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Yoneda I, Nishiyama M, Watanabe T. Comparative experiment to select water quality parameters for modelling the survival of Escherichia coli in lakes. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2024; 357:124423. [PMID: 38909774 DOI: 10.1016/j.envpol.2024.124423] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/05/2024] [Revised: 05/01/2024] [Accepted: 06/20/2024] [Indexed: 06/25/2024]
Abstract
Numerical health risk assessment models have been developed to describe faecal contamination of water using Escherichia coli as an indicator bacterium. Although many previously established numerical models for E. coli in aquatic environments have only considered the effects of one or two water quality parameters such as temperature and sunlight, it is difficult to simulate E. coli survival with only one or two parameters because the aquatic environment is a complex system. This study conducted a series of comparative experiments to select water quality parameters that should be preferentially considered in a numerical model for E. coli survival in lakes. The parameters considered were temperature, pH, dissolved oxygen (DO), total dissolved solids (TDS), suspended solids (SS), coexisting microbes, and light intensity. In the laboratory experiments, the survival of E. coli was observed by controlling two of these seven parameters, and the effects of these parameters on the rate of E. coli population change were statistically compared. Consequently, light intensity affected the survival of E. coli most significantly, followed by the presence of coexisting microbes, temperature, pH, and TDS. However, DO and SS had smaller effects on survival than other parameters. High-impact interactions on E. coli survival were observed between temperature and TDS and temperature and coexisting microbes. These results suggest that existing numerical models for simulating E. coli survival in lakes should be modified to consider the independent and interactive effects of multiple parameters such as sunlight, coexisting microbes, temperature, pH, and TDS.
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Affiliation(s)
- Ichiro Yoneda
- Department of Regional Environment Creation, United Graduate School of Agricultural Sciences, Iwate University, 18-8 Ueda 3-Chome, Morioka, 020-8850, Japan.
| | - Masateru Nishiyama
- Department of Food, Life and Environmental Sciences, Faculty of Agriculture, Yamagata University, 1-23 Wakaba-Machi, Tsuruoka, 997-0037, Japan
| | - Toru Watanabe
- Department of Food, Life and Environmental Sciences, Faculty of Agriculture, Yamagata University, 1-23 Wakaba-Machi, Tsuruoka, 997-0037, Japan
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Liu C, Zhang F, Jim CY, Johnson VC, Tan ML, Shi J, Lin X. Controlled and driving mechanism of the SPM variation of shallow Brackish Lakes in arid regions. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 878:163127. [PMID: 37001663 DOI: 10.1016/j.scitotenv.2023.163127] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/08/2022] [Revised: 02/27/2023] [Accepted: 03/24/2023] [Indexed: 05/13/2023]
Abstract
Suspended particulate matter (SPM) in the brackish Ebinur Lake of arid northwest China profoundly affect its water quality and watershed habitat quality. However, the actual driving mechanisms of the Lake's SPM changes remain unclear. Therefore, the purpose of this study is to explore the controlling factors driving the variability of SPM in the Ebinur Lake. This study constructed month-by-month SPM maps of Ebinur Lake based on time-series remote-sensing imageries and SPM inversion model. Thirty-four factors that might influence SPM changes were extracted, and the Partial Least Squares Structural Equation Modeling (PLS-SEM), suitable for complex relationships and factor interactions, was applied to identify the relative influence of each factor quantitatively. The results showed: (1) a clear increasing trend of SPM concentration in Ebinur Lake from 2011 to 2020; (2) that SPM changes were influenced by external and internal factors, explaining 48.2 % and 46.9 % of the changes, respectively; (3) that, to the external factors, meteorological factors exerted the greatest influence on SPM (relative contribution of 38.9 %); that, to the internal factors, water salinity imposed the greatest influence on SPM (relative contribution of 43.3 %); (4) that, among the meteorological factors, the measured variable Alashankou wind speed expressed the most significant positive effect on SPM (weighting coefficient of 0.894), and sulfate generated the strongest positive effect on SPM (weighting coefficient of 0.791) among the water salinity factors. Hence, the quantitative identification of drivers of SPM changes in Ebinur Lake could provide a new perspective to investigate the driving mechanisms of lake water quality in arid areas and inform their sustainable restoration and management.
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Affiliation(s)
- Changjiang Liu
- Xinjiang Institute of Technology, Aksu 843000, China; College of Geography and Remote Sensing Sciences, Xinjiang University, Urumqi 830017, China
| | - Fei Zhang
- College of Geography and Environmental Sciences, Zhejiang Normal University, Jinhua 321004, China; College of Geography and Remote Sensing Sciences, Xinjiang University, Urumqi 830017, China.
| | - Chi-Yung Jim
- Department of Social Sciences, Education University of Hong Kong, Lo Ping Road, Tai Po 999077, Hong Kong
| | - Verner Carl Johnson
- Department of Physical and Environmental Sciences, Colorado Mesa University, Grand Junction, CO 81501, USA
| | - Mou Leong Tan
- GeoInformatic Unit, Geography Section, School of Humanities, Universiti Sains Malaysia, USM, Penang 11800, Malaysia
| | - Jingchao Shi
- Departments of Earth Sciences, the University of Memphis, Memphis, TN 38152, USA
| | - Xingwen Lin
- College of Geography and Environmental Sciences, Zhejiang Normal University, Jinhua 321004, China
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Finlayson-Trick E, Nearing J, Fischer JAJ, Ma Y, Wang S, Krouen H, Goldfarb DM, Karakochuk CD. The Effect of Oral Iron Supplementation on Gut Microbial Composition: a Secondary Analysis of a Double-Blind, Randomized Controlled Trial among Cambodian Women of Reproductive Age. Microbiol Spectr 2023; 11:e0527322. [PMID: 37199608 PMCID: PMC10269596 DOI: 10.1128/spectrum.05273-22] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2022] [Accepted: 04/28/2023] [Indexed: 05/19/2023] Open
Abstract
The World Health Organization recommends untargeted iron supplementation for women of reproductive age (WRA) in countries where anemia prevalence is greater than 40%, such as Cambodia. Iron supplements, however, often have poor bioavailability, so the majority remains unabsorbed in the colon. The gut houses many iron-dependent bacterial enteropathogens; thus, providing iron to individuals may be more harmful than helpful. We examined the effects of two oral iron supplements with differing bioavailability on the gut microbiomes in Cambodian WRA. This study is a secondary analysis of a double-blind, randomized controlled trial of oral iron supplementation in Cambodian WRA. For 12 weeks, participants received ferrous sulfate, ferrous bisglycinate, or placebo. Participants provided stool samples at baseline and 12 weeks. A subset of stool samples (n = 172), representing the three groups, were randomly selected for gut microbial analysis by 16S rRNA gene sequencing and targeted real-time PCR (qPCR). At baseline, 1% of women had iron-deficiency anemia. The most abundant gut phyla were Bacteroidota (45.7%) and Firmicutes (42.1%). Iron supplementation did not alter gut microbial diversity. Ferrous bisglycinate increased the relative abundance of Enterobacteriaceae, and there was a trend towards an increase in the relative abundance of Escherichia-Shigella. qPCR detected an increase in the enteropathogenic Escherichia coli (EPEC) virulence gene, bfpA, in the group that received ferrous sulfate. Thus, iron supplementation did not affect overall gut bacterial diversity in predominantly iron-replete Cambodian WRA, however, evidence does suggest an increase in relative abundance within the broad family Enterobacteriaceae associated with ferrous bisglycinate use. IMPORTANCE To the best of our knowledge, this is the first published study to characterize the effects of oral iron supplementation on the gut microbiomes of Cambodian WRA. Our study found that iron supplementation with ferrous bisglycinate increases the relative abundance of Enterobacteriaceae, which is a family of bacteria that includes many Gram-negative enteric pathogens like Salmonella, Shigella, and Escherichia coli. Using qPCR for additional analysis, we were able to detect genes associated with enteropathogenic E. coli, a type of diarrheagenic E. coli known to be present around the world, including water systems in Cambodia. The current WHO guidelines recommend blanket (untargeted) iron supplementation for Cambodian WRA despite a lack of studies in this population examining iron's effect on the gut microbiome. This study can facilitate future research that may inform evidence-based global practice and policy.
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Affiliation(s)
- Emma Finlayson-Trick
- Faculty of Medicine, University of British Columbia, Vancouver, British Columbia, Canada
| | - Jacob Nearing
- Department of Microbiology and Immunology, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Jordie AJ. Fischer
- Food, Nutrition and Health, University of British Columbia, Vancouver, British Columbia, Canada
- BC Children’s Hospital Research Institute, Vancouver, British Columbia, Canada
| | - Yvonne Ma
- Food, Nutrition and Health, University of British Columbia, Vancouver, British Columbia, Canada
| | - Siyun Wang
- Food, Nutrition and Health, University of British Columbia, Vancouver, British Columbia, Canada
| | - Hou Krouen
- Helen Keller International, Phnom Penh, Cambodia
| | - David M. Goldfarb
- Faculty of Medicine, University of British Columbia, Vancouver, British Columbia, Canada
- BC Children’s Hospital Research Institute, Vancouver, British Columbia, Canada
- Department of Pathology and Laboratory Medicine, BC Children’s and Women’s Hospital and University of British Columbia, Vancouver, British Columbia, Canada
| | - Crystal D. Karakochuk
- Food, Nutrition and Health, University of British Columbia, Vancouver, British Columbia, Canada
- BC Children’s Hospital Research Institute, Vancouver, British Columbia, Canada
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