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The food of common bream (Abramis brama L.) in a biomanipulated water supply reservoir Полный текст
2012
Zapletal, T., Mendelova Univ., Brno (Czech Republic). Ustav Zoologie, Rybarstvi, Hydrobiologie a Vcelarstvi | Mares, J., Mendelova Univ., Brno (Czech Republic). Ustav Zoologie, Rybarstvi, Hydrobiologie a Vcelarstvi | Jurajda, P., Akademie Ved, Brno (Czech Republic). Ustav Biologie Obratlovcu | Vsetickova, L., Akademie Ved, Brno (Czech Republic). Ustav Biologie Obratlovcu
Food composition of Abramis brama was studied in the shallow, meso-eutrophic Hamry reservoir (Czech Republic). Fish were sampled during the daytime in the pre-spawning period (April), the post-spawning (June), summer (July) and autumn (October) in 2011. The bream sampled comprised two main size groups: small (124-186 mm) and large (210-315 mm) standard length. Twenty specimens of each size group (except April - 40 large fish) were taken for analysis on each sampling occasion. Food composition was evaluated using gravimetric methods. Over the whole season, detritus and aquatic vegetation were the dominant dietary items taken. During summer, the diet of large bream comprised mainly aquatic vegetation. Benthic macroinvertebrates and zooplankton formed a minor part of bream diet over the whole season. Specific food habits of bream could be explained by specific conditions within the reservoir and available food resources.
Показать больше [+] Меньше [-]Fecal Indicator Bacteria along Multiple Environmental Transmission Pathways (Water, Hands, Food, Soil, Flies) and Subsequent Child Diarrhea in Rural Bangladesh Полный текст
2018
Pickering, Amy J. | Ercumen, Ayse | Arnold, Benjamin F. | Kwong, Laura H. | Parvez, Sarker Masud | Alam, Mahfuja | Sen, Debashis | Islam, Sharmin | Kullmann, Craig | Chase, Claire | Ahmed, Rokeya | Unicomb, Leanne | Colford, John M. | Luby, Stephen P.
Enteric pathogens can be transmitted through multiple environmental pathways, yet little is known about the relative contribution of each pathway to diarrhea risk among children. We aimed to identify fecal transmission pathways in the household environment associated with prospectively measured child diarrhea in rural Bangladesh. We measured the presence and levels of Escherichia coli in tube wells, stored drinking water, pond water, child hand rinses, courtyard soil, flies, and food in 1843 households. Gastrointestinal symptoms among children ages 0–60 months were recorded concurrently at the time of environmental sample collection and again a median of 6 days later. Incident diarrhea (3 or more loose stools in a 24-h period) was positively associated with the concentration of E. coli on child hands measured on the first visit (incidence rate ratio [IRR] = 1.23, 95% CI 1.06, 1.43 for a log₁₀ increase), while other pathways were not associated. In cross-sectional analysis, there were no associations between concurrently measured environmental contamination and diarrhea. Our findings suggest higher levels of E. coli on child hands are strongly associated with subsequent diarrheal illness rates among children in rural Bangladesh.
Показать больше [+] Меньше [-]Animal Feces Contribute to Domestic Fecal Contamination: Evidence from E. coli Measured in Water, Hands, Food, Flies, and Soil in Bangladesh Полный текст
2017
Ercumen, Ayse | Pickering, Amy J. | Kwong, Laura H. | Arnold, Benjamin F. | Parvez, Sarker Masud | Alam, Mahfuja | Sen, Debashis | Islam, Sharmin | Kullmann, Craig | Chase, Claire | Ahmed, Rokeya | Unicomb, Leanne | Luby, Stephen P. | Colford, John M.
Fecal-oral pathogens are transmitted through complex, environmentally mediated pathways. Sanitation interventions that isolate human feces from the environment may reduce transmission but have shown limited impact on environmental contamination. We conducted a study in rural Bangladesh to (1) quantify domestic fecal contamination in settings with high on-site sanitation coverage; (2) determine how domestic animals affect fecal contamination; and (3) assess how each environmental pathway affects others. We collected water, hand rinse, food, soil, and fly samples from 608 households. We analyzed samples with IDEXX Quantitray for the most probable number (MPN) of E. coli. We detected E. coli in source water (25%), stored water (77%), child hands (43%), food (58%), flies (50%), ponds (97%), and soil (95%). Soil had >120 000 mean MPN E. coli per gram. In compounds with vs without animals, E. coli was higher by 0.54 log₁₀ in soil, 0.40 log₁₀ in stored water and 0.61 log₁₀ in food (p < 0.05). E. coli in stored water and food increased with increasing E. coli in soil, ponds, source water and hands. We provide empirical evidence of fecal transmission in the domestic environment despite on-site sanitation. Animal feces contribute to fecal contamination, and fecal indicator bacteria do not strictly indicate human fecal contamination when animals are present.
Показать больше [+] Меньше [-]Do Sanitation Improvements Reduce Fecal Contamination of Water, Hands, Food, Soil, and Flies? Evidence from a Cluster-Randomized Controlled Trial in Rural Bangladesh Полный текст
2018
Ercumen, Ayse | Pickering, Amy J. | Kwong, Laura H. | Mertens, Andrew | Arnold, Benjamin F. | Benjamin-Chung, Jade | Hubbard, Alan E. | Alam, Mahfuja | Sen, Debashis | Islam, Sharmin | Rahman, Md Zahidur | Kullmann, Craig | Chase, Claire | Ahmed, Rokeya | Parvez, Sarker Masud | Unicomb, Leanne | Rahman, Mahbubur | Ram, Pavani K. | Clasen, Thomas | Luby, Stephen P. | Colford, John M.
Sanitation improvements have had limited effectiveness in reducing the spread of fecal pathogens into the environment. We conducted environmental measurements within a randomized controlled trial in Bangladesh that implemented individual and combined water treatment, sanitation, handwashing (WSH) and nutrition interventions (WASH Benefits, NCT01590095). Following approximately 4 months of intervention, we enrolled households in the trial’s control, sanitation and combined WSH arms to assess whether sanitation improvements, alone and coupled with water treatment and handwashing, reduce fecal contamination in the domestic environment. We quantified fecal indicator bacteria in samples of drinking and ambient waters, child hands, food given to young children, courtyard soil and flies. In the WSH arm, Escherichia coli prevalence in stored drinking water was reduced by 62% (prevalence ratio = 0.38 (0.32, 0.44)) and E. coli concentration by 1-log (Δlog₁₀ = −0.88 (−1.01, −0.75)). The interventions did not reduce E. coli along other sampled pathways. Ambient contamination remained high among intervention households. Potential reasons include noncommunity-level sanitation coverage, child open defecation, animal fecal sources, or naturalized E. coli in the environment. Future studies should explore potential threshold effects of different levels of community sanitation coverage on environmental contamination.
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