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Singh M, Chandra D, Jagdish S, Nandi D. Global transcriptome analysis reveals Salmonella Typhimurium employs nitrate metabolism to combat bile stress. FEBS Lett 2024; 598:1605-1619. [PMID: 38503554 DOI: 10.1002/1873-3468.14853] [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: 11/20/2023] [Revised: 02/20/2024] [Accepted: 02/21/2024] [Indexed: 03/21/2024]
Abstract
Salmonella Typhimurium is an enteric pathogen that is highly tolerant to bile. Next-generation mRNA sequencing was performed to analyze the adaptive responses to bile in two S. Typhimurium strains: wild type (WT) and a mutant lacking cold shock protein E (ΔcspE). CspE is an RNA chaperone which is crucial for survival of S. Typhimurium during bile stress. This study identifies transcriptional responses in bile-tolerant WT and bile-sensitive ΔcspE. Upregulation of several genes involved in nitrate metabolism was observed, including fnr, a global regulator of nitrate metabolism. Notably, Δfnr was susceptible to bile stress. Also, complementation with fnr lowered reactive oxygen species and enhanced the survival of bile-sensitive ΔcspE. Importantly, intracellular nitrite amounts were highly induced in bile-treated WT compared to ΔcspE. Also, the WT strain pre-treated with nitrate displayed better growth with bile. These results demonstrate that nitrate-dependent metabolism promotes adaptation of S. Typhimurium to bile.
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Affiliation(s)
- Madhulika Singh
- Department of Biochemistry, Indian Institute of Science, Bangalore, India
| | - Deepti Chandra
- Department of Biochemistry, Indian Institute of Science, Bangalore, India
| | - Sirisha Jagdish
- Department of Biochemistry, Indian Institute of Science, Bangalore, India
| | - Dipankar Nandi
- Department of Biochemistry, Indian Institute of Science, Bangalore, India
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2
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Buschi E, Dell’Anno A, Tangherlini M, Candela M, Rampelli S, Turroni S, Palladino G, Esposito E, Martire ML, Musco L, Stefanni S, Munari C, Fiori J, Danovaro R, Corinaldesi C. Resistance to freezing conditions of endemic Antarctic polychaetes is enhanced by cryoprotective proteins produced by their microbiome. SCIENCE ADVANCES 2024; 10:eadk9117. [PMID: 38905343 PMCID: PMC11192080 DOI: 10.1126/sciadv.adk9117] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/19/2023] [Accepted: 05/14/2024] [Indexed: 06/23/2024]
Abstract
The microbiome plays a key role in the health of all metazoans. Whether and how the microbiome favors the adaptation processes of organisms to extreme conditions, such as those of Antarctica, which are incompatible with most metazoans, is still unknown. We investigated the microbiome of three endemic and widespread species of Antarctic polychaetes: Leitoscoloplos geminus, Aphelochaeta palmeri, and Aglaophamus trissophyllus. We report here that these invertebrates contain a stable bacterial core dominated by Meiothermus and Anoxybacillus, equipped with a versatile genetic makeup and a unique portfolio of proteins useful for coping with extremely cold conditions as revealed by pangenomic and metaproteomic analyses. The close phylosymbiosis between Meiothermus and Anoxybacillus and these Antarctic polychaetes indicates a connection with their hosts that started in the past to support holobiont adaptation to the Antarctic Ocean. The wide suite of bacterial cryoprotective proteins found in Antarctic polychaetes may be useful for the development of nature-based biotechnological applications.
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Affiliation(s)
- Emanuela Buschi
- Department of Ecosustainable Marine Biotechnology, Stazione Zoologica “Anton Dohrn,” Fano Marine Centre, Fano, Italy
- Department of Life and Environmental Sciences, Polytechnic University of Marche, Ancona, Italy
| | - Antonio Dell’Anno
- Department of Life and Environmental Sciences, Polytechnic University of Marche, Ancona, Italy
| | - Michael Tangherlini
- Department of Research Infrastructures for Marine Biological Resources, Stazione Zoologica “Anton Dohrn,” Fano Marine Centre, Fano, Italy
| | - Marco Candela
- Department of Pharmacy and Biotechnology, University of Bologna, Bologna, Italy
- Fano Marine Center, the Inter-Institute Center for Research on Marine Biodiversity, Resources and Biotechnologies, Fano, Italy
| | - Simone Rampelli
- Department of Pharmacy and Biotechnology, University of Bologna, Bologna, Italy
- Fano Marine Center, the Inter-Institute Center for Research on Marine Biodiversity, Resources and Biotechnologies, Fano, Italy
| | - Silvia Turroni
- Department of Pharmacy and Biotechnology, University of Bologna, Bologna, Italy
| | - Giorgia Palladino
- Department of Pharmacy and Biotechnology, University of Bologna, Bologna, Italy
- Fano Marine Center, the Inter-Institute Center for Research on Marine Biodiversity, Resources and Biotechnologies, Fano, Italy
| | - Erika Esposito
- Department of Chemistry “G. Ciamician” Alma Mater Studiorum, University of Bologna, Bologna, Italy
- IRCCS Istituto delle Scienze Neurologiche di Bologna, Bologna, Italia
| | - Marco Lo Martire
- Department of Life and Environmental Sciences, Polytechnic University of Marche, Ancona, Italy
| | - Luigi Musco
- Department of Biological and Environmental Sciences and Technologies, University of Salento, Lecce, Italy
| | - Sergio Stefanni
- Department of Biology and Evolution of Marine Organisms, Stazione Zoologica “Anton Dohrn,” Villa Comunale, Napoli, Italy
| | - Cristina Munari
- Department of Chemical and Pharmaceutical Sciences, University of Ferrara, Ferrara, Italy
| | - Jessica Fiori
- Department of Chemistry “G. Ciamician” Alma Mater Studiorum, University of Bologna, Bologna, Italy
- IRCCS Istituto delle Scienze Neurologiche di Bologna, Bologna, Italia
| | - Roberto Danovaro
- Department of Life and Environmental Sciences, Polytechnic University of Marche, Ancona, Italy
| | - Cinzia Corinaldesi
- Department of Materials, Environmental Sciences and Urban Planning, Polytechnic University of Marche, Ancona, Italy
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3
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Anthony WE, Geng W, Diao J, Carr RR, Wang B, Ning J, Moon TS, Dantas G, Zhang F. Increased triacylglycerol production in Rhodococcus opacus by overexpressing transcriptional regulators. BIOTECHNOLOGY FOR BIOFUELS AND BIOPRODUCTS 2024; 17:83. [PMID: 38898475 PMCID: PMC11186279 DOI: 10.1186/s13068-024-02523-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/19/2024] [Accepted: 05/23/2024] [Indexed: 06/21/2024]
Abstract
Lignocellulosic biomass is currently underutilized, but it offers promise as a resource for the generation of commercial end-products, such as biofuels, detergents, and other oleochemicals. Rhodococcus opacus PD630 is an oleaginous, Gram-positive bacterium with an exceptional ability to utilize recalcitrant aromatic lignin breakdown products to produce lipid molecules such as triacylglycerols (TAGs), which are an important biofuel precursor. Lipid carbon storage molecules accumulate only under growth-limiting low nitrogen conditions, representing a significant challenge toward using bacterial biorefineries for fuel precursor production. In this work, we screened overexpression of 27 native transcriptional regulators for their abilities to improve lipid accumulation under nitrogen-rich conditions, resulting in three strains that accumulate increased lipids, unconstrained by nitrogen availability when grown in phenol or glucose. Transcriptomic analyses revealed that the best strain (#13) enhanced FA production via activation of the β-ketoadipate pathway. Gene deletion experiments confirm that lipid accumulation in nitrogen-replete conditions requires reprogramming of phenylalanine metabolism. By generating mutants decoupling carbon storage from low nitrogen environments, we move closer toward optimizing R. opacus for efficient bioproduction on lignocellulosic biomass.
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Affiliation(s)
- Winston E Anthony
- The Edison Family Center for Genome Sciences and Systems Biology, Washington University School of Medicine, St. Louis, MO, 63110, USA
- Department of Pathology and Immunology, Division of Laboratory and Genomic Medicine, Washington University School of Medicine, St. Louis, MO, 63110, USA
- Earth and Biological Systems Directorate, Pacific Northwest National Laboratory, Seattle, USA
| | - Weitao Geng
- Department of Energy, Environmental and Chemical Engineering, Washington University in St. Louis, St. Louis, MO, 63130, USA
| | - Jinjin Diao
- Department of Energy, Environmental and Chemical Engineering, Washington University in St. Louis, St. Louis, MO, 63130, USA
| | - Rhiannon R Carr
- Department of Energy, Environmental and Chemical Engineering, Washington University in St. Louis, St. Louis, MO, 63130, USA
| | - Bin Wang
- The Edison Family Center for Genome Sciences and Systems Biology, Washington University School of Medicine, St. Louis, MO, 63110, USA
- Department of Pathology and Immunology, Division of Laboratory and Genomic Medicine, Washington University School of Medicine, St. Louis, MO, 63110, USA
| | - Jie Ning
- The Edison Family Center for Genome Sciences and Systems Biology, Washington University School of Medicine, St. Louis, MO, 63110, USA
- Department of Pathology and Immunology, Division of Laboratory and Genomic Medicine, Washington University School of Medicine, St. Louis, MO, 63110, USA
| | - Tae Seok Moon
- Department of Energy, Environmental and Chemical Engineering, Washington University in St. Louis, St. Louis, MO, 63130, USA.
- Division of Biology and Biomedical Sciences, Washington University in St. Louis, St. Louis, MO, 63130, USA.
| | - Gautam Dantas
- The Edison Family Center for Genome Sciences and Systems Biology, Washington University School of Medicine, St. Louis, MO, 63110, USA.
- Department of Energy, Environmental and Chemical Engineering, Washington University in St. Louis, St. Louis, MO, 63130, USA.
- Division of Biology and Biomedical Sciences, Washington University in St. Louis, St. Louis, MO, 63130, USA.
- Department of Molecular Microbiology, Washington University School of Medicine in St Louis, St Louis, MO, 63110, USA.
- Department of Pediatrics, Washington University School of Medicine in St Louis, St Louis, MO, 63110, USA.
- Department of Biomedical Engineering, Washington University in St. Louis, St. Louis, MO, 63130, USA.
| | - Fuzhong Zhang
- Department of Energy, Environmental and Chemical Engineering, Washington University in St. Louis, St. Louis, MO, 63130, USA.
- Division of Biology and Biomedical Sciences, Washington University in St. Louis, St. Louis, MO, 63130, USA.
- Institute of Materials Science & Engineering, Washington University in St Louis, St Louis, MO, 63130, USA.
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Mani P, Priyadarsini S, K Channabasappa N, Sahoo PR, Singh R, Saxena M, Upmanyu V, Agrawal RK, Singh P, Saini M, Kumar A. Role of narL gene in the pathogenesis of Salmonella Typhimurium. J Basic Microbiol 2024; 64:e2300456. [PMID: 38059734 DOI: 10.1002/jobm.202300456] [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: 08/09/2023] [Revised: 10/03/2023] [Accepted: 11/01/2023] [Indexed: 12/08/2023]
Abstract
Salmonella Typhimurium (STM) is a facultative anaerobe and one of the causative agents of nontyphoidal salmonellosis (NTS). Its anaerobic metabolism is enabled under the hypoxic environment that is encountered inside macrophages and the gut lumen of the host. In both of these niches, free radicals and oxidative intermediates are released by neutrophils as an inflammatory response. These chemical species further undergo reactions to produce nitrate, which is preferably taken up by STM as an electron acceptor in the absence of oxygen. NarL, the response regulator of the two-component regulatory system NarX/L, and a transcription factor, gets activated under anaerobic nitrate-rich conditions and upregulates the nitrate reduction during anaerobic respiration of STM. To understand the role of NarL in the pathogenesis of STM, we generated a narL-knockout (STM:ΔnarL) as well as a narL-complemented strain of STM. Anaerobically, the mutant displayed no growth defect but a significant attenuation in the swimming (26%) and swarming (61%) motility, and biofilm-forming ability (73%) in vitro, while these morphotypes got rescued upon genetic complementation. We also observed a downregulation in the expression of genes associated with nitrate reduction (narG) and biofilm formation (csgA and csgD) in anaerobically grown STM:ΔnarL. As compared with wild STM, narL mutant exhibited a threefold reduction in the intracellular replication in both intestinal epithelial cells (INT- 407) and monocyte-derived macrophages of poultry origin. Further, in vivo competitive assay in the liver and spleen of the murine model showed a competitive index of 0.48 ± 0.58 and 0.403668 ± 0.32, respectively, for STM:ΔnarL.
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Affiliation(s)
- Pashupathi Mani
- Division of Biochemistry, Indian Veterinary Research Institute, Izatnagar, Bareilly, India
| | | | - Nikhil K Channabasappa
- Department of Veterinary Physiology and Biochemistry, College of Veterinary Science and Animal Husbandry, Rewa, NDVSU, India
| | - Pravas Ranjan Sahoo
- Division of Biochemistry, Indian Veterinary Research Institute, Izatnagar, Bareilly, India
| | - Rohit Singh
- Division of Veterinary Pathology, Indian Veterinary Research Institute, Izatnagar, Bareilly, India
| | - Meeta Saxena
- Division of Biochemistry, Indian Veterinary Research Institute, Izatnagar, Bareilly, India
| | - Vikramaditya Upmanyu
- Division of Biological Standardization, Indian Veterinary Research Institute, Izatnagar, Bareilly, India
| | - Ravi Kant Agrawal
- Division of Livestock Products Technology, Indian Veterinary Research Institute, Izatnagar, Bareilly, India
| | - Praveen Singh
- Division of Biochemistry, Indian Veterinary Research Institute, Izatnagar, Bareilly, India
| | - Mohini Saini
- Division of Biochemistry, Indian Veterinary Research Institute, Izatnagar, Bareilly, India
| | - Ajay Kumar
- Division of Biochemistry, Indian Veterinary Research Institute, Izatnagar, Bareilly, India
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Yadav M, Sathe J, Teronpi V, Kumar A. Navigating the signaling landscape of Ralstonia solanacearum: a study of bacterial two-component systems. World J Microbiol Biotechnol 2024; 40:153. [PMID: 38564115 DOI: 10.1007/s11274-024-03950-y] [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: 01/16/2024] [Accepted: 03/10/2024] [Indexed: 04/04/2024]
Abstract
Ralstonia solanacearum, the bacterium that causes bacterial wilt, is a destructive phytopathogen that can infect over 450 different plant species. Several agriculturally significant crop plants, including eggplant, tomato, pepper, potato, and ginger, are highly susceptible to this plant disease, which has a global impact on crop quality and yield. There is currently no known preventive method that works well for bacterial wilt. Bacteria use two-component systems (TCSs) to sense their environment constantly and react appropriately. This is achieved by an extracellular sensor kinase (SK) capable of sensing a suitable signal and a cytoplasmic response regulator (RR) which gives a downstream response. Moreover, our investigation revealed that R. solanacearum GMI1000 possesses a substantial count of TCSs, specifically comprising 36 RRs and 27 SKs. While TCSs are known targets for various human pathogenic bacteria, such as Salmonella, the role of TCSs in R. solanacearum remains largely unexplored in this context. Notably, numerous inhibitors targeting TCSs have been identified, including GHL (Gyrase, Hsp, and MutL) compounds, Walk inhibitors, and anti-TCS medications like Radicicol. Consequently, the investigation into the involvement of TCSs in virulence and pathogenesis has gained traction; however, further research is imperative to ascertain whether TCSs could potentially supplant conventional anti-wilt therapies. This review delves into the prospective utilization of TCSs as an alternative anti-wilt therapy, focusing on the lethal phytopathogen R. solanacearum.
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Affiliation(s)
- Mohit Yadav
- Department of Molecular Biology and Biotechnology, Tezpur University, Tezpur, Assam, 784028, India
| | - Janhavi Sathe
- Department of Molecular Biology and Biotechnology, Tezpur University, Tezpur, Assam, 784028, India
- Institute for Stem Cell Science and Regenerative Medicine, Bangalore, Karnataka, 560065, India
| | - Valentina Teronpi
- Department of Zoology, Pandit Deendayal Upadhyaya Adarsha Mahavidyalaya, Behali, Biswanath, Assam, 784184, India
| | - Aditya Kumar
- Department of Molecular Biology and Biotechnology, Tezpur University, Tezpur, Assam, 784028, India.
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6
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Zhang LQ, Shen YL, Ye BC, Zhou Y. Acetylation of K188 and K192 inhibits the DNA-binding ability of NarL to regulate Salmonella virulence. Appl Environ Microbiol 2023; 89:e0068523. [PMID: 37732772 PMCID: PMC10617396 DOI: 10.1128/aem.00685-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2023] [Accepted: 07/26/2023] [Indexed: 09/22/2023] Open
Abstract
Salmonella infection significantly increases nitrate levels in the intestine, immune cells, and immune organs of the host, and it can exploit nitrate as an electron acceptor to enhance its growth. In the presence of nitrate or nitrite, NarL, a regulatory protein of the Nar two-component system, is activated and regulates a number of genes involved in nitrate metabolism. However, research on NarL at the post-translational level is limited. In this study, we demonstrate that the DNA-binding sites K188 and 192 of NarL can be acetylated by bacterial metabolite acetyl phosphate and that the degree of acetylation has a considerable influence on the regulatory function of NarL. Specifically, acetylation of NarL negatively regulates the transcription of narG, narK, and napF, which affects the utilization of nitrate in Salmonella. Besides, both cell and mouse models show that acetylated K188 and K192 result in attenuated replication in RAW 264.7 cells, as well as impaired virulence in mouse model. Together, this research identifies a novel NarL acetylation mechanism that regulates Salmonella virulence, providing a new insight and target for salmonellosis treatment.IMPORTANCESalmonella is an important intracellular pathogen that can cause limited gastroenteritis and self-limiting gastroenteritis in immunocompetent humans. Nitrate, the highest oxidation state form of nitrogen, is critical in the formation of systemic infection in Salmonella. It functions as a signaling molecule that influences Salmonella chemotaxis, in addition to acting as a reduced external electron acceptor for Salmonella anaerobic respiration. NarL is an essential regulatory protein involved in nitrate metabolism in Salmonella, and comprehending its regulatory mechanism is necessary. Previous research has linked NarL phosphorylation to the formation of its dimer, which is required for NarL to perform its regulatory functions. Our research demonstrated that acetylation also affects the regulatory function of NarL. We found that acetylation affects Salmonella pathogenicity by weakening the ability of NarL to bind to the target sequence, further refining the mechanism of the anaerobic nitrate respiration pathway.
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Affiliation(s)
- Liu-Qing Zhang
- Lab of Biosystems and Microanalysis, State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai, China
| | - Yi-Lin Shen
- Lab of Biosystems and Microanalysis, State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai, China
| | - Bang-Ce Ye
- Lab of Biosystems and Microanalysis, State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai, China
| | - Ying Zhou
- Lab of Biosystems and Microanalysis, State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai, China
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Fu J, Nisbett LM, Guo Y, Boon EM. NosP Detection of Heme Modulates Burkholderia thailandensis Biofilm Formation. Biochemistry 2023; 62:2426-2441. [PMID: 37498555 PMCID: PMC10478957 DOI: 10.1021/acs.biochem.3c00187] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/28/2023]
Abstract
Aggregated bacteria embedded within self-secreted extracellular polymeric substances, or biofilms, are resistant to antibiotics and cause chronic infections. As such, they are a significant public health threat. Heme is an abundant iron source for pathogenic bacteria during infection; many bacteria have systems to detect heme assimilated from host cells, which is correlated with the transition between acute and chronic infection states. Here, we investigate the heme-sensing function of a newly discovered multifactorial sensory hemoprotein called NosP and its role in biofilm regulation in the soil-dwelling bacterium Burkholderia thailandensis, the close surrogate of Bio-Safety-Level-3 pathogen Burkholderia pseudomallei. The NosP family protein has previously been shown to exhibit both nitric oxide (NO)- and heme-sensing functions and to regulate biofilms through NosP-associated histidine kinases and two-component systems. Our in vitro studies suggest that BtNosP exhibits heme-binding kinetics and thermodynamics consistent with a labile heme-responsive protein and that the holo-form of BtNosP acts as an inhibitor of its associated histidine kinase BtNahK. Furthermore, our in vivo studies suggest that increasing the concentration of extracellular heme decreases B. thailandensis biofilm formation, and deletion of nosP and nahK abolishes this phenotype, consistent with a model that BtNosP detects heme and exerts an inhibitory effect on BtNahK to decrease the biofilm.
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Affiliation(s)
- Jiayuan Fu
- Department of Chemistry and Institute of Chemical Biology & Drug Discovery, Stony Brook University, Stony Brook, New York 11794-3400, United States
| | - Lisa-Marie Nisbett
- Department of Chemistry and Institute of Chemical Biology & Drug Discovery, Stony Brook University, Stony Brook, New York 11794-3400, United States
| | - Yulong Guo
- Department of Chemistry and Institute of Chemical Biology & Drug Discovery, Stony Brook University, Stony Brook, New York 11794-3400, United States
| | - Elizabeth M Boon
- Department of Chemistry and Institute of Chemical Biology & Drug Discovery, Stony Brook University, Stony Brook, New York 11794-3400, United States
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Long DR, Penewit K, Lo HY, Almazan J, Holmes EA, Bryan AB, Wolter DJ, Lewis JD, Waalkes A, Salipante SJ. In Vitro Selection Identifies Staphylococcus aureus Genes Influencing Biofilm Formation. Infect Immun 2023; 91:e0053822. [PMID: 36847490 PMCID: PMC10016075 DOI: 10.1128/iai.00538-22] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2022] [Accepted: 02/13/2023] [Indexed: 03/01/2023] Open
Abstract
Staphylococcus aureus generates biofilms during many chronic human infections, which contributes to its growth and persistence in the host. Multiple genes and pathways necessary for S. aureus biofilm production have been identified, but knowledge is incomplete, and little is known about spontaneous mutations that increase biofilm formation as infection progresses. Here, we performed in vitro selection of four S. aureus laboratory strains (ATCC 29213, JE2, N315, and Newman) to identify mutations associated with enhanced biofilm production. Biofilm formation increased in passaged isolates from all strains, exhibiting from 1.2- to 5-fold the capacity of parental lines. Whole-genome sequencing identified nonsynonymous mutations affecting 23 candidate genes and a genomic duplication encompassing sigB. Six candidate genes significantly impacted biofilm formation as isogenic transposon knockouts: three were previously reported to impact S. aureus biofilm formation (icaR, spdC, and codY), while the remaining three (manA, narH, and fruB) were newly implicated by this study. Plasmid-mediated genetic complementation of manA, narH, and fruB transposon mutants corrected biofilm deficiencies, with high-level expression of manA and fruB further enhancing biofilm formation over basal levels. This work recognizes genes not previously identified as contributing to biofilm formation in S. aureus and reveals genetic changes able to augment biofilm production by that organism.
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Affiliation(s)
- Dustin R. Long
- Division of Critical Care Medicine, Department of Anesthesiology and Pain Medicine, University of Washington School of Medicine, Seattle, Washington, USA
| | - Kelsi Penewit
- Department of Laboratory Medicine and Pathology, University of Washington School of Medicine, Seattle, Washington, USA
| | - Hsin-Yu Lo
- Department of Laboratory Medicine and Pathology, University of Washington School of Medicine, Seattle, Washington, USA
| | - Jared Almazan
- Department of Laboratory Medicine and Pathology, University of Washington School of Medicine, Seattle, Washington, USA
| | - Elizabeth A. Holmes
- Department of Laboratory Medicine and Pathology, University of Washington School of Medicine, Seattle, Washington, USA
| | - Andrew B. Bryan
- Department of Laboratory Medicine and Pathology, University of Washington School of Medicine, Seattle, Washington, USA
| | - Daniel J. Wolter
- Department of Pediatrics, University of Washington School of Medicine, Seattle, Washington, USA
| | - Janessa D. Lewis
- Department of Laboratory Medicine and Pathology, University of Washington School of Medicine, Seattle, Washington, USA
| | - Adam Waalkes
- Department of Laboratory Medicine and Pathology, University of Washington School of Medicine, Seattle, Washington, USA
| | - Stephen J. Salipante
- Department of Laboratory Medicine and Pathology, University of Washington School of Medicine, Seattle, Washington, USA
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Gálvez-Roldán C, Cerna-Vargas JP, Rodríguez-Herva JJ, Krell T, Santamaría-Hernando S, López-Solanilla E. A Nitrate-Sensing Domain-Containing Chemoreceptor Is Required for Successful Entry and Virulence of Dickeya dadantii 3937 in Potato Plants. PHYTOPATHOLOGY 2023; 113:390-399. [PMID: 36399025 DOI: 10.1094/phyto-10-22-0367-r] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
Nitrate metabolism plays an important role in bacterial physiology. During the interaction of plant-pathogenic bacteria with their hosts, bacteria face variable conditions with respect to nitrate availability. Perception mechanisms through the chemosensory pathway drive the entry and control the colonization of the plant host in phytopathogenic bacteria. In this work, the identification and characterization of the nitrate- and nitrite-sensing (NIT) domain-containing chemoreceptor of Dickeya dadantii 3937 (Dd3937) allowed us to unveil the key role of nitrate sensing not only for the entry into the plant apoplast through wounds but also for infection success. We determined the specificity of this chemoreceptor to bind nitrate and nitrite, with a slight ligand preference for nitrate. Gene expression analysis showed that nitrate perception controls not only the expression of nitrate reductase genes involved in respiratory and assimilatory metabolic processes but also the expression of gyrA, hrpN, and bgxA, three well-known virulence determinants in Dd3937.
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Affiliation(s)
- Clara Gálvez-Roldán
- Centro de Biotecnología y Genómica de Plantas CBGP, Universidad Politécnica de Madrid-Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria/CSIC, Parque Científico y Tecnológico de la UPM, Pozuelo de Alarcón, Madrid, Spain
| | - Jean Paul Cerna-Vargas
- Centro de Biotecnología y Genómica de Plantas CBGP, Universidad Politécnica de Madrid-Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria/CSIC, Parque Científico y Tecnológico de la UPM, Pozuelo de Alarcón, Madrid, Spain
- Departamento de Protección Ambiental, Estación Experimental del Zaidín, Consejo Superior de Investigaciones Científicas, Granada, Spain
| | - José Juan Rodríguez-Herva
- Centro de Biotecnología y Genómica de Plantas CBGP, Universidad Politécnica de Madrid-Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria/CSIC, Parque Científico y Tecnológico de la UPM, Pozuelo de Alarcón, Madrid, Spain
- Departamento de Biotecnología-Biología Vegetal, Escuela Técnica Superior de Ingeniería Agronómica, Alimentaria y de Biosistemas, Universidad Politécnica de Madrid, Madrid, Spain
| | - Tino Krell
- Departamento de Protección Ambiental, Estación Experimental del Zaidín, Consejo Superior de Investigaciones Científicas, Granada, Spain
| | - Saray Santamaría-Hernando
- Centro de Biotecnología y Genómica de Plantas CBGP, Universidad Politécnica de Madrid-Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria/CSIC, Parque Científico y Tecnológico de la UPM, Pozuelo de Alarcón, Madrid, Spain
| | - Emilia López-Solanilla
- Centro de Biotecnología y Genómica de Plantas CBGP, Universidad Politécnica de Madrid-Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria/CSIC, Parque Científico y Tecnológico de la UPM, Pozuelo de Alarcón, Madrid, Spain
- Departamento de Biotecnología-Biología Vegetal, Escuela Técnica Superior de Ingeniería Agronómica, Alimentaria y de Biosistemas, Universidad Politécnica de Madrid, Madrid, Spain
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Nyanasegran PK, Nathan S, Firdaus-Raih M, Muhammad NAN, Ng CL. Biofilm Signaling, Composition and Regulation in Burkholderia pseudomallei. J Microbiol Biotechnol 2023; 33:15-27. [PMID: 36451302 PMCID: PMC9899790 DOI: 10.4014/jmb.2207.07032] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2022] [Revised: 10/10/2022] [Accepted: 10/11/2022] [Indexed: 12/04/2022]
Abstract
The incidence of melioidosis cases caused by the gram-negative pathogen Burkholderia pseudomallei (BP) is seeing an increasing trend that has spread beyond its previously known endemic regions. Biofilms produced by BP have been associated with antimicrobial therapy limitation and relapse melioidosis, thus making it urgently necessary to understand the mechanisms of biofilm formation and their role in BP biology. Microbial cells aggregate and enclose within a self-produced matrix of extracellular polymeric substances (EPSs) to form biofilm. The transition mechanism of bacterial cells from planktonic state to initiate biofilm formation, which involves the formation of surface attachment microcolonies and the maturation of the biofilm matrix, is a dynamic and complex process. Despite the emerging findings on the biofilm formation process, systemic knowledge on the molecular mechanisms of biofilm formation in BP remains fractured. This review provides insights into the signaling systems, matrix composition, and the biosynthesis regulation of EPSs (exopolysaccharide, eDNA and proteins) that facilitate the formation of biofilms in order to present an overview of our current knowledge and the questions that remain regarding BP biofilms.
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Affiliation(s)
| | - Sheila Nathan
- Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 UKM Bangi, Selangor, Malaysia
| | - Mohd Firdaus-Raih
- Institute of Systems Biology, Universiti Kebangsaan Malaysia, 43600 UKM Bangi, Selangor, Malaysia,Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 UKM Bangi, Selangor, Malaysia
| | - Nor Azlan Nor Muhammad
- Institute of Systems Biology, Universiti Kebangsaan Malaysia, 43600 UKM Bangi, Selangor, Malaysia
| | - Chyan Leong Ng
- Institute of Systems Biology, Universiti Kebangsaan Malaysia, 43600 UKM Bangi, Selangor, Malaysia,Corresponding author Phone: +03 8921 4561 Fax: +603 8921 3398 E-mail:
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Shaw C, Hess M, Weimer BC. Two-component systems regulate bacterial virulence in response to the host gastrointestinal environment and metabolic cues. Virulence 2022; 13:1666-1680. [PMID: 36128741 PMCID: PMC9518994 DOI: 10.1080/21505594.2022.2127196] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022] Open
Abstract
Two-component systems are ubiquitous signaling mechanisms in bacteria that enable intracellular changes from extracellular cues. These bacterial regulatory systems couple external stimuli to control genetic expression via an autophosphorylation cascade that transduces membrane signals to intracellular locations, thereby allowing bacteria to rapidly adapt to the changing environmental conditions. Well known to control basic cellular processes, it is evident that two-component systems also exercise control over virulence traits, such as motility, secretion systems, and stress responses that impact the complex cascade of networks that alter virulence traits. In the gastrointestinal system, cues for activation of virulence-related two-component systems include metal ions, host-derived metabolites, and gut conditions. The diversity and origin of these cues suggest that the host can exert control over enteric pathogenicity via regulation in the gastrointestinal system. With the rise in multi-drug resistant pathogens, the potential control of pathogenicity with host cues via two-component systems presents a potential alternative to antimicrobials. Though the signaling mechanism itself is well studied, to date there is no systematic review compiling the host-associated cues of two-component systems and virulence traits. This review highlights the direct link between the host gastrointestinal environment and pathogenicity by focusing on two-component systems that are associated with the genetic expression of virulence traits, and that are activated by host-derived cues. The direct link between the host gastrointestinal environment, metabolites, and pathogenicity established in this review both underscores the importance of host-derived cues on bacterial activity and presents an enticing therapeutic target in the fight against antimicrobial resistant pathogens.
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Affiliation(s)
- Claire Shaw
- Department of Animal Science, Systems Microbiology & Natural Products Laboratory, University of California, Davis, USA
| | - Matthias Hess
- Department of Animal Science, Systems Microbiology & Natural Products Laboratory, University of California, Davis, USA
| | - Bart C Weimer
- Department of Population Health and Reproduction, 100K Pathogen Genome Project, University of California, Davis, CA, USA
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Genome Capture Sequencing Selectively Enriches Bacterial DNA and Enables Genome-Wide Measurement of Intrastrain Genetic Diversity in Human Infections. mBio 2022; 13:e0142422. [PMID: 36121157 PMCID: PMC9601202 DOI: 10.1128/mbio.01424-22] [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] [Indexed: 11/25/2022] Open
Abstract
Within-host evolution produces genetic diversity in bacterial strains that cause chronic human infections. However, the lack of facile methods to measure bacterial allelic variation in clinical samples has limited understanding of intrastrain diversity’s effects on disease. Here, we report a new method termed genome capture sequencing (GenCap-Seq) in which users inexpensively make hybridization probes from genomic DNA or PCR amplicons to selectively enrich and sequence targeted bacterial DNA from clinical samples containing abundant human or nontarget bacterial DNA. GenCap-Seq enables accurate measurement of allele frequencies over targeted regions and is scalable from specific genes to entire genomes, including the strain-specific accessory genome. The method is effective with samples in which target DNA is rare and inhibitory and DNA-degrading substances are abundant, including human sputum and feces. In proof-of-principle experiments, we used GenCap-Seq to investigate the responses of diversified Pseudomonas aeruginosa populations chronically infecting the lungs of people with cystic fibrosis to in vivo antibiotic exposure, and we found that treatment consistently reduced intrastrain genomic diversity. In addition, analysis of gene-level allele frequency changes suggested that some genes without conventional resistance functions may be important for bacterial fitness during in vivo antibiotic exposure. GenCap-Seq’s ability to scalably enrich targeted bacterial DNA from complex samples will enable studies on the effects of intrastrain and intraspecies diversity in human infectious disease.
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Borlee GI, Mangalea MR, Martin KH, Plumley BA, Golon SJ, Borlee BR. Disruption of c-di-GMP Signaling Networks Unlocks Cryptic Expression of Secondary Metabolites during Biofilm Growth in Burkholderia pseudomallei. Appl Environ Microbiol 2022; 88:e0243121. [PMID: 35357191 PMCID: PMC9040570 DOI: 10.1128/aem.02431-21] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2021] [Accepted: 03/04/2022] [Indexed: 11/20/2022] Open
Abstract
The regulation and production of secondary metabolites during biofilm growth of Burkholderia spp. is not well understood. To learn more about the crucial role and regulatory control of cryptic molecules produced during biofilm growth, we disrupted c-di-GMP signaling in Burkholderia pseudomallei, a soilborne bacterial saprophyte and the etiologic agent of melioidosis. Our approach to these studies combined transcriptional profiling with genetic deletions that targeted key c-di-GMP regulatory components to characterize responses to changes in temperature. Mutational analyses and conditional expression studies of c-di-GMP genes demonstrates their contribution to phenotypes such as biofilm formation, colony morphology, motility, and expression of secondary metabolite biosynthesis when grown as a biofilm at different temperatures. RNA-seq analysis was performed at various temperatures in a ΔII2523 mutant background that is responsive to temperature alterations resulting in hypobiofilm- and hyperbiofilm-forming phenotypes. Differential regulation of genes was observed for polysaccharide biosynthesis, secretion systems, and nonribosomal peptide and polyketide synthase (NRPS/PKS) clusters in response to temperature changes. Deletion mutations of biosynthetic gene clusters (BGCs) 2, 11, 14 (syrbactin), and 15 (malleipeptin) in parental and ΔII2523 backgrounds also reveal the contribution of these BGCs to biofilm formation and colony morphology in addition to inhibition of Bacillus subtilis and Rhizoctonia solani. Our findings suggest that II2523 impacts the regulation of genes that contribute to biofilm formation and competition. Characterization of cryptic BGCs under different environmental conditions will allow for a better understanding of the role of secondary metabolites in the context of biofilm formation and microbe-microbe interactions. IMPORTANCE Burkholderia pseudomallei is a saprophytic bacterium residing in the environment that switches to a pathogenic lifestyle during infection of a wide range of hosts. The environmental cues that serve as the stimulus to trigger this change are largely unknown. However, it is well established that the cellular level of c-di-GMP, a secondary signal messenger, controls the switch from growth as planktonic cells to growth as a biofilm. Disrupting the signaling mediated by c-di-GMP allows for a better understanding of the regulation and the contribution of the surface associated and secreted molecules that contribute to the various lifestyles of this organism. The genome of B. pseudomallei also encodes cryptic biosynthetic gene clusters predicted to encode small molecules that potentially contribute to growth as a biofilm, adaptation, and interactions with other organisms. A better understanding of the regulation of these molecules is crucial to understanding how this versatile pathogen alters its lifestyle.
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Affiliation(s)
- Grace I. Borlee
- Department of Microbiology, Immunology, and Pathology, Colorado State University, Fort Collins, Colorado, USA
| | - Mihnea R. Mangalea
- Department of Microbiology, Immunology, and Pathology, Colorado State University, Fort Collins, Colorado, USA
| | - Kevin H. Martin
- Department of Microbiology, Immunology, and Pathology, Colorado State University, Fort Collins, Colorado, USA
| | - Brooke A. Plumley
- Department of Microbiology, Immunology, and Pathology, Colorado State University, Fort Collins, Colorado, USA
| | - Samuel J. Golon
- Department of Microbiology, Immunology, and Pathology, Colorado State University, Fort Collins, Colorado, USA
| | - Bradley R. Borlee
- Department of Microbiology, Immunology, and Pathology, Colorado State University, Fort Collins, Colorado, USA
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Pseudomonas aeruginosa Initiates a Rapid and Specific Transcriptional Response during Surface Attachment. J Bacteriol 2022; 204:e0008622. [PMID: 35467391 PMCID: PMC9112911 DOI: 10.1128/jb.00086-22] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Chronic biofilm infections by Pseudomonas aeruginosa are a major contributor to the morbidity and mortality of patients. The formation of multicellular bacterial aggregates, called biofilms, is associated with increased resistance to antimicrobials and immune clearance and the persistence of infections. Biofilm formation is dependent on bacterial cell attachment to surfaces, and therefore, attachment plays a key role in chronic infections. We hypothesized that bacteria sense various surfaces and initiate a rapid, specific response to increase adhesion and establish biofilms. RNA sequencing (RNA-Seq) analysis identified transcriptional changes of adherent cells during initial attachment, identifying the bacterial response to an abiotic surface over a 1-h period. Subsequent screens investigating the most highly regulated genes in surface attachment identified 4 genes, pfpI, phnA, leuD, and moaE, all of which have roles in both metabolism and biofilm formation. In addition, the transcriptional responses to several different medically relevant abiotic surfaces were compared after initial attachment. Surprisingly, there was a specific transcriptional response to each surface, with very few genes being regulated in response to surfaces in general. We identified a set of 20 genes that were differentially expressed across all three surfaces, many of which have metabolic functions, including molybdopterin cofactor biosynthesis and nitrogen metabolism. This study has advanced the understanding of the kinetics and specificity of bacterial transcriptional responses to surfaces and suggests that metabolic cues are important signals during the transition from a planktonic to a biofilm lifestyle. IMPORTANCE Bacterial biofilms are a significant concern in many aspects of life, including chronic infections of airways, wounds, and indwelling medical devices; biofouling of industrial surfaces relevant for food production and marine surfaces; and nosocomial infections. The effects of understanding surface adhesion could impact many areas of life. This study utilized emerging technology in a novel approach to address a key step in bacterial biofilm development. These findings have elucidated both conserved and surface-specific responses to several disease-relevant abiotic surfaces. Future work will expand on this report to identify mechanisms of biofilm initiation with the aim of identifying bacterial factors that could be targeted to prevent biofilms.
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