scholarly journals Spatial and temporal variations of faecal indicator bacteria in Lake Bunyonyi, South-Western Uganda

2021 ◽  
Vol 3 (7) ◽  
Author(s):  
Alex Saturday ◽  
Thomas J. Lyimo ◽  
John Machiwa ◽  
Siajali Pamba

AbstractBackground Microbial water quality serves to indicate health risks associated with the consumption of contaminated water. Nevertheless, little is known about the microbiological characteristics of water in Lake Bunyonyi. This study was therefore undertaken to examine the spatial and temporal variations of faecal indicator bacteria (FIB) in relation to physicochemical parameters in Lake Bunyonyi. Result The FIB concentration was consistently measured during sampling months and correlated with each other showing the presumed human faecal pollution in the lake. The highest concentration values for E. coli (64.7 ± 47.3 CFU/100 mL) and enterococci (24.6 ± 32.4 CFU/100 mL were obtained in the station close to the Mugyera trading centre. On a temporal basis, the maximum values were recorded during the rainy season in October 2019 (70.7 ± 56.5 CFU/100 mL for E. coli and 38.44 ± 31.8 CFU/100 mL for enterococci. FIB did not differ significantly among the study stations (p > 0.05) but showed significant temporal variations among the months (p < 0.05) with concentrations being significantly high in wet season than dry season (U = 794, p < 0.0001 for E. coli; U = 993.5, p = 0.008 for enterococci). Spearman’s rank correlation revealed that FIB concentrations were significantly positively correlated with turbidity and DO concentration levels (p < 0.05). Approximately 97.2% of the water samples had E. coli and enterococci concentrations levels below USEPA threshold for recreational waters. Likewise, 98.1 and 90.7% of samples recorded E. coli and enterococci counts exceeding the UNBS, APHA, WHO and EU threshold values for drinking water. Conclusion The FIB counts show that the Lake Bunyonyi water is bacteriologically unsuitable for drinking unless it is treated since the FIB pose health risks to consumers. Besides, the water can be used for recreational purposes.

2015 ◽  
Vol 13 (4) ◽  
pp. 1029-1038 ◽  
Author(s):  
Jingfeng Fan ◽  
Hongxia Ming ◽  
Lili Li ◽  
Jie Su

The horizontal distribution and temporal variation of bacterial indicators (total coliforms (TC), fecal coliforms (FC), enterococcus (EC) and Escherichia coli (E. coli)) were investigated to identify the proper bacterial indicators for a marine bathing beach in China. Two different sampling efforts were conducted during dry weather and two large rain events at Xinghai Bathing Beach in Dalian, China. Samples were collected from three different water depths and analyzed for the four indicator bacteria. The results indicated that all four bacterial indicators exceeded the single sample standards at different levels. Specifically, the water quality exceeded the standard for TC, FC, EC and E. coli in 7%, 28%, 38% and 10% of the samples, respectively. Comparison of the rate of the indicators before and after rainfall revealed a significant increasing post-rainfall. The concentrations of bacteria differed significantly with distance from the shoreline, with knee-depth near the shore exceeding the standard most frequently. This was primarily due to contamination by excessive sewage discharge and rainfall. Based upon the concentration of indicators and exceedance rates, as well as the correlation between indicators, both EC and FC should be evaluated at the same time as fecal pollution bacterial indicators in marine bathing beaches in China.


2006 ◽  
Vol 54 (3) ◽  
pp. 169-175 ◽  
Author(s):  
R.S. Fujioka ◽  
T.M. Unutoa

The fate (stability, multiplication) of S. aureus, E. coli and E. faecalis was determined in three classes of recreational waters (seawater, estuarine, stream) supplemented with nutrients in the form of sewage and peptone. In the absence of sunlight (24±2 °C), all bacteria in all water samples did not multiply and were slowly (days) inactivated. When 50% sewage was added to all water samples, E. coli and E. faecalis multiplied but S. aureus did not. When peptone (0.05%, 0.5%) was the added nutrient, the three bacteria multiplied. In the presence of sunlight (15–27 °C), S. aureus was inactivated rapidly (hours) in all water samples. These results show that when their nutritional requirements are met, S. aureus, E. coli and E. faecalis can multiply in the high salinity conditions of seawater. However, under environmental conditions, sunlight is an effective natural bactericidal agent.


Author(s):  
Ainslie J. Butler ◽  
Katarina Pintar ◽  
Janis L. Thomas ◽  
Manon Fleury ◽  
Stefanie Kadykalo ◽  
...  

Abstract Recreational water use is an important source of human enteric illness. Enhanced (episodic) surveillance of natural recreational waters as a supplement to beach monitoring can enrich our understanding of human health risks. From 2011 to 2013, water sampling was undertaken at recreational sites on a watershed in eastern Canada. This study compared the prevalence and associations of human enteric pathogens and fecal indicator organisms. Beach water samples had lower pathogen presence than those along the main river, due to different pollution sources and the hydrological disposition. Pathogen profiles identified from the beach sites suggested a more narrow range of sources, including birds, indicating that wild bird management could help reduce public health risks at these sites. The presence and concentration of indicator organisms did not differ significantly between beaches and the river. However, higher concentrations of generic Escherichia coli were observed when Salmonella and Cryptosporidium were present at beach sites, when Salmonella was present at the river recreational site, and when verotoxigenic E. coli were present among all sites sampled. In this watershed, generic E. coli concentrations were good indicators of potential contamination, pathogen load, and elevated human health risk, supporting their use for routine monitoring where enhanced pathogen testing is not possible.


2019 ◽  
Vol 70 (2) ◽  
pp. 140-148 ◽  
Author(s):  
Urška Šunta ◽  
Miha Žitnik ◽  
Noemi Concetta Finocchiaro ◽  
Tjaša Griessler Bulc ◽  
Karmen Godič Torkar

AbstractThe aim of this study was to identify and quantify faecal indicator bacteria in blackwater collected from a source separation unit and determine the amount of E. coli isolates resistant to antimicrobials and their potential to produce extended spectrum β-lactamases (ESβLs) and metallo-β-lactamases (MβLs), which hydrolyse the most important antibiotics used in clinical practice. Most of the isolates were resistant to amoxicillin with clavulanic acid (36.4 %), followed by ticarcillin with clavulanic acid (22.7 %) and tetracycline (18.2 %). ESβL-producing genes blaCTX-M and blaTEM were found in three (13.6 %) and four (18.2 %) E. coli strains, respectively, while MβL genes were found in two (9.1 %). By separating at source, this pilot study clearly shows that gastrointestinal bacteria of healthy people can be an important source of antibiotic resistance released into the environment through wastewaters. One way to prevent that is to treat wastewater with a combination of TiO2, UV light, or ozone, as successful methods to remove resistant bacteria and prevent their spread in the environment.


2010 ◽  
Vol 56 (6) ◽  
pp. 471-479 ◽  
Author(s):  
W. Ahmed ◽  
A. Goonetilleke ◽  
T. Gardner

The study aimed to evaluate the suitability of Escherichia coli , enterococci, and Clostridium perfringens for assessing the microbiological quality of roof-harvested rainwater and assessing whether the concentrations of these faecal indicators can be used to predict the presence or absence of specific zoonotic bacterial or protozoan pathogens. From a total of 100 samples tested, 58%, 83%, and 46% of samples were found to be positive for, respectively, E. coli, enterococci, and Clostridium perfringens spores, as determined by traditional culture-based methods. Additionally, in the samples tested, 7%, 19%, 1%, 8%, 17%, and 15% were PCR positive for Aeromonas hydrophila lip, Campylobacter coli ceuE, Campylobacter jejuni mapA, Legionella pneumophila mip, Salmonella invA, and Giardia lamblia β-giardin genes, respectively. However, none of the samples was positive for E. coli O157 lipopolysaccharide, verocytotoxin 1, and verocytotoxin 2 and Cryptosporidium parvum oocyst wall protein genes. The presence or absence of these potential pathogens did not correlate with any of the faecal indicator bacterial concentrations as determined by a binary logistic regression model. The roof-harvested rainwater samples tested in this study appeared to be of poor microbiological quality, and no significant correlation was found between the concentration of faecal indicators and pathogenic microorganisms. The use of faecal indicator bacteria raises questions regarding their reliability in assessing the microbiological quality of water and particularly their poor correlation with pathogenic microorganisms. The presence of one or more zoonotic pathogens suggests that the microbiological analysis of water should be performed and that appropriate treatment measures should be undertaken, especially in tanks where the water is used for drinking.


1986 ◽  
Vol 96 (1) ◽  
pp. 75-82 ◽  
Author(s):  
R. C. Wright

SUMMARYNatural water sources used as drinking-water supplies by rural settlements in Sierra Leone were examined monthly over a one-year period to detect any seasonal variations in bacterial quality. The 37 °C colony count, levels of selected faecal indicator bacteria and the incidence of Salmonella spp. were monitored. A seasonality was demonstrated for all the variables, counts generally increasing with the progression of the dry season, culminating in peaks at the transition from dry to wet season. Some complications with respect to the interpretation of counts of faecal indicator bacteria from raw tropical waters are noted.


Water ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 2591
Author(s):  
Kane L. Offenbaume ◽  
Edoardo Bertone ◽  
Rodney A. Stewart

A comprehensive review was conducted to assess the current state of monitoring approaches for primary faecal indicator bacteria (FIB) E. coli and enterococci. Approaches were identified and examined in relation to their accuracy, ability to provide continuous data and instantaneous detection results, cost, environmental awareness regarding necessary reagent release or other pollution sources, in situ monitoring capability, and portability. Findings showed that several methods are precise and sophisticated but cannot be performed in real-time or remotely. This is mainly due to their laboratory testing requirements, such as lengthy sample preparations, the requirement for expensive reagents, and fluorescent tags. This study determined that portable fluorescence sensing, combined with advanced modelling methods to compensate readings for environmental interferences and false positives, can lay the foundations for a hybrid FIB sensing approach, allowing remote field deployment of a fleet of networked FIB sensors that can collect high-frequency data in near real-time. Such sensors will support proactive responses to sudden harmful faecal contamination events. A method is proposed to enable the development of the visioned FIB monitoring tool.


Author(s):  
Zullyadini Rahaman ◽  
Wan Ismail

Spatial and temporal variations of sedimentation rate in the Timah Tasoh Water Reservoir, Perlis, Malaysia Human activities such as logging, land conservation, road construction and other disturbances in watersheds will increase erosion rate and thus the amount of sediment transported into the river that reaches lakes, reservoirs and sea. Accelerated sedimentation rate in the reservoir can significantly reduce a reservoir's surface area, eliminating wetland area surrounding the reservoir and shallow the areas near the shore of the reservoir. A study of sedimentation rate in the Timah Tasoh water reservoir was carried out from May 2001 to April 2002 by means of sediment traps. The aim of this study is to determine the spatial and temporal pattern of sedimentation rates in the reservoir. The sediment traps were installed at five different locations in the reservoir and replaced every month. Gross sedimentation rates measured in the sediment traps vary from about an average of 1.4 kg/m2/month or 16.3 kg/m2/yr in the deepest part of the reservoir to about 79.2 kg/m2/yr (monthly average of 6.6 kg/m2/month) and 47.1 kg/m2/yr (monthly average of 3.9 kg/m2/month) near the inlet of the Pelarit River and the Tasoh River respectively. The sedimentation rate near the Pelarit River and the Tasoh River inflow is correlated with the water and suspended sediment discharge in the river, owing to its proximity to the rivers and the flooding effect, mainly during the wet season. The sedimentation rate decreases southward along the reservoir, as a result of increasing distance from the river mouth. The total suspended sediment load of the Upper Pelarit River and the Jarum River flowing into the reservoir is 11.4 × 103 ton/year and 5.41 × 103 ton//year respectively.


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