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Liu Z, Zhou Y, Wang H, Liu C, Wang L. Recent advances in understanding the fitness and survival mechanisms of Vibrio parahaemolyticus. Int J Food Microbiol 2024; 417:110691. [PMID: 38631283 DOI: 10.1016/j.ijfoodmicro.2024.110691] [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: 12/12/2023] [Revised: 03/14/2024] [Accepted: 04/02/2024] [Indexed: 04/19/2024]
Abstract
The presence of Vibrio parahaemolyticus (Vp) in different production stages of seafood has generated negative impacts on both public health and the sustainability of the industry. To further better investigate the fitness of Vp at the phenotypical level, a great number of studies have been conducted in recent years using plate counting methods. In the meantime, with the increasing accessibility of the next generation sequencing and the advances in analytical chemistry techniques, omics-oriented biotechnologies have further advanced our knowledge in the survival and virulence mechanisms of Vp at various molecular levels. These observations provide insights to guide the development of novel prevention and control strategies and benefit the monitoring and mitigation of food safety risks associated with Vp contamination. To timely capture these recent advances, this review firstly summarizes the most recent phenotypical level studies and provide insights about the survival of Vp under important in vitro stresses and on aquatic products. After that, molecular survival mechanisms of Vp at transcriptomic and proteomic levels are summarized and discussed. Looking forward, other newer omics-biotechnology such as metabolomics and secretomics show great potential to be used for confirming the cellular responses of Vp. Powerful data mining tools from the field of machine learning and artificial intelligence, that can better utilize the omics data and solve complex problems in the processing, analysis, and interpretation of omics data, will further improve our mechanistic understanding of Vp.
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Affiliation(s)
- Zhuosheng Liu
- Department of Food Science and Technology, University of California Davis, Davis, CA 95618, USA
| | - Yi Zhou
- Department of Food Science and Technology, University of California Davis, Davis, CA 95618, USA
| | - Hongye Wang
- Department of Food Science and Technology, University of California Davis, Davis, CA 95618, USA
| | - Chengchu Liu
- University of Maryland Sea Grant Extension Program, UMES Center for Food Science and Technology, Princess Anne, MD, United States
| | - Luxin Wang
- Department of Food Science and Technology, University of California Davis, Davis, CA 95618, USA.
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2
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Zhang J, Lu X. Susceptibility of Campylobacter jejuni to Stressors in Agrifood Systems and Induction of a Viable-but-Nonculturable State. Appl Environ Microbiol 2023; 89:e0009623. [PMID: 37067418 PMCID: PMC10231195 DOI: 10.1128/aem.00096-23] [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: 01/19/2023] [Accepted: 04/03/2023] [Indexed: 04/18/2023] Open
Abstract
Many bacteria can become viable but nonculturable (VBNC) in response to stressors commonly identified in agrifood systems. Campylobacter is able to enter the VBNC state to evade unfavorable environmental conditions, but how food processing can induce Campylobacter jejuni to enter this state and the potential role of foods in inducing the VBNC state in C. jejuni remains largely unknown. In this study, the culturability and viability of C. jejuni cells were investigated under chlorine treatment (25 ppm), aerobic stress (atmospheric condition), and low-temperature (4°C) conditions that mimicked food processing. In addition, the behaviors of C. jejuni cells in ultrahigh-temperature (UHT) and pasteurized milk were also monitored during refrigerated storage. The numbers of viable and culturable C. jejuni cells in both the pure bacterial culture and food matrices were separately determined by propidium monoazide (PMA)-quantitative PCR (qPCR) and plating assay. The C. jejuni cells lost their culturability but partially retained their viability (1% to 10%) once mixed with chlorine. In comparison, ~10% of C. jejuni cells were induced to enter the VBNC state after 24 h and 20 days under aerobic and low-temperature conditions, respectively. The viability of the C. jejuni cells remained stable during the induction process in UHT (>10%) and pasteurized (>10%) milk. The number of culturable C. jejuni cells decreased quickly in pasteurized milk, but culturable cells could still be detected in the end (day 21). In contrast, the number of culturable C. jejuni cells slowly decreased, and they became undetectable after >42 days in UHT milk. The C. jejuni cells responded differently to various stress conditions and survived in high numbers in the VBNC state in agrifood systems. IMPORTANCE The VBNC state of pathogens can pose risks to food safety and public health because the pathogens cannot be detected using conventional microbiological culture-based methods but can resuscitate under favorable conditions to develop virulence. As a leading cause of human gastroenteritis worldwide, C. jejuni can enter the VBNC state to survive in the environment and food-processing chain with high prevalence. In this study, the effect of food-processing conditions and food products on the development of VBNC state in C. jejuni was investigated, providing a better understanding of the interaction between C. jejuni and the agroecosystem. The knowledge elicited from this study can aid in developing novel intervention strategies to reduce the food safety risks associated with this microbe.
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Affiliation(s)
- Jingbin Zhang
- Department of Food Science and Agricultural Chemistry, Faculty of Agricultural and Environmental Sciences, McGill University, Sainte-Anne-de-Bellevue, Quebec, Canada
| | - Xiaonan Lu
- Department of Food Science and Agricultural Chemistry, Faculty of Agricultural and Environmental Sciences, McGill University, Sainte-Anne-de-Bellevue, Quebec, Canada
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Prosdocimi EM, Arioli S, Mapelli F, Zeaiter Z, Fusi M, Daffonchio D, Borin S, Crotti E. Cell phenotype changes and oxidative stress response in Vibrio spp. induced into viable but non-culturable (VBNC) state. ANN MICROBIOL 2023. [DOI: 10.1186/s13213-022-01703-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Abstract
Purpose
Aquatic bacteria of the genus Vibrio include animal and human pathogens. The occurrence of Vibrio-related diseases has been associated with the current climate change-driven increase of sea surface temperature. Vibrio spp. can enter into the viable but non-culturable (VBNC) state, as a consequence of starvation in seawater at low temperatures. In such physiological state, Vibrio cells are no longer culturable on standard media agar plates but can resuscitate if incubated at 30 °C prior to plating, retaining virulence. Since limited information is available on regards to this topic, in this work, we characterized the phenotypic changes of four Vibrio spp. strains (one laboratory strain and three environmental isolates) in cold seawater microcosms, investigating the relationship between resuscitation and a hydrogen peroxide-induced oxidative stress.
Methods
Cell phenotypic changes and the effect of hydrogen peroxide and/or catalase addition to the medium were studied on VBNC and resuscitated cells by flow cytometry in microcosm experiments, paralleled by culturability experiments by plating.
Results
The cells of all the Vibrio strains changed their phenotype upon the induction of the VBNC state resulting in cell dwarfing and decrease in DNA quantity, losing the ability to grow on solid media. These features were partially or totally reverted when the cells were treated for resuscitation. Hydrogen peroxide at concentrations as low as 0.007 mM prevented resuscitation and a prolonged exposure to hydrogen peroxide at concentrations far under those inhibiting the growth of log-phase cells permanently damaged VBNC cells, which could not be resuscitated. However, the potential of culturability of VBNC cells could be preserved, at least for a part of the population, by plating the cells in the presence of catalase. The study also showed that during the resuscitation process, the cells gradually increased their resistance to hydrogen peroxide.
Conclusions
The timing and mode of induction of the VBNC state, as well as cell resuscitation and response to hydrogen peroxide, differed among Vibrio strains, indicating that induction and resuscitation from dormancy could vary in the context of species belonging to a single genus.
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García-Hernández J, Hernández M, Moreno Y. Combination of Direct Viable Count and Fluorescent In Situ Hybridization (DVC-FISH) as a Potential Method for Identifying Viable Vibrio parahaemolyticus in Oysters and Mussels. Foods 2021; 10:foods10071502. [PMID: 34209577 PMCID: PMC8303443 DOI: 10.3390/foods10071502] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2021] [Revised: 06/18/2021] [Accepted: 06/25/2021] [Indexed: 11/21/2022] Open
Abstract
Vibrio parahaemolyticus is a human food-borne pathogen with the ability to enter the food chain. It is able to acquire a viable, non-cultivable state (VBNC), which is not detected by traditional methods. The combination of the direct viable count method and a fluorescent in situ hybridization technique (DVC-FISH) makes it possible to detect microorganisms that can present VBNC forms in complex samples The optimization of the in vitro DVC-FISH technique for V. parahaemolyticus was carried out. The selected antibiotic was ciprofloxacin at a concentration of 0.75 μg/mL with an incubation time in DVC broth of 5 h. The DVC-FISH technique and the traditional plate culture were applied to detect and quantify the viable cells of the affected pathogen in artificially contaminated food matrices at different temperatures. The results obtained showed that low temperatures produced an important logarithmic decrease of V. parahaemolyticus, while at 22 °C, it proliferated rapidly. The DVC-FISH technique proved to be a useful tool for the detection and quantification of V. parahaemolyticus in the two seafood matrices of oysters and mussels. This is the first study in which this technique has been developed to detect viable cells for this microorganism.
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Affiliation(s)
- Jorge García-Hernández
- Advanced Center for Food Microbiology, Biotechnology Department, Universitat Politècnica de València, 46022 Valencia, Spain;
- Correspondence: ; Tel.: +34-658993099
| | - Manuel Hernández
- Advanced Center for Food Microbiology, Biotechnology Department, Universitat Politècnica de València, 46022 Valencia, Spain;
| | - Yolanda Moreno
- Research Institute of Water and Environmental Ingeneering (IIAMA), Universitat Politècnica de València, 46022 Valencia, Spain;
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A Possible Flow Cytometry-Based Viability and Vitality Assessment Protocol for Pathogenic Vibrio cholerae O1 and O139 Postexposure to Simulated Gastric Fluid. BIOMED RESEARCH INTERNATIONAL 2021; 2021:5551845. [PMID: 34212032 PMCID: PMC8208853 DOI: 10.1155/2021/5551845] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/08/2021] [Revised: 05/21/2021] [Accepted: 05/27/2021] [Indexed: 12/26/2022]
Abstract
During the intake of contaminated water, for diarrheal disease to occur, Vibrio cholerae must survive through the bactericidal digestive secretion of gastric fluid during passage through the stomach. Determining the viability of these bacteria is challenging, with the standard cultivation methods for viability being time-consuming and unable to culture cells that may still function accordingly. This study assessed the use of enzyme action and membrane integrity as alternatives for determining vitality and viability, respectively, in gastric acid-stressed pathogenic Vibrio cholerae O1 and O139, using fluorescent probes thiazole orange (TO) for viability based on membrane integrity, carboxyfluorescein diacetate (CFDA) with acetoxymethyl ester (AM) for vitality based on metabolic activity, and propidium iodide (PI) for cell death/damage due to loss of membrane integrity, with flow cytometry. Simulated gastric fluid-treated bacterial cells were labelled with blends of TO+PI and CFDA-AM+PI, and these stained cells were separated into heterologous populations based on their fluorescence signal. The gastric acid exposed cells presented with high green fluorescence signals after staining with the metabolic probe CFDA-AM, which indicated intact (live) cells due to being metabolically active, whereas when the same cells were stained with the DNA probe (TO), these appeared to be in a “stressed state” due to loss of membrane integrity. Damaged cells (dead cells) showed high red fluorescence levels after staining with PI probe. The use of flow cytometry with fluorescent probes is a favorable method for evaluating the vitality and viability of bacteria when cells are labelled with a combination of CFDA-AM+PI.
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Orruño M, Parada C, Kaberdin VR, Arana I. The Effect of Visible Light on Cell Envelope Subproteome during Vibrio harveyi Survival at 20 °C in Seawater. Microorganisms 2021; 9:microorganisms9030594. [PMID: 33805730 PMCID: PMC8001661 DOI: 10.3390/microorganisms9030594] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2021] [Revised: 03/10/2021] [Accepted: 03/11/2021] [Indexed: 11/16/2022] Open
Abstract
A number of Vibrio spp. belong to the well-studied model organisms used to understand the strategies developed by marine bacteria to cope with adverse conditions (starvation, suboptimal temperature, solar radiation, etc.) in their natural environments. Temperature and nutrient availability are considered to be the key factors that influence Vibrio harveyi physiology, morphology, and persistence in aquatic systems. In contrast to the well-studied effects of temperature and starvation on Vibrio survival, little is known about the impact of visible light able to cause photooxidative stress. Here we employ V. harveyi ATCC 14126T as a model organism to analyze and compare the survival patterns and changes in the protein composition of its cell envelope during the long-term permanence of this bacterium in seawater microcosm at 20 °C in the presence and absence of illumination with visible light. We found that V. harveyi exposure to visible light reduces cell culturability likely inducing the entry into the Viable but Non Culturable state (VBNC), whereas populations maintained in darkness remained culturable for at least 21 days. Despite these differences, the starved cells in both populations underwent morphological changes by reducing their size. Moreover, further proteomic analysis revealed a number of changes in the composition of cell envelope potentially accountable for the different adaptation pattern manifested in the absence and presence of visible light.
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Affiliation(s)
- Maite Orruño
- Department of Immunology, Microbiology and Parasitology, Faculty of Science and Technology, University of the Basque Country UPV/EHU, 48340 Leioa, Spain; (M.O.); (C.P.); (V.R.K.)
- Research Centre for Experimental Marine Biology and Biotechnology (PIE-UPV/EHU), 48620 Plentzia, Spain
| | - Claudia Parada
- Department of Immunology, Microbiology and Parasitology, Faculty of Science and Technology, University of the Basque Country UPV/EHU, 48340 Leioa, Spain; (M.O.); (C.P.); (V.R.K.)
| | - Vladimir R. Kaberdin
- Department of Immunology, Microbiology and Parasitology, Faculty of Science and Technology, University of the Basque Country UPV/EHU, 48340 Leioa, Spain; (M.O.); (C.P.); (V.R.K.)
- Research Centre for Experimental Marine Biology and Biotechnology (PIE-UPV/EHU), 48620 Plentzia, Spain
- IKERBASQUE, Basque Foundation for Science, 48013 Bilbao, Spain
| | - Inés Arana
- Department of Immunology, Microbiology and Parasitology, Faculty of Science and Technology, University of the Basque Country UPV/EHU, 48340 Leioa, Spain; (M.O.); (C.P.); (V.R.K.)
- Research Centre for Experimental Marine Biology and Biotechnology (PIE-UPV/EHU), 48620 Plentzia, Spain
- Correspondence:
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Yoon JH, Bae YM, Jo S, Moon SK, Oh SW, Lee SY. Optimization of resuscitation-promoting broths for the revival of Vibrio parahaemolyticus from a viable but nonculturable state. Food Sci Biotechnol 2021; 30:159-169. [PMID: 33552627 DOI: 10.1007/s10068-020-00843-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2020] [Revised: 08/19/2020] [Accepted: 10/23/2020] [Indexed: 12/19/2022] Open
Abstract
This study was conducted to examine the effect of formulated resuscitation-promoting broths on the revival of viable but nonculturable Vibrio parahaemolyticus induced by cold and starvation stresses. Vibrio parahaemolyticus was incubated in artificial sea water at 4 °C for more than 8 months until this bacterium became undetectable, while retaining its intact cell count of more than 105 CFU/field over time. On day 250, V. parahaemolyticus was collected and enriched in tryptic soy broth supplemented with 3% NaCl, 10,000 U/mg catalase, 2% sodium pyruvate, 20 mM MgSO4, 5 mM EDTA, and a cell-free supernatant taken from V. parahaemolyticus ATCC 17802 in the stationary phase (pH 8). V. parahaemolyticus returned partially to a culturable state with a maximal cell density of 7.91 log CFU/mL in this formulated medium following 7 days of enrichment at 25 °C. In contrast, no V. parahaemolyticus was resuscitated when enriched in alkaline peptone water and tryptic soy broth.
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Affiliation(s)
- Jae-Hyun Yoon
- Department of Food and Nutrition, Chung-Ang University, 4726, Seodong-daero, Anseong-si, Gyeonggi-do Republic of Korea
| | - Young-Min Bae
- Department of Food and Nutrition, Chung-Ang University, 4726, Seodong-daero, Anseong-si, Gyeonggi-do Republic of Korea
| | - Suyoung Jo
- Department of Food and Nutrition, Chung-Ang University, 4726, Seodong-daero, Anseong-si, Gyeonggi-do Republic of Korea
| | - Sung-Kwon Moon
- Department of Food and Nutrition, Chung-Ang University, 4726, Seodong-daero, Anseong-si, Gyeonggi-do Republic of Korea
| | - Se-Wook Oh
- Department of Food and Nutrition, Kookmin University, 77, Jeongneung-ro, Seongbuk-gu, Seoul, Republic of Korea
| | - Sun-Young Lee
- Department of Food and Nutrition, Chung-Ang University, 4726, Seodong-daero, Anseong-si, Gyeonggi-do Republic of Korea
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Wasfi R, Abdellatif GR, Elshishtawy HM, Ashour HM. First-time characterization of viable but non-culturable Proteus mirabilis: Induction and resuscitation. J Cell Mol Med 2020; 24:2791-2801. [PMID: 32030883 PMCID: PMC7077546 DOI: 10.1111/jcmm.15031] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2019] [Revised: 11/12/2019] [Accepted: 12/22/2019] [Indexed: 12/11/2022] Open
Abstract
Pathogenic bacteria can enter into a viable but non‐culturable (VBNC) state under unfavourable conditions. Proteus mirabilis is responsible for dire clinical consequences including septicaemia, urinary tract infections and pneumonia, but is not a species previously known to enter VBNC state. We suggested that stress‐induced P. mirabilis can enter a VBNC state in which it retains virulence. P. mirabilis isolates were incubated in extreme osmotic pressure, starvation, low temperature and low pH to induce a VBNC state. Resuscitation was induced by temperature upshift and inoculation in tryptone soy broth with Tween 20 and brain heart infusion broth. Cellular ultrastructure and gene expression were examined using transmission electron microscopy (TEM) and quantitative real‐time polymerase chain reaction (qPCR), respectively. High osmotic pressure and low acidity caused rapid entry into VBNC state. Temperature upshift caused the highest percentage of resuscitation (93%) under different induction conditions. In the VBNC state, cells showed aberrant and dwarf morphology, virulence genes and stress response genes (envZ and rpoS) were expressed (levels varied depending on strain and inducing factors). This is the first‐time characterization of VBNC P. mirabilis. The ability of P. mirabilis pathogenic strains to enter a stress‐induced VBNC state can be a serious public health threat.
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Affiliation(s)
- Reham Wasfi
- Department of Microbiology and Immunology, Faculty of Pharmacy, October University for Modern Sciences and Arts (MSA), Giza, Egypt
| | - Ghada Refaat Abdellatif
- Department of Microbiology and Immunology, Faculty of Pharmacy, Ahram Canadian University (ACU), Giza, Egypt
| | - Hisham Mohamed Elshishtawy
- Microbial Genetics Laboratory, Agricultural Genetic Engineering Research Institute (AGERI), Agricultural Research Center (ARC), Giza, Egypt
| | - Hossam M Ashour
- Department of Biological Sciences, College of Arts and Sciences, University of South Florida St. Petersburg, St. Petersburg, Florida.,Department of Microbiology and Immunology, Faculty of Pharmacy, Cairo University, Cairo, Egypt
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Battistelli M, Falcieri E. Apoptotic Bodies: Particular Extracellular Vesicles Involved in Intercellular Communication. BIOLOGY 2020; 9:E21. [PMID: 31968627 PMCID: PMC7168913 DOI: 10.3390/biology9010021] [Citation(s) in RCA: 220] [Impact Index Per Article: 55.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/05/2019] [Revised: 01/09/2020] [Accepted: 01/12/2020] [Indexed: 12/20/2022]
Abstract
In the last decade, a new method of cell-cell communication mediated by membranous extracellular vesicles (EVs) has emerged. EVs, including exosomes, microvesicles, and apoptotic bodies (ApoBDs), represent a new and important topic, because they are a means of communication between cells and they can also be involved in removing cellular contents. EVs are characterized by differences in size, origin, and content and different types have different functions. They appear as membranous sacs released by a variety of cells, in different physiological and patho-physiological conditions. Intringuingly, exosomes and microvesicles are a potent source of genetic information carriers between different cell types both within a species and even across a species barrier. New, and therefore still relatively poorly known vesicles are apoptotic bodies, on which numerous in-depth studies are needed in order to understand their role and possible function. In this review we would like to analyze their morpho-functional characteristics.
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Affiliation(s)
- Michela Battistelli
- Department of Biomolecular Sciences (DiSB), Urbino University Carlo Bo, 61029 Urbino (PU), Italy;
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10
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Yoon JH, Lee SY. Characteristics of viable-but-nonculturable Vibrio parahaemolyticus induced by nutrient-deficiency at cold temperature. Crit Rev Food Sci Nutr 2019; 60:1302-1320. [DOI: 10.1080/10408398.2019.1570076] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Affiliation(s)
- Jae-Hyun Yoon
- Department of Food and Nutrition, Chung-Ang University, Anseong-si, Gyeonggi-do, Republic of Korea
| | - Sun-Young Lee
- Department of Food and Nutrition, Chung-Ang University, Anseong-si, Gyeonggi-do, Republic of Korea
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Schrammel B, Cervero-Aragó S, Dietersdorfer E, Walochnik J, Lück C, Sommer R, Kirschner A. Differential development of Legionella sub-populations during short- and long-term starvation. WATER RESEARCH 2018; 141:417-427. [PMID: 29685632 DOI: 10.1016/j.watres.2018.04.027] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/05/2017] [Revised: 04/10/2018] [Accepted: 04/10/2018] [Indexed: 06/08/2023]
Abstract
Legionellae are among the most important waterborne pathogens in industrialized countries. Monitoring and surveillance of Legionella in engineered water systems is usually performed with culture-based methods. Since the advent of culture-independent techniques, it has become clear that Legionella concentrations are often several orders of magnitude higher than those measured by culture-based techniques and that a variable proportion of these non-culturable cells are viable. In engineered water systems, the formation of these viable but non-culturable (VBNC) cells can be caused by different kinds of stress, such as, and most importantly, nutrient starvation, oxidative stress and heat. In this study, the formation of VBNC cells of six Legionella strains under conditions of starvation was monitored in mono-species microcosms for up to one year using a combination of different viability indicators. Depending on the strain, complete loss of culturability was observed from 11 days to 8 weeks. During the starvation process, three distinct phases and different sub-populations of VBNC cells were identified. Until complete loss of culturability, the number of membrane-intact cells decreased rapidly to 5.5-69% of the initial cell concentration. The concentration of the sub-population with low esterase activity dropped to 0.03-55%, and the concentration of the highly esterase-active sub-population dropped to 0.01-1.2% of the initial concentration; these sub-populations remained stable for several weeks to months. Only after approximately 200 days of starvation, the number of VBNC cells started to decrease below detection limits. The most abundant VBNC sub-populations were characterized by partially damaged membranes and low esterase-activity. With this study, we showed that upon starvation, a stable VBNC Legionella community may be present over several months in a strain-dependent manner even under harsh conditions. Even after one year of starvation, a small proportion of L. pneumophila cells with high esterase-activity was detected. We speculate that this highly active VBNC subpopulation is able to infect amoebae and human macrophages.
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Affiliation(s)
- Barbara Schrammel
- Institute for Hygiene and Applied Immunology, Water Hygiene, Center for Pathophysiology, Infectiology and Immunology, Medical University of Vienna, Austria
| | - Sílvia Cervero-Aragó
- Institute for Hygiene and Applied Immunology, Water Hygiene, Center for Pathophysiology, Infectiology and Immunology, Medical University of Vienna, Austria; Interuniversity Cooperation Centre for Water and Health, Austria
| | - Elisabeth Dietersdorfer
- Institute for Specific Prophylaxis and Tropical Medicine, Center for Pathophysiology, Infectiology and Immunology, Medical University of Vienna, Austria
| | - Julia Walochnik
- Institute for Specific Prophylaxis and Tropical Medicine, Center for Pathophysiology, Infectiology and Immunology, Medical University of Vienna, Austria
| | - Christian Lück
- Institute for Medical Microbiology and Hygiene, Medical Faculty "Carl Gustav Carus", Technical University Dresden, Germany
| | - Regina Sommer
- Institute for Hygiene and Applied Immunology, Water Hygiene, Center for Pathophysiology, Infectiology and Immunology, Medical University of Vienna, Austria; Interuniversity Cooperation Centre for Water and Health, Austria
| | - Alexander Kirschner
- Institute for Hygiene and Applied Immunology, Water Hygiene, Center for Pathophysiology, Infectiology and Immunology, Medical University of Vienna, Austria; Interuniversity Cooperation Centre for Water and Health, Austria.
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12
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Schrammel B, Petzold M, Cervero-Aragó S, Sommer R, Lück C, Kirschner A. Persistent presence of outer membrane epitopes during short- and long-term starvation of five Legionella pneumophila strains. BMC Microbiol 2018; 18:75. [PMID: 30016940 PMCID: PMC6050704 DOI: 10.1186/s12866-018-1220-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2018] [Accepted: 06/29/2018] [Indexed: 11/25/2022] Open
Abstract
Background Legionella pneumophila, the causative agent of Legionnaire’s disease, may enter a viable but non-culturable (VBNC) state triggered by environmental stress conditions. Specific outer-membrane epitopes of L. pneumophila are used in many diagnostic applications and some of them are linked to important virulence-related factors or endotoxins. However, it is not clear how the presence and status of these epitopes are influenced by environmental stress conditions. In this study, changes of outer membrane epitopes for monoclonal antibodies (mAb) from the Dresden panel and the major outer membrane protein MOMP were analysed for five L. pneumophila strains during short- and long-term starvation in ultrapure water. Results With ELISA and single cell immuno-fluorescence analysis, we could show that for most of the investigated mAb-strain combinations the total number of mAb-stained Legionella cells stayed constant for up to 400 days. Especially the epitopes of mAb 3/1, 8/5, 26/1 and 20/1, which are specific for L. pneumophila serogroup 1 subtypes, and the mAb 9/1, specific for serogroup 6, showed long-term persistence. For most mAb- stained cells, a high percentage of viable cells was observed at least until 118 days of starvation. At the same time, we observed a reduction of the fluorescence intensity of the stained cells during starvation indicating a loss of epitopes from the cell surface. However, most of the epitopes, including the virulence-associated mAb 3/1 epitope were still present with high fluorescence intensity after 400 days of starvation in up to 50% of the starved L. pneumophila population. Conclusions The results demonstrate the continuous presence of outer membrane epitopes of L. pneumophila during short-term and long-term starvation. Thus, culture-independent mAb-based diagnostic and detection tools, such as immuno-magnetic separation and microarray techniques are applicable for both L. pneumophila in the culturable and the VBNC state even after long-term starvation but nevertheless require careful testing before application. However, the mere presence of those epitopes is not necessarily an indication of viability or infectivity. Electronic supplementary material The online version of this article (10.1186/s12866-018-1220-x) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Barbara Schrammel
- Institute for Hygiene and Applied Immunology - Water Hygiene, Center for Pathophysiology, Infectiology and Immunology, Medical University of Vienna, Kinderspitalgasse 15, A-1090, Vienna, Austria
| | - Markus Petzold
- Institute for Medical Microbiology and Hygiene, Medical Faculty "Carl Gustav Carus", University of Technology Dresden, Dresden, Germany
| | - Sílvia Cervero-Aragó
- Institute for Hygiene and Applied Immunology - Water Hygiene, Center for Pathophysiology, Infectiology and Immunology, Medical University of Vienna, Kinderspitalgasse 15, A-1090, Vienna, Austria.,Interuniversity Cooperation Centre for Water and Health, Vienna, Austria
| | - Regina Sommer
- Institute for Hygiene and Applied Immunology - Water Hygiene, Center for Pathophysiology, Infectiology and Immunology, Medical University of Vienna, Kinderspitalgasse 15, A-1090, Vienna, Austria.,Interuniversity Cooperation Centre for Water and Health, Vienna, Austria
| | - Christian Lück
- Institute for Medical Microbiology and Hygiene, Medical Faculty "Carl Gustav Carus", University of Technology Dresden, Dresden, Germany
| | - Alexander Kirschner
- Institute for Hygiene and Applied Immunology - Water Hygiene, Center for Pathophysiology, Infectiology and Immunology, Medical University of Vienna, Kinderspitalgasse 15, A-1090, Vienna, Austria. .,Interuniversity Cooperation Centre for Water and Health, Vienna, Austria.
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13
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Ciacci C, Manti A, Canonico B, Campana R, Camisassi G, Baffone W, Canesi L. Responses of Mytilus galloprovincialis hemocytes to environmental strains of Vibrio parahaemolyticus, Vibrio alginolyticus, Vibrio vulnificus. FISH & SHELLFISH IMMUNOLOGY 2017; 65:80-87. [PMID: 28390964 DOI: 10.1016/j.fsi.2017.04.002] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/01/2017] [Revised: 03/28/2017] [Accepted: 04/04/2017] [Indexed: 06/07/2023]
Abstract
Marine bivalves are exposed to different types of bacteria in the surrounding waters, in particular of the Vibrio genus. In the hemocytes of the mussel Mytilus spp. immune responses to different vibrios have been largely characterized. However, little information is available on the hemocyte responses to human pathogenic vibrios commonly detected in coastal waters and bivalve tissues that are involved in seafood-borne diseases. In this work, functional parameters of the hemocytes from the Mediterranean mussel M. galloprovincialis were evaluated in response to in vitro challenge with different vibrios isolated from environmental samples of the Adriatic sea (Italy): V. parahaemolyticus Conero, V. alginolyticus 1513 and V. vulnificus 509. V. parahaemolyticus ATCC 43996 was used for comparison. At the 50:1 bacteria hemocyte ratio, only V. parahaemolyticus strains induced significant lysosomal membrane destabilisation. Stimulation of extracellular lysozyme release, total ROS, O2- and NO production were observed, although to different extents and with distinct time courses for different vibrios, V. vulnificus 509 in particular. Further comparisons between V. parahaemolyticus Conero and V. vulnificus 509 showed that only the latter induced dysregulation of the phosphorylation state of p38 MAP Kinase and apoptotic processes. The results indicate that mussel hemocytes can mount an efficient immune response towards V. parahaemolyticus and V. alginolyticus strains, whereas V. vulnificus 509 may affect the hemocyte function. This is the first report on immune responses of mussels to local environmental isolates of human pathogenic vibrios. These data reinforce the hypothesis that Mytilus hemocytes show specific responses to different vibrio species and strains.
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Affiliation(s)
- C Ciacci
- Department of Biomolecular Science (DISB), University of Urbino "Carlo Bo", Urbino, Italy
| | - A Manti
- Department of Biomolecular Science (DISB), University of Urbino "Carlo Bo", Urbino, Italy
| | - B Canonico
- Department of Biomolecular Science (DISB), University of Urbino "Carlo Bo", Urbino, Italy
| | - R Campana
- Department of Biomolecular Science (DISB), University of Urbino "Carlo Bo", Urbino, Italy
| | - G Camisassi
- Department of Earth, Environment and Life Sciences (DISTAV), University of Genova, Italy
| | - W Baffone
- Department of Biomolecular Science (DISB), University of Urbino "Carlo Bo", Urbino, Italy
| | - L Canesi
- Department of Earth, Environment and Life Sciences (DISTAV), University of Genova, Italy.
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14
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Orruño M, Kaberdin VR, Arana I. Survival strategies of Escherichia coli and Vibrio spp.: contribution of the viable but nonculturable phenotype to their stress-resistance and persistence in adverse environments. World J Microbiol Biotechnol 2017; 33:45. [PMID: 28161849 DOI: 10.1007/s11274-017-2218-5] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2016] [Accepted: 01/23/2017] [Indexed: 12/11/2022]
Abstract
In their natural ecosystems, bacteria are continuously exposed to changing environmental factors including physicochemical parameters (e.g. temperature, pH, etc.), availability of nutrients as well as interaction(s) with other organisms. To increase their tolerance and survival under adverse conditions, bacteria trigger a number of adaptation mechanisms. One of the well-known adaptation responses of the non-spore-forming bacteria is the acquisition of the viable but non-culturable (VBNC) state. This phenotype is induced by different stress factors (e.g. low temperature) and is characterized by the temporal loss of culturability, which can potentially be restored. Moreover, this response can be combined with the bust and boom strategy, which implies the death of the main population of the stressed cells (or their entry into the VBNC state) upon stress, thus enabling the remaining cells (i.e. residual culturable population) to subsist at the expense of the dead or/and VBNC cells. In this review, we discuss the characteristics of the VBNC state, its biological significance and contribution to bacterial survival.
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Affiliation(s)
- M Orruño
- Department of Immunology, Microbiology and Parasitology, University of the Basque Country (UPV/EHU), Barrio Sarriena S/n, 48940, Leioa, Spain
| | - V R Kaberdin
- Department of Immunology, Microbiology and Parasitology, University of the Basque Country (UPV/EHU), Barrio Sarriena S/n, 48940, Leioa, Spain.,IKERBASQUE, Basque Foundation for Science, María Díaz de Haro 3, 48013, Bilbao, Spain
| | - I Arana
- Department of Immunology, Microbiology and Parasitology, University of the Basque Country (UPV/EHU), Barrio Sarriena S/n, 48940, Leioa, Spain.
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15
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Elhadidy AM, Van Dyke MI, Peldszus S, Huck PM. Application of flow cytometry to monitor assimilable organic carbon (AOC) and microbial community changes in water. J Microbiol Methods 2016; 130:154-163. [DOI: 10.1016/j.mimet.2016.09.009] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2016] [Revised: 09/12/2016] [Accepted: 09/12/2016] [Indexed: 01/30/2023]
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16
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Parada C, Orruño M, Kaberdin V, Bravo Z, Barcina I, Arana I. Changes in the Vibrio harveyi Cell Envelope Subproteome During Permanence in Cold Seawater. MICROBIAL ECOLOGY 2016; 72:549-558. [PMID: 27324654 DOI: 10.1007/s00248-016-0802-0] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/15/2015] [Accepted: 06/13/2016] [Indexed: 06/06/2023]
Abstract
Previous work demonstrated that physiological, morphological, and gene expression changes as well as the time-dependent entry into the viable but not culturable (VBNC) state are used by Vibrio species to survive and cope with diverse stress conditions including seasonal temperature downshifts and starvation. To learn more about the nature and specific contribution of membrane proteins to cell adaptation and survival, we analyzed variations in the protein composition of cell envelope and related them to morphological and physiological changes that were taking place during the long-term permanence of Vibrio harveyi in seawater microcosm at 4 °C. We found that after 21 days of permanence, nearly all population (ca. 99 %) of V. harveyi acquired the VBNC phenotype. Although the size of V. harveyi cells gradually decreased during the incubation time, we found that this morphological change was not directly related to their entry into the VBNC state. Our proteomic study revealed that the level of membrane proteins playing key roles in cellular transport, maintenance of cell structure, and in bioenergetics processes remained unchanged along starvation at low temperature, thus suggesting that V. harveyi might need these proteins for the long-term survival and/or for the resuscitation process. On a contrary, the level of two proteins, elongation factor Tu (EF-TU) and bacterioferritin, greatly increased reaching the maximal values by the end of the incubation period. We further discuss the above data with respect to the putative roles likely exerted by membrane proteins during transition to and maintaining of the VBNC state.
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Affiliation(s)
- Claudia Parada
- Department of Immunology, Microbiology and Parasitology, Faculty of Science and Technology, University of Basque Country (UPV/EHU), Bilbao, Spain
| | - Maite Orruño
- Department of Immunology, Microbiology and Parasitology, Faculty of Pharmacy, University of Basque Country (UPV/EHU), Bilbao, Spain
| | - Vladimir Kaberdin
- Department of Immunology, Microbiology and Parasitology, Faculty of Science and Technology, University of Basque Country (UPV/EHU), Bilbao, Spain
- Department of Immunology, Microbiology and Parasitology, IKERBASQUE, Basque Foundation for Science, Bilbao, Spain
| | - Zaloa Bravo
- Department of Immunology, Microbiology and Parasitology, Faculty of Science and Technology, University of Basque Country (UPV/EHU), Bilbao, Spain
| | - Isabel Barcina
- Department of Immunology, Microbiology and Parasitology, Faculty of Science and Technology, University of Basque Country (UPV/EHU), Bilbao, Spain
| | - Inés Arana
- Department of Immunology, Microbiology and Parasitology, Faculty of Science and Technology, University of Basque Country (UPV/EHU), Bilbao, Spain.
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17
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Pienaar JA, Singh A, Barnard TG. The viable but non-culturable state in pathogenic Escherichia coli: A general review. Afr J Lab Med 2016; 5:368. [PMID: 28879110 PMCID: PMC5436400 DOI: 10.4102/ajlm.v5i1.368] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2015] [Accepted: 01/14/2016] [Indexed: 12/12/2022] Open
Abstract
Background The persistence and pathogenicity of pathogenic bacteria are dependent on the ability of the species to survive in adverse conditions. During the infectious process, the organism may need to pass through certain hostile anatomical sites, such as the stomach. Under various environmental stresses, many bacteria enter into the viable but non-culturable (VBNC) state, where they are ‘alive’ or metabolically active, but will not grow on conventional media. Escherichia coli bacteria encounter several diverse stress factors during their growth, survival and infection and thus may enter into the VBNC state. Objectives This review discusses various general aspects of the VBNC state, the mechanisms and possible public health impact of indicator and pathogenic E. coli entering into the VBNC state. Method A literature review was conducted to ascertain the possible impact of E. coli entering into the VBNC state. Results Escherichia coli enter into the VBNC state by means of several induction mechanisms. Various authors have found that E. coli can be resuscitated post-VBNC. Certain strains of pathogenic E. coli are still able to produce toxins in the VBNC state, whilst others are avirulent during the VBNC state but are able to regain virulence after resuscitation. Conclusion Pathogenic and indicator E. coli entering into the VBNC state could have an adverse effect on public health if conventional detection methods are used, where the number of viable cells could be underestimated and the VBNC cells still produce toxins or could, at any time, be resuscitated and become virulent again.
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Affiliation(s)
- Jennifer A Pienaar
- Faculty of Health Sciences, Department of Biomedical Technology, University of Johannesburg, Johannesburg, South Africa.,Water and Health Research Centre, Faculty of Health Sciences, University of Johannesburg, Johannesburg, South Africa
| | - Atheesha Singh
- Water and Health Research Centre, Faculty of Health Sciences, University of Johannesburg, Johannesburg, South Africa
| | - Tobias G Barnard
- Water and Health Research Centre, Faculty of Health Sciences, University of Johannesburg, Johannesburg, South Africa
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18
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Helmi K, Barthod F, Méheut G, Henry A, Poty F, Laurent F, Charni-Ben-Tabassi N. Methods for microbiological quality assessment in drinking water: a comparative study. JOURNAL OF WATER AND HEALTH 2015; 13:34-41. [PMID: 25719463 DOI: 10.2166/wh.2014.056] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
The present study aimed to compare several methods for quantifying and discriminating between the different physiological states of a bacterial population present in drinking water. Flow cytometry (FCM), solid-phase cytometry (SPC), epifluorescence microscopy (MSP) and culture method performances were assessed by comparing the results obtained for different water samples. These samples, including chlorinated and non-chlorinated water, were collected in a drinking water treatment plant. Total bacteria were quantified by using SYBR Green II (for FCM) and 4',6'-diamino-2-phenylindole (DAPI) (for MSP), viable and non-viable bacteria were distinguished by using SYBR Green II and propidium iodide dual staining (for FCM), and active cells were distinguished by using CTC (for MSP) and Chemchrome V6 (for FCM and SPC). In our conditions, counts using microscopy and FCM were significantly correlated regarding total bacteria and active cells. Conversely, counts were not significantly similar using solid-phase and FCM for active bacteria. Moreover, the R2A medium showed that bacterial culturability could be recovered after chlorination. This study highlights that FCM appears to be a useful and powerful technique for drinking water production monitoring.
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Affiliation(s)
- K Helmi
- Veolia Environnement Recherche et Innovation, Immeuble le Dufy, 1 Place de Turenne, 94417 St Maurice Cedex, France E-mail:
| | - F Barthod
- Veolia Environnement Recherche et Innovation, Immeuble le Dufy, 1 Place de Turenne, 94417 St Maurice Cedex, France E-mail:
| | - G Méheut
- Veolia Environnement Recherche et Innovation, Immeuble le Dufy, 1 Place de Turenne, 94417 St Maurice Cedex, France E-mail:
| | - A Henry
- Veolia Environnement Recherche et Innovation, Immeuble le Dufy, 1 Place de Turenne, 94417 St Maurice Cedex, France E-mail:
| | - F Poty
- Veolia Environnement Recherche et Innovation, Immeuble le Dufy, 1 Place de Turenne, 94417 St Maurice Cedex, France E-mail:
| | - F Laurent
- Veolia Environnement Recherche et Innovation, Immeuble le Dufy, 1 Place de Turenne, 94417 St Maurice Cedex, France E-mail:
| | - N Charni-Ben-Tabassi
- Veolia Environnement Recherche et Innovation, Immeuble le Dufy, 1 Place de Turenne, 94417 St Maurice Cedex, France E-mail:
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Zeng J, Wei H, Zhang L, Liu X, Zhang H, Cheng J, Ma D, Zhang X, Fu P, Liu L. Rapid detection of Vibrio parahaemolyticus in raw oysters using immunomagnetic separation combined with loop-mediated isothermal amplification. Int J Food Microbiol 2014; 174:123-8. [DOI: 10.1016/j.ijfoodmicro.2014.01.004] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2013] [Revised: 11/16/2013] [Accepted: 01/04/2014] [Indexed: 10/25/2022]
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20
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Aoyagi H, Kuroda A. Effects of low-shear modeled microgravity on a microbial community filtered through a 0.2-μm filter and its potential application in screening for novel microorganisms. J Biosci Bioeng 2012; 114:73-9. [PMID: 22571963 DOI: 10.1016/j.jbiosc.2012.02.021] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2011] [Revised: 02/21/2012] [Accepted: 02/22/2012] [Indexed: 11/24/2022]
Abstract
The effects of low-shear modeled microgravity (LSMMG) on a microbial community filtered through a 0.2-μm filter were investigated, and the potential application of LSMMG in the screening of microorganisms was evaluated. Pond water was passed through a 0.2-μm filter and the filtrate inoculated into two kinds of media (Schneider's insect medium, and ten-times-diluted Schneider's insect [0.1-Sch] medium). The cultures were incubated under LSMMG and normal-gravity and the microbial cell growth rates compared. Cell growth rates, final cell concentrations, and substrate consumption rates were higher in the LSMMG culture than in the normal-gravity culture. The microbial communities obtained under the various culture conditions were subjected to denaturing gradient gel electrophoresis (DGGE), revealing three different groups of microorganisms: (i) microorganisms whose growth rates were increased by LSMMG; (ii) microorganisms whose growth rates were suppressed or inhibited by LSMMG; and (iii) microorganisms whose growth rates were not affected by LSMMG. Sequence analysis of the microorganisms whose growth rates were increased by LSMMG showed that some had high similarity with unculturable microorganisms. When these microorganisms that displayed similarity with unculturable microorganisms were cultivated on agar plates, some of the DGGE bands present in the LSMMG culture were also present. We show that it is possible to isolate and cultivate uncultured microorganisms by using combinations of LSMMG, normal-gravity, and agar plate culturing techniques.
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Affiliation(s)
- Hideki Aoyagi
- Faculty of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Ibaraki 305-8572, Japan.
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21
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Montañez-Izquierdo VY, Salas-Vázquez DI, Rodríguez-Jerez JJ. Use of epifluorescence microscopy to assess the effectiveness of phage P100 in controlling Listeria monocytogenes biofilms on stainless steel surfaces. Food Control 2012. [DOI: 10.1016/j.foodcont.2011.08.016] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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22
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Ramseier MK, von Gunten U, Freihofer P, Hammes F. Kinetics of membrane damage to high (HNA) and low (LNA) nucleic acid bacterial clusters in drinking water by ozone, chlorine, chlorine dioxide, monochloramine, ferrate(VI), and permanganate. WATER RESEARCH 2011; 45:1490-500. [PMID: 21146846 DOI: 10.1016/j.watres.2010.11.016] [Citation(s) in RCA: 123] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/08/2010] [Revised: 11/08/2010] [Accepted: 11/10/2010] [Indexed: 05/21/2023]
Abstract
Drinking water was treated with ozone, chlorine, chlorine dioxide, monochloramine, ferrate(VI), and permanganate to investigate the kinetics of membrane damage of native drinking water bacterial cells. Membrane damage was measured by flow cytometry using a combination of SYBR Green I and propidium iodide (SGI+PI) staining as indicator for cells with permeabilized membranes and SGI alone to measure total cell concentration. SGI+PI staining revealed that the cells were permeabilized upon relatively low oxidant exposures of all tested oxidants without a detectable lag phase. However, only ozonation resulted in a decrease of the total cell concentrations for the investigated reaction times. Rate constants for the membrane damage reaction varied over seven orders of magnitude in the following order: ozone > chlorine > chlorine dioxide ≈ ferrate > permanganate > chloramine. The rate constants were compared to literature data and were in general smaller than previously measured rate constants. This confirmed that membrane integrity is a conservative and therefore safe parameter for disinfection control. Interestingly, the cell membranes of high nucleic acid (HNA) content bacteria were damaged much faster than those of low nucleic acid (LNA) content bacteria during treatment with chlorine dioxide and permanganate. However, only small differences were observed during treatment with chlorine and chloramine, and no difference was observed for ferrate treatment. Based on the different reactivity of these oxidants it was suggested that HNA and LNA bacterial cell membranes have a different chemical constitution.
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Affiliation(s)
- Maaike K Ramseier
- Eawag, Swiss Federal Institute of Aquatic Science and Technology, Ueberlandstrasse 133, CH-8600 Duebendorf, Switzerland
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Hammes F, Egli T. Cytometric methods for measuring bacteria in water: advantages, pitfalls and applications. Anal Bioanal Chem 2010; 397:1083-95. [DOI: 10.1007/s00216-010-3646-3] [Citation(s) in RCA: 128] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2010] [Revised: 03/05/2010] [Accepted: 03/08/2010] [Indexed: 11/30/2022]
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24
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Tracy BP, Gaida SM, Papoutsakis ET. Flow cytometry for bacteria: enabling metabolic engineering, synthetic biology and the elucidation of complex phenotypes. Curr Opin Biotechnol 2010; 21:85-99. [DOI: 10.1016/j.copbio.2010.02.006] [Citation(s) in RCA: 125] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2009] [Revised: 01/29/2010] [Accepted: 02/02/2010] [Indexed: 02/01/2023]
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