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Yan CH, Chen FH, Yang YL, Zhan YF, Herman RA, Gong LC, Sheng S, Wang J. The Transcription Factor CsgD Contributes to Engineered Escherichia coli Resistance by Regulating Biofilm Formation and Stress Responses. Int J Mol Sci 2023; 24:13681. [PMID: 37761984 PMCID: PMC10530992 DOI: 10.3390/ijms241813681] [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] [Received: 07/31/2023] [Revised: 08/30/2023] [Accepted: 09/02/2023] [Indexed: 09/29/2023] Open
Abstract
The high cell density, immobilization and stability of biofilms are ideal characteristics for bacteria in resisting antibiotic therapy. CsgD is a transcription activating factor that regulates the synthesis of curly fimbriae and cellulose in Escherichia coli, thereby enhancing bacterial adhesion and promoting biofilm formation. To investigate the role of CsgD in biofilm formation and stress resistance in bacteria, the csgD deletion mutant ΔcsgD was successfully constructed from the engineered strain E. coli BL21(DE3) using the CRISPR/Cas9 gene-editing system. The results demonstrated that the biofilm of ΔcsgD decreased by 70.07% (p < 0.05). Additionally, the mobility and adhesion of ΔcsgD were inhibited due to the decrease in curly fimbriae and extracellular polymeric substances. Furthermore, ΔcsgD exhibited a significantly decreased resistance to acid, alkali and osmotic stress conditions (p < 0.05). RNA-Seq results revealed 491 differentially expressed genes between the parent strain and ΔcsgD, with enrichment primarily observed in metabolism-related processes as well as cell membrane structure and catalytic activity categories. Moreover, CsgD influenced the expression of biofilm and stress response genes pgaA, motB, fimA, fimC, iraP, ompA, osmC, sufE and elaB, indicating that the CsgD participated in the resistance of E. coli by regulating the expression of biofilm and stress response. In brief, the transcription factor CsgD plays a key role in the stress resistance of E. coli, and is a potential target for treating and controlling biofilm.
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Affiliation(s)
- Cheng-Hai Yan
- Jiangsu Key Laboratory of Sericultural Biology and Biotechnology, School of Biotechnology, Jiangsu University of Science and Technology, Zhenjiang 212100, China; (C.-H.Y.); (F.-H.C.); (Y.-L.Y.); (Y.-F.Z.); (R.A.H.); (L.-C.G.); (S.S.)
| | - Fang-Hui Chen
- Jiangsu Key Laboratory of Sericultural Biology and Biotechnology, School of Biotechnology, Jiangsu University of Science and Technology, Zhenjiang 212100, China; (C.-H.Y.); (F.-H.C.); (Y.-L.Y.); (Y.-F.Z.); (R.A.H.); (L.-C.G.); (S.S.)
| | - Yu-Lu Yang
- Jiangsu Key Laboratory of Sericultural Biology and Biotechnology, School of Biotechnology, Jiangsu University of Science and Technology, Zhenjiang 212100, China; (C.-H.Y.); (F.-H.C.); (Y.-L.Y.); (Y.-F.Z.); (R.A.H.); (L.-C.G.); (S.S.)
| | - Yu-Fan Zhan
- Jiangsu Key Laboratory of Sericultural Biology and Biotechnology, School of Biotechnology, Jiangsu University of Science and Technology, Zhenjiang 212100, China; (C.-H.Y.); (F.-H.C.); (Y.-L.Y.); (Y.-F.Z.); (R.A.H.); (L.-C.G.); (S.S.)
| | - Richard A. Herman
- Jiangsu Key Laboratory of Sericultural Biology and Biotechnology, School of Biotechnology, Jiangsu University of Science and Technology, Zhenjiang 212100, China; (C.-H.Y.); (F.-H.C.); (Y.-L.Y.); (Y.-F.Z.); (R.A.H.); (L.-C.G.); (S.S.)
| | - Lu-Chan Gong
- Jiangsu Key Laboratory of Sericultural Biology and Biotechnology, School of Biotechnology, Jiangsu University of Science and Technology, Zhenjiang 212100, China; (C.-H.Y.); (F.-H.C.); (Y.-L.Y.); (Y.-F.Z.); (R.A.H.); (L.-C.G.); (S.S.)
- Key Laboratory of Silkworm and Mulberry Genetic Improvement, Ministry of Agriculture and Rural Affairs, Sericultural Research Institute, Chinese Academy of Agricultural Sciences, Zhenjiang 212100, China
| | - Sheng Sheng
- Jiangsu Key Laboratory of Sericultural Biology and Biotechnology, School of Biotechnology, Jiangsu University of Science and Technology, Zhenjiang 212100, China; (C.-H.Y.); (F.-H.C.); (Y.-L.Y.); (Y.-F.Z.); (R.A.H.); (L.-C.G.); (S.S.)
- Key Laboratory of Silkworm and Mulberry Genetic Improvement, Ministry of Agriculture and Rural Affairs, Sericultural Research Institute, Chinese Academy of Agricultural Sciences, Zhenjiang 212100, China
| | - Jun Wang
- Jiangsu Key Laboratory of Sericultural Biology and Biotechnology, School of Biotechnology, Jiangsu University of Science and Technology, Zhenjiang 212100, China; (C.-H.Y.); (F.-H.C.); (Y.-L.Y.); (Y.-F.Z.); (R.A.H.); (L.-C.G.); (S.S.)
- Key Laboratory of Silkworm and Mulberry Genetic Improvement, Ministry of Agriculture and Rural Affairs, Sericultural Research Institute, Chinese Academy of Agricultural Sciences, Zhenjiang 212100, China
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2
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Römling U. Is biofilm formation intrinsic to the origin of life? Environ Microbiol 2023; 25:26-39. [PMID: 36655713 PMCID: PMC10086821 DOI: 10.1111/1462-2920.16179] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2022] [Accepted: 08/19/2022] [Indexed: 01/21/2023]
Abstract
Biofilms are multicellular, often surface-associated, communities of autonomous cells. Their formation is the natural mode of growth of up to 80% of microorganisms living on this planet. Biofilms refractory towards antimicrobial agents and the actions of the immune system due to their tolerance against multiple environmental stresses. But how did biofilm formation arise? Here, I argue that the biofilm lifestyle has its foundation already in the fundamental, surface-triggered chemical reactions and energy preserving mechanisms that enabled the development of life on earth. Subsequently, prototypical biofilm formation has evolved and diversified concomitantly in composition, cell morphology and regulation with the expansion of prokaryotic organisms and their radiation by occupation of diverse ecological niches. This ancient origin of biofilm formation thus mirrors the harnessing environmental conditions that have been the rule rather than the exception in microbial life. The subsequent emergence of the association of microbes, including recent human pathogens, with higher organisms can be considered as the entry into a nutritional and largely stress-protecting heaven. Nevertheless, basic mechanisms of biofilm formation have surprisingly been conserved and refunctionalized to promote sustained survival in new environments.
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Affiliation(s)
- Ute Römling
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Stockholm, Sweden
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3
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Du M, Wang J, Jin Y, Fan J, Zan S, Li Z. Response mechanism of microbial community during anaerobic biotransformation of marine toxin domoic acid. ENVIRONMENTAL RESEARCH 2022; 215:114410. [PMID: 36154856 DOI: 10.1016/j.envres.2022.114410] [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: 07/01/2022] [Revised: 09/12/2022] [Accepted: 09/19/2022] [Indexed: 06/16/2023]
Abstract
Domoic acid (DA) is a potent neurotoxin produced by toxigenic Pseudo-nitzschia blooms and quickly transfers to the benthic anaerobic environment by marine snow particles. DA anaerobic biotransformation is driven by microbial interactions, in which trace amounts of DA can cause physiological stress in marine microorganisms. However, the underlying response mechanisms of microbial community to DA stress remain unclear. In this study, we utilized an anaerobic marine DA-degrading consortium GLY (using glycine as co-substrate) to systematically investigate the global response mechanisms of microbial community during DA anaerobic biotransformation.16S rRNA gene sequencing and metatranscriptomic analyses were applied to measure microbial community structure, function and metabolic responses. Results showed that DA stress markedly changed the composition of main species, with increased levels of Firmicutes and decreased levels of Proteobacteria, Cyanobacteria, Bacteroidetes and Actinobacteria. Several genera of tolerated bacteria (Bacillus and Solibacillus) were increased, while, Stenotrophomonas, Sphingomonas and Acinetobacter were decreased. Metatranscriptomic analyses indicated that DA stimulated the expression of quorum sensing, extracellular polymeric substance (EPS) production, sporulation, membrane transporters, bacterial chemotaxis, flagellar assembly and ribosome protection in community, promoting bacterial adaptation ability under DA stress. Moreover, amino acid metabolism, carbohydrate metabolism and lipid metabolism were modulated during DA anaerobic biotransformation to reduce metabolic burden, increase metabolic demands for EPS production and DA degradation. This study provides the new insights into response of microbial community to DA stress and its potential impact on benthic microorganisms in marine environments.
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Affiliation(s)
- Miaomiao Du
- Key Laboratory of Industrial Ecology and Environmental Engineering (Ministry of Education), School of Environmental Science and Technology, Dalian University of Technology, Dalian, 116024, PR China
| | - Jing Wang
- Key Laboratory of Industrial Ecology and Environmental Engineering (Ministry of Education), School of Environmental Science and Technology, Dalian University of Technology, Dalian, 116024, PR China.
| | - Yuan Jin
- Marine Ecology Department, National Marine Environmental Monitoring Center, Dalian, 116023, PR China
| | - Jingfeng Fan
- Marine Ecology Department, National Marine Environmental Monitoring Center, Dalian, 116023, PR China
| | - Shuaijun Zan
- Key Laboratory of Industrial Ecology and Environmental Engineering (Ministry of Education), School of Environmental Science and Technology, Dalian University of Technology, Dalian, 116024, PR China
| | - Zelong Li
- Key Laboratory of Industrial Ecology and Environmental Engineering (Ministry of Education), School of Environmental Science and Technology, Dalian University of Technology, Dalian, 116024, PR China
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4
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Mb CS, Ja MF, Ja SB, R VDLR, Jr IR, J MU, C C, N CDC. Structural variations on Salmonella biofilm by exposition to river water. INTERNATIONAL JOURNAL OF ENVIRONMENTAL HEALTH RESEARCH 2022; 32:1626-1643. [PMID: 33944621 DOI: 10.1080/09603123.2021.1901863] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/13/2021] [Accepted: 03/08/2021] [Indexed: 06/12/2023]
Abstract
Biofilm formation, as adapting strategies, is the result of stressful conditions that Salmonella faces in hostile environments like surface water. We evaluated river water effect on Salmonella biofilm formation ability in terms of physical, morphological characteristics and chemical composition. A new morphotype SPAM (soft, pink and mucoid) was detected in Oranienburg strains S-76 and S-347 (environmental and clinical isolate). Oranienburg serotypes showed very marked behavior in adherence, pellicle liquid-air and resistance, being Oranienburg S-76 the strongest biofilm producer. All strains when exposed to river water presented an overlapping mucoid layer in the morphotype and increased their motility except Oranienburg S-347. The most motile was Typhimurium (control) and the least Infantis S-304 (clinical isolate). Mannose, glucose, galactose and ribose were the main biofilm sugar components; type and concentration of sugar suggest a morphotype/serotype dependent pattern. Strong morphotypes expressed in this study may be an effective protective strategy for Salmonella in hostile environments.
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Affiliation(s)
- Contreras-Soto Mb
- Laboratorio Nacional para la Investigación en Inocuidad Alimentaria, Centro de Investigación en Alimentación y Desarrollo, Culiacán, Sinaloa, México
| | - Medrano-Félix Ja
- Cátedras CONACYT - Centro de Investigación en Alimentación y Desarrollo, Culiacán, Sinaloa, México
| | - Sañudo-Barajas Ja
- Laboratorio de Fisiología y Bioquímica Vegetal, Centro de Investigación en Alimentación y Desarrollo, Culiacán, Sinaloa, México
| | - Vélez-de la Rocha R
- Laboratorio de Fisiología y Bioquímica Vegetal, Centro de Investigación en Alimentación y Desarrollo, Culiacán, Sinaloa, México
| | - Ibarra-Rodríguez Jr
- Centro de Investigación Oncológica de Sinaloa S. C, Departamento de Investigación Clínica, Culiacán, Sinaloa, México
| | - Martínez-Urtaza J
- Department of Genetics and Microbiology, Universitat Autònoma de Barcelona (UAB), Barcelona, Spain
| | - Chaidez C
- Laboratorio Nacional para la Investigación en Inocuidad Alimentaria, Centro de Investigación en Alimentación y Desarrollo, Culiacán, Sinaloa, México
| | - Castro-Del Campo N
- Laboratorio Nacional para la Investigación en Inocuidad Alimentaria, Centro de Investigación en Alimentación y Desarrollo, Culiacán, Sinaloa, México
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5
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Zwe YH, Ten MMZ, Pang X, Wong CH, Li D. Differential Survivability of Two Genetically Similar Salmonella Thompson Strains on Pre-harvest Sweet Basil ( Ocimum basilicum) Leaves. Front Microbiol 2021; 12:740983. [PMID: 34950113 PMCID: PMC8689135 DOI: 10.3389/fmicb.2021.740983] [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: 07/14/2021] [Accepted: 11/12/2021] [Indexed: 11/13/2022] Open
Abstract
Although conventionally considered an animal pathogen, recent evidence increasingly suggests that fresh produce may act as significant transmission vehicles and alternative hosts to Salmonella. This study reports the differential survivability of two genetically similar Salmonella Thompson strains (ST 889B and ST 688C) on the adaxial surface of pre-harvest basil (Ocimum basilicum) leaves. Upon inoculation, two distinct phenomena, a dried water-print or a macroscopic lesion, were observed within 24 h. ST 889B survived better than ST 688C on healthy-looking leaves without lesions, possibly due to its higher biofilm-forming ability. Both strains survived better on the leaves with lesions than on the healthy-looking leaves (ST 688C: 4.39 ± 0.68 vs. 2.18 ± 0.29; ST 889B: 4.78 ± 0.12 vs. 2.83 ± 0.18 log CFU per sample at 6 days post-inoculation). ST 889B caused the formation of lesions at a higher frequency [70/117 leaves (59.8%)] than ST 688C [35/96 leaves (36.5%)]. Thus, we highlighted two distinct Salmonella survival strategies in the basil pathosystem and demonstrated gene expression polymorphism (variations in the expression of the same set of genes) as an indispensable strategy in the colonization of plants as hosts by the human pathogens.
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Affiliation(s)
- Ye Htut Zwe
- Department of Food Science and Technology, National University of Singapore, Singapore, Singapore
| | - Michelle Mei Zhen Ten
- Department of Food Science and Technology, National University of Singapore, Singapore, Singapore
| | - Xinyi Pang
- Department of Food Science and Technology, National University of Singapore, Singapore, Singapore
| | - Chun Hong Wong
- Department of Food Science and Technology, National University of Singapore, Singapore, Singapore
| | - Dan Li
- Department of Food Science and Technology, National University of Singapore, Singapore, Singapore
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6
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Abidi W, Torres-Sánchez L, Siroy A, Krasteva PV. Weaving of bacterial cellulose by the Bcs secretion systems. FEMS Microbiol Rev 2021; 46:6388354. [PMID: 34634120 PMCID: PMC8892547 DOI: 10.1093/femsre/fuab051] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2021] [Accepted: 10/08/2021] [Indexed: 12/13/2022] Open
Abstract
Cellulose is the most abundant biological compound on Earth and while it is the predominant building constituent of plants, it is also a key extracellular matrix component in many diverse bacterial species. While bacterial cellulose was first described in the 19th century, it was not until this last decade that a string of structural works provided insights into how the cellulose synthase BcsA, assisted by its inner-membrane partner BcsB, senses c-di-GMP to simultaneously polymerize its substrate and extrude the nascent polysaccharide across the inner bacterial membrane. It is now established that bacterial cellulose can be produced by several distinct types of cellulose secretion systems and that in addition to BcsAB, they can feature multiple accessory subunits, often indispensable for polysaccharide production. Importantly, the last years mark significant progress in our understanding not only of cellulose polymerization per se but also of the bigger picture of bacterial signaling, secretion system assembly, biofilm formation and host tissue colonization, as well as of structural and functional parallels of this dominant biosynthetic process between the bacterial and eukaryotic domains of life. Here, we review current mechanistic knowledge on bacterial cellulose secretion with focus on the structure, assembly and cooperativity of Bcs secretion system components.
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Affiliation(s)
- Wiem Abidi
- 'Structural Biology of Biofilms' group, European Institute of Chemistry and Biology (IECB), F-33600 Pessac, France.,Université de Bordeaux, CNRS, Bordeaux INP, CBMN, UMR 5248, F-33600 Pessac, France.,École doctorale 'Innovation thérapeutique: du fundamental à l'appliqué' (ITFA), Université Paris-Saclay, 92296, Chatenay-Malabry, France
| | - Lucía Torres-Sánchez
- 'Structural Biology of Biofilms' group, European Institute of Chemistry and Biology (IECB), F-33600 Pessac, France.,Université de Bordeaux, CNRS, Bordeaux INP, CBMN, UMR 5248, F-33600 Pessac, France.,École doctorale 'Innovation thérapeutique: du fundamental à l'appliqué' (ITFA), Université Paris-Saclay, 92296, Chatenay-Malabry, France
| | - Axel Siroy
- 'Structural Biology of Biofilms' group, European Institute of Chemistry and Biology (IECB), F-33600 Pessac, France.,Université de Bordeaux, CNRS, Bordeaux INP, CBMN, UMR 5248, F-33600 Pessac, France
| | - Petya Violinova Krasteva
- 'Structural Biology of Biofilms' group, European Institute of Chemistry and Biology (IECB), F-33600 Pessac, France.,Université de Bordeaux, CNRS, Bordeaux INP, CBMN, UMR 5248, F-33600 Pessac, France
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7
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Clarithromycin Exerts an Antibiofilm Effect against Salmonella enterica Serovar Typhimurium rdar Biofilm Formation and Transforms the Physiology towards an Apparent Oxygen-Depleted Energy and Carbon Metabolism. Infect Immun 2020; 88:IAI.00510-20. [PMID: 32839186 DOI: 10.1128/iai.00510-20] [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: 08/13/2020] [Accepted: 08/16/2020] [Indexed: 11/20/2022] Open
Abstract
Upon biofilm formation, production of extracellular matrix components and alteration in physiology and metabolism allows bacteria to build up multicellular communities which can facilitate nutrient acquisition during unfavorable conditions and provide protection toward various forms of environmental stresses to individual cells. Thus, bacterial cells within biofilms become tolerant against antimicrobials and the immune system. In the present study, we evaluated the antibiofilm activity of the macrolides clarithromycin and azithromycin. Clarithromycin showed antibiofilm activity against rdar (red, dry, and rough) biofilm formation of the gastrointestinal pathogen Salmonella enterica serovar Typhimurium ATCC 14028 (Nalr) at a 1.56 μM subinhibitory concentration in standing culture and dissolved cell aggregates at 15 μM in a microaerophilic environment, suggesting that the oxygen level affects the activity of the drug. Treatment with clarithromycin significantly decreased transcription and production of the rdar biofilm activator CsgD, with biofilm genes such as csgB and adrA to be concomitantly downregulated. Although fliA and other flagellar regulon genes were upregulated, apparent motility was downregulated. RNA sequencing showed a holistic cell response upon clarithromycin exposure, whereby not only genes involved in the biofilm-related regulatory pathways but also genes that likely contribute to intrinsic antimicrobial resistance, and the heat shock stress response were differentially regulated. Most significantly, clarithromycin exposure shifted the cells toward an apparent oxygen- and energy-depleted status, whereby the metabolism that channels into oxidative phosphorylation was downregulated, and energy gain by degradation of propane 1,2-diol, ethanolamine and l-arginine catabolism, potentially also to prevent cytosolic acidification, was upregulated. This analysis will allow the subsequent identification of novel intrinsic antimicrobial resistance determinants.
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8
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Sokaribo AS, Hansen EG, McCarthy M, Desin TS, Waldner LL, MacKenzie KD, Mutwiri G, Herman NJ, Herman DJ, Wang Y, White AP. Metabolic Activation of CsgD in the Regulation of Salmonella Biofilms. Microorganisms 2020; 8:E964. [PMID: 32604994 PMCID: PMC7409106 DOI: 10.3390/microorganisms8070964] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2020] [Revised: 06/09/2020] [Accepted: 06/20/2020] [Indexed: 12/31/2022] Open
Abstract
Among human food-borne pathogens, gastroenteritis-causing Salmonella strains have the most real-world impact. Like all pathogens, their success relies on efficient transmission. Biofilm formation, a specialized physiology characterized by multicellular aggregation and persistence, is proposed to play an important role in the Salmonella transmission cycle. In this manuscript, we used luciferase reporters to examine the expression of csgD, which encodes the master biofilm regulator. We observed that the CsgD-regulated biofilm system responds differently to regulatory inputs once it is activated. Notably, the CsgD system became unresponsive to repression by Cpx and H-NS in high osmolarity conditions and less responsive to the addition of amino acids. Temperature-mediated regulation of csgD on agar was altered by intracellular levels of RpoS and cyclic-di-GMP. In contrast, the addition of glucose repressed CsgD biofilms seemingly independent of other signals. Understanding the fine-tuned regulation of csgD can help us to piece together how regulation occurs in natural environments, knowing that all Salmonella strains face strong selection pressures both within and outside their hosts. Ultimately, we can use this information to better control Salmonella and develop strategies to break the transmission cycle.
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Affiliation(s)
- Akosiererem S. Sokaribo
- Vaccine and Infectious Disease Organization-International Vaccine Centre, University of Saskatchewan, Saskatoon, SK S7N 5E3, Canada; (A.S.S.); (E.G.H.); (M.M.); (L.L.W.); (G.M.J.); (N.J.H.); (D.J.H.)
- Department of Biochemistry, Microbiology and Immunology, University of Saskatchewan, Saskatoon, SK S7N 5E5, Canada;
| | - Elizabeth G. Hansen
- Vaccine and Infectious Disease Organization-International Vaccine Centre, University of Saskatchewan, Saskatoon, SK S7N 5E3, Canada; (A.S.S.); (E.G.H.); (M.M.); (L.L.W.); (G.M.J.); (N.J.H.); (D.J.H.)
| | - Madeline McCarthy
- Vaccine and Infectious Disease Organization-International Vaccine Centre, University of Saskatchewan, Saskatoon, SK S7N 5E3, Canada; (A.S.S.); (E.G.H.); (M.M.); (L.L.W.); (G.M.J.); (N.J.H.); (D.J.H.)
- Department of Biochemistry, Microbiology and Immunology, University of Saskatchewan, Saskatoon, SK S7N 5E5, Canada;
| | - Taseen S. Desin
- Department of Biochemistry, Microbiology and Immunology, University of Saskatchewan, Saskatoon, SK S7N 5E5, Canada;
- Basic Sciences Department, King Saud bin Abdulaziz University for Health Sciences, Riyadh 11481, Saudi Arabia
| | - Landon L. Waldner
- Vaccine and Infectious Disease Organization-International Vaccine Centre, University of Saskatchewan, Saskatoon, SK S7N 5E3, Canada; (A.S.S.); (E.G.H.); (M.M.); (L.L.W.); (G.M.J.); (N.J.H.); (D.J.H.)
| | - Keith D. MacKenzie
- Institute for Microbial Systems and Society, Faculty of Science, University of Regina, Regina, SK S4S 0A2, Canada;
- Department of Biology, University of Regina, Regina, SK S4S 0A2, Canada
| | - George Mutwiri
- Vaccine and Infectious Disease Organization-International Vaccine Centre, University of Saskatchewan, Saskatoon, SK S7N 5E3, Canada; (A.S.S.); (E.G.H.); (M.M.); (L.L.W.); (G.M.J.); (N.J.H.); (D.J.H.)
| | - Nancy J. Herman
- Vaccine and Infectious Disease Organization-International Vaccine Centre, University of Saskatchewan, Saskatoon, SK S7N 5E3, Canada; (A.S.S.); (E.G.H.); (M.M.); (L.L.W.); (G.M.J.); (N.J.H.); (D.J.H.)
| | - Dakoda J. Herman
- Vaccine and Infectious Disease Organization-International Vaccine Centre, University of Saskatchewan, Saskatoon, SK S7N 5E3, Canada; (A.S.S.); (E.G.H.); (M.M.); (L.L.W.); (G.M.J.); (N.J.H.); (D.J.H.)
| | - Yejun Wang
- Department of Cell Biology and Genetics, School of Basic Medicine, Shenzhen University Health Science, Shenzhen 518060, China;
| | - Aaron P. White
- Vaccine and Infectious Disease Organization-International Vaccine Centre, University of Saskatchewan, Saskatoon, SK S7N 5E3, Canada; (A.S.S.); (E.G.H.); (M.M.); (L.L.W.); (G.M.J.); (N.J.H.); (D.J.H.)
- Department of Biochemistry, Microbiology and Immunology, University of Saskatchewan, Saskatoon, SK S7N 5E5, Canada;
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9
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Graça-Lopes G, Graça G, Barahona S, Moreira RN, Arraiano CM, Gonçalves LG. NMR-Metabolomics Shows That BolA Is an Important Modulator of Salmonella Typhimurium Metabolic Processes under Virulence Conditions. Metabolites 2019; 9:metabo9110243. [PMID: 31652780 PMCID: PMC6918366 DOI: 10.3390/metabo9110243] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2019] [Revised: 10/14/2019] [Accepted: 10/18/2019] [Indexed: 12/28/2022] Open
Abstract
BolA is a ubiquitous global transcription factor. Despite its clear role in the induction of important stress-resistant physiological changes and its recent implication in the virulence of Salmonella, further research is required to shed light on the pathways modulated by BolA. In this study, we resorted to untargeted 1H-NMR metabolomics to understand the impact of BolA on the metabolic profile of Salmonella Typhimurium, under virulence conditions. Three strains of S. Typhimurium SL1344 were studied: An SL1344 strain transformed with an empty plasmid (control), a bolA knockout mutant (ΔbolA), and a strain overexpressing bolA (bolA+). These strains were grown in a minimal virulence-inducing medium and cells were collected at the end of the exponential and stationary phases. The extracts were analyzed by NMR, and multivariate and univariate statistical analysis were performed to identify significant alterations. Principal component analysis (PCA) and partial least squares discriminant analysis (PLS-DA) of 1H-NMR data allowed the discrimination between the metabolic profiles of these strains, revealing increased levels of acetate, valine, alanine, NAD+, succinate, coenzyme A, glutathione, and putrescine in bolA+. These results indicate that BolA regulates pathways related to stress resistance and virulence, being an important modulator of the metabolic processes needed for S. Typhimurium infection.
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Affiliation(s)
- Gil Graça-Lopes
- ITQB Nova-Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Av. da República, 2780-157 Oeiras, Portugal.
| | - Gonçalo Graça
- Department of Metabolism, Digestion and Reproduction, Faculty of Medicine, Imperial College London, Sir Alexander Fleming Building, London, SW7 2AZ, UK.
| | - Susana Barahona
- ITQB Nova-Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Av. da República, 2780-157 Oeiras, Portugal.
| | - Ricardo N Moreira
- ITQB Nova-Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Av. da República, 2780-157 Oeiras, Portugal.
| | - Cecília M Arraiano
- ITQB Nova-Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Av. da República, 2780-157 Oeiras, Portugal.
| | - Luís G Gonçalves
- ITQB Nova-Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Av. da República, 2780-157 Oeiras, Portugal.
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10
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Rhen M. Salmonella and Reactive Oxygen Species: A Love-Hate Relationship. J Innate Immun 2019; 11:216-226. [PMID: 30943492 DOI: 10.1159/000496370] [Citation(s) in RCA: 55] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2018] [Accepted: 12/19/2018] [Indexed: 12/22/2022] Open
Abstract
Salmonella enterica represents an enterobacterial species including numerous serovars that cause infections at, or initiated at, the intestinal epithelium. Many serovars also act as facultative intracellular pathogens with a tropism for phagocytic cells. These bacteria not only survive in phagocytes but also undergo de facto replication therein. Phagocytes, through the activities of phagocyte NADPH-dependent oxidase and inducible nitric oxide synthase, are very proficient in converting molecular oxygen to reactive oxygen (ROS) and nitrogen species (RNS). These compounds represent highly efficient effectors of the innate immune defense. Salmonella is by no means resistant to these effectors, which may stand in contrast to the host niches chosen. To cope with this paradox, these bacteria rely on an array of detoxification and repair systems. Combination these systems allows for a high enough tolerance to ROS and RNS to enable establishment of infection. In addition, salmonella possesses protein factors that have the potential to dampen the infection-associated inflammation, which evidently results in a reduced exposure to ROS and RNS. This review attempts to summarize the activities and strategies by which salmonella tries to cope with ROS and RNS and how the bacterium can make use of these innate defense factors.
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Affiliation(s)
- Mikael Rhen
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Stockholm, Sweden, .,Department of Molecular Biology, Laboratory for Molecular Infection Medicine Sweden (MIMS), Umeå University, Umeå, Sweden, .,Umeå Centre for Microbial Research (UCMR), Umeå University, Umeå, Sweden,
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11
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Moshiri J, Kaur D, Hambira CM, Sandala JL, Koopman JA, Fuchs JR, Gunn JS. Identification of a Small Molecule Anti-biofilm Agent Against Salmonella enterica. Front Microbiol 2018; 9:2804. [PMID: 30515144 PMCID: PMC6256085 DOI: 10.3389/fmicb.2018.02804] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2018] [Accepted: 10/31/2018] [Indexed: 12/20/2022] Open
Abstract
Biofilm formation is a common strategy utilized by bacterial pathogens to establish persistence in a host niche. Salmonella enterica serovar Typhi, the etiological agent of Typhoid fever, relies on biofilm formation in the gallbladder to chronically colonize asymptomatic carriers, allowing for transmission to uninfected individuals. S. enterica serovar Typhimurium utilizes biofilms to achieve persistence in human and animal hosts, an issue of both clinical and agricultural importance. Here, we identify a compound that selectively inhibits biofilm formation in both S. Typhi and S. Typhimurium serovars at early stages of biofilm development with an EC50 of 21.0 and 7.4 μM, respectively. We find that this compound, T315, also reduces biofilm formation in Acinetobacter baumannii, a nosocomial and opportunistic pathogen with rising antibiotic resistance. T315 treatment in conjunction with sub-MIC dosing of ciprofloxacin further reduces S. enterica biofilm formation, demonstrating the potential of such combination therapies for therapeutic development. Through synthesis of two biotin-labeled T315 probes and subsequent pull-down and proteomics analysis, we identified a T315 binding target: WrbA, a flavin mononucleotide-dependent NADH:quinone oxidoreductase. Using a S. Typhimurium strain lacking WrbA we demonstrate that this factor contributes to endogenous S. enterica biofilm formation processes and is required for full T315 anti-biofilm activity. We suggest WrbA as a promising target for further development of anti-biofilm agents in Salmonella, with potential for use against additional bacterial pathogens. The development of anti-biofilm therapeutics will be essential to combat chronic carriage of Typhoid fever and thus accomplish a meaningful reduction of global disease burden.
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Affiliation(s)
- Jasmine Moshiri
- Department of Microbial Infection and Immunity, Infectious Diseases Institute, The Ohio State University, Columbus, OH, United States
| | - Darpan Kaur
- Department of Microbial Infection and Immunity, Infectious Diseases Institute, The Ohio State University, Columbus, OH, United States
| | - Chido M Hambira
- Division of Medicinal Chemistry and Pharmacognosy, College of Pharmacy, The Ohio State University, Columbus, OH, United States
| | - Jenna L Sandala
- Department of Microbial Infection and Immunity, Infectious Diseases Institute, The Ohio State University, Columbus, OH, United States
| | - Jacob A Koopman
- Department of Microbial Infection and Immunity, Infectious Diseases Institute, The Ohio State University, Columbus, OH, United States
| | - James R Fuchs
- Division of Medicinal Chemistry and Pharmacognosy, College of Pharmacy, The Ohio State University, Columbus, OH, United States
| | - John S Gunn
- Department of Microbial Infection and Immunity, Infectious Diseases Institute, The Ohio State University, Columbus, OH, United States
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12
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Di Sante L, Pugnaloni A, Biavasco F, Giovanetti E, Vignaroli C. Multicellular behavior of environmental Escherichia coli isolates grown under nutrient-poor and low-temperature conditions. Microbiol Res 2018; 210:43-50. [DOI: 10.1016/j.micres.2018.03.004] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2017] [Revised: 02/20/2018] [Accepted: 03/10/2018] [Indexed: 11/26/2022]
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13
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Paytubi S, Cansado C, Madrid C, Balsalobre C. Nutrient Composition Promotes Switching between Pellicle and Bottom Biofilm in Salmonella. Front Microbiol 2017; 8:2160. [PMID: 29163440 PMCID: PMC5673991 DOI: 10.3389/fmicb.2017.02160] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2017] [Accepted: 10/20/2017] [Indexed: 11/24/2022] Open
Abstract
Salmonella is one of the most frequently reported causes of foodborne illness worldwide. Non-typhoidal serovars cause gastroenteritis in humans. Salmonella can grow on surfaces forming biofilms, contributing to its persistence since biofilms are difficult to eradicate due to the high resistance to antimicrobials and disinfectants. It has been described that there are two crucial biofilm promoting factors in Salmonella: curli and cellulose. The expression of both factors is coordinately regulated by the transcriptional regulator CsgD. Most biofilm studies of Salmonella have been performed by growing bacteria in low osmolarity rich medium and low temperature (25°C). In such conditions, the biofilm is formed at the air–liquid interface (pellicle biofilm). Remarkably, when Salmonella grow in minimal medium, biofilm formation switches from the air–liquid interface to the solid–liquid interface (bottom biofilm). In this report, the switching between pellicle and bottom biofilm has been characterized. Our data indicate that curli, but not cellulose, is crucial for the formation of both kinds of biofilms. In minimal medium, conditions promoting formation of bottom biofilm, a high transcriptional expression of csgD and consequently of the genes involved in the synthesis of curli and cellulose was detected. The nutritional status of the cells seems to be pivotal for the spatial distribution of the biofilms formed. When bacteria is growing in minimal medium the addition of amino acids downregulates the expression of csgB and causes the switch between bottom and pellicle biofilm. The crosstalk between general metabolism and biofilm formation is also highlighted by the fact that the metabolic sensor cAMP modulates the type of biofilm generated by Salmonella. Moreover, cAMP regulates transcriptional expression of csgD and stimulates pellicle biofilm formation, suggesting that the physiological conditions define the type of biofilm formed by Salmonella. The consequences of the switching between pellicle and bottom biofilm during either infection or survival in natural environments remain undercover.
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Affiliation(s)
- Sonia Paytubi
- Section of Microbiology, Virology and Biotechnology, Department of Genetics, Microbiology and Statistics, University of Barcelona, Barcelona, Spain
| | - Cintia Cansado
- Section of Microbiology, Virology and Biotechnology, Department of Genetics, Microbiology and Statistics, University of Barcelona, Barcelona, Spain
| | - Cristina Madrid
- Section of Microbiology, Virology and Biotechnology, Department of Genetics, Microbiology and Statistics, University of Barcelona, Barcelona, Spain
| | - Carlos Balsalobre
- Section of Microbiology, Virology and Biotechnology, Department of Genetics, Microbiology and Statistics, University of Barcelona, Barcelona, Spain
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14
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The Production of Curli Amyloid Fibers Is Deeply Integrated into the Biology of Escherichia coli. Biomolecules 2017; 7:biom7040075. [PMID: 29088115 PMCID: PMC5745457 DOI: 10.3390/biom7040075] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2017] [Revised: 10/13/2017] [Accepted: 10/23/2017] [Indexed: 12/29/2022] Open
Abstract
Curli amyloid fibers are the major protein component of the extracellular matrix produced by Enterobacteriaceae during biofilm formation. Curli are required for proper biofilm development and environmental persistence by Escherichia coli. Here, we present a complete and vetted genetic analysis of functional amyloid fiber biogenesis. The Keio collection of single gene deletions was screened on Congo red indicator plates to identify E. coli mutants that had defective amyloid production. We discovered that more than three hundred gene products modulated curli production. These genes were involved in fundamental cellular processes such as regulation, environmental sensing, respiration, metabolism, cell envelope biogenesis, transport, and protein turnover. The alternative sigma factors, σS and σE, had opposing roles in curli production. Mutations that induced the σE or Cpx stress response systems had reduced curli production, while mutant strains with increased σS levels had increased curli production. Mutations in metabolic pathways, including gluconeogenesis and the biosynthesis of lipopolysaccharide (LPS), produced less curli. Regulation of the master biofilm regulator, CsgD, was diverse, and the screen revealed several proteins and small RNAs (sRNA) that regulate csgD messenger RNA (mRNA) levels. Using previously published studies, we found minimal overlap between the genes affecting curli biogenesis and genes known to impact swimming or swarming motility, underlying the distinction between motile and sessile lifestyles. Collectively, the diversity and number of elements required suggest curli production is part of a highly regulated and complex developmental pathway in E. coli.
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15
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Maršíková J, Wilkinson D, Hlaváček O, Gilfillan GD, Mizeranschi A, Hughes T, Begany M, Rešetárová S, Váchová L, Palková Z. Metabolic differentiation of surface and invasive cells of yeast colony biofilms revealed by gene expression profiling. BMC Genomics 2017; 18:814. [PMID: 29061122 PMCID: PMC5654107 DOI: 10.1186/s12864-017-4214-4] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2017] [Accepted: 10/16/2017] [Indexed: 12/19/2022] Open
Abstract
Background Yeast infections are often connected with formation of biofilms that are extremely difficult to eradicate. An excellent model system for deciphering multifactorial determinants of yeast biofilm development is the colony biofilm, composed of surface (“aerial”) and invasive (“root”) cells. While surface cells have been partially analyzed before, we know little about invasive root cells. In particular, information on the metabolic, chemical and morphogenetic properties of invasive versus surface cells is lacking. In this study, we used a new strategy to isolate invasive cells from agar and extracellular matrix, and employed it to perform genome wide expression profiling and biochemical analyses of surface and invasive cells. Results RNA sequencing revealed expression differences in 1245 genes with high statistical significance, indicating large genetically regulated metabolic differences between surface and invasive cells. Functional annotation analyses implicated genes involved in stress defense, peroxisomal fatty acid β-oxidation, autophagy, protein degradation, storage compound metabolism and meiosis as being important in surface cells. In contrast, numerous genes with functions in nutrient transport and diverse synthetic metabolic reactions, including genes involved in ribosome biogenesis, biosynthesis and translation, were found to be important in invasive cells. Variation in gene expression correlated significantly with cell-type specific processes such as autophagy and storage compound accumulation as identified by microscopic and biochemical analyses. Expression profiling also provided indications of cell-specific regulations. Subsequent knockout strain analyses identified Gip2p, a regulatory subunit of type 1 protein phosphatase Glc7p, to be essential for glycogen accumulation in surface cells. Conclusions This is the first study reporting genome wide differences between surface and invasive cells of yeast colony biofilms. New findings show that surface and invasive cells display very different physiology, adapting to different conditions in different colony areas and contributing to development and survival of the colony biofilm as a whole. Notably, surface and invasive cells of colony biofilms differ significantly from upper and lower cells of smooth colonies adapted to plentiful laboratory conditions. Electronic supplementary material The online version of this article (doi:10.1186/s12864-017-4214-4) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Jana Maršíková
- Department of Genetics and Microbiology, Faculty of Science, Charles University, BIOCEV, 252 50, Vestec, Czech Republic
| | - Derek Wilkinson
- Department of Genetics and Microbiology, Faculty of Science, Charles University, BIOCEV, 252 50, Vestec, Czech Republic
| | - Otakar Hlaváček
- Institute of Microbiology of the Czech Academy of Sciences, BIOCEV, 252 50, Vestec, Czech Republic
| | | | - Alexandru Mizeranschi
- Department of Genetics and Microbiology, Faculty of Science, Charles University, BIOCEV, 252 50, Vestec, Czech Republic
| | - Timothy Hughes
- Oslo University Hospital and University of Oslo, 0450, Oslo, Norway.,NORMENT, Institute of Clinical Medicine, University of Oslo, 0450, Oslo, Norway
| | - Markéta Begany
- Institute of Microbiology of the Czech Academy of Sciences, BIOCEV, 252 50, Vestec, Czech Republic
| | - Stanislava Rešetárová
- Institute of Microbiology of the Czech Academy of Sciences, BIOCEV, 252 50, Vestec, Czech Republic
| | - Libuše Váchová
- Institute of Microbiology of the Czech Academy of Sciences, BIOCEV, 252 50, Vestec, Czech Republic
| | - Zdena Palková
- Department of Genetics and Microbiology, Faculty of Science, Charles University, BIOCEV, 252 50, Vestec, Czech Republic.
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16
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Kaplan M, Kale H, Karaman K, Unlukara A. Influence of different irrigation and nitrogen levels on crude oil and fatty acid composition of maize ( Zea mays L.). GRASAS Y ACEITES 2017. [DOI: 10.3989/gya.0222171] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
The effect of irrigation and nitrogen fertilizer levels on the crude oil and fatty acid composition of maize cultivars was studied. Three levels of irrigation (50, 75 and 100% of field capacity) and nitrogen (100, 200 and 300 kg·ha-1) were used for treatment groups. After harvest, the crude oils were extracted and fatty acid profiles were determined by Gas Chromatography system. The study was repeated for two years and the interaction effects of fertilizer and irrigation were determined. Our results show that the crude oil content was affected positively by the fertilizer and the irrigation applications. As expected, the most abundant fatty acid was linoleic and the harvest year did not alter it. The highest linoleic acid content value was obtained with a 50% field capacity and 300 kg·ha-1 fertilizer treatment combination. In addition, fatty acid contents varied with the changing of interaction effects except for myristic and palmitic acid. Oleic acid was the second abundant fatty acid in the oil samples and the lowest oleic acid value was obtained with a 50% field capacity and 300 kg·ha-1 fertilizer treatment combination. Oleic acid content tended to increase with 75% field capacity but 100% field capacity treatment decreased in it.
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17
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MacKenzie KD, Palmer MB, Köster WL, White AP. Examining the Link between Biofilm Formation and the Ability of Pathogenic Salmonella Strains to Colonize Multiple Host Species. Front Vet Sci 2017; 4:138. [PMID: 29159172 PMCID: PMC5581909 DOI: 10.3389/fvets.2017.00138] [Citation(s) in RCA: 59] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2017] [Accepted: 08/09/2017] [Indexed: 12/11/2022] Open
Abstract
Salmonella are important pathogens worldwide and a predominant number of human infections are zoonotic in nature. The ability of strains to form biofilms, which is a multicellular behavior characterized by the aggregation of cells, is predicted to be a conserved strategy for increased persistence and survival. It may also contribute to the increasing number of infections caused by ingestion of contaminated fruits and vegetables. There is a correlation between biofilm formation and the ability of strains to colonize and replicate within the intestines of multiple host species. These strains predominantly cause localized gastroenteritis infections in humans. In contrast, there are salmonellae that cause systemic, disseminated infections in a select few host species; these “invasive” strains have a narrowed host range, and most are unable to form biofilms. This includes host-restricted Salmonella serovar Typhi, which are only able to infect humans, and atypical gastroenteritis strains associated with the opportunistic infection of immunocompromised patients. From the perspective of transmission, biofilm formation is advantageous for ensuring pathogen survival in the environment. However, from an infection point of view, biofilm formation may be an anti-virulence trait. We do not know if the capacity to form biofilms prevents a strain from accessing the systemic compartments within the host or if loss of the biofilm phenotype reflects a change in a strain’s interaction with the host. In this review, we examine the connections between biofilm formation, Salmonella disease states, degrees of host adaptation, and how this might relate to different transmission patterns. A better understanding of the dynamic lifecycle of Salmonella will allow us to reduce the burden of livestock and human infections caused by these important pathogens.
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Affiliation(s)
- Keith D MacKenzie
- Vaccine and Infectious Disease Organization-International Vaccine Centre, Saskatoon, SK, Canada.,Department of Microbiology and Immunology, University of Saskatchewan, Saskatoon, SK, Canada
| | - Melissa B Palmer
- Vaccine and Infectious Disease Organization-International Vaccine Centre, Saskatoon, SK, Canada.,Department of Microbiology and Immunology, University of Saskatchewan, Saskatoon, SK, Canada
| | - Wolfgang L Köster
- Vaccine and Infectious Disease Organization-International Vaccine Centre, Saskatoon, SK, Canada.,Department of Veterinary Microbiology, University of Saskatchewan, Saskatoon, SK, Canada
| | - Aaron P White
- Vaccine and Infectious Disease Organization-International Vaccine Centre, Saskatoon, SK, Canada.,Department of Microbiology and Immunology, University of Saskatchewan, Saskatoon, SK, Canada
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18
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NandaKafle G, Seale T, Flint T, Nepal M, Venter SN, Brözel VS. Distribution of Diverse Escherichia coli between Cattle and Pasture. Microbes Environ 2017; 32:226-233. [PMID: 28747587 PMCID: PMC5606692 DOI: 10.1264/jsme2.me17030] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
Escherichia coli is widely considered to not survive for extended periods outside the intestines of warm-blooded animals; however, recent studies demonstrated that E. coli strains maintain populations in soil and water without any known fecal contamination. The objective of this study was to investigate whether the niche partitioning of E. coli occurs between cattle and their pasture. We attempted to clarify whether E. coli from bovine feces differs phenotypically and genotypically from isolates maintaining a population in pasture soil over winter. Soil, bovine fecal, and run-off samples were collected before and after the introduction of cattle to the pasture. Isolates (363) were genotyped by uidA and mutS sequences and phylogrouping, and evaluated for curli formation (Rough, Dry, And Red, or RDAR). Three types of clusters emerged, viz. bovine-associated, clusters devoid of cattle isolates and representing isolates endemic to the pasture environment, and clusters with both. All isolates clustered with strains of E. coli sensu stricto, distinct from the cryptic species Clades I, III, IV, and V. Pasture soil endemic and bovine fecal populations had very different phylogroup distributions, indicating niche partitioning. The soil endemic population was largely comprised of phylogroup B1 and had a higher average RDAR score than other isolates. These results indicate the existence of environmental E. coli strains that are phylogenetically distinct from bovine fecal isolates, and that have the ability to maintain populations in the soil environment.
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Affiliation(s)
| | - Tarren Seale
- Department of Microbiology and Plant Pathology, University of Pretoria
| | - Toby Flint
- Department of Mathematics and Statistics, South Dakota State University
| | - Madhav Nepal
- Department of Biology and Microbiology, South Dakota State University
| | | | - Volker S Brözel
- Department of Biology and Microbiology, South Dakota State University.,Department of Microbiology and Plant Pathology, University of Pretoria
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19
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Beyond Antimicrobial Resistance: Evidence for a Distinct Role of the AcrD Efflux Pump in Salmonella Biology. mBio 2016; 7:mBio.01916-16. [PMID: 27879336 PMCID: PMC5120143 DOI: 10.1128/mbio.01916-16] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
For over 20 years, bacterial multidrug resistance (MDR) efflux pumps have been studied because of their impact on resistance to antimicrobials. However, critical questions remain, including why produce efflux pumps under non-antimicrobial treatment conditions, and why have multiple pumps if their only purpose is antimicrobial efflux? Salmonella spp. possess five efflux pump families, including the resistance-nodulation-division (RND) efflux pumps. Notably, the RND efflux pump AcrD has a unique substrate profile, distinct from other Salmonella efflux pumps. Here we show that inactivation of acrD results in a profoundly altered transcriptome and modulation of pathways integral to Salmonella biology. The most significant transcriptome changes were central metabolism related, with additional changes observed in pathogenicity, environmental sensing, and stress response pathway expression. The extent of tricarboxylic acid cycle and fumarate metabolism expression changes led us to hypothesize that acrD inactivation may result in motility defects due to perturbation of metabolite concentrations, such as fumarate, for which a role in motility has been established. Despite minimal detectable changes in flagellar gene expression, we found that an acrD mutant Salmonella enterica serovar Typhimurium isolate was significantly impaired for swarming motility, which was restored by addition of fumarate. The acrD mutant outcompeted the wild type in fitness experiments. The results of these diverse experiments provide strong evidence that the AcrD efflux pump is not simply a redundant system providing response resilience, but also has distinct physiological functions. Together, these data indicate that the AcrD efflux pump has a significant and previously underappreciated impact on bacterial biology, despite only minor perturbations of antibiotic resistance profiles. Efflux pumps in Gram-negative bacteria are studied because of their important contributions to antimicrobial resistance. However, the role of these pumps in bacterial biology has remained surprisingly elusive. Here, we provide evidence that loss of the AcrD efflux pump significantly impacts the physiology of Salmonella enterica serovar Typhimurium. Inactivation of acrD led to changes in the expression of 403 genes involved in fundamental processes, including basic metabolism, virulence, and stress responses. Pathways such as these allow Salmonella to grow, survive in the environment, and cause disease. Indeed, our data show that the acrD mutant is more fit than wild-type Salmonella under standard lab conditions. We hypothesized that inactivation of acrD would alter levels of bacterial metabolites, impacting traits such as swarming motility. We demonstrated this by exogenous addition of the metabolite fumarate, which partially restored the acrD mutant’s swarming defect. This work extends our understanding of the role of bacterial efflux pumps.
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20
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Liao Y, Williams TJ, Ye J, Charlesworth J, Burns BP, Poljak A, Raftery MJ, Cavicchioli R. Morphological and proteomic analysis of biofilms from the Antarctic archaeon, Halorubrum lacusprofundi. Sci Rep 2016; 6:37454. [PMID: 27874045 PMCID: PMC5118699 DOI: 10.1038/srep37454] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2016] [Accepted: 10/26/2016] [Indexed: 12/21/2022] Open
Abstract
Biofilms enhance rates of gene exchange, access to specific nutrients, and cell survivability. Haloarchaea in Deep Lake, Antarctica, are characterized by high rates of intergenera gene exchange, metabolic specialization that promotes niche adaptation, and are exposed to high levels of UV-irradiation in summer. Halorubrum lacusprofundi from Deep Lake has previously been reported to form biofilms. Here we defined growth conditions that promoted the formation of biofilms and used microscopy and enzymatic digestion of extracellular material to characterize biofilm structures. Extracellular DNA was found to be critical to biofilms, with cell surface proteins and quorum sensing also implicated in biofilm formation. Quantitative proteomics was used to define pathways and cellular processes involved in forming biofilms; these included enhanced purine synthesis and specific cell surface proteins involved in DNA metabolism; post-translational modification of cell surface proteins; specific pathways of carbon metabolism involving acetyl-CoA; and specific responses to oxidative stress. The study provides a new level of understanding about the molecular mechanisms involved in biofilm formation of this important member of the Deep Lake community.
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Affiliation(s)
- Y Liao
- School of Biotechnology and Biomolecular Sciences, The University of New South Wales, Sydney, New South Wales, 2052, Australia
| | - T J Williams
- School of Biotechnology and Biomolecular Sciences, The University of New South Wales, Sydney, New South Wales, 2052, Australia
| | - J Ye
- School of Biotechnology and Biomolecular Sciences, The University of New South Wales, Sydney, New South Wales, 2052, Australia.,Centre for Marine Bio-Innovation, The University of New South Wales, Sydney, New South Wales, 2052, Australia
| | - J Charlesworth
- School of Biotechnology and Biomolecular Sciences, The University of New South Wales, Sydney, New South Wales, 2052, Australia
| | - B P Burns
- School of Biotechnology and Biomolecular Sciences, The University of New South Wales, Sydney, New South Wales, 2052, Australia
| | - A Poljak
- Bioanalytical Mass Spectrometry Facility, The University of New South Wales, Sydney, New South Wales, Australia
| | - M J Raftery
- Bioanalytical Mass Spectrometry Facility, The University of New South Wales, Sydney, New South Wales, Australia
| | - R Cavicchioli
- School of Biotechnology and Biomolecular Sciences, The University of New South Wales, Sydney, New South Wales, 2052, Australia
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21
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Besharova O, Suchanek VM, Hartmann R, Drescher K, Sourjik V. Diversification of Gene Expression during Formation of Static Submerged Biofilms by Escherichia coli. Front Microbiol 2016; 7:1568. [PMID: 27761132 PMCID: PMC5050211 DOI: 10.3389/fmicb.2016.01568] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2016] [Accepted: 09/20/2016] [Indexed: 11/23/2022] Open
Abstract
Many bacteria primarily exist in nature as structured multicellular communities, so called biofilms. Biofilm formation is a highly regulated process that includes the transition from the motile planktonic to sessile biofilm lifestyle. Cellular differentiation within a biofilm is a commonly accepted concept but it remains largely unclear when, where and how exactly such differentiation arises. Here we used fluorescent transcriptional reporters to quantitatively analyze spatio-temporal expression patterns of several groups of genes during the formation of submerged Escherichia coli biofilms in an open static system. We first confirm that formation of such submerged biofilms as well as pellicles at the liquid-air interface requires the major matrix component, curli, and flagella-mediated motility. We further demonstrate that in this system, diversification of gene expression leads to emergence of at least three distinct subpopulations of E. coli, which differ in their levels of curli and flagella expression, and in the activity of the stationary phase sigma factor σS. Our study reveals mutually exclusive expression of curli fibers and flagella at the single cell level, with high curli levels being confined to dense cell aggregates/microcolonies and flagella expression showing an opposite expression pattern. Interestingly, despite the known σS-dependence of curli induction, there was only a partial correlation between the σS activity and curli expression, with subpopulations of cells having high σS activity but low curli expression and vice versa. Finally, consistent with different physiology of the observed subpopulations, we show striking differences between the growth rates of cells within and outside of aggregates.
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Affiliation(s)
- Olga Besharova
- Max Planck Institute for Terrestrial MicrobiologyMarburg, Germany
- LOEWE Center for Synthetic Microbiology (SYNMIKRO)Marburg, Germany
| | - Verena M. Suchanek
- Max Planck Institute for Terrestrial MicrobiologyMarburg, Germany
- LOEWE Center for Synthetic Microbiology (SYNMIKRO)Marburg, Germany
- Zentrum für Molekulare Biologie der Universität Heidelberg, DKFZ-ZMBH AllianceHeidelberg, Germany
| | - Raimo Hartmann
- Max Planck Institute for Terrestrial MicrobiologyMarburg, Germany
| | - Knut Drescher
- Max Planck Institute for Terrestrial MicrobiologyMarburg, Germany
| | - Victor Sourjik
- Max Planck Institute for Terrestrial MicrobiologyMarburg, Germany
- LOEWE Center for Synthetic Microbiology (SYNMIKRO)Marburg, Germany
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22
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Tan MSF, Moore SC, Tabor RF, Fegan N, Rahman S, Dykes GA. Attachment of Salmonella strains to a plant cell wall model is modulated by surface characteristics and not by specific carbohydrate interactions. BMC Microbiol 2016; 16:212. [PMID: 27629769 PMCID: PMC5024418 DOI: 10.1186/s12866-016-0832-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2015] [Indexed: 12/04/2022] Open
Abstract
Background Processing of fresh produce exposes cut surfaces of plant cell walls that then become vulnerable to human foodborne pathogen attachment and contamination, particularly by Salmonella enterica. Plant cell walls are mainly composed of the polysaccharides cellulose, pectin and hemicelluloses (predominantly xyloglucan). Our previous work used bacterial cellulose-based plant cell wall models to study the interaction between Salmonella and the various plant cell wall components. We demonstrated that Salmonella attachment was favoured in the presence of pectin while xyloglucan had no effect on its attachment. Xyloglucan significantly increased the attachment of Salmonella cells to the plant cell wall model only when it was in association with pectin. In this study, we investigate whether the plant cell wall polysaccharides mediate Salmonella attachment to the bacterial cellulose-based plant cell wall models through specific carbohydrate interactions or through the effects of carbohydrates on the physical characteristics of the attachment surface. Results We found that none of the monosaccharides that make up the plant cell wall polysaccharides specifically inhibit Salmonella attachment to the bacterial cellulose-based plant cell wall models. Confocal laser scanning microscopy showed that Salmonella cells can penetrate and attach within the tightly arranged bacterial cellulose network. Analysis of images obtained from atomic force microscopy revealed that the bacterial cellulose-pectin-xyloglucan composite with 0.3 % (w/v) xyloglucan, previously shown to have the highest number of Salmonella cells attached to it, had significantly thicker cellulose fibrils compared to other composites. Scanning electron microscopy images also showed that the bacterial cellulose and bacterial cellulose-xyloglucan composites were more porous when compared to the other composites containing pectin. Conclusions Our study found that the attachment of Salmonella cells to cut plant cell walls was not mediated by specific carbohydrate interactions. This suggests that the attachment of Salmonella strains to the plant cell wall models were more dependent on the structural characteristics of the attachment surface. Pectin reduces the porosity and space between cellulose fibrils, which then forms a matrix that is able to retain Salmonella cells within the bacterial cellulose network. When present with pectin, xyloglucan provides a greater surface for Salmonella cells to attach through the thickening of cellulose fibrils.
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Affiliation(s)
- Michelle Sze-Fan Tan
- School of Science, Monash University Malaysia, Jalan Lagoon Selatan, 47500, Bandar Sunway, Selangor Darul Ehsan, Malaysia
| | - Sean C Moore
- CSIRO Agriculture and Food, 671 Sneydes Road, Werribee, VIC, 3030, Australia
| | - Rico F Tabor
- School of Chemistry, Monash University, Clayton campus, Wellington Road, Clayton, VIC, 3800, Australia
| | - Narelle Fegan
- CSIRO Agriculture and Food, 671 Sneydes Road, Werribee, VIC, 3030, Australia
| | - Sadequr Rahman
- School of Science, Monash University Malaysia, Jalan Lagoon Selatan, 47500, Bandar Sunway, Selangor Darul Ehsan, Malaysia
| | - Gary A Dykes
- School of Public Health, Curtin University, Perth, WA, 6845, Australia.
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Evidence of Naturalized Stress-Tolerant Strains of Escherichia coli in Municipal Wastewater Treatment Plants. Appl Environ Microbiol 2016; 82:5505-18. [PMID: 27371583 PMCID: PMC5007776 DOI: 10.1128/aem.00143-16] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2016] [Accepted: 06/23/2016] [Indexed: 01/06/2023] Open
Abstract
Escherichia coli has been proposed to have two habitats—the intestines of mammals/birds and the nonhost environment. Our goal was to assess whether certain strains of E. coli have evolved toward adaptation and survival in wastewater. Raw sewage samples from different treatment plants were subjected to chlorine stress, and ∼59% of the surviving E. coli strains were found to contain a genetic insertion element (IS30) located within the uspC-flhDC intergenic region. The positional location of the IS30 element was not observed across a library of 845 E. coli isolates collected from various animal hosts or within GenBank or whole-genome reference databases for human and animal E. coli isolates (n = 1,177). Phylogenetics clustered the IS30 element-containing wastewater E. coli isolates into a distinct clade, and biomarker analysis revealed that these wastewater isolates contained a single nucleotide polymorphism (SNP) biomarker pattern that was specific for wastewater. These isolates belonged to phylogroup A, possessed generalized stress response (RpoS) activity, and carried the locus of heat resistance, features likely relevant to nonhost environmental survival. Isolates were screened for 28 virulence genes but carried only the fimH marker. Our data suggest that wastewater contains a naturalized resident population of E. coli. We developed an endpoint PCR targeting the IS30 element within the uspC-flhDC intergenic region, and all raw sewage samples (n = 21) were positive for this marker. Conversely, the prevalence of this marker in E. coli-positive surface and groundwater samples was low (≤5%). This simple PCR assay may represent a convenient microbial source-tracking tool for identification of water samples affected by municipal wastewater. IMPORTANCE The results of this study demonstrate that some strains of E. coli appear to have evolved to become naturalized populations in the wastewater environment and possess a number of stress-related genetic elements likely important for survival in this nonhost environment. The presence of non-host-adapted strains in wastewater challenges our understanding of using E. coli as a microbial indicator of wastewater treatment performance, suggesting that the E. coli strains present in human and animal feces may be very different from those found in treated wastewater.
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A Modular, Tn7-Based System for Making Bioluminescent or Fluorescent Salmonella and Escherichia coli Strains. Appl Environ Microbiol 2016; 82:4931-43. [PMID: 27260360 DOI: 10.1128/aem.01346-16] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2016] [Accepted: 05/31/2016] [Indexed: 12/21/2022] Open
Abstract
UNLABELLED Our goal was to develop a robust tagging method that can be used to track bacterial strains in vivo To address this challenge, we adapted two existing systems: a modular plasmid-based reporter system (pCS26) that has been used for high-throughput gene expression studies in Salmonella and Escherichia coli and Tn7 transposition. We generated kanamycin- and chloramphenicol-resistant versions of pCS26 with bacterial luciferase, green fluorescent protein (GFP), and mCherry reporters under the control of σ(70)-dependent promoters to provide three different levels of constitutive expression. We improved upon the existing Tn7 system by modifying the delivery vector to accept pCS26 constructs and moving the transposase genes from a nonreplicating helper plasmid into a temperature-sensitive plasmid that can be conditionally maintained. This resulted in a 10- to 30-fold boost in transposase gene expression and transposition efficiencies of 10(-8) to 10(-10) in Salmonella enterica serovar Typhimurium and E. coli APEC O1, whereas the existing Tn7 system yielded no successful transposition events. The new reporter strains displayed reproducible signaling in microwell plate assays, confocal microscopy, and in vivo animal infections. We have combined two flexible and complementary tools that can be used for a multitude of molecular biology applications within the Enterobacteriaceae This system can accommodate new promoter-reporter combinations as they become available and can help to bridge the gap between modern, high-throughput technologies and classical molecular genetics. IMPORTANCE This article describes a flexible and efficient system for tagging bacterial strains. Using our modular plasmid system, a researcher can easily change the reporter type or the promoter driving expression and test the parameters of these new constructs in vitro Selected constructs can then be stably integrated into the chromosomes of desired strains in two simple steps. We demonstrate the use of this system in Salmonella and E. coli, and we predict that it will be widely applicable to other bacterial strains within the Enterobacteriaceae This technology will allow for improved in vivo analysis of bacterial pathogens.
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Santiago-Martínez MG, Encalada R, Lira-Silva E, Pineda E, Gallardo-Pérez JC, Reyes-García MA, Saavedra E, Moreno-Sánchez R, Marín-Hernández A, Jasso-Chávez R. The nutritional status of Methanosarcina acetivorans regulates glycogen metabolism and gluconeogenesis and glycolysis fluxes. FEBS J 2016; 283:1979-99. [PMID: 27000496 DOI: 10.1111/febs.13717] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2015] [Revised: 03/10/2016] [Accepted: 03/17/2016] [Indexed: 11/27/2022]
Abstract
Gluconeogenesis is an essential pathway in methanogens because they are unable to use exogenous hexoses as carbon source for cell growth. With the aim of understanding the regulatory mechanisms of central carbon metabolism in Methanosarcina acetivorans, the present study investigated gene expression, the activities and metabolic regulation of key enzymes, metabolite contents and fluxes of gluconeogenesis, as well as glycolysis and glycogen synthesis/degradation pathways. Cells were grown with methanol as a carbon source. Key enzymes were kinetically characterized at physiological pH/temperature. Active consumption of methanol during exponential cell growth correlated with significant methanogenesis, gluconeogenic flux and steady glycogen synthesis. After methanol exhaustion, cells reached the stationary growth phase, which correlated with the rise in glycogen consumption and glycolytic flux, decreased methanogenesis, negligible acetate production and an absence of gluconeogenesis. Elevated activities of carbon monoxide dehydrogenase/acetyl-CoA synthetase complex and pyruvate: ferredoxin oxidoreductase suggested the generation of acetyl-CoA and pyruvate for glycogen synthesis. In the early stationary growth phase, the transcript contents and activities of pyruvate phosphate dikinase, fructose 1,6-bisphosphatase and glycogen synthase decreased, whereas those of glycogen phosphorylase, ADP-phosphofructokinase and pyruvate kinase increased. Therefore, glycogen and gluconeogenic metabolites were synthesized when an external carbon source was provided. Once such a carbon source became depleted, glycolysis and methanogenesis fed by glycogen degradation provided the ATP supply. Weak inhibition of key enzymes by metabolites suggested that the pathways evaluated were mainly transcriptionally regulated. Because glycogen metabolism and glycolysis/gluconeogenesis are not present in all methanogens, the overall data suggest that glycogen storage might represent an environmental advantage for methanosarcinales when carbon sources are scarce. Also, the understanding of the central carbohydrate metabolism in methanosarcinales may help to optimize methane production.
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Affiliation(s)
| | - Rusely Encalada
- Departamento de Bioquímica, Instituto Nacional de Cardiología, México DF, México
| | - Elizabeth Lira-Silva
- Departamento de Bioquímica, Instituto Nacional de Cardiología, México DF, México
| | - Erika Pineda
- Departamento de Bioquímica, Instituto Nacional de Cardiología, México DF, México
| | | | | | - Emma Saavedra
- Departamento de Bioquímica, Instituto Nacional de Cardiología, México DF, México
| | | | | | - Ricardo Jasso-Chávez
- Departamento de Bioquímica, Instituto Nacional de Cardiología, México DF, México
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Abstract
Bacteria have traditionally been studied as single-cell organisms. In laboratory settings, aerobic bacteria are usually cultured in aerated flasks, where the cells are considered essentially homogenous. However, in many natural environments, bacteria and other microorganisms grow in mixed communities, often associated with surfaces. Biofilms are comprised of surface-associated microorganisms, their extracellular matrix material, and environmental chemicals that have adsorbed to the bacteria or their matrix material. While this definition of a biofilm is fairly simple, biofilms are complex and dynamic. Our understanding of the activities of individual biofilm cells and whole biofilm systems has developed rapidly, due in part to advances in molecular, analytical, and imaging tools and the miniaturization of tools designed to characterize biofilms at the enzyme level, cellular level, and systems level.
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FabR regulates Salmonella biofilm formation via its direct target FabB. BMC Genomics 2016; 17:253. [PMID: 27004424 PMCID: PMC4804515 DOI: 10.1186/s12864-016-2387-x] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2015] [Accepted: 01/08/2016] [Indexed: 12/02/2022] Open
Abstract
Background Biofilm formation is an important survival strategy of Salmonella in all environments. By mutant screening, we showed a knock-out mutant of fabR, encoding a repressor of unsaturated fatty acid biosynthesis (UFA), to have impaired biofilm formation. In order to unravel how this regulator impinges on Salmonella biofilm formation, we aimed at elucidating the S. Typhimurium FabR regulon. Hereto, we applied a combinatorial high-throughput approach, combining ChIP-chip with transcriptomics. Results All the previously identified E. coli FabR transcriptional target genes (fabA, fabB and yqfA) were shown to be direct S. Typhimurium FabR targets as well. As we found a fabB overexpressing strain to partly mimic the biofilm defect of the fabR mutant, the effect of FabR on biofilms can be attributed at least partly to FabB, which plays a key role in UFA biosynthesis. Additionally, ChIP-chip identified a number of novel direct FabR targets (the intergenic regions between hpaR/hpaG and ddg/ydfZ) and yet putative direct targets (i.a. genes involved in tRNA metabolism, ribosome synthesis and translation). Next to UFA biosynthesis, a number of these direct targets and other indirect targets identified by transcriptomics (e.g. ribosomal genes, ompA, ompC, ompX, osmB, osmC, sseI), could possibly contribute to the effect of FabR on biofilm formation. Conclusion Overall, our results point at the importance of FabR and UFA biosynthesis in Salmonella biofilm formation and their role as potential targets for biofilm inhibitory strategies. Electronic supplementary material The online version of this article (doi:10.1186/s12864-016-2387-x) contains supplementary material, which is available to authorized users.
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Linares D, Jean N, Van Overtvelt P, Ouidir T, Hardouin J, Blache Y, Molmeret M. The marine bacteria Shewanella frigidimarina NCIMB400 upregulates the type VI secretion system during early biofilm formation. ENVIRONMENTAL MICROBIOLOGY REPORTS 2016; 8:110-121. [PMID: 26617163 DOI: 10.1111/1758-2229.12358] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/18/2015] [Accepted: 11/19/2015] [Indexed: 06/05/2023]
Abstract
Shewanella sp. are facultative anaerobic Gram-negative bacteria, extensively studied for their electron transfer ability. Shewanella frigidimarina has been detected and isolated from marine environments, and in particular, from biofilms. However, its ability to adhere to surfaces and form a biofilm is poorly understood. In this study, we show that the ability to adhere and to form a biofilm of S. frigidimarina NCIMB400 is significantly higher than that of Shewanella oneidensis in our conditions. We also show that this strain forms a biofilm in artificial seawater, whereas in Luria-Bertani, this capacity is reduced. To identify proteins involved in early biofilm formation, a proteomic analysis of sessile versus planktonic membrane-enriched fractions allowed the identification of several components of the same type VI secretion system gene cluster: putative Hcp1 and ImpB proteins as well as a forkhead-associated domain-containing protein. The upregulation of Hcp1 a marker of active translocation has been confirmed using quantitative reverse transcription polymerase chain reaction. Our data demonstrated the presence of a single and complete type VI secretion system in S. frigidimarina NCIMB400 genome, upregulated in sessile compared with planktonic conditions. The fact that three proteins including the secreted protein Hcp1 have been identified may suggest that this type VI secretion system is functional.
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Affiliation(s)
- Denis Linares
- Université de Toulon, MAPIEM, EA4323, 83957, La Garde, France
| | | | | | - Tassadit Ouidir
- UMR 6270 CNRS, Laboratoire Polymères, Biopolymères, Surfaces, Université de Rouen, Mont-Saint-Aignan, F-76820, France
| | - Julie Hardouin
- UMR 6270 CNRS, Laboratoire Polymères, Biopolymères, Surfaces, Université de Rouen, Mont-Saint-Aignan, F-76820, France
| | - Yves Blache
- Université de Toulon, MAPIEM, EA4323, 83957, La Garde, France
| | - Maëlle Molmeret
- Université de Toulon, MAPIEM, EA4323, 83957, La Garde, France
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29
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Wang H, Dong Y, Wang G, Xu X, Zhou G. Effect of growth media on gene expression levels in Salmonella Typhimurium biofilm formed on stainless steel surface. Food Control 2016. [DOI: 10.1016/j.foodcont.2015.06.026] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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30
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Giaouris E, Heir E, Desvaux M, Hébraud M, Møretrø T, Langsrud S, Doulgeraki A, Nychas GJ, Kačániová M, Czaczyk K, Ölmez H, Simões M. Intra- and inter-species interactions within biofilms of important foodborne bacterial pathogens. Front Microbiol 2015; 6:841. [PMID: 26347727 PMCID: PMC4542319 DOI: 10.3389/fmicb.2015.00841] [Citation(s) in RCA: 177] [Impact Index Per Article: 19.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2015] [Accepted: 07/31/2015] [Indexed: 12/15/2022] Open
Abstract
A community-based sessile life style is the normal mode of growth and survival for many bacterial species. Under such conditions, cell-to-cell interactions are inevitable and ultimately lead to the establishment of dense, complex and highly structured biofilm populations encapsulated in a self-produced extracellular matrix and capable of coordinated and collective behavior. Remarkably, in food processing environments, a variety of different bacteria may attach to surfaces, survive, grow, and form biofilms. Salmonella enterica, Listeria monocytogenes, Escherichia coli, and Staphylococcus aureus are important bacterial pathogens commonly implicated in outbreaks of foodborne diseases, while all are known to be able to create biofilms on both abiotic and biotic surfaces. Particularly challenging is the attempt to understand the complexity of inter-bacterial interactions that can be encountered in such unwanted consortia, such as competitive and cooperative ones, together with their impact on the final outcome of these communities (e.g., maturation, physiology, antimicrobial resistance, virulence, dispersal). In this review, up-to-date data on both the intra- and inter-species interactions encountered in biofilms of these pathogens are presented. A better understanding of these interactions, both at molecular and biophysical levels, could lead to novel intervention strategies for controlling pathogenic biofilm formation in food processing environments and thus improve food safety.
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Affiliation(s)
- Efstathios Giaouris
- Department of Food Science and Nutrition, Faculty of the Environment, University of the Aegean, Myrina, Lemnos Island, Greece
| | - Even Heir
- Nofima, Norwegian Institute of Food, Fisheries and Aquaculture Research, Ås, Norway
| | - Mickaël Desvaux
- INRA, UR454 Microbiologie, Centre Auvergne-Rhône-Alpes, Saint-Genès-Champanelle, France
| | - Michel Hébraud
- INRA, UR454 Microbiologie, Centre Auvergne-Rhône-Alpes, Saint-Genès-Champanelle, France
| | - Trond Møretrø
- Nofima, Norwegian Institute of Food, Fisheries and Aquaculture Research, Ås, Norway
| | - Solveig Langsrud
- Nofima, Norwegian Institute of Food, Fisheries and Aquaculture Research, Ås, Norway
| | - Agapi Doulgeraki
- Laboratory of Microbiology and Biotechnology of Foods, Department of Food Science and Human Nutrition, Faculty of Foods, Biotechnology and Development, Agricultural University of Athens, Athens, Greece
| | - George-John Nychas
- Laboratory of Microbiology and Biotechnology of Foods, Department of Food Science and Human Nutrition, Faculty of Foods, Biotechnology and Development, Agricultural University of Athens, Athens, Greece
| | - Miroslava Kačániová
- Department of Microbiology, Faculty of Biotechnology and Food Sciences, Slovak University of Agriculture in Nitra, Nitra, Slovakia
| | - Katarzyna Czaczyk
- Department of Biotechnology and Food Microbiology, Poznan University of Life Sciences, Poznań, Poland
| | - Hülya Ölmez
- TÜBİTAK Marmara Research Center, Food Institute, Gebze, Kocaeli, Turkey
| | - Manuel Simões
- Laboratory for Process Engineering, Environment, Biotechnology and Energy, Department of Chemical Engineering, Faculty of Engineering, University of Porto, Porto, Portugal
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Simm R, Ahmad I, Rhen M, Le Guyon S, Römling U. Regulation of biofilm formation in Salmonella enterica serovar Typhimurium. Future Microbiol 2015; 9:1261-82. [PMID: 25437188 DOI: 10.2217/fmb.14.88] [Citation(s) in RCA: 59] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
In animals, plants and the environment, Salmonella enterica serovar Typhimurium forms the red dry and rough (rdar) biofilm characterized by extracellular matrix components curli and cellulose. With complex expression control by at least ten transcription factors, the bistably expressed orphan response regulator CsgD directs rdar morphotype development. CsgD expression is an integral part of the Hfq regulon and the complex cyclic diguanosine monophosphate signaling network partially controlled by the global RNA-binding protein CsrA. Cell wall turnover and the periplasmic redox status regulate csgD expression on a post-transcriptional level by unknown mechanisms. Furthermore, phosphorylation of CsgD is a potential inactivation and degradation signal in biofilm dissolution. Including complex incoherent feed-forward loops, regulation of biofilm formation versus motility and virulence is of recognized complexity.
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Affiliation(s)
- Roger Simm
- Department of Biochemistry, Institute for Cancer Research, Oslo University Hospital, The Norwegian Radium Hospital, Montebello, Oslo, Norway
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32
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Römling U, Galperin MY. Bacterial cellulose biosynthesis: diversity of operons, subunits, products, and functions. Trends Microbiol 2015; 23:545-57. [PMID: 26077867 DOI: 10.1016/j.tim.2015.05.005] [Citation(s) in RCA: 310] [Impact Index Per Article: 34.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2015] [Revised: 05/05/2015] [Accepted: 05/18/2015] [Indexed: 12/30/2022]
Abstract
Recent studies of bacterial cellulose biosynthesis, including structural characterization of a functional cellulose synthase complex, provided the first mechanistic insight into this fascinating process. In most studied bacteria, just two subunits, BcsA and BcsB, are necessary and sufficient for the formation of the polysaccharide chain in vitro. Other subunits - which differ among various taxa - affect the enzymatic activity and product yield in vivo by modulating (i) the expression of the biosynthesis apparatus, (ii) the export of the nascent β-D-glucan polymer to the cell surface, and (iii) the organization of cellulose fibers into a higher-order structure. These auxiliary subunits play key roles in determining the quantity and structure of resulting biofilms, which is particularly important for the interactions of bacteria with higher organisms - leading to rhizosphere colonization and modulating the virulence of cellulose-producing bacterial pathogens inside and outside of host cells. We review the organization of four principal types of cellulose synthase operon found in various bacterial genomes, identify additional bcs genes that encode components of the cellulose biosynthesis and secretion machinery, and propose a unified nomenclature for these genes and subunits. We also discuss the role of cellulose as a key component of biofilms and in the choice between acute infection and persistence in the host.
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Affiliation(s)
- Ute Römling
- Department of Microbiology, Tumor and Cell Biology (MTC), Karolinska Institutet, Stockholm, Sweden.
| | - Michael Y Galperin
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, MD 20894, USA.
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MacKenzie KD, Wang Y, Shivak DJ, Wong CS, Hoffman LJL, Lam S, Kröger C, Cameron ADS, Townsend HGG, Köster W, White AP. Bistable expression of CsgD in Salmonella enterica serovar Typhimurium connects virulence to persistence. Infect Immun 2015; 83:2312-26. [PMID: 25824832 PMCID: PMC4432751 DOI: 10.1128/iai.00137-15] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2015] [Accepted: 03/20/2015] [Indexed: 11/20/2022] Open
Abstract
Pathogenic bacteria often need to survive in the host and the environment, and it is not well understood how cells transition between these equally challenging situations. For the human and animal pathogen Salmonella enterica serovar Typhimurium, biofilm formation is correlated with persistence outside a host, but the connection to virulence is unknown. In this study, we analyzed multicellular-aggregate and planktonic-cell subpopulations that coexist when S. Typhimurium is grown under biofilm-inducing conditions. These cell types arise due to bistable expression of CsgD, the central biofilm regulator. Despite being exposed to the same stresses, the two cell subpopulations had 1,856 genes that were differentially expressed, as determined by transcriptome sequencing (RNA-seq). Aggregated cells displayed the characteristic gene expression of biofilms, whereas planktonic cells had enhanced expression of numerous virulence genes. Increased type three secretion synthesis in planktonic cells correlated with enhanced invasion of a human intestinal cell line and significantly increased virulence in mice compared to the aggregates. However, when the same groups of cells were exposed to desiccation, the aggregates survived better, and the competitive advantage of planktonic cells was lost. We hypothesize that CsgD-based differentiation is a form of bet hedging, with single cells primed for host cell invasion and aggregated cells adapted for persistence in the environment. This allows S. Typhimurium to spread the risks of transmission and ensures a smooth transition between the host and the environment.
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Affiliation(s)
- Keith D MacKenzie
- Vaccine and Infectious Disease Organization-International Vaccine Centre, Saskatoon, Saskatchewan, Canada Department of Microbiology and Immunology, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
| | - Yejun Wang
- Vaccine and Infectious Disease Organization-International Vaccine Centre, Saskatoon, Saskatchewan, Canada
| | - Dylan J Shivak
- Vaccine and Infectious Disease Organization-International Vaccine Centre, Saskatoon, Saskatchewan, Canada Department of Microbiology and Immunology, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
| | - Cynthia S Wong
- Vaccine and Infectious Disease Organization-International Vaccine Centre, Saskatoon, Saskatchewan, Canada
| | - Leia J L Hoffman
- Vaccine and Infectious Disease Organization-International Vaccine Centre, Saskatoon, Saskatchewan, Canada
| | - Shirley Lam
- Vaccine and Infectious Disease Organization-International Vaccine Centre, Saskatoon, Saskatchewan, Canada
| | - Carsten Kröger
- Institute of Integrative Biology, University of Liverpool, Liverpool, United Kingdom
| | - Andrew D S Cameron
- Department of Biology, University of Regina, Regina, Saskatchewan, Canada
| | - Hugh G G Townsend
- Vaccine and Infectious Disease Organization-International Vaccine Centre, Saskatoon, Saskatchewan, Canada Department of Large Animal Clinical Sciences, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
| | - Wolfgang Köster
- Vaccine and Infectious Disease Organization-International Vaccine Centre, Saskatoon, Saskatchewan, Canada Department of Veterinary Microbiology, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
| | - Aaron P White
- Vaccine and Infectious Disease Organization-International Vaccine Centre, Saskatoon, Saskatchewan, Canada Department of Microbiology and Immunology, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
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34
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Wong HS, Maker GL, Trengove RD, O'Handley RM. Gas chromatography-mass spectrometry-based metabolite profiling of Salmonella enterica serovar Typhimurium differentiates between biofilm and planktonic phenotypes. Appl Environ Microbiol 2015; 81:2660-6. [PMID: 25636852 PMCID: PMC4375307 DOI: 10.1128/aem.03658-14] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2014] [Accepted: 01/27/2015] [Indexed: 11/20/2022] Open
Abstract
The aim of this study was to utilize gas chromatography coupled with mass spectrometry (GC-MS) to compare and identify patterns of biochemical change between Salmonella cells grown in planktonic and biofilm phases and Salmonella biofilms of different ages. Our results showed a clear separation between planktonic and biofilm modes of growth. The majority of metabolites contributing to variance between planktonic and biofilm supernatants were identified as amino acids, including alanine, glutamic acid, glycine, and ornithine. Metabolites contributing to variance in intracellular profiles were identified as succinic acid, putrescine, pyroglutamic acid, and N-acetylglutamic acid. Principal-component analysis revealed no significant differences between the various ages of intracellular profiles, which would otherwise allow differentiation of biofilm cells on the basis of age. A shifting pattern across the score plot was illustrated when analyzing extracellular metabolites sampled from different days of biofilm growth, and amino acids were again identified as the metabolites contributing most to variance. An understanding of biofilm-specific metabolic responses to perturbations, especially antibiotics, can lead to the identification of novel drug targets and potential therapies for combating biofilm-associated diseases. We concluded that under the conditions of this study, GC-MS can be successfully applied as a high-throughput technique for "bottom-up" metabolomic biofilm research.
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Affiliation(s)
- Hui San Wong
- The University of Adelaide, School of Animal and Veterinary Science, Adelaide, South Australia, Australia Murdoch University, School of Veterinary and Life Sciences, Perth, Western Australia, Australia
| | - Garth L Maker
- Murdoch University, School of Veterinary and Life Sciences, Perth, Western Australia, Australia Murdoch University, Metabolomics Australia, Perth, Western Australia, Australia
| | - Robert D Trengove
- Murdoch University, Metabolomics Australia, Perth, Western Australia, Australia
| | - Ryan M O'Handley
- The University of Adelaide, School of Animal and Veterinary Science, Adelaide, South Australia, Australia
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Metabolic responses to Orientia tsutsugamushi infection in a mouse model. PLoS Negl Trop Dis 2015; 9:e3427. [PMID: 25569562 PMCID: PMC4287389 DOI: 10.1371/journal.pntd.0003427] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2014] [Accepted: 11/17/2014] [Indexed: 01/10/2023] Open
Abstract
Tsutsugamushi disease is an infectious disease transmitted to humans through the bite of the Orientia tsutsugamushi-infected chigger mite; however, host-pathogen interactions and the precise mechanisms of damage in O. tsutsugamushi infections have not been fully elucidated. Here, we analyzed the global metabolic effects of O. tsutsugamushi infection on the host using 1H-NMR and UPLC-Q-TOF mass spectroscopy coupled with multivariate statistical analysis. In addition, the effect of O. tsutsugamushi infection on metabolite concentrations over time was analyzed by two-way ANOVAs. Orthogonal partial least squares-discriminant analysis (OPLS-DA) showed distinct metabolic patterns between control and O. tsutsugamushi-infected mice in liver, spleen, and serum samples. O. tsutsugamushi infection caused decreased energy production and deficiencies in both remethylation sources and glutathione. In addition, O. tsutsugamushi infection accelerated uncommon energy production pathways (i.e., excess fatty acid and protein oxidation) in host body. Infection resulted in an enlarged spleen with distinct phospholipid and amino acid characteristics. This study suggests that metabolite profiling of multiple organ tissues and serum could provide insight into global metabolic changes and mechanisms of pathology in O. tsutsugamushi-infected hosts. Scrub typhus is an acute febrile illness caused by attacks of Orientia tsutsugamushi-carrying mites, and is the most prevalent febrile illness in the Asia-Pacific region. If not properly treated with antibiotics, patients often develop severe vasculitis that affects multiple organs, and the mortality rate can reach 30%. To explore the pathogenic mechanisms underlying the host-pathogen interaction, we characterized metabolic changes in various organs and the serum of O. tsutsugamushi-infected hosts. After O. tsutsugamushi infection, the host experienced decreased energy production, as well as a severe deficiency in re-methylation sources and glutathione, which impaired purine synthesis, DNA and protein methylation. In addition, abnormal pathways for phosphatidylcholine (PC) biosynthesis and phosphoethanolamine methylation were utilized in the enlarged spleen of O. tsutsugamushi-infected hosts. These results suggested that metabolic profiling could provide insight into global metabolic changes in O. tsutsugamushi-infected hosts, and increase our understanding of the pathogenic mechanisms of O. tsutsugamushi, as well as providing novel therapeutic targets for scrub typhus.
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Mujahid M, Prasuna ML, Sasikala C, Ramana CV. Integrated Metabolomic and Proteomic Analysis Reveals Systemic Responses of Rubrivivax benzoatilyticus JA2 to Aniline Stress. J Proteome Res 2014; 14:711-27. [DOI: 10.1021/pr500725b] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Md Mujahid
- Department
of Plant Sciences, School of Life Sciences, University of Hyderabad, P.O. Central University, Hyderabad 500 046, India
| | - M Lakshmi Prasuna
- Department
of Plant Sciences, School of Life Sciences, University of Hyderabad, P.O. Central University, Hyderabad 500 046, India
| | - Ch Sasikala
- Bacterial
Discovery Laboratory, Center for Environment, IST, JNT University Hyderabad, Kukatpally, Hyderabad 500 085, India
| | - Ch Venkata Ramana
- Department
of Plant Sciences, School of Life Sciences, University of Hyderabad, P.O. Central University, Hyderabad 500 046, India
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rpoS-Regulated core genes involved in the competitive fitness of Salmonella enterica Serovar Kentucky in the intestines of chickens. Appl Environ Microbiol 2014; 81:502-14. [PMID: 25362062 DOI: 10.1128/aem.03219-14] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Salmonella enterica serovar Kentucky has become the most frequently isolated serovar from poultry in the United States over the past decade. Despite its prevalence in poultry, it causes few human illnesses in the United States. The dominance of S. Kentucky in poultry does not appear to be due to single introduction of a clonal strain, and its reduced virulence appears to correlate with the absence of virulence genes grvA, sseI, sopE, and sodC1. S. Kentucky's prevalence in poultry is possibly attributable to its metabolic adaptation to the chicken cecum. While there were no difference in the growth rate of S. Kentucky and S. Typhimurium grown microaerophilically in cecal contents, S. Kentucky persisted longer when chickens were coinfected with S. Typhimurium. The in vivo advantage that S. Kentucky has over S. Typhimurium appears to be due to differential regulation of core Salmonella genes via the stationary-phase sigma factor rpoS. Microarray analysis of Salmonella grown in cecal contents in vitro identified several metabolic genes and motility and adherence genes that are differentially activated in S. Kentucky. The contributions of four of these operons (mgl, prp, nar, and csg) to Salmonella colonization in chickens were assessed. Deletion of mgl and csg reduced S. Kentucky persistence in competition studies in chickens infected with wild-type or mutant strains. Subtle mutations affecting differential regulation of core Salmonella genes appear to be important in Salmonella's adaptation to its animal host and especially for S. Kentucky's emergence as the dominant serovar in poultry.
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Robijns SCA, Roberfroid S, Van Puyvelde S, De Pauw B, Uceda Santamaría E, De Weerdt A, De Coster D, Hermans K, De Keersmaecker SCJ, Vanderleyden J, Steenackers HPL. A GFP promoter fusion library for the study of Salmonella biofilm formation and the mode of action of biofilm inhibitors. BIOFOULING 2014; 30:605-625. [PMID: 24735176 DOI: 10.1080/08927014.2014.907401] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Salmonella, an important foodborne pathogen, forms biofilms in many different environments. The composition of these biofilms differs depending on the growth conditions, and their development is highly coordinated in time. To develop efficient treatments, it is therefore essential that biofilm formation and its inhibition be understood in different environments and in a time-dependent manner. Many currently used techniques, such as transcriptomics or proteomics, are still expensive and thus limited in their application. Therefore, a GFP-promoter fusion library with 79 important Salmonella biofilm genes was developed (covering among other things matrix production, fimbriae and flagella synthesis, and c-di-GMP regulation). This library is a fast, inexpensive, and easy-to-use tool, and can therefore be conducted in different experimental setups in a time-dependent manner. In this paper, four possible applications are highlighted to illustrate and validate the use of this reporter fusion library.
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Affiliation(s)
- S C A Robijns
- a Department of Microbial and Molecular Systems, Centre of Microbial and Plant Genetics , KU Leuven , Leuven , Belgium
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Okegbe C, Price-Whelan A, Dietrich LEP. Redox-driven regulation of microbial community morphogenesis. Curr Opin Microbiol 2014; 18:39-45. [PMID: 24607644 DOI: 10.1016/j.mib.2014.01.006] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2013] [Revised: 01/13/2014] [Accepted: 01/20/2014] [Indexed: 12/22/2022]
Abstract
During growth on surfaces, diverse microbial communities display topographies with captivating patterns. The quality and quantity of matrix excreted by resident cells play major roles in determining community architecture. Two current publications indicate that the cellular redox state and respiratory activity are important parameters affecting matrix output in the divergent bacteria Pseudomonas aeruginosa and Bacillus subtilis. These and related studies have identified regulatory proteins with the potential to respond to changes in redox state and respiratory electron transport and modulate the activity of the signal transduction pathways that control matrix production. These developments hint at the critical mechanistic links between environmental sensing and community behavior, and provide an exciting new context within which to interpret the molecular details of biofilm structure determination.
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Affiliation(s)
- Chinweike Okegbe
- Department of Biological Sciences, Columbia University, New York, NY 10027, United States
| | - Alexa Price-Whelan
- Department of Biological Sciences, Columbia University, New York, NY 10027, United States
| | - Lars E P Dietrich
- Department of Biological Sciences, Columbia University, New York, NY 10027, United States.
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CsgD regulatory network in a bacterial trait-altering biofilm formation. Emerg Microbes Infect 2014; 3:e1. [PMID: 26038492 PMCID: PMC3913822 DOI: 10.1038/emi.2014.1] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2013] [Revised: 10/20/2013] [Accepted: 11/25/2013] [Indexed: 11/23/2022]
Abstract
In response to the limited nutrients and stressful conditions of their habitats, many microorganisms including Salmonella form a biofilm by secreting a polymeric matrix to interweave individual cells and to build structural communities on an abiotic or living surface. The biofilm formation in Salmonella is tightly regulated by a regulatory network that involves multiple transcriptional regulators. As a master transcriptional regulator in biofilm formation, curli subunit gene D (csgD) functions by activating the biosynthesis of the extracellular polymeric matrix composed of exopolysaccharide cellulose, curli and biofilm-associated proteins (Baps), assisting bacterial cells in transitioning from the planktonic stage to the multicellular state. The expression of CsgD itself is affected by cell growth stage and environmental stimuli through the action of other transcriptional factors, bis-(3′–5′)-cyclic dimeric guanosine monophosphate (c-di-GMP), regulatory small RNAs (sRNAs) and other elements. The formation of biofilm confers new physiological characteristics on the bacteria within, especially resistance against unfavorable environmental conditions. Herein, we summarize the CsgD regulatory network of Salmonella biofilm formation and the new traits acquired by Salmonella when within biofilm.
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Hammarlöf DL, Canals R, Hinton JCD. The FUN of identifying gene function in bacterial pathogens; insights from Salmonella functional genomics. Curr Opin Microbiol 2013; 16:643-51. [PMID: 24021902 DOI: 10.1016/j.mib.2013.07.009] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2013] [Accepted: 07/12/2013] [Indexed: 02/01/2023]
Abstract
The availability of thousands of genome sequences of bacterial pathogens poses a particular challenge because each genome contains hundreds of genes of unknown function (FUN). How can we easily discover which FUN genes encode important virulence factors? One solution is to combine two different functional genomic approaches. First, transcriptomics identifies bacterial FUN genes that show differential expression during the process of mammalian infection. Second, global mutagenesis identifies individual FUN genes that the pathogen requires to cause disease. The intersection of these datasets can reveal a small set of candidate genes most likely to encode novel virulence attributes. We demonstrate this approach with the Salmonella infection model, and propose that a similar strategy could be used for other bacterial pathogens.
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Affiliation(s)
- Disa L Hammarlöf
- Institute of Integrative Biology, University of Liverpool, Crown Street, Liverpool L69 7ZB, United Kingdom
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Identification of Salmonella enterica serovar Typhimurium genes regulated during biofilm formation on cholesterol gallstone surfaces. Infect Immun 2013; 81:3770-80. [PMID: 23897604 DOI: 10.1128/iai.00647-13] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Salmonella spp. are able to form biofilms on abiotic and biotic surfaces. In vivo studies in our laboratory have shown that Salmonella can form biofilms on the surfaces of cholesterol gallstones in the gallbladders of mice and human carriers. Biofilm formation on gallstones has been demonstrated to be a mechanism of persistence. The purpose of this work was to identify and evaluate Salmonella sp. cholesterol-dependent biofilm factors. Differential gene expression analysis between biofilms on glass or cholesterol-coated surfaces and subsequent quantitative real-time PCR (qRT-PCR) revealed that type 1 fimbria structural genes and a gene encoding a putative outer membrane protein (ycfR) were specifically upregulated in Salmonella enterica serovar Typhimurium biofilms grown on cholesterol-coated surfaces. Spatiotemporal expression of ycfR and FimA verified their regulation during biofilm development on cholesterol-coated surfaces. Surprisingly, confocal and scanning electron microscopy demonstrated that a mutant of type 1 fimbria structural genes (ΔfimAICDHF) and a ycfR mutant showed increased biofilm formation on cholesterol-coated surfaces. In vivo experiments using Nramp1(+/+) mice harboring gallstones showed that only the ΔycfR mutant formed extensive biofilms on mouse gallstones at 7 and 21 days postinfection; ΔfimAICDHF was not observed on gallstone surfaces after the 7-day-postinfection time point. These data suggest that in Salmonella spp., wild-type type 1 fimbriae are important for attachment to and/or persistence on gallstones at later points of chronic infection, whereas YcfR may represent a specific potential natural inhibitor of initial biofilm formation on gallstones.
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The influence of CsgD on the expression of genes of folate metabolism and hmp in Escherichia coli K-12. Arch Microbiol 2013; 195:559-69. [PMID: 23824318 DOI: 10.1007/s00203-013-0909-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2013] [Revised: 06/04/2013] [Accepted: 06/20/2013] [Indexed: 10/26/2022]
Abstract
The csgD gene codes for the regulatory protein CsgD. CsgD upregulates the synthesis of the adhesive fimbriae, curli, that are important for biofilm formation and downregulates flagellar synthesis. We compared the expression of genes involved in folate metabolism and a gene (hmp) in strains with an intact csgD gene and with a deletion in csgD. The hmp gene codes a flavohemoglobin that inactivates nitric oxide. Expression was monitored by measuring light production from single copy lux operon fusions. At late times of growth, expression of genes responsible for methylene tetrahydrofolate synthesis (glyA and gcvTHP) and formyltetrahydrofolate recycling (purU) was higher in cells with CsgD than those without. In contrast, expression of hmp was lower in the presence of CsgD throughout the period monitored. We used a novel defined medium which should assist in defining nutritional factors that contribute to curli formation.
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44
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Kim YM, Schmidt BJ, Kidwai AS, Jones MB, Deatherage Kaiser BL, Brewer HM, Mitchell HD, Palsson BO, McDermott JE, Heffron F, Smith RD, Peterson SN, Ansong C, Hyduke DR, Metz TO, Adkins JN. Salmonella modulates metabolism during growth under conditions that induce expression of virulence genes. MOLECULAR BIOSYSTEMS 2013; 9:1522-34. [PMID: 23559334 PMCID: PMC3665296 DOI: 10.1039/c3mb25598k] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Salmonella enterica serovar Typhimurium (S. Typhimurium) is a facultative pathogen that uses complex mechanisms to invade and proliferate within mammalian host cells. To investigate possible contributions of metabolic processes to virulence in S. Typhimurium grown under conditions known to induce expression of virulence genes, we used a metabolomics-driven systems biology approach coupled with genome-scale modeling. First, we identified distinct metabolite profiles associated with bacteria grown in either rich or virulence-inducing media and report the most comprehensive coverage of the S. Typhimurium metabolome to date. Second, we applied an omics-informed genome-scale modeling analysis of the functional consequences of adaptive alterations in S. Typhimurium metabolism during growth under our conditions. Modeling efforts highlighted a decreased cellular capability to both produce and utilize intracellular amino acids during stationary phase culture in virulence conditions, despite significant abundance increases for these molecules as observed by our metabolomics measurements. Furthermore, analyses of omics data in the context of the metabolic model indicated rewiring of the metabolic network to support pathways associated with virulence. For example, cellular concentrations of polyamines were perturbed, as well as the predicted capacity for secretion and uptake.
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Affiliation(s)
- Young-Mo Kim
- Fundamental and Computational Sciences Directorate, Pacific Northwest National Laboratory, Richland, WA 99352
| | - Brian J. Schmidt
- Department of Bioengineering, University of California at San Diego, San Diego, CA 92093
| | - Afshan S. Kidwai
- Department of Molecular Microbiology and Immunology, Oregon Health & Science University, Portland, OR 97239
| | | | - Brooke L. Deatherage Kaiser
- Fundamental and Computational Sciences Directorate, Pacific Northwest National Laboratory, Richland, WA 99352
| | - Heather M. Brewer
- Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, Richland, WA 99352
| | - Hugh D. Mitchell
- Fundamental and Computational Sciences Directorate, Pacific Northwest National Laboratory, Richland, WA 99352
| | - Bernhard O. Palsson
- Department of Bioengineering, University of California at San Diego, San Diego, CA 92093
| | - Jason E. McDermott
- Fundamental and Computational Sciences Directorate, Pacific Northwest National Laboratory, Richland, WA 99352
| | - Fred Heffron
- Department of Molecular Microbiology and Immunology, Oregon Health & Science University, Portland, OR 97239
| | - Richard D. Smith
- Fundamental and Computational Sciences Directorate, Pacific Northwest National Laboratory, Richland, WA 99352
| | | | - Charles Ansong
- Fundamental and Computational Sciences Directorate, Pacific Northwest National Laboratory, Richland, WA 99352
| | - Daniel R. Hyduke
- Department of Bioengineering, University of California at San Diego, San Diego, CA 92093
| | - Thomas O. Metz
- Fundamental and Computational Sciences Directorate, Pacific Northwest National Laboratory, Richland, WA 99352
| | - Joshua N. Adkins
- Fundamental and Computational Sciences Directorate, Pacific Northwest National Laboratory, Richland, WA 99352
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45
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Ansong C, Deatherage BL, Hyduke D, Schmidt B, McDermott JE, Jones MB, Chauhan S, Charusanti P, Kim YM, Nakayasu ES, Li J, Kidwai A, Niemann G, Brown RN, Metz TO, McAteer K, Heffron F, Peterson SN, Motin V, Palsson BO, Smith RD, Adkins JN. Studying Salmonellae and Yersiniae host-pathogen interactions using integrated 'omics and modeling. Curr Top Microbiol Immunol 2013; 363:21-41. [PMID: 22886542 DOI: 10.1007/82_2012_247] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
Salmonella and Yersinia are two distantly related genera containing species with wide host-range specificity and pathogenic capacity. The metabolic complexity of these organisms facilitates robust lifestyles both outside of and within animal hosts. Using a pathogen-centric systems biology approach, we are combining a multi-omics (transcriptomics, proteomics, metabolomics) strategy to define properties of these pathogens under a variety of conditions including those that mimic the environments encountered during pathogenesis. These high-dimensional omics datasets are being integrated in selected ways to improve genome annotations, discover novel virulence-related factors, and model growth under infectious states. We will review the evolving technological approaches toward understanding complex microbial life through multi-omic measurements and integration, while highlighting some of our most recent successes in this area.
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Affiliation(s)
- Charles Ansong
- Biological Separations and Mass Spectroscopy Group, Pacific Northwest National Laboratory, PO Box 999, MSIN: K8-98, Richland, WA, 99352, USA
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46
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Bernier SP, Surette MG. Concentration-dependent activity of antibiotics in natural environments. Front Microbiol 2013; 4:20. [PMID: 23422936 PMCID: PMC3574975 DOI: 10.3389/fmicb.2013.00020] [Citation(s) in RCA: 145] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2012] [Accepted: 01/28/2013] [Indexed: 11/26/2022] Open
Abstract
Bacterial responses to antibiotics are concentration-dependent. At high concentrations, antibiotics exhibit antimicrobial activities on susceptible cells, while subinhibitory concentrations induce diverse biological responses in bacteria. At non-lethal concentrations, bacteria may sense antibiotics as extracellular chemicals to trigger different cellular responses, which may include an altered antibiotic resistance/tolerance profile. In natural settings, microbes are typically in polymicrobial communities and antibiotic-mediated interactions between species may play a significant role in bacterial community structure and function. However, these aspects have not yet fully been explored at the community level. Here we discuss the different types of interactions mediated by antibiotics and non-antibiotic metabolites as a function of their concentrations and speculate on how these may amplify the overall antibiotic resistance/tolerance and the spread of antibiotic resistance determinants in a context of polymicrobial community.
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Affiliation(s)
- Steve P Bernier
- Farncombe Family Digestive Health Research Institute, Department of Medicine, Faculty of Health Sciences, McMaster University Hamilton, ON, Canada
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47
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Van Puyvelde S, Steenackers HP, Vanderleyden J. Small RNAs regulating biofilm formation and outer membrane homeostasis. RNA Biol 2013; 10:185-91. [PMID: 23324602 DOI: 10.4161/rna.23341] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Nowadays, the identification of small non-coding RNAs takes a prominent role in deciphering complex bacterial phenotypes. Evidences are given that the post-transcriptional layer of regulation mediated by sRNAs plays an important role in the formation of bacterial biofilms. These sRNAs exert their activity on various targets, be it directly or indirectly linked to biofilm formation. First, and best described, are the sRNAs that act in core regulatory pathways of biofilm formation, such as those regulating motility and matrix production. Second, overlaps between the regulation of biofilm formation and the outer membrane (OM) are becoming obvious. Additionally, different studies indicate that defects in the OM itself affect biofilm formation through this shared cascade, thereby forming a feedback mechanism. Interestingly, it is known that the OM itself is extensively regulated by different sRNAs. Third, biofilms are also linked to global metabolic changes. There is also evidence that metabolic pathways and the process of biofilm formation share sRNAs.
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Affiliation(s)
- Sandra Van Puyvelde
- Centre of Microbial and Plant Genetics, Katholieke Universiteit Leuven, Leuven, Belgium
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48
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Giaouris E, Samoilis G, Chorianopoulos N, Ercolini D, Nychas GJ. Differential protein expression patterns between planktonic and biofilm cells of Salmonella enterica serovar Enteritidis PT4 on stainless steel surface. Int J Food Microbiol 2013; 162:105-13. [PMID: 23376784 DOI: 10.1016/j.ijfoodmicro.2012.12.023] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2012] [Revised: 12/27/2012] [Accepted: 12/28/2012] [Indexed: 10/27/2022]
Abstract
In the present study, the proteome of a strain of S. enterica serovar Enteritidis PT4, grown either as biofilm on stainless steel surface or as free-floating (planktonic) in Brain Heart (BH) broth, was investigated in order to detect the strong differences in whole-cell protein expression patterns between the two growth styles. The proteins extracted from both types of cells were subjected to 2-D PAGE, followed by in-gel tryptic digestion, extraction, subsequent MALDI-TOF mass spectrometry (MS) analysis and finally database searches for protein identification. Using this approach, 30 proteins were identified as differentially expressed between the two growth modes on an "on-off" basis, that is, proteins that were detected in one case but not in the other. In particular, 20 and 10 proteins were identified in biofilm and planktonic-grown cells, respectively. The group of proteins whose expression was visible only during biofilm growth included proteins involved in global regulation and stress response (ArcA, BtuE, Dps, OsmY, SspA, TrxA, YbbN and YhbO), nutrient transport (Crr, DppA, Fur and SufC), degradation and energy metabolism (GcvT, GpmA, RibB), detoxification (SseA and YibF), DNA metabolism (SSB), curli production (CsgF), and murein synthesis (MipA). To summarize, this study demonstrates that biofilm growth of S. Enteritidis causes distinct changes in protein expression and offers valuable new data regarding some of the proteins presumably involved in this process. The putative role of these proteins in the maintenance of a biofilm community in Salmonella and other bacteria is discussed.
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Affiliation(s)
- Efstathios Giaouris
- Department of Food Science and Nutrition, University of the Aegean, Mitropoliti Ioakeim 2, Myrina, 81400 Lemnos, Greece.
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Waldner LL, MacKenzie KD, Köster W, White AP. From Exit to Entry: Long-term Survival and Transmission of Salmonella. Pathogens 2012; 1:128-55. [PMID: 25436767 PMCID: PMC4235688 DOI: 10.3390/pathogens1020128] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2012] [Revised: 09/15/2012] [Accepted: 10/10/2012] [Indexed: 02/01/2023] Open
Abstract
Salmonella spp. are a leading cause of human infectious disease worldwide and pose a serious health concern. While we have an improving understanding of pathogenesis and the host-pathogen interactions underlying the infection process, comparatively little is known about the survival of pathogenic Salmonella outside their hosts. This review focuses on three areas: (1) in vitro evidence that Salmonella spp. can survive for long periods of time under harsh conditions; (2) observations and conclusions about Salmonella persistence obtained from human outbreaks; and (3) new information revealed by genomic- and population-based studies of Salmonella and related enteric pathogens. We highlight the mechanisms of Salmonella persistence and transmission as an essential part of their lifecycle and a prerequisite for their evolutionary success as human pathogens.
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Affiliation(s)
- Landon L Waldner
- Vaccine and Infectious Disease Organization, University of Saskatchewan, Saskatoon, Saskatchewan, S7N 5E3, Canada.
| | - Keith D MacKenzie
- Vaccine and Infectious Disease Organization, University of Saskatchewan, Saskatoon, Saskatchewan, S7N 5E3, Canada.
| | - Wolfgang Köster
- Vaccine and Infectious Disease Organization, University of Saskatchewan, Saskatoon, Saskatchewan, S7N 5E3, Canada.
| | - Aaron P White
- Vaccine and Infectious Disease Organization, University of Saskatchewan, Saskatoon, Saskatchewan, S7N 5E3, Canada.
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50
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Maharjan RP, Ferenci T, Reeves PR, Li Y, Liu B, Wang L. The multiplicity of divergence mechanisms in a single evolving population. Genome Biol 2012; 13:R41. [PMID: 22682524 PMCID: PMC3446313 DOI: 10.1186/gb-2012-13-6-r41] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2012] [Revised: 04/25/2012] [Accepted: 06/08/2012] [Indexed: 01/06/2023] Open
Abstract
Background Evolutionary divergence is common within bacterial species and populations, even during a single bacterial infection. We use large-scale genomic and phenotypic analysis to identify the extent of diversification in controlled experimental populations and apply these data to differentiate between several potential mechanisms of evolutionary divergence. Results We defined testable differences between five proposed mechanisms and used experimental evolution studies to follow eight glucose-limited Escherichia coli chemostat populations at two growth rates. Simple phenotypic tests identified 11 phenotype combinations evolving under glucose limitation. Each evolved population exhibited 3 to 5 different combinations of the 11 phenotypic clusters. Genome sequencing of a representative of each phenotypic cluster from each population identified 193 mutations in 48 isolates. Only two of the 48 strains had evolved identically. Convergent paths to the same phenotype occurred, but two pleiotropic mutations were unique to slow-growing bacteria, permitting them greater phenotypic variance. Indeed, greater diversity arose in slower-growing, more stressed cultures. Mutation accumulation, hypermutator presence and fitness mechanisms varied between and within populations, with the evolved fitness considerably more uniform with fast growth cultures. Negative frequency-dependent fitness was shown by a subset of isolates. Conclusions Evolutionary diversity is unlikely to be explained by any one of the available mechanisms. For a large population as used in this study, our results suggest that multiple mechanisms contribute to the mix of phenotypes and evolved fitness types in a diversifying population. Another major conclusion is that the capacity of a population to diversify is a function of growth rate.
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Affiliation(s)
- Ram P Maharjan
- TEDA School of Biological Sciences and Biotechnology, Nankai University, Tianjin, PR China
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