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Sun Y, Gao R, Liao X, Shen M, Chen X, Feng J, Ding T. Stress response of Salmonella Newport with various sequence types toward plasma-activated water: Viable but nonculturable state formation and outer membrane vesicle production. Curr Res Food Sci 2024; 8:100764. [PMID: 38779345 PMCID: PMC11109322 DOI: 10.1016/j.crfs.2024.100764] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2024] [Revised: 04/29/2024] [Accepted: 05/06/2024] [Indexed: 05/25/2024] Open
Abstract
This study aims to investigate the response of Salmonella Newport to plasma-activated water (PAW), a novel disinfectant that attracts attention due to its broad-spectrum antimicrobial efficacy and eco-friendliness. In this work, we demonstrated that S. Newport of different sequence types (STs) could be induced into the viable but nonculturable (VBNC) state by PAW treatment. Notably, a remarkable 99.96% of S. Newport ST45 strain entered the VBNC state after a 12-min PAW treatment, which was the fastest observed among the five S. Newport STs (ST31, ST45, ST46, ST166, ST2364). Secretion of outer membrane vesicles was observed in ST45, suggesting a potential strategy against PAW treatment. Genes related to oxidative stress (sodA, katE, trxA), outer membrane proteins (ompA, ompC, ompD, ompF) and virulence (pagC, sipC, sopE2) were upregulated in the PAW-treated S. Newport, especially in ST45. A reduction of 38-65% in intracellular ATP level after PAW treatment was observed, indicating a contributor to the formation of the VBNC state. In addition, a rapid method for detecting the proportion of VBNC cells in food products based on pagC was established. This study contributes to understanding the formation mechanism of the VBNC state in S. Newport under PAW stress and offers insights for controlling microbial risks in the food industry.
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Affiliation(s)
- Yuhao Sun
- Department of Food Science and Nutrition, College of Biosystems Engineering and Food Science, Zhejiang University, Hangzhou, 310058, China
- Future Food Laboratory, Innovation Center of Yangtze River Delta, Zhejiang University, Jiaxing, 314100, China
| | - Rui Gao
- Department of Food Science and Nutrition, College of Biosystems Engineering and Food Science, Zhejiang University, Hangzhou, 310058, China
| | - Xinyu Liao
- Department of Food Science and Nutrition, College of Biosystems Engineering and Food Science, Zhejiang University, Hangzhou, 310058, China
- Future Food Laboratory, Innovation Center of Yangtze River Delta, Zhejiang University, Jiaxing, 314100, China
| | - Mofei Shen
- Department of Food Science and Nutrition, College of Biosystems Engineering and Food Science, Zhejiang University, Hangzhou, 310058, China
| | - Xiuqin Chen
- Department of Food Science and Nutrition, College of Biosystems Engineering and Food Science, Zhejiang University, Hangzhou, 310058, China
| | - Jinsong Feng
- Department of Food Science and Nutrition, College of Biosystems Engineering and Food Science, Zhejiang University, Hangzhou, 310058, China
| | - Tian Ding
- Department of Food Science and Nutrition, College of Biosystems Engineering and Food Science, Zhejiang University, Hangzhou, 310058, China
- Future Food Laboratory, Innovation Center of Yangtze River Delta, Zhejiang University, Jiaxing, 314100, China
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2
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Borkar SB, Negi M, Acharya TR, Lamichhane P, Kaushik N, Choi EH, Kaushik NK. Mitigation of T3SS-mediated virulence in waterborne pathogenic bacteria by multi-electrode cylindrical-DBD plasma-generated nitric oxide water. CHEMOSPHERE 2024; 350:140997. [PMID: 38128737 DOI: 10.1016/j.chemosphere.2023.140997] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/13/2023] [Revised: 12/06/2023] [Accepted: 12/18/2023] [Indexed: 12/23/2023]
Abstract
S. enterica, S. flexneri, and V. parahaemolyticus bacteria are globally recognized to cause severe diarrheal diseases, consisting of Type III Secretion System (T3SS) effectors that help in bacterial infection and virulence in host cells. This study investigates the properties of multi-electrode cylindrical DBD plasma-generated nitric oxide water (MCDBD-PG-NOW) treatment on the survival and virulence of S. enterica, S. flexneri, and V. parahaemolyticus bacteria. The Colony Forming Unit (CFU) assay, live/dead cell staining, lipid peroxidation assay, and bacteria morphological analysis showed substantial growth inhibition of bacteria. Moreover, to confirm the interaction of reactive nitrogen species (RNS) with bacterial membrane biotin switch assay, DAF-FM, and FTIR analysis were carried out, which established the formation of S-nitrosothiols in the cell membrane, intracellular accumulation of RNS, and changes in the cell composition post-PG-NOW treatment. Furthermore, the conventional culture-based method and a quantitative PCR using propidium monoazide showed minimal VBNC induction under similar condition. The efficiency of bacteria to adhere to mammalian colon cells was significantly reduced. In addition, the infection rate was also controlled by disrupting the virulent genes, leading to the collapse of the infection mechanism. This study provides insights into whether RNS generated from PG-NOW might be beneficial for preventing diarrheal infections.
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Affiliation(s)
- Shweta B Borkar
- Department of Electrical and Biological Physics /Plasma Bioscience Research Center, Kwangwoon University, Seoul, 01897, South Korea
| | - Manorma Negi
- Department of Electrical and Biological Physics /Plasma Bioscience Research Center, Kwangwoon University, Seoul, 01897, South Korea
| | - Tirtha Raj Acharya
- Department of Electrical and Biological Physics /Plasma Bioscience Research Center, Kwangwoon University, Seoul, 01897, South Korea
| | - Prajwal Lamichhane
- Department of Electrical and Biological Physics /Plasma Bioscience Research Center, Kwangwoon University, Seoul, 01897, South Korea
| | - Neha Kaushik
- Department of Biotechnology, College of Engineering, The University of Suwon, Hwaseong, 18323, South Korea.
| | - Eun Ha Choi
- Department of Electrical and Biological Physics /Plasma Bioscience Research Center, Kwangwoon University, Seoul, 01897, South Korea.
| | - Nagendra Kumar Kaushik
- Department of Electrical and Biological Physics /Plasma Bioscience Research Center, Kwangwoon University, Seoul, 01897, South Korea.
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3
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Lima Â, Muzny CA, Cerca N. An Indirect Fluorescence Microscopy Method to Assess Vaginal Lactobacillus Concentrations. Microorganisms 2024; 12:114. [PMID: 38257941 PMCID: PMC10820742 DOI: 10.3390/microorganisms12010114] [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: 11/21/2023] [Revised: 12/12/2023] [Accepted: 12/13/2023] [Indexed: 01/24/2024] Open
Abstract
Lactobacillus species are the main colonizers of the vaginal microbiota in healthy women. Their absolute quantification by culture-based methods is limited due to their fastidious growth. Flow cytometry can quantify the bacterial concentration of these bacteria but requires the acquisition of expensive equipment. More affordable non-culturable methods, such as fluorescence microscopy, are hampered by the small size of the bacteria. Herein, we developed an indirect fluorescence microscopy method to determine vaginal lactobacilli concentration by determining the correlation between surface area bacterial measurement and initial concentration of an easily cultivable bacterium (Escherichia coli) and applying it to lactobacilli fluorescence microscopy counts. In addition, vaginal lactobacilli were quantified by colony-forming units and flow cytometry in order to compare these results with the indirect method results. The colony-forming-unit values were lower than the results obtained from the other two techniques, while flow cytometry and fluorescence microscopy results agreed. Thus, our developed method was able to accurately quantify vaginal lactobacilli.
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Affiliation(s)
- Ângela Lima
- Laboratory of Research in Biofilms Rosário Oliveira (LIBRO), Centre of Biological Engineering (CEB), University of Minho, Campus de Gualtar, 4710-057 Braga, Portugal;
| | - Christina A. Muzny
- Division of Infectious Diseases, University of Alabama at Birmingham, Birmingham, AL 35233, USA;
| | - Nuno Cerca
- Laboratory of Research in Biofilms Rosário Oliveira (LIBRO), Centre of Biological Engineering (CEB), University of Minho, Campus de Gualtar, 4710-057 Braga, Portugal;
- LABBELS—Associate Laboratory, 4710-057 Braga, Portugal
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4
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Borkar SB, Negi M, Jaiswal A, Raj Acharya T, Kaushik N, Choi EH, Kaushik NK. Plasma-generated nitric oxide water: A promising strategy to combat bacterial dormancy (VBNC state) in environmental contaminant Micrococcus luteus. JOURNAL OF HAZARDOUS MATERIALS 2024; 461:132634. [PMID: 37793251 DOI: 10.1016/j.jhazmat.2023.132634] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/06/2023] [Revised: 09/08/2023] [Accepted: 09/24/2023] [Indexed: 10/06/2023]
Abstract
The viable but non-culturable (VBNC) is an inactive state, and certain bacteria can enter under adverse conditions. The VBNC state challenges the environment, food safety, and public health since VBNCs may resuscitate and pose a risk to human health. The aim of this study was to investigate the effect of plasma-generated nitric oxide water (PG-NOW) on airborne contaminant Micrococcus luteus (M. luteus) and examine its potential to induce the VBNC state. The essential conditions for bacteria to enter VBNC state are low metabolic activity and rare or no culturable counts. The results indicated that PG-NOW effectively eliminates M. luteus, and the remaining bacteria are in culturable condition. Moreover, the conventional cultured-based method combined with a propidium iodide monoazide quantitative PCR (PMAxxTM-qPCR) showed no significant VBNC induction and moderate culturable counts. Results from the qPCR revealed that gene levels in PG-NOW treated bacteria related to resuscitation-promoting factors, amino acid biosynthesis, and fatty acid metabolism were notably upregulated. PG-NOW inactivated M. luteus showed negligible VBNC formation and alleviated infection ability in lung cells. This study provides new insights into the potential use of PG-NOW reactive species for the prevention and control of the VBNC state of M. luteus.
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Affiliation(s)
- Shweta B Borkar
- Department of Electrical and Biological Physics/Plasma Bioscience Research Center, Kwangwoon University, Seoul 01897, South Korea
| | - Manorma Negi
- Department of Electrical and Biological Physics/Plasma Bioscience Research Center, Kwangwoon University, Seoul 01897, South Korea
| | - Apurva Jaiswal
- Department of Electrical and Biological Physics/Plasma Bioscience Research Center, Kwangwoon University, Seoul 01897, South Korea
| | - Tirtha Raj Acharya
- Department of Electrical and Biological Physics/Plasma Bioscience Research Center, Kwangwoon University, Seoul 01897, South Korea
| | - Neha Kaushik
- Department of Biotechnology, College of Engineering, The University of Suwon, Hwaseong 18323, South Korea.
| | - Eun Ha Choi
- Department of Electrical and Biological Physics/Plasma Bioscience Research Center, Kwangwoon University, Seoul 01897, South Korea.
| | - Nagendra Kumar Kaushik
- Department of Electrical and Biological Physics/Plasma Bioscience Research Center, Kwangwoon University, Seoul 01897, South Korea.
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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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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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7
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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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Pseudomonas fluorescens Cells’ Recovery after Exposure to BAC and DBNPA Biocides. Antibiotics (Basel) 2022; 11:antibiotics11081042. [PMID: 36009911 PMCID: PMC9405490 DOI: 10.3390/antibiotics11081042] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2022] [Revised: 07/28/2022] [Accepted: 08/01/2022] [Indexed: 02/01/2023] Open
Abstract
A proper assessment of the effects of biocides on bacterial cells is key to the prevention of antimicrobial resistance and the implementation of suitable biocidal programmes. It is particularly relevant regarding the ability of dead-labelled cells to recover their functional processes once the biocide is removed. In the present work, we studied how Pseudomonas fluorescens cells previously exposed to different concentrations of BAC (benzalkonium chloride) and DBNPA (2,2-Dibromo-3-nitrilopropionamide) behave upon the restoration of optimum growth conditions. The following indicators were evaluated: culturability, membrane integrity, metabolic activity (resazurin), cellular energy (ATP), and cell structure and morphology (transmission electron microscopy (TEM)). The results demonstrated that cells previously labelled as ‘dead’ recovered to a greater extent in all indicators. Only cells previously exposed to BAC at 160 mg/L (concentration above the MBC) showed significant reductions on all the evaluated indicators. However, the obtained values were much higher than the ‘death’ thresholds found for the autoclaved cells. This suggests that cells exposed to this concentration take more time to rebuild their functional processes. The recovery of DBNPA-treated cells did not seem to be related to the biocide concentration. Finally, a reflection on what kind of cells were able to recover (remaining cells below the detection limit and/or dormant cells) is also presented.
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9
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An Exploration of Listeria monocytogenes, Its Influence on the UK Food Industry and Future Public Health Strategies. Foods 2022; 11:foods11101456. [PMID: 35627026 PMCID: PMC9141670 DOI: 10.3390/foods11101456] [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: 04/27/2022] [Revised: 05/12/2022] [Accepted: 05/16/2022] [Indexed: 02/04/2023] Open
Abstract
Listeria monocytogenes is a Gram-positive intracellular pathogen that can cause listeriosis, an invasive disease affecting pregnant women, neonates, the elderly, and immunocompromised individuals. Principally foodborne, the pathogen is transmitted typically through contaminated foods. As a result, food manufacturers exert considerable efforts to eliminate L. monocytogenes from foodstuffs and the environment through food processing and disinfection. However, L. monocytogenes demonstrates a range of environmental stress tolerances, resulting in persistent colonies that act as reservoirs for the reintroduction of L. monocytogenes to food contact surfaces and food. Novel technologies for the rapid detection of L. monocytogenes and disinfection of food manufacturing industries have been developed to overcome these obstacles to minimise the risk of outbreaks and sporadic cases of listeriosis. This review is aimed at exploring L. monocytogenes in the UK, providing a summary of outbreaks, current routine microbiological testing and the increasing awareness of biocide tolerances. Recommendations for future research in the UK are made, pertaining to expanding the understanding of L. monocytogenes dissemination in the UK food industry and the continuation of novel technological developments for disinfection of food and the food manufacturing environment.
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10
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Lotoux A, Milohanic E, Bierne H. The Viable But Non-Culturable State of Listeria monocytogenes in the One-Health Continuum. Front Cell Infect Microbiol 2022; 12:849915. [PMID: 35372114 PMCID: PMC8974916 DOI: 10.3389/fcimb.2022.849915] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2022] [Accepted: 02/07/2022] [Indexed: 11/13/2022] Open
Abstract
Many bacterial species, including several pathogens, can enter a so-called “viable but non-culturable” (VBNC) state when subjected to stress. Bacteria in the VBNC state are metabolically active but have lost their ability to grow on standard culture media, which compromises their detection by conventional techniques based on bacterial division. Under certain conditions, VBNC bacteria can regain their growth capacity and, for pathogens, their virulence potential, through a process called resuscitation. Here, we review the current state of knowledge of the VBNC state of Listeria monocytogenes (Lm), a Gram-positive pathogenic bacterium responsible for listeriosis, one of the most dangerous foodborne zoonosis. After a brief summary of characteristics of VBNC bacteria, we highlight work on VBNC Lm in the environment and in agricultural and food industry settings, with particular emphasis on the impact of antimicrobial treatments. We subsequently discuss recent data suggesting that Lm can enter the VBNC state in the host, raising the possibility that VBNC forms contribute to the asymptomatic carriage of this pathogen in wildlife, livestock and even humans. We also consider the resuscitation and virulence potential of VBNC Lm and the danger posed by these bacteria to at-risk individuals, particularly pregnant women. Overall, we put forth the hypothesis that VBNC forms contribute to adaptation, persistence, and transmission of Lm between different ecological niches in the One-Health continuum, and suggest that screening for healthy carriers, using alternative techniques to culture-based enrichment methods, should better prevent listeriosis risks.
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11
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Arvizu IS, Murray SR. A simple, quantitative assay for the detection of viable but non-culturable (VBNC) bacteria. STAR Protoc 2021; 2:100738. [PMID: 34430913 PMCID: PMC8365524 DOI: 10.1016/j.xpro.2021.100738] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
This protocol determines the fraction of a bacterial population that is viable and culturable, viable and non-culturable, or non-viable (dead). Each population is detected by isolating colonies on agar plates, performing direct counts, and staining for live or dead cells. Its application is limited to bacteria that are stainable and when permissible growth conditions are known. The quantitative data extracted allow for the detection of a viable but non-culturable (alive and non-dividing) population from a liquid culture. For complete details on the use and execution of this protocol, please refer to Stott et al. (2015). Liquid cultures are spread onto agar plates to quantify CFU/mL Direct counting is performed to determine the total number of bacteria per mL Fluorescence microscopy is used to distinguish between live and dead bacteria In sum, the protocol can reveal VBNC populations in a culture
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Affiliation(s)
- Ignacio Servando Arvizu
- Department of Biology, California State University, Northridge, 18111 Nordhoff Street, Northridge, CA 91330, USA
| | - Sean Richard Murray
- Department of Biology, California State University, Northridge, 18111 Nordhoff Street, Northridge, CA 91330, USA
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12
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Antibody- and nucleic acid-based lateral flow immunoassay for Listeria monocytogenes detection. Anal Bioanal Chem 2021; 413:4161-4180. [PMID: 34041576 DOI: 10.1007/s00216-021-03402-8] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2021] [Revised: 04/30/2021] [Accepted: 05/10/2021] [Indexed: 01/02/2023]
Abstract
Listeria monocytogenes is an invasive opportunistic foodborne pathogen and its routine surveillance is critical for protecting the food supply and public health. The traditional detection methods are time-consuming and require trained personnel. Lateral flow immunoassay (LFIA), on the other hand, is an easy-to-perform, rapid point-of-care test and has been widely used as an inexpensive surveillance tool. In recent times, nucleic acid-based lateral flow immunoassays (NALFIA) are also developed to improve sensitivity and specificity. A significant improvement in lateral flow-based assays has been reported in recent years, especially the ligands (antibodies, nucleic acids, aptamers, bacteriophage), labeling molecules, and overall assay configurations to improve detection sensitivity, specificity, and automated interpretation of results. In most commercial applications, LFIA has been used with enriched food/environmental samples to ensure detection of live cells thus prolonging the assay time to 24-48 h; however, with the recent improvement in LFIA sensitivity, results can be obtained in less than 8 h with shortened and improved enrichment practices. Incorporation of surface-enhanced Raman spectroscopy and/or immunomagnetic separation could significantly improve LFIA sensitivity for near-real-time point-of-care detection of L. monocytogenes for food safety and public health applications.
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13
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How to Evaluate Non-Growing Cells-Current Strategies for Determining Antimicrobial Resistance of VBNC Bacteria. Antibiotics (Basel) 2021; 10:antibiotics10020115. [PMID: 33530321 PMCID: PMC7912045 DOI: 10.3390/antibiotics10020115] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2020] [Revised: 01/19/2021] [Accepted: 01/22/2021] [Indexed: 12/17/2022] Open
Abstract
Thanks to the achievements in sanitation, hygiene practices, and antibiotics, we have considerably improved in our ongoing battle against pathogenic bacteria. However, with our increasing knowledge about the complex bacterial lifestyles and cycles and their plethora of defense mechanisms, it is clear that the fight is far from over. One of these resistance mechanisms that has received increasing attention is the ability to enter a dormancy state termed viable but non-culturable (VBNC). Bacteria that enter the VBNC state, either through unfavorable environmental conditions or through potentially lethal stress, lose their ability to grow on standard enrichment media, but show a drastically increased tolerance against antimicrobials including antibiotics. The inability to utilize traditional culture-based methods represents a considerable experimental hurdle to investigate their increased antimicrobial resistance and impedes the development and evaluation of effective treatments or interventions against bacteria in the VBNC state. Although experimental approaches were developed to detect and quantify VBNCs, only a few have been utilized for antimicrobial resistance screening and this review aims to provide an overview of possible methodological approaches.
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14
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Gao R, Liao X, Zhao X, Liu D, Ding T. The diagnostic tools for viable but nonculturable pathogens in the food industry: Current status and future prospects. Compr Rev Food Sci Food Saf 2021; 20:2146-2175. [PMID: 33484068 DOI: 10.1111/1541-4337.12695] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2020] [Revised: 12/21/2020] [Accepted: 12/28/2020] [Indexed: 12/21/2022]
Abstract
Viable but nonculturable (VBNC) microorganisms have been recognized as pathogenic contaminants in foods and environments. The failure of VBNC cells to form the visible colonies hinders the ability to use conventional media for their detection. Efficient and rapid detection of pathogens in the VBNC state is a prerequisite to ensure the food safety and public health. Despite their nonculturability, VBNC cells have distinct characteristics, such as morphology, metabolism, chemical composition, and gene and protein expression, that have been used as the basis for the development of abundant diagnostic tools. This review covers the current status and advances in various approaches for examining microorganisms in the VBNC state, including but not limited to the methodological aspects, advantages, and drawbacks of each technique. Existing methods, such as direct viable count, SYTO/PI dual staining, and propidium monoazide quantitative polymerase chain reaction (PCR), as well as some techniques with potential to be applied in the future, such as digital PCR, enhanced-surface Raman spectroscopy, and impedance-based techniques, are summarized in depth. Finally, future prospects for the one-step detection of VBNC bacteria are proposed and discussed. We believe that this review can provide more optional methods for researchers and promote the development of rapid, accurate detecting methods, and for inspectors, the diagnostic tools can provide data to undertake risk analysis of VBNC cells.
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Affiliation(s)
- Rui Gao
- Key Laboratory for Agro-Products Postharvest Handling of Ministry of Agriculture, Zhejiang Key Laboratory for Agro-Food Processing, Department of Food Science and Nutrition, Zhejiang University, Hangzhou, Zhejiang, China
| | - Xinyu Liao
- Key Laboratory for Agro-Products Postharvest Handling of Ministry of Agriculture, Zhejiang Key Laboratory for Agro-Food Processing, Department of Food Science and Nutrition, Zhejiang University, Hangzhou, Zhejiang, China
| | - Xihong Zhao
- Research Center for Environmental Ecology and Engineering, Key Laboratory for Green Chemical Process of Ministry of Education, Hubei Key Laboratory of Novel Reactor and Green Chemical Technology, School of Environmental Ecology and Biological Engineering, Wuhan Institute of Technology, Wuhan, China
| | - Donghong Liu
- Key Laboratory for Agro-Products Postharvest Handling of Ministry of Agriculture, Zhejiang Key Laboratory for Agro-Food Processing, Department of Food Science and Nutrition, Zhejiang University, Hangzhou, Zhejiang, China
| | - Tian Ding
- Key Laboratory for Agro-Products Postharvest Handling of Ministry of Agriculture, Zhejiang Key Laboratory for Agro-Food Processing, Department of Food Science and Nutrition, Zhejiang University, Hangzhou, Zhejiang, China
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15
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Detection and Potential Virulence of Viable but Non-Culturable (VBNC) Listeria monocytogenes: A Review. Microorganisms 2021; 9:microorganisms9010194. [PMID: 33477778 PMCID: PMC7832328 DOI: 10.3390/microorganisms9010194] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2020] [Revised: 01/13/2021] [Accepted: 01/15/2021] [Indexed: 01/04/2023] Open
Abstract
The detection, enumeration, and virulence potential of viable but non-culturable (VBNC) pathogens continues to be a topic of discussion. While there is a lack of definitive evidence that VBNC Listeria monocytogenes (Lm) pose a public health risk, recent studies suggest that Lm in its VBNC state remains virulent. VBNC bacteria cannot be enumerated by traditional plating methods, so the results from routine Lm testing may not demonstrate a sample's true hazard to public health. We suggest that supplementing routine Lm testing methods with methods designed to enumerate VBNC cells may more accurately represent the true level of risk. This review summarizes five methods for enumerating VNBC Lm: Live/Dead BacLightTM staining, ethidium monoazide and propidium monoazide-stained real-time polymerase chain reaction (EMA- and PMA-PCR), direct viable count (DVC), 5-cyano-2,3-ditolyl tetrazolium chloride-4',6-diamidino-2-phenylindole (CTC-DAPI) double staining, and carboxy-fluorescein diacetate (CDFA) staining. Of these five supplementary methods, the Live/Dead BacLightTM staining and CFDA-DVC staining currently appear to be the most accurate for VBNC Lm enumeration. In addition, the impact of the VBNC state on the virulence of Lm is reviewed. Widespread use of these supplemental methods would provide supporting data to identify the conditions under which Lm can revert from its VBNC state into an actively multiplying state and help identify the environmental triggers that can cause Lm to become virulent. Highlights: Rationale for testing for all viable Listeria (Lm) is presented. Routine environmental sampling and plating methods may miss viable Lm cells. An overview and comparison of available VBNC testing methods is given. There is a need for resuscitation techniques to recover Lm from VBNC. A review of testing results for post VBNC virulence is compared.
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16
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Natural Plant-Derived Chemical Compounds as Listeria monocytogenes Inhibitors In Vitro and in Food Model Systems. Pathogens 2020; 10:pathogens10010012. [PMID: 33375619 PMCID: PMC7823385 DOI: 10.3390/pathogens10010012] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2020] [Revised: 12/07/2020] [Accepted: 12/22/2020] [Indexed: 01/08/2023] Open
Abstract
Listeria monocytogenes is a foodborne pathogen, sporadically present in various food product groups. An illness caused by the pathogen, named listeriosis, has high fatality rates. Even though L. monocytogenes is resistant to many environmental factors, e.g., low temperatures, low pH and high salinity, it is susceptible to various natural plant-derived antimicrobials (NPDA), including thymol, carvacrol, eugenol, trans-cinnamaldehyde, carvone S, linalool, citral, (E)-2-hexenal and many others. This review focuses on identifying NPDAs active against L. monocytogenes and their mechanisms of action against the pathogen, as well as on studies that showed antimicrobial action of the compounds against the pathogen in food model systems. Synergistic action of NDPA with other factors, biofilm inhibition and alternative delivery systems (encapsulation and active films) of the compounds tested against L. monocytogenes are also summarized briefly.
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17
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De Jesus AJ, Sheth I, Kwon HJ, Gao Z, Palmer J, Hur M, Hammack TS, Macarisin D, Chen Y. Survival of a serotype 4b strain and a serotype 1/2a strain of Listeria monocytogenes, isolated from a stone fruit outbreak investigation, on whole stone fruit at 4 °C. Int J Food Microbiol 2020; 334:108801. [PMID: 32795712 DOI: 10.1016/j.ijfoodmicro.2020.108801] [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: 04/30/2019] [Revised: 04/02/2020] [Accepted: 07/25/2020] [Indexed: 11/29/2022]
Abstract
In the summer of 2014, a multistate outbreak of listeriosis associated with contaminated stone fruit (peach and nectarine) was reported. A serotype 4b variant Listeria monocytogenes (Lm) strain of singleton Sequence Type (ST) 382 was isolated from clinical samples and stone fruit associated with the outbreak. A serotype 1/2b Lm strain of ST5, Clonal Complex 5 was isolated only from outbreak-associated stone fruit, not from clinical samples. Here we investigated the fate of the serotype 4b and 1/2b strains, at two inoculation levels (high level at 3.7 logCFU/fruit and low level at 2.7 logCFU/fruit), on the surfaces of white peach, yellow peach and yellow nectarine stored at 4 °C for 26 days. After rinsing the fruits, we determined the Lm levels in the rinsates and on the peels. We enumerated Lm using a direct plating method and compared two chromogenic agars. The Lm populations rapidly declined in the first 3 days and then declined more slowly until Day 19/21. The maximum decline was 1.6 logCFU/fruit on yellow peach inoculated with serotype 4b at high level. For fruits inoculated with high-level Lm, the lowest level of Lm (1.7 logCFU/fruit) was observed on for white peach inoculated with serotype 1/2b, and the highest level of Lm (2.6 logCFU/fruit) on Day 19/21 was observed on yellow peach inoculated with the serotype 1/2b strain. For fruits inoculated with low-level Lm, the lowest level of Lm (1.3 logCFU/fruit) was observed on yellow nectarine inoculated with either the serotype 4b or 1/2b strain, and the highest level of Lm (1.7 logCFU/fruit) on Day 19/21 was observed on yellow peach inoculated with ST382. The D-values ranged from 15 days to 28 days. Lm remained viable until the end of storage (Day 26), but the levels were not significantly different from those on Day 19/21. The types of stone fruit and Lm strain did not significantly affect the survival of Lm. These results demonstrate that contaminated stone fruit can carry a potential risk for causing listeriosis in susceptible populations. Comparison of direct plating results using two chromogenic agars showed that RAPID' L. mono and Agar Listeria Ottavani & Agosti performed equivalently for enumerating Lm on stone fruit. The fruit rinsing recovered 80% to 84% of Lm from fruit surfaces.
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Affiliation(s)
- Antonio J De Jesus
- Center for Food Safety and Applied Nutrition, 5001 Campus Dr., College Park, MD 20740, United States of America
| | - Ishani Sheth
- Center for Food Safety and Applied Nutrition, 5001 Campus Dr., College Park, MD 20740, United States of America
| | - Hee Jin Kwon
- Center for Food Safety and Applied Nutrition, 5001 Campus Dr., College Park, MD 20740, United States of America
| | - Zhujun Gao
- Center for Food Safety and Applied Nutrition, 5001 Campus Dr., College Park, MD 20740, United States of America
| | - Jessica Palmer
- Center for Food Safety and Applied Nutrition, 5001 Campus Dr., College Park, MD 20740, United States of America
| | - Minji Hur
- Center for Food Safety and Applied Nutrition, 5001 Campus Dr., College Park, MD 20740, United States of America
| | - Thomas S Hammack
- Center for Food Safety and Applied Nutrition, 5001 Campus Dr., College Park, MD 20740, United States of America
| | - Dumitru Macarisin
- Center for Food Safety and Applied Nutrition, 5001 Campus Dr., College Park, MD 20740, United States of America
| | - Yi Chen
- Center for Food Safety and Applied Nutrition, 5001 Campus Dr., College Park, MD 20740, United States of America.
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18
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Li Y, Huang TY, Mao Y, Chen Y, Shi F, Peng R, Chen J, Yuan L, Bai C, Chen L, Wang K, Liu J. Study on the Viable but Non-culturable (VBNC) State Formation of Staphylococcus aureus and Its Control in Food System. Front Microbiol 2020; 11:599739. [PMID: 33324380 PMCID: PMC7726111 DOI: 10.3389/fmicb.2020.599739] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2020] [Accepted: 10/14/2020] [Indexed: 02/05/2023] Open
Abstract
A Viable but non-culturable (VBNC) state is a bacterial survival strategy under reverse conditions. It poses a significant challenge for public health and food safety. In this study, the effect of external environmental conditions including acid, nutrition, and salt concentrations on the formation of S. aureus VBNC states at low temperatures were investigated. Different acidity and nutritional conditions were then applied to food products to control the VBNC state formation. Four different concentration levels of each factor (acid, nutrition, and salt) were selected in a total of 16 experimental groups. Nutrition showed the highest influence on the VBNC state formation S. aureus, followed by acid and salt. The addition of 1% acetic acid could directly kill S. aureus cells and inhibit the formation of the VBNC state with a nutrition concentration of 25, 50, and 100%. A propidium monoazide-polymerase chain reaction (PMA-PCR) assay was applied and considered as a rapid and sensitive method to detect S. aureus in VBNC state with the detection limit of 104 CFU/mL.
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Affiliation(s)
- Yanmei Li
- Department of Haematology, Guangzhou Women and Children’s Medical Center, Guangzhou Medical University, Guangzhou, China
| | - Teng-Yi Huang
- Department of Laboratory Medicine, The Second Affiliated Hospital of Shantou University Medical College, Shantou, China
| | - Yuzhu Mao
- Guangdong Province Key Laboratory for Green Processing of Natural Products and Product Safety, School of Food Science and Engineering, South China University of Technology, Guangzhou, China
| | - Yanni Chen
- Guangdong Province Key Laboratory for Green Processing of Natural Products and Product Safety, School of Food Science and Engineering, South China University of Technology, Guangzhou, China
| | - Fan Shi
- Guangdong Province Key Laboratory for Green Processing of Natural Products and Product Safety, School of Food Science and Engineering, South China University of Technology, Guangzhou, China
| | - Ruixin Peng
- Guangdong Province Key Laboratory for Green Processing of Natural Products and Product Safety, School of Food Science and Engineering, South China University of Technology, Guangzhou, China
| | - Jinxuan Chen
- Guangdong Province Key Laboratory for Green Processing of Natural Products and Product Safety, School of Food Science and Engineering, South China University of Technology, Guangzhou, China
| | - Lei Yuan
- College of Food Science and Engineering, Yangzhou University, Yangzhou, China
| | - Caiying Bai
- Guangdong Women and Children Hospital, Guangzhou, China
| | - Ling Chen
- Guangdong Province Key Laboratory for Green Processing of Natural Products and Product Safety, School of Food Science and Engineering, South China University of Technology, Guangzhou, China
- Research Institute for Food Nutrition and Human Health, Guangzhou, China
| | - Kan Wang
- Research Center for Translational Medicine, The Second Affiliated Hospital, Medical College of Shantou University, Shantou, China
| | - Junyan Liu
- Department of Civil and Environmental Engineering, University of Maryland, College Park, MD, United States
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19
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Khezri M, Rezaei M, Mohabbati Mobarez A, Zolfaghari M. Viable but non culturable state and expression of pathogenic genes of
Escherichia coli
O157
:
H7
in salted silver carp. J Food Saf 2020. [DOI: 10.1111/jfs.12843] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Mohammad Khezri
- Department of Seafood Processing, Faculty of Marine Sciences Tarbiat Modares University Noor Iran
| | - Masoud Rezaei
- Department of Seafood Processing, Faculty of Marine Sciences Tarbiat Modares University Noor Iran
| | | | - Mehdi Zolfaghari
- Faculty of Fisheries and Environmental Sciences Agricultur and Natural Resource University of Gorgan Gorgan Iran
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20
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Salive AFV, Prudêncio CV, Baglinière F, Oliveira LL, Ferreira SO, Vanetti MCD. Comparison of stress conditions to induce viable but non-cultivable state in Salmonella. Braz J Microbiol 2020; 51:1269-1277. [PMID: 32291740 DOI: 10.1007/s42770-020-00261-w] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2019] [Accepted: 03/10/2020] [Indexed: 12/18/2022] Open
Abstract
Salmonella can enter on the viable but non-culturable state (VBNC), characterized by the loss of ability to grow in routine culture media hindering detection by conventional methods and underestimation of the pathogen. Despite advances in research done so far, studies comparing conditions that lead Salmonella into the VBNC state are scarce. The main objective of this study was to evaluate different stresses to induce Salmonella to the VNBC state. Osmotic (1.2 M NaCl), acid (peracetic acid, 5.66 mg/mL) and oxidative (hydrogen peroxide, 1.20 mg/mL) stress were used at 4 °C to induce Salmonella enterica serovars Enteritidis and Typhimurium to the VBNC state. The culturability loss was monitored in the brain heart infusion (BHI) broth and agar, and the viability was determined by fluorescence microscopy, using the Live/Dead® kit, and by flow cytometry. Besides, the morphological characterization by atomic force microscopy (AFM) was performed. Storage in 1.2 M NaCl at 4 °C induced the VBNC state in Salmonella cells for periods longer than 121 days, and the percentage of viable cells has reached above 80.9%. More aggressive stress conditions promoted by peracetic acid and hydrogen peroxide induced the VBNC state in periods of, at most 0.14 day, and resulted in percentages of 8.5% to 45.5% viable cells, respectively. The counts of viable cells in the flow cytometer corroborate the results obtained by microscopic counts. The VBNC cells obtained in 1.2 M NaCl at 4 °C showed morphological changes, reducing the size and changing the morphology from bacillary to coccoid. No morphological change was observed on the cells stressed by acid or oxidant compounds.
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Affiliation(s)
| | - Cláudia Vieira Prudêncio
- Center of Biological and Health Sciences, Federal University of Western of Bahia, Barreiras, Bahia, Brazil
| | - François Baglinière
- Department of Microbiology, Federal University of Viçosa, Viçosa, Minas Gerais, Brazil
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21
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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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22
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Gholipour S, Nikaeen M, Farhadkhani M, Nikmanesh B. Survey of Listeria monocytogenes contamination of various environmental samples and associated health risks. Food Control 2020. [DOI: 10.1016/j.foodcont.2019.106843] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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23
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Noll M, Trunzer K, Vondran A, Vincze S, Dieckmann R, Al Dahouk S, Gold C. Benzalkonium Chloride Induces a VBNC State in Listeria monocytogenes. Microorganisms 2020; 8:microorganisms8020184. [PMID: 32012868 PMCID: PMC7074807 DOI: 10.3390/microorganisms8020184] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2019] [Revised: 01/14/2020] [Accepted: 01/23/2020] [Indexed: 02/07/2023] Open
Abstract
The objective of our study was to investigate the effects of benzalkonium chloride (BC) adaptation of L. monocytogenes on the susceptibility to antimicrobial agents and on the viable but non culturable (VBNC) state of the bacterial cells. We adapted L. monocytogenes SLCC2540 to BC by applying BC below minimum inhibitory concentration (MIC) to above minimum bactericidal concentration (MBC). The culturable fractions and the susceptibility of adapted and parental cells to BC were assessed. In addition, cell membrane permeability and glucose uptake were analyzed by multi parametric flow cytometry using the fluorescent agents SYTO9, propidium iodide, and 2-deoxy-2-[(7-nitro-2,1,3-benzoxadiazol-4-yl)amino]-D-glucose (2-NBDG). Adapted cells displayed a two-fold MIC increase of BC and reduced antibiotic susceptibility. At high BC concentrations, the decrease in the number of colony forming units was significantly lower in the population of adapted cells compared to parental cells. At the same time, the number of metabolically active cells with intact membranes was significantly higher than the number of culturable cells. Growth-independent viability assays revealed an adapted subpopulation after BC application that was not culturable, indicating increased abundance of viable but nonculturable (VBNC) cells. Moreover, adapted cells can outcompete non-adapted cells under sublethal concentrations of disinfectants, which may lead to novel public health risks.
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Affiliation(s)
- Matthias Noll
- Institute for Bioanalysis, Department of Applied Sciences, Coburg University of Applied Sciences and Arts, Friedrich-Streib-Straße 2, D-96450 Coburg, Germany; (K.T.); (A.V.); (C.G.)
- Correspondence: ; Tel.: +49-09561-317645
| | - Katharina Trunzer
- Institute for Bioanalysis, Department of Applied Sciences, Coburg University of Applied Sciences and Arts, Friedrich-Streib-Straße 2, D-96450 Coburg, Germany; (K.T.); (A.V.); (C.G.)
| | - Antje Vondran
- Institute for Bioanalysis, Department of Applied Sciences, Coburg University of Applied Sciences and Arts, Friedrich-Streib-Straße 2, D-96450 Coburg, Germany; (K.T.); (A.V.); (C.G.)
| | - Szilvia Vincze
- German Federal Institute for Risk Assessment, Max-Dohrn-Str. 8-10, 10589 Berlin, Germany; (S.V.); (R.D.); (S.A.D.)
| | - Ralf Dieckmann
- German Federal Institute for Risk Assessment, Max-Dohrn-Str. 8-10, 10589 Berlin, Germany; (S.V.); (R.D.); (S.A.D.)
| | - Sascha Al Dahouk
- German Federal Institute for Risk Assessment, Max-Dohrn-Str. 8-10, 10589 Berlin, Germany; (S.V.); (R.D.); (S.A.D.)
| | - Carolin Gold
- Institute for Bioanalysis, Department of Applied Sciences, Coburg University of Applied Sciences and Arts, Friedrich-Streib-Straße 2, D-96450 Coburg, Germany; (K.T.); (A.V.); (C.G.)
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Li Y, Huang TY, Ye C, Chen L, Liang Y, Wang K, Liu J. Formation and Control of the Viable but Non-culturable State of Foodborne Pathogen Escherichia coli O157:H7. Front Microbiol 2020; 11:1202. [PMID: 32612584 PMCID: PMC7308729 DOI: 10.3389/fmicb.2020.01202] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2020] [Accepted: 05/12/2020] [Indexed: 02/05/2023] Open
Abstract
As a common foodborne pathogen, Escherichia coli O157:H7 produces toxins causing serious diseases. However, traditional methods failed in detecting E. coli O157:H7 cells in the viable but non-culturable (VBNC) state, which poses a threat to food safety. This study aimed at investigating the formation, control, and detection of the VBNC state of E. coli O157:H7. Three factors including medium, salt, and acid concentrations were selected as a single variation. Orthogonal experiments were designed with three factors and four levels, and 16 experimental schemes were used. The formation of the VBNC state was examined by agar plate counting and LIVE/DEAD® BacLightTM bacterial viability kit with fluorescence microscopy. According to the effects of environmental conditions on the formation of the VBNC state of E. coli O157:H7, the inhibition on VBNC state formation was investigated. In addition, E. coli in the VBNC state in food samples (crystal cake) was detected by propidium monoazide-polymerase chain reaction (PMA-PCR) assays. Acetic acid concentration showed the most impact on VBNC formation of E. coli O157:H7, followed by medium and salt concentration. The addition of 1.0% acetic acid could directly kill E. coli O157:H7 and eliminate its VBNC formation. In crystal cake, 25, 50, or 100% medium with 1.0% acetic acid could inhibit VBNC state formation and kill E. coli O157:H7 within 3 days. The VBNC cell number was reduced by adding 1.0% acetic acid. PMA-PCR assay could be used to detect E. coli VBNC cells in crystal cake with detection limit at 104 CFU/ml. The understanding on the inducing and inhibitory conditions for the VBNC state of E. coli O157:H7 in a typical food system, as well as the development of an efficient VBNC cell detection method might aid in the control of VBNC E. coli O157:H7 cells in the food industry.
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Affiliation(s)
- Yanmei Li
- Department of Haematology, Guangzhou Women and Children’s Medical Center, Guangzhou Medical University, Guangzhou, China
| | - Teng-Yi Huang
- Department of Laboratory Medicine, The Second Affiliated Hospital of Shantou University Medical College, Shantou, China
| | - Congxiu Ye
- Department of Dermato-Venereology, Third Affiliated Hospital of Sun Yat-sen University, Guangzhou, China
| | - Ling Chen
- School of Food Science and Engineering, Guangdong Province Key Laboratory for Green Processing of Natural Products and Product Safety, South China University of Technology, Guangzhou, China
| | - Yi Liang
- Guangdong Zhongqing Font Biochemical Science and Technology Co. Ltd., Maoming, China
| | - Kan Wang
- Research Center for Translational Medicine, The Second Affiliated Hospital, Medical College of Shantou University, Shantou, China
- *Correspondence: Junyan Liu,
| | - Junyan Liu
- Department of Civil and Environmental Engineering, A. James Clark School of Engineering, University of Maryland, College Park, MD, United States
- Kan Wang,
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25
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Dong K, Pan H, Yang D, Rao L, Zhao L, Wang Y, Liao X. Induction, detection, formation, and resuscitation of viable but non‐culturable state microorganisms. Compr Rev Food Sci Food Saf 2019; 19:149-183. [DOI: 10.1111/1541-4337.12513] [Citation(s) in RCA: 47] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2019] [Revised: 10/21/2019] [Accepted: 11/14/2019] [Indexed: 01/05/2023]
Affiliation(s)
- Kai Dong
- Beijing Advanced Innovation Center for Food Nutrition and Human HealthCollege of Food Science and Nutritional EngineeringChina Agricultural University Beijing China
- College of Food Science and Nutritional EngineeringChina Agricultural University Beijing China
- Key Lab of Fruit and Vegetable ProcessingMinistry of Agriculture and Rural Affairs Beijing China
| | - Hanxu Pan
- Beijing Advanced Innovation Center for Food Nutrition and Human HealthCollege of Food Science and Nutritional EngineeringChina Agricultural University Beijing China
- College of Food Science and Nutritional EngineeringChina Agricultural University Beijing China
- Key Lab of Fruit and Vegetable ProcessingMinistry of Agriculture and Rural Affairs Beijing China
| | - Dong Yang
- Beijing Advanced Innovation Center for Food Nutrition and Human HealthCollege of Food Science and Nutritional EngineeringChina Agricultural University Beijing China
- College of Food Science and Nutritional EngineeringChina Agricultural University Beijing China
- Key Lab of Fruit and Vegetable ProcessingMinistry of Agriculture and Rural Affairs Beijing China
| | - Lei Rao
- Beijing Advanced Innovation Center for Food Nutrition and Human HealthCollege of Food Science and Nutritional EngineeringChina Agricultural University Beijing China
- College of Food Science and Nutritional EngineeringChina Agricultural University Beijing China
- Key Lab of Fruit and Vegetable ProcessingMinistry of Agriculture and Rural Affairs Beijing China
| | - Liang Zhao
- College of Food Science and Nutritional EngineeringChina Agricultural University Beijing China
- Key Lab of Fruit and Vegetable ProcessingMinistry of Agriculture and Rural Affairs Beijing China
| | - Yongtao Wang
- College of Food Science and Nutritional EngineeringChina Agricultural University Beijing China
- Key Lab of Fruit and Vegetable ProcessingMinistry of Agriculture and Rural Affairs Beijing China
| | - Xiaojun Liao
- Beijing Advanced Innovation Center for Food Nutrition and Human HealthCollege of Food Science and Nutritional EngineeringChina Agricultural University Beijing China
- College of Food Science and Nutritional EngineeringChina Agricultural University Beijing China
- Key Lab of Fruit and Vegetable ProcessingMinistry of Agriculture and Rural Affairs Beijing China
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26
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Zolfaghari M, Rezaei M, Mohabbati Mobarez A, Forozandeh Moghaddam M, Hosseini H, Khezri M. Virulence genes expression in viable but non-culturable state of Listeria monocytogenes in fish meat. FOOD SCI TECHNOL INT 2019; 26:205-212. [PMID: 31583896 DOI: 10.1177/1082013219877267] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
This study aimed to evaluate the fate of Listeria monocytogenes in water microcosm and rainbow trout fillet under salinity stress of 0% and 30% NaCl at refrigerator temperature (4 ± 2 ℃). Bacterial culturability was studied by standard culture and colony count method. Reverse transcription-PCR (RT-PCR) of 16 S rRNA gene was used to detect viability of non-culturable bacteria. Also, the qualitative expression of pathogenic genes (hly and inlA) was studied using RT-PCR. The results showed that bacteria in water microcosm lost their culturability at 13 days under 0% salinity (starvation or distilled water) and at 27 days under 30% salinity; however, bacteria in rainbow trout fillet remained culturable under 0% and 30% NaCl. RT-PCR of 16 S rRNA gene was positive for all treatments during the period of this study, indicating the entering of L. monocytogenes into the viable but non-culturable state in water microcosm under 0% and 30% NaCl. Also, viable but non-culturable L. monocytogenes retained the expression of hly and inlA genes. So, it could be concluded that L. monocytogenes in viable but non-culturable state can cause serious health problems and further investigation is necessary to elucidate the effects of other processing and storage conditions (light, dark, smoking, etc.) on behavior of L. monocytogenes in smoked and salted fish.
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Affiliation(s)
- Mehdi Zolfaghari
- Fisheries Sciences Department, Gorgan University of Agricultural Sciences and Natural Resources, Gorgan, Iran
| | - Masoud Rezaei
- Seafood Processing Department, Faculty of Marine Sciences, Tarbiat Modares University, Noor, Iran
| | | | | | - Hedayat Hosseini
- Food Science and Technology Department, Faculty of Nutrition Sciences and Food Technology, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Mohammad Khezri
- Seafood Processing Department, Faculty of Marine Sciences, Tarbiat Modares University, Noor, Iran
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27
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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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28
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Kragh ML, Thykier M, Truelstrup Hansen L. A long-amplicon quantitative PCR assay with propidium monoazide to enumerate viable Listeria monocytogenes after heat and desiccation treatments. Food Microbiol 2019; 86:103310. [PMID: 31703859 DOI: 10.1016/j.fm.2019.103310] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2019] [Revised: 06/16/2019] [Accepted: 08/20/2019] [Indexed: 01/22/2023]
Abstract
The objective of this study was to develop a qPCR method for specific enumeration of viable Listeria monocytogenes in food processing facilities and heat treated products. Primers specific for L. monocytogenes were designed to amplify a short (199 bp) or long (1561 bp) fragment of the listeriolysin (hly) gene. The short- and long-amplicon qPCR methods with and without propidium monoazide (PMA) treatment of the cells were tested for their ability to discriminate between viable (no heat) and heat-killed cells (90 °C, 10 min). The PMA-qPCR methods were subsequently used to assess the survival of L. monocytogenes during desiccation (33% RH, 15 °C) on stainless steel surfaces for ten days with and without prior biofilm formation. The long-amplicon qPCR method had a limit of quantification (LOQ) of 1.32 log CFU/reaction (efficiency 92%, R2 = 0.991), while the LOQ for the short-amplicon qPCR method was 1.44 log CFU/reaction (efficiency 102%, R2 = 0.991). PMA was essential for detection of viable cells, and the long-amplicon PMA-qPCR significantly (p < 0.05) reduced the signal from heat-killed cells compared to the short-amplicon method. L. monocytogenes survival during desiccation without biofilm formation was accurately enumerated with the long-amplicon PMA-qPCR method. However, when L. monocytogenes had formed biofilm prior to desiccation, the long-amplicon PMA-qPCR accurately measured the log fold inactivation but underestimated the number of viable cells even with use of an optimized DNA extraction method. This long-amplicon PMA-qPCR method can aid in the detection and enumeration of viable L. monocytogenes cells to further the understanding of its survival and persistence in food processing facilities. The developed method was demonstrated to work on both heat and desiccation treated cells and highlights the importance of amplicon size in viability-qPCR.
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Affiliation(s)
- Martin Laage Kragh
- National Food Institute, Technical University of Denmark, Kemitorvet, DK-2800, Kgs. Lyngby, Denmark
| | - Mikala Thykier
- National Food Institute, Technical University of Denmark, Kemitorvet, DK-2800, Kgs. Lyngby, Denmark
| | - Lisbeth Truelstrup Hansen
- National Food Institute, Technical University of Denmark, Kemitorvet, DK-2800, Kgs. Lyngby, Denmark.
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29
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Liao H, Jiang L, Zhang R. Induction of a viable but non-culturable state in Salmonella Typhimurium by thermosonication and factors affecting resuscitation. FEMS Microbiol Lett 2019; 365:4668413. [PMID: 29186410 DOI: 10.1093/femsle/fnx249] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2017] [Accepted: 11/26/2017] [Indexed: 12/13/2022] Open
Abstract
The objective of this work was to analyze the effects of thermosonication (TS) on induction of a viable but non-culturable (VBNC) state in Salmonella Typhimurium and to examine incubation factors affecting subsequent resuscitation of cells. A TS treatment of 380 W at 53°C for 30 min induced the VBNC state in S. Typhimurium cells in beef peptone yeast (BPY) broth, apple/carrot juice, physiological saline and phosphate buffer solution. The logarithmic and decline phases of growth were more sensitive to the TS treatment compared to stationary phase cells. Meanwhile, VBNC S. Typhimurium could be resuscitated back to culturable cells by using suitable incubation temperatures and media. Addition of Tween 20 hindered resuscitation compared to the use of BPY medium alone. The optimal growth temperature (i.e. 37°C) was the most suitable temperature to resuscitate cells from the VBNC state. The VBNC incidence index decreased with the addition of sodium pyruvate during TS treatment, as it accelerated resuscitation. The results demonstrated that free radicals produced during TS processing and the growth phase of cells affected induction of the VBNC state in S. Typhimurium. Hence, the kinds and amounts of free radicals generated during TS treatment should be analyzed in the future.
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Affiliation(s)
- Hongmei Liao
- School of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu, China
| | - Lifen Jiang
- School of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu, China
| | - Ruirui Zhang
- School of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu, China
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30
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Ampicillin-treated Lactococcus lactis MG1363 populations contain persisters as well as viable but non-culturable cells. Sci Rep 2019; 9:9867. [PMID: 31285492 PMCID: PMC6614399 DOI: 10.1038/s41598-019-46344-z] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2019] [Accepted: 06/23/2019] [Indexed: 12/12/2022] Open
Abstract
Lactococcus lactis is used as cell-factory and strain selections are regularly performed to improve production processes. When selection regimes only allow desired phenotypes to survive, for instance by using antibiotics to select for cells that do not grow in a specific condition, the presence of more resistant subpopulations with a wildtype genotype severely slows down the procedure. While the food grade organism L. lactis is not often exposed to antibiotics we characterized its response to ampicillin in more detail, to better understand emerging population heterogeneity and how this might affect strain selection procedures. Using growth-dependent viability assays we identified persister subpopulations in stationary and exponential phase. Growth-independent viability assays revealed a 100 times larger subpopulation that did not grow on plates or in liquid medium, but had an intact membrane and could maintain a pH gradient. Over one third of these cells restored their intracellular pH when we induced a temporary collapse, indicating that this subpopulation was metabolically active and in a viable but non-culturable state. Exposure of L. lactis MG1363 to ampicillin therefore results in a heterogeneous population response with different dormancy states. These dormant cells should be considered in survival-based strain selection procedures.
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31
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Bai H, Zhao F, Li M, Qin L, Yu H, Lu L, Zhang T. Citric acid can force Staphylococcus aureus into viable but nonculturable state and its characteristics. Int J Food Microbiol 2019; 305:108254. [PMID: 31238194 DOI: 10.1016/j.ijfoodmicro.2019.108254] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2019] [Revised: 06/15/2019] [Accepted: 06/17/2019] [Indexed: 12/11/2022]
Abstract
Pathogens in viable but nonculturable (VBNC) state can escape traditional detection methods based on culturable ability, thus bringing risks to food safety and human health. Considering Staphylococcus aureus as a kind of primary foodborne pathogen, this study attempted to investigate whether citric acid, a food additive commonly used, can force S. aureus into VBNC state along with low temperature. Treated with citric acid solution (pH 4.0) at 4 °C, S. aureus was confirmed to enter into VBNC state after induction for 18 days. Meanwhile, resuscitation was achieved in culture medium rather than in nutrition-free saline solution. In VBNC cells, ATP concentration still maintained at a high level, as about two-thirds of exponential-phase cells. For survival, intracellular structure of VBNC cells changed remarkably, including irregular cell shape, denser cytoplasm, space between cell wall and cell membrane, and decreased density of nuclear region. Notably, resistance of VBNC cells to simulated gastric fluid improved when compared with exponential-phase cells. What are noted above suggests that VBNC state adopted by S. aureus might be a survival strategy to the adverse environment (acidity stress and low temperature). In conclusion, our study sounds an alarm for the safety of citric acid-containing foods.
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Affiliation(s)
- Hong Bai
- College of Food Science and Engineering, Jilin University, 5333 Xi'an Road, Changchun 130062, PR China
| | - Feng Zhao
- College of Food Science and Engineering, Jilin University, 5333 Xi'an Road, Changchun 130062, PR China.
| | - Meng Li
- College of Food Science and Engineering, Jilin University, 5333 Xi'an Road, Changchun 130062, PR China
| | - Liangyun Qin
- College of Food Science and Engineering, Jilin University, 5333 Xi'an Road, Changchun 130062, PR China
| | - Huilin Yu
- College of Food Science and Engineering, Jilin University, 5333 Xi'an Road, Changchun 130062, PR China
| | - Linhan Lu
- College of Food Science and Engineering, Jilin University, 5333 Xi'an Road, Changchun 130062, PR China
| | - Tiehua Zhang
- College of Food Science and Engineering, Jilin University, 5333 Xi'an Road, Changchun 130062, PR China
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32
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Robben C, Witte AK, Schoder D, Stessl B, Rossmanith P, Mester P. A Fast and Easy ATP-Based Approach Enables MIC Testing for Non-resuscitating VBNC Pathogens. Front Microbiol 2019; 10:1365. [PMID: 31258524 PMCID: PMC6587809 DOI: 10.3389/fmicb.2019.01365] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2019] [Accepted: 05/31/2019] [Indexed: 12/14/2022] Open
Abstract
Many bacteria enter the viable but non-culturable (VBNC) state to maximize resources and increase their tolerance to harmful conditions to cope with environmental stress, which has been described for a plethora of important human and foodborne pathogens. VBNC pathogens can potentially present a serious risk to human health as they are invisible to routine microbiological culture-based methods. Of high importance is the increased tolerance to antibiotics or disinfectant measures while in the VBNC state. The greatest remaining challenge for such investigations is the lack of an appropriate, cost-effective multi-species screening method due to experimental constraints. In this study, we investigated if de novo ATP production of cells in the VBNC state is a suitable indicator for overall cell viability that can be utilized to determine the minimum ATP inhibitory concentration (MAIC) of antibiotics and other antimicrobials. To validate this approach, heat-stress time-kill experiments were performed with both culturable and VBNC cells. We developed a comprehensive experimental setup and demonstrated the applicability of this VBNC–MIC assay for testing the tolerance of 12 strains of 4 important bacterial species (Escherichia coli, Bacillus cereus, Pseudomonas aeruginosa, and Listeria monocytogenes) in the VBNC state to eight important antimicrobials including four different antibiotics. We confirmed that bacteria in the VBNC state were resistant to all tested antibiotics (ampicillin, imipenem, ciprofloxacin, and gentamicin) and additionally insensitive to disinfectants (benzalkonium chloride and trioctylmethylammonium chloride) and preservatives (bronopol and sodium azide). These data emphasize the need for further research regarding the characteristics of bacterial pathogens in the VBNC state and present the advantages and high-throughput capabilities of ATP determinations to investigate tolerance of VBNC pathogens to antimicrobials. The presented method should be helpful in order to identify appropriate countermeasures, treatments, or disinfectants when confronted with bacterial pathogens in the VBNC state.
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Affiliation(s)
- Christian Robben
- Christian Doppler Laboratory for Monitoring of Microbial Contaminants, Department of Farm Animal and Public Health in Veterinary Medicine, Institute for Milk Hygiene, Milk Technology and Food Science, University of Veterinary Medicine, Vienna, Austria
| | - Anna Kristina Witte
- Christian Doppler Laboratory for Monitoring of Microbial Contaminants, Department of Farm Animal and Public Health in Veterinary Medicine, Institute for Milk Hygiene, Milk Technology and Food Science, University of Veterinary Medicine, Vienna, Austria
| | - Dagmar Schoder
- Christian Doppler Laboratory for Monitoring of Microbial Contaminants, Department of Farm Animal and Public Health in Veterinary Medicine, Institute for Milk Hygiene, Milk Technology and Food Science, University of Veterinary Medicine, Vienna, Austria.,Department of Farm Animal and Public Health in Veterinary Medicine, Institute of Milk Hygiene, Milk Technology and Food Science, University of Veterinary Medicine, Vienna, Austria
| | - Beatrix Stessl
- Department of Farm Animal and Public Health in Veterinary Medicine, Institute of Milk Hygiene, Milk Technology and Food Science, University of Veterinary Medicine, Vienna, Austria
| | - Peter Rossmanith
- Christian Doppler Laboratory for Monitoring of Microbial Contaminants, Department of Farm Animal and Public Health in Veterinary Medicine, Institute for Milk Hygiene, Milk Technology and Food Science, University of Veterinary Medicine, Vienna, Austria.,Department of Farm Animal and Public Health in Veterinary Medicine, Institute of Milk Hygiene, Milk Technology and Food Science, University of Veterinary Medicine, Vienna, Austria
| | - Patrick Mester
- Christian Doppler Laboratory for Monitoring of Microbial Contaminants, Department of Farm Animal and Public Health in Veterinary Medicine, Institute for Milk Hygiene, Milk Technology and Food Science, University of Veterinary Medicine, Vienna, Austria
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33
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Kumar SS, Ghosh AR. Assessment of bacterial viability: a comprehensive review on recent advances and challenges. Microbiology (Reading) 2019; 165:593-610. [DOI: 10.1099/mic.0.000786] [Citation(s) in RCA: 55] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Affiliation(s)
- Shravanthi S. Kumar
- Department of Integrative Biology, School of Bio Sciences and Technology, Vellore Institute of Technology, Vellore-632014, Tamil Nadu, India
| | - Asit Ranjan Ghosh
- Department of Integrative Biology, School of Bio Sciences and Technology, Vellore Institute of Technology, Vellore-632014, Tamil Nadu, India
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34
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Listeria monocytogenes survival in raw Atlantic salmon (Salmo salar) fillet under in vitro simulated gastrointestinal conditions by culture, qPCR and PMA-qPCR detection methods. Lebensm Wiss Technol 2019. [DOI: 10.1016/j.lwt.2019.03.015] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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35
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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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36
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Robben C, Fister S, Witte AK, Schoder D, Rossmanith P, Mester P. Induction of the viable but non-culturable state in bacterial pathogens by household cleaners and inorganic salts. Sci Rep 2018; 8:15132. [PMID: 30310128 PMCID: PMC6181970 DOI: 10.1038/s41598-018-33595-5] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2018] [Accepted: 09/28/2018] [Indexed: 12/28/2022] Open
Abstract
Effective monitoring of microbial pathogens is essential for a successful preventive food safety and hygiene strategy. However, as most monitoring strategies are growth-based, these tests fail to detect pathogenic bacteria that have entered the viable but non-culturable (VBNC) state. The present study reports the induction of the VBNC state in five human pathogens by commercially available household cleaners in combination with inorganic salts. We determined that non-ionic surfactants, a common ingredient in household cleaners, can induce the VBNC state, when combined with salts. A screening study with 630 surfactant/salt combinations indicates a correlation between the hydrophobicity of the surfactant and VBNC induction in L. monocytogenes, E. coli, S. enterica serovar Typhimurium, S. aureus and toxin-producing enteropathogenic E. coli. Cells that were exposed to combinations of surfactants and salts for 5 min and up to 1 h lost their culturability on standard growth media while retaining their ATP production, fermentation of sugars and membrane integrity, which suggests intact and active metabolism. Screening also revealed major differences between Gram-negative and Gram-positive bacteria; the latter being more susceptible to VBNC induction. Combinations of such detergents and salts are found in many different environments and reflect realistic conditions in industrial and domestic surroundings. VBNC cells present in industrial environments, food-processing plants and even our daily routine represent a serious health risk due to possible resuscitation, unknown spreading, production of toxins and especially their invisibility to routine detection methods, which rely on culturability of cells and fail to detect VBNC pathogens.
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Affiliation(s)
- Christian Robben
- Christian Doppler-Laboratory for Monitoring of Microbial Contaminants, Institute for Milk Hygiene, Milk Technology and Food Science, Department of Farm Animal and Public Health in Veterinary Medicine, University of Veterinary Medicine, Veterinärplatz 1, 1210, Vienna, Austria
| | - Susanne Fister
- Christian Doppler-Laboratory for Monitoring of Microbial Contaminants, Institute for Milk Hygiene, Milk Technology and Food Science, Department of Farm Animal and Public Health in Veterinary Medicine, University of Veterinary Medicine, Veterinärplatz 1, 1210, Vienna, Austria
| | - Anna Kristina Witte
- Christian Doppler-Laboratory for Monitoring of Microbial Contaminants, Institute for Milk Hygiene, Milk Technology and Food Science, Department of Farm Animal and Public Health in Veterinary Medicine, University of Veterinary Medicine, Veterinärplatz 1, 1210, Vienna, Austria
| | - Dagmar Schoder
- Christian Doppler-Laboratory for Monitoring of Microbial Contaminants, Institute for Milk Hygiene, Milk Technology and Food Science, Department of Farm Animal and Public Health in Veterinary Medicine, University of Veterinary Medicine, Veterinärplatz 1, 1210, Vienna, Austria.,Institute of Milk Hygiene, Milk Technology and Food Science, Department of Farm Animal and Public Health in Veterinary Medicine, University of Veterinary Medicine, Veterinärplatz 1, 1210, Vienna, Austria
| | - Peter Rossmanith
- Christian Doppler-Laboratory for Monitoring of Microbial Contaminants, Institute for Milk Hygiene, Milk Technology and Food Science, Department of Farm Animal and Public Health in Veterinary Medicine, University of Veterinary Medicine, Veterinärplatz 1, 1210, Vienna, Austria.,Institute of Milk Hygiene, Milk Technology and Food Science, Department of Farm Animal and Public Health in Veterinary Medicine, University of Veterinary Medicine, Veterinärplatz 1, 1210, Vienna, Austria
| | - Patrick Mester
- Christian Doppler-Laboratory for Monitoring of Microbial Contaminants, Institute for Milk Hygiene, Milk Technology and Food Science, Department of Farm Animal and Public Health in Veterinary Medicine, University of Veterinary Medicine, Veterinärplatz 1, 1210, Vienna, Austria.
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Saraoui T, Leroi F, Chevalier F, Cappelier JM, Passerini D, Pilet MF. Bioprotective Effect of Lactococcus piscium CNCM I-4031 Against Listeria monocytogenes Growth and Virulence. Front Microbiol 2018; 9:1564. [PMID: 30065705 PMCID: PMC6056605 DOI: 10.3389/fmicb.2018.01564] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2018] [Accepted: 06/25/2018] [Indexed: 11/13/2022] Open
Abstract
Listeria monocytogenes is a Gram-positive pathogen occurring in many refrigerated ready-to-eat foods. It is responsible for foodborne listeriosis, a rare but severe disease with a high mortality rate (20-30%). Lactococcus piscium CNCM I-4031 has the capacity to prevent the growth of L. monocytogenes in contaminated peeled and cooked shrimp and in a chemically defined medium using a cell-to-cell contact-dependent mechanism. To characterize this inhibition further, the effect of L. piscium was tested on a collection of 42 L. monocytogenes strains. All strains were inhibited but had different sensitivities. The effect of the initial concentration of the protective and the target bacteria revealed that the inhibition always occurred when L. piscium had reached its maximum population density, whatever the initial concentration of the protective bacteria. Viewed by scanning electron microscopy, L. monocytogenes cell shape and surface appeared modified in co-culture with L. piscium CNCM I-4031. Lastly, L. monocytogenes virulence, evaluated by a plaque-forming assay on the HT-29 cell line, was reduced after cell pre-treatment by the protective bacteria. In conclusion, the bioprotective effect of L. piscium toward L. monocytogenes growth and virulence was demonstrated, and a hypothesis for the inhibition mechanism is put forward.
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Affiliation(s)
- Taous Saraoui
- Laboratoire Ecosystèmes Microbiens et Molécules Marines pour les Biotechnologies (EMB), L’Institut Français de Recherche pour l’Exploitation de la Mer (Ifremer), Nantes, France
- UMR1014 SECALIM, INRA, École Nationale Vétérinaire, Agroalimentaire et de l’Alimentation de Nantes-Atlantique (ONIRIS), Nantes, France
| | - Françoise Leroi
- Laboratoire Ecosystèmes Microbiens et Molécules Marines pour les Biotechnologies (EMB), L’Institut Français de Recherche pour l’Exploitation de la Mer (Ifremer), Nantes, France
| | - Frédérique Chevalier
- Laboratoire Ecosystèmes Microbiens et Molécules Marines pour les Biotechnologies (EMB), L’Institut Français de Recherche pour l’Exploitation de la Mer (Ifremer), Nantes, France
| | - Jean-Michel Cappelier
- UMR1014 SECALIM, INRA, École Nationale Vétérinaire, Agroalimentaire et de l’Alimentation de Nantes-Atlantique (ONIRIS), Nantes, France
| | - Delphine Passerini
- Laboratoire Ecosystèmes Microbiens et Molécules Marines pour les Biotechnologies (EMB), L’Institut Français de Recherche pour l’Exploitation de la Mer (Ifremer), Nantes, France
| | - Marie-France Pilet
- UMR1014 SECALIM, INRA, École Nationale Vétérinaire, Agroalimentaire et de l’Alimentation de Nantes-Atlantique (ONIRIS), Nantes, France
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Zhang C, Chen X, Xia X, Li B, Hung YC. Viability assay of E. coli O157: H7 treated with electrolyzed oxidizing water using flow cytometry. Food Control 2018. [DOI: 10.1016/j.foodcont.2017.12.029] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
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39
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Bierne H, Milohanic E, Kortebi M. To Be Cytosolic or Vacuolar: The Double Life of Listeria monocytogenes. Front Cell Infect Microbiol 2018; 8:136. [PMID: 29868493 PMCID: PMC5962784 DOI: 10.3389/fcimb.2018.00136] [Citation(s) in RCA: 32] [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: 02/07/2018] [Accepted: 04/18/2018] [Indexed: 01/06/2023] Open
Abstract
Intracellular bacterial pathogens are generally classified into two types: those that exploit host membrane trafficking to construct specific niches in vacuoles (i.e., "vacuolar pathogens"), and those that escape from vacuoles into the cytosol, where they proliferate and often spread to neighboring cells (i.e., "cytosolic pathogens"). However, the boundary between these distinct intracellular phenotypes is tenuous and may depend on the timing of infection and on the host cell type. Here, we discuss recent progress highlighting this phenotypic duality in Listeria monocytogenes, which has long been a model for cytosolic pathogens, but now emerges as a bacterium also capable of residing in vacuoles, in a slow/non-growing state. The ability of L. monocytogenes to enter a persistence stage in vacuoles might play a role during the asymptomatic incubation period of listeriosis and/or the carriage of this pathogen in asymptomatic hosts. Moreover, persistent vacuolar Listeria could be less susceptible to antibiotics and more difficult to detect by routine techniques of clinical biology. These hypotheses deserve to be explored in order to better manage the risks related to this food-borne pathogen.
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Affiliation(s)
- Hélène Bierne
- Epigenetics and Cellular Microbiology Team, Micalis Institute, Institut National de la Recherche Agronomique, AgroParisTech, Université Paris-Saclay, Jouy-en-Josas, France
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40
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Purevdorj-Gage L, Nixon B, Bodine K, Xu Q, Doerrler WT. Differential Effect of Food Sanitizers on Formation of Viable but Nonculturable Salmonella enterica in Poultry. J Food Prot 2018; 81:386-393. [PMID: 29419335 DOI: 10.4315/0362-028x.jfp-17-335] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
A method for microscopic enumeration of viable Salmonella enterica in meat samples was developed by using the LIVE/DEAD BacLight kit technology. A two-step centrifugation and wash process was developed to clean the samples from food and chemical impurities that might otherwise interfere with the appropriate staining reactions. The accuracy of the BacLight kit-based viability assessments was confirmed with various validation tests that were conducted by following the manufacturer's instructions. For the biocide challenge tests, chicken parts each bearing around 8.5 log of S. enterica were sprayed with common food sanitizers such as 1,3-dibromo-5,5-dimethylhydantoin (DBDMH), lactic acid (LA), and peracetic acid (PAA). The log reduction (LR) of S. enterica for each test biocide was evaluated by microscopic and conventional culture plate methods. The results show that both LA and PAA treatments generated a greater number of microscopic counts compared with the corresponding plate counts with differences being around half a log. This discrepancy is believed to occur when cells enter a so-called viable but nonculturable (VBNC) state, and to our knowledge, this is the first report documenting the presence of VBNC in PAA- and LA-treated food samples. In contrast, the BacLight-based viable counts were comparable to the culture-based enumerations of all DBDMH-treated samples. Therefore, we concluded that DBDMH-treated meat did not contain significant VBNC populations of S. enterica. A detailed description of our spray system, the dye validation, and the treatment reproducibility are also provided in this work.
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Affiliation(s)
- Laura Purevdorj-Gage
- 1 The Process Development Center, Albemarle Corporation, Gulf States Road, Baton Rouge, Louisiana 70805
| | - Brian Nixon
- 1 The Process Development Center, Albemarle Corporation, Gulf States Road, Baton Rouge, Louisiana 70805
| | - Kyle Bodine
- 1 The Process Development Center, Albemarle Corporation, Gulf States Road, Baton Rouge, Louisiana 70805
| | - Qilong Xu
- 2 Southern Microbiological Services, 8000 Innovation Park Drive, Baton Rouge, Louisiana 70820
| | - William T Doerrler
- 2 Southern Microbiological Services, 8000 Innovation Park Drive, Baton Rouge, Louisiana 70820.,3 Department of Biological Sciences, Louisiana State University, 202 Life Sciences Building, Baton Rouge, Louisiana 70803, USA
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41
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Seafood spoilage microbiota and associated volatile organic compounds at different storage temperatures and packaging conditions. Int J Food Microbiol 2018; 280:87-99. [PMID: 29478710 DOI: 10.1016/j.ijfoodmicro.2017.12.029] [Citation(s) in RCA: 94] [Impact Index Per Article: 15.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2017] [Revised: 12/21/2017] [Accepted: 12/30/2017] [Indexed: 01/12/2023]
Abstract
Seafood comprising of both vertebrate and invertebrate aquatic organisms are nutritious, rich in omega-3 fatty acids, essential vitamins, proteins, minerals and form part of healthy diet. However, despite the health and nutritional benefits, seafood is highly perishable. Spoilage of seafood could be as a result of microbial activity, autolysis or chemical oxidation. Microbial activity constitutes more spoilage than others. Spoilage bacteria are commonly Gram negative and produce off odours and flavours in seafood as a result of their metabolic activities. Storage temperature, handling and packaging conditions affect microbial growth and thus the shelf-life of seafood. Due to the complexity of the microbial communities in seafood, culture dependent methods of detection may not be useful, hence the need for culture independent methods are necessary to understand the diversity of microbiota and spoilage process. Similarly, the volatile organic compounds released by spoilage bacteria are not fully understood in some seafood. This review therefore highlights current knowledge and understanding of seafood spoilage microbiota, volatile organic compounds, effects of storage temperature and packaging conditions on quality of seafood.
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42
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Kortebi M, Milohanic E, Mitchell G, Péchoux C, Prevost MC, Cossart P, Bierne H. Listeria monocytogenes switches from dissemination to persistence by adopting a vacuolar lifestyle in epithelial cells. PLoS Pathog 2017; 13:e1006734. [PMID: 29190284 PMCID: PMC5708623 DOI: 10.1371/journal.ppat.1006734] [Citation(s) in RCA: 46] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2017] [Accepted: 11/04/2017] [Indexed: 12/26/2022] Open
Abstract
Listeria monocytogenes causes listeriosis, a foodborne disease that poses serious risks to fetuses, newborns and immunocompromised adults. This intracellular bacterial pathogen proliferates in the host cytosol and exploits the host actin polymerization machinery to spread from cell-to-cell and disseminate in the host. Here, we report that during several days of infection in human hepatocytes or trophoblast cells, L. monocytogenes switches from this active motile lifestyle to a stage of persistence in vacuoles. Upon intercellular spread, bacteria gradually stopped producing the actin-nucleating protein ActA and became trapped in lysosome-like vacuoles termed Listeria-Containing Vacuoles (LisCVs). Subpopulations of bacteria resisted degradation in LisCVs and entered a slow/non-replicative state. During the subculture of host cells harboring LisCVs, bacteria showed a capacity to cycle between the vacuolar and the actin-based motility stages. When ActA was absent, such as in ΔactA mutants, vacuolar bacteria parasitized host cells in the so-called “viable but non-culturable” state (VBNC), preventing their detection by conventional colony counting methods. The exposure of infected cells to high doses of gentamicin did not trigger the formation of LisCVs, but selected for vacuolar and VBNC bacteria. Together, these results reveal the ability of L. monocytogenes to enter a persistent state in a subset of epithelial cells, which may favor the asymptomatic carriage of this pathogen, lengthen the incubation period of listeriosis, and promote bacterial survival during antibiotic therapy. L. monocytogenes is a model intracellular pathogen that replicates in the cytoplasm of mammalian cells and disseminate in the host using actin-based motility. Here, we reveal that L. monocytogenes changes its lifestyle and persists in lysosomal vacuoles during long-term infection of human hepatocytes and trophoblast cells. When the virulence factor ActA is not expressed, subpopulations of vacuolar bacteria enter a dormant viable but non-culturable (VBNC) state. This novel facet of the L. monocytogenes intracellular life could contribute to the asymptomatic carriage of this pathogen in epithelial tissues and render it tolerant to antibiotic therapy and undetectable by routine culture techniques.
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Affiliation(s)
- Mounia Kortebi
- Micalis Institute, Inra, AgroParisTech, Université Paris-Saclay, Equipe Epigénétique et Microbiologie Cellulaire, Jouy-en-Josas, France
| | - Eliane Milohanic
- Micalis Institute, Inra, AgroParisTech, Université Paris-Saclay, Equipe Epigénétique et Microbiologie Cellulaire, Jouy-en-Josas, France
| | - Gabriel Mitchell
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, California, United States of America
| | - Christine Péchoux
- Unité GABI, Inra, AgroParisTech, Université Paris-Saclay, Plate-Forme MIMA2, Jouy-en-Josas, France
| | | | - Pascale Cossart
- Institut Pasteur, Unité des interactions Bactéries-Cellules, Paris, France
- Inserm, U604, Paris, France
- Inra, USC2020, Paris, France
| | - Hélène Bierne
- Micalis Institute, Inra, AgroParisTech, Université Paris-Saclay, Equipe Epigénétique et Microbiologie Cellulaire, Jouy-en-Josas, France
- * E-mail:
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Jarvis NA, O'Bryan CA, Martin EM, Ricke SC, Johnson MG, Crandall PG. Further Evidence of How Unbuffered Starvation at 4°C Influences Listeria monocytogenes EGD-e, HCC23, F2365, and Scott A. J Food Prot 2017; 80:1749-1759. [PMID: 28922027 DOI: 10.4315/0362-028x.jfp-17-041] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
The soilborne pathogen Listeria monocytogenes frequently contaminates food products and food processing environments and is able to survive desiccation, high osmotic pressures, and starvation. However, little is known about how this pathogen survives starvation at 4°C. This study provides evidence that L. monocytogenes is able to survive total nutrient starvation for 4 weeks. L. monocytogenes strains EGD-e, Scott A, F2365, and HCC23 were starved individually in sterile water. Colony counts declined over 4 weeks, with Scott A declining the most rapidly. Transmission electron microscopy images revealed degradation of starving cell membranes and altered cytosols. Starving cells were subjected to the metabolic inhibitors fluoride, arsenite, 2,4-dinitrophenol, iodoacetate, and cyanide individually. Iodoacetate, which inhibits glyceraldehyde-3-phosphate dehydrogenase, completely reduced cultivable counts below the level of detection compared with the control starving cells; 2,4-dinitrophenol, which dissipates proton motive force, almost completely reduced cultivable counts. These results suggest that L. monocytogenes strains EGD-e, Scott A, F2365, and HCC23 are actively using part of the glycolysis pathway while starving. These results suggest that starving L. monocytogenes cells retain aspects of active metabolism.
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Affiliation(s)
| | | | - Elizabeth M Martin
- 2 Institute for Nanoscience and Engineering, University of Arkansas, Fayetteville, Arkansas 72704, USA
| | - Steven C Ricke
- 1 Department of Food Science and Center for Food Safety and
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Ding T, Suo Y, Zhang Z, Liu D, Ye X, Chen S, Zhao Y. A Multiplex RT-PCR Assay for S. aureus, L. monocytogenes, and Salmonella spp. Detection in Raw Milk with Pre-enrichment. Front Microbiol 2017; 8:989. [PMID: 28620364 PMCID: PMC5449760 DOI: 10.3389/fmicb.2017.00989] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2017] [Accepted: 05/16/2017] [Indexed: 11/13/2022] Open
Abstract
This study firstly developed a multiplex real-time PCR (RT-PCR) technique combined with a pre-enrichment step to simultaneously detect Staphylococcus aureus (S. aureus), Listeria monocytogenes (L. monocytogenes) and Salmonella spp. in raw milk and the dairy farm environment (feces, soil, feed, water) in one reaction. Brain heart infusion (BHI) broth was selected for the enrichment step to increase the density of the target bacteria by using an incubation of 4 h before multiplex RT-PCR. The results showed that the detection limit of the multiplex real-time assay was approximately 102 CFU/mL for pure cultures and artificially contaminated milk without enrichment, while 12, 14, and 10 CFU/25 mL, respectively, for S. aureus, L. monocytogenes, and Salmonella spp. after pre-enrichment. The newly developed multiplex RT-PCR assay was applied to 46 dairy farm environmental samples and raw milk samples covering a wide variety of sample types. The results demonstrated that the multiplex RT-PCR assay coupled with the BHI enrichment broth was suitable for the simultaneous screening of S. aureus, L. monocytogenes, and Salmonella spp. in the pasture environment and in raw milk. The multiplex RT-PCR assay clearly and successfully shortened the total detection time and reduced labor compared to conventional culture-based methods for testing natural samples.
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Affiliation(s)
- Tian Ding
- Department of Food Science and Nutrition, Zhejiang Key Laboratory for Agro-Food Processing, Zhejiang UniversityHangzhou, China
| | - Yuanjie Suo
- Department of Food Science and Nutrition, Zhejiang Key Laboratory for Agro-Food Processing, Zhejiang UniversityHangzhou, China
| | - Zhaohuan Zhang
- College of Food Science and Technology, Shanghai Ocean UniversityShanghai, China
| | - Donghong Liu
- Department of Food Science and Nutrition, Zhejiang Key Laboratory for Agro-Food Processing, Zhejiang UniversityHangzhou, China
| | - Xingqian Ye
- Department of Food Science and Nutrition, Zhejiang Key Laboratory for Agro-Food Processing, Zhejiang UniversityHangzhou, China
| | - Shiguo Chen
- Department of Food Science and Nutrition, Zhejiang Key Laboratory for Agro-Food Processing, Zhejiang UniversityHangzhou, China
| | - Yong Zhao
- College of Food Science and Technology, Shanghai Ocean UniversityShanghai, China
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Effects of varying concentrations of sodium chloride and acidic conditions on the behavior of Vibrio parahaemolyticus and Vibrio vulnificus cold-starved in artificial sea water microcosms. Food Sci Biotechnol 2017; 26:829-839. [PMID: 30263610 DOI: 10.1007/s10068-017-0105-3] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2016] [Revised: 02/28/2017] [Accepted: 03/01/2017] [Indexed: 12/19/2022] Open
Abstract
There has been limited information available on the behavior of Vibrio parahaemolyticus and Vibrio vulnificus as a function of higher levels of NaCl in combination with acidic pH. In the present study, bacterial suspensions were transferred into artificial seawater (pH 4-7) microcosms containing 0.75% NaCl and supplemented with 5, 10, and 30% NaCl, respectively. Each of V. parahaemolyticus and V. vulnificus was inoculated in these microcosms and fermented seafood, and then stored at 4 °C until the microbial populations reached below the detectable levels on agar plates (thiosulphate-citrate-bile salts-sucrose agar and tryptic soy agar amended with 3% NaCl). Consequently, V. parahaemolyticus ATCC 27969, V. parahaemolyticus ATCC 33844, and V. vulnificus ATCC 33815 rapidly reached the viable-but-nonculturable (VBNC) state with increasing levels (≤30%) of NaCl at 4 °C. Within seven days, these pathogens in seafood appeared to enter the VBNC state at 4 °C, as shown by the fluorescence microscopic assay.
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46
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Transcriptomic analysis on the formation of the viable putative non-culturable state of beer-spoilage Lactobacillus acetotolerans. Sci Rep 2016; 6:36753. [PMID: 27819317 PMCID: PMC5098190 DOI: 10.1038/srep36753] [Citation(s) in RCA: 62] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2016] [Accepted: 10/20/2016] [Indexed: 02/08/2023] Open
Abstract
Lactic acid bacteria (LAB) are the most common beer-spoilage bacteria regardless of beer type, and thus pose significant problems for the brewery industry. The aim of this study was to investigate the genetic mechanisms involved in the ability of the hard-to-culture beer-spoilage bacterium Lactobacillus acetotolerans to enter into the viable putative non-culturable (VPNC) state. A genome-wide transcriptional analysis of beer-spoilage L. acetotolerans strains BM-LA14526, BM-LA14527, and BM-LA14528 under normal, mid-term and VPNC states were performed using RNA-sequencing (RNA-seq) and further bioinformatics analyses. GO function, COG category, and KEGG pathway enrichment analysis were conducted to investigate functional and related metabolic pathways of the differentially expressed genes. Functional and pathway enrichment analysis indicated that heightened stress response and reduction in genes associated with transport, metabolic process, and enzyme activity might play important roles in the formation of the VPNC state. This is the first transcriptomic analysis on the formation of the VPNC state of beer spoilage L. acetotolerans.
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Deshmukh RA, Joshi K, Bhand S, Roy U. Recent developments in detection and enumeration of waterborne bacteria: a retrospective minireview. Microbiologyopen 2016; 5:901-922. [PMID: 27397728 PMCID: PMC5221461 DOI: 10.1002/mbo3.383] [Citation(s) in RCA: 51] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2015] [Revised: 04/20/2016] [Accepted: 05/02/2016] [Indexed: 12/17/2022] Open
Abstract
Waterborne diseases have emerged as global health problems and their rapid and sensitive detection in environmental water samples is of great importance. Bacterial identification and enumeration in water samples is significant as it helps to maintain safe drinking water for public consumption. Culture‐based methods are laborious, time‐consuming, and yield false‐positive results, whereas viable but nonculturable (VBNCs) microorganisms cannot be recovered. Hence, numerous methods have been developed for rapid detection and quantification of waterborne pathogenic bacteria in water. These rapid methods can be classified into nucleic acid‐based, immunology‐based, and biosensor‐based detection methods. This review summarizes the principle and current state of rapid methods for the monitoring and detection of waterborne bacterial pathogens. Rapid methods outlined are polymerase chain reaction (PCR), digital droplet PCR, real‐time PCR, multiplex PCR, DNA microarray, Next‐generation sequencing (pyrosequencing, Illumina technology and genomics), and fluorescence in situ hybridization that are categorized as nucleic acid‐based methods. Enzyme‐linked immunosorbent assay (ELISA) and immunofluorescence are classified into immunology‐based methods. Optical, electrochemical, and mass‐based biosensors are grouped into biosensor‐based methods. Overall, these methods are sensitive, specific, time‐effective, and important in prevention and diagnosis of waterborne bacterial diseases.
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Affiliation(s)
- Rehan A Deshmukh
- Department of Biological Sciences, Birla Institute of Technology and Science, Pilani-K.K. Birla Goa Campus, NH17B Bypass, Zuarinagar, Goa, 403726, India
| | - Kopal Joshi
- Department of Biological Sciences, Birla Institute of Technology and Science, Pilani-K.K. Birla Goa Campus, NH17B Bypass, Zuarinagar, Goa, 403726, India
| | - Sunil Bhand
- Biosensor Lab, Department of Chemistry, Birla Institute of Technology and Science, Pilani-K.K. Birla Goa Campus, NH17B Bypass, Zuarinagar, Goa, 403726, India
| | - Utpal Roy
- Department of Biological Sciences, Birla Institute of Technology and Science, Pilani-K.K. Birla Goa Campus, NH17B Bypass, Zuarinagar, Goa, 403726, India
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48
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Gurresch A, Gerner W, Pin C, Wagner M, Hein I. Evidence of metabolically active but non-culturable Listeria monocytogenes in long-term growth at 10 °C. Res Microbiol 2016; 167:334-343. [DOI: 10.1016/j.resmic.2016.01.003] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2015] [Revised: 11/16/2015] [Accepted: 01/11/2016] [Indexed: 10/22/2022]
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49
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A multi-parametric assessment of decontamination protocols for the subglacial Lake Ellsworth probe. J Microbiol Methods 2016; 123:87-93. [DOI: 10.1016/j.mimet.2016.02.012] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2015] [Revised: 02/12/2016] [Accepted: 02/13/2016] [Indexed: 11/18/2022]
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50
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Desneux J, Biscuit A, Picard S, Pourcher AM. Fate of Viable but Non-culturable Listeria monocytogenes in Pig Manure Microcosms. Front Microbiol 2016; 7:245. [PMID: 26973623 PMCID: PMC4773784 DOI: 10.3389/fmicb.2016.00245] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2015] [Accepted: 02/15/2016] [Indexed: 11/15/2022] Open
Abstract
The fate of two strains of Listeria monocytogenes and their ability to become viable but non-culturable (VBNC) was investigated in microcosms containing piggery effluents (two raw manures and two biologically treated manures) stored for 2 months at 8 and 20°C. Levels of L. monocytogenes were estimated using the culture method, qPCR, and propidium monoazide treatment combined with qPCR (qPCRPMA). The chemical composition and the microbial community structure of the manures were also analyzed. The strains showed similar decline rates and persisted up to 63 days. At day zero, the percentage of VBNC cells among viable cells was higher in raw manures (81.5-94.8%) than in treated manures (67.8-79.2%). The changes in their proportion over time depended on the temperature and on the type of effluent: the biggest increase was observed in treated manures at 20°C and the smallest increase in raw manures at 8°C. The chemical parameters had no influence on the behavior of the strains, but decrease of the persistence of viable cells was associated with an increase in the microbial richness of the manures. This study demonstrated that storing manure altered the culturability of L. monocytogenes, which rapidly entered the VBNC state, and underlines the importance of including VBNC cells when estimating the persistence of the pathogens in farm effluents.
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Affiliation(s)
- Jérémy Desneux
- Irstea-RennesRennes, France
- Université Européenne de BretagneRennes, France
| | - Audrey Biscuit
- Irstea-RennesRennes, France
- Université Européenne de BretagneRennes, France
| | - Sylvie Picard
- Irstea-RennesRennes, France
- Université Européenne de BretagneRennes, France
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