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Morrison BH, Jones JL, Dzwonkowski B, Krause JW. Tracking Vibrio: population dynamics and ecology of Vibrio parahaemolyticus and V. vulnificus in an Alabama estuary. Microbiol Spectr 2024; 12:e0367423. [PMID: 38578091 DOI: 10.1128/spectrum.03674-23] [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] [Received: 10/27/2023] [Accepted: 03/05/2024] [Indexed: 04/06/2024] Open
Abstract
Vibrio is a genus of halophilic, gram-negative bacteria found in estuaries around the globe. Integral parts of coastal cultures often involve contact with vectors of pathogenic Vibrio spp. (e.g., consuming raw shellfish). High rates of mortality from certain Vibrio spp. infections demonstrate the need for an improved understanding of Vibrio spp. dynamics in estuarine regions. Our study assessed meteorological, hydrographic, and biological correlates of Vibrio parahaemolyticus and V. vulnificus at 10 sites in the Eastern Mississippi Sound System (EMSS) from April to October 2019. During the sampling period, median abundances of V. parahaemolyticus and V. vulnificus were 2.31 log MPN/L and 2.90 log MPN/L, respectively. Vibrio spp. dynamics were largely driven by site-based variation, with sites closest to freshwater inputs having the highest abundances. The E-W wind scalar, which affects Ekman transport, was a novel Vibrio spp. correlate observed. A potential salinity effect on bacterial-particle associations was identified, where V. vulnificus was associated with larger particles in conditions outside of their optimal salinity. Additionally, V. vulnificus abundances were correlated to those of harmful algal species that did not dominate community chlorophyll. Correlates from this study may be used to inform the next iteration of regionally predictive Vibrio models and may lend additional insight to Vibrio spp. ecology in similar systems. IMPORTANCE Vibrio spp. are bacteria found in estuaries worldwide; some species can cause illness and infections in humans. Relationships between Vibrio spp. abundance, salinity, and temperature are well documented, but correlations to other environmental parameters are less understood. This study identifies unique correlates (e.g., E-W wind scalar and harmful algal species) that could potentially inform the next iteration of predictive Vibrio models for the EMSS region. Additionally, these correlates may allow existing environmental monitoring efforts to be leveraged in providing data inputs for future Vibrio risk models. An observed correlation between salinity and V. vulnificus/particle-size associations suggests that predicted environmental changes may affect the abundance of Vibrio spp. in certain reservoirs, which may alter which vectors present the greatest vibrio risk.
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Affiliation(s)
- Blair H Morrison
- Dauphin Island Sea Lab, Dauphin Island, Alabama, USA
- Stokes School of Marine and Environmental Sciences, University of South Alabama, Mobile, Alabama, USA
- FDA, Division of Seafood Science and Technology, Gulf Coast Seafood Laboratory, Dauphin Island, Alabama, USA
| | - Jessica L Jones
- FDA, Division of Seafood Science and Technology, Gulf Coast Seafood Laboratory, Dauphin Island, Alabama, USA
| | - Brian Dzwonkowski
- Dauphin Island Sea Lab, Dauphin Island, Alabama, USA
- Stokes School of Marine and Environmental Sciences, University of South Alabama, Mobile, Alabama, USA
| | - Jeffrey W Krause
- Dauphin Island Sea Lab, Dauphin Island, Alabama, USA
- Stokes School of Marine and Environmental Sciences, University of South Alabama, Mobile, Alabama, USA
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2
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Savas S, Saricam M. Rapid method for detection of Vibrio cholerae from drinking water with nanomaterials enhancing electrochemical biosensor. J Microbiol Methods 2024; 216:106862. [PMID: 38030087 DOI: 10.1016/j.mimet.2023.106862] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2023] [Revised: 11/11/2023] [Accepted: 11/22/2023] [Indexed: 12/01/2023]
Abstract
Cholera is a potentially fatal diarrheal disease caused by Vibrio cholerae and is spread to humans from contaminated food and water. In order to prevent spread of epidemic chlorea, the development of novel sensitive, selective, user-friendly, cost-effective and rapid detection systems to detect of V. cholerae are necessary. Therefore, in this study, it was aimed to develop a specific, electrochemical immunoassay with high selectivitiy and sensitivity for detection of V. cholerae from drinking water using in house synthesized Gold Nanoparticles (AuNPs). The synthesized AuNPs were characterized by UV/Vis spectroscopy, Dynamic Light Scattering (DLS) and Atomic Force Microscopy (AFM) and electrochemical techniques were applied to confirm the succesful fabrication of the immunosensor. Also, this study focuses on the development of an antibody sensor for V. cholerae detection using a standard immunoassay without using nanoparticle. To accomplish that, in house spherical synthesized AuNPs at various sizes were synthesized, conjugated with secondary antibody-horseradish peroxidase enzyme (HRP) complex and their possible effect on the lowest detection limit of V. cholerae was investigated in comparison to commercially available AuNPs. The AuNPs-immunosensor on the results enabled the quantification of V. cholerae in a wide concentration range with a high sensitivity limit of detection (1 Colony-Forming Units/Milliliter) and specificity. Although the effect of 33 and 54 nm AuNPs on the process is close to each other, it has been observed that there is a 34% loss of efficiency when the size of the nanoparticle increases. With this study, a novel V. cholerae specific immunosensor was developed and the effects of in house synthesized AuNPs with various diameter on this developed biosensor were investigated in detail.
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Affiliation(s)
- Sumeyra Savas
- Bandirma Onyedi Eylul University, Medical School, Department of Clinical Microbiology, Bandirma, Balikesir, Turkey.
| | - Melike Saricam
- TUBITAK Marmara Research Center, Life Sciences Vice Presidency, CBRN Defense Technologies Research Group, Kocaeli, Turkey.
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3
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Jutla A, Usmani M, Brumfield KD, Singh K, McBean F, Potter A, Gutierrez A, Gama S, Huq A, Colwell RR. Anticipatory decision-making for cholera in Malawi. mBio 2023; 14:e0052923. [PMID: 37962395 PMCID: PMC10746182 DOI: 10.1128/mbio.00529-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2023] Open
Abstract
Climate change raises an old disease to a new level of public health threat. The causative agent, Vibrio cholerae, native to aquatic ecosystems, is influenced by climate and weather processes. The risk of cholera is elevated in vulnerable populations lacking access to safe water and sanitation infrastructure. Predictive intelligence, employing mathematical algorithms that integrate earth observations and heuristics derived from microbiological, sociological, and weather data, can provide anticipatory decision-making capabilities to reduce the burden of cholera and save human lives. An example offered here is the recent outbreak of cholera in Malawi, predicted in advance by such algorithms.
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Affiliation(s)
- Antarpreet Jutla
- Department of Environmental Engineering Sciences, GeoHealth and Hydrology Laboratory, University of Florida, Gainesville, Florida, USA
| | - Moiz Usmani
- Department of Environmental Engineering Sciences, GeoHealth and Hydrology Laboratory, University of Florida, Gainesville, Florida, USA
| | - Kyle D. Brumfield
- Maryland Pathogen Research Institute, University of Maryland, College Park, Maryland, USA
- University of Maryland Institute for Advanced Computer Studies, University of Maryland, College Park, Maryland, USA
| | - Komalpreet Singh
- Department of Environmental Engineering Sciences, GeoHealth and Hydrology Laboratory, University of Florida, Gainesville, Florida, USA
| | - Fergus McBean
- Foreign, Commonwealth & Development Office, London, United Kingdom
| | - Amy Potter
- Foreign, Commonwealth & Development Office, London, United Kingdom
| | - Angelica Gutierrez
- Office of Water Prediction, National Oceanic and Atmospheric Administration (NOAA), Silver Spring, Maryland, USA
| | - Samuel Gama
- Department of Disaster Management Affairs, Office of the President and Cabinet, Lilongwe, Malawi
| | - Anwar Huq
- Maryland Pathogen Research Institute, University of Maryland, College Park, Maryland, USA
- University of Maryland Institute for Advanced Computer Studies, University of Maryland, College Park, Maryland, USA
| | - Rita R. Colwell
- Maryland Pathogen Research Institute, University of Maryland, College Park, Maryland, USA
- University of Maryland Institute for Advanced Computer Studies, University of Maryland, College Park, Maryland, USA
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4
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Nuttall RA, Moisander PH. Vibrio cyclitrophicus population-specific biofilm formation and epibiotic growth on marine copepods. Environ Microbiol 2023; 25:2534-2548. [PMID: 37612139 DOI: 10.1111/1462-2920.16483] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2022] [Accepted: 07/31/2023] [Indexed: 08/25/2023]
Abstract
Vibrio spp. form a part of the microbiome of copepods-an abundant component of marine mesozooplankton. The biological mechanisms of the Vibrio-copepod association are largely unknown. In this study we compared biofilm formation of V. cyclitrophicus isolated from copepods (L-strains related to other particle-associated strains) and closely related strains originating from seawater (S-strains), and visualized and quantified their attachment and growth on copepods. The S- and L-strains formed similar biofilms in the presence of complete sea salts, suggesting previously unknown biofilm mechanisms in the S-strains. No biofilms formed if sodium chloride was present as the only salt but added calcium significantly enhanced biofilms in the L-strains. GFP-L-strain cells attached to live copepods at higher numbers than the S-strains, suggesting distinct mechanisms, potentially including calcium, support their colonization of copepods. The cells grew on live copepods after attachment, demonstrating that copepods sustain epibiotic V. cyclitrophicus growth in situ. The results demonstrate that in spite of their 99.1% average nucleotide identity, these V. cyclitrophicus strains have a differential capacity to colonize marine copepods. The introduced V. cyclitrophicus-A. tonsa model could be informative in future studies on Vibrio-copepod association.
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Affiliation(s)
- Ryan A Nuttall
- Department of Biology, University of Massachusetts Dartmouth, North Dartmouth, Massachusetts, USA
| | - Pia H Moisander
- Department of Biology, University of Massachusetts Dartmouth, North Dartmouth, Massachusetts, USA
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5
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Li X, Li X, Zhang H, Kan B, Fan F. VP3 Phage Combined with High Salt Promotes the Lysis of Biofilm-Associated Vibrio cholerae. Viruses 2023; 15:1639. [PMID: 37631982 PMCID: PMC10458087 DOI: 10.3390/v15081639] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2023] [Revised: 07/22/2023] [Accepted: 07/24/2023] [Indexed: 08/27/2023] Open
Abstract
Cholera, caused by pathogenic Vibrio cholerae, poses a significant public health risk through water and food transmission. Biofilm-associated V. cholerae plays a crucial role in seasonal cholera outbreaks as both a reservoir in aquatic environments and a direct source of human infection. Although VP3, a lytic phage, shows promise in eliminating planktonic V. cholerae from the aquatic environment, its effectiveness against biofilm-associated V. cholerae is limited. To address this limitation, our proposed approach aims to enhance the efficacy of VP3 in eliminating biofilm-associated V. cholerae by augmenting the availability of phage receptors on the surface of Vibrio cholerae. TolC is a receptor of VP3 and a salt efflux pump present in many bacteria. In this study, we employed NaCl as an enhancer to stimulate TolC expression and observed a significant enhancement of TolC expression in both planktonic and biofilm cells of V. cholerae. This enhancement led to improved adsorption of VP3. Importantly, our findings provide strong evidence that high salt concentrations combined with VP3 significantly improve the elimination of biofilm-associated V. cholerae. This approach offers a potential strategy to eliminate biofilm-formation bacteria by enhancing phage-host interaction.
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Affiliation(s)
- Xu Li
- School of Light Industry, Beijing Technology and Business University, Beijing 100048, China
| | - Xiaorui Li
- State Key Laboratory of Infectious Disease Prevention and Control, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing 102206, China
| | - Huayao Zhang
- Department of Epidemiology, School of Public Health, Cheeloo College of Medicine, Shandong University, Jinan 250012, China
| | - Biao Kan
- State Key Laboratory of Infectious Disease Prevention and Control, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing 102206, China
| | - Fenxia Fan
- State Key Laboratory of Infectious Disease Prevention and Control, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing 102206, China
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Norfolk WA, Melendez-Declet C, Lipp EK. Coral Disease and Ingestion: Investigating the Role of Heterotrophy in the Transmission of Pathogenic Vibrio spp. using a Sea Anemone ( Exaiptasia pallida) Model System. Appl Environ Microbiol 2023:e0018723. [PMID: 37191521 DOI: 10.1128/aem.00187-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/17/2023] Open
Abstract
Understanding disease transmission in corals can be complicated given the intricacy of the holobiont and difficulties associated with ex situ coral cultivation. As a result, most of the established transmission pathways for coral disease are associated with perturbance (i.e., damage) rather than evasion of immune defenses. Here, we investigate ingestion as a potential pathway for the transmission of coral pathogens that evades the mucus membrane. Using sea anemones (Exaiptasia pallida) and brine shrimp (Artemia sp.) to model coral feeding, we tracked the acquisition of the putative pathogens, Vibrio alginolyticus, V. harveyi, and V. mediterranei using GFP-tagged strains. Vibrio sp. were provided to anemones using 3 experimental exposures (i) direct water exposure alone, (ii) water exposure in the presence of a food source (non-spiked Artemia), and (iii) through a "spiked" food source (Vibrio-colonized Artemia) created by exposing Artemia cultures to GFP-Vibrio via the ambient water overnight. Following a 3 h feeding/exposure duration, the level of acquired GFP-Vibrio was quantified from anemone tissue homogenate. Ingestion of spiked Artemia resulted in a significantly greater burden of GFP-Vibrio equating to an 830-fold, 3,108-fold, and 435-fold increase in CFU mL-1 when compared to water exposed trials and a 207-fold, 62-fold, and 27-fold increase in CFU mL-1 compared to water exposed with food trials for V. alginolyticus, V. harveyi, and V. mediterranei, respectively. These data suggest that ingestion can facilitate delivery of an elevated dose of pathogenic bacteria in cnidarians and may describe an important portal of entry for pathogens in the absence of perturbing conditions. IMPORTANCE The front line of pathogen defense in corals is the mucus membrane. This membrane coats the surface body wall creating a semi-impermeable layer that inhibits pathogen entry from the ambient water both physically and biologically through mutualistic antagonism from resident mucus microbes. To date, much of the coral disease transmission research has been focused on mechanisms associated with perturbance of this membrane such as direct contact, vector lesions (predation/biting), and waterborne exposure through preexisting lesions. The present research describes a potential transmission pathway that evades the defenses provided by this membrane allowing unencumbered entry of bacteria as in association with food. This pathway may explain an important portal of entry for emergence of idiopathic infections in otherwise healthy corals and can be used to improve management practices for coral conservation.
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Affiliation(s)
- William A Norfolk
- Department of Environmental Health Science, University of Georgia, Athens, Georgia, USA
| | | | - Erin K Lipp
- Department of Environmental Health Science, University of Georgia, Athens, Georgia, USA
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7
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Environmental Reservoirs of Pathogenic Vibrio spp. and Their Role in Disease: The List Keeps Expanding. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2023; 1404:99-126. [PMID: 36792873 DOI: 10.1007/978-3-031-22997-8_6] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/17/2023]
Abstract
Vibrio species are natural inhabitants of aquatic environments and have complex interactions with the environment that drive the evolution of traits contributing to their survival. These traits may also contribute to their ability to invade or colonize animal and human hosts. In this review, we attempt to summarize the relationships of Vibrio spp. with other organisms in the aquatic environment and discuss how these interactions could potentially impact colonization of animal and human hosts.
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8
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Combating cholera by building predictive capabilities for pathogenic Vibrio cholerae in Yemen. Sci Rep 2023; 13:2255. [PMID: 36755108 PMCID: PMC9908932 DOI: 10.1038/s41598-022-22946-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2022] [Accepted: 10/21/2022] [Indexed: 02/10/2023] Open
Abstract
Cholera remains a global public health threat in regions where social vulnerabilities intersect with climate and weather processes that impact infectious Vibrio cholerae. While access to safe drinking water and sanitation facilities limit cholera outbreaks, sheer cost of building such infrastructure limits the ability to safeguard the population. Here, using Yemen as an example where cholera outbreak was reported in 2016, we show how predictive abilities for forecasting risk, employing sociodemographical, microbiological, and climate information of cholera, can aid in combating disease outbreak. An epidemiological analysis using Bradford Hill Criteria was employed in near-real-time to understand a predictive model's outputs and cholera cases in Yemen. We note that the model predicted cholera risk at least four weeks in advance for all governorates of Yemen with overall 72% accuracy (varies with the year). We argue the development of anticipatory decision-making frameworks for climate modulated diseases to design intervention activities and limit exposure of pathogens preemptively.
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9
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Moradi A, Zeinoddini M, Robatjazi SM. Rapid Concentration and Detection of Vibrio cholerae Using Magnetic Nanoparticles. J WATER CHEM TECHNO+ 2023. [DOI: 10.3103/s1063455x2301006x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/19/2023]
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10
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Usmani M, Brumfield KD, Magers BM, Huq A, Barciela R, Nguyen TH, Colwell RR, Jutla A. Predictive Intelligence for Cholera in Ukraine? GEOHEALTH 2022; 6:e2022GH000681. [PMID: 36185317 PMCID: PMC9514009 DOI: 10.1029/2022gh000681] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/27/2022] [Revised: 08/02/2022] [Accepted: 08/06/2022] [Indexed: 06/16/2023]
Abstract
Cholera, an ancient waterborne diarrheal disease, remains a threat to public health, especially when climate/weather processes, microbiological parameters, and sociological determinants intersect with population vulnerabilities of loss of access to safe drinking water and sanitation infrastructure. The ongoing war in Ukraine has either damaged or severely crippled civil infrastructure, following which the human population is at risk of health disasters. This editorial highlights a perspective on using predictive intelligence to combat potential (and perhaps impending) cholera outbreaks in various regions of Ukraine. Reliable and judicious use of existing earth observations inspired mathematical algorithms integrating heuristic understanding of microbiological, sociological, and weather parameters have the potential to save or reduce the disease burden.
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Affiliation(s)
- Moiz Usmani
- GeoHealth and Hydrology LaboratoryDepartment of Environmental Engineering SciencesUniversity of FloridaGainesvilleFLUSA
| | - Kyle D. Brumfield
- Maryland Pathogen Research InstituteUniversity of MarylandCollege ParkMDUSA
- University of Maryland Institute for Advanced Computer StudiesUniversity of MarylandCollege ParkMDUSA
| | - Bailey M. Magers
- GeoHealth and Hydrology LaboratoryDepartment of Environmental Engineering SciencesUniversity of FloridaGainesvilleFLUSA
| | - Anwar Huq
- Maryland Pathogen Research InstituteUniversity of MarylandCollege ParkMDUSA
- University of Maryland Institute for Advanced Computer StudiesUniversity of MarylandCollege ParkMDUSA
| | | | - Thanh H. Nguyen
- Department of Civil and Environmental EngineeringUniversity of Illinois at Urbana‐ChampaignUrbanaILUSA
| | - Rita R. Colwell
- Maryland Pathogen Research InstituteUniversity of MarylandCollege ParkMDUSA
- University of Maryland Institute for Advanced Computer StudiesUniversity of MarylandCollege ParkMDUSA
| | - Antarpreet Jutla
- GeoHealth and Hydrology LaboratoryDepartment of Environmental Engineering SciencesUniversity of FloridaGainesvilleFLUSA
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11
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Oza HH, Holmes EB, Bailey ES, Coleman CK, Sobsey MD. Microbial reductions and physical characterization of chitosan flocs when using chitosan acetate as a cloth filter aid in water treatment. PLoS One 2022; 17:e0262341. [PMID: 35061779 PMCID: PMC8782320 DOI: 10.1371/journal.pone.0262341] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2021] [Accepted: 12/22/2021] [Indexed: 11/19/2022] Open
Abstract
The World Health Organization (WHO) estimates 2.1 billion people lack access to safely managed water. Cloth filtration is often employed in rural and developing communities of South Asia for point-of-use water treatment, but bacteria and viruses are too small for efficient removal by this filtration method. Chitosan is a biodegradable, cationic, organic polymer derived from the chemical treatment of chitin that acts as a coagulant and flocculant of contaminant of microbes and other particles in water, thereby facilitating filtration of microbes. This research 1) evaluated the use of chitosan acetate as a pre-treatment coagulation-flocculation process followed by cloth filtration for microbial reductions and 2) assessed floc particle size under three stirring conditions. E. coli KO11 bacteria and MS2 coliphage virus removals were quantified using culture-based methods. Chitosan acetate coagulation-flocculation pre-treatment of water, followed by cloth filtration, met or exceeded the protective (2-star) WHO performance levels for bacteria (2 log10 reduction) and viruses (3 log10 reduction), and filtrate turbidity was consistently reduced to < 1 NTU, meeting United States Environmental Protection Agency (EPA) and WHO targets.
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Affiliation(s)
- Hemali H. Oza
- Gangarosa Department of Environmental Health, Rollins School of Public Health, Emory University, Atlanta, GA, United States of America
- Department of Environmental Sciences and Engineering, Gillings School of Global Public Health, University of North Carolina, Chapel Hill, NC, United States of America
| | - Eleanor B. Holmes
- Department of Environmental Sciences and Engineering, Gillings School of Global Public Health, University of North Carolina, Chapel Hill, NC, United States of America
| | - Emily S. Bailey
- Texas Tech University Health Sciences Center, Graduate School of Biomedical Sciences, Julia Jones Matthews Department of Public Health, Abilene, TX, United States of America
| | - Collin K. Coleman
- Department of Environmental Sciences and Engineering, Gillings School of Global Public Health, University of North Carolina, Chapel Hill, NC, United States of America
| | - Mark D. Sobsey
- Department of Environmental Sciences and Engineering, Gillings School of Global Public Health, University of North Carolina, Chapel Hill, NC, United States of America
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12
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Chamanrokh P, Colwell RR, Huq A. Loop-Mediated Isothermal Amplification (LAMP) Assay for Rapid Detection of viable but non-culturable Vibrio cholerae O1. Can J Microbiol 2021; 68:103-110. [PMID: 34793252 DOI: 10.1139/cjm-2021-0142] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Vibrio cholerae, an important waterborne pathogen, is a rod-shaped bacterium that naturally exists in aquatic environments. When conditions are unfavorable for growth, the bacterium can undergo morphological and physiological changes to assume a coccoid morphology. This stage in its life cycle is referred to as viable but non-culturable (VBNC) since VBNC cells do not grow on conventional bacteriological culture media. The current study compared polymerase chain reaction (PCR) and loop-mediated isothermal amplification (LAMP) to detect and identify VBNC V. cholerae. Because it is difficult to detect and identify VBNC V. cholerae, the results of the current study are useful in showing LAMP to be more sensitive and rapid than PCR in detecting and identifying non-culturable, coccoid forms of V. cholerae. Furthermore, the LAMP method is effective in detecting and identifying very low numbers of coccoid VBNC V. cholerae in environmental water samples, with the added benefit of being inexpensive to perform.
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Affiliation(s)
- Parastoo Chamanrokh
- University of Maryland College Park, Maryland Pathogen Research Institute, College Park, Maryland, United States;
| | - Rita R Colwell
- University of Maryland at College Park, 1068, Maryland Pathogen Research Institute, College Park, Maryland, United States.,University of Maryland at College Park, 1068, Maryland Institute of Applied Environmental Health, College Park, Maryland, United States.,University of Maryland at College Park, 1068, CBCB. UMIACS, College Park, Maryland, United States.,Johns Hopkins University Bloomberg School of Public Health, 25802, Baltimore, Maryland, United States;
| | - Anwar Huq
- University of Maryland at College Park, 1068, Maryland Pathogen Research Institute, College Park, Maryland, United States;
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Brumfield KD, Usmani M, Chen KM, Gangwar M, Jutla AS, Huq A, Colwell RR. Environmental parameters associated with incidence and transmission of pathogenic Vibrio spp. Environ Microbiol 2021; 23:7314-7340. [PMID: 34390611 DOI: 10.1111/1462-2920.15716] [Citation(s) in RCA: 37] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2021] [Revised: 07/27/2021] [Accepted: 08/10/2021] [Indexed: 12/17/2022]
Abstract
Vibrio spp. thrive in warm water and moderate salinity, and they are associated with aquatic invertebrates, notably crustaceans and zooplankton. At least 12 Vibrio spp. are known to cause infection in humans, and Vibrio cholerae is well documented as the etiological agent of pandemic cholera. Pathogenic non-cholera Vibrio spp., e.g., Vibrio parahaemolyticus and Vibrio vulnificus, cause gastroenteritis, septicemia, and other extra-intestinal infections. Incidence of vibriosis is rising globally, with evidence that anthropogenic factors, primarily emissions of carbon dioxide associated with atmospheric warming and more frequent and intense heatwaves, significantly influence environmental parameters, e.g., temperature, salinity, and nutrients, all of which can enhance growth of Vibrio spp. in aquatic ecosystems. It is not possible to eliminate Vibrio spp., as they are autochthonous to the aquatic environment and many play a critical role in carbon and nitrogen cycling. Risk prediction models provide an early warning that is essential for safeguarding public health. This is especially important for regions of the world vulnerable to infrastructure instability, including lack of 'water, sanitation, and hygiene' (WASH), and a less resilient infrastructure that is vulnerable to natural calamity, e.g., hurricanes, floods, and earthquakes, and/or social disruption and civil unrest, arising from war, coups, political crisis, and economic recession. Incorporating environmental, social, and behavioural parameters into such models allows improved prediction, particularly of cholera epidemics. We have reported that damage to WASH infrastructure, coupled with elevated air temperatures and followed by above average rainfall, promotes exposure of a population to contaminated water and increases the risk of an outbreak of cholera. Interestingly, global predictive risk models successful for cholera have the potential, with modification, to predict diseases caused by other clinically relevant Vibrio spp. In the research reported here, the focus was on environmental parameters associated with incidence and distribution of clinically relevant Vibrio spp. and their role in disease transmission. In addition, molecular methods designed for detection and enumeration proved useful for predictive modelling and are described, namely in the context of prediction of environmental conditions favourable to Vibrio spp., hence human health risk.
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Affiliation(s)
- Kyle D Brumfield
- Maryland Pathogen Research Institute, University of Maryland, College Park, MD, USA.,University of Maryland Institute for Advanced Computer Studies, University of Maryland, College Park, MD, USA
| | - Moiz Usmani
- Geohealth and Hydrology Laboratory, Department of Environmental Engineering Sciences, University of Florida, Gainesville, FL, USA
| | - Kristine M Chen
- Geohealth and Hydrology Laboratory, Department of Environmental Engineering Sciences, University of Florida, Gainesville, FL, USA
| | - Mayank Gangwar
- Geohealth and Hydrology Laboratory, Department of Environmental Engineering Sciences, University of Florida, Gainesville, FL, USA
| | - Antarpreet S Jutla
- Geohealth and Hydrology Laboratory, Department of Environmental Engineering Sciences, University of Florida, Gainesville, FL, USA
| | - Anwar Huq
- Maryland Pathogen Research Institute, University of Maryland, College Park, MD, USA
| | - Rita R Colwell
- Maryland Pathogen Research Institute, University of Maryland, College Park, MD, USA.,University of Maryland Institute for Advanced Computer Studies, University of Maryland, College Park, MD, USA
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14
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Usmani M, Brumfield KD, Jamal Y, Huq A, Colwell RR, Jutla A. A Review of the Environmental Trigger and Transmission Components for Prediction of Cholera. Trop Med Infect Dis 2021; 6:tropicalmed6030147. [PMID: 34449728 PMCID: PMC8396309 DOI: 10.3390/tropicalmed6030147] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2021] [Revised: 07/29/2021] [Accepted: 07/31/2021] [Indexed: 11/16/2022] Open
Abstract
Climate variables influence the occurrence, growth, and distribution of Vibrio cholerae in the aquatic environment. Together with socio-economic factors, these variables affect the incidence and intensity of cholera outbreaks. The current pandemic of cholera began in the 1960s, and millions of cholera cases are reported each year globally. Hence, cholera remains a significant health challenge, notably where human vulnerability intersects with changes in hydrological and environmental processes. Cholera outbreaks may be epidemic or endemic, the mode of which is governed by trigger and transmission components that control the outbreak and spread of the disease, respectively. Traditional cholera risk assessment models, namely compartmental susceptible-exposed-infected-recovered (SEIR) type models, have been used to determine the predictive spread of cholera through the fecal–oral route in human populations. However, these models often fail to capture modes of infection via indirect routes, such as pathogen movement in the environment and heterogeneities relevant to disease transmission. Conversely, other models that rely solely on variability of selected environmental factors (i.e., examine only triggers) have accomplished real-time outbreak prediction but fail to capture the transmission of cholera within impacted populations. Since the mode of cholera outbreaks can transition from epidemic to endemic, a comprehensive transmission model is needed to achieve timely and reliable prediction with respect to quantitative environmental risk. Here, we discuss progression of the trigger module associated with both epidemic and endemic cholera, in the context of the autochthonous aquatic nature of the causative agent of cholera, V. cholerae, as well as disease prediction.
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Affiliation(s)
- Moiz Usmani
- Geohealth and Hydrology Laboratory, Department of Environmental Engineering Sciences, University of Florida, Gainesville, FL 32603, USA; (M.U.); (Y.J.); (A.J.)
| | - Kyle D. Brumfield
- Maryland Pathogen Research Institute, University of Maryland, College Park, MD 20742, USA; (K.D.B.); (A.H.)
- University of Maryland Institute for Advanced Computer Studies, University of Maryland, College Park, MD 20742, USA
| | - Yusuf Jamal
- Geohealth and Hydrology Laboratory, Department of Environmental Engineering Sciences, University of Florida, Gainesville, FL 32603, USA; (M.U.); (Y.J.); (A.J.)
| | - Anwar Huq
- Maryland Pathogen Research Institute, University of Maryland, College Park, MD 20742, USA; (K.D.B.); (A.H.)
| | - Rita R. Colwell
- Maryland Pathogen Research Institute, University of Maryland, College Park, MD 20742, USA; (K.D.B.); (A.H.)
- University of Maryland Institute for Advanced Computer Studies, University of Maryland, College Park, MD 20742, USA
- Correspondence:
| | - Antarpreet Jutla
- Geohealth and Hydrology Laboratory, Department of Environmental Engineering Sciences, University of Florida, Gainesville, FL 32603, USA; (M.U.); (Y.J.); (A.J.)
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Jiang Z, Nero T, Mukherjee S, Olson R, Yan J. Searching for the Secret of Stickiness: How Biofilms Adhere to Surfaces. Front Microbiol 2021; 12:686793. [PMID: 34305846 PMCID: PMC8295476 DOI: 10.3389/fmicb.2021.686793] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2021] [Accepted: 05/28/2021] [Indexed: 01/01/2023] Open
Abstract
Bacterial biofilms are communities of cells enclosed in an extracellular polymeric matrix in which cells adhere to each other and to foreign surfaces. The development of a biofilm is a dynamic process that involves multiple steps, including cell-surface attachment, matrix production, and population expansion. Increasing evidence indicates that biofilm adhesion is one of the main factors contributing to biofilm-associated infections in clinics and biofouling in industrial settings. This review focuses on describing biofilm adhesion strategies among different bacteria, including Vibrio cholerae, Pseudomonas aeruginosa, and Staphylococcus aureus. Techniques used to characterize biofilm adhesion are also reviewed. An understanding of biofilm adhesion strategies can guide the development of novel approaches to inhibit or manipulate biofilm adhesion and growth.
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Affiliation(s)
- Zhaowei Jiang
- Department of Molecular, Cellular and Developmental Biology, Yale University, New Haven, CT, United States
| | - Thomas Nero
- Department of Molecular, Cellular and Developmental Biology, Yale University, New Haven, CT, United States
| | - Sampriti Mukherjee
- Department of Molecular Genetics and Cell Biology, University of Chicago, Chicago, IL, United States
| | - Rich Olson
- Department of Molecular Biology and Biochemistry, Molecular Biophysics Program, Wesleyan University, Middletown, CT, United States
| | - Jing Yan
- Department of Molecular, Cellular and Developmental Biology, Yale University, New Haven, CT, United States.,Quantitative Biology Institute, Yale University, New Haven, CT, United States
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16
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Nasreen T, Hussain NAS, Islam MT, Orata FD, Kirchberger PC, Case RJ, Alam M, Yanow SK, Boucher YF. Simultaneous Quantification of Vibrio metoecus and Vibrio cholerae with Its O1 Serogroup and Toxigenic Subpopulations in Environmental Reservoirs. Pathogens 2020; 9:pathogens9121053. [PMID: 33339261 PMCID: PMC7766680 DOI: 10.3390/pathogens9121053] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2020] [Revised: 12/11/2020] [Accepted: 12/12/2020] [Indexed: 12/14/2022] Open
Abstract
Vibrio metoecus is a recently described aquatic bacterium and opportunistic pathogen, closely related to and often coexisting with Vibrio cholerae. To study the relative abundance and population dynamics of both species in aquatic environments of cholera-endemic and cholera-free regions, we developed a multiplex qPCR assay allowing simultaneous quantification of total V. metoecus and V. cholerae (including toxigenic and O1 serogroup) cells. The presence of V. metoecus was restricted to samples from regions that are not endemic for cholera, where it was found at 20% of the abundance of V. cholerae. In this environment, non-toxigenic O1 serogroup V. cholerae represents almost one-fifth of the total V. cholerae population. In contrast, toxigenic O1 serogroup V. cholerae was also present in low abundance on the coast of cholera-endemic regions, but sustained in relatively high proportions throughout the year in inland waters. The majority of cells from both Vibrio species were recovered from particles rather than free-living, indicating a potential preference for attached versus planktonic lifestyles. This research further elucidates the population dynamics underpinning V. cholerae and its closest relative in cholera-endemic and non-endemic regions through culture-independent quantification from environmental samples.
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Affiliation(s)
- Tania Nasreen
- Department of Biological Sciences, University of Alberta, Edmonton, AB T6G 2E9, Canada; (T.N.); (N.A.S.H.); (M.T.I.); (F.D.O.); (R.J.C.)
| | - Nora A. S. Hussain
- Department of Biological Sciences, University of Alberta, Edmonton, AB T6G 2E9, Canada; (T.N.); (N.A.S.H.); (M.T.I.); (F.D.O.); (R.J.C.)
| | - Mohammad Tarequl Islam
- Department of Biological Sciences, University of Alberta, Edmonton, AB T6G 2E9, Canada; (T.N.); (N.A.S.H.); (M.T.I.); (F.D.O.); (R.J.C.)
| | - Fabini D. Orata
- Department of Biological Sciences, University of Alberta, Edmonton, AB T6G 2E9, Canada; (T.N.); (N.A.S.H.); (M.T.I.); (F.D.O.); (R.J.C.)
| | - Paul C. Kirchberger
- Department of Integrative Biology, University of Texas at Austin, Austin, TX 78712, USA;
| | - Rebecca J. Case
- Department of Biological Sciences, University of Alberta, Edmonton, AB T6G 2E9, Canada; (T.N.); (N.A.S.H.); (M.T.I.); (F.D.O.); (R.J.C.)
- Singapore Centre for Environmental Life Sciences Engineering (SCELSE), Nanyang Technological University, Singapore 637551, Singapore
- School of Biological Sciences, Nanyang Technological University, Singapore 637551, Singapore
| | - Munirul Alam
- Centre for Communicable Diseases, International Centre for Diarrhoeal Disease Research, Bangladesh (ICDDR, B), Dhaka 1000, Bangladesh;
| | - Stephanie K. Yanow
- School of Public Health, University of Alberta, Edmonton, AB T6G 1C9, Canada;
- Department of Medical Microbiology and Immunology, University of Alberta, Edmonton, AB T6G 2E1, Canada
| | - Yann F. Boucher
- Department of Biological Sciences, University of Alberta, Edmonton, AB T6G 2E9, Canada; (T.N.); (N.A.S.H.); (M.T.I.); (F.D.O.); (R.J.C.)
- Singapore Centre for Environmental Life Sciences Engineering (SCELSE), National University of Singapore, Singapore 637551, Singapore
- Saw Swee Hock School of Public Health, National University of Singapore, Singapore 117549, Singapore
- Correspondence:
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Brao KJ, Wille BP, Lieberman J, Ernst RK, Shirtliff ME, Harro JM. Scnn1b-Transgenic BALB/c Mice as a Model of Pseudomonas aeruginosa Infections of the Cystic Fibrosis Lung. Infect Immun 2020; 88:e00237-20. [PMID: 32631918 PMCID: PMC7440770 DOI: 10.1128/iai.00237-20] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2020] [Accepted: 06/30/2020] [Indexed: 02/07/2023] Open
Abstract
The opportunistic pathogen Pseudomonas aeruginosa is responsible for much of the morbidity and mortality associated with cystic fibrosis (CF), a condition that predisposes patients to chronic lung infections. P. aeruginosa lung infections are difficult to treat because P. aeruginosa adapts to the CF lung, can develop multidrug resistance, and can form biofilms. Despite the clinical significance of P. aeruginosa, modeling P. aeruginosa infections in CF has been challenging. Here, we characterize Scnn1b-transgenic (Tg) BALB/c mice as P. aeruginosa lung infection models. Scnn1b-Tg mice overexpress the epithelial Na+ channel (ENaC) in their lungs, driving increased sodium absorption that causes lung pathology similar to CF. We intranasally infected Scnn1b-Tg mice and wild-type littermates with the laboratory P. aeruginosa strain PAO1 and CF clinical isolates and then assessed differences in bacterial clearance, cytokine responses, and histological features up to 12 days postinfection. Scnn1b-Tg mice carried higher bacterial burdens when infected with biofilm-grown rather than planktonic PAO1; Scnn1b-Tg mice also cleared infections more slowly than their wild-type littermates. Infection with PAO1 elicited significant increases in proinflammatory and Th17-linked cytokines on day 3. Scnn1b-Tg mice infected with nonmucoid early CF isolates maintained bacterial burdens and mounted immune responses similar to those of PAO1-infected Scnn1b-Tg mice. In contrast, Scnn1b-Tg mice infected with a mucoid CF isolate carried high bacterial burdens, produced significantly more interleukin 1β (IL-1β), IL-13, IL-17, IL-22, and KC, and showed severe immune cell infiltration into the bronchioles. Taken together, these results show the promise of Scnn1b-Tg mice as models of early P. aeruginosa colonization in the CF lung.
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Affiliation(s)
- Kristen J Brao
- Department of Microbial Pathogenesis, University of Maryland School of Dentistry, Baltimore, Maryland, USA
- Department of Molecular Microbiology and Immunology, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Brendan P Wille
- Department of Microbial Pathogenesis, University of Maryland School of Dentistry, Baltimore, Maryland, USA
| | - Joshua Lieberman
- Division of Microbiology, Department of Laboratory Medicine, University of Washington, Seattle, Washington, USA
| | - Robert K Ernst
- Department of Microbial Pathogenesis, University of Maryland School of Dentistry, Baltimore, Maryland, USA
- Department of Molecular Microbiology and Immunology, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Mark E Shirtliff
- Department of Microbial Pathogenesis, University of Maryland School of Dentistry, Baltimore, Maryland, USA
- Department of Molecular Microbiology and Immunology, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Janette M Harro
- Department of Microbial Pathogenesis, University of Maryland School of Dentistry, Baltimore, Maryland, USA
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18
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Stine OC. The Growth of Young Children and Associations With Their Intestinal Microbiota and Campylobacter. Clin Infect Dis 2019; 71:1008-1009. [DOI: 10.1093/cid/ciz907] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2019] [Accepted: 09/12/2019] [Indexed: 12/14/2022] Open
Affiliation(s)
- O Colin Stine
- Department of Epidemiology and Public Health, University of Maryland, Baltimore, Maryland, USA
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19
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Li S, Zhang H, Hu S, Liu J, Zhu Q, Zhang S. Synthesis of Hierarchical Porous Carbon in Molten Salt and Its Application for Dye Adsorption. NANOMATERIALS 2019; 9:nano9081098. [PMID: 31370302 PMCID: PMC6723312 DOI: 10.3390/nano9081098] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/12/2019] [Revised: 07/29/2019] [Accepted: 07/29/2019] [Indexed: 11/16/2022]
Abstract
Hierarchical porous carbon was successfully synthesized from glucose in a molten salt at 800 °C for 2 h. It was amorphous and contained numerous oxygen containing functional groups on its surface. The porous carbon with 1.0 wt% Fe(NO3)3·9H2O oxidizing agent showed the highest specific surface area of 1078 m2/g, and the largest pore volume of 0.636 cm3/g, among all of the samples. Raman and TEM results revealed that it had more defects and pores than other as-prepared carbon materials. The adsorption capacities of as-prepared porous carbon for methylene blue (MB) and methyl orange (MO) were 506.8 mg/g and 683.8 mg/g, respectively. The adsorption isotherms fit the Langmuir model and the adsorption kinetics followed the pseudo-second-order kinetic model.
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Affiliation(s)
- Saisai Li
- The State Key Laboratory of Refractories and Metallurgy, Wuhan University of Science and Technology, Wuhan 430081, China
| | - Haijun Zhang
- The State Key Laboratory of Refractories and Metallurgy, Wuhan University of Science and Technology, Wuhan 430081, China.
| | - Shiya Hu
- The State Key Laboratory of Refractories and Metallurgy, Wuhan University of Science and Technology, Wuhan 430081, China
| | - Jie Liu
- The State Key Laboratory of Refractories and Metallurgy, Wuhan University of Science and Technology, Wuhan 430081, China
| | - Qing Zhu
- The State Key Laboratory of Refractories and Metallurgy, Wuhan University of Science and Technology, Wuhan 430081, China
| | - Shaowei Zhang
- College of Engineering, Mathematics and Physical Sciences, University of Exeter, Exeter EX4 4QF, UK.
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20
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Balaji R, Yaakob O, Koh KK, Adnan FAB, Ismail NB, Ahmad BB, Ismail MAB. A Study of Ballast Water Treatment Using Engine Waste Heat. JOURNAL OF THE INSTITUTION OF ENGINEERS (INDIA): SERIES C 2019; 100:255-269. [DOI: 10.1007/s40032-018-0468-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/05/2016] [Accepted: 04/13/2018] [Indexed: 09/01/2023]
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21
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Structural basis of mammalian glycan targeting by Vibrio cholerae cytolysin and biofilm proteins. PLoS Pathog 2018; 14:e1006841. [PMID: 29432487 PMCID: PMC5825169 DOI: 10.1371/journal.ppat.1006841] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2017] [Revised: 02/23/2018] [Accepted: 12/21/2017] [Indexed: 11/19/2022] Open
Abstract
Vibrio cholerae is an aquatic gram-negative microbe responsible for cholera, a pandemic disease causing life-threatening diarrheal outbreaks in populations with limited access to health care. Like most pathogenic bacteria, V. cholerae secretes virulence factors to assist colonization of human hosts, several of which bind carbohydrate receptors found on cell-surfaces. Understanding how pathogenic virulence proteins specifically target host cells is important for the development of treatment strategies to fight bacterial infections. Vibrio cholerae cytolysin (VCC) is a secreted pore-forming toxin with a carboxy-terminal β-prism domain that targets complex N-glycans found on mammalian cell-surface proteins. To investigate glycan selectivity, we studied the VCC β-prism domain and two additional β-prism domains found within the V. cholerae biofilm matrix protein RbmC. We show that the two RbmC β-prism domains target a similar repertoire of complex N-glycan receptors as VCC and find through binding and modeling studies that a branched pentasaccharide core (GlcNAc2-Man3) represents the likely footprint interacting with these domains. To understand the structural basis of V. cholerae β-prism selectivity, we solved high-resolution crystal structures of fragments of the pentasaccharide core bound to one RbmC β-prism domain and conducted mutagenesis experiments on the VCC toxin. Our results highlight a common strategy for cell-targeting utilized by both toxin and biofilm matrix proteins in Vibrio cholerae and provide a structural framework for understanding the specificity for individual receptors. Our results suggest that a common strategy for disrupting carbohydrate interactions could affect multiple virulence factors produced by V. cholerae, as well as similar β-prism domains found in other vibrio pathogens.
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Abstract
Infectious diseases kill nearly 9 million people annually. Bacterial pathogens are responsible for a large proportion of these diseases, and the bacterial agents of pneumonia, diarrhea, and tuberculosis are leading causes of death and disability worldwide. Increasingly, the crucial role of nonhost environments in the life cycle of bacterial pathogens is being recognized. Heightened scrutiny has been given to the biological processes impacting pathogen dissemination and survival in the natural environment, because these processes are essential for the transmission of pathogenic bacteria to new hosts. This chapter focuses on the model environmental pathogen Vibrio cholerae to describe recent advances in our understanding of how pathogens survive between hosts and to highlight the processes necessary to support the cycle of environmental survival, transmission, and dissemination. We describe the physiological and molecular responses of V. cholerae to changing environmental conditions, focusing on its survival in aquatic reservoirs between hosts and its entry into and exit from human hosts.
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23
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Khandeparker L, Eswaran R, Gardade L, Kuchi N, Mapari K, Naik SD, Anil AC. Elucidation of the tidal influence on bacterial populations in a monsoon influenced estuary through simultaneous observations. ENVIRONMENTAL MONITORING AND ASSESSMENT 2017; 189:41. [PMID: 28035613 DOI: 10.1007/s10661-016-5687-3] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/19/2016] [Accepted: 11/07/2016] [Indexed: 06/06/2023]
Abstract
The influence of tides on bacterial populations in a monsoon influenced tropical estuary was assessed through fine resolution sampling (1 to 3 h) during spring and neap tides from mouth to the freshwater end at four stations during pre-monsoon, monsoon and post-monsoon seasons. Higher abundance of total bacterial count (TBC) in surface water near the river mouth, compared to the upstream, during pre-monsoon was followed by an opposite scenario during the monsoon When seasonally compared, it was during the post-monsoon season when TBC in surface water was highest, with simultaneous decrease in their count in the river sediment. The total viable bacterial count (TVC) was influenced by the depth-wise stratification of salinity, which varied with tidal fluctuation, usually high and low during the neap and spring tides respectively. The abundance of both the autochthonous Vibrio spp. and allochthonous coliform bacteria was influenced by the concentrations of dissolved nutrients and suspended particulate matter (SPM). It is concluded that depending on the interplay of riverine discharge and tidal amplitude, sediment re-suspension mediated increase in SPM significantly regulates bacteria populations in the estuarine water, urging the need of systematic regular monitoring for better prediction of related hazards, including those associated with the rise in pathogenic Vibrio spp. in the changing climatic scenarios.
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Affiliation(s)
| | - Ranjith Eswaran
- CSIR-National Institute of Oceanography, Dona Paula, Goa, India
| | - Laxman Gardade
- CSIR-National Institute of Oceanography, Dona Paula, Goa, India
| | - Nishanth Kuchi
- CSIR-National Institute of Oceanography, Dona Paula, Goa, India
| | - Kaushal Mapari
- CSIR-National Institute of Oceanography, Dona Paula, Goa, India
| | - Sneha D Naik
- CSIR-National Institute of Oceanography, Dona Paula, Goa, India
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Briquaire R, Colwell RR, Boncy J, Rossignol E, Dardy A, Pandini I, Villeval F, Machuron JL, Huq A, Rashed S, Vandevelde T, Rozand C. Application of a paper based device containing a new culture medium to detect Vibrio cholerae in water samples collected in Haiti. J Microbiol Methods 2016; 133:23-31. [PMID: 28007529 DOI: 10.1016/j.mimet.2016.12.014] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2016] [Revised: 12/15/2016] [Accepted: 12/16/2016] [Indexed: 01/25/2023]
Abstract
Cholera is now considered to be endemic in Haiti, often with increased incidence during rainy seasons. The challenge of cholera surveillance is exacerbated by the cost of sample collection and laboratory analysis. A diagnostic tool is needed that is low cost, easy-to-use, and able to detect and quantify Vibrio cholerae accurately in water samples within 18-24h, and perform reliably in remote settings lacking laboratory infrastructure and skilled staff. The two main objectives of this study were to develop and evaluate a new culture medium embedded in a new diagnostic tool (PAD for paper based analytical device) for detecting Vibrio cholerae from water samples collected in Haiti. The intent is to provide guidance for corrective action, such as chlorination, for water positive for V. cholerae epidemic strains. For detecting Vibrio cholerae, a new chromogenic medium was designed and evaluated as an alternative to thiosulfate citrate bile salts sucrose (TCBS) agar for testing raw water samples. Sensitivity and specificity of the medium were assessed using both raw and spiked water samples. The Vibrio cholerae chromogenic medium was proved to be highly selective against most of the cultivable bacteria in the water samples, without loss of sensitivity in detection of V. cholerae. Thus, reliability of this new culture medium for detection of V. cholerae in the presence of other Vibrio species in water samples offers a significant advantage. A new paper based device containing the new chromogenic medium previously evaluated was compared with reference methods for detecting V. cholerae from spiked water sample. The microbiological PAD specifications were evaluated in Haiti. More precisely, a total of 185 water samples were collected at five sites in Haiti, June 2014 and again in June 2015. With this new tool, three V. cholerae O1 and 17 V. cholerae non-O1/O139 strains were isolated. The presence of virulence-associated and regulatory genes, including ctxA, zot, ace, and toxR, was confirmed using multiplex PCR. The three V. cholerae O1 isolates were positive for three of the four virulence-associated and regulatory genes. Twelve of the V. cholerae non-O1/O139 isolates were found to carry toxR, but none were ctxA+, zot+, or ace+. However, six of the V. cholerae non-O1/O139 isolates were resistant to penicillin, ampicillin, trimethoprim/sulfamethoxazole, nalidixic acid, and ciprofloxacin. The paper based analytical device (PAD) provides advantages in that standard culture methods employing agar plates are not required. Also, intermediary isolation steps were not required, including transfer to selective growth media, hence these steps being omitted reduced time to results. Furthermore, experienced technical skills also were not required. Thus, PAD is well suited for resource-limited settings.
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Affiliation(s)
- Romain Briquaire
- PAH - Les Pharmaciens Humanitaires, 84 rue de Charonne, 75011 Paris 11, France.
| | - Rita R Colwell
- Institute for Advanced Computer Studies, University of Maryland College Park, College Park, MD 20742, USA; Department of Cell Biology and Molecular Genetics, Maryland Pathogen Research Institute, University of Maryland College Park, College Park, MD 20742, USA
| | - Jacques Boncy
- Laboratoire National de Santé Publique, Rue Chardonnier #2 and Delmas 33, Port-au-Prince, Haiti
| | - Emmanuel Rossignol
- Laboratoire National de Santé Publique, Rue Chardonnier #2 and Delmas 33, Port-au-Prince, Haiti
| | - Aline Dardy
- bioMérieux, Novel Analytical Devices, Innovation Unit, 69280, Marcy L'Etoile, France
| | | | | | - Jean-Louis Machuron
- PAH - Les Pharmaciens Humanitaires, 84 rue de Charonne, 75011 Paris 11, France
| | - Anwar Huq
- Department of Cell Biology and Molecular Genetics, Maryland Pathogen Research Institute, University of Maryland College Park, College Park, MD 20742, USA
| | - Shah Rashed
- Department of Cell Biology and Molecular Genetics, Maryland Pathogen Research Institute, University of Maryland College Park, College Park, MD 20742, USA
| | | | - Christine Rozand
- bioMérieux, Novel Analytical Devices, Innovation Unit, 69280, Marcy L'Etoile, France.
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Abstract
Members of the genus Vibrio are known to interact with phyto- and zooplankton in aquatic environments. These interactions have been proven to protect the bacterium from various environmental stresses, serve as a nutrient source, facilitate exchange of DNA, and to serve as vectors of disease transmission. This review highlights the impact of Vibrio-zooplankton interactions at the ecosystem scale and the importance of studies focusing on a wide range of Vibrio-zooplankton interactions. The current knowledge on chitin utilization (i.e., chemotaxis, attachment, and degradation) and the role of these factors in attachment to nonchitinous zooplankton is also presented.
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Multifaceted roles of extracellular DNA in bacterial physiology. Curr Genet 2015; 62:71-9. [PMID: 26328805 PMCID: PMC4723616 DOI: 10.1007/s00294-015-0514-x] [Citation(s) in RCA: 65] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2015] [Revised: 08/20/2015] [Accepted: 08/21/2015] [Indexed: 11/08/2022]
Abstract
In textbooks, DNA is generally defined as the universal storage material for genetic information in all branches of life. Beyond this important intracellular role, DNA can also be present outside of living cells and is an abundant biopolymer in aquatic and terrestrial ecosystems. The origin of extracellular DNA in such ecological niches is diverse: it can be actively secreted or released by prokaryotic and eukaryotic cells by means of autolysis, apoptosis, necrosis, bacterial secretion systems or found in association with extracellular bacterial membrane vesicles. Especially for bacteria, extracellular DNA represents a significant and convenient element that can be enzymatically modulated and utilized for multiple purposes. Herein, we discuss briefly the main origins of extracellular DNA and the most relevant roles for the bacterial physiology, such as biofilm formation, nutrient source, antimicrobial means and horizontal gene transfer.
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Abstract
Vibrio cholerae is widely known to be the etiological agent of the life-threatening diarrheal disease cholera. Cholera remains a major scourge in many developing countries, infecting hundreds of thousands every year. Remarkably, V. cholerae is a natural inhabitant of brackish riverine, estuarine, and coastal waters, and only a subset of strains are known to be pathogenic to humans. Recent studies have begun to uncover a very complex network of relationships between V. cholerae and other sea dwellers, and the mechanisms associated with the occurrence of seasonal epidemics in regions where cholera is endemic are beginning to be elucidated. Many of the factors required for the organism's survival and persistence in its natural environment have been revealed, as well as the ubiquitous presence of horizontal gene transfer in the emergence of pathogenic strains of V. cholerae. In this article, we will focus on the environmental stage of pathogenic V. cholerae and the interactions of the microorganism with other inhabitants of aquatic environments. We will discuss the impact that its environmental reservoirs have on disease transmission and the distinction between reservoirs of V. cholerae and the vectors that establish cholera as a zoonosis.
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In situ proteolysis of the Vibrio cholerae matrix protein RbmA promotes biofilm recruitment. Proc Natl Acad Sci U S A 2015; 112:10491-6. [PMID: 26240338 DOI: 10.1073/pnas.1512424112] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The estuarine gram-negative rod and human diarrheal pathogen Vibrio cholerae synthesizes a VPS exopolysaccharide-dependent biofilm matrix that allows it to form a 3D structure on surfaces. Proteins associated with the matrix include, RbmA, RbmC, and Bap1. RbmA, a protein whose crystallographic structure suggests two binding surfaces, associates with cells by means of a VPS-dependent mechanism and promotes biofilm cohesiveness and recruitment of cells to the biofilm. Here, we show that RbmA undergoes limited proteolysis within the biofilm. This proteolysis, which is carried out by the hemagglutinin/protease and accessory proteases, yields the 22-kDa C-terminal polypeptide RbmA*. RbmA* remains biofilm-associated. Unlike full-length RbmA, the association of RbmA* with cells is no longer VPS-dependent, likely due to an electropositive surface revealed by proteolysis. We provide evidence that this proteolysis event plays a role in recruitment of VPS(-) cells to the biofilm surface. Based on our findings, we propose that association of RbmA with the matrix reinforces the biofilm structure and leads to limited proteolysis of RbmA to RbmA*. RbmA*, in turn, promotes recruitment of cells that have not yet initiated VPS synthesis to the biofilm surface. The assignment of two functions to RbmA, separated by a proteolytic event that depends on matrix association, dictates an iterative cycle in which reinforcement of recently added biofilm layers precedes the recruitment of new VPS(-) cells to the biofilm.
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Abstract
ABSTRACT
Various studies have examined the relationships between vibrios and the environmental conditions surrounding them. However, very few reviews have compiled these studies into cohesive points. This may be due to the fact that these studies examine different environmental parameters, use different sampling, detection, and enumeration methodologies, and occur in diverse geographic locations. The current article is one approach to compile these studies into a cohesive work that assesses the importance of environmental determinants on the abundance of vibrios in coastal ecosystems.
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Whitfield GB, Marmont LS, Howell PL. Enzymatic modifications of exopolysaccharides enhance bacterial persistence. Front Microbiol 2015; 6:471. [PMID: 26029200 PMCID: PMC4432689 DOI: 10.3389/fmicb.2015.00471] [Citation(s) in RCA: 81] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2015] [Accepted: 04/29/2015] [Indexed: 12/25/2022] Open
Abstract
Biofilms are surface-attached communities of bacterial cells embedded in a self-produced matrix that are found ubiquitously in nature. The biofilm matrix is composed of various extracellular polymeric substances, which confer advantages to the encapsulated bacteria by protecting them from eradication. The matrix composition varies between species and is dependent on the environmental niche that the bacteria inhabit. Exopolysaccharides (EPS) play a variety of important roles in biofilm formation in numerous bacterial species. The ability of bacteria to thrive in a broad range of environmental settings is reflected in part by the structural diversity of the EPS produced both within individual bacterial strains as well as by different species. This variability is achieved through polymerization of distinct sugar moieties into homo- or hetero-polymers, as well as post-polymerization modification of the polysaccharide. Specific enzymes that are unique to the production of each polymer can transfer or remove non-carbohydrate moieties, or in other cases, epimerize the sugar units. These modifications alter the physicochemical properties of the polymer, which in turn can affect bacterial pathogenicity, virulence, and environmental adaptability. Herein, we review the diversity of modifications that the EPS alginate, the Pel polysaccharide, Vibrio polysaccharide, cepacian, glycosaminoglycans, and poly-N-acetyl-glucosamine undergo during biosynthesis. These are EPS produced by human pathogenic bacteria for which studies have begun to unravel the effect modifications have on their physicochemical and biological properties. The biological advantages these polymer modifications confer to the bacteria that produce them will be discussed. The expanding list of identified modifications will allow future efforts to focus on linking these modifications to specific biosynthetic genes and biofilm phenotypes.
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Affiliation(s)
- Gregory B Whitfield
- Program in Molecular Structure and Function, Research Institute, The Hospital for Sick Children Toronto, ON, Canada ; Department of Biochemistry, Faculty of Medicine, University of Toronto Toronto, ON, Canada
| | - Lindsey S Marmont
- Program in Molecular Structure and Function, Research Institute, The Hospital for Sick Children Toronto, ON, Canada ; Department of Biochemistry, Faculty of Medicine, University of Toronto Toronto, ON, Canada
| | - P Lynne Howell
- Program in Molecular Structure and Function, Research Institute, The Hospital for Sick Children Toronto, ON, Canada ; Department of Biochemistry, Faculty of Medicine, University of Toronto Toronto, ON, Canada
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Hobley L, Harkins C, MacPhee CE, Stanley-Wall NR. Giving structure to the biofilm matrix: an overview of individual strategies and emerging common themes. FEMS Microbiol Rev 2015; 39:649-69. [PMID: 25907113 PMCID: PMC4551309 DOI: 10.1093/femsre/fuv015] [Citation(s) in RCA: 319] [Impact Index Per Article: 35.4] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/09/2015] [Indexed: 01/24/2023] Open
Abstract
Biofilms are communities of microbial cells that underpin diverse processes including sewage bioremediation, plant growth promotion, chronic infections and industrial biofouling. The cells resident in the biofilm are encased within a self-produced exopolymeric matrix that commonly comprises lipids, proteins that frequently exhibit amyloid-like properties, eDNA and exopolysaccharides. This matrix fulfils a variety of functions for the community, from providing structural rigidity and protection from the external environment to controlling gene regulation and nutrient adsorption. Critical to the development of novel strategies to control biofilm infections, or the capability to capitalize on the power of biofilm formation for industrial and biotechnological uses, is an in-depth knowledge of the biofilm matrix. This is with respect to the structure of the individual components, the nature of the interactions between the molecules and the three-dimensional spatial organization. We highlight recent advances in the understanding of the structural and functional role that carbohydrates and proteins play within the biofilm matrix to provide three-dimensional architectural integrity and functionality to the biofilm community. We highlight, where relevant, experimental techniques that are allowing the boundaries of our understanding of the biofilm matrix to be extended using Escherichia coli, Staphylococcus aureus, Vibrio cholerae, and Bacillus subtilis as exemplars. Examining the structure and function of the biofilm extracellular matrix.
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Affiliation(s)
- Laura Hobley
- Division of Molecular Microbiology, College of Life Sciences, University of Dundee, Dundee DD1 5EH, UK
| | - Catriona Harkins
- Division of Molecular Microbiology, College of Life Sciences, University of Dundee, Dundee DD1 5EH, UK
| | - Cait E MacPhee
- James Clerk Maxwell Building, School of Physics, University of Edinburgh, Edinburgh EH9 3JZ, UK
| | - Nicola R Stanley-Wall
- Division of Molecular Microbiology, College of Life Sciences, University of Dundee, Dundee DD1 5EH, UK
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Townsley L, Yildiz FH. Temperature affects c-di-GMP signalling and biofilm formation in Vibrio cholerae. Environ Microbiol 2015; 17:4290-305. [PMID: 25684220 DOI: 10.1111/1462-2920.12799] [Citation(s) in RCA: 71] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2014] [Revised: 01/19/2015] [Accepted: 01/31/2015] [Indexed: 02/04/2023]
Abstract
Biofilm formation is crucial to the environmental survival and transmission of Vibrio cholerae, the facultative human pathogen responsible for the disease cholera. During its infectious cycle, V. cholerae experiences fluctuations in temperature within the aquatic environment and during the transition between human host and aquatic reservoirs. In this study, we report that biofilm formation is induced at low temperatures through increased levels of the signalling molecule, cyclic diguanylate (c-di-GMP). Strains harbouring in frame deletions of all V. cholerae genes that are predicted to encode diguanylate cyclases (DGCs) or phosphodiesterases (PDEs) were screened for their involvement in low-temperature-induced biofilm formation and Vibrio polysaccharide gene expression. Of the 52 mutants tested, deletions of six DGCs and three PDEs were found to affect these phenotypes at low temperatures. Unlike wild type, a strain lacking all six DGCs did not exhibit a low-temperature-dependent increase in c-di-GMP, indicating that these DGCs are required for temperature modulation of c-di-GMP levels. We also show that temperature modulates c-di-GMP levels in a similar fashion in the Gram-negative pathogen Pseudomonas aeruginosa but not in the Gram-positive pathogen Listeria monocytogenes. This study uncovers the role of temperature in environmental regulation of biofilm formation and c-di-GMP signalling.
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Affiliation(s)
- Loni Townsley
- Department of Microbiology and Environmental Toxicology, University of California, Santa Cruz, CA, 95064, USA
| | - Fitnat H Yildiz
- Department of Microbiology and Environmental Toxicology, University of California, Santa Cruz, CA, 95064, USA
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Quorum sensing-regulated chitin metabolism provides grazing resistance to Vibrio cholerae biofilms. ISME JOURNAL 2015; 9:1812-20. [PMID: 25615438 PMCID: PMC4511936 DOI: 10.1038/ismej.2014.265] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/29/2014] [Accepted: 12/08/2014] [Indexed: 12/28/2022]
Abstract
Association of Vibrio cholerae with chitinous surfaces of zooplankton is important for its persistence in marine environments, as it provides accessibility to nutrients and resistance to stresses. Predation by heterotrophic protists has a major impact on the survival of V. cholerae. V. cholerae forms biofilms as its main defensive strategy, and quorum sensing (QS) additionally regulates the production of antiprotozoal factors. The role of chitin and QS regulation in V. cholerae grazing resistance was investigated by exposing V. cholerae wild-type (WT) and QS mutant biofilms grown on chitin flakes to the bacteriotrophic, surface-feeding flagellate Rhynchomonas nasuta. V. cholerae formed more biofilm biomass on chitin flakes compared with nonchitinous surfaces. The growth of R. nasuta was inhibited by WT biofilms grown on chitin flakes, whereas the inhibition was attenuated in QS mutant biofilms. The chitin-dependent toxicity was also observed when the V. cholerae biofilms were developed under continuous flow or grown on a natural chitin source, the exoskeleton of Artemia. In addition, the antiprotozoal activity and ammonium concentration of V. cholerae biofilm supernatants were quantified. The ammonium levels (3.5 mM) detected in the supernatants of V. cholerae WT biofilms grown on chitin flakes were estimated to reduce the number of R. nasuta by >80% in add-back experiments, and the supernatant of QS mutant biofilms was less toxic owing to a decrease in ammonium production. Transcriptomic analysis revealed that the majority of genes involved in chitin metabolism and chemotaxis were significantly downregulated in QS mutant biofilms when grown on chitin compared with the WT biofilms.
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Salem W, Leitner DR, Zingl FG, Schratter G, Prassl R, Goessler W, Reidl J, Schild S. Antibacterial activity of silver and zinc nanoparticles against Vibrio cholerae and enterotoxic Escherichia coli. Int J Med Microbiol 2015; 305:85-95. [PMID: 25466205 PMCID: PMC4300426 DOI: 10.1016/j.ijmm.2014.11.005] [Citation(s) in RCA: 176] [Impact Index Per Article: 19.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2014] [Revised: 10/30/2014] [Accepted: 11/04/2014] [Indexed: 11/17/2022] Open
Abstract
Vibrio cholerae and enterotoxic Escherichia coli (ETEC) remain two dominant bacterial causes of severe secretory diarrhea and still a significant cause of death, especially in developing countries. In order to investigate new effective and inexpensive therapeutic approaches, we analyzed nanoparticles synthesized by a green approach using corresponding salt (silver or zinc nitrate) with aqueous extract of Caltropis procera fruit or leaves. We characterized the quantity and quality of nanoparticles by UV-visible wavelength scans and nanoparticle tracking analysis. Nanoparticles could be synthesized in reproducible yields of approximately 10(8) particles/ml with mode particles sizes of approx. 90-100 nm. Antibacterial activity against two pathogens was assessed by minimal inhibitory concentration assays and survival curves. Both pathogens exhibited similar resistance profiles with minimal inhibitory concentrations ranging between 5×10(5) and 10(7) particles/ml. Interestingly, zinc nanoparticles showed a slightly higher efficacy, but sublethal concentrations caused adverse effects and resulted in increased biofilm formation of V. cholerae. Using the expression levels of the outer membrane porin OmpT as an indicator for cAMP levels, our results suggest that zinc nanoparticles inhibit adenylyl cyclase activity. This consequently deceases the levels of this second messenger, which is a known inhibitor of biofilm formation. Finally, we demonstrated that a single oral administration of silver nanoparticles to infant mice colonized with V. cholerae or ETEC significantly reduces the colonization rates of the pathogens by 75- or 100-fold, respectively.
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Affiliation(s)
- Wesam Salem
- University of Graz, Institute of Molecular Biosciences, BioTechMed-Graz, Humboldtstrasse 50, A-8010 Graz, Austria; South Valley University, Faculty of Science, Qena, Egypt
| | - Deborah R Leitner
- University of Graz, Institute of Molecular Biosciences, BioTechMed-Graz, Humboldtstrasse 50, A-8010 Graz, Austria
| | - Franz G Zingl
- University of Graz, Institute of Molecular Biosciences, BioTechMed-Graz, Humboldtstrasse 50, A-8010 Graz, Austria
| | - Gebhart Schratter
- Institute of Biophysics, Medical University of Graz, BioTechMed-Graz, Schmiedlstraße 6, 8042 Graz, Austria
| | - Ruth Prassl
- Institute of Biophysics, Medical University of Graz, BioTechMed-Graz, Schmiedlstraße 6, 8042 Graz, Austria
| | - Walter Goessler
- Institute for Chemistry, Analytical Chemistry, University of Graz, BioTechMed-Graz, 8010 Graz, Austria
| | - Joachim Reidl
- University of Graz, Institute of Molecular Biosciences, BioTechMed-Graz, Humboldtstrasse 50, A-8010 Graz, Austria
| | - Stefan Schild
- University of Graz, Institute of Molecular Biosciences, BioTechMed-Graz, Humboldtstrasse 50, A-8010 Graz, Austria.
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Song T, Sabharwal D, Gurung JM, Cheng AT, Sjöström AE, Yildiz FH, Uhlin BE, Wai SN. Vibrio cholerae utilizes direct sRNA regulation in expression of a biofilm matrix protein. PLoS One 2014; 9:e101280. [PMID: 25054332 PMCID: PMC4108314 DOI: 10.1371/journal.pone.0101280] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2014] [Accepted: 06/05/2014] [Indexed: 11/18/2022] Open
Abstract
Vibrio cholerae biofilms contain exopolysaccharide and three matrix proteins RbmA, RbmC and Bap1. While much is known about exopolysaccharide regulation, little is known about the mechanisms by which the matrix protein components of biofilms are regulated. VrrA is a conserved, 140-nt sRNA of V. cholerae, whose expression is controlled by sigma factor σE. In this study, we demonstrate that VrrA negatively regulates rbmC translation by pairing to the 5′ untranslated region of the rbmC transcript and that this regulation is not stringently dependent on the RNA chaperone protein Hfq. These results point to VrrA as a molecular link between the σE-regulon and biofilm formation in V. cholerae. In addition, VrrA represents the first example of direct regulation of sRNA on biofilm matrix component, by-passing global master regulators.
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Affiliation(s)
- Tianyan Song
- Department of Molecular Biology, Umeå University, Umeå, Sweden
- The Laboratory for Molecular Infection Medicine Sweden (MIMS), Umeå University, Umeå, Sweden
- Umeå Centre for Microbial Research (UCMR), Umeå University, Umeå, Sweden
| | - Dharmesh Sabharwal
- Department of Molecular Biology, Umeå University, Umeå, Sweden
- The Laboratory for Molecular Infection Medicine Sweden (MIMS), Umeå University, Umeå, Sweden
- Umeå Centre for Microbial Research (UCMR), Umeå University, Umeå, Sweden
| | - Jyoti Mohan Gurung
- Department of Molecular Biology, Umeå University, Umeå, Sweden
- The Laboratory for Molecular Infection Medicine Sweden (MIMS), Umeå University, Umeå, Sweden
- Umeå Centre for Microbial Research (UCMR), Umeå University, Umeå, Sweden
| | - Andrew T. Cheng
- Department of Microbiology and Environmental Toxicology, University of California Santa Cruz, Santa Cruz, California, United States of America
| | - Annika E. Sjöström
- Department of Molecular Biology, Umeå University, Umeå, Sweden
- The Laboratory for Molecular Infection Medicine Sweden (MIMS), Umeå University, Umeå, Sweden
- Umeå Centre for Microbial Research (UCMR), Umeå University, Umeå, Sweden
| | - Fitnat H. Yildiz
- Department of Microbiology and Environmental Toxicology, University of California Santa Cruz, Santa Cruz, California, United States of America
| | - Bernt Eric Uhlin
- Department of Molecular Biology, Umeå University, Umeå, Sweden
- The Laboratory for Molecular Infection Medicine Sweden (MIMS), Umeå University, Umeå, Sweden
- Umeå Centre for Microbial Research (UCMR), Umeå University, Umeå, Sweden
| | - Sun Nyunt Wai
- Department of Molecular Biology, Umeå University, Umeå, Sweden
- The Laboratory for Molecular Infection Medicine Sweden (MIMS), Umeå University, Umeå, Sweden
- Umeå Centre for Microbial Research (UCMR), Umeå University, Umeå, Sweden
- * E-mail:
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Identification of genes induced in Vibrio cholerae in a dynamic biofilm system. Int J Med Microbiol 2014; 304:749-63. [PMID: 24962154 PMCID: PMC4101255 DOI: 10.1016/j.ijmm.2014.05.011] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2014] [Revised: 05/23/2014] [Accepted: 05/25/2014] [Indexed: 12/13/2022] Open
Abstract
The facultative human pathogen Vibrio cholerae, the causative agent of the severe secretory diarrheal disease cholera, persists in its aquatic reservoirs in biofilms during interepidemic periods. Biofilm is a likely form in which clinically relevant V. cholerae is taken up by humans, providing an infective dose. Thus, a better understanding of biofilm formation of V. cholerae is relevant for the ecology and epidemiology of cholera as well as a target to control the disease. Most previous studies have investigated static biofilms of V. cholerae and elucidated structural prerequisites like flagella, pili and a biofilm matrix including extracellular DNA, numerous matrix proteins and exopolysaccharide, as well as the involvement of regulatory pathways like two-component systems, quorum sensing and c-di-GMP signaling. However, aquatic environments are more likely to reflect an open, dynamic system. Hence, we used a biofilm system with constant medium flow and a temporal controlled reporter-system of transcription to identify genes induced during dynamic biofilm formation. We identified genes known or predicted to be involved in c-di-GMP signaling, motility and chemotaxis, metabolism, and transport. Subsequent phenotypic characterization of mutants with independent mutations in candidate dynamic biofilm-induced genes revealed novel insights into the physiology of static and dynamic biofilm conditions. The results of this study also reinforce the hypotheses that distinct differences in regulatory mechanisms governing biofilm development are present under dynamic conditions compared to static conditions.
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Tewksbury JJ, Anderson JGT, Bakker JD, Billo TJ, Dunwiddie PW, Groom MJ, Hampton SE, Herman SG, Levey DJ, Machnicki NJ, del Rio CM, Power ME, Rowell K, Salomon AK, Stacey L, Trombulak SC, Wheeler TA. Natural History's Place in Science and Society. Bioscience 2014. [DOI: 10.1093/biosci/biu032] [Citation(s) in RCA: 190] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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Structural characterization of the extracellular polysaccharide from Vibrio cholerae O1 El-Tor. PLoS One 2014; 9:e86751. [PMID: 24520310 PMCID: PMC3901696 DOI: 10.1371/journal.pone.0086751] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2013] [Accepted: 12/15/2013] [Indexed: 11/19/2022] Open
Abstract
The ability to form biofilms is important for environmental survival, transmission, and infectivity of Vibrio cholerae, the causative agent of cholera in humans. To form biofilms, V. cholerae produces an extracellular matrix composed of proteins, nucleic acids and a glycoconjugate, termed Vibrio exopolysaccharide (VPS). Here, we present the data on isolation and characterization of the polysaccharide part of the VPS (VPS-PS), which has the following structure: -4)-α-GulpNAcAGly3OAc-(1-4)-β-D-Glcp-(1-4)-α-Glcp-(1-4)-α-D-Galp-(1- where α-D-Glc is partially (∼20%) replaced with α-D-GlcNAc. α-GulNAcAGly is an amide between 2-acetamido-2-deoxy-α-guluronic acid and glycine. Apparently, the polysaccharide is bound to a yet unidentified component, which gives it high viscosity and completely suppresses any NMR signals belonging to the sugar chains of the VPS. The only reliable method to remove this component at present is a treatment of the whole glycoconjugate with concentrated hydrochloric acid.
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Lutz C, Erken M, Noorian P, Sun S, McDougald D. Environmental reservoirs and mechanisms of persistence of Vibrio cholerae. Front Microbiol 2013; 4:375. [PMID: 24379807 PMCID: PMC3863721 DOI: 10.3389/fmicb.2013.00375] [Citation(s) in RCA: 153] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2013] [Accepted: 11/21/2013] [Indexed: 12/23/2022] Open
Abstract
It is now well accepted that Vibrio cholerae, the causative agent of the water-borne disease cholera, is acquired from environmental sources where it persists between outbreaks of the disease. Recent advances in molecular technology have demonstrated that this bacterium can be detected in areas where it has not previously been isolated, indicating a much broader, global distribution of this bacterium outside of endemic regions. The environmental persistence of V. cholerae in the aquatic environment can be attributed to multiple intra- and interspecific strategies such as responsive gene regulation and biofilm formation on biotic and abiotic surfaces, as well as interactions with a multitude of other organisms. This review will discuss some of the mechanisms that enable the persistence of this bacterium in the environment. In particular, we will discuss how V. cholerae can survive stressors such as starvation, temperature, and salinity fluctuations as well as how the organism persists under constant predation by heterotrophic protists.
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Affiliation(s)
- Carla Lutz
- Centre for Marine Bio-Innovation, School of Biotechnology and Biomolecular Science, University of New South Wales Sydney, NSW, Australia
| | - Martina Erken
- Centre for Marine Bio-Innovation, School of Biotechnology and Biomolecular Science, University of New South Wales Sydney, NSW, Australia ; Advanced Environmental Biotechnology Centre, Nanyang Environment and Water Research Institute, School of Biological Sciences, Nanyang Technological University Singapore, Singapore
| | - Parisa Noorian
- Centre for Marine Bio-Innovation, School of Biotechnology and Biomolecular Science, University of New South Wales Sydney, NSW, Australia
| | - Shuyang Sun
- The Singapore Centre on Environmental Life Sciences Engineering, Nanyang Technological University Singapore, Singapore
| | - Diane McDougald
- Centre for Marine Bio-Innovation, School of Biotechnology and Biomolecular Science, University of New South Wales Sydney, NSW, Australia ; Advanced Environmental Biotechnology Centre, Nanyang Environment and Water Research Institute, School of Biological Sciences, Nanyang Technological University Singapore, Singapore
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Structural basis for biofilm formation via the Vibrio cholerae matrix protein RbmA. J Bacteriol 2013; 195:3277-86. [PMID: 23687270 DOI: 10.1128/jb.00374-13] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
During the transition from a free-swimming, single-cell lifestyle to a sessile, multicellular state called a biofilm, bacteria produce and secrete an extracellular matrix comprised of nucleic acids, exopolysaccharides, and adhesion proteins. The Vibrio cholerae biofilm matrix contains three major protein components, RbmA, Bap1, and RbmC, which are unique to Vibrio cholerae and appear to support biofilm formation at particular steps in the process. Here, we focus on RbmA, a structural protein with an unknown fold. RbmA participates in the early cell-cell adhesion events and is found throughout the biofilm where it localizes to cell-cell contact sites. We determined crystal structures of RbmA and revealed that the protein folds into tandem fibronectin type III (FnIII) folds. The protein is dimeric in solution and in crystals, with the dimer interface displaying a surface groove that is lined with several positively charged residues. Structure-guided mutagenesis studies establish a crucial role for this surface patch for RbmA function. On the basis of the structure, we hypothesize that RbmA serves as a tether by maintaining flexible linkages between cells and the extracellular matrix.
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Sun S, Kjelleberg S, McDougald D. Relative contributions of Vibrio polysaccharide and quorum sensing to the resistance of Vibrio cholerae to predation by heterotrophic protists. PLoS One 2013; 8:e56338. [PMID: 23441178 PMCID: PMC3575383 DOI: 10.1371/journal.pone.0056338] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2012] [Accepted: 01/08/2013] [Indexed: 12/04/2022] Open
Abstract
Protozoan grazing is a major mortality factor faced by bacteria in the environment. Vibrio cholerae, the causative agent of the disease cholera, is a natural inhabitant of aquatic ecosystems, and its survival depends on its ability to respond to stresses, such as predation by heterotrophic protists. Previous results show that grazing pressure induces biofilm formation and enhances a smooth to rugose morphotypic shift, due to increased expression of Vibrio polysaccharide (VPS). In addition to negatively controlling vps genes, the global quorum sensing (QS) regulator, HapR, plays a role in grazing resistance as the ΔhapR strain is efficiently consumed while the wild type (WT) is not. Here, the relative and combined contributions of VPS and QS to grazing resistance were investigated by exposing VPS and HapR mutants and double mutants in VPS and HapR encoding genes at different phases of biofilm development to amoeboid and flagellate grazers. Data show that the WT biofilms were grazing resistant, the VPS mutants were less resistant than the WT strain, but more resistant than the QS mutant strain, and that QS contributes to grazing resistance mainly in mature biofilms. In addition, grazing effects on biofilms of mixed WT and QS mutant strains were investigated. The competitive fitness of each strain in mixed biofilms was determined by CFU and microscopy. Data show that protozoa selectively grazed the QS mutant in mixed biofilms, resulting in changes in the composition of the mixed community. A small proportion of QS mutant cells which comprised 4% of the mixed biofilm biovolume were embedded in grazing resistant WT microcolonies and shielded from predation, indicating the existence of associational protection in mixed biofilms.
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Affiliation(s)
- Shuyang Sun
- Centre for Marine Bio-Innovation, School of Biotechnology and Biomolecular Sciences, The University of New South Wales, Sydney, New South Wales, Australia
| | - Staffan Kjelleberg
- Centre for Marine Bio-Innovation, School of Biotechnology and Biomolecular Sciences, The University of New South Wales, Sydney, New South Wales, Australia
- Singapore Centre on Environmental Life Sciences Engineering, Nanyang Technological University, Singapore, Singapore
| | - Diane McDougald
- Centre for Marine Bio-Innovation, School of Biotechnology and Biomolecular Sciences, The University of New South Wales, Sydney, New South Wales, Australia
- School of Biological Sciences, Nanyang Technological University, Singapore, Singapore
- Advanced Environmental Biotechnology Centre, Nanyang Environment and Water Institute, Nanyang Technological University, Singapore, Singapore
- * E-mail:
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Abstract
Glucose-specific enzyme IIA (EIIAGlc) is a central regulator of bacterial metabolism and an intermediate in the phosphoenolpyruvate phosphotransferase system (PTS), a conserved phosphotransfer cascade that controls carbohydrate transport. We previously reported that EIIAGlc activates transcription of the genes required for Vibrio cholerae biofilm formation. While EIIAGlc modulates the function of many proteins through a direct interaction, none of the known regulatory binding partners of EIIAGlc activates biofilm formation. Therefore, we used tandem affinity purification (TAP) to compare binding partners of EIIAGlc in both planktonic and biofilm cells. A surprising number of novel EIIAGlc binding partners were identified predominantly under one condition or the other. Studies of planktonic cells revealed established partners of EIIAGlc, such as adenylate cyclase and glycerol kinase. In biofilms, MshH, a homolog of Escherichia coli CsrD, was found to be a dominant binding partner of EIIAGlc. Further studies revealed that MshH inhibits biofilm formation. This function was independent of the Carbon storage regulator (Csr) pathway and dependent on EIIAGlc. To explore the existence of multiprotein complexes centered on EIIAGlc, we also affinity purified the binding partners of adenylate cyclase from biofilm cells. In addition to EIIAGlc, this analysis yielded many of the same proteins that copurified with EIIAGlc. We hypothesize that EIIAGlc serves as a hub for multiprotein complexes and furthermore that these complexes may provide a mechanism for competitive and cooperative interactions between binding partners. EIIAGlc is a global regulator of microbial physiology that acts through direct interactions with other proteins. This work represents the first demonstration that the protein partners of EIIAGlc are distinct in the microbial biofilm. Furthermore, it provides the first evidence that EIIAGlc may exist in multiprotein complexes with its partners, setting the stage for an investigation of how the multiple partners of EIIAGlc influence one another. Last, it provides a connection between the phosphoenolpyruvate phosphotransferase (PTS) and Csr regulatory systems. This work increases our understanding of the complexity of regulation by EIIAGlc and provides a link between the PTS and Csr networks, two global regulatory cascades that influence microbial physiology.
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Spatially selective colonization of the arthropod intestine through activation of Vibrio cholerae biofilm formation. Proc Natl Acad Sci U S A 2011; 108:19737-42. [PMID: 22106284 DOI: 10.1073/pnas.1111530108] [Citation(s) in RCA: 55] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Vibrio cholerae is an estuarine bacterium and the human pathogen responsible for the diarrheal disease cholera. In the environment, arthropods are proposed to be carriers and reservoirs of V. cholerae. However, the molecular basis of the association between V. cholerae and viable arthropods has not been elucidated previously. Here, we show that the V. cholerae Vibrio polysaccharide (VPS)-dependent biofilm is highly activated upon entry into the arthropod intestine and is specifically required for colonization of the arthropod rectum. Although the V. cholerae VPS-dependent biofilm has been studied in the laboratory for many years, the function of this biofilm in the natural habitats of V. cholerae has been elusive. Our results provide evidence that the VPS-dependent biofilm is required for intestinal colonization of an environmental host.
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Seper A, Fengler VHI, Roier S, Wolinski H, Kohlwein SD, Bishop AL, Camilli A, Reidl J, Schild S. Extracellular nucleases and extracellular DNA play important roles in Vibrio cholerae biofilm formation. Mol Microbiol 2011; 82:1015-37. [PMID: 22032623 PMCID: PMC3212620 DOI: 10.1111/j.1365-2958.2011.07867.x] [Citation(s) in RCA: 149] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Biofilms are a preferred mode of survival for many microorganisms including Vibrio cholerae, the causative agent of the severe secretory diarrhoeal disease cholera. The ability of the facultative human pathogen V. cholerae to form biofilms is a key factor for persistence in aquatic ecosystems and biofilms act as a source for new outbreaks. Thus, a better understanding of biofilm formation and transmission of V. cholerae is an important target to control the disease. So far the Vibrio exopolysaccharide was the only known constituent of the biofilm matrix. In this study we identify and characterize extracellular DNA as a component of the Vibrio biofilm matrix. Furthermore, we show that extracellular DNA is modulated and controlled by the two extracellular nucleases Dns and Xds. Our results indicate that extracellular DNA and the extracellular nucleases are involved in diverse processes including the development of a typical biofilm architecture, nutrient acquisition, detachment from biofilms and the colonization fitness of biofilm clumps after ingestion by the host. This study provides new insights into biofilm development and transmission of biofilm-derived V. cholerae.
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Affiliation(s)
- Andrea Seper
- Institut fuer Molekulare Biowissenschaften, Karl-Franzens-Universitaet Graz, Humboldtstrasse 50, 8010 Graz, Austria
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Mukherjee R, Halder D, Saha S, Shyamali R, Subhranshu C, Ramakrishnan R, Murhekar MV, Hutin YJ. Five pond-centred outbreaks of cholera in villages of West Bengal, India: evidence for focused interventions. JOURNAL OF HEALTH, POPULATION, AND NUTRITION 2011; 29:421-428. [PMID: 22106747 PMCID: PMC3225103 DOI: 10.3329/jhpn.v29i5.8895] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
In rural West Bengal, outbreaks of cholera are often centred around ponds that is a feature of the environment. Five investigations of laboratory-confirmed, pond-centred outbreaks of cholera were reviewed. Case-control odds ratios were approximated with relative risks (RRs) as the incidence was low. The environment was investigated to understand how the pond(s) could have become contaminated and could have infected villagers. The five outbreaks of cholera in 2004-2008 led to 277 cases and three deaths (median attack rate: 51/1,000 people; case fatality: 1.1%; median age of case-patients: 22 years; median duration: 13 days, range: 6-15 days). Factors significantly (p<0.05) associated with cholera in the case-control (n=4) and cohort investigations (n=1) included washing utensils in ponds (4 outbreaks of cholera, RR range: 6-12), bathing (3 outbreaks of cholera, RR range: 3.5-9.3), and exposure to pond water, including drinking (2 outbreaks of cholera, RR range: 2.1-3.2), mouth washing (1 outbreak of cholera, RR: 4.8), and cooking (1 outbreak of cholera, RR: 3.0). Initial case-patients contaminated ponds through washing soiled clothes (n=4) or defaecation (n=1). Ubiquitous ponds used for many purposes transmit cholera in West Bengal. Focused health education, hygiene, and sanitation must protect villagers, particularly following the occurrence of an index case in a village that has ponds.
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Affiliation(s)
- Rita Mukherjee
- Field Epidemiology Training Programme, National Institute of Epidemiology, Chennai, Tamil Nadu, India
| | - Debasish Halder
- Field Epidemiology Training Programme, National Institute of Epidemiology, Chennai, Tamil Nadu, India
- West Bengal Health Services, Kolkata, West Bengal, India
| | - Subhasish Saha
- Field Epidemiology Training Programme, National Institute of Epidemiology, Chennai, Tamil Nadu, India
- West Bengal Health Services, Kolkata, West Bengal, India
| | - Rudra Shyamali
- Field Epidemiology Training Programme, National Institute of Epidemiology, Chennai, Tamil Nadu, India
- West Bengal Health Services, Kolkata, West Bengal, India
| | - Chakrabarti Subhranshu
- Field Epidemiology Training Programme, National Institute of Epidemiology, Chennai, Tamil Nadu, India
- West Bengal Health Services, Kolkata, West Bengal, India
| | - R. Ramakrishnan
- Field Epidemiology Training Programme, National Institute of Epidemiology, Chennai, Tamil Nadu, India
| | - Manoj V. Murhekar
- Field Epidemiology Training Programme, National Institute of Epidemiology, Chennai, Tamil Nadu, India
| | - Yvan J. Hutin
- Field Epidemiology Training Programme, National Institute of Epidemiology, Chennai, Tamil Nadu, India
- WHO India Office, New Delhi, India
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Guo Y, Rowe-Magnus DA. Overlapping and unique contributions of two conserved polysaccharide loci in governing distinct survival phenotypes in Vibrio vulnificus. Environ Microbiol 2011; 13:2888-990. [PMID: 21895917 DOI: 10.1111/j.1462-2920.2011.02564.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
As an aetiological agent of bacterial sepsis and wound infections, Vibrio vulnificus is unique among the Vibrionacea. Its continued environmental persistence and transmission are bolstered by its ability to colonize shellfish and form biofilms on various marine biotic surfaces. We previously identified a polysaccharide locus, brp, which contributes to the survival phenotypes of biofilm formation, rugose colony formation and stress resistance. Here, we describe a second polysaccharide locus, rbd (regulation of biofilm development), which also enhanced biofilm formation when expressed. Despite this functional overlap, the development of stress resistance and rugosity could be uniquely attributed to brp expression, whereas rbd expression augmented aggregate formation. Simultaneous expression of both loci led to the formation of a dramatic pellicle and maximum biofilm formation. Unlike the brp locus, transcription of the rbd locus was regulated not by c-di-GMP, but by a response regulator (RbdG) that was encoded within the locus. We propose that the ability to regulate the expression of polysaccharides with overlapping and unique characteristics in response to different environmental cues enables V. vulnificus to 'fine tune' its biofilm lifestyle to the prevailing environmental conditions and maximally benefit from the characteristics associated with each polysaccharide.
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Affiliation(s)
- Yunzhi Guo
- Department of Laboratory Medicine & Pathobiology, Faculty of Medicine, University of Toronto, Toronto, ON, Canada
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A communal bacterial adhesin anchors biofilm and bystander cells to surfaces. PLoS Pathog 2011; 7:e1002210. [PMID: 21901100 PMCID: PMC3161981 DOI: 10.1371/journal.ppat.1002210] [Citation(s) in RCA: 92] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2011] [Accepted: 06/26/2011] [Indexed: 12/21/2022] Open
Abstract
While the exopolysaccharide component of the biofilm matrix has been intensively studied, much less is known about matrix-associated proteins. To better understand the role of these proteins, we undertook a proteomic analysis of the V. cholerae biofilm matrix. Here we show that the two matrix-associated proteins, Bap1 and RbmA, perform distinct roles in the biofilm matrix. RbmA strengthens intercellular attachments. In contrast, Bap1 is concentrated on surfaces where it serves to anchor the biofilm and recruit cells not yet committed to the sessile lifestyle. This is the first example of a biofilm-derived, communally synthesized conditioning film that stabilizes the association of multilayer biofilms with a surface and facilitates recruitment of planktonic bystanders to the substratum. These studies define a novel paradigm for spatial and functional differentiation of proteins in the biofilm matrix and provide evidence for bacterial cooperation in maintenance and expansion of the multilayer biofilm.
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Role of zooplankton diversity in Vibrio cholerae population dynamics and in the incidence of cholera in the Bangladesh Sundarbans. Appl Environ Microbiol 2011; 77:6125-32. [PMID: 21764957 DOI: 10.1128/aem.01472-10] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Vibrio cholerae, a bacterium autochthonous to the aquatic environment, is the causative agent of cholera, a severe watery, life-threatening diarrheal disease occurring predominantly in developing countries. V. cholerae, including both serogroups O1 and O139, is found in association with crustacean zooplankton, mainly copepods, and notably in ponds, rivers, and estuarine systems globally. The incidence of cholera and occurrence of pathogenic V. cholerae strains with zooplankton were studied in two areas of Bangladesh: Bakerganj and Mathbaria. Chitinous zooplankton communities of several bodies of water were analyzed in order to understand the interaction of the zooplankton population composition with the population dynamics of pathogenic V. cholerae and incidence of cholera. Two dominant zooplankton groups were found to be consistently associated with detection of V. cholerae and/or occurrence of cholera cases, namely, rotifers and cladocerans, in addition to copepods. Local differences indicate there are subtle ecological factors that can influence interactions between V. cholerae, its plankton hosts, and the incidence of cholera.
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