分（超过30%），并且相对于其他存在的水传播细菌，它们优先分配到气溶胶中（超过80%）。该研究结果有力地证实了气溶胶分配是这些环境中疾病传播的一种机制。结果还表明，公共卫生设施和机构目前使用的培养方案对于潜在病原体的检测和计数严重不足。
