Wolmarans E, du Preez H H, de Wet C M E, Venter S N
Department of Microbiology and Plant Pathology, University of Pretoria, South Africa.
Water Sci Technol. 2005;52(8):171-5.
The implication of invertebrates found in drinking water distribution networks to public health is of concern to water utilities. Previous studies have shown that the bacteria associated with the invertebrates could be potentially pathogenic to humans. This study investigated the level and identity of bacteria commonly associated with invertebrates collected from the drinking water treatment systems as well as from the main pipelines leaving the treatment works. On all sampling occasions bacteria were isolated from the invertebrate samples collected. The highest bacterial counts were observed for the samples taken before filtration as was expected. There were, however, indications that optimal removal of invertebrates from water did not always occur. During the investigation, 116 colonies were sampled for further identification. The isolates represent several bacterial genera and species that are pathogenic or opportunistic pathogens of humans. Diarrhoea, meningitis, septicaemia and skin infections are among the diseases associated with these organisms. The estimated number of bacteria that could be associated with a single invertebrate (as based on average invertebrate numbers) could range from 10 to 4000 bacteria per organism. It can, therefore, be concluded that bacteria associated with invertebrates might under the worst case scenario pose a potential health risk to water users. In the light of the above findings it is clear that invertebrates in drinking water should be controlled at levels as low as technically and economically feasible.
饮用水分配网络中发现的无脊椎动物对公共健康的影响是水务公司关注的问题。先前的研究表明，与这些无脊椎动物相关的细菌可能对人类具有潜在致病性。本研究调查了从饮用水处理系统以及离开处理厂的主管道中采集的无脊椎动物通常所携带细菌的水平和种类。在所有采样过程中，均从采集的无脊椎动物样本中分离出了细菌。正如预期的那样，在过滤前采集的样本中观察到了最高的细菌计数。然而，有迹象表明，并非总能实现从水中最佳去除无脊椎动物的目标。在调查过程中，对116个菌落进行了采样以作进一步鉴定。分离出的细菌代表了几个属和种，它们是人类的致病原或机会致病菌。腹泻、脑膜炎、败血症和皮肤感染等疾病都与这些微生物有关。根据无脊椎动物的平均数量估算，单个无脊椎动物可能携带的细菌数量范围为每个生物体10至4000个细菌。因此，可以得出结论，在最坏的情况下，与无脊椎动物相关的细菌可能会对用水者构成潜在的健康风险。鉴于上述发现，很明显，应在技术和经济可行的前提下，将饮用水中的无脊椎动物控制在尽可能低的水平。
