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Chen S, Du F, Shang K, Chen H, Guo R, Liao C, Jia Y, Yu Z, Li J, Zhang C, Ding K. Colonization Mediated by T6SS-ClpV Disrupts Host Gut Microbiota and Enhances Virulence of Salmonella enterica serovar Typhimurium. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2024; 72:19155-19166. [PMID: 39161106 DOI: 10.1021/acs.jafc.4c03735] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/21/2024]
Abstract
Salmonella enterica serovar Typhimurium (S. Typhimurium) is a common foodborne enteric pathogen that infects humans or mammals and colonizes the intestinal tract primarily by invading the host following ingestion. Meanwhile, ClpV is a core secreted protein of the bacterial type VI secretion system (T6SS). Because elucidating ClpV's role in the pathogenesis of T6SS is pivotal for revealing the virulence mechanism of Salmonella, in our study, clpV gene deletion mutants were constructed using a λ-red-based recombination system, and the effect of clpV mutation on SL1344's pathogenicity was examined in terms of stress resistance, motility, cytokine secretion, gut microbiota, and a BALB/c mouse model. Among the results, ClpV affected SL1344's motility and was also involved in cell invasion, adhesion, and intracellular survival in the MDBK cell model but did not affect invasion or intracellular survival in the RAW264.7 cell model. Moreover, clpV gene deletion significantly reduced the transcription levels of GBP2b, IFNB1, IL-6, NLRP3, NOS2, and TNF-α proinflammatory factor levels but significantly increased transcription levels of IL-4 and IL-10 anti-inflammatory factors. Last, ClpV appeared to closely relate to the pathogenicity of S. Typhimurium in vivo, which can change the gut environment and cause dysbiosis of gut microbiota. Our findings elucidate the functions of ClpV in S. Typhimurium and illustrating interactions between T6SS and gut microbiota help to clarify the mechanisms of the pathogenesis of foodborne diseases.
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Affiliation(s)
- Songbiao Chen
- College of Animal Science and Technology/Laboratory of Functional Microbiology and Animal Health, Henan University of Science and Technology, Luoyang 471023, China
- Luoyang Key Laboratory of Live Carrier Biomaterial and Animal Disease Prevention and Control, Henan University of Science and Technology, Luoyang 471003, China
- The Key Lab of Animal Disease and Public Health, Henan University of Science and Technology, Luoyang 471023, China
- Ministry of Education Key Laboratory for Animal Pathogens and Biosafety, Zhengzhou, Henan 450000, China
| | - Fuxi Du
- College of Animal Science and Technology/Laboratory of Functional Microbiology and Animal Health, Henan University of Science and Technology, Luoyang 471023, China
- Luoyang Key Laboratory of Live Carrier Biomaterial and Animal Disease Prevention and Control, Henan University of Science and Technology, Luoyang 471003, China
- The Key Lab of Animal Disease and Public Health, Henan University of Science and Technology, Luoyang 471023, China
| | - Ke Shang
- College of Animal Science and Technology/Laboratory of Functional Microbiology and Animal Health, Henan University of Science and Technology, Luoyang 471023, China
- Luoyang Key Laboratory of Live Carrier Biomaterial and Animal Disease Prevention and Control, Henan University of Science and Technology, Luoyang 471003, China
- The Key Lab of Animal Disease and Public Health, Henan University of Science and Technology, Luoyang 471023, China
| | - Huimin Chen
- College of Animal Science and Technology/Laboratory of Functional Microbiology and Animal Health, Henan University of Science and Technology, Luoyang 471023, China
- Luoyang Key Laboratory of Live Carrier Biomaterial and Animal Disease Prevention and Control, Henan University of Science and Technology, Luoyang 471003, China
- The Key Lab of Animal Disease and Public Health, Henan University of Science and Technology, Luoyang 471023, China
| | - Rongxian Guo
- College of Animal Science and Technology/Laboratory of Functional Microbiology and Animal Health, Henan University of Science and Technology, Luoyang 471023, China
- Luoyang Key Laboratory of Live Carrier Biomaterial and Animal Disease Prevention and Control, Henan University of Science and Technology, Luoyang 471003, China
- The Key Lab of Animal Disease and Public Health, Henan University of Science and Technology, Luoyang 471023, China
| | - Chengshui Liao
- College of Animal Science and Technology/Laboratory of Functional Microbiology and Animal Health, Henan University of Science and Technology, Luoyang 471023, China
- Luoyang Key Laboratory of Live Carrier Biomaterial and Animal Disease Prevention and Control, Henan University of Science and Technology, Luoyang 471003, China
- The Key Lab of Animal Disease and Public Health, Henan University of Science and Technology, Luoyang 471023, China
- Ministry of Education Key Laboratory for Animal Pathogens and Biosafety, Zhengzhou, Henan 450000, China
| | - Yanyan Jia
- College of Animal Science and Technology/Laboratory of Functional Microbiology and Animal Health, Henan University of Science and Technology, Luoyang 471023, China
- Luoyang Key Laboratory of Live Carrier Biomaterial and Animal Disease Prevention and Control, Henan University of Science and Technology, Luoyang 471003, China
- The Key Lab of Animal Disease and Public Health, Henan University of Science and Technology, Luoyang 471023, China
| | - Zuhua Yu
- College of Animal Science and Technology/Laboratory of Functional Microbiology and Animal Health, Henan University of Science and Technology, Luoyang 471023, China
- Luoyang Key Laboratory of Live Carrier Biomaterial and Animal Disease Prevention and Control, Henan University of Science and Technology, Luoyang 471003, China
- The Key Lab of Animal Disease and Public Health, Henan University of Science and Technology, Luoyang 471023, China
| | - Jing Li
- College of Animal Science and Technology/Laboratory of Functional Microbiology and Animal Health, Henan University of Science and Technology, Luoyang 471023, China
- Luoyang Key Laboratory of Live Carrier Biomaterial and Animal Disease Prevention and Control, Henan University of Science and Technology, Luoyang 471003, China
- The Key Lab of Animal Disease and Public Health, Henan University of Science and Technology, Luoyang 471023, China
| | - Chunjie Zhang
- College of Animal Science and Technology/Laboratory of Functional Microbiology and Animal Health, Henan University of Science and Technology, Luoyang 471023, China
- Luoyang Key Laboratory of Live Carrier Biomaterial and Animal Disease Prevention and Control, Henan University of Science and Technology, Luoyang 471003, China
- The Key Lab of Animal Disease and Public Health, Henan University of Science and Technology, Luoyang 471023, China
| | - Ke Ding
- College of Animal Science and Technology/Laboratory of Functional Microbiology and Animal Health, Henan University of Science and Technology, Luoyang 471023, China
- Luoyang Key Laboratory of Live Carrier Biomaterial and Animal Disease Prevention and Control, Henan University of Science and Technology, Luoyang 471003, China
- The Key Lab of Animal Disease and Public Health, Henan University of Science and Technology, Luoyang 471023, China
- Ministry of Education Key Laboratory for Animal Pathogens and Biosafety, Zhengzhou, Henan 450000, China
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Garai S, Bhowal B, Gupta M, Sopory SK, Singla-Pareek SL, Pareek A, Kaur C. Role of methylglyoxal and redox homeostasis in microbe-mediated stress mitigation in plants. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2024; 338:111922. [PMID: 37952767 DOI: 10.1016/j.plantsci.2023.111922] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/17/2023] [Revised: 10/04/2023] [Accepted: 11/07/2023] [Indexed: 11/14/2023]
Abstract
One of the general consequences of stress in plants is the accumulation of reactive oxygen (ROS) and carbonyl species (like methylglyoxal) to levels that are detrimental for plant growth. These reactive species are inherently produced in all organisms and serve different physiological functions but their excessive accumulation results in cellular toxicity. It is, therefore, essential to restore equilibrium between their synthesis and breakdown to ensure normal cellular functioning. Detoxification mechanisms that scavenge these reactive species are considered important for stress mitigation as they maintain redox balance by restricting the levels of ROS, methylglyoxal and other reactive species in the cellular milieu. Stress tolerance imparted to plants by root-associated microbes involves a multitude of mechanisms, including maintenance of redox homeostasis. By improving the overall antioxidant response in plants, microbes can strengthen defense pathways and hence, the adaptive abilities of plants to sustain growth under stress. Hence, through this review we wish to highlight the contribution of root microbiota in modulating the levels of reactive species and thereby, maintaining redox homeostasis in plants as one of the important mechanisms of stress alleviation. Further, we also examine the microbial mechanisms of resistance to oxidative stress and their role in combating plant stress.
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Affiliation(s)
- Sampurna Garai
- International Centre for Genetic Engineering and Biotechnology, New Delhi, India
| | - Bidisha Bhowal
- International Centre for Genetic Engineering and Biotechnology, New Delhi, India
| | - Mayank Gupta
- International Centre for Genetic Engineering and Biotechnology, New Delhi, India
| | - Sudhir K Sopory
- International Centre for Genetic Engineering and Biotechnology, New Delhi, India
| | - Sneh L Singla-Pareek
- International Centre for Genetic Engineering and Biotechnology, New Delhi, India
| | - Ashwani Pareek
- National Agri-Food Biotechnology Institute, SAS Nagar, Mohali, Punjab 140306, India
| | - Charanpreet Kaur
- National Agri-Food Biotechnology Institute, SAS Nagar, Mohali, Punjab 140306, India.
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Yang XT, Wang J, Jiang YH, Zhang L, Du L, Li J, Liu F. Insight into the mechanism of gallstone disease by proteomic and metaproteomic characterization of human bile. Front Microbiol 2023; 14:1276951. [PMID: 38111640 PMCID: PMC10726133 DOI: 10.3389/fmicb.2023.1276951] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2023] [Accepted: 11/16/2023] [Indexed: 12/20/2023] Open
Abstract
Introduction Cholesterol gallstone disease is a prevalent condition that has a significant economic impact. However, the role of the bile microbiome in its development and the host's responses to it remain poorly understood. Methods In this study, we conducted a comprehensive analysis of microbial and human bile proteins in 40 individuals with either gallstone disease or gallbladder polyps. We employed a combined proteomic and metaproteomic approach, as well as meta-taxonomic analysis, functional pathway enrichment, and Western blot analyses. Results Our metaproteomic analysis, utilizing the lowest common ancestor algorithm, identified 158 microbial taxa in the bile samples. We discovered microbial taxa that may contribute to gallstone formation, including β-glucuronidase-producing bacteria such as Streptococcus, Staphylococcus, and Clostridium, as well as those involved in biofilm formation like Helicobacter, Cyanobacteria, Pseudomonas, Escherichia coli, and Clostridium. Furthermore, we identified 2,749 human proteins and 87 microbial proteins with a protein false discovery rate (FDR) of 1% and at least 2 distinct peptides. Among these proteins, we found microbial proteins crucial to biofilm formation, such as QDR3, ompA, ndk, pstS, nanA, pfIB, and dnaK. Notably, QDR3 showed a gradual upregulation from chronic to acute cholesterol gallstone disease when compared to polyp samples. Additionally, we discovered other microbial proteins that enhance bacterial virulence and gallstone formation by counteracting host oxidative stress, including sodB, katG, rbr, htrA, and ahpC. We also identified microbial proteins like lepA, rtxA, pckA, tuf, and tpiA that are linked to bacterial virulence and potential gallstone formation, with lepA being upregulated in gallstone bile compared to polyp bile. Furthermore, our analysis of the host proteome in gallstone bile revealed enhanced inflammatory molecular profiles, including innate immune molecules against microbial infections. Gallstone bile exhibited overrepresented pathways related to blood coagulation, folate metabolism, and the IL-17 pathway. However, we observed suppressed metabolic activities, particularly catabolic metabolism and transport activities, in gallstone bile compared to polyp bile. Notably, acute cholelithiasis bile demonstrated significantly impaired metabolic activities compared to chronic cholelithiasis bile. Conclusion Our study provides a comprehensive metaproteomic analysis of bile samples related to gallstone disease, offering new insights into the microbiome-host interaction and gallstone formation mechanism.
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Affiliation(s)
- Xue-Ting Yang
- Minhang Hospital, Fudan University, and Shanghai Key Laboratory of Medical Epigenetics, The International Co-laboratory of Medical Epigenetics and Metabolism, Ministry of Science and Technology, Institutes of Biomedical of Sciences, Fudan University, Shanghai, China
| | - Jie Wang
- Minhang Hospital, Fudan University, and Shanghai Key Laboratory of Medical Epigenetics, The International Co-laboratory of Medical Epigenetics and Metabolism, Ministry of Science and Technology, Institutes of Biomedical of Sciences, Fudan University, Shanghai, China
| | - Ying-Hua Jiang
- Minhang Hospital, Fudan University, and Shanghai Key Laboratory of Medical Epigenetics, The International Co-laboratory of Medical Epigenetics and Metabolism, Ministry of Science and Technology, Institutes of Biomedical of Sciences, Fudan University, Shanghai, China
| | - Lei Zhang
- Minhang Hospital, Fudan University, and Shanghai Key Laboratory of Medical Epigenetics, The International Co-laboratory of Medical Epigenetics and Metabolism, Ministry of Science and Technology, Institutes of Biomedical of Sciences, Fudan University, Shanghai, China
| | - Ling Du
- Key Laboratory of Digestive Cancer Full Cycle Monitoring and Precise Intervention of Shanghai Municipal Health Commission, Minhang Hospital, Fudan University, Shanghai, China
| | - Jun Li
- Department of Surgery, Tongren Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China
| | - Feng Liu
- Minhang Hospital, Fudan University, and Shanghai Key Laboratory of Medical Epigenetics, The International Co-laboratory of Medical Epigenetics and Metabolism, Ministry of Science and Technology, Institutes of Biomedical of Sciences, Fudan University, Shanghai, China
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Uppalapati SR, Vazquez-Torres A. Manganese Utilization in Salmonella Pathogenesis: Beyond the Canonical Antioxidant Response. Front Cell Dev Biol 2022; 10:924925. [PMID: 35903545 PMCID: PMC9315381 DOI: 10.3389/fcell.2022.924925] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2022] [Accepted: 06/22/2022] [Indexed: 11/16/2022] Open
Abstract
The metal ion manganese (Mn2+) is equally coveted by hosts and bacterial pathogens. The host restricts Mn2+ in the gastrointestinal tract and Salmonella-containing vacuoles, as part of a process generally known as nutritional immunity. Salmonella enterica serovar Typhimurium counteract Mn2+ limitation using a plethora of metal importers, whose expression is under elaborate transcriptional and posttranscriptional control. Mn2+ serves as cofactor for a variety of enzymes involved in antioxidant defense or central metabolism. Because of its thermodynamic stability and low reactivity, bacterial pathogens may favor Mn2+-cofactored metalloenzymes during periods of oxidative stress. This divalent metal catalyzes metabolic flow through lower glycolysis, reductive tricarboxylic acid and the pentose phosphate pathway, thereby providing energetic, redox and biosynthetic outputs associated with the resistance of Salmonella to reactive oxygen species generated in the respiratory burst of professional phagocytic cells. Combined, the oxyradical-detoxifying properties of Mn2+ together with the ability of this divalent metal cation to support central metabolism help Salmonella colonize the mammalian gut and establish systemic infections.
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Affiliation(s)
- Siva R. Uppalapati
- Department of Immunology & Microbiology, University of Colorado School of Medicine, Aurora, CO, United States,*Correspondence: Siva R. Uppalapati, ; Andres Vazquez-Torres,
| | - Andres Vazquez-Torres
- Department of Immunology & Microbiology, University of Colorado School of Medicine, Aurora, CO, United States,Veterans Affairs Eastern Colorado Health Care System, Denver, CO, United States,*Correspondence: Siva R. Uppalapati, ; Andres Vazquez-Torres,
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He Y, Chen R, Qi Y, Salazar JK, Zhang S, Tortorello ML, Deng X, Zhang W. Survival and transcriptomic response of Salmonella enterica on fresh-cut fruits. Int J Food Microbiol 2021; 348:109201. [PMID: 33930836 DOI: 10.1016/j.ijfoodmicro.2021.109201] [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: 12/26/2020] [Revised: 03/26/2021] [Accepted: 04/13/2021] [Indexed: 01/21/2023]
Abstract
Salmonella enterica is frequently implicated in foodborne disease outbreaks associated with fresh-cut fruits. In the U.S., more than one third of fruit-related outbreaks have been linked to two S. enterica serotypes Newport and Typhimurium. Approximately 80% of fruit-related human salmonellosis cases were associated with tomatoes, cantaloupes and cucumbers. In this study, we investigated the population dynamics of S. Newport and S. Typhimurium on fresh-cut tomato, cantaloupe, cucumber and apple under short-term storage conditions. We further compared the transcriptomic profiles of a S. Newport strain on fresh-cut tomato and cantaloupe using high-throughput RNA-seq. We demonstrated that both S. enterica Newport and Typhimurium survived well on various fresh-cut fruit items under refrigeration storage conditions, independent of inoculation levels. However, S. enterica displayed variable survival behaviors on different types of fruits. For example, at 7 d storage, the population of S. enterica reduced less than 0.2 log (p > 0.05) on fresh-cut tomato and cantaloupe, in contrast to ~0.5 log (p < 0.05) on cucumber and apple. RNA-seq analysis suggested that S. enterica mediates its survival on fresh-cut fruits through differentially regulating genes involved in specific carbon utilization and metabolic pathways. Several known bacterial virulence factors (e.g., pag gene) were found to be differentially regulated on fresh-cut tomato and cantaloupe, suggesting a link between the events of food contamination and subsequent human infection. Findings from this study contribute to a better understanding of S. enterica survival mechanisms on fresh-cut produce.
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Affiliation(s)
- Yingshu He
- Department of Food Science and Nutrition & Institute for Food Safety and Health, Illinois Institute of Technology, Bedford Park, IL, USA; Center for Food Safety, College of Agricultural and Environmental Sciences, University of Georgia, Griffin, GA, USA.
| | - Ruixi Chen
- Department of Food Science and Nutrition & Institute for Food Safety and Health, Illinois Institute of Technology, Bedford Park, IL, USA
| | - Yan Qi
- Center for Food Safety, College of Agricultural and Environmental Sciences, University of Georgia, Griffin, GA, USA
| | - Joelle K Salazar
- Division of Food Processing Science and Technology, U. S. Food and Drug Administration, Bedford Park, IL, USA
| | - Shimei Zhang
- Department of Food Science and Nutrition & Institute for Food Safety and Health, Illinois Institute of Technology, Bedford Park, IL, USA
| | - Mary Lou Tortorello
- Division of Food Processing Science and Technology, U. S. Food and Drug Administration, Bedford Park, IL, USA
| | - Xiangyu Deng
- Center for Food Safety, College of Agricultural and Environmental Sciences, University of Georgia, Griffin, GA, USA
| | - Wei Zhang
- Department of Food Science and Nutrition & Institute for Food Safety and Health, Illinois Institute of Technology, Bedford Park, IL, USA
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Costa OY, Zerillo MM, Zühlke D, Kielak AM, Pijl A, Riedel K, Kuramae EE. Responses of Acidobacteria Granulicella sp. WH15 to High Carbon Revealed by Integrated Omics Analyses. Microorganisms 2020; 8:E244. [PMID: 32059463 PMCID: PMC7074687 DOI: 10.3390/microorganisms8020244] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2020] [Revised: 02/08/2020] [Accepted: 02/10/2020] [Indexed: 01/18/2023] Open
Abstract
The phylum Acidobacteria is widely distributed in soils, but few representatives have been cultured. In general, Acidobacteria are oligotrophs and exhibit slow growth under laboratory conditions. We sequenced the genome of Granulicella sp. WH15, a strain obtained from decaying wood, and determined the bacterial transcriptome and proteome under growth in poor medium with a low or high concentration of sugar. We detected the presence of 217 carbohydrate-associated enzymes in the genome of strain WH15. Integrated analysis of the transcriptomic and proteomic profiles showed that high sugar triggered a stress response. As part of this response, transcripts related to cell wall stress, such as sigma factor σW and toxin-antitoxin (TA) systems, were upregulated, as were several proteins involved in detoxification and repair, including MdtA and OprM. KEGG metabolic pathway analysis indicated the repression of carbon metabolism (especially the pentose phosphate pathway) and the reduction of protein synthesis, carbohydrate metabolism, and cell division, suggesting the arrest of cell activity and growth. In summary, the stress response of Granulicella sp. WH15 induced by the presence of a high sugar concentration in the medium resulted in the intensification of secretion functions to eliminate toxic compounds and the reallocation of resources to cell maintenance instead of growth.
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Affiliation(s)
- Ohana Y.A. Costa
- Department of Microbial Ecology, Netherlands Institute of Ecology (NIOO-KNAW), Droevendaalsesteeg 10, 6708 PB Wageningen, The Netherlands (M.M.Z.); (A.M.K.); (A.P.)
| | - Marcelo M. Zerillo
- Department of Microbial Ecology, Netherlands Institute of Ecology (NIOO-KNAW), Droevendaalsesteeg 10, 6708 PB Wageningen, The Netherlands (M.M.Z.); (A.M.K.); (A.P.)
| | - Daniela Zühlke
- Institute of Microbiology, University of Greifswald, Felix-Hausdorff-Strasse 8, 17487 Greifswald, Germany; (D.Z.); (K.R.)
| | - Anna M. Kielak
- Department of Microbial Ecology, Netherlands Institute of Ecology (NIOO-KNAW), Droevendaalsesteeg 10, 6708 PB Wageningen, The Netherlands (M.M.Z.); (A.M.K.); (A.P.)
| | - Agata Pijl
- Department of Microbial Ecology, Netherlands Institute of Ecology (NIOO-KNAW), Droevendaalsesteeg 10, 6708 PB Wageningen, The Netherlands (M.M.Z.); (A.M.K.); (A.P.)
| | - Katharina Riedel
- Institute of Microbiology, University of Greifswald, Felix-Hausdorff-Strasse 8, 17487 Greifswald, Germany; (D.Z.); (K.R.)
| | - Eiko E. Kuramae
- Department of Microbial Ecology, Netherlands Institute of Ecology (NIOO-KNAW), Droevendaalsesteeg 10, 6708 PB Wageningen, The Netherlands (M.M.Z.); (A.M.K.); (A.P.)
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García-Torres I, De la Mora-De la Mora I, Hernández-Alcántara G, Molina-Ortiz D, Caballero-Salazar S, Olivos-García A, Nava G, López-Velázquez G, Enríquez-Flores S. First characterization of a microsporidial triosephosphate isomerase and the biochemical mechanisms of its inactivation to propose a new druggable target. Sci Rep 2018; 8:8591. [PMID: 29872223 PMCID: PMC5988755 DOI: 10.1038/s41598-018-26845-z] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2018] [Accepted: 05/17/2018] [Indexed: 12/21/2022] Open
Abstract
The microsporidia are a large group of intracellular parasites with a broad range of hosts, including humans. Encephalitozoon intestinalis is the second microsporidia species most frequently associated with gastrointestinal disease in humans, especially immunocompromised or immunosuppressed individuals, including children and the elderly. The prevalence reported worldwide in these groups ranges from 0 to 60%. Currently, albendazole is most commonly used to treat microsporidiosis caused by Encephalitozoon species. However, the results of treatment are variable, and relapse can occur. Consequently, efforts are being directed toward identifying more effective drugs for treating microsporidiosis, and the study of new molecular targets appears promising. These parasites lack mitochondria, and oxidative phosphorylation therefore does not occur, which suggests the enzymes involved in glycolysis as potential drug targets. Here, we have for the first time characterized the glycolytic enzyme triosephosphate isomerase of E. intestinalis at the functional and structural levels. Our results demonstrate the mechanisms of inactivation of this enzyme by thiol-reactive compounds. The most striking result of this study is the demonstration that established safe drugs such as omeprazole, rabeprazole and sulbutiamine can effectively inactivate this microsporidial enzyme and might be considered as potential drugs for treating this important disease.
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Affiliation(s)
- Itzhel García-Torres
- Grupo de Investigación en Biomoléculas, Laboratorio de Errores Innatos del Metabolismo y Tamiz, Instituto Nacional de Pediatría, Ciudad de México, 04530, Mexico
| | - Ignacio De la Mora-De la Mora
- Grupo de Investigación en Biomoléculas, Laboratorio de Errores Innatos del Metabolismo y Tamiz, Instituto Nacional de Pediatría, Ciudad de México, 04530, Mexico
| | - Gloria Hernández-Alcántara
- Departamento de Bioquímica, Facultad de Medicina, Universidad Nacional Autónoma de México, Ciudad de México, 04510, Mexico
| | - Dora Molina-Ortiz
- Laboratorio de Toxicología Genética, Instituto Nacional de Pediatría, Ciudad de México, 04530, Mexico
| | - Silvia Caballero-Salazar
- Laboratorio de Parasitología Experimental, Instituto Nacional de Pediatría, Ciudad de México, 04530, Mexico
| | - Alfonso Olivos-García
- Unidad de Investigación en Medicina Experimental, Facultad de Medicina, Universidad Nacional Autónoma de México y Hospital General, Ciudad de México, 04510, Mexico
| | - Gabriela Nava
- Departamento de Microbiología y Parasitología, Facultad de Medicina, Universidad Nacional Autónoma de México, Ciudad de México, 04510, Mexico
| | - Gabriel López-Velázquez
- Grupo de Investigación en Biomoléculas, Laboratorio de Errores Innatos del Metabolismo y Tamiz, Instituto Nacional de Pediatría, Ciudad de México, 04530, Mexico.
| | - Sergio Enríquez-Flores
- Grupo de Investigación en Biomoléculas, Laboratorio de Errores Innatos del Metabolismo y Tamiz, Instituto Nacional de Pediatría, Ciudad de México, 04530, Mexico.
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Thompson A, Fulde M, Tedin K. The metabolic pathways utilized by Salmonella Typhimurium during infection of host cells. ENVIRONMENTAL MICROBIOLOGY REPORTS 2018; 10:140-154. [PMID: 29411544 DOI: 10.1111/1758-2229.12628] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/19/2017] [Revised: 01/29/2018] [Accepted: 01/31/2018] [Indexed: 06/08/2023]
Abstract
Only relatively recently has research on the metabolism of intracellular bacterial pathogens within their host cells begun to appear in the published literature. This reflects in part the experimental difficulties encountered in separating host metabolic processes from those of the resident pathogen. One of the most genetically tractable and thoroughly studied intracellular bacterial pathogens, Salmonella enterica serovar Typhimurium (S. Typhimurium), has been at the forefront of metabolic studies within eukaryotic host cells. In this review, we offer a synthesis of what has been discovered to date regarding the metabolic adaptation of S. Typhimurium to survival and growth within the infected host. We discuss many studies in the context of techniques used, types of host cells, how host metabolites contribute to intracellular survival and proliferation of the pathogen and how bacterial metabolism affects the virulence and persistence of the pathogen.
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Affiliation(s)
- Arthur Thompson
- Institute for Food Research, Norwich Research Park, Norwich NR4 7UA, UK
| | - Marcus Fulde
- Centre for Infection Medicine, Institute of Microbiology and Epizootics, Freie Universität Berlin, 14163 Berlin, Germany
| | - Karsten Tedin
- Centre for Infection Medicine, Institute of Microbiology and Epizootics, Freie Universität Berlin, 14163 Berlin, Germany
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9
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Westfall CS, Levin PA. Comprehensive analysis of central carbon metabolism illuminates connections between nutrient availability, growth rate, and cell morphology in Escherichia coli. PLoS Genet 2018; 14:e1007205. [PMID: 29432413 PMCID: PMC5825171 DOI: 10.1371/journal.pgen.1007205] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2017] [Revised: 02/23/2018] [Accepted: 01/17/2018] [Indexed: 01/23/2023] Open
Abstract
Bacterial morphology is a complex trait that is highly sensitive to changes in the environment. For heterotrophic organisms, such as Escherichia coli, increases in nutrient levels are frequently accompanied by several-fold increases in both size and growth rate. Despite the dramatic nature of these changes, how alterations in nutrient availability translate into changes in growth and morphology remains a largely open question. To understand the signaling networks coupling nutrient availability with size and shape, we examined the impact of deletions in the entirety of non-essential central carbon metabolic genes on E. coli growth rate and cell size. Our data reveal the presence of multiple metabolic nodes that play important yet distinctive roles in dictating biosynthetic capacity and shaping cell morphology. Specifically, perturbations of acetyl-CoA metabolism impact cell size and division through changes in fatty acid synthesis. Additionally, we identify a genetic pathway linking glucose levels to cell width through the signaling molecule cyclic-AMP. Together our findings highlight a surprising diversity of factors and mechanisms contributing to growth potential and cell morphology, providing a foundation for further studies. Often taken for granted, the shape of bacterial cells is a complex trait that is highly sensitive to environmental perturbations. Nutrients in particular, strongly impact bacterial morphology together with growth rate. The ubiquitous, rod-shaped bacteria Escherichia coli increases both length and width several fold upon a shift from nutrient poor to nutrient rich medium, a change accompanied by an equally dramatic increase in growth rate. Central carbon metabolism is an obvious site for the integration of nutrient dependent signals that dictate cell size and shape. To develop a clearer picture of the molecular mechanisms coupling nutrient assimilation with cell growth and morphology, we screened the entirety of non-essential carbon metabolic genes for their contribution to growth rate and cell shape. Our data reveal the presence of multiple regulatory circuits coordinating different metabolic pathways with specific aspects of cell growth and morphology. Together, these data firmly establish a role for central carbon metabolism as an environmentally sensitive sculptor of bacterial cells.
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Affiliation(s)
- Corey S. Westfall
- Department of Biology, Washington University, St. Louis, Missouri, United States of America
| | - Petra Anne Levin
- Department of Biology, Washington University, St. Louis, Missouri, United States of America
- * E-mail:
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10
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Mandal RK, Kwon YM. Global Screening of Salmonella enterica Serovar Typhimurium Genes for Desiccation Survival. Front Microbiol 2017; 8:1723. [PMID: 28943871 PMCID: PMC5596212 DOI: 10.3389/fmicb.2017.01723] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2017] [Accepted: 08/24/2017] [Indexed: 01/13/2023] Open
Abstract
Salmonella spp., one of the most common foodborne bacterial pathogens, has the ability to survive under desiccation conditions in foods and food processing facilities for years. This raises the concerns of Salmonella infection in humans associated with low water activity foods. Salmonella responds to desiccation stress via complex pathways involving immediate physiological actions as well as coordinated genetic responses. However, the exact mechanisms of Salmonella to resist desiccation stress remain to be fully elucidated. In this study, we screened a genome-saturating transposon (Tn5) library of Salmonella Typhimurium (S. Typhimurium) 14028s under the in vitro desiccation stress using transposon sequencing (Tn-seq). We identified 61 genes and 6 intergenic regions required to overcome desiccation stress. Salmonella desiccation resistance genes were mostly related to energy production and conversion; cell wall/membrane/envelope biogenesis; inorganic ion transport and metabolism; regulation of biological process; DNA metabolic process; ABC transporters; and two component system. More than 20% of the Salmonella desiccation resistance genes encode either putative or hypothetical proteins. Phenotypic evaluation of 12 single gene knockout mutants showed 3 mutants (atpH, atpG, and corA) had significantly (p < 0.02) reduced survival as compared to the wild type during desiccation survival. Thus, our study provided new insights into the molecular mechanisms utilized by Salmonella for survival against desiccation stress. The findings might be further exploited to develop effective control strategies against Salmonella contamination in low water activity foods and food processing facilities.
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Affiliation(s)
- Rabindra K Mandal
- Department of Poultry Science, University of ArkansasFayetteville, AR, United States
| | - Young M Kwon
- Department of Poultry Science, University of ArkansasFayetteville, AR, United States.,Cell and Molecular Biology Program, University of ArkansasFayetteville, AR, United States
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11
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Jain VK, Tear CJY, Lim CY. Dihydroxyacetone production in an engineered Escherichia coli through expression of Corynebacterium glutamicum dihydroxyacetone phosphate dephosphorylase. Enzyme Microb Technol 2016; 86:39-44. [PMID: 26992791 DOI: 10.1016/j.enzmictec.2016.01.015] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2015] [Revised: 01/27/2016] [Accepted: 01/28/2016] [Indexed: 11/18/2022]
Abstract
Dihydroxyacetone (DHA) has several industrial applications such as a tanning agent in tanning lotions in the cosmetic industry; its production via microbial fermentation would present a more sustainable option for the future. Here we genetically engineered Escherichia coli (E. coli) for DHA production from glucose. Deletion of E. coli triose phosphate isomerase (tpiA) gene was carried out to accumulate dihydroxyacetone phosphate (DHAP), for use as the main intermediate or precursor for DHA production. The accumulated DHAP was then converted to DHA through the heterologous expression of Corynebacterium glutamicum DHAP dephosphorylase (cghdpA) gene. To conserve DHAP exclusively for DHA production we removed methylglyoxal synthase (mgsA) gene in the ΔtpiA strain. This drastically improved DHA production from 0.83g/l (0.06g DHA/g glucose) in the ΔtpiA strain bearing cghdpA to 5.84g/l (0.41g DHA/g glucose) in the ΔtpiAΔmgsA double mutant containing the same gene. To limit the conversion of intracellular DHA to glycerol, glycerol dehydrogenase (gldA) gene was further knocked out resulting in a ΔtpiAΔmgsAΔgldA triple mutant. This triple mutant expressing the cghdpA gene produced 6.60g/l of DHA at 87% of the maximum theoretical yield. In summary, we demonstrated an efficient system for DHA production in genetically engineered E. coli strain.
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Affiliation(s)
- Vishist Kumar Jain
- Industrial Biotechnology Division, Institute of Chemical & Engineering Sciences, Agency for Science, Technology and Research (A-STAR), 1, Pesek Road, Jurong Island 627833, Singapore.
| | - Crystal Jing Ying Tear
- Industrial Biotechnology Division, Institute of Chemical & Engineering Sciences, Agency for Science, Technology and Research (A-STAR), 1, Pesek Road, Jurong Island 627833, Singapore
| | - Chan Yuen Lim
- Industrial Biotechnology Division, Institute of Chemical & Engineering Sciences, Agency for Science, Technology and Research (A-STAR), 1, Pesek Road, Jurong Island 627833, Singapore
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Dandekar T, Fieselmann A, Fischer E, Popp J, Hensel M, Noster J. Salmonella-how a metabolic generalist adopts an intracellular lifestyle during infection. Front Cell Infect Microbiol 2015; 4:191. [PMID: 25688337 PMCID: PMC4310325 DOI: 10.3389/fcimb.2014.00191] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2014] [Accepted: 12/21/2014] [Indexed: 12/12/2022] Open
Abstract
The human-pathogenic bacterium Salmonella enterica adjusts and adapts to different environments while attempting colonization. In the course of infection nutrient availabilities change drastically. New techniques, "-omics" data and subsequent integration by systems biology improve our understanding of these changes. We review changes in metabolism focusing on amino acid and carbohydrate metabolism. Furthermore, the adaptation process is associated with the activation of genes of the Salmonella pathogenicity islands (SPIs). Anti-infective strategies have to take these insights into account and include metabolic and other strategies. Salmonella infections will remain a challenge for infection biology.
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Affiliation(s)
- Thomas Dandekar
- Department of Bioinformatics, Biocenter, University of Würzburg Würzburg, Germany
| | - Astrid Fieselmann
- Department of Bioinformatics, Biocenter, University of Würzburg Würzburg, Germany
| | - Eva Fischer
- Department of Bioinformatics, Biocenter, University of Würzburg Würzburg, Germany
| | - Jasmin Popp
- Division of Microbiology, Biology/Chemistry, University of Osnabrück Osnabrück, Germany
| | - Michael Hensel
- Division of Microbiology, Biology/Chemistry, University of Osnabrück Osnabrück, Germany
| | - Janina Noster
- Division of Microbiology, Biology/Chemistry, University of Osnabrück Osnabrück, Germany
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Triosephosphate isomerase is dispensable in vitro yet essential for Mycobacterium tuberculosis to establish infection. mBio 2014; 5:e00085. [PMID: 24757211 PMCID: PMC3994511 DOI: 10.1128/mbio.00085-14] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Triosephosphate isomerase (TPI) catalyzes the interconversion of dihydroxyacetone phosphate (DHAP) and glyceraldehyde-3-phosphate (G3P). This reaction is required for glycolysis and gluconeogenesis, and tpi has been predicted to be essential for growth of Mycobacterium tuberculosis. However, when studying a conditionally regulated tpi knockdown mutant, we noticed that depletion of TPI reduced growth of M. tuberculosis in media containing a single carbon source but not in media that contained both a glycolytic and a gluconeogenic carbon source. We used such two-carbon-source media to isolate a tpi deletion (Δtpi) mutant. The Δtpi mutant did not survive with single carbon substrates but grew like wild-type (WT) M. tuberculosis in the presence of both a glycolytic and a gluconeogenic carbon source. 13C metabolite tracing revealed the accumulation of TPI substrates in Δtpi and the absence of alternative triosephosphate isomerases and metabolic bypass reactions, which confirmed the requirement of TPI for glycolysis and gluconeogenesis in M. tuberculosis. The Δtpi strain was furthermore severely attenuated in the mouse model of tuberculosis, suggesting that M. tuberculosis cannot simultaneously access sufficient quantities of glycolytic and gluconeogenic carbon substrates to establish infection in mice. The importance of central carbon metabolism for the pathogenesis of M. tuberculosis has recently been recognized, but the consequences of depleting specific metabolic enzymes remain to be identified for many enzymes. We investigated triosephosphate isomerase (TPI) because it is central to both glycolysis and gluconeogenesis and had been predicted to be essential for growth of M. tuberculosis. This work identified metabolic conditions that make TPI dispensable for M. tuberculosis growth in culture and proved that M. tuberculosis relies on a single TPI enzyme and has no metabolic bypass for the TPI-dependent interconversion of dihydroxyacetone phosphate and glyceraldehyde-3-phosphate in glycolysis and gluconeogenesis. Finally, we demonstrate that TPI is essential for growth of the pathogen in mouse lungs.
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14
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Dorion S, Clendenning A, Jeukens J, Salas JJ, Parveen N, Haner AA, Law RD, Force EM, Rivoal J. A large decrease of cytosolic triosephosphate isomerase in transgenic potato roots affects the distribution of carbon in primary metabolism. PLANTA 2012; 236:1177-90. [PMID: 22678033 DOI: 10.1007/s00425-012-1675-1] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/26/2012] [Accepted: 05/23/2012] [Indexed: 05/04/2023]
Abstract
Triosephosphate isomerase (TPI, EC 5.3.1.1) catalyzes the interconversion of dihydroxyacetone-P and glyceraldehyde 3-P in the glycolytic pathway. A constitutively expressed antisense construct for cytosolic TPI was introduced into potato (Solanum tuberosum) using Agrobacterium rhizogenes to examine the metabolic effects of a reduction in cytosolic TPI in roots. We obtained a population of transgenic root clones displaying ~36 to 100 % of the TPI activity found in control clones carrying an empty binary vector. Ion exchange chromatography and immunoblot analysis showed that the antisense strategy significantly decreased the cytosolic TPI isoform, while levels of plastidial TPI activity remained apparently unaffected. Transgenic roots were characterized with respect to the activity of glycolytic enzymes, their metabolite contents and carbon fluxes. Metabolite profiling of sugars, organic acids, amino acids and lipids showed elevated levels of sucrose, glucose, fructose, fumarate, isocitrate, 4-aminobutyrate, alanine, glycine, aromatic amino acids and saturated long chain fatty acids in roots containing the lowest TPI activity. Labelings with (14)C-glucose, (14)C-sucrose and (14)C-acetate indicated that a reduction of cytosolic TPI activity in roots increased carbon metabolism through the pentose phosphate pathway, O(2) uptake and catabolism of sucrose to CO(2), and capacity for lipid synthesis. These results demonstrate that a large reduction of cytosolic TPI alters the distribution of carbon in plant primary metabolism.
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Affiliation(s)
- Sonia Dorion
- IRBV, Université de Montréal, 4101 rue Sherbrooke est, Montréal, QC H1X 2B2, Canada
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Dandekar T, Astrid F, Jasmin P, Hensel M. Salmonella enterica: a surprisingly well-adapted intracellular lifestyle. Front Microbiol 2012; 3:164. [PMID: 22563326 PMCID: PMC3342586 DOI: 10.3389/fmicb.2012.00164] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2011] [Accepted: 04/12/2012] [Indexed: 11/15/2022] Open
Abstract
The infectious intracellular lifestyle of Salmonella enterica relies on the adaptation to nutritional conditions within the Salmonella-containing vacuole (SCV) in host cells. We summarize latest results on metabolic requirements for Salmonella during infection. This includes intracellular phenotypes of mutant strains based on metabolic modeling and experimental tests, isotopolog profiling using 13C-compounds in intracellular Salmonella, and complementation of metabolic defects for attenuated mutant strains towards a comprehensive understanding of the metabolic requirements of the intracellular lifestyle of Salmonella. Helpful for this are also genomic comparisons. We outline further recent studies and which analyses of intracellular phenotypes and improved metabolic simulations were done and comment on technical required steps as well as progress involved in the iterative refinement of metabolic flux models, analyses of mutant phenotypes, and isotopolog analyses. Salmonella lifestyle is well-adapted to the SCV and its specific metabolic requirements. Salmonella metabolism adapts rapidly to SCV conditions, the metabolic generalist Salmonella is quite successful in host infection.
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Affiliation(s)
- Thomas Dandekar
- Department of Bioinformatics, Biocenter, University of Würzburg, Würzburg, Germany
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16
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Ehrt S, Rhee K. Mycobacterium tuberculosis metabolism and host interaction: mysteries and paradoxes. Curr Top Microbiol Immunol 2012; 374:163-88. [PMID: 23242856 DOI: 10.1007/82_2012_299] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Metabolism is a widely recognized facet of all host-pathogen interactions. Knowledge of its roles in pathogenesis, however, remains comparatively incomplete. Existing studies have emphasized metabolism as a cell autonomous property of pathogens used to fuel replication in a quantitative, rather than qualitatively specific, manner. For Mycobacterium tuberculosis, however, matters could not be more different. M. tuberculosis is a chronic facultative intracellular pathogen that resides in humans as its only known host. Within humans, M. tuberculosis resides chiefly within the macrophage phagosome, the cell type, and compartment most committed to its eradication. M. tuberculosis has thus evolved its metabolic network to both maintain and propagate its survival as a species within a single host. The specific ways in which its metabolic network serves these distinct, through interdependent, functions, however, remain incompletely defined. Here, we review existing knowledge of the M. tuberculosis-host interaction, highlighting the distinct phases of its natural life cycle and the diverse microenvironments encountered therein.
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Affiliation(s)
- Sabine Ehrt
- Department of Microbiology and Immunology, Weill Cornell Medical College, New York, NY, 10065, USA,
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17
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Bowden SD, Ramachandran VK, Knudsen GM, Hinton JCD, Thompson A. An incomplete TCA cycle increases survival of Salmonella Typhimurium during infection of resting and activated murine macrophages. PLoS One 2010; 5:e13871. [PMID: 21079785 PMCID: PMC2975626 DOI: 10.1371/journal.pone.0013871] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2009] [Accepted: 10/14/2010] [Indexed: 12/22/2022] Open
Abstract
BACKGROUND In comparison to the comprehensive analyses performed on virulence gene expression, regulation and action, the intracellular metabolism of Salmonella during infection is a relatively under-studied area. We investigated the role of the tricarboxylic acid (TCA) cycle in the intracellular replication of Salmonella Typhimurium in resting and activated macrophages, epithelial cells, and during infection of mice. METHODOLOGY/PRINCIPAL FINDINGS We constructed deletion mutations of 5 TCA cycle genes in S. Typhimurium including gltA, mdh, sdhCDAB, sucAB, and sucCD. We found that the mutants exhibited increased net intracellular replication in resting and activated murine macrophages compared to the wild-type. In contrast, an epithelial cell infection model showed that the S. Typhimurium ΔsucCD and ΔgltA strains had reduced net intracellular replication compared to the wild-type. The glyoxylate shunt was not responsible for the net increased replication of the TCA cycle mutants within resting macrophages. We also confirmed that, in a murine infection model, the S. Typhimurium ΔsucAB and ΔsucCD strains are attenuated for virulence. CONCLUSIONS/SIGNIFICANCE Our results suggest that disruption of the TCA cycle increases the ability of S. Typhimurium to survive within resting and activated murine macrophages. In contrast, epithelial cells are non-phagocytic cells and unlike macrophages cannot mount an oxidative and nitrosative defence response against pathogens; our results show that in HeLa cells the S. Typhimurium TCA cycle mutant strains show reduced or no change in intracellular levels compared to the wild-type. The attenuation of the S. Typhimurium ΔsucAB and ΔsucCD mutants in mice, compared to their increased net intracellular replication in resting and activated macrophages suggest that Salmonella may encounter environments within the host where a complete TCA cycle is advantageous.
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Affiliation(s)
| | | | | | - Jay C. D. Hinton
- Moyne Institute of Preventive Medicine, School of Genetics and Microbiology, Trinity College, Dublin, Ireland
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Paterson GK, Cone DB, Peters SE, Maskell DJ. The enzyme phosphoglucomutase (Pgm) is required by Salmonella enterica serovar Typhimurium for O-antigen production, resistance to antimicrobial peptides and in vivo fitness. MICROBIOLOGY-SGM 2009; 155:3403-3410. [PMID: 19589833 DOI: 10.1099/mic.0.029553-0] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The enzyme phosphoglucomutase (Pgm) catalyses the interconversion of glucose 1-phosphate and glucose 6-phosphate and contributes to glycolysis and the generation of sugar nucleotides for biosynthesis. To assess the role of this enzyme in the biology of the pathogen Salmonella enterica serovar Typhimurium we have characterized a pgm deletion mutant in strain SL1344. Compared to SL1344, SL1344 pgm had impaired growth in vitro, was deficient in the ability to utilize galactose as a carbon source and displayed reduced O-antigen polymer length. The mutant was also more susceptible to antimicrobial peptides and showed decreased fitness in the mouse typhoid model. The in vivo phenotype of SL1344 pgm indicated a role for pgm in the early stages of infection, most likely through deficient O-antigen production. Although pgm mutants in other pathogens have potential as live attenuated vaccine strains, SL1344 pgm was not sufficiently attenuated for such use.
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Affiliation(s)
- G K Paterson
- Department of Veterinary Medicine, University of Cambridge, Madingley Road, Cambridge CB3 0ES, UK
| | - D B Cone
- Department of Veterinary Medicine, University of Cambridge, Madingley Road, Cambridge CB3 0ES, UK
| | - S E Peters
- Department of Veterinary Medicine, University of Cambridge, Madingley Road, Cambridge CB3 0ES, UK
| | - D J Maskell
- Department of Veterinary Medicine, University of Cambridge, Madingley Road, Cambridge CB3 0ES, UK
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