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Gaviria-Cantin T, Fernández-Coll L, Vargas AF, Jiménez CJ, Madrid C, Balsalobre C. Expression of accessory genes in Salmonella requires the presence of the Gre factors. Genomics 2024; 116:110777. [PMID: 38163572 DOI: 10.1016/j.ygeno.2023.110777] [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: 08/03/2023] [Revised: 12/13/2023] [Accepted: 12/29/2023] [Indexed: 01/03/2024]
Abstract
Genomic studies with Salmonella enterica serovar Typhimurium reveal a crucial role of horizontal gene transfer (HGT) in the acquisition of accessory cellular functions involved in host-interaction. Many virulence genes are located in genomic islands, plasmids and prophages. GreA and GreB proteins, Gre factors, interact transiently with the RNA polymerase alleviating backtracked complexes during transcription elongation. The overall effect of Gre factors depletion in Salmonella expression profile was studied. Both proteins are functionally redundant since only when both Gre factors were depleted a major effect in gene expression was detected. Remarkably, the accessory gene pool is particularly sensitive to the lack of Gre factors, with 18.6% of accessory genes stimulated by the Gre factors versus 4.4% of core genome genes. Gre factors involvement is particularly relevant for the expression of genes located in genomic islands. Our data reveal that Gre factors are required for the expression of accessory genes.
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Affiliation(s)
- Tania Gaviria-Cantin
- Department of Genetics, Microbiology and Statistics, School of Biology, Universitat de Barcelona, Avda. Diagonal 643, Barcelona 08028, Spain
| | - Llorenç Fernández-Coll
- Department of Genetics, Microbiology and Statistics, School of Biology, Universitat de Barcelona, Avda. Diagonal 643, Barcelona 08028, Spain
| | - Andrés Felipe Vargas
- Department of Genetics, Microbiology and Statistics, School of Biology, Universitat de Barcelona, Avda. Diagonal 643, Barcelona 08028, Spain
| | - Carlos Jonay Jiménez
- Department of Genetics, Microbiology and Statistics, School of Biology, Universitat de Barcelona, Avda. Diagonal 643, Barcelona 08028, Spain
| | - Cristina Madrid
- Department of Genetics, Microbiology and Statistics, School of Biology, Universitat de Barcelona, Avda. Diagonal 643, Barcelona 08028, Spain
| | - Carlos Balsalobre
- Department of Genetics, Microbiology and Statistics, School of Biology, Universitat de Barcelona, Avda. Diagonal 643, Barcelona 08028, Spain.
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Mkangara M. Prevention and Control of Human Salmonella enterica Infections: An Implication in Food Safety. INTERNATIONAL JOURNAL OF FOOD SCIENCE 2023; 2023:8899596. [PMID: 37727836 PMCID: PMC10506869 DOI: 10.1155/2023/8899596] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/10/2022] [Revised: 08/19/2023] [Accepted: 08/26/2023] [Indexed: 09/21/2023]
Abstract
Salmonella is a foodborne zoonotic pathogen causing diarrhoeal disease to humans after consuming contaminated water, animal, and plant products. The bacterium is the third leading cause of human death among diarrhoeal diseases worldwide. Therefore, human salmonellosis is of public health concern demanding integrated interventions against the causative agent, Salmonella enterica. The prevention of salmonellosis in humans is intricate due to several factors, including an immune-stable individual infected with S. enterica continuing to shed live bacteria without showing any clinical signs. Similarly, the asymptomatic Salmonella animals are the source of salmonellosis in humans after consuming contaminated food products. Furthermore, the contaminated products of plant and animal origin are a menace in food industries due to Salmonella biofilms, which enhance colonization, persistence, and survival of bacteria on equipment. The contaminated food products resulting from bacteria on equipment offset the economic competition of food industries and partner institutions in international business. The most worldwide prevalent broad-range Salmonella serovars affecting humans are Salmonella Typhimurium and Salmonella Enteritidis, and poultry products, among others, are the primary source of infection. The broader range of Salmonella serovars creates concern over multiple strategies for preventing and controlling Salmonella contamination in foods to enhance food safety for humans. Among the strategies for preventing and controlling Salmonella spread in animal and plant products include biosecurity measures, isolation and quarantine, epidemiological surveillance, farming systems, herbs and spices, and vaccination. Other measures are the application of phages, probiotics, prebiotics, and nanoparticles reduced and capped with antimicrobial agents. Therefore, Salmonella-free products, such as beef, pork, poultry meat, eggs, milk, and plant foods, such as vegetables and fruits, will prevent humans from Salmonella infection. This review explains Salmonella infection in humans caused by consuming contaminated foods and the interventions against Salmonella contamination in foods to enhance food safety and quality for humans.
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Affiliation(s)
- Mwanaisha Mkangara
- Department of Science and Laboratory Technology, Dar es Salaam Institute of Technology, P.O. Box 2958, Dar es Salaam, Tanzania
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3
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Hodges FJ, Torres VVL, Cunningham AF, Henderson IR, Icke C. Redefining the bacterial Type I protein secretion system. Adv Microb Physiol 2023; 82:155-204. [PMID: 36948654 DOI: 10.1016/bs.ampbs.2022.10.003] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Type I secretion systems (T1SS) are versatile molecular machines for protein transport across the Gram-negative cell envelope. The archetypal Type I system mediates secretion of the Escherichia coli hemolysin, HlyA. This system has remained the pre-eminent model of T1SS research since its discovery. The classic description of a T1SS is composed of three proteins: an inner membrane ABC transporter, a periplasmic adaptor protein and an outer membrane factor. According to this model, these components assemble to form a continuous channel across the cell envelope, an unfolded substrate molecule is then transported in a one-step mechanism, directly from the cytosol to the extracellular milieu. However, this model does not encapsulate the diversity of T1SS that have been characterized to date. In this review, we provide an updated definition of a T1SS, and propose the subdivision of this system into five subgroups. These subgroups are categorized as T1SSa for RTX proteins, T1SSb for non-RTX Ca2+-binding proteins, T1SSc for non-RTX proteins, T1SSd for class II microcins, and T1SSe for lipoprotein secretion. Although often overlooked in the literature, these alternative mechanisms of Type I protein secretion offer many avenues for biotechnological discovery and application.
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Affiliation(s)
- Freya J Hodges
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD, Australia
| | - Von Vergel L Torres
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD, Australia
| | - Adam F Cunningham
- Institute of Immunology and Immunotherapy, University of Birmingham, Birmingham, United Kingdom
| | - Ian R Henderson
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD, Australia.
| | - Christopher Icke
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD, Australia.
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Morasi RM, Rall VLM, Dantas STA, Alonso VPP, Silva NCC. Salmonella spp. in low water activity food: Occurrence, survival mechanisms, and thermoresistance. J Food Sci 2022; 87:2310-2323. [PMID: 35478321 DOI: 10.1111/1750-3841.16152] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2021] [Revised: 03/04/2022] [Accepted: 03/22/2022] [Indexed: 01/17/2023]
Abstract
The occurrence of disease outbreaks involving low-water-activity (aw ) foods has gained increased prominence due in part to the fact that reducing free water in these foods is normally a measure that controls the growth and multiplication of pathogenic microorganisms. Salmonella, one of the main bacteria involved in these outbreaks, represents a major public health problem worldwide and in Brazil, which highlights the importance of good manufacturing and handling practices for food quality. The virulence of this pathogen, associated with its high ability to persist in the environment, makes Salmonella one of the main challenges for the food industry. The objectives of this article are to present the general characteristics, virulence, thermoresistance, control, and relevance of Salmonella in foodborne diseases, and describe the so-called low-water-activity foods and the salmonellosis outbreaks involving them.
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Affiliation(s)
- Rafaela Martins Morasi
- Department of Food Sciences And Nutrition, Faculty of Food Engineering, State University of Campinas (UNICAMP), Monteiro Lobato Street, 80, Campinas, São Paulo, Brazil
| | - Vera Lúcia Mores Rall
- Sector of Microbiology and Immunology, Department of Chemical and Biological Sciences, Institute of Biosciences of Botucatu, São Paulo State University (UNESP), Botucatu, Brazil
| | - Stéfani Thais Alves Dantas
- Sector of Microbiology and Immunology, Department of Chemical and Biological Sciences, Institute of Biosciences of Botucatu, São Paulo State University (UNESP), Botucatu, Brazil
| | - Vanessa Pereira Perez Alonso
- Department of Food Sciences And Nutrition, Faculty of Food Engineering, State University of Campinas (UNICAMP), Monteiro Lobato Street, 80, Campinas, São Paulo, Brazil
| | - Nathália Cristina Cirone Silva
- Department of Food Sciences And Nutrition, Faculty of Food Engineering, State University of Campinas (UNICAMP), Monteiro Lobato Street, 80, Campinas, São Paulo, Brazil
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Chen Z, Zhao Z, Hui X, Zhang J, Hu Y, Chen R, Cai X, Hu Y, Wang Y. T1SEstacker: A Tri-Layer Stacking Model Effectively Predicts Bacterial Type 1 Secreted Proteins Based on C-Terminal Non-repeats-in-Toxin-Motif Sequence Features. Front Microbiol 2022; 12:813094. [PMID: 35211101 PMCID: PMC8861453 DOI: 10.3389/fmicb.2021.813094] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2021] [Accepted: 12/20/2021] [Indexed: 11/21/2022] Open
Abstract
Type 1 secretion systems play important roles in pathogenicity of Gram-negative bacteria. However, the substrate secretion mechanism remains largely unknown. In this research, we observed the sequence features of repeats-in-toxin (RTX) proteins, a major class of type 1 secreted effectors (T1SEs). We found striking non-RTX-motif amino acid composition patterns at the C termini, most typically exemplified by the enriched “[FLI][VAI]” at the most C-terminal two positions. Machine-learning models, including deep-learning ones, were trained using these sequence-based non-RTX-motif features and further combined into a tri-layer stacking model, T1SEstacker, which predicted the RTX proteins accurately, with a fivefold cross-validated sensitivity of ∼0.89 at the specificity of ∼0.94. Besides substrates with RTX motifs, T1SEstacker can also well distinguish non-RTX-motif T1SEs, further suggesting their potential existence of common secretion signals. T1SEstacker was applied to predict T1SEs from the genomes of representative Salmonella strains, and we found that both the number and composition of T1SEs varied among strains. The number of T1SEs is estimated to reach 100 or more in each strain, much larger than what we expected. In summary, we made comprehensive sequence analysis on the type 1 secreted RTX proteins, identified common sequence-based features at the C termini, and developed a stacking model that can predict type 1 secreted proteins accurately.
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Affiliation(s)
- Zewei Chen
- Youth Innovation Team of Medical Bioinformatics, Shenzhen University Health Science Center, Shenzhen, China
| | - Ziyi Zhao
- Youth Innovation Team of Medical Bioinformatics, Shenzhen University Health Science Center, Shenzhen, China
| | - Xinjie Hui
- Department of Respiratory Medicine, Xuanwu Hospital, Capital Medical University, Beijing, China
| | - Junya Zhang
- Youth Innovation Team of Medical Bioinformatics, Shenzhen University Health Science Center, Shenzhen, China
| | - Yixue Hu
- Youth Innovation Team of Medical Bioinformatics, Shenzhen University Health Science Center, Shenzhen, China
| | - Runhong Chen
- Youth Innovation Team of Medical Bioinformatics, Shenzhen University Health Science Center, Shenzhen, China
| | - Xuxia Cai
- Youth Innovation Team of Medical Bioinformatics, Shenzhen University Health Science Center, Shenzhen, China
| | - Yueming Hu
- Youth Innovation Team of Medical Bioinformatics, Shenzhen University Health Science Center, Shenzhen, China
| | - Yejun Wang
- Youth Innovation Team of Medical Bioinformatics, Shenzhen University Health Science Center, Shenzhen, China
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Soffer G, Perry JM, Shih SCC. Real-Time Optogenetics System for Controlling Gene Expression Using a Model-Based Design. Anal Chem 2021; 93:3181-3188. [PMID: 33543619 DOI: 10.1021/acs.analchem.0c04594] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Optimization of engineered biological systems requires precise control over the rates and timing of gene expression. Optogenetics is used to dynamically control gene expression as an alternative to conventional chemical-based methods since it provides a more convenient interface between digital control software and microbial culture. Here, we describe the construction of a real-time optogenetics platform, which performs closed-loop control over the CcaR-CcaS two-plasmid system in Escherichia coli. We showed the first model-based design approach by constructing a nonlinear representation of the CcaR-CcaS system, tuned the model through open-loop experimentation to capture the experimental behavior, and applied the model in silico to inform the necessary changes to build a closed-loop optogenetic control system. Our system periodically induces and represses the CcaR-CcaS system while recording optical density and fluorescence using image processing techniques. We highlight the facile nature of constructing our system and how our model-based design approach will potentially be used to model other systems requiring closed-loop optogenetic control.
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Affiliation(s)
- Guy Soffer
- Department of Electrical and Computer Engineering, Concordia University, 1455 de Maisonneuve Blvd West, Montréal, Québec H3G1M8, Canada.,Centre for Applied Synthetic Biology, Concordia University, 7141 Sherbrooke St. West, Montréal, Québec H4B1R6, Canada
| | - James M Perry
- Centre for Applied Synthetic Biology, Concordia University, 7141 Sherbrooke St. West, Montréal, Québec H4B1R6, Canada.,Department of Biology, Concordia University, 7141 Sherbrooke St. West, Montréal, Québec H4B1R6, Canada
| | - Steve C C Shih
- Department of Electrical and Computer Engineering, Concordia University, 1455 de Maisonneuve Blvd West, Montréal, Québec H3G1M8, Canada.,Centre for Applied Synthetic Biology, Concordia University, 7141 Sherbrooke St. West, Montréal, Québec H4B1R6, Canada.,Department of Biology, Concordia University, 7141 Sherbrooke St. West, Montréal, Québec H4B1R6, Canada
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