1
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Hong H, Choi J, Kim HJ, Park SH. Microbial Pathogenesis Stress Resistance Insights of 65 Listeria Strains: Acidic, Low Temperature, and High Salt Environments. Microb Pathog 2024:106793. [PMID: 39004154 DOI: 10.1016/j.micpath.2024.106793] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2024] [Revised: 07/10/2024] [Accepted: 07/12/2024] [Indexed: 07/16/2024]
Abstract
Genetically, Listeria monocytogenes is closely related to non-L. monocytogenes (L. innocua, L. welshimeri, L. grayi, L. aquatica, and L. fleischimannii). This bacterium is well known for its resistance to harsh conditions including acidity, low temperatures, and high salt concentrations. This study explored the responses of 65 Listeria strains to stress conditions and characterized the prevalence of stress-related genes. The 65 Listeria strains were isolated from different environments and their viability was assessed in four different tests: independent tests for pH 3, 1 °C, and 5% salt concentration and multiple resistance tests that combined pH 3, 1 °C, 5% salt. From the data, the 65 strains were categorized into stress-resistant (56) or stress-sensitive groups (9), with approximately 4 log CFU/mL differences. The PCR assay analyzed the prevalence of two virulence genes prfA and inlA, and eight stress-related genes: three acid (gadB, gadC, and atpD), two low temperature (betL and opuCA) and three salt resistance genes (flaA, cysS, and fbp). Two low temperature (bet and opuCA) and salt resistance (fbp) genes were more prevalent in the stress-resistant strains than in the stress-sensitive Listeria group.
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Affiliation(s)
- Hyunhee Hong
- Department of Food Science and Technology, Oregon State University, Corvallis, OR, USA
| | - Jungmin Choi
- Department of Food Science and Technology, Oregon State University, Corvallis, OR, USA
| | - Hyun Jung Kim
- Korea Food Research Institute, Wanju-gun, Jeollabuk-do, Republic of Korea
| | - Si Hong Park
- Department of Food Science and Technology, Oregon State University, Corvallis, OR, USA.
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2
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Liang Q, Huang W, Xiao T, Zhang L, Lei G, Lv H, Yang X. Characteristics of Clinical Isolates of Listeria monocytogenes in Sichuan, China, in 2022 Based on Whole Genome Sequencing Analysis. Foodborne Pathog Dis 2024; 21:424-430. [PMID: 38597599 DOI: 10.1089/fpd.2023.0173] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/11/2024] Open
Abstract
Listeria monocytogenes is a foodborne pathogen. In 2022, we collected 15 strains of L. monocytogenes isolated from patients in some foodborne disease sentinel monitoring hospitals in Sichuan Province. Through whole genome sequencing (WGS), we obtained the virulence genes carried by the strains, multi-locus sequence typing (MLST), core genome MLST (cgMLST), clonal complex (CC), and serum groups and constructed a phylogenetic tree and minimum spanning tree with nonhuman strains. An analysis shows that all 15 strains of L. monocytogenes carry virulence genes LIPI-1 and LIPI-2, whereas the carrying rates of LIPI-3 and LIPI-4 virulence genes are relatively low. The MLST typing results showed a total of 10 sequence types (ST), including 10 CCs, with ST7 being the dominant type. The cgMLST clearly distinguishes strains of different lineages and CC types. The serum group is divided into three types: IIa, IIb, and IVb, with IIa being the dominant serum group. An analysis of antibiotic genes showed that all 15 strains carried FosX, lin, mprF, and norB with high carrying rates. The minimum inhibitory concentration results indicated that all were susceptible to eight antibiotics (ampicillin, penicillin, tetracycline, meropenem, erythromycin, vancomycin, ciprofloxacin, and trimethoprim-sulfamethoxazole). The analysis of strains isolated from different sources of Listeria revealed varying degrees of diversity, and the contamination of meat and environment within the province is closely related to clinical cases. L. monocytogenes isolated from clinical cases in Sichuan Province carry multiple virulence and antibiotic genes, with high potential pathogenicity. It is necessary to further strengthen the monitoring and control of food and environment by L. monocytogenes within Sichuan Province.
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Affiliation(s)
- Qian Liang
- Center for Disease Control and Prevention of Sichuan Province, Chengdu, China
| | - Weifeng Huang
- Center for Disease Control and Prevention of Sichuan Province, Chengdu, China
| | - Tao Xiao
- Center for Disease Control and Prevention of Sichuan Province, Chengdu, China
| | - Lin Zhang
- Center for Disease Control and Prevention of Sichuan Province, Chengdu, China
| | - Gaopeng Lei
- Center for Disease Control and Prevention of Sichuan Province, Chengdu, China
| | - Hong Lv
- Center for Disease Control and Prevention of Sichuan Province, Chengdu, China
| | - Xiaorong Yang
- Center for Disease Control and Prevention of Sichuan Province, Chengdu, China
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3
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Alejandro-Navarreto X, Freitag NE. Revisiting old friends: updates on the role of two-component signaling systems in Listeria monocytogenes survival and pathogenesis. Infect Immun 2024; 92:e0034523. [PMID: 38591895 PMCID: PMC11003226 DOI: 10.1128/iai.00345-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/10/2024] Open
Abstract
Listeria monocytogenes is well recognized for both its broad resistance to stress conditions and its ability to transition from a soil bacterium to an intracellular pathogen of mammalian hosts. The bacterium's impressive ability to adapt to changing environments and conditions requires the rapid sensing of environmental cues and the coordinated response of gene products that enable bacterial growth and survival. Two-component signaling systems (TCSs) have been long recognized for their ability to detect environmental stimuli and transmit those signals into transcriptional responses; however, often the precise nature of the stimulus triggering TCS responses can be challenging to define. L. monocytogenes has up to 16 TCSs that have been recognized based on homology and included in this list are several whose functions remain poorly described. This review highlights the current understanding of the breadth and scope of L. monocytogenes TCS as relates to stress resistance and pathogenesis. Precise signals still often remain elusive, but the gene networks associated with TCSs are providing clues into possible functions.
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Affiliation(s)
| | - Nancy E. Freitag
- Department of Microbiology and Immunology, University of Illinois at Chicago, Chicago, Illinois, USA
- Department of Pharmaceutical Sciences, University of Illinois at Chicago, Chicago, Illinois, USA
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4
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Zhou G, Dong P, Luo X, Zhu L, Mao Y, Liu Y, Zhang Y. Combined effects of cold and acid on dual-species biofilms of Pseudomonas fluorescens and Listeria monocytogenes under simulated chilled beef processing conditions. Food Microbiol 2024; 117:104394. [PMID: 37919003 DOI: 10.1016/j.fm.2023.104394] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2023] [Revised: 09/21/2023] [Accepted: 10/02/2023] [Indexed: 11/04/2023]
Abstract
Interactions across bacterial species boundaries are usually influenced by environmental stresses, yet little has been evaluated regarding multifactorial stresses on the fate of dual-species biofilm formation in food industry. In this study, the processing conditions of chilled beef were established as a combination of cold and acid stresses (4 °C and pH 5.4), with pH 7.0 or 25 °C serving as the controls, to investigate the interaction of dual-species biofilm between Pseudomonas fluorescens and Listeria monocytogenes. Dual-species biofilms significantly increased biofilm formation at 72 h under the condition of 25°C-pH7.0 and 25°C-pH5.4 (P < 0.05). Compared with mono-species biofilms, the cell numbers of L. monocytogenes in dual-species biofilms were lower at 25 °C (P < 0.05), however, the adherent cells of L. monocytogenes was higher in dual-species biofilms at 4 °C (P < 0.05). Furthermore, the amount of extracellular polysaccharides and proteins secreted by single P. fluorescens biofilms at 4 °C was more than three times than those at 25 °C. The surface-enhanced Raman spectroscopy further profiled the variability of extracellular polymeric substances (EPS) composition. Additionally, RT-qPCR results revealed an upregulation of biofilm-related and genes in co-culture species. It provides valuable insights into the strategies for removing mixed biofilms under diverse stressful conditions in practical food processing.
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Affiliation(s)
- Guanghui Zhou
- College of Food Science and Engineering, Shandong Agricultural University, Tai'an, Shandong, 271018, China; National R&D Center for Beef Processing Technology, Tai'an, Shandong, 271018, China
| | - Pengcheng Dong
- College of Food Science and Engineering, Shandong Agricultural University, Tai'an, Shandong, 271018, China; National R&D Center for Beef Processing Technology, Tai'an, Shandong, 271018, China
| | - Xin Luo
- College of Food Science and Engineering, Shandong Agricultural University, Tai'an, Shandong, 271018, China; National R&D Center for Beef Processing Technology, Tai'an, Shandong, 271018, China
| | - Lixian Zhu
- College of Food Science and Engineering, Shandong Agricultural University, Tai'an, Shandong, 271018, China; National R&D Center for Beef Processing Technology, Tai'an, Shandong, 271018, China
| | - Yanwei Mao
- College of Food Science and Engineering, Shandong Agricultural University, Tai'an, Shandong, 271018, China; National R&D Center for Beef Processing Technology, Tai'an, Shandong, 271018, China
| | - Yunge Liu
- College of Food Science and Engineering, Shandong Agricultural University, Tai'an, Shandong, 271018, China; National R&D Center for Beef Processing Technology, Tai'an, Shandong, 271018, China.
| | - Yimin Zhang
- College of Food Science and Engineering, Shandong Agricultural University, Tai'an, Shandong, 271018, China; National R&D Center for Beef Processing Technology, Tai'an, Shandong, 271018, China.
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5
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Ekonomou SI, Boziaris IS. Fate of osmotically adapted and biofilm Listeria monocytogenes cells after exposure to salt, heat, and liquid smoke, mimicking the stresses induced during the processing of hot smoked fish. Food Microbiol 2024; 117:104392. [PMID: 37919014 DOI: 10.1016/j.fm.2023.104392] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2023] [Revised: 09/16/2023] [Accepted: 09/24/2023] [Indexed: 11/04/2023]
Abstract
The study aimed to investigate the response of osmotically adapted and detached biofilm Listeria monocytogenes cells following sequential stresses that occur during the processing of hot smoking, such as heating and smoke application. Thermal resistance of L. monocytogenes was significantly affected by previous osmotic adaptation of the cells. D60oC-values of osmotically adapted L. monocytogenes cells were significantly higher than control cells. The osmotically adapted and subsequently heat-injured cells were more resistant to PALCAM and less resistant to TSAYE with 5.00% NaCl (TSAYE/NaCl) than control cells. Detached biofilm cells were more thermotolerant and less resistant to PALCAM and TSAYE/NaCl than control cells. The sequential effect of smoking against heat-treated (60 °C, 20 min) and osmotically adapted or detached L. monocytogenes biofilm cells was investigated using two liquid smoke extracts (L9 and G6). L9 led to significantly higher reductions (>3.00-Log CFU) compared to G6. The heat-treated, detached biofilm cells revealed resistance to L9, presumably due to metabolic downregulation and physical protection by the extracellular polymeric substances (EPS). These data highlight the potential of the food industry to make informed decisions for using safe heat treatments during hot smoking to effectively inactivate L. monocytogenes and maintain rigorous environmental sanitation practices to control biofilm cells.
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Affiliation(s)
- S I Ekonomou
- Laboratory of Marketing and Technology of Aquatic Products and Foods, Department of Ichthyology and Aquatic Environment, School of Agricultural Sciences, University of Thessaly, Fytokou Street, 38446, Volos, Greece
| | - I S Boziaris
- Laboratory of Marketing and Technology of Aquatic Products and Foods, Department of Ichthyology and Aquatic Environment, School of Agricultural Sciences, University of Thessaly, Fytokou Street, 38446, Volos, Greece.
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Wiśniewski P, Chajęcka-Wierzchowska W, Zadernowska A. Impact of High-Pressure Processing (HPP) on Listeria monocytogenes-An Overview of Challenges and Responses. Foods 2023; 13:14. [PMID: 38201041 PMCID: PMC10778341 DOI: 10.3390/foods13010014] [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: 12/03/2023] [Revised: 12/12/2023] [Accepted: 12/18/2023] [Indexed: 01/12/2024] Open
Abstract
High-pressure processing (HPP) is currently one of the leading methods of non-thermal food preservation as an alternative to traditional methods based on thermal processing. The application of HPP involves the simultaneous action of a combination of several factors-pressure values (100-600 MPa), time of operation (a few-several minutes), and temperature of operation (room temperature or lower)-using a liquid medium responsible for pressure transfer. The combination of these three factors results in the inactivation of microorganisms, thus extending food shelf life and improving the food's microbiological safety. HPP can provide high value for the sensory and quality characteristics of products and reduce the population of pathogenic microorganisms such as L. monocytogenes to the required safety level. Nevertheless, the technology is not without impact on the cellular response of pathogens. L. monocytogenes cells surviving the HPP treatment may have multiple damages, which may impact the activation of mechanisms involved in the repair of cellular damage, increased virulence, or antibiotic resistance, as well as an increased expression of genes encoding pathogenicity and antibiotic resistance. This review has demonstrated that HPP is a technology that can reduce L. monocytogenes cells to below detection levels, thus indicating the potential to provide the desired level of safety. However, problems have been noted related to the possibilities of cell recovery during storage and changes in virulence and antibiotic resistance due to the activation of gene expression mechanisms, and the lack of a sufficient number of studies explaining these changes has been reported.
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Affiliation(s)
- Patryk Wiśniewski
- Department of Food Microbiology, Meat Technology and Chemistry, Faculty of Food Science, University of Warmia and Mazury, Plac Cieszyński 1, 10-726 Olsztyn, Poland; (W.C.-W.); (A.Z.)
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7
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Byun KH, Kim HJ. Survival strategies of Listeria monocytogenes to environmental hostile stress: biofilm formation and stress responses. Food Sci Biotechnol 2023; 32:1631-1651. [PMID: 37780599 PMCID: PMC10533466 DOI: 10.1007/s10068-023-01427-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2023] [Revised: 08/29/2023] [Accepted: 08/31/2023] [Indexed: 10/03/2023] Open
Abstract
Listeria monocytogenes is a critical foodborne pathogen that causes listeriosis and threatens public health. This pathogenic microorganism forms a transmission cycle in nature, food industry, and humans, expanding the areas of contamination among them and influencing food safety. L. monocytogenes forms biofilms to protect itself and promotes survival through stress responses to the various stresses (e.g., temperature, pH, and antimicrobial agents) that may be inflicted during food processing. Biofilms and mechanisms of resistance to hostile external or general stresses allow L. monocytogenes to survive despite a variety of efforts to ensure food safety. The current review article focuses on biofilm formation, resistance mechanisms through biofilms, and external specific or general stress responses of L. monocytogenes to help understand the unexpected survival rates of this bacterium; it also proposes the use of obstacle technology to effectively cope with it in the food industry.
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Affiliation(s)
- Kye-Hwan Byun
- Food Safety and Distribution Research Group, Korea Food Research Institute, Jeollabuk-Do, Wanju, 55365 Republic of Korea
| | - Hyun Jung Kim
- Food Safety and Distribution Research Group, Korea Food Research Institute, Jeollabuk-Do, Wanju, 55365 Republic of Korea
- Department of Food Biotechnology, University of Science and Technology, Daejeon, 34113 Republic of Korea
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8
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Liao J, Guo X, Li S, Anupoju SMB, Cheng RA, Weller DL, Sullivan G, Zhang H, Deng X, Wiedmann M. Comparative genomics unveils extensive genomic variation between populations of Listeria species in natural and food-associated environments. ISME COMMUNICATIONS 2023; 3:85. [PMID: 37598265 PMCID: PMC10439904 DOI: 10.1038/s43705-023-00293-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/12/2023] [Revised: 08/02/2023] [Accepted: 08/04/2023] [Indexed: 08/21/2023]
Abstract
Comprehending bacterial genomic variation linked to distinct environments can yield novel insights into mechanisms underlying differential adaptation and transmission of microbes across environments. Gaining such insights is particularly crucial for pathogens as it benefits public health surveillance. However, the understanding of bacterial genomic variation is limited by a scarcity of investigations in genomic variation coupled with different ecological contexts. To address this limitation, we focused on Listeria, an important bacterial genus for food safety that includes the human pathogen L. monocytogenes, and analyzed a large-scale genomic dataset collected by us from natural and food-associated environments across the United States. Through comparative genomics analyses on 449 isolates from the soil and 390 isolates from agricultural water and produce processing facilities representing L. monocytogenes, L. seeligeri, L. innocua, and L. welshimeri, we find that the genomic profiles strongly differ by environments within each species. This is supported by the environment-associated subclades and differential presence of plasmids, stress islands, and accessory genes involved in cell envelope biogenesis and carbohydrate transport and metabolism. Core genomes of Listeria species are also strongly associated with environments and can accurately predict isolation sources at the lineage level in L. monocytogenes using machine learning. We find that the large environment-associated genomic variation in Listeria appears to be jointly driven by soil property, climate, land use, and accompanying bacterial species, chiefly representing Actinobacteria and Proteobacteria. Collectively, our data suggest that populations of Listeria species have genetically adapted to different environments, which may limit their transmission from natural to food-associated environments.
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Affiliation(s)
- Jingqiu Liao
- Department of Food Science, Cornell University, Ithaca, NY, USA.
- Department of Civil and Environmental Engineering, Virginia Tech, Blacksburg, VA, USA.
| | - Xiaodong Guo
- Department of Food Science, Cornell University, Ithaca, NY, USA
| | - Shaoting Li
- School of Biomedical and Pharmaceutical Sciences, Guangdong University of Technology, Guangzhou, Guangdong, China
| | | | - Rachel A Cheng
- Department of Food Science and Technology, Virginia Tech, Blacksburg, VA, USA
| | - Daniel L Weller
- Department of Food Science and Technology, Virginia Tech, Blacksburg, VA, USA
- Department of Biostatistics and Computational Biology, University of Rochester Medical Center, Rochester, NY, USA
| | | | - Hailong Zhang
- Department of Business Information Technology, Virginia Tech, Blacksburg, VA, USA
| | - Xiangyu Deng
- Center for Food Safety, University of Georgia, Griffin, GA, USA
| | - Martin Wiedmann
- Department of Food Science, Cornell University, Ithaca, NY, USA
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9
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Poimenidou SV, Caccia N, Paramithiotis S, Hébraud M, Nychas GJ, Skandamis PN. Influence of temperature on regulation of key virulence and stress response genes in Listeria monocytogenes biofilms. Food Microbiol 2023; 111:104190. [PMID: 36681396 DOI: 10.1016/j.fm.2022.104190] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2022] [Revised: 10/19/2022] [Accepted: 11/21/2022] [Indexed: 11/24/2022]
Abstract
Temperature is a major determinant of Listeria (L.) monocytogenes adherence and biofilm formation on abiotic surfaces. However, its role on gene regulation of L. monocytogenes mature biofilms has not been investigated. In the present study, we aimed to evaluate the impact of temperature up- and down-shift on L. monocytogenes biofilms gene transcription. L. monocytogenes strain EGD-e biofilms were first developed on stainless steel surfaces in Brain Heart Infusion broth at 20 °C for 48 h. Then, nutrient broth was renewed, and mature biofilms were exposed to 10 °C, 20 °C or 37 °C for 24 h. Biofilm cells were harvested and RNA levels of plcA, prfA, hly, mpl, plcB, sigB, bapL, fbpA, fbpB, lmo2178, lmo0880, lmo0160, lmo1115, lmo 2089, lmo2576, lmo0159 and lmo0627 were evaluated by quantitative RT-PCR. The results revealed an over-expression of all genes tested in biofilm cells compared to planktonic cells. When biofilms were further allowed to proliferate at 20 °C for 24 h, the transcription levels of key virulence, stress response and putative binding proteins genes plcA, sigB, fbpA, fbpB, lmo1115, lmo0880 and lmo2089 decreased. A temperature-dependent transcription for sigB, plcA, hly, and lmo2089 genes was observed after biofilm proliferation at 10 °C or 37 °C. Our findings suggest that temperature differentially affects gene regulation of L. monocytogenes mature biofilms, thus modulating attributes such as virulence, stress response and pathogenesis.
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Affiliation(s)
- Sofia V Poimenidou
- Agricultural University of Athens, Department of Food Science and Human Nutrition, Laboratory of Food Quality Control and Hygiene. Iera Odos 75, 11855, Athens, Greece
| | - Nelly Caccia
- University Clermont Auvergne (UCA), Institut National de Recherche pour L'Agriculture, L'alimentation et L'environnement (INRAE), UMR Microbiologie, Environnement Digestif et Santé (MEDiS), Site de Theix, F-63122 Saint-Genès Champanelle, France
| | - Spiros Paramithiotis
- Agricultural University of Athens, Department of Food Science and Human Nutrition, Laboratory of Food Quality Control and Hygiene. Iera Odos 75, 11855, Athens, Greece; Agricultural University of Athens, Department of Food Science and Human Nutrition, Laboratory of Food Process Engineering. Iera Odos 75, 11855, Athens, Greece
| | - Michel Hébraud
- University Clermont Auvergne (UCA), Institut National de Recherche pour L'Agriculture, L'alimentation et L'environnement (INRAE), UMR Microbiologie, Environnement Digestif et Santé (MEDiS), Site de Theix, F-63122 Saint-Genès Champanelle, France
| | - George-John Nychas
- Agricultural University of Athens, Department of Food Science and Human Nutrition, Laboratory of Food Microbiology and Biotechnology. Iera Odos 75, 11855, Athens, Greece
| | - Panagiotis N Skandamis
- Agricultural University of Athens, Department of Food Science and Human Nutrition, Laboratory of Food Quality Control and Hygiene. Iera Odos 75, 11855, Athens, Greece.
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Oliveira AH, Tiensuu T, Guerreiro D, Tükenmez H, Dessaux C, García-Del Portillo F, O'Byrne C, Johansson J. The Virulence and Infectivity of Listeria monocytogenes Are Not Substantially Altered by Elevated SigB Activity. Infect Immun 2023:e0057122. [PMID: 37125941 DOI: 10.1128/iai.00571-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/02/2023] Open
Abstract
Listeria monocytogenes is a bacterial pathogen capable of causing severe infections but also thriving outside the host. To respond to different stress conditions, L. monocytogenes mainly utilizes the general stress response regulon, which largely is controlled by the alternative sigma factor Sigma B (SigB). In addition, SigB is important for virulence gene expression and infectivity. Upon encountering stress, a large multicomponent protein complex known as the stressosome becomes activated, ultimately leading to SigB activation. RsbX is a protein needed to reset a "stressed" stressosome and prevent unnecessary SigB activation in nonstressed conditions. Consequently, absence of RsbX leads to constitutive activation of SigB even without prevailing stress stimulus. To further examine the involvement of SigB in the virulence of this pathogen, we investigated whether a strain with constitutively active SigB would be affected in virulence factor expression and/or infectivity in cultured cells and in a chicken embryo infection model. Our results suggest that increased SigB activity does not substantially alter virulence gene expression compared with the wild-type (WT) strain at transcript and protein levels. Bacteria lacking RsbX were taken up by phagocytic and nonphagocytic cells at a similar frequency to WT bacteria, both in stressed and nonstressed conditions. Finally, the absence of RsbX only marginally affected the ability of bacteria to infect chicken embryos. Our results suggest only a minor role of RsbX in controlling virulence factor expression and infectivity under these conditions.
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Affiliation(s)
- Ana H Oliveira
- Laboratory for Molecular Infection Medicine Sweden, Umeå University, Umeå, Sweden
- Department of Molecular Biology, Umeå University, Umeå, Sweden
- Umeå Centre of Microbial Research, Umeå University, Umeå, Sweden
| | - Teresa Tiensuu
- Laboratory for Molecular Infection Medicine Sweden, Umeå University, Umeå, Sweden
- Department of Molecular Biology, Umeå University, Umeå, Sweden
- Umeå Centre of Microbial Research, Umeå University, Umeå, Sweden
| | - Duarte Guerreiro
- Laboratory for Molecular Infection Medicine Sweden, Umeå University, Umeå, Sweden
- Department of Molecular Biology, Umeå University, Umeå, Sweden
- Umeå Centre of Microbial Research, Umeå University, Umeå, Sweden
- Bacterial Stress Response Group, Microbiology, School of Biological and Chemical Sciences, University of Galway, Galway, Ireland
| | - Hasan Tükenmez
- Laboratory for Molecular Infection Medicine Sweden, Umeå University, Umeå, Sweden
- Department of Molecular Biology, Umeå University, Umeå, Sweden
- Umeå Centre of Microbial Research, Umeå University, Umeå, Sweden
- Department of Chemistry, Umeå University, Umeå, Sweden
| | - Charlotte Dessaux
- Laboratory of Intracellular Bacterial Pathogens, National Center of Biotechnology, (CNB)-CSIC, Madrid, Spain
| | | | - Conor O'Byrne
- Bacterial Stress Response Group, Microbiology, School of Biological and Chemical Sciences, University of Galway, Galway, Ireland
| | - Jörgen Johansson
- Laboratory for Molecular Infection Medicine Sweden, Umeå University, Umeå, Sweden
- Department of Molecular Biology, Umeå University, Umeå, Sweden
- Umeå Centre of Microbial Research, Umeå University, Umeå, Sweden
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11
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Hanes R, Zhang F, Huang Z. Protein Interaction Network Analysis to Investigate Stress Response, Virulence, and Antibiotic Resistance Mechanisms in Listeria monocytogenes. Microorganisms 2023; 11:microorganisms11040930. [PMID: 37110353 PMCID: PMC10144942 DOI: 10.3390/microorganisms11040930] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2023] [Revised: 03/29/2023] [Accepted: 03/31/2023] [Indexed: 04/05/2023] Open
Abstract
Listeria monocytogenes is a deadly and costly foodborne pathogen that has a high fatality rate in the elderly, pregnant women, and people with weakened immunity. It can survive under various stress conditions and is a significant concern for the food industry. In this work, a data analysis approach was developed with existing tools and databases and used to create individual and combined protein interaction networks to study stress response, virulence, and antimicrobial resistance and their interaction with L. monocytogenes. The networks were analyzed, and 28 key proteins were identified that may serve as potential targets for new strategies to combat L. monocytogenes. Five of the twenty-eight proteins (i.e., sigB, flaA, cheA, cheY, and lmo0693) represent the most promising targets because they are highly interconnected within the combined network. The results of this study provide a new set of targets for future work to identify new strategies to improve food preservation methods and treatments for L. monocytogenes.
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Affiliation(s)
- Robert Hanes
- Department of Chemical Engineering, Villanova University, Villanova, PA 19085, USA
| | - Fangyuan Zhang
- Department of Chemical Engineering, Villanova University, Villanova, PA 19085, USA
| | - Zuyi Huang
- Department of Chemical Engineering, Villanova University, Villanova, PA 19085, USA
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12
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Tran BM, Linnik DS, Punter CM, Śmigiel WM, Mantovanelli L, Iyer A, O’Byrne C, Abee T, Johansson J, Poolman B. Super-resolving microscopy reveals the localizations and movement dynamics of stressosome proteins in Listeria monocytogenes. Commun Biol 2023; 6:51. [PMID: 36641529 PMCID: PMC9840623 DOI: 10.1038/s42003-023-04423-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2022] [Accepted: 01/04/2023] [Indexed: 01/15/2023] Open
Abstract
The human pathogen Listeria monocytogenes can cope with severe environmental challenges, for which the high molecular weight stressosome complex acts as the sensing hub in a complicated signal transduction pathway. Here, we show the dynamics and functional roles of the stressosome protein RsbR1 and its paralogue, the blue-light receptor RsbL, using photo-activated localization microscopy combined with single-particle tracking and single-molecule displacement mapping and supported by physiological studies. In live cells, RsbR1 is present in multiple states: in protomers with RsbS, large clusters of stressosome complexes, and in connection with the plasma membrane via Prli42. RsbL diffuses freely in the cytoplasm but forms clusters upon exposure to light. The clustering of RsbL is independent of the presence of Prli42. Our work provides a comprehensive view of the spatial organization and intracellular dynamics of the stressosome proteins in L. monocytogenes, which paves the way towards uncovering the stress-sensing mechanism of this signal transduction pathway.
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Affiliation(s)
- Buu Minh Tran
- grid.4830.f0000 0004 0407 1981Department of Biochemistry, University of Groningen, Groningen, the Netherlands
| | - Dmitrii Sergeevich Linnik
- grid.4830.f0000 0004 0407 1981Department of Biochemistry, University of Groningen, Groningen, the Netherlands
| | - Christiaan Michiel Punter
- grid.4830.f0000 0004 0407 1981Department of Biochemistry, University of Groningen, Groningen, the Netherlands
| | - Wojciech Mikołaj Śmigiel
- grid.4830.f0000 0004 0407 1981Department of Biochemistry, University of Groningen, Groningen, the Netherlands
| | - Luca Mantovanelli
- grid.4830.f0000 0004 0407 1981Department of Biochemistry, University of Groningen, Groningen, the Netherlands
| | - Aditya Iyer
- grid.4830.f0000 0004 0407 1981Department of Biochemistry, University of Groningen, Groningen, the Netherlands
| | - Conor O’Byrne
- Microbiology, School of Biological & Chemical Sciences, Ryan Institute, University of Galway, Galway, Ireland
| | - Tjakko Abee
- grid.4818.50000 0001 0791 5666Laboratory of Food Microbiology, Wageningen University & Research, Wageningen, the Netherlands
| | - Jörgen Johansson
- grid.12650.300000 0001 1034 3451Department of Molecular Biology, Umeå University, Umeå, Sweden
| | - Bert Poolman
- grid.4830.f0000 0004 0407 1981Department of Biochemistry, University of Groningen, Groningen, the Netherlands
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13
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Deciphering the induction of Listeria monocytogenes into sublethal injury using fluorescence microscopy and RT-qPCR. Int J Food Microbiol 2023; 385:109983. [DOI: 10.1016/j.ijfoodmicro.2022.109983] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2022] [Revised: 10/16/2022] [Accepted: 10/17/2022] [Indexed: 11/22/2022]
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14
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Muchaamba F, von Ah U, Stephan R, Stevens MJA, Tasara T. Deciphering the global roles of Cold shock proteins in Listeria monocytogenes nutrient metabolism and stress tolerance. Front Microbiol 2022; 13:1057754. [PMID: 36605504 PMCID: PMC9808409 DOI: 10.3389/fmicb.2022.1057754] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2022] [Accepted: 11/23/2022] [Indexed: 12/24/2022] Open
Abstract
Listeria monocytogenes (Lm) accounts for serious public health and food safety problems owing to its stress resilience and pathogenicity. Based on their regulatory involvement in global gene expression events, cold-shock domain family proteins (Csps) are crucial in expression of various stress fitness and virulence phenotypes in bacteria. Lm possesses three Csps (CspA, CspB, and CspD) whose regulatory roles in the context of the genetic diversity of this bacterium are not yet fully understood. We examined the impacts of Csps deficiency on Lm nutrient metabolism and stress tolerance using a set of csp deletion mutants generated in different genetic backgrounds. Phenotype microarrays (PM) analysis showed that the absence of Csps in ∆cspABD reduces carbon (C-) source utilization capacity and increases Lm sensitivity to osmotic, pH, various chemical, and antimicrobial stress conditions. Single and double csp deletion mutants in different Lm genetic backgrounds were used to further dissect the roles of individual Csps in these phenotypes. Selected PM-based observations were further corroborated through targeted phenotypic assays, confirming that Csps are crucial in Lm for optimal utilization of various C-sources including rhamnose and glucose as well as tolerance against NaCl, β-phenyethylamine (PEA), and food relevant detergent stress conditions. Strain and genetic lineage background-based differences, division of labour, epistasis, and functional redundancies among the Csps were uncovered with respect to their roles in various processes including C-source utilization, cold, and PEA stress resistance. Finally, targeted transcriptome analysis was performed, revealing the activation of csp gene expression under defined stress conditions and the impact of Csps on expression regulation of selected rhamnose utilization genes. Overall, our study shows that Csps play important roles in nutrient utilization and stress responses in Lm strains, contributing to traits that are central to the public health and food safety impacts of this pathogen.
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Affiliation(s)
- Francis Muchaamba
- Institute for Food Safety and Hygiene, Vetsuisse Faculty, University of Zurich, Zurich, Switzerland,*Correspondence: Francis Muchaamba,
| | | | - Roger Stephan
- Institute for Food Safety and Hygiene, Vetsuisse Faculty, University of Zurich, Zurich, Switzerland
| | - Marc J. A. Stevens
- Institute for Food Safety and Hygiene, Vetsuisse Faculty, University of Zurich, Zurich, Switzerland
| | - Taurai Tasara
- Institute for Food Safety and Hygiene, Vetsuisse Faculty, University of Zurich, Zurich, Switzerland
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15
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Abdelhamed H, Ramachandran R, Narayanan L, Islam S, Ozan O, Freitag N, Lawrence ML. Role of FruR transcriptional regulator in virulence of Listeria monocytogenes and identification of its regulon. PLoS One 2022; 17:e0274005. [PMID: 36054213 PMCID: PMC9439231 DOI: 10.1371/journal.pone.0274005] [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: 05/04/2022] [Accepted: 08/19/2022] [Indexed: 11/29/2022] Open
Abstract
Listeria monocytogenes is a ubiquitous opportunistic foodborne pathogen capable of survival in various adverse environmental conditions. Pathogenesis of L. monocytogenes is tightly controlled by a complex regulatory network of transcriptional regulators that are necessary for survival and adaptations to harsh environmental conditions both inside and outside host cells. Among these regulatory pathways are members of the DeoR-family transcriptional regulators that are known to play a regulatory role in sugar metabolism. In this study, we deciphered the role of FruR, a DeoR family protein, which is a fructose operon transcriptional repressor protein, in L. monocytogenes pathogenesis and growth. Following intravenous (IV) inoculation in mice, a mutant strain with deletion of fruR exhibited a significant reduction in bacterial burden in liver and spleen tissues compared to the parent strain. Further, the ΔfruR strain had a defect in cell-to-cell spread in L2 fibroblast monolayers. Constitutive activation of PrfA, a pleiotropic activator of L. monocytogenes virulence factors, did not restore virulence to the ΔfruR strain, suggesting that the attenuation was not a result of impaired PrfA activation. Transcriptome analysis revealed that FruR functions as a positive regulator for genes encoding enzymes involved in the pentose phosphate pathway (PPP) and as a repressor for genes encoding enzymes in the glycolysis pathway. These results suggested that FruR may function to facilitate NADPH regeneration, which is necessary for full protection from oxidative stress. Interestingly, deletion of fruR increased sensitivity of L. monocytogenes to H2O2, confirming a role for FruR in survival of L. monocytogenes during oxidative stress. Using anti-mouse neutrophil/monocyte monoclonal antibody RB6-8C5 (RB6) in an in vivo infection model, we found that FruR has a specific function in protecting L. monocytogenes from neutrophil/monocyte-mediated killing. Overall, this work clarifies the role of FruR in controlling L. monocytogenes carbon flow between glycolysis and PPP for NADPH homeostasis, which provides a new mechanism allowing metabolic adaptation of L. monocytogenes to oxidative stress.
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Affiliation(s)
- Hossam Abdelhamed
- Department of Comparative Biomedical Sciences, College of Veterinary Medicine, Mississippi State University, Starkville, MS, United States of America
- * E-mail:
| | - Reshma Ramachandran
- Department of Comparative Biomedical Sciences, College of Veterinary Medicine, Mississippi State University, Starkville, MS, United States of America
- Department of Poultry Science, Mississippi State University, Starkville, MS, United States of America
| | - Lakshmi Narayanan
- Department of Comparative Biomedical Sciences, College of Veterinary Medicine, Mississippi State University, Starkville, MS, United States of America
| | - Shamima Islam
- Department of Comparative Biomedical Sciences, College of Veterinary Medicine, Mississippi State University, Starkville, MS, United States of America
| | - Ozdemir Ozan
- Department of Comparative Biomedical Sciences, College of Veterinary Medicine, Mississippi State University, Starkville, MS, United States of America
| | - Nancy Freitag
- Department of Pharmaceutical Sciences, University of Illinois at Chicago, Chicago, Illinois, United States of America
| | - Mark L. Lawrence
- Department of Comparative Biomedical Sciences, College of Veterinary Medicine, Mississippi State University, Starkville, MS, United States of America
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16
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Rukit J, Boonmee A, Kijpornyongpan T, Tulsook K, Baranyi J, Chaturongakul S. Roles of Alternative Sigma Factors in Invasion and Growth Characteristics of Listeria monocytogenes 10403S Into Human Epithelial Colorectal Adenocarcinoma Caco-2 Cell. Front Microbiol 2022; 13:901484. [PMID: 35910626 PMCID: PMC9329085 DOI: 10.3389/fmicb.2022.901484] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2022] [Accepted: 06/13/2022] [Indexed: 11/22/2022] Open
Abstract
Listeria monocytogenes is a Gram-positive facultative intracellular bacterium with a broad host range. With its housekeeping sigma factor and four alternative ones (namely SigB, SigC, SigH, and SigL), L. monocytogenes can express genes in response to changing environments. However, the roles of these sigma factors in intracellular survival are still unclear. The objectives of this study were to characterize the role of each alternative σ factor on L. monocytogenes invasion and growth inside human epithelial colorectal adenocarcinoma Caco-2 cells. We used L. monocytogenes 10403S wild type and its 15 alternative sigma factor deletion mutants at a multiplicity of infection of 100 and 1 in invasion and intracellular growth assays in the Caco-2 cells, respectively. At 1.5, 2, 4, 6, 8, 10, and 12 h post-infection, Caco-2 cells were lysed, and intracellular L. monocytogenes were enumerated on brain-heart infusion agar. Colony-forming and growth rates were compared among strains. The results from phenotypic characterization confirmed that (i) SigB is the key factor for L. monocytogenes invasion and (ii) having only SigA (ΔsigBCHL strain) is sufficient to invade and multiply in the host cell at similar levels as the wild type. Our previous study suggested the negative role of SigL in bile stress response. In this study, we have shown that additional deletion of the rpoN (or sigL) gene to ΔsigB, ΔsigC, or ΔsigH could restore the impaired invasion efficiencies of the single mutant, suggesting the absence of SigL could enhance host invasion. Therefore, we further investigated the role of SigL during extracellular and intracellular life cycles. Using RNA sequencing, we identified 118 and 16 SigL-dependent genes during the extracellular and intracellular life cycles, respectively. The sigL gene itself was induced by fivefolds prior to the invasion, and 5.3 folds during Caco-2 infection, further suggesting the role of SigL in intracellular growth.
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Affiliation(s)
- Junyaluck Rukit
- Department of Microbiology, Faculty of Science, Mahidol University, Bangkok, Thailand
| | - Atsadang Boonmee
- Department of Microbiology, Faculty of Science, Chulalongkorn University, Bangkok, Thailand
| | - Teeratas Kijpornyongpan
- Department of Botany and Plant Pathology, Purdue University, West Lafayette, IN, United States
| | - Kan Tulsook
- National Center for Genetic Engineering and Biotechnology (BIOTEC), National Science and Technology Development Agency (NSTDA), Pathum Thani, Thailand
| | - József Baranyi
- Institute of Nutrition, University of Debrecen, Debrecen, Hungary
| | - Soraya Chaturongakul
- Department of Microbiology, Faculty of Science, Mahidol University, Bangkok, Thailand
- Molecular Medical Biosciences Cluster, Institute of Molecular Biosciences, Mahidol University, Nakhon Pathom, Thailand
- *Correspondence: Soraya Chaturongakul,
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17
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Structural and biochemical analyses of the flagellar expression regulator DegU from Listeria monocytogenes. Sci Rep 2022; 12:10856. [PMID: 35798759 PMCID: PMC9263151 DOI: 10.1038/s41598-022-14459-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2021] [Accepted: 06/07/2022] [Indexed: 11/24/2022] Open
Abstract
Listeria monocytogenes is a pathogenic bacterium that produces flagella, the locomotory organelles, in a temperature-dependent manner. At 37 °C inside humans, L. monocytogenes employs MogR to repress the expression of flagellar proteins, thereby preventing the production of flagella. However, in the low-temperature environment outside of the host, the antirepressor GmaR inactivates MogR, allowing flagellar formation. Additionally, DegU is necessary for flagellar expression at low temperatures. DegU transcriptionally activates the expression of GmaR and flagellar proteins by binding the operator DNA in the fliN-gmaR promoter as a response regulator of a two-component regulatory system. To determine the DegU-mediated regulation mechanism, we performed structural and biochemical analyses on the recognition of operator DNA by DegU. The DegU-DNA interaction is primarily mediated by a C-terminal DNA-binding domain (DBD) and can be fortified by an N-terminal receiver domain (RD). The DegU DBD adopts a tetrahelical helix-turn-helix structure and assembles into a dimer. The DegU DBD dimer recognizes the operator DNA using a positive patch. Unexpectedly, unlike typical response regulators, DegU interacts with operator DNA in both unphosphorylated and phosphorylated states with similar binding affinities. Therefore, we conclude that DegU is a noncanonical response regulator that is constitutively active irrespective of phosphorylation.
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18
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Melian C, Bentencourt E, Castellano P, Ploper D, Vignolo G, Mendoza LM. Biofilm genes expression of Listeria monocytogenes exposed to Latilactobacillus curvatus bacteriocins at 10 °C. Int J Food Microbiol 2022; 370:109648. [DOI: 10.1016/j.ijfoodmicro.2022.109648] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2021] [Revised: 03/10/2022] [Accepted: 03/24/2022] [Indexed: 10/18/2022]
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19
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Muchaamba F, Eshwar AK, Stevens MJA, Stephan R, Tasara T. Different Shades of Listeria monocytogenes: Strain, Serotype, and Lineage-Based Variability in Virulence and Stress Tolerance Profiles. Front Microbiol 2022; 12:792162. [PMID: 35058906 PMCID: PMC8764371 DOI: 10.3389/fmicb.2021.792162] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2021] [Accepted: 11/11/2021] [Indexed: 12/30/2022] Open
Abstract
Listeria monocytogenes is a public health and food safety challenge due to its virulence and natural stress resistance phenotypes. The variable distribution of L. monocytogenes molecular subtypes with respect to food products and processing environments and among human and animal clinical listeriosis cases is observed. Sixty-two clinical and food-associated L. monocytogenes isolates were examined through phenome and genome analysis. Virulence assessed using a zebrafish infection model revealed serotype and genotype-specific differences in pathogenicity. Strains of genetic lineage I serotype 4b and multilocus sequence type clonal complexes CC1, CC2, CC4, and CC6 grew and survived better and were more virulent than serotype 1/2a and 1/2c lineage II, CC8, and CC9 strains. Hemolysis, phospholipase activity, and lysozyme tolerance profiles were associated with the differences observed in virulence. Osmotic stress resistance evaluation revealed serotype 4b lineage I CC2 and CC4 strains as more osmotolerant, whereas serotype 1/2c lineage II CC9 strains were more osmo-sensitive than others. Variable tolerance to the widely used quaternary ammonium compound benzalkonium chloride (BC) was observed. Some outbreak and sporadic clinical case associated strains demonstrated BC tolerance, which might have contributed to their survival and transition in the food-processing environment facilitating food product contamination and ultimately outbreaks or sporadic listeriosis cases. Genome comparison uncovered various moderate differences in virulence and stress associated genes between the strains indicating that these differences in addition to gene expression regulation variations might largely be responsible for the observed virulence and stress sensitivity phenotypic differences. Overall, our study uncovered strain and genotype-dependent variation in virulence and stress resilience among clinical and food-associated L. monocytogenes isolates with potential public health risk implications. The extensive genome and phenotypic data generated provide a basis for developing improved Listeria control strategies and policies.
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Affiliation(s)
- Francis Muchaamba
- Institute for Food Safety and Hygiene, Vetsuisse Faculty, University of Zürich, Zurich, Switzerland
| | - Athmanya K Eshwar
- Institute for Food Safety and Hygiene, Vetsuisse Faculty, University of Zürich, Zurich, Switzerland
| | - Marc J A Stevens
- Institute for Food Safety and Hygiene, Vetsuisse Faculty, University of Zürich, Zurich, Switzerland
| | - Roger Stephan
- Institute for Food Safety and Hygiene, Vetsuisse Faculty, University of Zürich, Zurich, Switzerland
| | - Taurai Tasara
- Institute for Food Safety and Hygiene, Vetsuisse Faculty, University of Zürich, Zurich, Switzerland
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20
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Byun KH, Ha Han S, Woo Choi M, Hong Park S, Ha SD. Effect of sublethal concentrations of bactericidal antibiotics on mutation frequency and stress response of Listeria monocytogenes. Food Res Int 2022; 151:110903. [PMID: 34980420 DOI: 10.1016/j.foodres.2021.110903] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2021] [Revised: 12/06/2021] [Accepted: 12/13/2021] [Indexed: 11/04/2022]
Abstract
The purpose of this study was to investigate sublethal concentrations (SLC) of bactericidal antibiotics (ampicillin, gentamicin, kanamycin, and vancomycin) on the mutation frequency and stress response of antibiotic-induced-mutated (AIM) Listeria monocytogenes. Three L. monocytogenes strains (reference, clinical, and food isolate strains) were used in this study. SLC of bactericidal antibiotics significantly increased the mutation frequency in L. monocytogenes. It was found that AIM L. monocytogenes had a superior biofilm-forming ability than nontreated L. monocytogenes. This result correlated with the amounts of EPS produced (polysaccharide and protein) in the early stage of biofilm formation. AIM L. monocytogenes showed strong viability under food-associated stress (thermal, osmotic, and acidic) compared to nontreated L. monocytogenes. In addition, expression levels of motility (flaA) and virulence genes (hlyA, actA, and prfA) of AIM L. monocytogenes were significantly downregulated in the reference strain but significantly upregulated or similar to the expression levels in the clinical and food isolate strains compared to nontreated L. monocytogenes. Based on our results, SLC of bactericidal antibiotics increased the mutation frequency in L. monocytogenes, facilitated the adaptation of the bacterium to food-associated stress, and led to an increase in its pathogenicity.
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Affiliation(s)
- Kye-Hwan Byun
- Department of Food Science and Technology, Advanced Food Safety Research Group, Brain Korea 21 Plus, Chung-Ang University, Nae-ri, Daeduk-myun, Ansung, Kyunggido 17546, Republic of Korea
| | - Sang Ha Han
- Department of Food Science and Technology, Advanced Food Safety Research Group, Brain Korea 21 Plus, Chung-Ang University, Nae-ri, Daeduk-myun, Ansung, Kyunggido 17546, Republic of Korea
| | - Min Woo Choi
- Department of Food Science and Technology, Advanced Food Safety Research Group, Brain Korea 21 Plus, Chung-Ang University, Nae-ri, Daeduk-myun, Ansung, Kyunggido 17546, Republic of Korea
| | - Si Hong Park
- Food Science and Technology, Oregon State University, Corvallis, OR, USA
| | - Sang-Do Ha
- Department of Food Science and Technology, Advanced Food Safety Research Group, Brain Korea 21 Plus, Chung-Ang University, Nae-ri, Daeduk-myun, Ansung, Kyunggido 17546, Republic of Korea.
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21
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Aljasir SF, D'Amico DJ. Effect of pre-exposure to protective bacterial cultures in food on Listeria monocytogenes virulence. Lebensm Wiss Technol 2021. [DOI: 10.1016/j.lwt.2021.112373] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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22
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In vitro virulence potential, surface attachment and transcriptional response of sublethally injured Listeria monocytogenes following exposure to peracetic acid. Appl Environ Microbiol 2021; 88:e0158221. [PMID: 34731051 DOI: 10.1128/aem.01582-21] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The disinfectant Peracetic acid (PAA) can cause high levels of sublethal injury to L. monocytogenes. This study aims to evaluate phenotypic and transcriptional characteristics concerning surface attachment and virulence potential of sublethally injured L. monocytogenes ScottA and EGDe after exposure to 0.75 ppm PAA for 90 min at 4°C and subsequent incubation in TSBY at 4°C. Results showed that injured L. monocytogenes cells (99% of total population) were able to attach (after 2 and 24h) on stainless steel coupons at 4°C and 20°C. In vitro virulence assays using human intestinal epithelial Caco-2 cells showed that injured L. monocytogenes could invade host cells but could not proliferate intracellularly. In vitro virulence response was strain-dependent; injured ScottA was more invasive than EGDe. Assessment of PAA-injury at the transcriptional level showed upregulation of genes (motB, flaA) involved in flagellum motility and surface attachment. The transcriptional response of L. monocytogenes EGDe and ScottA was different; only injured ScottA demonstrated upregulation of the virulence genes inlA and plcA. Downregulation of the stress-related genes fri and kat, and upregulation of lmo0669 was observed in injured ScottA. The obtained results indicate that sublethally-injured L. monocytogenes cells may retain part of their virulence properties as well as their ability to adhere on food processing surfaces. Transmission to food products and introduction of these cells in the food chain is therefore a plausible scenario that is worth taking into consideration in terms of risk assessment. Importance L. monocytogenes is the causative agent of listeriosis a serious food-borne illness. Antimicrobial practices, such as disinfectants used for the elimination of this pathogen in food industry can produce a sublethally injured population fraction. Injured cells of this pathogen, that may survive an antimicrobial treatment, may pose a food safety-risk. Nevertheless, knowledge regarding how sublethal injury may impact important cellular traits and phenotypic responses of this pathogen is limited. This work suggests that sublethally injured L. monocytogenes cells maintain the virulence and surface attachment potential and highlights the importance of the occurrence of sublethally injured cells regarding food safety.
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23
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Unrath N, McCabe E, Macori G, Fanning S. Application of Whole Genome Sequencing to Aid in Deciphering the Persistence Potential of Listeria monocytogenes in Food Production Environments. Microorganisms 2021; 9:1856. [PMID: 34576750 PMCID: PMC8464834 DOI: 10.3390/microorganisms9091856] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2021] [Revised: 08/23/2021] [Accepted: 08/25/2021] [Indexed: 01/26/2023] Open
Abstract
Listeria monocytogenes is the etiological agent of listeriosis, a foodborne illness associated with high hospitalizations and mortality rates. This bacterium can persist in food associated environments for years with isolates being increasingly linked to outbreaks. This review presents a discussion of genomes of Listeria monocytogenes which are commonly regarded as persisters within food production environments, as well as genes which are involved in mechanisms aiding this phenotype. Although criteria for the detection of persistence remain undefined, the advent of whole genome sequencing (WGS) and the development of bioinformatic tools have revolutionized the ability to find closely related strains. These advancements will facilitate the identification of mechanisms responsible for persistence among indistinguishable genomes. In turn, this will lead to improved assessments of the importance of biofilm formation, adaptation to stressful conditions and tolerance to sterilizers in relation to the persistence of this bacterium, all of which have been previously associated with this phenotype. Despite much research being published around the topic of persistence, more insights are required to further elucidate the nature of true persistence and its implications for public health.
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Affiliation(s)
- Natalia Unrath
- UCD-Centre for Food Safety, School of Public Health, Physiotherapy & Sports Science, University College Dublin, D04 N2E5 Dublin, Ireland; (N.U.); (E.M.); (G.M.)
| | - Evonne McCabe
- UCD-Centre for Food Safety, School of Public Health, Physiotherapy & Sports Science, University College Dublin, D04 N2E5 Dublin, Ireland; (N.U.); (E.M.); (G.M.)
- Department of Microbiology, St. Vincent’s University Hospital, D04 T6F4 Dublin, Ireland
| | - Guerrino Macori
- UCD-Centre for Food Safety, School of Public Health, Physiotherapy & Sports Science, University College Dublin, D04 N2E5 Dublin, Ireland; (N.U.); (E.M.); (G.M.)
| | - Séamus Fanning
- UCD-Centre for Food Safety, School of Public Health, Physiotherapy & Sports Science, University College Dublin, D04 N2E5 Dublin, Ireland; (N.U.); (E.M.); (G.M.)
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24
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Li M, Carpenter CE, Broadbent JR. Organic Acid Exposure Enhances Virulence in Some Listeria monocytogenes Strains Using the Galleria mellonella Infection Model. Front Microbiol 2021; 12:675241. [PMID: 34295317 PMCID: PMC8290484 DOI: 10.3389/fmicb.2021.675241] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2021] [Accepted: 06/14/2021] [Indexed: 01/01/2023] Open
Abstract
Prior research has suggested that the use of organic acids in the food industry may unintentionally enhance pathogenicity of Listeria monocytogenes strain N1-227 and R2-499. This study explored the connection between habituation to L-lactic acid or acetic acid and virulence in L. monocytogenes strains N1-227 and R2-499 using selected gene expression analysis and the in vivo Galleria mellonella wax worm model for infection. Expression of transcription factors (sigB and prfA) and genes related to acid resistance (gadD2, gadD3, and arcA) and bile resistance (bsh and bilE) or to virulence (inlA, inlB, hly, plcA, plcB, uhpT, and actA) was investigated by quantitative real-time PCR (qRT-PCR), while in vivo virulence was assessed by following the lethal time to 50% population mortality (LT50) of G. mellonella larvae after injection of untreated and habituated L. monocytogenes. Twenty minutes of habituation to the organic acids at pH 6.0 significantly increased expression of key acid and bile stress response genes in both strains, while expression of virulence genes was strain-dependent. The expression of transcription factor sigB was strain-dependent and there was no significant change in the expression of transcription factor prfA in both strains. Habituation to acid increased virulence of both strains as evidenced by decreased LT50 of G. mellonella larvae injected with Listeria habituated to either acid. In summary, habituation of both L. monocytogenes strains to organic acids up-regulated expression of several stress and virulence genes and concurrently increased virulence as measured using the G. mellonella model.
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Affiliation(s)
- Minghao Li
- Department of Nutrition, Dietetics and Food Sciences, Utah State University, Logan, UT, United States
| | - Charles E Carpenter
- Department of Nutrition, Dietetics and Food Sciences, Utah State University, Logan, UT, United States
| | - Jeff R Broadbent
- Department of Nutrition, Dietetics and Food Sciences, Utah State University, Logan, UT, United States
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Doghri I, Cherifi T, Goetz C, Malouin F, Jacques M, Fravalo P. Counteracting Bacterial Motility: A Promising Strategy to Narrow Listeria monocytogenes Biofilm in Food Processing Industry. Front Microbiol 2021; 12:673484. [PMID: 34149663 PMCID: PMC8206544 DOI: 10.3389/fmicb.2021.673484] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2021] [Accepted: 05/04/2021] [Indexed: 12/21/2022] Open
Abstract
Listeria monocytogenes (L. monocytogenes) is often associated with processed food as it can form biofilms that represent a source of contamination at all stages of the manufacturing chain. The control and prevention of biofilms in food-processing plants are of utmost importance. This study explores the efficacy of prospect molecules for counteracting bacterial mechanisms leading to biofilm formation. The compounds included the phytomolecule tomatidine, zinc chloride (ZnCl2), ethylenediaminetetraacetic acid (EDTA), and a more complexed mixture of bacterial compounds from coagulase-negative staphylococci (CNS exoproducts). Significant inhibition of L. monocytogenes biofilm formation was evidenced using a microfluidic system and confocal microscopic analyses (p < 0.001). Active molecules were effective at an early stage of biofilm development (≥50% of inhibition) but failed to disperse mature biofilms of L. monocytogenes. According to our findings, prevention of surface attachment was associated with a disruption of bacterial motility. Indeed, agar cell motility assays demonstrated the effectiveness of these molecules. Overall, results highlighted the critical role of motility in biofilm formation and allow to consider flagellum-mediated motility as a promising molecular target in control strategies against L. monocytogenes in food processing environments.
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Affiliation(s)
- Ibtissem Doghri
- Département de Pathologie et Microbiologie, Faculté de Médecine Vétérinaire, Université de Montréal, Saint-Hyacinthe, QC, Canada.,Regroupement de Recherche pour un Lait de Qualité Optimale (Op+Lait), Montreal, QC, Cananda
| | - Tamazight Cherifi
- Département de Pathologie et Microbiologie, Faculté de Médecine Vétérinaire, Université de Montréal, Saint-Hyacinthe, QC, Canada.,Chaire de Recherche en Salubrité des Viandes (CRSV), Montreal, QC, Cananda
| | - Coralie Goetz
- Département de Pathologie et Microbiologie, Faculté de Médecine Vétérinaire, Université de Montréal, Saint-Hyacinthe, QC, Canada.,Regroupement de Recherche pour un Lait de Qualité Optimale (Op+Lait), Montreal, QC, Cananda
| | - François Malouin
- Regroupement de Recherche pour un Lait de Qualité Optimale (Op+Lait), Montreal, QC, Cananda.,Département de Biologie, Faculté des Sciences, Université de Sherbrooke, Sherbrooke, QC, Canada
| | - Mario Jacques
- Département de Pathologie et Microbiologie, Faculté de Médecine Vétérinaire, Université de Montréal, Saint-Hyacinthe, QC, Canada.,Regroupement de Recherche pour un Lait de Qualité Optimale (Op+Lait), Montreal, QC, Cananda
| | - Philippe Fravalo
- Département de Pathologie et Microbiologie, Faculté de Médecine Vétérinaire, Université de Montréal, Saint-Hyacinthe, QC, Canada.,Chaire de Recherche en Salubrité des Viandes (CRSV), Montreal, QC, Cananda
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26
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Long filamentous state of Listeria monocytogenes induced by sublethal sodium chloride stress poses risk of rapid increase in colony-forming units. Food Control 2021. [DOI: 10.1016/j.foodcont.2020.107860] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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Listeria monocytogenes Cold Shock Proteins: Small Proteins with A Huge Impact. Microorganisms 2021; 9:microorganisms9051061. [PMID: 34068949 PMCID: PMC8155936 DOI: 10.3390/microorganisms9051061] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2021] [Revised: 05/11/2021] [Accepted: 05/12/2021] [Indexed: 01/26/2023] Open
Abstract
Listeria monocytogenes has evolved an extensive array of mechanisms for coping with stress and adapting to changing environmental conditions, ensuring its virulence phenotype expression. For this reason, L. monocytogenes has been identified as a significant food safety and public health concern. Among these adaptation systems are cold shock proteins (Csps), which facilitate rapid response to stress exposure. L. monocytogenes has three highly conserved csp genes, namely, cspA, cspB, and cspD. Using a series of csp deletion mutants, it has been shown that L. monocytogenes Csps are important for biofilm formation, motility, cold, osmotic, desiccation, and oxidative stress tolerance. Moreover, they are involved in overall virulence by impacting the expression of virulence-associated phenotypes, such as hemolysis and cell invasion. It is postulated that during stress exposure, Csps function to counteract harmful effects of stress, thereby preserving cell functions, such as DNA replication, transcription and translation, ensuring survival and growth of the cell. Interestingly, it seems that Csps might suppress tolerance to some stresses as their removal resulted in increased tolerance to stresses, such as desiccation for some strains. Differences in csp roles among strains from different genetic backgrounds are apparent for desiccation tolerance and biofilm production. Additionally, hierarchical trends for the different Csps and functional redundancies were observed on their influences on stress tolerance and virulence. Overall current data suggest that Csps have a wider role in bacteria physiology than previously assumed.
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28
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Nikparvar B, Andreevskaya M, Duru IC, Bucur FI, Grigore-Gurgu L, Borda D, Nicolau AI, Riedel CU, Auvinen P, Bar N. Analysis of temporal gene regulation of Listeria monocytogenes revealed distinct regulatory response modes after exposure to high pressure processing. BMC Genomics 2021; 22:266. [PMID: 33853520 PMCID: PMC8045354 DOI: 10.1186/s12864-021-07461-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2020] [Accepted: 02/10/2021] [Indexed: 01/16/2023] Open
Abstract
BACKGROUND The pathogen Listeria (L.) monocytogenes is known to survive heat, cold, high pressure, and other extreme conditions. Although the response of this pathogen to pH, osmotic, temperature, and oxidative stress has been studied extensively, its reaction to the stress produced by high pressure processing HPP (which is a preservation method in the food industry), and the activated gene regulatory network (GRN) in response to this stress is still largely unknown. RESULTS We used RNA sequencing transcriptome data of L. monocytogenes (ScottA) treated at 400 MPa and 8∘C, for 8 min and combined it with current information in the literature to create a transcriptional regulation database, depicting the relationship between transcription factors (TFs) and their target genes (TGs) in L. monocytogenes. We then applied network component analysis (NCA), a matrix decomposition method, to reconstruct the activities of the TFs over time. According to our findings, L. monocytogenes responded to the stress applied during HPP by three statistically different gene regulation modes: survival mode during the first 10 min post-treatment, repair mode during 1 h post-treatment, and re-growth mode beyond 6 h after HPP. We identified the TFs and their TGs that were responsible for each of the modes. We developed a plausible model that could explain the regulatory mechanism that L. monocytogenes activated through the well-studied CIRCE operon via the regulator HrcA during the survival mode. CONCLUSIONS Our findings suggest that the timely activation of TFs associated with an immediate stress response, followed by the expression of genes for repair purposes, and then re-growth and metabolism, could be a strategy of L. monocytogenes to survive and recover extreme HPP conditions. We believe that our results give a better understanding of L. monocytogenes behavior after exposure to high pressure that may lead to the design of a specific knock-out process to target the genes or mechanisms. The results can help the food industry select appropriate HPP conditions to prevent L. monocytogenes recovery during food storage.
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Affiliation(s)
- Bahareh Nikparvar
- Department of Chemical Engineering, Norwegian University of Science and Technology, Trondheim, Norway
| | | | - Ilhan C Duru
- Institute of Biotechnology, University of Helsinki, Helsinki, Finland
| | - Florentina I Bucur
- Faculty of Food Science and Engineering, Dunarea de Jos University of Galati, Galati, Romania
| | - Leontina Grigore-Gurgu
- Faculty of Food Science and Engineering, Dunarea de Jos University of Galati, Galati, Romania
| | - Daniela Borda
- Faculty of Food Science and Engineering, Dunarea de Jos University of Galati, Galati, Romania
| | - Anca I Nicolau
- Faculty of Food Science and Engineering, Dunarea de Jos University of Galati, Galati, Romania
| | - Christian U Riedel
- Institute of Microbiology and Biotechnology, Ulm University, Ulm, Germany
| | - Petri Auvinen
- Institute of Biotechnology, University of Helsinki, Helsinki, Finland
| | - Nadav Bar
- Department of Chemical Engineering, Norwegian University of Science and Technology, Trondheim, Norway.
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29
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Transcriptome Analysis of Listeria monocytogenes Exposed to Beef Fat Reveals Antimicrobial and Pathogenicity Attenuation Mechanisms. Appl Environ Microbiol 2021; 87:AEM.03027-20. [PMID: 33608290 DOI: 10.1128/aem.03027-20] [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: 12/14/2020] [Accepted: 02/09/2021] [Indexed: 12/13/2022] Open
Abstract
Listeria monocytogenes is a deadly intracellular pathogen mostly associated with consumption of ready-to-eat foods. This study investigated the effectiveness of total beef fat (BF-T) from flaxseed-fed cattle and its fractions enriched with monounsaturated fatty acids (BF-MUFA) and polyunsaturated fatty acids (BF-PUFA), along with commercially available long-chain fatty acids (LC-FA), as natural antimicrobials against L. monocytogenes BF-T was ineffective at concentrations up to 6 mg/ml, while L. monocytogenes was susceptible to BF-MUFA and BF-PUFA, with MICs at pH 7 of 0.33 ± 0.21 mg/ml and 0.06 ± 0.03 mg/ml, respectively. The MIC of C14:0 was significantly lower than those of C16:0 and C18:0 (P < 0.05). Fatty acids c9-C16:1, C18:2n-6, and C18:3n-3 showed stronger inhibitory activity than c9-C18:1 and conjugated C18:2, with MICs of <1 mg/ml. Furthermore, global transcriptional analysis by transcriptome sequencing (RNA-seq) was performed to characterize the response of L. monocytogenes to selected fatty acids. Functional analysis indicated that antimicrobial LC-UFA repressed the expression of genes associated with nutrient transmembrane transport, energy generation, and oxidative stress resistance. On the other hand, upregulation of ribosome assembly and translation process is possibly associated with adaptive and repair mechanisms activated in response to LC-UFA. Virulence genes and genes involved in bile, acid, and osmotic stresses were largely downregulated, and more so for c9-C16:1, C18:2n-6, and C18:3n-3, likely through interaction with the master virulence regulator PrfA and the alternative sigma factor σB IMPORTANCE Listeria monocytogenes is a bacterial pathogen known for its ability to survive and thrive under adverse environments and, as such, its control poses a significant challenge, especially with the trend of minimally processed and ready-to-eat foods. This work investigated the effectiveness of fatty acids from various sources as natural antimicrobials against L. monocytogenes and evaluated their potential role in L. monocytogenes pathogenicity modulation, using the strain ATCC 19111. The findings show that long-chain unsaturated fatty acids (LC-UFA), including unsaturated beef fat fractions from flaxseed-fed cattle, could have the potential to be used as effective antimicrobials for L. monocytogenes through controlling growth as well as virulence attenuation. This not only advances our understanding of the mode of action of LC-UFA against L. monocytogenes but also suggests the potential for use of beef fat or its fractions as natural antimicrobials for controlling foodborne pathogens.
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30
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Castro-Seriche S, Jerez-Morales A, Smith CT, Sánchez-Alonzo K, García-Cancino A. Candida albicans, a reservoir of Listeria monocytogenes? INFECTION GENETICS AND EVOLUTION 2021; 90:104779. [PMID: 33639305 DOI: 10.1016/j.meegid.2021.104779] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/17/2020] [Revised: 12/04/2020] [Accepted: 02/20/2021] [Indexed: 11/25/2022]
Abstract
Listeria monocytogenes is a pathogen causing serious or mortal infections in human risk populations. Its infectivity is in part due to its ability to infect diverse eukaryotic cells. Since several bacteria can enter into yeast cells, including Candida albicans, the aims of this work were to evaluate if L. monocytogenes was able to harbor, retaining its viability, within C. albicans cells and to evaluate the effect of temperature and an antibiotic as stressing factors in its rate of entry into yeast cells. Both microorganisms were co-incubated in BHI broth during 48 h and the entry of bacteria into yeast cells was evaluated at different times. Then, yeasts free of extracellular bacteria were obtained seeding samples of the co-culture on YGC agar, which contains chloramphenicol, to obtain extracellular bacteria-free yeasts. These extracellular bacteria free yeasts were used to search for bacterial DNA in total yeast DNA and to evaluate the viability of intra-yeast bacteria. Finally, the effect of temperature and of chloramphenicol as inducers of stress on the rate of bacterial entry into yeast cells were investigated. After co-culturing both microorganisms, wet mount optical microscopy showed the presence of moving bacteria within yeasts and transmission electron microscopy confirmed the presence of intra-yeast bacteria. PCR allowed to amplify L. monocytogenes iap gene in C. albicans total DNA obtained from yeasts free of extracellular bacteria. Moreover, the SYTO 9 green fluorescence observed in bacterial cells within vacuoles of yeasts suggests that intra-yeast bacteria remain viable. Furthermore, the entry of L. monocytogenes into yeasts cells was favored by the presence of stressing factors (chloramphenicol and temperature). Therefore, yeasts may be reservoirs of viable L. monocytogenes and might spread them to the following generations of yeasts.
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Affiliation(s)
- Susana Castro-Seriche
- Bacterial Pathogenicity Laboratory, Department of Microbiology, Faculty of Biological Sciences, Universidad de Concepción, Concepción, Chile
| | - Alonso Jerez-Morales
- Bacterial Pathogenicity Laboratory, Department of Microbiology, Faculty of Biological Sciences, Universidad de Concepción, Concepción, Chile
| | - Carlos T Smith
- Department of Microbiology, Faculty of Biological Sciences, Universidad de Concepción, Concepción, Chile
| | - Kimberly Sánchez-Alonzo
- Bacterial Pathogenicity Laboratory, Department of Microbiology, Faculty of Biological Sciences, Universidad de Concepción, Concepción, Chile
| | - Apolinaria García-Cancino
- Bacterial Pathogenicity Laboratory, Department of Microbiology, Faculty of Biological Sciences, Universidad de Concepción, Concepción, Chile.
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31
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Tran BM, Prabha H, Iyer A, O'Byrne C, Abee T, Poolman B. Measurement of Protein Mobility in Listeria monocytogenes Reveals a Unique Tolerance to Osmotic Stress and Temperature Dependence of Diffusion. Front Microbiol 2021; 12:640149. [PMID: 33679676 PMCID: PMC7925416 DOI: 10.3389/fmicb.2021.640149] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2020] [Accepted: 01/21/2021] [Indexed: 11/18/2022] Open
Abstract
Protein mobility in the cytoplasm is essential for cellular functions, and slow diffusion may limit the rates of biochemical reactions in the living cell. Here, we determined the apparent lateral diffusion coefficient (DL) of GFP in Listeria monocytogenes as a function of osmotic stress, temperature, and media composition. We find that DL is much less affected by hyperosmotic stress in L. monocytogenes than under similar conditions in Lactococcus lactis and Escherichia coli. We find a temperature optimum for protein diffusion in L. monocytogenes at 30°C, which deviates from predicted trends from the generalized Stokes-Einstein equation under dilute conditions and suggests that the structure of the cytoplasm and macromolecular crowding vary as a function of temperature. The turgor pressure of L. monocytogenes is comparable to other Gram-positive bacteria like Bacillus subtilis and L. lactis but higher in a knockout strain lacking the stress-inducible sigma factor SigB. We discuss these findings in the context of how L. monocytogenes survives during environmental transmission and interaction with the human host.
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Affiliation(s)
- Buu Minh Tran
- Department of Biochemistry, University of Groningen, Groningen, Netherlands
| | - Haritha Prabha
- Department of Biochemistry, University of Groningen, Groningen, Netherlands
| | - Aditya Iyer
- Department of Biochemistry, University of Groningen, Groningen, Netherlands
| | - Conor O'Byrne
- School of Natural Sciences, National University of Ireland, Galway, Ireland
| | - Tjakko Abee
- Laboratory of Food Microbiology, Wageningen University Research, Wageningen, Netherlands
| | - Bert Poolman
- Department of Biochemistry, University of Groningen, Groningen, Netherlands
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32
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Lucas JR, Alía A, Velasco R, Selgas MD, Cabeza MC. Effect of E-beam treatment on expression of virulence and stress-response genes of Listeria monocytogenes in dry-cured ham. Int J Food Microbiol 2021; 340:109057. [PMID: 33460999 DOI: 10.1016/j.ijfoodmicro.2021.109057] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2020] [Revised: 12/05/2020] [Accepted: 01/01/2021] [Indexed: 12/30/2022]
Abstract
Various adverse conditions can trigger defensive mechanisms in Listeria monocytogenes that can increase the virulence of surviving cells. The objective of this study was to evaluate the expression of one stress-response (sigB) and three virulence (plcA, hly, and iap) genes in L. monocytogenes exposed to a sub lethal dose of E-beam irradiation in dry-cured ham. To accomplish this, dry-cured ham slices (10 g) were immersed in a 109 CFU/mL suspension of L. monocytogenes strain S4-2 and subsequently irradiated with 1, 2, or 3 kGy. After irradiation, samples were stored at 7 °C or 15 °C for 30 days. Absolute gene expression levels were determined by RT-qPCR, and numbers of surviving Listeria cells were assessed by microbial counts after different storage times (0, 7, 15, and 30 days). At 7 °C, after E-beam treatment at doses of 2 or 3 kGy, Listeria gene expression significantly increased (p ≤ 0.05) up to day 15. Listeria counts decreased with increasing dosage. The relationship between absolute gene expression and the number of surviving Listeria cells could indicate that sublethal doses of E-beam irradiation can increase expression of the genes studied. We observed no significant influence of storage time or temperature on gene expression (p > 0.05). Listeria that survives E-beam treatment may display increased virulence, constituting a significant potential public health risk.
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Affiliation(s)
- J R Lucas
- Food Technology Dept. Section, Veterinary Faculty, Complutense University, Avd. Puerta de Hierro s/n, 28040 Madrid, Spain.
| | - A Alía
- Food Hygiene and Safety, Meat and Meat Products Research Institute, University of Extremadura, Avda. de la Universidad, s/n., 10003 Cáceres, Spain
| | - R Velasco
- Food Technology Dept. Section, Veterinary Faculty, Complutense University, Avd. Puerta de Hierro s/n, 28040 Madrid, Spain
| | - M D Selgas
- Food Technology Dept. Section, Veterinary Faculty, Complutense University, Avd. Puerta de Hierro s/n, 28040 Madrid, Spain
| | - M C Cabeza
- Food Technology Dept. Section, Veterinary Faculty, Complutense University, Avd. Puerta de Hierro s/n, 28040 Madrid, Spain
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33
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Mattila M, Somervuo P, Korkeala H, Stephan R, Tasara T. Transcriptomic and Phenotypic Analyses of the Sigma B-Dependent Characteristics and the Synergism between Sigma B and Sigma L in Listeria monocytogenes EGD-e. Microorganisms 2020; 8:microorganisms8111644. [PMID: 33114171 PMCID: PMC7690807 DOI: 10.3390/microorganisms8111644] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2020] [Revised: 10/20/2020] [Accepted: 10/21/2020] [Indexed: 12/19/2022] Open
Abstract
Numerous gene expression and stress adaptation responses in L. monocytogenes are regulated through alternative sigma factors σB and σL. Stress response phenotypes and transcriptomes were compared between L. monocytogenes EGD-e and its ΔsigB and ΔsigBL mutants. Targeted growth phenotypic analysis revealed that the ΔsigB and ΔsigBL mutants are impaired during growth under cold and organic-acid stress conditions. Phenotypic microarrays revealed increased sensitivity in both mutants to various antimicrobial compounds. Genes de-regulated in these two mutants were identified by genome-wide transcriptome analysis during exponential growth in BHI. The ΔsigB and ΔsigBL strains repressed 198 and 254 genes, respectively, compared to the parent EGD-e strain at 3 °C, whereas 86 and 139 genes, respectively, were repressed in these mutants during growth at 37 °C. Genes repressed in these mutants are involved in various cellular functions including transcription regulation, energy metabolism and nutrient transport functions, and viral-associated processes. Exposure to cold stress induced a significant increase in σB and σL co-dependent genes of L. monocytogenes EGD-e since most (62%) of the down-regulated genes uncovered at 3 °C were detected in the ΔsigBL double-deletion mutant but not in ΔsigB or ΔsigL single-deletion mutants. Overall, the current study provides an expanded insight into σB and σL phenotypic roles and functional interactions in L. monocytogenes. Besides previously known σB- and σL-dependent genes, the transcriptomes defined in ΔsigB and ΔsigBL mutants reveal several new genes that are positively regulated by σB alone, as well as those co-regulated through σB- and σL-dependent mechanisms during L. monocytogenes growth under optimal and cold-stress temperature conditions.
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Affiliation(s)
- Mirjami Mattila
- Department of Food Hygiene and Environmental Health, Faculty of Veterinary Medicine, University of Helsinki, P.O. Box 66, 00014 Helsinki, Finland; (M.M.); (P.S.); (H.K.)
| | - Panu Somervuo
- Department of Food Hygiene and Environmental Health, Faculty of Veterinary Medicine, University of Helsinki, P.O. Box 66, 00014 Helsinki, Finland; (M.M.); (P.S.); (H.K.)
| | - Hannu Korkeala
- Department of Food Hygiene and Environmental Health, Faculty of Veterinary Medicine, University of Helsinki, P.O. Box 66, 00014 Helsinki, Finland; (M.M.); (P.S.); (H.K.)
| | - Roger Stephan
- Institute for Food Safety and Hygiene, Vetsuisse Faculty, University of Zurich, Winterthurerstr. 272, CH-8057 Zurich, Switzerland;
| | - Taurai Tasara
- Institute for Food Safety and Hygiene, Vetsuisse Faculty, University of Zurich, Winterthurerstr. 272, CH-8057 Zurich, Switzerland;
- Correspondence: ; Tel.: +41-44-635-8669
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34
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Rodriguez Ayala F, Bartolini M, Grau R. The Stress-Responsive Alternative Sigma Factor SigB of Bacillus subtilis and Its Relatives: An Old Friend With New Functions. Front Microbiol 2020; 11:1761. [PMID: 33042030 PMCID: PMC7522486 DOI: 10.3389/fmicb.2020.01761] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2020] [Accepted: 07/06/2020] [Indexed: 12/13/2022] Open
Abstract
Alternative sigma factors have led the core RNA polymerase (RNAP) to recognize different sets of promoters to those recognized by the housekeeping sigma A-directed RNAP. This change in RNAP promoter selectivity allows a rapid and flexible reformulation of the genetic program to face environmental and metabolic stimuli that could compromise bacterial fitness. The model bacterium Bacillus subtilis constitutes a matchless living system in the study of the role of alternative sigma factors in gene regulation and physiology. SigB from B. subtilis was the first alternative sigma factor described in bacteria. Studies of SigB during the last 40 years have shown that it controls a genetic universe of more than 150 genes playing crucial roles in stress response, adaption, and survival. Activation of SigB relies on three separate pathways that specifically respond to energy, environmental, and low temperature stresses. SigB homologs, present in other Gram-positive bacteria, also play important roles in virulence against mammals. Interestingly, during recent years, other unexpected B. subtilis responses were found to be controlled by SigB. In particular, SigB controls the efficiencies of spore and biofilm formation, two important features that play critical roles in adaptation and survival in planktonic and sessile B. subtilis communities. In B. subtilis, SigB induces the expression of the Spo0E aspartyl-phosphatase, which is responsible for the blockage of sporulation initiation. The upregulated activity of Spo0E connects the two predominant adaptive pathways (i.e., sporulation and stress response) present in B. subtilis. In addition, the RsbP serine-phosphatase, belonging to the energy stress arm of the SigB regulatory cascade, controls the expression of the key transcription factor SinR to decide whether cells residing in the biofilm remain in and maintain biofilm growth or scape to colonize new niches through biofilm dispersal. SigB also intervenes in the recognition of and response to surrounding microorganisms, a new SigB role that could have an agronomic impact. SigB is induced when B. subtilis is confronted with phytopathogenic fungi (e.g., Fusarium verticillioides) and halts fungal growth to the benefit of plant growth. In this article, we update and review literature on the different regulatory networks that control the activation of SigB and the new roles that have been described the recent years.
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Affiliation(s)
- Facundo Rodriguez Ayala
- Departamento de Micro y Nanotecnología, Instituto de Nanociencia y Nanotecnología - Comisión Nacional de Energía Atómica (CNEA), Buenos Aires, Argentina.,Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina
| | - Marco Bartolini
- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina.,Departamento de Microbiología, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Rosario, Argentina
| | - Roberto Grau
- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina.,Departamento de Microbiología, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Rosario, Argentina
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35
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Pérez-Baltar A, Alía A, Rodríguez A, Córdoba JJ, Medina M, Montiel R. Impact of Water Activity on the Inactivation and Gene Expression of Listeria monocytogenes during Refrigerated Storage of Pressurized Dry-Cured Ham. Foods 2020; 9:E1092. [PMID: 32785197 PMCID: PMC7466251 DOI: 10.3390/foods9081092] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2020] [Revised: 08/06/2020] [Accepted: 08/07/2020] [Indexed: 12/26/2022] Open
Abstract
Listeria monocytogenes population and the expression patterns of three virulence (plcA, hly, and iap) and one stress-related (sigB) genes in dry-cured ham with different water activity (aw) values (0.92, 0.88, and 0.84) and treated with high pressure processing (HPP, 450 MPa/10 min and 600 MPa/5 min) were monitored throughout 30 days (d) at 4 °C. The antimicrobial effect of HPP at 600 MPa against L. monocytogenes S4-2 (serotype 1/2b) and S12-1 (serotype 1/2c) was greater in dry-cured ham with aw values of 0.92, with reductions of 2.5 and 2.8 log units, respectively. The efficacy of HPP treatments decreased at lower aw values. Regarding gene expression, L. monocytogenes strains responded differently to HPP. For strain S4-2, the four target genes were generally overexpressed in dry-cured ham immediately after HPP treatments at the three aw values investigated, although the extent of this induction was lower in the samples pressurized at 600 MPa and with aw values of 0.84. For strain S12-1, the expression of all target genes was repressed at the three aw values investigated. The antimicrobial efficacy of HPP against L. monocytogenes could be compromised by low aw values in food products. However, no growth of HPP-survival cells was observed during refrigerated storage in low-aw dry-cured ham, and the overexpression of virulence and stress-related genes decreased.
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Affiliation(s)
- Aida Pérez-Baltar
- Departamento de Tecnología de Alimentos, INIA, Carretera de La Coruña Km 7, 28040 Madrid, Spain; (A.P.-B.); (M.M.)
| | - Alberto Alía
- Instituto Universitario de Investigación de Carne y Productos Cárnicos, Facultad de Veterinaria, Universidad de Extremadura, Avda. de la Universidad, s/n., 10003 Cáceres, Spain; (A.A.); (A.R.); (J.J.C.)
| | - Alicia Rodríguez
- Instituto Universitario de Investigación de Carne y Productos Cárnicos, Facultad de Veterinaria, Universidad de Extremadura, Avda. de la Universidad, s/n., 10003 Cáceres, Spain; (A.A.); (A.R.); (J.J.C.)
| | - Juan José Córdoba
- Instituto Universitario de Investigación de Carne y Productos Cárnicos, Facultad de Veterinaria, Universidad de Extremadura, Avda. de la Universidad, s/n., 10003 Cáceres, Spain; (A.A.); (A.R.); (J.J.C.)
| | - Margarita Medina
- Departamento de Tecnología de Alimentos, INIA, Carretera de La Coruña Km 7, 28040 Madrid, Spain; (A.P.-B.); (M.M.)
| | - Raquel Montiel
- Departamento de Tecnología de Alimentos, INIA, Carretera de La Coruña Km 7, 28040 Madrid, Spain; (A.P.-B.); (M.M.)
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Nguyen PL, van Baalen M. On the difficult evolutionary transition from the free-living lifestyle to obligate symbiosis. PLoS One 2020; 15:e0235811. [PMID: 32730262 PMCID: PMC7392539 DOI: 10.1371/journal.pone.0235811] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2019] [Accepted: 06/23/2020] [Indexed: 12/17/2022] Open
Abstract
Obligate symbiosis evolved from free-living individuals most likely via the intermediate stage of facultative symbiosis. However, why should facultative symbionts, who can live independently but also benefit from their partners if these are available, give up this best of both worlds? Using the adaptive dynamics approach, we analyse a simple model, focusing on one partner of the symbiosis, to gain more insight into the selective forces that make individuals forgo the ability to reproduce in the free-living state. Our results suggest that, similar to the parasitism-mutualism continuum, the free-living way of life and obligate symbiosis are two extremes of a continuum of the ability to reproduce independently of a partner. More importantly, facultative symbiosis should be the rule as for many parameter combinations completely giving up independent reproduction or adopting a pure free-living strategy is not so easy. We also show that if host encounter comes at a cost, individuals that put more effort into increasing the chances to meet with their partners are more likely to give up the ability to reproduce independently. Finally, our model does not specify the ecological interactions between hosts and symbionts but we discuss briefly how the ecological nature of an interaction can influence the transition from facultative to obligate symbiosis.
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Affiliation(s)
| | - Minus van Baalen
- Institut de Biologie de l’École Normale Supérieur, Paris, France
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Different carbon sources result in differential activation of sigma B and stress resistance in Listeria monocytogenes. Int J Food Microbiol 2020; 320:108504. [DOI: 10.1016/j.ijfoodmicro.2019.108504] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2019] [Revised: 11/23/2019] [Accepted: 12/27/2019] [Indexed: 12/16/2022]
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The Response to Oxidative Stress in Listeria monocytogenes Is Temperature Dependent. Microorganisms 2020; 8:microorganisms8040521. [PMID: 32260575 PMCID: PMC7232520 DOI: 10.3390/microorganisms8040521] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2020] [Revised: 03/30/2020] [Accepted: 04/03/2020] [Indexed: 11/24/2022] Open
Abstract
The stress response of 11 strains of Listeria monocytogenes to oxidative stress was studied. The strains included ST1, ST5, ST7, ST6, ST9, ST87, ST199 and ST321 and were isolated from diverse food processing environments (a meat factory, a dairy plant and a seafood company) and sample types (floor, wall, drain, boxes, food products and water machine). Isolates were exposed to two oxidizing agents: 13.8 mM cumene hydroperoxide (CHP) and 100 mM hydrogen peroxide (H2O2) at 10 °C and 37 °C. Temperature affected the oxidative stress response as cells treated at 10 °C survived better than those treated at 37 °C. H2O2 at 37 °C was the condition tested resulting in poorest L. monocytogenes survival. Strains belonging to STs of Lineage I (ST5, ST6, ST87, ST1) were more resistant to oxidative stress than those of Lineage II (ST7, ST9, ST199 and ST321), with the exception of ST7 that showed tolerance to H2O2 at 10 °C. Isolates of each ST5 and ST9 from different food industry origins showed differences in oxidative stress response. The gene expression of two relevant virulence (hly) and stress (clpC) genes was studied in representative isolates in the stressful conditions. hly and clpC were upregulated during oxidative stress at low temperature. Our results indicate that conditions prevalent in food industries may allow L. monocytogenes to develop survival strategies: these include activating molecular mechanisms based on cross protection that can promote virulence, possibly increasing the risk of virulent strains persisting in food processing plants.
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39
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Cortes BW, Naditz AL, Anast JM, Schmitz-Esser S. Transcriptome Sequencing of Listeria monocytogenes Reveals Major Gene Expression Changes in Response to Lactic Acid Stress Exposure but a Less Pronounced Response to Oxidative Stress. Front Microbiol 2020; 10:3110. [PMID: 32038553 PMCID: PMC6985202 DOI: 10.3389/fmicb.2019.03110] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2019] [Accepted: 12/23/2019] [Indexed: 12/15/2022] Open
Abstract
Listeria monocytogenes is a well-characterized pathogen that represents a major threat to food safety. In this study, we examine the chromosomal and plasmid transcriptomes of two different L. monocytogenes strains, 6179 [belonging to sequence type (ST) 121] and R479a (ST8), in response to 30 min exposure to oxidative (0.01% hydrogen peroxide) and acid (1% lactic acid, pH 3.4) stress. The exposure to oxidative stress resulted in 102 and 9 differentially expressed (DE) genes in the chromosomal transcriptomes of 6179 and R479a, respectively. In contrast, 2280 and 2151 DE genes were observed in the respective chromosomal transcriptomes of 6179 and R479a in response to lactic acid stress. During lactic acid stress, we observed upregulation of numerous genes known to be involved in the L. monocytogenes stress response, including multiple members of the σB regulon, many of which have not been functionally characterized. Among these genes, homologs of lmo2230 were highly upregulated in both strains. Most notably, the σB-dependent non-coding RNA Rli47 was by far the most highly expressed gene in both 6179 and R479a, accounting for an average of 28 and 38% of all mapped reads in the respective chromosomal transcriptomes. In response to oxidative stress, one DE gene was identified in the 6179 plasmid transcriptome, and no DE genes were observed in the transcriptome of the R479a plasmid. However, lactic acid exposure resulted in upregulation of the stress response gene clpL, among others, on the 6179 plasmid. In R479a, a number of uncharacterized plasmid genes were upregulated, indicating a potential role in stress response. Furthermore, an average of 65% of all mapped transcriptome reads for the R479a plasmid following acid stress were mapped to an intergenic region bearing similarity to riboswitches involved in transition metal resistance. The results of this study support the conclusion that members of the σB regulon, particularly lmo2230 and the non-coding RNA Rli47, play an integral role in the response of L. monocytogenes to acid stress. Furthermore, we report the first global transcriptome sequencing analysis of L. monocytogenes plasmid gene expression and identify a putative, plasmid-encoded riboswitch with potential involvement in response to acid exposure.
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Affiliation(s)
- Bienvenido W Cortes
- Interdepartmental Microbiology Graduate Program, Iowa State University, Ames, IA, United States.,Department of Animal Science, Iowa State University, Ames, IA, United States
| | - Annabel L Naditz
- Interdepartmental Microbiology Graduate Program, Iowa State University, Ames, IA, United States.,Department of Animal Science, Iowa State University, Ames, IA, United States
| | - Justin M Anast
- Interdepartmental Microbiology Graduate Program, Iowa State University, Ames, IA, United States.,Department of Animal Science, Iowa State University, Ames, IA, United States
| | - Stephan Schmitz-Esser
- Interdepartmental Microbiology Graduate Program, Iowa State University, Ames, IA, United States.,Department of Animal Science, Iowa State University, Ames, IA, United States
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40
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Stratakos AC, Ijaz UZ, Ward P, Linton M, Kelly C, Pinkerton L, Scates P, McBride J, Pet I, Criste A, Stef D, Couto JM, Sloan WT, Dorrell N, Wren BW, Stef L, Gundogdu O, Corcionivoschi N. In vitro and in vivo characterisation of Listeria monocytogenes outbreak isolates. Food Control 2020. [DOI: 10.1016/j.foodcont.2019.106784] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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41
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Augagneur Y, King AN, Germain-Amiot N, Sassi M, Fitzgerald JW, Sahukhal GS, Elasri MO, Felden B, Brinsmade SR. Analysis of the CodY RNome reveals RsaD as a stress-responsive riboregulator of overflow metabolism in Staphylococcus aureus. Mol Microbiol 2019; 113:309-325. [PMID: 31696578 DOI: 10.1111/mmi.14418] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/05/2019] [Indexed: 11/28/2022]
Abstract
In Staphylococcus aureus, the transcription factor CodY modulates the expression of hundreds of genes, including most virulence factors, in response to the availability of key nutrients like GTP and branched-chain amino acids. Despite numerous studies examining how CodY controls gene expression directly or indirectly, virtually nothing is known about the extent to which CodY exerts its effect through small regulatory RNAs (sRNAs). Herein, we report the first set of sRNAs under the control of CodY. We reveal that staphylococcal sRNA RsaD is overexpressed >20-fold in a CodY-deficient strain in three S. aureus clinical isolates and in S. epidermidis. We validated the CodY-dependent regulation of rsaD and demonstrated that CodY directly represses rsaD expression by binding the promoter. Using a combination of molecular techniques, we show that RsaD posttranscriptionally regulates alsS (acetolactate synthase) mRNA and enzyme levels. We further show that RsaD redirects carbon overflow metabolism, contributing to stationary phase cell death during exposure to weak acid stress. Taken together, our data delineate a role for CodY in controlling sRNA expression in a major human pathogen and indicate that RsaD may integrate nutrient depletion and other signals to mount a response to physiological stress experienced by S. aureus in diverse environments.
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Affiliation(s)
- Yoann Augagneur
- INSERM U1230 Biochimie Pharmaceutique, Université de Rennes I, Rennes, France
| | - Alyssa N King
- Department of Biology, Georgetown University, Washington, DC, USA
| | | | - Mohamed Sassi
- INSERM U1230 Biochimie Pharmaceutique, Université de Rennes I, Rennes, France
| | | | - Gyan S Sahukhal
- Center of Molecular and Cellular Biosciences, The University of Southern Mississippi, Hattiesburg, MS, USA
| | - Mohamed O Elasri
- Center of Molecular and Cellular Biosciences, The University of Southern Mississippi, Hattiesburg, MS, USA
| | - Brice Felden
- INSERM U1230 Biochimie Pharmaceutique, Université de Rennes I, Rennes, France
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42
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Patange A, O’Byrne C, Boehm D, Cullen PJ, Keener K, Bourke P. The Effect of Atmospheric Cold Plasma on Bacterial Stress Responses and Virulence Using Listeria monocytogenes Knockout Mutants. Front Microbiol 2019; 10:2841. [PMID: 31921026 PMCID: PMC6918802 DOI: 10.3389/fmicb.2019.02841] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2019] [Accepted: 11/22/2019] [Indexed: 12/28/2022] Open
Abstract
Listeria monocytogenes is an opportunistic intracellular pathogen commonly associated with serious infections and multiple food-borne outbreaks. In this study, we investigated the influence of atmospheric cold plasma (80 kV, 50 Hz) on L. monocytogenes (EGD-e) and its knockout mutants of sigB, rsbR, prfA, gadD, and lmo0799 genes at different treatment time intervals. Further, to ascertain if sub-lethal environmental stress conditions could influence L. monocytogenes survival and growth responses, atmospheric cold plasma (ACP) resistance was evaluated for the cultures exposed to cold (4°C) or acid (pH 4) stress for 1 h. The results demonstrate that both wild-type and knockout mutants were similarly affected after 1 min exposure to ACP (p > 0.05), with a difference in response noted only after 3 min of treatment. While all L. monocytogenes strains exposed to acid/cold stress were hypersensitive to ACP treatment and were significantly reduced or inactivated within 1 min of treatment (p < 0.05). The results indicate sigB and prfA are important for general stress resistance and biofilm, respectively, loss of these two genes significantly reduced bacterial resistance to ACP treatment. In addition, exposure to sub-lethal 1min ACP increased the gene expression of stress associated genes. SigB showed the highest gene expression, increasing by 15.60 fold, followed by gadD2 (7.19) and lmo0799 (8.6) after 1 min exposure. Overall, an increase in gene expression was seen in all stress associated genes analyzed both at 1 min treatment; while long treatment time reduced the gene expression and some cases down-regulated prfA and gadD3 gene expression. By comparing the response of mutants under ACP exposure to key processing parameters, the experimental results presented here provide a baseline for understanding the bacterial genetic response and resistance to cold plasma stress and offers promising insights for optimizing ACP applications.
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Affiliation(s)
- Apurva Patange
- School of Food Science and Environmental Health, Technological University Dublin, Dublin, Ireland
| | - Conor O’Byrne
- Bacterial Stress Response Group, School of Natural Sciences, National University of Ireland, Galway, Galway, Ireland
| | - Daniela Boehm
- School of Food Science and Environmental Health, Technological University Dublin, Dublin, Ireland
| | - P. J. Cullen
- School of Food Science and Environmental Health, Technological University Dublin, Dublin, Ireland
- School of Chemical and Biomolecular Engineering, The University of Sydney, Sydney, NSW, Australia
| | - Kevin Keener
- School of Food Science and Environmental Health, Technological University Dublin, Dublin, Ireland
- Department of Food Science and Human Nutrition, Iowa State University, Ames, IA, United States
| | - Paula Bourke
- School of Food Science and Environmental Health, Technological University Dublin, Dublin, Ireland
- School of Biological Sciences, IGFS, Queen’s University Belfast, Belfast, United Kingdom
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43
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Cross Talk between SigB and PrfA in Listeria monocytogenes Facilitates Transitions between Extra- and Intracellular Environments. Microbiol Mol Biol Rev 2019; 83:83/4/e00034-19. [PMID: 31484692 DOI: 10.1128/mmbr.00034-19] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
The foodborne pathogen Listeria monocytogenes can modulate its transcriptome and proteome to ensure its survival during transmission through vastly differing environmental conditions. While L. monocytogenes utilizes a large array of regulators to achieve survival and growth in different intra- and extrahost environments, the alternative sigma factor σB and the transcriptional activator of virulence genes protein PrfA are two key transcriptional regulators essential for responding to environmental stress conditions and for host infection. Importantly, emerging evidence suggests that the shift from extrahost environments to the host gastrointestinal tract and, subsequently, to intracellular environments requires regulatory interplay between σB and PrfA at transcriptional, posttranscriptional, and protein activity levels. Here, we review the current evidence for cross talk and interplay between σB and PrfA and their respective regulons and highlight the plasticity of σB and PrfA cross talk and the role of this cross talk in facilitating successful transition of L. monocytogenes from diverse extrahost to diverse extra- and intracellular host environments.
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44
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Vasilijević B, Mitić-Ćulafić D, Djekic I, Marković T, Knežević-Vukčević J, Tomasevic I, Velebit B, Nikolić B. Antibacterial effect of Juniperus communis and Satureja montana essential oils against Listeria monocytogenes in vitro and in wine marinated beef. Food Control 2019. [DOI: 10.1016/j.foodcont.2019.01.025] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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45
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Liu Y, Orsi RH, Gaballa A, Wiedmann M, Boor KJ, Guariglia-Oropeza V. Systematic review of the Listeria monocytogenes σB regulon supports a role in stress response, virulence and metabolism. Future Microbiol 2019; 14:801-828. [DOI: 10.2217/fmb-2019-0072] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Aim: Among the alternative sigma factors of Listeria monocytogenes, σB controls the largest regulon. The aim of this study was to perform a comprehensive review of σB-regulated genes, and the functions they confer. Materials & methods: A systematic search of PubMed and Web of Knowledge was carried out to identify members of the σB regulon based on experimental evidence of σB-dependent transcription and presence of a consensus σB-dependent promoter. Results: The literature review identified σB-dependent transcription units encompassing 304 genes encoding different functions including stress response and virulence. Conclusion: Our review supports the well-known roles of σB in virulence and stress response and provides new insight into novel roles for σB in metabolism and overall resilience of L. monocytogenes.
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Affiliation(s)
- Yichang Liu
- Department of Food Science, Cornell University, Ithaca, NY 14850, USA
| | - Renato H Orsi
- Department of Food Science, Cornell University, Ithaca, NY 14850, USA
| | - Ahmed Gaballa
- Department of Food Science, Cornell University, Ithaca, NY 14850, USA
| | - Martin Wiedmann
- Department of Food Science, Cornell University, Ithaca, NY 14850, USA
| | - Kathryn J Boor
- Department of Food Science, Cornell University, Ithaca, NY 14850, USA
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46
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Lanciotti R, Braschi G, Patrignani F, Gobbetti M, De Angelis M. How Listeria monocytogenes Shapes Its Proteome in Response to Natural Antimicrobial Compounds. Front Microbiol 2019; 10:437. [PMID: 30930865 PMCID: PMC6423498 DOI: 10.3389/fmicb.2019.00437] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2018] [Accepted: 02/20/2019] [Indexed: 12/19/2022] Open
Abstract
The goal of this study was to investigate the adaptation of L. monocytogenes Scott A cells to treatments with sublethal doses of antimicrobials (ethanol, citral, carvacrol, E-2-hexenal and thyme essential oil). The survival of L. monocytogenes cells was not affected by the antimicrobials at the concentrations assayed, with the exception of ethanol (1% v/v) and thyme essential oil (100 mg/L), which decreased cell viability from 8.53 ± 0.36 to 7.20 ± 0.22 log CFU/mL (P = 0.04). We subsequently evaluated how L. monocytogenes regulates and shapes its proteome in response to antimicrobial compounds. Compared to the control cells grown under optimal conditions, L. monocytogenes treated for 1 h with the antimicrobial compounds showed increased or decreased (≥ or ≤2-fold, respectively, P < 0.05) levels of protein synthesis for 223 protein spots. As shown multivariate clustering analysis, the proteome profiles differed between treatments. Adaptation and shaping of proteomes mainly concerned cell cycle control, cell division, chromosome, motility and regulatory related proteins, carbohydrate, pyruvate, nucleotide and nitrogen metabolism, cofactors and vitamins and stress response with contrasting responses for different stresses. Ethanol, citral (85 mg/l) or (E)-2-hexenal (150 mg/L) adapted cells increased survival during acid stress imposed under model (BHI) and food-like systems.
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Affiliation(s)
- Rosalba Lanciotti
- Dipartmento di Scienze e Tecnologie Agro-Alimentari, Università degli Studi di Bologna, Bologna, Italy
| | - Giacomo Braschi
- Dipartmento di Scienze e Tecnologie Agro-Alimentari, Università degli Studi di Bologna, Bologna, Italy
| | - Francesca Patrignani
- Dipartmento di Scienze e Tecnologie Agro-Alimentari, Università degli Studi di Bologna, Bologna, Italy
| | | | - Maria De Angelis
- Dipartimento di Scienze del Suolo, della Pianta e degli Alimenti, Università di Bari Aldo Moro, Bari, Italy
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47
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Zetzmann M, Bucur FI, Crauwels P, Borda D, Nicolau AI, Grigore-Gurgu L, Seibold GM, Riedel CU. Characterization of the biofilm phenotype of a Listeria monocytogenes mutant deficient in agr peptide sensing. Microbiologyopen 2019; 8:e00826. [PMID: 30843349 PMCID: PMC6741131 DOI: 10.1002/mbo3.826] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2018] [Revised: 02/01/2019] [Accepted: 02/04/2019] [Indexed: 12/12/2022] Open
Abstract
Listeria monocytogenes is a food‐borne human pathogen and a serious concern in food production and preservation. Previous studies have shown that biofilm formation of L. monocytogenes and presence of extracellular DNA (eDNA) in the biofilm matrix varies with environmental conditions and may involve agr peptide sensing. Experiments in normal and diluted (hypoosmotic) complex media at different temperatures revealed reduced biofilm formation of L. monocytogenes EGD‐e ΔagrD, a mutant deficient in agr peptide sensing, specifically in diluted Brain Heart Infusion at 25°C. This defect was not related to reduced sensitivity to DNase treatment suggesting sufficient levels of eDNA. Re‐analysis of a previously published transcriptional profiling indicated that a total of 132 stress‐related genes, that is 78.6% of the SigB‐dependent stress regulon, are differentially expressed in the ΔagrD mutant. Additionally, a number of genes involved in flagellar motility and a large number of other surface proteins including internalins, peptidoglycan binding and cell wall modifying proteins showed agr‐dependent gene expression. However, survival of the ΔagrD mutant in hypoosmotic conditions or following exposure to high hydrostatic pressure was comparable to the wild type. Also, flagellar motility and surface hydrophobicity were not affected. However, the ΔagrD mutant displayed a significantly reduced viability upon challenge with lysozyme. These results suggest that the biofilm phenotype of the ΔagrD mutant is not a consequence of reduced resistance to hypoosmotic or high pressure stress, motility or surface hydrophobicity. Instead, agr peptide sensing seems to be required for proper regulation of biosynthesis, structure and function of the cell envelope, adhesion to the substratum, and/or interaction of bacteria within a biofilm.
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Affiliation(s)
- Marion Zetzmann
- Institute of Microbiology and Biotechnology, University of Ulm, Ulm, Germany
| | - Florentina Ionela Bucur
- Faculty of Food Science and Engineering, Dunarea de Jos University of Galati, Galati, Romania
| | - Peter Crauwels
- Institute of Microbiology and Biotechnology, University of Ulm, Ulm, Germany
| | - Daniela Borda
- Faculty of Food Science and Engineering, Dunarea de Jos University of Galati, Galati, Romania
| | - Anca Ioana Nicolau
- Faculty of Food Science and Engineering, Dunarea de Jos University of Galati, Galati, Romania
| | - Leontina Grigore-Gurgu
- Faculty of Food Science and Engineering, Dunarea de Jos University of Galati, Galati, Romania
| | - Gerd M Seibold
- Institute of Microbiology and Biotechnology, University of Ulm, Ulm, Germany
| | - Christian U Riedel
- Institute of Microbiology and Biotechnology, University of Ulm, Ulm, Germany
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48
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Gözel B, Monney C, Aguilar‐Bultet L, Rupp S, Frey J, Oevermann A. Hyperinvasiveness of Listeria monocytogenes sequence type 1 is independent of lineage I-specific genes encoding internalin-like proteins. Microbiologyopen 2019; 8:e00790. [PMID: 30656829 PMCID: PMC6612545 DOI: 10.1002/mbo3.790] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2018] [Revised: 11/26/2018] [Accepted: 11/28/2018] [Indexed: 01/24/2023] Open
Abstract
Listeriosis is a severe disease caused by the opportunistic bacterial pathogen Listeria monocytogenes (L. monocytogenes). Previous studies indicate that of the four phylogenetical lineages known, lineage I strains are significantly more prevalent in clinical infections than in the environment. Among lineage 1, sequence type (ST1) belongs to the most frequent genotypes in clinical infections and behaves hyperinvasive in experimental in vitro infections compared to lineage II strains suggesting that yet uncharacterized virulence genes contribute to high virulence of certain lineage I strains. This study investigated the effect of four specific lineage I genes encoding surface proteins with internalin-like structures on cellular infection. CNS derived cell lines (fetal bovine brain cells, human microglia cells) and non-CNS derived cell lines (bovine macrophage cells, human adenocarcinoma cells) that represent the various target cells of L. monocytogenes were infected with the parental ST1 strain and deletion mutants of the four genes. Despite their association with lineage I, deletion of the four genes investigated did not dampen the hyperinvasiveness of the ST1 strain. Similarly, these genes did not contribute to the intracellular survival and intercellular spread of L. monocytogenes ST1, indicating that these genes may have other functions, either during the infection process or outside the host.
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Affiliation(s)
- Bulent Gözel
- Division of Neurological Sciences, Vetsuisse FacultyUniversity of BernBernSwitzerland,Graduate School for Cellular and Biomedical SciencesUniversity of BernBernSwitzerland
| | - Camille Monney
- Division of Neurological Sciences, Vetsuisse FacultyUniversity of BernBernSwitzerland
| | - Lisandra Aguilar‐Bultet
- Graduate School for Cellular and Biomedical SciencesUniversity of BernBernSwitzerland,Vetsuisse FacultyUniversity of BernBernSwitzerland
| | - Sebastian Rupp
- Division of Neurological Sciences, Vetsuisse FacultyUniversity of BernBernSwitzerland,Graduate School for Cellular and Biomedical SciencesUniversity of BernBernSwitzerland
| | - Joachim Frey
- Vetsuisse FacultyUniversity of BernBernSwitzerland
| | - Anna Oevermann
- Division of Neurological Sciences, Vetsuisse FacultyUniversity of BernBernSwitzerland
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49
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Role and regulation of the stress activated sigma factor sigma B (σ B) in the saprophytic and host-associated life stages of Listeria monocytogenes. ADVANCES IN APPLIED MICROBIOLOGY 2019; 106:1-48. [PMID: 30798801 DOI: 10.1016/bs.aambs.2018.11.001] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
The stress activated sigma factor sigma B (σB) plays a pivotal role in allowing the food-borne bacterial pathogen Listeria monocytogenes to modulate its transcriptional landscape in order to survive in a variety of harsh environments both outside and within the host. While we have a comparatively good understanding of the systems under the control of this sigma factor much less is known about how the activity of σB is controlled. In this review, we present a current model describing how this sigma factor is thought to be controlled including an overview of what is known about stress sensing and the early signal transduction events that trigger its activation. We discuss the known regulatory overlaps between σB and other protein and RNA regulators in the cell. Finally, we describe the role of σB in surviving both saprophytic and host-associated stresses. The complexity of the regulation of this sigma factor reflects the significant role that it plays in the persistence of this important pathogen in the natural environment, the food chain as well as within the host during the early stages of an infection. Understanding its regulation will be a critical step in helping to develop rational strategies to prevent its growth and survival in the food destined for human consumption and in the prevention of listeriosis.
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50
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Bucur FI, Grigore-Gurgu L, Crauwels P, Riedel CU, Nicolau AI. Resistance of Listeria monocytogenes to Stress Conditions Encountered in Food and Food Processing Environments. Front Microbiol 2018; 9:2700. [PMID: 30555426 PMCID: PMC6282059 DOI: 10.3389/fmicb.2018.02700] [Citation(s) in RCA: 143] [Impact Index Per Article: 23.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2018] [Accepted: 10/23/2018] [Indexed: 12/17/2022] Open
Abstract
Listeria monocytogenes is a human food-borne facultative intracellular pathogen that is resistant to a wide range of stress conditions. As a consequence, L. monocytogenes is extremely difficult to control along the entire food chain from production to storage and consumption. Frequent and recent outbreaks of L. monocytogenes infections illustrate that current measures of decontamination and preservation are suboptimal to control L. monocytogenes in food. In order to develop efficient measures to prevent contamination during processing and control growth during storage of food it is crucial to understand the mechanisms utilized by L. monocytogenes to tolerate the stress conditions in food matrices and food processing environments. Food-related stress conditions encountered by L. monocytogenes along the food chain are acidity, oxidative and osmotic stress, low or high temperatures, presence of bacteriocins and other preserving additives, and stresses as a consequence of applying alternative decontamination and preservation technologies such high hydrostatic pressure, pulsed and continuous UV light, pulsed electric fields (PEF). This review is aimed at providing a summary of the current knowledge on the response of L. monocytogenes toward these stresses and the mechanisms of stress resistance employed by this important food-borne bacterium. Circumstances when L. monocytogenes cells become more sensitive or more resistant are mentioned and existence of a cross-resistance when multiple stresses are present is pointed out.
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Affiliation(s)
- Florentina Ionela Bucur
- Faculty of Food Science and Engineering, Dunarea de Jos University of Galati, Galati, Romania
| | - Leontina Grigore-Gurgu
- Faculty of Food Science and Engineering, Dunarea de Jos University of Galati, Galati, Romania
| | - Peter Crauwels
- Institute of Microbiology and Biotechnology, Ulm University, Ulm, Germany
| | | | - Anca Ioana Nicolau
- Faculty of Food Science and Engineering, Dunarea de Jos University of Galati, Galati, Romania
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