Bacteria from the Genus Arcobacter Are Abundant in Effluent from Wastewater Treatment Plants
Bacteria from the Genus Arcobacter Are Abundant in Effluent from Wastewater Treatment Plants
复制标题
DOI：
10.1128/aem.03044-19
复制
发表时间：
2020-05-01
影响因子：
4.4
通讯作者：
Nielsen, Per Halkjaer
中科院分区：
文献类型：
--
作者：
Kristensen, Jannie Munk;Nierychlo, Marta;Nielsen, Per Halkjaer
通常认为废水中的致病菌可以在生物废水处理厂中得到有效去除。这种理解几乎完全基于基于培养的控制措施，在这里，我们通过应用独立于培养的方法表明，与进水废水中许多其他丰富的属相比，弓形杆菌属物种的去除效果较差。弓形杆菌是 14 个城市污水处理厂进水废水中含量最丰富的菌属之一，在所有污水处理厂的“干净”污水中也含量丰富，根据 16S rRNA 基因扩增子测序分析，其比例高达所有细菌的 30%。宏基因组分析、培养、弓形杆菌分离株的基因组测序以及荧光原位杂交 (FISH) 可视化证实了进水和出水中均存在人类致病性冷冻弓形杆菌和 A. butzleri。出水中相对丰度较高的主要原因可能是，与进水中其他丰富属的细胞相比，弓形杆菌细胞没有絮凝并很好地附着在活性污泥絮凝物上，留下相对较大的部分分散在水相中。该研究表明，迫切需要对废水中的病原体进行新的、与培养无关的标准化测量，例如扩增子测序，并在全球范围内对这一问题进行调查，以量化对人类和牲畜的风险。 重要性 在处理城市废水的 14 个丹麦废水处理厂的废水中，弓形杆菌属出乎意料地丰富，该物种包括人类致病性嗜冷曲霉和布兹勒曲霉。最近的研究表明，弓形杆菌在全世界废水中很常见，因此研究表明弓形杆菌属成员的排放可能是一个全球性问题，需要进一步研究来量化风险并尽可能减少排放。该研究还表明，基于培养的分析不足以进行适当的废水质量控制，应考虑对涵盖大多数病原体的废水质量进行新的标准化独立于培养的测量。
Pathogenic bacteria in wastewater are generally considered to be efficiently removed in biological wastewater treatment plants. This understanding is almost solely based on culture-based control measures, and here we show, by applying culture-independent methods, that the removal of species in the genus Arcobacter was less effective than for many other abundant genera in the influent wastewater. Arcobacter was one of the most abundant genera in influent wastewater at 14 municipal wastewater treatment plants and was also abundant in the "clean" effluent from all the plants, reaching up to 30% of all bacteria as analyzed by 16S rRNA gene amplicon sequencing. Metagenomic analyses, culturing, genome sequencing of Arcobacter isolates, and visualization by fluorescent in situ hybridization (FISH) confirmed the presence of the human-pathogenic Arcobacter cryaerophilus and A. butzleri in both influent and effluent. The main reason for the high relative abundance in the effluent was probably that Arcobacter cells, compared to those of other abundant genera in the influent, did not flocculate and attach well to the activated sludge flocs, leaving a relatively large fraction dispersed in the water phase. The study shows there is an urgent need for new standardized culture-independent measurements of pathogens in effluent wastewaters, e.g., amplicon sequencing, and an investigation of the problem on a global scale to quantify the risk for humans and livestock.IMPORTANCE The genus Arcobacter was unexpectedly abundant in the effluent from 14 Danish wastewater treatment plants treating municipal wastewater, and the species included the human-pathogenic A. cryaerophilus and A. butzleri. Recent studies have shown that Arcobacter is common in wastewater worldwide, so the study indicates that discharge of members of the genus Arcobacter may be a global problem, and further studies are needed to quantify the risk and potentially minimize the discharge. The study also shows that culture-based analyses are insufficient for proper effluent quality control, and new standardized culture-independent measurements of effluent quality encompassing most pathogens should be considered.