Inactivation of enteric microbes in water by electro-chemical oxidant from brine (NaCl) and free chlorine

2004 ◽  
Vol 50 (1) ◽  
pp. 141-146 ◽  
Author(s):  
L.V. Venczel ◽  
C.A. Likirdopulos ◽  
C.E. Robinson ◽  
M.D. Sobsey
Keyword(s):  
Escherichia Coli ◽  
Drinking Water ◽  
Vibrio Cholerae ◽  
Clostridium Perfringens ◽  
Cryptosporidium Parvum ◽  
Free Chlorine ◽  
Inactivation Kinetics ◽  
Nacl Solution ◽  
E Coli ◽  
Cryptosporidium Parvum Oocysts

Oxidant solutions of mostly free chlorine can be electrochemically produced on-site from brine (NaCl) solution and used to disinfect water at the household or community level. In this study electrochemical oxidant (ECO) from brine and free chlorine were evaluated under laboratory conditions for inactivation of test microbes. Purified suspensions of Escherichia coli, the rugose strain of Vibrio cholerae, Clostridium perfringens spores, MS2 coliphage and Cryptosporidium parvum oocysts were treated with 2 mg/L or 5 mg/L solutions of ECO or free chlorine at 5°C and 25°C and pH 6, 8, and 10 (pH 7 and 25°C only for C. parvum oocysts) for contact times <60 min. Under nearly all conditions, inactivation kinetics were more rapid for E. coli, V. cholerae, C. perfringens spores and MS2 coliphage with ECO than with free chlorine. ECO reduced E. coli, V. cholerae and MS2 by >4 log10 within 30 min and C. perfringens spores by >2 log10 within 10 min at pH 8 and 25°C. Contrary to previous results, however, C. parvum oocysts were not inactivated by ECO, and the reasons for this difference are uncertain. The on-site electrolytic generation of oxidants from brine provided a convenient and inexpensive disinfectant containing free chlorine that was effective against many enteric microbes, for the treatment of household and community drinking-water supplies worldwide. However, the effectiveness of such oxidants for inactivating C. parvum oocysts was variable and sometimes ineffective.

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 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.

Inactivation of Cryptosporidium parvum Oocysts and Clostridium perfringens Spores by a Mixed-Oxidant Disinfectant and by Free Chlorine

1997 ◽  
Vol 63 (11) ◽  
pp. 4625-4625
Author(s):  
L V Venczel ◽  
M Arrowood ◽  
M Hurd ◽  
M D Sobsey
Keyword(s):  
Clostridium Perfringens ◽  
Cryptosporidium Parvum ◽  
Free Chlorine ◽  
Cryptosporidium Parvum Oocysts

Volume 63, no. 4, p. 1600: The caption to Table 2 should read as follows: "Inactivation of Clostridium perfringens spores by 5-mg/liter doses of mixed oxidants or free chlorine in buffer at pH 7 at 25(deg)C." [This corrects the article on p. 1598 in vol. 63.].

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.

Inactivation of Cryptosporidium parvum oocysts and other microbes in water and wastewater by electrochemically generated mixed oxidants

2000 ◽  
Vol 41 (7) ◽  
pp. 127-134 ◽  
Author(s):  
M. J. Casteel ◽  
M. D. Sobsey ◽  
M. J. Arrowood
Keyword(s):  
Escherichia Coli ◽  
Cell Culture ◽  
Cryptosporidium Parvum ◽  
Propidium Iodide ◽  
Treated Wastewater ◽  
E Coli ◽  
Water And Wastewater ◽  
Cryptosporidium Parvum Oocysts ◽  
Cell Culture Assay ◽  
Escherichia Coli B

Alternative disinfectants of water and wastewater are needed because conventional chlorination is ineffective against C. parvum oocysts. Reliable indicators of disinfection efficacy against C. parvum also are needed. Mixedoxidants (MO) electrochemically generated from brine were evaluated in batch disinfection experiments for inactivation of C. parvum oocysts and Cl. perfringensspores in both oxidant demand-free (ODF) water and treated wastewater. Coliphage MS2 and Escherichia coli B were also tested under some conditions. C. parvum oocyst infectivity was quantified by cell culture assay, and the dyes DAPI (4′,6-diamidino-2-phenylindole) and propidium iodide (PI) were used to assess oocyst viability in wastewater experiments. In treated wastewater dosed with 10–13 mg/L MO, inactivation after 90 minutes was about 3 log10 for C. parvum and about 2.5 log10 for Cl. perfringens spores; MS2 and E. coli were rapidly inactivated by &gt; 5 log10. In ODF water, a 4 mg/L dose of MO inactivated ∼3 log10 of C. parvum oocysts and ∼1.5 log10 of Cl. perfringens spores. Inactivation of C. parvum oocysts and Cl. perfringensspores was less extensive at a lower MO dose of 2 mg/L. The use of DAPI and PI to determine viability of oocysts treated with MO did not correlate with, and greatly overestimated, cell culture infectivity. At practical doses and contact times, MO disinfection of water and wastewater achieves appreciable inactivation of both C. parvum oocysts and Cl. perfringens spores. Cl. perfringens spores reliably indicated oocyst inactivation by MO, but E. coli and coliphage MS2 were inactivated much too rapidly to indicate C. parvum inactivation.

scholarly journals Environmental Survey of Drinking Water Sources in Kampala, Uganda, during a Typhoid Fever Outbreak

2017 ◽  
Vol 83 (23) ◽  
Author(s):  
J. L. Murphy ◽  
A. M. Kahler ◽  
I. Nansubuga ◽  
E. M. Nanyunja ◽  
B. Kaplan ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Drinking Water ◽  
Typhoid Fever ◽  
Water Samples ◽  
Water Sources ◽  
Free Chlorine ◽  
Water Utility ◽  
Content Type ◽  
Environmental Survey ◽  
E Coli

ABSTRACT In 2015, a typhoid fever outbreak began in downtown Kampala, Uganda, and spread into adjacent districts. In response, an environmental survey of drinking water source types was conducted in areas of the city with high case numbers. A total of 122 samples was collected from 12 source types and tested for Escherichia coli, free chlorine, and conductivity. An additional 37 grab samples from seven source types and 16 paired large volume (20 liter) samples from wells and springs were also collected and tested for the presence of Salmonella enterica serovar Typhi. Escherichia coli was detected in 60% of kaveras (drinking water sold in plastic bags) and 80% of refilled water bottles; free chlorine was not detected in either source type. Most jerry cans (68%) contained E. coli and had free chlorine residuals below the WHO-recommended level of 0.5 mg/liter during outbreaks. Elevated conductivity readings for kaveras, refilled water bottles, and jerry cans (compared to treated surface water supplied by the water utility) suggested that they likely contained untreated groundwater. All unprotected springs and wells and more than 60% of protected springs contained E. coli. Water samples collected from the water utility were found to have acceptable free chlorine levels and no detectable E. coli. While S. Typhi was not detected in water samples, Salmonella spp. were detected in samples from two unprotected springs, one protected spring, and one refilled water bottle. These data provided clear evidence that unregulated vended water and groundwater represented a risk for typhoid transmission. IMPORTANCE Despite the high incidence of typhoid fever globally, relatively few outbreak investigations incorporate drinking water testing. During waterborne disease outbreaks, measurement of physical-chemical parameters, such as free chlorine residual and electrical conductivity, and of microbiological parameters, such as the presence of E. coli or the implicated etiologic agent, in drinking water samples can identify contaminated sources. This investigation indicated that unregulated vended water and groundwater sources were contaminated and were therefore a risk to consumers during the 2015 typhoid fever outbreak in Kampala. Identification of contaminated drinking water sources and sources that do not contain adequate disinfectant levels can lead to rapid targeted interventions.

scholarly journals Vibrio cholerae Triggers SOS and Mutagenesis in Response to a Wide Range of Antibiotics: a Route towards Multiresistance

2011 ◽  
Vol 55 (5) ◽  
pp. 2438-2441 ◽  
Author(s):  
Zeynep Baharoglu ◽  
Didier Mazel
Keyword(s):  
Escherichia Coli ◽  
Antibiotic Resistance ◽  
Vibrio Cholerae ◽  
Fluorescent Protein ◽  
Resistance Development ◽  
Content Type ◽  
E Coli ◽  
Wide Range ◽  
Green Fluorescent ◽  
Regulated Promoters

ABSTRACTAntibiotic resistance development has been linked to the bacterial SOS stress response. InEscherichia coli, fluoroquinolones are known to induce SOS, whereas other antibiotics, such as aminoglycosides, tetracycline, and chloramphenicol, do not. Here we address whether various antibiotics induce SOS inVibrio cholerae. Reporter green fluorescent protein (GFP) fusions were used to measure the response of SOS-regulated promoters to subinhibitory concentrations of antibiotics. We show that unlike the situation withE. coli, all these antibiotics induce SOS inV. cholerae.

scholarly journals Inativação de microrganismos indicadores de contaminação fecal por radiação ultravioleta e avaliação dos fenômenos de fotorreativação e recuperação no escuro

2018 ◽  
Vol 23 (5) ◽  
pp. 987-994
Author(s):  
Carlos Raphael Pedroso ◽  
Jeanette Beber de Souza ◽  
Thaís Kovalski ◽  
Carlos Magno de Sousa Vidal ◽  
Kelly Geronazzo Martins
Keyword(s):  
Escherichia Coli ◽  
Clostridium Perfringens ◽  
E Coli

RESUMO Esta pesquisa teve como objetivo avaliar o desempenho da radiação ultravioleta (UV) para a desinfecção de efluente final de estação de tratamento de esgoto (ETE) sanitário municipal, em escala de bancada de laboratório e operação em batelada. Foram analisadas as interferências dos parâmetros operacionais tempo de exposição (s) à radiação e altura de lâmina líquida (cm) do efluente no reator UV. A eficiência do processo de desinfecção foi avaliada empregando os microrganismos indicadores Clostridium perfringens (C. perfringens), colifagos, Escherichia coli (E. coli) e coliformes totais (CT). Após a desinfecção, foram avaliados os fenômenos de recuperação microbiológica fotorreativação e recuperação no escuro para E. coli e CT. Os resultados indicaram efetiva inativação dos microrganismos indicadores à radiação UV no decorrer do tempo de exposição, o que foi comprovado estatisticamente pela ANOVA de medidas repetidas. C. perfringens foi o microrganismo que apresentou a maior resistência à inativação. Nos ensaios de recuperação microbiológica, ambos os mecanismos foram considerados insignificantes, o que foi comprovado estatisticamente pelos testes t de Student (dados paramétricos) e Wilcoxon (dados não paramétricos). Em todas as análises, o nível de significância foi de 5%.

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.

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