Model of Vibrio cholerae biofilm as a mechanism of its survival in surface water reservoirs

2014 ◽  
Vol 7 (1) ◽  
pp. 12-18
Author(s):  
E. S. Kulikalova ◽  
S. G. Sappo ◽  
L. Ya. Urbanovich ◽  
E. Yu. Markov ◽  
L. V. Mironova ◽  
...  
Keyword(s):  
Surface Water ◽  
Vibrio Cholerae ◽  
Water Reservoirs

scholarly journals Assessing the Efciency of Detection of Vibrio cholerae Genetic Determinants Through Waterbody Vibrioflora Monitoring System

2021 ◽  
pp. 89-97
Author(s):  
L. V. Mironova ◽  
A. S. Ponomareva ◽  
E. A. Basov ◽  
I. S. Fedotova ◽  
Zh. Yu. Khunkheeva ◽  
...  
Keyword(s):  
Surface Water ◽  
Vibrio Cholerae ◽  
Monitoring System ◽  
Water Samples ◽  
Genetic Determinants ◽  
Water Reservoirs ◽  
Pcr Assay ◽  
Pcr Screening ◽  
Peptone Water ◽  
Integrated Study

Objective of the study was to assess the effectiveness of PCR screening of Vibrio cholerae genetic determinants in samples from surface water reservoirs for optimization of the cholera microbiological monitoring system.Materials and methods. The study was carried out as a part of the vibrioflora monitoring in surface water bodies in Irkutsk city. The study design included: 1) PCR screening of V. cholerae genetic determinants in nutrient-enriched (1 % peptone water) samples from surface water reservoirs during the monitoring period (824 samples); 2) studying of the V. cholerae DNA accumulation dynamics applying PCR assay of the samples from surface water reservoirs during cultivation on the enriched media (16 samples in dynamics); 3) experimental study of the detected V. cholerae concentrations in samples from surface water reservoirs. Species-specifc (hlyA, toxR) and serogroup-specifc (wbeT, wbfR) V. cholerae determinants were indicated in PCR with hybridization-fluorescent and electrophoretic detection.Results and discussion. At the frst stage it was found that the proportion of the positive samples through PCR screening (33.9 %) exceeded the percentage of the positive samples in bacteriological examination (19.3 %) (t=6.6; p<0,01). In the assessment of DNA accumulation dynamics, a decrease in the threshold cycle (Ct) by 1.2–5.2 times was recorded, indicating an increase in the V. cholerae concentration and proving the detection of genetic determinants of viable forms during PCR screening. An extended study of PCR-positive but bacteriologically negative samples made it possible to additionally isolate 4 V. cholerae cultures. However, there were no differences in the sensitivity of PCR screening and bacteriological analysis in the experiment with water samples artifcially contaminated with V. cholerae unlike the analysis of the enriched native samples. It can be determined by the metabolism and adaptation peculiarities of the microorganism in different environmental conditions. The results of the integrated study indicate the epidemiological effectiveness of PCR screening which gives grounds to recommend its application in monitoring studies of vibrioflora from environment after preliminary enrichment on liquid nutrient media in the work of federal, territorial, and regional laboratories.

scholarly journals Molecular characterization of Vibrio cholerae O1 and non-O1 from human and environmental sources in Malaysia

1999 ◽  
Vol 123 (2) ◽  
pp. 225-232 ◽  
Author(s):  
S. RADU ◽  
Y. K. HO ◽  
S. LIHAN ◽  
YUHERMAN ◽  
G. RUSUL ◽  
...  
Keyword(s):  
Antibiotic Resistance ◽  
Surface Water ◽  
Vibrio Cholerae ◽  
Genetic Relatedness ◽  
Profile Analysis ◽  
Random Amplified Polymorphic Dna ◽  
Plasmid Profile ◽  
Significant Public Health ◽  
Resistance Patterns ◽  
Wide Variability

A total of 31 strains of Vibrio cholerae O1 (10 from outbreak cases and 7 from surface water) and non-O1 (4 from clinical and 10 from surface water sources) isolated between 1993 and 1997 were examined with respect to presence of cholera enterotoxin (CT) gene by PCR-based assays, resistance to antibiotics, plasmid profiles and random amplified polymorphic DNA (RAPD) analysis. All were resistant to 9 or more of the 17 antibiotics tested. Identical antibiotic resistance patterns of the isolates may indicate that they share a common mode of developing antibiotic resistance. Furthermore, the multiple antibiotic resistance indexing showed that all strains tested originated from high risk contamination. Plasmid profile analysis by agarose gel electrophoresis showed the presence of small plasmids in 12 (7 non-O1 and 5 O1 serotypes) with sizes ranging 1·3–4·6 MDa. The CT gene was detected in all clinical isolates but was present in only 14 (6 O1 serotype and 8 non-O1 serotype) isolates from environmental waters. The genetic relatedness of the clinical and environmental Vibrio cholerae O1 and non-O1 strains was investigated by RAPD fingerprinting with four primers. The four primers generated polymorphisms in all 31 strains of Vibrio cholerae tested, producing bands ranging from <250 to 4500 bp. The RAPD profiles revealed a wide variability and no correlation with the source of isolation. This study provides evidence that Vibrio cholerae O1 and non-O1 have significant public health implications.

Effect of dynamically varying zone-based hedging policies on the operational performance of surface water reservoirs during climate change

2018 ◽  
Vol 488 (1) ◽  
pp. 277-289 ◽  
Author(s):  
Adebayo J. Adeloye ◽  
Bankaru-Swamy Soundharajan
Keyword(s):  
Climate Change ◽  
Surface Water ◽  
Operational Performance ◽  
Dynamic Hedging ◽  
Water Reservoirs ◽  
Complex Dynamic ◽  
Water Shortages ◽  
Operational Conditions ◽  
Static Hedging ◽  
The Impact

AbstractHedging is universally recognized as a useful operational practice in surface water reservoirs to temporally redistribute water supplies and thereby avoid large, crippling water shortages. When based on the zones of available water in storage, hedging has traditionally involved a static rationing (i.e. supply to demand) ratio. However, given the usual seasonality of reservoir inflows, it is also possible that hedging could be dynamic with seasonally varying rationing ratios. This study examined the effect of static and dynamic hedging policies on the performance of the Pong reservoir in India during a period of climate change. The results show that the reservoir vulnerability was unacceptably high (≥60%) without hedging and that this vulnerability further deteriorated as the catchment became drier due to projected climate change. The time- and volume-based reliabilities were acceptable. The introduction of static hedging drastically reduced the vulnerability to <25%, although the hedging reduction in the water supplied during normal operational conditions was only 17%. Further analyses with dynamic hedging provided only modest improvements in vulnerability. The significance of this study is its demonstration of the effectiveness of hedging in offsetting the impact of water shortages caused by climate change and the fact that static hedging can match more complex dynamic hedging policies.

Occurrence of Vibrio cholerae in water reservoirs of Burkina Faso

2018 ◽  
Vol 169 (1) ◽  
pp. 1-10 ◽  
Author(s):  
Saidou Kaboré ◽  
Philippe Cecchi ◽  
Thomas Mosser ◽  
Mylène Toubiana ◽  
Oumar Traoré ◽  
...  
Keyword(s):  
Burkina Faso ◽  
Vibrio Cholerae ◽  
Water Reservoirs

scholarly journals Formulated Mathematical Model for Delayed Particle Flow in Cascaded Sub-Surface Water Reservoirs with Validation on River Flow

2018 ◽  
Author(s):  
Ombaki Richard ◽  
Kerongo Joash ◽  
Okwoyo M. James
Keyword(s):  
Mathematical Model ◽  
Time Delay ◽  
Surface Water ◽  
Discrete Time ◽  
River Flow ◽  
Water Reservoir ◽  
Point Sources ◽  
Water Reservoirs ◽  
Discrete Time Delay ◽  
Mixing Problem

Pollution of sub-surface water reservoirs mainly rivers and streams through contaminated water point sources (CWPS) was studied. The objective was to formulate a discrete time delay mathematical model which describes the dynamics of reservoir pollution using mixing-problem processes that involve single species contaminants such as nitrates, phosphorous and detergents. The concentration &nbsp;of pollutants was expressed as a function of the inflow and outflow rates using the principle for the conservation of mass. Systems of ODEs generated from principles of mixing problems were refined into a system of DDEs so that the concentration of pollutant leaving the reservoir at time would be determined at some earlier instant, for the delay. The formulated model is a mathematical discrete time delay model which would be used to describe the dynamics of sub-surface water reservoir pollution. The results from the validation of the model were analyzed &nbsp;&nbsp;to determine how time delays in the mixing processes affect the rate of particle movement in water reservoirs.

scholarly journals Quantifying Focused Groundwater Recharge Induced by Irrigation Surface Water Reservoirs in Crystalline Basement Areas for Complementary Irrigation

Water ◽  
2020 ◽  
Vol 12 (10) ◽  
pp. 2880
Author(s):  
Apolline Bambara ◽  
Philippe Orban ◽  
Issoufou Ouedraogo ◽  
Eric Hallot ◽  
Francis Guyon ◽  
...  
Keyword(s):  
Surface Water ◽  
Groundwater Recharge ◽  
Large Diameter ◽  
Spatiotemporal Analysis ◽  
Sub Saharan Africa ◽  
Water Reservoirs ◽  
Water Shortages ◽  
Physico Chemical ◽  
Drying Up ◽  
Sub Saharan

Through the practice of irrigation, surface water reservoirs (SWRs) contribute to the socio-economic development and food production activities of populations in Sub-Saharan Africa (SSA). However, they tend to dry up prematurely. One solution to circumvent these irrigation water shortages is to ensure their conjunctive use with groundwater. The objective of this study is to better understand the contribution of SWRs to groundwater recharge and to determine if groundwater may be considered as a complementary local resource for irrigation. The study was carried out on two watersheds in Burkina Faso, Kierma and Mogtedo. The spatiotemporal analysis of piezometric and SWRs level records coupled with physico-chemical analyses of water was used to characterize exchanges between SWRs and groundwater. The regional groundwater recharge at the scale of the watersheds was assessed. At the SWRs scale, a water balance methodology was developed and used to estimate focused recharge. The results show that SWRs interact almost continuously with groundwater and contribute focused recharge. The magnitude of this recharge is a function of the geological context and the sediment texture of the SWRs. It is estimated at 5 mm/day in Kierma and 4 mm/day in Mogtédo. These values are higher than the natural recharge estimated at 0.2 mm/day in Kierma and 0.1 mm/day in Mogtédo. Additionally, the values of hydraulic conductivity are between 0.01 and 2 m/day in Kierma and between 1 × 10−4 and 0.2 m/day in Mogtédo. These conductivities could allow pumping in large-diameter hand-dug wells with a significant yield between 0.5 and 120 m3/day in Kierma and between 0 and 10 m3/day in Mogtédo to palliate the early drying up of the SWRs.

Assessment of the geometry and volumes of small surface water reservoirs by remote sensing in a semi-arid region with high reservoir density

2019 ◽  
Vol 64 (1) ◽  
pp. 66-79 ◽  
Author(s):  
Bruno Pereira ◽  
Pedro Medeiros ◽  
Till Francke ◽  
Geraldo Ramalho ◽  
Saskia Foerster ◽  
...  
Keyword(s):  
Remote Sensing ◽  
Surface Water ◽  
Arid Region ◽  
Water Reservoirs ◽  
Small Surface ◽  
Semi Arid Region ◽  
Semi Arid

Turkey's Water Resources and Hydropower Potential

2005 ◽  
Vol 23 (1) ◽  
pp. 19-29 ◽  
Author(s):  
Ayhan Demirbaş ◽  
Recep Bakiş
Keyword(s):  
Surface Water ◽  
Water Resources ◽  
Ground Water ◽  
Annual Rainfall ◽  
Water Reservoirs ◽  
Total Potential ◽  
Hydropower Potential ◽  
Different Types

The aim of this paper is to investigate water resources in Turkey. Annual rainfall varies from 220 mm to 2500 mm with an average of 643 mm, which means total volume of 501 km3 and average annual potential of surface water is 186 km3 and 95 km3 of this amount potential can be feasibly developed. Ground water reservoirs are estimated to be around 12 km3. As a result of construction of 700 dams, with different types, purposes and sizes, 140 km3 of water is being stored in the reservoirs. Total hydropower potential of Turkey is annually 433,000 GWh. Almost 50% of the total potential is technically exploitable, and 29% is (122,322 GWh/year) economically exploitable.

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