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Zheng Q, Liu X, Mao C, Liu H, Jin L, Wang C, Zhu S, Zheng Y, Li Z, Jiang H, Cui Z, Zhang Y, Chu PK, Wu S. Tribovoltaic Effect Strengthened Microwave Catalytic Antibacterial Composite Hydrogel. Adv Healthc Mater 2024:e2402266. [PMID: 39138999 DOI: 10.1002/adhm.202402266] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2024] [Revised: 07/22/2024] [Indexed: 08/15/2024]
Abstract
Microwave (MW) therapy is an emerging therapy with high efficiency and deep penetration to combat the crisis of bacterial resistance. However, as the energy of MW is too low to induce electron transition, the mechanism of MW catalytic effect remains ambiguous. Herein, a cerium-based metal-organic framework (MOF) is fabricated and used in MW therapy. The MW-catalytic performance of CeTCPP is largely dependent on the ions in the liquid environment, and the electron transition is achieved through a "tribovoltaic effect" between water molecules and CeTCPP. By this way, CeTCPP can generate reactive oxygen species (ROS) in saline under pulsed MW irradiation, showing 99.9995 ± 0.0002% antibacterial ratio against Staphylococcus aureus (S. aureus) upon two cycles of MW irradiation. Bacterial metabolomics further demonstrates that the diffusion of ROS into bacteria led to the bacterial metabolic disorders. The bacteria are finally killed due to "amino acid starvation". In order to improve the applicability of CeTCPP, It is incorporated into alginate-based hydrogel, which maintains good MW catalytic antibacterial efficiency and also good biocompatibility. Therefore, this work provides a comprehensive instruction of using CeTCPP in MW therapy, from mechanism to application. This work also provides new perspectives for the design of antibacterial composite hydrogel.
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Affiliation(s)
- Qiyao Zheng
- School of Materials Science & Engineering, Peking University, Yiheyuan Road 5#, Beijing, 100871, China
| | - Xiangmei Liu
- Biomedical Materials Engineering Research Center, Hubei Key Laboratory of Polymer Materials, Ministry-of-Education Key Laboratory for the Green Preparation and Application of Functional Materials, School of Materials Science & Engineering, State Key Laboratory of Biocatalysis and Enzyme Engineering, Hubei University, Wuhan, 430062, China
- School of Health Science & Biomedical Engineering, Hebei University of Technology, Xiping Avenue 5340#, Tianjin, 300401, China
| | - Congyang Mao
- Biomedical Materials Engineering Research Center, Hubei Key Laboratory of Polymer Materials, Ministry-of-Education Key Laboratory for the Green Preparation and Application of Functional Materials, School of Materials Science & Engineering, State Key Laboratory of Biocatalysis and Enzyme Engineering, Hubei University, Wuhan, 430062, China
| | - Hanpeng Liu
- School of Materials Science & Engineering, the Key Laboratory of Advanced Ceramics and Machining Technology by the Ministry of Education of China, Tianjin University, Yaguan Road 135#, Tianjin, 300072, China
| | - Liguo Jin
- School of Materials Science & Engineering, the Key Laboratory of Advanced Ceramics and Machining Technology by the Ministry of Education of China, Tianjin University, Yaguan Road 135#, Tianjin, 300072, China
| | - Chaofeng Wang
- School of Health Science & Biomedical Engineering, Hebei University of Technology, Xiping Avenue 5340#, Tianjin, 300401, China
| | - Shengli Zhu
- School of Materials Science & Engineering, the Key Laboratory of Advanced Ceramics and Machining Technology by the Ministry of Education of China, Tianjin University, Yaguan Road 135#, Tianjin, 300072, China
| | - Yufeng Zheng
- School of Materials Science & Engineering, Peking University, Yiheyuan Road 5#, Beijing, 100871, China
| | - Zhaoyang Li
- School of Materials Science & Engineering, the Key Laboratory of Advanced Ceramics and Machining Technology by the Ministry of Education of China, Tianjin University, Yaguan Road 135#, Tianjin, 300072, China
| | - Hui Jiang
- School of Materials Science & Engineering, the Key Laboratory of Advanced Ceramics and Machining Technology by the Ministry of Education of China, Tianjin University, Yaguan Road 135#, Tianjin, 300072, China
| | - Zhenduo Cui
- School of Materials Science & Engineering, the Key Laboratory of Advanced Ceramics and Machining Technology by the Ministry of Education of China, Tianjin University, Yaguan Road 135#, Tianjin, 300072, China
| | - Yu Zhang
- Department of Orthopedics, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou, 510080, China
| | - Paul K Chu
- Department of Physics, Department of Materials Science and Engineering, and Department of Biomedical Engineering, City University of Hong Kong, Tat Chee Avenue, Hong Kong, 999077, China
| | - Shuilin Wu
- School of Materials Science & Engineering, Peking University, Yiheyuan Road 5#, Beijing, 100871, China
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2
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Fletcher JR, Hansen LA, Martinez R, Freeman CD, Thorns N, Villareal AR, Penningroth MR, Vogt GA, Tyler M, Hines KM, Hunter RC. Commensal-derived short-chain fatty acids disrupt lipid membrane homeostasis in Staphylococcus aureus. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.08.12.607382. [PMID: 39185181 PMCID: PMC11343118 DOI: 10.1101/2024.08.12.607382] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 08/27/2024]
Abstract
The role of commensal anaerobic bacteria in chronic respiratory infections is unclear, yet they can exist in abundances comparable to canonical pathogens in vivo. Their contributions to the metabolic landscape of the host environment may influence pathogen behavior by competing for nutrients and creating inhospitable conditions via toxic metabolites. Here, we reveal a mechanism by which the anaerobe-derived short chain fatty acids (SCFAs) propionate and butyrate negatively affect Staphylococcus aureus physiology by disrupting branched chain fatty acid (BCFA) metabolism. In turn, BCFA impairment results in impaired growth, diminished expression of the agr quorum sensing system, as well as increased sensitivity to membrane-targeting antimicrobials. Altered BCFA metabolism also reduces S. aureus fitness in competition with Pseudomonas aeruginosa, suggesting that airway microbiome composition and the metabolites they produce and exchange directly impact pathogen succession over time. The pleiotropic effects of these SCFAs on S. aureus fitness and their ubiquity as metabolites in animals also suggests that they may be effective as sensitizers to traditional antimicrobial agents when used in combination.
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Affiliation(s)
- Joshua R. Fletcher
- Department of Microbiology & Immunology, University of Minnesota, Minneapolis, MN 55455
- Department of Population Health and Pathobiology, North Carolina State University College of Veterinary Medicine, Raleigh, NC 27695
| | - Lisa A. Hansen
- Department of Microbiology & Immunology, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, Buffalo, NY, 14203
| | - Richard Martinez
- Department of Microbiology & Immunology, University of Minnesota, Minneapolis, MN 55455
| | | | - Niall Thorns
- Department of Microbiology & Immunology, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, Buffalo, NY, 14203
| | - Alex R. Villareal
- Department of Microbiology & Immunology, University of Minnesota, Minneapolis, MN 55455
| | | | - Grace A. Vogt
- Department of Microbiology & Immunology, University of Minnesota, Minneapolis, MN 55455
| | - Matthew Tyler
- Department of Otolaryngology, University of Minnesota, Minneapolis, MN, 55455
| | - Kelly M. Hines
- Department of Chemistry, University of Georgia, Athens, GA, 30602
| | - Ryan C. Hunter
- Department of Microbiology & Immunology, University of Minnesota, Minneapolis, MN 55455
- Department of Microbiology & Immunology, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, Buffalo, NY, 14203
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3
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Hu M, Du Y, Li W, Zong X, Du W, Sun H, Liu H, Zhao K, Li J, Farooq MZ, Wu J, Xu Q. Interplay of Food-Derived Bioactive Peptides with Gut Microbiota: Implications for Health and Disease Management. Mol Nutr Food Res 2024:e2400251. [PMID: 39097954 DOI: 10.1002/mnfr.202400251] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2024] [Revised: 06/19/2024] [Indexed: 08/06/2024]
Abstract
Bioactive peptides (BPs) are protein fragments with beneficial effects on metabolism, physiology, and diseases. This review focuses on proteolytic BPs, which are produced by the action of gut microbiota on proteins in food and have demonstrated to influence the composition of gut microbes. And gut microbiota are candidate targets of BPs to alleviate oxidative stress, enhance immunity, and control diseases, including diabetes, hypertension, obesity, cancer, and immune and neurodegenerative diseases. Despite promising results, further research is needed to understand the mechanisms underlying the interactions between BPs and gut microbes, and to identify and screen more BPs for industrial applications. Overall, BPs offer potential as therapeutic agents for various diseases through their interactions with gut microbes, highlighting the importance of continued research in this area.
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Affiliation(s)
- Mingyang Hu
- College of Animal Sciences and Technology, Huazhong Agricultural University, Wuhan, 430070, China
| | - Yufeng Du
- College of Animal Sciences and Technology, Huazhong Agricultural University, Wuhan, 430070, China
| | - Wenyue Li
- College of Animal Sciences and Technology, Huazhong Agricultural University, Wuhan, 430070, China
| | - Xiaomei Zong
- College of Animal Sciences and Technology, Huazhong Agricultural University, Wuhan, 430070, China
| | - Wenjuan Du
- College of Animal Sciences and Technology, Huazhong Agricultural University, Wuhan, 430070, China
| | - Huizeng Sun
- Institute of Dairy Science, MoE Key Laboratory of Molecular Animal Nutrition, College of Animal Sciences, Zhejiang University, Hangzhou, 310058, China
| | - Hongyun Liu
- Institute of Dairy Science, MoE Key Laboratory of Molecular Animal Nutrition, College of Animal Sciences, Zhejiang University, Hangzhou, 310058, China
| | - Ke Zhao
- Institute of Food Science, Zhejiang Academy of Agricultural Sciences, Hangzhou, 310058, China
| | - Jianxiong Li
- Wuhan Jason Biotech Co., Ltd., Wuhan, 430070, China
| | - Muhammad Zahid Farooq
- Department of Animal Science, University of Veterinary and Animal Science, Lahore, 54000, Pakistan
| | - Jianping Wu
- Department of Agricultural, Food and Nutritional Science, University of Alberta, 4-10 Ag/For Building, Edmonton, Alberta, T6G 2P5, Canada
| | - Qingbiao Xu
- College of Animal Sciences and Technology, Huazhong Agricultural University, Wuhan, 430070, China
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4
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Pugazhendhi AS, Neal CJ, Ta KM, Molinari M, Kumar U, Wei F, Kolanthai E, Ady A, Drake C, Hughes M, Yooseph S, Seal S, Coathup MJ. A neoteric antibacterial ceria-silver nanozyme for abiotic surfaces. Biomaterials 2024; 307:122527. [PMID: 38518591 DOI: 10.1016/j.biomaterials.2024.122527] [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: 01/16/2024] [Revised: 03/01/2024] [Accepted: 03/08/2024] [Indexed: 03/24/2024]
Abstract
Community-associated and hospital-acquired infections caused by bacteria continue to yield major global challenges to human health. Bacterial contamination on abiotic surfaces is largely spread via high-touch surfaces and contemporary standard disinfection practices show limited efficacy, resulting in unsatisfactory therapeutic outcomes. New strategies that offer non-specific and broad protection are urgently needed. Herein, we report our novel ceria-silver nanozyme engineered at a molar ratio of 5:1 and with a higher trivalent (Ce3+) surface fraction. Our results reveal potent levels of surface catalytic activity on both wet and dry surfaces, with rapid, and complete eradication of Pseudomonas aeruginosa, Staphylococcus aureus, and methicillin resistant S. aureus, in both planktonic and biofilm form. Preferential electrostatic adherence of anionic bacteria to the cationic nanozyme surface leads to a catastrophic loss in both aerobic and anaerobic respiration, DNA damage, osmodysregulation, and finally, programmed bacterial lysis. Our data reveal several unique mechanistic avenues of synergistic ceria-Ag efficacy. Ag potentially increases the presence of Ce3+ sites at the ceria-Ag interface, thereby facilitating the formation of harmful H2O2, followed by likely permeation across the cell wall. Further, a weakened Ag-induced Ce-O bond may drive electron transfer from the Ec band to O2, thereby further facilitating the selective reduction of O2 toward H2O2 formation. Ag destabilizes the surface adsorption of molecular H2O2, potentially leading to higher concentrations of free H2O2 adjacent to bacteria. To this end, our results show that H2O2 and/or NO/NO2-/NO3- are the key liberators of antibacterial activity, with a limited immediate role being offered by nanozyme-induced ROS including O2•- and OH•, and likely other light-activated radicals. A mini-pilot proof-of-concept study performed in a pediatric dental clinic setting confirms residual, and continual nanozyme antibacterial efficacy over a 28-day period. These findings open a new approach to alleviate infections caused by bacteria for use on high-touch hard surfaces.
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Affiliation(s)
- Abinaya Sindu Pugazhendhi
- Biionix Cluster, College of Medicine, University of Central Florida, Orlando, FL, 32827, United States
| | - Craig J Neal
- Advanced Materials Processing and Analysis Centre, Nanoscience Technology Center (NSTC), University of Central Florida, Orlando, FL, 32826, United States
| | - Khoa Minh Ta
- Department of Chemical Sciences, School of Applied Sciences, University of Huddersfield, Huddersfield, HD1 3DH, United Kingdom
| | - Marco Molinari
- Department of Chemical Sciences, School of Applied Sciences, University of Huddersfield, Huddersfield, HD1 3DH, United Kingdom.
| | - Udit Kumar
- Advanced Materials Processing and Analysis Centre, Nanoscience Technology Center (NSTC), University of Central Florida, Orlando, FL, 32826, United States
| | - Fei Wei
- Biionix Cluster, College of Medicine, University of Central Florida, Orlando, FL, 32827, United States
| | - Elayaraja Kolanthai
- Advanced Materials Processing and Analysis Centre, Nanoscience Technology Center (NSTC), University of Central Florida, Orlando, FL, 32826, United States
| | - Andrew Ady
- Biionix Cluster, College of Medicine, University of Central Florida, Orlando, FL, 32827, United States
| | - Christina Drake
- Kismet Technologies, 7101 TPC Drive, Suite 130, Orlando, FL, 32822, United States
| | - Megan Hughes
- University of Cardiff, Cardiff, CF10 3AT, Wales, United Kingdom
| | - Shibu Yooseph
- Kravis Department of Integrated Sciences, Claremont McKenna College, Claremont, CA 91711, United States
| | - Sudipta Seal
- Biionix Cluster, College of Medicine, University of Central Florida, Orlando, FL, 32827, United States; Advanced Materials Processing and Analysis Centre, Nanoscience Technology Center (NSTC), University of Central Florida, Orlando, FL, 32826, United States
| | - Melanie J Coathup
- Biionix Cluster, College of Medicine, University of Central Florida, Orlando, FL, 32827, United States.
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5
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Lux J, Sánchez García L, Chaparro Fernández P, Laloli L, Licheri MF, Gallay C, Hermans PWM, Croucher NJ, Veening JW, Dijkman R, Straume D, Hathaway LJ. AmiA and AliA peptide ligands, found in Klebsiella pneumoniae, are imported into pneumococci and alter the transcriptome. Sci Rep 2024; 14:12416. [PMID: 38816440 PMCID: PMC11139975 DOI: 10.1038/s41598-024-63217-2] [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: 12/14/2023] [Accepted: 05/27/2024] [Indexed: 06/01/2024] Open
Abstract
Klebsiella pneumoniae releases the peptides AKTIKITQTR and FNEMQPIVDRQ, which bind the pneumococcal proteins AmiA and AliA respectively, two substrate-binding proteins of the ABC transporter Ami-AliA/AliB oligopeptide permease. Exposure to these peptides alters pneumococcal phenotypes such as growth. Using a mutant in which a permease domain of the transporter was disrupted, by growth analysis and epifluorescence microscopy, we confirmed peptide uptake via the Ami permease and intracellular location in the pneumococcus. By RNA-sequencing we found that the peptides modulated expression of genes involved in metabolism, as pathways affected were mostly associated with energy or synthesis and transport of amino acids. Both peptides downregulated expression of genes involved in branched-chain amino acid metabolism and the Ami permease; and upregulated fatty acid biosynthesis genes but differed in their regulation of genes involved in purine and pyrimidine biosynthesis. The transcriptomic changes are consistent with growth suppression by peptide treatment. The peptides inhibited growth of pneumococcal isolates of serotypes 3, 8, 9N, 12F and 19A, currently prevalent in Switzerland, and caused no detectable toxic effect to primary human airway epithelial cells. We conclude that pneumococci take up K. pneumoniae peptides from the environment via binding and transport through the Ami permease. This changes gene expression resulting in altered phenotypes, particularly reduced growth.
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Affiliation(s)
- Janine Lux
- Institute for Infectious Diseases, Faculty of Medicine, University of Bern, Friedbühlstrasse 25, CH-3001, Bern, Switzerland
- Graduate School for Cellular and Biomedical Sciences, University of Bern, Bern, Switzerland
| | - Lucía Sánchez García
- Institute for Infectious Diseases, Faculty of Medicine, University of Bern, Friedbühlstrasse 25, CH-3001, Bern, Switzerland
| | - Patricia Chaparro Fernández
- Institute for Infectious Diseases, Faculty of Medicine, University of Bern, Friedbühlstrasse 25, CH-3001, Bern, Switzerland
| | - Laura Laloli
- Institute for Infectious Diseases, Faculty of Medicine, University of Bern, Friedbühlstrasse 25, CH-3001, Bern, Switzerland
| | - Manon F Licheri
- Institute for Infectious Diseases, Faculty of Medicine, University of Bern, Friedbühlstrasse 25, CH-3001, Bern, Switzerland
| | - Clement Gallay
- Department of Fundamental Microbiology, University of Lausanne, Lausanne, Switzerland
| | - Peter W M Hermans
- Julius Centre for Health Sciences and Primary Care, University Medical Centre Utrecht (UMCU), Utrecht, The Netherlands
| | - Nicholas J Croucher
- MRC Centre for Global Infectious Disease Analysis, White City Campus, Imperial College London, Sir Michael Uren Hub, London, UK
| | - Jan-Willem Veening
- Department of Fundamental Microbiology, University of Lausanne, Lausanne, Switzerland
| | - Ronald Dijkman
- Institute for Infectious Diseases, Faculty of Medicine, University of Bern, Friedbühlstrasse 25, CH-3001, Bern, Switzerland
- Multidisciplinary Center for Infectious Diseases, University of Bern, Bern, Switzerland
- Microscopy Imaging Centre (MIC), Theodor Kocher Institute, University of Bern, Bern, Switzerland
- European Virus Bioinformatics Center, Jena, Germany
| | - Daniel Straume
- Faculty of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences, 1430, Ås, Norway
| | - Lucy J Hathaway
- Institute for Infectious Diseases, Faculty of Medicine, University of Bern, Friedbühlstrasse 25, CH-3001, Bern, Switzerland.
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Lilien TA, Brinkman P, Fenn DW, van Woensel JBM, Bos LDJ, Bem RA. Breath Markers of Oxidative Stress in Children with Severe Viral Lower Respiratory Tract Infection. Am J Respir Cell Mol Biol 2024; 70:392-399. [PMID: 38315815 DOI: 10.1165/rcmb.2023-0349oc] [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: 09/29/2023] [Accepted: 02/05/2024] [Indexed: 02/07/2024] Open
Abstract
Severe viral lower respiratory tract infection (LRTI), resulting in both acute and long-term pulmonary disease, constitutes a substantial burden among young children. Viral LRTI triggers local oxidative stress pathways by infection and inflammation, and supportive care in the pediatric intensive care unit may further aggravate oxidative injury. The main goal of this exploratory study was to identify and monitor breath markers linked to oxidative stress in children over the disease course of severe viral LRTI. Exhaled breath was sampled during invasive ventilation, and volatile organic compounds (VOCs) were analyzed using gas chromatography and mass spectrometry. VOCs were selected in an untargeted principal component analysis and assessed for change over time. In addition, identified VOCs were correlated with clinical parameters. Seventy breath samples from 21 patients were analyzed. A total of 15 VOCs were identified that contributed the most to the explained variance of breath markers. Of these 15 VOCs, 10 were previously linked to pathways of oxidative stress. Eight VOCs, including seven alkanes and methyl alkanes, significantly decreased from the initial phase of ventilation to the day of extubation. No correlation was observed with the administered oxygen dose, whereas six VOCs showed a poor to strong positive correlation with driving pressure. In this prospective study of children with severe viral LRTI, the majority of VOCs that were most important for the explained variance mirrored clinical improvement. These breath markers could potentially help monitor the pulmonary oxidative status in these patients, but further research with other objective measures of pulmonary injury is required.
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Affiliation(s)
- Thijs A Lilien
- Department of Pediatric Intensive Care Medicine, Emma Children's Hospital
- Amsterdam Reproduction and Development Research Institute, Amsterdam, the Netherlands
| | | | | | - Job B M van Woensel
- Department of Pediatric Intensive Care Medicine, Emma Children's Hospital
- Amsterdam Reproduction and Development Research Institute, Amsterdam, the Netherlands
| | - Lieuwe D J Bos
- Department of Pulmonology, and
- Department of Intensive Care Medicine, Amsterdam UMC location University of Amsterdam, Amsterdam, the Netherlands; and
| | - Reinout A Bem
- Department of Pediatric Intensive Care Medicine, Emma Children's Hospital
- Amsterdam Reproduction and Development Research Institute, Amsterdam, the Netherlands
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7
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dos Santos Ferreira MC, Pendleton A, Yeo W, Málaga Gadea FC, Camelo D, McGuire M, Brinsmade SR. In Staphylococcus aureus, the acyl-CoA synthetase MbcS supports branched-chain fatty acid synthesis from carboxylic acid and aldehyde precursors. Mol Microbiol 2024; 121:865-881. [PMID: 38366323 PMCID: PMC11167679 DOI: 10.1111/mmi.15237] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2023] [Revised: 01/16/2024] [Accepted: 01/22/2024] [Indexed: 02/18/2024]
Abstract
In the human pathogen Staphylococcus aureus, branched-chain fatty acids (BCFAs) are the most abundant fatty acids in membrane phospholipids. Strains deficient for BCFAs synthesis experience auxotrophy in laboratory culture and attenuated virulence during infection. Furthermore, the membrane of S. aureus is among the main targets for antibiotic therapy. Therefore, determining the mechanisms involved in BCFAs synthesis is critical to manage S. aureus infections. Here, we report that the overexpression of SAUSA300_2542 (annotated to encode an acyl-CoA synthetase) restores BCFAs synthesis in strains lacking the canonical biosynthetic pathway catalyzed by the branched-chain α-keto acid dehydrogenase (BKDH) complex. We demonstrate that the acyl-CoA synthetase activity of MbcS activates branched-chain carboxylic acids (BCCAs), and is required by S. aureus to utilize the isoleucine derivative 2-methylbutyraldehyde to restore BCFAs synthesis in S. aureus. Based on the ability of some staphylococci to convert branched-chain aldehydes into their respective BCCAs and our findings demonstrating that branched-chain aldehydes are in fact BCFAs precursors, we propose that MbcS promotes the scavenging of exogenous BCCAs and mediates BCFA synthesis via a de novo alternative pathway.
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Affiliation(s)
| | - Augustus Pendleton
- Department of BiologyGeorgetown UniversityWashingtonDistrict of ColumbiaUSA
- Present address:
Department of MicrobiologyCornell UniversityIthacaNew YorkUSA
| | - Won‐Sik Yeo
- Department of BiologyGeorgetown UniversityWashingtonDistrict of ColumbiaUSA
| | | | - Danna Camelo
- Department of BiologyGeorgetown UniversityWashingtonDistrict of ColumbiaUSA
| | - Maeve McGuire
- Department of BiologyGeorgetown UniversityWashingtonDistrict of ColumbiaUSA
| | - Shaun R. Brinsmade
- Department of BiologyGeorgetown UniversityWashingtonDistrict of ColumbiaUSA
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8
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Emilia N, Pia SV, Tiina HP, Antti N, Anniina V, Anneli R, Michael L, Natalia RS. In vitro protein digestion and carbohydrate colon fermentation of microbial biomass samples from bacterial, filamentous fungus and yeast sources. Food Res Int 2024; 182:114146. [PMID: 38519176 DOI: 10.1016/j.foodres.2024.114146] [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: 12/08/2023] [Revised: 02/13/2024] [Accepted: 02/17/2024] [Indexed: 03/24/2024]
Abstract
This study evaluated the nutritional quality of different microbial biomass samples by assessing their protein digestibility and carbohydrate fermentability in the colon using in vitro methods. Four microbial samples were produced: one hydrogen-oxidizing bacterial strain (Nocardioides nitrophenolicus KGS-27), two strains of filamentous fungi (Rhizopus oligosporus and Paecilomyces variotii), and one yeast strain (Rhodotorula babjevae). The microorganisms were grown in bioreactors, harvested and dried before analysis. The commercial fungal product Quorn was used as a reference. The protein digestibility of the microbial samples was analysed using the INFOGEST in vitro model, followed by quantification of N-terminal amine groups. An in vitro faecal fermentation experiment was also performed to evaluate the degradation of carbohydrates in microbial biomass samples and formation of short-chain fatty acids (SCFA). The fungal biomass samples had higher protein hydrolysis (60-75 %) than the bacterial sample (12 %) and Quorn (45 %), while the yeast biomass had the highest protein digestibility (85 %). Heat-treatment of the biomass significantly reduced its protein digestibility. Total dietary fibre (DF) content of fungal biomass was 31 - 43 %(DW), mostly insoluble, whereas the bacterial biomass contained mainly soluble DF (total DF: 25.7 %, of which 23.5 % were soluble and 2.2 % insoluble). After 24 h of colonic in vitro fermentation, SCFA production from the biomass of Paecilomyces, Quorn and Rhodotorula was similar to that of wheat bran, while 17 % and 32 % less SCFA were produced from the biomass of Rhizopus and the bacterial strain, respectively. Further studies are needed to clarify the reasons for the observed differences in protein digestibility and DF fermentability, especially regarding the cell wall structures and role of post-processing.
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Affiliation(s)
- Nordlund Emilia
- VTT Technical Research Centre of Finland, Ltd, P.O. Box 1000, FI-02044, Finland.
| | | | | | - Nyyssölä Antti
- VTT Technical Research Centre of Finland, Ltd, P.O. Box 1000, FI-02044, Finland
| | - Valtonen Anniina
- VTT Technical Research Centre of Finland, Ltd, P.O. Box 1000, FI-02044, Finland; Nordic Umami Company Ltd., Karamalmintie 2, 02630 Espoo, Finland(1)
| | - Ritala Anneli
- VTT Technical Research Centre of Finland, Ltd, P.O. Box 1000, FI-02044, Finland
| | - Lienemann Michael
- VTT Technical Research Centre of Finland, Ltd, P.O. Box 1000, FI-02044, Finland
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9
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Lilien TA, Fenn DW, Brinkman P, Hagens LA, Smit MR, Heijnen NFL, van Woensel JBM, Bos LDJ, Bem RA. HS-GC-MS analysis of volatile organic compounds after hyperoxia-induced oxidative stress: a validation study. Intensive Care Med Exp 2024; 12:14. [PMID: 38345723 PMCID: PMC10861410 DOI: 10.1186/s40635-024-00600-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2023] [Accepted: 01/26/2024] [Indexed: 02/15/2024] Open
Abstract
BACKGROUND Exhaled volatile organic compounds (VOCs), particularly hydrocarbons from oxidative stress-induced lipid peroxidation, are associated with hyperoxia exposure. However, important heterogeneity amongst identified VOCs and concerns about their precise pathophysiological origins warrant translational studies assessing their validity as a marker of hyperoxia-induced oxidative stress. Therefore, this study sought to examine changes in VOCs previously associated with the oxidative stress response in hyperoxia-exposed lung epithelial cells. METHODS A549 alveolar epithelial cells were exposed to hyperoxia for 24 h, or to room air as normoxia controls, or hydrogen peroxide as oxidative-stress positive controls. VOCs were sampled from the headspace, analysed by gas chromatography coupled with mass spectrometry and compared by targeted and untargeted analyses. A secondary analysis of breath samples from a large cohort of critically ill adult patients assessed the association of identified VOCs with clinical oxygen exposure. RESULTS Following cellular hyperoxia exposure, none of the targeted VOCs, previously proposed as breath markers of oxidative stress, were increased, and decane was significantly decreased. Untargeted analysis did not reveal novel identifiable hyperoxia-associated VOCs. Within the clinical cohort, three previously proposed breath markers of oxidative stress, hexane, octane, and decane had no real diagnostic value in discriminating patients exposed to hyperoxia. CONCLUSIONS Hyperoxia exposure of alveolar epithelial cells did not result in an increase in identifiable VOCs, whilst VOCs previously linked to oxidative stress were not associated with oxygen exposure in a cohort of critically ill patients. These findings suggest that the pathophysiological origin of previously proposed breath markers of oxidative stress is more complex than just oxidative stress from hyperoxia at the lung epithelial cellular level.
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Affiliation(s)
- Thijs A Lilien
- Department of Paediatric Intensive Care Medicine, Emma Children's Hospital, Amsterdam UMC Location University of Amsterdam, Meibergdreef 9, Amsterdam, The Netherlands.
- Laboratory of Experimental Intensive Care and Anaesthesiology, Amsterdam UMC Location University of Amsterdam, Meibergdreef 9, Amsterdam, The Netherlands.
| | - Dominic W Fenn
- Laboratory of Experimental Intensive Care and Anaesthesiology, Amsterdam UMC Location University of Amsterdam, Meibergdreef 9, Amsterdam, The Netherlands
- Department of Pulmonary Medicine, Amsterdam UMC Location University of Amsterdam, Meibergdreef 9, Amsterdam, The Netherlands
| | - Paul Brinkman
- Department of Pulmonary Medicine, Amsterdam UMC Location University of Amsterdam, Meibergdreef 9, Amsterdam, The Netherlands
| | - Laura A Hagens
- Department of Intensive Care Medicine, Amsterdam UMC Location University of Amsterdam, Meibergdreef 9, Amsterdam, The Netherlands
| | - Marry R Smit
- Department of Intensive Care Medicine, Amsterdam UMC Location University of Amsterdam, Meibergdreef 9, Amsterdam, The Netherlands
| | - Nanon F L Heijnen
- Department of Intensive Care Medicine, Maastricht University Medical Centre+, Maastricht, The Netherlands
| | - Job B M van Woensel
- Department of Paediatric Intensive Care Medicine, Emma Children's Hospital, Amsterdam UMC Location University of Amsterdam, Meibergdreef 9, Amsterdam, The Netherlands
| | - Lieuwe D J Bos
- Laboratory of Experimental Intensive Care and Anaesthesiology, Amsterdam UMC Location University of Amsterdam, Meibergdreef 9, Amsterdam, The Netherlands
- Department of Intensive Care Medicine, Amsterdam UMC Location University of Amsterdam, Meibergdreef 9, Amsterdam, The Netherlands
| | - Reinout A Bem
- Department of Paediatric Intensive Care Medicine, Emma Children's Hospital, Amsterdam UMC Location University of Amsterdam, Meibergdreef 9, Amsterdam, The Netherlands
- Amsterdam Reproduction and Development Research Institute, Amsterdam UMC Location University of Amsterdam, Meibergdreef 9, Amsterdam, The Netherlands
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10
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Liu S, Huang Y, Jensen S, Laman P, Kramer G, Zaat SAJ, Brul S. Molecular physiological characterization of the dynamics of persister formation in Staphylococcus aureus. Antimicrob Agents Chemother 2024; 68:e0085023. [PMID: 38051079 PMCID: PMC10777834 DOI: 10.1128/aac.00850-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2023] [Accepted: 10/24/2023] [Indexed: 12/07/2023] Open
Abstract
Bacteria possess the ability to enter a growth-arrested state known as persistence in order to survive antibiotic exposure. Clinically, persisters are regarded as the main causative agents for chronic and recurrent infectious diseases. To combat this antibiotic-tolerant population, a better understanding of the molecular physiology of persisters is required. In this study, we collected samples at different stages of the biphasic kill curve to reveal the dynamics of the cellular molecular changes that occur in the process of persister formation. After exposure to antibiotics with different modes of action, namely, vancomycin and enrofloxacin, similar persister levels were obtained. Both shared and distinct stress responses were enriched for the respective persister populations. However, the dynamics of the presence of proteins linked to the persister phenotype throughout the biphasic kill curve and the molecular profiles in a stable persistent population did show large differences, depending on the antibiotic used. This suggests that persisters at the molecular level are highly stress specific, emphasizing the importance of characterizing persisters generated under different stress conditions. Additionally, although generated persisters exhibited cross-tolerance toward tested antibiotics, combined therapies were demonstrated to be a promising approach to reduce persister levels. In conclusion, this investigation sheds light on the stress-specific nature of persisters, highlighting the necessity of tailored treatment approaches and the potential of combined therapy.
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Affiliation(s)
- Shiqi Liu
- Department of Molecular Biology and Microbial Food Safety, University of Amsterdam, Swammerdam Institute for Life Sciences, Amsterdam, the Netherlands
| | - Yixuan Huang
- Laboratory for Mass Spectrometry of Biomolecules, University of Amsterdam, Swammerdam Institute for Life Sciences, Amsterdam, the Netherlands
| | - Sean Jensen
- Department of Molecular Biology and Microbial Food Safety, University of Amsterdam, Swammerdam Institute for Life Sciences, Amsterdam, the Netherlands
| | - Paul Laman
- Department of Molecular Biology and Microbial Food Safety, University of Amsterdam, Swammerdam Institute for Life Sciences, Amsterdam, the Netherlands
| | - Gertjan Kramer
- Laboratory for Mass Spectrometry of Biomolecules, University of Amsterdam, Swammerdam Institute for Life Sciences, Amsterdam, the Netherlands
| | - Sebastian A. J. Zaat
- Department of Medical Microbiology and Infection Prevention, Amsterdam institute for Infection and Immunity, Amsterdam UMC, University of Amsterdam, Amsterdam, the Netherlands
| | - Stanley Brul
- Department of Molecular Biology and Microbial Food Safety, University of Amsterdam, Swammerdam Institute for Life Sciences, Amsterdam, the Netherlands
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11
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Lu B, Zhang J, Zhu G, Liu T, Chen J, Liang X. Highly hydrophilic and dispersed TiO 2 nano-system with enhanced photocatalytic antibacterial activities and accelerated tissue regeneration under visible light. J Nanobiotechnology 2023; 21:491. [PMID: 38115054 PMCID: PMC10731761 DOI: 10.1186/s12951-023-02241-2] [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: 09/26/2023] [Accepted: 12/03/2023] [Indexed: 12/21/2023] Open
Abstract
Titanium dioxide (TiO2)-based photodynamic antibacterial (PDA) agents present a novel approach for addressing drug-resistant bacterial infections and the associated tissue damage. However, the suboptimal dispersibility, negative charge, and weak photocatalytic activity under visible light of TiO2 hinder its practical applications. This study aimed to address these limitations by developing a highly hydrophilic and dispersed Zn-TiO2/reduced graphene oxide (rGO) (HTGZ) nano-system with exceptional visible light catalytic activity and tissue repair ability. HTGZ produced an antibacterial ratio over 98% within a short time, likely due to the enhanced production of reactive oxygen species under visible light. After being co-cultured for 4 days, L929 cells and BMSCs maintained over 90% activity, indicating that HTGZ had no significant cytotoxicity. Furthermore, the transcriptomic and metabolic analyses revealed that the antibacterial mechanism mainly came from the destruction of cell membranes and the disruption of various metabolic processes, such as purine metabolism and fatty acid biosynthesis. Critically, results of in vivo experiments had authenticated that HTGZ significantly promoted infected tissue regeneration by slaughtering bacteria and release Zn2+. After 14 days, the wound area was only one-third that of the control group. Overall, the enhanced antibacterial efficacy and wound-healing potential position HTGZ as a promising nano-antibacterial medication for the clinical treatment of infectious bacterial diseases.
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Affiliation(s)
- Boyao Lu
- State Key Laboratory of Oral Diseases & National Center for Stomatology & National Clinical Research Center for Oral Diseases, Department of Prosthodontics II of West China Hospital of Stomatology, Sichuan University, Chengdu, 610041, Sichuan, China
| | - Jie Zhang
- College of Materials Science and Engineering, Sichuan University, Chengdu, 610065, China
| | - Guixin Zhu
- State Key Laboratory of Oral Diseases & National Center for Stomatology & National Clinical Research Center for Oral Diseases, Department of Prosthodontics II of West China Hospital of Stomatology, Sichuan University, Chengdu, 610041, Sichuan, China
| | - Tiqian Liu
- State Key Laboratory of Oral Diseases & National Center for Stomatology & National Clinical Research Center for Oral Diseases, Department of Prosthodontics II of West China Hospital of Stomatology, Sichuan University, Chengdu, 610041, Sichuan, China
| | - Jinwei Chen
- College of Materials Science and Engineering, Sichuan University, Chengdu, 610065, China.
- Engineering Research Center of Alternative Energy Materials & Devices, Ministry of Education, Sichuan University, Chengdu, 610065, China.
| | - Xing Liang
- State Key Laboratory of Oral Diseases & National Center for Stomatology & National Clinical Research Center for Oral Diseases, Department of Prosthodontics II of West China Hospital of Stomatology, Sichuan University, Chengdu, 610041, Sichuan, China.
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12
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Sun MC, Li DD, Chen YX, Fan XJ, Gao Y, Ye H, Zhang T, Zhao C. Insights into the Mechanisms of Reuterin against Staphylococcus aureus Based on Membrane Damage and Untargeted Metabolomics. Foods 2023; 12:4208. [PMID: 38231661 DOI: 10.3390/foods12234208] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2023] [Revised: 11/19/2023] [Accepted: 11/20/2023] [Indexed: 01/19/2024] Open
Abstract
Reuterin is a dynamic small-molecule complex produced through glycerol fermentation by Limosilactobacillus reuteri and has potential as a food biopreservative. Despite its broad-spectrum antimicrobial activity, the underlying mechanism of action of reuterin is still elusive. The present paper aimed to explore the antibacterial mechanism of reuterin and its effects on membrane damage and the intracellular metabolome of S. aureus. Our results showed that reuterin has a minimum inhibitory concentration of 18.25 mM against S. aureus, based on the 3-hydroxypropionaldehyde level. Key indicators such as extracellular electrical conductivity, membrane potential and permeability were significantly increased, while intracellular pH, ATP and DNA were markedly decreased, implying that reuterin causes a disruption to the structure of the cell membrane. The morphological damage to the cells was confirmed by scanning electron microscopy. Subsequent metabolomic analysis identified significant alterations in metabolites primarily involved in lipid, amino acid, carbohydrate metabolism and phosphotransferase system, which is crucial for cell membrane regulation and energy supply. Consequently, these findings indicated that the antibacterial mechanism of reuterin initially targets lipid and amino acid metabolism, leading to cell membrane damage, which subsequently results in energy metabolism disorder and, ultimately, cell death. This paper offers innovative perspectives on the antibacterial mechanism of reuterin, contributing to its potential application as a food preservative.
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Affiliation(s)
- Mao-Cheng Sun
- College of Food Science and Engineering, Changchun University, Changchun 130022, China
| | - Dian-Dian Li
- College of Food Science and Engineering, Changchun University, Changchun 130022, China
| | - Yu-Xin Chen
- College of Food Science and Engineering, Changchun University, Changchun 130022, China
| | - Xiu-Juan Fan
- College of Food Science and Engineering, Changchun University, Changchun 130022, China
| | - Yu Gao
- College of Food Science and Engineering, Changchun University, Changchun 130022, China
| | - Haiqing Ye
- College of Food Science and Engineering, Jilin University, Changchun 130062, China
| | - Tiehua Zhang
- College of Food Science and Engineering, Jilin University, Changchun 130062, China
| | - Changhui Zhao
- College of Food Science and Engineering, Jilin University, Changchun 130062, China
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13
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Li XY, Zeng ZX, Cheng ZX, Wang YL, Yuan LJ, Zhai ZY, Gong W. Common pathogenic bacteria-induced reprogramming of the host proteinogenic amino acids metabolism. Amino Acids 2023; 55:1487-1499. [PMID: 37814028 PMCID: PMC10689525 DOI: 10.1007/s00726-023-03334-w] [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: 04/02/2023] [Accepted: 09/12/2023] [Indexed: 10/11/2023]
Abstract
Apart from cancer, metabolic reprogramming is also prevalent in other diseases, such as bacterial infections. Bacterial infections can affect a variety of cells, tissues, organs, and bodies, leading to a series of clinical diseases. Common Pathogenic bacteria include Helicobacter pylori, Salmonella enterica, Mycobacterium tuberculosis, Staphylococcus aureus, and so on. Amino acids are important and essential nutrients in bacterial physiology and support not only their proliferation but also their evasion of host immune defenses. Many pathogenic bacteria or opportunistic pathogens infect the host and lead to significant changes in metabolites, especially the proteinogenic amino acids, to inhibit the host's immune mechanism to achieve its immune evasion and pathogenicity. Here, we review the regulation of host metabolism, while host cells are infected by some common pathogenic bacteria, and discuss how amino acids of metabolic reprogramming affect bacterial infections, revealing the potential adjunctive application of amino acids alongside antibiotics.
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Affiliation(s)
- Xiao-Yue Li
- The First School of Clinical Medicine, Southern Medical University, Guangdong, 510515, China
| | - Zi-Xin Zeng
- The First School of Clinical Medicine, Southern Medical University, Guangdong, 510515, China
| | - Zhi-Xing Cheng
- The First School of Clinical Medicine, Southern Medical University, Guangdong, 510515, China
| | - Yi-Lin Wang
- The First School of Clinical Medicine, Southern Medical University, Guangdong, 510515, China
| | - Liang-Jun Yuan
- The First School of Clinical Medicine, Southern Medical University, Guangdong, 510515, China
| | - Zhi-Yong Zhai
- Shenzhen Hospital, Southern Medical University, Shenzhen Clinical Medical College, Southern Medical University, Guangdong, 518101, China.
| | - Wei Gong
- Shenzhen Hospital, Southern Medical University, Shenzhen Clinical Medical College, Southern Medical University, Guangdong, 518101, China.
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14
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Chen X, Xue J, Dong X, Lu P. Uncovering virulence factors in Cronobacter sakazakii: insights from genetic screening and proteomic profiling. Appl Environ Microbiol 2023; 89:e0102823. [PMID: 37750707 PMCID: PMC10617496 DOI: 10.1128/aem.01028-23] [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: 06/20/2023] [Accepted: 07/15/2023] [Indexed: 09/27/2023] Open
Abstract
The increasing problem of antibiotic resistance has driven the search for virulence factors in pathogenic bacteria, which can serve as targets for the development of new antibiotics. Although whole-genome Tn5 transposon mutagenesis combined with phenotypic assays has been a widely used approach, its efficiency remains low due to labor-intensive processes. In this study, we aimed to identify specific genes and proteins associated with the virulence of Cronobacter sakazakii, a pathogenic bacterium known for causing severe infections, particularly in infants and immunocompromised individuals. By employing a combination of genetic screening, comparative proteomics, and in vivo validation using zebrafish and rat models, we rapidly screened highly virulent strains and identified two genes, rcsA and treR, as potential regulators of C. sakazakii toxicity toward zebrafish and rats. Proteomic profiling revealed upregulated proteins upon knockout of rcsA and treR, including FabH, GshA, GppA, GcvH, IhfB, RfaC, MsyB, and three unknown proteins. Knockout of their genes significantly weakened bacterial virulence, confirming their role as potential virulence factors. Our findings contribute to understanding the pathogenicity of C. sakazakii and provide insights into the development of targeted interventions and therapies against this bacterium.IMPORTANCEThe emergence of antibiotic resistance in pathogenic bacteria has become a critical global health concern, necessitating the identification of virulence factors as potential targets for the development of new antibiotics. This study addresses the limitations of conventional approaches by employing a combination of genetic screening, comparative proteomics, and in vivo validation to rapidly identify specific genes and proteins associated with the virulence of Cronobacter sakazakii, a highly pathogenic bacterium responsible for severe infections in vulnerable populations. The identification of two genes, rcsA and treR, as potential regulators of C. sakazakii toxicity toward zebrafish and rats and the proteomic profiling upon knockout of rcsA and treR provides novel insights into the mechanisms underlying bacterial virulence. The findings contribute to our understanding of C. sakazakii's pathogenicity, shed light on the regulatory pathways involved in bacterial virulence, and offer potential targets for the development of novel interventions against this highly virulent bacterium.
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Affiliation(s)
- Xi Chen
- Tianjin Eye Hospital, Tianjin Eye Institute,Tianjin Key Laboratory of Ophthalmology and Visual Science, Tianjin, China
| | - Juan Xue
- Institute of Infection and Immunity, Taihe Hospital, Hubei University of Medicine, Shiyan, China
| | - Xiaoli Dong
- Tianjin Eye Hospital, Tianjin Eye Institute,Tianjin Key Laboratory of Ophthalmology and Visual Science, Tianjin, China
| | - Ping Lu
- Tianjin Eye Hospital, Tianjin Eye Institute,Tianjin Key Laboratory of Ophthalmology and Visual Science, Tianjin, China
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15
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Subramanian C, Yun MK, Frank MM, Rock CO. Lysophosphatidylglycerol (LPG) phospholipase D maintains membrane homeostasis in Staphylococcus aureus by converting LPG to lysophosphatidic acid. J Biol Chem 2023; 299:104863. [PMID: 37236358 PMCID: PMC10404611 DOI: 10.1016/j.jbc.2023.104863] [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: 04/14/2023] [Revised: 05/17/2023] [Accepted: 05/18/2023] [Indexed: 05/28/2023] Open
Abstract
Lysophospholipids are deacylated derivatives of their bilayer forming phospholipid counterparts that are present at low concentrations in cells. Phosphatidylglycerol (PG) is the principal membrane phospholipid in Staphylococcus aureus and lysophosphatidylglycerol (LPG) is detected in low abundance. Here, we used a mass spectrometry screen to identify locus SAUSA300_1020 as the gene responsible for maintaining low concentrations of 1-acyl-LPG in S. aureus. The SAUSA300_1020 gene encodes a protein with a predicted amino terminal transmembrane α-helix attached to a globular glycerophosphodiester phosphodiesterase (GDPD) domain. We determined that the purified protein lacking the hydrophobic helix (LpgDΔN) possesses cation-dependent lysophosphatidylglycerol phospholipase D activity that generates both lysophosphatidic acid (LPA) and cyclic-LPA products and hydrolyzes cyclic-LPA to LPA. Mn2+ was the highest affinity cation and stabilized LpgDΔN to thermal denaturation. LpgDΔN was not specific for the phospholipid headgroup and degraded 1-acyl-LPG, but not 2-acyl-LPG. Furthermore, a 2.1 Å crystal structure shows that LpgDΔN adopts the GDPD variation of the TIM barrel architecture except for the length and positioning of helix α6 and sheet β7. These alterations create a hydrophobic diffusion path for LPG to access the active site. The LpgD active site has the canonical GDPD metal binding and catalytic residues, and our biochemical characterization of site-directed mutants support a two-step mechanism involving a cyclic-LPA intermediate. Thus, the physiological function of LpgD in S. aureus is to convert LPG to LPA, which is re-cycled into the PG biosynthetic pathway at the LPA acyltransferase step to maintain membrane PG molecular species homeostasis.
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Affiliation(s)
- Chitra Subramanian
- Department of Infectious Diseases, St Jude Children's Research Hospital, Memphis, Tennessee, USA
| | - Mi-Kyung Yun
- Department of Infectious Diseases, St Jude Children's Research Hospital, Memphis, Tennessee, USA
| | - Matthew M Frank
- Department of Infectious Diseases, St Jude Children's Research Hospital, Memphis, Tennessee, USA
| | - Charles O Rock
- Department of Infectious Diseases, St Jude Children's Research Hospital, Memphis, Tennessee, USA.
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16
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Fenn D, Ahmed WM, Lilien TA, Kos R, Tuip de Boer AM, Fowler SJ, Schultz MJ, Maitland-van der Zee AH, Brinkman P, Bos LDJ. Influence of bacterial and alveolar cell co-culture on microbial VOC production using HS-GC/MS. Front Mol Biosci 2023; 10:1160106. [PMID: 37179567 PMCID: PMC10169821 DOI: 10.3389/fmolb.2023.1160106] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2023] [Accepted: 03/30/2023] [Indexed: 05/15/2023] Open
Abstract
Volatile organic compounds (VOCs) found in exhaled breath continue to garner interest as an alternative diagnostic tool in pulmonary infections yet, their clinical integration remains a challenge with difficulties in translating identified biomarkers. Alterations in bacterial metabolism secondary to host nutritional availability may explain this but is often inadequately modelled in vitro. The influence of more clinically relevant nutrients on VOC production for two common respiratory pathogens was investigated. VOCs from Staphylococcus aureus (S.aureus) and Pseudomonas aeruginosa (P.aeruginosa) cultured with and without human alveolar A549 epithelial cells were analyzed using headspace extraction coupled with gas chromatography-mass spectrometry. Untargeted and targeted analyses were performed, volatile molecules identified from published data, and the differences in VOC production evaluated. Principal component analysis (PCA) could differentiate alveolar cells from either S. aureus or P. aeruginosa when cultured in isolation based on PC1 (p = 0.0017 and 0.0498, respectively). However, this separation was lost for S. aureus (p = 0.31) but not for P. aeruginosa (p = 0.028) when they were cultured with alveolar cells. S. aureus cultured with alveolar cells led to higher concentrations of two candidate biomarkers, 3-methyl-1-butanol (p = 0.001) and 3-methylbutanal (p = 0.002) when compared to S. aureus, alone. P. aeruginosa metabolism resulted in less generation of pathogen-associated VOCs when co-cultured with alveolar cells compared to culturing in isolation. VOC biomarkers previously considered indicative of bacterial presence are influenced by the local nutritional environment and this should be considered when evaluating their biochemical origin.
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Affiliation(s)
- Dominic Fenn
- Department of Pulmonary medicine, Amsterdam UMC, University of Amsterdam, Amsterdam, Netherlands
- Laboratory of Experimental Intensive Care and Anaesthesiology, Amsterdam UMC, University of Amsterdam, Amsterdam, Netherlands
| | - Waqar M. Ahmed
- Division of Immunology, Immunity to Infection and Respiratory Medicine, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, United Kingdom
| | - Thijs A. Lilien
- Laboratory of Experimental Intensive Care and Anaesthesiology, Amsterdam UMC, University of Amsterdam, Amsterdam, Netherlands
- NIHR-Manchester Biomedical Research Centre, Manchester University Hospitals NHS Foundation Trust, Amsterdam, United Kingdom
| | - Renate Kos
- Department of Pulmonary medicine, Amsterdam UMC, University of Amsterdam, Amsterdam, Netherlands
| | - Anita M. Tuip de Boer
- Laboratory of Experimental Intensive Care and Anaesthesiology, Amsterdam UMC, University of Amsterdam, Amsterdam, Netherlands
| | - Stephen J. Fowler
- Division of Immunology, Immunity to Infection and Respiratory Medicine, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, United Kingdom
- Paediatric Intensive Care Unit, Emma Children’s Hospital, Amsterdam UMC, University of Amsterdam, Amsterdam, Netherlands
| | - Marcus J. Schultz
- Intensive Care, Amsterdam UMC, University of Amsterdam, Amsterdam, Netherlands
| | | | - Paul Brinkman
- Department of Pulmonary medicine, Amsterdam UMC, University of Amsterdam, Amsterdam, Netherlands
| | - Lieuwe D. J. Bos
- Department of Pulmonary medicine, Amsterdam UMC, University of Amsterdam, Amsterdam, Netherlands
- Laboratory of Experimental Intensive Care and Anaesthesiology, Amsterdam UMC, University of Amsterdam, Amsterdam, Netherlands
- Intensive Care, Amsterdam UMC, University of Amsterdam, Amsterdam, Netherlands
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17
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Subramanian C, Frank MW, Yun MK, Rock CO. The Phospholipase A1 Activity of Glycerol Ester Hydrolase (Geh) Is Responsible for Extracellular 2-12( S)-Methyltetradecanoyl-Lysophosphatidylglycerol Production in Staphylococcus aureus. mSphere 2023; 8:e0003123. [PMID: 36976028 PMCID: PMC10117073 DOI: 10.1128/msphere.00031-23] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2023] [Accepted: 03/07/2023] [Indexed: 03/29/2023] Open
Abstract
Phosphatidylglycerol (PG) is the major membrane phospholipid of Staphylococcus aureus and predominately consists of molecular species with ≥16-carbon acyl chains in the 1-position and anteiso 12(S)-methyltetradecaonate (a15) esterified at the 2-position. The analysis of the growth media for PG-derived products shows S. aureus releases essentially pure 2-12(S)-methyltetradecanoyl-sn-glycero-3-phospho-1'-sn-glycerol (a15:0-LPG) derived from the hydrolysis of the 1-position of PG into the environment. The cellular lysophosphatidylglycerol (LPG) pool is dominated by a15-LPG but also consists of ≥16-LPG species arising from the removal of the 2-position. Mass tracing experiments confirmed a15-LPG was derived from isoleucine metabolism. A screen of candidate secreted lipase knockout strains pinpointed glycerol ester hydrolase (geh) as the gene required for generating extracellular a15-LPG, and complementation of a Δgeh strain with a Geh expression plasmid restored extracellular a15-LPG formation. Orlistat, a covalent inhibitor of Geh, also attenuated extracellular a15-LPG accumulation. Purified Geh hydrolyzed the 1-position acyl chain of PG and generated only a15-LPG from a S. aureus lipid mixture. The Geh product was 2-a15-LPG, which spontaneously isomerizes with time to a mixture of 1- and 2-a15-LPG. Docking PG in the Geh active site provides a structural rationale for the positional specificity of Geh. These data demonstrate a physiological role for Geh phospholipase A1 activity in S. aureus membrane phospholipid turnover. IMPORTANCE Glycerol ester hydrolase, Geh, is an abundant secreted lipase whose expression is controlled by the accessory gene regulator (Agr) quorum-sensing signal transduction pathway. Geh is thought to have a role in virulence based on its ability to hydrolyze host lipids at the infection site to provide fatty acids for membrane biogenesis and substrates for oleate hydratase, and Geh inhibits immune cell activation by hydrolyzing lipoprotein glycerol esters. The discovery that Geh is the major contributor to the formation and release of a15-LPG reveals an unappreciated physiological role for Geh acting as a phospholipase A1 in the degradation of S. aureus membrane phosphatidylglycerol. The role(s) for extracellular a15-LPG in S. aureus biology remain to be elucidated.
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Affiliation(s)
- Chitra Subramanian
- Department of Infectious Diseases, St. Jude Children’s Research Hospital, Memphis, Tennessee, USA
| | - Matthew W. Frank
- Department of Infectious Diseases, St. Jude Children’s Research Hospital, Memphis, Tennessee, USA
| | - My-Kyung Yun
- Department of Infectious Diseases, St. Jude Children’s Research Hospital, Memphis, Tennessee, USA
| | - Charles O. Rock
- Department of Infectious Diseases, St. Jude Children’s Research Hospital, Memphis, Tennessee, USA
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18
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Xie W, Chen J, Cheng X, Feng H, Zhang X, Zhu Z, Dong S, Wan Q, Pei X, Wang J. Multi-Mechanism Antibacterial Strategies Enabled by Synergistic Activity of Metal-Organic Framework-Based Nanosystem for Infected Tissue Regeneration. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2023; 19:e2205941. [PMID: 36587967 DOI: 10.1002/smll.202205941] [Citation(s) in RCA: 14] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/27/2022] [Revised: 11/20/2022] [Indexed: 06/17/2023]
Abstract
Drug-resistant bacterial infection impairs tissue regeneration and is a challenging clinical problem. Metal-organic frameworks (MOFs)-based photodynamic therapy (PDT) opens up a new era for antibiotic-free infection treatment. However, the MOF-based PDT normally encounters limited photon absorbance under visible light and notorious recombination of photogenerated holes and electrons, which significantly impede their applications. Herein, a MOFs-based nanosystem (AgNPs@MOFs) with enhanced visible light response and charge carrier separation is developed by modifying MOFs with silver nanoparticles (AgNPs) to improve PDT efficiency. The AgNPs@MOFs with enhanced photodynamic performance under visible light irradiation mainly disrupt bacteria translation process and the metabolism of purine and pyrimidine. In addition, the introduction of AgNPs endows nanosystems with chemotherapy ability, which causes destructive effect on bacterial cell membrane, including membrane ATPase protein and fatty acids. AgNPs@MOFs show excellent synergistic drug-resistant bacterial killing efficiency through multiple mechanisms, which further restrain bacterial resistance. In addition, biocompatible AgNPs@MOFs pose potential tissue regeneration ability in both Methicillin-resistant Staphylococcus aureus (MRSA)-related soft and hard tissue infection. Overall, this study provides a promising perspective in the exploration of AgNPs@MOFs as nano antibacterial medicine against drug-resistant bacteria for infected tissue regeneration in the future.
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Affiliation(s)
- Wenjia Xie
- State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, Department of Prosthodontics, West China Hospital of Stomatology, Sichuan University, Chengdu, 610041, China
| | - Junyu Chen
- State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, Department of Prosthodontics, West China Hospital of Stomatology, Sichuan University, Chengdu, 610041, China
| | - Xinting Cheng
- State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, Department of Prosthodontics, West China Hospital of Stomatology, Sichuan University, Chengdu, 610041, China
- Stomatology Hospital, School of Stomatology, Zhejiang University School of Medicine, Zhejiang Provincial Clinical Research Center for Oral Diseases, Key Laboratory of Oral Biomedical Research of Zhejiang Province, Cancer Center of Zhejiang University, Hangzhou, 310006, China
| | - Hao Feng
- State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, Department of Prosthodontics, West China Hospital of Stomatology, Sichuan University, Chengdu, 610041, China
| | - Xin Zhang
- State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, Department of Prosthodontics, West China Hospital of Stomatology, Sichuan University, Chengdu, 610041, China
| | - Zhou Zhu
- State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, Department of Prosthodontics, West China Hospital of Stomatology, Sichuan University, Chengdu, 610041, China
| | - Shanshan Dong
- Key Laboratory of Jiangxi Province for Persistent Pollutants Control and Resources Recycle, School of Environmental and Chemical Engineering, Nanchang Hangkong University, Nanchang, 330063, China
| | - Qianbing Wan
- State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, Department of Prosthodontics, West China Hospital of Stomatology, Sichuan University, Chengdu, 610041, China
| | - Xibo Pei
- State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, Department of Prosthodontics, West China Hospital of Stomatology, Sichuan University, Chengdu, 610041, China
| | - Jian Wang
- State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, Department of Prosthodontics, West China Hospital of Stomatology, Sichuan University, Chengdu, 610041, China
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19
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Ahmed WM, Fenn D, White IR, Dixon B, Nijsen TME, Knobel HH, Brinkman P, Van Oort PMP, Schultz MJ, Dark P, Goodacre R, Felton T, Bos LDJ, Fowler SJ. Microbial Volatiles as Diagnostic Biomarkers of Bacterial Lung Infection in Mechanically Ventilated Patients. Clin Infect Dis 2023; 76:1059-1066. [PMID: 36310531 PMCID: PMC10029988 DOI: 10.1093/cid/ciac859] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2022] [Revised: 10/18/2022] [Accepted: 10/27/2022] [Indexed: 12/23/2022] Open
Abstract
BACKGROUND Early and accurate recognition of respiratory pathogens is crucial to prevent increased risk of mortality in critically ill patients. Microbial-derived volatile organic compounds (mVOCs) in exhaled breath could be used as noninvasive biomarkers of infection to support clinical diagnosis. METHODS In this study, we investigated the diagnostic potential of in vitro-confirmed mVOCs in the exhaled breath of patients under mechanical ventilation from the BreathDx study. Samples were analyzed by thermal desorption-gas chromatography-mass spectrometry. RESULTS Pathogens from bronchoalveolar lavage (BAL) cultures were identified in 45 of 89 patients and Staphylococcus aureus was the most commonly identified pathogen (n = 15). Of 19 mVOCs detected in the in vitro culture headspace of 4 common respiratory pathogens (S. aureus, Pseudomonas aeruginosa, Klebsiella pneumoniae, and Escherichia coli), 14 were found in exhaled breath samples. Higher concentrations of 2 mVOCs were found in the exhaled breath of patients infected with S. aureus compared to those without (3-methylbutanal: P < .01, area under the receiver operating characteristic curve [AUROC] = 0.81-0.87; and 3-methylbutanoic acid: P = .01, AUROC = 0.79-0.80). In addition, bacteria identified from BAL cultures that are known to metabolize tryptophan (E. coli, Klebsiella oxytoca, and Haemophilus influenzae) were grouped and found to produce higher concentrations of indole compared to breath samples with culture-negative (P = .034) and other pathogen-positive (P = .049) samples. CONCLUSIONS This study demonstrates the capability of using mVOCs to detect the presence of specific pathogen groups with potential to support clinical diagnosis. Although not all mVOCs were found in patient samples within this small pilot study, further targeted and qualitative investigation is warranted using multicenter clinical studies.
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Affiliation(s)
- Waqar M Ahmed
- Division of Infection, Immunity and Respiratory Medicine, School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, and Manchester Academic Health Science Centre and National Institute for Health Research Biomedical Research Centre, Manchester University Hospitals NHS Foundation Trust, Manchester, United Kingdom
| | - Dominic Fenn
- Department of Respiratory Medicine, Amsterdam UMC-location AMC, University of Amsterdam, Amsterdam, The Netherlands
- Laboratory of Experimental Intensive Care and Anaesthesiology, Amsterdam University Medical Center (UMC), Academic Medical Center (AMC), Amsterdam, The Netherlands
| | - Iain R White
- Division of Infection, Immunity and Respiratory Medicine, School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, and Manchester Academic Health Science Centre and National Institute for Health Research Biomedical Research Centre, Manchester University Hospitals NHS Foundation Trust, Manchester, United Kingdom
- Laboratory for Environmental and Life Science, University of Nova Gorica, Nova Gorica, Slovenia
| | - Breanna Dixon
- Division of Infection, Immunity and Respiratory Medicine, School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, and Manchester Academic Health Science Centre and National Institute for Health Research Biomedical Research Centre, Manchester University Hospitals NHS Foundation Trust, Manchester, United Kingdom
| | | | - Hugo H Knobel
- Eurofins Materials Science Netherlands BV, High Tech Campus, Eindhoven, The Netherlands
| | - Paul Brinkman
- Department of Respiratory Medicine, Amsterdam UMC-location AMC, University of Amsterdam, Amsterdam, The Netherlands
| | - Pouline M P Van Oort
- Department of Anaesthesiology, Amsterdam UMC Location VU Medical Center, Amsterdam, The Netherlands
| | - Marcus J Schultz
- Intensive Care, Amsterdam UMC Location AMC, Amsterdam, The Netherlands
- Mahidol-Oxford Tropical Medicine Research Unit, Mahidol University, Bangkok, Thailand
- Department of Clinical Affairs, Hamilton Medical AG, Chur, Switzerland
| | - Paul Dark
- Division of Infection, Immunity and Respiratory Medicine, School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, and Manchester Academic Health Science Centre and National Institute for Health Research Biomedical Research Centre, Manchester University Hospitals NHS Foundation Trust, Manchester, United Kingdom
- Critical Care Unit, Salford Royal NHS Foundation Trust, Northern Care Alliance NHS Group, Manchester, United Kingdom
| | - Royston Goodacre
- Centre for Metabolomics Research, Department of Biochemistry and Systems Biology, Institute of Systems, Molecular and Integrative Biology, University of Liverpool, Liverpool, United Kingdom
| | - Timothy Felton
- Division of Infection, Immunity and Respiratory Medicine, School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, and Manchester Academic Health Science Centre and National Institute for Health Research Biomedical Research Centre, Manchester University Hospitals NHS Foundation Trust, Manchester, United Kingdom
| | - Lieuwe D J Bos
- Department of Respiratory Medicine, Amsterdam UMC-location AMC, University of Amsterdam, Amsterdam, The Netherlands
- Laboratory of Experimental Intensive Care and Anaesthesiology, Amsterdam University Medical Center (UMC), Academic Medical Center (AMC), Amsterdam, The Netherlands
- Mahidol-Oxford Tropical Medicine Research Unit, Mahidol University, Bangkok, Thailand
| | - Stephen J Fowler
- Division of Infection, Immunity and Respiratory Medicine, School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, and Manchester Academic Health Science Centre and National Institute for Health Research Biomedical Research Centre, Manchester University Hospitals NHS Foundation Trust, Manchester, United Kingdom
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20
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Whaley SG, Frank MW, Rock CO. A short-chain acyl-CoA synthetase that supports branched-chain fatty acid synthesis in Staphylococcus aureus. J Biol Chem 2023; 299:103036. [PMID: 36806679 PMCID: PMC10026030 DOI: 10.1016/j.jbc.2023.103036] [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: 12/19/2022] [Revised: 01/24/2023] [Accepted: 02/09/2023] [Indexed: 02/18/2023] Open
Abstract
Staphylococcus aureus controls its membrane biophysical properties using branched-chain fatty acids (BCFAs). The branched-chain acyl-CoA precursors, utilized to initiate fatty acid synthesis, are derived from branched-chain ketoacid dehydrogenase (Bkd), a multiprotein complex that converts α-keto acids to their corresponding acyl-CoAs; however, Bkd KO strains still contain BCFAs. Here, we show that commonly used rich medias contain substantial concentrations of short-chain acids, like 2-methylbutyric and isobutyric acids, that are incorporated into membrane BCFAs. Bkd-deficient strains cannot grow in defined medium unless it is supplemented with either 2-methylbutyric or isobutyric acid. We performed a screen of candidate KO strains and identified the methylbutyryl-CoA synthetase (mbcS gene; SAUSA300_2542) as required for the incorporation of 2-methylbutyric and isobutyric acids into phosphatidylglycerol. Our mass tracing experiments show that isobutyric acid is converted to isobutyryl-CoA that flows into the even-chain acyl-acyl carrier protein intermediates in the type II fatty acid biosynthesis elongation cycle. Furthermore, purified MbcS is an ATP-dependent acyl-CoA synthetase that selectively catalyzes the activation of 2-methylbutyrate and isobutyrate. We found that butyrate and isovalerate are poor MbcS substrates and activity was not detected with acetate or short-chain dicarboxylic acids. Thus, MbcS functions to convert extracellular 2-methylbutyric and isobutyric acids to their respective acyl-CoAs that are used by 3-ketoacyl-ACP synthase III (FabH) to initiate BCFA biosynthesis.
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Affiliation(s)
- Sarah G Whaley
- Department of Infectious Diseases, St Jude Children's Research Hospital, Memphis, Tennessee, USA
| | - Matthew W Frank
- Department of Infectious Diseases, St Jude Children's Research Hospital, Memphis, Tennessee, USA
| | - Charles O Rock
- Department of Infectious Diseases, St Jude Children's Research Hospital, Memphis, Tennessee, USA.
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21
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Ahmed W, Bardin E, Davis MD, Sermet-Gaudelus I, Grassin Delyle S, Fowler SJ. Volatile metabolites differentiate air-liquid interface cultures after infection with Staphylococcus aureus. Analyst 2023; 148:618-627. [PMID: 36597770 DOI: 10.1039/d2an01205g] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Early detection of lung infection is critical to clinical diagnosis, treatment, and monitoring. Measuring volatile organic compounds (VOCs) in exhaled breath has shown promise as a rapid and accurate method of evaluating disease metabolism and phenotype. However, further investigations of the role and function of VOCs in bacterial-host-stress response is required and this can only be realised through representative in vitro models. In this study we sampled VOCs from the headspace of A549 cells at an air-liquid interface (ALI). We hypothesised VOC sampling from ALI cultures could be used to profile potential biomarkers of S. aureus lung infection. VOCs were collected using thin film microextraction (TFME) and were analysed by thermal desorption-gas chromatography-mass spectrometry. After optimising ALI cultures, we observed seven VOCs changed between A549 and media control samples. After infecting cells with S. aureus, supervised principal component-discriminant function analysis revealed 22 VOCs were found to be significantly changed in infected cells compared to uninfected cells (p < 0.05), five of which were also found in parallel axenic S. aureus cultures. We have demonstrated VOCs that could be used to identify S. aureus in ALI cultures, supporting further investigation of VOC analysis as a highly sensitive and specific test for S. aureus lung infection.
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Affiliation(s)
- Waqar Ahmed
- Division of Immunology, Immunity to infection & Respiratory Medicine, Faculty of Biology, Medicine, and Health, University of Manchester, Manchester, UK
| | - Emmanuelle Bardin
- Institut Necker-Enfants Malades, Paris, France.,Université Paris-Saclay, UVSQ, INSERM, Infection et inflammation, Montigny le Bretonneux, France
| | - Michael D Davis
- Herman B Wells Center for Pediatric Research, Pediatric Pulmonology, Allergy, and Sleep Medicine, Indiana University School of Medicine, Indianapolis, USA
| | - Isabelle Sermet-Gaudelus
- Institut Necker-Enfants Malades, Paris, France.,Service de Pneumo-Pédiatrie, Université René Descartes, Hôpital Necker-Enfants Malades, Paris, France
| | - Stanislas Grassin Delyle
- Université Paris-Saclay, UVSQ, INSERM, Infection et inflammation, Montigny le Bretonneux, France.,Hôpital Foch, Exhalomics, Département des maladies des voies respiratoires, Suresnes, France
| | - Stephen J Fowler
- Division of Immunology, Immunity to infection & Respiratory Medicine, Faculty of Biology, Medicine, and Health, University of Manchester, Manchester, UK.,NIHR Manchester Biomedical Research Centre, Manchester University Hospitals NHS Foundation Trust, Education and Research Centre, W ythenshawe Hospital, Manchester, M23 9LT, UK.
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22
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Zhang B, Hu S, Sun S, Fang T, Yu Y, Sun X, Xu N. Transcriptomic analysis provides insights into the algicidal mechanism of cocamidopropyl betaine against the red tide microalgae Skeletonema costatum. MARINE ENVIRONMENTAL RESEARCH 2023; 183:105838. [PMID: 36525828 DOI: 10.1016/j.marenvres.2022.105838] [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: 11/04/2022] [Revised: 11/25/2022] [Accepted: 11/27/2022] [Indexed: 06/17/2023]
Abstract
This study investigated the effect of the surfactant cocamidopropyl betaine (CAB) on the growth of red tide microalgae Skeletonema costatum. It was found that CAB caused cell lysis in a time- and dose-dependent manner and significantly inhibited the growth of S. costatum. Additionally, the transcriptomic approach was coupled with physiological analysis to elucidate the inhibitory mechanism of CAB on S. costatum. Among the 30726 genes identified, 17720 and 20583 genes were differentially expressed after treatment for 3 h and 6 h, respectively, which revealed that CAB redirected metabolic pathways, of which the expressions of genes related to the proteasome, ABC transporters, and amino acid-related metabolism were significantly upregulated, while genes involved in photosynthesis, biofilm and cell wall synthesis, mitogen-activated protein kinase (MAPK) cascades and antioxidant system were downregulated. The results above corresponded to the decreasing antioxidant enzymes activities, protein and photosynthetic pigments contents, as well as the increasing malondialdehyde (MDA) content. Our study presented herein shed light on the algicidal mechanism of CAB at the transcriptome level and was useful to red tide control, and marine environmental protection.
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Affiliation(s)
- Bo Zhang
- Key Laboratory of Marine Biotechnology of Zhejiang Province, School of Marine Sciences, Ningbo University, Ningbo, 315211, Zhejiang, China
| | - Shanshan Hu
- Key Laboratory of Marine Biotechnology of Zhejiang Province, School of Marine Sciences, Ningbo University, Ningbo, 315211, Zhejiang, China
| | - Siqi Sun
- Key Laboratory of Marine Biotechnology of Zhejiang Province, School of Marine Sciences, Ningbo University, Ningbo, 315211, Zhejiang, China
| | - Tian Fang
- Key Laboratory of Marine Biotechnology of Zhejiang Province, School of Marine Sciences, Ningbo University, Ningbo, 315211, Zhejiang, China
| | - Yanyan Yu
- Key Laboratory of Marine Biotechnology of Zhejiang Province, School of Marine Sciences, Ningbo University, Ningbo, 315211, Zhejiang, China
| | - Xue Sun
- Key Laboratory of Marine Biotechnology of Zhejiang Province, School of Marine Sciences, Ningbo University, Ningbo, 315211, Zhejiang, China
| | - Nianjun Xu
- Key Laboratory of Marine Biotechnology of Zhejiang Province, School of Marine Sciences, Ningbo University, Ningbo, 315211, Zhejiang, China.
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23
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Pendleton A, Yeo WS, Alqahtani S, DiMaggio DA, Stone CJ, Li Z, Singh VK, Montgomery CP, Bae T, Brinsmade SR. Regulation of the Sae Two-Component System by Branched-Chain Fatty Acids in Staphylococcus aureus. mBio 2022; 13:e0147222. [PMID: 36135382 PMCID: PMC9600363 DOI: 10.1128/mbio.01472-22] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2022] [Accepted: 09/01/2022] [Indexed: 11/29/2022] Open
Abstract
Staphylococcus aureus is a ubiquitous Gram-positive bacterium and an opportunistic human pathogen. S. aureus pathogenesis relies on a complex network of regulatory factors that adjust gene expression. Two important factors in this network are CodY, a repressor protein responsive to nutrient availability, and the SaeRS two-component system (TCS), which responds to neutrophil-produced factors. Our previous work revealed that CodY regulates the secretion of many toxins indirectly via Sae through an unknown mechanism. We report that disruption of codY results in increased levels of phosphorylated SaeR (SaeR~P) and that codY mutant cell membranes contain a higher percentage of branched-chain fatty acids (BCFAs) than do wild-type membranes, prompting us to hypothesize that changes to membrane composition modulate the activity of the SaeS sensor kinase. Disrupting the lpdA gene encoding dihydrolipoyl dehydrogenase, which is critical for BCFA synthesis, significantly reduced the abundance of SaeR, phosphorylated SaeR, and BCFAs in the membrane, resulting in reduced toxin production and attenuated virulence. Lower SaeR levels could be explained in part by reduced stability. Sae activity in the lpdA mutant could be complemented genetically and chemically with exogenous short- or full-length BCFAs. Intriguingly, lack of lpdA also alters the activity of other TCSs, suggesting a specific BCFA requirement managing the basal activity of multiple TCSs. These results reveal a novel method of posttranscriptional virulence regulation via BCFA synthesis, potentially linking CodY activity to multiple virulence regulators in S. aureus. IMPORTANCE Two-component systems (TCSs) are an essential way that bacteria sense and respond to their environment. These systems are usually composed of a membrane-bound histidine kinase that phosphorylates a cytoplasmic response regulator. Because most of the histidine kinases are embedded in the membrane, lipids can allosterically regulate the activity of these sensors. In this study, we reveal that branched-chain fatty acids (BCFAs) are required for the activation of multiple TCSs in Staphylococcus aureus. Using both genetic and biochemical data, we show that the activity of the virulence activator SaeS and the phosphorylation of its response regulator SaeR are reduced in a branched-chain keto-acid dehydrogenase complex mutant and that defects in BCFA synthesis have far-reaching consequences for exotoxin secretion and virulence. Finally, we show that mutation of the global nutritional regulator CodY alters BCFA content in the membrane, revealing a potential mechanism of posttranscriptional regulation of the Sae system by CodY.
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Affiliation(s)
| | - Won-Sik Yeo
- Department of Biology, Georgetown University, Washington, DC, USA
| | - Shahad Alqahtani
- Department of Biology, Georgetown University, Washington, DC, USA
| | | | - Carl J. Stone
- Department of Biology, Georgetown University, Washington, DC, USA
| | - Zhaotao Li
- Center for Microbial Pathogenesis, Abigail Wexner Institute at Nationwide Children’s Hospital, Columbus, Ohio, USA
| | - Vineet K. Singh
- Department of Microbiology and Immunology, A.T. Still University of Health Sciences, Kirksville, Missouri, USA
| | - Christopher P. Montgomery
- Center for Microbial Pathogenesis, Abigail Wexner Institute at Nationwide Children’s Hospital, Columbus, Ohio, USA
- Department of Pediatrics, College of Medicine, The Ohio State University, Columbus, Ohio, USA
| | - Taeok Bae
- Department of Microbiology and Immunology, Indiana University School of Medicine-Northwest, Gary, Indiana, USA
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24
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Zhou J, Zhao H, Yang H, He C, Shu W, Cui Z, Liu Q. Insights Into the Impact of Small RNA SprC on the Metabolism and Virulence of Staphylococcus aureus. Front Cell Infect Microbiol 2022; 12:746746. [PMID: 35281456 PMCID: PMC8905650 DOI: 10.3389/fcimb.2022.746746] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2021] [Accepted: 01/31/2022] [Indexed: 11/24/2022] Open
Abstract
Aim Our previous proteomic analysis showed that small RNA SprC (one of the small pathogenicity island RNAs) of Staphylococcus aureus possesses the ability to regulate the expression of multiple bacterial proteins. In this study, our objective was to further provide insights into the regulatory role of SprC in gene transcription and metabolism of S. aureus. Methods Gene expression profiles were obtained from S. aureus N315 wild-type and its sprC deletion mutant strains by RNA-sequencing (RNA-seq), and differentially expressed genes (DEGs) were screened by R language with a |log2(fold change)| ≥1 and a false discovery rate (FDR) ≤ 0.05. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis were carried out to understand the significance of the DEGs. The quality of RNA-seq was further verified by quantitative real-time PCR (qRT-PCR), mRNA target prediction, metabolomics analysis and transcript-level expression analysis of genes of sprC complementation strain. Results A total of 2497 transcripts were identified, of which 60 transcripts expressions in sprC knockout strain were significantly different (37 up-regulated and 23 down-regulated DEGs). GO analysis showed that the functions of these DEGs were mainly concentrated in the biological process and molecular function related to metabolism and pathogenesis, and a higher number of genes were involved in the oxidation-reduction process, catalytic activity and binding. KEGG pathways enrichment analysis demonstrated that metabolism and pathogenesis were the most affected pathways, such as metabolic pathways, biosynthesis of secondary metabolites, purine metabolism, fructose and mannose metabolism and S. aureus infection. The qRT-PCR results of the DEGs with defined functions in the sprC deletion and complementation strains were in general agreement with those obtained by RNA-seq. Metabolomics analysis revealed 77 specific pathways involving metabolic pathways. Among them, many, such as metabolic pathways, biosynthesis of secondary metabolites and purine metabolism, were consistent with those enriched in the RNA-seq analysis. Conclusion This study offered valuable and reliable information about the regulatory roles of SprC in S. aureus biology through transcriptomics and metabolomics analysis. These results may provide clues for new potential targets for anti-virulence adjuvant therapy on S. aureus infection.
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Affiliation(s)
- Jingwen Zhou
- Department of Clinical Laboratory, Shanghai General Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China
| | - Huanqiang Zhao
- Obstetrics and Gynaecology Hospital, Fudan University, Shanghai, China
- The Shanghai Key Laboratory of Female Reproductive Endocrine-Related Diseases, Shanghai, China
| | - Han Yang
- Department of Clinical Laboratory, Shanghai General Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China
| | - Chunyan He
- Department of Clinical Laboratory, Shanghai General Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China
| | - Wen Shu
- Department of Clinical Laboratory, Shanghai General Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China
| | - Zelin Cui
- Department of Clinical Laboratory, Shanghai General Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China
| | - Qingzhong Liu
- Department of Clinical Laboratory, Shanghai Municipal Hospital of Traditional Chinese Medicine, Shanghai University of Traditional Chinese Medicine, Shanghai, China
- *Correspondence: Qingzhong Liu,
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25
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Whaley SG, Radka CD, Subramanian C, Frank MW, Rock CO. Malonyl-acyl carrier protein decarboxylase activity promotes fatty acid and cell envelope biosynthesis in Proteobacteria. J Biol Chem 2021; 297:101434. [PMID: 34801557 PMCID: PMC8666670 DOI: 10.1016/j.jbc.2021.101434] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2021] [Revised: 11/02/2021] [Accepted: 11/09/2021] [Indexed: 11/20/2022] Open
Abstract
Bacterial fatty acid synthesis in Escherichia coli is initiated by the condensation of an acetyl-CoA with a malonyl-acyl carrier protein (ACP) by the β-ketoacyl-ACP synthase III enzyme, FabH. E. coli ΔfabH knockout strains are viable because of the yiiD gene that allows FabH-independent fatty acid synthesis initiation. However, the molecular function of the yiiD gene product is not known. Here, we show the yiiD gene product is a malonyl-ACP decarboxylase (MadA). MadA has two independently folded domains: an amino-terminal N-acetyl transferase (GNAT) domain (MadAN) and a carboxy-terminal hot dog dimerization domain (MadAC) that encodes the malonyl-ACP decarboxylase function. Members of the proteobacterial Mad protein family are either two domain MadA (GNAT-hot dog) or standalone MadB (hot dog) decarboxylases. Using structure-guided, site-directed mutagenesis of MadB from Shewanella oneidensis, we identified Asn45 on a conserved catalytic loop as critical for decarboxylase activity. We also found that MadA, MadAC, or MadB expression all restored normal cell size and growth rates to an E. coli ΔfabH strain, whereas the expression of MadAN did not. Finally, we verified that GlmU, a bifunctional glucosamine-1-phosphate N-acetyl transferase/N-acetyl-glucosamine-1-phosphate uridylyltransferase that synthesizes the key intermediate UDP-GlcNAc, is an ACP binding protein. Acetyl-ACP is the preferred glucosamine-1-phosphate N-acetyl transferase/N-acetyl-glucosamine-1-phosphate uridylyltransferase substrate, in addition to being the substrate for the elongation-condensing enzymes FabB and FabF. Thus, we conclude that the Mad family of malonyl-ACP decarboxylases supplies acetyl-ACP to support the initiation of fatty acid, lipopolysaccharide, peptidoglycan, and enterobacterial common antigen biosynthesis in Proteobacteria.
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Affiliation(s)
- Sarah G Whaley
- Department of Infectious Diseases, St Jude Children's Research Hospital, Memphis, Tennessee, USA
| | - Christopher D Radka
- Department of Infectious Diseases, St Jude Children's Research Hospital, Memphis, Tennessee, USA
| | - Chitra Subramanian
- Department of Infectious Diseases, St Jude Children's Research Hospital, Memphis, Tennessee, USA
| | - Matthew W Frank
- Department of Infectious Diseases, St Jude Children's Research Hospital, Memphis, Tennessee, USA
| | - Charles O Rock
- Department of Infectious Diseases, St Jude Children's Research Hospital, Memphis, Tennessee, USA.
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