Denissen Julia K, Reyneke Brandon, Waso Monique, Khan Sehaam, Khan Wesaal
Department of Microbiology, Faculty of Science, Stellenbosch University, Stellenbosch, South Africa.
Faculty of Health Sciences, University of Johannesburg, Doornfontein, South Africa.
Front Microbiol. 2021 May 7;12:659784. doi: 10.3389/fmicb.2021.659784. eCollection 2021.
Roof-harvested rainwater (RHRW) was investigated for the presence of the human pathogenic bacteria (), spp. and (). While spp. were detected in 92% ( = 25) of the RHRW samples, and and were detected in 100% ( = 25) of the samples, a significantly higher mean concentration (1.4 × 10 cells/100 mL) was recorded for over the sampling period. As the identification of appropriate water quality indicators is crucial to ensure access to safe water sources, correlation of the pathogens to traditional indicator organisms [ () and spp.] and microbial source tracking (MST) markers ( HF183, adenovirus and Lachnospiraceae) was conducted. A significant positive correlation was then recorded for versus ( = 0.6738; = 0.000), and spp. versus the HF183 marker ( = 0.4071; = 0.043), while a significant negative correlation was observed for versus the HF183 marker ( = -0.4558; = 0.022). Quantitative microbial risk assessment indicated that the mean annual risk of infection posed by in the RHRW samples exceeded the annual infection risk benchmark limit (1 × 10 infections per person per year) for intentional drinking (∼10). In comparison, the mean annual risk of infection posed by was exceeded for intentional drinking (∼10), accidental consumption (∼10) and cleaning of the home (∼10). However, while the risk posed by for the two relevant exposure scenarios [garden hosing (∼10) and washing laundry by hand (∼10)] was below the benchmark limit, the risk posed by adenovirus for garden hosing (∼10) and washing laundry by hand (∼10) exceeded the benchmark limit. Thus, while the correlation analysis confirms that traditional indicators and MST markers should be used in combination to accurately monitor the pathogen-associated risk linked to the utilisation of RHRW, the integration of QMRA offers a more site-specific approach to monitor and estimate the human health risks associated with the use of RHRW.
对屋顶收集的雨水（RHRW）进行了检测，以确定其中是否存在人类致病细菌（）、 菌属和（）。虽然在92%（n = 25）的RHRW样本中检测到了 菌属，并且在100%（n = 25）的样本中检测到了 和，但在整个采样期间，记录到 的平均浓度（1.4×10⁵个细胞/100 mL）显著更高。由于确定合适的水质指标对于确保获得安全水源至关重要，因此对这些病原体与传统指示生物[（）和 菌属]以及微生物源追踪（MST）标志物（HF183、腺病毒和毛螺菌科）进行了相关性分析。随后记录到 与 之间存在显著正相关（r = 0.6738；p = 0.000）， 菌属与HF183标志物之间存在显著正相关（r = 0.4071；p = 0.043），而 与HF183标志物之间存在显著负相关（r = -0.4558；p = 0.022）。定量微生物风险评估表明，RHRW样本中 造成的年平均感染风险超过了故意饮用（10⁻⁴）的年感染风险基准限值（每人每年1×10⁻⁶次感染）。相比之下， 造成的年平均感染风险在故意饮用（10⁻⁴）、意外摄入（10⁻⁶）和家庭清洁（10⁻⁶）时均超过了基准限值。然而，虽然 在两种相关暴露场景[花园浇水（10⁻⁶）和手洗衣物（10⁻⁶）]下造成的风险低于基准限值，但腺病毒在花园浇水（10⁻⁵）和手洗衣物（10⁻⁵）时造成的风险超过了基准限值。因此，虽然相关性分析证实应结合使用传统指标和MST标志物来准确监测与RHRW利用相关的病原体相关风险，但定量微生物风险评估的整合提供了一种更具针对性的方法来监测和估计与使用RHRW相关的人类健康风险。
