Comparative performance of colisureTM and accepted methods in the detection of chlorine-injured total coliforms and E. coli

1995 ◽  
Vol 31 (5-6) ◽  
pp. 259-261
Author(s):  
G. A. McFeters ◽  
S. C. Broadaway ◽  
B. H. Pyle ◽  
M. Pickett ◽  
Y. Egozy

Studies were done to examine the comparability of ColisureTM and accepted reference methods to detect low numbers of total coliform bacteria and E. coli subjected to chlorine stress. ColisureTM is a medium designed to concurrently detect coliform bacteria and E. coli in drinking water by the specific action of β-galactosidase (total coliforms) and β-glucuronidase (E. coli). The methods used to compare the performance of various media followed a protocol established by the USEPA. Samples (31) of sewage from six different regions of the US were treated with sufficient concentrations of chlorine (1.2-2.5mg/l) to reduce viability 1-3 logs (39% average injury) and diluted with drinking water to achieve ca. 3 viable coliforms/100ml. The mean log reductions in viable bacteria, determined with various media following disinfection of the 31 samples were: mEndo = 1.87 (TC), ColisureTM = 1.55 (TC), mTec = 3.63 (E. coli) and ColisureTM = 2.01 (E. coli). When ColisureTM was compared with accepted methods to detect total coliforms in the dilute, disinfected samples, ColisureTM yielded results that were 1.6 times greater than LTB confirmed in BGLB at 28h. ColisureTM also detected 1.7 times greater levels of E. coli than LTB confirmed in EC/MUG at 28h. Sensitivity and specificity of ColisureTM were between 96 and 100% when positive and negative tests were verified. These findings indicate that ColisureTM is superior to certain accepted reference methods in the detection of chlorine-injured coliforms and E. coli under conditions that resemble contaminated drinking water.

1993 ◽  
Vol 27 (3-4) ◽  
pp. 261-265 ◽  
Author(s):  
Gordon A. McFeters ◽  
Barry H. Pyle ◽  
Shaun J. Gillis ◽  
Carole J. Acomb ◽  
David Ferrazza

Several factors have stimulated interest in recently developed substrate specific media for the detection of coliform bacteria in water. This study compared the performance of Colisure™ (Millipore), ColiLert™ (Environetics) and ColiQuick™ (Hach) with accepted membrane filtration and MPN methodologies for the enumeration of total coliforms and E. coli in chlorinated water. The performance of all three media was compared, in MPN configuration, with LTB/MPN (confirmed) using a variety of drinking and source water samples, both with and without chlorination. The Cochran-Mantel-Haenszel test yielded statistical correlations between results obtained with each of the three new enzyme detection media and accepted reference methods for the detection of low numbers of total coliforms. Another series of tests compared the performance of Colisure with accepted methods (LTB/MPN confirmed with BGLB and EC-MUG) in the detection of total coliforms and E. coli in sewage-spiked samples simulating contaminated drinking water, using an USEPA/AWWA test protocol. The results demonstrated that Colisure detected these indicator bacteria with greater sensitivity than the accepted methods and that this difference increased between 24 and 28 hours of incubation. The results of this study collectively support the validity of the new enzyme detection method for the detection of low levels of coliform bacteria and E. coli in source water and contaminated drinking water.


Author(s):  
Francesca Rubino ◽  
Yahaira Corona ◽  
José Guadalupe Jiménez Pérez ◽  
Charlotte D. Smith

In many regions where drinking water supply is intermittent and unreliable, households adapt by storing water in cisterns or rooftop tanks. Both intermittent supply and stored water can be vulnerable to contamination by microorganisms with deleterious health effects. The Guadalajara Metropolitan Area is a rapidly growing urban center with over five million residents where household storage is nearly ubiquitous. This pilot study was conducted in July 2018 to examine the microbiological quality of drinking water in Guadalajara. Samples were tested for free available chlorine residual, total coliform bacteria, and E. coli. A survey on access to water and public perspectives was also conducted. Water exiting rooftop tanks exceeded regulatory limits for total coliform levels in half of the homes studied. Piped water arriving at two homes had total coliform levels that far exceeded regulatory limits. No E. coli were detected in any of the samples. Only 35% of homes had a chlorine residual between the recommended 0.2 and 1.5 mg/L. Many homes reported unpleasant odors and colors. Only 7% of residents drank the piped water. Future studies are needed, especially during April and May when many homes reported a higher disruption to water service.


Author(s):  
Francesca Rubino ◽  
Yahaira Corona ◽  
José Guadalupe Jiménez Pérez ◽  
Charlotte Smith

In many regions where drinking water supply is intermittent and unreliable, households adapt by storing water in cisterns or rooftop tanks. Both intermittent supply and stored water can be vulnerable to contamination by microorganisms with deleterious health effects. The Metropolitan Zone of Guadalajara is a rapidly growing urban center with over five million residents where household storage is nearly ubiquitous. This pilot study was conducted in July 2018 to examine the microbiological quality of drinking water in Guadalajara. Samples were tested for free available chlorine residual, total coliform bacteria, and Escherichia coli. A survey on access to water and public perspectives was also conducted. Water exiting rooftop tanks exceeded regulatory limits for total coliform levels in half of the homes studied. Piped water arriving at two homes had total coliform levels that far exceeded regulatory limits. No E. coli were detected in any of the samples. Only 35% of homes had a chlorine residual between the recommended 0.2 and 1.5 mg/L. Many homes reported unpleasant odors and colors. Only 7% of residents drank the piped water. Future studies are needed, especially during April and May when many homes reported a higher disruption to water service.


1994 ◽  
Vol 77 (1) ◽  
pp. 58-63 ◽  
Author(s):  
Philip T Feldsine ◽  
Maria T Falbo-Nelson ◽  
David L Hustead

Abstract The ColiComplete® substrate-supporting disc (SSD) method for simultaneous confirmed total coliform count and Escherichia coli determination in all foods was compared with the AOAC most probable number (MPN) methods 966.23 and 966.24. In this comparative study, 20 water and food types were analyzed; 7 of these foods were naturally contaminated with coliform bacteria, 6 food types were naturally contaminated with E. coli, and the remaining foods were inoculated with coliform bacteria and/or E. coli. Data were analyzed separately for total coliform bacteria and for E. coli. Mean log MPN counts were determined by the SSD method and the appropriate AOAC MPN procedure. Results were then analyzed for mean log MPN differences and variance, according to methods described by AOAC INTERNATIONAL Results for both total conforms and E. coli indicate that the SSD method is equivalent to or better than AOAC MPN methods 966.23 and 966.24.


2017 ◽  
Vol 6 (2) ◽  
pp. 411 ◽  
Author(s):  
Kirsten Ngaire Nicholson ◽  
Klaus Neumann ◽  
Carolyn Dowling ◽  
Subodh Sharma

During the 2016 pre-monsoon dry season, we undertook a systematic study of water quality, specifically fecal contamination of drinking water, in the Khumbu Valley, Sagarmatha National Park (SNP, Mt. Everest region) and SNP buffer zone, Nepal. Our goal was to quantify physical parameters (temperature, pH, conductivity and total dissolved solids), and the presence of fecal coliforms (E. coli and total coliforms) in drinking water and drinking water sources (predominately groundwater-fed springs). This data set will function as a baseline for access to potable water and further monitoring. Sample sites were selected based on primary use as a drinking water and/or drinking water source for each community. In general, there is little correlation between and physical parameters however, there are very weak correlations between total coliform data and increasing temperature, and decreasing elevation and pH. There does, however, appear to be a correlation between population (including tourist numbers) and both E. coli and total coliforms. Our study clearly indicates that the presence of bacterial indicators of fecal pollution during the dry season. Samples from the more populated, lower altitude areas had higher levels of E. coli and coliform bacteria. Importantly, drinking water that was stored in tanks or transported long distances had a much higher incidence of E. coli and total coliforms suggesting that a change in water handling practices might have an important impact on drinking water quality and population health. 


Author(s):  
Francesca Rubino ◽  
Yahaira Corona ◽  
José Guadalupe Jiménez Pérez ◽  
Charlotte Smith

In many regions where drinking water supply is intermittent and unreliable, households adapt by storing water in cisterns or rooftop tanks. Both intermittent supply and stored water can be vulnerable to contamination by microorganisms with deleterious health effects. The Guadalajara Metropolitan Area is a rapidly growing urban center with over five million residents where household storage is nearly ubiquitous. This pilot study was conducted in July 2018 to examine the microbiological quality of drinking water in Guadalajara. Samples were tested for free available chlorine residual, total coliform bacteria, and E. coli. A survey on access to water and public perspectives was also conducted. Water exiting rooftop tanks exceeded regulatory limits for total coliform levels in half of the homes studied. Piped water arriving at two homes had total coliform levels that far exceeded regulatory limits. No E. coli were detected in any of the samples. Only 35% of homes had a chlorine residual between the recommended 0.2 and 1.5 mg/L. Many homes reported unpleasant odors and colors. Only 7% of residents drank the piped water. Future studies are needed, especially during April and May when many homes reported a higher disruption to water service.


2019 ◽  
Vol 65 (2) ◽  
pp. 23-32
Author(s):  
Marta Nedelkova ◽  
Angela Delova ◽  
Tanja Petreska Ivanovska ◽  
Zoran Zhivikj ◽  
Lidija Petrushevska-Tozi

The aim of this paper is to analyze the presence of Escherichia coli (E. coli) and total coliform bacteria (CB) in the drinking water of urban and rural areas of the Bitola region, as indicators for water quality and safety. All water in urban area is chlorinated, while at the same time the water in rural areas is non-chlorinated. The samples were analyzed according to the international standard method of membrane filtration MKC EN ISO 9308-1:2015. In all examined samples of drinking water in urban area, presence of E. coli and CB was not detected as a result of the disinfection of the water. On contrary, in all tested samples of the water from the rural water supply, presence of E. coli and CB was confirmed. Significant increase in coliform bacterial counts probably weather-related was found in the period from April to September. In addition, in the third quarter including July, August, and September, in many measurements, E. coli as an indicator of faecal contamination was identified in drinking water. In accordance with these findings and in order to provide safe drinking water, it is necessary to modernize the water supply for the population in rural areas, to disinfect permanently the drinking water and to apply regular laboratory controls which are a basic pre-condition. Otherwise, inappropriate management of the water systems can cause serious decrease in the quality and safety of the drinking water associated with an increased risk of appearance of the infectious diseases in people and hydric epidemic. Key words: drinking water, Escherichia coli, coliform bacteria, membrane filtration


1997 ◽  
Vol 35 (11-12) ◽  
pp. 419-422
Author(s):  
G. McFeters ◽  
M. Pickett ◽  
S. Broadaway ◽  
B. Pyle

This study compared a chromogenic and fluorogenic substrate based medium, Colisure, with the conventional fermentation based medium, lauryl tryptose broth (LTB), for the recovery of chlorine-injured and non-injured coliforms and E. coli. Mixed natural populations of coliforms from sewage, with and without chlorine exposure, and untreated surface water samples were examined following a USEPA established procedure. Colisure and LTB were examined after 20, 24, 28 and 48h incubation and reactions verified. There were slight increases in positive reactions over time with unchlorinated samples, for which the two media gave similar kinetic patterns. The increases over time with chlorinated samples were much greater than with unchlorinated samples. LTB gave significantly lower total positive responses and had a more pronounced lag period than did Colisure. Total coliform bacteria from surface water samples gave somewhat different reactions with more of an increase with time. Colisure recovered comparable or higher numbers of total coliforms and E. coli in 20–28h than LTB after 48h. These results confirm that Colisure gives improved recovery of chlorine-injured total coliforms and E. coli under conditions simulating treated drinking and source water, resulting in a more realistic estimate of the actual population of indicator bacteria in public water supplies.


el–Hayah ◽  
2019 ◽  
Vol 7 (1) ◽  
pp. 28-35
Author(s):  
Muhamad Syamsussabri ◽  
Riza Nurhermi Ningtyas ◽  
Amalia Ainun Najah ◽  
M. Saiful Fahmi ◽  
Endang Suarsini

This study aims to determine the contamination of coliform bacteria in drinking water sources of residents in Malang City. Type of this research is explorative descriptive research. The study population was all drinking water sources of residents throughout Malang City, while the research sample was 15 residents wells in five subdistricts of Malang City with each sample taken three sample points. The samples were tested using 3M petrifilm E. coli/coliform count plate. The results showed that all the samples studied were contaminated with coliform bacteria with the highest percentage of 23.01% for E. coli bacteria contamination and 15.41% for total coliform bacterial contamination with an average of bacterial colonies 200 colonies.


2014 ◽  
Vol 17 ◽  
pp. 122-131 ◽  
Author(s):  
Partha Pal

The coliform group has been used extensively as an indicator of water quality and has historically led to the public health protection concept. Total coliforms are a group of bacteria commonly found in the environment, for example in soil or vegetation, as well as the intestines of mammals, including humans. Total coliform bacteria are not likely to cause illness, but their presence indicates that the water supply may be vulnerable to contamination by more harmful microorganisms. Escherichia coli (E. coli) is the only member of the total coliform group of bacteria that is found only in the intestines of mammals, including humans. The presence of E. coli in water indicates recent fecal contamination and may indicate the possible presence of disease-causing pathogens, such as bacteria, viruses, and parasites. Although most strains of E. coli bacteria are harmless, certain strains, such as E.coli 0157:H7, may cause illness. About 80 % of communicable diseases in the world are waterborne. According to WHO estimate about 80 % of water pollution in developing country, like India is carried by domestic waste. In India 70 % of the water is seriously polluted and 75 % of illness and 80 % of the child mortality is attributed to water pollution. The improper management of water systems may cause serious problems in availability and quality of water. The major pathogenic bacteria responsible for water borne disease are spread by the faeco-oral route, in which water may play an intermediate role. The aim of this review is to examine methods currently in use for the detection of coliforms in drinking water and also to evaluate the possible health hazards associated with drinking water contaminated with coliforms.


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