Virological examination of drinking water: a Canadian collaborative study

1984 ◽  
Vol 30 (1) ◽  
pp. 105-112 ◽  
Author(s):  
Pierre Payment ◽  
Michel Trudel ◽  
S.A. Sattar ◽  
V. S. Springthorpe ◽  
T. P. Subrahmanyan ◽  
...  

A collaborative virological survey of drinking water was initiated in three major Canadian urban areas, Montreal, Ottawa, and Toronto. In each selected area, three water purification plants were sampled monthly for up to 18 months. The total population served by all nine plants was about 1 500 000. Samples of raw (100 L) and treated (1000 L) water were examined by virus concentration procedures based on adsorption–elution. Sample concentrates were assayed for cytopathic viruses on BS-C-1 cells and the results were expressed as the most probable number of cytopathic units (MPNCU). Viruses were detected in 57% (0–15.35 MPNCU/L) of the raw water samples from Montreal, 37% (0–46.0 MPNCU/L) in Ottawa, and 33% (0–4.91 MPNCU/L) in Toronto. The majority of isolates were reoviruses, but picornaviruses were also found. All finished waters (177 samples) met bacteriological, turbidity, and residual chlorine standards and were free of detectable viruses.

2019 ◽  
Author(s):  
Goyitom Gebremedhn ◽  
Abera Aregawi Berhe ◽  
Abraham Aregay Desta ◽  
Lemlem Legesse

Abstract Background Fecal contamination of drinking water sources is the main cause of diarrhea with estimated incidence of 4.6 billion episodes and 2.2 million deaths every year. Methods A total of 145 water samples of different source type were collected from different areas in Tigray region from August 2018 to January 2019. The water samples from each site were selected purposively which involved sampling of water sources with the highest number of users and functionality status during the study period. Most Probable Number (MPN) protocol was used for the bacteriological analysis of the samples. Results A total of 145 water samples were collected from six zones in Tigray region, Ethiopia from August 2018 to January 2019. The study indicated that 63(43.5%) of the water samples were detected to have fecal coliform which is E.coli. In Mekelle city, which is the capital city of Tigray region, three in five 34(60.7%) of the collected samples were confirmed to have fecal coliform. Water samples from health facilities were 9.48 times [AOR=9.48, 95%CI: (1.59, 56.18)] more likely to have fecal coliform. Water samples from wells were 10.23 times [AOR=10.23, 95%CI: (2.74, 38.26)] more likely to have fecal coliform than water samples from Tap/Pipe. Similarly, water samples from hand pumps were 22.28 times [AOR=22.28, 95%CI: (1.26, 393.7)] more likely to have fecal coliform than water samples from Tap/Pipe. Water samples reported to be not chlorinated were 3.51 times [AOR=3.51, 95%CI: (1.35, 9.13)] more likely to have fecal coliform than water samples from chlorinated sources. Conclusion In this study all water source, including the chlorinated drinking water sources, were found highly contaminated with fecal origin bacteria. This may be mainly due to constructional defects, poor sanitation inspection, poor maintenance, intermittent water supply and irregular chlorination.


2021 ◽  
Vol 27 (2) ◽  
Author(s):  
Alok Kumar Singh ◽  
Anand Prakash Singh ◽  
Sanjay Srivastava

In India source of drinking water at Varanasi city for common people are tap water, well, hand pump, Ganga river and stored tank water collected from bore well. All water samples were studied to assess their bacteriological characteristics and suitability for potable purposes. A cross-sectional epidemiological method was adopted to investigate the drinking water of six different sites of Varanasi city. The bacteriological examination of water samples included the most probable number of presumptive coliforms, faecal coliforms, and total bacterial count. The results showed that the total coliform count was detected in all the site. In all the methods coliforms presence was indicated. Maximum number of coliform observed in all the seasons, were from river and well water followed by hand pump, tap water and stored tank. The most common group of indicator organisms used in water quality monitoring are coliforms. These organisms are representative of bacteria normally present in the intestinal tract of mammals including human. Contamination of water may occur through different way like sewage disposal in the river, seepage of bathing near sites, fecal excreta of human, bird and other animals. Improving and expanding the existing water treatment and sanitation systems are more likely to provide good, safe and sustainable sources of water in the long term.


2014 ◽  
Vol 4 (3) ◽  
pp. 384-390 ◽  
Author(s):  
Bayeh Abera ◽  
Mulugeta Kibret ◽  
Goraw Goshu ◽  
Mulat Yimer

A cross-sectional study was conducted to determine the bacterial quality and antimicrobial susceptibility profiles of Enterobacteriaceae from drinking water in Bahir Dar city. A total of 140 water samples were collected in the wet and dry periods from springs (n = 4), reservoirs (n = 10) and private tap water at households (n = 126). Bacteriological analysis of water was conducted using multiple tube method. Overall, 21.4%, 18.6% and 17.8% of drinking water samples had total coliforms (TC), faecal coliforms (FC) and Escherichia coli, respectively. All spring water samples and 29.2% of private tap water had the highest TC load (18 most probable number/100 mL, 95% CI: 100). For FC, 81.4% of the drinking water supplies tested complied with both World Health Organization and Ethiopian Standards. High levels of resistance (98–100%) were observed for ampicillin by Enterobacteriaceae and Pseudomonas aeruginosa. All P. aeruginosa isolates and 20 (66.7%) of E. coli revealed multiple drug resistance. Enterobacteriaceae and P. aeruginosa isolates exhibited high levels of antimicrobial resistance. The bacterial quality of drinking water in Bahir Dar city was poor. Microbial surveillance and monitoring with periodic assessment on physical integrity of the water pipelines need to be undertaken.


2020 ◽  
Vol 6 (1) ◽  
Author(s):  
Ruth Adi Agyo ◽  
Raph Agbo Ofukwu ◽  
Anthony Ekle J. Okoh ◽  
Charity A. Agada

Aim: This study aimed at examined the presence of coliform bacteria in private wells and boreholes (BH) in peri-urban areas of Makurdi, Benue State, Nigeria, using the approaches of most probable number (MPN) index and coliform count. Materials and Methods: Seven hundred and sixty-eight water samples were randomly collected during a 1-year period from non-cased wells, burn brick cased wells (BBW), concrete cased wells, and BH in four locations; A, B, C, and D during the wet and dry seasons. One liter of water was obtained from each well at every visit to the four sites, and eight water samples were collected from each visit. The samples were analyzed using multiple tube fermentation methods and pour plate techniques to determine the MPN of coliform/100 ml of water, reading from the MPN statistics table. Results: One-way analysis of variance statistics was applied using Duncan's new multiple range test to separate the means where there was a significant difference. The result revealed that the MPN index and total coliform counts in all the wells in the locations were above the World Health Organization (WHO) permissible limit for potable water. The highest MPN index of 54.807 was recorded in Location A and followed by 42.679 in Location B. The MPN index in Locations C and D was 36.740 and 30.943, respectively. There was significantly (p=0.000) higher total coliform count in the wet season (41.48±7.09) than in the dry season (38.33±2.83). Conclusion: This study shows the presence of coliform bacteria isolates in all the wells and BH that exceeded the WHO permissible limits for drinking water. The water from these sources is unsafe for drinking except after dosing with appropriate germicides. Sensitization of the population on the actions they can take to make the water safe for domestic use is suggested.


2021 ◽  
Vol 23 (2) ◽  
pp. 146-152
Author(s):  
Bharati Shakya ◽  
Supri Raj Shrestha ◽  
Vinutha Silvanus

Water safety and quality are fundamental to human development and well-being. Yet, at least 2 billion people are using a drinking water source contaminated with feces worldwide. This study was conducted to assess the types of water supply, storage and methods of purification of drinking water and to examine the bacteriological quality of supplied and drinking water at household level by most probable number (MPN) test in Makalbari area in Gokarneshwor Municipality, Kathmandu. A total of 80 households were selected using simple random sampling technique and two samples (one from main water supply and another from drinking water, n=160 water samples) were collected from each household. Ethical clearance was taken from the Nepal Medical College Institutional Review Committee. SPSS version 16.0 was used for statistical analysis. Majority of water supply samples 65 (81.2%) were from tap, 11 (13.8%) were from well and 4 (5.0%) samples were from bore well. Bacteriologically, of the total water supply samples, 34 (42.5%) samples were excellent, 16 (20.0%) samples were suspicious and 30 (37.5%) samples were unsatisfactory by MPN index quality. Most of the households stored drinking water in the tanks 34 (42.5%). Most of the water samples 29 (36.3%) were directly consumed from the water supply without purification. Among the directly consumed drinking water samples, 13 (44.8%) samples showed unsatisfactory MPN index. Most commonly used methods of water purification was filtration 21 (26.2%). Of the total drinking water samples, 33 (41.25%) samples were positive for total coliform. Thirty-two (40.0%) of the households reported diarrhea in past one year. A highly significant association was found between MPN index of drinking water and occurrence of diarrhea in the households. The quality of the most of the water samples from water supply and drinking water were unsatisfactory. Inspite of this, drinking water was not purified in some of the households. Moreover, few of the drinking water samples were not potable even after purification. Therefore, community should be made aware to improve quality of drinking water in households.


2020 ◽  
Vol 202 ◽  
pp. 05019
Author(s):  
Diana R. U. S. Rahayu ◽  
Sutrisno Anggoro ◽  
Tri R. Soeprobowati

Wadaslintang Reservoir has potential as a source of raw water for drinking water. One indicator to determine water quality is to use coliform bacteria. The purpose of this study is to determine the water quality of the Wadaslintang Reservoir as a source of drinking water based on microbiological parameters by referring to Government Regulation of the Republic of Indonesia Number 82 of 2001 concerning water quality management and water pollution control. The water sampling method is based on purposive sampling at ten research stations for eight months, microbiological analysis using the Most Probable Number (MPN) method. The results showed that the status of the Wadaslintang Reservoir was polluted based on total coliform criteria. Utilization of reservoir water as raw water for drinking water needs to be done further processing to anticipate deterioration in health.


1982 ◽  
Vol 89 (2) ◽  
pp. 185-190 ◽  
Author(s):  
F. J. Bolton ◽  
P. M. Hinchliffe ◽  
D. Coates ◽  
L. Robertson

SUMMARYA most probable number (MPN) method capable of estimating as few as ten campylobacters per 100 ml of water is described. The method gave results close to those obtained by the viable count method of Miles, Misra & Irwin (1938) with graded suspensions of Campylobacter jejuni. The method was used to test raw water samples: counts were obtained ranging from 10 to 230 campylobacters per 100 ml for 11 of 49 coastal and estuary water samples, and from 10 to 36 campylobacters per 100 ml for 7 of 44 river samples. Campylobacters were isolated from an additional 24 of the ‘negative’ samples by testing 200 ml volumes by glass microfibre filtration and enrichment culture methods. The MPN method should prove to be a useful epidemiological tool particularly suited to the enumeration of campylobacters in particulate fluids.


2009 ◽  
Vol 8 (2) ◽  
pp. 399-404 ◽  
Author(s):  
Maria Tereza Pepe Razzolini ◽  
Thaís Filomena da Silva Santos ◽  
Veridiana Karmann Bastos

The protozoan parasites Giardia and Cryptosporidium have been described as important waterborne disease pathogens, and are associated with severe gastrointestinal illnesses. The objective of this paper was to investigate the presence of Giardia cysts and Cryptosporidium oocysts in samples from watershed catchments and treated water sources. A total of 25 water samples were collected and examined according to the US EPA—Method 1623, 2005, consisting of 12 from drinking water and 13 from raw water. Positive samples from raw water for Giardia cysts and Cryptosporidium oocysts were 46.1 and 7.6%, respectively. In finished water, positive samples were 41.7% for Giardia cysts and 25.0% for Cryptosporidium oocysts. Concentrations of Giardia cysts found in raw water samples ranged from “not detected” to 3.4 cysts/L, whereas concentrations of Cryptoporidium oocysts ranged from “not detected” to 0.1 oocysts/L. In finished water, Giardia concentrations ranged from “not detected” to 0.06 cysts/L, and Cryptosporidium, from “not detected” to 0.01 oocysts/L. Concentrations of Giardia cysts and Cryptosporidium oocysts were not high in the samples analyzed. Nevertheless, the results of this study highlight the need to monitor these organisms in both raw and drinking water.


2014 ◽  
Vol 3 (3) ◽  
pp. 139-145 ◽  
Author(s):  
Upendra Thapa Shrestha ◽  
Hishila Sujakhu

Water borne infections in Nepal, especially in Kathmandu valley is one the major public health problems, causing thousands of deaths every year. Among three cities in the valley, the water borne infection including cholera is most predominant in Bhaktapur district. So the study was carried out to know the microbial drinking water quality in the city and to determine the prevalence of water borne infections in the specified region of the district in 2012. Altogether eighty (two samples from a single site at different interval-2/3 days) water samples were collected from Bhaktapur Municipality, one of the most vulnerable regions for water borne diseases, following standard methods as described by APHA, 2010. All samples were transferred to Microbiology laboratory of Khwopa College, Dekocha, Bhaktapur and preceded immediately for Microbial analysis. The coliform density in the water samples were determined by Most Probable Number (MPN) method followed by microscopy, colonial morphology and biochemical characterization. Subsequently, the presence of Vibrio cholerae, a causative agent of Cholera was analyzed in the same samples by enrichment in alkaline peptone water followed by culture on Thiosulphate citrate bile-salt sucrose (TCBS) agar, a selective media for Vibrio spp. The biochemical tests were then performed to identify V. cholerae. Among eighty water samples, 87.5 percent water samples contained coliforms and half of which (45%) contained feacal coliforms, Escherichia coli and remaining 12.5 percent water samples contained no coliforms. Vibrio cholerae were isolated from four water samples (5%). The drinking water quality in the region was found to be very poor. Therefore, the people in the region were suggested to treat the drinking water by using any of physical or chemical disinfection methods prior to drinking. DOI: http://dx.doi.org/10.3126/ije.v3i3.11073 International Journal of Environment Vol.3(3) 2014: 139-145


1977 ◽  
Vol 23 (4) ◽  
pp. 465-470 ◽  
Author(s):  
James A. Clark ◽  
Jane E. Pagel

A total of 3819 bacterial cultures isolated from municipal water samples were identified using a combination of Enterotubes and confirmatory media. Frequency distributions for the different genera or groups of bacteria were similar for raw water and drinking water isolations, except for Escherichia organisms which doubled their frequency in raw water. Differences between the membrane filter (MF) and presence–absence (P–A) test with regard to types of organisms isolated were limited to Klebsiella organisms which were preferentially cultured from MF plates. Members of the genus Enterobacter were isolated more than twice as frequently as any of the other coliform genera dealt with in this study. Aeromonas organisms were detected almost as often as such individual genera as Escherichia, Citrobacter, or Klebsiella.Although non-lactose fermenting colonies (false-negatives) of the coliform genera would not be detected by the MF technique, their lack of detection would likely be offset by the Aeromonas colonies (false-positives). At least 25% of the coliform isolates were either anaerogenic or non-lactose fermenters and would therefore go undetected by the most probable number (MPN) technique.


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