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Tang M, Lei Y, Chen K, Ding M, Ou Q, Tang J, Zhang Y, Tang T, Wang C. Reducing the degree of crosslinking of peptidoglycan in Listeria monocytogenes promoted the secretion of membrane vesicles. Biotechnol Bioeng 2024. [PMID: 39014884 DOI: 10.1002/bit.28807] [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: 03/11/2024] [Revised: 06/18/2024] [Accepted: 06/23/2024] [Indexed: 07/18/2024]
Abstract
Listeria monocytogenes (LM) is a Gram-positive (G+) bacterium that secretes nanoscale membrane vesicles (MVs). LM MVs comprise various bacterial components and may have potential as an antigen or drug-delivery vehicle; however, the low yield of the LM MVs limits related research. G+-bacterial MVs germinate from the bacterial plasma membrane and must pass through a thick crosslinked peptidoglycan layer for release. Herein, we aimed to increase the release of MVs by reducing the degree of crosslinking of peptidoglycan. We knocked out two genes related to the longitudinal crosslinking of peptidoglycan, dal and dat, and supplemented the knocked-out dal gene through plasmid expression to obtain a stably inherited recombinant strain LMΔdd::pCW633. The structure, particle size, and main protein components of MVs secreted by this recombinant strain were consistent with those secreted from the wild strain, but the yield of MVs was considerably increased (p < 0.05). Furthermore, Listeria ivanovii (LI) was found to secrete MVs that differed in the composition of the main proteins compared with those of LM MVs. The abovementioned method was also feasible for promoting the secretion of MVs from the attenuated LM strain and LI wild-type and attenuated strains. Our study provides a new method to increase the secretion of MVs derived from Listeria that could be extended to other G+ bacteria.
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Affiliation(s)
- Mingyuan Tang
- Department of Public Health Laboratory Sciences, West China School of Public Health and West China Fourth Hospital, Sichuan University, Chengdu, China
| | - Yao Lei
- Department of Public Health Laboratory Sciences, West China School of Public Health and West China Fourth Hospital, Sichuan University, Chengdu, China
| | - Kehan Chen
- Department of Public Health Laboratory Sciences, West China School of Public Health and West China Fourth Hospital, Sichuan University, Chengdu, China
| | - Mingming Ding
- College of Polymer Science and Engineering, State Key Laboratory of Polymer Materials Engineering, Sichuan University, Chengdu, China
| | - Qian Ou
- Department of Public Health Laboratory Sciences, West China School of Public Health and West China Fourth Hospital, Sichuan University, Chengdu, China
| | - Jing Tang
- Department of Public Health Laboratory Sciences, West China School of Public Health and West China Fourth Hospital, Sichuan University, Chengdu, China
| | - Yunwen Zhang
- Department of Public Health Laboratory Sciences, West China School of Public Health and West China Fourth Hospital, Sichuan University, Chengdu, China
| | - Tian Tang
- Department of Public Health Laboratory Sciences, West China School of Public Health and West China Fourth Hospital, Sichuan University, Chengdu, China
| | - Chuan Wang
- Department of Public Health Laboratory Sciences, West China School of Public Health and West China Fourth Hospital, Sichuan University, Chengdu, China
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2
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Chioti VT, McWhorter KL, Blue TC, Li Y, Xu F, Jeffrey PD, Davis KM, Seyedsayamdost MR. Potent and specific antibiotic combination therapy against Clostridioides difficile. Nat Chem Biol 2024; 20:924-933. [PMID: 38942968 DOI: 10.1038/s41589-024-01651-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2023] [Accepted: 05/15/2024] [Indexed: 06/30/2024]
Abstract
Keratinicyclins and keratinimicins are recently discovered glycopeptide antibiotics. Keratinimicins show broad-spectrum activity against Gram-positive bacteria, while keratinicyclins form a new chemotype by virtue of an unusual oxazolidinone moiety and exhibit specific antibiosis against Clostridioides difficile. Here we report the mechanism of action of keratinicyclin B (KCB). We find that steric constraints preclude KCB from binding peptidoglycan termini. Instead, KCB inhibits C. difficile growth by binding wall teichoic acids (WTAs) and interfering with cell wall remodeling. A computational model, guided by biochemical studies, provides an image of the interaction of KCB with C. difficile WTAs and shows that the same H-bonding framework used by glycopeptide antibiotics to bind peptidoglycan termini is used by KCB for interacting with WTAs. Analysis of KCB in combination with vancomycin (VAN) shows highly synergistic and specific antimicrobial activity, and that nanomolar combinations of the two drugs are sufficient for complete growth inhibition of C. difficile, while leaving common commensal strains unaffected.
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Affiliation(s)
| | | | - Tamra C Blue
- Department of Chemistry, Emory University, Atlanta, GA, USA
| | - Yuchen Li
- Department of Chemistry, Princeton University, Princeton, NJ, USA
| | - Fei Xu
- Institute of Pharmaceutical Biotechnology and Department of Gastroenterology of the Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Philip D Jeffrey
- Department of Molecular Biology, Princeton University, Princeton, NJ, USA
| | | | - Mohammad R Seyedsayamdost
- Department of Chemistry, Princeton University, Princeton, NJ, USA.
- Department of Molecular Biology, Princeton University, Princeton, NJ, USA.
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3
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Batt SM, Abrahams KA, Besra GS. Top five unanswered questions in bacterial cell wall research. Cell Surf 2024; 11:100122. [PMID: 38425882 PMCID: PMC10902140 DOI: 10.1016/j.tcsw.2024.100122] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2023] [Revised: 02/15/2024] [Accepted: 02/20/2024] [Indexed: 03/02/2024] Open
Affiliation(s)
| | | | - Gurdyal S. Besra
- Institute of Microbiology and Infection, School of Biosciences, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK
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4
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Sacco MD, Hammond LR, Noor RE, Bhattacharya D, McKnight LJ, Madsen JJ, Zhang X, Butler SG, Kemp MT, Jaskolka-Brown AC, Khan SJ, Gelis I, Eswara P, Chen Y. Staphylococcus aureus FtsZ and PBP4 bind to the conformationally dynamic N-terminal domain of GpsB. eLife 2024; 13:e85579. [PMID: 38639993 PMCID: PMC11062636 DOI: 10.7554/elife.85579] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2022] [Accepted: 04/15/2024] [Indexed: 04/20/2024] Open
Abstract
In the Firmicutes phylum, GpsB is a membrane associated protein that coordinates peptidoglycan synthesis with cell growth and division. Although GpsB has been studied in several bacteria, the structure, function, and interactome of Staphylococcus aureus GpsB is largely uncharacterized. To address this knowledge gap, we solved the crystal structure of the N-terminal domain of S. aureus GpsB, which adopts an atypical, asymmetric dimer, and demonstrates major conformational flexibility that can be mapped to a hinge region formed by a three-residue insertion exclusive to Staphylococci. When this three-residue insertion is excised, its thermal stability increases, and the mutant no longer produces a previously reported lethal phenotype when overexpressed in Bacillus subtilis. In S. aureus, we show that these hinge mutants are less functional and speculate that the conformational flexibility imparted by the hinge region may serve as a dynamic switch to fine-tune the function of the GpsB complex and/or to promote interaction with its various partners. Furthermore, we provide the first biochemical, biophysical, and crystallographic evidence that the N-terminal domain of GpsB binds not only PBP4, but also FtsZ, through a conserved recognition motif located on their C-termini, thus coupling peptidoglycan synthesis to cell division. Taken together, the unique structure of S. aureus GpsB and its direct interaction with FtsZ/PBP4 provide deeper insight into the central role of GpsB in S. aureus cell division.
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Affiliation(s)
- Michael D Sacco
- Department of Molecular Medicine, Morsani College of Medicine, University of South FloridaTampaUnited States
| | - Lauren R Hammond
- Department of Molecular Biosciences, University of South FloridaTampaUnited States
| | - Radwan E Noor
- Department of Chemistry, University of South FloridaTampaUnited States
| | | | - Lily J McKnight
- Department of Molecular Biosciences, University of South FloridaTampaUnited States
| | - Jesper J Madsen
- Department of Molecular Medicine, Morsani College of Medicine, University of South FloridaTampaUnited States
- Global and Planetary Health, College of Public Health, University of South FloridaTampaUnited States
| | - Xiujun Zhang
- Department of Molecular Medicine, Morsani College of Medicine, University of South FloridaTampaUnited States
| | - Shane G Butler
- Department of Molecular Medicine, Morsani College of Medicine, University of South FloridaTampaUnited States
| | - M Trent Kemp
- Department of Molecular Medicine, Morsani College of Medicine, University of South FloridaTampaUnited States
| | - Aiden C Jaskolka-Brown
- Department of Molecular Medicine, Morsani College of Medicine, University of South FloridaTampaUnited States
| | - Sebastian J Khan
- Department of Molecular Biosciences, University of South FloridaTampaUnited States
| | - Ioannis Gelis
- Department of Chemistry, University of South FloridaTampaUnited States
| | - Prahathees Eswara
- Department of Molecular Biosciences, University of South FloridaTampaUnited States
| | - Yu Chen
- Department of Molecular Medicine, Morsani College of Medicine, University of South FloridaTampaUnited States
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5
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Zhang XL, Báti G, Li C, Guo A, Yeo C, Ding H, Pal KB, Xu Y, Qiao Y, Liu XW. GlcNAc-1,6-anhydro-MurNAc Moiety Affords Unusual Glycosyl Acceptor that Terminates Peptidoglycan Elongation. J Am Chem Soc 2024; 146:7400-7407. [PMID: 38456799 DOI: 10.1021/jacs.3c12526] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/09/2024]
Abstract
Peptidoglycan (PG), an essential exoskeletal polymer in bacteria, is a well-known antibiotic target. PG polymerization requires the action of bacterial transglycosylases (TGases), which couple the incoming glycosyl acceptor to the donor. Interfering with the TGase activity can interrupt the PG assembly. Existing TGase inhibitors like moenomycin and Lipid II analogues always occupy the TGase active sites; other strategies to interfere with proper PG elongation have not been widely exploited. Inspired by the natural 1,6-anhydro-MurNAc termini that mark the ends of PG strands in bacteria, we hypothesized that the incorporation of an anhydromuramyl-containing glycosyl acceptor by TGase into the growing PG may effectively inhibit PG elongation. To explore this possibility, we synthesized 4-O-(N-acetyl-β-d-glucosaminyl)-1,6-anhydro-N-acetyl-β-d-muramyl-l-Ala-γ-d-Glu-l-Lys-d-Ala-d-Ala, 1, within 15 steps, and demonstrated that this anhydromuropeptide and its analogue lacking the peptide, 1-deAA, were both utilized by bacterial TGase as noncanonical anhydro glycosyl acceptors in vitro. The incorporation of an anhydromuramyl moiety into PG strands by TGases afforded efficient termination of glycan chain extension. Moreover, the preliminary in vitro studies of 1-deAA against Staphylococcus aureus showed that 1-deAA served as a reasonable antimicrobial adjunct of vancomycin. These insights imply the potential application of such anhydromuropeptides as novel classes of PG-terminating inhibitors, pointing toward novel strategies in antibacterial agent development.
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Affiliation(s)
- Xiao-Lin Zhang
- School of Chemistry, Chemical Engineering and Biotechnology, Nanyang Technological University, Singapore 637371, Singapore
| | - Gábor Báti
- School of Chemistry, Chemical Engineering and Biotechnology, Nanyang Technological University, Singapore 637371, Singapore
| | - Chenyu Li
- School of Chemistry, Chemical Engineering and Biotechnology, Nanyang Technological University, Singapore 637371, Singapore
| | - Aoxin Guo
- School of Chemistry, Chemical Engineering and Biotechnology, Nanyang Technological University, Singapore 637371, Singapore
| | - Claresta Yeo
- School of Chemistry, Chemical Engineering and Biotechnology, Nanyang Technological University, Singapore 637371, Singapore
| | - Han Ding
- School of Chemistry, Chemical Engineering and Biotechnology, Nanyang Technological University, Singapore 637371, Singapore
| | - Kumar Bhaskar Pal
- School of Chemistry, Chemical Engineering and Biotechnology, Nanyang Technological University, Singapore 637371, Singapore
| | - Yuan Xu
- School of Chemistry, Chemical Engineering and Biotechnology, Nanyang Technological University, Singapore 637371, Singapore
| | - Yuan Qiao
- School of Chemistry, Chemical Engineering and Biotechnology, Nanyang Technological University, Singapore 637371, Singapore
| | - Xue-Wei Liu
- School of Chemistry, Chemical Engineering and Biotechnology, Nanyang Technological University, Singapore 637371, Singapore
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6
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Li FKK, Worrall LJ, Gale RT, Brown ED, Strynadka NCJ. Cryo-EM analysis of S. aureus TarL, a polymerase in wall teichoic acid biogenesis central to virulence and antibiotic resistance. SCIENCE ADVANCES 2024; 10:eadj3864. [PMID: 38416829 PMCID: PMC10901376 DOI: 10.1126/sciadv.adj3864] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/28/2023] [Accepted: 01/23/2024] [Indexed: 03/01/2024]
Abstract
Wall teichoic acid (WTA), a covalent adduct of Gram-positive bacterial cell wall peptidoglycan, contributes directly to virulence and antibiotic resistance in pathogenic species. Polymerization of the Staphylococcus aureus WTA ribitol-phosphate chain is catalyzed by TarL, a member of the largely uncharacterized TagF-like family of membrane-associated enzymes. We report the cryo-electron microscopy structure of TarL, showing a tetramer that forms an extensive membrane-binding platform of monotopic helices. TarL is composed of an amino-terminal immunoglobulin-like domain and a carboxyl-terminal glycosyltransferase-B domain for ribitol-phosphate polymerization. The active site of the latter is complexed to donor substrate cytidine diphosphate-ribitol, providing mechanistic insights into the catalyzed phosphotransfer reaction. Furthermore, the active site is surrounded by electropositive residues that serve to retain the lipid-linked acceptor for polymerization. Our data advance general insight into the architecture and membrane association of the still poorly characterized monotopic membrane protein class and present molecular details of ribitol-phosphate polymerization that may aid in the design of new antimicrobials.
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Affiliation(s)
- Franco K K Li
- Department of Biochemistry and Molecular Biology, The University of British Columbia, Vancouver, British Columbia, Canada
- Centre for Blood Research, The University of British Columbia, Vancouver, British Columbia, Canada
| | - Liam J Worrall
- Department of Biochemistry and Molecular Biology, The University of British Columbia, Vancouver, British Columbia, Canada
- Centre for Blood Research, The University of British Columbia, Vancouver, British Columbia, Canada
| | - Robert T Gale
- Department of Biochemistry and Biomedical Sciences, Michael G. DeGroote Institute for Infectious Disease Research, McMaster University, Hamilton, Ontario, Canada
| | - Eric D Brown
- Department of Biochemistry and Biomedical Sciences, Michael G. DeGroote Institute for Infectious Disease Research, McMaster University, Hamilton, Ontario, Canada
| | - Natalie C J Strynadka
- Department of Biochemistry and Molecular Biology, The University of British Columbia, Vancouver, British Columbia, Canada
- Centre for Blood Research, The University of British Columbia, Vancouver, British Columbia, Canada
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7
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Ibrahim AM, Azam MS, Schneewind O, Missiakas D. Processing of LtaS restricts LTA assembly and YSIRK preprotein trafficking into Staphylococcus aureus cross-walls. mBio 2024; 15:e0285223. [PMID: 38174934 PMCID: PMC10865820 DOI: 10.1128/mbio.02852-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2023] [Accepted: 10/31/2023] [Indexed: 01/05/2024] Open
Abstract
Septal membranes of Staphylococcus aureus serve as the site of secretion for precursors endowed with the YSIRK motif. Depletion of ltaS, a gene required for lipoteichoic acid (LTA) synthesis, results in the loss of restricted trafficking of YSIRK precursors to septal membranes. Here, we seek to understand the mechanism that ties LTA assembly and trafficking of YSIRK precursors. We confirm that catalytically inactive lipoteichoic acid synthase (LtaS)T300A does not support YSIRK precursor trafficking to septa. We hypothesize that the enzyme's reactants [gentiobiosyldiacylglycerol (Glc2-DAG) and phosphatidylglycerol (PG)] or products [LTA and diacylglycerol (DAG)], not LtaS, must drive this process. Indeed, we observe that septal secretion of the staphylococcal protein A YSIRK precursor is lost in ypfP and ltaA mutants that produce glycerophosphate polymers [poly(Gro-P)] without the Glc2-DAG lipid anchor. These mutants display longer poly(Gro-P) chains, implying enhanced PG consumption and DAG production. Our experiments also reveal that in the absence of Glc2-DAG, the processing of LtaS to the extracellular catalytic domain, eLtaS, is impaired. Conversely, LTA polymerization is delayed in a strain producing LtaSS218P, a variant processed more slowly than LtaS. We conclude that Glc2-DAG binding to the enzyme couples catalysis by LtaS and the physical release of eLtaS. We propose a model for the temporal and localized assembly of LTA into cross-walls. When LtaS is not processed in a timely manner, eLtaS no longer diffuses upon daughter cell splitting, LTA assembly continues, and the unique septal-lipid pool, PG over DAG ratio, is not established. This results in profound physiological changes in S. aureus cells, including the inability to restrict the secretion of YSIRK precursors at septal membranes.IMPORTANCEIn Staphylococcus aureus, peptidoglycan is assembled at the septum. Dedicated cell division proteins coordinate septal formation and the fission of daughter cells. Lipoteichoic acid (LTA) assembly and trafficking of preproteins with a YSIRK motif also occur at the septum. This begs the question as to whether cell division components also recruit these two pathways. This study shows that the processing of lipoteichoic acid synthase (LtaS) to extracellular LtaS by signal peptidase is regulated by gentiobiosyldiacylglycerol (Glc2-DAG), the priming substrate for LTA assembly. A model is proposed whereby a key substrate controls the temporal and spatial activity of an enzyme. In turn, this mechanism enables the establishment of a unique and transient lipid pool that defines septal membranes as a targeting site for the secretion of YSIRK preproteins.
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Affiliation(s)
- Amany M. Ibrahim
- Department of Microbiology, Howard Taylor Ricketts Laboratory, The University of Chicago, Lemont, Illinois, USA
- Department of Microbiology and Immunology, Faculty of Pharmacy, Sinai University, Arish, Egypt
| | - Muhammad S. Azam
- Department of Microbiology, Howard Taylor Ricketts Laboratory, The University of Chicago, Lemont, Illinois, USA
| | - Olaf Schneewind
- Department of Microbiology, Howard Taylor Ricketts Laboratory, The University of Chicago, Lemont, Illinois, USA
| | - Dominique Missiakas
- Department of Microbiology, Howard Taylor Ricketts Laboratory, The University of Chicago, Lemont, Illinois, USA
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Heidarian S, Guliaev A, Nicoloff H, Hjort K, Andersson DI. High prevalence of heteroresistance in Staphylococcus aureus is caused by a multitude of mutations in core genes. PLoS Biol 2024; 22:e3002457. [PMID: 38175839 PMCID: PMC10766187 DOI: 10.1371/journal.pbio.3002457] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2023] [Accepted: 11/30/2023] [Indexed: 01/06/2024] Open
Abstract
Heteroresistance (HR) is an enigmatic phenotype where, in a main population of susceptible cells, small subpopulations of resistant cells exist. This is a cause for concern, as this small subpopulation is difficult to detect by standard antibiotic susceptibility tests, and upon antibiotic exposure the resistant subpopulation may increase in frequency and potentially lead to treatment complications or failure. Here, we determined the prevalence and mechanisms of HR for 40 clinical Staphylococcus aureus isolates, against 6 clinically important antibiotics: daptomycin, gentamicin, linezolid, oxacillin, teicoplanin, and vancomycin. High frequencies of HR were observed for gentamicin (69.2%), oxacillin (27%), daptomycin (25.6%), and teicoplanin (15.4%) while none of the isolates showed HR toward linezolid or vancomycin. Point mutations in various chromosomal core genes, including those involved in membrane and peptidoglycan/teichoic acid biosynthesis and transport, tRNA charging, menaquinone and chorismite biosynthesis and cyclic-di-AMP biosynthesis, were the mechanisms responsible for generating the resistant subpopulations. This finding is in contrast to gram-negative bacteria, where increased copy number of bona fide resistance genes via tandem gene amplification is the most prevalent mechanism. This difference can be explained by the observation that S. aureus has a low content of resistance genes and absence of the repeat sequences that allow tandem gene amplification of these genes as compared to gram-negative species.
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Affiliation(s)
- Sheida Heidarian
- Department of Medical Biochemistry and Microbiology, Uppsala University, Uppsala, Sweden
| | - Andrei Guliaev
- Department of Medical Biochemistry and Microbiology, Uppsala University, Uppsala, Sweden
| | - Hervé Nicoloff
- Department of Medical Biochemistry and Microbiology, Uppsala University, Uppsala, Sweden
| | - Karin Hjort
- Department of Medical Biochemistry and Microbiology, Uppsala University, Uppsala, Sweden
| | - Dan I. Andersson
- Department of Medical Biochemistry and Microbiology, Uppsala University, Uppsala, Sweden
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9
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Lyou ES, Kim MS, Kim SB, Park M, Kim KD, Jung WH, Lee TK. Single-cell phenotypes revealed as a key biomarker in bacterial-fungal interactions: a case study of Staphylococcus and Malassezia. Microbiol Spectr 2023; 11:e0043723. [PMID: 37909790 PMCID: PMC10714763 DOI: 10.1128/spectrum.00437-23] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2023] [Accepted: 09/28/2023] [Indexed: 11/03/2023] Open
Abstract
IMPORTANCE Evaluating bacterial-fungal interactions is important for understanding ecological functions in a natural habitat. Many studies have defined bacterial-fungal interactions according to changes in growth rates when co-cultivated. However, the current literature lacks detailed studies on phenotypic changes in single cells associated with transcriptomic profiles to understand the bacterial-fungal interactions. In our study, we measured the single-cell phenotypes of bacteria co-cultivated with fungi using Raman spectroscopy with its transcriptomic profiles and determined the consequence of these interactions in detail. This rapid and reliable phenotyping approach has the potential to provide new insights regarding bacterial-fungal interactions.
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Affiliation(s)
- Eun Sun Lyou
- Department of Environmental & Energy Engineering, Yonsei University, Wonju, South Korea
| | - Min Sung Kim
- Department of Environmental & Energy Engineering, Yonsei University, Wonju, South Korea
- Bio-Chemical Analysis Group, Centre for Research Equipment, Korea Basic Science Institute, Cheongju, South Korea
| | - Soo Bin Kim
- Department of Environmental & Energy Engineering, Yonsei University, Wonju, South Korea
| | - MinJi Park
- Department of Systems Biotechnology, Chung-Ang University, Anseong, South Korea
| | - Kyong-Dong Kim
- Department of Systems Biotechnology, Chung-Ang University, Anseong, South Korea
| | - Won Hee Jung
- Department of Systems Biotechnology, Chung-Ang University, Anseong, South Korea
| | - Tae Kwon Lee
- Department of Environmental & Energy Engineering, Yonsei University, Wonju, South Korea
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10
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Lu S, Xu J, Zhao Z, Guo Y, Zhang H, Jurutka PW, Huang D, Cao C, Cheng S. Dietary Lactobacillus rhamnosus GG extracellular vesicles enhance antiprogrammed cell death 1 (anti-PD-1) immunotherapy efficacy against colorectal cancer. Food Funct 2023; 14:10314-10328. [PMID: 37916395 DOI: 10.1039/d3fo02018e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2023]
Abstract
There is a need to explore combination therapy to improve the efficacy of immunotherapy for colorectal cancer through food probiotics. In this study, extracellular vesicles (EV) derived from Lactobacillus rhamnosus GG (LGG-EV) were successfully isolated. Adjusting the culture temperature to 30 °C led to an elevated LGG-EV yield, and the addition of penicillin resulted in a decrease in particle size. In addition, LGG-EV have better gastrointestinal tract stability in a Ca2+ environment in vivo and in vitro. Oral administration of LGG-EV synergistically improved anti-PD-1 immunotherapy efficacy against colorectal cancer. Mechanistically, LGG-EV modulated intestinal immunity by increasing the CD8+ T/CD4+ T cell ratio in mesenteric lymph nodes and enhancing the ratio of MHC II+ DC cells, CD4+ T cells, and CD8+ T cells in tumor tissues. Meanwhile, the diversity of the gut microbiota and the abundance of beneficial bacteria, such as Lactobacillus, increased in the combined-treatment mice. In addition, there were significant changes in the levels of serum metabolites associated with the microbiota and anti-tumor effects, including uridine, which was elevated by the combination of anti-PD-1 and LGG-EV treatment. Our findings provide theoretical and mechanistic insights into the development of LGG-EV as postbiotics in combination with immune checkpoint inhibitors for cancer therapy.
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Affiliation(s)
- Shun Lu
- Department of Food Nutrition and Safety, School of Engineering, China Pharmaceutical University, Nanjing 211198, P. R. China.
| | - Jing Xu
- Department of Food Nutrition and Safety, School of Engineering, China Pharmaceutical University, Nanjing 211198, P. R. China.
| | - Zihao Zhao
- Department of Food Nutrition and Safety, School of Engineering, China Pharmaceutical University, Nanjing 211198, P. R. China.
| | - Yuheng Guo
- Department of Food Nutrition and Safety, School of Engineering, China Pharmaceutical University, Nanjing 211198, P. R. China.
| | - Hanwen Zhang
- Department of Food Nutrition and Safety, School of Engineering, China Pharmaceutical University, Nanjing 211198, P. R. China.
| | - Peter W Jurutka
- School of Mathematical and Natural Sciences, Arizona State University, AZ 85306, USA
| | - Dechun Huang
- Department of Pharmaceutical Engineering, School of Engineering, China Pharmaceutical University, Nanjing 211198, P. R. China
| | - Chongjiang Cao
- Department of Food Nutrition and Safety, School of Engineering, China Pharmaceutical University, Nanjing 211198, P. R. China.
| | - Shujie Cheng
- Department of Food Nutrition and Safety, School of Engineering, China Pharmaceutical University, Nanjing 211198, P. R. China.
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11
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Wilson SA, Tank RKJ, Hobbs JK, Foster SJ, Garner EC. An exhaustive multiple knockout approach to understanding cell wall hydrolase function in Bacillus subtilis. mBio 2023; 14:e0176023. [PMID: 37768080 PMCID: PMC10653849 DOI: 10.1128/mbio.01760-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2023] [Accepted: 08/03/2023] [Indexed: 09/29/2023] Open
Abstract
IMPORTANCE In order to grow, bacterial cells must both create and break down their cell wall. The enzymes that are responsible for these processes are the target of some of our best antibiotics. Our understanding of the proteins that break down the wall- cell wall hydrolases-has been limited by redundancy among the large number of hydrolases many bacteria contain. To solve this problem, we identified 42 cell wall hydrolases in Bacillus subtilis and created a strain lacking 40 of them. We show that cells can survive using only a single cell wall hydrolase; this means that to understand the growth of B. subtilis in standard laboratory conditions, it is only necessary to study a very limited number of proteins, simplifying the problem substantially. We additionally show that the ∆40 strain is a research tool to characterize hydrolases, using it to identify three "helper" hydrolases that act in certain stress conditions.
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Affiliation(s)
- Sean A. Wilson
- Department of Molecular and Cellular Biology, Harvard University, Cambridge, Massachusetts, USA
- Center for Systems Biology, Harvard University, Cambridge, Massachusetts, USA
| | - Raveen K. J. Tank
- Department of Physics and Astronomy, University of Sheffield, Sheffield, United Kingdom
| | - Jamie K. Hobbs
- Department of Physics and Astronomy, University of Sheffield, Sheffield, United Kingdom
| | - Simon J. Foster
- School of Biosciences, University of Sheffield, Sheffield, United Kingdom
| | - Ethan C. Garner
- Department of Molecular and Cellular Biology, Harvard University, Cambridge, Massachusetts, USA
- Center for Systems Biology, Harvard University, Cambridge, Massachusetts, USA
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12
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Axelrod S, Li X, Sun Y, Lincoln S, Terceros A, O’Neil J, Wang Z, Nguyen A, Vora A, Spicer C, Shapiro B, Young MW. The Drosophila blood-brain barrier regulates sleep via Moody G protein-coupled receptor signaling. Proc Natl Acad Sci U S A 2023; 120:e2309331120. [PMID: 37831742 PMCID: PMC10589661 DOI: 10.1073/pnas.2309331120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2023] [Accepted: 08/28/2023] [Indexed: 10/15/2023] Open
Abstract
Sleep is vital for most animals, yet its mechanism and function remain unclear. We found that permeability of the BBB (blood-brain barrier)-the organ required for the maintenance of homeostatic levels of nutrients, ions, and other molecules in the brain-is modulated by sleep deprivation (SD) and can cell-autonomously effect sleep changes. We observed increased BBB permeability in known sleep mutants as well as in acutely sleep-deprived animals. In addition to molecular tracers, SD-induced BBB changes also increased the penetration of drugs used in the treatment of brain pathologies. After chronic/genetic or acute SD, rebound sleep or administration of the sleeping aid gaboxadol normalized BBB permeability, showing that SD effects on the BBB are reversible. Along with BBB permeability, RNA levels of the BBB master regulator moody are modulated by sleep. Conversely, altering BBB permeability alone through glia-specific modulation of moody, gαo, loco, lachesin, or neuroglian-each a well-studied regulator of BBB function-was sufficient to induce robust sleep phenotypes. These studies demonstrate a tight link between BBB permeability and sleep and indicate a unique role for the BBB in the regulation of sleep.
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Affiliation(s)
- Sofia Axelrod
- Laboratory of Genetics, The Rockefeller University, New York, NY10065
| | - Xiaoling Li
- International Personalized Cancer Center, Tianjin Cancer Hospital Airport Hospital, Tianjin300308, China
| | - Yingwo Sun
- Laboratory of Genetics, The Rockefeller University, New York, NY10065
| | - Samantha Lincoln
- Laboratory of Genetics, The Rockefeller University, New York, NY10065
| | - Andrea Terceros
- Laboratory of Genetics, The Rockefeller University, New York, NY10065
| | - Jenna O’Neil
- Laboratory of Genetics, The Rockefeller University, New York, NY10065
| | - Zikun Wang
- Laboratory of Genetics, The Rockefeller University, New York, NY10065
| | - Andrew Nguyen
- Laboratory of Genetics, The Rockefeller University, New York, NY10065
| | - Aabha Vora
- Laboratory of Genetics, The Rockefeller University, New York, NY10065
| | - Carmen Spicer
- Laboratory of Genetics, The Rockefeller University, New York, NY10065
| | - Benjamin Shapiro
- Laboratory of Genetics, The Rockefeller University, New York, NY10065
| | - Michael W. Young
- Laboratory of Genetics, The Rockefeller University, New York, NY10065
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13
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Sutton JAF, Cooke M, Tinajero-Trejo M, Wacnik K, Salamaga B, Portman-Ross C, Lund VA, Hobbs JK, Foster SJ. The roles of GpsB and DivIVA in Staphylococcus aureus growth and division. Front Microbiol 2023; 14:1241249. [PMID: 37711690 PMCID: PMC10498921 DOI: 10.3389/fmicb.2023.1241249] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2023] [Accepted: 08/04/2023] [Indexed: 09/16/2023] Open
Abstract
The spheroid bacterium Staphylococcus aureus is often used as a model of morphogenesis due to its apparently simple cell cycle. S. aureus has many cell division proteins that are conserved across bacteria alluding to common functions. However, despite intensive study, we still do not know the roles of many of these components. Here, we have examined the functions of the paralogues DivIVA and GpsB in the S. aureus cell cycle. Cells lacking gpsB display a more spherical phenotype than the wild-type cells, which is associated with a decrease in peripheral cell wall peptidoglycan synthesis. This correlates with increased localization of penicillin-binding proteins at the developing septum, notably PBPs 2 and 3. Our results highlight the role of GpsB as an apparent regulator of cell morphogenesis in S. aureus.
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Affiliation(s)
- Joshua A. F. Sutton
- School of Biosciences, University of Sheffield, Sheffield, United Kingdom
- The Florey Institute for Host-Pathogen Interactions, University of Sheffield, Sheffield, United Kingdom
| | - Mark Cooke
- School of Biosciences, University of Sheffield, Sheffield, United Kingdom
| | - Mariana Tinajero-Trejo
- School of Biosciences, University of Sheffield, Sheffield, United Kingdom
- The Florey Institute for Host-Pathogen Interactions, University of Sheffield, Sheffield, United Kingdom
| | - Katarzyna Wacnik
- School of Biosciences, University of Sheffield, Sheffield, United Kingdom
- The Florey Institute for Host-Pathogen Interactions, University of Sheffield, Sheffield, United Kingdom
| | - Bartłomiej Salamaga
- School of Biosciences, University of Sheffield, Sheffield, United Kingdom
- The Florey Institute for Host-Pathogen Interactions, University of Sheffield, Sheffield, United Kingdom
| | - Callum Portman-Ross
- School of Biosciences, University of Sheffield, Sheffield, United Kingdom
- The Florey Institute for Host-Pathogen Interactions, University of Sheffield, Sheffield, United Kingdom
| | - Victoria A. Lund
- School of Biosciences, University of Sheffield, Sheffield, United Kingdom
- The Florey Institute for Host-Pathogen Interactions, University of Sheffield, Sheffield, United Kingdom
| | - Jamie K. Hobbs
- The Florey Institute for Host-Pathogen Interactions, University of Sheffield, Sheffield, United Kingdom
- Department of Physics and Astronomy, University of Sheffield, Sheffield, United Kingdom
| | - Simon J. Foster
- School of Biosciences, University of Sheffield, Sheffield, United Kingdom
- The Florey Institute for Host-Pathogen Interactions, University of Sheffield, Sheffield, United Kingdom
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14
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Lade H, Kim JS. Molecular Determinants of β-Lactam Resistance in Methicillin-Resistant Staphylococcus aureus (MRSA): An Updated Review. Antibiotics (Basel) 2023; 12:1362. [PMID: 37760659 PMCID: PMC10525618 DOI: 10.3390/antibiotics12091362] [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: 08/07/2023] [Revised: 08/21/2023] [Accepted: 08/24/2023] [Indexed: 09/29/2023] Open
Abstract
The development of antibiotic resistance in Staphylococcus aureus, particularly in methicillin-resistant S. aureus (MRSA), has become a significant health concern worldwide. The acquired mecA gene encodes penicillin-binding protein 2a (PBP2a), which takes over the activities of endogenous PBPs and, due to its low affinity for β-lactam antibiotics, is the main determinant of MRSA. In addition to PBP2a, other genetic factors that regulate cell wall synthesis, cell signaling pathways, and metabolism are required to develop high-level β-lactam resistance in MRSA. Although several genetic factors that modulate β-lactam resistance have been identified, it remains unclear how they alter PBP2a expression and affect antibiotic resistance. This review describes the molecular determinants of β-lactam resistance in MRSA, with a focus on recent developments in our understanding of the role of mecA-encoded PBP2a and on other genetic factors that modulate the level of β-lactam resistance. Understanding the molecular determinants of β-lactam resistance can aid in developing novel strategies to combat MRSA.
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Affiliation(s)
| | - Jae-Seok Kim
- Department of Laboratory Medicine, Hallym University College of Medicine, Kangdong Sacred Heart Hospital, Seoul 05355, Republic of Korea;
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15
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Agrawal S, Broderick NA. Inside help from the microbiome. eLife 2023; 12:e88873. [PMID: 37272924 PMCID: PMC10241506 DOI: 10.7554/elife.88873] [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] [Indexed: 06/06/2023] Open
Abstract
Elucidating the role of one of the proteins produced by Lactiplantibacillus plantarum reveals a new molecule that allows this gut bacterium to support the development of fruit fly larvae.
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Affiliation(s)
- Sneha Agrawal
- Department of Biology, Johns Hopkins UniversityBaltimoreUnited States
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16
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Lu Y, Chen F, Zhao Q, Cao Q, Chen R, Pan H, Wang Y, Huang H, Huang R, Liu Q, Li M, Bae T, Liang H, Lan L. Modulation of MRSA virulence gene expression by the wall teichoic acid enzyme TarO. Nat Commun 2023; 14:1594. [PMID: 36949052 PMCID: PMC10032271 DOI: 10.1038/s41467-023-37310-5] [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: 07/01/2022] [Accepted: 03/10/2023] [Indexed: 03/24/2023] Open
Abstract
Phenol-soluble modulins (PSMs) and Staphylococcal protein A (SpA) are key virulence determinants for community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA), an important human pathogen that causes a wide range of diseases. Here, using chemical and genetic approaches, we show that inhibition of TarO, the first enzyme in the wall teichoic acid (WTA) biosynthetic pathway, decreases the expression of genes encoding PSMs and SpA in the prototypical CA-MRSA strain USA300 LAC. Mechanistically, these effects are linked to the activation of VraRS two-component system that directly represses the expression of accessory gene regulator (agr) locus and spa. The activation of VraRS was due in part to the loss of the functional integrity of penicillin-binding protein 2 (PBP2) in a PBP2a-dependent manner. TarO inhibition can also activate VraRS in a manner independent of PBP2a. We provide multiple lines of evidence that accumulation of lipid-linked peptidoglycan precursors is a trigger for the activation of VraRS. In sum, our results reveal that WTA biosynthesis plays an important role in the regulation of virulence gene expression in CA-MRSA, underlining TarO as an attractive target for anti-virulence therapy. Our data also suggest that acquisition of PBP2a-encoding mecA gene can impart an additional regulatory layer for the modulation of key signaling pathways in S. aureus.
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Affiliation(s)
- Yunfu Lu
- School of Pharmaceutical Science and Technology, Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, Hangzhou, 310024, China
- State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, 201203, China
- University of Chinese Academy of Sciences, No. 19A Yuquan Road, Beijing, 100049, China
| | - Feifei Chen
- School of Pharmaceutical Science and Technology, Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, Hangzhou, 310024, China
- State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, 201203, China
- College of Life Science, Northwest University, Xi'an, 710127, China
| | - Qingmin Zhao
- School of Pharmaceutical Science and Technology, Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, Hangzhou, 310024, China
- State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, 201203, China
- University of Chinese Academy of Sciences, No. 19A Yuquan Road, Beijing, 100049, China
| | - Qiao Cao
- School of Pharmaceutical Science and Technology, Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, Hangzhou, 310024, China
- State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, 201203, China
- College of Life Science, Northwest University, Xi'an, 710127, China
| | - Rongrong Chen
- School of Pharmaceutical Science and Technology, Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, Hangzhou, 310024, China
- State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, 201203, China
- University of Chinese Academy of Sciences, No. 19A Yuquan Road, Beijing, 100049, China
| | - Huiwen Pan
- School of Pharmaceutical Science and Technology, Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, Hangzhou, 310024, China
- State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, 201203, China
- University of Chinese Academy of Sciences, No. 19A Yuquan Road, Beijing, 100049, China
| | - Yanhui Wang
- School of Pharmaceutical Science and Technology, Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, Hangzhou, 310024, China
- State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, 201203, China
- University of Chinese Academy of Sciences, No. 19A Yuquan Road, Beijing, 100049, China
| | - Haixin Huang
- State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, 201203, China
| | - Ruimin Huang
- State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, 201203, China
- University of Chinese Academy of Sciences, No. 19A Yuquan Road, Beijing, 100049, China
| | - Qian Liu
- Department of Laboratory Medicine, School of Medicine, Renji Hospital, Shanghai Jiao Tong University, Shanghai, 200127, China
| | - Min Li
- Department of Laboratory Medicine, School of Medicine, Renji Hospital, Shanghai Jiao Tong University, Shanghai, 200127, China
| | - Taeok Bae
- Department of Microbiology and Immunology, Indiana University School of Medicine-Northwest, Gary, IN, 46408, USA
| | - Haihua Liang
- College of Life Science, Northwest University, Xi'an, 710127, China.
- School of Medicine, Southern University of Science and Technology, Shenzhen, 518055, China.
| | - Lefu Lan
- School of Pharmaceutical Science and Technology, Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, Hangzhou, 310024, China.
- State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, 201203, China.
- University of Chinese Academy of Sciences, No. 19A Yuquan Road, Beijing, 100049, China.
- College of Life Science, Northwest University, Xi'an, 710127, China.
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17
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Malet-Villemagne J, Yucheng L, Evanno L, Denis-Quanquin S, Hugonnet JE, Arthur M, Janoir C, Candela T. Polysaccharide II Surface Anchoring, the Achilles' Heel of Clostridioides difficile. Microbiol Spectr 2023; 11:e0422722. [PMID: 36815772 PMCID: PMC10100865 DOI: 10.1128/spectrum.04227-22] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2022] [Accepted: 01/25/2023] [Indexed: 02/24/2023] Open
Abstract
Cell wall glycopolymers (CWPGs) in Gram-positive bacteria have been reported to be involved in several bacterial processes. These polymers, pillars for proteins and S-layer, are essential for the bacterial surface setup, could be essential for growth, and, in pathogens, participate most often in virulence. CWGPs are covalently anchored to peptidoglycan by proteins that belong to the LytR-CpsA-PSr (LCP) family. This anchoring, important for growth, was reported as essential for some bacteria such as Bacillus subtilis, but the reason why CWGP anchoring is essential remains unknown. We studied LcpA and LcpB of Clostridioides difficile and showed that they have a redundant activity. To delete both lcp genes, we set up the first conditional-lethal mutant method in C. difficile and showed that polysaccharide II (PSII) anchoring at the bacterial surface is essential for C. difficile survival. In the conditional-lethal mutant, C. difficile morphology was impaired, suggesting that peptidoglycan synthesis was affected. Because Lcp proteins are transferring CWPGs from the C55-undecaprenyl phosphate (also needed in the peptidoglycan synthesis process), we assumed that there was competition between PSII and peptidoglycan synthesis pathways. We confirmed that UDP-MurNAc-pentapeptide precursor was accumulated, showing that peptidoglycan synthesis was blocked. Our results provide an explanation for the essentiality of PSII anchoring in C. difficile and suggest that the essentiality of the anchoring of CWPGs in other bacteria can also be explained by the blocking of peptidoglycan synthesis. To conclude, our results suggest that Lcps are potential new targets to combat C. difficile infection. IMPORTANCE Cell wall glycopolymers (CWGPs) in Gram-positive bacteria have been reported to be involved in several bacterial processes. CWGP anchoring to peptidoglycan is important for growth and virulence. We set up the first conditional-lethal mutant method in Clostridioides difficile to study LcpA and LcpB involved in the anchoring of CWPGs to peptidoglycan. This study offers new tools to reveal the role of essential genes in C. difficile. LcpA and LcpB activity was shown to be essential, suggesting that they are potential new targets to combat C. difficile infection. In this study, we also showed that there is competition between the polysaccharide II synthesis pathway and peptidoglycan synthesis that probably exists in other Gram-positive bacteria. A better understanding of these mechanisms allows us to define the Lcp proteins as a therapeutic target for potential design of novel antibiotics against pathogenic Gram-positive bacteria.
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Affiliation(s)
| | - Liang Yucheng
- INSERM UMR-S 1138, Centre de Recherche des Cordeliers, Sorbonne Université, Université Paris Cité, Paris, France
| | - Laurent Evanno
- Biomolécules: Conception, Isolement et Synthèse (BioCIS), Université Paris-Saclay, CNRS, Orsay, France
| | | | - Jean-Emmanuel Hugonnet
- INSERM UMR-S 1138, Centre de Recherche des Cordeliers, Sorbonne Université, Université Paris Cité, Paris, France
| | - Michel Arthur
- INSERM UMR-S 1138, Centre de Recherche des Cordeliers, Sorbonne Université, Université Paris Cité, Paris, France
| | - Claire Janoir
- Micalis Institute, Université Paris-Saclay, INRAE, AgroParisTech, Jouy-en-Josas, France
| | - Thomas Candela
- Micalis Institute, Université Paris-Saclay, INRAE, AgroParisTech, Jouy-en-Josas, France
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18
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Ersoy SC, Gonçalves B, Cavaco G, Manna AC, Sobral RG, Nast CC, Proctor RA, Chambers HF, Cheung A, Bayer AS. Influence of Sodium Bicarbonate on Wall Teichoic Acid Synthesis and β-Lactam Sensitization in NaHCO 3-Responsive and Nonresponsive Methicillin-Resistant Staphylococcus aureus. Microbiol Spectr 2022; 10:e0342222. [PMID: 36377886 PMCID: PMC9769754 DOI: 10.1128/spectrum.03422-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2022] [Accepted: 10/13/2022] [Indexed: 11/16/2022] Open
Abstract
Methicillin-resistant Staphylococcus aureus (MRSA) strains pose major treatment challenges due to their innate resistance to most β-lactams under standard in vitro antimicrobial susceptibility testing conditions. A novel phenotype among MRSA, termed "NaHCO3 responsiveness," where certain strains display increased susceptibility to β-lactams in the presence of NaHCO3, has been identified among a relatively large proportion of MRSA isolates. One underlying mechanism of NaHCO3 responsiveness appears to be related to decreased expression and altered functionality of several genes and proteins involved in cell wall synthesis and maturation. Here, we studied the impact of NaHCO3 on wall teichoic acid (WTA) synthesis, a process intimately linked to peptidoglycan (PG) synthesis and functionality, in NaHCO3-responsive versus -nonresponsive MRSA isolates. NaHCO3 sensitized responsive MRSA strains to cefuroxime, a specific penicillin-binding protein 2 (PBP2)-inhibitory β-lactam known to synergize with early WTA synthesis inhibitors (e.g., ticlopidine). Combining cefuroxime with ticlopidine with or without NaHCO3 suggested that these latter two agents target the same step in WTA synthesis. Further, NaHCO3 decreased the abundance and molecular weight of WTA only in responsive strains. Additionally, NaHCO3 stimulated increased autolysis and aberrant cell division in responsive strains, two phenotypes associated with disruption of WTA synthesis. Of note, studies of key genes involved in the WTA biosynthetic pathway (e.g., tarO, tarG, dltA, and fmtA) indicated that the inhibitory impact of NaHCO3 on WTA biosynthesis in responsive strains likely occurred posttranslationally. IMPORTANCE MRSA is generally viewed as resistant to standard β-lactam antibiotics. However, a NaHCO3-responsive phenotype is observed in a substantial proportion of clinical MRSA strains in vitro, i.e., isolates which demonstrate enhanced susceptibility to standard β-lactam antibiotics (e.g., oxacillin) in the presence of NaHCO3. This phenotype correlates with increased MRSA clearance in vivo by standard β-lactam antibiotics, suggesting that patients with infections caused by such MRSA strains might be amenable to treatment with β-lactams. The mechanism(s) behind this phenotype is not fully understood but appears to involve mecA-PBP2a production and maturation axes. Our study adds significantly to this body of knowledge in terms of additional mechanistic targets of NaHCO3 in selected MRSA strains. This investigation demonstrates that NaHCO3 has direct impacts on S. aureus wall teichoic acid biosynthesis in NaHCO3-responsive MRSA. These findings provide an additional target for new agents being designed to synergistically kill MRSA using β-lactam antibiotics.
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Affiliation(s)
| | - Barbara Gonçalves
- Laboratory of Molecular Microbiology of Bacterial Pathogens, UCIBIO, Applied Molecular Biosciences Unit, Department of Life Sciences, Nova School of Science and Technology, Universidade Nova de Lisboa, Caparica, Portugal
- Associate Laboratory i4HB, Institute for Health and Bioeconomy, Nova School of Science and Technology, Universidade Nova de Lisboa, Caparica, Portugal
| | - Gonçalo Cavaco
- Laboratory of Molecular Microbiology of Bacterial Pathogens, UCIBIO, Applied Molecular Biosciences Unit, Department of Life Sciences, Nova School of Science and Technology, Universidade Nova de Lisboa, Caparica, Portugal
- Associate Laboratory i4HB, Institute for Health and Bioeconomy, Nova School of Science and Technology, Universidade Nova de Lisboa, Caparica, Portugal
| | - Adhar C. Manna
- Department of Microbiology & Immunology, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire, USA
| | - Rita G. Sobral
- Laboratory of Molecular Microbiology of Bacterial Pathogens, UCIBIO, Applied Molecular Biosciences Unit, Department of Life Sciences, Nova School of Science and Technology, Universidade Nova de Lisboa, Caparica, Portugal
- Associate Laboratory i4HB, Institute for Health and Bioeconomy, Nova School of Science and Technology, Universidade Nova de Lisboa, Caparica, Portugal
| | - Cynthia C. Nast
- Cedars-Sinai Medical Center, Los Angeles, California, USA
- Geffen School of Medicine at UCLA, Los Angeles, California, USA
| | - Richard A. Proctor
- Department of Medicine, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin, USA
- Department of Medical Microbiology/Immunology, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin, USA
| | | | - Ambrose Cheung
- Department of Microbiology & Immunology, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire, USA
| | - Arnold S. Bayer
- The Lundquist Institute, Torrance, California, USA
- Geffen School of Medicine at UCLA, Los Angeles, California, USA
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19
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Lund V, Gangotra H, Zhao Z, Sutton JAF, Wacnik K, DeMeester K, Liang H, Santiago C, Leimkuhler Grimes C, Jones S, Foster SJ. Coupling Novel Probes with Molecular Localization Microscopy Reveals Cell Wall Homeostatic Mechanisms in Staphylococcus aureus. ACS Chem Biol 2022; 17:3298-3305. [PMID: 36414253 PMCID: PMC9764285 DOI: 10.1021/acschembio.2c00741] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Bacterial cell wall peptidoglycan is essential for viability, and its synthesis is targeted by antibiotics, including penicillin. To determine how peptidoglycan homeostasis controls cell architecture, growth, and division, we have developed novel labeling approaches. These are compatible with super-resolution fluorescence microscopy to examine peptidoglycan synthesis, hydrolysis, and the localization of the enzymes required for its biosynthesis (penicillin binding proteins (PBPs)). Synthesis of a cephalosporin-based fluorescent probe revealed a pattern of PBPs at the septum during division, supporting a model of dispersed peptidoglycan synthesis. Metabolic and hydroxylamine-based probes respectively enabled the synthesis of glycan strands and associated reducing termini of the peptidoglycan to be mapped. Foci and arcs of reducing termini appear as a result of both synthesis of glycan strands and glucosaminidase activity of the major peptidoglycan hydrolase, SagB. Our studies provide molecular level details of how essential peptidoglycan dynamics are controlled during growth and division.
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Affiliation(s)
- Victoria
A. Lund
- School
of Biosciences, University of Sheffield, Sheffield S10 2TN, United Kingdom,The
Florey Institute for Host−Pathogen Interactions, University of Sheffield, Sheffield S10 2TN, United Kingdom
| | - Haneesh Gangotra
- The
Florey Institute for Host−Pathogen Interactions, University of Sheffield, Sheffield S10 2TN, United Kingdom,The
Department of Chemistry, University of Sheffield, Sheffield S3 7HF, United Kingdom
| | - Zhen Zhao
- The
Florey Institute for Host−Pathogen Interactions, University of Sheffield, Sheffield S10 2TN, United Kingdom,The
Department of Chemistry, University of Sheffield, Sheffield S3 7HF, United Kingdom
| | - Joshua A. F. Sutton
- School
of Biosciences, University of Sheffield, Sheffield S10 2TN, United Kingdom,The
Florey Institute for Host−Pathogen Interactions, University of Sheffield, Sheffield S10 2TN, United Kingdom
| | - Katarzyna Wacnik
- School
of Biosciences, University of Sheffield, Sheffield S10 2TN, United Kingdom,The
Florey Institute for Host−Pathogen Interactions, University of Sheffield, Sheffield S10 2TN, United Kingdom
| | - Kristen DeMeester
- Department
of Chemistry and Biochemistry and Department of Biological Sciences, University of Delaware, Newark, Delaware 19716, United States
| | - Hai Liang
- Department
of Chemistry and Biochemistry and Department of Biological Sciences, University of Delaware, Newark, Delaware 19716, United States
| | - Cintia Santiago
- Department
of Chemistry and Biochemistry and Department of Biological Sciences, University of Delaware, Newark, Delaware 19716, United States
| | - Catherine Leimkuhler Grimes
- Department
of Chemistry and Biochemistry and Department of Biological Sciences, University of Delaware, Newark, Delaware 19716, United States
| | - Simon Jones
- The
Florey Institute for Host−Pathogen Interactions, University of Sheffield, Sheffield S10 2TN, United Kingdom,The
Department of Chemistry, University of Sheffield, Sheffield S3 7HF, United Kingdom,E-mail:
| | - Simon J. Foster
- School
of Biosciences, University of Sheffield, Sheffield S10 2TN, United Kingdom,The
Florey Institute for Host−Pathogen Interactions, University of Sheffield, Sheffield S10 2TN, United Kingdom,E-mail:
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20
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Barbuti MD, Myrbråten IS, Morales Angeles D, Kjos M. The cell cycle of Staphylococcus aureus: An updated review. Microbiologyopen 2022; 12:e1338. [PMID: 36825883 PMCID: PMC9733580 DOI: 10.1002/mbo3.1338] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2022] [Revised: 11/29/2022] [Accepted: 11/29/2022] [Indexed: 12/13/2022] Open
Abstract
As bacteria proliferate, DNA replication, chromosome segregation, cell wall synthesis, and cytokinesis occur concomitantly and need to be tightly regulated and coordinated. Although these cell cycle processes have been studied for decades, several mechanisms remain elusive, specifically in coccus-shaped cells such as Staphylococcus aureus. In recent years, major progress has been made in our understanding of how staphylococci divide, including new, fundamental insights into the mechanisms of cell wall synthesis and division site selection. Furthermore, several novel proteins and mechanisms involved in the regulation of replication initiation or progression of the cell cycle have been identified and partially characterized. In this review, we will summarize our current understanding of the cell cycle processes in the spheroid model bacterium S. aureus, with a focus on recent advances in the understanding of how these processes are regulated.
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Affiliation(s)
- Maria D. Barbuti
- Faculty of Chemistry, Biotechnology and Food ScienceNorwegian University of Life Sciences (NMBU)ÅsNorway
| | - Ine S. Myrbråten
- Faculty of Chemistry, Biotechnology and Food ScienceNorwegian University of Life Sciences (NMBU)ÅsNorway
| | - Danae Morales Angeles
- Faculty of Chemistry, Biotechnology and Food ScienceNorwegian University of Life Sciences (NMBU)ÅsNorway
| | - Morten Kjos
- Faculty of Chemistry, Biotechnology and Food ScienceNorwegian University of Life Sciences (NMBU)ÅsNorway
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21
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The Staphylococcus aureus cell division protein, DivIC, interacts with the cell wall and controls its biosynthesis. Commun Biol 2022; 5:1228. [DOI: 10.1038/s42003-022-04161-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2022] [Accepted: 10/24/2022] [Indexed: 11/13/2022] Open
Abstract
AbstractBacterial cell division is a complex, dynamic process that requires multiple protein components to orchestrate its progression. Many division proteins are highly conserved across bacterial species alluding to a common, basic mechanism. Central to division is a transmembrane trimeric complex involving DivIB, DivIC and FtsL in Gram-positives. Here, we show a distinct, essential role for DivIC in division and survival of Staphylococcus aureus. DivIC spatially regulates peptidoglycan synthesis, and consequently cell wall architecture, by influencing the recruitment to the division septum of the major peptidoglycan synthetases PBP2 and FtsW. Both the function of DivIC and its recruitment to the division site depend on its extracellular domain, which interacts with the cell wall via binding to wall teichoic acids. DivIC facilitates the spatial and temporal coordination of peptidoglycan synthesis with the developing architecture of the septum during cell division. A better understanding of the cell division mechanisms in S. aureus and other pathogenic microorganisms can provide possibilities for the development of new, more effective treatments for bacterial infections.
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22
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Zhou J, Cai Y, Liu Y, An H, Deng K, Ashraf MA, Zou L, Wang J. Breaking down the cell wall: Still an attractive antibacterial strategy. Front Microbiol 2022; 13:952633. [PMID: 36212892 PMCID: PMC9544107 DOI: 10.3389/fmicb.2022.952633] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2022] [Accepted: 08/18/2022] [Indexed: 11/17/2022] Open
Abstract
Since the advent of penicillin, humans have known about and explored the phenomenon of bacterial inhibition via antibiotics. However, with changes in the global environment and the abuse of antibiotics, resistance mechanisms have been selected in bacteria, presenting huge threats and challenges to the global medical and health system. Thus, the study and development of new antimicrobials is of unprecedented urgency and difficulty. Bacteria surround themselves with a cell wall to maintain cell rigidity and protect against environmental insults. Humans have taken advantage of antibiotics to target the bacterial cell wall, yielding some of the most widely used antibiotics to date. The cell wall is essential for bacterial growth and virulence but is absent from humans, remaining a high-priority target for antibiotic screening throughout the antibiotic era. Here, we review the extensively studied targets, i.e., MurA, MurB, MurC, MurD, MurE, MurF, Alr, Ddl, MurI, MurG, lipid A, and BamA in the cell wall, starting from the very beginning to the latest developments to elucidate antimicrobial screening. Furthermore, recent advances, including MraY and MsbA in peptidoglycan and lipopolysaccharide, and tagO, LtaS, LspA, Lgt, Lnt, Tol-Pal, MntC, and OspA in teichoic acid and lipoprotein, have also been profoundly discussed. The review further highlights that the application of new methods such as macromolecular labeling, compound libraries construction, and structure-based drug design will inspire researchers to screen ideal antibiotics.
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Affiliation(s)
- Jingxuan Zhou
- The People’s Hospital of China Three Gorges University, Yichang, Hubei, China
- Hubei Key Laboratory of Tumor Microenvironment and Immunotherapy, College of Basic Medical Sciences, China Three Gorges University, Yichang, Hubei, China
- The Institute of Infection and Inflammation, College of Basic Medical Sciences, China Three Gorges University, Yichang, Hubei, China
| | - Yi Cai
- Hubei Key Laboratory of Tumor Microenvironment and Immunotherapy, College of Basic Medical Sciences, China Three Gorges University, Yichang, Hubei, China
- The Institute of Infection and Inflammation, College of Basic Medical Sciences, China Three Gorges University, Yichang, Hubei, China
| | - Ying Liu
- Hubei Key Laboratory of Tumor Microenvironment and Immunotherapy, College of Basic Medical Sciences, China Three Gorges University, Yichang, Hubei, China
- The Institute of Infection and Inflammation, College of Basic Medical Sciences, China Three Gorges University, Yichang, Hubei, China
| | - Haoyue An
- Hubei Key Laboratory of Tumor Microenvironment and Immunotherapy, College of Basic Medical Sciences, China Three Gorges University, Yichang, Hubei, China
- The Institute of Infection and Inflammation, College of Basic Medical Sciences, China Three Gorges University, Yichang, Hubei, China
| | - Kaihong Deng
- Hubei Key Laboratory of Tumor Microenvironment and Immunotherapy, College of Basic Medical Sciences, China Three Gorges University, Yichang, Hubei, China
- The Institute of Infection and Inflammation, College of Basic Medical Sciences, China Three Gorges University, Yichang, Hubei, China
| | - Muhammad Awais Ashraf
- Department of Microbiology, Government College University Faisalabad, Faisalabad, Pakistan
| | - Lili Zou
- Hubei Key Laboratory of Tumor Microenvironment and Immunotherapy, College of Basic Medical Sciences, China Three Gorges University, Yichang, Hubei, China
- The Institute of Infection and Inflammation, College of Basic Medical Sciences, China Three Gorges University, Yichang, Hubei, China
| | - Jun Wang
- The People’s Hospital of China Three Gorges University, Yichang, Hubei, China
- *Correspondence: Jun Wang,
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Guérin H, Kulakauskas S, Chapot-Chartier MP. Structural variations and roles of rhamnose-rich cell wall polysaccharides in Gram-positive bacteria. J Biol Chem 2022; 298:102488. [PMID: 36113580 PMCID: PMC9574508 DOI: 10.1016/j.jbc.2022.102488] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Revised: 09/08/2022] [Accepted: 09/10/2022] [Indexed: 11/17/2022] Open
Abstract
Rhamnose-rich cell wall polysaccharides (Rha-CWPSs) have emerged as crucial cell wall components of numerous Gram-positive, ovoid-shaped bacteria—including streptococci, enterococci, and lactococci—of which many are of clinical or biotechnological importance. Rha-CWPS are composed of a conserved polyrhamnose backbone with side-chain substituents of variable size and structure. Because these substituents contain phosphate groups, Rha-CWPS can also be classified as polyanionic glycopolymers, similar to wall teichoic acids, of which they appear to be functional homologs. Recent advances have highlighted the critical role of these side-chain substituents in bacterial cell growth and division, as well as in specific interactions between bacteria and infecting bacteriophages or eukaryotic hosts. Here, we review the current state of knowledge on the structure and biosynthesis of Rha-CWPS in several ovoid-shaped bacterial species. We emphasize the role played by multicomponent transmembrane glycosylation systems in the addition of side-chain substituents of various sizes as extracytoplasmic modifications of the polyrhamnose backbone. We provide an overview of the contribution of Rha-CWPS to cell wall architecture and biogenesis and discuss current hypotheses regarding their importance in the cell division process. Finally, we sum up the critical roles that Rha-CWPS can play as bacteriophage receptors or in escaping host defenses, roles that are mediated mainly through their side-chain substituents. From an applied perspective, increased knowledge of Rha-CWPS can lead to advancements in strategies for preventing phage infection of lactococci and streptococci in food fermentation and for combating pathogenic streptococci and enterococci.
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Affiliation(s)
- Hugo Guérin
- Université Paris-Saclay, INRAE, AgroParisTech, Micalis Institute, Jouy-en-Josas, France
| | - Saulius Kulakauskas
- Université Paris-Saclay, INRAE, AgroParisTech, Micalis Institute, Jouy-en-Josas, France
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24
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Wall Teichoic Acids Facilitate the Release of Toxins from the Surface of Staphylococcus aureus. Microbiol Spectr 2022; 10:e0101122. [PMID: 35863033 PMCID: PMC9430763 DOI: 10.1128/spectrum.01011-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
A major feature of the pathogenicity of Staphylococcus aureus is its ability to secrete cytolytic toxins. This process involves the translocation of the toxins from the cytoplasm through the bacterial membrane and the cell wall to the external environment. The process of their movement through the membrane is relatively well defined, involving both general and toxin-specific secretory systems. Movement of the toxins through the cell wall was considered to involve the passive diffusion of the proteins through the porous cell wall structures; however, recent work suggests that this is more complex, and here we demonstrate a role for the wall teichoic acids (WTA) in this process. Utilizing a genome-wide association approach, we identified a polymorphism in the locus encoding the WTA biosynthetic machinery as associated with the cytolytic activity of the bacteria. We verified this association using an isogenic mutant set and found that WTA are required for the release of several cytolytic toxins from the bacterial cells. We show that this effect is mediated by a change in the electrostatic charge across the cell envelope that results from the loss of WTA. As a major target for the development of novel therapeutics, it is important that we fully understand the entire process of cytolytic toxin production and release. These findings open up a new aspect to the process of toxin release by a major human pathogen while also demonstrating that clinical isolates can utilize WTA production to vary their cytotoxicity, thereby altering their pathogenic capabilities. IMPORTANCE The production and release of cytolytic toxins is a critical aspect for the pathogenicity of many bacterial pathogens. In this study, we demonstrate a role for wall teichoic acids, molecules that are anchored to the peptidoglycan of the bacterial cell wall, in the release of toxins from S. aureus cells into the extracellular environment. Our findings suggest that this effect is mediated by a gradient of electrostatic charge which the presence of the negatively charged WTA molecules create across the cell envelope. This work brings an entirely new aspect to our understanding of the cytotoxicity of S. aureus and demonstrates a further means by which this major human pathogen can adapt its pathogenic capabilities.
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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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Hammond LR, Sacco MD, Khan SJ, Spanoudis C, Hough-Neidig A, Chen Y, Eswara PJ. GpsB Coordinates Cell Division and Cell Surface Decoration by Wall Teichoic Acids in Staphylococcus aureus. Microbiol Spectr 2022; 10:e0141322. [PMID: 35647874 PMCID: PMC9241681 DOI: 10.1128/spectrum.01413-22] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2022] [Accepted: 05/12/2022] [Indexed: 11/20/2022] Open
Abstract
Bacterial cell division is a complex and highly regulated process requiring the coordination of many different proteins. Despite substantial work in model organisms, our understanding of the systems regulating cell division in noncanonical organisms, including critical human pathogens, is far from complete. One such organism is Staphylococcus aureus, a spherical bacterium that lacks known cell division regulatory proteins. Recent studies on GpsB, a protein conserved within the Firmicutes phylum, have provided insight into cell division regulation in S. aureus and other related organisms. It has been revealed that GpsB coordinates cell division and cell wall synthesis in multiple species. In S. aureus, we have previously shown that GpsB directly regulates FtsZ polymerization. In this study, using Bacillus subtilis as a tool, we isolated spontaneous suppressors that abrogate the lethality of S. aureus GpsB overproduction in B. subtilis. Through characterization, we identified several residues important for the function of GpsB. Furthermore, we discovered an additional role for GpsB in wall teichoic acid (WTA) biosynthesis in S. aureus. Specifically, we show that GpsB directly interacts with the WTA export protein TarG. We also identified a region in GpsB that is crucial for this interaction. Analysis of TarG localization in S. aureus suggests that WTA machinery is part of the divisome complex. Taken together, this research illustrates how GpsB performs an essential function in S. aureus by directly linking the tightly regulated cell cycle processes of cell division and WTA-mediated cell surface decoration. IMPORTANCE Cytokinesis in bacteria involves an intricate orchestration of several key cell division proteins and other factors involved in building a robust cell envelope. Presence of teichoic acids is a signature characteristic of the Gram-positive cell wall. By characterizing the role of Staphylococcus aureus GpsB, an essential cell division protein in this organism, we have uncovered an additional role for GpsB in wall teichoic acid (WTA) biosynthesis. We show that GpsB directly interacts with TarG of the WTA export complex. We also show that this function of GpsB may be conserved in other GpsB homologs as GpsB and the WTA exporter complex follow similar localization patterns. It has been suggested that WTA acts as a molecular signal to control the activity of autolytic enzymes, especially during the separation of conjoined daughter cells. Thus, our results reveal that GpsB, in addition to playing a role in cell division, may also help coordinate WTA biogenesis.
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Affiliation(s)
- Lauren R. Hammond
- Department of Cell Biology, Microbiology, and Molecular Biology, University of South Florida, Tampa, Florida, USA
| | - Michael D. Sacco
- Department of Molecular Medicine, University of South Florida, Tampa, Florida, USA
| | - Sebastian J. Khan
- Department of Cell Biology, Microbiology, and Molecular Biology, University of South Florida, Tampa, Florida, USA
| | - Catherine Spanoudis
- Department of Cell Biology, Microbiology, and Molecular Biology, University of South Florida, Tampa, Florida, USA
| | - Abigail Hough-Neidig
- Department of Cell Biology, Microbiology, and Molecular Biology, University of South Florida, Tampa, Florida, USA
| | - Yu Chen
- Department of Molecular Medicine, University of South Florida, Tampa, Florida, USA
| | - Prahathees J. Eswara
- Department of Cell Biology, Microbiology, and Molecular Biology, University of South Florida, Tampa, Florida, USA
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27
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Wysocka A, Łężniak Ł, Jagielska E, Sabała I. Electrostatic Interaction with the Bacterial Cell Envelope Tunes the Lytic Activity of Two Novel Peptidoglycan Hydrolases. Microbiol Spectr 2022; 10:e0045522. [PMID: 35467396 PMCID: PMC9241647 DOI: 10.1128/spectrum.00455-22] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2022] [Accepted: 04/04/2022] [Indexed: 12/14/2022] Open
Abstract
Peptidoglycan (PG) hydrolases, due to their crucial role in the metabolism of the bacterial cell wall (CW), are increasingly being considered suitable targets for therapies, and a potent alternative to conventional antibiotics. In the light of contradictory data reported, detailed mechanism of regulation of enzymes activity based on electrostatic interactions between hydrolase molecule and bacterial CW surface remains unknown. Here, we report a comprehensive study on this phenomenon using as a model two novel PG hydrolases, SpM23_A, and SpM23_B, which although share the same bacterial host, similarities in sequence conservation, domain architecture, and structure, display surprisingly distinct net charges (in 2D electrophoresis, pI 6.8, and pI 9.7, respectively). We demonstrate a strong correlation between hydrolases surface net charge and the enzymes activity by modulating the charge of both, enzyme molecule and bacterial cell surface. Teichoic acids, anionic polymers present in the bacterial CW, are shown to be involved in the mechanism of enzymes activity regulation by the electrostatics-based interplay between charged bacterial envelope and PG hydrolases. These data serve as a hint for the future development of chimeric PG hydrolases of desired antimicrobial specificity. IMPORTANCE This study shows direct relationship between the surface charge of two recently described enzymes, SpM23_A and SpM23_B, and bacterial cell walls. We demonstrate that by (i) surface charge probing of bacterial strains collection, (ii) reduction of the net charge of the positively charged enzyme, and (iii) altering the net charge of the bacterial surface by modifying the content and composition of teichoic acids. In all cases, we observed that lytic activity and binding strength of SpM23 enzymes, are regulated by electrostatic interactions with the bacterial cell envelope and that this interaction contributes to the determination of the spectrum of susceptible bacterial species. Moreover, we revealed the regulatory role of charged cell wall components, namely, teichoic and lipoteichoic acids, over the SpM23 enzymes. We believe that our findings make an important contribution to understand the means of hydrolases activity regulation in the complex environment of the bacterial cell wall.
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Affiliation(s)
- Alicja Wysocka
- International Institute of Molecular and Cell Biology in Warsaw, Warsaw, Poland
| | - Łukasz Łężniak
- International Institute of Molecular and Cell Biology in Warsaw, Warsaw, Poland
| | - Elżbieta Jagielska
- International Institute of Molecular and Cell Biology in Warsaw, Warsaw, Poland
- Mossakowski Medical Research Institute Polish Academy of Sciences, Warsaw, Poland
| | - Izabela Sabała
- International Institute of Molecular and Cell Biology in Warsaw, Warsaw, Poland
- Mossakowski Medical Research Institute Polish Academy of Sciences, Warsaw, Poland
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28
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Encapsulation of the septal cell wall protects Streptococcus pneumoniae from its major peptidoglycan hydrolase and host defenses. PLoS Pathog 2022; 18:e1010516. [PMID: 35731836 PMCID: PMC9216600 DOI: 10.1371/journal.ppat.1010516] [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: 08/16/2021] [Accepted: 04/11/2022] [Indexed: 11/19/2022] Open
Abstract
Synthesis of the capsular polysaccharide, a major virulence factor for many pathogenic bacteria, is required for bacterial survival within the infected host. In Streptococcus pneumoniae, Wze, an autophosphorylating tyrosine kinase, and Wzd, a membrane protein required for Wze autophosphorylation, co-localize at the division septum and guarantee the presence of capsule at this subcellular location. To determine how bacteria regulate capsule synthesis, we studied pneumococcal proteins that interact with Wzd and Wze using bacterial two hybrid assays and fluorescence microscopy. We found that Wzd interacts with Wzg, the putative ligase that attaches capsule to the bacterial cell wall, and recruits it to the septal area. This interaction required residue V56 of Wzd and both the transmembrane regions and DNA-PPF domain of Wzg. When compared to the wild type, Wzd null pneumococci lack capsule at midcell, bind the peptidoglycan hydrolase LytA better and are more susceptible to LytA-induced lysis, and are less virulent in a zebrafish embryo infection model. In this manuscript, we propose that the Wzd/Wze pair guarantees full encapsulation of pneumococcal bacteria by recruiting Wzg to the division septum, ensuring that capsule attachment is coordinated with peptidoglycan synthesis. Impairing the encapsulation process, at localized subcellular sites, may facilitate elimination of bacteria by strategies that target the pneumococcal peptidoglycan.
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Penicillin-Binding Protein 1 (PBP1) of Staphylococcus aureus Has Multiple Essential Functions in Cell Division. mBio 2022; 13:e0066922. [PMID: 35703435 PMCID: PMC9426605 DOI: 10.1128/mbio.00669-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
Bacterial cell division is a complex process requiring the coordination of multiple components to allow the appropriate spatial and temporal control of septum formation and cell scission. Peptidoglycan (PG) is the major structural component of the septum, and our recent studies in the human pathogen Staphylococcus aureus have revealed a complex, multistage PG architecture that develops during septation. Penicillin-binding proteins (PBPs) are essential for the final steps of PG biosynthesis; their transpeptidase activity links the peptide side chains of nascent glycan strands. PBP1 is required for cell division in S. aureus, and here, we demonstrate that it has multiple essential functions associated with its enzymatic activity and as a regulator of division. Loss of PBP1, or just its C-terminal PASTA domains, results in cessation of division at the point of septal plate formation. The PASTA domains can bind PG and thereby potentially coordinate the cell division process. The transpeptidase activity of PBP1 is also essential, but its loss leads to a strikingly different phenotype of thickened and aberrant septa, which is phenocopied by the morphological effects of adding the PBP1-specific β-lactam, meropenem. Together, these results lead to a model for septal PG synthesis where PBP1 enzyme activity is required for the characteristic architecture of the septum and PBP1 protein molecules enable the formation of the septal plate.
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Berry KA, Verhoef MTA, Leonard AC, Cox G. Staphylococcus aureus adhesion to the host. Ann N Y Acad Sci 2022; 1515:75-96. [PMID: 35705378 DOI: 10.1111/nyas.14807] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Staphylococcus aureus is a pathobiont capable of colonizing and infecting most tissues within the human body, resulting in a multitude of different clinical outcomes. Adhesion of S. aureus to the host is crucial for both host colonization and the establishment of infections. Underlying the pathogen's success is a complex and diverse arsenal of adhesins. In this review, we discuss the different classes of adhesins, including a consideration of the various adhesion sites throughout the body and the clinical outcomes of each infection type. The development of therapeutics targeting the S. aureus host-pathogen interaction is a relatively understudied area. Due to the increasing global threat of antimicrobial resistance, it is crucial that innovative and alternative approaches are considered. Neutralizing virulence factors, through the development of antivirulence agents, could reduce bacterial pathogenicity and the ever-increasing burden of S. aureus infections. This review provides insight into potentially efficacious adhesion-associated targets for the development of novel decolonizing and antivirulence strategies.
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Affiliation(s)
- Kirsten A Berry
- Department of Molecular and Cellular Biology, College of Biological Sciences, University of Guelph, Guelph, Ontario, Canada
| | - Mackenzie T A Verhoef
- Department of Molecular and Cellular Biology, College of Biological Sciences, University of Guelph, Guelph, Ontario, Canada
| | - Allison C Leonard
- Department of Molecular and Cellular Biology, College of Biological Sciences, University of Guelph, Guelph, Ontario, Canada
| | - Georgina Cox
- Department of Molecular and Cellular Biology, College of Biological Sciences, University of Guelph, Guelph, Ontario, Canada
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31
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Wang M, Buist G, van Dijl JM. Staphylococcus aureus cell wall maintenance - the multifaceted roles of peptidoglycan hydrolases in bacterial growth, fitness, and virulence. FEMS Microbiol Rev 2022; 46:6604383. [PMID: 35675307 PMCID: PMC9616470 DOI: 10.1093/femsre/fuac025] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2021] [Revised: 04/22/2022] [Accepted: 05/25/2022] [Indexed: 01/07/2023] Open
Abstract
Staphylococcus aureus is an important human and livestock pathogen that is well-protected against environmental insults by a thick cell wall. Accordingly, the wall is a major target of present-day antimicrobial therapy. Unfortunately, S. aureus has mastered the art of antimicrobial resistance, as underscored by the global spread of methicillin-resistant S. aureus (MRSA). The major cell wall component is peptidoglycan. Importantly, the peptidoglycan network is not only vital for cell wall function, but it also represents a bacterial Achilles' heel. In particular, this network is continuously opened by no less than 18 different peptidoglycan hydrolases (PGHs) encoded by the S. aureus core genome, which facilitate bacterial growth and division. This focuses attention on the specific functions executed by these enzymes, their subcellular localization, their control at the transcriptional and post-transcriptional levels, their contributions to staphylococcal virulence and their overall importance in bacterial homeostasis. As highlighted in the present review, our understanding of the different aspects of PGH function in S. aureus has been substantially increased over recent years. This is important because it opens up new possibilities to exploit PGHs as innovative targets for next-generation antimicrobials, passive or active immunization strategies, or even to engineer them into effective antimicrobial agents.
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Affiliation(s)
- Min Wang
- Department of Medical Microbiology, University of Groningen, University Medical Center Groningen, Hanzeplein 1, PO Box 30001, 9700 RB Groningen, the Netherlands
| | | | - Jan Maarten van Dijl
- Corresponding author: Department of Medical Microbiology, University of Groningen, University Medical Center Groningen, Hanzeplein 1, P.O. box 30001, HPC EB80, 9700 RB Groningen, the Netherlands, Tel. +31-50-3615187; Fax. +31-50-3619105; E-mail:
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32
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Chee Wezen X, Chandran A, Eapen RS, Waters E, Bricio-Moreno L, Tosi T, Dolan S, Millership C, Kadioglu A, Gründling A, Itzhaki LS, Welch M, Rahman T. Structure-Based Discovery of Lipoteichoic Acid Synthase Inhibitors. J Chem Inf Model 2022; 62:2586-2599. [PMID: 35533315 PMCID: PMC9131456 DOI: 10.1021/acs.jcim.2c00300] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2022] [Indexed: 01/20/2023]
Abstract
Lipoteichoic acid synthase (LtaS) is a key enzyme for the cell wall biosynthesis of Gram-positive bacteria. Gram-positive bacteria that lack lipoteichoic acid (LTA) exhibit impaired cell division and growth defects. Thus, LtaS appears to be an attractive antimicrobial target. The pharmacology around LtaS remains largely unexplored with only two small-molecule LtaS inhibitors reported, namely "compound 1771" and the Congo red dye. Structure-based drug discovery efforts against LtaS remain unattempted due to the lack of an inhibitor-bound structure of LtaS. To address this, we combined the use of a molecular docking technique with molecular dynamics (MD) simulations to model a plausible binding mode of compound 1771 to the extracellular catalytic domain of LtaS (eLtaS). The model was validated using alanine mutagenesis studies combined with isothermal titration calorimetry. Additionally, lead optimization driven by our computational model resulted in an improved version of compound 1771, namely, compound 4 which showed greater affinity for binding to eLtaS than compound 1771 in biophysical assays. Compound 4 reduced LTA production in S. aureus dose-dependently, induced aberrant morphology as seen for LTA-deficient bacteria, and significantly reduced bacteria titers in the lung of mice infected with S. aureus. Analysis of our MD simulation trajectories revealed the possible formation of a transient cryptic pocket in eLtaS. Virtual screening (VS) against the cryptic pocket led to the identification of a new class of inhibitors that could potentiate β-lactams against methicillin-resistant S. aureus. Our overall workflow and data should encourage further drug design campaign against LtaS. Finally, our work reinforces the importance of considering protein conformational flexibility to a successful VS endeavor.
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Affiliation(s)
- Xavier Chee Wezen
- Science
Program, School of Chemical Engineering and Science, Faculty of Engineering,
Computing and Science, Swinburne University
of Technology Sarawak, Kuching 93350, Malaysia
| | - Aneesh Chandran
- Department
of Biotechnology & Microbiology, Kannur
University, Kannur 670 661, Kerala, India
| | | | - Elaine Waters
- Department
of Clinical Infection Microbiology and Immunology, Institute of Infection
and Global Health, University of Liverpool, Liverpool L69 7BE, U.K.
| | - Laura Bricio-Moreno
- Department
of Clinical Infection Microbiology and Immunology, Institute of Infection
and Global Health, University of Liverpool, Liverpool L69 7BE, U.K.
| | - Tommaso Tosi
- Section
of Molecular Microbiology and MRC Centre for Molecular Bacteriology
and Infection, Imperial College London, London SW7 2AZ, U.K.
| | - Stephen Dolan
- Department
of Biochemistry, University of Cambridge, Cambridge CB2 1QW, U.K.
| | - Charlotte Millership
- Section
of Molecular Microbiology and MRC Centre for Molecular Bacteriology
and Infection, Imperial College London, London SW7 2AZ, U.K.
| | - Aras Kadioglu
- Department
of Clinical Infection Microbiology and Immunology, Institute of Infection
and Global Health, University of Liverpool, Liverpool L69 7BE, U.K.
| | - Angelika Gründling
- Section
of Molecular Microbiology and MRC Centre for Molecular Bacteriology
and Infection, Imperial College London, London SW7 2AZ, U.K.
| | - Laura S. Itzhaki
- Department
of PharmacologyUniversity of CambridgeCambridgeCB2 1PDU.K.
| | - Martin Welch
- Department
of Biochemistry, University of Cambridge, Cambridge CB2 1QW, U.K.
| | - Taufiq Rahman
- Department
of PharmacologyUniversity of CambridgeCambridgeCB2 1PDU.K.
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33
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Harden MM, Anderson ME, Grossman AD. A
CRISPR
interference screen reveals a role for cell wall teichoic acids in conjugation in
Bacillus subtilis. Mol Microbiol 2022; 117:1366-1383. [PMID: 35490406 PMCID: PMC9324163 DOI: 10.1111/mmi.14914] [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: 12/10/2021] [Revised: 04/19/2022] [Accepted: 04/27/2022] [Indexed: 11/30/2022]
Abstract
Conjugative elements are widespread in bacteria and include plasmids and integrative and conjugative elements (ICEs). They transfer from donor to recipient cells via an element‐encoded type IV secretion system. These elements interact with and utilize host functions for their lifecycles. We sought to identify essential host genes involved in the lifecycle of the integrative and conjugative element ICEBs1 of Bacillus subtilis. We constructed a library of strains for inducible knockdown of essential B. subtilis genes using CRISPR interference. Each strain expressed one guide RNA in ICEBs1. We induced partial interference of essential genes and identified those that caused an acute defect in acquisition of ICEBs1 by recipient cells. This screen revealed that reducing expression of genes needed for synthesis of cell wall teichoic acids caused a decrease in conjugation. Using three different ways to reduce their synthesis, we found that wall teichoic acids were necessary in both donors and recipients for efficient conjugative transfer of ICEBs1. Further, we found that depletion of wall teichoic acids caused cells involved in ICEBs1 conjugation to die, most likely from damage to the cell envelope. Our results indicate that wall teichoic acids help protect against envelope stress caused by active conjugation machines.
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Affiliation(s)
- M. Michael Harden
- Department of Biology Massachusetts Institute of Technology Cambridge, MA 02139
| | - Mary E. Anderson
- Department of Biology Massachusetts Institute of Technology Cambridge, MA 02139
| | - Alan D. Grossman
- Department of Biology Massachusetts Institute of Technology Cambridge, MA 02139
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34
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Abstract
Cell division and cell wall synthesis in staphylococci need to be precisely coordinated and controlled to allow the cell to multiply while maintaining its nearly spherical shape. The mechanisms ensuring correct placement of the division plane and synthesis of new cell wall have been studied intensively. However, hitherto unknown factors and proteins are likely to play key roles in this complex interplay. Here, we identified and investigated a protein with a major influence on cell morphology in Staphylococcus aureus. The protein, named SmdA (for staphylococcal morphology determinant A), is a membrane protein with septum-enriched localization. By CRISPRi knockdown and overexpression combined with different microscopy techniques, we demonstrated that proper levels of SmdA were necessary for cell division, including septum formation and cell splitting. We also identified conserved residues in SmdA that were critical for its functionality. Pulldown and bacterial two-hybrid interaction experiments showed that SmdA interacted with several known cell division and cell wall synthesis proteins, including penicillin-binding proteins (PBPs) and EzrA. Notably, SmdA also affected susceptibility to cell wall targeting antibiotics, particularly in methicillin-resistant S. aureus (MRSA). Together, our results showed that S. aureus was dependent on balanced amounts of membrane attached SmdA to carry out proper cell division.
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35
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Villageliu DN, Samuelson DR. The Role of Bacterial Membrane Vesicles in Human Health and Disease. Front Microbiol 2022; 13:828704. [PMID: 35300484 PMCID: PMC8923303 DOI: 10.3389/fmicb.2022.828704] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2021] [Accepted: 01/31/2022] [Indexed: 12/12/2022] Open
Abstract
Bacterial membrane vesicles (MVs) are nanoparticles derived from the membrane components of bacteria that transport microbial derived substances. MVs are ubiquitous across a variety of terrestrial and marine environments and vary widely in their composition and function. Membrane vesicle functional diversity is staggering: MVs facilitate intercellular communication by delivering quorum signals, genetic information, and small molecules active against a variety of receptors. MVs can deliver destructive virulence factors, alter the composition of the microbiota, take part in the formation of biofilms, assist in the uptake of nutrients, and serve as a chemical waste removal system for bacteria. MVs also facilitate host-microbe interactions including communication. Released in mass, MVs overwhelm the host immune system and injure host tissues; however, there is also evidence that vesicles may take part in processes which promote host health. This review will examine the ascribed functions of MVs within the context of human health and disease.
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Affiliation(s)
| | - Derrick R. Samuelson
- Division of Pulmonary, Critical Care, and Sleep, Department of Internal Medicine, University of Nebraska Medical Center, Omaha, NE, United States
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36
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Gouveia A, Pinto D, Veiga H, Antunes W, Pinho MG, São-José C. Synthetic antimicrobial peptides as enhancers of the bacteriolytic action of staphylococcal phage endolysins. Sci Rep 2022; 12:1245. [PMID: 35075218 PMCID: PMC8786859 DOI: 10.1038/s41598-022-05361-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2021] [Accepted: 01/10/2022] [Indexed: 01/09/2023] Open
Abstract
Bacteriophage endolysins degrade the bacterial cell wall and are therefore considered promising antimicrobial alternatives to fight pathogens resistant to conventional antibiotics. Gram-positive bacteria are usually considered easy targets to exogenously added endolysins, since their cell walls are not shielded by an outer membrane. However, in nutrient rich environments these bacteria can also tolerate endolysin attack if they keep an energized cytoplasmic membrane. Hence, we have hypothesized that the membrane depolarizing action of antimicrobial peptides (AMPs), another attractive class of alternative antibacterials, could be explored to overcome bacterial tolerance to endolysins and consequently improve their antibacterial potential. Accordingly, we show that under conditions supporting bacterial growth, Staphylococcus aureus becomes much more susceptible to the bacteriolytic action of endolysins if an AMP is also present. The bactericidal gain resulting from the AMP/endolysin combined action ranged from 1 to 3 logs for different S. aureus strains, which included drug-resistant clinical isolates. In presence of an AMP, as with a reduced content of cell wall teichoic acids, higher endolysin binding to cells is observed. However, our results indicate that this higher endolysin binding alone does not fully explain the higher susceptibility of S. aureus to lysis in these conditions. Other factors possibly contributing to the increased endolysin susceptibility in presence of an AMP are discussed.
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Affiliation(s)
- Ana Gouveia
- Research Institute for Medicines (iMed.ULisboa), Faculdade de Farmácia da Universidade de Lisboa, Av. Prof. Gama Pinto, 1649-003, Lisbon, Portugal
| | - Daniela Pinto
- Research Institute for Medicines (iMed.ULisboa), Faculdade de Farmácia da Universidade de Lisboa, Av. Prof. Gama Pinto, 1649-003, Lisbon, Portugal
| | - Helena Veiga
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Av. da Républica, 2780-157, Oeiras, Portugal
| | - Wilson Antunes
- Unidade Militar Laboratorial de Defesa Biológica e Química (UMLDBQ), Instituto Universitário Militar, Centro de Investigação da Academia Militar (CINAMIL), Av. Dr. Alfredo Bensaúde, 1849-012, Lisbon, Portugal
| | - Mariana G Pinho
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Av. da Républica, 2780-157, Oeiras, Portugal
| | - Carlos São-José
- Research Institute for Medicines (iMed.ULisboa), Faculdade de Farmácia da Universidade de Lisboa, Av. Prof. Gama Pinto, 1649-003, Lisbon, Portugal.
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37
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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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38
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Ferraro NJ, Kim S, Im W, Pires MM. Systematic Assessment of Accessibility to the Surface of Staphylococcus aureus. ACS Chem Biol 2021; 16:2527-2536. [PMID: 34609132 DOI: 10.1021/acschembio.1c00604] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Proteins from bacterial foes, antimicrobial peptides, and host immune proteins must navigate past a dense layer of bacterial surface biomacromolecules to reach the peptidoglycan (PG) layer of Gram-positive bacteria. A subclass of molecules (e.g., antibiotics with intracellular targets) also must permeate through the PG (in a molecular sieving manner) to reach the cytoplasmic membrane. Despite the biological and therapeutic importance of surface accessibility, systematic analyses in live bacterial cells have been lacking. We describe a live cell fluorescence assay that is robust, shows a high level of reproducibility, and reports on the permeability of molecules to and within the PG scaffold. Moreover, our study shows that teichoic acids impede the permeability of molecules of a wide range of sizes and chemical composition.
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Affiliation(s)
- Noel J. Ferraro
- Department of Chemistry, University of Virginia, Charlottesville, Virginia 22904, United States
| | - Seonghoon Kim
- School of Computational Sciences, Korea Institute for Advanced Study, Seoul 02455, Republic of Korea
| | - Wonpil Im
- Departments of Biological Sciences, Chemistry, and Bioengineering, Lehigh University, Bethlehem, Pennsylvania 18015, United States
| | - Marcos M. Pires
- Department of Chemistry, University of Virginia, Charlottesville, Virginia 22904, United States
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39
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Cai Y, Zheng L, Lu Y, Zhao X, Sun Y, Tang X, Xiao J, Wang C, Tong C, Zhao L, Xiao Y, Zhao X, Xue H. Inducible Resistance to β-Lactams in Oxacillin-Susceptible mecA1-Positive Staphylococcus sciuri Isolated From Retail Pork. Front Microbiol 2021; 12:721426. [PMID: 34745029 PMCID: PMC8564388 DOI: 10.3389/fmicb.2021.721426] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2021] [Accepted: 09/27/2021] [Indexed: 11/20/2022] Open
Abstract
Most isolated strains of Staphylococcus sciuri contain mecA1, the evolutionary origin of mecA, but are sensitive to β-lactams (OS-MRSS, oxacillin-susceptible mecA1-positive S. sciuri). In order to improve the efficacy of antibiotic treatment, it is important to clarify whether the resistance of OS-MRSS to β-lactams is an inducible phenotype. In this study, three OS-MRSS strains with oxacillin MIC = 1 μg/ml were isolated from 29 retail pork samples. The resistance of OS-MRSS to β-lactams (MIC > 256 μg/ml) was found to be induced by oxacillin, and the induced resistance was observed to remain stable within a certain period of time. Interestingly, the induced β-lactam resistance was not caused by mecA1, heterogeneous resistance, or any genetic mutation, but mainly due to increased wall teichoic acid (WTA) synthesis that thickened the cell wall. The induced strains also showed slower growth rate, as well as decreased adhesion ability and biofilm thickness. These phenotypes were found to be achieved through altered gene expression in associated pathways, such as the citrate cycle and pentose phosphate pathway. The results challenge the traditional antibiotic sensitivity test. In the presence of β-lactam antibiotics, OS-MRSS that was initially sensitive to β-lactams was observed to gradually develop β-lactam resistance in several days. This often-neglected phenomenon in antibiotic sensitivity tests requires further research attention.
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Affiliation(s)
- Yifei Cai
- College of Animal Science and Technology, Northwest A&F University, Xianyang, China
| | - Liangjun Zheng
- College of Animal Science and Technology, Northwest A&F University, Xianyang, China
| | - Yao Lu
- College of Animal Science and Technology, Northwest A&F University, Xianyang, China
| | - Xu Zhao
- College of Animal Science and Technology, Northwest A&F University, Xianyang, China
| | - Yanting Sun
- College of Animal Science and Technology, Northwest A&F University, Xianyang, China
| | - Xingyuan Tang
- College of Animal Science and Technology, Northwest A&F University, Xianyang, China
| | - Jinhe Xiao
- College of Animal Science and Technology, Northwest A&F University, Xianyang, China
| | - Chen Wang
- College of Animal Science and Technology, Northwest A&F University, Xianyang, China
| | - Chao Tong
- College of Veterinary Medicine, Henan Agricultural University, Zhengzhou, China
| | - Lili Zhao
- College of Animal Science and Technology, Northwest A&F University, Xianyang, China
| | - Yingping Xiao
- Institute of Quality and Standard for Agro-Products, Zhejiang Academy of Agricultural Sciences, Hangzhou, China
| | - Xin Zhao
- Department of Animal Science, McGill University, Sainte-Anne-de-Bellevue, QC, Canada
| | - Huping Xue
- College of Animal Science and Technology, Northwest A&F University, Xianyang, China
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40
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Hort M, Bertsche U, Nozinovic S, Dietrich A, Schrötter AS, Mildenberger L, Axtmann K, Berscheid A, Bierbaum G. The Role of β-Glycosylated Wall Teichoic Acids in the Reduction of Vancomycin Susceptibility in Vancomycin-Intermediate Staphylococcus aureus. Microbiol Spectr 2021; 9:e0052821. [PMID: 34668723 PMCID: PMC8528128 DOI: 10.1128/spectrum.00528-21] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2021] [Accepted: 09/12/2021] [Indexed: 11/20/2022] Open
Abstract
Staphylococcus aureus is an opportunistic pathogen that causes a wide range of infections. Due to the rapid evolution of antibiotic resistance that leads to treatment failure, it is important to understand the underlying mechanisms. Here, the cell wall structures of several laboratory vancomycin-intermediate S. aureus (VISA) strains were analyzed. Among the VISA strains were S. aureus VC40, which accumulated 79 mutations, including most importantly 2 exchanges in the histidine-kinase VraS, and developed full resistance against vancomycin (MIC, 64 μg/ml); a revertant S. aureus VC40R, which has an additional mutation in vraR (MIC, 4 μg/ml); and S. aureus VraS(VC40), in which the 2 vraS mutations were reconstituted into a susceptible background (MIC, 4 μg/ml). A ultraperformance liquid chromatography (UPLC) analysis showed that S. aureus VC40 had a significantly decreased cross-linking of the peptidoglycan. Both S. aureus VC40 and S. aureus VraS(VC40) displayed reduced autolysis and an altered autolysin profile in a zymogram. Most striking was the significant increase in d-alanine and N-acetyl-d-glucosamine (GlcNAc) substitution of the wall teichoic acids (WTAs) in S. aureus VC40. Nuclear magnetic resonance (NMR) analysis revealed that this strain had mostly β-glycosylated WTAs in contrast to the other strains, which showed only the α-glycosylation peak. Salt stress induced the incorporation of β-GlcNAc anomers and drastically increased the vancomycin MIC for S. aureus VC40R. In addition, β-glycosylated WTAs decreased the binding affinity of AtlA, the major autolysin of S. aureus, to the cell wall, compared with α-glycosylated WTAs. In conclusion, there is a novel connection between wall teichoic acids, autolysis, and vancomycin susceptibility in S. aureus. IMPORTANCE Infections with methicillin-resistant Staphylococcus aureus are commonly treated with vancomycin. This antibiotic inhibits cell wall biosynthesis by binding to the cell wall building block lipid II. We set out to characterize the mechanisms leading to decreased vancomycin susceptibility in a laboratory-generated strain, S. aureus VC40. This strain has an altered cell wall architecture with a thick cell wall with low cross-linking, which provides decoy binding sites for vancomycin. The low cross-linking, necessary for this resistance mechanism, decreases the stability of the cell wall against lytic enzymes, which separate the daughter cells. Protection against these enzymes is provided by another cell wall polymer, the teichoic acids, which contain an unusually high substitution with sugars in the β-conformation. By experimentally increasing the proportion of β-N-acetyl-d-glucosamine in a closely related isolate through the induction of salt stress, we could show that the β-conformation of the sugars plays a vital role in the resistance of S. aureus VC40.
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Affiliation(s)
- Michael Hort
- Institute of Medical Microbiology, Immunology and Parasitology, University Clinics of Bonn, Bonn, Germany
| | - Ute Bertsche
- Department of Infection Biology, University of Tuebingen, Tuebingen, Germany
| | | | - Alina Dietrich
- Institute of Medical Microbiology, Immunology and Parasitology, University Clinics of Bonn, Bonn, Germany
| | - Anne Sophie Schrötter
- Institute of Medical Microbiology, Immunology and Parasitology, University Clinics of Bonn, Bonn, Germany
| | - Laura Mildenberger
- Institute of Medical Microbiology, Immunology and Parasitology, University Clinics of Bonn, Bonn, Germany
| | - Katharina Axtmann
- Institute of Medical Microbiology, Immunology and Parasitology, University Clinics of Bonn, Bonn, Germany
| | - Anne Berscheid
- Institute of Medical Microbiology, Immunology and Parasitology, University Clinics of Bonn, Bonn, Germany
| | - Gabriele Bierbaum
- Institute of Medical Microbiology, Immunology and Parasitology, University Clinics of Bonn, Bonn, Germany
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41
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Sun Y, Liu M, Niu M, Zhao X. Phenotypic Switching of Staphylococcus aureus Mu50 Into a Large Colony Variant Enhances Heritable Resistance Against β-Lactam Antibiotics. Front Microbiol 2021; 12:709841. [PMID: 34690952 PMCID: PMC8530407 DOI: 10.3389/fmicb.2021.709841] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2021] [Accepted: 09/13/2021] [Indexed: 11/24/2022] Open
Abstract
Phenotypic heterogeneity within a bacterial population may confer new functionality and allow microorganisms to adapt to fluctuating environments. Previous work has suggested that Staphylococcus aureus could form small colony variants to avoid elimination by therapeutic antibiotics and host immunity systems. Here we show that a reversible non-pigment large colony morphology (Mu50∆lcpA-LC) was observed in S. aureus Mu50 after knocking out lcpA, coding for the LytR-CpsA-Psr family A protein. Mu50∆lcpA-LC increased resistance to β-lactam antibiotics, in addition, the enlarged cell size, enhanced spreading ability on solid medium, and reduced biofilm formation, suggesting better abilities for bacterial expansion. Moreover, the expression of spa encoding protein A was significantly increased in Mu50∆lcpA-LC. This study shows that besides the small colony variants, S. aureus could fight against antibiotics and host immunity through phenotype switching into a large colony variant.
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Affiliation(s)
- Yajun Sun
- College of Animal Science and Technology, Northwest A&F University, Yangling, China
| | - Miaomiao Liu
- College of Animal Science and Technology, Northwest A&F University, Yangling, China
| | - Mingze Niu
- College of Animal Science and Technology, Northwest A&F University, Yangling, China
| | - Xin Zhao
- College of Animal Science and Technology, Northwest A&F University, Yangling, China.,Department of Animal Science, McGill University, Montreal, QC, Canada
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42
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Apostolos AJ, Ferraro NJ, Dalesandro BE, Pires MM. SaccuFlow: A High-Throughput Analysis Platform to Investigate Bacterial Cell Wall Interactions. ACS Infect Dis 2021; 7:2483-2491. [PMID: 34291914 DOI: 10.1021/acsinfecdis.1c00255] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Bacterial cell walls are formidable barriers that protect bacterial cells against external insults and oppose internal turgor pressure. While cell wall composition is variable across species, peptidoglycan is the principal component of all cell walls. Peptidoglycan is a mesh-like scaffold composed of cross-linked strands that can be heavily decorated with anchored proteins. The biosynthesis and remodeling of peptidoglycan must be tightly regulated by cells because disruption to this biomacromolecule is lethal. This essentiality is exploited by the human innate immune system in resisting colonization and by a number of clinically relevant antibiotics that target peptidoglycan biosynthesis. Evaluation of molecules or proteins that interact with peptidoglycan can be a complicated and, typically, qualitative effort. We have developed a novel assay platform (SaccuFlow) that preserves the native structure of bacterial peptidoglycan and is compatible with high-throughput flow cytometry analysis. We show that the assay is facile and versatile as demonstrated by its compatibility with sacculi from Gram-positive bacteria, Gram-negative bacteria, and mycobacteria. Finally, we highlight the utility of this assay to assess the activity of sortase A from Staphylococcus aureus against potential antivirulence agents.
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Affiliation(s)
- Alexis J. Apostolos
- Department of Chemistry, University of Virginia, Charlottesville, Virginia 22904, United States
| | - Noel J. Ferraro
- Department of Chemistry, University of Virginia, Charlottesville, Virginia 22904, United States
| | - Brianna E. Dalesandro
- Department of Chemistry, University of Virginia, Charlottesville, Virginia 22904, United States
| | - Marcos M. Pires
- Department of Chemistry, University of Virginia, Charlottesville, Virginia 22904, United States
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43
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Zhang K, Raju C, Zhong W, Pethe K, Gründling A, Chan-Park MB. Cationic Glycosylated Block Co-β-peptide Acts on the Cell Wall of Gram-Positive Bacteria as Anti-biofilm Agents. ACS APPLIED BIO MATERIALS 2021; 4:3749-3761. [PMID: 35006805 DOI: 10.1021/acsabm.0c01241] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Antimicrobial resistance is a global threat. In addition to the emergence of resistance to last resort drugs, bacteria escape antibiotics killing by forming complex biofilms. Strategies to tackle antibiotic resistance as well as biofilms are urgently needed. Wall teichoic acid (WTA), a generic anionic glycopolymer present on the cell surface of many Gram-positive bacteria, has been proposed as a possible therapeutic target, but its druggability remains to be demonstrated. Here we report a cationic glycosylated block co-β-peptide that binds to WTA. By doing so, the co-β-peptide not only inhibits biofilm formation, it also disperses preformed biofilms in several Gram-positive bacteria and resensitizes methicillin-resistant Staphylococcus aureus to oxacillin. The cationic block of the co-β-peptide physically interacts with the anionic WTA within the cell envelope, whereas the glycosylated block forms a nonfouling corona around the bacteria. This reduces physical interaction between bacteria-substrate and bacteria-biofilm matrix, leading to biofilm inhibition and dispersal. The WTA-targeting co-β-peptide is a promising lead for the future development of broad-spectrum anti-biofilm strategies against Gram-positive bacteria.
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Affiliation(s)
- Kaixi Zhang
- School of Chemical and Biomedical Engineering, Nanyang Technological University, 62 Nanyang Drive, Singapore 637459.,Centre for Antimicrobial Bioengineering, Nanyang Technological University, 62 Nanyang Drive, Singapore 637459
| | - Cheerlavancha Raju
- School of Chemical and Biomedical Engineering, Nanyang Technological University, 62 Nanyang Drive, Singapore 637459.,Centre for Antimicrobial Bioengineering, Nanyang Technological University, 62 Nanyang Drive, Singapore 637459
| | - Wenbin Zhong
- School of Chemical and Biomedical Engineering, Nanyang Technological University, 62 Nanyang Drive, Singapore 637459.,Centre for Antimicrobial Bioengineering, Nanyang Technological University, 62 Nanyang Drive, Singapore 637459
| | - Kevin Pethe
- Centre for Antimicrobial Bioengineering, Nanyang Technological University, 62 Nanyang Drive, Singapore 637459.,Lee Kong Chian School of Medicine, Nanyang Technological University, 59 Nanyang Drive, Singapore 636921.,School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore 637551
| | - Angelika Gründling
- Faculty of Medicine, Department of Infectious Disease, Imperial College London, Flowers Building London, London SW7 2AZ, United Kingdom
| | - Mary B Chan-Park
- School of Chemical and Biomedical Engineering, Nanyang Technological University, 62 Nanyang Drive, Singapore 637459.,Centre for Antimicrobial Bioengineering, Nanyang Technological University, 62 Nanyang Drive, Singapore 637459.,Lee Kong Chian School of Medicine, Nanyang Technological University, 59 Nanyang Drive, Singapore 636921
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44
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Zhang R, Shebes MA, Kho K, Scaffidi SJ, Meredith TC, Yu W. Spatial regulation of protein A in Staphylococcus aureus. Mol Microbiol 2021; 116:589-605. [PMID: 33949015 DOI: 10.1111/mmi.14734] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2021] [Revised: 04/29/2021] [Accepted: 04/30/2021] [Indexed: 12/31/2022]
Abstract
Surface proteins of Staphylococcus aureus play vital roles in bacterial physiology and pathogenesis. Recent work suggests that surface proteins are spatially regulated by a YSIRK/GXXS signal peptide that promotes cross-wall targeting at the mid-cell, though the mechanisms remain unclear. We previously showed that protein A (SpA), a YSIRK/GXXS protein and key staphylococcal virulence factor, mis-localizes in a ltaS mutant deficient in lipoteichoic acid (LTA) production. Here, we identified that SpA contains another cross-wall targeting signal, the LysM domain, which, in addition to the YSIRK/GXXS signal peptide, significantly enhances SpA cross-wall targeting. We show that LTA synthesis, but not LtaS, is required for SpA septal anchoring and cross-wall deposition. Interestingly, LTA is predominantly found at the peripheral cell membrane and is diminished at the septum of dividing staphylococcal cells, suggesting a restriction mechanism for SpA septal localization. Finally, we show that D-alanylation of LTA abolishes SpA cross-wall deposition by disrupting SpA distribution in the peptidoglycan layer without altering SpA septal anchoring. Our study reveals that multiple factors contribute to the spatial regulation and cross-wall targeting of SpA via different mechanisms, which coordinately ensures efficient incorporation of surface proteins into the growing peptidoglycan during the cell cycle.
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Affiliation(s)
- Ran Zhang
- Department of Cell Biology, Microbiology and Molecular Biology (CMMB), University of South Florida, Tampa, FL, USA
| | - Mac A Shebes
- Department of Cell Biology, Microbiology and Molecular Biology (CMMB), University of South Florida, Tampa, FL, USA
| | - Kelvin Kho
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA, USA
| | - Salvatore J Scaffidi
- Department of Cell Biology, Microbiology and Molecular Biology (CMMB), University of South Florida, Tampa, FL, USA
| | - Timothy C Meredith
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA, USA
| | - Wenqi Yu
- Department of Cell Biology, Microbiology and Molecular Biology (CMMB), University of South Florida, Tampa, FL, USA
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Lade H, Kim JS. Bacterial Targets of Antibiotics in Methicillin-Resistant Staphylococcus aureus. Antibiotics (Basel) 2021; 10:398. [PMID: 33917043 PMCID: PMC8067735 DOI: 10.3390/antibiotics10040398] [Citation(s) in RCA: 34] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2021] [Revised: 04/02/2021] [Accepted: 04/05/2021] [Indexed: 12/17/2022] Open
Abstract
Methicillin-resistant Staphylococcus aureus (MRSA) is one of the most prevalent bacterial pathogens and continues to be a leading cause of morbidity and mortality worldwide. MRSA is a commensal bacterium in humans and is transmitted in both community and healthcare settings. Successful treatment remains a challenge, and a search for new targets of antibiotics is required to ensure that MRSA infections can be effectively treated in the future. Most antibiotics in clinical use selectively target one or more biochemical processes essential for S. aureus viability, e.g., cell wall synthesis, protein synthesis (translation), DNA replication, RNA synthesis (transcription), or metabolic processes, such as folic acid synthesis. In this review, we briefly describe the mechanism of action of antibiotics from different classes and discuss insights into the well-established primary targets in S. aureus. Further, several components of bacterial cellular processes, such as teichoic acid, aminoacyl-tRNA synthetases, the lipid II cycle, auxiliary factors of β-lactam resistance, two-component systems, and the accessory gene regulator quorum sensing system, are discussed as promising targets for novel antibiotics. A greater molecular understanding of the bacterial targets of antibiotics has the potential to reveal novel therapeutic strategies or identify agents against antibiotic-resistant pathogens.
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Affiliation(s)
| | - Jae-Seok Kim
- Department of Laboratory Medicine, Kangdong Sacred Heart Hospital, Hallym University College of Medicine, Seoul 05355, Korea;
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Li FKK, Gale RT, Petrotchenko EV, Borchers CH, Brown ED, Strynadka NCJ. Crystallographic analysis of TarI and TarJ, a cytidylyltransferase and reductase pair for CDP-ribitol synthesis in Staphylococcus aureus wall teichoic acid biogenesis. J Struct Biol 2021; 213:107733. [PMID: 33819634 DOI: 10.1016/j.jsb.2021.107733] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2020] [Revised: 03/29/2021] [Accepted: 03/30/2021] [Indexed: 11/18/2022]
Abstract
The cell wall of many pathogenic Gram-positive bacteria contains ribitol-phosphate wall teichoic acid (WTA), a polymer that is linked to virulence and regulation of essential physiological processes including cell division. CDP-ribitol, the activated precursor for ribitol-phosphate polymerization, is synthesized by a cytidylyltransferase and reductase pair known as TarI and TarJ, respectively. In this study, we present crystal structures of Staphylococcus aureus TarI and TarJ in their apo forms and in complex with substrates and products. The TarI structures illustrate the mechanism of CDP-ribitol synthesis from CTP and ribitol-phosphate and reveal structural changes required for substrate binding and catalysis. Insights into the upstream step of ribulose-phosphate reduction to ribitol-phosphate is provided by the structures of TarJ. Furthermore, we propose a general topology of the enzymes in a heterotetrameric form built using restraints from crosslinking mass spectrometry analysis. Together, our data present molecular details of CDP-ribitol production that may aid in the design of inhibitors against WTA biosynthesis.
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Affiliation(s)
- Franco K K Li
- Department of Biochemistry and Molecular Biology and Centre for Blood Research, The University of British Columbia, Vancouver, British Columbia V6T 1Z3, Canada
| | - Robert T Gale
- Department of Biochemistry and Biomedical Sciences, Michael G. DeGroote Institute for Infectious Disease Research, McMaster University, Hamilton, Ontario L8N 3ZS, Canada
| | - Evgeniy V Petrotchenko
- Segal Cancer Proteomics Centre, Lady Davis Institute, Jewish General Hospital, McGill University, Montreal, Quebec H3T 1E2, Canada; Center for Computational and Data-Intensive Science and Engineering, Skolkovo Institute of Science and Technology, Moscow 121205, Russia
| | - Christoph H Borchers
- Segal Cancer Proteomics Centre, Lady Davis Institute, Jewish General Hospital, McGill University, Montreal, Quebec H3T 1E2, Canada; Center for Computational and Data-Intensive Science and Engineering, Skolkovo Institute of Science and Technology, Moscow 121205, Russia; Gerald Bronfman Department of Oncology, Jewish General Hospital, McGill University, Montreal, Quebec H3T 1E2, Canada
| | - Eric D Brown
- Department of Biochemistry and Biomedical Sciences, Michael G. DeGroote Institute for Infectious Disease Research, McMaster University, Hamilton, Ontario L8N 3ZS, Canada
| | - Natalie C J Strynadka
- Department of Biochemistry and Molecular Biology and Centre for Blood Research, The University of British Columbia, Vancouver, British Columbia V6T 1Z3, Canada.
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Fisher JF, Mobashery S. β-Lactams against the Fortress of the Gram-Positive Staphylococcus aureus Bacterium. Chem Rev 2021; 121:3412-3463. [PMID: 33373523 PMCID: PMC8653850 DOI: 10.1021/acs.chemrev.0c01010] [Citation(s) in RCA: 41] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The biological diversity of the unicellular bacteria-whether assessed by shape, food, metabolism, or ecological niche-surely rivals (if not exceeds) that of the multicellular eukaryotes. The relationship between bacteria whose ecological niche is the eukaryote, and the eukaryote, is often symbiosis or stasis. Some bacteria, however, seek advantage in this relationship. One of the most successful-to the disadvantage of the eukaryote-is the small (less than 1 μm diameter) and nearly spherical Staphylococcus aureus bacterium. For decades, successful clinical control of its infection has been accomplished using β-lactam antibiotics such as the penicillins and the cephalosporins. Over these same decades S. aureus has perfected resistance mechanisms against these antibiotics, which are then countered by new generations of β-lactam structure. This review addresses the current breadth of biochemical and microbiological efforts to preserve the future of the β-lactam antibiotics through a better understanding of how S. aureus protects the enzyme targets of the β-lactams, the penicillin-binding proteins. The penicillin-binding proteins are essential enzyme catalysts for the biosynthesis of the cell wall, and understanding how this cell wall is integrated into the protective cell envelope of the bacterium may identify new antibacterials and new adjuvants that preserve the efficacy of the β-lactams.
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Affiliation(s)
- Jed F Fisher
- Department of Chemistry and Biochemistry, McCourtney Hall, University of Notre Dame, Notre Dame Indiana 46556, United States
| | - Shahriar Mobashery
- Department of Chemistry and Biochemistry, McCourtney Hall, University of Notre Dame, Notre Dame Indiana 46556, United States
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Guo Y, Pfahler NM, Völpel SL, Stehle T. Cell wall glycosylation in Staphylococcus aureus: targeting the tar glycosyltransferases. Curr Opin Struct Biol 2021; 68:166-174. [PMID: 33540375 DOI: 10.1016/j.sbi.2021.01.003] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2020] [Revised: 12/14/2020] [Accepted: 01/07/2021] [Indexed: 11/26/2022]
Abstract
Peptidoglycan (PG) is the major structural polymer of the bacterial cell wall. The PG layer of gram-positive bacterial pathogens such as Staphylococcus aureus (S. aureus) is permeated with anionic glycopolymers known as wall teichoic acids (WTAs) and lipoteichoic acids (LTAs). In S. aureus, the WTA backbone typically consists of repeating ribitol-5-phosphate units, which are modified by enzymes that introduce glycosylation as well as amino acids at different locations. These modifications are key determinants of phage adhesion, bacterial biofilm formation and virulence of S. aureus. In this review, we examine differences in WTA structures in gram-positive bacteria, focusing in particular on three enzymes, TarM, TarS, and TarP that glycosylate the WTA of S. aureus at different locations. Infections with S. aureus pose an increasing threat to human health, particularly through the emergence of multidrug-resistant strains. Recently obtained structural information on TarM, TarS and TarP has helped to better understand the strategies used by S. aureus to establish resistance and to evade host defense mechanisms. Moreover, structures of complexes with poly-RboP and its analogs can serve as a platform for the development of new inhibitors that could form a basis for the development of antibiotic agents.
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Affiliation(s)
- Yinglan Guo
- Interfaculty Institute of Biochemistry, University of Tübingen, Germany
| | - Nina M Pfahler
- Interfaculty Institute of Biochemistry, University of Tübingen, Germany
| | - Simon L Völpel
- Interfaculty Institute of Biochemistry, University of Tübingen, Germany
| | - Thilo Stehle
- Interfaculty Institute of Biochemistry, University of Tübingen, Germany; Vanderbilt University School of Medicine, Nashville, USA.
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LytR-CpsA-Psr Glycopolymer Transferases: Essential Bricks in Gram-Positive Bacterial Cell Wall Assembly. Int J Mol Sci 2021; 22:ijms22020908. [PMID: 33477538 PMCID: PMC7831098 DOI: 10.3390/ijms22020908] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2020] [Revised: 01/14/2021] [Accepted: 01/14/2021] [Indexed: 12/28/2022] Open
Abstract
The cell walls of Gram-positive bacteria contain a variety of glycopolymers (CWGPs), a significant proportion of which are covalently linked to the peptidoglycan (PGN) scaffolding structure. Prominent CWGPs include wall teichoic acids of Staphylococcus aureus, streptococcal capsules, mycobacterial arabinogalactan, and rhamnose-containing polysaccharides of lactic acid bacteria. CWGPs serve important roles in bacterial cellular functions, morphology, and virulence. Despite evident differences in composition, structure and underlaying biosynthesis pathways, the final ligation step of CWGPs to the PGN backbone involves a conserved class of enzymes-the LytR-CpsA-Psr (LCP) transferases. Typically, the enzymes are present in multiple copies displaying partly functional redundancy and/or preference for a distinct CWGP type. LCP enzymes require a lipid-phosphate-linked glycan precursor substrate and catalyse, with a certain degree of promiscuity, CWGP transfer to PGN of different maturation stages, according to in vitro evidence. The prototype attachment mode is that to the C6-OH of N-acetylmuramic acid residues via installation of a phosphodiester bond. In some cases, attachment proceeds to N-acetylglucosamine residues of PGN-in the case of the Streptococcus agalactiae capsule, even without involvement of a phosphate bond. A novel aspect of LCP enzymes concerns a predicted role in protein glycosylation in Actinomyces oris. Available crystal structures provide further insight into the catalytic mechanism of this biologically important class of enzymes, which are gaining attention as new targets for antibacterial drug discovery to counteract the emergence of multidrug resistant bacteria.
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Masters EA, de Mesy Bentley KL, Gill AL, Hao SP, Galloway CA, Salminen AT, Guy DR, McGrath JL, Awad HA, Gill SR, Schwarz EM. Identification of Penicillin Binding Protein 4 (PBP4) as a critical factor for Staphylococcus aureus bone invasion during osteomyelitis in mice. PLoS Pathog 2020; 16:e1008988. [PMID: 33091079 PMCID: PMC7608983 DOI: 10.1371/journal.ppat.1008988] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2020] [Revised: 11/03/2020] [Accepted: 09/17/2020] [Indexed: 12/03/2022] Open
Abstract
Staphylococcus aureus infection of bone is challenging to treat because it colonizes the osteocyte lacuno-canalicular network (OLCN) of cortical bone. To elucidate factors involved in OLCN invasion and identify novel drug targets, we completed a hypothesis-driven screen of 24 S. aureus transposon insertion mutant strains for their ability to propagate through 0.5 μm-sized pores in the Microfluidic Silicon Membrane Canalicular Arrays (μSiM-CA), developed to model S. aureus invasion of the OLCN. This screen identified the uncanonical S. aureus transpeptidase, penicillin binding protein 4 (PBP4), as a necessary gene for S. aureus deformation and propagation through nanopores. In vivo studies revealed that Δpbp4 infected tibiae treated with vancomycin showed a significant 12-fold reduction in bacterial load compared to WT infected tibiae treated with vancomycin (p<0.05). Additionally, Δpbp4 infected tibiae displayed a remarkable decrease in pathogenic bone-loss at the implant site with and without vancomycin therapy. Most importantly, Δpbp4 S. aureus failed to invade and colonize the OLCN despite high bacterial loads on the implant and in adjacent tissues. Together, these results demonstrate that PBP4 is required for S. aureus colonization of the OLCN and suggest that inhibitors may be synergistic with standard of care antibiotics ineffective against bacteria within the OLCN. Staphylococcus aureus is the most prevalent pathogen in osteomyelitis, and its infection of bone is difficult to cure. S. aureus colonization of the osteocyte lacuno-canalicular network (OLCN) of cortical bone has been identified as a novel pathogenetic mechanism in chronic osteomyelitis. To elucidate factors involved in OLCN invasion, we conducted an in vitro genetic screen that identified pbp4 as a critical gene for S. aureus cell deformation and propagation through nanopores and demonstrated that PBP4 is critical for OLCN colonization in murine osteomyelitis. Thus, PBP4 inhibitors may be novel drugs to treat osteomyelitis in combination with standard of care antibiotics.
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Affiliation(s)
- Elysia A. Masters
- Center for Musculoskeletal Research, University of Rochester Medical Center, Rochester, NY, United States of America
- Department of Biomedical Engineering, University of Rochester Medical Center, Rochester, NY, United States of America
| | - Karen L. de Mesy Bentley
- Center for Musculoskeletal Research, University of Rochester Medical Center, Rochester, NY, United States of America
- Department of Pathology and Laboratory Medicine, University of Rochester Medical Center, Rochester, NY, United States of America
- Department of Orthopaedics, University of Rochester Medical Center, Rochester, NY, United States of America
| | - Ann Lindley Gill
- Department of Microbiology and Immunology, University of Rochester Medical Center, Rochester, NY, United States of America
| | - Stephanie P. Hao
- Center for Musculoskeletal Research, University of Rochester Medical Center, Rochester, NY, United States of America
| | - Chad A. Galloway
- Center for Musculoskeletal Research, University of Rochester Medical Center, Rochester, NY, United States of America
- Department of Pathology and Laboratory Medicine, University of Rochester Medical Center, Rochester, NY, United States of America
| | - Alec T. Salminen
- Department of Biomedical Engineering, University of Rochester Medical Center, Rochester, NY, United States of America
| | - Diamond R. Guy
- Center for Musculoskeletal Research, University of Rochester Medical Center, Rochester, NY, United States of America
| | - James L. McGrath
- Department of Biomedical Engineering, University of Rochester Medical Center, Rochester, NY, United States of America
| | - Hani A. Awad
- Center for Musculoskeletal Research, University of Rochester Medical Center, Rochester, NY, United States of America
- Department of Biomedical Engineering, University of Rochester Medical Center, Rochester, NY, United States of America
| | - Steven R. Gill
- Department of Microbiology and Immunology, University of Rochester Medical Center, Rochester, NY, United States of America
| | - Edward M. Schwarz
- Center for Musculoskeletal Research, University of Rochester Medical Center, Rochester, NY, United States of America
- Department of Biomedical Engineering, University of Rochester Medical Center, Rochester, NY, United States of America
- Department of Orthopaedics, University of Rochester Medical Center, Rochester, NY, United States of America
- * E-mail:
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