A presence–absence (P–A) test providing sensitive and inexpensive detection of coliforms, fecal coliforms, and fecal streptococci in municipal drinking water supplies

1968 ◽  
Vol 14 (1) ◽  
pp. 13-18 ◽  
Author(s):  
J. A. Clark
Keyword(s):  
Drinking Water ◽  
Water Samples ◽  
Membrane Filter ◽  
Gas Production ◽  
Fecal Coliforms ◽  
Coliform Bacteria ◽  
Isolation Medium ◽  
Negative Results ◽  
Fecal Streptococci ◽  
Confirmatory Tests

A simple presence–absence (P–A) test was developed to provide a more economical and more sensitive method for conducting coliform analyses on municipal drinking water samples than the membrane filter (MF) technique. Over ninety percent of these samples routinely gave negative results by the MF method. A modified MacConkey broth, enriched to improve on acid and gas production by coliforms, was the isolation medium for the presumptive part of the P–A test.Parallel analyses of water samples were made by both the P–A and MF methods. Confirmatory tests established the reliability of the respective procedures to detect coliform bacteria. A statistical analysis of the results showed that the P–A test was more sensitive for detecting lower levels of pollution than the MF technique. Many of the confirmed positive P–A results came from P–A bottles that produced presumptive positive tests only after an extended incubation period of two to five days.The P–A test was about five times less expensive than the MF technique and by adding a few simple tests, the P–A procedure could give information on the presence of both fecal coliforms and fecal streptococci. For several samples, fecal streptococci were found by P–A tests in the absence of detectable coliform bacteria by either the MF or P–A methods of analysis.

The detection of various bacteria indicative of water pollution by a presence–absence (P–A) procedure

1969 ◽  
Vol 15 (7) ◽  
pp. 771-780 ◽  
Author(s):  
J. A. Clark
Keyword(s):  
Water Pollution ◽  
Drinking Water ◽  
Membrane Filter ◽  
Fecal Coliforms ◽  
Aeromonas Species ◽  
Fecal Streptococci ◽  
Confirmatory Tests ◽  
Green Fluorescent ◽  
Bacterial Groups ◽  
Drinking Water Samples

Results of a previously described presence–absence (P–A) test were compared with those of the membrane filter (MF) technique for detecting fecal coliforms, coliforms, and anaerogenic coliforms in municipal drinking water samples. The P–A test allowed more frequent isolation of these organisms and, when supplemented by simple confirmatory tests, could also indicate the presence of fecal streptococci, green fluorescent pseudomonads, Aeromonas species, and Clostridium perfringens. In the absence of coliform detection, the occurrence of these other bacterial groups could give warning of unusual fecal or organic pollution.A comparison of coliform and non-coliform isolates from MF and P–A tests indicated that similar organisms were detected by both methods. The finding of false-positive "sheen" colonies was attributable to the presence of ethyl alcohol in the MF Endo medium. Although organisms giving rise to such colonies were non-coliforms, their presence was suggestive of inadequate water treatment.

Characterization of indicator bacteria in municipal raw water, drinking water, and new main water samples

1982 ◽  
Vol 28 (9) ◽  
pp. 1002-1013 ◽  
Author(s):  
J. A. Clark ◽  
C. A. Burger ◽  
L. E. Sabatinos
Keyword(s):  
Drinking Water ◽  
Water Samples ◽  
Membrane Filter ◽  
Bacterial Species ◽  
Gas Production ◽  
Indicator Bacteria ◽  
Water Type ◽  
Raw Water ◽  
Water Drinking ◽  
Pollution Indicator

Municipal water samples were analyzed by membrane filter (MF) and presence–absence (P-A) tests for pollution indicator bacteria. In four years, 11 514 bacterial cultures were isolated from either raw water, drinking water, or new main water samples submitted to three environmental laboratories. The bacterial species occurring most often in all types of water samples were Escherichia coli (11.6–39.7%), Enterobacter aerogenes (18.1–26.3%), Aeromonas hydrophila (8.8–17.0%), Klebsiella pneumoniae (7.7–10.3%), and Citrobacter freundii (5.09–22.7%). A lactose – lauryl tryptose – tryptone broth was examined as an alternative medium to modified MacConkey broth in the presumptive portion of the P-A test. The intensity of acid and gas production in presumptive positive P-A bottles was compared with the types and frequencies of indicator bacteria shown by confirmatory tests. The results of detecting indicator bacteria following the analysis of 53 130 samples over a 2-year period were arranged by water source (well, lake, river, mixed) and water type (raw or drinking) to determine the influence of these parameters on the recovery of indicator bacteria. A further subdivision of the sample types into raw surface, raw ground, in-plant, plant discharge, reservoir, and distribution samples demonstrated the effect of water treatment practices.

Microbial Assessment of Irrigation Water Used for Production of Fruit and Vegetables in Ontario, Canada

2005 ◽  
Vol 68 (7) ◽  
pp. 1388-1392 ◽  
Author(s):  
MARINA STEELE ◽  
ABDULLAHI MAHDI ◽  
JOSEPH ODUMERU
Keyword(s):  
Water Quality ◽  
Irrigation Water ◽  
Water Samples ◽  
Linear Regression Analysis ◽  
Total Coliform ◽  
Fecal Coliforms ◽  
Coliform Bacteria ◽  
Irrigation Season ◽  
Quality Guidelines ◽  
Fecal Streptococci

Five hundred one irrigation water samples were collected from 27 irrigation water sources on 17 farms in southern Ontario, Canada, over a single irrigation season in 2002. The water samples were tested for the presence of the following bacterial water quality indicators: total coliform bacteria, fecal coliforms, Escherichia coli, and fecal streptococci. The median values per 100 ml of these indicators in the irrigation water samples were 3,000, 33, 15, and 1, respectively. Between 70.6 and 98.2% of irrigation water samples contained acceptable levels of fecal coliforms or E. coli, according to published irrigation water quality guidelines. Significant correlations (P < 0.05) were observed between the concentrations of different bacterial indicators and the degree of recent precipitation and concentrations of total coliforms and fecal streptococci. With the exception of fecal streptococci, which increased in number toward the end of the study, none of the indicators displayed a significant trend over the course of the season, as determined by linear regression analysis of indicator concentrations over time (P > 0.05).

Virus occurrence in municipal groundwater sources in Quebec, Canada

2007 ◽  
Vol 53 (6) ◽  
pp. 688-694 ◽  
Author(s):  
Annie Locas ◽  
Christine Barthe ◽  
Benoit Barbeau ◽  
Annie Carrière ◽  
Pierre Payment
Keyword(s):  
Drinking Water ◽  
Sampling Site ◽  
Enteric Viruses ◽  
Fecal Coliforms ◽  
Coliform Bacteria ◽  
Raw Water ◽  
Total Coliforms ◽  
Two Samples ◽  
Historic Data ◽  
Human Enteric Viruses

A 1 year study was undertaken on groundwater that was a source of drinking water in the province of Quebec, Canada. Twelve municipal wells (raw water) were sampled monthly during a 1 year period, for a total of 160 samples. Using historic data, the 12 sites were categorized into 3 groups: group A (no known contamination), group B (sporadically contaminated by total coliforms), and group C (historic and continuous contamination by total coliforms and (or) fecal coliforms). Bacterial indicators (total coliform, Escherichia coli , enteroccoci), viral indicators (somatic and male-specific coliphages), total culturable human enteric viruses, and noroviruses were analyzed at every sampling site. Total coliforms were the best indicator of microbial degradation, and coliform bacteria were always present at the same time as human enteric viruses. Two samples contained human enteric viruses but no fecal pollution indicators (E. coli, enterococci, or coliphages), suggesting the limited value of these microorganisms in predicting the presence of human enteric viruses in groundwater. Our results underline the value of historic data in assessing the vulnerability of a well on the basis of raw water quality and in detecting degradation of the source. This project allowed us to characterize the microbiologic and virologic quality of groundwater used as municipal drinking water sources in Quebec.

scholarly journals Investigating the presence of enteric bacteria and their antibiotic resistance in drinking water samples of slum households in Port City Chattogram, Bangladesh

2020 ◽  
Author(s):  
Sidratun Nur Chowdhury ◽  
Nazifa Rafa ◽  
Sayed Mohammad Nazim Uddin ◽  
A. K. M. Moniruzzaman Mollah
Keyword(s):  
Water Samples ◽  
Integrated Approach ◽  
Enteric Bacteria ◽  
Fecal Coliforms ◽  
Coliform Bacteria ◽  
Penicillin G ◽  
Most Probable Number ◽  
Port City ◽  
Probable Number ◽  
Unsafe Water

Abstract Globally, unsafe water supplies due to contamination with fecal coliforms are major issues in urban slums. To determine the presence of microbial risk, water samples were collected from three slums in the port city Chattogram and the most probable number (MPN) method was used to test for the presence of fecal coliform. All of the samples tested positive by the MPN test. The highest count was 1,100 MPN/100 mL and the lowest count was 7.2 MPN/100 mL. Water stored in containers was prone to being more contaminated than water collected directly from the source. To understand the antibiotic resistivity of the coliform bacteria isolated from the water samples, antibiotic susceptibility was evaluated using the Kirby-Bauer disc method for six antibiotics. All the bacteria were 100% resistant to penicillin-G and ampicillin, and 91.7% showed resistance to amoxicillin and mecillinam. An integrated approach to water, sanitation, and hygiene education must be undertaken when providing sustainable interventions in slums.

scholarly journals Microbiological Analysis of Drinking Water of Kathmandu Valley

1970 ◽  
Vol 5 (5) ◽  
pp. 112-114 ◽  
Author(s):  
Tista Prasai ◽  
Binod Lekhak ◽  
Dev Raj Joshi ◽  
Madhav Prasad Baral
Keyword(s):  
Public Health ◽  
Drinking Water ◽  
Water Samples ◽  
Enteric Bacteria ◽  
Coliform Bacteria ◽  
Kathmandu Valley ◽  
Microbiological Analysis ◽  
Public Health Importance ◽  
Guideline Value ◽  
Drinking Water Samples

Drinking water quality assessment in Kathmandu valley has always been crucial with reference to public health importance. A study was conducted to evaluate the quality of drinking water of the valley. A total of 132 drinking water samples were randomly collected from 49 tube wells, 57 wells, 17 taps and 9 stone spouts in different places of Kathmandu valley. The samples were analyzed for microbiological parameters. Total plate and coliform count revealed that 82.6% and 92.4% of drinking water samples found to cross the WHO guideline value for drinking water. During the study, 238 isolates of enteric bacteria were identified, of which 26.4% were Escherichia coli, 25.6% were Enterobacter spp, 23% were Citrobacter spp, 6.3% were Pseudomonas aeruginosa, 5.4% were Klebsiella spp, 4.0% were Shigella spp, 3.0% were Salmonella typhi, 3.0% were Proteus vulgaris, 3.0% were Serratia spp and 1.0% were Vibrio cholerae . Key words: Drinking water; Public health; Coliform; Bacteria. DOI: 10.3126/sw.v5i5.2667 Scientific World, Vol. 5, No. 5, July 2007 112-114

scholarly journals Point-of-Use Water Treatment Methods and the Microbiological Quality of Drinking Water in a Peri-Urban Community of Bonendale, Douala IV, Cameroon

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Ngouakam H ◽  
◽  
Fru Cho J ◽  
Tientche B ◽  
◽  
...  
Keyword(s):  
Drinking Water ◽  
Water Samples ◽  
Microbiological Quality ◽  
Coliform Bacteria ◽  
Cross Sectional ◽  
Potential Health ◽  
Coliform Count ◽  
Point Of Use ◽  
Dug Wells

Background: The study aimed at assessing the knowledge of Bonendale populations related to safe drinking water; determine the microbiological quality and the household treatment practices of drinking water at the point of use (PoU). Methods: The study was descriptive and cross-sectional, conducted between November 2017 and November 2018 in Bonendale, Douala IV. A systematic random sampling method was used to select 237 households. Results: The main source of drinking water in the study population was dug wells (64.9%). The major activity around the boreholes was agriculture 50% (6/12) while agriculture and livestock rearing were practiced around 34.3% (12/35) and 42.8% (15/35) of dug wells respectively. Nearly half 110 (46.4%) of respondents had a good knowledge of physical properties of drinking water. Fifty-nine water samples out of a total of 60 tested (98.3%) were contaminated by coliform bacteria. Analysis of water samples indicated that 47.6% (10/21) of dug wells, 37.0% (10/27) of Camwater, and 41.2% (5/12) of boreholes had a total coliform count varying between 101-1000 CFU/100mL. And only a single Camwater water sample 1 (137%) had a coliform count of 0 CFU/100mL. Conclusion: These findings indicated the poor microbiological quality of point water used by Bonendale populations representing an important potential health risk of water-borne diseases. The results also reveal that a very high proportion of households treat their PoU before drinking.

PATHOGENS FROM DRINKING WATER

2018 ◽  
Vol 20 (04) ◽  
pp. 760-765
Author(s):  
Mohammad Din ◽  
Zafar Ahmad ◽  
Abdul Aleem ◽  
G.S. Pirkani ◽  
Amir Mohammad ◽  
...  
Keyword(s):  
Drinking Water ◽  
Water Samples ◽  
Pathogenic Bacteria ◽  
Clinical Medicine ◽  
Membrane Filter ◽  
Wide Spectrum ◽  
Bacterial Load ◽  
Antibiotic Sensitivity ◽  
Viable Count ◽  
Serological Tests

… Objectives: Main objective was to check drinking water for pathogenic bacterialload, their resistance to antimicrobials and to create awareness among the people of Quetta cityabout safe drinking water. Place and Duration of Study: The study was conducted inDepartment of Microbiology Bolan Medical Complex Hospital Quetta during the hot season inQuetta City (June- September 2013). Methodology: One hundred and twenty five (125) tapewater samples were collected aseptically in 200 ml sterile caped glass bottles from differentlocalities of Quetta city. Samples were passed through mille pore assembly containing 0.45 μmpore-sizecellulose nitrate sterile membrane filter (MF).Viable count technique was used forenumeration of water samples having high bacterial burden. Serological tests and analyticalprofile index API-20E (Biomerieux France) were used to identify pathogens according to themanufacturer’s directions. Standardized antibiotic sensitivity test was performed on MuellerHinton agar using disc diffusion Kirby Bauer technique and McFarland Turbidity Standardmethod 0.5 following CLSI protocols. Results: Out of hundred and twenty five (125) tape watersamples 110 (88 %) showed highly pathogenic bacterial load, in which the most prominentorganism was E.coli 36 (28.8 %), followed by Enterobacter 35 (28 %), Klebsiella 24 (19.2 %),Pseudomonas, 10 (08 %), and Salmonella 05 (04 %). All pathogens in this study expressed a highlevel of resistance to antimicrobials that are commonly used in clinical medicine i.e. Tetracycline,Gentamycin, Sulphamethaxazole, Piperacillin, Ampicillin, Augmentin and Imipenam etc. Only 15(12 %) samples were pathogens free. Conclusion: Among drinking water samples the presenceof pathogenic bacteria (88%) is alarming for public health authorities. The emergence ofresistance and decreasing level of susceptibility of pathogens to a wide spectrum ofantimicrobials is a matter of great concern, because it may limit the availability of antimicrobialsfor clinical management of water born outbreaks in future.

scholarly journals Metallic and Microbial Contaminants in Drinking Water of Cankiri, Turkey

2012 ◽  
Vol 9 (2) ◽  
pp. 608-614 ◽  
Author(s):  
Emrah Caylak ◽  
Mustafa Tokar
Keyword(s):  
Drinking Water ◽  
Human Health ◽  
Water Samples ◽  
Tap Water ◽  
Total Coliform ◽  
Coliform Bacteria ◽  
Quality Of Water ◽  
Bacterial Indicator ◽  
Sewage Contamination ◽  
Microbial Contaminants

Safe and good quality drinking water is very important for human health. Water provides some heavy metals, such as As, B, Cd, Cn, Cr, Cu, F, Cl, Hg, Ni, Pb, Se, and Sn. These are undesirable substances dangerous to human health and cause chronic diseases and various cancers. Coliform bacteria are a commonly used bacterial indicator of sanitary quality of water.E. coli, total coliform and enterococci have been used as indicators of possible sewage contamination might pose a health risk. In this study, water samples were taken from thirty different waterworks in Cankiri, Turkey and metallic and microbial contaminants were investigated. In the drinking tap water samples have been found at concentrations exceeding the Turkish regulations (As and free Cl) and the WHO guidelines (As and B). Our results also indicate that significant microbiological contaminations were found above the guidelines for drinking waters given by the WHO, because of the fact that in the distribution of water is not appropriate.

scholarly journals Vulnerability of Drinking-Water Wells in La Crosse, Wisconsin, to Enteric-Virus Contamination from Surface Water Contributions

2004 ◽  
Vol 70 (10) ◽  
pp. 5937-5946 ◽  
Author(s):  
Mark A. Borchardt ◽  
Nathaniel L. Haas ◽  
Randall J. Hunt
Keyword(s):  
Drinking Water ◽  
Surface Water ◽  
River Water ◽  
Water Samples ◽  
Hepatitis A Virus ◽  
Enteric Viruses ◽  
Coliform Bacteria ◽  
Well Water ◽  
Rt Pcr ◽  
Water Wells

ABSTRACT Human enteric viruses can contaminate municipal drinking-water wells, but few studies have examined the routes by which viruses enter these wells. In the present study, the objective was to monitor the municipal wells of La Crosse, Wisconsin, for enteric viruses and determine whether the amount of Mississippi River water infiltrating the wells was related to the frequency of virus detection. From March 2001 to February 2002, one river water site and four wells predicted by hydrogeological modeling to have variable degrees of surface water contributions were sampled monthly for enteric viruses, microbial indicators of sanitary quality, and oxygen and hydrogen isotopes. 18O/16O and 2H/1H ratios were used to determine the level of surface water contributions. All samples were collected prior to chlorination at the wellhead. By reverse transcription-PCR (RT-PCR), 24 of 48 municipal well water samples (50%) were positive for enteric viruses, including enteroviruses, rotavirus, hepatitis A virus (HAV), and noroviruses. Of 12 river water samples, 10 (83%) were virus positive by RT-PCR. Viable enteroviruses were not detected by cell culture in the well samples, although three well samples were positive for culturable HAV. Enteroviruses detected in the wells by RT-PCR were identified as several serotypes of echoviruses and group A and group B coxsackieviruses. None of the well water samples was positive for indicators of sanitary quality, namely male-specific and somatic coliphages, total coliform bacteria, Escherichia coli, and fecal enterococci. Contrary to expectations, viruses were found in all wells regardless of the level of surface water contributions. This result suggests that there were other unidentified sources, in addition to surface water, responsible for the contamination.

Sign in / Sign up

Export Citation Format

Share Document