scholarly journals Evaluating the impact of hydrometeorological conditions on E. coli concentration in farmed mussels and clams: experience in Central Italy

2021 ◽  
Author(s):  
Valentina Colaiuda ◽  
Federica Di Giacinto ◽  
Annalina Lombardi ◽  
Carla Ippoliti ◽  
Carla Giansante ◽  
...  
Keyword(s):  
River Discharge ◽  
Rank Order ◽  
Central Italy ◽  
Weather System ◽  
E Coli ◽  
Untreated Wastewater ◽  
High Concentrations ◽  
Production Areas ◽  
The Impact ◽  
Hydrometeorological Conditions

Abstract Highly populated coastal environments receive large quantities of treated and untreated wastewater from human and industrial sources. Bivalve molluscs accumulate and retain contaminants, and their analysis provides evidence of past contamination. Rivers and precipitation are major routes of bacteriological pollution from surface or sub-surface runoff flowing into coastal areas. However, relationships between runoff, precipitation, and bacterial contamination are site-specific and dependent on the physiographical characteristics of each catchment. In this work, we evaluated the influence of precipitation and river discharge on molluscs' Escherichia coli concentrations at three sites in Central Italy, aiming at quantifying how hydrometeorological conditions affect bacteriological contamination of selected bivalve production areas. Rank-order correlation analysis indicated a stronger association between E. coli concentrations and the modelled Pescara River discharge maxima (r = 0.69) than between E. coli concentration and rainfall maxima (r = 0.35). Discharge peaks from the Pescara River caused an increase in E. coli concentration in bivalves in 87% of cases, provided that the runoff peak occurred 1–6 days prior to the sampling date. Precipitation in coastal area was linked to almost 60% of cases of E. coli high concentrations and may enhance bacterial transportation offshore, when associated with a larger-scale weather system, which causes overflow occurrence.

scholarly journals Impact of mcr-1 on the Development of High Level Colistin Resistance in Klebsiella pneumoniae and Escherichia coli

2021 ◽  
Vol 12 ◽  
Author(s):  
Xiao-Qing Zhu ◽  
Yi-Yun Liu ◽  
Renjie Wu ◽  
Haoliang Xun ◽  
Jian Sun ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Klebsiella Pneumoniae ◽  
Bacterial Species ◽  
Survival Rates ◽  
Genetic Alterations ◽  
Colistin Resistance ◽  
E Coli ◽  
High Concentrations ◽  
High Level ◽  
The Impact

Plasmid-mediated colistin resistance gene mcr-1 generally confers low-level resistance. The purpose of this study was to investigate the impact of mcr-1 on the development of high-level colistin resistance (HLCR) in Klebsiella pneumoniae and Escherichia coli. In this study, mcr-1-negative K. pneumoniae and E. coli strains and their corresponding mcr-1-positive transformants were used to generate HLCR mutants via multiple passages in the presence of increasing concentrations of colistin. We found that for K. pneumoniae, HLCR mutants with minimum inhibitory concentrations (MICs) of colistin from 64 to 1,024 mg/L were generated. Colistin MICs increased 256- to 4,096-fold for mcr-1-negative K. pneumoniae strains but only 16- to 256-fold for the mcr-1-harboring transformants. For E. coli, colistin MICs increased 4- to 64-folds, but only 2- to 16-fold for their mcr-1-harboring transformants. Notably, mcr-1 improved the survival rates of both E. coli and K. pneumoniae strains when challenged with relatively high concentrations of colistin. In HLCR K. pneumoniae mutants, amino acid alterations predominately occurred in crrB, followed by phoQ, crrA, pmrB, mgrB, and phoP, while in E. coli mutants, genetic alterations were mostly occurred in pmrB and phoQ. Additionally, growth rate analyses showed that the coexistence of mcr-1 and chromosomal mutations imposed a fitness burden on HLCR mutants of K. pneumoniae. In conclusion, HLCR was more likely to occur in K. pneumoniae strains than E. coli strains when exposed to colistin. The mcr-1 gene could improve the survival rates of strains of both bacterial species but could not facilitate the evolution of high-level colistin resistance.

An assessment of water quality in a coastal embayment (Phaleron Bay, Greece)

1995 ◽  
Vol 32 (7) ◽  
pp. 25-32 ◽  
Author(s):  
A. J. Theodorou
Keyword(s):  
Water Quality ◽  
Environmental Management ◽  
Water Column ◽  
Chlorophyll A ◽  
River Discharge ◽  
Benthic Communities ◽  
Coastal Embayment ◽  
Oceanographic Data ◽  
High Concentrations ◽  
The Impact

Athens basin drains by gravity to the coast into the Phaleron Bay by the Kifissos river. The Phaleron coast is currently undergoing extensive remodelling and is scheduled for development as a major amenity and recreational centre. Thus, an assessment of the Phaleron Bay's present water quality constitutes a prerequisite for the future environmental management of its waters. Analysis of oceanographic data, collected during 1989–1990, showed that eutrophic conditions prevail in the vicinity of Kifissos river, where nutrients and chlorophyll-a occur in high concentrations. Also in this area, the benthic communities have been modified and they are dominated by detritus or sediment feeding polychaetes. However, beyond this region the impact of the river discharge diminishes with distance offshore and in the entrance of the bay, both water column quality and benthos are indistinguishable from those of the open Saronikos Gulf.

On the impact of the hydrological model and catchment hydrology on the design flood estimation in a small catchment in Central Italy affected by the recent 2016 earthquake events

2020 ◽  
Author(s):  
Shima Azimi ◽  
Silvia Barbetta ◽  
Tommaso Moramarco ◽  
Angelica Tarpanelli ◽  
Stefania Camici ◽  
...  
Keyword(s):  
Climate Change ◽  
Time Series ◽  
River Discharge ◽  
Hydrological Model ◽  
Central Italy ◽  
Change Scenario ◽  
Catchment Hydrology ◽  
Design Flood ◽  
Flood Estimation ◽  
The Impact

<p>Flood is one of the most frequent disasters which dangerously impacts societies and economies worldwide. Floodplain management and hydraulic risk analysis based on design flood estimation are essential tools to reduce damages and save human lives. Flood Frequency Analysis (FFA) has been classically used to derive design river discharge estimates, however, the scarce availability of discharge observations, especially in small catchments (<150 km2), makes its application not always possible. In addition, with the projections foreseen by the International Panel on Climate Change (IPCC) the use of FFA might lead to incorrect estimates of design river discharge as FFA is based on the concept of stationarity. Generally, long rainfall and temperature time series are much more available than discharge observations but their temporal coverage is often not sufficient for carrying out FFA via a hydrological simulation.</p><p>To handle these drawbacks, the combination of a stochastic generation of rainfall and temperature time series, Regional Circulation Model (RCM) projections and continuous hydrological models provides a reliable tool for obtaining long river discharge time series to implement FFA. However, design flood estimations can be significantly uncertain due to several factors such as 1) the specific model structure, parameterizations and processes representation, 2) the catchment hydrology and 3) the specific climate change scenario.</p><p>The primary objective of this study is to explore the sensitivity of the design river discharge estimates to the hydrological model complexity and parameterization. For this, three continuous hydrological distributed models named the Modello Idrologico SemiDistribuito in continuo (MISDc), the Soil & Water Assessment Tool (SWAT) and GEOFrame NewAGE model are forced with long timeseries of rainfall and temperature obtained via the Neyman-Scott rectangular pulse model (NSRP) for stochastic rainfall generation, and the fractionally differenced ARIMA model (FARIMA) for stochastic temperature generation. A secondary objective is to understand the impact of climate change and the catchment hydrology on the design river discharge estimates via the use of different RCM projections.</p><p>The study is carried in the Upper Nera catchment in Central Italy which was impacted by the recent 2016 earthquake and for which is necessary to identify hydraulic risk mitigation measures and adaptation for a forward planning in the floodplain areas where new settlements will be rebuilt.</p><p>Preliminary results suggest the high dependency of the design river discharge estimates to the chosen hydrological model and a different response of the sub-catchments to the climate change scenario.</p>

scholarly journals Impact of Different Land Uses on the Escherichia coli Concentrations, Physical and Chemical Water Quality Parameters in a Tropical Stream

2016 ◽  
Vol 2 (2) ◽  
pp. 42-51
Author(s):  
Ling Teck Yee ◽  
Lim Swee Wee ◽  
Lesley Maurice Bilung ◽  
Lee Nyanti
Keyword(s):  
Water Quality ◽  
Quality Parameters ◽  
Point Sources ◽  
Water Quality Parameters ◽  
Land Uses ◽  
Human Settlement ◽  
Tropical Stream ◽  
E Coli ◽  
High Concentrations ◽  
The Impact

Rural streams are important source of water for the nearby communities. However, bacterial contamination from agriculture and human settlement may render the water unsuitable for drinking and body contact recreation. Hence, the objective of this study was to determine the impact of different land uses such as animal farming and human settlement on E. coli concentrations in the Serin River, a tropical stream. Samplings were conducted at 9 stations from September 2009 to March 2010. Results showed that E. coli concentrations ranged from 2,000-6,900,000 CFU/100 mL with E. coli concentrations in fish aquaculture water exceeding the WHO standard. Animal and crop farming stations showed the highest E. coli concentrations in the tributaries. Re-suspension from stream sediment and non-point sources such as runoff contributed to the high concentrations observed in the main river. Multiple linear regressions indicated that total suspended solids and dissolved oxygen were significant water quality parameters and they explained 68.1% of the total E. coli variations observed.

COASTAL AND ESTUARINE SEDIMENT DYNAMICS IN THE MEZEN BAY AND ESTUARIES MEZEN AND KULOY

2018 ◽  
Author(s):  
Н. Демиденко ◽  
N. Demidenko
Keyword(s):  
River Water ◽  
River Discharge ◽  
Sea Water ◽  
Sediment Dynamics ◽  
Estuarine Sediment ◽  
Sea Surface ◽  
Cross Sectional ◽  
Sand Waves ◽  
Tidal Estuaries ◽  
High Concentrations

In the Mezen bay and estuaries Mezen and Kuloy can be high concentrations of mud suspension there, involving the formation at times mobile suspensions and settled mud. Within estuaries the river water is mixed with the sea water by the action of tidal motions, by waves on the sea surface and by the river discharge forcing its way to the sea. Nearly all shallow tidal estuaries, where currents exceed about 1,0m s-1 and where sand is present, have sand waves. Sand waves have a variety of cross-sectional and plan forms.

Impact of Raw Materials and Processing Techniques on The Microbiological Quality of Egyptian Domiati Cheese

2020 ◽  
Keyword(s):  
Raw Materials ◽  
Microbiological Quality ◽  
Raw Milk ◽  
Plate Count ◽  
E Coli ◽  
Fresh Cheese ◽  
Processing Techniques ◽  
The Impact ◽  
Total Yeast

Domiati cheese is the most popular brand of cheese ripened in brine in the Middle East in terms of consumed quantities. This study was performed to investigate the impact of the microbiological quality of the used raw materials, the applied traditional processing techniques and ripening period on the quality and safety of the produced cheese. Three hundred random composite samples were collected from three factories at Fayoum Governorate, Egypt. Collected samples represent twenty-five each of: raw milk, table salt, calf rennet, microbial rennet, water, environmental air, whey, fresh cheese, ripened cheese & swabs from: worker hands; cheese molds and utensils; tanks. All samples were examined microbiologically for Standard Plate Count (SPC), coliforms count, Staphylococcus aureus (S. aureus) count, total yeast & mould count, presence of E. coli, Salmonellae and Listeria monocytogenes (L. monocytogenes). The mean value of SPC, coliforms, S. aureus and total yeast & mould counts ranged from (79×102 CFU/m3 for air to 13×108 CFU/g for fresh cheese), (7×102 MPN/ cm2 for tank swabs to 80×106 MPN/ml for raw milk), (9×102 CFU/g for salt to 69×106 CFU/g for fresh cheese) and (2×102 CFU/cm2 for hand swabs to 60×104 CFU/g for fresh cheese), respectively. Whereas, E. coli, Salmonella and L. monocytogenes failed to be detected in all examined samples. There were significant differences in all determined microbiological parameters (p ≤0.05) between fresh and ripened cheese which may be attributed to different adverse conditions such as water activity, pH, salt content and temperature carried out to improve the quality of the product.

Hygienic risk assessment by monitoring pathogens in municipal sewage

2002 ◽  
Vol 2 (3) ◽  
pp. 23-28 ◽  
Author(s):  
C.-H. von Bonsdorff ◽  
L. Maunula ◽  
R.M. Niemi ◽  
R. Rimhanen-Finne ◽  
M.-L. Hänninen ◽  
...  
Keyword(s):  
Enteric Viruses ◽  
Detection Methods ◽  
Municipal Sewage ◽  
Small Community ◽  
E Coli ◽  
Cryptosporidium Oocysts ◽  
High Concentrations ◽  
One Year ◽  
Enteric Protozoa ◽  
Day Care Centre

The purpose of this study was to monitor the levels of human enteric viruses and enteric protozoa and to relate their presence to the microbes used as hygienic quality indicators in domestic sewage from a small community in Finland during a period of one year. Genome-based sensitive detection methods for the pathogens selected (astro- and Norwalk-like viruses, Giardia and Cryptosporidium) have become available only recently and thus no earlier data was available. The effluent sewage is delivered into a river that serves as raw water for a larger town and the pathogens therefore constitute a health risk. The results showed that all the monitored pathogens could be detected, and that enteric viruses were present at considerable concentrations in sewage. High concentrations of astrovirus in raw sewage were observed during a diarrhea epidemic in the local day-care centre. The presence of viruses did not correlate with the monitored bacterial indicators of faecal contamination (coliforms, E. coli and enterococci) or with bacteriophages (somatic coliphages, F-specific RNA phages and B. fragilis phages). Giardia cysts and Cryptosporidium oocysts were detected from one sample (1/10) each.

The ecological state of the Elefsis Bay prior to the operation of the athens sea outfall

1994 ◽  
Vol 30 (10) ◽  
pp. 161-171 ◽  
Author(s):  
A. J. Theodorou
Keyword(s):  
River Discharge ◽  
Thermal Stratification ◽  
Lower Layer ◽  
Ecological State ◽  
Annual Cycles ◽  
Untreated Wastewater ◽  
Resistant Species ◽  
Acartia Clausi ◽  
Gyrodinium Aureolum ◽  
Agricultural Areas

Nutrient pollution in Elefsis Bay arises mainly from the disposal of Athens untreated wastewater at the eastern entrance of the Bay. The absence of river discharge, lack of cultivated agricultural areas providing runoff and the Bay's limited circulation provide the conditions for the Bay's eutrophication by the discharge of untreated wastewater. In the spring of 1993 this discharge was replaced by a new deep outfall system. To monitor any future changes an assessment of the present ecological state of the Bay is required. Analysis of appropriate data showed that Elefsis Bay accumulates nutrients. In summer a strong thermal stratification causes anoxic conditions to occur in the lower layer. The ecosystem exhibits reduced species diversity and strong oscillations of plankton annual cycles. Flagellates (Cryptomonas sp.) dominate the phytoplankton, followed by dinoflagellates (Gyrodinium aureolum, Prorocentum dentatum) and only in the spring diatoms (Nitzschia) predominate. The zooplankton was dominated by copepods (Acartia clausi) and cladoceran (Podon polyphemoides). Macrobenthos consists of a small number of pollution-resistant species of Polychaeta (Capitela capitata), whilst in summer only one species of Molluscs (Corbula gibba) survives.

Identification of N-Substituted Triazolo-azetidines as Novel Antibacterials using pDualrep2 HTS Platform

2019 ◽  
Vol 22 (5) ◽  
pp. 346-354
Author(s):  
Yan A. Ivanenkov ◽  
Renat S. Yamidanov ◽  
Ilya A. Osterman ◽  
Petr V. Sergiev ◽  
Vladimir A. Aladinskiy ◽  
...  
Keyword(s):  
Antibacterial Activity ◽  
Large Scale ◽  
Underlying Mechanism ◽  
Luciferase Assay ◽  
Reporter System ◽  
E Coli ◽  
Starting Point ◽  
High Concentrations ◽  
Mic Value

Aim and Objective: Antibiotic resistance is a serious constraint to the development of new effective antibacterials. Therefore, the discovery of the new antibacterials remains one of the main challenges in modern medicinal chemistry. This study was undertaken to identify novel molecules with antibacterial activity. Materials and Methods: Using our unique double-reporter system, in-house large-scale HTS campaign was conducted for the identification of antibacterial potency of small-molecule compounds. The construction allows us to visually assess the underlying mechanism of action. After the initial HTS and rescreen procedure, luciferase assay, C14-test, determination of MIC value and PrestoBlue test were carried out. Results: HTS rounds and rescreen campaign have revealed the antibacterial activity of a series of Nsubstituted triazolo-azetidines and their isosteric derivatives that has not been reported previously. Primary hit-molecule demonstrated a MIC value of 12.5 µg/mL against E. coli Δ tolC with signs of translation blockage and no SOS-response. Translation inhibition (26%, luciferase assay) was achieved at high concentrations up to 160 µg/mL, while no activity was found using C14-test. The compound did not demonstrate cytotoxicity in the PrestoBlue assay against a panel of eukaryotic cells. Within a series of direct structural analogues bearing the same or bioisosteric scaffold, compound 2 was found to have an improved antibacterial potency (MIC=6.25 µg/mL) close to Erythromycin (MIC=2.5-5 µg/mL) against the same strain. In contrast to the parent hit, this compound was more active and selective, and provided a robust IP position. Conclusion: N-substituted triazolo-azetidine scaffold may be used as a versatile starting point for the development of novel active and selective antibacterial compounds.

scholarly journals KUALITAS AIR SUNGAI DI KAWASAN WISATA PANTAI PETITENGET, KEROBOKAN KABUPATEN BADUNG BALI

2018 ◽  
Vol 12 (2) ◽  
pp. 226
Author(s):  
Wayan Budiarsa Suyasa ◽  
Sri Kunti Pancadewi G. A ◽  
Iryanti E. Suprihatin ◽  
Dwi Adi Suastuti G. A.
Keyword(s):  
Water Quality ◽  
Structural Changes ◽  
Pollution Index ◽  
Basic Structure ◽  
Physical Damage ◽  
E Coli ◽  
Pollutant Source ◽  
Quality Category ◽  
Index Value ◽  
The Impact

In order to maintain the environmental carrying capacity of coastal tourism, this research was conducted to determine the condition of river water environmental pollution in the Petitenget beach area and pollutant source activities. Determination of water quality is carried out by analyzing the water quality taken at several sampling points in the four rivers that lead to the Petitenget beach. Determined the pollution index value (IP) of the physical chemical and biological pollution parameters. The results showed that the four rivers that flow into the Petitenget Beach area had been contaminated with indications of pH, BOD, COD, ammonia, Coliform and E. coli which exceeded water quality category III class quality (PerGub Bali No 16 Year 2016). The four rivers are included in the criteria of severe contamination. The four rivers have experienced physical damage or structural changes that have very high discharge fluctuations both in quantity and quality. Slimy basic structure, smelly and slum aesthetic waters. While the indication of the impact of pollution is waste water which is directly discharged into the river from hotels, restaurants, homestays, commercial centers and settlements.

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