scholarly journals Taqman hydrolysis probe application for Escherichia coli, Salmonella enterica, and Vibrio cholerae detection in surface and drinking water

2019 ◽  
Vol 9 (3) ◽  
pp. 492-499
Author(s):  
Ahmed K. A. El-Sayed ◽  
Mohamed I. Abou-Dobara ◽  
Camelia A. Abdel-Malak ◽  
Amira A. E. El-Badaly
Keyword(s):  
Escherichia Coli ◽  
Drinking Water ◽  
Vibrio Cholerae ◽  
Salmonella Enterica ◽  
Membrane Filtration ◽  
Quantitative Polymerase Chain Reaction ◽  
Bacterial Count ◽  
Distribution Networks ◽  
E Coli ◽  
Taqman Qpcr

Abstract This study explored the applicability of using TaqMan qPCR (quantitative polymerase chain reaction) for Escherichia coli, Salmonella enterica and non-virulent Vibrio cholerae detection in surface and drinking water. One hundred and twenty water samples were collected monthly (January 2017–December 2017) from the surface water (input) and drinking water (output and distribution networks) of two drinking water treatment plants (DWTPs) in Damietta County, Egypt. The distribution of the studied bacteria based on their detection by TaqMan qPCR compared with membrane filtration (MF) technique showed that the higher positive samples were detected by TaqMan qPCR. The bacterial count was totally absent in all output samples. TaqMan qPCR assay (based on sequence detection of uidA, invA, and ompW) revealed 97.96%, 99.14%, and 98.3% specificity for E. coli, S. enterica, and non-virulent V. cholerae, respectively, compared with 100% specificity for all strains when MF cultures were applied. TaqMan qPCR exhibited 100% sensitivity for all strains, while it was 91.67%, 80%, and 50% using MF cultures for E. coli, S. enterica, and non-virulent V. cholerae, respectively. In conclusion, TaqMan qPCR sensitivity makes it a useful tool for urgent fast monitoring of water contamination, especially in network samples that contain low bacterial count.

Comparison of three different media for the detection of E. coli and coliforms in water

2006 ◽  
Vol 54 (3) ◽  
pp. 141-145 ◽  
Author(s):  
C. Bernasconi ◽  
G. Volponi ◽  
L. Bonadonna
Keyword(s):  
Escherichia Coli ◽  
Drinking Water ◽  
Membrane Filtration ◽  
Simultaneous Detection ◽  
Alternative Methods ◽  
Phenotypic Characteristic ◽  
Iso Standard ◽  
E Coli ◽  
Microbiological Parameters ◽  
Filtration Technique

The European Drinking Water Directive defines reference methods for the enumeration of microbiological parameters in drinking water. The method to be used for Escherichia coli and coliforms is the membrane filtration technique on Lactose TTC agar with Tergitol 7. Many technical drawbacks of the procedure, as well as its limitations regarding the recent taxonomy of coliforms, make it necessary to evaluate alternative methods. Two alternative assays, a chromogenic media (m-ColiBlu24®) and a defined substrate technology-DST test (Colilert 18/Quanty Tray™) were compared with the ISO standard with attention to the phenotypic characteristic of the isolates. Results showed that the ISO method failed to detect an important percentage of coliforms and E. coli while m-ColiBlu24® and Colilert 18 provided results in a shorter time allowing the simultaneous detection of E. coli and coliforms with no further confirmation steps.

scholarly journals PCR detection of Vibrio cholerae, Escherichia coli, and Salmonella sp. from bottled drinking water in Iran

2018 ◽  
Vol 12 (09) ◽  
pp. 700-705
Author(s):  
Mojtaba Bonyadian ◽  
Hamdallah Moshtaghi ◽  
Hanie Nadi
Keyword(s):  
Escherichia Coli ◽  
Drinking Water ◽  
Vibrio Cholerae ◽  
Screening Method ◽  
Chain Reaction ◽  
Culture Methods ◽  
E Coli ◽  
Drinking Waters ◽  
Polymerase Chain

Introduction: The quality of drinking water has an important role in human health. This study was aimed to detect Escherichia. coli, Salmonella sp. and Vibrio cholerae from bottled drinking waters produced in Iran. Methodology: A total of 240 samples of bottled water of different brands were collected for testing between March 2015 to December 2015 in Shahrekord-Iran. Samples were examined by polymerase chain reaction (PCR) combined with culture methods for the detection of E. coli, Salmonella sp., and V. cholerae. Results: The results of PCR revealed that the uidA gene from E. coli, IpaB gene from Salmonella sp, and epsM gene from V. cholerae were detected in 6 (2.5%), 1 (0.4 %), 0 (0%) of the samples, respectively. But in culture methods, only E. coli 5 (2.1%) were isolated from the samples. The contamination with E. coli was significantly higher (P < 0.05) in water produced during the hot seasons than the cold seasons. Conclusions: This study confirmed the presence of Escherichia coli as the main microorganism in bottle drinking water in Iran. Also, our study showed that PCR can be used as a screening method for monitoring the enteric pathogens in drinking water.

scholarly journals Detection of Escherichia coli in Biofilms from Pipe Samples and Coupons in Drinking Water Distribution Networks

2007 ◽  
Vol 73 (22) ◽  
pp. 7456-7464 ◽  
Author(s):  
T. Juhna ◽  
D. Birzniece ◽  
S. Larsson ◽  
D. Zulenkovs ◽  
A. Sharipo ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Drinking Water ◽  
Cast Iron ◽  
Water Distribution ◽  
Distribution Networks ◽  
Water Distribution Networks ◽  
Bacterial Number ◽  
E Coli ◽  
Drinking Water Distribution ◽  
Enzymatic Methods

ABSTRACT Fluorescence in situ hybridization (FISH) was used for direct detection of Escherichia coli on pipe surfaces and coupons in drinking water distribution networks. Old cast iron main pipes were removed from water distribution networks in France, England, Portugal, and Latvia, and E. coli was analyzed in the biofilm. In addition, 44 flat coupons made of cast iron, polyvinyl chloride, or stainless steel were placed into and continuously exposed to water on 15 locations of 6 distribution networks in France and Latvia and examined after 1 to 6 months exposure to the drinking water. In order to increase the signal intensity, a peptide nucleic acid (PNA) 15-mer probe was used in the FISH screening for the presence or absence of E. coli on the surface of pipes and coupons, thus reducing occasional problems of autofluorescence and low fluorescence of the labeled bacteria. For comparison, cells were removed from the surfaces and examined with culture-based or enzymatic (detection of β-d-glucuronidase) methods. An additional verification was made by using PCR. Culture method indicated presence of E. coli in one of five pipes, whereas all pipes were positive with the FISH methods. E. coli was detected in 56% of the coupons using PNA FISH, but no E. coli was detected using culture or enzymatic methods. PCR analyses confirmed the presence of E. coli in samples that were negative according to culture-based and enzymatic methods. The viability of E. coli cells in the samples was demonstrated by the cell elongation after resuscitation in low-nutrient medium supplemented with pipemidic acid, suggesting that the cells were present in an active but nonculturable state, unable to grow on agar media. E. coli contributed to ca. 0.001 to 0.1% of the total bacterial number in the samples. The presence and number of E. coli did not correlate with any of physical and/or chemical characteristic of the drinking water (e.g., temperature, chlorine, or biodegradable organic matter concentration). We show here that E. coli is present in the biofilms of drinking water networks in Europe. Some of the cells are metabolically active but are often not detected due to limitations of traditionally used culture-based methods, indicating that biofilm should be considered as a reservoir that must be investigated further in order to evaluate the risk for human health.

scholarly journals Abundance of pathogenic Escherichia coli, Salmonella typhimurium and Vibrio cholerae in Nkonkobe drinking water sources

2006 ◽  
Vol 4 (3) ◽  
pp. 289-296 ◽  
Author(s):  
Maggy N. B. Momba ◽  
Veronica K. Malakate ◽  
Jacques Theron
Keyword(s):  
Escherichia Coli ◽  
Drinking Water ◽  
Salmonella Typhimurium ◽  
Vibrio Cholerae ◽  
Water Samples ◽  
Pathogenic Bacteria ◽  
Culture Media ◽  
Water Sources ◽  
E Coli ◽  
Drinking Water Sources

In order to study the prevalence of enteric pathogens capable of causing infection and disease in the rural communities of Nkonkobe, bacterial isolates were collected from several surface water and groundwater sources used by the community for their daily water needs. By making use of selective culture media and the 20E API kit, presumptive Escherichia coli, Salmonella spp. and Vibrio cholerae isolates were obtained and then analysed by polymerase chain reaction assays (PCR). The PCR successfully amplified from water samples a fragment of E. coli uidA gene that codes for β-D-glucuronidase which is a highly specific characteristic of enteropathogenic E. coli, enterotoxigenic E. coli and entero-invasive E. coli. The PCR also amplified the epsM gene from water samples containing toxigenic V. cholerae. Although E. coli was mostly detected in groundwater sources, toxigenic V. cholerae was detected in both surface and groundwater sources. There was a possibility of Salmonella typhimurium in Ngqele and Dyamala borehole water samples. The presence of these pathogenic bacteria in the above drinking water sources may pose a serious health risk to consumers.

scholarly journals Application of DVC-FISH method in tracking Escherichia coli in drinking water distribution networks

2013 ◽  
Vol 6 (1) ◽  
pp. 25-31 ◽  
Author(s):  
L. Mezule ◽  
S. Larsson ◽  
T. Juhna
Keyword(s):  
Escherichia Coli ◽  
Drinking Water ◽  
Distribution System ◽  
Water Distribution ◽  
Water Distribution System ◽  
Distribution Networks ◽  
Water Distribution Networks ◽  
Water Safety ◽  
E Coli ◽  
Drinking Water Distribution

Abstract. Sporadic detection of live (viable) Escherichia coli in drinking water and biofilm with molecular methods but not with standard plate counts has raised concerns about the reliability of this indicator in the surveillance of drinking water safety. The aim of this study was to determine spatial distribution of different viability forms of E. coli in a drinking water distribution system which complies with European Drinking Water Directive (98/83/EC). For two years coupons (two week old) and pre-concentrated (100 times with ultrafilters) water samples were collected after treatment plants and from four sites in the distribution network at several distances. The samples were analyzed for total, viable (able to divide as DVC-FISH positive) and cultivable E. coli. The results showed that low numbers of E. coli enters the distribution sytem from the treatment plants and tend to accumulate in the biofilm of water distribution system. Almost all of the samples contained metabolically active E. coli in the range of 1 to 50 cells per litre or cm2 which represented approximately 53% of all E. coli detected. The amount of viable E. coli significantly increased into the network irrespective of the season. The study has shown that DVC-FISH method in combination with water pre-concentration and biofilm sampling allows to better understand the behaviour of E. coli in water distribution networks, thus, it provides new evidences for water safety control.

scholarly journals Assessment of microbial contamination of drinking water with total coliform bacteria and Escherichia coli in the Bitola region

2019 ◽  
Vol 65 (2) ◽  
pp. 23-32
Author(s):  
Marta Nedelkova ◽  
Angela Delova ◽  
Tanja Petreska Ivanovska ◽  
Zoran Zhivikj ◽  
Lidija Petrushevska-Tozi
Keyword(s):  
Escherichia Coli ◽  
Drinking Water ◽  
Water Supply ◽  
Rural Areas ◽  
Membrane Filtration ◽  
Total Coliform ◽  
Coliform Bacteria ◽  
Quality And Safety ◽  
E Coli ◽  
Total Coliform Bacteria

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

Influence of algal organic matter on Escherichia coli behaviour

2004 ◽  
Vol 4 (5-6) ◽  
pp. 399-407
Author(s):  
C. Bouteleux ◽  
S. Saby ◽  
D. Tozza ◽  
J. Cavard ◽  
V. Lahoussine ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Drinking Water ◽  
Organic Matter ◽  
Algal Bloom ◽  
Distribution Networks ◽  
Biological Stability ◽  
E Coli ◽  
Algal Organic Matter ◽  
Ozone Stress

This study was undertaken after a report of drinking water industries which suggested the existence of a relation between algal proliferation (algal bloom) in resource water and coliform non-conformity in distribution networks. Our objective was thus to estimate if algal organic matter (AOM) could be used as a substrate by E. coli and explain its resuscitation in drinking water. For this purpose, E. coli was inoculated in sterile dechlorinated drinking water supplemented with organic matter of various origins in order to reach +0.2 (±0.1) mg BDOC L−1 (AOM, glucose or acetate). The results showed that the addition of AOM (naturally secreted by algae or released after a chlorine or ozone stress) in drinking water can represent a risk for water biological stability: indeed, AOM allowed either a higher cellular production, or a better maintenance of cultivability of E. coli than those observed in non-supplemented sterile drinking water, glucose or acetate solutions (in spite of equivalent additions of BDOC). Growth of E. coli was even up to 10 times higher in the presence of AOM coming from ozonated algae.

scholarly journals A Syringe-Based Biosensor to Rapidly Detect Low Levels of Escherichia Coli (ECOR13) in Drinking Water Using Engineered Bacteriophages

Sensors ◽  
2020 ◽  
Vol 20 (7) ◽  
pp. 1953 ◽  
Author(s):  
Troy C. Hinkley ◽  
Spencer Garing ◽  
Paras Jain ◽  
John Williford ◽  
Anne-Laure M. Le Ny ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Drinking Water ◽  
Membrane Filtration ◽  
Genetically Engineered ◽  
World Health ◽  
Selective Enrichment ◽  
E Coli ◽  
Detection Assay ◽  
Colony Forming Units ◽  
Health Organization

A sanitized drinking water supply is an unconditional requirement for public health and the overall prosperity of humanity. Potential microbial and chemical contaminants of drinking water have been identified by a joint effort between the World Health Organization (WHO) and the United Nations Children’s Fund (UNICEF), who together establish guidelines that define, in part, that the presence of Escherichia coli (E. coli) in drinking water is an indication of inadequate sanitation and a significant health risk. As E. coli is a nearly ubiquitous resident of mammalian gastrointestinal tracts, no detectable counts in 100 mL of drinking water is the standard used worldwide as an indicator of sanitation. The currently accepted EPA method relies on filtration, followed by growth on selective media, and requires 24–48 h from sample to results. In response, we developed a rapid bacteriophage-based detection assay with detection limit capabilities comparable to traditional methods in less than a quarter of the time. We coupled membrane filtration with selective enrichment using genetically engineered bacteriophages to identify less than 20 colony forming units (CFU) E. coli in 100 mL drinking water within 5 h. The combination of membrane filtration with phage infection produced a novel assay that demonstrated a rapid, selective, and sensitive detection of an indicator organism in large volumes of drinking water as recommended by the leading world regulatory authorities.

scholarly journals Isolation of Multi Drug Resistant Escherichia coli from drinking water of Lahore City, Pakistan

2021 ◽  
Vol 15 (5) ◽  
pp. 1080-1083
Author(s):  
Nazia Mir ◽  
Sidrah Saleem ◽  
Muhammad Imran ◽  
Ayesha Ghazal ◽  
Muhammad Usman
Keyword(s):  
Escherichia Coli ◽  
Drinking Water ◽  
Membrane Filtration ◽  
Diffusion Method ◽  
Resistant Bacteria ◽  
Drug Resistant ◽  
Antibiotic Resistant ◽  
Acinetobacter Species ◽  
E Coli ◽  
Lahore City

Background: The major faecal coliform is Escherichia coli which contaminates the drinking water from human and animal faecal waste. In developing regions drinking water is a vital source of microbiological pathogens. Multi-drug resistant (MDR) is defined as resistance to one or more antibiotic groups. An E. coli count greater than 4/dl in municipal drinking water is indicative of unacceptable fecal contamination. Aim: To find out the frequency of MDR E. coli in water system of Lahore, Pakistan. Methodology: Drinking water was collected from different towns of Lahore. The samples were processed using Membrane Filtration Technique. In the present study, Multidrug Resistant E.coli was isolated and antibiotic resistant pattern was seen against 16 most commonly antimicrobials, using Kirby Bauer disc diffusion method. Results: Total 100 water samples were collected, frequency of Escherichia coliisolated was 27% and frequency of MDR E.coli was 19%. The highest resistance showed by the organism towards Ampicillin (AMP) 21(81.48%), Augmentin (AMC), and Ceftazidime (CAZ) 14(51.85%) respectively. In this study also frequency of Extended Spectrum β-Lactamases were seen. Most common organisms isolated were E. coli 7% and Klebsiella 5%. Frequency of other coliforms isolated from drinking water other than E. coli was Klebsiella species 26%, Pseudomonas species 27%, Enterobacter 7%, Citrobacter species 8% and Acinetobacter species 5%. Conclusion: This study revealed that drinking water of Lahore city is heavilycontaminated with pathogenic microorganisms. A high proportion of antibiotic resistant is due to overuse of antibiotics, in patients with mild infections and secretion of these resistant bacteria from patients to environment. One of the reasons could be the mixing of sewage lines with drinking water supply. So, there is solely requirement for further studies for the identification of the sources for these contaminants. Keywords: Isolates, E. coli, Klebsiella, Multi-drug resistant (MDR)

scholarly journals Development of an Escherichia coli K12-specific quantitative polymerase chain reaction assay and DNA isolation suited to biofilms associated with iron drinking water pipe corrosion products

2014 ◽  
Vol 12 (4) ◽  
pp. 763-771 ◽  
Author(s):  
Jingrang Lu ◽  
Tammie L. Gerke ◽  
Helen Y. Buse ◽  
Nicholas J. Ashbolt
Keyword(s):  
Escherichia Coli ◽  
Polymerase Chain Reaction ◽  
Drinking Water ◽  
Polymerase Chain Reaction Assay ◽  
Quantitative Polymerase Chain Reaction ◽  
The Novel ◽  
Water Pipe ◽  
Chain Reaction ◽  
E Coli ◽  
Polymerase Chain

A quantitative polymerase chain reaction assay (115 bp amplicon) specific to Escherichia coli K12 with an ABITM internal control was developed based on sequence data encoding the rfb gene cluster. Assay specificity was evaluated using three E. coli K12 strains (ATCC W3110, MG1655 & DH1), 24 non-K12 E. coli and 23 bacterial genera. The biofilm detection limit was 103 colony-forming units (CFU) E. coli K12 mL−1, but required a modified protocol, which included a bio-blocker Pseudomonas aeruginosa with ethylenediaminetetraacetic acid buffered to pH 5 prior to cell lysis/DNA extraction. The novel protocol yielded the same sensitivity for drinking water biofilms associated with Fe3O4 (magnetite)-coated SiO2 (quartz) grains and biofilm-surface iron corrosion products from a drinking water distribution system. The novel DNA extraction protocol and specific E. coli K12 assay are sensitive and robust enough for detection and quantification within iron drinking water pipe biofilms, and are particularly well suited for studying enteric bacterial interactions within biofilms.

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