Water and Health Research Centre, Faculty of Health Sciences, University of Johannesburg, Johannesburg 2094, South Africa.
CB Scientific, Roodepoort 1724, South Africa.
Int J Environ Res Public Health. 2021 Apr 8;18(8):3912. doi: 10.3390/ijerph18083912.
Free-living amoebae (FLA) are ubiquitous in nature, whereas amoeba-resistant bacteria (ARB) have evolved virulent mechanisms that allow them to resist FLA digestion mechanisms and survive inside the amoeba during hostile environmental conditions. This study assessed the prevalence of FLA and ARB species in borehole water before and after a ceramic point-of-use intervention in rural households. A total of 529 water samples were collected over a five-month period from 82 households. All water samples were subjected to amoebal enrichment, bacterial isolation on selective media, and molecular identification using 16S PCR/sequencing to determine ARB species and 18S rRNA PCR/sequencing to determine FLA species present in the water samples before and after the ceramic pot intervention. Several FLA species including spp. and spp. were isolated. The ceramic pot filter removed many of these microorganisms from the borehole water. However, design flaws could have been responsible for some FLA and ARB detected in the filtered water. FLA and their associated ARB are ubiquitous in borehole water, and some of these species might be potentially harmful and a health risk to vulnerable individuals. There is a need to do more investigations into the health risk of these organisms after point-of-use treatment.
自由生活的阿米巴虫（FLA）在自然界中无处不在，而阿米巴虫抗性细菌（ARB）则进化出了致命机制，使它们能够抵抗 FLA 的消化机制，并在恶劣的环境条件下在阿米巴虫内存活。本研究评估了农村家庭中使用陶瓷点源干预前后钻孔水中 FLA 和 ARB 物种的流行情况。在五个月的时间里，从 82 户家庭中采集了总共 529 份水样。所有水样均进行了阿米巴虫富集、选择性培养基上的细菌分离，以及使用 16S PCR/测序进行分子鉴定，以确定 ARB 物种，以及使用 18S rRNA PCR/测序确定水样中存在的 FLA 物种。分离出了几种 FLA 物种，包括 spp. 和 spp.。陶瓷锅过滤器从钻孔水中去除了许多这些微生物。然而，设计缺陷可能是导致过滤水中检测到一些 FLA 和 ARB 的原因。FLA 及其相关的 ARB 在钻孔水中普遍存在，其中一些物种可能对脆弱个体具有潜在的危害和健康风险。需要对这些生物体在使用点处理后的健康风险进行更多的调查。
