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Basu Choudhury G, Datta S. Implication of Molecular Constraints Facilitating the Functional Evolution of Pseudomonas aeruginosa KPR2 into a Versatile α-Keto-Acid Reductase. Biochemistry 2024. [PMID: 38962820 DOI: 10.1021/acs.biochem.4c00087] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/05/2024]
Abstract
Theoretical concepts linking the structure, function, and evolution of a protein, while often intuitive, necessitate validation through investigations in real-world systems. Our study empirically explores the evolutionary implications of multiple gene copies in an organism by shedding light on the structure-function modulations observed in Pseudomonas aeruginosa's second copy of ketopantoate reductase (PaKPR2). We demonstrated with two apo structures that the typical active site cleft of the protein transforms into a two-sided pocket where a molecular gate made up of two residues controls the substrate entry site, resulting in its inactivity toward the natural substrate ketopantoate. Strikingly, this structural modification made the protein active against several important α-keto-acid substrates with varied efficiency. Structural constraints at the binding site for this altered functional trait were analyzed with two binary complexes that show the conserved residue microenvironment faces restricted movements due to domain closure. Finally, its mechanistic highlights gathered from a ternary complex structure help in delineating the molecular perspectives behind its kinetic cooperativity toward these broad range of substrates. Detailed structural characteristics of the protein presented here also identified four key amino acid residues responsible for its versatile α-keto-acid reductase activity, which can be further modified to improve its functional properties through protein engineering.
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Affiliation(s)
- Gourab Basu Choudhury
- CSIR-Indian Institute of Chemical Biology, Raja S C Mullick Road, Jadavpur, Kolkata 700032, India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India
| | - Saumen Datta
- CSIR-Indian Institute of Chemical Biology, Raja S C Mullick Road, Jadavpur, Kolkata 700032, India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India
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2
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Gadallah AH, Hafez RS, Fahim KM, Ahmed LI. Application of rosemary oil nano-emulsion as antimicrobial and antioxidant natural alternative in pasteurized cream and Karish cheese. Int J Food Microbiol 2024; 422:110823. [PMID: 38991433 DOI: 10.1016/j.ijfoodmicro.2024.110823] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2024] [Revised: 07/01/2024] [Accepted: 07/02/2024] [Indexed: 07/13/2024]
Abstract
Essential oils possess significant antimicrobial and antioxidant properties and are increasingly used as natural substitutes for food preservation. Therefore, this study investigated the potential application of rosemary essential oil (REO) and REO nano-emulsion in the dairy plant. The antimicrobial effects of REO and REO nano-emulsion were determined by an agar well diffusion assay after chemical profiling by Gas Chromatography-Mass Spectrometry (GC-MS). The REO nano-emulsion was characterized by a Transmission Electron Microscope (TEM). The REO chemical profile revealed the presence of 42 chemical compounds, including 1, 8-cineole (9.72 %), and α-pinene (5.46 %) as major active components. REO nano-emulsion demonstrated significant antimicrobial activity compared to REO (P < 0.05) with a MIC value of 0.0001 mg/ml against Listeria monocytogenes and Aspergillus flavus and 0.001 mg/ml against Pseudomonas aeruginosa and Bacillus cereus. REO nano-emulsion enhanced the oxidative stability of pasteurized fresh cream, revealing a non-significant difference compared with that inoculated with butylated hydroxy anisol (BHA; synthetic antioxidant) (P˃ 0.05). Fortified cream and Karish cheese with REO nano-emulsion were evaluated organoleptically, and the results showed higher grades of overall acceptability when compared to control samples with a statistically significant difference (P < 0.05). Viability studies were estimated using the previously mentioned microorganisms in fortified fresh cream and Karish cheese with REO nano-emulsion. Results of the fortified cream showed a complete reduction of L. monocytogenes, A. flavus, and B. cereus on days 5, 7, and 10, respectively, and a 96.93 % reduction of P. aeruginosa by the end of the storage period. Regarding Karish cheese viability studies, C. albicans, A. flavus, and P. aeruginosa exhibited complete reduction on days 10, 10, and 15 of storage, respectively. In conclusion, REO nano-emulsion was recommended as a natural, safe, and effective antimicrobial and antioxidant additive in the dairy industry.
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Affiliation(s)
- Ahmed Hussein Gadallah
- Department of Food Hygiene and Control, Faculty of Veterinary Medicine, Cairo University, Giza 12211, Egypt.
| | - Ragaa Shehata Hafez
- Department of Food Hygiene and Control, Faculty of Veterinary Medicine, Cairo University, Giza 12211, Egypt
| | - Karima Mogahed Fahim
- Department of Food Hygiene and Control, Faculty of Veterinary Medicine, Cairo University, Giza 12211, Egypt
| | - Lamiaa Ibrahim Ahmed
- Department of Food Hygiene and Control, Faculty of Veterinary Medicine, Cairo University, Giza 12211, Egypt
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3
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Azad A, Sheikh MN, Hai FI. A critical review of the mechanisms, factors, and performance of pervious concrete to remove contaminants from stormwater runoff. WATER RESEARCH 2024; 251:121101. [PMID: 38218072 DOI: 10.1016/j.watres.2024.121101] [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: 08/26/2023] [Revised: 12/01/2023] [Accepted: 01/01/2024] [Indexed: 01/15/2024]
Abstract
Stormwater can carry pollutants accumulated on impervious surfaces in urban areas into natural water bodies in absence of stormwater quality improvement devices. Pervious concrete (PC) pavement is one of the low-impact development practices introduced for urban flooding prevention and stormwater pollution reduction. PC removes various types of water contaminants. Mechanisms contributing to the water pollution removal capacity of PC can be categorized into three groups: physical, chemical, and biological. Properties of PC such as permeability, porosity, thickness, and adsorption capacity influence removal of all contaminants, although their impact might differ depending on the pollutant properties. Chemical mechanisms include precipitation, co-precipitation, ion and ligand exchange, complexation, diffusion, and sorption. Bulk organics and nutrients are removed primarily by biodegradation. Physical filtration is the primary mechanism to retain suspended solids, although biological activities may have a minor contribution. Release of calcium (Ca2+) and hydroxide (OH-) from hardened cement elevates the effluent pH, which is an environmental concern. However, the pH elevation is also the prime contributor to heavy metals and nutrients removal through precipitation. Specific cementitious materials (e.g., Pozzolans and nanoparticles) and carbonation curing approach are recommended to control effluent pH elevation. Complexation, diffusion, ion solubility, and stability constants are other mechanisms and parameters that influence heavy metal removal. Organic matter availability, electrostatic attraction, temperature, pH, contact time, specific surface area, and roughness of PC pores contribute to the pathogen removal process. Although PC has been found promising in removing various water pollutants, limited salinity removal can be achieved due to the inherent release of Ca2+and OH- from PC.
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Affiliation(s)
- Armin Azad
- Strategic Water Infrastructure Laboratory, School of Civil, Mining, Environmental and Architectural Engineering, University of Wollongong, Wollongong, NSW 2522, Australia
| | - M Neaz Sheikh
- School of Civil, Mining, Environmental and Architectural Engineering, University of Wollongong, Wollongong, NSW 2522, Australia
| | - Faisal I Hai
- Strategic Water Infrastructure Laboratory, School of Civil, Mining, Environmental and Architectural Engineering, University of Wollongong, Wollongong, NSW 2522, Australia.
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4
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Gill CP, Phan C, Platt V, Worrell D, Andl T, Roy H. The MprF homolog LysX synthesizes lysyl-diacylglycerol contributing to antibiotic resistance and virulence. Microbiol Spectr 2023; 11:e0142923. [PMID: 37768052 PMCID: PMC10580965 DOI: 10.1128/spectrum.01429-23] [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: 04/03/2023] [Accepted: 07/10/2023] [Indexed: 09/29/2023] Open
Abstract
Lysyl-diacylglycerol (Lys-DAG) was identified three decades ago in Mycobacterium phlei, but the biosynthetic pathway and function of this aminoacylated lipid have since remained uncharacterized. Combining genetic methods, mass spectrometry, and biochemical approaches, we show that the multiple peptide resistance factor (MprF) homolog LysX from Corynebacterium pseudotuberculosis and two mycobacterial species is responsible for Lys-DAG synthesis. LysX is conserved in most Actinobacteria and was previously implicated in the synthesis of another modified lipid, lysyl-phosphatidylglycerol (Lys-PG), in Mycobacterium tuberculosis. Although we detected low levels of Lys-PG in the membrane of C. pseudotuberculosis, our data suggest that Lys-PG is not directly synthesized by LysX and may require an additional downstream pathway, which is as yet undefined. Our results show that LysX in C. pseudotuberculosis is a major factor of resistance against a variety of positively charged antibacterial agents, including cationic antimicrobial peptides (e.g., human peptide LL-37 and polymyxin B) and aminoglycosides (e.g., gentamycin and apramycin). Deletion of lysX caused an increase in cellular membrane permeability without dissipation of the membrane potential, suggesting that loss of the protein does not result in mechanical damage to the cell membrane. Furthermore, lysX-deficient cells exhibited an attenuated virulence phenotype in a Galleria mellonella infection model, supporting a role for LysX during infection. Altogether, Lys-DAG represents a novel molecular determinant for antimicrobial resistance and virulence that may be widespread in Actinobacteria and points to a richer landscape than previously realized of lipid components contributing to overall membrane physiology in this important bacterial phylum. IMPORTANCE In the past two decades, tRNA-dependent modification of membrane phosphatidylglycerol has been implicated in altering the biochemical properties of the cell surface, thereby enhancing the antimicrobial resistance and virulence of various bacterial pathogens. Here, we show that in several Actinobacteria, the multifunctional protein LysX attaches lysine to diacylglycerol instead of phosphatidylglycerol. We found that lysyl-diacylglycerol (Lys-DAG) confers high levels of resistance against various cationic antimicrobial peptides and aminoglycosides and also enhances virulence. Our data show that Lys-DAG is a lipid commonly found in important actinobacterial pathogens, including Mycobacterium and Corynebacterium species.
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Affiliation(s)
- Cameron P. Gill
- Burnett School of Biomedical Sciences, College of Medicine, University of Central Florida, Orlando, Florida, USA
| | - Christopher Phan
- Burnett School of Biomedical Sciences, College of Medicine, University of Central Florida, Orlando, Florida, USA
| | - Vivien Platt
- Burnett School of Biomedical Sciences, College of Medicine, University of Central Florida, Orlando, Florida, USA
| | - Danielle Worrell
- Burnett School of Biomedical Sciences, College of Medicine, University of Central Florida, Orlando, Florida, USA
| | - Thomas Andl
- Burnett School of Biomedical Sciences, College of Medicine, University of Central Florida, Orlando, Florida, USA
| | - Hervé Roy
- Burnett School of Biomedical Sciences, College of Medicine, University of Central Florida, Orlando, Florida, USA
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Modi SK, Gaur S, Sengupta M, Singh MS. Mechanistic insights into nanoparticle surface-bacterial membrane interactions in overcoming antibiotic resistance. Front Microbiol 2023; 14:1135579. [PMID: 37152753 PMCID: PMC10160668 DOI: 10.3389/fmicb.2023.1135579] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2023] [Accepted: 03/30/2023] [Indexed: 05/09/2023] Open
Abstract
Antimicrobial Resistance (AMR) raises a serious concern as it contributes to the global mortality by 5 million deaths per year. The overall impact pertaining to significant membrane changes, through broad spectrum drugs have rendered the bacteria resistant over the years. The economic expenditure due to increasing drug resistance poses a global burden on healthcare community and must be dealt with immediate effect. Nanoparticles (NP) have demonstrated inherent therapeutic potential or can serve as nanocarriers of antibiotics against multidrug resistant (MDR) pathogens. These carriers can mask the antibiotics and help evade the resistance mechanism of the bacteria. The targeted delivery can be fine-tuned through surface functionalization of Nanocarriers using aptamers, antibodies etc. This review covers various molecular mechanisms acquired by resistant bacteria towards membrane modification. Mechanistic insight on 'NP surface-bacterial membrane' interactions are crucial in deciding the role of NP as therapeutic. Finally, we highlight the potential accessible membrane targets for designing smart surface-functionalized nanocarriers which can act as bacteria-targeted robots over the existing clinically available antibiotics. As the bacterial strains around us continue to evolve into resistant versions, nanomedicine can offer promising and alternative tools in overcoming AMR.
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Affiliation(s)
- Suraj Kumar Modi
- Department of Biotechnology, Bennett University, Greater Noida, Uttar Pradesh, India
- Centre of Excellence for Nanosensors and Nanomedicine, Bennett University, Greater Noida, Uttar Pradesh, India
| | - Smriti Gaur
- Department of Biotechnology, Bennett University, Greater Noida, Uttar Pradesh, India
| | - Mrittika Sengupta
- Department of Biotechnology, Bennett University, Greater Noida, Uttar Pradesh, India
- Centre of Excellence for Nanosensors and Nanomedicine, Bennett University, Greater Noida, Uttar Pradesh, India
- Mrittika Sengupta, ;
| | - Manu Smriti Singh
- Department of Biotechnology, Bennett University, Greater Noida, Uttar Pradesh, India
- Centre of Excellence for Nanosensors and Nanomedicine, Bennett University, Greater Noida, Uttar Pradesh, India
- *Correspondence: Manu Smriti Singh, ;
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6
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Bacterial Communities Associated with Crude Oil Bioremediation through Composting Approaches with Indigenous Bacterial Isolate. Life (Basel) 2022; 12:life12111712. [DOI: 10.3390/life12111712] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2022] [Revised: 10/24/2022] [Accepted: 10/25/2022] [Indexed: 11/16/2022] Open
Abstract
In this study, we aim to investigate the efficiency of crude oil bioremediation through composting and culture-assisted composting. First, forty-eight bacteria were isolated from a crude oil-contaminated soil, and the isolate with the highest crude oil degradation activity, identified as Pseudomonas aeruginosa, was selected. The bioremediation was then investigated and compared between crude oil-contaminated soil (S), the contaminated soil composted with fruit-based waste (SW), and the contaminated soil composted with the same waste with the addition of the selected bacterium (SWB). Both compost-based methods showed high efficiencies of crude oil bioremediation (78.1% and 83.84% for SW and SWB, respectively). However, only a slight difference between the treatments without and with the addition of P. aeruginosa was observed. To make a clear understanding of this point, bacterial communities throughout the 4-week bioremediation period were analyzed. It was found that the community dynamics between both composted treatments were similar, which corresponds with their similar bioremediation efficiencies. Interestingly, Pseudomonas disappeared from the system after one week, which suggests that this genus was not the key degrader or only involved in the early stage of the process. Altogether, our results elaborate that fruit-based composting is an effective approach for crude oil bioremediation.
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7
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Giacometti SI, MacRae MR, Dancel-Manning K, Bhabha G, Ekiert DC. Lipid Transport Across Bacterial Membranes. Annu Rev Cell Dev Biol 2022; 38:125-153. [PMID: 35850151 DOI: 10.1146/annurev-cellbio-120420-022914] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The movement of lipids within and between membranes in bacteria is essential for building and maintaining the bacterial cell envelope. Moving lipids to their final destination is often energetically unfavorable and does not readily occur spontaneously. Bacteria have evolved several protein-mediated transport systems that bind specific lipid substrates and catalyze the transport of lipids across membranes and from one membrane to another. Specific protein flippases act in translocating lipids across the plasma membrane, overcoming the obstacle of moving relatively large and chemically diverse lipids between leaflets of the bilayer. Active transporters found in double-membraned bacteria have evolved sophisticated mechanisms to traffic lipids between the two membranes, including assembling to form large, multiprotein complexes that resemble bridges, shuttles, and tunnels, shielding lipids from the hydrophilic environment of the periplasm during transport. In this review, we explore our current understanding of the mechanisms thought to drive bacterial lipid transport.
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Affiliation(s)
- Sabrina I Giacometti
- Department of Cell Biology, New York University School of Medicine, New York, NY, USA; , , ,
| | - Mark R MacRae
- Department of Cell Biology, New York University School of Medicine, New York, NY, USA; , , ,
| | - Kristen Dancel-Manning
- Office of Science and Research, New York University School of Medicine, New York, NY, USA;
| | - Gira Bhabha
- Department of Cell Biology, New York University School of Medicine, New York, NY, USA; , , ,
| | - Damian C Ekiert
- Department of Cell Biology, New York University School of Medicine, New York, NY, USA; , , ,
- Department of Microbiology, New York University School of Medicine, New York, NY, USA
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8
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Lyon R, Jones RA, Shropshire H, Aberdeen I, Scanlan DJ, Millard A, Chen Y. Membrane lipid renovation in Pseudomonas aeruginosa - implications for phage therapy? Environ Microbiol 2022; 24:4533-4546. [PMID: 35837865 PMCID: PMC9804370 DOI: 10.1111/1462-2920.16136] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2021] [Revised: 07/11/2022] [Accepted: 07/12/2022] [Indexed: 01/05/2023]
Abstract
Pseudomonas aeruginosa is an important Gram-negative pathogen with intrinsic resistance to many clinically used antibiotics. It is particularly troublesome in nosocomial infections, immunocompromised patients, and individuals with cystic fibrosis. Antimicrobial resistance (AMR) is a huge threat to global health, with a predicted 10 million people dying from resistant infections by 2050. A promising therapy for combatting AMR infections is phage therapy. However, more research is required to investigate mechanisms that may influence the efficacy of phage therapy. An important overlooked aspect is the impact of membrane lipid remodelling on phage binding ability. P. aeruginosa undergoes changes in membrane lipids when it encounters phosphorus stress, an environmental perturbation that is likely to occur during infection. Lipid changes include the substitution of glycerophospholipids with surrogate glycolipids and the over-production of ornithine-containing aminolipids. Given that membrane lipids are known to influence the structure and function of membrane proteins, we propose that changes in the composition of membrane lipids during infection may alter phage binding and subsequent phage infection dynamics. Consideration of such effects needs to be urgently prioritised in order to develop the most effective phage therapy strategies for P. aeruginosa infections.
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Affiliation(s)
- Rhiannon Lyon
- BBSRC Midlands Integrative Biosciences Training PartnershipUniversity of WarwickCoventryUK,School of Life SciencesUniversity of WarwickCoventryUK
| | - Rebekah A. Jones
- School of Life SciencesUniversity of WarwickCoventryUK,MRC Doctoral Training PartnershipUniversity of WarwickCoventryUK
| | - Holly Shropshire
- BBSRC Midlands Integrative Biosciences Training PartnershipUniversity of WarwickCoventryUK,School of Life SciencesUniversity of WarwickCoventryUK
| | - Isabel Aberdeen
- BBSRC Midlands Integrative Biosciences Training PartnershipUniversity of WarwickCoventryUK,School of Life SciencesUniversity of WarwickCoventryUK
| | | | - Andrew Millard
- Department of Genetics and Genome BiologyUniversity of LeicesterUK
| | - Yin Chen
- School of Life SciencesUniversity of WarwickCoventryUK
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9
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Ravi A, Ravuri M, Krishnan R, Narenkumar J, Anu K, Alsalhi MS, Devanesan S, Kamala-Kannan S, Rajasekar A. Characterization of petroleum degrading bacteria and its optimization conditions on effective utilization of petroleum hydrocarbons. Microbiol Res 2022; 265:127184. [PMID: 36115172 DOI: 10.1016/j.micres.2022.127184] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2022] [Revised: 08/17/2022] [Accepted: 09/02/2022] [Indexed: 11/27/2022]
Abstract
Hydrocarbon contamination is continuing to be a serious environmental problem because of their toxicity. Hydrocarbon components have been known to be carcinogens and neurotoxic organic pollutants. The physical and chemical methods of petroleum removal have become ineffective and also are very costly. Therefore, bioremediation is considered the promising technology for the treatment of these contaminated sites since it is cost-effective and will lead to complete mineralization.The current study also concentrates on bioremediation of petroleum products by bacterium isolated from petroleum hydrocarbon contaminated soil. The current work shows that bacterial strains obtained from a petroleum hydrocarbon contaminated environment may degrade petroleum compounds. Two strains Bacillus licheniformis ARMP2 and Pseudomonas aeruginosa ARMP8 were identified as petroleum-degrading bacteria of the isolated bacterial colonies. The best growth conditions for the ARMP2 strain were determined to be pH 9, temperature 29 °C with sodium nitrate as its nitrogen source, whereas for the ARMP8 strain the optimal growth was found at pH 7, temperature 39 °C, and ammonium chloride as the nitrogen source. Both strains were shown to be effective at degrading petroleum chemicals confirmed by GCMS. Overall petroleum product degradation efficiency of the strains ARMP2 and ARMP8 was about 88 % and 73 % respectively in 48 h.The strains Bacillus licheniformis ARMP2 and Pseudomonas aeruginosa ARMP8 were shown to be effective at degrading petroleum compounds in the current study. Even greater results might be obtained if the organisms were utilised in consortia or the degradation time period was extended.
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Affiliation(s)
- Ashwini Ravi
- Department of Biotechnology, Dwaraka Doss Goverdhan Doss Vaishnav College (Autonomous), Chennai, Tamilnadu 600106, India.
| | - Mounesh Ravuri
- Department of Biotechnology, Dwaraka Doss Goverdhan Doss Vaishnav College (Autonomous), Chennai, Tamilnadu 600106, India
| | - Ramkishore Krishnan
- Department of Biotechnology, Dwaraka Doss Goverdhan Doss Vaishnav College (Autonomous), Chennai, Tamilnadu 600106, India
| | - Jayaraman Narenkumar
- Centre for Materials Engineering and Regenerative Medicine, Bharath Institute of Higher Education and Research, Selaiyur, Chennai, Tamil Nadu 600073, India
| | - Kasi Anu
- PG and Research Department of Zoology, Auxilium College for Women (Autonomous), Gandhinagar, Vellore, Tamilnadu 632007, India
| | - Mohamad S Alsalhi
- Department of Physics and Astronomy, College of Science, King Saud University, P.O. Box, 2455, Riyadh, 11451, Saudi Arabia
| | - Sandhanasamy Devanesan
- Department of Physics and Astronomy, College of Science, King Saud University, P.O. Box, 2455, Riyadh, 11451, Saudi Arabia.
| | - Seralathan Kamala-Kannan
- Division of Biotechnology Advanced Institute of Environment and Bioscience, College of Environmental and Bioresource Science, Jeonbuk National University, Iksan 54596, South Korea
| | - Aruliah Rajasekar
- Environmental Molecular Microbiology Research Laboratory, Department of Biotechnology, Thiruvalluvar University, Serkkadu, Vellore, Tamil Nadu 632115, India.
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10
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Grob G, Hemmerle M, Yakobov N, Mahmoudi N, Fischer F, Senger B, Becker HD. tRNA-dependent addition of amino acids to cell wall and membrane components. Biochimie 2022; 203:93-105. [DOI: 10.1016/j.biochi.2022.09.017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2022] [Revised: 09/23/2022] [Accepted: 09/26/2022] [Indexed: 11/16/2022]
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Transient Complexity of E. coli Lipidome Is Explained by Fatty Acyl Synthesis and Cyclopropanation. Metabolites 2022; 12:metabo12090784. [PMID: 36144187 PMCID: PMC9500627 DOI: 10.3390/metabo12090784] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2022] [Revised: 08/22/2022] [Accepted: 08/23/2022] [Indexed: 12/04/2022] Open
Abstract
In the case of many bacteria, such as Escherichia coli, the composition of lipid molecules, termed the lipidome, temporally adapts to different environmental conditions and thus modifies membrane properties to permit growth and survival. Details of the relationship between the environment and lipidome composition are lacking, particularly for growing cultures under either favourable or under stress conditions. Here, we highlight compositional lipidome changes by describing the dynamics of molecular species throughout culture-growth phases. We show a steady cyclopropanation of fatty acyl chains, which acts as a driver for lipid diversity. There is a bias for the cyclopropanation of shorter fatty acyl chains (FA 16:1) over longer ones (FA 18:1), which likely reflects a thermodynamic phenomenon. Additionally, we observe a nearly two-fold increase in saturated fatty acyl chains in response to the presence of ampicillin and chloramphenicol, with consequences for membrane fluidity and elasticity, and ultimately bacterial stress tolerance. Our study provides the detailed quantitative lipidome composition of three E. coli strains across culture-growth phases and at the level of the fatty acyl chains and provides a general reference for phospholipid composition changes in response to perturbations. Thus, lipidome diversity is largely transient and the consequence of lipid synthesis and cyclopropanation.
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12
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Blair JMA, Zeth K, Bavro VN, Sancho-Vaello E. The role of bacterial transport systems in the removal of host antimicrobial peptides in Gram-negative bacteria. FEMS Microbiol Rev 2022; 46:6617596. [PMID: 35749576 PMCID: PMC9629497 DOI: 10.1093/femsre/fuac032] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2021] [Revised: 05/23/2022] [Accepted: 06/22/2022] [Indexed: 01/09/2023] Open
Abstract
Antibiotic resistance is a global issue that threatens our progress in healthcare and life expectancy. In recent years, antimicrobial peptides (AMPs) have been considered as promising alternatives to the classic antibiotics. AMPs are potentially superior due to their lower rate of resistance development, since they primarily target the bacterial membrane ('Achilles' heel' of the bacteria). However, bacteria have developed mechanisms of AMP resistance, including the removal of AMPs to the extracellular space by efflux pumps such as the MtrCDE or AcrAB-TolC systems, and the internalization of AMPs to the cytoplasm by the Sap transporter, followed by proteolytic digestion. In this review, we focus on AMP transport as a resistance mechanism compiling all the experimental evidence for the involvement of efflux in AMP resistance in Gram-negative bacteria and combine this information with the analysis of the structures of the efflux systems involved. Finally, we expose some open questions with the aim of arousing the interest of the scientific community towards the AMPs-efflux pumps interactions. All the collected information broadens our understanding of AMP removal by efflux pumps and gives some clues to assist the rational design of AMP-derivatives as inhibitors of the efflux pumps.
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Affiliation(s)
- Jessica M A Blair
- College of Medical and Dental Sciences, Institute of Microbiology and Infection, University of Birmingham, Edgbaston, Birmingham, B15 2TT, United Kingdom
| | - Kornelius Zeth
- Department of Science and Environment, Roskilde University, Universitetsvej 1, 4000 Roskilde, Denmark
| | - Vassiliy N Bavro
- School of Life Sciences, University of Essex, Colchester, CO4 3SQ, United Kingdom
| | - Enea Sancho-Vaello
- Corresponding author. College of Medical and Dental Sciences, Institute of Microbiology and Infection, University of Birmingham, Edgbaston, Birmingham, B15 2TT, United Kingdom. E-mail:
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13
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Naguib M, Feldman N, Zarodkiewicz P, Shropshire H, Biamis C, El-Halfawy OM, McCain J, Dezanet C, Décout JL, Chen Y, Cosa G, Valvano MA. An evolutionary conserved detoxification system for membrane lipid-derived peroxyl radicals in Gram-negative bacteria. PLoS Biol 2022; 20:e3001610. [PMID: 35580139 PMCID: PMC9113575 DOI: 10.1371/journal.pbio.3001610] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2021] [Accepted: 03/18/2022] [Indexed: 11/30/2022] Open
Abstract
How double-membraned Gram-negative bacteria overcome lipid peroxidation is virtually unknown. Bactericidal antibiotics and superoxide ion stress stimulate the transcription of the Burkholderia cenocepacia bcnA gene that encodes a secreted lipocalin. bcnA gene orthologs are conserved in bacteria and generally linked to a conserved upstream gene encoding a cytochrome b561 membrane protein (herein named lcoA, lipocalin-associated cytochrome oxidase gene). Mutants in bcnA, lcoA, and in a gene encoding a conserved cytoplasmic aldehyde reductase (peroxidative stress-associated aldehyde reductase gene, psrA) display enhanced membrane lipid peroxidation. Compared to wild type, the levels of the peroxidation biomarker malondialdehyde (MDA) increase in the mutants upon exposure to sublethal concentrations of the bactericidal antibiotics polymyxin B and norfloxacin. Microscopy with lipid peroxidation-sensitive fluorescent probes shows that lipid peroxyl radicals accumulate at the bacterial cell poles and septum and peroxidation is associated with a redistribution of anionic phospholipids and reduced antimicrobial resistance in the mutants. We conclude that BcnA, LcoA, and PsrA are components of an evolutionary conserved, hitherto unrecognized peroxidation detoxification system that protects the bacterial cell envelope from lipid peroxyl radicals.
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Affiliation(s)
- Marwa Naguib
- Wellcome-Wolfson Institute for Experimental Medicine, Queen’s University Belfast, Belfast, United Kingdom
- Department of Microbiology and Immunology, Faculty of Pharmacy, Damanhour University, Damanhour, Egypt
| | - Nicolás Feldman
- Wellcome-Wolfson Institute for Experimental Medicine, Queen’s University Belfast, Belfast, United Kingdom
| | - Paulina Zarodkiewicz
- Wellcome-Wolfson Institute for Experimental Medicine, Queen’s University Belfast, Belfast, United Kingdom
| | - Holly Shropshire
- School of Life Sciences, University of Warwick, Coventry, United Kingdom
| | - Christina Biamis
- Wellcome-Wolfson Institute for Experimental Medicine, Queen’s University Belfast, Belfast, United Kingdom
| | - Omar M. El-Halfawy
- Department of Chemistry and Biochemistry, Faculty of Science, University of Regina, Regina, Saskatchewan, Canada
- Department of Microbiology and Immunology, Faculty of Pharmacy, Alexandria University, Alexandria, Egypt
| | - Julia McCain
- Department of Chemistry and Quebec Center for Advanced Materials, McGill University, Montreal, Québec, Canada
| | - Clément Dezanet
- Department of Molecular Pharmacochemistry, Université Grenoble Alpes/CNRS, Grenoble, France
| | - Jean-Luc Décout
- Department of Molecular Pharmacochemistry, Université Grenoble Alpes/CNRS, Grenoble, France
| | - Yin Chen
- School of Life Sciences, University of Warwick, Coventry, United Kingdom
| | - Gonzalo Cosa
- Department of Chemistry and Quebec Center for Advanced Materials, McGill University, Montreal, Québec, Canada
| | - Miguel A. Valvano
- Wellcome-Wolfson Institute for Experimental Medicine, Queen’s University Belfast, Belfast, United Kingdom
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14
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Hong J, Li X, Jiang M, Hong R. Co-expression Mechanism Analysis of Different Tachyplesin I-Resistant Strains in Pseudomonas aeruginosa Based on Transcriptome Sequencing. Front Microbiol 2022; 13:871290. [PMID: 35464984 PMCID: PMC9022664 DOI: 10.3389/fmicb.2022.871290] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2022] [Accepted: 03/10/2022] [Indexed: 11/23/2022] Open
Abstract
Tachyplesin I is a cationic antimicrobial peptide with 17 amino acids. The long-term continuous exposure to increased concentrations of tachyplesin I induced resistance in Pseudomonas aeruginosa. The global gene expression profiling of tachyplesin I–resistant P. aeruginosa strains PA-60 and PA-99 and the sensitive strain P. aeruginosa CGMCC1.2620 (PA1.2620) were conducted by transcriptome sequencing to analyze the common underlying mechanism of resistance to tachyplesin I in low- or high-resistance mutants. The co-expression patterns, gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment, sRNA target genes, and single-nucleotide polymorphism (SNP) change were analyzed for the co-expressed genes in this study. A total of 661 differentially co-expressed genes under treatments of PA1.2620 vs. PA-99 and PA1.2620 vs. PA-60 (HL) were divided into 12 kinds of expression patterns. GO and KEGG pathway enrichment analyses indicated that the enrichment of co-expressed genes was mainly associated with oxidoreductase activity, mismatched DNA binding, mismatch repair, RNA degradation of GO terms, aminoacyl-tRNA biosynthesis, and aminobenzoate degradation pathways, and so forth. The co-expressed resistance-related genes were mainly involved in antibiotic efflux and antibiotic inactivation. Seven co-expressed genes had SNP changes. Some co-expressed sRNAs were involved in P. aeruginosa resistance to tachyplesin I by regulating target genes and pathways related to resistance. The common resistance mechanism of P. aeruginosa among different mutants to tachyplesin I was mainly associated with the expression alteration of several genes and sRNA-regulated target genes related to resistance; few genes had base mutations. The findings of this study might provide guidance for understanding the resistance mechanism of P. aeruginosa to tachyplesin I.
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Affiliation(s)
- Jun Hong
- College of Life Science and Engineering, Henan University of Urban Construction, Pingdingshan, China
| | - Xinyang Li
- College of Life Science and Engineering, Henan University of Urban Construction, Pingdingshan, China
| | - Mengyao Jiang
- College of Life Science and Engineering, Henan University of Urban Construction, Pingdingshan, China
| | - Ruofei Hong
- School of International Education, Henan University of Technology, Zhengzhou, China
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15
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Boldrin F, Cioetto Mazzabò L, Lanéelle MA, Rindi L, Segafreddo G, Lemassu A, Etienne G, Conflitti M, Daffé M, Garzino Demo A, Manganelli R, Marrakchi H, Provvedi R. LysX2 is a Mycobacterium tuberculosis membrane protein with an extracytoplasmic MprF-like domain. BMC Microbiol 2022; 22:85. [PMID: 35365094 PMCID: PMC8974105 DOI: 10.1186/s12866-022-02493-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2021] [Accepted: 03/11/2022] [Indexed: 11/17/2022] Open
Abstract
Background Aminoacyl-phosphatidylglycerol (aaPG) synthases are bacterial enzymes that usually catalyze transfer of aminoacyl residues to the plasma membrane phospholipid phosphatidylglycerol (PG). The result is introduction of positive charges onto the cytoplasmic membrane, yielding reduced affinity towards cationic antimicrobial peptides, and increased resistance to acidic environments. Therefore, these enzymes represent an important defense mechanism for many pathogens, including Staphylococcus aureus and Mycobacterium tuberculosis (Mtb), which are known to encode for lysyl-(Lys)-PG synthase MprF and LysX, respectively. Here, we used a combination of bioinformatic, genetic and bacteriological methods to characterize a protein encoded by the Mtb genome, Rv1619, carrying a domain with high similarity to MprF-like domains, suggesting that this protein could be a new aaPG synthase family member. However, unlike homologous domains of MprF and LysX that are positioned in the cytoplasm, we predicted that the MprF-like domain in LysX2 is in the extracytoplasmic region. Results Using genetic fusions to the Escherichia coli proteins PhoA and LacZ of LysX2, we confirmed this unique membrane topology, as well as LysX and MprF as benchmarks. Expression of lysX2 in Mycobacterium smegmatis increased cell resistance to human β-defensin 2 and sodium nitrite, enhanced cell viability and delayed biofilm formation in acidic pH environment. Remarkably, MtLysX2 significantly reduced the negative charge on the bacterial surface upon exposure to an acidic environment. Additionally, we found LysX2 orthologues in major human pathogens and in rapid-growing mycobacteria frequently associated with human infections, but not in environmental and non-pathogenic mycobacteria. Conclusions Overall, our data suggest that LysX2 is a prototype of a new class within the MprF-like protein family that likely enhances survival of the pathogenic species through its catalytic domain which is exposed to the extracytoplasmic side of the cell membrane and is required to decrease the negative charge on the bacterial surface through a yet uncharacterized mechanism. Supplementary Information The online version contains supplementary material available at 10.1186/s12866-022-02493-2.
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Affiliation(s)
| | | | - Marie-Antoinette Lanéelle
- Institut de Pharmacologie et de Biologie Structurale, IPBS, Université de Toulouse, CNRS, UPS, Toulouse, France
| | - Laura Rindi
- Department of Translational Research, University of Pisa, Pisa, Italy
| | - Greta Segafreddo
- Department of Molecular Medicine, University of Padua, Padua, Italy
| | - Anne Lemassu
- Institut de Pharmacologie et de Biologie Structurale, IPBS, Université de Toulouse, CNRS, UPS, Toulouse, France
| | - Gilles Etienne
- Institut de Pharmacologie et de Biologie Structurale, IPBS, Université de Toulouse, CNRS, UPS, Toulouse, France
| | - Marta Conflitti
- Department of Molecular Medicine, University of Padua, Padua, Italy
| | - Mamadou Daffé
- Institut de Pharmacologie et de Biologie Structurale, IPBS, Université de Toulouse, CNRS, UPS, Toulouse, France
| | - Alfredo Garzino Demo
- Department of Molecular Medicine, University of Padua, Padua, Italy.,Department of Microbiology and Immunology, School of Medicine, University of Maryland, Baltimore, Maryland, USA
| | | | - Hedia Marrakchi
- Institut de Pharmacologie et de Biologie Structurale, IPBS, Université de Toulouse, CNRS, UPS, Toulouse, France
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16
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Abstract
AbstractThe complex composition of bacterial membranes has a significant impact on the understanding of pathogen function and their development towards antibiotic resistance. In addition to the inherent complexity and biosafety risks of studying biological pathogen membranes, the continual rise of antibiotic resistance and its significant economical and clinical consequences has motivated the development of numerous in vitro model membrane systems with tuneable compositions, geometries, and sizes. Approaches discussed in this review include liposomes, solid-supported bilayers, and computational simulations which have been used to explore various processes including drug-membrane interactions, lipid-protein interactions, host–pathogen interactions, and structure-induced bacterial pathogenesis. The advantages, limitations, and applicable analytical tools of all architectures are summarised with a perspective for future research efforts in architectural improvement and elucidation of resistance development strategies and membrane-targeting antibiotic mechanisms.
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17
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MacDermott-Opeskin HI, Gupta V, O’Mara ML. Lipid-mediated antimicrobial resistance: a phantom menace or a new hope? Biophys Rev 2022; 14:145-162. [PMID: 35251360 PMCID: PMC8880301 DOI: 10.1007/s12551-021-00912-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2021] [Accepted: 11/14/2021] [Indexed: 02/06/2023] Open
Abstract
Abstract The proposition of a post-antimicrobial era is all the more realistic with the continued rise of antimicrobial resistance. The development of new antimicrobials is failing to counter the ever-increasing rates of bacterial antimicrobial resistance. This necessitates novel antimicrobials and drug targets. The bacterial cell membrane is an essential and highly conserved cellular component in bacteria and acts as the primary barrier for entry of antimicrobials into the cell. Although previously under-exploited as an antimicrobial target, the bacterial cell membrane is attractive for the development of novel antimicrobials due to its importance in pathogen viability. Bacterial cell membranes are diverse assemblies of macromolecules built around a central lipid bilayer core. This lipid bilayer governs the overall membrane biophysical properties and function of its membrane-embedded proteins. This mini-review will outline the mechanisms by which the bacterial membrane causes and controls resistance, with a focus on alterations in the membrane lipid composition, chemical modification of constituent lipids, and the efflux of antimicrobials by membrane-embedded efflux systems. Thorough insight into the interplay between membrane-active antimicrobials and lipid-mediated resistance is needed to enable the rational development of new antimicrobials. In particular, the union of computational approaches and experimental techniques for the development of innovative and efficacious membrane-active antimicrobials is explored.
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Affiliation(s)
- Hugo I. MacDermott-Opeskin
- Research School of Chemistry, College of Science, The Australian National University, Canberra, ACT 2601 Australia
| | - Vrinda Gupta
- Research School of Chemistry, College of Science, The Australian National University, Canberra, ACT 2601 Australia
| | - Megan L. O’Mara
- Research School of Chemistry, College of Science, The Australian National University, Canberra, ACT 2601 Australia
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18
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Leggett A, Li DW, Sindeldecker D, Staats A, Rigel N, Bruschweiler-Li L, Brüschweiler R, Stoodley P. Cadaverine Is a Switch in the Lysine Degradation Pathway in Pseudomonas aeruginosa Biofilm Identified by Untargeted Metabolomics. Front Cell Infect Microbiol 2022; 12:833269. [PMID: 35237533 PMCID: PMC8884266 DOI: 10.3389/fcimb.2022.833269] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2021] [Accepted: 01/18/2022] [Indexed: 12/16/2022] Open
Abstract
There is a critical need to accurately diagnose, prevent, and treat biofilms in humans. The biofilm forming P. aeruginosa bacteria can cause acute and chronic infections, which are difficult to treat due to their ability to evade host defenses along with an inherent antibiotic-tolerance. Using an untargeted NMR-based metabolomics approach, we identified statistically significant differences in 52 metabolites between P. aeruginosa grown in the planktonic and lawn biofilm states. Among them, the metabolites of the cadaverine branch of the lysine degradation pathway were systematically decreased in biofilm. Exogenous supplementation of cadaverine caused significantly increased planktonic growth, decreased biofilm accumulation by 49% and led to altered biofilm morphology, converting to a pellicle biofilm at the air-liquid interface. Our findings show how metabolic pathway differences directly affect the growth mode in P. aeruginosa and could support interventional strategies to control biofilm formation.
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Affiliation(s)
- Abigail Leggett
- Ohio State Biochemistry Program, The Ohio State University, Columbus, OH, United States
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, OH, United States
- Department of Microbial Infection and Immunity, The Ohio State University, Columbus, OH, United States
| | - Da-Wei Li
- Campus Chemical Instrument Center, The Ohio State University, Columbus, OH, United States
| | - Devin Sindeldecker
- Department of Microbial Infection and Immunity, The Ohio State University, Columbus, OH, United States
- Biomedical Sciences Graduate Program, The Ohio State University, Columbus, OH, United States
| | - Amelia Staats
- Department of Microbial Infection and Immunity, The Ohio State University, Columbus, OH, United States
- Department of Microbiology, The Ohio State University, Columbus, OH, United States
| | - Nicholas Rigel
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, OH, United States
| | - Lei Bruschweiler-Li
- Campus Chemical Instrument Center, The Ohio State University, Columbus, OH, United States
| | - Rafael Brüschweiler
- Ohio State Biochemistry Program, The Ohio State University, Columbus, OH, United States
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, OH, United States
- Campus Chemical Instrument Center, The Ohio State University, Columbus, OH, United States
- Department of Biological Chemistry and Pharmacology, The Ohio State University, Columbus, OH, United States
- *Correspondence: Rafael Brüschweiler, ; Paul Stoodley,
| | - Paul Stoodley
- Department of Microbial Infection and Immunity, The Ohio State University, Columbus, OH, United States
- Department of Microbiology, The Ohio State University, Columbus, OH, United States
- Department of Orthopaedics, The Ohio State University, Columbus, OH, United States
- National Biofilm Innovation Centre (NBIC) and National Centre for Advanced Tribology at Southampton (nCATS), Mechanical Engineering, University of Southampton, Southampton, United Kingdom
- *Correspondence: Rafael Brüschweiler, ; Paul Stoodley,
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19
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Escobar‐Salom M, Torrens G, Jordana‐Lluch E, Oliver A, Juan C. Mammals' humoral immune proteins and peptides targeting the bacterial envelope: from natural protection to therapeutic applications against multidrug‐resistant
Gram
‐negatives. Biol Rev Camb Philos Soc 2022; 97:1005-1037. [PMID: 35043558 PMCID: PMC9304279 DOI: 10.1111/brv.12830] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2021] [Revised: 12/12/2021] [Accepted: 12/15/2021] [Indexed: 12/11/2022]
Abstract
Mammalian innate immunity employs several humoral ‘weapons’ that target the bacterial envelope. The threats posed by the multidrug‐resistant ‘ESKAPE’ Gram‐negative pathogens (Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter spp.) are forcing researchers to explore new therapeutic options, including the use of these immune elements. Here we review bacterial envelope‐targeting (peptidoglycan and/or membrane‐targeting) proteins/peptides of the mammalian immune system that are most likely to have therapeutic applications. Firstly we discuss their general features and protective activity against ESKAPE Gram‐negatives in the host. We then gather, integrate, and discuss recent research on experimental therapeutics harnessing their bactericidal power, based on their exogenous administration and also on the discovery of bacterial and/or host targets that improve the performance of this endogenous immunity, as a novel therapeutic concept. We identify weak points and knowledge gaps in current research in this field and suggest areas for future work to obtain successful envelope‐targeting therapeutic options to tackle the challenge of antimicrobial resistance.
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Affiliation(s)
- María Escobar‐Salom
- Department of Microbiology University Hospital Son Espases‐Health Research Institute of the Balearic Islands (IdISBa) Carretera de Valldemossa 79 Palma Balearic Islands 07010 Spain
| | - Gabriel Torrens
- Department of Microbiology University Hospital Son Espases‐Health Research Institute of the Balearic Islands (IdISBa) Carretera de Valldemossa 79 Palma Balearic Islands 07010 Spain
| | - Elena Jordana‐Lluch
- Department of Microbiology University Hospital Son Espases‐Health Research Institute of the Balearic Islands (IdISBa) Carretera de Valldemossa 79 Palma Balearic Islands 07010 Spain
| | - Antonio Oliver
- Department of Microbiology University Hospital Son Espases‐Health Research Institute of the Balearic Islands (IdISBa) Carretera de Valldemossa 79 Palma Balearic Islands 07010 Spain
| | - Carlos Juan
- Department of Microbiology University Hospital Son Espases‐Health Research Institute of the Balearic Islands (IdISBa) Carretera de Valldemossa 79 Palma Balearic Islands 07010 Spain
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20
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Cell Envelope Stress Response in Pseudomonas aeruginosa. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2022; 1386:147-184. [DOI: 10.1007/978-3-031-08491-1_6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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21
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Mevo SIU, Ashrafudoulla M, Furkanur Rahaman Mizan M, Park SH, Ha SD. Promising strategies to control persistent enemies: Some new technologies to combat biofilm in the food industry-A review. Compr Rev Food Sci Food Saf 2021; 20:5938-5964. [PMID: 34626152 DOI: 10.1111/1541-4337.12852] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2021] [Revised: 09/01/2021] [Accepted: 09/04/2021] [Indexed: 01/22/2023]
Abstract
Biofilm is an advanced form of protection that allows bacterial cells to withstand adverse environmental conditions. The complex structure of biofilm results from genetic-related mechanisms besides other factors such as bacterial morphology or substratum properties. Inhibition of biofilm formation of harmful bacteria (spoilage and pathogenic bacteria) is a critical task in the food industry because of the enhanced resistance of biofilm bacteria to stress, such as cleaning and disinfection methods traditionally used in food processing plants, and the increased food safety risks threatening consumer health caused by recurrent contamination and rapid deterioration of food by biofilm cells. Therefore, it is urgent to find methods and strategies for effectively combating bacterial biofilm formation and eradicating mature biofilms. Innovative and promising approaches to control bacteria and their biofilms are emerging. These new approaches range from methods based on natural ingredients to the use of nanoparticles. This literature review aims to describe the efficacy of these strategies and provide an overview of recent promising biofilm control technologies in the food processing sector.
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Affiliation(s)
| | - Md Ashrafudoulla
- Food Science and Technology Department, Chung-Ang University, Anseong, Republic of Korea
| | | | - Si Hong Park
- Department of Food Science and Technology, Oregon State University, Corvallis, Oregon, USA
| | - Sang-Do Ha
- Food Science and Technology Department, Chung-Ang University, Anseong, Republic of Korea
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22
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Chen D, Förster H, Nguyen K, Adaskaveg JE. Organic Acid Sanitizers for Natamycin and Other Fungicides in Recirculating Application Systems for Citrus Postharvest Decay Management. PLANT DISEASE 2021; 105:2907-2913. [PMID: 33822660 DOI: 10.1094/pdis-01-21-0227-re] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Natamycin is a new postharvest biofungicide for citrus and some other fruit crops in the United States that can be effectively used in recycling drench or flooder treatments. These applications necessitate sanitation of the fungicide solution to ensure that it remains free from contamination by bacteria that are potentially human pathogens. During in vitro experiments, heated (48°C) citric acid (1,100 or 2,200 μg/ml) amended with sodium dodecylbenzenesulfonate (SDBS) (60 or 120 μg/ml, respectively) significantly reduced the viability of a nonpathogenic strain of Escherichia coli in natamycin solutions by >5 log10 compared with the control. During laboratory studies with Penicillium digitatum-inoculated lemon fruit, 1,000 μg/ml of natamycin mixed with 1,000 μg/ml of lactic acid or citric acid and with or without SDBS (55 μg/ml) effectively and significantly reduced green mold. Natamycin mixed with lactic acid at ≥2,000 μg/ml, however, caused fruit injury, resulting in browning and rind pitting. Natamycin was incompatible with peroxyacetic acid, resulting in reduced efficacy against green mold. Sodium hypochlorite mixed with natamycin lost its toxicity to E. coli; however, the performance of natamycin was not affected. With heated (average 49°C) drench treatments on an experimental packing line, natamycin (1,000 μg/ml), fludioxonil (300 μg/ml), or azoxystrobin (300 μg/ml) mixed with citric acid (1,000 μg/ml) and SDBS (55 μg/ml) were effective against green mold without fruit injury. At a pH between 3.6 and 3.8, citric acid-SDBS significantly reduced the viability of E. coli by approximately 4 log10 in mixtures with fludioxonil or azoxystrobin, but not with natamycin. However, natamycin at 1,000 μg/ml mixed with 2,000 μg/ml of citric acid and SDBS (55 μg/ml) significantly reduced E. coli counts by >4 log10 within 4 min when the pH was maintained between 3.0 and 3.3, and the efficacy of the fungicide was retained. The use of citric acid with a surfactant can be a viable alternative sanitation method for natamycin in citrus packinghouses utilizing heated recirculating fungicide systems.
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Affiliation(s)
- Daniel Chen
- Department of Microbiology and Plant Pathology, University of California, Riverside, CA 92521
| | - Helga Förster
- Department of Microbiology and Plant Pathology, University of California, Riverside, CA 92521
| | - Kevin Nguyen
- Department of Microbiology and Plant Pathology, University of California, Riverside, CA 92521
| | - James E Adaskaveg
- Department of Microbiology and Plant Pathology, University of California, Riverside, CA 92521
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23
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Phospholipid translocation captured in a bifunctional membrane protein MprF. Nat Commun 2021; 12:2927. [PMID: 34006869 PMCID: PMC8131360 DOI: 10.1038/s41467-021-23248-z] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2021] [Accepted: 04/16/2021] [Indexed: 01/07/2023] Open
Abstract
As a large family of membrane proteins crucial for bacterial physiology and virulence, the Multiple Peptide Resistance Factors (MprFs) utilize two separate domains to synthesize and translocate aminoacyl phospholipids to the outer leaflets of bacterial membranes. The function of MprFs enables Staphylococcus aureus and other pathogenic bacteria to acquire resistance to daptomycin and cationic antimicrobial peptides. Here we present cryo-electron microscopy structures of MprF homodimer from Rhizobium tropici (RtMprF) at two different states in complex with lysyl-phosphatidylglycerol (LysPG). RtMprF contains a membrane-embedded lipid-flippase domain with two deep cavities opening toward the inner and outer leaflets of the membrane respectively. Intriguingly, a hook-shaped LysPG molecule is trapped inside the inner cavity with its head group bent toward the outer cavity which hosts a second phospholipid-binding site. Moreover, RtMprF exhibits multiple conformational states with the synthase domain adopting distinct positions relative to the flippase domain. Our results provide a detailed framework for understanding the mechanisms of MprF-mediated modification and translocation of phospholipids.
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24
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Yang B, Liu C, Pan X, Fu W, Fan Z, Jin Y, Bai F, Cheng Z, Wu W. Identification of Novel PhoP-PhoQ Regulated Genes That Contribute to Polymyxin B Tolerance in Pseudomonas aeruginosa. Microorganisms 2021; 9:microorganisms9020344. [PMID: 33572426 PMCID: PMC7916210 DOI: 10.3390/microorganisms9020344] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2021] [Revised: 02/06/2021] [Accepted: 02/08/2021] [Indexed: 12/14/2022] Open
Abstract
Polymyxin B and E (colistin) are the last resorts to treat multidrug-resistant Gram-negative pathogens. Pseudomonas aeruginosa is intrinsically resistant to a variety of antibiotics. The PhoP-PhoQ two-component regulatory system contributes to the resistance to polymyxins by regulating an arnBCADTEF-pmrE operon that encodes lipopolysaccharide modification enzymes. To identify additional PhoP-regulated genes that contribute to the tolerance to polymyxin B, we performed a chromatin immunoprecipitation sequencing (ChIP-Seq) assay and found novel PhoP binding sites on the chromosome. We further verified that PhoP directly controls the expression of PA14_46900, PA14_50740 and PA14_52340, and the operons of PA14_11970-PA14_11960 and PA14_52350-PA14_52370. Our results demonstrated that mutation of PA14_46900 increased the bacterial binding and susceptibility to polymyxin B. Meanwhile, mutation of PA14_11960 (papP), PA14_11970 (mpl), PA14_50740 (slyB), PA14_52350 (ppgS), and PA14_52370 (ppgH) reduced the bacterial survival rates and increased ethidium bromide influx under polymyxin B or Sodium dodecyl sulfate (SDS) treatment, indicating roles of these genes in maintaining membrane integrity in response to the stresses. By 1-N-phenylnaphthylamine (NPN) and propidium iodide (PI) staining assay, we found that papP and slyB are involved in maintaining outer membrane integrity, and mpl and ppgS-ppgH are involved in maintaining inner membrane integrity. Overall, our results reveal novel PhoP-PhoQ regulated genes that contribute to polymyxin B tolerance.
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25
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Simcock PW, Bublitz M, Cipcigan F, Ryadnov MG, Crain J, Stansfeld PJ, Sansom MSP. Membrane Binding of Antimicrobial Peptides Is Modulated by Lipid Charge Modification. J Chem Theory Comput 2021; 17:1218-1228. [PMID: 33395285 DOI: 10.1021/acs.jctc.0c01025] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Peptide interactions with lipid bilayers play a key role in a range of biological processes and depend on electrostatic interactions between charged amino acids and lipid headgroups. Antimicrobial peptides (AMPs) initiate the killing of bacteria by binding to and destabilizing their membranes. The multiple peptide resistance factor (MprF) provides a defense mechanism for bacteria against a broad range of AMPs. MprF reduces the negative charge of bacterial membranes through enzymatic conversion of the anionic lipid phosphatidyl glycerol (PG) to either zwitterionic alanyl-phosphatidyl glycerol (Ala-PG) or cationic lysyl-phosphatidyl glycerol (Lys-PG). The resulting change in the membrane charge is suggested to reduce the binding of AMPs to membranes, thus impeding downstream AMP activity. Using coarse-grained molecular dynamics to investigate the effects of these modified lipids on AMP binding to model membranes, we show that AMPs have substantially reduced affinity for model membranes containing Ala-PG or Lys-PG. More than 5000 simulations in total are used to define the relationship between lipid bilayer composition, peptide sequence (using five different membrane-active peptides), and peptide binding to membranes. The degree of interaction of a peptide with a membrane correlates with the membrane surface charge density. Free energy profile (potential of mean force) calculations reveal that the lipid modifications due to MprF alter the energy barrier to peptide helix penetration of the bilayer. These results will offer a guide to the design of novel peptides, which addresses the issue of resistance via MprF-mediated membrane modification.
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Affiliation(s)
- Patrick W Simcock
- Department of Biochemistry, University of Oxford, Oxford OX1 3QU, U.K
| | - Maike Bublitz
- Department of Biochemistry, University of Oxford, Oxford OX1 3QU, U.K
| | | | - Maxim G Ryadnov
- National Physical Laboratory, Hampton Road, Teddington TW11 0LW, U.K
| | - Jason Crain
- Department of Biochemistry, University of Oxford, Oxford OX1 3QU, U.K
- IBM Research UK, Hartree Centre, Daresbury WA4 4AD, U.K
| | - Phillip J Stansfeld
- Department of Biochemistry, University of Oxford, Oxford OX1 3QU, U.K
- School of Life Sciences and Department of Chemistry, University of Warwick, Coventry CV4 7AL, U.K
| | - Mark S P Sansom
- Department of Biochemistry, University of Oxford, Oxford OX1 3QU, U.K
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26
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Cardoso P, Glossop H, Meikle TG, Aburto-Medina A, Conn CE, Sarojini V, Valery C. Molecular engineering of antimicrobial peptides: microbial targets, peptide motifs and translation opportunities. Biophys Rev 2021; 13:35-69. [PMID: 33495702 PMCID: PMC7817352 DOI: 10.1007/s12551-021-00784-y] [Citation(s) in RCA: 44] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2020] [Accepted: 01/07/2021] [Indexed: 02/07/2023] Open
Abstract
The global public health threat of antimicrobial resistance has led the scientific community to highly engage into research on alternative strategies to the traditional small molecule therapeutics. Here, we review one of the most popular alternatives amongst basic and applied research scientists, synthetic antimicrobial peptides. The ease of peptide chemical synthesis combined with emerging engineering principles and potent broad-spectrum activity, including against multidrug-resistant strains, has motivated intense scientific focus on these compounds for the past decade. This global effort has resulted in significant advances in our understanding of peptide antimicrobial activity at the molecular scale. Recent evidence of molecular targets other than the microbial lipid membrane, and efforts towards consensus antimicrobial peptide motifs, have supported the rise of molecular engineering approaches and design tools, including machine learning. Beyond molecular concepts, supramolecular chemistry has been lately added to the debate; and helped unravel the impact of peptide self-assembly on activity, including on biofilms and secondary targets, while providing new directions in pharmaceutical formulation through taking advantage of peptide self-assembled nanostructures. We argue that these basic research advances constitute a solid basis for promising industry translation of rationally designed synthetic peptide antimicrobials, not only as novel drugs against multidrug-resistant strains but also as components of emerging antimicrobial biomaterials. This perspective is supported by recent developments of innovative peptide-based and peptide-carrier nanobiomaterials that we also review.
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Affiliation(s)
- Priscila Cardoso
- School of Health and Biomedical Sciences, RMIT University, Melbourne, Australia.,School of Science, RMIT University, Melbourne, Australia
| | - Hugh Glossop
- School of Chemical Sciences, University of Auckland, Auckland, New Zealand
| | | | | | | | | | - Celine Valery
- School of Health and Biomedical Sciences, RMIT University, Melbourne, Australia
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Incledion A, Boseley M, Moses RL, Moseley R, Hill KE, Thomas DW, Adams RA, Jones TP, BéruBé KA. A New Look at the Purported Health Benefits of Commercial and Natural Clays. Biomolecules 2021; 11:biom11010058. [PMID: 33466399 PMCID: PMC7824833 DOI: 10.3390/biom11010058] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2020] [Revised: 12/30/2020] [Accepted: 12/31/2020] [Indexed: 11/16/2022] Open
Abstract
Clays attributed to have medicinal properties have been used since prehistoric times and are still used today as complementary medicines, which has given rise to unregulated “bioceutical” clays to treat skin conditions. Recently, clays with antibacterial characteristics have been proposed as alternatives to antibiotics, potentially overcoming modern day antibiotic resistance. Clays with suggested antibacterial properties were examined to establish their effects on common wound-infecting bacteria. Geochemical, microscopical, and toxicological characterization of clay particulates, their suspensions and filtered leachates was performed on THP-1 and HaCaT cell lines. Cytoskeletal toxicity, cell proliferation/viability (MTT assays), and migration (scratch wounds) were further evaluated. Clays were assayed for antibacterial efficacy using minimum inhibitory concentration assays. All clays possessed a mineral content with antibacterial potential; however, clay leachates contained insufficient ions to have any antibacterial effects. All clay leachates displayed toxicity towards THP-1 monocytes, while clay suspensions showed less toxicity, suggesting immunogenicity. Reduced clay cytotoxicity on HaCaTs was shown, as many leachates stimulated wound-healing responses. The “Green” clay exhibited antibacterial effects and only in suspension, which was lost upon neutralization. pH and its interaction with clay particle surface charge is more significant than previously understood to emphasize dangers of unregulated marketing and unsubstantiated bioceutical claims.
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Affiliation(s)
- Alexander Incledion
- School of Biosciences, Cardiff University, Cardiff CF10 3AX, UK;
- Cardiff Institute for Tissue Engineering and Repair, Cardiff University, Cardiff CF10 3BG, UK; (M.B.); (R.L.M.); (R.M.)
| | - Megan Boseley
- Cardiff Institute for Tissue Engineering and Repair, Cardiff University, Cardiff CF10 3BG, UK; (M.B.); (R.L.M.); (R.M.)
- School of Dentistry, Cardiff University, Cardiff CF14 4XY, UK; (K.E.H.); (D.W.T.)
| | - Rachael L. Moses
- Cardiff Institute for Tissue Engineering and Repair, Cardiff University, Cardiff CF10 3BG, UK; (M.B.); (R.L.M.); (R.M.)
- School of Dentistry, Cardiff University, Cardiff CF14 4XY, UK; (K.E.H.); (D.W.T.)
| | - Ryan Moseley
- Cardiff Institute for Tissue Engineering and Repair, Cardiff University, Cardiff CF10 3BG, UK; (M.B.); (R.L.M.); (R.M.)
- School of Dentistry, Cardiff University, Cardiff CF14 4XY, UK; (K.E.H.); (D.W.T.)
| | - Katja E. Hill
- School of Dentistry, Cardiff University, Cardiff CF14 4XY, UK; (K.E.H.); (D.W.T.)
| | - David W. Thomas
- School of Dentistry, Cardiff University, Cardiff CF14 4XY, UK; (K.E.H.); (D.W.T.)
| | - Rachel A. Adams
- School of Sport & Health Sciences, Cardiff Metropolitan University, Cardiff CF5 2YB, UK;
| | - Tim P. Jones
- School of Earth and Ocean Sciences, Cardiff University, Cardiff CF10 3AT, UK;
| | - Kelly A. BéruBé
- School of Biosciences, Cardiff University, Cardiff CF10 3AX, UK;
- Cardiff Institute for Tissue Engineering and Repair, Cardiff University, Cardiff CF10 3BG, UK; (M.B.); (R.L.M.); (R.M.)
- Correspondence: ; Tel.: +44-0-292-087-6012
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Park J, Kim SJ, Kim EB. Changes in the Microbial Community of the Mottled Skate ( Beringraja pulchra) During Alkaline Fermentation. J Microbiol Biotechnol 2020; 30:1195-1206. [PMID: 32423184 PMCID: PMC9728196 DOI: 10.4014/jmb.2003.03024] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2020] [Accepted: 05/06/2020] [Indexed: 12/15/2022]
Abstract
Beringraja pulchra, Cham-hong-eo in Korean, is a mottled skate which is belonging to the cartilaginous fish. Although this species is economically valuable in South Korea as an alkalinefermented food, there are few microbial studies on such fermentation. Here, we analyzed microbial changes and pH before, during, and after fermentation and examined the effect of inoculation by a skin microbiota mixture on the skate fermentation (control vs. treatment). To analyze microbial community, the V4 regions of bacterial 16S rRNA genes from the skates were amplified, sequenced and analyzed. During the skate fermentation, pH and total number of marine bacteria increased in both groups, while microbial diversity decreased after fermentation. Pseudomonas, which was predominant in the initial skate, declined by fermentation (Day 0: 11.39 ± 5.52%; Day 20: 0.61 ± 0.9%), while the abundance of Pseudoalteromonas increased dramatically (Day 0: 1.42 ± 0.41%; Day 20: 64.92 ± 24.15%). From our co-occurrence analysis, the Pseudoalteromonas was positively correlated with Aerococcaceae (r = 0.638) and Moraxella (r = 0.474), which also increased with fermentation, and negatively correlated with Pseudomonas (r = -0.847) during fermentation. There are no critically significant differences between control and treatment. These results revealed that the alkaline fermentation of skates dramatically changed the microbiota, but the initial inoculation by a skin microbiota mixture didn't show critical changes in the final microbial community. Our results extended understanding of microbial interactions and provided the new insights of microbial changes during alkaline fermentation.
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Affiliation(s)
- Jongbin Park
- Department of Applied Animal Science, College of Animal Life Sciences, Kangwon National University, Chuncheon 24341, Republic of Korea
| | - Soo Jin Kim
- Department of Animal Life Science, College of Animal Life Sciences, Kangwon National University, Chuncheon 24341, Republic of Korea
| | - Eun Bae Kim
- Department of Applied Animal Science, College of Animal Life Sciences, Kangwon National University, Chuncheon 24341, Republic of Korea,Department of Animal Life Science, College of Animal Life Sciences, Kangwon National University, Chuncheon 24341, Republic of Korea,Corresponding author Phone: +82-33-250-8642 Fax: +82-33-259-5574 E-mail:
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Blevins MS, James VK, Herrera CM, Purcell AB, Trent MS, Brodbelt JS. Unsaturation Elements and Other Modifications of Phospholipids in Bacteria: New Insight from Ultraviolet Photodissociation Mass Spectrometry. Anal Chem 2020; 92:9146-9155. [PMID: 32479092 PMCID: PMC7384744 DOI: 10.1021/acs.analchem.0c01449] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Glycerophospholipids (GPLs), one of the main components of bacterial cell membranes, exhibit high levels of structural complexity that are directly correlated with biophysical membrane properties such as permeability and fluidity. This structural complexity arises from the substantial variability in the individual GPL structural components such as the acyl chain length and headgroup type and is further amplified by the presence of modifications such as double bonds and cyclopropane rings. Here we use liquid chromatography coupled to high-resolution and high-mass-accuracy ultraviolet photodissociation mass spectrometry for the most in-depth study of bacterial GPL modifications to date. In doing so, we unravel a diverse array of unexplored GPL modifications, ranging from acyl chain hydroxyl groups to novel headgroup structures. Along with characterizing these modifications, we elucidate general trends in bacterial GPL unsaturation elements and thus aim to decipher some of the biochemical pathways of unsaturation incorporation in bacterial GPLs. Finally, we discover aminoacyl-PGs not only in Gram-positive bacteria but also in Gram-negative C. jejuni, advancing our knowledge of the methods of surface charge modulation that Gram-negative organisms may adopt for antibiotic resistance.
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Affiliation(s)
- Molly S Blevins
- Department of Chemistry, University of Texas at Austin, Austin, Texas 78712, United States
| | - Virginia K James
- Department of Chemistry, University of Texas at Austin, Austin, Texas 78712, United States
| | - Carmen M Herrera
- Department of Infectious Diseases, College of Veterinary Medicine, University of Georgia, Athens, Georgia 30602, United States
| | - Alexandria B Purcell
- Department of Infectious Diseases, College of Veterinary Medicine, University of Georgia, Athens, Georgia 30602, United States
| | - M Stephen Trent
- Department of Infectious Diseases, College of Veterinary Medicine, University of Georgia, Athens, Georgia 30602, United States
- Department of Microbiology, College of Arts and Sciences, University of Georgia, Athens, Georgia 30602, United States
- Center for Vaccines and Immunology, University of Georgia, Athens, Georgia 30602, United States
| | - Jennifer S Brodbelt
- Department of Chemistry, University of Texas at Austin, Austin, Texas 78712, United States
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30
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Arab B, Hassanpour F, Arshadi M, Yaghmaei S, Hamedi J. Optimized bioleaching of copper by indigenous cyanogenic bacteria isolated from the landfill of e-waste. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2020; 261:110124. [PMID: 31999614 DOI: 10.1016/j.jenvman.2020.110124] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/14/2019] [Revised: 12/18/2019] [Accepted: 01/10/2020] [Indexed: 06/10/2023]
Abstract
In this study, indigenous cyanogenic bacterial strains were isolated on nutrient, minimal salt, and soil extract media at various culture conditions from two distinct landfills of e-waste, Iran. Based on their cyanide formation profiles, five most potent isolates were selected for optimization and to this end, the influence of the most effective factors on cyanide production including pH, glycine concentration and temperature were assessed using one-factor at a time method (OFAT). Initial pH of 7, glycine concentration of 2 g/L and temperature of 30°C were obtained as optimal conditions for most of the isolates. Additionally, two bioleaching processes were applied for each bacteria to detect the effect of optimal conditions on bioleaching and to assay their potential in the mobilization of copper. Under optimal conditions and pulp density of 1 g/L, copper recoveries were recorded as 96.73%, 82.49%, 81.17%, 41.72%, and 31.52% by S22, N13, N37, N23, and N41 respectively during 10 days which is approximately 1.5-5 times higher than the recovery obtained without optimization. During the optimization and the bioleaching process, the pH fluctuation of the flasks was monitored which validated the activity of the microorganisms.
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Affiliation(s)
- Bahareh Arab
- Chemical and Petroleum Engineering Department, Sharif University of Technology, Tehran, Iran.
| | - Fatemeh Hassanpour
- Chemical and Petroleum Engineering Department, Sharif University of Technology, Tehran, Iran.
| | - Mahdokht Arshadi
- Chemical and Petroleum Engineering Department, Sharif University of Technology, Tehran, Iran.
| | - Soheila Yaghmaei
- Chemical and Petroleum Engineering Department, Sharif University of Technology, Tehran, Iran.
| | - Javad Hamedi
- Department of Microbial Biotechnology, School of Biology, University of Tehran, Tehran, Iran.
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Di Somma A, Moretta A, Canè C, Cirillo A, Duilio A. Antimicrobial and Antibiofilm Peptides. Biomolecules 2020; 10:biom10040652. [PMID: 32340301 PMCID: PMC7226136 DOI: 10.3390/biom10040652] [Citation(s) in RCA: 116] [Impact Index Per Article: 29.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2020] [Revised: 04/17/2020] [Accepted: 04/21/2020] [Indexed: 12/11/2022] Open
Abstract
The increasing onset of multidrug-resistant bacteria has propelled microbiology research towards antimicrobial peptides as new possible antibiotics from natural sources. Antimicrobial peptides are short peptides endowed with a broad range of activity against both Gram-positive and Gram-negative bacteria and are less prone to trigger resistance. Besides their activity against planktonic bacteria, many antimicrobial peptides also show antibiofilm activity. Biofilms are ubiquitous in nature, having the ability to adhere to virtually any surface, either biotic or abiotic, including medical devices, causing chronic infections that are difficult to eradicate. The biofilm matrix protects bacteria from hostile environments, thus contributing to the bacterial resistance to antimicrobial agents. Biofilms are very difficult to treat, with options restricted to the use of large doses of antibiotics or the removal of the infected device. Antimicrobial peptides could represent good candidates to develop new antibiofilm drugs as they can act at different stages of biofilm formation, on disparate molecular targets and with various mechanisms of action. These include inhibition of biofilm formation and adhesion, downregulation of quorum sensing factors, and disruption of the pre-formed biofilm. This review focuses on the proprieties of antimicrobial and antibiofilm peptides, with a particular emphasis on their mechanism of action, reporting several examples of peptides that over time have been shown to have activity against biofilm.
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Affiliation(s)
- Angela Di Somma
- Dipartimento di Scienze Chimiche, Università Federico II, 80126 Naples, Italy; (A.D.S.); (C.C.)
- Istituto Nazionale Biostrutture e Biosistemi (INBB), 00136 Rome, Italy
| | - Antonio Moretta
- Dipartimento di Scienze, Università degli Studi della Basilicata, 85100 Potenza, Italy;
| | - Carolina Canè
- Dipartimento di Scienze Chimiche, Università Federico II, 80126 Naples, Italy; (A.D.S.); (C.C.)
| | | | - Angela Duilio
- Dipartimento di Scienze Chimiche, Università Federico II, 80126 Naples, Italy; (A.D.S.); (C.C.)
- Correspondence:
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Mechanisms of bactericidal action and resistance of polymyxins for Gram-positive bacteria. Appl Microbiol Biotechnol 2020; 104:3771-3780. [PMID: 32157424 DOI: 10.1007/s00253-020-10525-y] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2019] [Revised: 02/25/2020] [Accepted: 03/03/2020] [Indexed: 10/24/2022]
Abstract
Polymyxins are cationic antimicrobial peptides used as the last-line therapy to treat multidrug-resistant Gram-negative bacterial infections. The bactericidal activity of polymyxins against Gram-negative bacteria relies on the electrostatic interaction between the positively charged polymyxins and the negatively charged lipid A of lipopolysaccharide (LPS). Given that Gram-positive bacteria lack an LPS-containing outer membrane, it is generally acknowledged that polymyxins are less active against Gram-positive bacteria. However, Gram-positive bacteria produce negatively charged teichoic acids, which may act as the target of polymyxins. More and more studies suggest that polymyxins have potential as a treatment for Gram-positive bacterial infection. This mini-review discusses recent advances in the mechanism of the antibacterial activity and resistance of polymyxins in Gram-positive bacteria.Key Points• Teichoic acids play a key role in the action of polymyxins on Gram-positive bacteria.• Polymyxin kills Gram-positive bacteria by disrupting cell surface and oxidative damage.• Modification of teichoic acids and phospholipids contributes to polymyxin resistance in Gram-positive bacteria.• Polymyxins have potential as a treatment for Gram-positive bacterial infection.
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33
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Baindara P, Ghosh AK, Mandal SM. Coevolution of Resistance Against Antimicrobial Peptides. Microb Drug Resist 2020; 26:880-899. [PMID: 32119634 DOI: 10.1089/mdr.2019.0291] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Antimicrobial peptides (AMPs) are produced by all forms of life, ranging from eukaryotes to prokaryotes, and they are a crucial component of innate immunity, involved in clearing infection by inhibiting pathogen colonization. In the recent past, AMPs received high attention due to the increase of extensive antibiotic resistance by these pathogens. AMPs exhibit a diverse spectrum of activity against bacteria, fungi, parasites, and various types of cancer. AMPs are active against various bacterial pathogens that cause disease in animals and plants. However, because of the coevolution of host and pathogen interaction, bacteria have developed the mechanisms to sense and exhibit an adaptive response against AMPs. These resistance mechanisms are playing an important role in bacterial virulence within the host. Here, we have discussed the different resistance mechanisms used by gram-positive and gram-negative bacteria to sense and combat AMP actions. Understanding the mechanism of AMP resistance may provide directions toward the development of novel therapeutic strategies to control multidrug-resistant pathogens.
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Affiliation(s)
- Piyush Baindara
- Department of Microbiology and Immunology, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA
| | - Ananta K Ghosh
- Department of Biotechnology, Central Research Facility, Indian Institute of Technology Kharagpur, Kharagpur, India
| | - Santi M Mandal
- Department of Biotechnology, Central Research Facility, Indian Institute of Technology Kharagpur, Kharagpur, India
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Zingl FG, Kohl P, Cakar F, Leitner DR, Mitterer F, Bonnington KE, Rechberger GN, Kuehn MJ, Guan Z, Reidl J, Schild S. Outer Membrane Vesiculation Facilitates Surface Exchange and In Vivo Adaptation of Vibrio cholerae. Cell Host Microbe 2019; 27:225-237.e8. [PMID: 31901519 DOI: 10.1016/j.chom.2019.12.002] [Citation(s) in RCA: 61] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2019] [Revised: 10/25/2019] [Accepted: 12/05/2019] [Indexed: 10/25/2022]
Abstract
Gram-negative bacteria release outer membrane vesicles into the external milieu to deliver effector molecules that alter the host and facilitate virulence. Vesicle formation is driven by phospholipid accumulation in the outer membrane and regulated by the phospholipid transporter VacJ/Yrb. We use the facultative human pathogen Vibrio cholerae to show that VacJ/Yrb is silenced early during mammalian infection, which stimulates vesiculation that expedites bacterial surface exchange and adaptation to the host environment. Hypervesiculating strains rapidly alter their bacterial membrane composition and exhibit enhanced intestinal colonization fitness. This adaptation is exemplified by faster accumulation of glycine-modified lipopolysaccharide (LPS) and depletion of outer membrane porin OmpT, which confers resistance to host-derived antimicrobial peptides and bile, respectively. The competitive advantage of hypervesiculation is lost upon pre-adaptation to bile and antimicrobial peptides, indicating the importance of these adaptive processes. Thus, bacteria use outer membrane vesiculation to exchange cell surface components, thereby increasing survival during mammalian infection.
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Affiliation(s)
- Franz G Zingl
- Institute of Molecular Biosciences, University of Graz, 8010 Graz, Austria
| | - Paul Kohl
- Institute of Molecular Biosciences, University of Graz, 8010 Graz, Austria
| | - Fatih Cakar
- Institute of Molecular Biosciences, University of Graz, 8010 Graz, Austria
| | - Deborah R Leitner
- Institute of Molecular Biosciences, University of Graz, 8010 Graz, Austria
| | - Fabian Mitterer
- Institute of Molecular Biosciences, University of Graz, 8010 Graz, Austria
| | | | - Gerald N Rechberger
- Institute of Molecular Biosciences, University of Graz, 8010 Graz, Austria; Center for Explorative Lipidomics, BioTechMed Graz, 8010 Graz, Austria
| | - Meta J Kuehn
- Duke University Medical Center, Durham, NC 27710, USA
| | - Ziqiang Guan
- Department of Biochemistry, Duke University Medical Center, Durham, NC 27710, USA
| | - Joachim Reidl
- Institute of Molecular Biosciences, University of Graz, 8010 Graz, Austria; BioTechMed Graz, 8010 Graz, Austria
| | - Stefan Schild
- Institute of Molecular Biosciences, University of Graz, 8010 Graz, Austria; BioTechMed Graz, 8010 Graz, Austria.
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Khan A, Davlieva M, Panesso D, Rincon S, Miller WR, Diaz L, Reyes J, Cruz MR, Pemberton O, Nguyen AH, Siegel SD, Planet PJ, Narechania A, Latorre M, Rios R, Singh KV, Ton-That H, Garsin DA, Tran TT, Shamoo Y, Arias CA. Antimicrobial sensing coupled with cell membrane remodeling mediates antibiotic resistance and virulence in Enterococcus faecalis. Proc Natl Acad Sci U S A 2019; 116:26925-26932. [PMID: 31818937 PMCID: PMC6936494 DOI: 10.1073/pnas.1916037116] [Citation(s) in RCA: 48] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Bacteria have developed several evolutionary strategies to protect their cell membranes (CMs) from the attack of antibiotics and antimicrobial peptides (AMPs) produced by the innate immune system, including remodeling of phospholipid content and localization. Multidrug-resistant Enterococcus faecalis, an opportunistic human pathogen, evolves resistance to the lipopeptide daptomycin and AMPs by diverting the antibiotic away from critical septal targets using CM anionic phospholipid redistribution. The LiaFSR stress response system regulates this CM remodeling via the LiaR response regulator by a previously unknown mechanism. Here, we characterize a LiaR-regulated protein, LiaX, that senses daptomycin or AMPs and triggers protective CM remodeling. LiaX is surface exposed, and in daptomycin-resistant clinical strains, both LiaX and the N-terminal domain alone are released into the extracellular milieu. The N-terminal domain of LiaX binds daptomycin and AMPs (such as human LL-37) and functions as an extracellular sentinel that activates the cell envelope stress response. The C-terminal domain of LiaX plays a role in inhibiting the LiaFSR system, and when this domain is absent, it leads to activation of anionic phospholipid redistribution. Strains that exhibit LiaX-mediated CM remodeling and AMP resistance show enhanced virulence in the Caenorhabditis elegans model, an effect that is abolished in animals lacking an innate immune pathway crucial for producing AMPs. In conclusion, we report a mechanism of antibiotic and AMP resistance that couples bacterial stress sensing to major changes in CM architecture, ultimately also affecting host-pathogen interactions.
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Affiliation(s)
- Ayesha Khan
- Center for Antimicrobial Resistance and Microbial Genomics, McGovern Medical School, University of Texas Health Science Center, Houston, TX 77030
- Division of Infectious Diseases, McGovern Medical School, University of Texas Health Science Center, Houston, TX 77030
- Department of Microbiology and Molecular Genetics, McGovern Medical School, University of Texas Health Science Center, Houston, TX 77030
- MD Anderson Cancer Center, University of Texas Health Graduate School of Biomedical Sciences, Houston, TX 77030
| | - Milya Davlieva
- Department of Biosciences, Rice University, Houston, TX 77005
| | - Diana Panesso
- Center for Antimicrobial Resistance and Microbial Genomics, McGovern Medical School, University of Texas Health Science Center, Houston, TX 77030
- Division of Infectious Diseases, McGovern Medical School, University of Texas Health Science Center, Houston, TX 77030
- Molecular Genetics and Antimicrobial Resistance Unit, International Center for Microbial Genomics, Universidad El Bosque, 110111 Bogotá, Colombia
| | - Sandra Rincon
- Molecular Genetics and Antimicrobial Resistance Unit, International Center for Microbial Genomics, Universidad El Bosque, 110111 Bogotá, Colombia
| | - William R. Miller
- Center for Antimicrobial Resistance and Microbial Genomics, McGovern Medical School, University of Texas Health Science Center, Houston, TX 77030
- Division of Infectious Diseases, McGovern Medical School, University of Texas Health Science Center, Houston, TX 77030
| | - Lorena Diaz
- Molecular Genetics and Antimicrobial Resistance Unit, International Center for Microbial Genomics, Universidad El Bosque, 110111 Bogotá, Colombia
- Millennium Initiative for Collaborative Research On Bacterial Resistance (MICROB-R), 8320000 Santiago, Chile
| | - Jinnethe Reyes
- Molecular Genetics and Antimicrobial Resistance Unit, International Center for Microbial Genomics, Universidad El Bosque, 110111 Bogotá, Colombia
| | - Melissa R. Cruz
- Department of Microbiology and Molecular Genetics, McGovern Medical School, University of Texas Health Science Center, Houston, TX 77030
| | | | - April H. Nguyen
- Center for Antimicrobial Resistance and Microbial Genomics, McGovern Medical School, University of Texas Health Science Center, Houston, TX 77030
- Division of Infectious Diseases, McGovern Medical School, University of Texas Health Science Center, Houston, TX 77030
- Department of Microbiology and Molecular Genetics, McGovern Medical School, University of Texas Health Science Center, Houston, TX 77030
- MD Anderson Cancer Center, University of Texas Health Graduate School of Biomedical Sciences, Houston, TX 77030
| | - Sara D. Siegel
- Department of Microbiology and Molecular Genetics, McGovern Medical School, University of Texas Health Science Center, Houston, TX 77030
| | - Paul J. Planet
- Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104
- Pediatric Infectious Disease Division, Children’s Hospital of Philadelphia, Philadelphia, PA
- Sackler Institute for Comparative Genomics, American Museum of Natural History, New York, NY 12560
| | - Apurva Narechania
- Sackler Institute for Comparative Genomics, American Museum of Natural History, New York, NY 12560
| | - Mauricio Latorre
- Center for Genome Regulation and Center for Mathematical Modeling, Universidad de Chile, 8320000 Santiago, Chile
- Laboratorio de Bioinformática y Expresión Génica, Instituto de Nutrición y Tecnología de los Alimentos, Universidad de Chile, 8320000 Santiago, Chile
- Laboratorio de Biotecnología, Instituto de Ciencias de la Ingeniería, Universidad de O'Higgins, 2841158 Rancagua, Chile
| | - Rafael Rios
- Molecular Genetics and Antimicrobial Resistance Unit, International Center for Microbial Genomics, Universidad El Bosque, 110111 Bogotá, Colombia
| | - Kavindra V. Singh
- Center for Antimicrobial Resistance and Microbial Genomics, McGovern Medical School, University of Texas Health Science Center, Houston, TX 77030
- Division of Infectious Diseases, McGovern Medical School, University of Texas Health Science Center, Houston, TX 77030
| | - Hung Ton-That
- Division of Oral Biology and Medicine, School of Dentistry, University of California, Los Angeles, CA 90024
| | - Danielle A. Garsin
- Center for Antimicrobial Resistance and Microbial Genomics, McGovern Medical School, University of Texas Health Science Center, Houston, TX 77030
- Department of Microbiology and Molecular Genetics, McGovern Medical School, University of Texas Health Science Center, Houston, TX 77030
- MD Anderson Cancer Center, University of Texas Health Graduate School of Biomedical Sciences, Houston, TX 77030
| | - Truc T. Tran
- Center for Antimicrobial Resistance and Microbial Genomics, McGovern Medical School, University of Texas Health Science Center, Houston, TX 77030
- Division of Infectious Diseases, McGovern Medical School, University of Texas Health Science Center, Houston, TX 77030
| | - Yousif Shamoo
- Department of Biosciences, Rice University, Houston, TX 77005
| | - Cesar A. Arias
- Center for Antimicrobial Resistance and Microbial Genomics, McGovern Medical School, University of Texas Health Science Center, Houston, TX 77030
- Division of Infectious Diseases, McGovern Medical School, University of Texas Health Science Center, Houston, TX 77030
- Department of Microbiology and Molecular Genetics, McGovern Medical School, University of Texas Health Science Center, Houston, TX 77030
- MD Anderson Cancer Center, University of Texas Health Graduate School of Biomedical Sciences, Houston, TX 77030
- Molecular Genetics and Antimicrobial Resistance Unit, International Center for Microbial Genomics, Universidad El Bosque, 110111 Bogotá, Colombia
- Center for Infectious Diseases, School of Public Health, University of Texas Health Science Center, Houston, TX 77030
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Wüllner D, Haupt A, Prochnow P, Leontiev R, Slusarenko AJ, Bandow JE. Interspecies Comparison of the Bacterial Response to Allicin Reveals Species-Specific Defense Strategies. Proteomics 2019; 19:e1900064. [PMID: 31622046 DOI: 10.1002/pmic.201900064] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2019] [Revised: 09/16/2019] [Indexed: 12/22/2022]
Abstract
Allicin, a broad-spectrum antimicrobial agent from garlic, disrupts thiol and redox homeostasis, proteostasis, and cell membrane integrity. Since medicine demands antimicrobials with so far unexploited mechanisms, allicin is a promising lead structure. While progress is being made in unraveling its mode of action, little is known on bacterial adaptation strategies. Some isolates of Pseudomonas aeruginosa and Escherichia coli withstand exposure to high allicin concentrations due to as yet unknown mechanisms. To elucidate resistance and sensitivity-conferring cellular processes, the acute proteomic responses of a resistant P. aeruginosa strain and the sensitive species Bacillus subtilis are compared to the published proteomic response of E. coli to allicin treatment. The cellular defense strategies share functional features: proteins involved in translation and maintenance of protein quality, redox homeostasis, and cell envelope modification are upregulated. In both Gram-negative species, protein synthesis of the majority of proteins is downregulated while the Gram-positive B. subtilis responded by upregulation of multiple regulons. A comparison of the B. subtilis proteomic response to a library of responses to antibiotic treatment reveals 30 proteins specifically upregulated by allicin. Upregulated oxidative stress proteins are shared with nitrofurantoin and diamide. Microscopy-based assays further indicate that in B. subtilis cell wall integrity is impaired.
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Affiliation(s)
- Dominik Wüllner
- Applied Microbiology, Faculty of Biology and Biotechnology, Ruhr University Bochum, 44780, Bochum, Germany
| | - Annika Haupt
- Applied Microbiology, Faculty of Biology and Biotechnology, Ruhr University Bochum, 44780, Bochum, Germany
| | - Pascal Prochnow
- Applied Microbiology, Faculty of Biology and Biotechnology, Ruhr University Bochum, 44780, Bochum, Germany
| | - Roman Leontiev
- Department of Plant Physiology (Bio III), RWTH Aachen University, 52056, Aachen, Germany.,Division of Bioorganic Chemistry, School of Pharmacy, Saarland University, 66041, Saarbrücken, Germany
| | - Alan J Slusarenko
- Department of Plant Physiology (Bio III), RWTH Aachen University, 52056, Aachen, Germany
| | - Julia E Bandow
- Applied Microbiology, Faculty of Biology and Biotechnology, Ruhr University Bochum, 44780, Bochum, Germany
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Kim S, Ha J, Lee H, Lee S, Lee J, Choi Y, Oh H, Yoon Y, Choi KH. Role of Pseudomonas aeruginosa DesB in Adaptation to Osmotic Stress. J Food Prot 2019; 82:1278-1282. [PMID: 31298570 DOI: 10.4315/0362-028x.jfp-18-507] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Proper membrane fluidity is maintained by adjusting the ratio of saturated fatty acids to unsaturated fatty acids (UFAs), and the control of membrane fluidity plays an important role in bacterial adaptation to stress. Adaptability to these stresses involves survival and colonization of bacteria, thus contributing to bacterial contamination in food. UFAs are synthesized by FabAB- and Des-mediated pathways in Pseudomonas aeruginosa. Therefore, in this study, the roles of UFA-synthesizing proteins of P. aeruginosa in resistance to stresses were examined. The growth and transcription levels of wild-type (WT) P. aeruginosa PAO1 and its mutants were compared. The growth of all strains was inhibited by exposure to 0.5 or 1.0 M sodium chloride, but it was not affected by oxidative or pH stress. In particular, growth was impaired more substantially in the desB mutant than in the WT strain and other mutants, suggesting that DesB has a role in response to salt stress. A comparative transcriptional analysis showed that genes involved in the synthesis of osmoprotectants (trehalose, N-acetylglutaminylglutamine amide, and hydrophilin) were highly expressed in WT P. aeruginosa in response to high salt, but they were rarely expressed in the desB mutant. Furthermore, decreases in osmoprotectant production by the desB mutant were partially complemented by the addition of betaine. These results indicate that P. aeruginosa DesB contributes to adaptation to high salinity by positively regulating the synthesis of osmoprotectants.
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Affiliation(s)
- Sejeong Kim
- 1 Department of Food and Nutrition, Sookmyung Women's University, Seoul 140-742, Korea
| | - Jimyeong Ha
- 1 Department of Food and Nutrition, Sookmyung Women's University, Seoul 140-742, Korea
| | - Heeyoung Lee
- 1 Department of Food and Nutrition, Sookmyung Women's University, Seoul 140-742, Korea
| | - Soomin Lee
- 1 Department of Food and Nutrition, Sookmyung Women's University, Seoul 140-742, Korea
| | - Jeeyeon Lee
- 1 Department of Food and Nutrition, Sookmyung Women's University, Seoul 140-742, Korea
| | - Yukyung Choi
- 1 Department of Food and Nutrition, Sookmyung Women's University, Seoul 140-742, Korea
| | - Hyemin Oh
- 1 Department of Food and Nutrition, Sookmyung Women's University, Seoul 140-742, Korea
| | - Yohan Yoon
- 1 Department of Food and Nutrition, Sookmyung Women's University, Seoul 140-742, Korea
| | - Kyoung-Hee Choi
- 2 Department of Oral Microbiology, College of Dentistry, Wonkwang University, Iksan 570-749, Korea
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Myszka K, Olejnik A, Majcher M, Sobieszczańska N, Grygier A, Powierska-Czarny J, Rudzińska M. Green pepper essential oil as a biopreservative agent for fish-based products: Antimicrobial and antivirulence activities against Pseudomonas aeruginosa KM01. Lebensm Wiss Technol 2019. [DOI: 10.1016/j.lwt.2019.03.047] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
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Abbes I, Rihouey C, Hardouin J, Jouenne T, De E, Alexandre S. Identification by mass spectrometry of glucosaminylphosphatidylglycerol, a phosphatidylglycerol derivative, produced by Pseudomonas aeruginosa. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2018; 32:2113-2121. [PMID: 30171632 DOI: 10.1002/rcm.8277] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/12/2018] [Revised: 08/21/2018] [Accepted: 08/21/2018] [Indexed: 06/08/2023]
Abstract
RATIONALE Pseudomonas aeruginosa is an opportunistic pathogen bacterium widely considered to be an excellent research model in several areas of molecular studies, namely genomics and proteomics. However, its lipid metabolism is still not totally decrypted. While it is known that this bacterium has the particularity to produce phosphatidylcholine, a lipid mainly found in eukaryotes, other singularities are still to be discovered. METHODS P. aeruginosa was grown as planktonic cultures to the stationary state. Membrane pellets were collected and lipids were extracted using the Bligh and Dyer protocol. Lipid extracts were analyzed by Electrospray Ionization Mass Spectrometry (ESI-MS) using high-resolution mass spectrometer (LTQ Orbitrap Elite, Thermo Scientific) in the negative mode. MSn spectra were recorded both in the Orbitrap and in the ion trap analyzer (collision-induced dissociation (CID) or higher energy collision-induced dissociation (HCD) mode). RESULTS We observed by mass spectrometry and thin layer chromatography that P. aeruginosa produced an unreferenced lipid in classical growth conditions. MS2 analysis of the unknown ion indicates that it is a phosphatidylglycerol derivative. The exact mass shift corresponds to glucosamine which is largely found in the metabolism of this bacterium. MS3 analysis of secondary ions allowed us to conclude that this lipid is a glucosaminylphosphatidylglycerol, a phosphatidylglycerol derivative containing a glucosamine substituted at C4. CONCLUSIONS We show here that P. aeruginosa is able to produce glucosaminylphosphatidylglycerols via a probable esterification of phosphatidylglycerols by glucosamine.
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Affiliation(s)
- Imen Abbes
- CNRS, UMR 6270, "Polymères, Biopolymères, Surfaces", Université de Rouen, F-76821, Mont-Saint-Aignan, France
- Normandie Université, F-14032, Caen, France
| | - Christophe Rihouey
- CNRS, UMR 6270, "Polymères, Biopolymères, Surfaces", Université de Rouen, F-76821, Mont-Saint-Aignan, France
- Normandie Université, F-14032, Caen, France
| | - Julie Hardouin
- CNRS, UMR 6270, "Polymères, Biopolymères, Surfaces", Université de Rouen, F-76821, Mont-Saint-Aignan, France
- Normandie Université, F-14032, Caen, France
- PISSARO proteomics facility, Université de Rouen, F-76821, Mont-Saint-Aignan, France
| | - Thierry Jouenne
- CNRS, UMR 6270, "Polymères, Biopolymères, Surfaces", Université de Rouen, F-76821, Mont-Saint-Aignan, France
- Normandie Université, F-14032, Caen, France
- PISSARO proteomics facility, Université de Rouen, F-76821, Mont-Saint-Aignan, France
| | - Emmanuelle De
- CNRS, UMR 6270, "Polymères, Biopolymères, Surfaces", Université de Rouen, F-76821, Mont-Saint-Aignan, France
- Normandie Université, F-14032, Caen, France
| | - Stéphane Alexandre
- CNRS, UMR 6270, "Polymères, Biopolymères, Surfaces", Université de Rouen, F-76821, Mont-Saint-Aignan, France
- Normandie Université, F-14032, Caen, France
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Groenewold MK, Hebecker S, Fritz C, Czolkoss S, Wiesselmann M, Heinz DW, Jahn D, Narberhaus F, Aktas M, Moser J. Virulence of Agrobacterium tumefaciens requires lipid homeostasis mediated by the lysyl-phosphatidylglycerol hydrolase AcvB. Mol Microbiol 2018; 111:269-286. [PMID: 30353924 DOI: 10.1111/mmi.14154] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/17/2018] [Indexed: 12/24/2022]
Abstract
Agrobacterium tumefaciens transfers oncogenic T-DNA via the type IV secretion system (T4SS) into plants causing tumor formation. The acvB gene encodes a virulence factor of unknown function required for plant transformation. Here we specify AcvB as a periplasmic lysyl-phosphatidylglycerol (L-PG) hydrolase, which modulates L-PG homeostasis. Through functional characterization of recombinant AcvB variants, we showed that the C-terminal domain of AcvB (residues 232-456) is sufficient for full enzymatic activity and defined key residues for catalysis. Absence of the hydrolase resulted in ~10-fold increase in L-PG in Agrobacterium membranes and abolished T-DNA transfer and tumor formation. Overproduction of the L-PG synthase gene (lpiA) in wild-type A. tumefaciens resulted in a similar increase in the L-PG content (~7-fold) and a virulence defect even in the presence of intact AcvB. These results suggest that elevated L-PG amounts (either by overproduction of the synthase or absence of the hydrolase) are responsible for the virulence phenotype. Gradually increasing the L-PG content by complementation with different acvB variants revealed that cellular L-PG levels above 3% of total phospholipids interfere with T-DNA transfer. Cumulatively, this study identified AcvB as a novel virulence factor required for membrane lipid homeostasis and T-DNA transfer.
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Affiliation(s)
- Maike K Groenewold
- Structure and Function of Proteins, Helmholtz Centre for Infection Research, 38124, Braunschweig, Germany
| | - Stefanie Hebecker
- Institute for Microbiology, Technische Universität Braunschweig, 38106, Braunschweig, Germany
| | - Christiane Fritz
- Lehrstuhl für Biologie der Mikroorganismen, Ruhr-Universität Bochum, 44780, Bochum, Germany
| | - Simon Czolkoss
- Lehrstuhl für Biologie der Mikroorganismen, Ruhr-Universität Bochum, 44780, Bochum, Germany
| | - Milan Wiesselmann
- Institute for Microbiology, Technische Universität Braunschweig, 38106, Braunschweig, Germany
| | - Dirk W Heinz
- Structure and Function of Proteins, Helmholtz Centre for Infection Research, 38124, Braunschweig, Germany
| | - Dieter Jahn
- Institute for Microbiology, Technische Universität Braunschweig, 38106, Braunschweig, Germany
| | - Franz Narberhaus
- Lehrstuhl für Biologie der Mikroorganismen, Ruhr-Universität Bochum, 44780, Bochum, Germany
| | - Meriyem Aktas
- Lehrstuhl für Biologie der Mikroorganismen, Ruhr-Universität Bochum, 44780, Bochum, Germany
| | - Jürgen Moser
- Institute for Microbiology, Technische Universität Braunschweig, 38106, Braunschweig, Germany
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Interaction of gentamicin sulfate with alginate and consequences on the physico-chemical properties of alginate-containing biofilms. Int J Biol Macromol 2018; 121:390-397. [PMID: 30304700 DOI: 10.1016/j.ijbiomac.2018.10.025] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2018] [Revised: 10/04/2018] [Accepted: 10/05/2018] [Indexed: 12/13/2022]
Abstract
BACKGROUND Alginate is one of the main extracellular polymeric substances (EPS) in biofilms of Cystic Fibrosis (CF) patients suffering from pulmonary infections. Gentamicin sulfate (GS) can strongly bind to alginate resulting in loss of pharmacological activity; however neither the mechanism nor its repercussion is fully understood. In this study, we investigated how GS modifies the alginate macromolecular network and its microenvironment. MATERIAL AND METHODS Alginate gels of two different compositions (either enriched in guluronate units (G) or enriched in mannuronate units (M)) were crosslinked with Ca2+ and exposed to GS at varying times and concentrations. The complexes formed were characterized via turbidimetry, mechanical tests, swelling assay, calorimetry techniques, nuclear magnetic resonance, Ca2+ displacement, macromolecular probe diffusion and pH alteration. RESULTS In presence of GS, the alginate network and its environment undergo a tremendous reorganization in terms of gel density, stiffness, diffusion property, presence and state of the water molecules. We noted that the intensity of those alterations is directly dependent on the polysaccharide motif composition (ratio M/G). CONCLUSION Our results underline the importance of alginate as biofilm component, its pernicious role during antibiotherapy and could represent a potential macromolecular target to improve anti-infectious therapies.
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Bleem A, Christiansen G, Madsen DJ, Maric H, Strømgaard K, Bryers JD, Daggett V, Meyer RL, Otzen DE. Protein Engineering Reveals Mechanisms of Functional Amyloid Formation in Pseudomonas aeruginosa Biofilms. J Mol Biol 2018; 430:3751-3763. [PMID: 29964047 DOI: 10.1016/j.jmb.2018.06.043] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2018] [Revised: 06/22/2018] [Accepted: 06/25/2018] [Indexed: 11/25/2022]
Abstract
Amyloids are typically associated with neurodegenerative diseases, but recent research demonstrates that several bacteria utilize functional amyloid fibrils to fortify the biofilm extracellular matrix and thereby resist antibiotic treatments. In Pseudomonas aeruginosa, these fibrils are composed predominantly of FapC, a protein with high-sequence conservation among the genera. Previous studies established FapC as the major amyloid subunit, but its mechanism of fibril formation in P. aeruginosa remained largely unexplored. Here, we examine the FapC sequence in greater detail through a combination of bioinformatics and protein engineering, and we identify specific motifs that are implicated in amyloid formation. Sequence regions of high evolutionary conservation tend to coincide with regions of high amyloid propensity, and mutation of amyloidogenic motifs to a designed, non-amyloidogenic motif suppresses fibril formation in a pH-dependent manner. We establish the particular significance of the third repeat motif in promoting fibril formation and also demonstrate emergence of soluble oligomer species early in the aggregation pathway. The insights reported here expand our understanding of the mechanism of amyloid polymerization in P. aeruginosa, laying the foundation for development of new amyloid inhibitors to combat recalcitrant biofilm infections.
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Affiliation(s)
- Alissa Bleem
- Department of Bioengineering, University of Washington, Seattle, WA 98195, USA
| | - Gunna Christiansen
- Department of Biomedicine-Medical Microbiology and Immunology, Aarhus University, 8000 Aarhus C, Denmark
| | - Daniel J Madsen
- Interdisciplinary Nanoscience Center (iNANO), Department of Molecular Biology and Genetics, Aarhus University, 8000 Aarhus C, Denmark
| | - Hans Maric
- Department of Drug Design and Pharmacology, University of Copenhagen, 2100 Copenhagen Ø, Denmark
| | - Kristian Strømgaard
- Department of Drug Design and Pharmacology, University of Copenhagen, 2100 Copenhagen Ø, Denmark
| | - James D Bryers
- Department of Bioengineering, University of Washington, Seattle, WA 98195, USA
| | - Valerie Daggett
- Department of Bioengineering, University of Washington, Seattle, WA 98195, USA
| | - Rikke L Meyer
- Interdisciplinary Nanoscience Center (iNANO), Department of Molecular Biology and Genetics, Aarhus University, 8000 Aarhus C, Denmark
| | - Daniel E Otzen
- Interdisciplinary Nanoscience Center (iNANO), Department of Molecular Biology and Genetics, Aarhus University, 8000 Aarhus C, Denmark.
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Transcriptome Analysis of Neisseria gonorrhoeae during Natural Infection Reveals Differential Expression of Antibiotic Resistance Determinants between Men and Women. mSphere 2018; 3:3/3/e00312-18. [PMID: 29950382 PMCID: PMC6021601 DOI: 10.1128/mspheredirect.00312-18] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2018] [Accepted: 06/06/2018] [Indexed: 11/20/2022] Open
Abstract
Recent emergence of antimicrobial resistance of Neisseria gonorrhoeae worldwide has resulted in limited therapeutic choices for treatment of infections caused by this organism. We performed global transcriptomic analysis of N. gonorrhoeae in subjects with gonorrhea who attended a Nanjing, China, sexually transmitted infection (STI) clinic, where antimicrobial resistance of N. gonorrhoeae is high and increasing. We found that N. gonorrhoeae transcriptional responses to infection differed in genital specimens taken from men and women, particularly antibiotic resistance gene expression, which was increased in men. These sex-specific findings may provide a new approach to guide therapeutic interventions and preventive measures that are also sex specific while providing additional insight to address antimicrobial resistance of N. gonorrhoeae. Neisseria gonorrhoeae is a bacterial pathogen responsible for the sexually transmitted infection gonorrhea. Emergence of antimicrobial resistance (AMR) of N. gonorrhoeae worldwide has resulted in limited therapeutic choices for this infection. Men who seek treatment often have symptomatic urethritis; in contrast, gonococcal cervicitis in women is usually minimally symptomatic, but may progress to pelvic inflammatory disease. Previously, we reported the first analysis of gonococcal transcriptome expression determined in secretions from women with cervical infection. Here, we defined gonococcal global transcriptional responses in urethral specimens from men with symptomatic urethritis and compared these with transcriptional responses in specimens obtained from women with cervical infections and in vitro-grown N. gonorrhoeae isolates. This is the first comprehensive comparison of gonococcal gene expression in infected men and women. RNA sequencing analysis revealed that 9.4% of gonococcal genes showed increased expression exclusively in men and included genes involved in host immune cell interactions, while 4.3% showed increased expression exclusively in women and included phage-associated genes. Infected men and women displayed comparable antibiotic-resistant genotypes and in vitro phenotypes, but a 4-fold higher expression of the Mtr efflux pump-related genes was observed in men. These results suggest that expression of AMR genes is programed genotypically and also driven by sex-specific environments. Collectively, our results indicate that distinct N. gonorrhoeae gene expression signatures are detected during genital infection in men and women. We propose that therapeutic strategies could target sex-specific differences in expression of antibiotic resistance genes. IMPORTANCE Recent emergence of antimicrobial resistance of Neisseria gonorrhoeae worldwide has resulted in limited therapeutic choices for treatment of infections caused by this organism. We performed global transcriptomic analysis of N. gonorrhoeae in subjects with gonorrhea who attended a Nanjing, China, sexually transmitted infection (STI) clinic, where antimicrobial resistance of N. gonorrhoeae is high and increasing. We found that N. gonorrhoeae transcriptional responses to infection differed in genital specimens taken from men and women, particularly antibiotic resistance gene expression, which was increased in men. These sex-specific findings may provide a new approach to guide therapeutic interventions and preventive measures that are also sex specific while providing additional insight to address antimicrobial resistance of N. gonorrhoeae.
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A phosphatidic acid-binding protein is important for lipid homeostasis and adaptation to anaerobic biofilm conditions in Pseudomonas aeruginosa. Biochem J 2018; 475:1885-1907. [DOI: 10.1042/bcj20180257] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2018] [Revised: 04/27/2018] [Accepted: 05/01/2018] [Indexed: 01/22/2023]
Abstract
A quantitative Pseudomonas aeruginosa proteomics approach revealed increased abundance of the so-far uncharacterized protein PA3911 in anaerobic biofilms grown under conditions of the cystic fibrosis lung. Physiological relevance of ORF PA3911 was demonstrated, inter alia, using phenotype microarray experiments. The mutant strain showed increased susceptibility in the presence of antimicrobials (minocycline, nafcillin, oxacillin, chloramphenicol and thiamphenicol), enhanced twitching motility and significantly impaired biofilm formation. PA3911 is a soluble, cytoplasmic protein in P. aeruginosa. In protein–lipid overlay experiments, purified PA3911 bound specifically to phosphatidic acid (PA), the central hub of phospholipid metabolism. Structure-guided site-directed mutagenesis was used to explore the proposed ligand-binding cavity of PA3911. Protein variants of Leu56, Leu58, Val69 and Leu114 were shown to impair PA interaction. A comparative shotgun lipidomics approach demonstrated a multifaceted response of P. aeruginosa to anaerobic conditions at the lipid head group and fatty acid level. Lipid homeostasis in the PA3911 mutant strain was imbalanced with respect to lysophosphatidylcholine, phosphatidylcholine and diacylglycerol under anaerobic and/or aerobic conditions. The impact of the newly identified PA-binding protein on lipid homeostasis and the related macroscopic phenotypes of P. aeruginosa are discussed.
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Cunha MT, Murça MA, Nigro S, Klautau GB, Salles MJC. In vitro antibacterial activity of bioactive glass S53P4 on multiresistant pathogens causing osteomyelitis and prosthetic joint infection. BMC Infect Dis 2018; 18:157. [PMID: 29614973 PMCID: PMC5883601 DOI: 10.1186/s12879-018-3069-x] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2018] [Accepted: 03/26/2018] [Indexed: 01/12/2023] Open
Abstract
Background Conventional local treatment for medullary osteomyelitis (OM) includes insertion of antibiotic-loaded polymethylmethacrylate (PMMA) cement. Nevertheless, PMMA may delivery irregular concentration of antibiotic to surrounding tissue. We aimed to compare the in vitro antibacterial activity of Bioactive Glass (BAG) S53P4, which is a compound showing local antibacterial activity, to that of antibiotic-loaded PMMA against multidrug resistant bacteria from OM isolates. Methods We studied convenience samples of multidrug resistant (MDR) microorganisms obtained from patients presenting OM and prosthetic joint infection (PJI). Mixtures containing tryptic soy broth (TSB) and inert glass beads (2 mm), BAG-S53P4 granules (0.5–0.8 mm and < 45 mm) and Gentamicin or Vancomycin-loaded PMMA beads were inoculated with methicillin-resistant Staphylococcus aureus (MRSA) and methicillin-resistant coagulase-negative Staphylococcus (MR-CoNS), Pseudomonas aeruginosa or Klebsiella pneumoniae isolates. Glass beads (2.0 mm) were used as a control. Antibacterial activity was evaluated by means of time-kill curve, through seeding the strains on blood agar plates, and subsequently performing colony counts after 24, 48, 72, 96, 120 and 168 h of incubation. Differences between groups were evaluated by means of two-way analysis of variance (ANOVA) and Bonferroni’s t test. Results Inhibition of bacterial growth started soon after 48 h of incubation, reached zero CFU/ml between 120 and 168 h of incubation for both antibiotic-loaded PMMA and BAG S53P4 groups, in comparison with inert glass (p < 0.05). No difference regarding time-kill curves between antibiotic-loaded PMMA and BAG S53P4 was observed. Conclusions BAG S53P4 presented antibacterial properties as much as antibiotic-loaded PMMA for MDR bacteria producing OM and PJI. Electronic supplementary material The online version of this article (10.1186/s12879-018-3069-x) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Mateus Trinconi Cunha
- Division of Infectious Diseases, Department of Internal Medicine, Santa Casa de São Paulo School of Medical Sciences, São Paulo, Brazil
| | - Maria Aparecida Murça
- Department of Laboratory Medicine and Pathology, Santa Casa de São Paulo School of Medical Sciences, São Paulo, Brazil
| | - Stanley Nigro
- Department of Laboratory Medicine and Pathology, Santa Casa de São Paulo School of Medical Sciences, São Paulo, Brazil
| | - Giselle Burlamaqui Klautau
- Division of Infectious Diseases, Department of Internal Medicine, Santa Casa de São Paulo School of Medical Sciences, São Paulo, Brazil
| | - Mauro José Costa Salles
- Division of Infectious Diseases, Department of Internal Medicine, Santa Casa de São Paulo School of Medical Sciences, São Paulo, Brazil. .,Hospital da Irmandade da Santa Casa de Misericórdia de São Paulo, Rua Dr Cesário Mota Jr 112, CEP, São Paulo, SP, 01303-060, Brazil.
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Gritsch L, Lovell C, Goldmann WH, Boccaccini AR. Do bioresorbable polyesters have antimicrobial properties? JOURNAL OF MATERIALS SCIENCE. MATERIALS IN MEDICINE 2018; 29:18. [PMID: 29340853 PMCID: PMC5770478 DOI: 10.1007/s10856-017-6021-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/22/2017] [Accepted: 12/06/2017] [Indexed: 06/07/2023]
Abstract
Biodegradable and bioresorbable polyesters (BBPEs) are a widespread class of aliphatic polymers with a plethora of applications in the medical field. Some reports speculate that these polymers have intrinsic antibacterial activity as a consequence of their acidic degradation by-products. The release of organic acids as a result of the hydrolytic degradation of BBPEs in vivo and the resulting pH drop could be an effective inhibitor of the growth of pathogens in the local environment adjacent to BBPE-based devices. However, there is no clear and conclusive evidence in the literature concerning the antibacterial activity of BBPE to support or refute this hypothesis. In this communication we address this point through an assessment of the antibacterial properties of six well-established commercially available BBPEs. Agar diffusion assays and optical density measurements at 600 nm were performed on all the polymer samples to characterize the growth of bacteria and any potential inhibition over an incubation period of 24 h. The results indicated that BBPEs do not possess an intrinsic and immediate antibacterial activity, which is consistent with the clear mismatch between the time-scales for bacterial growth and the rate of degradation of the polyesters.
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Affiliation(s)
- Lukas Gritsch
- Institute of Biomaterials, University of Erlangen-Nuremberg, Cauerstraße 6, 91058, Erlangen, Germany
- Lucideon Ltd., Queens Road, Penkhull, Stoke-on-Trent, Staffordshire, ST4 7LQ, UK
| | - Christopher Lovell
- Lucideon Ltd., Queens Road, Penkhull, Stoke-on-Trent, Staffordshire, ST4 7LQ, UK
| | - Wolfgang H Goldmann
- Department of Biophysics, University of Erlangen-Nuremberg, Henkestrasse 91, 91052, Erlangen, Germany
| | - Aldo R Boccaccini
- Institute of Biomaterials, University of Erlangen-Nuremberg, Cauerstraße 6, 91058, Erlangen, Germany.
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Fields RN, Roy H. Deciphering the tRNA-dependent lipid aminoacylation systems in bacteria: Novel components and structural advances. RNA Biol 2017; 15:480-491. [PMID: 28816600 PMCID: PMC6103681 DOI: 10.1080/15476286.2017.1356980] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
tRNA-dependent addition of amino acids to lipids on the outer surface of the bacterial membrane results in decreased effectiveness of antimicrobials such as cationic antimicrobial peptides (CAMPs) that target the membrane, and increased virulence of several pathogenic species. After a brief introduction to CAMPs and the various bacterial resistance mechanisms used to counteract these compounds, this review focuses on recent advances in tRNA-dependent pathways for lipid modification in bacteria. Phenotypes associated with amino acid lipid modifications and regulation of their expression will also be discussed.
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Affiliation(s)
- Rachel N Fields
- a Burnett School of Biomedical Sciences, College of Medicine, University of Central Florida , Orlando , Florida , United States of America
| | - Hervé Roy
- a Burnett School of Biomedical Sciences, College of Medicine, University of Central Florida , Orlando , Florida , United States of America
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López-Lara IM, Geiger O. Bacterial lipid diversity. Biochim Biophys Acta Mol Cell Biol Lipids 2017; 1862:1287-1299. [DOI: 10.1016/j.bbalip.2016.10.007] [Citation(s) in RCA: 62] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2016] [Revised: 10/10/2016] [Accepted: 10/11/2016] [Indexed: 11/25/2022]
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Impact of Membrane Phospholipid Alterations in Escherichia coli on Cellular Function and Bacterial Stress Adaptation. J Bacteriol 2017; 199:JB.00849-16. [PMID: 28439040 DOI: 10.1128/jb.00849-16] [Citation(s) in RCA: 149] [Impact Index Per Article: 21.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2016] [Accepted: 04/20/2017] [Indexed: 11/20/2022] Open
Abstract
Bacteria have evolved multiple strategies to sense and rapidly adapt to challenging and ever-changing environmental conditions. The ability to alter membrane lipid composition, a key component of the cellular envelope, is crucial for bacterial survival and adaptation in response to environmental stress. However, the precise roles played by membrane phospholipids in bacterial physiology and stress adaptation are not fully elucidated. The goal of this study was to define the role of membrane phospholipids in adaptation to stress and maintenance of bacterial cell fitness. By using genetically modified strains in which the membrane phospholipid composition can be systematically manipulated, we show that alterations in major Escherichia coli phospholipids transform these cells globally. We found that alterations in phospholipids impair the cellular envelope structure and function, the ability to form biofilms, and bacterial fitness and cause phospholipid-dependent susceptibility to environmental stresses. This study provides an unprecedented view of the structural, signaling, and metabolic pathways in which bacterial phospholipids participate, allowing the design of new approaches in the investigation of lipid-dependent processes involved in bacterial physiology and adaptation.IMPORTANCE In order to cope with and adapt to a wide range of environmental conditions, bacteria have to sense and quickly respond to fluctuating conditions. In this study, we investigated the effects of systematic and controlled alterations in bacterial phospholipids on cell shape, physiology, and stress adaptation. We provide new evidence that alterations of specific phospholipids in Escherichia coli have detrimental effects on cellular shape, envelope integrity, and cell physiology that impair biofilm formation, cellular envelope remodeling, and adaptability to environmental stresses. These findings hold promise for future antibacterial therapies that target bacterial lipid biosynthesis.
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Abstract
Antimicrobial peptides (AMPs), also known as host defense peptides, are small naturally occurring microbicidal molecules produced by the host innate immune response that function as a first line of defense to kill pathogenic microorganisms by inducing deleterious cell membrane damage. AMPs also possess signaling and chemoattractant activities and can modulate the innate immune response to enhance protective immunity or suppress inflammation. Human pathogens have evolved defense molecules and strategies to counter and survive the AMPs released by host immune cells such as neutrophils and macrophages. Here, we review the various mechanisms used by human bacterial pathogens to resist AMP-mediated killing, including surface charge modification, active efflux, alteration of membrane fluidity, inactivation by proteolytic digestion, and entrapment by surface proteins and polysaccharides. Enhanced understanding of AMP resistance at the molecular level may offer insight into the mechanisms of bacterial pathogenesis and augment the discovery of novel therapeutic targets and drug design for the treatment of recalcitrant multidrug-resistant bacterial infections.
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