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Wang Z, Zhang H, Xiong Y, Zhang L, Cui J, Li G, Du C, Wen K. Remediation mechanism of high concentrations of multiple heavy metals in contaminated soil by Sedum alfredii and native microorganisms. J Environ Sci (China) 2025; 147:179-188. [PMID: 39003038 DOI: 10.1016/j.jes.2023.10.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2023] [Revised: 10/05/2023] [Accepted: 10/05/2023] [Indexed: 07/15/2024]
Abstract
Pollution accident of nonferrous metallurgy industry often lead to serious heavy metal pollution of the surrounding soil. Phytoremediation of contaminated soil is an environmental and sustainable technology, and soil native microorganisms in the process of phytoremediation also participate in the remediation of heavy metals. However, the effects of high concentrations of multiple heavy metals (HCMHMs) on plants and native soil microorganisms remain uncertain. Thus, further clarification of the mechanism of phytoremediation of HCMHMs soil by plants and native soil microorganisms is required. Using the plant Sedum alfredii (S. alfredii) to restore HCMHM-contaminated soil, we further explored the mechanism of S. alfredii and native soil microorganisms in the remediation of HCMHM soils. The results showed that (i) S. alfredii can promote heavy metals from non-rhizosphere soil to rhizosphere soil, which is conducive to the effect of plants on heavy metals. In addition, it can also enrich the absorbed heavy metals in its roots and leaves; (ii) native soil bacteria can increase the abundance of signal molecule-synthesizing enzymes, such as trpE, trpG, bjaI, rpfF, ACSL, and yidC, and promote the expression of the pathway that converts serine to cysteine, then synthesize substances to chelate heavy metals. In addition, we speculated that genes such as K19703, K07891, K09711, K19703, K07891, and K09711 in native bacteria may be involved in the stabilization or absorption of heavy metals. The results provide scientific basis for S. alfredii to remediate heavy metals contaminated soils, and confirm the potential of phytoremediation of HCMHM contaminated soil.
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Affiliation(s)
- Zihe Wang
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China
| | - Han Zhang
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China.
| | - Ying Xiong
- Beijing Water Science and Technology Institute, Beijing 100044, China
| | - Lieyu Zhang
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China
| | - Jianglong Cui
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China
| | - Guowen Li
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China
| | - Caili Du
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China
| | - Kaiyang Wen
- School of Architecture and Civil Engineering, Chengdu University, Chengdu 610106, China
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Markus V. Gut bacterial quorum sensing molecules and their association with inflammatory bowel disease: Advances and future perspectives. Biochem Biophys Res Commun 2024; 724:150243. [PMID: 38857558 DOI: 10.1016/j.bbrc.2024.150243] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2024] [Revised: 05/15/2024] [Accepted: 06/06/2024] [Indexed: 06/12/2024]
Abstract
Inflammatory Bowel Disease (IBD) is an enduring inflammatory disease of the gastrointestinal tract (GIT). The complexity of IBD, its profound impact on patient's quality of life, and its burden on healthcare systems necessitate continuing studies to elucidate its etiology, refine care strategies, improve treatment outcomes, and identify potential targets for novel therapeutic interventions. The discovery of a connection between IBD and gut bacterial quorum sensing (QS) molecules has opened exciting opportunities for research into IBD pathophysiology. QS molecules are small chemical messengers synthesized and released by bacteria based on population density. These chemicals are sensed not only by the microbial species but also by host cells and are essential in gut homeostasis. QS molecules are now known to interact with inflammatory pathways, therefore rendering them potential therapeutic targets for IBD management. Given these intriguing developments, the most recent research findings in this area are herein reviewed. First, the global burden of IBD and the disruptions of the gut microbiota and intestinal barrier associated with the disease are assessed. Next, the general QS mechanism and signaling molecules in the gut are discussed. Then, the roles of QS molecules and their connection with IBD are elucidated. Lastly, the review proposes potential QS-based therapeutic targets for IBD, offering insights into the future research trajectory in this field.
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Affiliation(s)
- Victor Markus
- Near East University, Faculty of Medicine, Department of Medical Biochemistry, Nicosia, TRNC Mersin 10, Turkey.
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3
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Bényei ÉB, Nazeer RR, Askenasy I, Mancini L, Ho PM, Sivarajan GAC, Swain JEV, Welch M. The past, present and future of polymicrobial infection research: Modelling, eavesdropping, terraforming and other stories. Adv Microb Physiol 2024; 85:259-323. [PMID: 39059822 DOI: 10.1016/bs.ampbs.2024.04.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/28/2024]
Abstract
Over the last two centuries, great advances have been made in microbiology as a discipline. Much of this progress has come about as a consequence of studying the growth and physiology of individual microbial species in well-defined laboratory media; so-called "axenic growth". However, in the real world, microbes rarely live in such "splendid isolation" (to paraphrase Foster) and more often-than-not, share the niche with a plethora of co-habitants. The resulting interactions between species (and even between kingdoms) are only very poorly understood, both on a theoretical and experimental level. Nevertheless, the last few years have seen significant progress, and in this review, we assess the importance of polymicrobial infections, and show how improved experimental traction is advancing our understanding of these. A particular focus is on developments that are allowing us to capture the key features of polymicrobial infection scenarios, especially as those associated with the human airways (both healthy and diseased).
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Affiliation(s)
| | | | - Isabel Askenasy
- Department of Biochemistry, Tennis Court Road, Cambridge, United Kingdom
| | - Leonardo Mancini
- Department of Biochemistry, Tennis Court Road, Cambridge, United Kingdom
| | - Pok-Man Ho
- Department of Biochemistry, Tennis Court Road, Cambridge, United Kingdom
| | | | - Jemima E V Swain
- Department of Biochemistry, Tennis Court Road, Cambridge, United Kingdom
| | - Martin Welch
- Department of Biochemistry, Tennis Court Road, Cambridge, United Kingdom.
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de la Fuente I, Manzano-Morales S, Sanz D, Prieto A, Barriuso J. Quorum sensing in bacteria: in silico protein analysis, ecophysiology, and reconstruction of their evolutionary history. BMC Genomics 2024; 25:441. [PMID: 38702600 PMCID: PMC11069264 DOI: 10.1186/s12864-024-10355-6] [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: 01/31/2024] [Accepted: 04/25/2024] [Indexed: 05/06/2024] Open
Abstract
BACKGROUND Quorum sensing (QS) is a sophisticated cell-to-cell signalling mechanism that allows the coordination of important processes in microbial populations. The AI-1 and AI-2 autoinducer systems are among the best characterized bacterial QS systems at the genetic level. RESULTS In this study, we present data derived from in silico screening of QS proteins from bacterial genomes available in public databases. Sequence analyses allowed identifying candidate sequences of known QS systems that were used to build phylogenetic trees. Eight categories were established according to the number of genes from the two major QS systems present in each genome, revealing a correlation with specific taxa, lifestyles or metabolic traits. Many species had incomplete QS systems, encoding the receptor protein but not the biosynthesis of the quorum sensing molecule (QSMs). Reconstruction of the evolutionary history of the LuxR family and prediction of the 3D structure of the ancestral protein suggested their monomeric configuration in the absence of the signal molecule and the presence of a cavity for its binding. CONCLUSIONS Here we correlate the taxonomic affiliation and lifestyle of bacteria from different genera with the QS systems encoded in their genomes. Moreover, we present the first ancestral reconstruction of the LuxR QS receptors, providing further insight in their evolutionary history.
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Affiliation(s)
- Iñigo de la Fuente
- Centro de Investigaciones Biológicas (CIB Margarita Salas), Department of Microbial and Plant Biotechnology, Consejo Superior de Investigaciones Científicas (CSIC), Ramiro de Maeztu 9, Madrid, 28040, Spain
| | - Saioa Manzano-Morales
- Centro de Investigaciones Biológicas (CIB Margarita Salas), Department of Microbial and Plant Biotechnology, Consejo Superior de Investigaciones Científicas (CSIC), Ramiro de Maeztu 9, Madrid, 28040, Spain
| | - David Sanz
- Centro de Investigaciones Biológicas (CIB Margarita Salas), Department of Microbial and Plant Biotechnology, Consejo Superior de Investigaciones Científicas (CSIC), Ramiro de Maeztu 9, Madrid, 28040, Spain
| | - Alicia Prieto
- Centro de Investigaciones Biológicas (CIB Margarita Salas), Department of Microbial and Plant Biotechnology, Consejo Superior de Investigaciones Científicas (CSIC), Ramiro de Maeztu 9, Madrid, 28040, Spain
| | - Jorge Barriuso
- Centro de Investigaciones Biológicas (CIB Margarita Salas), Department of Microbial and Plant Biotechnology, Consejo Superior de Investigaciones Científicas (CSIC), Ramiro de Maeztu 9, Madrid, 28040, Spain.
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Bilgin M, Dosler S, Otuk G. Antibiotic adjuvant activities of quorum sensing signal molecules DSF and BDSF against mature biofilms of Staphylococci. J Chemother 2024; 36:11-23. [PMID: 37873740 DOI: 10.1080/1120009x.2023.2270743] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2023] [Accepted: 10/09/2023] [Indexed: 10/25/2023]
Abstract
Among promising antibiofilm compounds, quorum-sensing (QS) molecules that regulate biological processes such as biofilm formation and intra- or interspecies communication appear to be good candidates. The invitro antibiotic-adjuvant effects of QS molecules diffusible signal factor (DSF) and B. cenocepacia producing-DSF (BDSF) were investigated against mature Staphylococcal biofilms. Broth microdilution methods were used for the determinations of MIC, MBC, MBIC, and MBEC, and bactericidal activities were determined by TKC method. The lowest MICs were obtained with ciprofloxacin and gentamicin, and MBECs with ciprofloxacin. DSF and BDSF at 0.5 µM decreased the MICs as 2-8, and 2-32 fold, respectively. In TKC studies, -cidal activities were achieved by BDSF + gentamycin, or ciprofloxacin, and DSF + daptomycin, vancomycin, meropenem or gentamycin combinations. Synergistic effects were generally obtained with BDSF + gentamicin combinations, followed by DSF + daptomycin against most S. aureus; while BDSF + gentamicin or ciprofloxacin, and DSF + vancomycin or meropenem were synergist against some S. epidermidis biofilms. Also, the antagonist effects were observed with BDSF + meropenem or ciprofloxacin against each MSSE and MSSA. It is estimated that these QS molecules, although it was strain dependent, generally enhanced the antibiotic activity, and would be a new and effective treatment strategy for biofilm control, either alone or as an antibiotic adjuvant.
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Affiliation(s)
- Merve Bilgin
- Department of Pharmaceutical Microbiology, Istanbul, Istanbul University, Institute of Graduate Studies in Health Sciences, Istanbul, Turkiye
- Department of Pharmaceutical Microbiology, Istanbul Health & Technology University, Faculty of Pharmacy, Istanbul, Turkiye
| | - Sibel Dosler
- Department of Pharmaceutical Microbiology, Istanbul, Istanbul University, Faculty of Pharmacy, Istanbul, Turkiye
| | - Gulten Otuk
- Department of Pharmaceutical Microbiology, Istanbul, Istanbul University, Faculty of Pharmacy, Istanbul, Turkiye
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Bhaumik R, Aungkur NZ, Anderson GG. A guide to Stenotrophomonas maltophilia virulence capabilities, as we currently understand them. Front Cell Infect Microbiol 2024; 13:1322853. [PMID: 38274738 PMCID: PMC10808757 DOI: 10.3389/fcimb.2023.1322853] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2023] [Accepted: 12/20/2023] [Indexed: 01/27/2024] Open
Abstract
The Gram-negative pathogen Stenotrophomonas maltophilia causes a wide range of human infections. It causes particularly serious lung infections in individuals with cystic fibrosis, leading to high mortality rates. This pathogen is resistant to most known antibiotics and harbors a plethora of virulence factors, including lytic enzymes and serine proteases, that cause acute infection in host organisms. S. maltophilia also establishes chronic infections through biofilm formation. The biofilm environment protects the bacteria from external threats and harsh conditions and is therefore vital for the long-term pathogenesis of the microbe. While studies have identified several genes that mediate S. maltophilia's initial colonization and biofilm formation, the cascade of events initiated by these factors is poorly understood. Consequently, understanding these and other virulence factors can yield exciting new targets for novel therapeutics.
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Affiliation(s)
| | | | - Gregory G. Anderson
- Department of Biology, Purdue School of Science, Indiana University Purdue University Indianapolis, Indianapolis, IN, United States
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Li Y, Liu X, Chen L, Shen X, Wang H, Guo R, Li X, Yu Z, Zhang X, Zhou Y, Fu L. Comparative genomics analysis of Stenotrophomonas maltophilia strains from a community. Front Cell Infect Microbiol 2023; 13:1266295. [PMID: 38089814 PMCID: PMC10715271 DOI: 10.3389/fcimb.2023.1266295] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2023] [Accepted: 11/07/2023] [Indexed: 12/18/2023] Open
Abstract
Background Stenotrophomonas maltophilia is a multidrug-resistant (MDR) opportunistic pathogen with high resistance to most clinically used antimicrobials. The dissemination of MDR S. maltophilia and difficult treatment of its infection in clinical settings are global issues. Methods To provide more genetic information on S. maltophilia and find a better treatment strategy, we isolated five S. maltophilia, SMYN41-SMYN45, from a Chinese community that were subjected to antibiotic susceptibility testing, biofilm formation assay, and whole-genome sequencing. Whole-genome sequences were compared with other thirty-seven S. maltophilia sequences. Results The five S. maltophilia strains had similar antibiotic resistance profiles and were resistant to β-lactams, aminoglycosides, and macrolides. They showed similar antimicrobial resistance (AMR) genes, including various efflux pumps, β-lactamase resistance genes (blaL1/2), aminoglycoside resistance genes [aac(6'), aph(3'/6)], and macrolide-resistant gene (MacB). Genome sequencing analysis revealed that SMYN41-SMYN45 belonged to sequence type 925 (ST925), ST926, ST926, ST31, and ST928, respectively, and three new STs were identified (ST925, ST926, and ST928). Conclusion This study provides genetic information by comparing genome sequences of several S. maltophilia isolates from a community of various origins, with the aim of optimizing empirical antibiotic medication and contributing to worldwide efforts to tackle antibiotic resistance.
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Affiliation(s)
- Yini Li
- Department of Ultrasound, Affiliated Hospital of Southwest Medical University, Southwest Medical University, Luzhou, China
| | - Xin Liu
- Department of Pathogen Biology, School of Basic Medicine, Public Center of Experimental Technology of Pathogen Biology Technology Platform, Southwest Medical University, Luzhou, China
| | - Lingzhi Chen
- Department of Ultrasound, Affiliated Hospital of Southwest Medical University, Southwest Medical University, Luzhou, China
| | - Xiao Shen
- Department of Pathogen Biology, School of Basic Medicine, Public Center of Experimental Technology of Pathogen Biology Technology Platform, Southwest Medical University, Luzhou, China
| | - Haihong Wang
- Department of Pathogen Biology, School of Basic Medicine, Public Center of Experimental Technology of Pathogen Biology Technology Platform, Southwest Medical University, Luzhou, China
| | - Ruiyu Guo
- Department of Pathogen Biology, School of Basic Medicine, Public Center of Experimental Technology of Pathogen Biology Technology Platform, Southwest Medical University, Luzhou, China
| | - Xiang Li
- Department of Pathogen Biology, School of Basic Medicine, Public Center of Experimental Technology of Pathogen Biology Technology Platform, Southwest Medical University, Luzhou, China
| | - Zehui Yu
- Laboratory Animal Center, Southwest Medical University, Luzhou, China
| | - Xiaoli Zhang
- Department of Allergy, Jiangnan University Medical Center, Wuxi, China
| | - Yingshun Zhou
- Department of Pathogen Biology, School of Basic Medicine, Public Center of Experimental Technology of Pathogen Biology Technology Platform, Southwest Medical University, Luzhou, China
| | - Li Fu
- Affiliated Hospital of Southwest Medical University, Southwest Medical University, Luzhou, China
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Lv L, Chen J, Liu X, Gao W, Sun L, Wang P, Ren Z, Zhang G, Li W. Roles and regulation of quorum sensing in anaerobic granular sludge: Research status, challenges, and perspectives. BIORESOURCE TECHNOLOGY 2023; 387:129644. [PMID: 37558106 DOI: 10.1016/j.biortech.2023.129644] [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: 05/20/2023] [Revised: 07/31/2023] [Accepted: 08/05/2023] [Indexed: 08/11/2023]
Abstract
Anaerobic granular sludge (AnGS) has a complex and important internal microbial communication system due to its unique microbial layered structure. As a concentration-dependent communication system between bacterial cells through signal molecules, QS (quorum sensing) is widespread in AnGS and exhibits great potential to regulate microbial behaviors. Therefore, the universal functions of QS in AnGS have been systematically summarized in this paper, including the influence on the metabolic activity, physicochemical properties, and microbial community of AnGS. Subsequently, the common QS-based AnGS regulation approaches are reviewed and analyzed comprehensively. The regulation mechanism of QS in AnGS is analyzed from two systems of single bacterium and mixed bacteria. This review can provide a comprehensive understanding of QS functions in AnGS systems, and promote the practical application of QS-based strategies in optimization of AnGS treatment process.
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Affiliation(s)
- Longyi Lv
- Tianjin Key Laboratory of Clean Energy and Pollution Control, School of Energy and Environmental Engineering, Hebei University of Technology, Tianjin 300401, PR China
| | - Jiarui Chen
- Tianjin Key Laboratory of Clean Energy and Pollution Control, School of Energy and Environmental Engineering, Hebei University of Technology, Tianjin 300401, PR China
| | - Xiaoyang Liu
- Tianjin Key Laboratory of Clean Energy and Pollution Control, School of Energy and Environmental Engineering, Hebei University of Technology, Tianjin 300401, PR China.
| | - Wenfang Gao
- Tianjin Key Laboratory of Clean Energy and Pollution Control, School of Energy and Environmental Engineering, Hebei University of Technology, Tianjin 300401, PR China
| | - Li Sun
- Tianjin Key Laboratory of Clean Energy and Pollution Control, School of Energy and Environmental Engineering, Hebei University of Technology, Tianjin 300401, PR China
| | - Pengfei Wang
- Tianjin Key Laboratory of Clean Energy and Pollution Control, School of Energy and Environmental Engineering, Hebei University of Technology, Tianjin 300401, PR China
| | - Zhijun Ren
- Tianjin Key Laboratory of Clean Energy and Pollution Control, School of Energy and Environmental Engineering, Hebei University of Technology, Tianjin 300401, PR China
| | - Guangming Zhang
- Tianjin Key Laboratory of Clean Energy and Pollution Control, School of Energy and Environmental Engineering, Hebei University of Technology, Tianjin 300401, PR China
| | - Weiguang Li
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology (SKLUWRE, HIT), Harbin 150090, PR China.
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Ray S, Jin JO, Choi I, Kim M. Cell-Free Supernatant of Bacillus thuringiensis Displays Anti-Biofilm Activity Against Staphylococcus aureus. Appl Biochem Biotechnol 2023; 195:5379-5393. [PMID: 35593953 DOI: 10.1007/s12010-022-03971-z] [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: 01/03/2022] [Accepted: 05/10/2022] [Indexed: 11/02/2022]
Abstract
Staphylococcus aureus is an important bacterial pathogen responsible for biofilm formation in medical devices. Due to the increasing antibiotic resistance of S. aureus, it is necessary to search for new anti-biofilm agents. In this study, the cell-free supernatant of Bacillus thuringiensis inhibited biofilm formation up to 93% and dispersed biofilms up to 83% without affecting the growth of S. aureus. The ethyl acetate extract of B. thuringiensis cell-free supernatant exhibited a dose-dependent anti-biofilm activity against S. aureus with the biofilm inhibition concentration ranging from 8 to 64 µg/mL. Scanning electron microscopy revealed that the cell-free supernatant extract of B. thuringiensis resulted in a significant reduction in S. aureus biofilms. The ethyl acetate extract of cell-free supernatant of B. thuringiensis was found to contain various compounds with structural similarity to known anti-biofilm compounds. In particular, squalene, cinnamic acid derivatives, and eicosapentaene seem to act synergistically against S. aureus biofilms. Hence, B. thuringiensis cell-free supernatant proved to be effective against S. aureus biofilms. The results clearly show the potential of natural molecules produced by B. thuringiensis as alternative therapies with anti-biofilm activity instead of bactericidal properties.
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Affiliation(s)
- Subhasree Ray
- Research Institute of Cell Culture, Yeungnam University, Gyeongsan, Gyeongsangbuk-do, 38541, Republic of Korea
- Department of Life Science, School of Basic Science and Research, Sharda University, Greater Noida, Uttar Pradesh, India
| | - Jun-O Jin
- Research Institute of Cell Culture, Yeungnam University, Gyeongsan, Gyeongsangbuk-do, 38541, Republic of Korea
- Department of Medical Biotechnology, Yeungnam University, Gyeongsan, Gyeongsangbuk-do, 38541, Republic of Korea
| | - Inho Choi
- Research Institute of Cell Culture, Yeungnam University, Gyeongsan, Gyeongsangbuk-do, 38541, Republic of Korea
- Department of Medical Biotechnology, Yeungnam University, Gyeongsan, Gyeongsangbuk-do, 38541, Republic of Korea
| | - Myunghee Kim
- Research Institute of Cell Culture, Yeungnam University, Gyeongsan, Gyeongsangbuk-do, 38541, Republic of Korea.
- Department of Food Science and Technology, Yeungnam University, Gyeongsan, Gyeongsangbuk-do, 38541, Republic of Korea.
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Dutta K, Shityakov S, Maruyama F. DSF inactivator RpfB homologous FadD upregulated in Bradyrhizobium japonicum under iron limiting conditions. Sci Rep 2023; 13:8701. [PMID: 37248242 DOI: 10.1038/s41598-023-35487-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2022] [Accepted: 05/18/2023] [Indexed: 05/31/2023] Open
Abstract
Phytopathogenic bacteria Xanthomonas campestris pv. campestris (Xcc) causes black rot and other plant diseases. Xcc senses diffusible signal factor (DSF) as a quorum-sensing (QS) signal that mediates mainly iron uptake and virulence. RpfB deactivates DSF in this DSF-QS circuit. We examined differential gene expression profiles of Bradyrhizobium japonicum under low versus high iron conditions and found that fadD and irr were upregulated under low iron (log2 fold change 0.825 and 1.716, respectively). In addition to having similar protein folding patterns and functional domain similarities, FadD shared 58% sequence similarity with RpfB of Xcc. The RpfB-DSF and FadD-DSF complexes had SWISSDock molecular docking scores of - 8.88 kcal/mol and - 9.85 kcal/mol, respectively, and the 100 ns molecular dynamics simulation results were in accord with the docking results. However, significant differences were found between the binding energies of FadD-DSF and RpfB-DSF, indicating possible FadD-dependent DSF turnover. The protein-protein interaction network showed that FadD connected indirectly with ABC transporter permease (ABCtp), which was also upregulated (log2 fold change 5.485). We speculate that the low iron condition may be a mimetic environmental stimulus for fadD upregulation in B. japonicum to deactivate DSF, inhibit iron uptake and virulence of DSF-producing neighbors. This finding provides a new option of using B. japonicum or a genetically improved B. japonicum as a potential biocontrol agent against Xcc, with the added benefit of plant growth-promoting properties.
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Affiliation(s)
- Kunal Dutta
- Laboratory of Chemoinformatics, Infochemistry Scientific Center, ITMO University, Saint Petersburg, Russian Federation.
| | - Sergey Shityakov
- Laboratory of Chemoinformatics, Infochemistry Scientific Center, ITMO University, Saint Petersburg, Russian Federation.
| | - Fumito Maruyama
- Microbial Genomics and Ecology, The IDEC Institute, Hiroshima University, Higashihiroshima, Japan.
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Shi Q, Wen H, Xu Y, Zhao X, Zhang J, Li Y, Meng Q, Yu F, Xiao J, Li X. Virtual screening-based discovery of AI-2 quorum sensing inhibitors that interact with an allosteric hydrophobic site of LsrK and their functional evaluation. Front Chem 2023; 11:1185224. [PMID: 37292175 PMCID: PMC10244669 DOI: 10.3389/fchem.2023.1185224] [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: 03/13/2023] [Accepted: 05/09/2023] [Indexed: 06/10/2023] Open
Abstract
Introduction: Quorum sensing (QS) is a bacterial intracellular and intercellular communication system that regulates virulence factor production, biofilm formation, and antibiotic sensitivity. Quorum-sensing inhibitors (QSIs) are a novel class of antibiotics that can effectively combat antibiotic resistance. Autoinducer-2 (AI-2) is a universal signaling molecule that mediates inter- and intraspecies QS systems among different bacteria. Furthermore, LsrK plays an important role in regulating the activity and stability of the intracellular AI-2 signaling pathway. Thus, LsrK is considered an important target for the development of QSIs. Methods: We designed a workflow integrating molecular dynamic (MD) simulations, virtual screening, LsrK inhibition assays, cell-based AI-2-mediated QS interference assays, and surface plasmon resonance (SPR)-based protein affinity assays to screen for potential LsrK kinase inhibitors. Results: MD simulation results of the LsrK/ATP complex revealed hydrogen bonds and salt bridge formation among four key residues, namely, Lys 431, Tyr 341, Arg 319, and Arg 322, which are critical for the binding of ATP to LsrK. Furthermore, MD simulation results indicated that the ATP-binding site has an allosteric pocket that can become larger and be occupied by small molecule compounds. Based on these MD simulation results, a constraint of forming at least one hydrogen bond with Arg 319, Arg 322, Lys 431, or Tyr 341 residues was introduced when performing virtual screening using Glide's virtual screening workflow (VSW). In the meantime, compounds with hydrophobic group likely to interact with the allosteric hydrophobic pocket are preferred when performing visual inspection. Seventy-four compounds were selected for the wet laboratory assays based on virtual screening and the absorption, distribution, metabolism, and excretion (ADME) properties of these compounds. LsrK inhibition assays revealed 12 compounds inhibiting LsrK by more than 60% at a 200 μM concentration; four of these (Y205-6768, D135-0149, 3284-1358, and N025-0038) had IC50 values below 50 μM and were confirmed as ATP-competitive inhibitors. Six of these 12 LsrK inhibitors exhibited high AI-2 QS inhibition, of which, Y205-6768 had the highest activity with IC50 = 11.28 ± 0.70 μM. The SPR assay verified that compounds Y205-6768 and N025-0038 specifically bound to LsrK. MD simulation analysis of the docking complexes of the four active compounds with LsrK further confirmed the importance of forming hydrogen bonds and salt bridges with key basic amino acid residues including Lys 431, Tyr 341, Arg 319, and Arg 322 and filling the allosteric hydrophobic pocket next to the purine-binding site of LsrK. Discussion: Our study clarified for the first time that there is an allosteric site near the ATP-binding site of Lsrk and that it enriches the structure-activity relationship information of Lsrk inhibitors. The four identified compounds showed novel structures, low molecular weights, high activities, and novel LsrK binding modes, rendering them suitable for further optimization for effective AI-2 QSIs. Our work provides a valuable reference for the discovery of QSIs that do not inhibit bacterial growth, thereby avoiding the emergence of drug resistance.
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Affiliation(s)
- Qianqian Shi
- School of Petrochemical Engineering, Liaoning Petrochemical University, Fushun, China
- National Engineering Research Center for the Emergency Strategic Drug, Beijing Institute of Pharmacology and Toxicology, Beijing, China
| | - Huiqi Wen
- State Key Laboratory of Pathogen and Biosecurity, Institute of Microbiology and Epidemiology, Academy of Military Medical Sciences, Beijing, China
| | - Yijie Xu
- National Engineering Research Center for the Emergency Strategic Drug, Beijing Institute of Pharmacology and Toxicology, Beijing, China
- State Key Laboratory of Toxicology and Medical Countermeasures, Beijing Institute of Pharmacology and Toxicology, Beijing, China
| | - Xu Zhao
- Department of Hepatology, Fifth Medical Center of Chinese PLA General Hospital, Beijing, China
| | - Jing Zhang
- Qionglai Medical Center Hospital, Chengdu, China
| | - Ye Li
- The No 968 Hospital of PLA, Jinzhou, China
| | - Qingbin Meng
- State Key Laboratory of Toxicology and Medical Countermeasures, Beijing Institute of Pharmacology and Toxicology, Beijing, China
| | - Fang Yu
- School of Petrochemical Engineering, Liaoning Petrochemical University, Fushun, China
- National Engineering Research Center for the Emergency Strategic Drug, Beijing Institute of Pharmacology and Toxicology, Beijing, China
| | - Junhai Xiao
- National Engineering Research Center for the Emergency Strategic Drug, Beijing Institute of Pharmacology and Toxicology, Beijing, China
- State Key Laboratory of Toxicology and Medical Countermeasures, Beijing Institute of Pharmacology and Toxicology, Beijing, China
| | - Xingzhou Li
- National Engineering Research Center for the Emergency Strategic Drug, Beijing Institute of Pharmacology and Toxicology, Beijing, China
- State Key Laboratory of Toxicology and Medical Countermeasures, Beijing Institute of Pharmacology and Toxicology, Beijing, China
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12
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Dai C, Qu Y, Wu W, Li S, Chen Z, Lian S, Jing J. QSP: An open sequence database for quorum sensing related gene analysis with an automatic annotation pipeline. WATER RESEARCH 2023; 235:119814. [PMID: 36934538 DOI: 10.1016/j.watres.2023.119814] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/23/2022] [Revised: 02/18/2023] [Accepted: 02/24/2023] [Indexed: 06/18/2023]
Abstract
Quorum sensing (QS) has attracted great attention due to its important role in the bacterial interactions and its relevance to water management. With the development of high-throughput sequencing technology, a specific database for QS-related sequence annotation is urgently needed. Here, Hidden Markov Model (HMM) profiles for 38 types of QS-related proteins were built using a total of 4024 collected seed sequences. Based on both homolog search and keywords confirmation against the non-redundant database, we established a QS-related protein (QSP) database, that includes 809,721 protein sequences and 186,133 nucleotide sequences, downloaded available at: https://github.com/chunxiao-dcx/QSP. The entries were classified into 38 types and 315 subtypes among 91 bacterial phyla. Furthermore, an automatic annotation pipeline, named QSAP, was developed for rapid annotation, classification and abundance quantification of QSP-like sequences from sequencing data. This pipeline provided the two homolog alignment strategies offered by Diamond (Blastp) or HMMER (Hmmscan), as well as a data cleansing function for a subset or union set of the hits. The pipeline was tested using 14 metagenomic samples from various water environments, including activated sludge, deep-sea sediments, estuary water, and reservoir water. The QSAP pipeline is freely available for academic use in the code repository at: https://github.com/chunxiao-dcx/QSAP. The establishment of this database and pipeline, provides a useful tool for QS-related sequence annotation in a wide range of projects, and will increase our understanding of QS communication in aquatic environments.
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Affiliation(s)
- Chunxiao Dai
- Key Laboratory of Industrial Ecology and Environmental Engineering (Ministry of Education) and Dalian POCT Laboratory, School of Environmental Science and Technology, Dalian University of Technology, Dalian 116024, China
| | - Yuanyuan Qu
- Key Laboratory of Industrial Ecology and Environmental Engineering (Ministry of Education) and Dalian POCT Laboratory, School of Environmental Science and Technology, Dalian University of Technology, Dalian 116024, China.
| | - Weize Wu
- Key Laboratory of Industrial Ecology and Environmental Engineering (Ministry of Education) and Dalian POCT Laboratory, School of Environmental Science and Technology, Dalian University of Technology, Dalian 116024, China
| | - Shuzhen Li
- Aquatic EcoHealth Group, Fujian Key Laboratory of Watershed Ecology, Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China
| | - Zhuo Chen
- Key Laboratory of Industrial Ecology and Environmental Engineering (Ministry of Education) and Dalian POCT Laboratory, School of Environmental Science and Technology, Dalian University of Technology, Dalian 116024, China
| | - Shengyang Lian
- Key Laboratory of Industrial Ecology and Environmental Engineering (Ministry of Education) and Dalian POCT Laboratory, School of Environmental Science and Technology, Dalian University of Technology, Dalian 116024, China
| | - Jiawei Jing
- Key Laboratory of Industrial Ecology and Environmental Engineering (Ministry of Education) and Dalian POCT Laboratory, School of Environmental Science and Technology, Dalian University of Technology, Dalian 116024, China
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13
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Microbiome engineering for bioremediation of emerging pollutants. Bioprocess Biosyst Eng 2023; 46:323-339. [PMID: 36029349 DOI: 10.1007/s00449-022-02777-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2022] [Accepted: 08/12/2022] [Indexed: 11/02/2022]
Abstract
Axenic microbial applications in the open environment are unrealistic and may not be always practically viable. Therefore, it is important to use mixed microbial cultures and their interactions with the microbiome in the targeted ecosystem to perform robust functions towards their sustainability in harsh environmental conditions. Emerging pollutants like phthalates and hydrocarbons that are toxic to several aquatic and terrestrial life forms in the water bodies and lands are an alarming situation. The present review explores the possibility of devising an inclusive eco-friendly strategy like microbiome engineering which proves to be a unique and crucial technology involving the power of microbial communication through quorum sensing. This review discusses the interspecies and intra-species communications between different microbial groups with their respective environments. Moreover, this review also envisages the efforts for designing the next level of microbiome-host engineering concept (MHEC). The focus of the review also extended toward using omics and metabolic network analysis-based tools for effective microbiome engineering. These approaches might be quite helpful in the future to understand such microbial interactions but it will be challenging to implement in the real environment to get the desired functions. Finally, the review also discusses multiple approaches for the bioremediation of toxic chemicals from the soil environment.
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RdmA Is a Key Regulator in Autoinduction of DSF Quorum Quenching in Pseudomonas nitroreducens HS-18. mBio 2023; 14:e0301022. [PMID: 36537811 PMCID: PMC9973270 DOI: 10.1128/mbio.03010-22] [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] [Indexed: 12/24/2022] Open
Abstract
Diffusible signal factor (DSF) represents a family of widely conserved quorum-sensing (QS) signals which regulate virulence factor production and pathogenicity in numerous Gram-negative bacterial pathogens. We recently reported the identification of a highly potent DSF-quenching bacterial isolate, Pseudomonas nitroreducens HS-18, which contains an operon with four DSF-inducible genes, digABCD, or digA-D, that are responsible for degradation of DSF signals. However, the regulatory mechanisms that govern the digA-D response to DSF induction have not yet been characterized. In this study, we identified a novel transcriptional regulator we designated RdmA (regulator of DSF metabolism) which negatively regulates the expression of digA-D and represses DSF degradation. In addition, we found that a gene cluster located adjacent to rdmA was also negatively regulated by RdmA and played a key role in DSF degradation; this cluster was hence named dmg (DSF metabolism genes). An electrophoretic mobility shift assay and genetic analysis showed that RdmA represses the transcriptional expression of the dmg genes in a direct manner. Further studies demonstrated that DSF acts as an antagonist and binds to RdmA, which abrogates RdmA binding to the target promoter and its suppression on transcriptional expression of the dmg genes. Taken together, the results from this study have unveiled a central regulator and a gene cluster associated with the autoinduction of DSF degradation in P. nitroreducens HS-18, and this will aid in the understanding of the genetic basis and regulatory mechanisms that govern the quorum-quenching activity of this potent biocontrol agent. IMPORTANCE DSF family quorum-sensing (QS) signals play important roles in regulation of bacterial physiology and virulence in a wide range of plant and human bacterial pathogens. Quorum quenching (QQ), which acts by either degrading QS signals or blocking QS communication, has proven to be a potent disease control strategy, but QQ mechanisms that target DSF family signals and associated regulatory mechanisms remain largely unknown. Recently, we identified four autoinduced DSF degradation genes (digABCD) in P. nitroreducens HS-18. By using a combination of transcriptome and genetic analysis, we identified a central regulator that plays a key role in autoinduction of dig expression, as well as a new gene cluster (dmgABCDEFGH) involved in DSF degradation. The significance of our study is in unveiling the autoinduction mechanism that governs DSF signal quorum quenching for the first time, to our knowledge, and in identification of new genes and enzymes responsible for DSF degradation. The findings from this study shed new light on our understanding of the DSF metabolism pathway and the regulatory mechanisms that modulate DSF quorum quenching and will provide useful clues for design and development of a new generation of highly potent QQ biocontrol agents against DSF-mediated bacterial infections.
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15
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Markus V, Paul AA, Teralı K, Özer N, Marks RS, Golberg K, Kushmaro A. Conversations in the Gut: The Role of Quorum Sensing in Normobiosis. Int J Mol Sci 2023; 24:ijms24043722. [PMID: 36835135 PMCID: PMC9963693 DOI: 10.3390/ijms24043722] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2022] [Revised: 02/03/2023] [Accepted: 02/11/2023] [Indexed: 02/15/2023] Open
Abstract
An imbalance in gut microbiota, termed dysbiosis, has been shown to affect host health. Several factors, including dietary changes, have been reported to cause dysbiosis with its associated pathologies that include inflammatory bowel disease, cancer, obesity, depression, and autism. We recently demonstrated the inhibitory effects of artificial sweeteners on bacterial quorum sensing (QS) and proposed that QS inhibition may be one mechanism behind such dysbiosis. QS is a complex network of cell-cell communication that is mediated by small diffusible molecules known as autoinducers (AIs). Using AIs, bacteria interact with one another and coordinate their gene expression based on their population density for the benefit of the whole community or one group over another. Bacteria that cannot synthesize their own AIs secretly "listen" to the signals produced by other bacteria, a phenomenon known as "eavesdropping". AIs impact gut microbiota equilibrium by mediating intra- and interspecies interactions as well as interkingdom communication. In this review, we discuss the role of QS in normobiosis (the normal balance of bacteria in the gut) and how interference in QS causes gut microbial imbalance. First, we present a review of QS discovery and then highlight the various QS signaling molecules used by bacteria in the gut. We also explore strategies that promote gut bacterial activity via QS activation and provide prospects for the future.
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Affiliation(s)
- Victor Markus
- Department of Medical Biochemistry, Faculty of Medicine, Near East University, Nicosia 99138, Cyprus
| | - Abraham Abbey Paul
- Avram and Stella Goldstein-Goren Department of Biotechnology Engineering, Ben-Gurion University of the Negev, Be’er Sheva 84105, Israel
| | - Kerem Teralı
- Department of Medical Biochemistry, Faculty of Medicine, Cyprus International University, Nicosia 99258, Cyprus
| | - Nazmi Özer
- Department of Biochemistry, Faculty of Pharmacy, Girne American University, Kyrenia 99428, Cyprus
| | - Robert S. Marks
- Avram and Stella Goldstein-Goren Department of Biotechnology Engineering, Ben-Gurion University of the Negev, Be’er Sheva 84105, Israel
- The Ilse Katz Center for Nanoscale Science and Technology, Ben-Gurion University of the Negev, Be’er Sheva 84105, Israel
| | - Karina Golberg
- Avram and Stella Goldstein-Goren Department of Biotechnology Engineering, Ben-Gurion University of the Negev, Be’er Sheva 84105, Israel
- Correspondence: (K.G.); (A.K.); Tel.: +972-74-7795293 (K.G.); +972-747795291 (A.K.)
| | - Ariel Kushmaro
- Avram and Stella Goldstein-Goren Department of Biotechnology Engineering, Ben-Gurion University of the Negev, Be’er Sheva 84105, Israel
- The Ilse Katz Center for Nanoscale Science and Technology, Ben-Gurion University of the Negev, Be’er Sheva 84105, Israel
- School of Sustainability and Climate Change, Ben-Gurion University of the Negev, Be’er Sheva 84105, Israel
- Correspondence: (K.G.); (A.K.); Tel.: +972-74-7795293 (K.G.); +972-747795291 (A.K.)
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16
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Zhuang X, Liu Y, Fang N, Bai Z, Gao J. Quorum sensing improves the plant growth-promoting ability of Stenotrophomonas rhizophila under saline-alkaline stress by enhancing its environmental adaptability. Front Microbiol 2023; 14:1155081. [PMID: 37113227 PMCID: PMC10126360 DOI: 10.3389/fmicb.2023.1155081] [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: 01/31/2023] [Accepted: 03/28/2023] [Indexed: 04/29/2023] Open
Abstract
Quorum sensing (QS) system has an essential function in plant growth-promoting rhizobacteria (PGPR) response to environmental stress and PGPR induction of plant tolerance to saline-alkaline stress. Nevertheless, there is a lack of understanding about how QS influences the growth-promoting effects of PGPR on plants. Stenotrophomonas rhizophila DSM14405T is a PGPR with a QS system, which can secrete diffusible signal factor (DSF), one of the QS signal molecules. In this study, we used the S. rhizophila wild type (WT) and an incompetent DSF production rpfF-knockout mutant strain to explore whether DSF-QS could affect the growth-promoting ability of PGPR in Brassica napus L. By measuring the seed germination rate, plant fresh weight, biomass, the total antioxidant capacity (T-AOC) level, and the content of chlorophyll in leaves, we found that DSF was unable to enhance the growth-promoting capacity of ΔrpfF and did not directly assist the plants in tolerating saline-alkaline stress. However, DSF aided S. rhizophila ΔrpfF in resisting stress during its effective period, and QS represents a continuous and precise regulatory mechanism. Altogether, our results show that DSF is helpful to improve the environmental adaptability and survival rate of S. rhizophila, thus indirectly improving the germination rate of seeds and helping plants grow under saline-alkaline stress. In this study, the mechanism of QS enhancing the environmental adaptability of PGPR was studied, which provided a theoretical basis for improving the application of PGPR to help plants better cope with saline-alkaline stress.
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Affiliation(s)
- Xuliang Zhuang
- CAS Key Laboratory of Environmental Biotechnology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, China
- College of Resources and Environment, University of Chinese Academy of Sciences, Beijing, China
- State Key Laboratory of Tibetan Plateau Earth System, Environment and Resources (TPESER), Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing, China
| | - Ying Liu
- CAS Key Laboratory of Environmental Biotechnology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, China
- Institute of Advanced Agricultural Sciences, Peking University, Weifang, China
| | - Na Fang
- CAS Key Laboratory of Environmental Biotechnology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, China
- Institute of International Rivers and Eco-security, Yunnan University, Kunming, China
| | - Zhihui Bai
- CAS Key Laboratory of Environmental Biotechnology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, China
- College of Resources and Environment, University of Chinese Academy of Sciences, Beijing, China
- Xiong’an Institute of Innovation, Xiong’an New Area, China
| | - Jie Gao
- CAS Key Laboratory of Environmental Biotechnology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, China
- College of Resources and Environment, University of Chinese Academy of Sciences, Beijing, China
- *Correspondence: Jie Gao,
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17
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Rather MA, Chowdhury R, Pavinski Bitar PD, Altier C. Recombinant production of a diffusible signal factor inhibits Salmonella invasion and animal carriage. Gut Microbes 2023; 15:2208498. [PMID: 37158497 PMCID: PMC10171134 DOI: 10.1080/19490976.2023.2208498] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/28/2023] [Accepted: 04/21/2023] [Indexed: 05/10/2023] Open
Abstract
The complex chemical environment of the intestine is defined largely by the metabolic products of the resident microbiota. Enteric pathogens, elegantly evolved to thrive in the gut, use these chemical products as signals to recognize specific niches and to promote their survival and virulence. Our previous work has shown that a specific class of quorum-sensing molecules found within the gut, termed diffusible signal factors (DSF), signals the repression of Salmonella tissue invasion, thus defining a means by which this pathogen recognizes its location and modulates virulence to optimize its survival. Here, we determined whether the recombinant production of a DSF could reduce Salmonella virulence in vitro and in vivo. We found that the most potent repressor of Salmonella invasion, cis-2-hexadecenoic acid (c2-HDA), could be recombinantly produced in E. coli by the addition of a single exogenous gene encoding a fatty acid enoyl-CoA dehydratase/thioesterase and that co-culture of the recombinant strain with Salmonella potently inhibited tissue invasion by repressing Salmonella genes required for this essential virulence function. Using the well characterized E. coli Nissle 1917 strain and a chicken infection model, we found that the recombinant DSF-producing strain could be stably maintained in the large intestine. Further, challenge studies demonstrated that this recombinant organism could significantly reduce Salmonella colonization of the cecum, the site of carriage in this animal species. These findings thus describe a plausible means by which Salmonella virulence may be affected in animals by in situ chemical manipulation of functions essential for colonization and virulence.
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Affiliation(s)
- Mudasir Ali Rather
- Department of Population Medicine and Diagnostic Sciences, Cornell University, Ithaca, NY, USA
| | - Rimi Chowdhury
- Department of Population Medicine and Diagnostic Sciences, Cornell University, Ithaca, NY, USA
| | | | - Craig Altier
- Department of Population Medicine and Diagnostic Sciences, Cornell University, Ithaca, NY, USA
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18
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Bozsó Z, Krüzselyi D, Szatmári Á, Csilléry G, Szarka J, Ott PG. Two Non-Necrotic Disease Resistance Types Distinctly Affect the Expression of Key Pathogenic Determinants of Xanthomonas euvesicatoria in Pepper. PLANTS (BASEL, SWITZERLAND) 2022; 12:89. [PMID: 36616218 PMCID: PMC9824575 DOI: 10.3390/plants12010089] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/03/2022] [Revised: 12/19/2022] [Accepted: 12/21/2022] [Indexed: 06/17/2023]
Abstract
Pepper (Capsicum annuum L.) carrying the gds (corresponding to bs5) gene can prevent the development of bacterial leaf spot disease without HR. However, little is known regarding the development of the resistance mechanism encoded by gds, especially its influence on the bacterium. Here, the effect of gds was compared with pattern-triggered immunity (PTI), another form of asymptomatic resistance, to reveal the interactions and differences between these two defense mechanisms. The level of resistance was examined by its effect on the bacterial growth and in planta expression of the stress and pathogenicity genes of Xanthomonas euvesicatoria. PTI, which was activated with a Pseudomonas syringae hrcC mutant pretreatment, inhibited the growth of Xanthomonas euvesicatoria to a greater extent than gds, and the effect was additive when PTI was activated in gds plants. The stronger influence of PTI was further supported by the expression pattern of the dpsA bacterial stress gene, which reached its highest expression level in PTI-induced plants. PTI inhibited the hrp/hrc expression, but unexpectedly, in gds plant leaves, the hrp/hrc genes were generally expressed at a higher level than in the susceptible one. These results imply that different mechanisms underlie the gds and PTI to perform the symptomless defense reaction.
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Affiliation(s)
- Zoltán Bozsó
- Plant Protection Institute, ELKH Centre for Agricultural Research, Herman Ottó Str. 15, H-1022 Budapest, Hungary
| | - Dániel Krüzselyi
- Plant Protection Institute, ELKH Centre for Agricultural Research, Herman Ottó Str. 15, H-1022 Budapest, Hungary
| | - Ágnes Szatmári
- Institute of Organic Chemistry, ELKH Research Centre for Natural Sciences, Magyar Tudósok Krt 2, H-1117 Budapest, Hungary
| | | | | | - Péter G. Ott
- Plant Protection Institute, ELKH Centre for Agricultural Research, Herman Ottó Str. 15, H-1022 Budapest, Hungary
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The Wsp chemosensory system modulates c-di-GMP-dependent biofilm formation by integrating DSF quorum sensing through the WspR-RpfG complex in Lysobacter. NPJ Biofilms Microbiomes 2022; 8:97. [PMID: 36526637 PMCID: PMC9758175 DOI: 10.1038/s41522-022-00365-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2022] [Accepted: 12/06/2022] [Indexed: 12/23/2022] Open
Abstract
The ubiquitous Wsp (wrinkly spreader phenotype) chemosensory system and DSF (diffusible signal factor) quorum sensing are two important chemically associated signaling systems that mediate bacterial communications between the host and environment. Although these two systems individually control biofilm formation in pathogenic bacteria via the ubiquitous second messenger c-di-GMP, their crosstalk mechanisms remain elusive. Here we present a scenario from the plant-beneficial and antifungal bacterium Lysobacter enzymogenes OH11, where biofilm formation favors the colonization of this bacterium in fungal hyphae. We found that the Wsp system regulated biofilm formation via WspR-mediated c-di-GMP signaling, whereas DSF system did not depend on the enzymatic activity of RpfG to regulate biofilm formation. We further found that WspR, a diguanylate cyclase (DGC) responsible for c-di-GMP synthesis, could directly bind to one of the DSF signaling components, RpfG, an active phosphodiesterase (PDE) responsible for c-di-GMP degradation. Thus, the WspR-RpfG complex represents a previously undiscovered molecular linker connecting the Wsp and DSF systems. Mechanistically, RpfG could function as an adaptor protein to bind and inhibit the DGC activity of unphosphorylated WspR independent of its PDE activity. Phosphorylation of WspR impaired its binding affinity to RpfG and also blocked the ability of RpfG to act as an adaptor protein, which enabled the Wsp system to regulate biofilm formation in a c-di-GMP-dependent manner by dynamically integrating the DSF system. Our findings demonstrated a previously uncharacterized mechanism of crosstalk between Wsp and DSF systems in plant-beneficial and antifungal bacteria.
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20
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Yu H, Chen WJ, Bhatt K, Zhou Z, Zhu X, Liu S, He J, Zhang LH, Chen S, Wang H, Liao L. A novel bacterial strain Burkholderia sp. F25 capable of degrading diffusible signal factor signal shows strong biocontrol potential. FRONTIERS IN PLANT SCIENCE 2022; 13:1071693. [PMID: 36507382 PMCID: PMC9730286 DOI: 10.3389/fpls.2022.1071693] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/16/2022] [Accepted: 11/03/2022] [Indexed: 06/12/2023]
Abstract
Vast quantities of synthetic pesticides have been widely applied in various fields to kill plant pathogens, resulting in increased pathogen resistance and decreased effectiveness of such chemicals. In addition, the increased presence of pesticide residues affects living organisms and the environment largely on a global scale. To mitigate the impact of crop diseases more sustainably on plant health and productivity, there is a need for more safe and more eco-friendly strategies as compared to chemical prevention. Quorum sensing (QS) is an intercellular communication mechanism in a bacterial population, through which bacteria adjust their population density and behavior upon sensing the levels of signaling molecules in the environment. As an alternative, quorum quenching (QQ) is a promising new strategy for disease control, which interferes with QS by blocking intercellular communication between pathogenic bacteria to suppress the expression of disease-causing genes. Black rot caused by Xanthomonas campestris pv. campestris (Xcc) is associated with the diffusible signal factor (DSF). As detailed in this study, a new QQ strain F25, identified as Burkholderia sp., displayed a superior ability to completely degrade 2 mM of DSF within 72 h. The main intermediate product in the biodegradation of DSF was identified as n-decanoic acid, based on gas chromatography-mass spectrometry (GC-MS). A metabolic pathway for DSF by strain F25 is proposed, based on the chemical structure of DSF and its intermediates, demonstrating the possible degradation of DSF via oxidation-reduction. The application of strain F25 and its crude enzyme as biocontrol agents significantly attenuated black rot caused by Xcc, and inhibited tissue maceration in the host plant Raphanus sativus L., without affecting the host plant. This suggests that agents produced from strain F25 and its crude enzyme have promising applications in controlling infectious diseases caused by DSF-dependent bacterial pathogens. These findings are expected to provide a new therapeutic strategy for controlling QS-mediated plant diseases.
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Affiliation(s)
- Hongxiao Yu
- Department of Plant Pathology, College of Plant Protection, South China Agricultural University, Guangzhou, China
| | - Wen-Juan Chen
- Department of Plant Pathology, College of Plant Protection, South China Agricultural University, Guangzhou, China
- Guangdong Province Key Laboratory of Microbial Signals and Disease Control, Integrative Microbiology Research Centre, South China Agricultural University, Guangzhou, China
| | - Kalpana Bhatt
- Department of Botany and Microbiology, Gurukula Kangri University, Haridwar, Uttarakhand, India
| | - Zhe Zhou
- Department of Plant Pathology, College of Plant Protection, South China Agricultural University, Guangzhou, China
- Guangdong Province Key Laboratory of Microbial Signals and Disease Control, Integrative Microbiology Research Centre, South China Agricultural University, Guangzhou, China
| | - Xixian Zhu
- Department of Plant Pathology, College of Plant Protection, South China Agricultural University, Guangzhou, China
- Guangdong Province Key Laboratory of Microbial Signals and Disease Control, Integrative Microbiology Research Centre, South China Agricultural University, Guangzhou, China
| | - Siqi Liu
- Department of Plant Pathology, College of Plant Protection, South China Agricultural University, Guangzhou, China
| | - Jiehua He
- Department of Plant Pathology, College of Plant Protection, South China Agricultural University, Guangzhou, China
| | - Lian-Hui Zhang
- Department of Plant Pathology, College of Plant Protection, South China Agricultural University, Guangzhou, China
- Guangdong Province Key Laboratory of Microbial Signals and Disease Control, Integrative Microbiology Research Centre, South China Agricultural University, Guangzhou, China
| | - Shaohua Chen
- Department of Plant Pathology, College of Plant Protection, South China Agricultural University, Guangzhou, China
- Guangdong Province Key Laboratory of Microbial Signals and Disease Control, Integrative Microbiology Research Centre, South China Agricultural University, Guangzhou, China
| | - Huishan Wang
- Department of Plant Pathology, College of Plant Protection, South China Agricultural University, Guangzhou, China
- Guangdong Province Key Laboratory of Microbial Signals and Disease Control, Integrative Microbiology Research Centre, South China Agricultural University, Guangzhou, China
| | - Lisheng Liao
- Department of Plant Pathology, College of Plant Protection, South China Agricultural University, Guangzhou, China
- Guangdong Province Key Laboratory of Microbial Signals and Disease Control, Integrative Microbiology Research Centre, South China Agricultural University, Guangzhou, China
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21
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Schulze AS, Kleinau G, Krakowsky R, Rochmann D, Das R, Worth CL, Krumbholz P, Scheerer P, Stäubert C. Evolutionary analyses reveal immune cell receptor GPR84 as a conserved receptor for bacteria-derived molecules. iScience 2022; 25:105087. [PMID: 36164652 PMCID: PMC9508565 DOI: 10.1016/j.isci.2022.105087] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2022] [Revised: 07/26/2022] [Accepted: 08/31/2022] [Indexed: 10/31/2022] Open
Abstract
The G protein-coupled receptor 84 (GPR84) is found in immune cells and its expression is increased under inflammatory conditions. Activation of GPR84 by medium-chain fatty acids results in pro-inflammatory responses. Here, we screened available vertebrate genome data and found that GPR84 is present in vertebrates for more than 500 million years but absent in birds and a pseudogene in bats. Cloning and functional characterization of several mammalian GPR84 orthologs in combination with evolutionary and model-based structural analyses revealed evidence for positive selection of bear GPR84 orthologs. Naturally occurring human GPR84 variants are most frequent in Asian populations causing a loss of function. Further, we identified cis- and trans-2-decenoic acid, both known to mediate bacterial communication, as evolutionary highly conserved ligands. Our integrated set of approaches contributes to a comprehensive understanding of GPR84 in terms of evolutionary and structural aspects, highlighting GPR84 as a conserved immune cell receptor for bacteria-derived molecules.
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Affiliation(s)
- Amadeus Samuel Schulze
- Rudolf Schönheimer Institute of Biochemistry, Faculty of Medicine, Leipzig University, Johannisallee 30, 04103 Leipzig, Germany
| | - Gunnar Kleinau
- Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Institute of Medical Physics and Biophysics, Group Protein X-ray Crystallography and Signal Transduction, Charitéplatz 1, 10117 Berlin, Germany
| | - Rosanna Krakowsky
- Rudolf Schönheimer Institute of Biochemistry, Faculty of Medicine, Leipzig University, Johannisallee 30, 04103 Leipzig, Germany
| | - David Rochmann
- Rudolf Schönheimer Institute of Biochemistry, Faculty of Medicine, Leipzig University, Johannisallee 30, 04103 Leipzig, Germany
| | - Ranajit Das
- Yenepoya Research Centre, Yenepoya University, Mangalore, Karnataka, India
| | - Catherine L Worth
- Independent Data Lab UG, Frauenmantelanger 31, 80937 Munich, Germany
| | - Petra Krumbholz
- Rudolf Schönheimer Institute of Biochemistry, Faculty of Medicine, Leipzig University, Johannisallee 30, 04103 Leipzig, Germany
| | - Patrick Scheerer
- Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Institute of Medical Physics and Biophysics, Group Protein X-ray Crystallography and Signal Transduction, Charitéplatz 1, 10117 Berlin, Germany
| | - Claudia Stäubert
- Rudolf Schönheimer Institute of Biochemistry, Faculty of Medicine, Leipzig University, Johannisallee 30, 04103 Leipzig, Germany
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Ye S, Yan R, Li X, Lin Y, Yang Z, Ma Y, Ding Z. Biocontrol potential of Pseudomonas rhodesiae GC-7 against the root-knot nematode Meloidogyne graminicola through both antagonistic effects and induced plant resistance. Front Microbiol 2022; 13:1025727. [PMID: 36386722 PMCID: PMC9651087 DOI: 10.3389/fmicb.2022.1025727] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2022] [Accepted: 09/23/2022] [Indexed: 11/22/2022] Open
Abstract
Plant-parasitic nematodes (PPNs) cause serious damage to agricultural production worldwide. Currently, because of a lack of effective and environmental-friendly chemical nematicides, the use of microbial nematicides has been proposed as an eco-friendly management strategy to control PPNs. A nematicidal bacterium GC-7 was originally isolated from the rice rhizosphere, and was identified as Pseudomonas rhodesiae. Treatment with the fermentation supernatant of GC-7 in vitro showed a highly lethal effect on second-stage juveniles of Meloidogyne graminicola, with the mortality rate increasing to 95.82% at 24 h and egg hatching significantly inhibited, with a hatch inhibition rate of 60.65% at 96 h. The bacterium significantly reduced the level of damage caused by M. graminicola infestations to rice (Oryza sativa) in greenhouse and field experiments. Under greenhouse conditions, the GC-7 culture efficiently reduced the gall index and nematode population in rice roots and soils, as well as inhibited nematode development compared to the control. Under field conditions, application of the GC-7 consistently showed a high biocontrol efficacy against M. graminicola (with a control efficiency of 58.85%) and promoted plant growth. In addition, the inoculation of GC-7 in M. graminicola-infested rice plant fields significantly suppressed final nematode populations in soil under natural conditions. Furthermore, activities of plant defense-related enzymes, peroxidase, polyphenol oxidase, and phenylalanine ammonia-lyase were remarkably increased in plant roots treated with GC-7 compared with roots that were challenge to M. graminicola. Moreover, quantitative real-time PCR analysis showed that GC-7 significantly enhanced the expression of defense genes (PR1a, WRKY45, JaMYB, AOS2, ERF1, and ACS1) related to salicylic acid, jasmonic acid, and ethylene signaling pathways in rice roots after inoculation with GC-7 at different levels. The results indicated that GC-7 could be an effective biological component in the integrated management of M. graminicola infecting rice.
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Affiliation(s)
- Shan Ye
- College of Plant Protection, Hunan Agricultural University, Changsha, Hunan, China
- Hunan Provincial Engineering & Technology Research Center for Biopesticide and Formulation Processing, Changsha, Hunan, China
| | - Rui Yan
- College of Plant Protection, Hunan Agricultural University, Changsha, Hunan, China
| | - Xinwen Li
- Agriculture and Rural Department of Hunan Province, Plant Protection and Inspection Station, Changsha, Hunan, China
| | - Yufeng Lin
- Agriculture and Rural Department of Hunan Province, Plant Protection and Inspection Station, Changsha, Hunan, China
| | - Zhuhong Yang
- College of Plant Protection, Hunan Agricultural University, Changsha, Hunan, China
- Hunan Provincial Engineering & Technology Research Center for Biopesticide and Formulation Processing, Changsha, Hunan, China
| | - Yihang Ma
- Department of Chemical Metrology and Reference Materials, Hunan Institute of Metrology and Test, Changsha, Hunan, China
| | - Zhong Ding
- College of Plant Protection, Hunan Agricultural University, Changsha, Hunan, China
- Hunan Provincial Engineering & Technology Research Center for Biopesticide and Formulation Processing, Changsha, Hunan, China
- *Correspondence: Zhong Ding,
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Wang Y, Bian Z, Wang Y. Biofilm formation and inhibition mediated by bacterial quorum sensing. Appl Microbiol Biotechnol 2022; 106:6365-6381. [DOI: 10.1007/s00253-022-12150-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2022] [Revised: 08/23/2022] [Accepted: 08/24/2022] [Indexed: 11/25/2022]
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Abdul Hamid NW, Nadarajah K. Microbe Related Chemical Signalling and Its Application in Agriculture. Int J Mol Sci 2022; 23:ijms23168998. [PMID: 36012261 PMCID: PMC9409198 DOI: 10.3390/ijms23168998] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2022] [Revised: 07/31/2022] [Accepted: 08/04/2022] [Indexed: 11/17/2022] Open
Abstract
The agriculture sector has been put under tremendous strain by the world’s growing population. The use of fertilizers and pesticides in conventional farming has had a negative impact on the environment and human health. Sustainable agriculture attempts to maintain productivity, while protecting the environment and feeding the global population. The importance of soil-dwelling microbial populations in overcoming these issues cannot be overstated. Various processes such as rhizospheric competence, antibiosis, release of enzymes, and induction of systemic resistance in host plants are all used by microbes to influence plant-microbe interactions. These processes are largely founded on chemical signalling. Producing, releasing, detecting, and responding to chemicals are all part of chemical signalling. Different microbes released distinct sorts of chemical signal molecules which interacts with the environment and hosts. Microbial chemicals affect symbiosis, virulence, competence, conjugation, antibiotic production, motility, sporulation, and biofilm growth, to name a few. We present an in-depth overview of chemical signalling between bacteria-bacteria, bacteria-fungi, and plant-microbe and the diverse roles played by these compounds in plant microbe interactions. These compounds’ current and potential uses and significance in agriculture have been highlighted.
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Li Y, Feng T, Wang Y. The role of bacterial signaling networks in antibiotics response and resistance regulation. MARINE LIFE SCIENCE & TECHNOLOGY 2022; 4:163-178. [PMID: 37073223 PMCID: PMC10077285 DOI: 10.1007/s42995-022-00126-1] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/25/2021] [Accepted: 01/07/2022] [Indexed: 05/03/2023]
Abstract
Excessive use of antibiotics poses a threat to public health and the environment. In ecosystems, such as the marine environment, antibiotic contamination has led to an increase in bacterial resistance. Therefore, the study of bacterial response to antibiotics and the regulation of resistance formation have become an important research field. Traditionally, the processes related to antibiotic responses and resistance regulation have mainly included the activation of efflux pumps, mutation of antibiotic targets, production of biofilms, and production of inactivated or passivation enzymes. In recent years, studies have shown that bacterial signaling networks can affect antibiotic responses and resistance regulation. Signaling systems mostly alter resistance by regulating biofilms, efflux pumps, and mobile genetic elements. Here we provide an overview of how bacterial intraspecific and interspecific signaling networks affect the response to environmental antibiotics. In doing so, this review provides theoretical support for inhibiting bacterial antibiotic resistance and alleviating health and ecological problems caused by antibiotic contamination.
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Affiliation(s)
- Yuying Li
- College of Marine Life Sciences, Ocean University of China, Qingdao, 266003 China
- Institute of Evolution and Marine Biodiversity, Ocean University of China, Qingdao, 266003 China
| | - Tao Feng
- College of Marine Life Sciences, Ocean University of China, Qingdao, 266003 China
- Institute of Evolution and Marine Biodiversity, Ocean University of China, Qingdao, 266003 China
| | - Yan Wang
- College of Marine Life Sciences, Ocean University of China, Qingdao, 266003 China
- Institute of Evolution and Marine Biodiversity, Ocean University of China, Qingdao, 266003 China
- Laboratory for Marine Ecology and Environmental Science, National Laboratory for Marine Science and Technology (Qingdao), Qingdao, 266071 China
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BDSF Is a Degradation-Prone Quorum-Sensing Signal Detected by the Histidine Kinase RpfC of Xanthomonas campestris pv. campestris. Appl Environ Microbiol 2022; 88:e0003122. [PMID: 35369702 DOI: 10.1128/aem.00031-22] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Diffusible signal factors (DSFs) are medium-chain fatty acids that induce bacterial quorum sensing. Among these compounds, BDSF is a structural analog of DSF that is commonly detected in bacterial species, and it is the predominant in planta quorum-sensing signal in Xanthomonas campestris. How BDSF is sensed in Xanthomonas spp. and the functional diversity between BDSF and DSF remain unclear. In this study, we generated genetic and biochemical evidence that BDSF is a low-active regulator of X. campestris pv. campestris quorum sensing, whereas trans-BDSF does not seem to be a signaling compound. BDSF is detected by the sensor histidine kinase RpfC. Although BDSF has relatively low physiological activities, it binds to the RpfC sensor with a high affinity and activates RpfC autophosphorylation to a level that is similar to that induced by DSF in vitro. The inconsistency in the physiological and biochemical activities of BDSF is not due to RpfC-RpfG phosphorylation or RpfG hydrolase. Neither BDSF nor DSF controls the phosphotransferase and phosphatase activities of RpfC or the ability of RpfG hydrolase activity to degrade the bacterial second messenger cyclic di-GMP. We demonstrated that BDSF is prone to degradation by RpfB, a critical fatty acyl coenzyme A ligase involved in the turnover of DSF-family signals. rpfB mutations lead to substantial increases in BDSF-induced quorum sensing. Although DSF and BDSF are similarly detected by RpfC, our data suggest that their differential degradation in cells is the major factor responsible for the diversity in their physiological effects. IMPORTANCE The diffusible signal factor (DSF) family consists of quorum-sensing signals employed by Gram-negative bacteria. These signals are a group of cis-2-unsaturated fatty acids, such as DSF, BDSF, IDSF, CDSF, and SDSF. However, the functional divergence of various DSF signals remains unclear. The present study demonstrates that though BDSF is a low active quorum-sensing signal, it binds histidine kinase RpfC with a higher affinity and activates RpfC autophosphorylation to the similar level as DSF. Rather than regulation of enzymatic activities of RpfC and its cognate response regulator RpfG encoding a c-di-GMP hydrolase, BDSF is prone to degradation in bacterial cells by RpfB, which effectively avoided the inhibition of bacterial growth by accumulating high concentrations of BDSF. Therefore, our study sheds new light on the functional differences of quorum-sensing signals and shows that bacteria balance quorum sensing and growth by fine-tuning concentrations of signaling chemicals.
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Keaney D, Lucey B, Quinn N, Finn K. The Effects of Freeze-Thaw and UVC Radiation on Microbial Survivability in a Selected Mars-like Environment. Microorganisms 2022; 10:microorganisms10030576. [PMID: 35336151 PMCID: PMC8956125 DOI: 10.3390/microorganisms10030576] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2022] [Revised: 02/23/2022] [Accepted: 03/04/2022] [Indexed: 02/06/2023] Open
Abstract
The purpose of this study was to determine survivability of Escherichia coli, Deinococcus radiodurans and Paraburkholderia fungorum under Mars-simulated conditions for freeze-thawing (−80 °C to +30 °C) and UV exposure alone and in combination. E. coli ATCC 25922, D. radiodurans and P. fungorum remained viable following 20 successive freeze-thaw cycles, exhibiting viabilities of 2.3%, 96% and 72.6%, respectively. E. coli ATCC 9079 was non-recoverable by cycle 9. When exposed to UV irradiation, cells withstood doses of 870 J/m2 (E. coli ATCC 25922), 200 J/m2 (E. coli ATCC 9079), 50,760 J/m2 (D. radiodurans) and 44,415 J/m2 (P. fungorum). Data suggests P. fungorum is highly UV-resistant. Combined freeze-thawing with UV irradiation showed freezing increased UV resistance in E. coli ATCC 25922, E. coli DSM 9079 and D. radiodurans by 6-fold, 30-fold and 1.2-fold, respectively. Conversely, freezing caused P. fungorum to exhibit a 1.75-fold increase in UV susceptibility. Strain-dependent experimentation demonstrated that freezing increases UV resistance and prolongs survival. These findings suggest that exposure to short wavelength UV rays (254 nm) and temperature cycles resembling the daily fluctuating conditions on Mars do not significantly affect survival of D. radiodurans, P. fungorum and E. coli ATCC 25922 following 20 days of exposure.
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Affiliation(s)
- Daniel Keaney
- Department of Biological Sciences, Munster Technological University, Bishopstown, T12 P928 Cork, Ireland; (D.K.); (B.L.)
| | - Brigid Lucey
- Department of Biological Sciences, Munster Technological University, Bishopstown, T12 P928 Cork, Ireland; (D.K.); (B.L.)
| | - Noreen Quinn
- Department of Mathematics, Munster Technological University, Bishopstown, T12 P928 Cork, Ireland;
| | - Karen Finn
- Department of Analytical, Biopharmaceutical and Medical Sciences, Galway-Mayo Institute of Technology, Old Dublin Road, H91 T8NW Galway, Ireland
- Correspondence:
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Dukare A, Mhatre P, Maheshwari HS, Bagul S, Manjunatha BS, Khade Y, Kamble U. Delineation of mechanistic approaches of rhizosphere microorganisms facilitated plant health and resilience under challenging conditions. 3 Biotech 2022; 12:57. [PMID: 35186654 PMCID: PMC8817020 DOI: 10.1007/s13205-022-03115-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2021] [Accepted: 01/12/2022] [Indexed: 12/27/2022] Open
Abstract
Sustainable agriculture demands the balanced use of inorganic, organic, and microbial biofertilizers for enhanced plant productivity and soil fertility. Plant growth-enhancing rhizospheric bacteria can be an excellent biotechnological tool to augment plant productivity in different agricultural setups. We present an overview of microbial mechanisms which directly or indirectly contribute to plant growth, health, and development under highly variable environmental conditions. The rhizosphere microbiomes promote plant growth, suppress pathogens and nematodes, prime plants immunity, and alleviate abiotic stress. The prospective of beneficial rhizobacteria to facilitate plant growth is of primary importance, particularly under abiotic and biotic stresses. Such microbe can promote plant health, tolerate stress, even remediate soil pollutants, and suppress phytopathogens. Providing extra facts and a superior understanding of microbial traits underlying plant growth promotion can stir the development of microbial-based innovative solutions for the betterment of agriculture. Furthermore, the application of novel scientific approaches for facilitating the design of crop-specific microbial biofertilizers is discussed. In this context, we have highlighted the exercise of "multi-omics" methods for assessing the microbiome's impact on plant growth, health, and overall fitness via analyzing biochemical, physiological, and molecular facets. Furthermore, the role of clustered regularly interspaced short palindromic repeats (CRISPR) based genome alteration and nanotechnology for improving the agronomic performance and rhizosphere microbiome is also briefed. In a nutshell, the paper summarizes the recent vital molecular processes that underlie the different beneficial plant-microbe interactions imperative for enhancing plant fitness and resilience under-challenged agriculture.
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Affiliation(s)
- Ajinath Dukare
- ICAR-Central Institute for Research on Cotton Technology (CIRCOT), Mumbai, Maharashtra India
| | - Priyank Mhatre
- ICAR-Central Potato Research Institute (Regional Station), Udhagamandalam, Tamil Nadu India
| | - Hemant S. Maheshwari
- ICAR-Indian Institute of Soybean Research (IISR), Indore, Madhya Pradesh India
- Present Address: Ecophysiology of Plants, Faculty of Science and Engineering, GELIFES-Groningen Institute for Evolutionary Life Sciences, The University of Groningen, Nijenborgh 7, 9747 AG Groningen, The Netherlands
| | - Samadhan Bagul
- ICAR-Directorate of Medicinal and Aromatic Plant Research, Anand, Gujarat India
| | - B. S. Manjunatha
- ICAR-National Institute of Natural Fibre Engineering and Technology, Kolkata, West Bengal India
| | - Yogesh Khade
- ICAR- Directorate of Onion and Garlic Research, Pune, Maharashtra India
| | - Umesh Kamble
- ICAR-Indian Institute of Wheat and Barley Research, Karnal, Haryana India
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29
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Macabuhay A, Arsova B, Walker R, Johnson A, Watt M, Roessner U. Modulators or facilitators? Roles of lipids in plant root-microbe interactions. TRENDS IN PLANT SCIENCE 2022; 27:180-190. [PMID: 34620547 DOI: 10.1016/j.tplants.2021.08.004] [Citation(s) in RCA: 25] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2020] [Revised: 07/28/2021] [Accepted: 08/24/2021] [Indexed: 05/15/2023]
Abstract
Lipids have diverse functions in regulating the plasma membrane's cellular processes and signaling mediation. Plasma membrane lipids are also involved in the plant's complex interactions with the surrounding microorganisms, with which plants are in various forms of symbiosis. The roles of lipids influence the whole microbial colonization process, thus shaping the rhizomicrobiome. As chemical signals, lipids facilitate the stages of rhizospheric interactions - from plant root to microbe, microbe to microbe, and microbe to plant root - and modulate the plant's defense responses upon perception or contact with either beneficial or phytopathogenic microorganisms. Although studies have come a long way, further investigation is needed to discover more lipid species and elucidate novel lipid functions and profiles under various stages of plant root-microbe interactions.
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Affiliation(s)
- Allene Macabuhay
- School of BioSciences, Faculty of Science, The University of Melbourne, Parkville, Victoria, 3010, Australia.
| | - Borjana Arsova
- Institute for Bio- & Geosciences, Plant Sciences (IBG-2), Forschungszentrum Jülich GmbH, Jülich, 52428, Germany
| | - Robert Walker
- School of BioSciences, Faculty of Science, The University of Melbourne, Parkville, Victoria, 3010, Australia
| | - Alexander Johnson
- School of BioSciences, Faculty of Science, The University of Melbourne, Parkville, Victoria, 3010, Australia
| | - Michelle Watt
- School of BioSciences, Faculty of Science, The University of Melbourne, Parkville, Victoria, 3010, Australia
| | - Ute Roessner
- School of BioSciences, Faculty of Science, The University of Melbourne, Parkville, Victoria, 3010, Australia
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30
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Yang K, Yu M, Zhu X, Xia Y, Li F, Li Y, Liu X, Wang J. Genetic Incorporation of Fluorescent Amino Acid into Fatty Acid Binding Protein for Fatty Acid Detection. J Mol Biol 2022; 434:167498. [DOI: 10.1016/j.jmb.2022.167498] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2021] [Revised: 02/06/2022] [Accepted: 02/09/2022] [Indexed: 01/13/2023]
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Fan Q, Wang H, Mao C, Li J, Zhang X, Grenier D, Yi L, Wang Y. Structure and Signal Regulation Mechanism of Interspecies and Interkingdom Quorum Sensing System Receptors. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2022; 70:429-445. [PMID: 34989570 DOI: 10.1021/acs.jafc.1c04751] [Citation(s) in RCA: 21] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Quorum sensing (QS) is a signaling mechanism for cell-to-cell communication between bacteria, fungi, and even eukaryotic hosts such as plant and animal cells. Bacteria in real life do not exist as isolated organisms but are found in complex, dynamic, and microecological environments. The study of interspecies QS and interkingdom QS is a valuable approach for exploring bacteria-bacteria interactions and bacteria-host interaction mechanisms and has received considerable attention from researchers. The correct combination of QS signals and receptors is key to initiating the QS process. Compared with intraspecies QS, the signal regulation mechanism of interspecies QS and interkingdom QS is often more complicated, and the distribution of receptors is relatively wide. The present review focuses on the latest progress with respect to the distribution, structure, and signal transduction of interspecies and interkingdom QS receptors and provides a guide for the investigation of new QS receptors in the future.
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Affiliation(s)
- Qingying Fan
- College of Animal Science and Technology, Henan University of Science and Technology, Luoyang 471000, China
- Key Laboratory of Molecular Pathogen and Immunology of Animal of Luoyang, Luoyang 471000, China
| | - Haikun Wang
- College of Animal Science and Technology, Henan University of Science and Technology, Luoyang 471000, China
- Key Laboratory of Molecular Pathogen and Immunology of Animal of Luoyang, Luoyang 471000, China
| | - Chenlong Mao
- College of Animal Science and Technology, Henan University of Science and Technology, Luoyang 471000, China
- Key Laboratory of Molecular Pathogen and Immunology of Animal of Luoyang, Luoyang 471000, China
| | - Jinpeng Li
- College of Animal Science and Technology, Henan University of Science and Technology, Luoyang 471000, China
- Key Laboratory of Molecular Pathogen and Immunology of Animal of Luoyang, Luoyang 471000, China
| | - Xiaoling Zhang
- College of Animal Science and Technology, Henan University of Science and Technology, Luoyang 471000, China
- Key Laboratory of Molecular Pathogen and Immunology of Animal of Luoyang, Luoyang 471000, China
| | - Daniel Grenier
- Groupe de Recherche en Écologie Buccale (GREB), Faculté de Médecine Dentaire, Université Laval, Quebec City, Quebec G1 V 0A6, Canada
| | - Li Yi
- College of Life Science, Luoyang Normal University, Luoyang 471023, China
| | - Yang Wang
- College of Animal Science and Technology, Henan University of Science and Technology, Luoyang 471000, China
- Key Laboratory of Molecular Pathogen and Immunology of Animal of Luoyang, Luoyang 471000, China
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The cis-2-dodecenoic acid (BDSF) quorum sensing system in Burkholderia cenocepacia. Appl Environ Microbiol 2022; 88:e0234221. [PMID: 34985987 DOI: 10.1128/aem.02342-21] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
It has been demonstrated that quorum sensing (QS) is widely employed by bacterial cells to coordinately regulate various group behaviors. Diffusible signal factor (DSF)-type signals have emerged as a growing family of conserved cell-cell communication signals. In addition to the DSF signal initially identified in Xanthomonas campestris pv. campestris, Burkholderia diffusible signal factor (BDSF, cis-2-dodecenoic acid) has been recognized as a conserved DSF-type signal with specific characteristics in both signal perception and transduction from DSF signals. Here, we review the history and current progress of the research of this type of signal, especially focusing on its biosynthesis, signaling pathways, and biological functions. We also discuss and explore the huge potential of targeting this kind of QS system as a new therapeutic strategy to control bacterial infections and diseases.
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Singh P, Verma RK, Chatterjee S. The diffusible signal factor synthase, RpfF, in Xanthomonas oryzae pv. oryzae is required for the maintenance of membrane integrity and virulence. MOLECULAR PLANT PATHOLOGY 2022; 23:118-132. [PMID: 34704368 PMCID: PMC8659556 DOI: 10.1111/mpp.13148] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/13/2021] [Revised: 09/03/2021] [Accepted: 09/24/2021] [Indexed: 05/12/2023]
Abstract
The Xanthomonas group of phytopathogens communicate with a fatty acid-like cell-cell signalling molecule, cis-11-2-methyl-dodecenoic acid, also known as diffusible signal factor (DSF). In the pathogen of rice, Xanthomonas oryzae pv. oryzae, DSF is involved in the regulation of several virulence-associated functions, including production and secretion of several cell wall hydrolysing type II secretion effectors. To understand the role of DSF in the secretion of type II effectors, we characterized DSF synthase-deficient (rpfF) and DSF-deficient, type II secretion (xpsE) double mutants. Mutant analysis by expression analysis, secretion assay, fatty acid analysis, and physiological studies indicated that rpfF mutants exhibit hypersecretion of several type II effectors due to a perturbed membrane and DSF is required for maintaining membrane integrity. The rpfF mutants exhibited significantly higher uptake of 1-N-phenylnapthylamine and ethidium bromide, and up-regulation of rpoE (σE ). Increasing the osmolarity of the medium could rescue the hypersecretion phenotype of the rpfF mutant. The rpfF mutant exhibited highly reduced virulence. We report for the first time that in X. oryzae pv. oryzae RpfF is involved in the maintenance of membrane integrity by playing a regulatory role in the fatty acid synthesis pathway.
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Affiliation(s)
- Prashantee Singh
- Laboratory of Plant Microbe InteractionsCentre for DNA Fingerprinting and DiagnosticsUppalIndia
- Graduate StudiesManipal Academy of Higher EducationMangaluruIndia
| | - Raj Kumar Verma
- Laboratory of Plant Microbe InteractionsCentre for DNA Fingerprinting and DiagnosticsUppalIndia
| | - Subhadeep Chatterjee
- Laboratory of Plant Microbe InteractionsCentre for DNA Fingerprinting and DiagnosticsUppalIndia
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Performance of halotolerant bacteria associated with Sahara-inhabiting halophytes Atriplex halimus L. and Lygeum spartum L. ameliorate tomato plant growth and tolerance to saline stress: from selective isolation to genomic analysis of potential determinants. World J Microbiol Biotechnol 2021; 38:16. [PMID: 34897563 DOI: 10.1007/s11274-021-03203-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2021] [Accepted: 12/05/2021] [Indexed: 11/25/2022]
Abstract
The use of halotolerant beneficial plant-growth-promoting (PGP) bacteria is considered as a promising eco-friendly approach to improve the salt tolerance of cash crops. One strategy to enhance the possibility of obtaining stress-alleviating bacteria is to screen salt impacted soils. In this study, amongst the 40 endophytic bacteria isolated from the roots of Sahara-inhabiting halophytes Atriplex halimus L. and Lygeum spartum L., 8 showed interesting NaCl tolerance in vitro. Their evaluation, through different tomato plant trials, permitted the isolate IS26 to be distinguished as the most effective seed inoculum for both plant growth promotion and mitigation of salt stress. On the basis of 16S rRNA gene sequence, the isolate was closely related to Stenotrophomonas rhizophila. It was then screened in vitro for multiple PGP traits and the strain-complete genome was sequenced and analysed to further decipher the genomic basis of the putative mechanisms underlying its osmoprotective and plant growth abilities. A remarkable number of genes putatively involved in mechanisms responsible for rhizosphere colonization, plant association, strong competition for nutrients, and the production of important plant growth regulator compounds, such as AIA and spermidine, were highlighted, as were substances protecting against stress, including different osmolytes like trehalose, glucosylglycerol, proline, and glycine betaine. By having genes related to complementary mechanisms of osmosensing, osmoregulation and osmoprotection, the strain confirmed its great capacity to adapt to highly saline environments. Moreover, the presence of various genes potentially related to multiple enzymatic antioxidant processes, able to reduce salt-induced overproduction of ROS, was also detected.
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35
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Controlled spatial organization of bacterial growth reveals key role of cell filamentation preceding Xylella fastidiosa biofilm formation. NPJ Biofilms Microbiomes 2021; 7:86. [PMID: 34876576 PMCID: PMC8651647 DOI: 10.1038/s41522-021-00258-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2021] [Accepted: 11/11/2021] [Indexed: 12/21/2022] Open
Abstract
The morphological plasticity of bacteria to form filamentous cells commonly represents an adaptive strategy induced by stresses. In contrast, for diverse human and plant pathogens, filamentous cells have been recently observed during biofilm formation, but their functions and triggering mechanisms remain unclear. To experimentally identify the underlying function and hypothesized cell communication triggers of such cell morphogenesis, spatially controlled cell patterning is pivotal. Here, we demonstrate highly selective cell adhesion of the biofilm-forming phytopathogen Xylella fastidiosa to gold-patterned SiO2 substrates with well-defined geometries and dimensions. The consequent control of both cell density and distances between cell clusters demonstrated that filamentous cell formation depends on cell cluster density, and their ability to interconnect neighboring cell clusters is distance-dependent. This process allows the creation of large interconnected cell clusters that form the structural framework for macroscale biofilms. The addition of diffusible signaling molecules from supernatant extracts provides evidence that cell filamentation is induced by quorum sensing. These findings and our innovative platform could facilitate therapeutic developments targeting biofilm formation mechanisms of X. fastidiosa and other pathogens.
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Importance of N-Acyl-Homoserine Lactone-Based Quorum Sensing and Quorum Quenching in Pathogen Control and Plant Growth Promotion. Pathogens 2021; 10:pathogens10121561. [PMID: 34959516 PMCID: PMC8706166 DOI: 10.3390/pathogens10121561] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2021] [Revised: 11/22/2021] [Accepted: 11/25/2021] [Indexed: 11/17/2022] Open
Abstract
The biological control of plant pathogens is linked to the composition and activity of the plant microbiome. Plant-associated microbiomes co-evolved with land plants, leading to plant holobionts with plant-beneficial microbes but also with plant pathogens. A diverse range of plant-beneficial microbes assists plants to reach their optimal development and growth under both abiotic and biotic stress conditions. Communication within the plant holobiont plays an important role, and besides plant hormonal interactions, quorum-sensing signalling of plant-associated microbes plays a central role. Quorum-sensing (QS) autoinducers, such as N-acyl-homoserine lactones (AHL) of Gram-negative bacteria, cause a pronounced interkingdom signalling effect on plants, provoking priming processes of pathogen defence and insect pest control. However, plant pathogenic bacteria also use QS signalling to optimise their virulence; these QS activities can be controlled by quorum quenching (QQ) and quorum-sensing inhibition (QSI) approaches by accompanying microbes and also by plants. Plant growth-promoting bacteria (PGPB) have also been shown to demonstrate QQ activity. In addition, some PGPB only harbour genes for AHL receptors, so-called luxR-solo genes, which can contribute to plant growth promotion and biological control. The presence of autoinducer solo receptors may reflect ongoing microevolution processes in microbe–plant interactions. Different aspects of QS systems in bacteria–plant interactions of plant-beneficial and pathogenic bacteria will be discussed, and practical applications of bacteria with AHL-producing or -quenching activity; QS signal molecules stimulating pathogen control and plant growth promotion will also be presented.
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Díaz-Núñez JL, Pérez-López M, Espinosa N, Campos-Hernández N, García-Contreras R, Díaz-Guerrero M, Cortes-López H, Vázquez-Sánchez M, Quezada H, Martínez-Vázquez M, Soto-Hernández RM, Burgos-Hernández M, González-Pedrajo B, Castillo-Juárez I. Anti-Virulence Properties of Plant Species: Correlation between In Vitro Activity and Efficacy in a Murine Model of Bacterial Infection. Microorganisms 2021; 9:2424. [PMID: 34946027 PMCID: PMC8706108 DOI: 10.3390/microorganisms9122424] [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: 10/02/2021] [Revised: 11/13/2021] [Accepted: 11/15/2021] [Indexed: 11/17/2022] Open
Abstract
Several plant extracts exhibit anti-virulence properties due to the interruption of bacterial quorum sensing (QS). However, studies on their effects at the preclinical level are scarce. Here, we used a murine model of abscess/necrosis induced by Pseudomonas aeruginosa to evaluate the anti-pathogenic efficacy of 24 plant extracts at a sub-inhibitory concentration. We analyzed their ability to inhibit QS-regulated virulence factors such as swarming, pyocyanin production, and secretion of the ExoU toxin via the type III secretion system (T3SS). Five of the seven extracts with the best anti-pathogenic activity reduced ExoU secretion, and the extracts of Diphysa americana and Hibiscus sabdariffa were identified as the most active. Therefore, the abscess/necrosis model allows identification of plant extracts that have the capacity to reduce pathogenicity of P. aeruginosa. Furthermore, we evaluated the activity of the plant extracts on Chromobacterium violaceum. T3SS (ΔescU) and QS (ΔcviI) mutant strains were assessed in both the abscess/necrosis and sepsis models. Only the ΔescU strain had lower pathogenicity in the animal models, although no activity of plant extracts was observed. These results demonstrate differences between the anti-virulence activity recorded in vitro and pathogenicity in vivo and between the roles of QS and T3S systems as virulence determinants.
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Affiliation(s)
- José Luis Díaz-Núñez
- Laboratorio de Fitoquímica, Posgrado de Botánica, Colegio de Postgraduados, Texcoco 56230, Mexico; (J.L.D.-N.); (M.P.-L.); (N.C.-H.); (H.C.-L.); (M.V.-S.); (R.M.S.-H.); (M.B.-H.)
| | - Macrina Pérez-López
- Laboratorio de Fitoquímica, Posgrado de Botánica, Colegio de Postgraduados, Texcoco 56230, Mexico; (J.L.D.-N.); (M.P.-L.); (N.C.-H.); (H.C.-L.); (M.V.-S.); (R.M.S.-H.); (M.B.-H.)
| | - Norma Espinosa
- Departamento de Genética Molecular, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, Ciudad de México 04510, Mexico; (N.E.); (M.D.-G.)
| | - Nayelli Campos-Hernández
- Laboratorio de Fitoquímica, Posgrado de Botánica, Colegio de Postgraduados, Texcoco 56230, Mexico; (J.L.D.-N.); (M.P.-L.); (N.C.-H.); (H.C.-L.); (M.V.-S.); (R.M.S.-H.); (M.B.-H.)
| | - Rodolfo García-Contreras
- Departamento de Microbiología y Parasitología, Facultad de Medicina, Universidad Nacional Autónoma de México, Ciudad de México 04510, Mexico;
| | - Miguel Díaz-Guerrero
- Departamento de Genética Molecular, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, Ciudad de México 04510, Mexico; (N.E.); (M.D.-G.)
| | - Humberto Cortes-López
- Laboratorio de Fitoquímica, Posgrado de Botánica, Colegio de Postgraduados, Texcoco 56230, Mexico; (J.L.D.-N.); (M.P.-L.); (N.C.-H.); (H.C.-L.); (M.V.-S.); (R.M.S.-H.); (M.B.-H.)
| | - Monserrat Vázquez-Sánchez
- Laboratorio de Fitoquímica, Posgrado de Botánica, Colegio de Postgraduados, Texcoco 56230, Mexico; (J.L.D.-N.); (M.P.-L.); (N.C.-H.); (H.C.-L.); (M.V.-S.); (R.M.S.-H.); (M.B.-H.)
| | - Héctor Quezada
- Laboratorio de Investigación en Inmunología y Proteómica, Hospital Infantil de México Federico Gómez, Ciudad de México 06720, Mexico;
| | - Mariano Martínez-Vázquez
- Departamento de Productos Naturales, Instituto de Química, Universidad Nacional Autόnoma de México, Ciudad de México 04510, Mexico;
| | - Ramón Marcos Soto-Hernández
- Laboratorio de Fitoquímica, Posgrado de Botánica, Colegio de Postgraduados, Texcoco 56230, Mexico; (J.L.D.-N.); (M.P.-L.); (N.C.-H.); (H.C.-L.); (M.V.-S.); (R.M.S.-H.); (M.B.-H.)
| | - Mireya Burgos-Hernández
- Laboratorio de Fitoquímica, Posgrado de Botánica, Colegio de Postgraduados, Texcoco 56230, Mexico; (J.L.D.-N.); (M.P.-L.); (N.C.-H.); (H.C.-L.); (M.V.-S.); (R.M.S.-H.); (M.B.-H.)
| | - Bertha González-Pedrajo
- Departamento de Genética Molecular, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, Ciudad de México 04510, Mexico; (N.E.); (M.D.-G.)
| | - Israel Castillo-Juárez
- Laboratorio de Fitoquímica, Posgrado de Botánica, Colegio de Postgraduados, Texcoco 56230, Mexico; (J.L.D.-N.); (M.P.-L.); (N.C.-H.); (H.C.-L.); (M.V.-S.); (R.M.S.-H.); (M.B.-H.)
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Hu M, Li C, Xue Y, Hu A, Chen S, Chen Y, Lu G, Zhou X, Zhou J. Isolation, Characterization, and Genomic Investigation of a Phytopathogenic Strain of Stenotrophomonas maltophilia. PHYTOPATHOLOGY 2021; 111:2088-2099. [PMID: 33759550 DOI: 10.1094/phyto-11-20-0501-r] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Stenotrophomonas maltophilia is ubiquitous in diverse environmental habitats. It merits significant concern because of its increasing incidence of nosocomial and community-acquired infection in immunocompromised patients and multiple drug resistance. It is rarely reported as a phytopathogen except in causing white stripe disease of rice in India and postharvest fruit rot of Lanzhou lily. For this study, Dickeya zeae and S. maltophilia strains were simultaneously isolated from soft rot leaves of Clivia miniata in Guangzhou, China, and were both demonstrated to be pathogenic to the host. Compared with the D. zeae strains, S. maltophilia strains propagated faster for greater growth in lysogeny broth medium and produced no cellulases or polygalacturonases, but did produce more proteases and fewer extracellular polysaccharides. Furthermore, S. maltophilia strains swam and swarmed dramatically less on semisolid media, but formed a great many more biofilms. Both D. zeae and S. maltophilia strains isolated from clivia caused rot symptoms on other monocot hosts, but not on dicots. Similar to previously reported S. maltophilia strains isolated from other sources, the strain JZL8 survived under many antibiotic stresses. The complete genome sequence of S. maltophilia strain JZL8 consists of a chromosome of 4,635,432 bp without a plasmid. Pan-genome analysis of JZL8 and 180 other S. maltophilia strains identified 50 genes that are unique to JZL8, seven of which implicate JZL8 as the potential pathogen contributor in plants. JZL8 also contains three copies of Type I Secretion System machinery; this is likely responsible for its greater production of proteases. Findings from this study extend our knowledge on the host range of S. maltophilia and provide insight into the phenotypic and genetic features underlying the plant pathogenicity of JZL8.
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Affiliation(s)
- Ming Hu
- Guangdong Laboratory for Lingnan Modern Agriculture, Guangdong Province Key Laboratory of Microbial Signals and Disease Control, Integrative Microbiology Research Centre, South China Agricultural University, Guangzhou 510642, China
| | - Chuhao Li
- Guangdong Laboratory for Lingnan Modern Agriculture, Guangdong Province Key Laboratory of Microbial Signals and Disease Control, Integrative Microbiology Research Centre, South China Agricultural University, Guangzhou 510642, China
| | - Yang Xue
- Guangdong Laboratory for Lingnan Modern Agriculture, Guangdong Province Key Laboratory of Microbial Signals and Disease Control, Integrative Microbiology Research Centre, South China Agricultural University, Guangzhou 510642, China
| | - Anqun Hu
- Guangdong Laboratory for Lingnan Modern Agriculture, Guangdong Province Key Laboratory of Microbial Signals and Disease Control, Integrative Microbiology Research Centre, South China Agricultural University, Guangzhou 510642, China
| | - Shanshan Chen
- Guangdong Laboratory for Lingnan Modern Agriculture, Guangdong Province Key Laboratory of Microbial Signals and Disease Control, Integrative Microbiology Research Centre, South China Agricultural University, Guangzhou 510642, China
| | - Yufan Chen
- Guangdong Laboratory for Lingnan Modern Agriculture, Guangdong Province Key Laboratory of Microbial Signals and Disease Control, Integrative Microbiology Research Centre, South China Agricultural University, Guangzhou 510642, China
| | - Guangtao Lu
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, College of Life Science and Technology, Guangxi University, Nanning 530004, China
| | - Xiaofan Zhou
- Guangdong Laboratory for Lingnan Modern Agriculture, Guangdong Province Key Laboratory of Microbial Signals and Disease Control, Integrative Microbiology Research Centre, South China Agricultural University, Guangzhou 510642, China
| | - Jianuan Zhou
- Guangdong Laboratory for Lingnan Modern Agriculture, Guangdong Province Key Laboratory of Microbial Signals and Disease Control, Integrative Microbiology Research Centre, South China Agricultural University, Guangzhou 510642, China
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Chowdhury R, Pavinski Bitar PD, Adams MC, Chappie JS, Altier C. AraC-type regulators HilC and RtsA are directly controlled by an intestinal fatty acid to regulate Salmonella invasion. Mol Microbiol 2021; 116:1464-1475. [PMID: 34687258 DOI: 10.1111/mmi.14835] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2021] [Revised: 10/18/2021] [Accepted: 10/18/2021] [Indexed: 01/30/2023]
Abstract
Invasion of the intestinal epithelium is an essential but energetically expensive survival strategy and is, therefore, tightly regulated by using specific cues from the environment. The enteric pathogen Salmonella controls its invasion machinery through the elegant coordination of three AraC-type transcription activators, HilD, HilC, and RtsA. Most environmental signals target HilD to control invasion, whereas HilC and RtsA are known only to augment these effects on HilD. Here we show that a fatty acid found in the murine colon, cis-2-hexadecenoic acid (c2-HDA), represses Salmonella invasion by directly targeting HilC and RtsA, in addition to HilD. c2-HDA directly binds each of these regulators and inhibits their attachment to DNA targets, repressing invasion even in the absence of HilD. Fatty acid binding, however, does not affect HilC and RtsA protein stability, unlike HilD. Importantly, we show that HilC and RtsA are highly effective in restoring HilD production and invasion gene expression after elimination of the repressive fatty acid c2-HDA. Together, these results illuminate a precise mechanism by which HilC and RtsA may modulate invasion as Salmonella navigates through different regions of the intestine, contributing to our understanding of how this enteric pathogen senses and adapts to a diverse intestinal environment while maintaining its virulence.
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Affiliation(s)
- Rimi Chowdhury
- Department of Population Medicine and Diagnostic Sciences, College of Veterinary Medicine, Cornell University, Ithaca, New York, USA
| | - Paulina D Pavinski Bitar
- Department of Population Medicine and Diagnostic Sciences, College of Veterinary Medicine, Cornell University, Ithaca, New York, USA
| | - Myfanwy C Adams
- Department of Molecular Medicine, Cornell University, Ithaca, New York, USA
| | - Joshua S Chappie
- Department of Molecular Medicine, Cornell University, Ithaca, New York, USA
| | - Craig Altier
- Department of Population Medicine and Diagnostic Sciences, College of Veterinary Medicine, Cornell University, Ithaca, New York, USA
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40
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Samal B, Chatterjee S. Bacterial quorum sensing facilitates Xanthomonas campesteris pv. campestris invasion of host tissue to maximize disease symptoms. JOURNAL OF EXPERIMENTAL BOTANY 2021; 72:6524-6543. [PMID: 33993246 DOI: 10.1093/jxb/erab211] [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: 11/03/2020] [Accepted: 05/12/2021] [Indexed: 06/12/2023]
Abstract
Quorum sensing (QS) helps the Xanthomonas group of phytopathogens to infect several crop plants. The vascular phytopathogen Xanthomonas campestris pv. campestris (Xcc) is the causal agent of black rot disease on Brassicaceae leaves, where a typical v-shaped lesion spans both vascular and mesophyll regions with progressive leaf chlorosis. Recently, the role of QS has been elucidated during Xcc early infection stages. However, a detailed insight into the possible role of QS-regulated bacterial invasion in host chlorophagy during late infection stages remains elusive. In this study, using QS-responsive whole-cell bioreporters of Xcc, we present a detailed chronology of QS-facilitated Xcc colonization in the mesophyll region of cabbage (Brassica oleracea) leaves. We report that QS-enabled localization of Xcc to parenchymal chloroplasts triggers leaf chlorosis and promotion of systemic infection. Our results indicate that the QS response in the Xanthomonas group of vascular phytopathogens maximizes their population fitness across host tissues to trigger stage-specific host chlorophagy and establish a systemic infection.
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Affiliation(s)
- Biswajit Samal
- Lab of Plant-Microbe Interactions, Centre for DNA Fingerprinting and Diagnostics, Hyderabad, Telangana, India
- Graduate Studies, Manipal Academy of Higher Education, Manipal, Karnataka, India
| | - Subhadeep Chatterjee
- Lab of Plant-Microbe Interactions, Centre for DNA Fingerprinting and Diagnostics, Hyderabad, Telangana, India
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41
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Galdiero E, Ricciardelli A, D'Angelo C, de Alteriis E, Maione A, Albarano L, Casillo A, Corsaro MM, Tutino ML, Parrilli E. Pentadecanoic acid against Candida albicans-Klebsiella pneumoniae biofilm: towards the development of an anti-biofilm coating to prevent polymicrobial infections. Res Microbiol 2021; 172:103880. [PMID: 34563667 DOI: 10.1016/j.resmic.2021.103880] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2021] [Revised: 09/07/2021] [Accepted: 09/09/2021] [Indexed: 12/15/2022]
Abstract
The ability to form biofilms is a common feature of microorganisms, which can colonize a variety of surfaces, such as host tissues and medical devices, resulting in infections highly resistant to conventional drugs. This aspect is particularly critical in polymicrobial biofilms involving both fungi and bacteria, therefore, to eradicate such severe infections, new and effective anti-biofilm strategies are needed. The efficacy of pentadecanal and pentadecanoic acid as anti-biofilm agents has been recently reported against different bacterial strains. Their chemical similarity with diffusible signal factors (DSFs), plus the already known ability of fatty acids to act as anti-biofilm agents, suggested to explore their use against Candida albicans and Klebsiella pneumoniae mixed biofilm. In this work, we demonstrated the ability of both molecules to prevent the formation and destabilize the structure of the dual-species biofilm. Moreover, the pentadecanoic acid anti-biofilm coating, previously developed through the adsorption of the fatty acid on polydimethylsiloxane (PDMS), was proved to prevent the polymicrobial biofilm formation in dynamic conditions by confocal laser scanning microscopy analysis. Finally, the evaluation of the expression levels of some biofilm-related genes of C. albicans and K. pneumoniae treated with pentadecanoic acid provided some insights into the molecular mechanisms underpinning its anti-biofilm effect.
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Affiliation(s)
- E Galdiero
- Department of Biology, University of Naples Federico II, Complesso Universitario Monte Santangelo, Via Cinthia 21, 80126, Naples, Italy
| | - A Ricciardelli
- Department of Chemical Sciences, University of Naples Federico II, 80125, Naples, Italy
| | - C D'Angelo
- Department of Chemical Sciences, University of Naples Federico II, 80125, Naples, Italy
| | - E de Alteriis
- Department of Biology, University of Naples Federico II, Complesso Universitario Monte Santangelo, Via Cinthia 21, 80126, Naples, Italy
| | - A Maione
- Department of Biology, University of Naples Federico II, Complesso Universitario Monte Santangelo, Via Cinthia 21, 80126, Naples, Italy
| | - L Albarano
- Department of Biology, University of Naples Federico II, Complesso Universitario Monte Santangelo, Via Cinthia 21, 80126, Naples, Italy; Department of Chemical Sciences, University of Naples Federico II, 80125, Naples, Italy; Department of Marine Biothecnology, Stazione Zoologica Anton Dohrn Villa Comunale, 80121, Naples, Italy
| | - A Casillo
- Department of Chemical Sciences, University of Naples Federico II, 80125, Naples, Italy
| | - M M Corsaro
- Department of Chemical Sciences, University of Naples Federico II, 80125, Naples, Italy
| | - M L Tutino
- Department of Chemical Sciences, University of Naples Federico II, 80125, Naples, Italy
| | - E Parrilli
- Department of Chemical Sciences, University of Naples Federico II, 80125, Naples, Italy.
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Identification of FadT as a Novel Quorum Quenching Enzyme for the Degradation of Diffusible Signal Factor in Cupriavidus pinatubonensis Strain HN-2. Int J Mol Sci 2021; 22:ijms22189862. [PMID: 34576026 PMCID: PMC8467058 DOI: 10.3390/ijms22189862] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2021] [Revised: 09/01/2021] [Accepted: 09/06/2021] [Indexed: 01/01/2023] Open
Abstract
Quorum sensing (QS) is a microbial cell–cell communication mechanism and plays an important role in bacterial infections. QS-mediated bacterial infections can be blocked through quorum quenching (QQ), which hampers signal accumulation, recognition, and communication. The pathogenicity of numerous bacteria, including Xanthomonas campestris pv. campestris (Xcc), is regulated by diffusible signal factor (DSF), a well-known fatty acid signaling molecule of QS. Cupriavidus pinatubonensis HN-2 could substantially attenuate the infection of XCC through QQ by degrading DSF. The QQ mechanism in strain HN-2, on the other hand, is yet to be known. To understand the molecular mechanism of QQ in strain HN-2, we used whole-genome sequencing and comparative genomics studies. We discovered that the fadT gene encodes acyl-CoA dehydrogenase as a novel QQ enzyme. The results of site-directed mutagenesis demonstrated the requirement of fadT gene for DSF degradation in strain HN-2. Purified FadT exhibited high enzymatic activity and outstanding stability over a broad pH and temperature range with maximal activity at pH 7.0 and 35 °C. No cofactors were required for FadT enzyme activity. The enzyme showed a strong ability to degrade DSF. Furthermore, the expression of fadT in Xcc results in a significant reduction in the pathogenicity in host plants, such as Chinese cabbage, radish, and pakchoi. Taken together, our results identified a novel DSF-degrading enzyme, FadT, in C. pinatubonensis HN-2, which suggests its potential use in the biological control of DSF-mediated pathogens.
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Bejarano A, Perazzolli M, Pertot I, Puopolo G. The Perception of Rhizosphere Bacterial Communication Signals Leads to Transcriptome Reprogramming in Lysobacter capsici AZ78, a Plant Beneficial Bacterium. Front Microbiol 2021; 12:725403. [PMID: 34489914 PMCID: PMC8416617 DOI: 10.3389/fmicb.2021.725403] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2021] [Accepted: 07/21/2021] [Indexed: 12/13/2022] Open
Abstract
The rhizosphere is a dynamic region governed by complex microbial interactions where diffusible communication signals produced by bacteria continuously shape the gene expression patterns of individual species and regulate fundamental traits for adaptation to the rhizosphere environment. Lysobacter spp. are common bacterial inhabitants of the rhizosphere and have been frequently associated with soil disease suppressiveness. However, little is known about their ecology and how diffusible communication signals might affect their behavior in the rhizosphere. To shed light on the aspects determining rhizosphere competence and functioning of Lysobacter spp., we carried out a functional and transcriptome analysis on the plant beneficial bacterium Lysobacter capsici AZ78 (AZ78) grown in the presence of the most common diffusible communication signals released by rhizosphere bacteria. Mining the genome of AZ78 and other Lysobacter spp. showed that Lysobacter spp. share genes involved in the production and perception of diffusible signal factors, indole, diffusible factors, and N-acyl-homoserine lactones. Most of the tested diffusible communication signals (i.e., indole and glyoxylic acid) influenced the ability of AZ78 to inhibit the growth of the phytopathogenic oomycete Pythium ultimum and the Gram-positive bacterium Rhodococcus fascians. Moreover, RNA-Seq analysis revealed that nearly 21% of all genes in AZ78 genome were modulated by diffusible communication signals. 13-Methyltetradecanoic acid, glyoxylic acid, and 2,3-butanedione positively influenced the expression of genes related to type IV pilus, which might enable AZ78 to rapidly colonize the rhizosphere. Moreover, glyoxylic acid and 2,3-butanedione downregulated tRNA genes, possibly as a result of the elicitation of biological stress responses. On its behalf, indole downregulated genes related to type IV pilus and the heat-stable antifungal factor, which might result in impairment of twitching motility and antibiotic production in AZ78. These results show that diffusible communication signals may affect the ecology of Lysobacter spp. in the rhizosphere and suggest that diffusible communication signals might be used to foster rhizosphere colonization and functioning of plant beneficial bacteria belonging to the genus Lysobacter.
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Affiliation(s)
- Ana Bejarano
- Center of Agriculture, Food, Environment, University of Trento, San Michele all'Adige, Italy.,Department of Sustainable Agro-Ecosystems and Bioresources, Research and Innovation Centre, Fondazione Edmund Mach, San Michele all'Adige, Italy
| | - Michele Perazzolli
- Center of Agriculture, Food, Environment, University of Trento, San Michele all'Adige, Italy.,Department of Sustainable Agro-Ecosystems and Bioresources, Research and Innovation Centre, Fondazione Edmund Mach, San Michele all'Adige, Italy
| | - Ilaria Pertot
- Center of Agriculture, Food, Environment, University of Trento, San Michele all'Adige, Italy.,Department of Sustainable Agro-Ecosystems and Bioresources, Research and Innovation Centre, Fondazione Edmund Mach, San Michele all'Adige, Italy
| | - Gerardo Puopolo
- Center of Agriculture, Food, Environment, University of Trento, San Michele all'Adige, Italy.,Department of Sustainable Agro-Ecosystems and Bioresources, Research and Innovation Centre, Fondazione Edmund Mach, San Michele all'Adige, Italy
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Diffusible signal factor signaling controls bioleaching activity and niche protection in the acidophilic, mineral-oxidizing leptospirilli. Sci Rep 2021; 11:16275. [PMID: 34381075 PMCID: PMC8357829 DOI: 10.1038/s41598-021-95324-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2021] [Accepted: 07/21/2021] [Indexed: 11/08/2022] Open
Abstract
Bioleaching of metal sulfide ores involves acidophilic microbes that catalyze the chemical dissolution of the metal sulfide bond that is enhanced by attached and planktonic cell mediated oxidation of iron(II)-ions and inorganic sulfur compounds. Leptospirillum spp. often predominate in sulfide mineral-containing environments, including bioheaps for copper recovery from chalcopyrite, as they are effective primary mineral colonizers and oxidize iron(II)-ions efficiently. In this study, we demonstrated a functional diffusible signal factor interspecies quorum sensing signaling mechanism in Leptospirillum ferriphilum and Leptospirillum ferrooxidans that produces (Z)-11-methyl-2-dodecenoic acid when grown with pyrite as energy source. In addition, pure diffusible signal factor and extracts from supernatants of pyrite grown Leptospirillum spp. inhibited biological iron oxidation in various species, and that pyrite grown Leptospirillum cells were less affected than iron grown cells to self inhibition. Finally, transcriptional analyses for the inhibition of iron-grown L. ferriphilum cells due to diffusible signal factor was compared with the response to exposure of cells to N- acyl-homoserine-lactone type quorum sensing signal compounds. The data suggested that Leptospirillum spp. diffusible signal factor production is a strategy for niche protection and defense against other microbes and it is proposed that this may be exploited to inhibit unwanted acidophile species.
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45
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Chow EWL, Pang LM, Wang Y. From Jekyll to Hyde: The Yeast-Hyphal Transition of Candida albicans. Pathogens 2021; 10:pathogens10070859. [PMID: 34358008 PMCID: PMC8308684 DOI: 10.3390/pathogens10070859] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2021] [Revised: 06/30/2021] [Accepted: 07/05/2021] [Indexed: 12/22/2022] Open
Abstract
Candida albicans is a major fungal pathogen of humans, accounting for 15% of nosocomial infections with an estimated attributable mortality of 47%. C. albicans is usually a benign member of the human microbiome in healthy people. Under constant exposure to highly dynamic environmental cues in diverse host niches, C. albicans has successfully evolved to adapt to both commensal and pathogenic lifestyles. The ability of C. albicans to undergo a reversible morphological transition from yeast to filamentous forms is a well-established virulent trait. Over the past few decades, a significant amount of research has been carried out to understand the underlying regulatory mechanisms, signaling pathways, and transcription factors that govern the C. albicans yeast-to-hyphal transition. This review will summarize our current understanding of well-elucidated signal transduction pathways that activate C. albicans hyphal morphogenesis in response to various environmental cues and the cell cycle machinery involved in the subsequent regulation and maintenance of hyphal morphogenesis.
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Affiliation(s)
- Eve Wai Ling Chow
- Institute of Molecular and Cell Biology (IMCB), Agency for Science, Technology and Research (A*STAR), 61 Biopolis Drive, Proteos, Singapore 138673, Singapore;
| | - Li Mei Pang
- National Dental Centre Singapore, National Dental Research Institute Singapore (NDRIS), 5 Second Hospital Ave, Singapore 168938, Singapore;
| | - Yue Wang
- Institute of Molecular and Cell Biology (IMCB), Agency for Science, Technology and Research (A*STAR), 61 Biopolis Drive, Proteos, Singapore 138673, Singapore;
- Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, 10 Medical Drive, Singapore 117597, Singapore
- Correspondence:
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Shah A, Nazari M, Antar M, Msimbira LA, Naamala J, Lyu D, Rabileh M, Zajonc J, Smith DL. PGPR in Agriculture: A Sustainable Approach to Increasing Climate Change Resilience. FRONTIERS IN SUSTAINABLE FOOD SYSTEMS 2021. [DOI: 10.3389/fsufs.2021.667546] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Growing environmental concerns are potentially narrowing global yield capacity of agricultural systems. Climate change is the most significant problem the world is currently facing. To meet global food demand, food production must be doubled by 2050; over exploitation of arable lands using unsustainable techniques might resolve food demand issues, but they have negative environmental effects. Current crop production systems are a major reason for changing global climate through diminishing biodiversity, physical and chemical soil degradation, and water pollution. The over application of fertilizers and pesticides contribute to climate change through greenhouse gas emissions (GHG) and toxic soil depositions. At this crucial time, there is a pressing need to transition to more sustainable crop production practices, ones that concentrate more on promoting sustainable mechanisms, which enable crops to grow well in resource limited and environmentally challenging environments, and also develop crops with greater resource use efficiency that have optimum sustainable yields across a wider array of environmental conditions. The phytomicrobiome is considered as one of the best strategies; a better alternative for sustainable agriculture, and a viable solution to meet the twin challenges of global food security and environmental stability. Use of the phytomicrobiome, due to its sustainable and environmentally friendly mechanisms of plant growth promotion, is becoming more widespread in the agricultural industry. Therefore, in this review, we emphasize the contribution of beneficial phytomicrobiome members, particularly plant growth promoting rhizobacteria (PGPR), as a strategy to sustainable improvement of plant growth and production in the face of climate change. Also, the roles of soil dwelling microbes in stress amelioration, nutrient supply (nitrogen fixation, phosphorus solubilization), and phytohormone production along with the factors that could potentially affect their efficiency have been discussed extensively. Lastly, limitations to expansion and use of biobased techniques, for instance, the perspective of crop producers, indigenous microbial competition and regulatory approval are discussed. This review largely focusses on the importance and need of sustainable and environmentally friendly approaches such as biobased/PGPR-based techniques in our agricultural systems, especially in the context of current climate change conditions, which are almost certain to worsen in near future.
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Lin Y, Liao YY, Huang RX, Li AZ, An SQ, Tang JL, Tang DJ. Extracellular Amylase Is Required for Full Virulence and Regulated by the Global Posttranscriptional Regulator RsmA in Xanthomonas campestris Pathovar campestris. PHYTOPATHOLOGY 2021; 111:1104-1113. [PMID: 33245253 DOI: 10.1094/phyto-08-20-0372-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: 06/11/2023]
Abstract
As with many phytopathogenic bacteria, the virulence of Xanthomonas campestris pv. campestris, the causal agent of black rot disease in cruciferous plants, relies on secretion of a suite of extracellular enzymes that includes cellulase (endoglucanase), pectinase, protease, and amylase. Although the role in virulence of a number of these enzymes has been assessed, the contribution of amylase to X. campestris pv. campestris virulence has yet to be established. In this work, we investigated both the role of extracellular amylase in X. campestris pv. campestris virulence and the control of its expression. Deletion of XC3487 (here renamed amyAXcc), a putative amylase-encoding gene from the genome of X. campestris pv. campestris strain 8004, resulted in a complete loss of extracellular amylase activity and significant reduction in virulence. The extracellular amylase activity and virulence of the amyAXcc mutant could be restored to the wild-type level by expressing amyAXcc in trans. These results demonstrated that amyAXcc is responsible for the extracellular amylase activity of X. campestris pv. campestris and indicated that extracellular amylase plays an important role in X. campestris pv. campestris virulence. We also found that the expression of amyAXcc is strongly induced by starch and requires activation by the global posttranscriptional regulator RsmA. RsmA binds specifically to the 5'-untranslated region of amyAXcc transcripts, suggesting that RsmA regulates amyAXcc directly at the posttranscriptional level. Unexpectedly, in addition to posttranscriptional regulation, the use of a transcriptional reporter demonstrated that RsmA also regulates amyAXcc expression at the transcriptional level, possibly by an indirect mechanism.
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Affiliation(s)
- Yan Lin
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, and College of Life Science and Technology, Guangxi University, Nanning, Guangxi 530004, China
| | - Yong-Yan Liao
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, and College of Life Science and Technology, Guangxi University, Nanning, Guangxi 530004, China
| | - Ru-Xia Huang
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, and College of Life Science and Technology, Guangxi University, Nanning, Guangxi 530004, China
| | - Ai-Zhou Li
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, and College of Life Science and Technology, Guangxi University, Nanning, Guangxi 530004, China
| | - Shi-Qi An
- National Biofilms Innovation Centre, Biological Sciences, University of Southampton, Southampton SO17 1BJ, United Kingdom
| | - Ji-Liang Tang
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, and College of Life Science and Technology, Guangxi University, Nanning, Guangxi 530004, China
| | - Dong-Jie Tang
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, and College of Life Science and Technology, Guangxi University, Nanning, Guangxi 530004, China
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Kim YG, Lee JH, Park S, Kim S, Lee J. Inhibition of polymicrobial biofilm formation by saw palmetto oil, lauric acid and myristic acid. Microb Biotechnol 2021; 15:590-602. [PMID: 34156757 PMCID: PMC8867970 DOI: 10.1111/1751-7915.13864] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2021] [Revised: 05/22/2021] [Accepted: 05/23/2021] [Indexed: 11/29/2022] Open
Abstract
Biofilms are communities of bacteria, fungi or yeasts that form on diverse biotic or abiotic surfaces, and play important roles in pathogenesis and drug resistance. A generic saw palmetto oil inhibited biofilm formation by Staphylococcus aureus, Escherichia coli O157:H7 and fungal Candida albicans without affecting their planktonic cell growth. Two main components of the oil, lauric acid and myristic acid, are responsible for this antibiofilm activity. Their antibiofilm activities were observed in dual-species biofilms as well as three-species biofilms of S. aureus, E. coli O157:H7 and C. albicans. Transcriptomic analysis showed that lauric acid and myristic acid repressed the expressions of haemolysin genes (hla and hld) in S. aureus, several biofilm-related genes (csgAB, fimH and flhD) in E. coli and hypha cell wall gene HWP1 in C. albicans, which supported biofilm inhibition. Also, saw palmetto oil, lauric acid and myristic acid reduced virulence of three microbes in a nematode infection model and exhibited minimal cytotoxicity. Furthermore, combinatorial treatment of fatty acids and antibiotics showed synergistic antibacterial efficacy against S. aureus and E. coli O157:H7. These results demonstrate that saw palmetto oil and its main fatty acids might be useful for controlling bacterial infections as well as multispecies biofilms.
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Affiliation(s)
- Yong-Guy Kim
- School of Chemical Engineering, Yeungnam University, 280 Daehak-Ro, Gyeongsan, Korea
| | - Jin-Hyung Lee
- School of Chemical Engineering, Yeungnam University, 280 Daehak-Ro, Gyeongsan, Korea
| | - Sunyoung Park
- School of Chemical Engineering, Yeungnam University, 280 Daehak-Ro, Gyeongsan, Korea
| | - Sanghun Kim
- School of Chemical Engineering, Yeungnam University, 280 Daehak-Ro, Gyeongsan, Korea
| | - Jintae Lee
- School of Chemical Engineering, Yeungnam University, 280 Daehak-Ro, Gyeongsan, Korea
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Harrison ZL, Awais R, Harris M, Raji B, Hoffman BC, Baker DL, Jennings JA. 2-Heptylcyclopropane-1-Carboxylic Acid Disperses and Inhibits Bacterial Biofilms. Front Microbiol 2021; 12:645180. [PMID: 34177826 PMCID: PMC8221421 DOI: 10.3389/fmicb.2021.645180] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2020] [Accepted: 04/29/2021] [Indexed: 12/23/2022] Open
Abstract
Fatty-acid signaling molecules can inhibit biofilm formation, signal dispersal events, and revert dormant cells within biofilms to a metabolically active state. We synthesized 2-heptylcyclopropane-1-carboxylic acid (2CP), an analog of cis-2-decenoic acid (C2DA), which contains a cyclopropanated bond that may lock the signaling factor in an active state and prevent isomerization to its least active trans-configuration (T2DA). 2CP was compared to C2DA and T2DA for ability to disperse biofilms formed by Staphylococcus aureus and Pseudomonas aeruginosa. 2CP at 125 μg/ml dispersed approximately 100% of S. aureus cells compared to 25% for C2DA; both 2CP and C2DA had significantly less S. aureus biofilm remaining compared to T2DA, which achieved no significant dispersal. 2CP at 125 μg/ml dispersed approximately 60% of P. aeruginosa biofilms, whereas C2DA and T2DA at the same concentration dispersed 40%. When combined with antibiotics tobramycin, tetracycline, or levofloxacin, 2CP decreased the minimum concentration required for biofilm inhibition and eradication, demonstrating synergistic and additive responses for certain combinations. Furthermore, 2CP supported fibroblast viability above 80% for concentrations below 1 mg/ml. This study demonstrates that 2CP shows similar or improved efficacy in biofilm dispersion, inhibition, and eradication compared to C2DA and T2DA and thus may be promising for use in preventing infection for healthcare applications.
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Affiliation(s)
- Zoe L Harrison
- Department of Biomedical Engineering, University of Memphis, Memphis, TN, United States
| | - Rukhsana Awais
- Department of Biomedical Engineering, University of Memphis, Memphis, TN, United States
| | - Michael Harris
- Department of Biomedical Engineering, University of Memphis, Memphis, TN, United States
| | - Babatunde Raji
- Department of Chemistry, University of Memphis, Memphis, TN, United States
| | - Brian C Hoffman
- Department of Chemistry, University of Memphis, Memphis, TN, United States
| | - Daniel L Baker
- Department of Chemistry, University of Memphis, Memphis, TN, United States
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Khanna K, Kohli SK, Ohri P, Bhardwaj R. Plants-nematodes-microbes crosstalk within soil: A trade-off among friends or foes. Microbiol Res 2021; 248:126755. [PMID: 33845302 DOI: 10.1016/j.micres.2021.126755] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2021] [Revised: 03/18/2021] [Accepted: 03/27/2021] [Indexed: 11/28/2022]
Abstract
Plants interact with enormous biotic and abiotic components within ecosystem. For instance, microbes, insects, herbivores, animals, nematodes etc. In general, these interactions are studied independently with plants, that condenses only specific information about the interaction. However, the limitation to study the cross-interactions masks the collaborative role of organisms within ecosystem. Beneficial microbes are most prominent organisms that are needed to be studied due to their bidirectional nature towards plants. Fascinatingly, Plant-Parasitic Nematodes (PPNs) have been profoundly observed to cause mass destruction of agricultural crops worldwide. The huge demand for agriculture for present-day population requires optimization of production potential by curbing the damage caused by PPNs. Chemical nematicides combats their proliferation, but their extended usage has abruptly affected flora, fauna and human populations. Because of consistent pressing issues in regard to environment, the use of biocontrol agents are most favourable alternatives for managing agriculture. However, this association is somehow, tug of war, and understanding of plant-nematode-microbial relation would enable the agriculturists to monitor the overall development of plants along with limiting the use of agrochemicals. Soil microbes are contemporary bio-nematicides emerging in the market, that stimulates the plant growth and impedes PPNs populations. They form natural enemies and trap nematodes, henceforth, it is crucial to understand these interactions for ecological and biotechnological perspectives for commercial use. Moreover, acquiring the diversity of their relationship and molecular-based mechanisms, outlines their cascade of signaling events to serve as biotechnological ecosystem engineers. The omics based mechanisms encompassing hormone gene regulatory pathways and elicitors released by microbes are able to modulate pathogenesis-related (PR) genes within plants. This is achieved via Induced Systemic Resistance (ISR) or acquired systemic channels. Taking into account all these validations, the present review mainly advocates the relationship among microbes and nematodes in plants. It is believed that this review will boost zest and zeal within researchers to effectively understand the plant-nematodes-microbes relations and their ecological perspectives.
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Affiliation(s)
- Kanika Khanna
- Department of Botanical and Environmental Sciences, Guru Nanak Dev University, Amritsar, 143005, Punjab, India.
| | - Sukhmeen Kaur Kohli
- Department of Botanical and Environmental Sciences, Guru Nanak Dev University, Amritsar, 143005, Punjab, India
| | - Puja Ohri
- Department of Zoology, Guru Nanak Dev University, Amritsar, 143005, Punjab, India.
| | - Renu Bhardwaj
- Department of Botanical and Environmental Sciences, Guru Nanak Dev University, Amritsar, 143005, Punjab, India.
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