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Zhu L, Torres M, Betancourt WQ, Sharma M, Micallef SA, Gerba C, Sapkota AR, Sapkota A, Parveen S, Hashem F, May E, Kniel K, Pop M, Ravishankar S. Incidence of fecal indicator and pathogenic bacteria in reclaimed and return flow waters in Arizona, USA. ENVIRONMENTAL RESEARCH 2019; 170:122-127. [PMID: 30579985 DOI: 10.1016/j.envres.2018.11.048] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/01/2018] [Revised: 11/13/2018] [Accepted: 11/30/2018] [Indexed: 06/09/2023]
Abstract
The quality of irrigation water used to cultivate produce that is consumed raw is an important issue with regard to food safety. In this study, the microbiological quality of potential irrigation water sources in Arizona was evaluated by testing for the presence of indicator and pathogenic bacteria. Reclaimed water samples were collected from two wastewater treatment plants and return flow samples were collected from two drainage canals and one return flow pond. Standard membrane filtration methods were used for detection of indicator bacteria. Water samples (n = 28) were filtered through cellulose ester membrane filters and bacterial populations were enumerated by placing the filters on selective agar. For detection of pathogens (Salmonella enterica, Listeria monocytogenes and Shiga toxin-producing E. coli (STEC)), water samples were filtered through Modified Moore swabs and enriched in Universal Pre-enrichment Broth, followed by selective enrichment broth for each pathogen. The enriched broth was streaked onto agar media selective for each pathogen. Presumptive colonies were confirmed by PCR/real-time PCR. Among the 14 reclaimed water samples from two sites, the ranges of recovered populations of E. coli, total coliforms, and enterococci were 0-1.3, 0.5-8.3 × 103, and 0-5.5 CFU/100 mL, respectively. No L. monocytogenes, Salmonella or STEC were found. In the 13 return flow water samples from 3 sites, the ranges of recovered populations of E. coli, total coliforms and enterococci were 1.9-5.3 × 102, 6.5 × 102-9.1 × 104, and 2.9-3.7× 103 CFU/100 mL, respectively. All samples were negative for L. monocytogenes. One (7.1%) of the return flow samples was positive for E. coli O145. Nine (64.3%) of the samples were positive for Salmonella. Both real-time PCR and culture-based methods were used for the detection of Salmonella and L. monocytogenes, and the results from the two methods were comparable. The findings of this study provide evidence that irrigation waters in Arizona, including reclaimed water and return flows, could be potential sources of bacterial contamination of produce. Additional work is needed to evaluate whether bacteria present in irrigation water sources transfer to the edible portion of irrigated plants and are capable of persisting through post-harvest activities.
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Affiliation(s)
- Libin Zhu
- School of Animal and Comparative Biomedical Sciences, University of Arizona, 1117 E. Lowell Street, Tucson, AZ 85721, United States
| | - Monique Torres
- School of Animal and Comparative Biomedical Sciences, University of Arizona, 1117 E. Lowell Street, Tucson, AZ 85721, United States
| | - Walter Q Betancourt
- Department of Soil, Water, and Environmental Science, University of Arizona, 2959 W Calle Agua Nueva, Tucson, AZ 85745, United States
| | - Manan Sharma
- Environmental Microbial & Food Safety Lab, USDA-ARS, 10300 Baltimore Avenue, Beltsville, MD 20705, United States
| | - Shirley A Micallef
- Department of Plant Science and Landscape Architecture, University of Maryland, 2126 Plant Sciences Building, College Park, MD 20742, United States; Centre for Food Safety and Security Systems, University of Maryland, College Park, MD 20742, United States
| | - Charles Gerba
- Department of Soil, Water, and Environmental Science, University of Arizona, 2959 W Calle Agua Nueva, Tucson, AZ 85745, United States
| | - Amy R Sapkota
- School of Public Health, University of Maryland, 2234P SPH Building, College Park, MD 20742, United States
| | - Amir Sapkota
- School of Public Health, University of Maryland, 2234P SPH Building, College Park, MD 20742, United States
| | - Salina Parveen
- Department of Agriculture, Food, and Resource Sciences, University of Maryland Eastern Shore, Princess Anne, MD 21853, United States
| | - Fawzy Hashem
- Department of Agriculture, Food, and Resource Sciences, University of Maryland Eastern Shore, Princess Anne, MD 21853, United States
| | - Eric May
- Department of Agriculture, Food, and Resource Sciences, University of Maryland Eastern Shore, Princess Anne, MD 21853, United States
| | - Kalmia Kniel
- Department of Animal and Food Sciences, University of Delaware, 044 Townsend Hall, Newark, DE 19716, United States
| | - Mihai Pop
- Department of Computer Science & the Center for Bioinformatics and Computational Biology, University of Maryland, 8223 Paint Branch Drive, College Park, MD 20742, United States
| | - Sadhana Ravishankar
- School of Animal and Comparative Biomedical Sciences, University of Arizona, 1117 E. Lowell Street, Tucson, AZ 85721, United States.
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Rybarczyk J, Kieckens E, Vanrompay D, Cox E. In vitro and in vivo studies on the antimicrobial effect of lactoferrin against Escherichia coli O157:H7. Vet Microbiol 2017; 202:23-28. [DOI: 10.1016/j.vetmic.2016.05.010] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2016] [Revised: 05/11/2016] [Accepted: 05/18/2016] [Indexed: 10/21/2022]
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3
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Tong ZX, Liu W, Huang H, Chen HZ, Liu XJ, Kuang YQ, Jiang JH. A ratiometric fluorescent pH probe based on keto–enol tautomerization for imaging of living cells in extreme acidity. Analyst 2017; 142:3906-3912. [DOI: 10.1039/c7an01103b] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
A ratiometric fluorescent pH probe (DDXC) has been developed for extreme acidity, the sensing mechanism of which is based on the reversible protonation of the carbonyl oxygen followed by keto–enol tautomerization.
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Affiliation(s)
- Zong-Xuan Tong
- State Key Laboratory of Chemo/Bio-Sensing and Chemometrics
- College of Chemistry and Chemical Engineering
- Hunan University
- Changsha 410082
- China
| | - Wei Liu
- State Key Laboratory of Chemo/Bio-Sensing and Chemometrics
- College of Chemistry and Chemical Engineering
- Hunan University
- Changsha 410082
- China
| | - Hui Huang
- State Key Laboratory of Chemo/Bio-Sensing and Chemometrics
- College of Chemistry and Chemical Engineering
- Hunan University
- Changsha 410082
- China
| | - Hong-Zong Chen
- State Key Laboratory of Chemo/Bio-Sensing and Chemometrics
- College of Chemistry and Chemical Engineering
- Hunan University
- Changsha 410082
- China
| | - Xian-Jun Liu
- State Key Laboratory of Chemo/Bio-Sensing and Chemometrics
- College of Chemistry and Chemical Engineering
- Hunan University
- Changsha 410082
- China
| | - Yong-Qing Kuang
- State Key Laboratory of Chemo/Bio-Sensing and Chemometrics
- College of Chemistry and Chemical Engineering
- Hunan University
- Changsha 410082
- China
| | - Jian-Hui Jiang
- State Key Laboratory of Chemo/Bio-Sensing and Chemometrics
- College of Chemistry and Chemical Engineering
- Hunan University
- Changsha 410082
- China
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4
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Lackraj T, Johnson-Henry K, Sherman PM, Goodman SD, Segall AM, Barnett Foster D. Novel antimicrobial peptide prevents C. rodentium infection in C57BL/6 mice by enhancing acid-induced pathogen killing. MICROBIOLOGY-SGM 2016; 162:1641-1650. [PMID: 27412446 DOI: 10.1099/mic.0.000335] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Citrobacter rodentium is a Gram-negative, murine-specific enteric pathogen that infects epithelial cells in the colon. It is closely related to the clinically relevant human pathogen, enterohemorrhagic Escherichia coli (EHEC), a leading cause of haemorrhagic colitis and haemolytic uremic syndrome. We have previously reported that a novel antimicrobial peptide, wrwycr, compromises bacterial DNA repair and significantly reduces the survival of acid-stressed EHEC, suggesting an antimicrobial strategy for targeting the survival of ingested EHEC. This study examines the impact of peptide pretreatment on survival of the closely related murine pathogen, C. rodentium, before and after acid stress, using both in vitro and in vivo investigations. Peptide pretreatment of C. rodentium significantly and dramatically increases acid-stress-induced killing in a peptide-dose-dependent and time-dependent manner. Reduction in survival rates after brief pretreatment with peptide (25-65 µM) followed by 1 h at pH 3.5 ranges from 6 to 8 log fold relative to untreated C. rodentium, with no detectable bacteria after 65 µM peptide-acid treatment. Using a C57BL/6 mouse model of infection, peptide pretreatment of C. rodentium with wrwycr prior to orogastric gavage eliminates evidence of infection based on C. rodentium colonization levels, faecal scores, colonic histology, faecal microbiome and visual observation of overall animal health. These findings provide compelling evidence for the role of the peptide wrwycr as a potential strategy to control the growth and colonization of enteric pathogens.
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Affiliation(s)
- Tracy Lackraj
- Department of Chemistry and Biology, Ryerson University, Toronto, ON, Canada
| | - Kathene Johnson-Henry
- Cell Biology Program, Research Institute, Division of Gastroenterology, Hepatology and Nutrition, Hospital for Sick Children, University of Toronto, Toronto, ON, Canada
| | - Philip M Sherman
- Cell Biology Program, Research Institute, Division of Gastroenterology, Hepatology and Nutrition, Hospital for Sick Children, University of Toronto, Toronto, ON, Canada
| | - Steve D Goodman
- Center for Microbial Pathogenesis, Nationwide Children's Hospital, Ohio State University, Columbus, OH, USA
| | - Anca M Segall
- Department of Biology, Viral Information Institute, San Diego State University, San Diego, CA, USA
| | - Debora Barnett Foster
- Department of Chemistry and Biology, Ryerson University, Toronto, ON, Canada.,Molecular Structure and Function Program, Research Institute, Hospital for Sick Children, Toronto, ON, Canada.,Faculty of Dentistry, University of Toronto, Toronto, ON, Canada
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5
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Prevalence of E. coli O157:H7 in water sources: an overview on associated diseases, outbreaks and detection methods. Diagn Microbiol Infect Dis 2015; 82:249-64. [DOI: 10.1016/j.diagmicrobio.2015.03.015] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2015] [Revised: 02/28/2015] [Accepted: 03/22/2015] [Indexed: 11/21/2022]
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6
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Barnett Foster D. Modulation of the enterohemorrhagic E. coli virulence program through the human gastrointestinal tract. Virulence 2013; 4:315-23. [PMID: 23552827 PMCID: PMC3710334 DOI: 10.4161/viru.24318] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Enteric pathogens must not only survive passage through the gastrointestinal tract but must also coordinate expression of virulence determinants in response to localized microenvironments with the host. Enterohemorrhagic Escherichia coli (EHEC), a serious food and waterborne human pathogen, is well equipped with an arsenal of molecular factors that allows it to survive passage through the gastrointestinal tract and successfully colonize the large intestine. This review will explore how EHEC responds to various environmental cues associated with particular microenvironments within the host and how it employs these cues to modulate virulence factor expression, with a view to developing a conceptual framework for understanding modulation of EHEC’s virulence program in response to the host. In vitro studies offer significant insights into the role of individual environmental cues but in vivo studies using animal models as well as data from natural infections will ultimately provide a more comprehensive picture of the highly regulated virulence program of this pathogen.
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Affiliation(s)
- Debora Barnett Foster
- Department of Chemistry and Biology, Faculty of Science, Ryerson University, Toronto, ONT, Canada.
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7
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Chaperone-dependent mechanisms for acid resistance in enteric bacteria. Trends Microbiol 2012; 20:328-35. [DOI: 10.1016/j.tim.2012.03.001] [Citation(s) in RCA: 75] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2011] [Revised: 02/26/2012] [Accepted: 03/02/2012] [Indexed: 01/13/2023]
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8
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Lino M, Kus JV, Tran SL, Naqvi Z, Binnington B, Goodman SD, Segall AM, Barnett Foster D. A novel antimicrobial peptide significantly enhances acid-induced killing of Shiga toxin-producing Escherichia coli O157 and non-O157 serotypes. MICROBIOLOGY-SGM 2011; 157:1768-1775. [PMID: 21454368 DOI: 10.1099/mic.0.047365-0] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Shiga toxin-producing Escherichia coli (STEC) colonizes the human intestine, causing haemorrhagic colitis and haemolytic uraemic syndrome (HUS). Treatment options are limited to intravenous fluids in part because sublethal doses of some antibiotics have been shown to stimulate increased toxin release and enhance the risk of progression to HUS. Preventative antimicrobial agents, especially those that build on the natural antimicrobial action of the host defence, may provide a better option. In order to survive the acid stress of gastric passage, STEC is equipped with numerous acid resistance and DNA repair mechanisms. Inhibition of acid-induced DNA repair may offer a strategy to target survival of ingested STEC. We report here that brief pretreatment with a novel antimicrobial peptide, which was previously shown to inhibit bacterial DNA repair, significantly and profoundly reduces survival of acid-stressed O157 : H7 and non-O157 : H7 STEC seropathotypes that are highly associated with HUS. Reduction in survival rates of STEC range from 3 to 5 log. We also show that peptide/acid treatment results in little or no increase in toxin production, thereby reducing the risk of progression to HUS. This study identifies the peptide wrwycr as a potential new candidate for a preventative antimicrobial for STEC infection.
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Affiliation(s)
- M Lino
- Department of Chemistry and Biology, Ryerson University, Toronto, ON, Canada
| | - J V Kus
- Department of Chemistry and Biology, Ryerson University, Toronto, ON, Canada
| | - S L Tran
- Department of Chemistry and Biology, Ryerson University, Toronto, ON, Canada
| | - Z Naqvi
- Department of Chemistry and Biology, Ryerson University, Toronto, ON, Canada
| | - B Binnington
- Molecular Structure and Function, Hospital for Sick Children, Toronto, ON, Canada
| | - S D Goodman
- Division of Biomedical Sciences, Herman Ostrow School of Dentistry of the University of Southern California, USA
| | - A M Segall
- Department of Biology, Center for Microbial Sciences and Molecular Biology Institute, San Diego State University, USA
| | - D Barnett Foster
- Molecular Structure and Function, Hospital for Sick Children, Toronto, ON, Canada.,Department of Chemistry and Biology, Ryerson University, Toronto, ON, Canada
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9
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Infectious Diarrhea. PEDIATRIC GASTROINTESTINAL AND LIVER DISEASE 2011. [PMCID: PMC7151906 DOI: 10.1016/b978-1-4377-0774-8.10039-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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10
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Affiliation(s)
- Todd F Hatchette
- Division of Microbiology, Department of Pathology and Laboratory Medicine, Capital District Health Authority, Halifax, NS.
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11
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Shiga-toxigenic Escherichia coli detection in stool samples screened for viral gastroenteritis in Alberta, Canada. J Clin Microbiol 2010; 49:574-8. [PMID: 21147949 DOI: 10.1128/jcm.01693-10] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Shiga-toxigenic Escherichia coli (STEC) is an important cause of diarrheal disease. The most notorious STEC serotype is O157:H7, which is associated with hemorrhagic colitis and hemolytic-uremic syndrome (HUS). As a result, this serotype is routinely screened for in clinical microbiology laboratories. With the bias toward the identification of the O157 serogroup in routine diagnostic processes, non-O157 STEC has been largely underrepresented in the epidemiology of STEC infections. This diagnostic bias is further complicated by the fact that many non-O157 STEC infections cause nonspecific gastroenteritis symptoms reminiscent of enteric viral infections. In this study, real-time PCR was used to amplify Shiga toxin genetic determinants (stx(1) and stx(2)) from enriched stool samples that were initially submitted for the testing of enteric viruses in patients with suspected viral gastroenteritis between May and September of 2006, 2007, and 2008 (n = 2,702). Samples were submitted from the province of Alberta, Yukon, the Northwest Territories, and Nunavut, Canada. A total of 38 samples (1.4%) tested positive for Shiga toxin genes, and 15 isolates were cultured for further characterization. Several of the serotypes identified (O157:H7, O26:HNM, O26:H11, O103:H25, O121:H19, and O145:HNM) have been previously associated with outbreaks and HUS. This study outlines the importance of combining molecular methods with classical culture techniques to enhance the detection of emerging non-O157 as well as O157 serotypes in diarrheal stool samples. Furthermore, atypical diarrhea disease caused by non-O157 STEC can be routinely missed due to screening only for viral agents.
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12
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Probiotic Lactobacillus reuteri ameliorates disease due to enterohemorrhagic Escherichia coli in germfree mice. Infect Immun 2010; 79:185-91. [PMID: 20974822 DOI: 10.1128/iai.00880-10] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Strains of enterohemorrhagic Escherichia coli (EHEC) are a group of Shiga toxin-producing food-borne pathogens that cause severe hemorrhagic colitis and can lead to hemolytic-uremic syndrome (HUS), a life-threatening condition that principally affects children and for which there is no effective treatment. We used a germfree mouse model of renal and enteric disease due to EHEC to determine if probiotic Lactobacillus reuteri ATCC PTA 6475 is effective in suppressing disease symptoms caused by EHEC. When germfree Swiss Webster mice are monocolonized with EHEC, they develop disease characterized by weight loss, cecal luminal fluid accumulation, and renal tubular necrosis. When L. reuteri was administered 1 day prior to EHEC challenge and every other day thereafter, EHEC colonization was suppressed and mice were significantly protected from the manifestations of disease. Protection from disease did not require the induction of the antimicrobial compound reuterin in L. reuteri prior to treatment. The twice-daily administration of L. reuteri appeared more effective than every-other-day administration. These data indicated that L. reuteri partially protects mice from disease manifestations of EHEC.
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13
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Girones R, Ferrús MA, Alonso JL, Rodriguez-Manzano J, Calgua B, Corrêa ADA, Hundesa A, Carratala A, Bofill-Mas S. Molecular detection of pathogens in water--the pros and cons of molecular techniques. WATER RESEARCH 2010; 44:4325-39. [PMID: 20619868 DOI: 10.1016/j.watres.2010.06.030] [Citation(s) in RCA: 142] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/01/2010] [Revised: 06/10/2010] [Accepted: 06/14/2010] [Indexed: 05/04/2023]
Abstract
Pollution of water by sewage and run-off from farms produces a serious public health problem in many countries. Viruses, along with bacteria and protozoa in the intestine or in urine are shed and transported through the sewer system. Even in highly industrialized countries, pathogens, including viruses, are prevalent throughout the environment. Molecular methods are used to monitor viral, bacterial, and protozoan pathogens, and to track pathogen- and source-specific markers in the environment. Molecular techniques, specifically polymerase chain reaction-based methods, provide sensitive, rapid, and quantitative analytical tools with which to study such pathogens, including new or emerging strains. These techniques are used to evaluate the microbiological quality of food and water, and to assess the efficiency of virus removal in drinking and wastewater treatment plants. The range of methods available for the application of molecular techniques has increased, and the costs involved have fallen. These developments have allowed the potential standardization and automation of certain techniques. In some cases they facilitate the identification, genotyping, enumeration, viability assessment, and source-tracking of human and animal contamination. Additionally, recent improvements in detection technologies have allowed the simultaneous detection of multiple targets in a single assay. However, the molecular techniques available today and those under development require further refinement in order to be standardized and applicable to a diversity of matrices. Water disinfection treatments may have an effect on the viability of pathogens and the numbers obtained by molecular techniques may overestimate the quantification of infectious microorganisms. The pros and cons of molecular techniques for the detection and quantification of pathogens in water are discussed.
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Affiliation(s)
- Rosina Girones
- Department of Microbiology, Faculty of Biology, University of Barcelona. Av. Diagonal 645, 08028 Barcelona, Spain.
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