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Kapinusova G, Lopez Marin MA, Uhlik O. Reaching unreachables: Obstacles and successes of microbial cultivation and their reasons. Front Microbiol 2023; 14:1089630. [PMID: 36960281 PMCID: PMC10027941 DOI: 10.3389/fmicb.2023.1089630] [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: 11/04/2022] [Accepted: 02/10/2023] [Indexed: 03/09/2023] Open
Abstract
In terms of the number and diversity of living units, the prokaryotic empire is the most represented form of life on Earth, and yet it is still to a significant degree shrouded in darkness. This microbial "dark matter" hides a great deal of potential in terms of phylogenetically or metabolically diverse microorganisms, and thus it is important to acquire them in pure culture. However, do we know what microorganisms really need for their growth, and what the obstacles are to the cultivation of previously unidentified taxa? Here we review common and sometimes unexpected requirements of environmental microorganisms, especially soil-harbored bacteria, needed for their replication and cultivation. These requirements include resuscitation stimuli, physical and chemical factors aiding cultivation, growth factors, and co-cultivation in a laboratory and natural microbial neighborhood.
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Affiliation(s)
| | | | - Ondrej Uhlik
- Department of Biochemistry and Microbiology, Faculty of Food and Biochemical Technology, University of Chemistry and Technology, Prague, Czechia
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2
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İzgördü ÖK, Darcan C, Kariptaş E. Overview of VBNC, a survival strategy for microorganisms. 3 Biotech 2022; 12:307. [PMID: 36276476 PMCID: PMC9526772 DOI: 10.1007/s13205-022-03371-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2022] [Accepted: 09/20/2022] [Indexed: 11/01/2022] Open
Abstract
Microorganisms are exposed to a wide variety of stress factors in their natural environments. Under that stressful conditions, they move into a viable but nonculturable (VBNC) state to survive and maintain the vitality. At VBNC state, microorganisms cannot be detected by traditional laboratory methods, but they can be revived under appropriate conditions. Therefore, VBNC organisms cause serious food safety and public health problems. To date, it has been determined that more than 100 microorganism species have entered the VBNC state through many chemical and physical factors. During the last four decades, dating from the initial detection of the VBNC condition, new approaches have been developed for the induction, detection, molecular mechanisms, and resuscitation of VBNC cells. This review evaluates the current data of recent years on the inducing conditions and detection methods of the VBNC state, including with microorganisms on the VBNC state, their virulence, pathogenicity, and molecular mechanisms.
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Affiliation(s)
- Özge Kaygusuz İzgördü
- Biotechnology Application and Research Center, Bilecik Şeyh Edebali University, Bilecik, Turkey
| | - Cihan Darcan
- Department of Molecular Biology and Genetics, Bilecik Şeyh Edebali University, Bilecik, Turkey
| | - Ergin Kariptaş
- Department of Microbiology, Faculty of Medicine, Samsun University, Samsun, Turkey
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3
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Lee HW, Yoon SR, Dang YM, Yun JH, Jeong H, Kim KN, Bae JW, Ha JH. Metatranscriptomic and metataxonomic insights into the ultra-small microbiome of the Korean fermented vegetable, kimchi. Front Microbiol 2022; 13:1026513. [PMID: 36274711 PMCID: PMC9581167 DOI: 10.3389/fmicb.2022.1026513] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2022] [Accepted: 09/20/2022] [Indexed: 11/13/2022] Open
Abstract
Presently, pertinent information on the ultra-small microbiome (USM) in fermented vegetables is still lacking. This study analyzed the metatranscriptome and metataxonome for the USM of kimchi. Tangential flow filtration was used to obtain a USM with a size of 0.2 μm or less from kimchi. The microbial diversity in the USM was compared with that of the normal microbiome (NM). Alpha diversity was higher in the USM than in NM, and the diversity of bacterial members of the NM was higher than that of the USM. At the phylum level, both USM and NM were dominated by Firmicutes. At the genus level, the USM and NM were dominated by Lactobacillus, Leuconostoc, and Weissella, belonging to lactic acid bacteria. However, as alpha diversity is higher in the USM than in the NM, the genus Akkermansia, belonging to the phylum Verrucomicrobia, was detected only in the USM. Compared to the NM, the USM showed a relatively higher ratio of transcripts related to “protein metabolism,” and the USM was suspected to be involved with the viable-but-nonculturable (VBNC) state. When comparing the sub-transcripts related to the “cell wall and capsule” of USM and NM, USM showed a proportion of transcripts suspected of being VBNC. In addition, the RNA virome was also identified, and both the USM and NM were confirmed to be dominated by pepper mild mottle virus (PMMoV). Additionally, the correlation between metataxonome and metatranscriptome identified USM and NM was estimated, however, only limited correlations between metataxonome and metatranscriptome were estimated. This study provided insights into the relationship between the potential metabolic activities of the USM of kimchi and the NM.
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Affiliation(s)
- Hae-Won Lee
- Hygienic Safety Packaging Research Group, World Institute of Kimchi, Gwangju, South Korea
- Department of Biology, Kyung Hee University, Seoul, South Korea
- Department of Life and Nanopharmaceutical Sciences, Kyung Hee University, Seoul, South Korea
| | - So-Ra Yoon
- Hygienic Safety Packaging Research Group, World Institute of Kimchi, Gwangju, South Korea
| | - Yun-Mi Dang
- Hygienic Safety Packaging Research Group, World Institute of Kimchi, Gwangju, South Korea
| | - Ji-Hyun Yun
- Department of Biology, Kyung Hee University, Seoul, South Korea
- Department of Life and Nanopharmaceutical Sciences, Kyung Hee University, Seoul, South Korea
| | - Hoibin Jeong
- Chuncheon Center, Korea Basic Science Institute (KBSI), Chuncheon, South Korea
- Korea Research Institute of Bioscience and Biotechnology (KRIBB), Daejeon, South Korea
| | - Kil-Nam Kim
- Korea Research Institute of Bioscience and Biotechnology (KRIBB), Daejeon, South Korea
| | - Jin-Woo Bae
- Department of Biology, Kyung Hee University, Seoul, South Korea
- Department of Life and Nanopharmaceutical Sciences, Kyung Hee University, Seoul, South Korea
- *Correspondence: Jin-Woo Bae,
| | - Ji-Hyoung Ha
- Hygienic Safety Packaging Research Group, World Institute of Kimchi, Gwangju, South Korea
- Ji-Hyoung Ha,
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4
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Trinh KTL, Lee NY. Recent Methods for the Viability Assessment of Bacterial Pathogens: Advances, Challenges, and Future Perspectives. Pathogens 2022; 11:pathogens11091057. [PMID: 36145489 PMCID: PMC9500772 DOI: 10.3390/pathogens11091057] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2022] [Revised: 09/14/2022] [Accepted: 09/15/2022] [Indexed: 11/28/2022] Open
Abstract
Viability assessment is a critical step in evaluating bacterial pathogens to determine infectious risks to public health. Based on three accepted viable criteria (culturability, metabolic activity, and membrane integrity), current viability assessments are categorized into three main strategies. The first strategy relies on the culturability of bacteria. The major limitation of this strategy is that it cannot detect viable but nonculturable (VBNC) bacteria. As the second strategy, based on the metabolic activity of bacteria, VBNC bacteria can be detected. However, VBNC bacteria sometimes can enter a dormant state that allows them to silence reproduction and metabolism; therefore, they cannot be detected based on culturability and metabolic activity. In order to overcome this drawback, viability assessments based on membrane integrity (third strategy) have been developed. However, these techniques generally require multiple steps, bulky machines, and laboratory technicians to conduct the tests, making them less attractive and popular applications. With significant advances in microfluidic technology, these limitations of current technologies for viability assessment can be improved. This review summarized and discussed the advances, challenges, and future perspectives of current methods for the viability assessment of bacterial pathogens.
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Affiliation(s)
- Kieu The Loan Trinh
- Department of Industrial Environmental Engineering, Gachon University, 1342 Seongnam-daero, Sujeong-gu, Seongnam-si 13120, Korea
| | - Nae Yoon Lee
- Department of BioNano Technology, Gachon University, 1342 Seongnam-daero, Sujeong-gu, Seongnam-si 13120, Korea
- Correspondence:
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5
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A Plasma-Based Decontamination Process Reveals Potential for an in-Process Surface-Sanitation Method. PLASMA 2022. [DOI: 10.3390/plasma5030027] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Methods, which use an indirect plasma treatment for the inactivation of microorganisms in foods, claim a vastly growing field of research. This paper presents a method that uses plasma-processed air (PPA) as a sanitizer. In addition to a sanitation concept for the decontamination of produce in the value chain, the presented method offers a possible application as an “in-process” surface sanitation. PPA provides antimicrobial-potent species, which are predominantly reactive nitrogen species (RNS); this has an outstanding groove penetration property. In an experimental approach, surfaces, made from materials, which are frequently used for the construction of food-processing plants, were inoculated with different microorganisms. Listeria monocytogenes (ATCC 15313), Staphylococcus aureus (ATCC 6538), Escherichia coli (ATCC 10538), Salmonella enterica subsp. enterica serovar Typhimurium (ATCC 43971), and Salmonella enterica subsp. enterica serovar Enteritidis (ATCC 13076) are all microorganisms that frequently appear in foods and possess the risk for cross-contamination from the plant to the produce or vice versa. The contaminated samples were treated for various treatment times (1–5 min) with PPA of different antimicrobial potencies. Subsequently, the microbial load on the specimens was determined and compared with the load of untreated samples. As a result, reduction factors (RF) up to several log10-steps were obtained. Although surface and the bacterial strain showed an influence on the RF, the major influence was seen by a prolongation of the treatment time and an increase in the potency of the PPA.
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Chiang ELC, Lee S, Medriano CA, Li L, Bae S. Assessment of physiological responses of bacteria to chlorine and UV disinfection using a plate count method, flow cytometry and viability PCR. J Appl Microbiol 2021; 132:1788-1801. [PMID: 34637587 DOI: 10.1111/jam.15325] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2021] [Revised: 10/03/2021] [Accepted: 10/05/2021] [Indexed: 11/28/2022]
Abstract
AIMS This study aimed to investigate the physiological responses of two gram-negative bacteria (Escherichia coli and Pseudomonas aeruginosa) and two gram-positive bacteria (Enterococcus faecalis and Bacillus sphaericus) to ultraviolet (UV) and chlorine disinfection. METHODS AND RESULTS Bacterial inactivation by UV and chlorine disinfection were evaluated with a plate count method for culturability, FCM and PMA-qPCR for membrane integrity and DyeTox13-qPCR for enzymatic activity, respectively. Both UV and chorine disinfection caused complete loss of culturability while membrane integrity remained intact after UV disinfection. Both DyeTox13-qPCR and PMA-qPCR showed high ΔCt values up to 8.9 after chlorine disinfection, indicating that both methods were able to distinguish non-treated from chlorine-treated cells. Although PMA-qPCR could not differentiate membrane integrity of cells on UV exposure, DyeTox13-qPCR showed significant differences in ΔCt values of 5.05 and 10.4 for gram-negative (E. coli) and gram-positive (Enterococcus) bacteria, respectively. However, DyeTox13-qPCR for gram-negative bacteria displayed relatively small differences in ΔCt values compared with gram-positive bacteria. CONCLUSION UV and chlorine disinfection led to changes in physiological state of gram-negative and gram-positive bacteria. Particularly, UV disinfection could induce active but non-culturable (ABNC) for gram-negative bacteria and dormant cell for gram-positive bacteria where intact cells no longer showed the enzymatic activity. SIGNIFICANCE AND IMPACT OF THE STUDY UV and chlorine are commonly used to disinfect water, food and fomites to inactivate pathogenic bacteria. However, a viable but non-culturable (VBNC) state of bacteria induced by disinfection may underestimate the health risks because of the potential resuscitation of VBNC cells. This study highlighted that bacteria could undergo different physiological (ABNC or dormant) states during UV and chlorine disinfection. In addition, viability PCR techniques could provide insight into the changes in physiological states during disinfection processes.
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Affiliation(s)
- Elaine L C Chiang
- Department of Civil and Environmental Engineering, National University of Singapore, Singapore, Singapore
| | - Seunguk Lee
- Department of Civil and Environmental Engineering, National University of Singapore, Singapore, Singapore
| | - Carl A Medriano
- Department of Civil and Environmental Engineering, National University of Singapore, Singapore, Singapore
| | - Liyan Li
- Department of Civil and Environmental Engineering, National University of Singapore, Singapore, Singapore
| | - Sungwoo Bae
- Department of Civil and Environmental Engineering, National University of Singapore, Singapore, Singapore
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7
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Oliveira MM, de Almeida FA, Baglinière F, de Oliveira LL, Vanetti MCD. Behavior of Salmonella Enteritidis and Shigella flexneri during induction and recovery of the viable but nonculturable state. FEMS Microbiol Lett 2021; 368:6316107. [PMID: 34227668 DOI: 10.1093/femsle/fnab087] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2021] [Accepted: 07/02/2021] [Indexed: 11/12/2022] Open
Abstract
Bacteria may enter into a viable but nonculturable (VBNC) state as a response to stresses, such as those found in food processing. Cells in the VBNC state lose the ability to grow in a conventional culture medium but man recover culturability. The viability, culturability and intracellular reactive oxygen species (ROS) of Salmonella Enteritidis and Shigella flexneri were evaluated under stress conditions to induce a VBNC state. Cells were maintained under nutritional, osmotic and cold stresses (long-term induction) in Butterfield's phosphate solution plus 1.2 M of NaCl at 4°C and under nutritional and oxidative stresses (short-term induction) in 10 mM of H2O2. Culture media, recovery agents, sterilization methods of media and incubation temperature, were combined and applied to recover the culturability of the VBNC cells. Salmonella entered in the VBNC state after 135 days under long-term induction, while Shigella maintained culturability after 240 days. Under short-term induction, Salmonella and Shigella lose culturability after 135 and 240 min, respectively. Flow cytometric analysis revealed viable cells and intracellular ROS in both species in VBNC. It was not possible to recover the culturability of VBNC cells using the 42 combinations of different factors.
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Affiliation(s)
- Mayara Messias Oliveira
- Department of Microbiology, Universidade Federal de Viçosa (UFV), Viçosa, MG, 36570-450, Brazil.,Department of Food Science, Universidade Estadual de Campinas (Unicamp), Campinas, SP, 13084-654, Brazil
| | - Felipe Alves de Almeida
- Department of Nutrition, Universidade Federal de Juiz de Fora (UFJF), Governador Valadares, MG, 35032-620, Brazil
| | - François Baglinière
- Department of Microbiology, Universidade Federal de Viçosa (UFV), Viçosa, MG, 36570-450, Brazil
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Impact of the Resistance Responses to Stress Conditions Encountered in Food and Food Processing Environments on the Virulence and Growth Fitness of Non-Typhoidal Salmonellae. Foods 2021; 10:foods10030617. [PMID: 33799446 PMCID: PMC8001757 DOI: 10.3390/foods10030617] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2021] [Revised: 02/24/2021] [Accepted: 03/10/2021] [Indexed: 01/22/2023] Open
Abstract
The success of Salmonella as a foodborne pathogen can probably be attributed to two major features: its remarkable genetic diversity and its extraordinary ability to adapt. Salmonella cells can survive in harsh environments, successfully compete for nutrients, and cause disease once inside the host. Furthermore, they are capable of rapidly reprogramming their metabolism, evolving in a short time from a stress-resistance mode to a growth or virulent mode, or even to express stress resistance and virulence factors at the same time if needed, thanks to a complex and fine-tuned regulatory network. It is nevertheless generally acknowledged that the development of stress resistance usually has a fitness cost for bacterial cells and that induction of stress resistance responses to certain agents can trigger changes in Salmonella virulence. In this review, we summarize and discuss current knowledge concerning the effects that the development of resistance responses to stress conditions encountered in food and food processing environments (including acid, osmotic and oxidative stress, starvation, modified atmospheres, detergents and disinfectants, chilling, heat, and non-thermal technologies) exerts on different aspects of the physiology of non-typhoidal Salmonellae, with special emphasis on virulence and growth fitness.
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9
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M Jayakumar J, Balasubramanian D, Reddi G, Almagro-Moreno S. Synergistic role of abiotic factors driving viable but non-culturable Vibrio cholerae. ENVIRONMENTAL MICROBIOLOGY REPORTS 2020; 12:454-465. [PMID: 32542975 DOI: 10.1111/1758-2229.12861] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/25/2020] [Revised: 06/06/2020] [Accepted: 06/13/2020] [Indexed: 06/11/2023]
Abstract
Vibrio cholerae O1, a natural inhabitant of estuarine environments, is found in a dormant, viable but non-culturable (VBNC) state during interepidemic periods. Although the individual roles of abiotic factors affecting VBNC formation have been extensively studied, their interplay in driving this phenomenon remains largely unaddressed. Here, we identified that major abiotic factors synergize with low nutrient conditions governing entry of cells into the VBNC state. Specifically, V. cholerae cells exposed to a combination of alkaline pH and high salinity under aeration at low temperatures (VBNC-inducing conditions) synergize to facilitate rapid entry into VBNC, whereas the opposite conditions prevented entry into the state. The major virulence regulator ToxR, and the stringent response protein RelA played opposing roles, repressing and facilitating VBNC entry respectively. Further, VBNC-inducing conditions negated the effects of ToxR and RelA, facilitating rapid formation of VBNC cells. In summary, this study highlights the synergy between critical abiotic factors and identified ToxR and RelA as two associated regulators, allowing for the persistence of V. cholerae in aquatic environments. Insights obtained in this study will help better understand environmental survival non-sporulating bacteria and transmission of facultative bacterial pathogens.
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Affiliation(s)
- Jane M Jayakumar
- Burnett School of Biomedical Sciences, College of Medicine, University of Central Florida, Orlando, FL, 32816
- National Center for Integrated Coastal Research, University of Central Florida, Orlando, FL, 32816
| | - Deepak Balasubramanian
- Burnett School of Biomedical Sciences, College of Medicine, University of Central Florida, Orlando, FL, 32816
- National Center for Integrated Coastal Research, University of Central Florida, Orlando, FL, 32816
| | - Geethika Reddi
- Burnett School of Biomedical Sciences, College of Medicine, University of Central Florida, Orlando, FL, 32816
- National Center for Integrated Coastal Research, University of Central Florida, Orlando, FL, 32816
| | - Salvador Almagro-Moreno
- Burnett School of Biomedical Sciences, College of Medicine, University of Central Florida, Orlando, FL, 32816
- National Center for Integrated Coastal Research, University of Central Florida, Orlando, FL, 32816
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10
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Gu G, Bolten S, Mowery J, Luo Y, Gulbronson C, Nou X. Susceptibility of foodborne pathogens to sanitizers in produce rinse water and potential induction of viable but non-culturable state. Food Control 2020. [DOI: 10.1016/j.foodcont.2020.107138] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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11
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Quorum sensing regulation confronts the development of a viable but
non‐culturable
state in
Vibrio cholerae. Environ Microbiol 2020; 22:4314-4322. [DOI: 10.1111/1462-2920.15026] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2019] [Revised: 04/10/2020] [Accepted: 04/13/2020] [Indexed: 12/01/2022]
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12
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Kadkhodaei S, Siavoshi F, Akbari Noghabi K. Mucoid and coccoid Helicobacter pylori with fast growth and antibiotic resistance. Helicobacter 2020; 25:e12678. [PMID: 31880001 DOI: 10.1111/hel.12678] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/02/2019] [Revised: 12/03/2019] [Accepted: 12/05/2019] [Indexed: 12/31/2022]
Abstract
BACKGROUND In this study, one Helicobacter pylori isolate, from gastric biopsy of a dyspeptic patient that turned into mucoid-coccoid (MC) form upon consecutive subcultures, was identified. The culturability, antibiotic resistance, and lipid contents of MC were compared with those of non-mucoid (NM) spiral H pylori. MATERIALS AND METHODS Mucoid-coccoid and NM H pylori were subcultured on Brucella blood agar (BBA) and incubated under aerobic and microaerobic atmospheres at 37°C. Cultures were examined for colony characteristics and bacterial morphology after 1-3 days. The isolates were identified by biochemical tests and detection of H pylori-16S rDNA. Antibiogram was performed with currently used antibiotics for H pylori eradication. Cellular lipid contents were extracted and analyzed by gas chromatography. RESULTS Compared with pin-pointed and glistening colonies of NM H pylori that appeared under microaerobic conditions, MC H pylori grew well in consecutive subcultures under aerobic and microaerobic atmospheres and produced white patches of mucoid colonies. MC exhibited coccoid and NM spiral morphology. Both isolates were catalase, oxidase, and urease positive and contained 16S rDNA. Compared with NM that was susceptible to almost all the antibiotics, MC was resistant to all the antibiotics. Lipid analyses showed high frequency of unsaturated fatty acids and cholesterol in MC. CONCLUSIONS Coccoid forms with high fatty acid and cholesterol contents that show resistance to antibiotics might resist against other stressful conditions such as gastric acidity and immune response. Moreover, mucoid property may enhance resistance of coccoids to stresses. With mucoid-coccoid lifestyle, H pylori may establish a chronic infection refractory to antimicrobial therapy.
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Affiliation(s)
- Sara Kadkhodaei
- Department of Microbiology, School of Biology, University College of Sciences, Tehran University, Tehran, Iran
| | - Farideh Siavoshi
- Department of Microbiology, School of Biology, University College of Sciences, Tehran University, Tehran, Iran
| | - Kambiz Akbari Noghabi
- Department of Molecular Genetics, National Institute of Genetic Engineering and Biotechnology (NIGEB), Tehran, Iran
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13
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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] [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,Address correspondence to: Nardhy Gomez-Lopez, MSc, PhD, Department of Obstetrics and Gynecology, Wayne State University School of Medicine, Perinatology Research Branch, NICHD/NIH/DHHS, 275 E. Hancock, Detroit, Michigan 48201, USA, Tel (313) 577-8904, ; , Roberto Romero, MD, D. Med. Sci. Perinatology Research Branch, NICHD/NIH/DHHS, Hutzel Women’s Hospital, 3990 John R, Box 4, Detroit, Michigan, 48201, USA, Telephone: (313) 993-2700, Fax: (313) 993-2694,
| | - 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,Address correspondence to: Nardhy Gomez-Lopez, MSc, PhD, Department of Obstetrics and Gynecology, Wayne State University School of Medicine, Perinatology Research Branch, NICHD/NIH/DHHS, 275 E. Hancock, Detroit, Michigan 48201, USA, Tel (313) 577-8904, ; , Roberto Romero, MD, D. Med. Sci. Perinatology Research Branch, NICHD/NIH/DHHS, Hutzel Women’s Hospital, 3990 John R, Box 4, Detroit, Michigan, 48201, USA, Telephone: (313) 993-2700, Fax: (313) 993-2694,
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14
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Guo L, Ye C, Cui L, Wan K, Chen S, Zhang S, Yu X. Population and single cell metabolic activity of UV-induced VBNC bacteria determined by CTC-FCM and D 2O-labeled Raman spectroscopy. ENVIRONMENT INTERNATIONAL 2019; 130:104883. [PMID: 31229870 DOI: 10.1016/j.envint.2019.05.077] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/10/2019] [Revised: 05/19/2019] [Accepted: 05/30/2019] [Indexed: 06/09/2023]
Abstract
The occurrence of viable but non-culturable (VBNC) bacteria will result in significant underestimation of viable bacterial counts in drinking water. Whereas, much is unknown in characterizing their viability. In this study, two environmental isolates (Aeromonas sp. and Pseudomonas sp.) and two model strains (E. coli and S. aureus) were induced into VBNC state by UV irradiation. Then, their metabolic activity was determined by 5-cyano-2,3-ditolyl tetrazolium chloride combination flow cytometry (CTC-FCM) and D2O-labeled Raman spectroscopy, respectively, at both population and single cell levels. The results showed that almost all strains could enter VBNC state irradiated by ≥ 5 mJ/cm2 UV. When determined by CTC-FCM, the population metabolic activity for each strain did not vary significantly (p > 0.05) unless the UV dose reached 200 mJ/cm2. Their single cell activity spectrum narrowed slightly, as indicated by changes in the standard deviation of the logarithmic normal distribution (σ) of 0.015-0.033. This minute difference suggested the CTC-FCM method was suitable for assessing the essential viability of VBNC bacteria. With respect to Raman method, an obvious dose-response effect was recorded. With the UV dosages increased from 10 to 200 mJ/cm2, the CD/(CD + CH) for the four strains were reduced to between 95.7% and 47.9% of unirradiated controls, depending on strain and UV dose. Meanwhile, the single cellular Raman spectrum showed much more heterogeneously metabolic activity distribution, with some cells even entering metabolic "silence". Considering the ubiquitous participation of water in biochemical processes, the Raman method was more appropriate in assessing the overall metabolic activity. The above findings can not only be a reference for VBNC mechanism studies, but also have the potential in optimizing disinfection and other bacterial removal processes.
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Affiliation(s)
- Lizheng Guo
- Key Lab of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China; University of Chinese Academy of Sciences, Beijing 100049, PR China
| | - Chengsong Ye
- Key Lab of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China
| | - Li Cui
- Key Lab of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China
| | - Kun Wan
- Key Lab of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China; University of Chinese Academy of Sciences, Beijing 100049, PR China
| | - Sheng Chen
- Key Lab of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China; University of Chinese Academy of Sciences, Beijing 100049, PR China
| | - Shenghua Zhang
- Key Lab of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China.
| | - Xin Yu
- Key Lab of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China.
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15
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Using diphenyleneiodonium to induce a viable but non-culturable phenotype in Mycobacterium tuberculosis and its metabolomics analysis. PLoS One 2019; 14:e0220628. [PMID: 31369628 PMCID: PMC6675104 DOI: 10.1371/journal.pone.0220628] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2019] [Accepted: 07/19/2019] [Indexed: 11/19/2022] Open
Abstract
Depletion of oxygen levels is a well-accepted model for induction of non-replicating, persistent states in mycobacteria. Increasing the stress levels in mycobacterium bacilli facilitates their entry into a non-cultivable, dormant state. In this study, it was shown that diphenyleneiodonium, an inhibitor of NADH oxidase, induced a viable, but non-culturable state in mycobacteria, having similar features to dormant bacilli, like loss of acid-fastness, upregulation of stress-regulated genes and decreased superoxide levels as compared to actively growing bacilli. Comprehensive, untargeted metabolic profiling also confirmed a decrease in biogenesis of amino acids, NAD, unsaturated fatty acids and nucleotides. Additionally, an increase in the level of lactate, fumarate, succinate and pentose phosphate pathways along with increased mycothiol and sulfate metabolites, similar to dormant bacilli, was observed in the granuloma. These non-cultivable bacilli were resuscitated by supplementation of fetal bovine serum, regaining their culturability in liquid as well as on agar medium. This study focused on the effect of diphenyleneiodonium treatment in causing mycobacteria to rapidly transition from an active state into a viable, but non-cultivable state, and comparing their characteristics with dormant phenotypes.
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16
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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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17
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Schnabel U, Handorf O, Yarova K, Zessin B, Zechlin S, Sydow D, Zellmer E, Stachowiak J, Andrasch M, Below H, Ehlbeck J. Plasma-Treated Air and Water-Assessment of Synergistic Antimicrobial Effects for Sanitation of Food Processing Surfaces and Environment. Foods 2019; 8:foods8020055. [PMID: 30717375 PMCID: PMC6406376 DOI: 10.3390/foods8020055] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2019] [Revised: 01/28/2019] [Accepted: 01/29/2019] [Indexed: 01/28/2023] Open
Abstract
The synergistic antimicrobial effects of plasma-processed air (PPA) and plasma-treated water (PTW), which are indirectly generated by a microwave-induced non-atmospheric pressure plasma, were investigated with the aid of proliferation assays. For this purpose, microorganisms (Listeria monocytogenes, Escherichia coli, Pectobacterium carotovorum, sporulated Bacillus atrophaeus) were cultivated as monocultures on specimens with polymeric surface structures. Both the distinct and synergistic antimicrobial potential of PPA and PTW were governed by the plasma-on time (5⁻50 s) and the treatment time of the specimens with PPA/PTW (1⁻5 min). In single PTW treatment of the bacteria, an elevation of the reduction factor with increasing treatment time could be observed (e.g., reduction factor of 2.4 to 3.0 for P. carotovorum). In comparison, the combination of PTW and subsequent PPA treatment leads to synergistic effects that are clearly not induced by longer treatment times. These findings have been valid for all bacteria (L. monocytogenes > P. carotovorum = E. coli). Controversially, the effect is reversed for endospores of B. atrophaeus. With pure PPA treatment, a strong inactivation at 50 s plasma-on time is detectable, whereas single PTW treatment shows no effect even with increasing treatment parameters. The use of synergistic effects of PTW for cleaning and PPA for drying shows a clear alternative for currently used sanitation methods in production plants. Highlights: Non-thermal atmospheric pressure microwave plasma source used indirect in two different modes-gaseous and liquid; Measurement of short and long-living nitrite and nitrate in corrosive gas PPA (plasma-processed air) and complex liquid PTW (plasma-treated water); Application of PTW and PPA in single and combined use for biological decontamination of different microorganisms.
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Affiliation(s)
- Uta Schnabel
- Plasma Bioengineering, Leibniz Institute for Plasma Science and Technology e.V., Felix-Hausdorff-Straße 2, 17491 Greifswald, Germany.
- School of Food Science and Environmental Health, College of Sciences and Health, Technological University Dublin, Cathal Brugha Street, D01 HV58 Dublin, Ireland.
| | - Oliver Handorf
- Plasma Bioengineering, Leibniz Institute for Plasma Science and Technology e.V., Felix-Hausdorff-Straße 2, 17491 Greifswald, Germany.
| | - Kateryna Yarova
- Plasma Bioengineering, Leibniz Institute for Plasma Science and Technology e.V., Felix-Hausdorff-Straße 2, 17491 Greifswald, Germany.
| | - Björn Zessin
- Plasma Bioengineering, Leibniz Institute for Plasma Science and Technology e.V., Felix-Hausdorff-Straße 2, 17491 Greifswald, Germany.
| | - Susann Zechlin
- Plasma Bioengineering, Leibniz Institute for Plasma Science and Technology e.V., Felix-Hausdorff-Straße 2, 17491 Greifswald, Germany.
| | - Diana Sydow
- Plasma Bioengineering, Leibniz Institute for Plasma Science and Technology e.V., Felix-Hausdorff-Straße 2, 17491 Greifswald, Germany.
| | - Elke Zellmer
- Institute for Hygiene and Environmental Medicine, Faculty of Medicine, University of Greifswald, Walter-Rathenau-Straße 49A, 17475 Greifswald, Germany.
| | - Jörg Stachowiak
- Plasma Bioengineering, Leibniz Institute for Plasma Science and Technology e.V., Felix-Hausdorff-Straße 2, 17491 Greifswald, Germany.
| | - Mathias Andrasch
- Plasma Bioengineering, Leibniz Institute for Plasma Science and Technology e.V., Felix-Hausdorff-Straße 2, 17491 Greifswald, Germany.
| | - Harald Below
- Institute for Hygiene and Environmental Medicine, Faculty of Medicine, University of Greifswald, Walter-Rathenau-Straße 49A, 17475 Greifswald, Germany.
| | - Jörg Ehlbeck
- Plasma Bioengineering, Leibniz Institute for Plasma Science and Technology e.V., Felix-Hausdorff-Straße 2, 17491 Greifswald, Germany.
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18
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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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19
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Schottroff F, Fröhling A, Zunabovic-Pichler M, Krottenthaler A, Schlüter O, Jäger H. Sublethal Injury and Viable but Non-culturable (VBNC) State in Microorganisms During Preservation of Food and Biological Materials by Non-thermal Processes. Front Microbiol 2018; 9:2773. [PMID: 30515140 PMCID: PMC6255932 DOI: 10.3389/fmicb.2018.02773] [Citation(s) in RCA: 79] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2018] [Accepted: 10/29/2018] [Indexed: 11/13/2022] Open
Abstract
The viable but non-culturable (VBNC) state, as well as sublethal injury of microorganisms pose a distinct threat to food safety, as the use of traditional, culture-based microbiological analyses might lead to an underestimation or a misinterpretation of the product's microbial status and recovery phenomena of microorganisms may occur. For thermal treatments, a large amount of data and experience is available and processes are designed accordingly. In case of innovative inactivation treatments, however, there are still several open points with relevance for the investigation of inactivation mechanisms as well as for the application and validation of the preservation processes. Thus, this paper presents a comprehensive compilation of non-thermal preservation technologies, i.e., high hydrostatic pressure (HHP), pulsed electric fields (PEFs), pulsed light (PL), and ultraviolet (UV) radiation, as well as cold plasma (CP) treatments. The basic technological principles and the cellular and molecular mechanisms of action are described. Based on this, appropriate analytical methods are outlined, i.e., direct viable count, staining, and molecular biological methods, in order to enable the differentiation between viable and dead cells, as well as the possible occurrence of an intermediate state. Finally, further research needs are outlined.
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Affiliation(s)
- Felix Schottroff
- Institute of Food Technology, University of Natural Resources and Life Sciences, Vienna, Austria
| | - Antje Fröhling
- Quality and Safety of Food and Feed, Leibniz Institute for Agricultural Engineering and Bioeconomy, Potsdam, Germany
| | | | - Anna Krottenthaler
- Institute of Food Technology, University of Natural Resources and Life Sciences, Vienna, Austria
| | - Oliver Schlüter
- Quality and Safety of Food and Feed, Leibniz Institute for Agricultural Engineering and Bioeconomy, Potsdam, Germany
| | - Henry Jäger
- Institute of Food Technology, University of Natural Resources and Life Sciences, Vienna, Austria
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20
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Liu J, Deng Y, Li L, Li B, Li Y, Zhou S, Shirtliff ME, Xu Z, Peters BM. Discovery and control of culturable and viable but non-culturable cells of a distinctive Lactobacillus harbinensis strain from spoiled beer. Sci Rep 2018; 8:11446. [PMID: 30061572 PMCID: PMC6065415 DOI: 10.1038/s41598-018-28949-y] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2018] [Accepted: 07/02/2018] [Indexed: 11/09/2022] Open
Abstract
Occasional beer spoilage incidents caused by false-negative isolation of lactic acid bacteria (LAB) in the viable but non-culturable (VBNC) state, result in significant profit loss and pose a major concern in the brewing industry. In this study, both culturable and VBNC cells of an individual Lactobacillus harbinensis strain BM-LH14723 were identified in one spoiled beer sample by genome sequencing, with the induction and resuscitation of VBNC state for this strain further investigated. Formation of the VBNC state was triggered by low-temperature storage in beer (175 ± 1.4 days) and beer subculturing (25 ± 0.8 subcultures), respectively, and identified by both traditional staining method and PMA-PCR. Resuscitated cells from the VBNC state were obtained by addition of catalase rather than temperature upshift, changing medium concentration, and adding other chemicals, and both VBNC and resuscitated cells retained similar beer-spoilage capability as exponentially growing cells. In addition to the first identification of both culturable and VBNC cells of an individual L. harbinensis strain from spoiled beer, this study also for the first time reported the VBNC induction and resuscitation, as well as verification of beer-spoilage capability of VBNC and resuscitated cells for the L. harbinensis strain. Genes in association with VBNC state were also identified by the first genome sequencing of beer spoilage L. harbinensis. The results derived from this study suggested the contamination and spoilage of beer products by VBNC and resuscitated L. harbinensis strain BM-LH14723.
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Affiliation(s)
- Junyan Liu
- School of Food Science and Engineering, South China University of Technology, Guangzhou, 510640, China.,Department of Clinical Pharmacy, College of Pharmacy, University of Tennessee Health Science Center, Memphis, TN, 38163, USA
| | - Yang Deng
- College of Food Science and Engineering, Qingdao Agricultural University, Qingdao, 266109, P.R. China
| | - Lin Li
- School of Food Science and Engineering, South China University of Technology, Guangzhou, 510640, China. .,School of Chemical Engineering and Energy Technology, Dongguan University of Technology, Dongguan, 523808, China. .,Guangdong Province Key Laboratory for Green Processing of Natural Products and Product Safety, Guangzhou, 510640, China.
| | - Bing Li
- School of Food Science and Engineering, South China University of Technology, Guangzhou, 510640, China.,Guangdong Province Key Laboratory for Green Processing of Natural Products and Product Safety, Guangzhou, 510640, China
| | - Yanyan Li
- Department of Cell Biology, Harvard Medical School, Boston, MA, 02115, USA
| | - Shishui Zhou
- School of Bioscience and Bioengineering, South China University of Technology, Guangzhou, 510006, China
| | - Mark E Shirtliff
- Department of Microbial Pathogenesis, School of Dentistry, University of Maryland, Baltimore MD, MA, 21201, USA
| | - Zhenbo Xu
- School of Food Science and Engineering, South China University of Technology, Guangzhou, 510640, China. .,College of Food Science and Engineering, Qingdao Agricultural University, Qingdao, 266109, P.R. China. .,Department of Microbial Pathogenesis, School of Dentistry, University of Maryland, Baltimore MD, MA, 21201, USA.
| | - Brian M Peters
- Department of Clinical Pharmacy, College of Pharmacy, University of Tennessee Health Science Center, Memphis, TN, 38163, USA
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21
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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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22
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Hosangadi D, Smith PG, Giersing BK. Considerations for using ETEC and Shigella disease burden estimates to guide vaccine development strategy. Vaccine 2017; 37:7372-7380. [PMID: 29031690 PMCID: PMC6892262 DOI: 10.1016/j.vaccine.2017.09.083] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2017] [Accepted: 09/26/2017] [Indexed: 01/09/2023]
Abstract
Enterotoxigenic E. coli (ETEC) and Shigella are enteropathogens causing significant global morbidity and mortality, particularly in low-income countries. No licensed vaccine exists for either pathogen, but candidates are in development, with the most advanced candidates potentially approaching pivotal efficacy testing within the next few years. A positive policy recommendation for introduction of any vaccine, following licensure, depends on evidence of vaccine cost-effectiveness and impact on morbidity and mortality. The mortality estimates for these two pathogens have fluctuated over recent years, which has led to uncertainty in the assessment of their relative public health importance for use in low and middle-income countries. This paper summarizes the various ETEC and Shigella disease burden estimates, based on a review of current literature and informal consultations with leading stakeholders in enteric disease modelling. We discuss the factors that underpin the variability, including differences in the modelling methodology; diagnostic tools used to ascertain diarrheal etiology; epidemiological setting; the data that are available to incorporate; and absolute changes in the total number of diarrheal deaths over time. We consider the further work that will strengthen the evidence needed to support future decision making with respect to recommendations on the relative utility of these vaccines.
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Affiliation(s)
- Divya Hosangadi
- Johns Hopkins Bloomberg School of Public Health, Baltimore, MD 21205, USA
| | - Peter G Smith
- MRC Tropical Epidemiology Group, London School of Hygiene & Tropical Medicine, London, UK
| | - Birgitte K Giersing
- Initiative for Vaccine Research, World Health Organization, CH-1211 Geneva 27, Switzerland.
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23
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Zhao X, Zhong J, Wei C, Lin CW, Ding T. Current Perspectives on Viable but Non-culturable State in Foodborne Pathogens. Front Microbiol 2017; 8:580. [PMID: 28421064 PMCID: PMC5378802 DOI: 10.3389/fmicb.2017.00580] [Citation(s) in RCA: 177] [Impact Index Per Article: 25.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2016] [Accepted: 03/21/2017] [Indexed: 01/24/2023] Open
Abstract
The viable but non-culturable (VBNC) state, a unique state in which a number of bacteria respond to adverse circumstances, was first discovered in 1982. Unfortunately, it has been reported that many foodborne pathogens can be induced to enter the VBNC state by the limiting environmental conditions during food processing and preservation, such as extreme temperatures, drying, irradiation, pulsed electric field, and high pressure stress, as well as the addition of preservatives and disinfectants. After entering the VBNC state, foodborne pathogens will introduce a serious crisis to food safety and public health because they cannot be detected using conventional plate counting techniques. This review provides an overview of the various features of the VBNC state, including the biological characteristics, induction and resuscitation factors, formation and resuscitation mechanisms, detection methods, and relationship to food safety.
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Affiliation(s)
- Xihong Zhao
- Key Laboratory for Green Chemical Process of Ministry of Education, Key Laboratory for Hubei Novel Reactor and Green Chemical Technology, School of Chemical Engineering and Pharmacy, Wuhan Institute of TechnologyWuhan, China
| | - Junliang Zhong
- Key Laboratory for Green Chemical Process of Ministry of Education, Key Laboratory for Hubei Novel Reactor and Green Chemical Technology, School of Chemical Engineering and Pharmacy, Wuhan Institute of TechnologyWuhan, China
| | - Caijiao Wei
- Key Laboratory for Green Chemical Process of Ministry of Education, Key Laboratory for Hubei Novel Reactor and Green Chemical Technology, School of Chemical Engineering and Pharmacy, Wuhan Institute of TechnologyWuhan, China
| | - Chii-Wann Lin
- Institute of Biomedical Engineering, National Taiwan UniversityTaipei, Taiwan
| | - Tian Ding
- Department of Food Science and Nutrition, Zhejiang Key Laboratory for Agro-Food Processing, Zhejiang UniversityHangzhou, China
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Sutton AO, Strickland D, Norris DR. Food storage in a changing world: implications of climate change for food-caching species. ACTA ACUST UNITED AC 2016. [DOI: 10.1186/s40665-016-0025-0] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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25
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Use of flow cytometry and PCR analysis to detect 5-carboxyfluoroscein-stained obligate intracellular bacteria Lawsonia intracellularis invasion of McCoy cells. J Microbiol Methods 2016; 126:60-6. [PMID: 27154728 DOI: 10.1016/j.mimet.2016.04.015] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2016] [Accepted: 04/29/2016] [Indexed: 11/23/2022]
Abstract
In this study, we describe a method to quantify invasion of obligate intracellular bacteria, Lawsonia intracellularis, inside McCoy cells. In immunological research, the cell-permeable fluorescent dye 5'-carboxyfluoroscein succidyl ester (CFSE) is commonly used to quantify eukaryotic cellular proliferation. Instead of using it in this traditional way, we stained L. intracellularis with CFSE dye prior to infection of McCoy cells. Flow cytometry was performed to quantify the percentage of eukaryotic cells which had taken up or were associated with fluorescent bacteria. As obligate intracellular bacteria, they cannot replicate outside of eukaryotic cells and thus qPCR analysis was used to quantify bacterial growth. Indirectly, PCR analysis confirmed invasion rather than adherence to the McCoy cell surface. Fluorescent activated cell sorting (FACS) was used to sort the CFSE(+) (i.e. infected) McCoy cells from the CFSE(-) (i.e. non-infected) McCoy cells and confocal microscopy was used to confirm bacterial invasion and cytosolic localization of CFSE-L. intracellularis. To show that this approach could be used in conjunction with functional assays, we investigated the effect that serum antibodies had on CFSE-bacterial invasion and growth. Instead of blocking invasion, rabbit hyperimmune serum augmented invasion of the bacteria inside McCoy cells and qPCR analysis confirmed bacterial growth over the course of 5days. We conclude that CFSE-labeling of bacteria and qPCR can be used to track and quantify bacterial invasion and may be a valuable tool for studying the invasive properties of bacteria, especially if commercial antibodies are not available. This approach may be adapted for use in other obligate intracellular bacteria and intracellular pathogens.
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Bekir K, Barhoumi H, Braiek M, Chrouda A, Zine N, Abid N, Maaref A, Bakhrouf A, Ouada HB, Jaffrezic-Renault N, Mansour HB. Electrochemical impedance immunosensor for rapid detection of stressed pathogenic Staphylococcus aureus bacteria. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2015; 22:15796-15803. [PMID: 26036585 DOI: 10.1007/s11356-015-4761-7] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/19/2015] [Accepted: 05/19/2015] [Indexed: 06/04/2023]
Abstract
In this work, we report the adaptation of bacteria to stress conditions that induce instability of their cultural, morphological, and enzymatic characters, on which the identification of pathogenic bacteria is based. These can raise serious issues during the characterization of bacteria. The timely detection of pathogens is also a subject of great importance. For this reason, our objective is oriented towards developing an immunosensing system for rapid detection and quantification of Staphylococcus aureus. Polyclonal anti-S. aureus are immobilized onto modified gold electrode by self-assembled molecular monolayer (SAM) method. The electrochemical performances of the developed immunosensor were evaluated by impedance spectroscopy through the monitoring of the charge transfer resistance at the modified solid/liquid interface using ferri-/ferrocyanide as redox probe. The developed immunosensor was applied to detect stressed and resuscitate bacteria. As a result, a stable and reproducible immunosensor with sensitivity of 15 kΩ/decade and a detection limit of 10 CFU/mL was obtained for the S. aureus concentrations ranging from 10(1) to 10(7) CFU/mL. A low deviation in the immunosensor response (±10 %) was signed when it is exposed to stressed and not stressed bacteria.
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Affiliation(s)
- Karima Bekir
- Laboratoire d'Analyse, Traitement et Valorisation des Polluants de l'Environnement et des Produits, Faculté de Pharmacie de Monastir, Monastir, Tunisia
| | - Houcine Barhoumi
- Laboratoire des Sciences Analytiques, UMR CNRS 5180, Université Claude Bernard-Lyon1, Bâtiment CPE, 69622, Villeurbanne Cedex, France
| | - Mohamed Braiek
- Laboratoire des Sciences Analytiques, UMR CNRS 5180, Université Claude Bernard-Lyon1, Bâtiment CPE, 69622, Villeurbanne Cedex, France
- Laboratoire de Physique et Chimie des Interfaces, Faculté des Sciences de Monastir, Tunisie, Avenue de l'Environnement, 5019, Monastir, Tunisia
| | - Amani Chrouda
- Laboratoire des Sciences Analytiques, UMR CNRS 5180, Université Claude Bernard-Lyon1, Bâtiment CPE, 69622, Villeurbanne Cedex, France
- Laboratoire de Physique et Chimie des Interfaces, Faculté des Sciences de Monastir, Tunisie, Avenue de l'Environnement, 5019, Monastir, Tunisia
| | - Nadia Zine
- Laboratoire des Sciences Analytiques, UMR CNRS 5180, Université Claude Bernard-Lyon1, Bâtiment CPE, 69622, Villeurbanne Cedex, France
| | - Nabil Abid
- Laboratoire d'Analyse, Traitement et Valorisation des Polluants de l'Environnement et des Produits, Faculté de Pharmacie de Monastir, Monastir, Tunisia
| | - Abdelrazek Maaref
- Laboratoire de Physique et Chimie des Interfaces, Faculté des Sciences de Monastir, Tunisie, Avenue de l'Environnement, 5019, Monastir, Tunisia
| | - Amina Bakhrouf
- Laboratoire d'Analyse, Traitement et Valorisation des Polluants de l'Environnement et des Produits, Faculté de Pharmacie de Monastir, Monastir, Tunisia
| | - Hafedh Ben Ouada
- Research Unit, Analysis and processes applied to Environment Higher Institute of Applied Sciences and Technology of Mahdia, Monastir University, Monastir, Tunisia
| | - Nicole Jaffrezic-Renault
- Laboratoire des Sciences Analytiques, UMR CNRS 5180, Université Claude Bernard-Lyon1, Bâtiment CPE, 69622, Villeurbanne Cedex, France
| | - Hedi Ben Mansour
- Research Unit, Analysis and processes applied to Environment Higher Institute of Applied Sciences and Technology of Mahdia, Monastir University, Monastir, Tunisia.
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27
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Helmi K, Barthod F, Méheut G, Henry A, Poty F, Laurent F, Charni-Ben-Tabassi N. Methods for microbiological quality assessment in drinking water: a comparative study. JOURNAL OF WATER AND HEALTH 2015; 13:34-41. [PMID: 25719463 DOI: 10.2166/wh.2014.056] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
The present study aimed to compare several methods for quantifying and discriminating between the different physiological states of a bacterial population present in drinking water. Flow cytometry (FCM), solid-phase cytometry (SPC), epifluorescence microscopy (MSP) and culture method performances were assessed by comparing the results obtained for different water samples. These samples, including chlorinated and non-chlorinated water, were collected in a drinking water treatment plant. Total bacteria were quantified by using SYBR Green II (for FCM) and 4',6'-diamino-2-phenylindole (DAPI) (for MSP), viable and non-viable bacteria were distinguished by using SYBR Green II and propidium iodide dual staining (for FCM), and active cells were distinguished by using CTC (for MSP) and Chemchrome V6 (for FCM and SPC). In our conditions, counts using microscopy and FCM were significantly correlated regarding total bacteria and active cells. Conversely, counts were not significantly similar using solid-phase and FCM for active bacteria. Moreover, the R2A medium showed that bacterial culturability could be recovered after chlorination. This study highlights that FCM appears to be a useful and powerful technique for drinking water production monitoring.
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Affiliation(s)
- K Helmi
- Veolia Environnement Recherche et Innovation, Immeuble le Dufy, 1 Place de Turenne, 94417 St Maurice Cedex, France E-mail:
| | - F Barthod
- Veolia Environnement Recherche et Innovation, Immeuble le Dufy, 1 Place de Turenne, 94417 St Maurice Cedex, France E-mail:
| | - G Méheut
- Veolia Environnement Recherche et Innovation, Immeuble le Dufy, 1 Place de Turenne, 94417 St Maurice Cedex, France E-mail:
| | - A Henry
- Veolia Environnement Recherche et Innovation, Immeuble le Dufy, 1 Place de Turenne, 94417 St Maurice Cedex, France E-mail:
| | - F Poty
- Veolia Environnement Recherche et Innovation, Immeuble le Dufy, 1 Place de Turenne, 94417 St Maurice Cedex, France E-mail:
| | - F Laurent
- Veolia Environnement Recherche et Innovation, Immeuble le Dufy, 1 Place de Turenne, 94417 St Maurice Cedex, France E-mail:
| | - N Charni-Ben-Tabassi
- Veolia Environnement Recherche et Innovation, Immeuble le Dufy, 1 Place de Turenne, 94417 St Maurice Cedex, France E-mail:
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Use of a culture-independent gastrointestinal multiplex PCR panel during a Shigellosis outbreak: considerations for clinical laboratories and public health. J Clin Microbiol 2015; 53:1048-9. [PMID: 25568430 DOI: 10.1128/jcm.03374-14] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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29
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Role of daptomycin in the induction and persistence of the viable but non-culturable state of Staphylococcus aureus biofilms. Pathogens 2014; 3:759-68. [PMID: 25438023 PMCID: PMC4243440 DOI: 10.3390/pathogens3030759] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2014] [Revised: 08/22/2014] [Accepted: 09/12/2014] [Indexed: 11/17/2022] Open
Abstract
We have recently demonstrated that antibiotic pressure can induce the viable but non-culturable (VBNC) state in Staphylococcus aureus biofilms. Since dormant bacterial cells can undermine anti-infective therapy, a greater understanding of the role of antibiotics of last resort, including daptomycin, is crucial. Methicillin-resistant S. aureus 10850 biofilms were maintained on non-nutrient (NN) agar in the presence or absence of the MIC of daptomycin until loss of culturability. Viable cells were monitored by epifluorescence microscopy and flow cytometry for 150 days. All biofilms reached non-culturability at 40 days and showed a similar amount of viable cells; however, in biofilms exposed to daptomycin, their number remained unchanged throughout the experiment, whereas in those maintained on NN agar alone, no viable cells were detected after 150 days. Gene expression assays showed that after achievement of non-culturability, 16S rDNA and mecA were expressed by all biofilms, whereas glt expression was found only in daptomycin-exposed biofilms. Our findings suggest that low daptomycin concentrations, such as those that are likely to obtain within biofilms, can influence the viability and gene expression of non-culturable S. aureus cells. Resuscitation experiments are needed to establish the VBNC state of daptomycin-exposed biofilms.
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30
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Membrane damage and active but nonculturable state in liquid cultures of Escherichia coli treated with an atmospheric pressure plasma jet. Bioelectrochemistry 2014; 103:7-14. [PMID: 25212700 DOI: 10.1016/j.bioelechem.2014.08.018] [Citation(s) in RCA: 79] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2014] [Revised: 08/14/2014] [Accepted: 08/18/2014] [Indexed: 11/23/2022]
Abstract
Electrical discharge plasmas can efficiently inactivate various microorganisms. Inactivation mechanisms caused by plasma, however, are not fully understood because of the complexity of both the plasma and biological systems. We investigated plasma-induced inactivation of Escherichia coli in water and mechanisms by which plasma affects bacterial cell membrane integrity. Atmospheric pressure argon plasma jet generated at ambient air in direct contact with bacterial suspension was used as a plasma source. We determined significantly lower counts of E. coli after treatment by plasma when they were assayed using a conventional cultivation technique than using a fluorescence-based LIVE/DEAD staining method, which indicated that bacteria may have entered the viable-but-nonculturable state (VBNC). We did not achieve resuscitation of these non-culturable cells, however, we detected their metabolic activity through the analysis of cellular mRNA, which suggests that cells may have been rather in the active-but-nonculturable state (ABNC). We hypothesize that peroxidation of cell membrane lipids by the reactive species produced by plasma was an important pathway of bacterial inactivation. Amount of malondialdehyde and membrane permeability of E. coli to propidium iodide increased with increasing bacterial inactivation by plasma. Membrane damage was also demonstrated by detection of free DNA in plasma-treated water.
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31
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Ramamurthy T, Ghosh A, Pazhani GP, Shinoda S. Current Perspectives on Viable but Non-Culturable (VBNC) Pathogenic Bacteria. Front Public Health 2014; 2:103. [PMID: 25133139 PMCID: PMC4116801 DOI: 10.3389/fpubh.2014.00103] [Citation(s) in RCA: 248] [Impact Index Per Article: 24.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2014] [Accepted: 07/15/2014] [Indexed: 11/07/2022] Open
Abstract
Under stress conditions, many species of bacteria enter into starvation mode of metabolism or a physiologically viable but non-culturable (VBNC) state. Several human pathogenic bacteria have been reported to enter into the VBNC state under these conditions. The pathogenic VBNC bacteria cannot be grown using conventional culture media, although they continue to retain their viability and express their virulence. Though there have been debates on the VBNC concept in the past, several molecular studies have shown that not only can the VBNC state be induced under in vitro conditions but also that resuscitation from this state is possible under appropriate conditions. The most notable advance in resuscitating VBNC bacteria is the discovery of resuscitation-promoting factor (Rpf), which is a bacterial cytokines found in both Gram-positive and Gram-negative organisms. VBNC state is a survival strategy adopted by the bacteria, which has important implication in several fields, including environmental monitoring, food technology, and infectious disease management; and hence it is important to investigate the association of bacterial pathogens under VBNC state and the water/foodborne outbreaks. In this review, we describe various aspects of VBNC bacteria, which include their proteomic and genetic profiles under the VBNC state, conditions of resuscitation, methods of detection, antibiotic resistance, and observations on Rpf.
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Affiliation(s)
| | - Amit Ghosh
- National Institute of Cholera and Enteric Diseases (NICED) , Kolkata , India
| | - Gururaja P Pazhani
- National Institute of Cholera and Enteric Diseases (NICED) , Kolkata , India
| | - Sumio Shinoda
- Collaborative Research Center of Okayama University for Infectious Diseases in India, NICED , Kolkata , India
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32
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Ceuppens S, Li D, Uyttendaele M, Renault P, Ross P, Ranst MV, Cocolin L, Donaghy J. Molecular Methods in Food Safety Microbiology: Interpretation and Implications of Nucleic Acid Detection. Compr Rev Food Sci Food Saf 2014; 13:551-577. [DOI: 10.1111/1541-4337.12072] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2014] [Accepted: 03/09/2014] [Indexed: 11/27/2022]
Affiliation(s)
- Siele Ceuppens
- Faculty of Bioscience Engineering; Laboratory of Food Microbiology and Food Preservation (LFMFP); Dept. of Food Safety and Food Quality; Ghent Univ.; Ghent Belgium
| | - Dan Li
- Faculty of Bioscience Engineering; Laboratory of Food Microbiology and Food Preservation (LFMFP); Dept. of Food Safety and Food Quality; Ghent Univ.; Ghent Belgium
| | - Mieke Uyttendaele
- Faculty of Bioscience Engineering; Laboratory of Food Microbiology and Food Preservation (LFMFP); Dept. of Food Safety and Food Quality; Ghent Univ.; Ghent Belgium
| | - Pierre Renault
- Inst. Scientifique de Recherche Agronomique (INRA); France
| | - Paul Ross
- Moorepark Biotechnology Centre; Teagasc; Moorepark; Fermoy Co. Cork Ireland
| | | | - Luca Cocolin
- Dept. of Agricultural; Forest and Food Sciences; Univ. of Torino; Grugliasco Torino Italy
| | - John Donaghy
- Food Safety Microbiology Group; Nestle Research Center; Lausanne Switzerland
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33
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Tian J, Lu J, Zhang Y, Li JC, Sun LC, Hu ZL. Microbial community structures and dynamics in the O3/BAC drinking water treatment process. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2014; 11:6281-90. [PMID: 24937529 PMCID: PMC4078579 DOI: 10.3390/ijerph110606281] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/21/2014] [Revised: 05/30/2014] [Accepted: 05/30/2014] [Indexed: 11/16/2022]
Abstract
Effectiveness of drinking water treatment, in particular pathogen control during the water treatment process, is always a major public health concern. In this investigation, the application of PCR-DGGE technology to the analysis of microbial community structures and dynamics in the drinking water treatment process revealed several dominant microbial populations including: α-Proteobacteria, β-Proteobacteria, γ-Proteobacteria, Bacteroidetes, Actinobacteria Firmicutes and Cyanobacteria. α-Proteobacteria and β-Proteobacteria were the dominant bacteria during the whole process. Bacteroidetes and Firmicutes were the dominant bacteria before and after treatment, respectively. Firmicutes showed season-dependent changes in population dynamics. Importantly, γ-Proteobacteria, which is a class of medically important bacteria, was well controlled by the O3/biological activated carbon (BAC) treatment, resulting in improved effluent water bio-safety.
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Affiliation(s)
- Jian Tian
- Shenzhen Key Laboratory of Marine Bioresource and Eco-environmental Science, Shenzhen Engineering Laboratory of Marine Algal Biotechnology, College of Life Science, Shenzhen University, Shenzhen 518060, China.
| | - Jun Lu
- Shenzhen Key Laboratory of Marine Bioresource and Eco-environmental Science, Shenzhen Engineering Laboratory of Marine Algal Biotechnology, College of Life Science, Shenzhen University, Shenzhen 518060, China.
| | - Yu Zhang
- Shenzhen Key Laboratory of Marine Bioresource and Eco-environmental Science, Shenzhen Engineering Laboratory of Marine Algal Biotechnology, College of Life Science, Shenzhen University, Shenzhen 518060, China.
| | - Jian-Cheng Li
- Shenzhen Key Laboratory of Marine Bioresource and Eco-environmental Science, Shenzhen Engineering Laboratory of Marine Algal Biotechnology, College of Life Science, Shenzhen University, Shenzhen 518060, China.
| | - Li-Chen Sun
- Shenzhen Key Laboratory of Marine Bioresource and Eco-environmental Science, Shenzhen Engineering Laboratory of Marine Algal Biotechnology, College of Life Science, Shenzhen University, Shenzhen 518060, China.
| | - Zhang-Li Hu
- Shenzhen Key Laboratory of Marine Bioresource and Eco-environmental Science, Shenzhen Engineering Laboratory of Marine Algal Biotechnology, College of Life Science, Shenzhen University, Shenzhen 518060, China.
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34
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Li L, Mendis N, Trigui H, Oliver JD, Faucher SP. The importance of the viable but non-culturable state in human bacterial pathogens. Front Microbiol 2014; 5:258. [PMID: 24917854 PMCID: PMC4040921 DOI: 10.3389/fmicb.2014.00258] [Citation(s) in RCA: 532] [Impact Index Per Article: 53.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2014] [Accepted: 05/12/2014] [Indexed: 12/12/2022] Open
Abstract
Many bacterial species have been found to exist in a viable but non-culturable (VBNC) state since its discovery in 1982. VBNC cells are characterized by a loss of culturability on routine agar, which impairs their detection by conventional plate count techniques. This leads to an underestimation of total viable cells in environmental or clinical samples, and thus poses a risk to public health. In this review, we present recent findings on the VBNC state of human bacterial pathogens. The characteristics of VBNC cells, including the similarities and differences to viable, culturable cells and dead cells, and different detection methods are discussed. Exposure to various stresses can induce the VBNC state, and VBNC cells may be resuscitated back to culturable cells under suitable stimuli. The conditions that trigger the induction of the VBNC state and resuscitation from it are summarized and the mechanisms underlying these two processes are discussed. Last but not least, the significance of VBNC cells and their potential influence on human health are also reviewed.
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Affiliation(s)
- Laam Li
- Department of Natural Resource Sciences, Faculty of Agricultural and Environmental Sciences, McGill University Ste-Anne-de-Bellevue, QC, Canada
| | - Nilmini Mendis
- Department of Natural Resource Sciences, Faculty of Agricultural and Environmental Sciences, McGill University Ste-Anne-de-Bellevue, QC, Canada
| | - Hana Trigui
- Department of Natural Resource Sciences, Faculty of Agricultural and Environmental Sciences, McGill University Ste-Anne-de-Bellevue, QC, Canada
| | - James D Oliver
- Department of Biology, University of North Carolina at Charlotte Charlotte, NC, USA
| | - Sebastien P Faucher
- Department of Natural Resource Sciences, Faculty of Agricultural and Environmental Sciences, McGill University Ste-Anne-de-Bellevue, QC, Canada
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35
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Pinto D, Santos MA, Chambel L. Thirty years of viable but nonculturable state research: unsolved molecular mechanisms. Crit Rev Microbiol 2013; 41:61-76. [PMID: 23848175 DOI: 10.3109/1040841x.2013.794127] [Citation(s) in RCA: 200] [Impact Index Per Article: 18.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Viable but nonculturable (VBNC) cells were recognized 30 years ago; and despite decades of research on the topic, most results are disperse and apparently incongruous. Since its description, a huge controversy arose regarding the ecological significance of this state: is it a degradation process without real significance for bacterial life cycles or is it an adaptive strategy of bacteria to cope with stressful conditions? In order to solve the molecular mechanisms of VBNC state induction and resuscitation, researchers in the field must be aware and overcome common issues delaying research progress. In this review, we discuss the intrinsic characteristic features of VBNC cells, the first clues on what is behind the VBNC state's induction, the models proposed for their resuscitation and the current methods to prove not only that cells are in VBNC state but also that they are able to resuscitate.
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Affiliation(s)
- Daniela Pinto
- Center for Biodiversity, Functional and Integrative Genomics (BioFIG), Faculty of Sciences, University of Lisbon , Lisbon , Portugal
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36
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Morishige Y, Fujimori K, Amano F. Differential resuscitative effect of pyruvate and its analogues on VBNC (viable but non-culturable) Salmonella. Microbes Environ 2013; 28:180-6. [PMID: 23595023 PMCID: PMC4070669 DOI: 10.1264/jsme2.me12174] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2012] [Accepted: 11/18/2012] [Indexed: 11/12/2022] Open
Abstract
An environmental isolate of Salmonella Enteritidis (SE), grown to the logarithmic phase, rapidly lost culturability by the addition of 3 mM H2O2 to cultures grown in Luria-Bertani (LB) medium; however, some H2O2-treated bacteria regained their culturability in M9 minimal medium, if sodium pyruvate was present at at least 0.3 mM. In addition, most pyruvate analogues, such as bromopyruvate or phenylpyruvate, did not show restoration activity similar to that of pyruvate, except in the case of α-ketobutyrate. Further analysis of the mechanism underlying the resuscitation by pyruvate revealed that although many of the bacteria showed respiratory activity on CTC (5-cyano-2,3-di-(p-tolyl) tetrazolium chloride) reduction with or without pyruvate, the biosynthesis of DNA and protein synthesis were quite different in the presence or absence of pyruvate, i.e., pyruvate endowed the cells with the ability to incorporate much more radio-label into precursors during the resuscitation process. These results suggest that pyruvate is one of the key molecules working in the resuscitation process by taking bacteria from the non-culturable state to the growing and colony-forming state by triggering the synthesis of macromolecules such as DNA and protein.
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Affiliation(s)
- Yuta Morishige
- Laboratory of Biodefense & Regulation, Osaka University of Pharmaceutical Sciences, Nasahara, Takatsuki, Osaka 569–1094, Japan
| | - Ko Fujimori
- Laboratory of Biodefense & Regulation, Osaka University of Pharmaceutical Sciences, Nasahara, Takatsuki, Osaka 569–1094, Japan
| | - Fumio Amano
- Laboratory of Biodefense & Regulation, Osaka University of Pharmaceutical Sciences, Nasahara, Takatsuki, Osaka 569–1094, Japan
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37
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Ryssel M, Duan Z, Siegumfeldt H. In situ examination of cell growth and death of Lactococcus lactis. FEMS Microbiol Lett 2013; 343:82-8. [PMID: 23516965 DOI: 10.1111/1574-6968.12134] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2012] [Revised: 03/15/2013] [Accepted: 03/15/2013] [Indexed: 11/29/2022] Open
Abstract
This study enables in situ studying of the growth and death of a large number of individual cells in a solid matrix. A wild type of Lactococcus lactis and several mutants with varying expression of GuaB was investigated. Large variability in the final size of individual microcolonies arising from clonal cells was observed. However, when growth was averaged over 16 locations in a specimen, the SEM was small and notable differences could be observed between the investigated strains, where mutants with lower expression of GuaB had a slower growth rate. The results show that the slow-growing mutants exhibited a lower fraction of dead cells, which indicate that slow-growing mutants are slightly more robust than the faster-growing strains. The large variability in the final size of individual microcolonies arising from clonal cells was quite surprising. We suggest that the control of the size of a microcolony is, at least partially, related to the actual microcolony depended on phenotypic heterogeneity. These findings are important to consider whenever a solid medium with discrete microcolonies is investigated.
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Affiliation(s)
- Mia Ryssel
- Department of Food Science, Food Microbiology, Faculty of Science, University of Copenhagen, Frederiksberg C, Denmark
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38
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Kusumoto A, Miyashita M, Kawamoto K. Deletion in the C-terminal domain of ClpX delayed entry of Salmonella enterica into a viable but non-culturable state. Res Microbiol 2013; 164:335-41. [PMID: 23385142 DOI: 10.1016/j.resmic.2013.01.011] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2012] [Accepted: 01/19/2013] [Indexed: 11/19/2022]
Abstract
Under stressful conditions, bacteria enter a viable but non-culturable (VBNC) state in which they are alive but fail to grow on conventional media. The molecular basis underlying this state is unknown. To identify the key gene responsible for the VBNC state in Salmonella spp., we examined a S. Typhimurium LT2 VBNC mutant, which shows a characteristic delay in entering the VBNC state. The mutant showed a higher level of expression of general stress sigma factor RpoS than wild-type LT2. The mutant carried a 99-bp in-frame deletion in the clpX gene (clpXΔ323-355). ClpX is known to form a ClpXP protease complex with ClpP, which plays a role in the degradation of RpoS. To investigate the effect of clpXΔ323-355 on VBNC induction, ΔclpX and clpXΔ323-355 strains were generated from LT2 cells. Compared to LT2, the ΔclpX and clpXΔ323-355 strains showed greater amounts of RpoS and required a longer incubation time for induction into the VBNC state. These results suggest that residues 323-355 of ClpX play a major role in the hexameric formation or function of ClpX and in the rate of induction of the VBNC state.
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Affiliation(s)
- Akiko Kusumoto
- Section of Food Microbiology and Immunology, Research Center for Animal Hygiene and Food Safety, Obihiro University of Agriculture and Veterinary Medicine, 2-11 Inada, Obihiro, Hokkaido 080-8555, Japan.
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Manina G, McKinney JD. A single-cell perspective on non-growing but metabolically active (NGMA) bacteria. Curr Top Microbiol Immunol 2013; 374:135-61. [PMID: 23793585 DOI: 10.1007/82_2013_333] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
A long-standing and fundamental problem in microbiology is the non-trivial discrimination between live and dead cells. The existence of physically intact and possibly viable bacterial cells that fail to replicate during a more or less protracted period of observation, despite environmental conditions that are ostensibly propitious for growth, has been extensively documented in many different organisms. In clinical settings, non-culturable cells may contribute to non-apparent infections capable of reactivating after months or years of clinical latency, a phenomenon that has been well documented in the specific case of Mycobacterium tuberculosis. The prevalence of these silent but potentially problematic bacterial reservoirs has been highlighted by classical approaches such as limiting culture dilution till extinction of growing cells, followed by resuscitation of apparently "viable but non-culturable" (VBNC) subpopulations. Although these assays are useful to demonstrate the presence of VBNC cells in a population, they are effectively retrospective and are not well suited to the analysis of non-replicating cells per se. Here, we argue that research on a closely related problem, which we shall refer to as the "non-growing but metabolically active" state, is poised to advance rapidly thanks to the recent development of novel technologies and methods for real-time single-cell analysis. In particular, the combination of fluorescent reporter dyes and strains, microfluidic and microelectromechanical systems, and time-lapse fluorescence microscopy offers tremendous and largely untapped potential for future exploration of the physiology of non-replicating cells.
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Affiliation(s)
- Giulia Manina
- School of Life Sciences, Swiss Federal Institute of Technology in Lausanne (EPFL), 1015, Lausanne, Switzerland,
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Hydroxycinnamic acid decarboxylase activity of Brettanomyces bruxellensis involved in volatile phenol production: Relationship with cell viability. Food Microbiol 2012; 32:230-4. [DOI: 10.1016/j.fm.2012.06.004] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2011] [Revised: 06/14/2012] [Accepted: 06/17/2012] [Indexed: 11/19/2022]
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Amado IR, Fuciños C, Fajardo P, Guerra NP, Pastrana L. Evaluation of two bacteriocin-producing probiotic lactic acid bacteria as inoculants for controlling Listeria monocytogenes in grass and maize silages. Anim Feed Sci Technol 2012. [DOI: 10.1016/j.anifeedsci.2012.05.006] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Kusumoto A, Asakura H, Kawamoto K. General stress sigma factor RpoS influences time required to enter the viable but non-culturable state in Salmonella enterica. Microbiol Immunol 2012; 56:228-37. [DOI: 10.1111/j.1348-0421.2012.00428.x] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Simultaneous detection of six diarrhea-causing bacterial pathogens with an in-house PCR-luminex assay. J Clin Microbiol 2011; 50:98-103. [PMID: 22075596 DOI: 10.1128/jcm.05416-11] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Diarrhea can be caused by a range of pathogens, including several bacteria. Conventional diagnostic methods, such as culture, biochemical tests, and enzyme-linked immunosorbent assay (ELISA), are laborious. We developed a 7-plex PCR-Luminex assay to simultaneously screen for several of the major diarrhea-causing bacteria directly in fecal specimens, including pathogenic Aeromonas, Campylobacter jejuni, Campylobacter coli, Salmonella, Shigella, enteroinvasive Escherichia coli (EIEC), Vibrio, and Yersinia. We included an extrinsic control to verify extraction and amplification. The assay was first validated with reference strains or isolates and exhibited a limit of detection of 10(3) to 10(5) CFU/g of stool for each pathogen as well as quantitative detection up to 10(9) CFU/g. A total of 205 clinical fecal specimens from individuals with diarrhea, previously cultured for enteric pathogens and tested for Campylobacter by ELISA, were evaluated. Using these predicate methods as standards, sensitivities and specificities of the PCR-Luminex assay were 89% and 94% for Aeromonas, 89% and 93% for Campylobacter, 96% and 95% for Salmonella, 94% and 94% for Shigella, 92% and 97% for Vibrio, and 100% and 100% for Yersinia, respectively. All discrepant results were further examined by singleplex real-time PCR assays targeting different gene regions, which revealed 89% (55/62 results) concordance with the PCR-Luminex assay. The fluorescent signals obtained with this approach exhibited a statistically significant correlation with the cycle threshold (C(T)) values from the cognate real-time PCR assays (P < 0.05). This multiplex PCR-Luminex assay enables sensitive, specific, and quantitative detection of the major bacterial causes of gastroenteritis.
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Aurass P, Prager R, Flieger A. EHEC/EAEC O104:H4 strain linked with the 2011 German outbreak of haemolytic uremic syndrome enters into the viable but non-culturable state in response to various stresses and resuscitates upon stress relief. Environ Microbiol 2011; 13:3139-48. [DOI: 10.1111/j.1462-2920.2011.02604.x] [Citation(s) in RCA: 82] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Krebs SJ, Taylor RK. Nutrient-dependent, rapid transition of Vibrio cholerae to coccoid morphology and expression of the toxin co-regulated pilus in this form. MICROBIOLOGY-SGM 2011; 157:2942-2953. [PMID: 21778208 DOI: 10.1099/mic.0.048561-0] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The acute diarrhoeal disease cholera is caused by the aquatic pathogen Vibrio cholerae upon ingestion of contaminated food or water by the human host. The mechanisms by which V. cholerae is able to persist and survive in the host and aquatic environments have been studied for years; however, little is known about the factors involved in the adaptation or response of V. cholerae transitioning between these two environments. The transition from bacillary to coccoid morphology is thought to be one mechanism of survival that V. cholerae uses in response to environmental stress. Coccoid morphology has been observed for V. cholerae while in a viable but non-culturable (VBNC) state, during times of nutrient limitation, and in the water-diluted stool of cholera-infected patients. In this study we sought conditions to study the coccoid morphology of V. cholerae, and found that coccoid-shaped cells can express and produce the virulence factor toxin co-regulated pilus (TCP) and are able to colonize the infant mouse to the same extent as bacillus-shaped cells. This study suggests that TCP may be one factor that V. cholerae utilizes for adaptation and survival during the transition between the host and the aquatic environment.
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Affiliation(s)
- Shelly J Krebs
- Department of Microbiology and Immunology, Dartmouth Medical School, Hanover, NH 03755, USA
| | - Ronald K Taylor
- Department of Microbiology and Immunology, Dartmouth Medical School, Hanover, NH 03755, USA
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Pinto D, Almeida V, Almeida Santos M, Chambel L. Resuscitation of Escherichia coli VBNC cells depends on a variety of environmental or chemical stimuli. J Appl Microbiol 2011; 110:1601-11. [DOI: 10.1111/j.1365-2672.2011.05016.x] [Citation(s) in RCA: 101] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Pawlowski DR, Metzger DJ, Raslawsky A, Howlett A, Siebert G, Karalus RJ, Garrett S, Whitehouse CA. Entry of Yersinia pestis into the viable but nonculturable state in a low-temperature tap water microcosm. PLoS One 2011; 6:e17585. [PMID: 21436885 PMCID: PMC3059211 DOI: 10.1371/journal.pone.0017585] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2010] [Accepted: 01/24/2011] [Indexed: 01/14/2023] Open
Abstract
Yersinia pestis, the causative agent of plague, has caused several pandemics throughout history and remains endemic in the rodent populations of the western United States. More recently, Y. pestis is one of several bacterial pathogens considered to be a potential agent of bioterrorism. Thus, elucidating potential mechanisms of survival and persistence in the environment would be important in the event of an intentional release of the organism. One such mechanism is entry into the viable but non-culturable (VBNC) state, as has been demonstrated for several other bacterial pathogens. In this study, we showed that Y. pestis became nonculturable by normal laboratory methods after 21 days in a low-temperature tap water microcosm. We further show evidence that, after the loss of culturability, the cells remained viable by using a variety of criteria, including cellular membrane integrity, uptake and incorporation of radiolabeled amino acids, and protection of genomic DNA from DNase I digestion. Additionally, we identified morphological and ultrastructural characteristics of Y. pestis VBNC cells, such as cell rounding and large periplasmic spaces, by electron microscopy, which are consistent with entry into the VBNC state in other bacteria. Finally, we demonstrated resuscitation of a small number of the non-culturable cells. This study provides compelling evidence that Y. pestis persists in a low-temperature tap water microcosm in a viable state yet is unable to be cultured under normal laboratory conditions, which may prove useful in risk assessment and remediation efforts, particularly in the event of an intentional release of this organism.
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Boukef I, El Bour M, Al Gallas N, El Bahri O, Mejri S, Mraouna R, Ben Aissa R, Boudabous A, Got P, Troussellier M. Survival of Escherichia coli strains in Mediterranean brackish water in the Bizerte lagoon in northern Tunisia. WATER ENVIRONMENT RESEARCH : A RESEARCH PUBLICATION OF THE WATER ENVIRONMENT FEDERATION 2010; 82:2249-2257. [PMID: 21141386 DOI: 10.2175/106143010x12609736967161] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
This study investigated survival and virulence of Escherichia coli strains exposed to natural conditions in brackish water. Two E. coli strains (O126:B16 and O55:B5) were incubated in water microcosms in the Bizerte lagoon in northern Tunisia and exposed for 12 days to natural sunlight in June (231 to 386 W/m2, 26 +/- 1 degrees C, 30 g/L) and in April (227 to 330 W/m2, 17 +/- 1 degrees C, 27 g/L) or maintained in darkness for 21 days (17 +/- 1 degrees C, 27 g/L). The results revealed that sunlight was the most significant inactivating factor (decrease of 3 Ulog within 48 hours for the two strains) compared to salinity and temperature (in darkness). Survival time of the strains was prolonged as they were maintained in darkness. Local strain (E. coli O55:B5) showed better survival capacity (T90 = 52 hours) than E. coli O126:B16 (T90 = 11 h). For both, modifications were noted only for some metabolic activities of carbohydrates hydrolysis. Cytotoxicity of the two strains, tested on Vero cell, was maintained during the period of survival.
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Affiliation(s)
- I Boukef
- National Institute of Sea Sciences and Technology, Laboratory of Microbiology, Salammbô, Tunisia
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Masakiyo Y, Yoshida A, Takahashi Y, Shintani Y, Awano S, Ansai T, Sawayama S, Shimakita T, Takehara T. Rapid LED-based fluorescence microscopy distinguishes between live and dead bacteria in oral clinical samples. Biomed Res 2010; 31:21-6. [DOI: 10.2220/biomedres.31.21] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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