Access to safe drinking water is now recognized as a human right by the United Nations. In developed countries like Canada, access to clean water is generally not a matter of concern. However, one in every five First Nations reserves is under a drinking water advisory, often due to unacceptable microbiological quality. In this study, we analyzed source and potable water from a First Nations community for the presence of coliform bacteria as well as various antibiotic resistance genes. Samples, including those from drinking water sources, were found to be positive for various antibiotic resistance genes, namely, ampC, tet(A), mecA, ␤-lactamase genes (SHV-type, TEM-type, CTX-M-type, OXA-1, and CMY-2-type), and carbapenemase genes (KPC, IMP, VIM, NDM, GES, and OXA-48 genes). Not surprisingly, substantial numbers of total coliforms, including Escherichia coli, were recovered from these samples, and this result was also confirmed using Illumina sequencing of the 16S rRNA gene. These findings deserve further attention, as the presence of coliforms and antibiotic resistance genes potentially puts the health of the community members at risk. IMPORTANCEIn this study, we highlight the poor microbiological quality of drinking water in a First Nations community in Canada. We examined the coliform load as well as the presence of antibiotic resistance genes in these samples. This study examined the presence of antibiotic-resistant genes in drinking water samples from a First Nations Community in Canada. We believe that our findings are of considerable significance, since the issue of poor water quality in First Nations communities in Canada is often ignored, and our findings will help shed some light on this important issue.A ntibiotic resistance in bacteria has been recognized as one of the greatest threats to human health by the World Health Organization (1). Overuse and misuse of antibiotics contribute to the buildup of selective pressure aiding the proliferation of antibiotic-resistant bacteria (2, 3). While hospital environments are notorious for selecting for antibiotic-resistant bacteria, it is now becoming increasingly evident that overuse and misuse of antibiotics are also creating a selective pressure outside hospital settings. Studies over the last few years have shown the presence of antibiotics and of antibiotic-resistant bacteria in the broader environment, including water supplies and soil samples (4). This is indeed alarming as the high number of antibiotic-resistant bacteria in communities makes the treatment of community-acquired infections increasingly challenging (5, 6).Not surprisingly, water samples from communities that lack access to clean water contain high numbers of bacteria (7-9). While a high bacterial count in the water supply itself poses an increased health risk (10), the presence of antibiotic-resistant bacteria makes this risk even more serious. Lack of access to clean and safe water is a problem that is generally associated with developing countries; however, this is a reality as wel...

Increased phosphorus (P) availability under flooded, anaerobic conditions may accelerate P loss from soils to water bodies. Existing knowledge on P release to floodwater from flooded soils is limited to summer conditions and/or room temperatures. Spring snowmelt runoff, which occurs under cold temperatures with frequent freeze-thaw events, is the dominant mode of P loss from agricultural lands to water bodies in the Canadian Prairies. This research examined the effects of temperature on P dynamics under flooded conditions in a laboratory study using five agricultural soils from Manitoba, Canada. The treatments were (a) freezing for 1 wk at −20 • C, thawing and flooding at 4 ± 1 • C (frozen, cold); (b) flooding unfrozen soil at 4 ± 1 • C (unfrozen, cold); and (c) flooding unfrozen soil at 20 ± 2 • C (warm). Pore water and surface water were collected weekly over 8 wk and analyzed for dissolved reactive phosphorus (DRP), pH, calcium, magnesium, iron (Fe), and manganese (Mn). Soils under warm flooding showed enhanced P release with significantly higher DRP concentrations in pore and surface floodwater compared with cold flooding of frozen and unfrozen soils.The development of anaerobic conditions was slow under cold flooding with only a slight decrease in Eh, whereas under warm flooding Eh declined sharply, favoring reductive dissolution reactions releasing P, Fe, and Mn. Pore water and floodwater DRP concentrations were similar between frozen and unfrozen soil under cold flooding, suggesting that one freeze-thaw event prior to flooding had minimal effect on P release under simulated snowmelt conditions. Abbreviations: DAF, days after flooding; DRP, dissolved reactive phosphorus.

Phosphorus (P) losses from flooded soils and subsequent transport to waterways contribute to eutrophication of surface waters. This study evaluated the effectiveness of MnO2 and a zeolite Y amendment in reducing P release from flooded soils and explored the underlying mechanisms controlling P release. Unamended and amended (MnO2 or zeolite, surface-amended at 5 Mg ha–1) soil monoliths from four clayey–alkaline soils were flooded at 22 ± 2 °C for 56 days. Soil redox potential and dissolved reactive P (DRP), pH, and concentrations of major cations and anions in porewater and floodwater were analyzed periodically. Soil P speciation was simulated using Visual MINTEQ at 1, 28, and 56 days after flooding (DAF) and P K-edge X-ray absorption near-edge structure spectroscopy and sequential fractionation at 56 DAF. Porewater DRP increased with DAF and correlated negatively with pe+pH and positively with dissolved Fe. Reductive dissolution of Fe-associated P was the dominant mechanism of flooding-induced P release. The MnO2 amendment reduced porewater DRP by 30%–50% by favoring calcium phosphates (Ca–P) precipitation and delaying the reductive dissolution reactions. In three soils, the zeolite amendment at some DAF increased porewater and/or floodwater DRP through dissolution of Ca–P and thus was not effective in reducing P release from flooded soils.

Anaerobic conditions induced by prolonged flooding often lead to an enhanced release of phosphorus (P) to floodwater; however, this effect is not consistent across soils. This study aimed to develop an index to predict P release potential from alkaline soils under simulated flooded conditions. Twelve unamended or manure-amended surface soils from Manitoba were analyzed for basic soil properties, Olsen P (Ols-P), Mehlich-3 extractable total P (M3P ICP ), Mehlich-3 extractable molybdate-reactive P (M3P MRP ), water extractable P (WEP), soil P fractions, single-point P sorption capacity (P 150 ), and Mehlich-3 extractable Ca (M3Ca), and Mg (M3Mg). Degree of P saturation (DPS) was calculated using Ols-P, M3P ICP or M3P MRP as the intensity factor, and an estimated adsorption maximum based on either P 150 or M3Ca + M3Mg as the capacity factor. To develop the model, we used the previously reported floodwater dissolved reactive P (DRP) concentration changes during 8 wk of flooding for the same unamended and manured soils. Relative changes in floodwater DRP concentration (DRP ratio ), calculated as the ratio of maximum to initial DRP concentration, ranged from 2 to 15 across ten of the soils, but were ≤1.5 in the two soils with the greatest clay content. Partial least squares analysis indicated that DPS3 calculated using M3P ICP as the intensity factor and (2 ´ P 150 ) + M3P ICP as the capacity factor with clay percentage can effectively predict DRP ratio (r 2 = 0.74). Results suggest that P release from a soil to floodwater may be predicted using simple and easily measurable soil properties measured before flooding, but validation with more soils is needed.Predicting Phosphorus Release from Anaerobic, Alkaline, Flooded Soils Geethani Amarawansha, Darshani Kumaragamage,* Don Flaten, Francis Zvomuya, and Mario Tenuta A ccumulation of phosphorus (P) in agricultural soils enhances P loss to waterways (Daniel et al., 1998;Sharpley, 1995) and leads to the eutrophication of surface water bodies (Schindler, 1977). Phosphorus release from soils to runoff water is often related to soil test P (STP) concentrations (Sharpley, 1995;Daniel et al., 1998;Vadas et al., 2005;Kumaragamage et al., 2011) and P retention in soil (Fang et al., 2002;Ige et al., 2005). Seasonally flooded conditions change the oxidation-reduction status that may alter the fate and transport of P in soils. Numerous studies conducted worldwide showed an enhanced P release from soils and sediments to soil solution and floodwater upon the development of anaerobic conditions (Pant et al., 2002;Ajmone-Marsan et al., 2006;Hoffman et al., 2009;Kröger et al., 2012;Scalenghe et al., 2012;Amarawansha et al., 2015). Our previous studies using anaerobic alkaline soils from Manitoba showed that the increase in dissolved reactive P (DRP) concentration in floodwater was highly variable depending on soil properties and was more than 10-fold in some soils (Amarawansha et al., 2015).Application of manure and fertilizer in excess of crop removal increases STP (Eghball et a...

Abbreviations: DAF, days after flooding; DPS, degree of phosphorus saturation; DRP, dissolved reactive phosphorus; DRP max , maximum dissolved reactive phosphorus concentration in floodwater; Eh, redox potential; M3P MRP , Mehlich-3 extractable molybdate reactive phosphorus; M3P TP , Mehlich-3 extractable total phosphorus; PSI, phosphorus saturation index; STP, soil test phosphorus. D. Kumaragamage (ORCID iD 0000-0002-7613-0667),