1
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Cantlay S, Garrison NL, Patterson R, Wagner K, Kirk Z, Fan J, Primerano DA, Sullivan MLG, Franks JM, Stolz DB, Horzempa J. Phenotypic and transcriptional characterization of F. tularensis LVS during transition into a viable but non-culturable state. Front Microbiol 2024; 15:1347488. [PMID: 38380104 PMCID: PMC10877056 DOI: 10.3389/fmicb.2024.1347488] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2023] [Accepted: 01/15/2024] [Indexed: 02/22/2024] Open
Abstract
Francisella tularensis is a gram-negative, intracellular pathogen which can cause serious, potentially fatal, illness in humans. Species of F. tularensis are found across the Northern Hemisphere and can infect a broad range of host species, including humans. Factors affecting the persistence of F. tularensis in the environment and its epidemiology are not well understood, however, the ability of F. tularensis to enter a viable but non-culturable state (VBNC) may be important. A broad range of bacteria, including many pathogens, have been observed to enter the VBNC state in response to stressful environmental conditions, such as nutrient limitation, osmotic or oxidative stress or low temperature. To investigate the transition into the VBNC state for F. tularensis, we analyzed the attenuated live vaccine strain, F. tularensis LVS grown under standard laboratory conditions. We found that F. tularensis LVS rapidly and spontaneously enters a VBNC state in broth culture at 37°C and that this transition coincides with morphological differentiation of the cells. The VBNC bacteria retained an ability to interact with both murine macrophages and human erythrocytes in in vitro assays and were insensitive to treatment with gentamicin. Finally, we present the first transcriptomic analysis of VBNC F. tularensis, which revealed clear differences in gene expression, and we identify sets of differentially regulated genes which are specific to the VBNC state. Identification of these VBNC specific genes will pave the way for future research aimed at dissecting the molecular mechanisms driving entry into the VBNC state.
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Affiliation(s)
- Stuart Cantlay
- Department of Biomedical Sciences, West Liberty University, West Liberty, WV, United States
| | - Nicole L. Garrison
- Department of Biomedical Sciences, West Liberty University, West Liberty, WV, United States
| | - Rachelle Patterson
- Department of Biomedical Sciences, West Liberty University, West Liberty, WV, United States
| | - Kassey Wagner
- Department of Biomedical Sciences, West Liberty University, West Liberty, WV, United States
| | - Zoei Kirk
- Department of Biomedical Sciences, West Liberty University, West Liberty, WV, United States
| | - Jun Fan
- Department of Biomedical Sciences, Joan C. Edwards School of Medicine, Marshall University, Huntington, WV, United States
| | - Donald A. Primerano
- Department of Biomedical Sciences, Joan C. Edwards School of Medicine, Marshall University, Huntington, WV, United States
| | - Mara L. G. Sullivan
- Department of Cell Biology, Center for Biologic Imaging, University of Pittsburgh, Pittsburgh, PA, United States
| | - Jonathan M. Franks
- Department of Cell Biology, Center for Biologic Imaging, University of Pittsburgh, Pittsburgh, PA, United States
| | - Donna B. Stolz
- Department of Cell Biology, Center for Biologic Imaging, University of Pittsburgh, Pittsburgh, PA, United States
| | - Joseph Horzempa
- Department of Biomedical Sciences, West Liberty University, West Liberty, WV, United States
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2
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Ralstonia solanacearum Facing Spread-Determining Climatic Temperatures, Sustained Starvation, and Naturally Induced Resuscitation of Viable but Non-Culturable Cells in Environmental Water. Microorganisms 2022; 10:microorganisms10122503. [PMID: 36557756 PMCID: PMC9784099 DOI: 10.3390/microorganisms10122503] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2022] [Revised: 12/06/2022] [Accepted: 12/12/2022] [Indexed: 12/23/2022] Open
Abstract
Ralstonia solanacearum is a bacterial phytopathogen affecting staple crops, originally from tropical and subtropical areas, whose ability to survive in temperate environments is of concern under global warming. In this study, two R. solanacearum strains from either cold or warm habitats were stressed by simultaneous exposure to natural oligotrophy at low (4 °C), temperate (14 °C), or warm (24 °C) temperatures in environmental water. At 4 °C, the effect of temperature was higher than that of oligotrophy, since R. solanacearum went into a viable but non-culturable (VBNC) state, which proved to be dependent on water nutrient contents. Resuscitation was demonstrated in vitro and in planta. At 14 °C and 24 °C, the effect of oligotrophy was higher than that of temperature on R. solanacearum populations, displaying starvation-survival responses and morphological changes which were stronger at 24 °C. In tomato plants, starved, cold-induced VBNC, and/or resuscitated cells maintained virulence. The strains behaved similarly regardless of their cold or warm areas of origin. This work firstly describes the natural nutrient availability of environmental water favoring R. solanacearum survival, adaptations, and resuscitation in conditions that can be found in natural settings. These findings will contribute to anticipate the ability of R. solanacearum to spread, establish, and induce disease in new geographical and climatic areas.
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3
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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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4
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Achouri F, Said MB, Wahab MA, Bousselmi L, Corbel S, Schneider R, Ghrabi A. Effect of photocatalysis (TiO 2/UV A) on the inactivation and inhibition of Pseudomonas aeruginosa virulence factors expression. ENVIRONMENTAL TECHNOLOGY 2021; 42:4237-4246. [PMID: 32241229 DOI: 10.1080/09593330.2020.1751729] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/14/2020] [Accepted: 03/30/2020] [Indexed: 06/11/2023]
Abstract
Water disinfection using visible light-active photocatalyst has recently attracted more attention due to its potential to inactivate microbes. In this study, we have investigated the efficiency of photocatalysis (TiO2/UVA) on the inactivation of Pseudomonas aeruginosa and the attenuation of its virulence factors. For this aim, the photocatalytic effects of TiO2/UVA on the cultivability and viability of P. aeruginosa were investigated. Furthermore, during the photocatalysis, the morphology of the bacterial cells was examined by atomic force microscopy (AFM) while the virulence factors were assessed by protease and lipase activities in addition to the mobility and communication of cells. The results revealed that during the photocatalysis the bacterial cells lost their cultivability and viability on agar under the action of the reactive oxygen species generated by the photocatalytic reaction. In addition, AFM observations have shown a damage of the bacterial membrane and a total disruption of the bacterial cells. Moreover, the major virulence factors such as biofilm, lipase and protease expression have been markedly inhibited by TiO2/UVA treatment. In addition, the bacteria lost their ability of communication 'quorum sensing' and mobility with twitching and swarming types after 60 min of photocatalytic treatment. Accordingly, TiO2/UVA is an effective method to reduce P. aeruginosa virulence and to prevent biofilm formation.
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Affiliation(s)
- Faouzi Achouri
- Laboratoire de Traitement des Eaux Usées, Centre de Recherches et des Technologies des Eaux (CERTE), Soliman, Tunisia
- Laboratoire Réactions et Génie des Procédés (LRGP), UMR7274, CNRS, Université de Lorraine, Nancy Cedex, France
- Faculté des Sciences de Bizerte, Université de Carthage, Bizerte, Tunisia
| | - Myriam Ben Said
- Laboratoire de Traitement des Eaux Usées, Centre de Recherches et des Technologies des Eaux (CERTE), Soliman, Tunisia
| | - Mohamed Ali Wahab
- Centre de Recherches et des Technologies des Eaux (CERTE), Laboratoire de Traitement et Valorisation des Rejets Hydriques, Université de Carthage, Soliman, Tunisia
| | - Latifa Bousselmi
- Laboratoire de Traitement des Eaux Usées, Centre de Recherches et des Technologies des Eaux (CERTE), Soliman, Tunisia
| | - Serge Corbel
- Laboratoire Réactions et Génie des Procédés (LRGP), UMR7274, CNRS, Université de Lorraine, Nancy Cedex, France
| | - Raphaël Schneider
- Laboratoire Réactions et Génie des Procédés (LRGP), UMR7274, CNRS, Université de Lorraine, Nancy Cedex, France
| | - Ahmed Ghrabi
- Laboratoire de Traitement des Eaux Usées, Centre de Recherches et des Technologies des Eaux (CERTE), Soliman, Tunisia
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5
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Abstract
Most bacteria are protected from environmental offenses by a cell wall consisting of strong yet elastic peptidoglycan. The cell wall is essential for preserving bacterial morphology and viability, and thus the enzymes involved in the production and turnover of peptidoglycan have become preferred targets for many of our most successful antibiotics. In the past decades, Vibrio cholerae, the gram-negative pathogen causing the diarrheal disease cholera, has become a major model for understanding cell wall genetics, biochemistry, and physiology. More than 100 articles have shed light on novel cell wall genetic determinants, regulatory links, and adaptive mechanisms. Here we provide the first comprehensive review of V. cholerae's cell wall biology and genetics. Special emphasis is placed on the similarities and differences with Escherichia coli, the paradigm for understanding cell wall metabolism and chemical structure in gram-negative bacteria.
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Affiliation(s)
- Laura Alvarez
- Department of Molecular Biology and Laboratory for Molecular Infection Medicine Sweden (MIMS), Umeå Centre for Microbial Research (UCMR), Umeå University, Umeå SE-90187, Sweden;
| | - Sara B Hernandez
- Department of Molecular Biology and Laboratory for Molecular Infection Medicine Sweden (MIMS), Umeå Centre for Microbial Research (UCMR), Umeå University, Umeå SE-90187, Sweden;
| | - Felipe Cava
- Department of Molecular Biology and Laboratory for Molecular Infection Medicine Sweden (MIMS), Umeå Centre for Microbial Research (UCMR), Umeå University, Umeå SE-90187, Sweden;
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6
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L-arabinose induces the formation of viable non-proliferating spheroplasts in Vibrio cholerae. Appl Environ Microbiol 2021; 87:AEM.02305-20. [PMID: 33355111 PMCID: PMC8090878 DOI: 10.1128/aem.02305-20] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Vibrio cholerae, the agent of the deadly human disease cholera, propagates as a curved rod-shaped bacterium in warm waters. It is sensitive to cold, but persists in cold waters under the form of viable but non-dividing coccoidal shaped cells. Additionally, V. cholerae is able to form non-proliferating spherical cells in response to cell wall damage. It was recently reported that L-arabinose, a component of the hemicellulose and pectin of terrestrial plants, stops the growth of V. cholerae. Here, we show that L-arabinose induces the formation of spheroplasts that lose the ability to divide and stop growing in volume over time. However, they remain viable and upon removal of L-arabinose they start expanding in volume, form branched structures and give rise to cells with a normal morphology after a few divisions. We further show that WigKR, a histidine kinase/response regulator pair implicated in the induction of a high expression of cell wall synthetic genes, prevents the lysis of the spheroplasts during growth restart. Finally, we show that the physiological perturbations result from the import and catabolic processing of L-arabinose by the V. cholerae homolog of the E. coli galactose transport and catabolic system. Taken together, our results suggest that the formation of non-growing spherical cells is a common response of Vibrios exposed to detrimental conditions. They also permit to define conditions preventing any physiological perturbation of V. cholerae when using L-arabinose to induce gene expression from the tightly regulated promoter of the Escherichia coli araBAD operon.Importance Vibrios among other bacteria form transient cell wall deficient forms as a response to different stresses and revert to proliferating rods when permissive conditions have been restored. Such cellular forms have been associated to antimicrobial tolerance, chronic infections and environmental dispersion.The effect of L-Ara on V. cholerae could provide an easily tractable model to study the ability of Vibrios to form viable reversible spheroplasts. Indeed, the quick transition to spheroplasts and reversion to proliferating rods by addition or removal of L-Ara is ideal to understand the genetic program governing this physiological state and the spatial rearrangements of the cellular machineries during cell shape transitions.
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7
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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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8
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Taneja N, Mishra A, Batra N, Gupta P, Mahindroo J, Mohan B. Inland cholera in freshwater environs of north India. Vaccine 2020; 38 Suppl 1:A63-A72. [DOI: 10.1016/j.vaccine.2019.06.038] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2019] [Revised: 05/15/2019] [Accepted: 06/17/2019] [Indexed: 01/02/2023]
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9
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Pan H, Dong K, Rao L, Zhao L, Wang Y, Liao X. The Association of Cell Division Regulated by DicC With the Formation of Viable but Non-culturable Escherichia coli O157:H7. Front Microbiol 2020; 10:2850. [PMID: 31921032 PMCID: PMC6915034 DOI: 10.3389/fmicb.2019.02850] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2019] [Accepted: 11/25/2019] [Indexed: 12/23/2022] Open
Abstract
The viable but non-culturable (VBNC) state, in which bacteria fail to grow on routine culture media but are actually alive, has been widely recognized as a strategy adopted by bacteria to cope with stressful environments. However, little is known regarding the molecular mechanism of VBNC formation. Here, we aimed to elucidate the specific roles of cell division regulatory proteins and the cell growth rate during VBNC Escherichia coli O157:H7 formation. We have previously found that expression of dicC is reduced by 20.08-fold in VBNC E. coli O157:H7 compared to non-VBNC cells. Little is known about DicC except that it, along with DicA, appears to act as a regulator of cell division by regulating expression of the cell division inhibitor DicB. First, our results showed that the VBNC cell number increased in the ΔdicC mutant as well as the DicA-overexpressing strain but decreased in the DicC-overexpressing strain induced by high-pressure carbon dioxide, acid, and H2O2. Furthermore, the growth rates of both the DicA-overexpressing strain and the ΔdicC mutant were higher than that of the control strain, while DicC-overexpressing strain grew significantly more slowly than the vector strain. The level of the dicB gene, regulated by dicA and dicC and inhibiting cell division, was increased in the DicC-overexpressing strain and decreased in the ΔdicC mutant and DicA-overexpressing strain, which was consistent with the growth phenotypes. In addition, the dwarfing cell morphology of the ΔdicC mutant and DicA-overexpressing strain were observed by SEM and TEM. Taken together, our study demonstrates that DicC negatively regulates the formation of the VBNC state, and DicA enhances the ability of cells to enter the VBNC state. Besides, the cell growth rate and dwarfing cell morphology may be correlated with the formation of the VBNC state.
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Affiliation(s)
- Hanxu Pan
- Beijing Advanced Innovation Center for Food Nutrition and Human Health, College of Food Science and Nutritional Engineering, China Agricultural University, Beijing, China.,Key Laboratory of Fruit and Vegetable Processing, Ministry of Agriculture and Rural Affairs, Beijing, China
| | - Kai Dong
- Beijing Advanced Innovation Center for Food Nutrition and Human Health, College of Food Science and Nutritional Engineering, China Agricultural University, Beijing, China.,Key Laboratory of Fruit and Vegetable Processing, Ministry of Agriculture and Rural Affairs, Beijing, China
| | - Lei Rao
- Beijing Advanced Innovation Center for Food Nutrition and Human Health, College of Food Science and Nutritional Engineering, China Agricultural University, Beijing, China.,Key Laboratory of Fruit and Vegetable Processing, Ministry of Agriculture and Rural Affairs, Beijing, China
| | - Liang Zhao
- Key Laboratory of Fruit and Vegetable Processing, Ministry of Agriculture and Rural Affairs, Beijing, China
| | - Yongtao Wang
- Beijing Advanced Innovation Center for Food Nutrition and Human Health, College of Food Science and Nutritional Engineering, China Agricultural University, Beijing, China.,Key Laboratory of Fruit and Vegetable Processing, Ministry of Agriculture and Rural Affairs, Beijing, China
| | - Xiaojun Liao
- Beijing Advanced Innovation Center for Food Nutrition and Human Health, College of Food Science and Nutritional Engineering, China Agricultural University, Beijing, China.,Key Laboratory of Fruit and Vegetable Processing, Ministry of Agriculture and Rural Affairs, Beijing, China
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10
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Dong K, Pan H, Yang D, Rao L, Zhao L, Wang Y, Liao X. Induction, detection, formation, and resuscitation of viable but non‐culturable state microorganisms. Compr Rev Food Sci Food Saf 2019; 19:149-183. [DOI: 10.1111/1541-4337.12513] [Citation(s) in RCA: 47] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2019] [Revised: 10/21/2019] [Accepted: 11/14/2019] [Indexed: 01/05/2023]
Affiliation(s)
- Kai Dong
- Beijing Advanced Innovation Center for Food Nutrition and Human HealthCollege of Food Science and Nutritional EngineeringChina Agricultural University Beijing China
- College of Food Science and Nutritional EngineeringChina Agricultural University Beijing China
- Key Lab of Fruit and Vegetable ProcessingMinistry of Agriculture and Rural Affairs Beijing China
| | - Hanxu Pan
- Beijing Advanced Innovation Center for Food Nutrition and Human HealthCollege of Food Science and Nutritional EngineeringChina Agricultural University Beijing China
- College of Food Science and Nutritional EngineeringChina Agricultural University Beijing China
- Key Lab of Fruit and Vegetable ProcessingMinistry of Agriculture and Rural Affairs Beijing China
| | - Dong Yang
- Beijing Advanced Innovation Center for Food Nutrition and Human HealthCollege of Food Science and Nutritional EngineeringChina Agricultural University Beijing China
- College of Food Science and Nutritional EngineeringChina Agricultural University Beijing China
- Key Lab of Fruit and Vegetable ProcessingMinistry of Agriculture and Rural Affairs Beijing China
| | - Lei Rao
- Beijing Advanced Innovation Center for Food Nutrition and Human HealthCollege of Food Science and Nutritional EngineeringChina Agricultural University Beijing China
- College of Food Science and Nutritional EngineeringChina Agricultural University Beijing China
- Key Lab of Fruit and Vegetable ProcessingMinistry of Agriculture and Rural Affairs Beijing China
| | - Liang Zhao
- College of Food Science and Nutritional EngineeringChina Agricultural University Beijing China
- Key Lab of Fruit and Vegetable ProcessingMinistry of Agriculture and Rural Affairs Beijing China
| | - Yongtao Wang
- College of Food Science and Nutritional EngineeringChina Agricultural University Beijing China
- Key Lab of Fruit and Vegetable ProcessingMinistry of Agriculture and Rural Affairs Beijing China
| | - Xiaojun Liao
- Beijing Advanced Innovation Center for Food Nutrition and Human HealthCollege of Food Science and Nutritional EngineeringChina Agricultural University Beijing China
- College of Food Science and Nutritional EngineeringChina Agricultural University Beijing China
- Key Lab of Fruit and Vegetable ProcessingMinistry of Agriculture and Rural Affairs Beijing China
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11
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Parlindungan E, Dekiwadia C, May BK, Jones OA. Nutrient stress as a means to enhance the storage stability of spray dried microencapsulated Lactobacillus plantarum B21. Lebensm Wiss Technol 2019. [DOI: 10.1016/j.lwt.2019.05.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
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12
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Brenzinger S, van der Aart LT, van Wezel GP, Lacroix JM, Glatter T, Briegel A. Structural and Proteomic Changes in Viable but Non-culturable Vibrio cholerae. Front Microbiol 2019; 10:793. [PMID: 31057510 PMCID: PMC6479200 DOI: 10.3389/fmicb.2019.00793] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2018] [Accepted: 03/28/2019] [Indexed: 11/13/2022] Open
Abstract
Aquatic environments are reservoirs of the human pathogen Vibrio cholerae O1, which causes the acute diarrheal disease cholera. Upon low temperature or limited nutrient availability, the cells enter a viable but non-culturable (VBNC) state. Characteristic of this state are an altered morphology, low metabolic activity, and lack of growth under standard laboratory conditions. Here, for the first time, the cellular ultrastructure of V. cholerae VBNC cells raised in natural waters was investigated using electron cryo-tomography. This was complemented by a comparison of the proteomes and the peptidoglycan composition of V. cholerae from LB overnight cultures and VBNC cells. The extensive remodeling of the VBNC cells was most obvious in the passive dehiscence of the cell envelope, resulting in improper embedment of flagella and pili. Only minor changes of the peptidoglycan and osmoregulated periplasmic glucans were observed. Active changes in VBNC cells included the production of cluster I chemosensory arrays and change of abundance of cluster II array proteins. Components involved in iron acquisition and storage, peptide import and arginine biosynthesis were overrepresented in VBNC cells, while enzymes of the central carbon metabolism were found at lower levels. Finally, several pathogenicity factors of V. cholerae were less abundant in the VBNC state, potentially limiting their infectious potential. This study gives unprecedented insight into the physiology of VBNC cells and the drastically altered presence of their metabolic and structural proteins.
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Affiliation(s)
- Susanne Brenzinger
- Department of Microbial Biotechnology & Health, Institute of Biology Leiden, Leiden University, Leiden, Netherlands
| | - Lizah T. van der Aart
- Department of Microbial Biotechnology & Health, Institute of Biology Leiden, Leiden University, Leiden, Netherlands
| | - Gilles P. van Wezel
- Department of Microbial Biotechnology & Health, Institute of Biology Leiden, Leiden University, Leiden, Netherlands
| | - Jean-Marie Lacroix
- Unité de Glycobiologie Structurale et Fonctionnelle, UMR CNRS 8576, Université de Lille Sciences et Technologies, Villeneuve d'Ascq, France
| | - Timo Glatter
- Facility for Bacterial Proteomics and Mass Spectrometry, Max-Planck Institute for Terrestrial Microbiology, Marburg, Germany
| | - Ariane Briegel
- Department of Microbial Biotechnology & Health, Institute of Biology Leiden, Leiden University, Leiden, Netherlands
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13
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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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14
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Ultee E, Ramijan K, Dame RT, Briegel A, Claessen D. Stress-induced adaptive morphogenesis in bacteria. Adv Microb Physiol 2019; 74:97-141. [PMID: 31126537 DOI: 10.1016/bs.ampbs.2019.02.001] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Bacteria thrive in virtually all environments. Like all other living organisms, bacteria may encounter various types of stresses, to which cells need to adapt. In this chapter, we describe how cells cope with stressful conditions and how this may lead to dramatic morphological changes. These changes may not only allow harmless cells to withstand environmental insults but can also benefit pathogenic bacteria by enabling them to escape from the immune system and the activity of antibiotics. A better understanding of stress-induced morphogenesis will help us to develop new approaches to combat such harmful pathogens.
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Affiliation(s)
- Eveline Ultee
- Molecular Biotechnology, Institute of Biology, Leiden University, Sylviusweg 72, 2333 BE Leiden, the Netherlands; Centre for Microbial Cell Biology, Leiden University, Leiden, the Netherlands
| | - Karina Ramijan
- Molecular Biotechnology, Institute of Biology, Leiden University, Sylviusweg 72, 2333 BE Leiden, the Netherlands; Centre for Microbial Cell Biology, Leiden University, Leiden, the Netherlands
| | - Remus T Dame
- Centre for Microbial Cell Biology, Leiden University, Leiden, the Netherlands; Macromolecular Biochemistry, Leiden Institute of Chemistry, Leiden University, Einsteinweg 55, 2333 CE Leiden, the Netherlands
| | - Ariane Briegel
- Molecular Biotechnology, Institute of Biology, Leiden University, Sylviusweg 72, 2333 BE Leiden, the Netherlands; Centre for Microbial Cell Biology, Leiden University, Leiden, the Netherlands
| | - Dennis Claessen
- Molecular Biotechnology, Institute of Biology, Leiden University, Sylviusweg 72, 2333 BE Leiden, the Netherlands; Centre for Microbial Cell Biology, Leiden University, Leiden, the Netherlands
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15
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Krzyżek P, Biernat MM, Gościniak G. Intensive formation of coccoid forms as a feature strongly associated with highly pathogenic Helicobacter pylori strains. Folia Microbiol (Praha) 2018; 64:273-281. [PMID: 30449016 PMCID: PMC6529389 DOI: 10.1007/s12223-018-0665-5] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2018] [Accepted: 11/12/2018] [Indexed: 12/11/2022]
Abstract
The variability of Helicobacter pylori morphology and the heterogeneity of virulence factors expressed by these bacteria play a key role as a driving force for adaptation to the hostile stomach environment. The aim of the study was to determine the relationship between the presence of certain genes encoding virulence factors and H. pylori morphology. One reference and 13 clinical H. pylori strains with a known virulence profile (vacA, cagA, babA2, dupA, and iceA) were used in this study. Bacteria were cultured for 1 h and 24 h in stressogenic culture conditions, i.e., serum-free BHI broths at suboptimal conditions (room temperature and atmosphere, without shaking). H. pylori cell morphology was observed by light and scanning electron microscopy. The vacA polymorphism and the cagA and babA2 presence were positively correlated with the reduction in cell size. Exposure to short-time stressogenic conditions caused more intense transformation to coccoid forms in highly pathogenic H. pylori type I strains (35.83% and 47.5% for type I s1m2 and I s1m1, respectively) than in intermediate-pathogenic type III (8.17%) and low pathogenic type II (9.92%) strains. The inverse relationship was observed for the number of rods, which were more common in type III (46.83%) and II (48.42%) strains than in type I s1m2 (19.25%) or I s1m1 (6.58%) strains. Our results suggest that there is a close relationship between the presence of virulence genes of H. pylori strains and their adaptive morphological features.
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Affiliation(s)
- Paweł Krzyżek
- Department of Microbiology, Faculty of Medicine, Wroclaw Medical University, Wroclaw, Poland.
| | - Monika M Biernat
- Department of Haematology, Blood Neoplasms, and Bone Marrow Transplantation, Faculty of Postgraduate Medical Training, Wroclaw Medical University, Wroclaw, Poland
| | - Grażyna Gościniak
- Department of Microbiology, Faculty of Medicine, Wroclaw Medical University, Wroclaw, Poland
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16
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Gao X, Pi D, Chen N, Li X, Liu X, Yang H, Wei W, Zhang X. Survival, Virulent Characteristics, and Transcriptomic Analyses of the Pathogenic Vibrio anguillarum Under Starvation Stress. Front Cell Infect Microbiol 2018; 8:389. [PMID: 30505805 PMCID: PMC6250815 DOI: 10.3389/fcimb.2018.00389] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2018] [Accepted: 10/15/2018] [Indexed: 12/16/2022] Open
Abstract
Many bacteria have developed strategies for metamorphosis into sophisticated survival forms to survive extended periods of environmental stress. As a global causative agent of vibriosis in marine fish farming, Vibrio anguillarum (V. anguillarum) can efficiently grow and proliferate under environmental stress, but the specific mechanism is not clear. In the present study, survival, virulent characteristics, and transcriptomic analysis of the V. anguillarum BH1 were performed under starvation stress. The results demonstrated that V. anguillarum was still culturable and showed rippled surface after 6 months of starvation. Starved cells maintained their infectivity in half-smooth tongue sole (Cynoglossus semilaevi). Detection of virulence factors and virulence-associated genes in starved cells showed that the starved strain still produced β-hemolysis on rabbit blood agar, caseinase, dnase, and gelatinase, and possessed empA, vah1, vah2, vah3, vah4, vah5, rtxA, flaA, flaD, flaE, virC, tonB, mreB, toxR, rpoS, and ftsZ virulence-related genes. In addition, we first reported the RNA-seq study for V. anguillarum with and without starvation treatment for a period of 6 months and emphasized the regulation of gene expression at the whole transcriptional level. It indicated that V. anguillarum expressed 3,089 and 3,072 genes in the control group and starvation stress group, respectively. The differently expressed genes (DEGs) of the starved strain were thereby identified, including 251 up-regulated genes and 272 down-regulated genes in comparison with the non-starved strain. Gene Ontology (GO) analysis and Kyto Encyclopedia Genes and Genomes (KEGG) enrichment analysis of DEGs were also analyzed. GO functional classification revealed that among the significantly regulated genes with known function categories, more genes affiliated with signal transducer activity, molecular transducer activity, and cell communication were significantly up-regulated, and more genes affiliated with cellular macromolecule, cellular component, and structural molecule activity were significantly down-regulated. In addition, the DEGs involved in the pathway of two-component system was significantly up-regulated, and the pathways of ribosome and flagellar assembly were significantly down-regulated. This study provides valuable insight into the survival strategies of V. anguillarum and suggests that a portion of the bacterial populations may remain pathogenic while persisting under starvation stress by up-regulating or down-regulating a series of genes.
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Affiliation(s)
- Xiaojian Gao
- College of Animal Science and Technology, Yangzhou University, Yangzhou, China
| | - Daming Pi
- College of Animal Science and Technology, Yangzhou University, Yangzhou, China
| | - Nan Chen
- College of Animal Science and Technology, Yangzhou University, Yangzhou, China
| | - Xixi Li
- College of Animal Science and Technology, Yangzhou University, Yangzhou, China
| | - Xiaodan Liu
- College of Animal Science and Technology, Yangzhou University, Yangzhou, China
| | - Hui Yang
- College of Animal Science and Technology, Yangzhou University, Yangzhou, China
| | - Wanhong Wei
- College of Animal Science and Technology, Yangzhou University, Yangzhou, China
| | - Xiaojun Zhang
- College of Animal Science and Technology, Yangzhou University, Yangzhou, China
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17
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Robben C, Fister S, Witte AK, Schoder D, Rossmanith P, Mester P. Induction of the viable but non-culturable state in bacterial pathogens by household cleaners and inorganic salts. Sci Rep 2018; 8:15132. [PMID: 30310128 PMCID: PMC6181970 DOI: 10.1038/s41598-018-33595-5] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2018] [Accepted: 09/28/2018] [Indexed: 12/28/2022] Open
Abstract
Effective monitoring of microbial pathogens is essential for a successful preventive food safety and hygiene strategy. However, as most monitoring strategies are growth-based, these tests fail to detect pathogenic bacteria that have entered the viable but non-culturable (VBNC) state. The present study reports the induction of the VBNC state in five human pathogens by commercially available household cleaners in combination with inorganic salts. We determined that non-ionic surfactants, a common ingredient in household cleaners, can induce the VBNC state, when combined with salts. A screening study with 630 surfactant/salt combinations indicates a correlation between the hydrophobicity of the surfactant and VBNC induction in L. monocytogenes, E. coli, S. enterica serovar Typhimurium, S. aureus and toxin-producing enteropathogenic E. coli. Cells that were exposed to combinations of surfactants and salts for 5 min and up to 1 h lost their culturability on standard growth media while retaining their ATP production, fermentation of sugars and membrane integrity, which suggests intact and active metabolism. Screening also revealed major differences between Gram-negative and Gram-positive bacteria; the latter being more susceptible to VBNC induction. Combinations of such detergents and salts are found in many different environments and reflect realistic conditions in industrial and domestic surroundings. VBNC cells present in industrial environments, food-processing plants and even our daily routine represent a serious health risk due to possible resuscitation, unknown spreading, production of toxins and especially their invisibility to routine detection methods, which rely on culturability of cells and fail to detect VBNC pathogens.
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Affiliation(s)
- Christian Robben
- Christian Doppler-Laboratory for Monitoring of Microbial Contaminants, Institute for Milk Hygiene, Milk Technology and Food Science, Department of Farm Animal and Public Health in Veterinary Medicine, University of Veterinary Medicine, Veterinärplatz 1, 1210, Vienna, Austria
| | - Susanne Fister
- Christian Doppler-Laboratory for Monitoring of Microbial Contaminants, Institute for Milk Hygiene, Milk Technology and Food Science, Department of Farm Animal and Public Health in Veterinary Medicine, University of Veterinary Medicine, Veterinärplatz 1, 1210, Vienna, Austria
| | - Anna Kristina Witte
- Christian Doppler-Laboratory for Monitoring of Microbial Contaminants, Institute for Milk Hygiene, Milk Technology and Food Science, Department of Farm Animal and Public Health in Veterinary Medicine, University of Veterinary Medicine, Veterinärplatz 1, 1210, Vienna, Austria
| | - Dagmar Schoder
- Christian Doppler-Laboratory for Monitoring of Microbial Contaminants, Institute for Milk Hygiene, Milk Technology and Food Science, Department of Farm Animal and Public Health in Veterinary Medicine, University of Veterinary Medicine, Veterinärplatz 1, 1210, Vienna, Austria.,Institute of Milk Hygiene, Milk Technology and Food Science, Department of Farm Animal and Public Health in Veterinary Medicine, University of Veterinary Medicine, Veterinärplatz 1, 1210, Vienna, Austria
| | - Peter Rossmanith
- Christian Doppler-Laboratory for Monitoring of Microbial Contaminants, Institute for Milk Hygiene, Milk Technology and Food Science, Department of Farm Animal and Public Health in Veterinary Medicine, University of Veterinary Medicine, Veterinärplatz 1, 1210, Vienna, Austria.,Institute of Milk Hygiene, Milk Technology and Food Science, Department of Farm Animal and Public Health in Veterinary Medicine, University of Veterinary Medicine, Veterinärplatz 1, 1210, Vienna, Austria
| | - Patrick Mester
- Christian Doppler-Laboratory for Monitoring of Microbial Contaminants, Institute for Milk Hygiene, Milk Technology and Food Science, Department of Farm Animal and Public Health in Veterinary Medicine, University of Veterinary Medicine, Veterinärplatz 1, 1210, Vienna, Austria.
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18
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Xu T, Cao H, Zhu W, Wang M, Du Y, Yin Z, Chen M, Liu Y, Yang B, Liu B. RNA-seq-based monitoring of gene expression changes of viable but non-culturable state of Vibrio cholerae induced by cold seawater. ENVIRONMENTAL MICROBIOLOGY REPORTS 2018; 10:594-604. [PMID: 30058121 DOI: 10.1111/1758-2229.12685] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/15/2018] [Accepted: 07/27/2018] [Indexed: 06/08/2023]
Abstract
Vibrio cholerae O1 is a natural inhabitant of aquatic environments and causes the acute diarrheal disease cholera. Entry into a viable but non-culturable (VBNC) state is a survival strategy by which V. cholerae withstands natural stresses and is important for the transition between the aquatic and host environments during the V. cholerae life cycle. In this study, the formation of VBNC V. cholerae induced by cold seawater exposure was investigated using RNA sequencing (RNA-seq). The analysis revealed that the expression of 1420 genes was changed on VBNC state formation. In the VBNC cells, genes related to biofilm formation, chitin utilization and stress responses were upregulated, whereas those related to cell division, morphology and ribosomal activity were mainly downregulated. The concurrent acquisition of a carbon source and the arrest of cell division in cells with low metabolic activity help bacteria increase their resistance to unfavourable environments. Moreover, two transcriptional regulators, SlmA and MetJ, were found to play roles in both VBNC formation and intestinal colonization, suggesting that some genes may function in both processes. This acquired knowledge will improve our understanding of the molecular mechanisms of stress tolerance and may help control future cholera infections and outbreaks.
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Affiliation(s)
- Tingting Xu
- TEDA Institute of Biological Sciences and Biotechnology, Nankai University, Tianjin, People's Republic of China
- College of Life Sciences, Nankai University, Tianjin, People's Republic of China
| | - Hengchun Cao
- TEDA Institute of Biological Sciences and Biotechnology, Nankai University, Tianjin, People's Republic of China
- Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Tianjin, People's Repubilc of China
- Tianjin Key Laboratory of Microbial Functional Genomics, Tianjin, People's Republic of China
| | - Wei Zhu
- TEDA Institute of Biological Sciences and Biotechnology, Nankai University, Tianjin, People's Republic of China
- Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Tianjin, People's Repubilc of China
- Tianjin Key Laboratory of Microbial Functional Genomics, Tianjin, People's Republic of China
| | - Min Wang
- TEDA Institute of Biological Sciences and Biotechnology, Nankai University, Tianjin, People's Republic of China
- Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Tianjin, People's Repubilc of China
- Tianjin Key Laboratory of Microbial Functional Genomics, Tianjin, People's Republic of China
| | - Yuhui Du
- TEDA Institute of Biological Sciences and Biotechnology, Nankai University, Tianjin, People's Republic of China
- Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Tianjin, People's Repubilc of China
- Tianjin Key Laboratory of Microbial Functional Genomics, Tianjin, People's Republic of China
| | - Zhiqiu Yin
- TEDA Institute of Biological Sciences and Biotechnology, Nankai University, Tianjin, People's Republic of China
- Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Tianjin, People's Repubilc of China
- Tianjin Key Laboratory of Microbial Functional Genomics, Tianjin, People's Republic of China
| | - Min Chen
- Lab of Microbiology, Shanghai Municipal Center for Disease Control & Prevention, Shanghai, People's Republic of China
| | - Yutao Liu
- TEDA Institute of Biological Sciences and Biotechnology, Nankai University, Tianjin, People's Republic of China
- Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Tianjin, People's Repubilc of China
- Tianjin Key Laboratory of Microbial Functional Genomics, Tianjin, People's Republic of China
| | - Bin Yang
- TEDA Institute of Biological Sciences and Biotechnology, Nankai University, Tianjin, People's Republic of China
- Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Tianjin, People's Repubilc of China
- Tianjin Key Laboratory of Microbial Functional Genomics, Tianjin, People's Republic of China
| | - Bin Liu
- TEDA Institute of Biological Sciences and Biotechnology, Nankai University, Tianjin, People's Republic of China
- Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Tianjin, People's Repubilc of China
- Tianjin Key Laboratory of Microbial Functional Genomics, Tianjin, People's Republic of China
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19
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Ben Hamed S, Tavares Ranzani-Paiva MJ, Tachibana L, de Carla Dias D, Ishikawa CM, Esteban MA. Fish pathogen bacteria: Adhesion, parameters influencing virulence and interaction with host cells. FISH & SHELLFISH IMMUNOLOGY 2018; 80:550-562. [PMID: 29966687 DOI: 10.1016/j.fsi.2018.06.053] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/28/2018] [Revised: 06/04/2018] [Accepted: 06/29/2018] [Indexed: 06/08/2023]
Abstract
Wild fisheries are declining due to over-fishing, climate change, pollution and marine habitat destructions among other factors, and, concomitantly, aquaculture is increasing significantly around the world. Fish infections caused by pathogenic bacteria are quite common in aquaculture, although their seriousness depends on the season. Drug-supplemented feeds are often used to keep farmed fish free from the diseases caused by such bacteria. However, given that bacteria can survive well in aquatic environments independently of their hosts, bacterial diseases have become major impediments to aquaculture development. On the other hand, the indiscriminate uses of antimicrobial agents has led to resistant strains and the need to switch to other antibiotics, although it seems that an integrated approach that considers not only the pathogen but also the host and the environment will be the most effective method in the long-term to improve aquatic animal health. This review covers the mechanisms of bacterial pathogenicity and details the foundations underlying the interactions occurring between pathogenic bacteria and the fish host in the aquatic environment, as well as the factors that influence virulence. Understanding and linking the different phenomena that occur from adhesion to colonization of the host will offer novel and useful means to help design suitable therapeutic strategies for disease prevention and treatment.
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Affiliation(s)
- Said Ben Hamed
- Fishery Institute-APTA - SAA, Research Center of Aquaculture, Av. Francisco Matarazzo, 455, CEP. 05001-900, Sao Paulo, SP, Brazil
| | - Maria José Tavares Ranzani-Paiva
- Fishery Institute-APTA - SAA, Research Center of Aquaculture, Av. Francisco Matarazzo, 455, CEP. 05001-900, Sao Paulo, SP, Brazil
| | - Leonardo Tachibana
- Fishery Institute-APTA - SAA, Research Center of Aquaculture, Av. Francisco Matarazzo, 455, CEP. 05001-900, Sao Paulo, SP, Brazil
| | - Danielle de Carla Dias
- Fishery Institute-APTA - SAA, Research Center of Aquaculture, Av. Francisco Matarazzo, 455, CEP. 05001-900, Sao Paulo, SP, Brazil
| | - Carlos Massatoshi Ishikawa
- Fishery Institute-APTA - SAA, Research Center of Aquaculture, Av. Francisco Matarazzo, 455, CEP. 05001-900, Sao Paulo, SP, Brazil
| | - María Angeles Esteban
- Fish Innate Immune System Group, Department of Cell Biology & Histology, Faculty of Biology, Regional Campus of International Excellence, ''Campus Mare Nostrum'', University of Murcia, 30100, Murcia, Spain.
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20
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Parlindungan E, Dekiwadia C, Tran KT, Jones OA, May BK. Morphological and ultrastructural changes in Lactobacillus plantarum B21 as an indicator of nutrient stress. Lebensm Wiss Technol 2018. [DOI: 10.1016/j.lwt.2018.02.072] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
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21
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Martins PMM, Merfa MV, Takita MA, De Souza AA. Persistence in Phytopathogenic Bacteria: Do We Know Enough? Front Microbiol 2018; 9:1099. [PMID: 29887856 PMCID: PMC5981161 DOI: 10.3389/fmicb.2018.01099] [Citation(s) in RCA: 59] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2018] [Accepted: 05/08/2018] [Indexed: 01/05/2023] Open
Abstract
Phytopathogenic bacteria affect a wide range of crops worldwide and have a negative impact in agriculture due to their associated economic losses and environmental impacts. Together with other biotic and abiotic stress factors, they pose a threat to global food production. Therefore, understanding bacterial survival strategies is an essential step toward the development of new strategies to control plant diseases. One mechanism used by bacteria to survive under stress conditions is the formation of persister cells. Persisters are a small fraction of phenotypic variants within an isogenic population that exhibits multidrug tolerance without undergoing genetic changes. They are dormant cells that survive treatment with antimicrobials by inactivating the metabolic functions that are disrupted by these compounds. They are thus responsible for the recalcitrance of many human diseases, and in the same way, they are thought to contribute to the survival of bacterial phytopathogens under a range of stresses they face in the environment. It is believed that persister cells of bacterial phytopathogens may lead to the reoccurrence of disease by recovering growth and recolonizing the host plant after the end of stress. However, compared to human pathogens, little is known about persister cells in phytopathogens, especially about their genetic regulation. In this review, we describe the overall knowledge on persister cells and their regulation in bacterial phytopathogens, focusing on their ability to survive stress conditions, to recover from dormancy and to maintain virulence.
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Affiliation(s)
- Paula M. M. Martins
- Laboratório de Biotecnologia, Centro de Citricultura, Instituto Agronômico de Campinas, Cordeiropolis, Brazil
| | - Marcus V. Merfa
- Department of Entomology and Plant Pathology, Auburn University, Auburn, AL, United States
| | - Marco A. Takita
- Laboratório de Biotecnologia, Centro de Citricultura, Instituto Agronômico de Campinas, Cordeiropolis, Brazil
| | - Alessandra A. De Souza
- Laboratório de Biotecnologia, Centro de Citricultura, Instituto Agronômico de Campinas, Cordeiropolis, Brazil
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22
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The fight for invincibility: Environmental stress response mechanisms and Aeromonas hydrophila. Microb Pathog 2018; 116:135-145. [PMID: 29355702 DOI: 10.1016/j.micpath.2018.01.023] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2017] [Revised: 01/15/2018] [Accepted: 01/15/2018] [Indexed: 12/11/2022]
Abstract
Aeromonas hydrophila is a freshwater-dwelling zoonotic bacterium that has economic importance in aquaculture. In the past decade, Aeromonas hydrophila has become increasingly important because of its emergence as a food-borne zoonotic pathogen that is resistant to different treatment regimes. Being an aquatic bacterium, Aeromonas hydrophila is frequently subjected to several stressful environmental conditions, including changes in temperature, acidic pH and starvation that challenge its survival. To cope with these stressful conditions, like every cell, A. hydrophila possesses stress response mechanisms, such as alternative sigma factors, two-component systems, heat shock proteins, cold shock proteins, and acid tolerance response systems that eventually lead the fittest to survive. Moreover, the establishment of genetic variations among the strains related to environmental stress is also of great concern. This review presents the understandings based on inter-strain variations and stress response behavior of A. hydrophila that are important to control the increasing outbreaks of this bacterium in both human populations and aquaculture.
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23
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Castro-Rosas J, Gómez-Aldapa CA, Villagómez Ibarra JR, Santos-López EM, Rangel-Vargas E. Heat resistance of viable but non-culturable Escherichia coli cells determined by differential scanning calorimetry. FEMS Microbiol Lett 2017; 364:4108096. [PMID: 28967946 DOI: 10.1093/femsle/fnx188] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2017] [Accepted: 08/30/2017] [Indexed: 11/14/2022] Open
Abstract
Several reports have suggested that the viable but non-culturable (VBNC) state is a resistant form of bacterial cells that allows them to remain in a dormant form in the environment. Nevertheless, studies on the resistance of VBNC bacterial cells to ecological factors are limited, mainly because techniques that allow this type of evaluation are lacking. Differential scanning calorimetry (DSC) has been used to study the thermal resistance of culturable bacteria but has never been used to study VBNC cells. In this work, the heat resistance of Escherichia coli cells in the VBNC state was studied using the DSC technique. The VBNC state was induced in E. coli ATCC 25922 by suspending bacterial cells in artificial sea water, followed by storage at 3 ± 2°C for 110 days. Periodically, the behaviour of E. coli cells was monitored by plate counts, direct viable counts and DSC. The entire bacterial population entered the VBNC state after 110 days of storage. The results obtained with DSC suggest that the VBNC state does not confer thermal resistance to E. coli cells in the temperature range analysed here.
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Affiliation(s)
- Javier Castro-Rosas
- Área Académica de Química. Instituto de Ciencias Básicas e Ingeniería, Universidad Autónoma del Estado de Hidalgo, Ciudad del Conocimiento, Carretera Pachuca-Tulancingo km. 4.5. Mineral de la Reforma, Hgo., C.P. 42184. México
| | - Carlos Alberto Gómez-Aldapa
- Área Académica de Química. Instituto de Ciencias Básicas e Ingeniería, Universidad Autónoma del Estado de Hidalgo, Ciudad del Conocimiento, Carretera Pachuca-Tulancingo km. 4.5. Mineral de la Reforma, Hgo., C.P. 42184. México
| | - José Roberto Villagómez Ibarra
- Área Académica de Química. Instituto de Ciencias Básicas e Ingeniería, Universidad Autónoma del Estado de Hidalgo, Ciudad del Conocimiento, Carretera Pachuca-Tulancingo km. 4.5. Mineral de la Reforma, Hgo., C.P. 42184. México
| | - Eva María Santos-López
- Área Académica de Química. Instituto de Ciencias Básicas e Ingeniería, Universidad Autónoma del Estado de Hidalgo, Ciudad del Conocimiento, Carretera Pachuca-Tulancingo km. 4.5. Mineral de la Reforma, Hgo., C.P. 42184. México
| | - Esmeralda Rangel-Vargas
- Área Académica de Química. Instituto de Ciencias Básicas e Ingeniería, Universidad Autónoma del Estado de Hidalgo, Ciudad del Conocimiento, Carretera Pachuca-Tulancingo km. 4.5. Mineral de la Reforma, Hgo., C.P. 42184. México
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24
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Sun J, Gao X, Qun J, Du X, Bi K, Zhang X, Lin L. Comparative analysis of the survival and gene expression of pathogenic strains Vibrio harveyi after starvation. FEMS Microbiol Lett 2016; 363:fnw250. [PMID: 27810886 DOI: 10.1093/femsle/fnw250] [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] [Revised: 09/01/2016] [Accepted: 10/31/2016] [Indexed: 12/18/2022] Open
Abstract
This study aimed to evaluate the survival and gene expression of Vibrio harveyi under starvation conditions. The microcosms V. harveyi were incubated in sterilized seawater for 4 weeks at room temperature. Overall, the cell numeration declined rapidly about 103 CFU/ml during starvation, with a tiny rebound at day 21. Scanning electron microscopy revealed that rod-shaped cells became sphere with a rippled cell surface. By polymerase chain reaction (PCR) assay, nine genes, named luxR, toxR, vhhB, flaA, topA, fur, rpoS, mreB and ftsZ, were detected in the non-starved cells. In the starved cells, the expression levels of the detected genes declined substantially ranging from 0.005-fold to 0.028-fold compared to the non-starved cells performed by reverse transcription quantitative real-time PCR with 16S rRNA as the internal control. In the recovering cells, the expression levels of the detected genes, except luxR and mreB, were upregulated dramatically compared to the wild, especially topA (23.720-fold), fur (39.400-fold) and toxR (9.837-fold), validating that the expressions of both the metabolism and virulence genes were important for growth and survival of V. harveyi. The results may shed a new light on understanding of stress adaptation in bacteria.
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Affiliation(s)
- Jingjing Sun
- College of Animal Science and Technology, Yangzhou University, Yangzhou 225009, China.,College of Ocean, Huaihai Institute of Technology, Lianyungang, Jiangsu 222005, China
| | - Xiaojian Gao
- College of Animal Science and Technology, Yangzhou University, Yangzhou 225009, China.,College of Ocean, Huaihai Institute of Technology, Lianyungang, Jiangsu 222005, China
| | - Jiang Qun
- College of Animal Science and Technology, Yangzhou University, Yangzhou 225009, China
| | - Xuedi Du
- College of Animal Science and Technology, Yangzhou University, Yangzhou 225009, China
| | - Keran Bi
- College of Ocean, Huaihai Institute of Technology, Lianyungang, Jiangsu 222005, China
| | - Xiaojun Zhang
- College of Animal Science and Technology, Yangzhou University, Yangzhou 225009, China
| | - Li Lin
- Department of Aquatic Animal Medicine, College of Fisheries, Huazhong Agricultural University, Wuhan 430070, China
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25
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Fernández-Delgado M, Rojas H, Duque Z, Suárez P, Contreras M, García-Amado MA, Alciaturi C. BIOFILM FORMATION OF Vibrio cholerae ON STAINLESS STEEL USED IN FOOD PROCESSING. Rev Inst Med Trop Sao Paulo 2016; 58:47. [PMID: 27253749 PMCID: PMC4880004 DOI: 10.1590/s1678-9946201658047] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2015] [Accepted: 11/17/2015] [Indexed: 11/22/2022] Open
Abstract
Vibrio cholerae represents a significant threat to human health in developing countries. This pathogen forms biofilms which favors its attachment to surfaces and its survival and transmission by water or food. This work evaluated the in vitro biofilm formation of V. cholerae isolated from clinical and environmental sources on stainless steel of the type used in food processing by using the environmental scanning electron microscopy (ESEM). Results showed no cell adhesion at 4 h and scarce surface colonization at 24 h. Biofilms from the environmental strain were observed at 48 h with high cellular aggregations embedded in Vibrio exopolysaccharide (VPS), while less confluence and VPS production with microcolonies of elongated cells were observed in biofilms produced by the clinical strain. At 96 h the biofilms of the environmental strain were released from the surface leaving coccoid cells and residual structures, whereas biofilms of the clinical strain formed highly organized structures such as channels, mushroom-like and pillars. This is the first study that has shown the in vitro ability of V. cholerae to colonize and form biofilms on stainless steel used in food processing.
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Affiliation(s)
- Milagro Fernández-Delgado
- Centro de Biofísica y Bioquímica, Laboratorio de Fisiología Gastrointestinal, Instituto Venezolano de Investigaciones Científicas, Caracas, Venezuela
| | - Héctor Rojas
- Instituto de Inmunología, Universidad Central de Venezuela, Caracas, Venezuela
| | - Zoilabet Duque
- Instituto Zuliano de Investigaciones Tecnológicas, Estado Zulia, Venezuela
| | - Paula Suárez
- Laboratorio de Microbiología Acuática, Departamento de Biología de Organismos, Universidad Simón Bolívar, Caracas, Venezuela
| | - Monica Contreras
- Centro de Biofísica y Bioquímica, Laboratorio de Fisiología Gastrointestinal, Instituto Venezolano de Investigaciones Científicas, Caracas, Venezuela
| | - M Alexandra García-Amado
- Centro de Biofísica y Bioquímica, Laboratorio de Fisiología Gastrointestinal, Instituto Venezolano de Investigaciones Científicas, Caracas, Venezuela
| | - Carlos Alciaturi
- Instituto Zuliano de Investigaciones Tecnológicas, Estado Zulia, Venezuela
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Shinoda S, Imamura D, Mizuno T, Miyoshi SI, Ramamurthy T. International collaborative research on infectious diseases by Japanese universities and institutes in Asia and Africa, with a special emphasis on J-GRID. Biocontrol Sci 2016; 20:77-89. [PMID: 26133505 DOI: 10.4265/bio.20.77] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022]
Abstract
In developed countries including Japan, malignant tumor (cancer), heart disease and cerebral apoplexy are major causes of death, but infectious diseases are still responsible for a high number of deaths in developing countries, especially among children aged less than 5 years. World Health Statistics published by WHO reports a high percentage of mortality from infectious diseases in children, and many of these diseases may be subject to transmission across borders and could possibly invade Japan. Given this situation, the Ministry of Education, Culture, Sports, Science and Technology (MEXT) of Japan initiated Phase I of the Program of Founding Research Centers for Emerging and Reemerging Infectious Disease, which ran from FY 2005 to 2009, and involved 8 Japanese universities and 2 research centers. The program was established for the following purposes: 1) creation of a domestic research structure to promote the accumulation of fundamental knowledge about infectious diseases, 2) establishment of 13 overseas research collaboration centers in 8 countries at high risk of emerging and reemerging infections and at which Japanese researchers are stationed and conduct research in partnership with overseas instructors, 3) development of a network among domestic and overseas research centers, and 4) development of human resources. The program was controlled under MEXT and managed by the RIKEN Center of Research Network for Infectious Diseases (Riken CRNID). Phase II of the program was set up as the Japan Initiative for Global Research Network on Infectious Diseases (J-GRID), and has been running in FY 2010-2014. Phase III will start in April 2015, and will be organized by the newly established Japanese governmental organization "Japan Agency for Medical Research and Development (AMED)", the so-called Japanese style NIH. The Collaborative Research Center of Okayama University for Infectious Diseases in India (CRCOUI) was started up in 2007 at the National Institute of Cholera and Enteric Disease, Kolkata, India. Major projects of CRCOUI are concerned with diarrheal diseases such as, 1) active surveillance of diarrheal patients, 2) development of dysentery vaccines, 3) viable but nonculturable (VBNC) Vibrio cholerae, and 4) pathogenic mechanisms of various diarrhogenic microorganisms. This review article outlines project of J-GRID and CRCOUI which the authors carried out collaboratively with NICED staff members.
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Affiliation(s)
- Sumio Shinoda
- Collaborative Research Center of Okayama University for Infectious Disease in India
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Staying in Shape: the Impact of Cell Shape on Bacterial Survival in Diverse Environments. Microbiol Mol Biol Rev 2016; 80:187-203. [PMID: 26864431 DOI: 10.1128/mmbr.00031-15] [Citation(s) in RCA: 159] [Impact Index Per Article: 19.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Bacteria display an abundance of cellular forms and can change shape during their life cycle. Many plausible models regarding the functional significance of cell morphology have emerged. A greater understanding of the genetic programs underpinning morphological variation in diverse bacterial groups, combined with assays of bacteria under conditions that mimic their varied natural environments, from flowing freshwater streams to diverse human body sites, provides new opportunities to probe the functional significance of cell shape. Here we explore shape diversity among bacteria, at the levels of cell geometry, size, and surface appendages (both placement and number), as it relates to survival in diverse environments. Cell shape in most bacteria is determined by the cell wall. A major challenge in this field has been deconvoluting the effects of differences in the chemical properties of the cell wall and the resulting cell shape perturbations on observed fitness changes. Still, such studies have begun to reveal the selective pressures that drive the diverse forms (or cell wall compositions) observed in mammalian pathogens and bacteria more generally, including efficient adherence to biotic and abiotic surfaces, survival under low-nutrient or stressful conditions, evasion of mammalian complement deposition, efficient dispersal through mucous barriers and tissues, and efficient nutrient acquisition.
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Kaberdin VR, Montánchez I, Parada C, Orruño M, Arana I, Barcina I. Unveiling the Metabolic Pathways Associated with the Adaptive Reduction of Cell Size During Vibrio harveyi Persistence in Seawater Microcosms. MICROBIAL ECOLOGY 2015; 70:689-700. [PMID: 25903990 DOI: 10.1007/s00248-015-0614-7] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/26/2015] [Accepted: 04/10/2015] [Indexed: 06/04/2023]
Abstract
Owing to their ubiquitous presence and ability to act as primary or opportunistic pathogens, Vibrio species greatly contribute to the diversity and evolution of marine ecosystems. This study was aimed at unveiling the cellular strategies enabling the marine gammaproteobacterium Vibrio harveyi to adapt and persist in natural aquatic systems. We found that, although V. harveyi incubation in seawater microcosm at 20 °C for 2 weeks did not change cell viability and culturability, it led to a progressive reduction in the average cell size. Microarray analysis revealed that this morphological change was accompanied by a profound decrease in gene expression affecting the central carbon metabolism, major biosynthetic pathways, and energy production. In contrast, V. harveyi elevated expression of genes closely linked to the composition and function of cell envelope. In addition to triggering lipid degradation via the β-oxidation pathway and apparently promoting the use of endogenous fatty acids as a major energy and carbon source, V. harveyi upregulated genes involved in ancillary mechanisms important for sustaining iron homeostasis, cell resistance to the toxic effect of reactive oxygen species, and recycling of amino acids. The above adaptation mechanisms and morphological changes appear to represent the major hallmarks of the initial V. harveyi response to starvation.
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Affiliation(s)
- Vladimir R Kaberdin
- Department of Immunology, Microbiology and Parasitology, University of the Basque Country UPV/EHU, Leioa, Spain.
- IKERBASQUE, Basque Foundation for Science, Maria Diaz de Haro 3, 48013, Bilbao, Spain.
| | - Itxaso Montánchez
- Department of Immunology, Microbiology and Parasitology, University of the Basque Country UPV/EHU, Leioa, Spain
| | - Claudia Parada
- Department of Immunology, Microbiology and Parasitology, University of the Basque Country UPV/EHU, Leioa, Spain
| | - Maite Orruño
- Department of Immunology, Microbiology and Parasitology, University of the Basque Country UPV/EHU, Leioa, Spain
| | - Inés Arana
- Department of Immunology, Microbiology and Parasitology, University of the Basque Country UPV/EHU, Leioa, Spain
| | - Isabel Barcina
- Department of Immunology, Microbiology and Parasitology, University of the Basque Country UPV/EHU, Leioa, Spain
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Li L, Mendis N, Trigui H, Faucher SP. Transcriptomic changes of Legionella pneumophila in water. BMC Genomics 2015; 16:637. [PMID: 26306795 PMCID: PMC4549902 DOI: 10.1186/s12864-015-1869-6] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2015] [Accepted: 08/19/2015] [Indexed: 11/10/2022] Open
Abstract
Background Legionella pneumophila (Lp) is a water-borne opportunistic pathogen. In water, Lp can survive for an extended period of time until it encounters a permissive host. Therefore, identifying genes that are required for survival in water may help develop strategies to prevent Legionella outbreaks. Results We compared the global transcriptomic response of Lp grown in a rich medium to that of Lp exposed to an artificial freshwater medium (Fraquil) for 2, 6 and 24 hours. We uncovered successive changes in gene expression required for the successful adaptation to a nutrient-limited water environment. The repression of major pathways involved in cell division, transcription and translation, suggests that Lp enters a quiescent state in water. The induction of flagella associated genes (flg, fli and mot), enhanced-entry genes (enh) and some Icm/Dot effector genes suggests that Lp is primed to invade a suitable host in response to water exposure. Moreover, many genes involved in resistance to antibiotic and oxidative stress were induced, suggesting that Lp may be more tolerant to these stresses in water. Indeed, Lp exposed to water is more resistant to erythromycin, gentamycin and kanamycin than Lp cultured in rich medium. In addition, the bdhA gene, involved in the degradation pathway of the intracellular energy storage compound polyhydroxybutyrate, is also highly expressed in water. Further characterization show that expression of bdhA during short-term water exposure is dependent upon RpoS, which is required for the survival of Lp in water. Deletion of bdhA reduces the survival of Lp in water at 37 °C. Conclusions The increase of antibiotic resistance and the importance of bdhA to the survival of Lp in water seem consistent with the observed induction of these genes when Lp is exposed to water. Other genes that are highly induced upon exposure to water could also be necessary for Lp to maintain viability in the water environment. Electronic supplementary material The online version of this article (doi:10.1186/s12864-015-1869-6) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Laam Li
- Department of Natural Resource Sciences, Faculty of Agricultural and Environmental Sciences, McGill University, 21,111 Lakeshore Road, Ste-Anne-de-Bellevue, Montreal, QC, H9X 3V9, Canada.
| | - Nilmini Mendis
- Department of Natural Resource Sciences, Faculty of Agricultural and Environmental Sciences, McGill University, 21,111 Lakeshore Road, Ste-Anne-de-Bellevue, Montreal, QC, H9X 3V9, Canada.
| | - Hana Trigui
- Department of Natural Resource Sciences, Faculty of Agricultural and Environmental Sciences, McGill University, 21,111 Lakeshore Road, Ste-Anne-de-Bellevue, Montreal, QC, H9X 3V9, Canada.
| | - Sébastien P Faucher
- Department of Natural Resource Sciences, Faculty of Agricultural and Environmental Sciences, McGill University, 21,111 Lakeshore Road, Ste-Anne-de-Bellevue, Montreal, QC, H9X 3V9, Canada.
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Fernández-Delgado M, García-Amado MA, Contreras M, Incani RN, Chirinos H, Rojas H, Suárez P. Survival, induction and resuscitation of Vibrio cholerae from the viable but non-culturable state in the Southern Caribbean Sea. Rev Inst Med Trop Sao Paulo 2015; 57:21-6. [PMID: 25651322 PMCID: PMC4325519 DOI: 10.1590/s0036-46652015000100003] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2013] [Accepted: 05/28/2014] [Indexed: 12/21/2022] Open
Abstract
The causative agent of cholera, Vibrio cholerae, can enter into a viable but non-culturable (VBNC) state in response to unfavorable conditions. The aim of this study was to evaluate the in situ survival of V. cholerae in an aquatic environment of the Southern Caribbean Sea, and its induction and resuscitation from the VBNC state. V. cholerae non-O1, non-O139 was inoculated into diffusion chambers placed at the Cuare Wildlife Refuge, Venezuela, and monitored for plate, total and viable cells counts. At 119 days of exposure to the environment, the colony count was < 10 CFU/mL and a portion of the bacterial population entered the VBNC state. Additionally, the viability decreased two orders of magnitude and morphological changes occurred from rod to coccoid cells. Among the aquatic environmental variables, the salinity had negative correlation with the colony counts in the dry season. Resuscitation studies showed significant recovery of cell cultivability with spent media addition (p < 0.05). These results suggest that V. cholerae can persist in the VBNC state in this Caribbean environment and revert to a cultivable form under favorable conditions. The VBNC state might represent a critical step in cholera transmission in susceptible areas.
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Affiliation(s)
| | - María Alexandra García-Amado
- Centro de Biofísica y Bioquímica, Laboratorio de Fisiología Gastrointestinal, Instituto Venezolano de Investigaciones Científicas, Altos de Pipe, Edo. Miranda, Venezuela
| | - Monica Contreras
- Centro de Biofísica y Bioquímica, Laboratorio de Fisiología Gastrointestinal, Instituto Venezolano de Investigaciones Científicas, Altos de Pipe, Edo. Miranda, Venezuela
| | - Renzo Nino Incani
- Departamento de Parasitología, Universidad de Carabobo, Valencia, Edo. Carabobo, Venezuela
| | | | - Héctor Rojas
- Instituto de Inmunología, Universidad Central de Venezuela, Caracas, Venezuela
| | - Paula Suárez
- Departamento de Biología de Organismos, Universidad Simón Bolívar, Caracas, Venezuela
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Almagro-Moreno S, Kim TK, Skorupski K, Taylor RK. Proteolysis of virulence regulator ToxR is associated with entry of Vibrio cholerae into a dormant state. PLoS Genet 2015; 11:e1005145. [PMID: 25849031 PMCID: PMC4388833 DOI: 10.1371/journal.pgen.1005145] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2014] [Accepted: 03/16/2015] [Indexed: 12/20/2022] Open
Abstract
Vibrio cholerae O1 is a natural inhabitant of aquatic environments and causes the diarrheal disease, cholera. Two of its primary virulence regulators, TcpP and ToxR, are localized in the inner membrane. TcpP is encoded on the Vibrio Pathogenicity Island (VPI), a horizontally acquired mobile genetic element, and functions primarily in virulence gene regulation. TcpP has been shown to undergo regulated intramembrane proteolysis (RIP) in response to environmental conditions that are unfavorable for virulence gene expression. ToxR is encoded in the ancestral genome and is present in non-pathogenic strains of V. cholerae, indicating it has roles outside of the human host. In this study, we show that ToxR undergoes RIP in V. cholerae in response to nutrient limitation at alkaline pH, a condition that occurs during the stationary phase of growth. This process involves the site-2 protease RseP (YaeL), and is dependent upon the RpoE-mediated periplasmic stress response, as deletion mutants for the genes encoding these two proteins cannot proteolyze ToxR under nutrient limitation at alkaline pH. We determined that the loss of ToxR, genetically or by proteolysis, is associated with entry of V. cholerae into a dormant state in which the bacterium is normally found in the aquatic environment called viable but nonculturable (VBNC). Strains that can proteolyze ToxR, or do not encode it, lose culturability, experience a change in morphology associated with cells in VBNC, yet remain viable under nutrient limitation at alkaline pH. On the other hand, mutant strains that cannot proteolyze ToxR remain culturable and maintain the morphology of cells in an active state of growth. Overall, our findings provide a link between the proteolysis of a virulence regulator and the entry of a pathogen into an environmentally persistent state.
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Affiliation(s)
- Salvador Almagro-Moreno
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire, United States of America
- * E-mail:
| | - Tae K. Kim
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire, United States of America
| | - Karen Skorupski
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire, United States of America
| | - Ronald K. Taylor
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire, United States of America
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Rodrigues S, Paillard C, Le Pennec G, Dufour A, Bazire A. Vibrio tapetis, the Causative Agent of Brown Ring Disease, Forms Biofilms with Spherical Components. Front Microbiol 2015; 6:1384. [PMID: 26696991 PMCID: PMC4672067 DOI: 10.3389/fmicb.2015.01384] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2015] [Accepted: 11/20/2015] [Indexed: 02/05/2023] Open
Abstract
Vibrio tapetis is a marine bacterium causing Brown Ring Disease (BRD) in the Manila clam Ruditapes philippinarum. V. tapetis biofilm formation remains unexplored depite the fact that it might be linked to pathogenicity. Our objectives were to characterize the in vitro biofilm formation of V. tapetis and evaluate the effects of culture conditions. Biofilm structure and its matrix composition were examined by confocal laser scanning microscopy and scanning electron microscopy. V. tapetis was able to form biofilms on a glass substratum within 24 h. Polysaccharides and extracellular DNA of the biofilm matrixes were differently distributed depending on the V. tapetis strains. Spherical components of about 1-2 μm diameter were found at the biofilm surface. They contain DNA, proteins, and seemed to be physically linked to bacteria and of cellular nature. Transmission electron microscopy showed that the spherical components were devoid of internal compartments. Temperatures >21°C inhibit BRD whereas low salinity (2%) favor it, none of the both conditions altered V. tapetis' ability to form biofilms in vitro. We suggest therefore that biofilm formation could play a role in the persistence of the pathogen in clam than in BRD symptoms.
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Affiliation(s)
- Sophie Rodrigues
- Université de Bretagne-Sud, EA 3884, LBCM, IUEMLorient, France
- UMR 6539 Laboratoire des Sciences de l'Environnement Marin, Centre National de la Recherche Scientifique, Institut Universitaire Européen de la Mer, Université de Brest, UBO, IRD, IfremerPlouzané, France
| | - Christine Paillard
- UMR 6539 Laboratoire des Sciences de l'Environnement Marin, Centre National de la Recherche Scientifique, Institut Universitaire Européen de la Mer, Université de Brest, UBO, IRD, IfremerPlouzané, France
| | - Gaël Le Pennec
- Université de Bretagne-Sud, EA 3884, LBCM, IUEMLorient, France
| | - Alain Dufour
- Université de Bretagne-Sud, EA 3884, LBCM, IUEMLorient, France
- *Correspondence: Alain Dufour
| | - Alexis Bazire
- Université de Bretagne-Sud, EA 3884, LBCM, IUEMLorient, France
- *Alexis Bazire
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Ramamurthy T, Ghosh A, Pazhani GP, Shinoda S. Current Perspectives on Viable but Non-Culturable (VBNC) Pathogenic Bacteria. Front Public Health 2014; 2:103. [PMID: 25133139 PMCID: PMC4116801 DOI: 10.3389/fpubh.2014.00103] [Citation(s) in RCA: 248] [Impact Index Per Article: 24.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2014] [Accepted: 07/15/2014] [Indexed: 11/07/2022] Open
Abstract
Under stress conditions, many species of bacteria enter into starvation mode of metabolism or a physiologically viable but non-culturable (VBNC) state. Several human pathogenic bacteria have been reported to enter into the VBNC state under these conditions. The pathogenic VBNC bacteria cannot be grown using conventional culture media, although they continue to retain their viability and express their virulence. Though there have been debates on the VBNC concept in the past, several molecular studies have shown that not only can the VBNC state be induced under in vitro conditions but also that resuscitation from this state is possible under appropriate conditions. The most notable advance in resuscitating VBNC bacteria is the discovery of resuscitation-promoting factor (Rpf), which is a bacterial cytokines found in both Gram-positive and Gram-negative organisms. VBNC state is a survival strategy adopted by the bacteria, which has important implication in several fields, including environmental monitoring, food technology, and infectious disease management; and hence it is important to investigate the association of bacterial pathogens under VBNC state and the water/foodborne outbreaks. In this review, we describe various aspects of VBNC bacteria, which include their proteomic and genetic profiles under the VBNC state, conditions of resuscitation, methods of detection, antibiotic resistance, and observations on Rpf.
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Affiliation(s)
| | - Amit Ghosh
- National Institute of Cholera and Enteric Diseases (NICED) , Kolkata , India
| | - Gururaja P Pazhani
- National Institute of Cholera and Enteric Diseases (NICED) , Kolkata , India
| | - Sumio Shinoda
- Collaborative Research Center of Okayama University for Infectious Diseases in India, NICED , Kolkata , India
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Induction, resuscitation and quantitative real-time polymerase chain reaction analyses of viable but nonculturable Vibrio vulnificus in artificial sea water. World J Microbiol Biotechnol 2014; 30:2205-12. [DOI: 10.1007/s11274-014-1640-1] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2013] [Accepted: 03/16/2014] [Indexed: 12/19/2022]
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Association of a D-alanyl-D-alanine carboxypeptidase gene with the formation of aberrantly shaped cells during the induction of viable but nonculturable Vibrio parahaemolyticus. Appl Environ Microbiol 2013; 79:7305-12. [PMID: 24056454 DOI: 10.1128/aem.01723-13] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Vibrio parahaemolyticus is a halophilic Gram-negative bacterium that causes human gastroenteritis. When the viable but nonculturable (VBNC) state of this bacterium was induced by incubation at 4°C in Morita minimal salt solution containing 0.5% NaCl, the rod-shaped cells became coccoid, and various aberrantly shaped intermediates were formed in the initial stage. This study examined the factors that influence the formation of these aberrantly shaped cells. The proportion of aberrantly shaped cells was not affected in a medium containing D-cycloserine (50 μg/ml) but was lower in a medium containing cephalosporin C (10 μg/ml) than in the control medium without antibiotics. The proportion of aberrantly shaped cells was higher in a culture medium that contained 0.5% NaCl than in culture media containing 1.0 or 1.5% NaCl. The expression of 15 of 17 selected genes associated with cell wall synthesis was enhanced, and the expression of VP2468 (dacB), which encodes D-alanyl-D-alanine carboxypeptidase, was enhanced the most. The proportion of aberrantly shaped cells was significantly lower in the dacB mutant strain than in the parent strain, but the proportion was restored in the presence of the complementary dacB gene. This study suggests that disturbance of the dynamics of cell wall synthesis by enhanced expression of the VP2468 gene is associated with the formation of aberrantly shaped cells in the initial stage of induction of VBNC V. parahaemolyticus cells under specific conditions.
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Kassem II, Chandrashekhar K, Rajashekara G. Of energy and survival incognito: a relationship between viable but non-culturable cells formation and inorganic polyphosphate and formate metabolism in Campylobacter jejuni. Front Microbiol 2013; 4:183. [PMID: 23847606 PMCID: PMC3705167 DOI: 10.3389/fmicb.2013.00183] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2013] [Accepted: 06/18/2013] [Indexed: 12/12/2022] Open
Abstract
Campylobacter jejuni is a Gram-negative food-borne bacterium that can cause mild to serious diseases in humans. A variety of stress conditions including exposure to formic acid, a weak organic acid, can cause C. jejuni to form viable but non-culturable cells (VBNC), which was proposed as a potential survival mechanism. The inability to detect C. jejuni VBNC using standard culturing techniques may increase the risk of exposure to foods contaminated with this pathogen. However, little is known about the cellular mechanisms and triggers governing VBNC formation. Here, we discuss novel mechanisms that potentially affect VBNC formation in C. jejuni and emphasize the impact of formic acid on this process. Specifically, we highlight findings that show that impairing inorganic polyphosphate (poly-P) metabolism reduces the ability of C. jejuni to form VBNC in a medium containing formic acid. We also discuss the potential effect of poly-P and formate metabolism on energy homeostasis and cognate VBNC formation. The relationship between poly-P metabolism and VBNC formation under acid stress has only recently been identified and may represent a breakthrough in understanding this phenomenon and its impact on food safety.
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Affiliation(s)
- Issmat I Kassem
- Food Animal Health Research Program, Ohio Agricultural Research and Development Center, Department of Veterinary Preventive Medicine, The Ohio State University Wooster, OH, USA
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Wang HW, Chung CH, Ma TY, Wong HC. Roles of alkyl hydroperoxide reductase subunit C (AhpC) in viable but nonculturable Vibrio parahaemolyticus. Appl Environ Microbiol 2013; 79:3734-43. [PMID: 23563952 PMCID: PMC3675929 DOI: 10.1128/aem.00560-13] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2013] [Accepted: 04/03/2013] [Indexed: 11/20/2022] Open
Abstract
Alkyl hydroperoxide reductase subunit C (AhpC) is the catalytic subunit responsible for the detoxification of reactive oxygen species that form in bacterial cells or are derived from the host; thus, AhpC facilitates the survival of pathogenic bacteria under environmental stresses or during infection. This study investigates the role of AhpC in the induction and maintenance of a viable but nonculturable (VBNC) state in Vibrio parahaemolyticus. In this investigation, ahpC1 (VPA1683) and ahpC2 (VP0580) were identified in chromosomes II and I of this pathogen, respectively. Mutants with deletions of these two ahpC genes and their complementary strains were constructed from the parent strain KX-V231. The growth of these strains was monitored on tryptic soy agar-3% NaCl in the presence of the extrinsic peroxides H(2)O(2) and tert-butyl hydroperoxide (t-BOOH) at different incubation temperatures. The results revealed that both ahpC genes were protective against t-BOOH, while ahpC1 was protective against H(2)O(2). The protective function of ahpC2 at 4°C was higher than that of ahpC1. The times required to induce the VBNC state (4.7 weeks) at 4°C in a modified Morita mineral salt solution with 0.5% NaCl and then to maintain the VBNC state (4.7 weeks) in an ahpC2 mutant and an ahpC1 ahpC2 double mutant were significantly shorter than those for the parent strain (for induction, 6.2 weeks; for maintenance, 7.8 weeks) and the ahpC1 mutant (for induction, 6.0 weeks; for maintenance, 8.0 weeks) (P < 0.03). Complementation with an ahpC2 gene reversed the effects of the ahpC2 mutation in shortening the times for induction and maintenance of the VBNC state. This investigation identified the different functions of the two ahpC genes and confirmed the particular role of ahpC2 in the VBNC state of V. parahaemolyticus.
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Affiliation(s)
- Hen-Wei Wang
- Department of Microbiology, Soochow University, Taipei, Taiwan, Republic of China
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Su CP, Jane WN, Wong HC. Changes of ultrastructure and stress tolerance of Vibrio parahaemolyticus upon entering viable but nonculturable state. Int J Food Microbiol 2012; 160:360-6. [PMID: 23290246 DOI: 10.1016/j.ijfoodmicro.2012.11.012] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2011] [Revised: 07/21/2012] [Accepted: 11/07/2012] [Indexed: 11/17/2022]
Abstract
This study examined the change of ultrastructure and stress tolerance of the marine foodborne pathogen, Vibrio parahaemolyticus 1137, when incubated under viable but nonculturable (VBNC) state induction conditions for different time intervals. The rod-shaped V. parahaemolyticus cells in the exponential phase became coccoid cells in the VBNC state, with aberrantly shaped cells formed in the initial stage. In the aberrantly shaped cells, the cell wall was loosened, flexible and allowed the cell to bulge, and the formation of new and thin cell wall or the expansion of cell wall was also discerned primarily at the polar position, enclosing an empty cellular space. The thickness of the cell wall increased with the VBNC induction time, and was increased in cultures that were removed from the induction conditions and whose temperature was upshifted to 25°C for 1 or 2days. The incubation of V. parahaemolyticus under the VBNC induction conditions significantly enhanced its tolerance to heat, H(2)O(2) and low salinity, but sensitized it to bile salts. Tolerance to heat, bile salts and low salinity was significantly higher in the temperature upshifted cultures than in the corresponding unheated cultures, and the heated cultures were also more susceptible to H(2)O(2). The V. parahaemolyticus cultures that were incubated in the VBNC state induction conditions and the corresponding temperature-upshifted cultures exhibited unique changes in ultrastructure and tolerance to various stresses, unlike the nutrient-starved cells.
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Affiliation(s)
- Chao-Ping Su
- Department of Microbiology, Soochow University, Taipei, Taiwan 111, Republic of China
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Arias CR, Lafrentz S, Cai W, Olivares-Fuster O. Adaptive response to starvation in the fish pathogen Flavobacterium columnare: cell viability and ultrastructural changes. BMC Microbiol 2012; 12:266. [PMID: 23163917 PMCID: PMC3517764 DOI: 10.1186/1471-2180-12-266] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2012] [Accepted: 10/31/2012] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The ecology of columnaris disease, caused by Flavobacterium columnare, is poorly understood despite the economic losses that this disease inflicts on aquaculture farms worldwide. Currently, the natural reservoir for this pathogen is unknown but limited data have shown its ability to survive in water for extended periods of time. The objective of this study was to describe the ultrastructural changes that F. columnare cells undergo under starvation conditions. Four genetically distinct strains of this pathogen were monitored for 14 days in media without nutrients. Culturability and cell viability was assessed throughout the study. In addition, cell morphology and ultrastructure was analyzed using light microscopy, scanning electron microscopy, and transmission electron microscopy. Revival of starved cells under different nutrient conditions and the virulence potential of the starved cells were also investigated. RESULTS Starvation induced unique and consistent morphological changes in all strains studied. Cells maintained their length and did not transition into a shortened, coccus shape as observed in many other Gram negative bacteria. Flavobacterium columnare cells modified their shape by morphing into coiled forms that comprised more than 80% of all the cells after 2 weeks of starvation. Coiled cells remained culturable as determined by using a dilution to extinction strategy. Statistically significant differences in cell viability were found between strains although all were able to survive in absence of nutrients for at least 14 days. In later stages of starvation, an extracellular matrix was observed covering the coiled cells. A difference in growth curves between fresh and starved cultures was evident when cultures were 3-months old but not when cultures were starved for only 1 month. Revival of starved cultures under different nutrients revealed that cells return back to their original elongated rod shape upon encountering nutrients. Challenge experiments shown that starved cells were avirulent for a fish host model. CONCLUSIONS Specific morphological and ultrastructural changes allowed F. columnare cells to remain viable under adverse conditions. Those changes were reversed by the addition of nutrients. This bacterium can survive in water without nutrients for extended periods of time although long-term starvation appears to decrease cell fitness and resulted in loss of virulence.
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Affiliation(s)
- Covadonga R Arias
- Department of Fisheries and Allied Aquacultures, Aquatic Microbiology Laboratory, Auburn University, 203 Swingle Hall, Auburn, AL 36849, USA.
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Puspita ID, Kamagata Y, Tanaka M, Asano K, Nakatsu CH. Are uncultivated bacteria really uncultivable? Microbes Environ 2012; 27:356-66. [PMID: 23059723 PMCID: PMC4103542 DOI: 10.1264/jsme2.me12092] [Citation(s) in RCA: 87] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2012] [Accepted: 06/20/2012] [Indexed: 11/16/2022] Open
Abstract
Many strategies have been used to increase the number of bacterial cells that can be grown from environmental samples but cultivation efficiency remains a challenge for microbial ecologists. The difficulty of cultivating a fraction of bacteria in environmental samples can be classified into two non-exclusive categories. Bacterial taxa with no cultivated representatives for which appropriate laboratory conditions necessary for growth are yet to be identified. The other class is cells in a non-dividing state (also known as dormant or viable but not culturable cells) that require the removal or addition of certain factors to re-initiate growth. A number of strategies, from simple to high throughput techniques, are reviewed that have been used to increase the cultivation efficiency of environmental samples. Some of the underlying mechanisms that contribute to the success of these cultivation strategies are described. Overall this review emphasizes the need of researchers to first understand the factors that are hindering cultivation to identify the best strategies to improve cultivation efficiency.
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Affiliation(s)
- Indun Dewi Puspita
- Graduate School of Agriculture, Hokkaido University, N9 W9, Kita-ku, Sapporo, Hokkaido 060–8589,
Japan
| | - Yoichi Kamagata
- Graduate School of Agriculture, Hokkaido University, N9 W9, Kita-ku, Sapporo, Hokkaido 060–8589,
Japan
- Bioproduction Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), 2–17 Tsukisamu-Higashi, Toyohira, Sapporo, Hokkaido 062–8517,
Japan
| | - Michiko Tanaka
- Graduate School of Agriculture, Hokkaido University, N9 W9, Kita-ku, Sapporo, Hokkaido 060–8589,
Japan
| | - Kozo Asano
- Graduate School of Agriculture, Hokkaido University, N9 W9, Kita-ku, Sapporo, Hokkaido 060–8589,
Japan
| | - Cindy H. Nakatsu
- Graduate School of Agriculture, Hokkaido University, N9 W9, Kita-ku, Sapporo, Hokkaido 060–8589,
Japan
- Department of Agronomy, Purdue University, West Lafayette, Indiana 47907,
USA
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Haley BJ, Chen A, Grim CJ, Clark P, Diaz CM, Taviani E, Hasan NA, Sancomb E, Elnemr WM, Islam MA, Huq A, Colwell RR, Benediktsdóttir E. Vibrio cholerae in an Historically Cholera-Free Country. ENVIRONMENTAL MICROBIOLOGY REPORTS 2012; 4:381-389. [PMID: 23185212 PMCID: PMC3505037 DOI: 10.1111/j.1758-2229.2012.00332.x] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
We report the autochthonous existence of Vibrio cholerae in coastal waters of Iceland, a geothermally active country where cholera is absent and has never been reported. Seawater, mussel, and macroalgae samples were collected close to and distant from sites where geothermal activity causes a significant increase in water temperature during low tides. V. cholerae was detected only at geothermal-influenced sites during low-tides. None of the V. cholerae isolates encoded cholera toxin (ctxAB) and all were non-O1/non-O139 serogroups. However, all isolates encoded other virulence factors that are associated with cholera as well as extra-intestinal V. cholerae infections. The virulence factors were functional at temperatures of coastal waters of Iceland, suggesting an ecological role. It is noteworthy that V. cholerae was isolated from samples collected at sites distant from anthropogenic influence, supporting the conclusion that V. cholerae is autochthonous to the aquatic environment of Iceland.
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Affiliation(s)
- Bradd J. Haley
- Maryland Pathogen Research Institute, University of Maryland, College Park, MD 20742, USA
| | - Arlene Chen
- Maryland Pathogen Research Institute, University of Maryland, College Park, MD 20742, USA
| | - Christopher J. Grim
- Maryland Pathogen Research Institute, University of Maryland, College Park, MD 20742, USA
| | - Philip Clark
- Maryland Pathogen Research Institute, University of Maryland, College Park, MD 20742, USA
| | - Celia Municio Diaz
- Institute of Biology, Askja, University of Iceland, 101 Reykjavík, Iceland
| | - Elisa Taviani
- Maryland Pathogen Research Institute, University of Maryland, College Park, MD 20742, USA
| | - Nur A. Hasan
- Maryland Pathogen Research Institute, University of Maryland, College Park, MD 20742, USA
- CosmosID™, 387 Technology Dr., College Park, MD 20742, USA
| | - Elizabeth Sancomb
- Maryland Pathogen Research Institute, University of Maryland, College Park, MD 20742, USA
| | - Wessam Mahmoud Elnemr
- Maryland Pathogen Research Institute, University of Maryland, College Park, MD 20742, USA
| | - Muhammad A. Islam
- Institute for the Biotechnology of Infectious Diseases, University of Technology, Sydney, NSW 2007, Australia
| | - Anwar Huq
- Maryland Pathogen Research Institute, University of Maryland, College Park, MD 20742, USA
| | - Rita R. Colwell
- Maryland Pathogen Research Institute, University of Maryland, College Park, MD 20742, USA
- CosmosID™, 387 Technology Dr., College Park, MD 20742, USA
- Center of Bioinformatics and Computational Biology, University of Maryland Institute of Advanced Computer Studies, University of Maryland, College Park, MD 20742, USA
- Johns Hopkins Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD 21205, USA
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Serpaggi V, Remize F, Recorbet G, Gaudot-Dumas E, Sequeira-Le Grand A, Alexandre H. Characterization of the "viable but nonculturable" (VBNC) state in the wine spoilage yeast Brettanomyces. Food Microbiol 2012; 30:438-47. [PMID: 22365358 DOI: 10.1016/j.fm.2011.12.020] [Citation(s) in RCA: 101] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2011] [Revised: 12/22/2011] [Accepted: 12/23/2011] [Indexed: 11/28/2022]
Abstract
Although the viable but not culturable (VBNC) state has been studied in detail in bacteria, it has been suggested that maintenance of viability with loss of culturability also exists in eukaryotic cells, such as in the wine spoilage yeast Brettanomyces. To provide conclusive evidence for the existence of a VBNC state in this yeast, we investigated its capacity to become viable and nonculturable after sulfite stress, and its ability to recover culturability after stressor removal. Sulfite addition induced loss of culturability but maintenance of viability. Increasing the medium pH to decrease the concentration of toxic SO(2) allowed yeast cells to become culturable again, thus demonstrating the occurrence of a VBNC state in Brettanomyces upon SO(2) exposure. Relative to culturable Brettanomyces, VBNC yeast cells were found to display a 22% decrease in size on the basis of laser granulometry. Assays for 4-ethylguaiacol and 4-ethylphenol, volatile phenols produced by Brettanomyces, indicated that spoilage compound production could persist in VBNC cells. These morphological and physiological changes in VBNC Brettanomyces were coupled to extensive protein pattern modifications, as inferred by comparative two-dimensional electrophoresis and mass spectrometric analyses. Upon identification of 53 proteins out of the 168 spots whose abundance was significantly modified in treated cells relative to control, we propose that the SO(2)-induced VBNC state in Brettanomyces is characterized by a reduced glycolytic flux coupled to changes in redox homeostatis/protein turnover-related processes. This study points out the existence of common mechanisms between yeast and bacteria upon entry to the VBNC state.
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Affiliation(s)
- Virginie Serpaggi
- Institut Universitaire de la Vigne et du Vin Jules Guyot, Université de Bourgogne, Rue Claude Ladrey, BP 27877, F-21078 Dijon Cedex, France
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Abstract
Bacteria survive treatments with antimicrobial agents; they achieve this in two ways. Firstly, bacteria quickly become tolerant to these agents. This tolerance is temporary, reversible, and associated with slowing of the multiplication rate. Secondly, bacteria can undergo genetic mutations leading to permanent clonal resistance to antimicrobial agents. In patients with infections, nonmultiplying bacteria, some of which may be viable but nonculturable, exist side by side with multiplying bacteria. Current antibiotics capable of killing actively multiplying bacteria have very limited or no effect against nonmultiplying bacteria. Treatment of such infections requires a regimen of multiple antimicrobial agents in order to control nonmultiplying persistent bacteria. This is especially important in tuberculosis where there is co-existence of slowly multiplying tolerant bacteria with fast growing sensitive organisms. For this reason, a prolonged length of chemotherapy, lasting 6 months, is necessary to achieve cure. This long duration of treatment is due to the slow, inadequate effect of antibiotics on nonmultiplying persistent bacteria. Similar problems with eradication of persistent bacteria are evident in the treatment of biofilms. These bacteria serve as a pool for recurrent infections. Extended courses of antibiotics increase the likelihood of genetic resistance, raise the cost of treatments, and lead to more side effects.
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Affiliation(s)
- Yanmin Hu
- Centre for Infection, St George's University of London, London, UK.
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Krebs SJ, Taylor RK. Nutrient-dependent, rapid transition of Vibrio cholerae to coccoid morphology and expression of the toxin co-regulated pilus in this form. MICROBIOLOGY-SGM 2011; 157:2942-2953. [PMID: 21778208 DOI: 10.1099/mic.0.048561-0] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The acute diarrhoeal disease cholera is caused by the aquatic pathogen Vibrio cholerae upon ingestion of contaminated food or water by the human host. The mechanisms by which V. cholerae is able to persist and survive in the host and aquatic environments have been studied for years; however, little is known about the factors involved in the adaptation or response of V. cholerae transitioning between these two environments. The transition from bacillary to coccoid morphology is thought to be one mechanism of survival that V. cholerae uses in response to environmental stress. Coccoid morphology has been observed for V. cholerae while in a viable but non-culturable (VBNC) state, during times of nutrient limitation, and in the water-diluted stool of cholera-infected patients. In this study we sought conditions to study the coccoid morphology of V. cholerae, and found that coccoid-shaped cells can express and produce the virulence factor toxin co-regulated pilus (TCP) and are able to colonize the infant mouse to the same extent as bacillus-shaped cells. This study suggests that TCP may be one factor that V. cholerae utilizes for adaptation and survival during the transition between the host and the aquatic environment.
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Affiliation(s)
- Shelly J Krebs
- Department of Microbiology and Immunology, Dartmouth Medical School, Hanover, NH 03755, USA
| | - Ronald K Taylor
- Department of Microbiology and Immunology, Dartmouth Medical School, Hanover, NH 03755, USA
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Pawlowski DR, Metzger DJ, Raslawsky A, Howlett A, Siebert G, Karalus RJ, Garrett S, Whitehouse CA. Entry of Yersinia pestis into the viable but nonculturable state in a low-temperature tap water microcosm. PLoS One 2011; 6:e17585. [PMID: 21436885 PMCID: PMC3059211 DOI: 10.1371/journal.pone.0017585] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2010] [Accepted: 01/24/2011] [Indexed: 01/14/2023] Open
Abstract
Yersinia pestis, the causative agent of plague, has caused several pandemics throughout history and remains endemic in the rodent populations of the western United States. More recently, Y. pestis is one of several bacterial pathogens considered to be a potential agent of bioterrorism. Thus, elucidating potential mechanisms of survival and persistence in the environment would be important in the event of an intentional release of the organism. One such mechanism is entry into the viable but non-culturable (VBNC) state, as has been demonstrated for several other bacterial pathogens. In this study, we showed that Y. pestis became nonculturable by normal laboratory methods after 21 days in a low-temperature tap water microcosm. We further show evidence that, after the loss of culturability, the cells remained viable by using a variety of criteria, including cellular membrane integrity, uptake and incorporation of radiolabeled amino acids, and protection of genomic DNA from DNase I digestion. Additionally, we identified morphological and ultrastructural characteristics of Y. pestis VBNC cells, such as cell rounding and large periplasmic spaces, by electron microscopy, which are consistent with entry into the VBNC state in other bacteria. Finally, we demonstrated resuscitation of a small number of the non-culturable cells. This study provides compelling evidence that Y. pestis persists in a low-temperature tap water microcosm in a viable state yet is unable to be cultured under normal laboratory conditions, which may prove useful in risk assessment and remediation efforts, particularly in the event of an intentional release of this organism.
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Lennon JT, Jones SE. Microbial seed banks: the ecological and evolutionary implications of dormancy. Nat Rev Microbiol 2011; 9:119-30. [PMID: 21233850 DOI: 10.1038/nrmicro2504] [Citation(s) in RCA: 870] [Impact Index Per Article: 66.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Dormancy is a bet-hedging strategy used by a wide range of taxa, including microorganisms. It refers to an organism's ability to enter a reversible state of low metabolic activity when faced with unfavourable environmental conditions. Dormant microorganisms generate a seed bank, which comprises individuals that are capable of being resuscitated following environmental change. In this Review, we highlight mechanisms that have evolved in microorganisms to allow them to successfully enter and exit a dormant state, and discuss the implications of microbial seed banks for evolutionary dynamics, population persistence, maintenance of biodiversity, and the stability of ecosystem processes.
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Affiliation(s)
- Jay T Lennon
- W.K. Kellogg Biological Station, Michigan State University, 3700 East Gull Lake Drive, Hickory Corners, Michigan 49060, USA.
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47
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Senoh M, Ghosh-Banerjee J, Ramamurthy T, Hamabata T, Kurakawa T, Takeda M, Colwell RR, Nair GB, Takeda Y. Conversion of viable but nonculturable Vibrio cholerae to the culturable state by co-culture with eukaryotic cells. Microbiol Immunol 2010; 54:502-7. [DOI: 10.1111/j.1348-0421.2010.00245.x] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Chen SY, Jane WN, Chen YS, Wong HC. Morphological changes of Vibrio parahaemolyticus under cold and starvation stresses. Int J Food Microbiol 2009; 129:157-65. [DOI: 10.1016/j.ijfoodmicro.2008.11.009] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2008] [Revised: 10/30/2008] [Accepted: 11/09/2008] [Indexed: 10/21/2022]
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50
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Álvarez B, López MM, Biosca EG. Survival strategies and pathogenicity of Ralstonia solanacearum phylotype II subjected to prolonged starvation in environmental water microcosms. MICROBIOLOGY-SGM 2008; 154:3590-3598. [PMID: 18957611 DOI: 10.1099/mic.0.2008/019448-0] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Survival strategies exhibited over 4 years by Ralstonia solanacearum phylotype (ph) II biovar (bv) 2 in environmental water microcosms were examined. The bacterium is a devastating phytopathogen whose ph II bv 2 causes bacterial wilt in solanaceous crops and ornamental plants. Outbreaks of the disease may originate from dissemination of the pathogen in watercourses, where it has to cope with prolonged nutrient limitation. To ascertain the effect of long-term starvation on survival and pathogenicity of R. solanacearum in natural water microcosms, survival experiments were conducted. Microcosms were prepared from different sterile river water samples, inoculated separately with two European strains of ph II at 10(6) c.f.u. ml(-1) and maintained at 24 degrees C for 4 years. In all assayed waters, starved R. solanacearum remained in a non-growing but culturable state during the first year, maintaining approximately the initial numbers. Thereafter, part of the population of R. solanacearum progressively lost the ability to form colonies, and non-culturable but metabolically active cells appeared. During the whole period, the bacterium remained pathogenic on host plants and underwent a transition from typical bacilli to small cocci which tended to aggregate. Some starved R. solanacearum cells filamented and formed buds. Starvation response, viable but non-culturable state, morphological changes and aggregation have not previously been reported for this pathogen as survival mechanisms induced in oligotrophic conditions. The potential existence of long-starved pathogenic cells in environmental waters may raise new concerns about the epidemiology of bacterial wilt disease.
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Affiliation(s)
- Belén Álvarez
- Instituto Valenciano de Investigaciones Agrarias (IVIA), Carretera de Moncada a Náquera km 4.5, Moncada 46113, Valencia, Spain
| | - María M López
- Instituto Valenciano de Investigaciones Agrarias (IVIA), Carretera de Moncada a Náquera km 4.5, Moncada 46113, Valencia, Spain
| | - Elena G Biosca
- Departamento de Microbiología y Ecología, Universidad de Valencia, Av. Dr Moliner 50, Burjasot 46100, Valencia, Spain
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