Effect of Heat Shock on Recovery of Escherichia coli from Drinking Water

1991 ◽  
Vol 24 (2) ◽  
pp. 85-88 ◽  
Author(s):  
C. Berry ◽  
B. J. Lloyd ◽  
J. S. Colbourne
Keyword(s):  
Escherichia Coli ◽  
Drinking Water ◽  
Heat Shock ◽  
Legionella Pneumophila ◽  
Traditional Culture ◽  
Culturable Bacteria ◽  
Water Industry ◽  
Culture Methods ◽  
E Coli ◽  
Response To Stress

Recent studies on the survival of bacteria in the aquatic environment have suggested that bacteria in water may enter a ‘viable non-culturable' phase in response to stress. Such bacteria are a cause of concern if pathogenic, because they cannot be detected using traditional culture methods. It has been found that mild heat shock causes viable non-culturable Legionella pneumophila to grow on laboratory media. The survival and culturability of Escherichia coli in sterile drinking water was investigated. The isolates used were from the environment rather than clinical. As expected, the count by culture on nutrient agar declined with time while the microscopy count remained approximately constant. Under laboratory conditions the E. coli isolates survived up to three months or more. After three months a portion of each suspension was heat shocked at 35°C for 20 minutes and then assayed by culture and microscopy immediately. An average increase of three log cycles was noted in the count by culture. There was no corresponding increase in the count by microscopy. Thus E. coli appears to exhibit viable non-culturable behaviour. Heat shock causes non-culturable bacteria to regain their ability to grow on artificial media. Such a finding may have several implications for the water industry and microbiology in general.

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 Comparison of four β-glucuronidase and β-galactosidase-based commercial culture methods used to detect Escherichia coli and total coliforms in water

2014 ◽  
Vol 13 (2) ◽  
pp. 340-352 ◽  
Author(s):  
Andrée F. Maheux ◽  
Vanessa Dion-Dupont ◽  
Sébastien Bouchard ◽  
Marc-Antoine Bisson ◽  
Michel G. Bergeron ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Drinking Water ◽  
Water Samples ◽  
Microbiological Quality ◽  
Total Coliform ◽  
Ease Of Use ◽  
Well Water ◽  
Positive Signal ◽  
Culture Methods ◽  
E Coli

The MI agar, Colilert®, Chromocult coliform® agar, and DC with BCIG agar chromogenic culture-based methods used to assess microbiological quality of drinking water were compared in terms of their ubiquity, sensitivity, ease of use, growth of atypical colonies and affordability. For ubiquity, 129 total coliform (representing 76 species) and 19 Escherichia coli strains were tested. Then, 635 1-L well water samples were divided into 100 mL subsamples for testing by all four methods. Test results showed that 70.5, 52.7, 36.4, and 23.3% of the non-E. coli total coliform strains and 94.7, 94.7, 89.5, and 89.5% of the 19 E. coli strains yielded a positive signal with the four methods, respectively. They also yielded a total coliform positive signal for 66.5, 51.7, 64.9, and 55.0% and an E. coli positive signal for 16.1, 14.8, 17.3, and 13.4% of the 635 well water samples tested, respectively. Results showed that Colilert® is the most expensive method tested in terms of reactants, yet it is the easiest to use. Large numbers of atypical colonies were also often observed on Chromocult coliform® and DC with BCIG, thereby challenging the target microorganism count. Thus, the MI agar method seems to be the best option for the assessment of drinking water quality.

scholarly journals Prevalence of Legionella spp. and Escherichia coli in the drinking water distribution system of Wrocław (Poland)

2020 ◽  
Vol 20 (3) ◽  
pp. 1083-1090
Author(s):  
M. Wolf-Baca ◽  
A. Siedlecka
Keyword(s):  
Escherichia Coli ◽  
Drinking Water ◽  
Legionella Pneumophila ◽  
Water Samples ◽  
Distribution System ◽  
Water Distribution ◽  
Tap Water ◽  
Potential Threat ◽  
E Coli ◽  
Drinking Water Distribution

Abstract Drinking water should be free from bacterial pathogens that threaten human health. The most recognised waterborne opportunistic pathogens, dwelling in tap water, are Legionella pneumophila and Escherichia coli. Drinking water samples were tested for the presence of Legionella spp., L. pneumophila, and E. coli in overall sample microbiomes using a quantitative real-time polymerase chain reaction (qPCR) approach. The results indicate a rather low contribution of Legionella spp. in total bacteria in the tested samples, but L. pneumophila was not detected in any sample. E. coli was detected in only one sample, but at a very low level. The qacEΔ1 gene, conferring resistance to quaternary ammonium compounds, was also not detected in any sample. The results point to generally sufficient quality of drinking water, although the presence of Legionella spp. in tap water samples suggests proliferation of these bacteria in heating units, causing a potential threat to consumer health.

scholarly journals Survival of Mycobacterium avium, Legionella pneumophila, Escherichia coli, and Caliciviruses in Drinking Water-Associated Biofilms Grown under High-Shear Turbulent Flow

2007 ◽  
Vol 73 (9) ◽  
pp. 2854-2859 ◽  
Author(s):  
Markku J. Lehtola ◽  
Eila Torvinen ◽  
Jaana Kusnetsov ◽  
Tarja Pitkänen ◽  
Leena Maunula ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Drinking Water ◽  
Turbulent Flow ◽  
Mycobacterium Avium ◽  
Legionella Pneumophila ◽  
Distribution Systems ◽  
Water Distribution ◽  
Water Distribution Systems ◽  
High Shear ◽  
Culture Methods

ABSTRACT Most of the bacteria in drinking water distribution systems are associated with biofilms. In biofilms, their nutrient supply is better than in water, and biofilms can provide shelter against disinfection. We used a Propella biofilm reactor for studying the survival of Mycobacterium avium, Legionella pneumophila, Escherichia coli, and canine calicivirus (CaCV) (as a surrogate for human norovirus) in drinking water biofilms grown under high-shear turbulent-flow conditions. The numbers of M. avium and L. pneumophila were analyzed with both culture methods and with peptide nucleic acid fluorescence in situ hybridization (FISH) methods. Even though the numbers of pathogens in biofilms decreased during the experiments, M. avium and L. pneumophila survived in biofilms for more than 2 to 4 weeks in culturable forms. CaCV was detectable with a reverse transcription-PCR method in biofilms for more than 3 weeks. E. coli was detectable by culture for only 4 days in biofilms and 8 days in water, suggesting that it is a poor indicator of the presence of certain waterborne pathogens. With L. pneumophila and M. avium, culture methods underestimated the numbers of bacteria present compared to the FISH results. This study clearly proved that pathogenic bacteria entering water distribution systems can survive in biofilms for at least several weeks, even under conditions of high-shear turbulent flow, and may be a risk to water consumers. Also, considering the low number of virus particles needed to result in an infection, their extended survival in biofilms must be taken into account as a risk for the consumer.

scholarly journals Occurrence of extended spectrum β-lactamase and AmpC-producing Escherichia coli in retail meat products from the Maritime Provinces, Canada

2020 ◽  
Author(s):  
Babafela Awosile ◽  
Jessica Eisnor ◽  
Matthew Elijah Saab ◽  
Luke C. Heider ◽  
J. Trenton McClure
Keyword(s):  
Escherichia Coli ◽  
Meat Products ◽  
Traditional Culture ◽  
Multi Drug Resistance ◽  
Maritime Provinces ◽  
Phylogenetic Groups ◽  
Culture Methods ◽  
E Coli ◽  
Extended Spectrum ◽  
Retail Meat

This study was conducted to determine the occurrence of antimicrobial resistance to the extended-spectrum cephalosporins (ESC) in Escherichia coli isolates recovered from retail meat products collected in the Maritime Provinces of Canada using both selective and traditional culture methods, and genotypically using multiplex polymerase chain reactions. ESC-R E. coli was detected in 33/559 (5.9%) samples using the traditional culture compared to 151/557 (27.1%) samples using the selective culture method. The recovery of ESC-R E. coli isolates was more common in poultry compared to beef and pork (P<0.001). Multi-drug resistance, ESBL, and AmpC phenotypes were more common in chicken-derived isolates than other retail meat products (P<0.001). From the 98 isolates selected, 76 (77.6%) isolates were positive for either ESBL and AmpC β-lactamases or both. Among the 76 isolates, blaCMY-2 (78.9%), blaCTXM (46.1%), blaTEM (21.1%), and blaSHV (1.3%) were detected. Among the blaCTXM-producing isolates; blaCTXM-1, blaCTXM-2, and blaCTXM-9 phylogenetic groups were detected. β-lactamase genes were detected more in chicken-derived isolates compared to other meat types (P<0.01). This study demonstrated the occurrence of ESBL and AmpC resistance genes in retail meat products in Maritime Provinces of Canada. Also, selective culture significantly improved the recovery of ESC-R E. coli isolates from retail meat samples.

scholarly journals Occurrence of extended spectrum β-lactamase and AmpC-producing Escherichia coli in retail meat products from the Maritime Provinces, Canada

2020 ◽  
Author(s):  
Babafela Awosile ◽  
Jessica Eisnor ◽  
Matthew E. Saab ◽  
Luke Heider ◽  
J T. McClure
Keyword(s):  
Escherichia Coli ◽  
Meat Products ◽  
Traditional Culture ◽  
Multi Drug Resistance ◽  
Maritime Provinces ◽  
Phylogenetic Groups ◽  
Culture Methods ◽  
E Coli ◽  
Extended Spectrum ◽  
Retail Meat

AbstractThis study was conducted to determine the occurrence of antimicrobial resistance to the extended-spectrum cephalosporins (ESC) in Escherichia coli isolates recovered from retail meat products collected in the Maritime Provinces of Canada using both selective and traditional culture methods, and genotypically using multiplex polymerase chain reactions.ESC-R E. coli was detected in 33/559 (5.9%) samples using the traditional culture compared to 151/557 (27.1%) samples using the selective culture method. The recovery of ESC-R E. coli isolates was more common in poultry compared to beef and pork (P<0.001). Multi-drug resistance, ESBL, and AmpC phenotypes were more common in chicken-derived isolates than other retail meat products (P<0.001). From the 98 isolates selected, 76 (77.6%) isolates were positive for either ESBL and AmpC β-lactamases or both. Among the 76 isolates, blaCMY-2 (78.9%), blaCTXM (46.1%), blaTEM (21.1%), and blaSHV (1.3%) were detected. Among the blaCTXM-producing isolates; blaCTXM-1, blaCTXM-2, and blaCTXM-9 phylogenetic groups were detected. β-lactamase genes were detected more in chicken-derived isolates compared to other meat types (P<0.01). This study demonstrated the occurrence of ESBL and AmpC resistance genes in retail meat products in Maritime Provinces of Canada. Also, selective culture significantly improved the recovery of ESC-R E. coli isolates from retail meat samples.

scholarly journals Drinking water and diarrhoeal disease due to Escherichia coli

2003 ◽  
Vol 1 (2) ◽  
pp. 65-72 ◽  
Author(s):  
Paul R. Hunter
Keyword(s):  
Escherichia Coli ◽  
Drinking Water ◽  
Clinical Presentation ◽  
Diarrhoeal Disease ◽  
Central Place ◽  
E Coli ◽  
Related Disease ◽  
Direct Damage ◽  
Water Microbiology

Escherichia coli has had a central place in water microbiology for decades as an indicator of faecal pollution. It is only relatively recently that the role of E. coli as pathogen, rather than indicator, in drinking water has begun to be stressed. Interest in the role of E. coli as a cause of diarrhoeal disease has increased because of the emergence of E. coli O157:H7 and other enterohaemorrhagic E. coli, due to the severity of the related disease. There are enterotoxigenic, enteropathogenic, enterohaemorrhagic, enteroinvasive, enteroaggregative and diffusely adherent strains of E. coli. Each type of E. coli causes diarrhoeal disease through different mechanisms and each causes a different clinical presentation. Several of the types cause diarrhoea by the elaboration of one or more toxins, others by some other form of direct damage to epithelial cells. This paper discusses each of these types in turn and also describes their epidemiology, with particular reference to whether they are waterborne or not.

Thermal and Starvation Stress Response of Escherichia coli O157:H7 Isolates Selected from Agricultural Environments

2016 ◽  
Vol 79 (10) ◽  
pp. 1673-1679 ◽  
Author(s):  
ACHYUT ADHIKARI ◽  
ANDY BARY ◽  
CRAIG COGGER ◽  
CALEB JAMES ◽  
GÜLHAN ÜNLÜ ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Heat Stress ◽  
Stress Response ◽  
Weibull Model ◽  
Stress Conditions ◽  
Inactivation Kinetics ◽  
Escherichia Coli O157 ◽  
Starvation Stress ◽  
E Coli ◽  
Response To Stress

ABSTRACT Pathogens exposed to agricultural production environments are subject to multiple stresses that may alter their survival under subsequent stress conditions. The objective of this study was to examine heat and starvation stress response of Escherichia coli O157:H7 strains isolated from agricultural matrices. Seven E. coli O157:H7 isolates from different agricultural matrices—soil, compost, irrigation water, and sheep manure—were selected, and two ATCC strains were used as controls. The E. coli O157:H7 isolates were exposed to heat stress (56°C in 0.1% peptone water for up to 1 h) and starvation (in phosphate-buffered saline at 37°C for 15 days), and their survival was examined. GInaFiT freeware tool was used to perform regression analyses of the surviving populations. The Weibull model was identified as the most appropriate model for response of the isolates to heat stress, whereas the biphasic survival curves during starvation were fitted using the double Weibull model, indicating the adaptation to starvation or a resistant subpopulation. The inactivation time during heating to achieve the first decimal reduction time (δ) calculated with the Weibull parameters was the highest (45 min) for a compost isolate (Comp60A) and the lowest (28 min) for ATCC strain 43895. Two of the nine isolates (ATCC 43895 and a manure isolate) had β &lt; 1, indicating that surviving populations adapted to heat stress, and six strains demonstrated downward concavity (β &gt; 1), indicating decreasing heat resistance over time. The ATCC strains displayed the longest δ2 (&gt;1,250 h) in response to starvation stress, compared with from 328 to 812 h for the environmental strains. The considerable variation in inactivation kinetics of E. coli O157:H7 highlights the importance of evaluating response to stress conditions among individual strains of a specific pathogen. Environmental isolates did not exhibit more robust response to stress conditions in this study compared with ATCC strains.

scholarly journals Spread of Antibiotic Resistance in Aquatic Environments: E. coli as a Case Study

Proceedings ◽  
2018 ◽  
Vol 2 (11) ◽  
pp. 693 ◽  
Author(s):  
Maria Adamantia Efstratiou ◽  
Marina Bountouni ◽  
Efthimios Kefalas
Keyword(s):  
Escherichia Coli ◽  
Drinking Water ◽  
Antibiotic Resistance ◽  
Rural Communities ◽  
Ground Water ◽  
Aquatic Environments ◽  
Multiple Resistance ◽  
E Coli ◽  
Of Greece

The aim of this study was to gather information on the spread of antibiotic resistance in Escherichia coli isolates from wells, boreholes and untreated drinking water in islands of Greece. We analyzed for antibiotic resistance 235 E. coli strains isolated from untreated drinking water of small rural communities, and ground water from 4 islands. Resistance was tested against Norfloxacin, Ciprofloxacin, Levofloxacin, Amoxicillin and Cefaclor. More than half (54.9%) were resistant to at least one of the antibiotics tested. Of these 26.3% showed multiple resistance (to two or more antibiotics). Strains from drinking water sources were overall more sensitive. Frequent resistance was observed for Amoxicillin (38.3%) and Levofloxacin (28.5%), low for Norfloxacin (5.5%).

scholarly journals Functional Analysis of Genes Comprising the Locus of Heat Resistance in Escherichia coli

2017 ◽  
Vol 83 (20) ◽  
Author(s):  
Ryan Mercer ◽  
Oanh Nguyen ◽  
Qixing Ou ◽  
Lynn McMullen ◽  
Michael G. Gänzle
Keyword(s):  
Escherichia Coli ◽  
Heat Shock ◽  
Heat Shock Proteins ◽  
Heat Resistance ◽  
Growth Phase ◽  
Genomic Island ◽  
Enteric Bacteria ◽  
Content Type ◽  
E Coli ◽  
Shock Proteins

ABSTRACT The locus of heat resistance (LHR) is a 15- to 19-kb genomic island conferring exceptional heat resistance to organisms in the family Enterobacteriaceae, including pathogenic strains of Salmonella enterica and Escherichia coli. The complement of LHR-comprising genes that is necessary for heat resistance and the stress-induced or growth-phase-induced expression of LHR-comprising genes are unknown. This study determined the contribution of the seven LHR-comprising genes yfdX1 GI, yfdX2, hdeD GI, orf11, trx GI, kefB, and psiE GI by comparing the heat resistances of E. coli strains harboring plasmid-encoded derivatives of the different LHRs in these genes. (Genes carry a subscript “GI” [genomic island] if an ortholog of the same gene is present in genomes of E. coli.) LHR-encoded heat shock proteins sHSP20, ClpKGI, and sHSPGI are not sufficient for the heat resistance phenotype; YfdX1, YfdX2, and HdeD are necessary to complement the LHR heat shock proteins and to impart a high level of resistance. Deletion of trx GI, kefB, and psiE GI from plasmid-encoded copies of the LHR did not significantly affect heat resistance. The effect of the growth phase and the NaCl concentration on expression from the putative LHR promoter p2 was determined by quantitative reverse transcription-PCR and by a plasmid-encoded p2:GFP promoter fusion. The expression levels of exponential- and stationary-phase E. coli cells were not significantly different, but the addition of 1% NaCl significantly increased LHR expression. Remarkably, LHR expression in E. coli was dependent on a chromosomal copy of evgA. In conclusion, this study improved our understanding of the genes required for exceptional heat resistance in E. coli and factors that increase their expression in food. IMPORTANCE The locus of heat resistance (LHR) is a genomic island conferring exceptional heat resistance to several foodborne pathogens. The exceptional level of heat resistance provided by the LHR questions the control of pathogens by current food processing and preparation techniques. The function of LHR-comprising genes and their regulation, however, remain largely unknown. This study defines a core complement of LHR-encoded proteins that are necessary for heat resistance and demonstrates that regulation of the LHR in E. coli requires a chromosomal copy of the gene encoding EvgA. This study provides insight into the function of a transmissible genomic island that allows otherwise heat-sensitive enteric bacteria, including pathogens, to lead a thermoduric lifestyle and thus contributes to the detection and control of heat-resistant enteric bacteria in food.

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