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Backer HD, Derlet RW, Hill VR. Wilderness Medical Society Clinical Practice Guidelines on Water Treatment for Wilderness, International Travel, and Austere Situations: 2024 Update. Wilderness Environ Med 2024; 35:45S-66S. [PMID: 38379474 PMCID: PMC10961906 DOI: 10.1177/10806032231218722] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/22/2024]
Abstract
To provide guidance to medical providers, wilderness users, and travelers, the Wilderness Medical Society convened an expert panel to develop evidence-based guidelines for treating water in situations where the potability of available water is not assured, including wilderness and international travel, areas impacted by disaster, and other areas without adequate sanitation. The guidelines present the available methods for reducing or eliminating microbiological contamination of water for individuals, groups, or households; evaluation of their effectiveness; and practical considerations. The evidence base includes both laboratory and clinical publications. The panel graded the recommendations based on the quality of supporting evidence and the balance between benefits and risks/burdens according to the criteria published by the American College of Chest Physicians.
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Affiliation(s)
| | - Robert W. Derlet
- Emergency Department, University of California, Davis, Sacramento, CA
| | - Vincent R. Hill
- Waterborne Disease Prevention Branch, Division of Foodborne, Waterborne and Environmental Diseases, Centers for Disease Control and Prevention, Atlanta, GA
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Cao X, van de Lest CH, Huang LZ, van Putten JP, Wösten MM. Campylobacter jejuni permeabilizes the host cell membrane by short chain lysophosphatidylethanolamines. Gut Microbes 2022; 14:2091371. [PMID: 35797141 PMCID: PMC9272830 DOI: 10.1080/19490976.2022.2091371] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Lysophospholipids (LPLs) are crucial for regulating epithelial integrity and homeostasis in eukaryotes, however the effects of LPLs produced by bacteria on host cells is largely unknown. The membrane of the human bacterial pathogen Campylobacter jejuni is rich in LPLs. Although C. jejuni possesses several virulence factors, it lacks traditional virulence factors like type III secretion systems, present in most enteropathogens. Here, we provide evidence that membrane lipids lysophosphatidylethanolamines (lysoPEs) of C. jejuni are able to lyse erythrocytes and are toxic for HeLa and Caco-2 cells. Lactate dehydrogenase (LDH) release assays and confocal microscopy revealed that lysoPE permeabilizes the cells. LysoPE toxicity was partially rescued by oxidative stress inhibitors, indicating that intracellular reactive oxygen species may contribute to the cell damage. Our results show that especially the short-chain lysoPEs (C:14) which is abundantly present in the C. jejuni membrane may be considered as a novel virulence factor.
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Affiliation(s)
- Xuefeng Cao
- Department Biomolecular Health Sciences, Utrecht University, Utrecht, Netherlands
| | | | - Liane Z.X. Huang
- Department Biomolecular Health Sciences, Utrecht University, Utrecht, Netherlands
| | - Jos P.M. van Putten
- Department Biomolecular Health Sciences, Utrecht University, Utrecht, Netherlands
| | - Marc M.S.M. Wösten
- Department Biomolecular Health Sciences, Utrecht University, Utrecht, Netherlands,CONTACT Marc M.S.M. Wösten Department Biomolecular Health Sciences, Utrecht University, Yalelaan 1, 3584 CL, Utrecht, Netherlands
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Everts RJ, Al Ghusaini S, Telfar-Barnard L, Barclay E, Tan S, Jekel S, Jennings L, Choi DH, Hilson D, Gibson B. Liquid-Immersion Reprocessing Effects on Filtration Efficiency of 'Single-Use' Commercial Medical Face Masks. Ann Work Expo Health 2022; 66:246-259. [PMID: 34564717 PMCID: PMC8500144 DOI: 10.1093/annweh/wxab079] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2021] [Revised: 08/08/2021] [Accepted: 09/01/2021] [Indexed: 11/28/2022] Open
Abstract
PURPOSE Medical masks have inferior filtration efficiency and fit to filtering facepiece respirators (FFRs) but are widely used in healthcare and the community. These masks are intended for disposal after use but in the event of mask shortage re-use after reprocessing may be an option. We investigated eight reprocessing methods that each involved washing or soaking in liquid, are likely to eliminate respiratory viruses, and are safe and available in most community and healthcare settings. METHODS Three brands of EN 14683 standards-compliant commercial medical mask were each reprocessed 10 times by one of eight methods. We measured filtration efficiency for poly-dispersed sodium chloride particles and pressure differential. RESULTS Compared with new medical masks, reprocessed masks had significantly reduced filtration efficiency. The reduction was mild-moderate (6.5-25.8%) after warm water wash, hot water soak or boiling water soak; and moderate-large (24.1-51.5%) after detergent, soap or laundry machine wash, or bleach soak. There were mixed and minor changes in pressure differential. Most reprocessed standards-compliant masks had better filtration efficiency than new non-standard commercial masks and then cotton and cotton-polyester mix fabric samples, even triple-layered fabrics. CONCLUSIONS High-quality commercial medical masks reprocessed 10 times by water immersion methods had better filtration efficiency than new non-standard masks and washable fabrics. These findings have particular relevance for community and low-resource healthcare settings.
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Affiliation(s)
- Richard J Everts
- Infectious Disease Service, Nelson Bays Primary Health, 281 Queen St, Richmond, Nelson, New Zealand
| | | | - Lucy Telfar-Barnard
- Department of Public Health, University of Otago, 23a Mein St, Newton, Wellington, New Zealand
| | - Ella Barclay
- University of Otago, 2 Riccarton Ave, Christchurch, New Zealand
| | - Shaun Tan
- Lanaco, 2–4 Sultan St, Ellerslie, Auckland, New Zealand
| | - Sonja Jekel
- Lanaco, 2–4 Sultan St, Ellerslie, Auckland, New Zealand
| | - Lance Jennings
- Department of Pathology and Biomedical Sciences, University of Otago, 2 Riccarton Ave, Christchurch, New Zealand
- Canterbury Health Laboratories, Hagley Ave, Christchurch, New Zealand
| | - Dong Hoon Choi
- Biomedical Engineering Department, Nelson Hospital, Tipahi St, Nelson, New Zealand
| | - Dougal Hilson
- University of Otago, 2 Riccarton Ave, Christchurch, New Zealand
| | - Barbara Gibson
- Infection Prevention and Control Service, Nelson Hospital, Tipahi St, Nelson, New Zealand
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Mao Q, Liu J, Wiertzema JR, Chen D, Chen P, Baumler DJ, Ruan R, Chen C. Identification of Quinone Degradation as a Triggering Event for Intense Pulsed Light-Elicited Metabolic Changes in Escherichia coli by Metabolomic Fingerprinting. Metabolites 2021; 11:metabo11020102. [PMID: 33578995 PMCID: PMC7916761 DOI: 10.3390/metabo11020102] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2021] [Revised: 02/04/2021] [Accepted: 02/09/2021] [Indexed: 11/26/2022] Open
Abstract
Intense pulsed light (IPL) is becoming a new technical platform for disinfecting food against pathogenic bacteria. Metabolic changes are deemed to occur in bacteria as either the causes or the consequences of IPL-elicited bactericidal and bacteriostatic effects. However, little is known about the influences of IPL on bacterial metabolome. In this study, the IPL treatment was applied to E. coli K-12 for 0–20 s, leading to time- and dose-dependent reductions in colony-forming units (CFU) and morphological changes. Both membrane lipids and cytoplasmic metabolites of the control and IPL-treated E. coli were examined by the liquid chromatography-mass spectrometry (LC-MS)-based metabolomic fingerprinting. The results from multivariate modeling and marker identification indicate that the metabolites in electron transport chain (ETC), redox response, glycolysis, amino acid, and nucleotide metabolism were selectively affected by the IPL treatments. The time courses and scales of these metabolic changes, together with the biochemical connections among them, revealed a cascade of events that might be initiated by the degradation of quinone electron carriers and then followed by oxidative stress, disruption of intermediary metabolism, nucleotide degradation, and morphological changes. Therefore, the degradations of membrane quinones, especially the rapid depletion of menaquinone-8 (MK-8), can be considered as a triggering event in the IPL-elicited metabolic changes in E. coli.
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Affiliation(s)
- Qingqing Mao
- Department of Food Science and Nutrition, University of Minnesota, 1334 Eckles Ave, Saint Paul, MN 55108, USA; (Q.M.); (J.L.); (J.R.W.); (D.C.); (D.J.B.)
| | - Juer Liu
- Department of Food Science and Nutrition, University of Minnesota, 1334 Eckles Ave, Saint Paul, MN 55108, USA; (Q.M.); (J.L.); (J.R.W.); (D.C.); (D.J.B.)
| | - Justin R. Wiertzema
- Department of Food Science and Nutrition, University of Minnesota, 1334 Eckles Ave, Saint Paul, MN 55108, USA; (Q.M.); (J.L.); (J.R.W.); (D.C.); (D.J.B.)
| | - Dongjie Chen
- Department of Food Science and Nutrition, University of Minnesota, 1334 Eckles Ave, Saint Paul, MN 55108, USA; (Q.M.); (J.L.); (J.R.W.); (D.C.); (D.J.B.)
| | - Paul Chen
- Department of Bioproducts and Biosystems Engineering, University of Minnesota, 1390 Eckles Ave., Saint Paul, MN 55108, USA; (P.C.); (R.R.)
| | - David J. Baumler
- Department of Food Science and Nutrition, University of Minnesota, 1334 Eckles Ave, Saint Paul, MN 55108, USA; (Q.M.); (J.L.); (J.R.W.); (D.C.); (D.J.B.)
| | - Roger Ruan
- Department of Bioproducts and Biosystems Engineering, University of Minnesota, 1390 Eckles Ave., Saint Paul, MN 55108, USA; (P.C.); (R.R.)
| | - Chi Chen
- Department of Food Science and Nutrition, University of Minnesota, 1334 Eckles Ave, Saint Paul, MN 55108, USA; (Q.M.); (J.L.); (J.R.W.); (D.C.); (D.J.B.)
- Correspondence: ; Tel.: +1-612-624-7704; Fax: +1-612-625-5272
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Backer HD, Derlet RW, Hill VR. Wilderness Medical Society Clinical Practice Guidelines for Water Disinfection for Wilderness, International Travel, and Austere Situations. Wilderness Environ Med 2019; 30:S100-S120. [PMID: 31668519 PMCID: PMC10961709 DOI: 10.1016/j.wem.2019.06.006] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2018] [Revised: 05/18/2019] [Accepted: 06/14/2019] [Indexed: 11/23/2022]
Abstract
To provide guidance to clinicians, the Wilderness Medical Society convened experts to develop evidence-based guidelines for water disinfection in situations where the potability of available water is not ensured, including wilderness and international travel, areas affected by disaster, and other areas without adequate sanitation. The guidelines present the available methods for reducing or eliminating microbiologic contamination of water for individuals, groups, or households; evaluation of their effectiveness; and practical considerations. The evidence evaluation includes both laboratory and clinical publications. The panel graded the recommendations based on the quality of supporting evidence and the balance between benefits and risks or burdens, according to the criteria published by the American College of Chest Physicians.
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Affiliation(s)
- Howard D Backer
- California Emergency Medical Services Authority, Racho Cordova, CA.
| | - Robert W Derlet
- Emergency Department, University of California, Davis, Sacramento, CA
| | - Vincent R Hill
- Division of Foodborne, Waterborne and Environmental Diseases, Waterborne Disease Prevention Branch, Centers for Disease Control and Prevention, Atlanta, GA
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Wadhawan T, Maruska ZB, Siripattanakul S, Hill CB, Gupta A, Prüss BM, McEvoy JM, Khan E. A new method to determine initial viability of entrapped cells using fluorescent nucleic acid staining. BIORESOURCE TECHNOLOGY 2011; 102:1622-1627. [PMID: 20933406 DOI: 10.1016/j.biortech.2010.09.027] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/06/2010] [Revised: 09/07/2010] [Accepted: 09/08/2010] [Indexed: 05/30/2023]
Abstract
Entrapped bacterial cells are widely used in several biotechnological applications. Cell entrapment procedures are known to affect the viability of bacterial cells. To determine the effect of entrapment procedures on viability of bacterial cells, dissolution of the entrapment matrices using chelating agents or heat is required immediately after the entrapment is completed. Chelating agents and heat applied in the matrix dissolution reduce cell viability and in turn hinder accurate quantification of viable cells. In this study, a method to determine the effect of entrapment procedure on bacterial cell viability which involves entrapping cells directly onto glass slides was developed. The developed method showed less viability reduction than the methods requiring matrix dissolution. The percentage of live cells in the culture before entrapment ranged from 54% to 74%, while the percent of live cells after entrapment determined by the developed method was 39-62%.
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Affiliation(s)
- Tanush Wadhawan
- Environmental and Conservation Sciences Program, North Dakota State University, Fargo, ND 58108, USA
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Wadhawan T, McEvoy J, Prüβ BM, Khan E. Assessing tetrazolium and ATP assays for rapid in situ viability quantification of bacterial cells entrapped in hydrogel beads. Enzyme Microb Technol 2010. [DOI: 10.1016/j.enzmictec.2010.05.003] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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Salih FM. Enhancement of solar inactivation of Escherichia coli by titanium dioxide photocatalytic oxidation. J Appl Microbiol 2002; 92:920-6. [PMID: 11972697 DOI: 10.1046/j.1365-2672.2002.01601.x] [Citation(s) in RCA: 72] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
AIMS To improve solar water disinfection using a photocatalysing semi-conductor and to study the mechanisms involved in this process. METHODS AND RESULTS Cells of Escherichia coli were used as the microbiological indicator to study the possibility of improving the efficiency of solar water disinfection using titanium dioxide (TiO2) as a photooxidizing semi-conductor. TiO2 was used either as a suspended powder or in an immobilized form. Both applications improved the efficiency of solar disinfection. TiO2 in suspension was more effective than the immobilized form, producing enhancement factors of 1.62 and 1.34, respectively. The concentration of TiO2 greatly affected efficiency, with a maximum effect at 1 mg ml(-1). Higher TiO2 concentrations reduced the efficiency. Dimethyl sulphoxide (DMSO) and cysteamine (Cys), hydroxyl radical (OH.) scavengers, were used to elucidate the mechanisms involved in the presence of TiO2. Both DMSO and Cys totally abolished the enhancing effect produced by the presence of TiO2. CONCLUSIONS Sunlight has a potential water disinfecting capacity. The use of TiO2 greatly improved this efficiency. The effect of TiO2 was mainly concentration-dependent, giving maximum efficiency at 1 mg ml(-1). The presence of DMSO and Cys removed the TiO2-induced enhancement, indicating that OH. may be involved in the process of cell killing. SIGNIFICANCE AND IMPACT OF THE STUDY The efficiency of solar disinfection is limited and time-consuming and needs to be improved. The use of a semi-conductor is promising as it reduces the time of exposure and therefore increases the efficiency of solar disinfection. This would allow for the availability of good quality water, and hence would improve the quality of life.
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Affiliation(s)
- F M Salih
- Department of Clinical and Biomedical Physics, Sultan Qaboos University College of Medicine, Sultanate of Oman.
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Backer H. Water disinfection for international and wilderness travelers. Clin Infect Dis 2002; 34:355-64. [PMID: 11774083 DOI: 10.1086/324747] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2001] [Revised: 09/20/2001] [Indexed: 11/03/2022] Open
Abstract
Acquisition of waterborne disease is a substantial risk for international travelers to countries with inadequate sanitation facilities. It also poses smaller but still significant risks for wilderness travelers who rely on surface water in developed countries with low rates of diarrheal illness, such as the United States. This article reviews the etiology and risks associated with waterborne disease that might be encountered by both types of travelers. It also summarizes--and makes recommendations for--the various water-treatment methods available to travelers for reducing their risk of contracting waterborne disease.
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Affiliation(s)
- Howard Backer
- Division of Communicable Disease Control, California Department of Health Services, Berkeley, CA 94704, USA.
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