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The microbial quality of two groundwater sources (well and borehole) and associated risks were quantitatively assessed. Water samples from the selected borehole and well were collected over a period of 12 weeks (n = 48). The concentrations of Escherichia coli, faecal coliforms, Salmonella, Shigella, Clostridium, Bifidobacterium and Campylobacter were determined using standard microbiological methods, which involve the use of a membrane filter technique. The water samples were filtered through a 0.45 μm membrane filter using vacuum pump pressure and plated on selective agar for the bacteria under test. The number of colonies of the bacterial growth observed after the incubation period was counted and recorded. The physicochemical properties of the water were determined using standard methods. The risk of Salmonella, Shigella, Clostridium and Campylobacter infections resulting from the ingestion of water from the borehole and well was estimated. The results showed that the levels of enteric bacteria in the borehole were higher than those in the well. The mean levels of E. coli in water from the borehole and well were 3.3 and 1.7 log10 cfu/100 ml, respectively, and exhibited a negative relationship with salinity (r = −0.53). The estimated risks of infection associated with the pathogens in water from the borehole and well were greater than the acceptable risk limit of 10−4 and followed this order Clostridium<Salmonella<Campylobacter<Shigella. The findings of this study suggest recent and continuous faecal contamination of the two groundwater sources, thus exposing the residents relying on the water for drinking to potential risks of gastrointestinal infections.

Aim This study set out to determine whether phage‐based indicators may provide a ‘low‐tech’ alternative to existing approaches that might help maintain the microbial safety of shellfish and their overlying waters. Methods and Results Mussels and their overlying waters were collected biweekly from an estuary in southeast England over a 2‐year period (May 2013–April 2015) (n = 48). Levels of bacterial indicators were determined using membrane filtration and most probable number methods and those of bacteriophages were determined by direct plaque assay. The detection of adenovirus was determined using real‐time polymerase chain reaction. The results revealed that somatic coliphages demonstrated the most significant correlations with AdV F and G in mussels (ρ = 0·55) and overlying waters (ρ = 0·66), followed by GB124 phages (ρ = 0·43) while Escherichia coli showed no correlation with AdV F and G in mussels. Conclusion This study demonstrates that the use of somatic coliphages and GB124 phages may provide a better indication of the risk of adenovirus contamination of mussels and their overlying waters than existing bacterial indicators. Significance and Impact of the Study Phage‐based detection may be particularly advantageous in low‐resource settings where viral infectious disease presents a significant burden to human health.

This study was carried out to determine the level of enteric bacteria in two surface water sources (river and stream) commonly used for domestic, recreational and agricultural purposes in Akure, Nigeria. This is to gain a better understanding of the level of faecal pollution of the water sources and the potential health risks associated with usage of the waters for human activities. Water samples were collected from the river and the stream from May to September, 2019 (n = 24). The concentration of enteric bacteria in the water samples were determined using membrane filtration technique while the physicochemical characteristics of the water samples were determined using standard method. Results revealed that the concentration of E. coli ranged from 3.00 to 4.78 log10 cfu/100ml and 3.48 to 5.75 log10 cfu/100ml in water samples from the river and stream respectively; Bifidobacterium ranged from 4.18 to 5.00 log10 cfu/100ml and 3.87 to 4.66 log10 cfu/100ml in water samples from the river and stream respectively; and Salmonella ranged from 3.30 to 4.30 log10 cfu/100ml and 2.60 to 4.32 log10 cfu/100ml in water samples from the river and stream respectively. Water temperature ranged from 22.1 to 28.5 °C and 23.64 to 25.56 °C in the river and stream respectively; and turbidity ranged from 12.28 to 29.11 NTU and 17.07 to 61.80 NTU in the river and stream respectively. Spearman's rank correlation showed that Salmonella had positive relationship with temperature (r = 0.556) in water samples from the stream whereas Bifidobacterium exhibited positive relationship with dissolved oxygen (r = 0.557) in water samples from the river. Whilst the stream appeared to have a higher turbidity than the river, the level of enteric bacteria in the river were more than those in the stream. Based on microbiological water quality categories, the findings from this study demonstrated that the level of enteric bacteria in the river and stream suggests strong faecal pollution that may pose potential risks of diarrheal diseases to humans. Water from these two surface water sources must be treated before use in order to protect human health.