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Sun WS, Torrens G, ter Beek J, Cava F, Berntsson RPA. Breaking barriers: pCF10 type 4 secretion system relies on a self-regulating muramidase to modulate the cell wall. mBio 2024; 15:e0048824. [PMID: 38940556 PMCID: PMC11323569 DOI: 10.1128/mbio.00488-24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2024] [Accepted: 05/29/2024] [Indexed: 06/29/2024] Open
Abstract
Conjugative type 4 secretion systems (T4SSs) are the main driver for the spread of antibiotic resistance genes and virulence factors in bacteria. To deliver the DNA substrate to recipient cells, it must cross the cell envelopes of both donor and recipient bacteria. In the T4SS from the enterococcal conjugative plasmid pCF10, PrgK is known to be the active cell wall degrading enzyme. It has three predicted extracellular hydrolase domains: metallo-peptidase (LytM), soluble lytic transglycosylase (SLT), and cysteine, histidine-dependent amidohydrolases/peptidases (CHAP). Here, we report the structure of the LytM domain and show that its active site is degenerate and lacks the active site metal. Furthermore, we show that only the predicted SLT domain is functional in vitro and that it unexpectedly has a muramidase instead of a lytic transglycosylase activity. While we did not observe any peptidoglycan hydrolytic activity for the LytM or CHAP domain, we found that these domains downregulated the SLT muramidase activity. The CHAP domain was also found to be involved in PrgK dimer formation. Furthermore, we show that PrgK interacts with PrgL, which likely targets PrgK to the rest of the T4SS. The presented data provides important information for understanding the function of Gram-positive T4SSs.IMPORTANCEAntibiotic resistance is a large threat to human health and is getting more prevalent. One of the major contributors to the spread of antibiotic resistance among different bacteria is type 4 secretion systems (T4SS). However, mainly T4SSs from Gram-negative bacteria have been studied in detail. T4SSs from Gram-positive bacteria, which stand for more than half of all hospital-acquired infections, are much less understood. The significance of our research is in identifying the function and regulation of a cell wall hydrolase, a key component of the pCF10 T4SS from Enterococcus faecalis. This system is one of the best-studied Gram-positive T4SSs, and this added knowledge aids in our understanding of horizontal gene transfer in E. faecalis as well as other medically relevant Gram-positive bacteria.
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Affiliation(s)
- Wei-Sheng Sun
- Department of Medical Biochemistry and Biophysics, Umeå University, Umeå, Sweden
- Wallenberg Centre for Molecular Medicine and Umeå Centre for Microbial Research, Umeå University, Umeå, Sweden
| | - Gabriel Torrens
- Department of Molecular Biology and Laboratory for Molecular Infection Medicine Sweden, Umeå Centre for Microbial Research, SciLifeLab, Umeå University, Umeå, Sweden
| | - Josy ter Beek
- Department of Medical Biochemistry and Biophysics, Umeå University, Umeå, Sweden
- Wallenberg Centre for Molecular Medicine and Umeå Centre for Microbial Research, Umeå University, Umeå, Sweden
| | - Felipe Cava
- Department of Molecular Biology and Laboratory for Molecular Infection Medicine Sweden, Umeå Centre for Microbial Research, SciLifeLab, Umeå University, Umeå, Sweden
| | - Ronnie P.-A. Berntsson
- Department of Medical Biochemistry and Biophysics, Umeå University, Umeå, Sweden
- Wallenberg Centre for Molecular Medicine and Umeå Centre for Microbial Research, Umeå University, Umeå, Sweden
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2
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Stege PB, Beekman JM, Hendrickx APA, van Eijk L, Rogers MRC, Suen SWF, Vonk AM, Willems RJL, Paganelli FL. Colonization of vancomycin-resistant Enterococcus faecium in human-derived colonic epithelium: unraveling the transcriptional dynamics of host-enterococcal interactions. FEMS MICROBES 2024; 5:xtae014. [PMID: 38813098 PMCID: PMC11134301 DOI: 10.1093/femsmc/xtae014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2024] [Revised: 03/27/2024] [Accepted: 05/06/2024] [Indexed: 05/31/2024] Open
Abstract
Enterococcus faecium is an opportunistic pathogen able to colonize the intestines of hospitalized patients. This initial colonization is an important step in the downstream pathogenesis, which includes outgrowth of the intestinal microbiota and potential infection of the host. The impact of intestinal overgrowth on host-enterococcal interactions is not well understood. We therefore applied a RNAseq approach in order to unravel the transcriptional dynamics of E. faecium upon co-culturing with human derived colonic epithelium. Co-cultures of colonic epithelium with a hospital-associated vancomycin resistant (vanA-type) E. faecium (VRE) showed that VRE resided on top of the colonic epithelium when analyzed by microscopy. RNAseq revealed that exposure to the colonic epithelium resulted in upregulation of 238 VRE genes compared to the control condition, including genes implicated in pili expression, conjugation (plasmid_2), genes related to sugar uptake, and biofilm formation (chromosome). In total, 260 were downregulated, including the vanA operon located on plasmid_3. Pathway analysis revealed an overall switch in metabolism to amino acid scavenging and reduction. In summary, our study demonstrates that co-culturing of VRE with human colonic epithelium promotes an elaborate gene response in VRE, enhancing our insight in host-E. faecium interactions, which might facilitate the design of novel anti-infectivity strategies.
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Affiliation(s)
- Paul B Stege
- Department of Medical Microbiology, UMC Utrecht, Utrecht, 3584CX, The Netherlands
| | - Jeffrey M Beekman
- Department of Pediatric Pulmonology, Wilhelmina Children's Hospital, University Medical Center Utrecht, Utrecht University, Utrecht, 3584CX, The Netherlands
- Regenerative Medicine Utrecht, University Medical Center Utrecht, Utrecht University, Utrecht, 3584CX, The Netherlands
| | - Antoni P A Hendrickx
- Centre for Infectious Disease Control, National Institute for Public Health and the Environment (RIVM), 3721MA, The Netherlands
| | - Laura van Eijk
- Department of Medical Microbiology, UMC Utrecht, Utrecht, 3584CX, The Netherlands
| | - Malbert R C Rogers
- Department of Medical Microbiology, UMC Utrecht, Utrecht, 3584CX, The Netherlands
| | - Sylvia W F Suen
- Department of Pediatric Pulmonology, Wilhelmina Children's Hospital, University Medical Center Utrecht, Utrecht University, Utrecht, 3584CX, The Netherlands
- Regenerative Medicine Utrecht, University Medical Center Utrecht, Utrecht University, Utrecht, 3584CX, The Netherlands
| | - Annelotte M Vonk
- Department of Pediatric Pulmonology, Wilhelmina Children's Hospital, University Medical Center Utrecht, Utrecht University, Utrecht, 3584CX, The Netherlands
- Regenerative Medicine Utrecht, University Medical Center Utrecht, Utrecht University, Utrecht, 3584CX, The Netherlands
| | - Rob J L Willems
- Department of Medical Microbiology, UMC Utrecht, Utrecht, 3584CX, The Netherlands
| | - Fernanda L Paganelli
- Department of Medical Microbiology, UMC Utrecht, Utrecht, 3584CX, The Netherlands
- Winclove Probiotics, Amsterdam, 1033JS, The Netherlands
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3
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Baroi AM, Fierascu I, Ghizdareanu AI, Trica B, Fistos T, Matei (Brazdis) RI, Fierascu RC, Firinca C, Sardarescu ID, Avramescu SM. Green Approach for Synthesis of Silver Nanoparticles with Antimicrobial and Antioxidant Properties from Grapevine Waste Extracts. Int J Mol Sci 2024; 25:4212. [PMID: 38673798 PMCID: PMC11050308 DOI: 10.3390/ijms25084212] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2024] [Revised: 04/04/2024] [Accepted: 04/09/2024] [Indexed: 04/28/2024] Open
Abstract
The present work aims to study the possibilities of developing silver nanoparticles using natural extracts of grape pomace wastes originating from the native variety of Fetească Neagră 6 Șt. This study focused on investigating the influence of grape pomace extract obtained by two different extraction methods (classical temperature extraction and microwave-assisted extraction) in the phytosynthesis process of metal nanoparticles. The total phenolic content of the extracts was assessed using the spectrophotometric method with the Folin-Ciocâlteu reagent, while the identification and quantification of specific components were conducted through high-performance liquid chromatography with a diode array detector (HPLC-DAD). The obtained nanoparticles were characterized by UV-Vis absorption spectroscopy, X-ray diffraction (XRD), and transmission electron microscopy (TEM), along with assessing their antioxidant and antimicrobial properties against Gram-positive bacteria. The data collected from the experiments indicated that the nanoparticles were formed in a relatively short period of time (96 h) and, for the experimental variant involving the use of a 1:1 ratio (v/v, grape pomace extract: silver nitrate) for the nanoparticle phytosynthesis, the smallest crystallite sizes (from X-ray diffraction-4.58 nm and 5.14 nm) as well as spherical or semispherical nanoparticles with the lowest average diameters were obtained (19.99-23 nm, from TEM analysis). The phytosynthesis process was shown to enhance the antioxidant properties (determined using the DPPH assay) and the antimicrobial potential (tested against Gram-positive strains) of the nanoparticles, as evidenced by comparing their properties with those of the parent extracts; at the same time, the nanoparticles exhibited a selectivity in action, being active against the Staphylococcus aureus strain while presenting no antimicrobial potential against the Enterococcus faecalis strain.
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Affiliation(s)
- Anda Maria Baroi
- National Institute for Research & Development in Chemistry and Petrochemistry–ICECHIM, 202 Spl. Independentei, 060021 Bucharest, Romania; (A.M.B.); (A.-I.G.); (B.T.); (T.F.); (R.I.M.); (R.C.F.); (C.F.)
- Faculty of Horticulture, University of Agronomic Sciences and Veterinary Medicine of Bucharest, 59 Marasti Blvd., 011464 Bucharest, Romania
| | - Irina Fierascu
- National Institute for Research & Development in Chemistry and Petrochemistry–ICECHIM, 202 Spl. Independentei, 060021 Bucharest, Romania; (A.M.B.); (A.-I.G.); (B.T.); (T.F.); (R.I.M.); (R.C.F.); (C.F.)
- Faculty of Horticulture, University of Agronomic Sciences and Veterinary Medicine of Bucharest, 59 Marasti Blvd., 011464 Bucharest, Romania
| | - Andra-Ionela Ghizdareanu
- National Institute for Research & Development in Chemistry and Petrochemistry–ICECHIM, 202 Spl. Independentei, 060021 Bucharest, Romania; (A.M.B.); (A.-I.G.); (B.T.); (T.F.); (R.I.M.); (R.C.F.); (C.F.)
| | - Bogdan Trica
- National Institute for Research & Development in Chemistry and Petrochemistry–ICECHIM, 202 Spl. Independentei, 060021 Bucharest, Romania; (A.M.B.); (A.-I.G.); (B.T.); (T.F.); (R.I.M.); (R.C.F.); (C.F.)
| | - Toma Fistos
- National Institute for Research & Development in Chemistry and Petrochemistry–ICECHIM, 202 Spl. Independentei, 060021 Bucharest, Romania; (A.M.B.); (A.-I.G.); (B.T.); (T.F.); (R.I.M.); (R.C.F.); (C.F.)
- Faculty of Chemical Engineering and Biotechnology, National University of Science and Technology Politehnica Bucharest, 1-7 Gh. Polizu Str., 011061 Bucharest, Romania;
| | - Roxana Ioana Matei (Brazdis)
- National Institute for Research & Development in Chemistry and Petrochemistry–ICECHIM, 202 Spl. Independentei, 060021 Bucharest, Romania; (A.M.B.); (A.-I.G.); (B.T.); (T.F.); (R.I.M.); (R.C.F.); (C.F.)
- Faculty of Chemical Engineering and Biotechnology, National University of Science and Technology Politehnica Bucharest, 1-7 Gh. Polizu Str., 011061 Bucharest, Romania;
| | - Radu Claudiu Fierascu
- National Institute for Research & Development in Chemistry and Petrochemistry–ICECHIM, 202 Spl. Independentei, 060021 Bucharest, Romania; (A.M.B.); (A.-I.G.); (B.T.); (T.F.); (R.I.M.); (R.C.F.); (C.F.)
- Faculty of Chemical Engineering and Biotechnology, National University of Science and Technology Politehnica Bucharest, 1-7 Gh. Polizu Str., 011061 Bucharest, Romania;
| | - Cristina Firinca
- National Institute for Research & Development in Chemistry and Petrochemistry–ICECHIM, 202 Spl. Independentei, 060021 Bucharest, Romania; (A.M.B.); (A.-I.G.); (B.T.); (T.F.); (R.I.M.); (R.C.F.); (C.F.)
- Department of Botany and Microbiology, Faculty of Biology, University of Bucharest, 91–95 Spl. Independenței, 050095 Bucharest, Romania
| | - Ionela Daniela Sardarescu
- Faculty of Chemical Engineering and Biotechnology, National University of Science and Technology Politehnica Bucharest, 1-7 Gh. Polizu Str., 011061 Bucharest, Romania;
- National Research and Development Institute for Biotechnology in Horticulture, Bucharet-Pitesti Str., 117715 Stefanesti, Romania
| | - Sorin Marius Avramescu
- Department of Inorganic Chemistry, Organic Chemistry, Biochemistry and Catalysis, Faculty of Chemistry, University of Bucharest, 030018 Bucharest, Romania;
- Research Centre for Environmental Protection and Waste Management (PROTMED), University of Bucharest, 91–95 Spl. Independenței, Sect. 5, 050107 Bucharest, Romania
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Kwan JMC, Liang Y, Ng EWL, Sviriaeva E, Li C, Zhao Y, Zhang XL, Liu XW, Wong SH, Qiao Y. In silico MS/MS prediction for peptidoglycan profiling uncovers novel anti-inflammatory peptidoglycan fragments of the gut microbiota. Chem Sci 2024; 15:1846-1859. [PMID: 38303944 PMCID: PMC10829024 DOI: 10.1039/d3sc05819k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2023] [Accepted: 12/19/2023] [Indexed: 02/03/2024] Open
Abstract
Peptidoglycan is an essential exoskeletal polymer across all bacteria. Gut microbiota-derived peptidoglycan fragments (PGNs) are increasingly recognized as key effector molecules that impact host biology. However, the current peptidoglycan analysis workflow relies on laborious manual identification from tandem mass spectrometry (MS/MS) data, impeding the discovery of novel bioactive PGNs in the gut microbiota. In this work, we built a computational tool PGN_MS2 that reliably simulates MS/MS spectra of PGNs and integrated it into the user-defined MS library of in silico PGN search space, facilitating automated PGN identification. Empowered by PGN_MS2, we comprehensively profiled gut bacterial peptidoglycan composition. Strikingly, the probiotic Bifidobacterium spp. manifests an abundant amount of the 1,6-anhydro-MurNAc moiety that is distinct from Gram-positive bacteria. In addition to biochemical characterization of three putative lytic transglycosylases (LTs) that are responsible for anhydro-PGN production in Bifidobacterium, we established that these 1,6-anhydro-PGNs exhibit potent anti-inflammatory activity in vitro, offering novel insights into Bifidobacterium-derived PGNs as molecular signals in gut microbiota-host crosstalk.
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Affiliation(s)
- Jeric Mun Chung Kwan
- School of Chemistry, Chemical Engineering and Biotechnology, Nanyang Technological University 21 Nanyang Link 637371 Singapore
- Lee Kong Chian School of Medicine, Nanyang Technological University 11 Mandalay Road 308232 Singapore
| | - Yaquan Liang
- School of Chemistry, Chemical Engineering and Biotechnology, Nanyang Technological University 21 Nanyang Link 637371 Singapore
| | - Evan Wei Long Ng
- School of Chemistry, Chemical Engineering and Biotechnology, Nanyang Technological University 21 Nanyang Link 637371 Singapore
| | - Ekaterina Sviriaeva
- Lee Kong Chian School of Medicine, Nanyang Technological University 11 Mandalay Road 308232 Singapore
| | - Chenyu Li
- School of Chemistry, Chemical Engineering and Biotechnology, Nanyang Technological University 21 Nanyang Link 637371 Singapore
| | - Yilin Zhao
- School of Chemistry, Chemical Engineering and Biotechnology, Nanyang Technological University 21 Nanyang Link 637371 Singapore
| | - Xiao-Lin Zhang
- School of Chemistry, Chemical Engineering and Biotechnology, Nanyang Technological University 21 Nanyang Link 637371 Singapore
| | - Xue-Wei Liu
- School of Chemistry, Chemical Engineering and Biotechnology, Nanyang Technological University 21 Nanyang Link 637371 Singapore
| | - Sunny H Wong
- Lee Kong Chian School of Medicine, Nanyang Technological University 11 Mandalay Road 308232 Singapore
| | - Yuan Qiao
- School of Chemistry, Chemical Engineering and Biotechnology, Nanyang Technological University 21 Nanyang Link 637371 Singapore
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5
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Li YQ, Sun R, Zhang CM, Liu ZX, Chen RT, Zhao J, Gu HD, Yin HC. Inactivation of pathogenic microorganisms in water by electron beam excitation multi-wavelength ultraviolet irradiation: Efficiency, influence factors and mechanism. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2024; 350:119597. [PMID: 38029495 DOI: 10.1016/j.jenvman.2023.119597] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/23/2023] [Revised: 10/27/2023] [Accepted: 11/10/2023] [Indexed: 12/01/2023]
Abstract
Due to the limitations of traditional ultraviolet (UV) in microbial inactivation in water, it is necessary to explore a more suitable and efficient UV disinfection method. In this study, an electron beam excitation multi-wavelength ultraviolet (EBE-MW-UV) system was established and aims to analyze its differential microbial inactivation capabilities in comparison to single-wavelength UV-LEDs in waterborne applications. Furthermore, the inactivation mechanisms of this system on microorganisms were explored. The results showed that EBE-MW-UV had significantly higher inactivation effects on the Escherichia coli, Pseudomonas aeruginosa, Bacillus subtilis and Candida albicans in water compared to UV-LEDs (p<0.05), and the inactivation effect of EBE-MW-UV on Escherichia coli and Pseudomonas aeruginosa at the same UV dose was 3.8 and 1.9 log higher than that of UV-LEDs, respectively, EBE-MW-UV exhibited better inactivation effects on Gram-negative bacteria. Further research found that, under the majority of irradiation doses, neither EBE-MW-UV nor UV-LEDs were significantly affected by the concentration of suspended solids (5 and 20 mg/L) or humic acids (2 and 5 mg/L) in the water. Mechanism analysis revealed that during the disinfection process of EBE-MW-UV, microbial DNA and proteins were initially damaged, which prevented the occurrence of dark repair and led to bacterial inactivation. In addition, UV irradiation led to the production of additional reactive oxygen species (ROS) inside the cells, increasing cell membrane permeability and exacerbating membrane damage. This was accompanied by a decrease in energy metabolism and depletion of ATP, ultimately resulting in microbial inactivation. Therefore, EBE-MW-UV demonstrated more effective disinfection than single-wavelength UV-LEDs, showing great potential. Our research gives new insights into the characteristics of multiple wavelength ultraviolet, and provides scientific basis for the selection of new light sources in the field of ultraviolet disinfection.
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Affiliation(s)
- Yong-Qiang Li
- School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, China; Key Lab of Northwest Water Resource, Environment and Ecology, Ministry of Education, Shaanxi Key Laboratory of Environmental Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, China
| | - Rui Sun
- School of Biomedical Engineering (Suzhou), Division of Life Science and Medicine, University of Science and Technology of China, Hefei 230026, China; Suzhou Institute of Biomedical Engineering and Technology, Chinese Academy of Sciences, Suzhou 215163, China
| | - Chong-Miao Zhang
- School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, China; Key Lab of Northwest Water Resource, Environment and Ecology, Ministry of Education, Shaanxi Key Laboratory of Environmental Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, China; International Science and Technology Cooperation Center for Urban Alternative Water Resources Development, Xi'an University of Architecture and Technology, Xi'an 710055, China.
| | - Zi-Xuan Liu
- School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, China; Suzhou Institute of Biomedical Engineering and Technology, Chinese Academy of Sciences, Suzhou 215163, China; Key Lab of Northwest Water Resource, Environment and Ecology, Ministry of Education, Shaanxi Key Laboratory of Environmental Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, China
| | - Rui-Tao Chen
- Suzhou Institute of Biomedical Engineering and Technology, Chinese Academy of Sciences, Suzhou 215163, China
| | - Jian Zhao
- Shanghai NovelUv Optoelectronics Technology Co., Ltd, Shanghai 200000, China
| | - Hua-Dong Gu
- Suzhou Institute of Biomedical Engineering and Technology, Chinese Academy of Sciences, Suzhou 215163, China
| | - Huan-Cai Yin
- Suzhou Institute of Biomedical Engineering and Technology, Chinese Academy of Sciences, Suzhou 215163, China.
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Pismennõi D, Kattel A, Belouah I, Nahku R, Vilu R, Kobrin EG. The Quantitative Measurement of Peptidoglycan Components Obtained from Acidic Hydrolysis in Gram-Positive and Gram-Negative Bacteria via Hydrophilic Interaction Liquid Chromatography Coupled with Mass Spectrometry. Microorganisms 2023; 11:2134. [PMID: 37763978 PMCID: PMC10534856 DOI: 10.3390/microorganisms11092134] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2023] [Revised: 07/21/2023] [Accepted: 08/21/2023] [Indexed: 09/29/2023] Open
Abstract
The high throughput in genome sequencing and metabolic model (MM) reconstruction has democratised bioinformatics approaches such as flux balance analysis. Fluxes' prediction accuracy greatly relates to the deepness of the MM curation for a specific organism starting from the cell composition. One component is the cell wall, which is a functional barrier (cell shape, exchanges) with the environment. The bacterial cell wall (BCW), including its thickness, structure, and composition, has been extensively studied in Escherichia coli but poorly described for other organisms. The peptidoglycan (PG) layer composing the BCW is usually thinner in Gram- bacteria than in Gram+ bacteria. In both bacteria groups, PG is a polymeric mesh-like structure of amino acids and sugars, including N-acetylglucosamine, N-acetylmuramic acid, and amino acids. In this study, we propose a high-throughput method to characterise and quantify PG in Gram-positive and Gram-negative bacteria using acidic hydrolysis and hydrophilic interaction liquid chromatography coupled with mass spectrometry (HILIC-MS). The method showed a relatively short time frame (11 min analytical run), low inter- and intraday variability (3.2% and 4%, respectively), and high sensitivity and selectivity (limits of quantification in the sub mg/L range). The method was successfully applied on two Gram-negative bacteria (Escherichia coli K12 MG1655, Bacteroides thetaiotaomicron DSM 2079) and one Gram-positive bacterium (Streptococcus salivarius ssp. thermophilus DSM20259). The PG concentration ranged from 1.6% w/w to 14% w/w of the dry cell weight. The results were in good correlation with previously published results. With further development, the PG concentration provided by this newly developed method could reinforce the curation of MM.
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Affiliation(s)
- Dmitri Pismennõi
- Center of Food and Fermentation Technologies (TFTAK), Mäealuse 2/4, 12618 Tallinn, Estonia; (D.P.); (A.K.); (I.B.); (R.N.); (R.V.)
- Department of Chemistry and Biotechnology, Tallinn University of Technology, Akadeemia Tee 15, 12618 Tallinn, Estonia
| | - Anna Kattel
- Center of Food and Fermentation Technologies (TFTAK), Mäealuse 2/4, 12618 Tallinn, Estonia; (D.P.); (A.K.); (I.B.); (R.N.); (R.V.)
- Department of Chemistry and Biotechnology, Tallinn University of Technology, Akadeemia Tee 15, 12618 Tallinn, Estonia
| | - Isma Belouah
- Center of Food and Fermentation Technologies (TFTAK), Mäealuse 2/4, 12618 Tallinn, Estonia; (D.P.); (A.K.); (I.B.); (R.N.); (R.V.)
| | - Ranno Nahku
- Center of Food and Fermentation Technologies (TFTAK), Mäealuse 2/4, 12618 Tallinn, Estonia; (D.P.); (A.K.); (I.B.); (R.N.); (R.V.)
| | - Raivo Vilu
- Center of Food and Fermentation Technologies (TFTAK), Mäealuse 2/4, 12618 Tallinn, Estonia; (D.P.); (A.K.); (I.B.); (R.N.); (R.V.)
| | - Eeva-Gerda Kobrin
- Center of Food and Fermentation Technologies (TFTAK), Mäealuse 2/4, 12618 Tallinn, Estonia; (D.P.); (A.K.); (I.B.); (R.N.); (R.V.)
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7
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Rimal B, Chang J, Liu C, Rashid R, Singh M, Kim SJ. The effects of daptomycin on cell wall biosynthesis in Enterococcal faecalis. Sci Rep 2023; 13:12227. [PMID: 37507537 PMCID: PMC10382475 DOI: 10.1038/s41598-023-39486-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2022] [Accepted: 07/26/2023] [Indexed: 07/30/2023] Open
Abstract
Daptomycin is a cyclic lipodepsipeptide antibiotic reserved for the treatment of serious infections by multidrug-resistant Gram-positive pathogens. Its mode of action is considered to be multifaceted, encompassing the targeting and depolarization of bacterial cell membranes, alongside the inhibition of cell wall biosynthesis. To characterize the daptomycin mode of action, 15N cross-polarization at magic-angle spinning NMR measurements were performed on intact whole cells of Staphylococcus aureus grown in the presence of a sub-inhibitory concentration of daptomycin in a chemically defined media containing L-[ϵ-15N]Lys. Daptomycin-treated cells showed a reduction in the lysyl-ε-amide intensity that was consistent with cell wall thinning. However, the reduced lysyl-ε-amine intensity at 10 ppm indicated that the daptomycin-treated cells did not accumulate in Park's nucleotide, the cytoplasmic peptidoglycan (PG) precursor. Consequently, daptomycin did not inhibit the transglycosylation step of PG biosynthesis. To further elucidate the daptomycin mode of action, the PG composition of daptomycin-susceptible Enterococcus faecalis grown in the presence of daptomycin was analyzed using liquid chromatography-mass spectrometry. Sixty-nine muropeptide ions correspond to PG with varying degrees of modifications including crosslinking, acetylation, alanylation, and 1,6-anhydrous ring formation at MurNAc were quantified. Analysis showed that the cell walls of daptomycin-treated E. faecalis had a significant reduction in PG crosslinking which was accompanied by an increase in lytic transglycosylase activities and a decrease in PG-stem modifications by the carboxypeptidases. The changes in PG composition suggest that daptomycin inhibits cell wall biosynthesis by impeding the incorporation of nascent PG into the cell walls by transpeptidases and maturation by carboxypeptidases. As a result, the newly formed cell walls become highly susceptible to degradation by the autolysins, resulting in thinning of the cell wall.
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Affiliation(s)
- Binayak Rimal
- Institute of Biomedical Studies, Baylor University, Waco, TX, 76798, USA
- Division of Infectious Diseases, Johns Hopkins University School of Medicine, Baltimore, MD, 21287, USA
| | - James Chang
- Department of Chemistry One Bear Place #97046, Baylor University, Waco, TX, 76798, USA
| | - Chengyin Liu
- Department of Chemistry, Howard University, Washington, DC, 20059, USA
| | - Raiyan Rashid
- Department of Chemistry, Howard University, Washington, DC, 20059, USA
| | - Manmilan Singh
- Department of Chemistry, Washington University, St. Louis, MO, 63110, USA
| | - Sung Joon Kim
- Department of Chemistry, Howard University, Washington, DC, 20059, USA.
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Razew A, Schwarz JN, Mitkowski P, Sabala I, Kaus-Drobek M. One fold, many functions-M23 family of peptidoglycan hydrolases. Front Microbiol 2022; 13:1036964. [PMID: 36386627 PMCID: PMC9662197 DOI: 10.3389/fmicb.2022.1036964] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2022] [Accepted: 10/05/2022] [Indexed: 12/02/2023] Open
Abstract
Bacterial cell walls are the guards of cell integrity. They are composed of peptidoglycan that provides rigidity to sustain internal turgor and ensures isolation from the external environment. In addition, they harbor the enzymatic machinery to secure cell wall modulations needed throughout the bacterial lifespan. The main players in this process are peptidoglycan hydrolases, a large group of enzymes with diverse specificities and different mechanisms of action. They are commonly, but not exclusively, found in prokaryotes. Although in most cases, these enzymes share the same molecular function, namely peptidoglycan hydrolysis, they are leveraged to perform a variety of physiological roles. A well-investigated family of peptidoglycan hydrolases is M23 peptidases, which display a very conserved fold, but their spectrum of lytic action is broad and includes both Gram- positive and Gram- negative bacteria. In this review, we summarize the structural, biochemical, and functional studies concerning the M23 family of peptidases based on literature and complement this knowledge by performing large-scale analyses of available protein sequences. This review has led us to gain new insight into the role of surface charge in the activity of this group of enzymes. We present relevant conclusions drawn from the analysis of available structures and indicate the main structural features that play a crucial role in specificity determination and mechanisms of latency. Our work systematizes the knowledge of the M23 family enzymes in the context of their unique antimicrobial potential against drug-resistant pathogens and presents possibilities to modulate and engineer their features to develop perfect antibacterial weapons.
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Affiliation(s)
| | | | | | - Izabela Sabala
- Laboratory of Protein Engineering, Mossakowski Medical Research Institute, Polish Academy of Sciences, Warsaw, Poland
| | - Magdalena Kaus-Drobek
- Laboratory of Protein Engineering, Mossakowski Medical Research Institute, Polish Academy of Sciences, Warsaw, Poland
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9
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Krause AL, Stinear TP, Monk IR. Barriers to genetic manipulation of Enterococci: Current Approaches and Future Directions. FEMS Microbiol Rev 2022; 46:6650352. [PMID: 35883217 PMCID: PMC9779914 DOI: 10.1093/femsre/fuac036] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2022] [Revised: 07/14/2022] [Accepted: 07/22/2022] [Indexed: 01/09/2023] Open
Abstract
Enterococcus faecalis and Enterococcus faecium are Gram-positive commensal gut bacteria that can also cause fatal infections. To study clinically relevant multi-drug resistant E. faecalis and E. faecium strains, methods are needed to overcome physical (thick cell wall) and enzymatic barriers that limit the transfer of foreign DNA and thus prevent facile genetic manipulation. Enzymatic barriers to DNA uptake identified in E. faecalis and E. faecium include type I, II and IV restriction modification systems and CRISPR-Cas. This review examines E. faecalis and E. faecium DNA defence systems and the methods with potential to overcome these barriers. DNA defence system bypass will allow the application of innovative genetic techniques to expedite molecular-level understanding of these important, but somewhat neglected, pathogens.
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Affiliation(s)
- Alexandra L Krause
- Department of Microbiology and Immunology, The University of Melbourne at the Peter Doherty Institute for Infection & Immunity, Melbourne, VIC 3000 Australia
| | - Timothy P Stinear
- Department of Microbiology and Immunology, The University of Melbourne at the Peter Doherty Institute for Infection & Immunity, Melbourne, VIC 3000 Australia
| | - Ian R Monk
- Corresponding author: Department of Microbiology and Immunology, The University of Melbourne at the Peter Doherty Institute for Infection & Immunity, Melbourne, VIC 3000 Australia. E-mail:
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10
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Rimal B, Senzani S, Ealand C, Lamichhane G, Kana B, Kim SJ. Peptidoglycan compositional analysis of Mycobacterium smegmatis using high-resolution LC-MS. Sci Rep 2022; 12:11061. [PMID: 35773428 PMCID: PMC9247062 DOI: 10.1038/s41598-022-15324-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2022] [Accepted: 06/22/2022] [Indexed: 11/21/2022] Open
Abstract
Peptidoglycan (PG) is the exoskeleton of bacterial cells and is required for their viability, growth, and cell division. Unlike most bacteria, mycobacteria possess an atypical PG characterized by a high degree of unique linkages and chemical modifications which most likely serve as important determinants of virulence and pathogenesis in mycobacterial diseases. Despite this important role, the chemical composition and molecular architecture of mycobacterial PG have yet to be fully determined. Here we determined the chemical composition of PG from Mycobacterium smegmatis using high-resolution liquid chromatography-mass spectrometry. Purified cell walls from the stationary phase were digested with mutanolysin and compositional analysis was performed on 130 muropeptide ions that were identified using an in silico PG library. The relative abundance for each muropeptide ion was measured by integrating the extracted-ion chromatogram. The percentage of crosslink per PG subunit was measured at 45%. While both 3→3 and 4→3 transpeptide cross-linkages were found in PG dimers, a high abundance of 3→3 linkages was found associated with the trimers. Approximately 43% of disaccharides in the PG of M. smegmatis showed modifications by acetylation or deacetylation. A significant number of PG trimers are found with a loss of 41.00 amu that is consistent with N-deacetylation, whereas the dimers show a gain of 42.01 amu corresponding to O-acetylation of the PG disaccharides. This suggests a possible role of PG acetylation in the regulation of cell wall homeostasis in M. smegmatis. Collectively, these data report important novel insights into the ultrastructure of mycobacterial PG.
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Affiliation(s)
- Binayak Rimal
- Institute of Biomedical Studies, Baylor University, Waco, TX, 76798, USA.,Division of Infectious Diseases, School of Medicine, Johns Hopkins University, Baltimore, MD, 21287, USA
| | - Sibusiso Senzani
- National Health Laboratory Service, Faculty of Health Sciences, DST/NRF Centre of Excellence for Biomedical TB Research, School of Pathology, University of the Witwatersrand, Johannesburg, 2001, South Africa
| | - Christopher Ealand
- National Health Laboratory Service, Faculty of Health Sciences, DST/NRF Centre of Excellence for Biomedical TB Research, School of Pathology, University of the Witwatersrand, Johannesburg, 2001, South Africa
| | - Gyanu Lamichhane
- Division of Infectious Diseases, School of Medicine, Johns Hopkins University, Baltimore, MD, 21287, USA
| | - Bavesh Kana
- National Health Laboratory Service, Faculty of Health Sciences, DST/NRF Centre of Excellence for Biomedical TB Research, School of Pathology, University of the Witwatersrand, Johannesburg, 2001, South Africa.
| | - Sung Joon Kim
- Department of Chemistry, Howard University, Chemistry Building, 525 College Street, Washington, DC, 20059, USA.
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11
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Pseudomonas aeruginosa Alters Peptidoglycan Composition under Nutrient Conditions Resembling Cystic Fibrosis Lung Infections. mSystems 2022; 7:e0015622. [PMID: 35545925 PMCID: PMC9239049 DOI: 10.1128/msystems.00156-22] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Epidemic strains of Pseudomonas aeruginosa are highly virulent opportunistic pathogens with increased transmissibility and enhanced antimicrobial resistance. Understanding the cellular mechanisms behind this heightened virulence and resistance is critical. Peptidoglycan (PG) is an integral component of P. aeruginosa cells that is essential to its survival and a target for antimicrobials. Here, we examined the global PG composition of two P. aeruginosa epidemic strains, LESB58 and LESlike1, and compared them to the common laboratory strains PAO1 and PA14. We also examined changes in PG composition when the strains were cultured under nutrient conditions that resembled cystic fibrosis lung infections. We identified 448 unique muropeptides and provide the first evidence for stem peptides modified with O-methylation, meso-diaminopimelic acid (mDAP) deamination, and novel substitutions of mDAP residues within P. aeruginosa PG. Our results also present the first evidence for both d,l- and l,d-endopeptidase activity on the PG sacculus of a Gram-negative organism. The PG composition of the epidemic strains varied significantly when grown under conditions resembling cystic fibrosis (CF) lung infections, showing increases in O-methylated stem peptides and decreases in l,d-endopeptidase activity as well as an increased abundance of de-N-acetylated sugars and l,d-transpeptidase activity, which are related to bacterial virulence and antibiotic resistance, respectively. We also identified strain-specific changes where LESlike1 increased the addition of unique amino acids to the terminus of the stem peptide and LESB58 increased amidase activity. Overall, this study demonstrates that P. aeruginosa PG composition is primarily influenced by nutrient conditions that mimic the CF lung; however, inherent strain-to-strain differences also exist. IMPORTANCE Using peptidoglycomics to examine the global composition of the peptidoglycan (PG) allows insights into the enzymatic activity that functions on this important biopolymer. Changes within the PG structure have implications for numerous physiological processes, including virulence and antimicrobial resistance. The identification of highly unique PG modifications illustrates the complexity of this biopolymer in Pseudomonas aeruginosa. Analyzing the PG composition of clinical P. aeruginosa epidemic strains provides insights into the increased virulence and antimicrobial resistance of these difficult-to-eradicate infections.
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12
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Lin H, Yang C, Wang W. Imitate to illuminate: labeling of bacterial peptidoglycan with fluorescent and bio-orthogonal stem peptide-mimicking probes. RSC Chem Biol 2022; 3:1198-1208. [PMID: 36320889 PMCID: PMC9533424 DOI: 10.1039/d2cb00086e] [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: 03/30/2022] [Accepted: 08/01/2022] [Indexed: 11/30/2022] Open
Abstract
Because of its high involvement in antibiotic therapy and the emergence of drug-resistance, the chemical structure and biosynthesis of bacterial peptidoglycan (PGN) have been some of the key topics in bacteriology for several decades. Recent advances in the development of fluorescent or bio-orthogonal stem peptide-mimicking probes for PGN-labeling have rekindled the interest of chemical biologists and microbiologists in this area. The structural designs, bio-orthogonal features and flexible uses of these peptide-based probes allow directly assessing, not only the presence of PGN in different biological systems, but also specific steps in PGN biosynthesis. In this review, we summarize the design rationales, functioning mechanisms, and microbial processes/questions involved in these PGN-targeting probes. Our perspectives on the limitations and future development of these tools are also presented. By imitating the structures of stem peptide, many fluorescent and bio-orthogonal labeling probes have been designed and used in illuminating the peptidoglycan biosynthesis processes.![]()
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Affiliation(s)
- Huibin Lin
- Institute of Molecular Medicine, Shanghai Key Laboratory for Nucleic Acid Chemistry and Nanomedicine, Renji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200127, China
| | - Chaoyong Yang
- Institute of Molecular Medicine, Shanghai Key Laboratory for Nucleic Acid Chemistry and Nanomedicine, Renji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200127, China
- The MOE Key Laboratory of Spectrochemical Analysis and Instrumentation, Key Laboratory for Chemical Biology of Fujian Province State Key Laboratory of Physical Chemistry of Solid Surfaces, Department of Chemical Biology, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, China
| | - Wei Wang
- Institute of Molecular Medicine, Shanghai Key Laboratory for Nucleic Acid Chemistry and Nanomedicine, Renji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200127, China
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13
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Ramos Y, Sansone S, Morales DK. Sugarcoating it: Enterococcal polysaccharides as key modulators of host-pathogen interactions. PLoS Pathog 2021; 17:e1009822. [PMID: 34499702 PMCID: PMC8428557 DOI: 10.1371/journal.ppat.1009822] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Affiliation(s)
- Yusibeska Ramos
- Department of Obstetrics and Gynecology, Weill Cornell Medicine, New York, New York, United States of America
| | - Stephanie Sansone
- Department of Obstetrics and Gynecology, Weill Cornell Medicine, New York, New York, United States of America
- Department of Urology, Weill Cornell Medicine, New York, New York, United States of America
| | - Diana K. Morales
- Department of Obstetrics and Gynecology, Weill Cornell Medicine, New York, New York, United States of America
- * E-mail:
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14
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Oncu A, Huang Y, Amasya G, Sevimay FS, Orhan K, Celikten B. Silver nanoparticles in endodontics: recent developments and applications. Restor Dent Endod 2021; 46:e38. [PMID: 34513644 PMCID: PMC8411004 DOI: 10.5395/rde.2021.46.e38] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2020] [Revised: 12/05/2020] [Accepted: 01/04/2021] [Indexed: 12/02/2022] Open
Abstract
The elimination of endodontic biofilms and the maintenance of a leak-proof canal filling are key aspects of successful root canal treatment. Several materials have been introduced to treat endodontic disease, although treatment success is limited by the features of the biomaterials used. Silver nanoparticles (AgNPs) have been increasingly considered in dental applications, especially endodontics, due to their high antimicrobial activity. For the present study, an electronic search was conducted using MEDLINE (PubMed), the Cochrane Central Register of Controlled Trials (CENTRAL), Google Scholar, and EMBASE. This review provides insights into the unique characteristics of AgNPs, including their chemical, physical, and antimicrobial properties; limitations; and potential uses. Various studies involving different application methods of AgNPs were carefully examined. Based on previous clinical studies, the synthesis, means of obtaining, usage conditions, and potential cytotoxicity of AgNPs were evaluated. The findings indicate that AgNPs are effective antimicrobial agents for the elimination of endodontic biofilms.
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Affiliation(s)
- Aysenur Oncu
- Department of Endodontics, Ankara University Faculty of Dentistry, Ankara, Turkey
| | - Yan Huang
- Department of Dental Hygiene Research & Development in Health & Care, Artevelde University of Applied Sciences, Ghent, Belgium
| | - Gulin Amasya
- Department of Pharmaceutical Technology, Ankara University Faculty of Pharmacy, Ankara, Turkey
| | - Fatma Semra Sevimay
- Department of Endodontics, Ankara University Faculty of Dentistry, Ankara, Turkey
| | - Kaan Orhan
- Department of Dentomaxillofacial Radiology, Ankara University Faculty of Dentistry, Ankara, Turkey
| | - Berkan Celikten
- Department of Endodontics, Ankara University Faculty of Dentistry, Ankara, Turkey
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15
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Abstract
The gut microbiota affects the physiology and metabolism of animals and its alteration can lead to diseases such as gut dysplasia or metabolic disorders. Several reports have shown that the immune system plays an important role in shaping both bacterial community composition and abundance in Drosophila, and that immune deficit, especially during aging, negatively affects microbiota richness and diversity. However, there has been little study at the effector level to demonstrate how immune pathways regulate the microbiota. A key set of Drosophila immune effectors are the antimicrobial peptides (AMPs), which confer defense upon systemic infection. AMPs and lysozymes, a group of digestive enzymes with antimicrobial properties, are expressed in the gut and are good candidates for microbiota regulation. Here, we take advantage of the model organism Drosophila melanogaster to investigate the role of AMPs and lysozymes in regulation of gut microbiota structure and diversity. Using flies lacking AMPs and newly generated lysozyme mutants, we colonized gnotobiotic flies with a defined set of commensal bacteria and analyzed changes in microbiota composition and abundance in vertical transmission and aging contexts through 16S rRNA gene amplicon sequencing. Our study shows that AMPs and, to a lesser extent, lysozymes are necessary to regulate the total and relative abundance of bacteria in the gut microbiota. We also decouple the direct function of AMPs from the immune deficiency (IMD) signaling pathway that regulates AMPs but also many other processes, more narrowly defining the role of these effectors in the microbial dysbiosis observed in IMD-deficient flies upon aging.
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16
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Martínez B, Rodríguez A, Kulakauskas S, Chapot-Chartier MP. Cell wall homeostasis in lactic acid bacteria: threats and defences. FEMS Microbiol Rev 2021; 44:538-564. [PMID: 32495833 PMCID: PMC7476776 DOI: 10.1093/femsre/fuaa021] [Citation(s) in RCA: 33] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2019] [Accepted: 06/03/2020] [Indexed: 12/16/2022] Open
Abstract
Lactic acid bacteria (LAB) encompasses industrially relevant bacteria involved in food fermentations as well as health-promoting members of our autochthonous microbiota. In the last years, we have witnessed major progresses in the knowledge of the biology of their cell wall, the outermost macrostructure of a Gram-positive cell, which is crucial for survival. Sophisticated biochemical analyses combined with mutation strategies have been applied to unravel biosynthetic routes that sustain the inter- and intra-species cell wall diversity within LAB. Interplay with global cell metabolism has been deciphered that improved our fundamental understanding of the plasticity of the cell wall during growth. The cell wall is also decisive for the antimicrobial activity of many bacteriocins, for bacteriophage infection and for the interactions with the external environment. Therefore, genetic circuits involved in monitoring cell wall damage have been described in LAB, together with a plethora of defence mechanisms that help them to cope with external threats and adapt to harsh conditions. Since the cell wall plays a pivotal role in several technological and health-promoting traits of LAB, we anticipate that this knowledge will pave the way for the future development and extended applications of LAB.
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Affiliation(s)
- Beatriz Martínez
- DairySafe research group. Department of Technology and Biotechnology of Dairy Products. Instituto de Productos Lácteos de Asturias, IPLA-CSIC. Paseo Río Linares s/n. 33300 Villaviciosa, Spain
| | - Ana Rodríguez
- DairySafe research group. Department of Technology and Biotechnology of Dairy Products. Instituto de Productos Lácteos de Asturias, IPLA-CSIC. Paseo Río Linares s/n. 33300 Villaviciosa, Spain
| | - Saulius Kulakauskas
- Université Paris-Saclay, INRAE, AgroParisTech, Micalis Institute, 78350, Jouy-en-Josas, France
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17
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New approaches and techniques for bacterial cell wall analysis. Curr Opin Microbiol 2021; 60:88-95. [PMID: 33631455 DOI: 10.1016/j.mib.2021.01.010] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2020] [Revised: 01/22/2021] [Accepted: 01/22/2021] [Indexed: 12/17/2022]
Abstract
Peptidoglycan (PG) has remained for decades in the spotlight of the never-ending battle against pathogenic bacteria as this essential bacterial structure is one of the most successful targets for antibiotics. Most of our current understanding about the composition, architecture, and dynamics of the PG relies on techniques which have experienced great technological and methodological improvements in the past years. Here we summarize recent advances in these methods with the intention to furnish a valuable resource for both PG experts and newcomers.
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18
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Vargas-Straube MJ, Beard S, Norambuena R, Paradela A, Vera M, Jerez CA. High copper concentration reduces biofilm formation in Acidithiobacillus ferrooxidans by decreasing production of extracellular polymeric substances and its adherence to elemental sulfur. J Proteomics 2020; 225:103874. [PMID: 32569817 DOI: 10.1016/j.jprot.2020.103874] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2020] [Revised: 06/04/2020] [Accepted: 06/06/2020] [Indexed: 12/14/2022]
Abstract
Acidithiobacillus ferrooxidans is an acidophilic bacterium able to grow in environments with high concentrations of metals. It is a chemolithoautotroph able to form biofilms on the surface of solid minerals to obtain its energy. The response of both planktonic and sessile cells of A. ferrooxidans ATCC 23270 grown in elemental sulfur and adapted to high copper concentration was analyzed by quantitative proteomics. It was found that 137 proteins varied their abundance when comparing both lifestyles. Copper effllux proteins, some subunits of the ATP synthase complex, porins, and proteins involved in cell wall modification increased their abundance in copper-adapted sessile lifestyle cells. On the other hand, planktonic copper-adapted cells showed increased levels of proteins such as: cupreredoxins involved in copper cell sequestration, some proteins related to sulfur metabolism, those involved in biosynthesis and transport of lipopolysaccharides, and in assembly of type IV pili. During copper adaptation a decreased formation of biofilms was measured as determined by epifluorescence microscopy. This was apparently due not only to a diminished number of sessile cells but also to their exopolysaccharides production. This is the first study showing that copper, a prevalent metal in biomining environments causes dispersion of A. ferrooxidans biofilms. SIGNIFICANCE: Copper is a metal frequently found in high concentrations at mining environments inhabitated by acidophilic microorganisms. Copper resistance determinants of A. ferrooxidans have been previously studied in planktonic cells. Although biofilms are recurrent in these types of environments, the effect of copper on their formation has not been studied so far. The results obtained indicate that high concentrations of copper reduce the capacity of A. ferrooxidans ATCC 23270 to form biofilms on sulfur. These findings may be relevant to consider for a bacterium widely used in copper bioleaching processes.
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Affiliation(s)
- M J Vargas-Straube
- Laboratory of Molecular Microbiology and Biotechnology, Department of Biology, Faculty of Sciences, University of Chile, Santiago, Chile
| | - S Beard
- Fundación Ciencia y Vida, Santiago, Chile
| | - R Norambuena
- Laboratory of Molecular Microbiology and Biotechnology, Department of Biology, Faculty of Sciences, University of Chile, Santiago, Chile
| | - A Paradela
- Proteomics Laboratory, National Biotechnology Center, CSIC, Madrid, Spain
| | - M Vera
- Institute for Biological and Medical Engineering, Schools of Engineering, Medicine and Biological Sciences, Pontificia Universidad Católica de Chile, Santiago, Chile.; Department of Hydraulic and Environmental Engineering, School of Engineering, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - C A Jerez
- Laboratory of Molecular Microbiology and Biotechnology, Department of Biology, Faculty of Sciences, University of Chile, Santiago, Chile..
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19
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Kelly E, Gidley M, Sinigalliano C, Kumar N, Brand L, Harris RJ, Solo-Gabriele HM. Proliferation of microalgae and enterococci in the Lake Okeechobee, St. Lucie, and Loxahatchee watersheds. WATER RESEARCH 2020; 171:115441. [PMID: 31927090 DOI: 10.1016/j.watres.2019.115441] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/31/2019] [Revised: 12/20/2019] [Accepted: 12/22/2019] [Indexed: 06/10/2023]
Abstract
This study is an analysis of relationships between microalgae (measured as chlorophyll a) and the fecal indicator bacteria enterococci. Microalgae blooms and enterococci exceedances have been occurring in Florida's recreational waterways for years. More recently, this has become a management concern as microalgae blooms have been attributed to potentially toxic cyanobacteria, and enterococci exceedances link to human infection/illness. Since both the microalgal blooms and bacterial exceedances occur in regions that receive managed freshwater releases from Lake Okeechobee, we hypothesized that both the blooms and exceedances are related to excess nutrients from the lake. Two experimental sites, on Lake Okeechobee and the St. Lucie River (downstream of the lake), plus a control site on the Loxahatchee River (which does not receive lake flow) were evaluated. The hypothesis was evaluated through three study components: 1) analysis of available long-term data from local environmental databases, 2) a year-long monthly sampling and analysis of chlorophyll a, enterococci, nutrients, and physical-chemical data, and 3) microcosm experiments with altered water/sediment conditions. Results support the hypothesis that excess nutrients play a role in both chlorophyll a and enterococci levels. For the St. Lucie River, analyses indicate that chlorophyll a correlated significantly with total Kjeldahl nitrogen (TKN) (R2 = 0.30, p = 0.008) and the strongest model for enterococci included nitrate-nitrite, TKN, total phosphorus, orthophosphorus, and turbidity in our long-term analysis (n = 39, R2 = 0.83, p ≤ 0.001). The microcosm results indicated that chlorophyll a and enterococci only persisted for 36 h in water from all sources, and that sediments from Lake Okeechobee may have allowed for sustained levels of chlorophyll a and enterococci levels. Overall similarities were observed in chlorophyll a and enterococci relationships with nutrient concentrations regardless of a Lake Okeechobee connection, as underscored by a study of flow out of the lake and downstream areas. This suggests that both nutrient-rich lake water and untreated surface water runoff contribute to microalgae blooms and enterococci exceedances in southeast Florida.
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Affiliation(s)
- E Kelly
- University of Miami Leonard and Jayne Abess Center for Ecosystem Science and Policy, Coral Gables, FL, USA; University of Miami Department of Civil, Architectural and Environmental Engineering, Coral Gables, FL, USA; NSF NIEHS Oceans and Human Health Center, Rosenstiel School of Marine and Atmospheric Science, University of Miami, Miami, FL, USA
| | - M Gidley
- NSF NIEHS Oceans and Human Health Center, Rosenstiel School of Marine and Atmospheric Science, University of Miami, Miami, FL, USA; National Oceanic and Atmospheric Administration (NOAA) Atlantic Oceanographic and Meteorological Laboratory (AOML) Environmental Microbiology, Miami, USA; University of Miami Cooperative Institute for Marine and Atmospheric Studies (CIMAS), Miami, USA
| | - C Sinigalliano
- NSF NIEHS Oceans and Human Health Center, Rosenstiel School of Marine and Atmospheric Science, University of Miami, Miami, FL, USA; National Oceanic and Atmospheric Administration (NOAA) Atlantic Oceanographic and Meteorological Laboratory (AOML) Environmental Microbiology, Miami, USA
| | - N Kumar
- University of Miami Department of Public Health Sciences, Division of Environment & Public Health, Miami, FL, USA
| | - L Brand
- NSF NIEHS Oceans and Human Health Center, Rosenstiel School of Marine and Atmospheric Science, University of Miami, Miami, FL, USA; University of Miami Department of Marine Biology and Ecology, Rosenstiel School of Marine and Atmospheric Science (RSMAS), Miami, FL, USA
| | - R J Harris
- Loxahatchee River District, Jupiter, FL, USA
| | - H M Solo-Gabriele
- University of Miami Leonard and Jayne Abess Center for Ecosystem Science and Policy, Coral Gables, FL, USA; University of Miami Department of Civil, Architectural and Environmental Engineering, Coral Gables, FL, USA; NSF NIEHS Oceans and Human Health Center, Rosenstiel School of Marine and Atmospheric Science, University of Miami, Miami, FL, USA.
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20
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Anderson EM, Sychantha D, Brewer D, Clarke AJ, Geddes-McAlister J, Khursigara CM. Peptidoglycomics reveals compositional changes in peptidoglycan between biofilm- and planktonic-derived Pseudomonas aeruginosa. J Biol Chem 2019; 295:504-516. [PMID: 31771981 DOI: 10.1074/jbc.ra119.010505] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2019] [Revised: 11/25/2019] [Indexed: 12/14/2022] Open
Abstract
Peptidoglycan (PG) is a critical component of the bacterial cell wall and is composed of a repeating β-1,4-linked disaccharide of N-acetylglucosamine and N-acetylmuramic acid appended with a highly conserved stem peptide. In Gram-negative bacteria, PG is assembled in the cytoplasm and exported into the periplasm where it undergoes considerable maturation, modification, or degradation depending on the growth phase or presence of environmental stressors. These modifications serve important functions in diverse processes, including PG turnover, cell elongation/division, and antibiotic resistance. Conventional methods for analyzing PG composition are complex and time-consuming. We present here a streamlined MS-based method that combines differential analysis with statistical 1D annotation approaches to quantitatively compare PGs produced in planktonic- and biofilm-cultured Pseudomonas aeruginosa We identified a core assembly of PG that is present in high abundance and that does not significantly differ between the two growth states. We also identified an adaptive PG assembly that is present in smaller amounts and fluctuates considerably between growth states in response to physiological changes. Biofilm-derived adaptive PG exhibited significant changes compared with planktonic-derived PG, including amino acid substitutions of the stem peptide and modifications that indicate changes in the activity of amidases, deacetylases, and lytic transglycosylases. The results of this work also provide first evidence of de-N-acetylated muropeptides from P. aeruginosa The method developed here offers a robust and reproducible workflow for accurately determining PG composition in samples that can be used to assess global PG fluctuations in response to changing growth conditions or external stimuli.
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Affiliation(s)
- Erin M Anderson
- Department of Molecular and Cellular Biology, University of Guelph, Ontario N1G 2W1, Canada
| | - David Sychantha
- Department of Molecular and Cellular Biology, University of Guelph, Ontario N1G 2W1, Canada
| | - Dyanne Brewer
- Mass Spectrometry Facility, University of Guelph, Ontario N1G 2W1, Canada
| | - Anthony J Clarke
- Department of Molecular and Cellular Biology, University of Guelph, Ontario N1G 2W1, Canada
| | - Jennifer Geddes-McAlister
- Department of Molecular and Cellular Biology, University of Guelph, Ontario N1G 2W1, Canada; Mass Spectrometry Facility, University of Guelph, Ontario N1G 2W1, Canada.
| | - Cezar M Khursigara
- Department of Molecular and Cellular Biology, University of Guelph, Ontario N1G 2W1, Canada; Mass Spectrometry Facility, University of Guelph, Ontario N1G 2W1, Canada.
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Abdrabou AM, Osman EY, Aboubakr OA. Comparative therapeutic efficacy study of Lactobacilli probiotics and citalopram in treatment of acute stress-induced depression in lab murine models. ACTA ACUST UNITED AC 2018. [DOI: 10.1016/j.humic.2018.08.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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