1
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Debnath A, Miyoshi SI. Effect of physicochemical and microbiological factors on the development of viable but non-culturable and resuscitation states of Vibrio cholerae. Arch Microbiol 2024; 206:224. [PMID: 38642319 DOI: 10.1007/s00203-024-03956-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2024] [Revised: 04/06/2024] [Accepted: 04/08/2024] [Indexed: 04/22/2024]
Abstract
BACKGROUND Vibrio cholerae can endure harsh environmental conditions by transitioning into viable but non-culturable (VBNC) form and resuscitate upon return of appropriate conditions. METHOD In this study, we assessed the impact of physicochemical and microbiological factors, on the development of low temperature-induced VBNC state and subsequent recovery by temperature upshift. RESULTS In estuarine water, Vibrio cholerae exhibits a slower decline in culturability over a period of 77 days as compared to 10 days in fresh water. When variable cell numbers from different growth phases were used for VBNC induction, it was observed that the higher inoculum size (106-107 cfu ml-1) from the late log phase culture appears to be crucial for entering the VBNC state. Conversely, starved cells could enter the VBNC state with an initial inoculum of 104-105 cfu ml-1, followed by resuscitation as well. The addition of glucose, GlcNAc and mannitol differentially affects progression into VBNC, while the addition of tryptone, yeast extract and casamino acid facilitated early entry into the VBNC state and shortened the length of the recovery period. CONCLUSION Altogether these findings demonstrated that the ionic strength of water, inoculum size and the availability of nutrients played distinct roles during VBNC induction and resuscitation.
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Affiliation(s)
- Anusuya Debnath
- Dentistry and Pharmaceutical Sciences, Okayama University, 1-1-1, Tsushimanaka, Kita-ku, 700-8530, Japan.
- Department of Biotechnology, Brainware University, Kolkata, India.
| | - Shin-Ichi Miyoshi
- Dentistry and Pharmaceutical Sciences, Okayama University, 1-1-1, Tsushimanaka, Kita-ku, 700-8530, Japan
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2
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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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3
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Pazos-Rojas LA, Cuellar-Sánchez A, Romero-Cerón AL, Rivera-Urbalejo A, Van Dillewijn P, Luna-Vital DA, Muñoz-Rojas J, Morales-García YE, Bustillos-Cristales MDR. The Viable but Non-Culturable (VBNC) State, a Poorly Explored Aspect of Beneficial Bacteria. Microorganisms 2023; 12:39. [PMID: 38257865 PMCID: PMC10818521 DOI: 10.3390/microorganisms12010039] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2023] [Revised: 12/20/2023] [Accepted: 12/22/2023] [Indexed: 01/24/2024] Open
Abstract
Many bacteria have the ability to survive in challenging environments; however, they cannot all grow on standard culture media, a phenomenon known as the viable but non-culturable (VBNC) state. Bacteria commonly enter the VBNC state under nutrient-poor environments or under stressful conditions. This review explores the concept of the VBNC state, providing insights into the beneficial bacteria known to employ this strategy. The investigation covers different chemical and physical factors that can induce the latency state, cell features, and gene expression observed in cells in the VBNC state. The review also covers the significance and applications of beneficial bacteria, methods of evaluating bacterial viability, the ability of bacteria to persist in environments associated with higher organisms, and the factors that facilitate the return to the culturable state. Knowledge about beneficial bacteria capable of entering the VBNC state remains limited; however, beneficial bacteria in this state could face adverse environmental conditions and return to a culturable state when the conditions become suitable and continue to exert their beneficial effects. Likewise, this unique feature positions them as potential candidates for healthcare applications, such as the use of probiotic bacteria to enhance human health, applications in industrial microbiology for the production of prebiotics and functional foods, and in the beer and wine industry. Moreover, their use in formulations to increase crop yields and for bacterial bioremediation offers an alternative pathway to harness their beneficial attributes.
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Affiliation(s)
- Laura Abisaí Pazos-Rojas
- Faculty of Stomatology, Meritorious Autonomous University of Puebla (BUAP), Puebla 72570, Mexico; (L.A.P.-R.); (A.R.-U.)
- Monterrey Institute of Technology, School of Engineering and Sciences, Monterrey 64700, Mexico; (A.C.-S.); (A.L.R.-C.); (D.A.L.-V.)
| | - Alma Cuellar-Sánchez
- Monterrey Institute of Technology, School of Engineering and Sciences, Monterrey 64700, Mexico; (A.C.-S.); (A.L.R.-C.); (D.A.L.-V.)
| | - Ana Laura Romero-Cerón
- Monterrey Institute of Technology, School of Engineering and Sciences, Monterrey 64700, Mexico; (A.C.-S.); (A.L.R.-C.); (D.A.L.-V.)
| | - América Rivera-Urbalejo
- Faculty of Stomatology, Meritorious Autonomous University of Puebla (BUAP), Puebla 72570, Mexico; (L.A.P.-R.); (A.R.-U.)
| | - Pieter Van Dillewijn
- Department of Environmental Protection, Estación Experimental del Zaidín, Consejo Superior de Investigaciones Científicas, 18008 Granada, Spain;
| | - Diego Armando Luna-Vital
- Monterrey Institute of Technology, School of Engineering and Sciences, Monterrey 64700, Mexico; (A.C.-S.); (A.L.R.-C.); (D.A.L.-V.)
| | - Jesús Muñoz-Rojas
- Ecology and Survival of Microorganisms Group, Laboratory of Microbial Molecular Ecology (LEMM), Center for Research in Microbiological Sciences, Institute of Sciences, Meritorious Autonomous University of Puebla (BUAP), Puebla 72570, Mexico;
| | - Yolanda Elizabeth Morales-García
- Ecology and Survival of Microorganisms Group, Laboratory of Microbial Molecular Ecology (LEMM), Center for Research in Microbiological Sciences, Institute of Sciences, Meritorious Autonomous University of Puebla (BUAP), Puebla 72570, Mexico;
- Faculty of Biological Sciences, Meritorious Autonomous University of Puebla (BUAP), Puebla 72570, Mexico
| | - María del Rocío Bustillos-Cristales
- Ecology and Survival of Microorganisms Group, Laboratory of Microbial Molecular Ecology (LEMM), Center for Research in Microbiological Sciences, Institute of Sciences, Meritorious Autonomous University of Puebla (BUAP), Puebla 72570, Mexico;
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4
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König P, Wilhelm A, Schaudinn C, Poehlein A, Daniel R, Widera M, Averhoff B, Müller V. The VBNC state: a fundamental survival strategy of Acinetobacter baumannii. mBio 2023; 14:e0213923. [PMID: 37768061 PMCID: PMC10653857 DOI: 10.1128/mbio.02139-23] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2023] [Accepted: 08/14/2023] [Indexed: 09/29/2023] Open
Abstract
IMPORTANCE Currently, the viable but non-culturable (VBNC) state is an underappreciated niche for pathogenic bacteria which provides a continuous source for recurrent infections and transmission. We propose the VBNC state to be a global persistence mechanism used by various A. baumannii strains to cope with many stresses it is confronted with in the clinical environment and in the host. This requires a novel strategy to detect viable cells of this pathogen that is not only based on plating assays.
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Affiliation(s)
- Patricia König
- Department of Molecular Microbiology & Bioenergetics, Institute of Molecular Biosciences, Goethe-University, Frankfurt am Main, Germany
| | - Alexander Wilhelm
- Institute for Medical Virology, University Hospital Frankfurt, Goethe University, Frankfurt am Main, Germany
| | - Christoph Schaudinn
- Advanced Light and Electron Microscopy ZBS4, Robert-Koch-Institute, Berlin, Germany
| | - Anja Poehlein
- Department of Genomic and Applied Microbiology & Göttingen Genomics Laboratory, Institute of Microbiology and Genetics, Georg-August University of Göttingen, Göttingen, Germany
| | - Rolf Daniel
- Department of Genomic and Applied Microbiology & Göttingen Genomics Laboratory, Institute of Microbiology and Genetics, Georg-August University of Göttingen, Göttingen, Germany
| | - Marek Widera
- Institute for Medical Virology, University Hospital Frankfurt, Goethe University, Frankfurt am Main, Germany
| | - Beate Averhoff
- Department of Molecular Microbiology & Bioenergetics, Institute of Molecular Biosciences, Goethe-University, Frankfurt am Main, Germany
| | - Volker Müller
- Department of Molecular Microbiology & Bioenergetics, Institute of Molecular Biosciences, Goethe-University, Frankfurt am Main, Germany
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5
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Qin ZX, Chen GZ, Yang QQ, Wu YJ, Sun CQ, Yang XM, Luo M, Yi CR, Zhu J, Chen WH, Liu Z. Cross-Platform Transcriptomic Data Integration, Profiling, and Mining in Vibrio cholerae. Microbiol Spectr 2023; 11:e0536922. [PMID: 37191528 PMCID: PMC10269641 DOI: 10.1128/spectrum.05369-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2022] [Accepted: 04/24/2023] [Indexed: 05/17/2023] Open
Abstract
A large number of transcriptome studies generate important data and information for the study of pathogenic mechanisms of pathogens, including Vibrio cholerae. V. cholerae transcriptome data include RNA-seq and microarray: microarray data mainly include clinical human and environmental samples, and RNA-seq data mainly focus on laboratory processing conditions, including different stresses and experimental animals in vivo. In this study, we integrated the data sets of both platforms using Rank-in and the Limma R package normalized Between Arrays function, achieving the first cross-platform transcriptome data integration of V. cholerae. By integrating the entire transcriptome data, we obtained the profiles of the most active or silent genes. By transferring the integrated expression profiles into the weighted correlation network analysis (WGCNA) pipeline, we identified the important functional modules of V. cholerae in vitro stress treatment, gene manipulation, and in vitro culture as DNA transposon, chemotaxis and signaling, signal transduction, and secondary metabolic pathways, respectively. The analysis of functional module hub genes revealed the uniqueness of clinical human samples; however, under specific expression patterning, the Δhns, ΔoxyR1 strains, and tobramycin treatment group showed high expression profile similarity with human samples. By constructing a protein-protein interaction (PPI) interaction network, we discovered several unreported novel protein interactions within transposon functional modules. IMPORTANCE We used two techniques to integrate RNA-seq data for laboratory studies with clinical microarray data for the first time. The interactions between V. cholerae genes were obtained from a global perspective, as well as comparing the similarity between clinical human samples and the current experimental conditions, and uncovering the functional modules that play a major role under different conditions. We believe that this data integration can provide us with some insight and basis for elucidating the pathogenesis and clinical control of V. cholerae.
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Affiliation(s)
- Zi-Xin Qin
- Department of Biotechnology, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Guo-Zhong Chen
- Department of Biotechnology, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Qian-Qian Yang
- Department of Biotechnology, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Ying-Jian Wu
- Department of Bioinformatics and Systems Biology, Huazhong University of Science and Technology College of Life Sciences and Technology, Wuhan, Hubei, China
| | - Chu-Qing Sun
- Department of Bioinformatics and Systems Biology, Huazhong University of Science and Technology College of Life Sciences and Technology, Wuhan, Hubei, China
| | - Xiao-Man Yang
- Department of Biotechnology, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Mei Luo
- Department of Biotechnology, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Chun-Rong Yi
- Department of Biotechnology, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Jun Zhu
- Department of Biotechnology, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Wei-Hua Chen
- Department of Bioinformatics and Systems Biology, Huazhong University of Science and Technology College of Life Sciences and Technology, Wuhan, Hubei, China
| | - Zhi Liu
- Department of Biotechnology, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei, China
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6
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Ayibieke A, Nishiyama A, Senoh M, Hamabata T. Gene expression analysis during the conversion from a viable but nonculturable to culturable state in Vibrio cholerae. Gene 2023; 863:147289. [PMID: 36804851 DOI: 10.1016/j.gene.2023.147289] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2022] [Revised: 01/26/2023] [Accepted: 02/13/2023] [Indexed: 02/18/2023]
Abstract
We previously reported that Vibrio cholerae in a viable but non-culturable (VBNC) state can be converted to a culturable state by treatment with catalase. This finding enabled us to develop an assay system to observe the time course of the conversion from VBNC to culturable in V. cholerae. VBNC cells began to convert to culturable cells as early as 2 h after catalase supplementation. Gene expression in VBNC cells during catalase treatment was analyzed using RNA microarray. Many ribosomal DNA genes were stimulated 6 h post catalase exposure, suggesting that the conversion-driving signal started prior to 6 h. Focusing on the period prior to cell proliferation, we found that 16 genes might be involved in the conversion mechanism in V. cholerae, and they showed enhanced expression at 2 h and 4 h after catalase addition. These upregulated genes included phage shock proteins (pspA, B, and C), alternative sigma factor (rpoE) and its negative regulator (rseA), cobW C terminal domain-containing protein, damage-inducible helicase (dinG), cholerae toxin secretion protein epsM, HTH-type transcription regulator (iscR), mechanosensitive ion channel family protein, anthranilate synthase component I, fructose-specific IIBC component, molybdenum import ATP-binding protein (modC), LysE family translocator, putative organic hydroperoxide resistance protein, and a hypothetical protein. This study identified genes involved in the catalase-induced conversion of V. cholerae VBNC cells to a culturable state and provided valuable insights into the mechanisms involved in the conversion process.
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Affiliation(s)
- Alafate Ayibieke
- Research Institute, National Center for Global Health and Medicine, 1-21-1 Toyama, Shinjuku, 162-8655 Tokyo, Japan
| | - Ayae Nishiyama
- Research Institute, National Center for Global Health and Medicine, 1-21-1 Toyama, Shinjuku, 162-8655 Tokyo, Japan
| | - Mitsutoshi Senoh
- Department of Bacteriology II, National Institute of Infectious Diseases, 4-7-1 Gakuen, Musashimurayama, 208-0011 Tokyo, Japan
| | - Takashi Hamabata
- Research Institute, National Center for Global Health and Medicine, 1-21-1 Toyama, Shinjuku, 162-8655 Tokyo, Japan.
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7
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Prosdocimi EM, Arioli S, Mapelli F, Zeaiter Z, Fusi M, Daffonchio D, Borin S, Crotti E. Cell phenotype changes and oxidative stress response in Vibrio spp. induced into viable but non-culturable (VBNC) state. ANN MICROBIOL 2023. [DOI: 10.1186/s13213-022-01703-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Abstract
Purpose
Aquatic bacteria of the genus Vibrio include animal and human pathogens. The occurrence of Vibrio-related diseases has been associated with the current climate change-driven increase of sea surface temperature. Vibrio spp. can enter into the viable but non-culturable (VBNC) state, as a consequence of starvation in seawater at low temperatures. In such physiological state, Vibrio cells are no longer culturable on standard media agar plates but can resuscitate if incubated at 30 °C prior to plating, retaining virulence. Since limited information is available on regards to this topic, in this work, we characterized the phenotypic changes of four Vibrio spp. strains (one laboratory strain and three environmental isolates) in cold seawater microcosms, investigating the relationship between resuscitation and a hydrogen peroxide-induced oxidative stress.
Methods
Cell phenotypic changes and the effect of hydrogen peroxide and/or catalase addition to the medium were studied on VBNC and resuscitated cells by flow cytometry in microcosm experiments, paralleled by culturability experiments by plating.
Results
The cells of all the Vibrio strains changed their phenotype upon the induction of the VBNC state resulting in cell dwarfing and decrease in DNA quantity, losing the ability to grow on solid media. These features were partially or totally reverted when the cells were treated for resuscitation. Hydrogen peroxide at concentrations as low as 0.007 mM prevented resuscitation and a prolonged exposure to hydrogen peroxide at concentrations far under those inhibiting the growth of log-phase cells permanently damaged VBNC cells, which could not be resuscitated. However, the potential of culturability of VBNC cells could be preserved, at least for a part of the population, by plating the cells in the presence of catalase. The study also showed that during the resuscitation process, the cells gradually increased their resistance to hydrogen peroxide.
Conclusions
The timing and mode of induction of the VBNC state, as well as cell resuscitation and response to hydrogen peroxide, differed among Vibrio strains, indicating that induction and resuscitation from dormancy could vary in the context of species belonging to a single genus.
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8
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Wagley S. The Viable but Non-Culturable (VBNC) State in Vibrio Species: Why Studying the VBNC State Now Is More Exciting than Ever. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2023; 1404:253-268. [PMID: 36792880 DOI: 10.1007/978-3-031-22997-8_13] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/17/2023]
Abstract
During periods that are not conducive for growth or when facing stressful conditions, Vibrios enter a dormant state called the Viable But Non-Culturable (VBNC) state. In this chapter, I will analyse the role of the VBNC state in Vibrio species survival and pathogenesis and the molecular mechanisms regulating this complex phenomenon. I will emphasise some of the novel findings that make studying the VBNC state now more exciting than ever and its significance in the epidemiology of these pathogens and critical role in food safety.
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Affiliation(s)
- Sariqa Wagley
- Biosciences, Faculty of Health and Life Sciences, University of Exeter, Exeter, Devon, UK.
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9
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Bai K, Jiang N, Chen X, Xu X, Li J, Luo L. RNA-Seq Analysis Discovers the Critical Role of Rel in ppGpp Synthesis, Pathogenicity, and the VBNC State of Clavibacter michiganensis. PHYTOPATHOLOGY 2022; 112:1844-1858. [PMID: 35341314 DOI: 10.1094/phyto-01-22-0023-r] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
The viable but nonculturable (VBNC) state is a unique survival strategy of bacteria in response to stress conditions. It was confirmed that Clavibacter michiganensis, the causal agent of bacterial canker in tomato, could be induced into the VBNC state by exposure to CuSO4 in an oligotrophic solution. RNA-sequencing analysis was used to monitor the mechanisms of the VBNC state during CuSO4 induction in C. michiganensis. The results identified that numerous genes involved in stringent response, copper resistance, and stress resistance were upregulated, and some involved in cell division were downregulated significantly. The study investigated the importance of Rel, which is an essential enzyme in the synthesis of the molecular alarmone ppGpp, via the generation of a Δrel mutant and its complementation strain. Biological characterization revealed that deficiency of rel reduced the bacterial growth, production of exopolysaccharides, and pathogenicity as well as ppGpp production. The Δrel mutant increased the sensitivity to environmental stress, exhibiting reduced growth on minimal media and a propensity to enter the VBNC state in response to CuSO4. These findings have important implications for the understanding of survival mechanism and management of C. michiganensis and other phytopathogenic bacteria.
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Affiliation(s)
- Kaihong Bai
- Department of Plant Pathology, China Agricultural University, Beijing Key Laboratory of Seed Disease Testing and Control, MOA Key Lab of Pest Monitoring and Green Management, Beijing, 100193, P.R. China
| | - Na Jiang
- Department of Plant Pathology, China Agricultural University, Beijing Key Laboratory of Seed Disease Testing and Control, MOA Key Lab of Pest Monitoring and Green Management, Beijing, 100193, P.R. China
| | - Xing Chen
- Department of Plant Pathology, China Agricultural University, Beijing Key Laboratory of Seed Disease Testing and Control, MOA Key Lab of Pest Monitoring and Green Management, Beijing, 100193, P.R. China
| | - Xiaoli Xu
- Department of Plant Pathology, China Agricultural University, Beijing Key Laboratory of Seed Disease Testing and Control, MOA Key Lab of Pest Monitoring and Green Management, Beijing, 100193, P.R. China
| | - Jianqiang Li
- Department of Plant Pathology, China Agricultural University, Beijing Key Laboratory of Seed Disease Testing and Control, MOA Key Lab of Pest Monitoring and Green Management, Beijing, 100193, P.R. China
| | - Laixin Luo
- Department of Plant Pathology, China Agricultural University, Beijing Key Laboratory of Seed Disease Testing and Control, MOA Key Lab of Pest Monitoring and Green Management, Beijing, 100193, P.R. China
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10
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Ma L, Feng J, Zhang J, Lu X. Campylobacter biofilms. Microbiol Res 2022; 264:127149. [DOI: 10.1016/j.micres.2022.127149] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2022] [Revised: 07/26/2022] [Accepted: 07/26/2022] [Indexed: 11/27/2022]
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11
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He Y, Zhao J, Yin H, Deng Y. Transcriptome Analysis of Viable but Non-Culturable Brettanomyces bruxellensis Induced by Hop Bitter Acids. Front Microbiol 2022; 13:902110. [PMID: 35707174 PMCID: PMC9189414 DOI: 10.3389/fmicb.2022.902110] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2022] [Accepted: 04/11/2022] [Indexed: 11/13/2022] Open
Abstract
The viable but non-culturable (VBNC) state has been studied in detail in bacteria. However, it has received much less attention in eukaryotic cells. The induction of a VBNC beer-spoilage yeast (Brettanomyces bruxellensis) by hop bitter acids with different concentrations and its recovery were studied in this work. B. bruxellensis cells were completely induced into the VBNC state by treatment of 250 mg/L hop bitter acids for 2 h. The addition of catalase at a concentration of 2,000 U/plate on YPD agars enabled these VBNC cells to recover their culturability within 2 days. Moreover, the transcriptome profiling revealed that 267 and 197 genes were significantly changed upon VBNC state entry and resuscitation, respectively. The differentially expressed genes involved in the peroxisome activities, ABC transporter, organic acid metabolism, and TCA cycle were mainly downregulated in the VBNC cells. In contrast, the amino acid and carbohydrate metabolism, cell division, and DNA replication were promoted. This study supplies a theoretical basis for microbial risk assessment in the brewing industry.
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Affiliation(s)
- Yang He
- State Key Laboratory of Biological Fermentation Engineering of Beer, Tsingtao Brewery Co. Ltd., Qingdao, China
| | - Junfeng Zhao
- College of Food Science and Engineering, Henan University of Science and Technology, Luoyang, China
| | - Hua Yin
- State Key Laboratory of Biological Fermentation Engineering of Beer, Tsingtao Brewery Co. Ltd., Qingdao, China
| | - Yuan Deng
- Animal Products Processing Laboratory, Hunan Institute of Animal Husbandry and Veterinary Science, Changsha, China
- *Correspondence: Yuan Deng
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12
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Igere BE, Okoh AI, Nwodo UU. Non-serogroup O1/O139 agglutinable Vibrio cholerae: a phylogenetically and genealogically neglected yet emerging potential pathogen of clinical relevance. Arch Microbiol 2022; 204:323. [PMID: 35567650 PMCID: PMC9107296 DOI: 10.1007/s00203-022-02866-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2021] [Revised: 03/17/2022] [Accepted: 03/20/2022] [Indexed: 12/19/2022]
Abstract
Somatic antigen agglutinable type-1/139 Vibrio cholerae (SAAT-1/139-Vc) members or O1/O139 V. cholerae have been described by various investigators as pathogenic due to their increasing virulence potential and production of choleragen. Reported cholera outbreak cases around the world have been associated with these choleragenic V. cholerae with high case fatality affecting various human and animals. These virulent Vibrio members have shown genealogical and phylogenetic relationship with the avirulent somatic antigen non-agglutinable strains of 1/139 V. cholerae (SANAS-1/139- Vc) or O1/O139 non-agglutinating V. cholerae (O1/O139-NAG-Vc). Reports on implication of O1/O139-NAGVc members in most sporadic cholera/cholera-like cases of diarrhea, production of cholera toxin and transmission via consumption and/or contact with contaminated water/seafood are currently on the rise. Some reported sporadic cases of cholera outbreaks and observed change in nature has also been tracable to these non-agglutinable Vibrio members (O1/O139-NAGVc) yet there is a sustained paucity of research interest on the non-agglutinable V. cholerae members. The emergence of fulminating extraintestinal and systemic vibriosis is another aspect of SANAS-1/139- Vc implication which has received low attention in terms of research driven interest. This review addresses the need to appraise and continually expand research based studies on the somatic antigen non-serogroup agglutinable type-1/139 V.cholerae members which are currently prevalent in studies of water bodies, fruits/vegetables, foods and terrestrial environment. Our opinion is amassed from interest in integrated surveillance studies, management/control of cholera outbreaks as well as diarrhea and other disease-related cases both in the rural, suburban and urban metropolis.
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Affiliation(s)
- Bright E Igere
- Department of Microbiology and Biotechnology, Western Delta University, Oghara, Delta State, Nigeria. .,Applied and Environmental Microbiology Research Group, Department of Biochemistry and Microbiology, University of Fort Hare, Alice, 5700, South Africa. .,SAMRC Microbial Water Quality Monitoring Centre, University of Fort Hare, Alice, 5700, South Africa.
| | - Anthony I Okoh
- Applied and Environmental Microbiology Research Group, Department of Biochemistry and Microbiology, University of Fort Hare, Alice, 5700, South Africa.,SAMRC Microbial Water Quality Monitoring Centre, University of Fort Hare, Alice, 5700, South Africa.,Department of Environmental Health Sciences, College of Health Sciences, University of Sharjah, Sharjah, United Arab Emirates
| | - Uchechukwu U Nwodo
- Applied and Environmental Microbiology Research Group, Department of Biochemistry and Microbiology, University of Fort Hare, Alice, 5700, South Africa.,SAMRC Microbial Water Quality Monitoring Centre, University of Fort Hare, Alice, 5700, South Africa
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13
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Xiao Y, Wang Z, Sun W, Luan Y, Piao M, Deng Y. Characterization and formation mechanisms of viable, but putatively non-culturable brewer's yeast induced by isomerized hop extract. Lebensm Wiss Technol 2022. [DOI: 10.1016/j.lwt.2021.112974] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
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14
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Debnath A, Miyoshi SI. The Impact of Protease during Recovery from Viable but Non-Culturable (VBNC) State in Vibrio cholerae. Microorganisms 2021; 9:microorganisms9122618. [PMID: 34946219 PMCID: PMC8707003 DOI: 10.3390/microorganisms9122618] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2021] [Revised: 12/10/2021] [Accepted: 12/15/2021] [Indexed: 11/16/2022] Open
Abstract
Vibrio cholerae can survive cold stress by entering into a viable but non-culturable (VBNC) state, and resuscitation can be induced either by temperature upshift only or the addition of an anti-dormancy stimulant such as resuscitation-promoting factors (Rpfs) at suitable temperature. In this study, the role of proteinase K was analyzed as an Rpf in V. cholerae. A VBNC state was induced in V. cholerae AN59 in artificial seawater (ASW) media at 4 °C, and recovery could be achieved in filtered VBNC microcosm, called spent ASW media, merely by a temperature upshift to 37 °C. The resuscitation ability of spent ASW was further enhanced by the addition of proteinase K. The mode of action of proteinase K was investigated by comparing its effect on the growth of the VBNC and culturable state of V. cholerae in ASW and spent ASW media. The presence of proteinase K allowed culturable cells to grow faster in ASW by reducing the generation time. However, this effect of proteinase K was more pronounced in stressed VBNC cells. Moreover, proteinase K-supplemented spent ASW could also accelerate the transition of VBNC into recovered cells followed by rapid growth. Additionally, we found that dead bacterial cells were the substrate on which proteinase K acts to support high growth in spent ASW. So, the conclusion is that the proteinase K could efficiently promote the recovery and growth of dormant VBNC cells at higher temperatures by decreasing the duration of the initial lag phase required for transitioning from the VBNC to recovery state and increasing the growth rate of these recovered cells.
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15
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Zhao S, Zhang J, Li Z, Han Y, Kan B. Enumeration of Viable Non-Culturable Vibrio cholerae Using Droplet Digital PCR Combined With Propidium Monoazide Treatment. Front Cell Infect Microbiol 2021; 11:753078. [PMID: 34796126 PMCID: PMC8592976 DOI: 10.3389/fcimb.2021.753078] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2021] [Accepted: 10/12/2021] [Indexed: 11/24/2022] Open
Abstract
Many bacterial species, including Vibrio cholerae (the pathogen that causes cholera), enter a physiologically viable but non-culturable (VBNC) state at low temperature or in conditions of low nutrition; this is a survival strategy to resist environmental stress. Identification, detection, and differentiation of VBNC cells and nonviable cells are essential for both microbiological study and disease surveillance/control. Enumeration of VBNC cells requires an accurate method. Traditional counting methods do not allow quantification of VBNC cells because they are not culturable. Morphology-based counting cannot distinguish between live and dead cells. A bacterial cell possesses one copy of the chromosome. Hence, counting single-copy genes on the chromosome is a suitable approach to count bacterial cells. In this study, we developed quantitative PCR-based methods, including real-time quantitative PCR (qPCR) and droplet digital PCR (ddPCR), to enumerate VBNC V. cholerae cells by counting the numbers of single-copy genes in samples during VBNC-state development. Propidium monoazide (PMA) treatment was incorporated to distinguish dead cells from viable cells. Both PCR methods could be used to quantify the number of DNA copies/mL and determine the proportion of dead cells (when PMA was used). The methods produced comparable counts using three single-copy genes (VC1376, thyA, and recA). However, ddPCR showed greater accuracy and sensitivity than qPCR. ddPCR also allows direct counting without the need to establish a standard curve. Our study develops a PMA-ddPCR method as a new tool to quantify VBNC cells of V. cholerae. The method can be extended to other bacterial species.
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Affiliation(s)
| | | | | | | | - Biao Kan
- State Key Laboratory of Infectious Disease Prevention and Control, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China
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16
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The Dynamic Transition of Persistence toward the Viable but Nonculturable State during Stationary Phase Is Driven by Protein Aggregation. mBio 2021; 12:e0070321. [PMID: 34340538 PMCID: PMC8406143 DOI: 10.1128/mbio.00703-21] [Citation(s) in RCA: 36] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Decades of research into bacterial persistence has been unable to fully characterize this antibiotic-tolerant phenotype, thereby hampering the development of therapies effective against chronic infections. Although some active persister mechanisms have been identified, the prevailing view is that cells become persistent because they enter a dormant state. We therefore characterized starvation-induced dormancy in Escherichia coli. Our findings indicate that dormancy develops gradually; persistence strongly increases during stationary phase and decreases again as persisters enter the viable but nonculturable (VBNC) state. Importantly, we show that dormancy development is tightly associated with progressive protein aggregation, which occurs concomitantly with ATP depletion during starvation. Persisters contain protein aggregates in an early developmental stage, while VBNC cells carry more mature aggregates. Finally, we show that at least one persister protein, ObgE, works by triggering aggregation, even at endogenous levels, and thereby changing the dynamics of persistence and dormancy development. These findings provide evidence for a genetically controlled, gradual development of persisters and VBNC cells through protein aggregation. IMPORTANCE While persistence and the viable but nonculturable (VBNC) state are currently investigated in isolation, our results strongly indicate that these phenotypes represent different stages of the same dormancy program and that they should therefore be studied within the same conceptual framework. Moreover, we show here for the first time that the dynamics of protein aggregation perfectly match the onset and further development of bacterial dormancy and that different dormant phenotypes are linked to different stages of protein aggregation. Our results thereby strongly hint at a causal relationship between both. Because many conditions known to trigger persistence are also known to influence aggregation, it is tempting to speculate that a variety of different persister pathways converge at the level of protein aggregation. If so, aggregation could emerge as a general principle that underlies the development of persistence which could be exploited for the design of antipersister therapies.
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17
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Mu DS, Du ZJ, Chen J, Austin B, Zhang XH. What do we mean by viability in terms of 'viable but non-culturable' cells? ENVIRONMENTAL MICROBIOLOGY REPORTS 2021; 13:248-252. [PMID: 33900036 DOI: 10.1111/1758-2229.12953] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/09/2021] [Accepted: 04/11/2021] [Indexed: 06/12/2023]
Affiliation(s)
- Da-Shuai Mu
- State Key Laboratory of Microbial Technology, Institute of Microbial Technology, Shandong University, Qingdao, 266237, China
| | - Zong-Jun Du
- State Key Laboratory of Microbial Technology, Institute of Microbial Technology, Shandong University, Qingdao, 266237, China
| | - Jixiang Chen
- College of Marine Life Sciences, and Frontiers Science Center for Deep Ocean Multispheres and Earth System, Ocean University of China, Qingdao, 266003, China
- School of Petrochemical Engineering, Lanzhou University of Technology, Lanzhou, 730050, China
| | - Brian Austin
- Institute of Aquaculture, University of Stirling, Stirling FK9 4LA, Scotland, UK
| | - Xiao-Hua Zhang
- College of Marine Life Sciences, and Frontiers Science Center for Deep Ocean Multispheres and Earth System, Ocean University of China, Qingdao, 266003, China
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18
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Bergkessel M, Delavaine L. Diversity in Starvation Survival Strategies and Outcomes among Heterotrophic Proteobacteria. Microb Physiol 2021; 31:146-162. [PMID: 34058747 DOI: 10.1159/000516215] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2021] [Accepted: 03/28/2021] [Indexed: 11/19/2022]
Abstract
Heterotrophic Proteobacteria are versatile opportunists that have been extensively studied as model organisms in the laboratory, as both pathogens and beneficial symbionts of plants and animals, and as ubiquitous organisms found free-living in many environments. Succeeding in these niches requires an ability to persist for potentially long periods of time in growth-arrested states when essential nutrients become limiting. The tendency of these bacteria to grow in dense biofilm communities frequently leads to the development of steep nutrient gradients and deprivation of interior cells even when the environment is nutrient rich. Surviving within host environments also likely requires tolerating growth arrest due to the host limiting access to nutrients and transitioning between hosts may require a period of survival in a nutrient-poor environment. Interventions to maximise plant-beneficial activities and minimise infections by bacteria will require a better understanding of metabolic and regulatory networks that contribute to starvation survival, and how these networks function in diverse organisms. Here we focus on carbon starvation as a growth-arresting condition that limits availability not only of substrates for biosynthesis but also of energy for ongoing maintenance of the electrochemical gradient across the cell envelope and cellular integrity. We first review models for studying bacterial starvation and known strategies that contribute to starvation survival. We then present the results of a survey of carbon starvation survival strategies and outcomes in ten bacterial strains, including representatives from the orders Enterobacterales and Pseudomonadales (both Gammaproteobacteria) and Burkholderiales (Betaproteobacteria). Finally, we examine differences in gene content between the highest and lowest survivors to identify metabolic and regulatory adaptations that may contribute to differences in starvation survival.
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Affiliation(s)
- Megan Bergkessel
- Division of Molecular Microbiology, School of Life Sciences, University of Dundee, Dundee, United Kingdom
| | - Laurent Delavaine
- Division of Molecular Microbiology, School of Life Sciences, University of Dundee, Dundee, United Kingdom
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19
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Orruño M, Parada C, Kaberdin VR, Arana I. The Effect of Visible Light on Cell Envelope Subproteome during Vibrio harveyi Survival at 20 °C in Seawater. Microorganisms 2021; 9:microorganisms9030594. [PMID: 33805730 PMCID: PMC8001661 DOI: 10.3390/microorganisms9030594] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2021] [Revised: 03/10/2021] [Accepted: 03/11/2021] [Indexed: 11/16/2022] Open
Abstract
A number of Vibrio spp. belong to the well-studied model organisms used to understand the strategies developed by marine bacteria to cope with adverse conditions (starvation, suboptimal temperature, solar radiation, etc.) in their natural environments. Temperature and nutrient availability are considered to be the key factors that influence Vibrio harveyi physiology, morphology, and persistence in aquatic systems. In contrast to the well-studied effects of temperature and starvation on Vibrio survival, little is known about the impact of visible light able to cause photooxidative stress. Here we employ V. harveyi ATCC 14126T as a model organism to analyze and compare the survival patterns and changes in the protein composition of its cell envelope during the long-term permanence of this bacterium in seawater microcosm at 20 °C in the presence and absence of illumination with visible light. We found that V. harveyi exposure to visible light reduces cell culturability likely inducing the entry into the Viable but Non Culturable state (VBNC), whereas populations maintained in darkness remained culturable for at least 21 days. Despite these differences, the starved cells in both populations underwent morphological changes by reducing their size. Moreover, further proteomic analysis revealed a number of changes in the composition of cell envelope potentially accountable for the different adaptation pattern manifested in the absence and presence of visible light.
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Affiliation(s)
- Maite Orruño
- Department of Immunology, Microbiology and Parasitology, Faculty of Science and Technology, University of the Basque Country UPV/EHU, 48340 Leioa, Spain; (M.O.); (C.P.); (V.R.K.)
- Research Centre for Experimental Marine Biology and Biotechnology (PIE-UPV/EHU), 48620 Plentzia, Spain
| | - Claudia Parada
- Department of Immunology, Microbiology and Parasitology, Faculty of Science and Technology, University of the Basque Country UPV/EHU, 48340 Leioa, Spain; (M.O.); (C.P.); (V.R.K.)
| | - Vladimir R. Kaberdin
- Department of Immunology, Microbiology and Parasitology, Faculty of Science and Technology, University of the Basque Country UPV/EHU, 48340 Leioa, Spain; (M.O.); (C.P.); (V.R.K.)
- Research Centre for Experimental Marine Biology and Biotechnology (PIE-UPV/EHU), 48620 Plentzia, Spain
- IKERBASQUE, Basque Foundation for Science, 48013 Bilbao, Spain
| | - Inés Arana
- Department of Immunology, Microbiology and Parasitology, Faculty of Science and Technology, University of the Basque Country UPV/EHU, 48340 Leioa, Spain; (M.O.); (C.P.); (V.R.K.)
- Research Centre for Experimental Marine Biology and Biotechnology (PIE-UPV/EHU), 48620 Plentzia, Spain
- Correspondence:
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20
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Furusawa G, Diyana T, Lau NS. Metabolic strategies of dormancy of a marine bacterium Microbulbifer aggregans CCB-MM1: Its alternative electron transfer chain and sulfate-reducing pathway. Genomics 2021; 114:443-455. [PMID: 33689784 DOI: 10.1016/j.ygeno.2021.02.024] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2020] [Revised: 01/26/2021] [Accepted: 02/28/2021] [Indexed: 12/26/2022]
Abstract
Bacterial dormancy plays a crucial role in maintaining the functioning and diversity of microbial communities in natural environments. However, the metabolic regulations of the dormancy of bacteria in natural habitats, especially marine habitats, have remained largely unknown. A marine bacterium, Microbulbifer aggregans CCB-MM1 exhibits rod-to-coccus cell shape change during the dormant state. Therefore, to clarify the metabolic regulation of the dormancy, differential gene expression analysis based on RNA-Seq was performed between rod- (vegetative), intermediate, and coccus-shaped cells (dormancy). The RNA-Seq data revealed that one of two distinct electron transfer chains was upregulated in the dormancy. Dissimilatory sulfite reductase and soluble hydrogenase were also highly upregulated in the dormancy. In addition, induction of the dormancy of MM1 in the absence of MgSO4 was slower than that in the presence of MgSO4. These results indicate that the sulfate-reducing pathway plays an important role in entering the dormancy of MM1.
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Affiliation(s)
- Go Furusawa
- Centre for Chemical Biology, Universiti Sains Malaysia, 10 Persiaran Bukit Jambul, 11900 Bayan Lepas, Penang, Malaysia.
| | - Tarmizi Diyana
- Centre for Chemical Biology, Universiti Sains Malaysia, 10 Persiaran Bukit Jambul, 11900 Bayan Lepas, Penang, Malaysia
| | - Nyok-Sean Lau
- Centre for Chemical Biology, Universiti Sains Malaysia, 10 Persiaran Bukit Jambul, 11900 Bayan Lepas, Penang, Malaysia
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21
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Dey R, Rieger A, Banting G, Ashbolt NJ. Role of amoebae for survival and recovery of 'non-culturable' Helicobacter pylori cells in aquatic environments. FEMS Microbiol Ecol 2021; 96:5902844. [PMID: 32897313 PMCID: PMC7494403 DOI: 10.1093/femsec/fiaa182] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2020] [Accepted: 09/02/2020] [Indexed: 12/12/2022] Open
Abstract
Helicobacter pylori is a fastidious Gram-negative bacterium that infects over half of the world's population, causing chronic gastritis and is a risk factor for stomach cancer. In developing and rural regions where prevalence rate exceeds 60%, persistence and waterborne transmission are often linked to poor sanitation conditions. Here we demonstrate that H. pylori not only survives but also replicates within acidified free-living amoebal phagosomes. Bacterial counts of the clinical isolate H. pylori G27 increased over 50-fold after three days in co-culture with amoebae. In contrast, a H. pylori mutant deficient in a cagPAI gene (cagE) showed little growth within amoebae, demonstrating the likely importance of a type IV secretion system in H. pylori for amoebal infection. We also demonstrate that H. pylori can be packaged by amoebae and released in extracellular vesicles. Furthermore, and for the first time, we successfully demonstrate the ability of two free-living amoebae to revert and recover viable but non-cultivable coccoid (VBNC)-H. pylori to a culturable state. Our studies provide evidence to support the hypothesis that amoebae and perhaps other free-living protozoa contribute to the replication and persistence of human-pathogenic H. pylori by providing a protected intracellular microenvironment for this pathogen to persist in natural aquatic environments and engineered water systems, thereby H. pylori potentially uses amoeba as a carrier and a vector of transmission.
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Affiliation(s)
- Rafik Dey
- School of Public Health, University of Alberta,11405-87 Avenue, Edmonton, Alberta T6G 1C9, Canada.,Deparment of Medical Microbiology and Immunology, University of Alberta, Edmonton, Alberta T6G 2E1, Canada
| | - Aja Rieger
- Deparment of Medical Microbiology and Immunology, University of Alberta, Edmonton, Alberta T6G 2E1, Canada
| | - Graham Banting
- School of Public Health, University of Alberta,11405-87 Avenue, Edmonton, Alberta T6G 1C9, Canada
| | - Nicholas J Ashbolt
- School of Public Health, University of Alberta,11405-87 Avenue, Edmonton, Alberta T6G 1C9, Canada.,Deparment of Medical Microbiology and Immunology, University of Alberta, Edmonton, Alberta T6G 2E1, Canada.,Provincial Laboratory for Public Health (ProvLab), Alberta Health Services, Edmonton, Canada.,School of Environmental, Sciense and Engineering, Southern Cross University, Lismore NSW, Australia
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22
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Gao R, Liao X, Zhao X, Liu D, Ding T. The diagnostic tools for viable but nonculturable pathogens in the food industry: Current status and future prospects. Compr Rev Food Sci Food Saf 2021; 20:2146-2175. [PMID: 33484068 DOI: 10.1111/1541-4337.12695] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2020] [Revised: 12/21/2020] [Accepted: 12/28/2020] [Indexed: 12/21/2022]
Abstract
Viable but nonculturable (VBNC) microorganisms have been recognized as pathogenic contaminants in foods and environments. The failure of VBNC cells to form the visible colonies hinders the ability to use conventional media for their detection. Efficient and rapid detection of pathogens in the VBNC state is a prerequisite to ensure the food safety and public health. Despite their nonculturability, VBNC cells have distinct characteristics, such as morphology, metabolism, chemical composition, and gene and protein expression, that have been used as the basis for the development of abundant diagnostic tools. This review covers the current status and advances in various approaches for examining microorganisms in the VBNC state, including but not limited to the methodological aspects, advantages, and drawbacks of each technique. Existing methods, such as direct viable count, SYTO/PI dual staining, and propidium monoazide quantitative polymerase chain reaction (PCR), as well as some techniques with potential to be applied in the future, such as digital PCR, enhanced-surface Raman spectroscopy, and impedance-based techniques, are summarized in depth. Finally, future prospects for the one-step detection of VBNC bacteria are proposed and discussed. We believe that this review can provide more optional methods for researchers and promote the development of rapid, accurate detecting methods, and for inspectors, the diagnostic tools can provide data to undertake risk analysis of VBNC cells.
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Affiliation(s)
- Rui Gao
- Key Laboratory for Agro-Products Postharvest Handling of Ministry of Agriculture, Zhejiang Key Laboratory for Agro-Food Processing, Department of Food Science and Nutrition, Zhejiang University, Hangzhou, Zhejiang, China
| | - Xinyu Liao
- Key Laboratory for Agro-Products Postharvest Handling of Ministry of Agriculture, Zhejiang Key Laboratory for Agro-Food Processing, Department of Food Science and Nutrition, Zhejiang University, Hangzhou, Zhejiang, China
| | - Xihong Zhao
- Research Center for Environmental Ecology and Engineering, Key Laboratory for Green Chemical Process of Ministry of Education, Hubei Key Laboratory of Novel Reactor and Green Chemical Technology, School of Environmental Ecology and Biological Engineering, Wuhan Institute of Technology, Wuhan, China
| | - Donghong Liu
- Key Laboratory for Agro-Products Postharvest Handling of Ministry of Agriculture, Zhejiang Key Laboratory for Agro-Food Processing, Department of Food Science and Nutrition, Zhejiang University, Hangzhou, Zhejiang, China
| | - Tian Ding
- Key Laboratory for Agro-Products Postharvest Handling of Ministry of Agriculture, Zhejiang Key Laboratory for Agro-Food Processing, Department of Food Science and Nutrition, Zhejiang University, Hangzhou, Zhejiang, China
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23
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Bacterial dormancy: A subpopulation of viable but non-culturable cells demonstrates better fitness for revival. PLoS Pathog 2021; 17:e1009194. [PMID: 33439894 PMCID: PMC7837498 DOI: 10.1371/journal.ppat.1009194] [Citation(s) in RCA: 32] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2020] [Revised: 01/26/2021] [Accepted: 11/27/2020] [Indexed: 01/08/2023] Open
Abstract
The viable but non culturable (VBNC) state is a condition in which bacterial cells are viable and metabolically active, but resistant to cultivation using a routine growth medium. We investigated the ability of V. parahaemolyticus to form VBNC cells, and to subsequently become resuscitated. The ability to control VBNC cell formation in the laboratory allowed us to selectively isolate VBNC cells using fluorescence activated cell sorting, and to differentiate subpopulations based on their metabolic activity, cell shape and the ability to cause disease in Galleria mellonella. Our results showed that two subpopulations (P1 and P2) of V. parahaemolyticus VBNC cells exist and can remain dormant in the VBNC state for long periods. VBNC subpopulation P2, had a better fitness for survival under stressful conditions and showed 100% revival under favourable conditions. Proteomic analysis of these subpopulations (at two different time points: 12 days (T12) and 50 days (T50) post VBNC) revealed that the proteome of P2 was more similar to that of the starting microcosm culture (T0) than the proteome of P1. Proteins that were significantly up or down-regulated between the different VBNC populations were identified and differentially regulated proteins were assigned into 23 functional groups, the majority being assigned to metabolism functional categories. A lactate dehydrogenase (lldD) protein, responsible for converting lactate to pyruvate, was significantly upregulated in all subpopulations of VBNC cells. Deletion of the lactate dehydrogenase (RIMD2210633:ΔlldD) gene caused cells to enter the VBNC state significantly more quickly compared to the wild-type, and adding lactate to VBNC cells aided their resuscitation and extended the resuscitation window. Addition of pyruvate to the RIMD2210633:ΔlldD strain restored the wild-type VBNC formation profile. This study suggests that lactate dehydrogenase may play a role in regulating the VBNC state.
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24
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Vatansever C, Turetgen I. Investigation of the effects of various stress factors on biofilms and planktonic bacteria in cooling tower model system. Arch Microbiol 2021; 203:1411-1425. [PMID: 33388788 DOI: 10.1007/s00203-020-02116-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2020] [Revised: 09/09/2020] [Accepted: 11/08/2020] [Indexed: 11/27/2022]
Abstract
Biofilm is a microbial population which live in a self-produced extracellular polymeric matrix by attaching to surfaces. Biofilms consist of different different types of organisms such as bacteria, fungi, protozoa, etc. Many biofilms that develop in nature consist of more than one type of organism. Biofilms protect bacteria from adverse conditions such as temperature fluctuation and disinfectants. The aim of this study was to determine the effective elimination strategies for combating biofilm and planktonic bacteria in cooling tower model system using different decontamination / disinfection techniques. In this study, 14 week-old biofilms were treated with temperatures of 4 °C, 65 °C; pH of 3, 11; 2 and 10 mg/l chlorine, 2 and 10 mg/l monochloramine; hypotonic salt (0.01% NaCl) and hypertonic salt (3% NaCl) solution. For enumeration, number of aerobic heterotrophic bacteria was determined by conventional culture method, number of live bacteria was determined by LIVE/DEAD viability kit, CTC-DAPI and Alamar blue staining methods. Temperature of 65 °C, pH of 3, 10 mg/l monochloramine and hypertonic salt solution were the most effective parameters for decontamination of biofilm and planktonic bacteria. Biofilm bacteria in the circulating water system were significantly more resistant than planktonic bacteria against stress factors. When the numbers of epifluorescence microscopy and conventional culture technique were compared, significantly higher number of live bacteria were detected using epifluorescence microscopy. Bacteria enter the viable but non-culturable phase by loosing their culturability under stress conditions. For this reason, the conventional culture method should be supported by different techniques to get more realistic numbers.
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Affiliation(s)
- Cansu Vatansever
- Faculty of Pharmacy, Department of Pharmaceutical Microbiology, Altinbas University, Istanbul, Turkey.
| | - Irfan Turetgen
- Faculty of Science, Department of Biology, Istanbul University, Istanbul, Turkey
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25
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López-Lara LI, Pazos-Rojas LA, López-Cruz LE, Morales-García YE, Quintero-Hernández V, de la Torre J, van Dillewijn P, Muñoz-Rojas J, Baez A. Influence of rehydration on transcriptome during resuscitation of desiccated Pseudomonas putida KT2440. ANN MICROBIOL 2020. [DOI: 10.1186/s13213-020-01596-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Abstract
Purpose
Pseudomonas putida KT2440 is a desiccation-sensitive bacterium that loses culturability after 15 days of air desiccation. We have previously shown that P. putida KT2440 can develop a viable but nonculturable (VBNC) state after being exposed to desiccation stress and eventually recover when desiccated cells are rehydrated for at least 24 h.
Methods
To determine which genes of transport, oxidation-reduction, and transcription processes could be involved in the return of P. putida KT2440 to the culturable state, a transcriptome analysis was carried out comparing the gene expression of non-desiccated samples with samples subjected to desiccation followed by 20 min of rehydration or desiccation followed by 24 h of rehydration.
Results
Desiccation stress triggered a VBNC state of P. putida. The major response was detected after 24 h of rehydration with 148 upregulated and 42 downregulated genes. During the VBNC state, P. putida activated transmembrane transport processes like that of siderophores through a TonB-dependent transporter and putative polyhydric alcohol transport systems. Prolonged rehydration with distilled water resuscitated P. putida KT2440 cells activating the catabolism of phenylalanine/tyrosine to provide energy and carbon for ubiquinone biosynthesis while maintaining a reduced protein synthesis. On the other hand, the interruption of the TonB-dependent receptor gene (PP_1446) increased desiccation survival of the mutant strain.
Conclusion
The activation of the iron transport system (TonB-dependent siderophore receptor) and alcohol transport can be helping the VBNC state of P. putida. Activation of catabolism of phenylalanine/tyrosine and reduced protein synthesis was needed for resuscitation from the VBNC state.
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Theis KR, Romero R, Motomura K, Galaz J, Winters AD, Pacora P, Miller D, Slutsky R, Florova V, Levenson D, Para R, Varrey A, Kacerovsky M, Hsu CD, Gomez-Lopez N. Microbial burden and inflammasome activation in amniotic fluid of patients with preterm prelabor rupture of membranes. J Perinat Med 2020; 48:115-131. [PMID: 31927525 PMCID: PMC7147952 DOI: 10.1515/jpm-2019-0398] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/25/2019] [Accepted: 12/01/2019] [Indexed: 02/07/2023]
Abstract
Background Intra-amniotic inflammation, which is associated with adverse pregnancy outcomes, can occur in the presence or absence of detectable microorganisms, and involves activation of the inflammasome. Intra-amniotic inflammasome activation has been reported in clinical chorioamnionitis at term and preterm labor with intact membranes, but it has not yet been investigated in women with preterm prelabor rupture of membranes (preterm PROM) in the presence/absence of detectable microorganisms. The aim of this study was to determine whether, among women with preterm PROM, there is an association between detectable microorganisms in amniotic fluid and intra-amniotic inflammation, and whether intra-amniotic inflammasome activation correlates with microbial burden. Methods Amniotic fluids from 59 cases of preterm PROM were examined for the presence/absence of microorganisms through culture and 16S ribosomal RNA (rRNA) gene quantitative real-time polymerase chain reaction (qPCR), and concentrations of interleukin-6 (IL-6) and ASC [apoptosis-associated spec-like protein containing a caspase recruitment domain (CARD)], an indicator of inflammasome activation, were determined. Results qPCR identified more microbe-positive amniotic fluids than culture. Greater than 50% of patients with a negative culture and high IL-6 concentration in amniotic fluid yielded a positive qPCR signal. ASC concentrations were greatest in patients with high qPCR signals and elevated IL-6 concentrations in amniotic fluid (i.e. intra-amniotic infection). ASC concentrations tended to increase in patients without detectable microorganisms but yet with elevated IL-6 concentrations (i.e. sterile intra-amniotic inflammation) compared to those without intra-amniotic inflammation. Conclusion qPCR is a valuable complement to microbiological culture for the detection of microorganisms in the amniotic cavity in women with preterm PROM, and microbial burden is associated with the severity of intra-amniotic inflammatory response, including inflammasome activation.
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Affiliation(s)
- Kevin R. Theis
- Perinatology Research Branch, Division of Obstetrics and Maternal-Fetal Medicine, Division of Intramural Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, U. S. Department of Health and Human Services, Bethesda, Maryland, and Detroit, Michigan, USA
- Department of Biochemistry, Microbiology, and Immunology, Wayne State University School of Medicine, Detroit, Michigan, USA
| | - Roberto Romero
- Perinatology Research Branch, Division of Obstetrics and Maternal-Fetal Medicine, Division of Intramural Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, U. S. Department of Health and Human Services, Bethesda, Maryland, and Detroit, Michigan, USA
- Department of Obstetrics and Gynecology, University of Michigan, Ann Arbor, Michigan, USA
- Department of Epidemiology and Biostatistics, Michigan State University, East Lansing, Michigan, USA
- Center for Molecular Medicine and Genetics, Wayne State University, Detroit, Michigan, USA
- Detroit Medical Center, Detroit, Michigan, USA
- Department of Obstetrics and Gynecology, Florida International University, Miami, Florida, USA
| | - Kenichiro Motomura
- Perinatology Research Branch, Division of Obstetrics and Maternal-Fetal Medicine, Division of Intramural Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, U. S. Department of Health and Human Services, Bethesda, Maryland, and Detroit, Michigan, USA
- Department of Obstetrics and Gynecology, Wayne State University School of Medicine, Detroit, Michigan, USA
| | - Jose Galaz
- Perinatology Research Branch, Division of Obstetrics and Maternal-Fetal Medicine, Division of Intramural Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, U. S. Department of Health and Human Services, Bethesda, Maryland, and Detroit, Michigan, USA
- Department of Obstetrics and Gynecology, Wayne State University School of Medicine, Detroit, Michigan, USA
- Department of Obstetrics and Gynecology, Faculty of Medicine, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Andrew D. Winters
- Perinatology Research Branch, Division of Obstetrics and Maternal-Fetal Medicine, Division of Intramural Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, U. S. Department of Health and Human Services, Bethesda, Maryland, and Detroit, Michigan, USA
- Department of Biochemistry, Microbiology, and Immunology, Wayne State University School of Medicine, Detroit, Michigan, USA
| | - Percy Pacora
- Perinatology Research Branch, Division of Obstetrics and Maternal-Fetal Medicine, Division of Intramural Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, U. S. Department of Health and Human Services, Bethesda, Maryland, and Detroit, Michigan, USA
- Department of Obstetrics and Gynecology, Wayne State University School of Medicine, Detroit, Michigan, USA
| | - Derek Miller
- Perinatology Research Branch, Division of Obstetrics and Maternal-Fetal Medicine, Division of Intramural Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, U. S. Department of Health and Human Services, Bethesda, Maryland, and Detroit, Michigan, USA
- Department of Obstetrics and Gynecology, Wayne State University School of Medicine, Detroit, Michigan, USA
| | - Rebecca Slutsky
- Perinatology Research Branch, Division of Obstetrics and Maternal-Fetal Medicine, Division of Intramural Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, U. S. Department of Health and Human Services, Bethesda, Maryland, and Detroit, Michigan, USA
| | - Violetta Florova
- Perinatology Research Branch, Division of Obstetrics and Maternal-Fetal Medicine, Division of Intramural Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, U. S. Department of Health and Human Services, Bethesda, Maryland, and Detroit, Michigan, USA
- Department of Obstetrics and Gynecology, Wayne State University School of Medicine, Detroit, Michigan, USA
| | - Dustyn Levenson
- Perinatology Research Branch, Division of Obstetrics and Maternal-Fetal Medicine, Division of Intramural Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, U. S. Department of Health and Human Services, Bethesda, Maryland, and Detroit, Michigan, USA
- Department of Obstetrics and Gynecology, Wayne State University School of Medicine, Detroit, Michigan, USA
| | - Robert Para
- Perinatology Research Branch, Division of Obstetrics and Maternal-Fetal Medicine, Division of Intramural Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, U. S. Department of Health and Human Services, Bethesda, Maryland, and Detroit, Michigan, USA
- Department of Obstetrics and Gynecology, Wayne State University School of Medicine, Detroit, Michigan, USA
| | - Aneesha Varrey
- Perinatology Research Branch, Division of Obstetrics and Maternal-Fetal Medicine, Division of Intramural Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, U. S. Department of Health and Human Services, Bethesda, Maryland, and Detroit, Michigan, USA
- Department of Obstetrics and Gynecology, Wayne State University School of Medicine, Detroit, Michigan, USA
| | - Marian Kacerovsky
- Perinatology Research Branch, Division of Obstetrics and Maternal-Fetal Medicine, Division of Intramural Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, U. S. Department of Health and Human Services, Bethesda, Maryland, and Detroit, Michigan, USA
- Department of Obstetrics and Gynecology, Wayne State University School of Medicine, Detroit, Michigan, USA
| | - Chaur-Dong Hsu
- Perinatology Research Branch, Division of Obstetrics and Maternal-Fetal Medicine, Division of Intramural Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, U. S. Department of Health and Human Services, Bethesda, Maryland, and Detroit, Michigan, USA
- Department of Obstetrics and Gynecology, Wayne State University School of Medicine, Detroit, Michigan, USA
- Department of Physiology, Wayne State University School of Medicine, Detroit, Michigan, USA
| | - Nardhy Gomez-Lopez
- Perinatology Research Branch, Division of Obstetrics and Maternal-Fetal Medicine, Division of Intramural Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, U. S. Department of Health and Human Services, Bethesda, Maryland, and Detroit, Michigan, USA
- Department of Obstetrics and Gynecology, Wayne State University School of Medicine, Detroit, Michigan, USA
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Wasfi R, Abdellatif GR, Elshishtawy HM, Ashour HM. First-time characterization of viable but non-culturable Proteus mirabilis: Induction and resuscitation. J Cell Mol Med 2020; 24:2791-2801. [PMID: 32030883 PMCID: PMC7077546 DOI: 10.1111/jcmm.15031] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2019] [Revised: 11/12/2019] [Accepted: 12/22/2019] [Indexed: 12/11/2022] Open
Abstract
Pathogenic bacteria can enter into a viable but non‐culturable (VBNC) state under unfavourable conditions. Proteus mirabilis is responsible for dire clinical consequences including septicaemia, urinary tract infections and pneumonia, but is not a species previously known to enter VBNC state. We suggested that stress‐induced P. mirabilis can enter a VBNC state in which it retains virulence. P. mirabilis isolates were incubated in extreme osmotic pressure, starvation, low temperature and low pH to induce a VBNC state. Resuscitation was induced by temperature upshift and inoculation in tryptone soy broth with Tween 20 and brain heart infusion broth. Cellular ultrastructure and gene expression were examined using transmission electron microscopy (TEM) and quantitative real‐time polymerase chain reaction (qPCR), respectively. High osmotic pressure and low acidity caused rapid entry into VBNC state. Temperature upshift caused the highest percentage of resuscitation (93%) under different induction conditions. In the VBNC state, cells showed aberrant and dwarf morphology, virulence genes and stress response genes (envZ and rpoS) were expressed (levels varied depending on strain and inducing factors). This is the first‐time characterization of VBNC P. mirabilis. The ability of P. mirabilis pathogenic strains to enter a stress‐induced VBNC state can be a serious public health threat.
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Affiliation(s)
- Reham Wasfi
- Department of Microbiology and Immunology, Faculty of Pharmacy, October University for Modern Sciences and Arts (MSA), Giza, Egypt
| | - Ghada Refaat Abdellatif
- Department of Microbiology and Immunology, Faculty of Pharmacy, Ahram Canadian University (ACU), Giza, Egypt
| | - Hisham Mohamed Elshishtawy
- Microbial Genetics Laboratory, Agricultural Genetic Engineering Research Institute (AGERI), Agricultural Research Center (ARC), Giza, Egypt
| | - Hossam M Ashour
- Department of Biological Sciences, College of Arts and Sciences, University of South Florida St. Petersburg, St. Petersburg, Florida.,Department of Microbiology and Immunology, Faculty of Pharmacy, Cairo University, Cairo, Egypt
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Ye C, Lin H, Zhang M, Chen S, Yu X. Characterization and potential mechanisms of highly antibiotic tolerant VBNC Escherichia coli induced by low level chlorination. Sci Rep 2020; 10:1957. [PMID: 32029755 PMCID: PMC7005040 DOI: 10.1038/s41598-020-58106-3] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2019] [Accepted: 01/08/2020] [Indexed: 12/29/2022] Open
Abstract
Escherichia coli is an important pathogenic indicator in drinking water. Viable but non-culturable (VBNC) E. coli induced by low level chlorination was found to have higher antibiotic tolerance. The emerging of VBNC bacteria in drinking water systems is posing challenges to the control of bio-safety. It is necessary to study the underlying mechanisms of VBNC state E. coli under actual residual chlorine condition of drinking water pipe network. In this study, we investigated the changes of morphology and gene expressions that might present such state. The results indicated that the size of VBNC E. coli was not remarkably changed or recovered culturability under favorable environmental conditions. Results from transcriptomic analysis revealed that the regulated genes related to fimbrial-like adhesin protein, putative periplasmic pilin chaperone, regulators of the transcriptional regulation, antibiotic resistance genes and stress-induced genes, rendering VBNC cells more tolerant to adverse environmental conditions. In total of 16 genes were significantly up-regulated under the VBNC state, including three genes encoding toxic protein (ygeG, ibsD, shoB), indicating that VBNC E. coil was still a threat to human. The work is of great relevance in the context of better understanding this poorly understood physiological state.
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Affiliation(s)
- Chengsong Ye
- College of the Environment&Ecology, Xiamen University, Xiamen, 361005, China
| | - Huirong Lin
- Department of Environmental Science and Engineering, College of Chemical Engineering, Huaqiao University, Xiamen, Fujian, 361021, China
| | - Menglu Zhang
- Key Lab of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen, 361021, People's Republic of China.,University of Chinese Academy of Sciences, Beijing, 100049, People's Republic of China
| | - Sheng Chen
- Key Lab of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen, 361021, People's Republic of China.,University of Chinese Academy of Sciences, Beijing, 100049, People's Republic of China
| | - Xin Yu
- College of the Environment&Ecology, Xiamen University, Xiamen, 361005, China. .,Key Lab of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen, 361021, People's Republic of China.
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29
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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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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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31
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Transcriptomic Analysis of Viable but Non-Culturable Escherichia coli O157:H7 Formation Induced by Low Temperature. Microorganisms 2019; 7:microorganisms7120634. [PMID: 31801285 PMCID: PMC6955965 DOI: 10.3390/microorganisms7120634] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2019] [Revised: 11/21/2019] [Accepted: 11/26/2019] [Indexed: 02/04/2023] Open
Abstract
Escherichia coli O157:H7 is one of the most common pathogenic bacteria that pose a threat to food safety. The aim of this study was to investigate the mechanisms of the formation of viable but non-culturable (VBNC) E. coli O157:H7 induced by low temperature (−20 °C) using RNA sequencing (RNA-Seq) transcriptomics analysis. The results of the present investigation revealed the presence of 2298 differentially expressed genes in VBNC cells, accounting for 46.03% of the total number of genes. Additionally, GO function and KEGG pathway enrichment analysis were performed to investigate the functional and related metabolic pathways of the differentially expressed genes. We found that the ion transport, protein synthesis, and protein transmembrane transport activities were significantly improved in the VBNC cells, indicating that E. coli O157:H7 cells synthesized a considerable amount of protein to maintain the levels of their functional metabolic processes and life activities in the VBNC state. In conclusion, we suggest that the increased synthesis of proteins such as SecY, FtsY, and Ffh might indicate that they are the key proteins involved in the improvement of the transmembrane transport activities in VBNC E. coli O157:H7 cells, maintaining their functional metabolism in the VBNC state and enhancing their survival ability under low temperatures.
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32
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Bai H, Zhao F, Li M, Qin L, Yu H, Lu L, Zhang T. Citric acid can force Staphylococcus aureus into viable but nonculturable state and its characteristics. Int J Food Microbiol 2019; 305:108254. [PMID: 31238194 DOI: 10.1016/j.ijfoodmicro.2019.108254] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2019] [Revised: 06/15/2019] [Accepted: 06/17/2019] [Indexed: 12/11/2022]
Abstract
Pathogens in viable but nonculturable (VBNC) state can escape traditional detection methods based on culturable ability, thus bringing risks to food safety and human health. Considering Staphylococcus aureus as a kind of primary foodborne pathogen, this study attempted to investigate whether citric acid, a food additive commonly used, can force S. aureus into VBNC state along with low temperature. Treated with citric acid solution (pH 4.0) at 4 °C, S. aureus was confirmed to enter into VBNC state after induction for 18 days. Meanwhile, resuscitation was achieved in culture medium rather than in nutrition-free saline solution. In VBNC cells, ATP concentration still maintained at a high level, as about two-thirds of exponential-phase cells. For survival, intracellular structure of VBNC cells changed remarkably, including irregular cell shape, denser cytoplasm, space between cell wall and cell membrane, and decreased density of nuclear region. Notably, resistance of VBNC cells to simulated gastric fluid improved when compared with exponential-phase cells. What are noted above suggests that VBNC state adopted by S. aureus might be a survival strategy to the adverse environment (acidity stress and low temperature). In conclusion, our study sounds an alarm for the safety of citric acid-containing foods.
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Affiliation(s)
- Hong Bai
- College of Food Science and Engineering, Jilin University, 5333 Xi'an Road, Changchun 130062, PR China
| | - Feng Zhao
- College of Food Science and Engineering, Jilin University, 5333 Xi'an Road, Changchun 130062, PR China.
| | - Meng Li
- College of Food Science and Engineering, Jilin University, 5333 Xi'an Road, Changchun 130062, PR China
| | - Liangyun Qin
- College of Food Science and Engineering, Jilin University, 5333 Xi'an Road, Changchun 130062, PR China
| | - Huilin Yu
- College of Food Science and Engineering, Jilin University, 5333 Xi'an Road, Changchun 130062, PR China
| | - Linhan Lu
- College of Food Science and Engineering, Jilin University, 5333 Xi'an Road, Changchun 130062, PR China
| | - Tiehua Zhang
- College of Food Science and Engineering, Jilin University, 5333 Xi'an Road, Changchun 130062, PR China
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Kumar SS, Ghosh AR. Assessment of bacterial viability: a comprehensive review on recent advances and challenges. Microbiology (Reading) 2019; 165:593-610. [DOI: 10.1099/mic.0.000786] [Citation(s) in RCA: 55] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Affiliation(s)
- Shravanthi S. Kumar
- Department of Integrative Biology, School of Bio Sciences and Technology, Vellore Institute of Technology, Vellore-632014, Tamil Nadu, India
| | - Asit Ranjan Ghosh
- Department of Integrative Biology, School of Bio Sciences and Technology, Vellore Institute of Technology, Vellore-632014, Tamil Nadu, India
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Debnath A, Mizuno T, Miyoshi SI. Comparative proteomic analysis to characterize temperature-induced viable but non-culturable and resuscitation states in Vibrio cholerae. MICROBIOLOGY-SGM 2019; 165:737-746. [PMID: 31124781 DOI: 10.1099/mic.0.000798] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Vibrio cholerae can survive environmental adversities by entering into a viable but non-culturable (VBNC) state and is able to resuscitate under favourable conditions. In this study, an environmental strain of V. cholerae (AN59) showed a decrease in culturability from 4×107 to ≤ 3 c.f.u. ml -1 in artificial seawater media at 4 °C within 35 days. During the course of VBNC progression, viability was confirmed by real-time RT-PCR which showed reduced but stable expression of molecular chaperones groEL and dnaK. Resuscitation was induced in VBNC microcosm by a temperature increase from 4 to 37 °C for 24 h. The results obtained from resuscitation and growth experiments suggest that 103-104 c.f.u. ml -1 of VBNC cells should recover upon temperature increase and grow to attain 107 c.f.u. ml -1. We used comparative proteomics to differentiate recovery from the VBNC state and selected 19 proteins whose expression was significantly variable between these two states. These proteins were mainly related to carbohydrate metabolism, phosphate utilization, stress response, transport and translation. The main difference in the proteome profile was higher protein expression in the recovery state compared to VBNC state. However, during recovery Pi-starvation led to expression of PhoX, PstB and Xds, which might help in utilization of extracellular DNA to promote growth after resuscitation. In addition, the expression of EctC suggests that osmotic adaptation is necessary to grow at high salinity. Detection of AhpC in the VBNC and recovery state indicates the significance of the oxidative stress response. A temperature-induced VBNC and recovery state is a combination of adaptive and survival responses under nutrient limitation.
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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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Dey R, Rieger AM, Stephens C, Ashbolt NJ. Interactions of Pseudomonas aeruginosa with Acanthamoeba polyphaga Observed by Imaging Flow Cytometry. Cytometry A 2019; 95:555-564. [PMID: 30985067 DOI: 10.1002/cyto.a.23768] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2018] [Revised: 03/05/2019] [Accepted: 04/01/2019] [Indexed: 12/22/2022]
Abstract
Pseudomonas aeruginosa is a Gram-negative bacterium that is abundant in the environment and water systems, with strains that cause serious infections, especially in patients with compromised immune systems. In times of stress or as part of its natural life cycle, P. aeruginosa can adopt a viable but not culturable (VBNC) state, which renders it undetectable by current conventional food and water testing methods and makes it highly resistant to antibiotic treatment. Specific conditions can resuscitate these coccoid VBNC P. aeruginosa cells, which returns them to their active, virulent rod-shaped form. Underreporting the VBNC cells of P. aeruginosa by standard culture-based methods in water distribution systems may therefore pose serious risks to public health. As such, being able to accurately detect and quantify the presence of VBNC P. aeruginosa, especially in a hospital setting, is of critical importance. Herein, we describe a method to analyze VBNC P. aeruginosa using imaging flow cytometry. With this technique, we can accurately distinguish between active and VBNC forms. We also show here that association of VBNC P. aeruginosa with Acanthamoeba polyphaga results in resuscitation of P. aeruginosa to an active form within 2 h. Our approach could provide an alternative, reliable detection method of VBNC P. aeruginosa when coupled with species-specific staining. Most importantly, our experiments demonstrate that the coculture with amoebae can lead to a resuscitation of P. aeruginosa of culturable morphology after only 2 h, indicating that VBNC P. aeruginosa could potentially resuscitate in piped water (healthcare) environments colonized with amoebae. © 2019 International Society for Advancement of Cytometry.
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Affiliation(s)
- Rafik Dey
- School of Public Health, University of Alberta, Edmonton, Alberta, Canada.,Department of Medical Microbiology and Immunology, University of Alberta, Edmonton, Alberta, Canada
| | - Aja M Rieger
- Department of Medical Microbiology and Immunology, University of Alberta, Edmonton, Alberta, Canada
| | - Caroline Stephens
- Department of Medical Microbiology and Immunology, University of Alberta, Edmonton, Alberta, Canada
| | - Nicholas J Ashbolt
- School of Public Health, University of Alberta, Edmonton, Alberta, Canada.,Department of Medical Microbiology and Immunology, University of Alberta, Edmonton, Alberta, Canada.,Provincial Laboratory for Public Health (ProvLab), Alberta Health Services, Edmonton, Alberta, Canada
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38
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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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39
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Bradley JA, Amend JP, LaRowe DE. Survival of the fewest: Microbial dormancy and maintenance in marine sediments through deep time. GEOBIOLOGY 2019; 17:43-59. [PMID: 30248245 PMCID: PMC6585783 DOI: 10.1111/gbi.12313] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/05/2018] [Revised: 07/17/2018] [Accepted: 08/21/2018] [Indexed: 06/01/2023]
Abstract
Microorganisms buried in marine sediments are known to endure starvation over geologic timescales. However, the mechanisms of how these microorganisms cope with prolonged energy limitation is unknown and therefore yet to be captured in a quantitative framework. Here, we present a novel mathematical model that considers (a) the physiological transitions between the active and dormant states of microorganisms, (b) the varying requirement for maintenance power between these phases, and (c) flexibility in the provenance (i.e., source) of energy from exogenous and endogenous catabolism. The model is applied to sediments underlying the oligotrophic South Pacific Gyre where microorganisms endure ultra-low fluxes of energy for tens of millions of years. Good fits between model simulations and measurements of cellular carbon and organic carbon concentrations are obtained and are interpreted as follows: (a) the unfavourable microbial habitat in South Pacific Gyre sediments triggers rapid mortality and a transition to dormancy; (b) there is minimal biomass growth, and organic carbon consumption is dominated by catabolism to support maintenance activities rather than new biomass synthesis; (c) the amount of organic carbon that microorganisms consume for maintenance activities is equivalent to approximately 2% of their carbon biomass per year; and (d) microorganisms must rely solely on exogenous rather than endogenous catabolism to persist in South Pacific Gyre sediments over long timescales. This leads us to the conclusion that under oligotrophic conditions, the fitness of an organism is determined by its ability to simply stay alive, rather than to grow. This modelling framework is designed to be flexible for application to other sites and habitats, and thus serves as a new quantitative tool for determining the habitability of and an ultimate limit for life in any environment.
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Affiliation(s)
- James A. Bradley
- Department of Earth SciencesUniversity of Southern CaliforniaLos AngelesCalifornia
| | - Jan P. Amend
- Department of Earth SciencesUniversity of Southern CaliforniaLos AngelesCalifornia
- Department of Biological SciencesUniversity of Southern CaliforniaLos AngelesCalifornia
| | - Douglas E. LaRowe
- Department of Earth SciencesUniversity of Southern CaliforniaLos AngelesCalifornia
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40
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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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41
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Ferdous J, Sultana R, Rashid RB, Tasnimuzzaman M, Nordland A, Begum A, Jensen PKM. A Comparative Analysis of Vibrio cholerae Contamination in Point-of-Drinking and Source Water in a Low-Income Urban Community, Bangladesh. Front Microbiol 2018; 9:489. [PMID: 29616005 PMCID: PMC5867346 DOI: 10.3389/fmicb.2018.00489] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2018] [Accepted: 03/02/2018] [Indexed: 11/13/2022] Open
Abstract
Bangladesh is a cholera endemic country with a population at high risk of cholera. Toxigenic and non-toxigenic Vibrio cholerae (V. cholerae) can cause cholera and cholera-like diarrheal illness and outbreaks. Drinking water is one of the primary routes of cholera transmission in Bangladesh. The aim of this study was to conduct a comparative assessment of the presence of V. cholerae between point-of-drinking water and source water, and to investigate the variability of virulence profile using molecular methods of a densely populated low-income settlement of Dhaka, Bangladesh. Water samples were collected and tested for V. cholerae from "point-of-drinking" and "source" in 477 study households in routine visits at 6 week intervals over a period of 14 months. We studied the virulence profiles of V. cholerae positive water samples using 22 different virulence gene markers present in toxigenic O1/O139 and non-O1/O139 V. cholerae using polymerase chain reaction (PCR). A total of 1,463 water samples were collected, with 1,082 samples from point-of-drinking water in 388 households and 381 samples from 66 water sources. V. cholerae was detected in 10% of point-of-drinking water samples and in 9% of source water samples. Twenty-three percent of households and 38% of the sources were positive for V. cholerae in at least one visit. Samples collected from point-of-drinking and linked sources in a 7 day interval showed significantly higher odds (P < 0.05) of V. cholerae presence in point-of-drinking compared to source [OR = 17.24 (95% CI = 7.14-42.89)] water. Based on the 7 day interval data, 53% (17/32) of source water samples were negative for V. cholerae while linked point-of-drinking water samples were positive. There were significantly higher odds (p < 0.05) of the presence of V. cholerae O1 [OR = 9.13 (95% CI = 2.85-29.26)] and V. cholerae O139 [OR = 4.73 (95% CI = 1.19-18.79)] in source water samples than in point-of-drinking water samples. Contamination of water at the point-of-drinking is less likely to depend on the contamination at the water source. Hygiene education interventions and programs should focus and emphasize on water at the point-of-drinking, including repeated cleaning of drinking vessels, which is of paramount importance in preventing cholera.
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Affiliation(s)
- Jannatul Ferdous
- Department of Microbiology, University of Dhaka, Dhaka, Bangladesh.,Section for Global Health, Department of Public Health, Copenhagen Center for Disaster Research, University of Copenhagen, Copenhagen, Denmark
| | - Rebeca Sultana
- Section for Global Health, Department of Public Health, Copenhagen Center for Disaster Research, University of Copenhagen, Copenhagen, Denmark.,International Centre for Diarrhoeal Disease Research, Dhaka, Bangladesh.,Institute of Health Economics, University of Dhaka, Dhaka, Bangladesh
| | - Ridwan B Rashid
- Department of Microbiology, University of Dhaka, Dhaka, Bangladesh
| | - Md Tasnimuzzaman
- Department of Microbiology, University of Dhaka, Dhaka, Bangladesh
| | - Andreas Nordland
- Section for Global Health, Department of Public Health, Copenhagen Center for Disaster Research, University of Copenhagen, Copenhagen, Denmark
| | - Anowara Begum
- Department of Microbiology, University of Dhaka, Dhaka, Bangladesh
| | - Peter K M Jensen
- Section for Global Health, Department of Public Health, Copenhagen Center for Disaster Research, University of Copenhagen, Copenhagen, Denmark
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42
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Nosho K, Fukushima H, Asai T, Nishio M, Takamaru R, Kobayashi-Kirschvink KJ, Ogawa T, Hidaka M, Masaki H. cAMP-CRP acts as a key regulator for the viable but non-culturable state in Escherichia coli. MICROBIOLOGY-SGM 2018; 164:410-419. [PMID: 29458560 DOI: 10.1099/mic.0.000618] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
A variety of bacteria, including Escherichia coli, are known to enter the viable but non-culturable (VBNC) state under various stress conditions. During this state, cells lose colony-forming activities on conventional agar plates while retaining signs of viability. Diverse environmental stresses including starvation induce the VBNC state. However, little is known about the genetic mechanism inducing this state. Here, we aimed to reveal the genetic determinants of the VBNC state of E. coli. We hypothesized that the VBNC state is a process wherein specific gene products important for colony formation are depleted during the extended period of stress conditions. If so, higher expression of these genes would maintain colony-forming activities, thereby restraining cells from entering the VBNC state. From an E. coli plasmid-encoded ORF library, we identified genes that were responsible for maintaining high colony-forming activities after exposure to starvation condition. Among these, cpdA encoding cAMP phosphodiesterase exhibited higher performance in the maintenance of colony-forming activities. As cpdA overexpression decreases intracellular cAMP, cAMP or its complex with cAMP-receptor protein (CRP) may negatively regulate colony-forming activities under stress conditions. We confirmed this using deletion mutants lacking adenylate cyclase or CRP. These mutants fully maintained colony-forming activities even after a long period of starvation, while wild-type cells lost most of this activity. Thus, we concluded that the lack of cAMP-CRP effectively retains high colony-forming activities, indicating that cAMP-CRP acts as a positive regulator necessary for the induction of the VBNC state in E. coli.
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Affiliation(s)
- Kazuki Nosho
- Department of Biotechnology, The University of Tokyo, Yayoi, Bunkyo-ku, Tokyo, Japan
| | - Hiroko Fukushima
- Department of Biotechnology, The University of Tokyo, Yayoi, Bunkyo-ku, Tokyo, Japan
| | - Takehiro Asai
- Department of Biotechnology, The University of Tokyo, Yayoi, Bunkyo-ku, Tokyo, Japan
| | - Masahiro Nishio
- Department of Biotechnology, The University of Tokyo, Yayoi, Bunkyo-ku, Tokyo, Japan
| | - Reiko Takamaru
- Department of Biotechnology, The University of Tokyo, Yayoi, Bunkyo-ku, Tokyo, Japan
| | | | - Tetsuhiro Ogawa
- Department of Biotechnology, The University of Tokyo, Yayoi, Bunkyo-ku, Tokyo, Japan
| | - Makoto Hidaka
- Department of Biotechnology, The University of Tokyo, Yayoi, Bunkyo-ku, Tokyo, Japan
| | - Haruhiko Masaki
- Department of Biotechnology, The University of Tokyo, Yayoi, Bunkyo-ku, Tokyo, Japan
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43
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Yamazaki K, Takeuchi K, Yamazaki Y, Mino S, Kasai H, Sawabe T, Sawabe T, Satomi M. Occurrence and Prevention of Injured Bacterial Cells in Fisheries. J JPN SOC FOOD SCI 2018. [DOI: 10.3136/nskkk.65.197] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Affiliation(s)
- Koji Yamazaki
- Laboratory of Marine Food Science, Faculty of Fisheries Sciences, Hokkaido University
| | - Kantaro Takeuchi
- Laboratory of Microbiology, Faculty of Fisheries Sciences, Hokkaido University
| | - Yohei Yamazaki
- Laboratory of Microbiology, Faculty of Fisheries Sciences, Hokkaido University
| | - Sayaka Mino
- Laboratory of Microbiology, Faculty of Fisheries Sciences, Hokkaido University
| | - Hisae Kasai
- Laboratory of Microbiology, Faculty of Fisheries Sciences, Hokkaido University
| | - Toko Sawabe
- Department of Food Nutrition, Hakodate Junior College Hakodate
| | - Tomoo Sawabe
- Laboratory of Microbiology, Faculty of Fisheries Sciences, Hokkaido University
| | - Masataka Satomi
- National Research Institute of Fisheries Science, Japan Fisheries Research and Education Agency
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44
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Bamford RA, Smith A, Metz J, Glover G, Titball RW, Pagliara S. Investigating the physiology of viable but non-culturable bacteria by microfluidics and time-lapse microscopy. BMC Biol 2017; 15:121. [PMID: 29262826 PMCID: PMC5738893 DOI: 10.1186/s12915-017-0465-4] [Citation(s) in RCA: 95] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2017] [Accepted: 11/30/2017] [Indexed: 11/29/2022] Open
Abstract
Background Clonal microbial populations often harbor rare phenotypic variants that are typically hidden within the majority of the remaining cells, but are crucial for the population’s resilience to external perturbations. Persister and viable but non-culturable (VBNC) cells are two important clonal bacterial subpopulations that can survive antibiotic treatment. Both persister and VBNC cells pose a serious threat to human health. However, unlike persister cells, which quickly resume growth following drug removal, VBNC cells can remain non-growing for prolonged periods of time, thus eluding detection via traditional microbiological assays. Therefore, understanding the molecular mechanisms underlying the formation of VBNC cells requires the characterization of the clonal population with single-cell resolution. A combination of microfluidics, time-lapse microscopy, and fluorescent reporter strains offers the perfect platform for investigating individual cells while manipulating their environment. Methods Here, we report a novel single-cell approach to investigate VBNC cells. We perform drug treatment, bacterial culturing, and live/dead staining in series by using transcriptional reporter strains and novel adaptations to the mother machine technology. Since we track each cell throughout the experiment, we are able to quantify the size, morphology and fluorescence that each VBNC cell displayed before, during and after drug treatment. Results We show that VBNC cells are not dead or dying cells but share similar phenotypic features with persister cells, suggesting a link between these two subpopulations, at least in the Escherichia coli strain under investigation. We strengthen this link by demonstrating that, before drug treatment, both persister and VBNC cells can be distinguished from the remainder of the population by their lower fluorescence when using a reporter strain for tnaC, encoding the leader peptide of the tnaCAB operon responsible for tryptophan metabolism. Conclusion Our data demonstrates the suitability of our approach for studying the physiology of non-growing cells in response to external perturbations. Our approach will allow the identification of novel biomarkers for the isolation of VBNC and persister cells and will open new opportunities to map the detailed biochemical makeup of these clonal subpopulations. Electronic supplementary material The online version of this article (doi:10.1186/s12915-017-0465-4) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Rosemary A Bamford
- Biosciences, University of Exeter, Exeter, Devon, EX4 4QD, UK.,Living Systems Institute, University of Exeter, Exeter, Devon, EX4 4QD, UK
| | - Ashley Smith
- Biosciences, University of Exeter, Exeter, Devon, EX4 4QD, UK.,Living Systems Institute, University of Exeter, Exeter, Devon, EX4 4QD, UK
| | - Jeremy Metz
- Biosciences, University of Exeter, Exeter, Devon, EX4 4QD, UK.,Living Systems Institute, University of Exeter, Exeter, Devon, EX4 4QD, UK
| | - Georgina Glover
- Biosciences, University of Exeter, Exeter, Devon, EX4 4QD, UK.,Living Systems Institute, University of Exeter, Exeter, Devon, EX4 4QD, UK
| | | | - Stefano Pagliara
- Biosciences, University of Exeter, Exeter, Devon, EX4 4QD, UK. .,Living Systems Institute, University of Exeter, Exeter, Devon, EX4 4QD, UK.
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45
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Asakura H, Kawase J, Ikeda T, Honda M, Sasaki Y, Uema M, Kabeya H, Sugiyama H, Igimi S, Takai S. Microbiological Quality Assessment of Game Meats at Retail in Japan. J Food Prot 2017; 80:2119-2126. [PMID: 29166176 DOI: 10.4315/0362-028x.jfp-17-137] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
In this study, we examined the prevalence of Shiga toxin-producing Escherichia coli and Salmonella spp. and the distribution of indicator bacteria in 248 samples of game meats (120 venison and 128 wild boar) retailed between November 2015 and March 2016 in Japan. No Salmonella spp. were detected in any of the samples, whereas Shiga toxin-producing Escherichia coli serotype OUT:H25 (stx2d+, eae-) was isolated from one deer meat sample, suggesting a possible source for human infection. Plate count assays indicated greater prevalence of coliforms and E. coli in wild boar meat than in venison, whereas their prevalence in processing facilities showed greater variation than in animal species. The 16S rRNA ion semiconductor sequencing analysis of 24 representative samples revealed that the abundances of Acinetobacter and Arthrobacter spp. significantly correlated with the prevalence of E. coli, and quantitative PCR analyses in combination with selective plate count assay verified these correlations. To our knowledge, this is the first report to characterize the diversity of microorganisms of game meats at retail in Japan, together with identification of dominant microbiota. Our data suggest the necessity of bottom-up hygienic assessment in areas of slaughtering and processing facilities to improve microbiological safety.
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Affiliation(s)
- Hiroshi Asakura
- 1 Division of Biomedical Food Research, National Institute of Health Sciences, Kamiyoga 1-18-1, Setagaya-ku, Tokyo 158-8501, Japan
| | - Jun Kawase
- 2 Shimane Prefectural Meat Inspection Centre, Asayama-cho senzan 1677-2, Ota, Shimane 699-2212, Japan
| | - Tetsuya Ikeda
- 3 Department of Infectious Diseases, Hokkaido Institute of Public Health, Kita19 Nishi 12, Kita-ku Sapporo, Hokkaido 060-0819, Japan
| | - Mioko Honda
- 4 Department of Animal Nursing Science, Yamazaki Gakuen University, Minami-Osawa 4-7-2, Hachioji 192-0364, Japan
| | - Yoshimasa Sasaki
- 1 Division of Biomedical Food Research, National Institute of Health Sciences, Kamiyoga 1-18-1, Setagaya-ku, Tokyo 158-8501, Japan
| | - Masashi Uema
- 1 Division of Biomedical Food Research, National Institute of Health Sciences, Kamiyoga 1-18-1, Setagaya-ku, Tokyo 158-8501, Japan
| | - Hidenori Kabeya
- 5 Department of Veterinary Public Health, Nihon University, Kameino 1866, Fujisawa, Kanagawa 252-0880, Japan
| | - Hiromu Sugiyama
- 6 Department of Parasitology, National Institute of Infectious Diseases, Toyama 1-23-1, Shinjuku-ku, Tokyo 162-8640, Japan
| | - Shizunobu Igimi
- 7 Department of Microbiology, Tokyo University of Agriculture, Sakuragaoka 1-1, Setagaya-ku, Tokyo 156-8502, Japan; and
| | - Shinji Takai
- 8 Department of Animal Hygiene, Kitasato University, Higashi 23-35-1, Towada, Aomori 034-8628, Japan
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46
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Almatroudi A, Tahir S, Hu H, Chowdhury D, Gosbell IB, Jensen SO, Whiteley GS, Deva AK, Glasbey T, Vickery K. Staphylococcus aureus dry-surface biofilms are more resistant to heat treatment than traditional hydrated biofilms. J Hosp Infect 2017; 98:161-167. [PMID: 28919336 DOI: 10.1016/j.jhin.2017.09.007] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2017] [Accepted: 09/11/2017] [Indexed: 01/07/2023]
Abstract
BACKGROUND The importance of biofilms to clinical practice is being increasingly realized. Biofilm tolerance to antibiotics is well described but limited work has been conducted on the efficacy of heat disinfection and sterilization against biofilms. AIM To test the susceptibility of planktonic, hydrated biofilm and dry-surface biofilm forms of Staphylococcus aureus, to dry-heat and wet-heat treatments. METHODS S. aureus was grown as both hydrated biofilm and dry-surface biofilm in the CDC biofilm generator. Biofilm was subjected to a range of temperatures in a hot-air oven (dry heat), water bath or autoclave (wet heat). FINDINGS Dry-surface biofilms remained culture positive even when treated with the harshest dry-heat condition of 100°C for 60min. Following autoclaving samples were culture negative but 62-74% of bacteria in dry-surface biofilms remained alive as demonstrated by live/dead staining and confocal microscopy. Dry-surface biofilms subjected to autoclaving at 121°C for up to 30min recovered and released planktonic cells. Recovery did not occur following autoclaving for longer or at 134°C, at least during the time-period tested. Hydrated biofilm recovered following dry-heat treatment up to 100°C for 10min but failed to recover following autoclaving despite the presence of 43-60% live cells as demonstrated by live/dead staining. CONCLUSION S. aureus dry-surface biofilms are less susceptible to killing by dry heat and steam autoclaving than hydrated biofilms, which are less susceptible to heat treatment than planktonic suspensions.
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Affiliation(s)
- A Almatroudi
- Surgical Infection Research Group, Faculty of Medicine and Health Sciences, Macquarie University, New South Wales, Australia; Department of Medical Laboratories, College of Applied Medical Sciences, Qassim University, Qassim, Saudi Arabia
| | - S Tahir
- Surgical Infection Research Group, Faculty of Medicine and Health Sciences, Macquarie University, New South Wales, Australia
| | - H Hu
- Surgical Infection Research Group, Faculty of Medicine and Health Sciences, Macquarie University, New South Wales, Australia
| | - D Chowdhury
- Surgical Infection Research Group, Faculty of Medicine and Health Sciences, Macquarie University, New South Wales, Australia
| | - I B Gosbell
- Antibiotic Resistance and Mobile Elements Group, Ingham Institute for Applied Medical Research, Liverpool, New South Wales, Australia; Medical Sciences Research Group, School of Medicine, Western Sydney University, New South Wales, Australia; Department of Microbiology & Infectious Diseases, Sydney South West Pathology Service, Liverpool, New South Wales Health Pathology, New South Wales, Australia
| | - S O Jensen
- Antibiotic Resistance and Mobile Elements Group, Ingham Institute for Applied Medical Research, Liverpool, New South Wales, Australia; Medical Sciences Research Group, School of Medicine, Western Sydney University, New South Wales, Australia
| | - G S Whiteley
- Medical Sciences Research Group, School of Medicine, Western Sydney University, New South Wales, Australia; Whiteley Corporation, North Sydney, New South Wales, Australia
| | - A K Deva
- Surgical Infection Research Group, Faculty of Medicine and Health Sciences, Macquarie University, New South Wales, Australia
| | - T Glasbey
- Whiteley Corporation, North Sydney, New South Wales, Australia
| | - K Vickery
- Surgical Infection Research Group, Faculty of Medicine and Health Sciences, Macquarie University, New South Wales, Australia.
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47
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Mackelprang R, Burkert A, Haw M, Mahendrarajah T, Conaway CH, Douglas TA, Waldrop MP. Microbial survival strategies in ancient permafrost: insights from metagenomics. ISME JOURNAL 2017; 11:2305-2318. [PMID: 28696425 PMCID: PMC5607373 DOI: 10.1038/ismej.2017.93] [Citation(s) in RCA: 63] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/03/2016] [Revised: 02/25/2017] [Accepted: 04/27/2017] [Indexed: 01/14/2023]
Abstract
In permafrost (perennially frozen ground) microbes survive oligotrophic conditions, sub-zero temperatures, low water availability and high salinity over millennia. Viable life exists in permafrost tens of thousands of years old but we know little about the metabolic and physiological adaptations to the challenges presented by life in frozen ground over geologic time. In this study we asked whether increasing age and the associated stressors drive adaptive changes in community composition and function. We conducted deep metagenomic and 16 S rRNA gene sequencing across a Pleistocene permafrost chronosequence from 19 000 to 33 000 years before present (kyr). We found that age markedly affected community composition and reduced diversity. Reconstruction of paleovegetation from metagenomic sequence suggests vegetation differences in the paleo record are not responsible for shifts in community composition and function. Rather, we observed shifts consistent with long-term survival strategies in extreme cryogenic environments. These include increased reliance on scavenging detrital biomass, horizontal gene transfer, chemotaxis, dormancy, environmental sensing and stress response. Our results identify traits that may enable survival in ancient cryoenvironments with no influx of energy or new materials.
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Affiliation(s)
- Rachel Mackelprang
- Department of Biology, California State University Northridge, Northridge, CA, USA
| | - Alexander Burkert
- Department of Biology, California State University Northridge, Northridge, CA, USA
| | - Monica Haw
- US Geological Survey, Menlo Park, CA, USA
| | - Tara Mahendrarajah
- Department of Biology, California State University Northridge, Northridge, CA, USA
| | | | - Thomas A Douglas
- US Army Cold Regions Research and Engineering Laboratory, Fort Wainwright, AK, USA
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48
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van Teeseling MCF, de Pedro MA, Cava F. Determinants of Bacterial Morphology: From Fundamentals to Possibilities for Antimicrobial Targeting. Front Microbiol 2017; 8:1264. [PMID: 28740487 PMCID: PMC5502672 DOI: 10.3389/fmicb.2017.01264] [Citation(s) in RCA: 70] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2017] [Accepted: 06/23/2017] [Indexed: 12/11/2022] Open
Abstract
Bacterial morphology is extremely diverse. Specific shapes are the consequence of adaptive pressures optimizing bacterial fitness. Shape affects critical biological functions, including nutrient acquisition, motility, dispersion, stress resistance and interactions with other organisms. Although the characteristic shape of a bacterial species remains unchanged for vast numbers of generations, periodical variations occur throughout the cell (division) and life cycles, and these variations can be influenced by environmental conditions. Bacterial morphology is ultimately dictated by the net-like peptidoglycan (PG) sacculus. The species-specific shape of the PG sacculus at any time in the cell cycle is the product of multiple determinants. Some morphological determinants act as a cytoskeleton to guide biosynthetic complexes spatiotemporally, whereas others modify the PG sacculus after biosynthesis. Accumulating evidence supports critical roles of morphogenetic processes in bacteria-host interactions, including pathogenesis. Here, we review the molecular determinants underlying morphology, discuss the evidence linking bacterial morphology to niche adaptation and pathogenesis, and examine the potential of morphological determinants as antimicrobial targets.
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Affiliation(s)
- Muriel C F van Teeseling
- Laboratory for Molecular Infection Medicine Sweden, Department of Molecular Biology, Umeå Centre for Microbial Research, Umeå UniversityUmeå, Sweden
| | - Miguel A de Pedro
- Centro de Biología Molecular "Severo Ochoa" - Consejo Superior de Investigaciones Científicas, Universidad Autónoma de MadridMadrid, Spain
| | - Felipe Cava
- Laboratory for Molecular Infection Medicine Sweden, Department of Molecular Biology, Umeå Centre for Microbial Research, Umeå UniversityUmeå, Sweden
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49
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Abstract
Infectious diseases kill nearly 9 million people annually. Bacterial pathogens are responsible for a large proportion of these diseases, and the bacterial agents of pneumonia, diarrhea, and tuberculosis are leading causes of death and disability worldwide. Increasingly, the crucial role of nonhost environments in the life cycle of bacterial pathogens is being recognized. Heightened scrutiny has been given to the biological processes impacting pathogen dissemination and survival in the natural environment, because these processes are essential for the transmission of pathogenic bacteria to new hosts. This chapter focuses on the model environmental pathogen Vibrio cholerae to describe recent advances in our understanding of how pathogens survive between hosts and to highlight the processes necessary to support the cycle of environmental survival, transmission, and dissemination. We describe the physiological and molecular responses of V. cholerae to changing environmental conditions, focusing on its survival in aquatic reservoirs between hosts and its entry into and exit from human hosts.
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50
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Fida TT, Moreno-Forero SK, Breugelmans P, Heipieper HJ, Röling WFM, Springael D. Physiological and Transcriptome Response of the Polycyclic Aromatic Hydrocarbon Degrading Novosphingobium sp. LH128 after Inoculation in Soil. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2017; 51:1570-1579. [PMID: 28040887 DOI: 10.1021/acs.est.6b03822] [Citation(s) in RCA: 52] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Soil bioaugmentation involves the inoculation of pollutant-degrading bacteria to accelerate pollutant degradation. Often the inoculum shows a dramatic decrease in Colony Forming Units (CFU) upon soil inoculation but this behavior is not well-understood. In this study, the physiology and transcriptomic response of a GFP tagged variant of Novosphingobium sp. LH128 was examined after inoculation into phenanthrene spiked soil. Four hours after inoculation, strain LH128-GFP showed about 99% reduction in CFU while microscopic counts of GFP-expressing cells were identical to the expected initial cell density, indicating that the reduction in CFU number is explained by cells entering into a Viable But Non-Culturable (VBNC)-like state and not by cell death. Transcriptome analysis showed a remarkably higher expression of phenanthrene degradation genes 4 h after inoculation, compared to the inoculum suspension concomitant with an increased expression of genes involved in stress response. This indicates that the cells were active in phenanthrene degradation while experiencing stress. Between 4 h and 10 days, CFU numbers increased to numbers comparable to the inoculated cell density. Our results suggest that strain LH128-GFP enters a VBNC-like state upon inoculation into soil but is metabolically active and that VBNC cells should be taken into account in evaluating bioaugmentation approaches.
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Affiliation(s)
- Tekle Tafese Fida
- Division of Soil and Water Management, KU Leuven , Kasteelpark Arenberg 20, 3001 Heverlee, Belgium
| | - Silvia K Moreno-Forero
- Department of Fundamental Microbiology, University of Lausanne, Bâtiment Biophore Quartier Unil-Sorge , 1015 Lausanne, Switzerland
| | - Philip Breugelmans
- Division of Soil and Water Management, KU Leuven , Kasteelpark Arenberg 20, 3001 Heverlee, Belgium
| | - Hermann J Heipieper
- Department Environmental Biotechnology, Helmholtz Centre for Environmental Research-UFZ , Permoserstrasse 15, 04318 Leipzig, Germany
| | - Wilfred F M Röling
- Molecular Cell Physiology, FALW, VU University Amsterdam , De Boelelaan 1085, 1081 HV Amsterdam, The Netherlands
| | - Dirk Springael
- Division of Soil and Water Management, KU Leuven , Kasteelpark Arenberg 20, 3001 Heverlee, Belgium
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