Australian Nuclear Science and Technology Organisation (ANSTO), New Illawarra Rd, Lucas Heights, NSW, 2234, Australia.
School of Biological, Earth and Environmental Sciences, UNSW Sydney, Sydney, NSW, 2052, Australia.
Sci Rep. 2020 Oct 26;10(1):18295. doi: 10.1038/s41598-020-75336-7.
Chronic kidney disease (CKD) of unknown etiology (CKDu) mostly affects agricultural communities in Central America, South Asia, Africa, but likely also in North America and Australia. One such area with increased CKDu prevalence is the Medawachchiya District Secretariat Division of the Anuradhapura District in the North Central Province of Sri Lanka. Recent research has focused on the presence of various microbial pathogens in drinking water as potential causal or contributing factors to CKDu, yet no study to date has performed a more comprehensive microbial and water chemistry assessment of household wells used for domestic water supply in areas of high CKDu prevalence. In this study, we describe the chemical composition and total microbial content in 30 domestic household wells in the Medawachchiya District Secretariat Division. While the chemical composition in the tested wells mostly lies within standard drinking water limits, except for high levels of fluoride (F), magnesium (Mg), sodium (Na), chloride (Cl) and calcium (Ca) in some samples, we find a frequent presence of cyanotoxin-producing Microcystis, confirming earlier studies in Sri Lanka. Since the total microbial content of drinking water also directly influences the composition of the human gut microbiome, it can be considered an important determinant of health. Several bacterial phyla were previously reported in the gut microbiome of patients with CKD. Using these bacteria phyla to define operational taxonomic units, we found that these bacteria also occur in the microbiome of the sampled well water. Based on available environmental data, our study demonstrates associations between the abundances of these bacteria with geographical distribution, well water temperature and likely fertilizer use in the local surface water catchment area of the individual household wells. Our results reinforce the recommendation that household wells with stagnant or infrequently used water should be purged prior to use for drinking water, bathing and irrigation. The latter is suggested because of the reported potential accumulation of bacterial toxins by agricultural crops. The observation that bacteria previously found in chronic kidney disease patients are also present in household wells requires a more detailed systematic study of both the human gut and drinking water microbiomes in CKDu patients, in relation to disease prevalence and progression.
慢性肾脏病（CKD）病因不明（CKDu）主要影响中美洲、南亚、非洲的农业社区，但也可能存在于北美和澳大利亚。斯里兰卡中北部安努拉达普拉区的马德瓦奇亚区行政司就是这样一个 CKDu 发病率上升的地区。最近的研究集中在饮用水中各种微生物病原体的存在上，这些病原体可能是 CKDu 的致病或促成因素，但迄今为止，没有研究对高 CKDu 流行地区用于家庭供水的家庭水井进行更全面的微生物和水化学评估。在这项研究中，我们描述了马德瓦奇亚区行政司 30 个家庭水井的化学成分和总微生物含量。虽然测试井的化学成分大多在标准饮用水限值范围内，但除了一些样本中氟化物 (F)、镁 (Mg)、钠 (Na)、氯 (Cl) 和钙 (Ca) 含量较高外，我们发现经常存在产蓝藻素的微囊藻，证实了斯里兰卡早期的研究。由于饮用水的总微生物含量也直接影响人体肠道微生物组的组成，因此可以被认为是健康的一个重要决定因素。以前有研究报告称，CKD 患者的肠道微生物组中存在几种细菌门。使用这些细菌门来定义操作分类单位，我们发现这些细菌也存在于采样井水中的微生物组中。根据现有环境数据，我们的研究表明，这些细菌的丰度与地理分布、井水温度以及当地地表水集水区可能的肥料使用之间存在关联。我们的研究结果强化了这样的建议，即对于静止或不常使用的井水，在用于饮用水、沐浴和灌溉之前，应先将其排空。这是因为据报道，农业作物可能会积累细菌毒素。以前在慢性肾病患者中发现的细菌也存在于家庭水井中的这一观察结果，需要对 CKDu 患者的人类肠道和饮用水微生物组进行更详细的系统研究，以了解与疾病流行和进展的关系。
