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Choi AJ, Bennison DJ, Kulkarni E, Azar H, Sun H, Li H, Bradshaw J, Yeap HW, Lim N, Mishra V, Crespo-Puig A, Mills EA, Davies F, Sriskandan S, Shenoy AR. Aminoglycoside heteroresistance in Enterobacter cloacae is driven by the cell envelope stress response. mBio 2024; 15:e0169924. [PMID: 39475244 PMCID: PMC11633387 DOI: 10.1128/mbio.01699-24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2024] [Accepted: 10/02/2024] [Indexed: 12/12/2024] Open
Abstract
Enterobacter cloacae is a Gram-negative nosocomial pathogen of the ESKAPE (Enterococcus, Staphylococcus, Klebsiella, Acinetobacter, Pseudomonas, and Enterobacter spp.) priority group with increasing multi-drug resistance via the acquisition of resistance plasmids. However, E. cloacae can also display forms of antibiotic refractoriness, such as heteroresistance and tolerance. Here, we report that E. cloacae displays transient heteroresistance to aminoglycosides, which is accompanied with the formation of small colony variants (SCVs) with increased minimum inhibitor concentration (MIC) of gentamicin and other aminoglycosides used in the clinic, but not other antibiotic classes. To explore the underlying mechanisms, we performed RNA sequencing of heteroresistant bacteria, which revealed global gene expression changes and a signature of the CpxRA cell envelope stress response. Deletion of the cpxRA two-component system abrogated aminoglycoside heteroresistance and SCV formation, pointing to its indispensable role in these processes. The introduction of a constitutively active allele of cpxA led to high aminoglycoside MICs, consistent with cell envelope stress response driving these behaviors in E. cloacae. Cell envelope stress can be caused by environmental cues, including heavy metals. Indeed, bacterial exposure to copper increased gentamicin MIC in the wild-type but not in the ΔcpxRA mutant. Moreover, copper exposure also elevated the gentamicin MICs of clinical isolates from bloodstream infections, suggesting that CpxRA- and copper-dependent aminoglycoside resistance is broadly conserved in E. cloacae strains. Altogether, we establish that E. cloacae relies on transcriptional reprogramming via the envelope stress response pathway for transient resistance to a major class of frontline antibiotic.IMPORTANCEEnterobacter cloacae is a bacterium that belongs to the WHO high-priority group and an increasing threat worldwide due its multi-drug resistance. E. cloacae can also display heteroresistance, which has been linked to treatment failure. We report that E. cloacae shows heteroresistance to aminoglycoside antibiotics. These are important frontline microbicidal drugs used against Gram-negative bacterial infections; therefore, understanding how resistance develops among sensitive strains is important. We show that aminoglycoside resistance is driven by the activation of the cell envelope stress response and transcriptional reprogramming via the CpxRA two-component system. Furthermore, heterologous activation of envelope stress via copper, typically a heavy metal with antimicrobial actions, also increased aminoglycoside MICs of the E. cloacae type strain and clinical strains isolated from bloodstream infections. Our study suggests aminoglycoside recalcitrance in E. cloacae could be broadly conserved and cautions against the undesirable effects of copper.
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Affiliation(s)
- Ana J. Choi
- Department of Infectious Disease, Imperial College London, London, United Kingdom
- Centre for Bacterial Resistance Biology, Imperial College London, London, United Kingdom
| | - Daniel J. Bennison
- Department of Infectious Disease, Imperial College London, London, United Kingdom
- Centre for Bacterial Resistance Biology, Imperial College London, London, United Kingdom
| | - Esha Kulkarni
- Department of Infectious Disease, Imperial College London, London, United Kingdom
- Centre for Bacterial Resistance Biology, Imperial College London, London, United Kingdom
| | - Hibah Azar
- Department of Infectious Disease, Imperial College London, London, United Kingdom
- Centre for Bacterial Resistance Biology, Imperial College London, London, United Kingdom
| | - Haoyu Sun
- Department of Infectious Disease, Imperial College London, London, United Kingdom
- Centre for Bacterial Resistance Biology, Imperial College London, London, United Kingdom
| | - Hanqi Li
- Department of Infectious Disease, Imperial College London, London, United Kingdom
- Centre for Bacterial Resistance Biology, Imperial College London, London, United Kingdom
| | - Jonathan Bradshaw
- Department of Infectious Disease, Imperial College London, London, United Kingdom
- Centre for Bacterial Resistance Biology, Imperial College London, London, United Kingdom
| | - Hui Wen Yeap
- Department of Infectious Disease, Imperial College London, London, United Kingdom
- Centre for Bacterial Resistance Biology, Imperial College London, London, United Kingdom
| | - Nicholas Lim
- Department of Infectious Disease, Imperial College London, London, United Kingdom
- Centre for Bacterial Resistance Biology, Imperial College London, London, United Kingdom
| | - Vishwas Mishra
- Department of Infectious Disease, Imperial College London, London, United Kingdom
- Centre for Bacterial Resistance Biology, Imperial College London, London, United Kingdom
| | - Anna Crespo-Puig
- Department of Infectious Disease, Imperial College London, London, United Kingdom
- Centre for Bacterial Resistance Biology, Imperial College London, London, United Kingdom
| | - Ewurabena A. Mills
- NIHR Health Protection Research Unit in Healthcare Associated Infections and Antimicrobial Resistance, Imperial College London, London, United Kingdom
| | - Frances Davies
- NIHR Health Protection Research Unit in Healthcare Associated Infections and Antimicrobial Resistance, Imperial College London, London, United Kingdom
| | - Shiranee Sriskandan
- Department of Infectious Disease, Imperial College London, London, United Kingdom
- Centre for Bacterial Resistance Biology, Imperial College London, London, United Kingdom
- NIHR Health Protection Research Unit in Healthcare Associated Infections and Antimicrobial Resistance, Imperial College London, London, United Kingdom
| | - Avinash R. Shenoy
- Department of Infectious Disease, Imperial College London, London, United Kingdom
- Centre for Bacterial Resistance Biology, Imperial College London, London, United Kingdom
- The Francis Crick Institute, London, United Kingdom
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2
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Benjamin SV, Jégouzo SAF, Lieng C, Daniels C, Coispeau M, Lau RJ, Kim S, Metaxa Y, Philpott J, Li T, Dai C, Wang X, Newby ML, Pier GB, Crispin M, Clements A, Taylor ME, Drickamer K. A human lectin array for characterizing host-pathogen interactions. J Biol Chem 2024; 300:107869. [PMID: 39384043 PMCID: PMC11566865 DOI: 10.1016/j.jbc.2024.107869] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2024] [Revised: 09/21/2024] [Accepted: 10/01/2024] [Indexed: 10/11/2024] Open
Abstract
A human lectin array has been developed to probe the interactions of innate immune receptors with pathogenic and commensal microorganisms. Following the successful introduction of a lectin array containing all of the cow C-type carbohydrate-recognition domains (CRDs), a human array described here contains the C-type CRDs as well as CRDs from other classes of sugar-binding receptors, including galectins, siglecs, R-type CRDs, ficolins, intelectins, and chitinase-like lectins. The array is constructed with CRDs modified with single-site biotin tags, ensuring that the sugar-binding sites in CRDs are displayed on a streptavidin-coated surface in a defined orientation and are accessible to the surfaces of microbes. A common approach used for expression and display of CRDs from all of the different structural categories of glycan-binding receptors allows comparisons across lectin families. In addition to previously documented protocols for binding of fluorescently labeled bacteria, methods have been developed for detecting unlabeled bacteria bound to the array by counter-staining with DNA-binding dye. Screening has also been undertaken with viral glycoproteins and bacterial and fungal polysaccharides. The array provides an unbiased screen for sugar ligands that interact with receptors and many show binding not anticipated from earlier studies. For example, some of the galectins bind with high affinity to bacterial glycans that lack lactose or N-acetyllactosamine. The results demonstrate the utility of the human lectin array for providing a unique overview of the interactions of multiple classes of glycan-binding proteins in the innate immune system with different types of microorganisms.
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Affiliation(s)
- Stefi V Benjamin
- Department of Life Sciences, Imperial College London, London, United Kingdom
| | - Sabine A F Jégouzo
- Department of Life Sciences, Imperial College London, London, United Kingdom
| | - Chloe Lieng
- Department of Life Sciences, Imperial College London, London, United Kingdom
| | - Connor Daniels
- Department of Life Sciences, Imperial College London, London, United Kingdom
| | - Marine Coispeau
- Department of Life Sciences, Imperial College London, London, United Kingdom
| | - Rikin J Lau
- Department of Life Sciences, Imperial College London, London, United Kingdom
| | - Suyeon Kim
- Department of Life Sciences, Imperial College London, London, United Kingdom
| | - Yasmine Metaxa
- Department of Life Sciences, Imperial College London, London, United Kingdom
| | - James Philpott
- Department of Life Sciences, Imperial College London, London, United Kingdom
| | - Tiannuo Li
- Department of Life Sciences, Imperial College London, London, United Kingdom
| | - Chao Dai
- Department of Life Sciences, Imperial College London, London, United Kingdom
| | - Xin Wang
- Department of Life Sciences, Imperial College London, London, United Kingdom
| | - Maddy L Newby
- School of Biological Sciences, University of Southampton, United Kingdom
| | - Gerald B Pier
- Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | - Max Crispin
- School of Biological Sciences, University of Southampton, United Kingdom
| | - Abigail Clements
- Department of Life Sciences, Imperial College London, London, United Kingdom
| | - Maureen E Taylor
- Department of Life Sciences, Imperial College London, London, United Kingdom
| | - Kurt Drickamer
- Department of Life Sciences, Imperial College London, London, United Kingdom.
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3
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van der Lans SPA, Bardoel BW, Ruyken M, de Haas CJC, Baijens S, Muts RM, Scheepmaker LM, Aerts PC, van 't Wout MFL, Preiner J, Marijnissen RJ, Schuurman J, Beurskens FJ, Kerkman PF, Rooijakkers SHM. Agnostic B cell selection approach identifies antibodies against K. pneumoniae that synergistically drive complement activation. Nat Commun 2024; 15:8100. [PMID: 39285158 PMCID: PMC11405761 DOI: 10.1038/s41467-024-52372-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2024] [Accepted: 09/02/2024] [Indexed: 09/22/2024] Open
Abstract
Antibody-dependent complement activation plays a key role in the natural human immune response to infections. Currently, the understanding of which antibody-antigen combinations drive a potent complement response on bacteria is limited. Here, we develop an antigen-agnostic approach to stain and single-cell sort human IgG memory B cells recognizing intact bacterial cells, keeping surface antigens in their natural context. With this method we successfully identified 29 antibodies against K. pneumoniae, a dominant cause of hospital-acquired infections with increasing antibiotic resistance. Combining genetic tools and functional analyses, we reveal that the capacity of antibodies to activate complement on K. pneumoniae critically depends on their antigenic target. Furthermore, we find that antibody combinations can synergistically activate complement on K. pneumoniae by strengthening each other's binding in an Fc-independent manner. Understanding the molecular basis of effective complement activation by antibody combinations to mimic a polyclonal response could accelerate the development of antibody-based therapies against problematic infections.
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Affiliation(s)
- Sjors P A van der Lans
- Medical Microbiology, University Medical Center Utrecht, Utrecht University, Utrecht, The Netherlands
| | - Bart W Bardoel
- Medical Microbiology, University Medical Center Utrecht, Utrecht University, Utrecht, The Netherlands
| | - Maartje Ruyken
- Medical Microbiology, University Medical Center Utrecht, Utrecht University, Utrecht, The Netherlands
| | - Carla J C de Haas
- Medical Microbiology, University Medical Center Utrecht, Utrecht University, Utrecht, The Netherlands
| | - Stan Baijens
- Medical Microbiology, University Medical Center Utrecht, Utrecht University, Utrecht, The Netherlands
| | - Remy M Muts
- Medical Microbiology, University Medical Center Utrecht, Utrecht University, Utrecht, The Netherlands
| | - Lisette M Scheepmaker
- Medical Microbiology, University Medical Center Utrecht, Utrecht University, Utrecht, The Netherlands
| | - Piet C Aerts
- Medical Microbiology, University Medical Center Utrecht, Utrecht University, Utrecht, The Netherlands
| | - Marije F L van 't Wout
- Medical Microbiology, University Medical Center Utrecht, Utrecht University, Utrecht, The Netherlands
| | | | | | | | | | - Priscilla F Kerkman
- Medical Microbiology, University Medical Center Utrecht, Utrecht University, Utrecht, The Netherlands
| | - Suzan H M Rooijakkers
- Medical Microbiology, University Medical Center Utrecht, Utrecht University, Utrecht, The Netherlands.
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4
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Wong BC, Law SKK, Md Zoqratt MZH, Ayub Q, Tan HS. Adaptation of a fluoroquinolone-sensitive Shigella sonnei to norfloxacin exposure. ROYAL SOCIETY OPEN SCIENCE 2024; 11:232025. [PMID: 39100177 PMCID: PMC11296047 DOI: 10.1098/rsos.232025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/29/2023] [Revised: 02/21/2024] [Accepted: 05/10/2024] [Indexed: 08/06/2024]
Abstract
Shigella causes shigellosis that requires antibiotic treatment in severe cases. Sublethal antibiotic concentrations can promote resistance, but their effect on antibiotic-sensitive bacteria before resistance development is unclear. This study investigated the effects of sublethal norfloxacin (NOR) challenges on a NOR-sensitive strain, Shigella sonnei UKMCC1015. Firstly, the whole genome of S. sonnei UKMCC1015 was assembled, and 45 antimicrobial resistance (AMR) genes were identified. Interestingly, transcriptomic analysis showed that low NOR levels do not change either the expression of the AMR genes or NOR targets such as gyrA. Instead, multiple ribosomal protein genes were downregulated, which could be attributed to decreased ribosomal protein promoter activity, modulated by elevated guanosine pentaphosphate and tetraphosphate (ppGpp) levels. This alarmone is involved in the bacterial stringent response during environmental stress, and it is mainly produced from the ppGpp synthetase (relA). Additionally, we observed that a relA overexpression (prolonged period of elevated ppGpp levels) may negatively affect the NOR tolerance of the bacteria. In conclusion, this study revealed that a NOR-sensitive strain responds differently to sublethal NOR than commonly reported in resistant strains.
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Affiliation(s)
- Bao Chi Wong
- School of Science, Monash University Malaysia, 47500 Bandar Sunway, Selangor Darul Ehsan, Malaysia
| | - Soffi Kei Kei Law
- School of Science, Monash University Malaysia, 47500 Bandar Sunway, Selangor Darul Ehsan, Malaysia
| | - Muhammad Zarul Hanifah Md Zoqratt
- School of Science, Monash University Malaysia, 47500 Bandar Sunway, Selangor Darul Ehsan, Malaysia
- Monash University Malaysia Genomics Platform, 47500 Bandar Sunway, Selangor Darul Ehsan, Malaysia
| | - Qasim Ayub
- School of Science, Monash University Malaysia, 47500 Bandar Sunway, Selangor Darul Ehsan, Malaysia
- Monash University Malaysia Genomics Platform, 47500 Bandar Sunway, Selangor Darul Ehsan, Malaysia
| | - Hock Siew Tan
- School of Science, Monash University Malaysia, 47500 Bandar Sunway, Selangor Darul Ehsan, Malaysia
- Tropical Medicine and Biology Multidisciplinary Platform, 47500 Bandar Sunway, Selangor Darul Ehsan, Malaysia
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5
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Leung PB, Matanza XM, Roche B, Ha KP, Cheung HC, Appleyard S, Collins T, Flanagan O, Marteyn BS, Clements A. Shigella sonnei utilises colicins during inter-bacterial competition. MICROBIOLOGY (READING, ENGLAND) 2024; 170:001434. [PMID: 38376387 PMCID: PMC10924462 DOI: 10.1099/mic.0.001434] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/11/2023] [Accepted: 01/25/2024] [Indexed: 02/21/2024]
Abstract
The mammalian colon is one of the most densely populated habitats currently recognised, with 1011-1013 commensal bacteria per gram of colonic contents. Enteric pathogens must compete with the resident intestinal microbiota to cause infection. Among these enteric pathogens are Shigella species which cause approximately 125 million infections annually, of which over 90 % are caused by Shigella flexneri and Shigella sonnei. Shigella sonnei was previously reported to use a Type VI Secretion System (T6SS) to outcompete E. coli and S. flexneri in in vitro and in vivo experiments. S. sonnei strains have also been reported to harbour colicinogenic plasmids, which are an alternative anti-bacterial mechanism that could provide a competitive advantage against the intestinal microbiota. We sought to determine the contribution of both T6SS and colicins to the anti-bacterial killing activity of S. sonnei. We reveal that whilst the T6SS operon is present in S. sonnei, there is evidence of functional degradation of the system through SNPs, indels and IS within key components of the system. We created strains with synthetically inducible T6SS operons but were still unable to demonstrate anti-bacterial activity of the T6SS. We demonstrate that the anti-bacterial activity observed in our in vitro assays was due to colicin activity. We show that S. sonnei no longer displayed anti-bacterial activity against bacteria that were resistant to colicins, and removal of the colicin plasmid from S. sonnei abrogated anti-bacterial activity of S. sonnei. We propose that the anti-bacterial activity demonstrated by colicins may be sufficient for niche competition by S. sonnei within the gastrointestinal environment.
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Affiliation(s)
- P. B. Leung
- Department of Life Sciences, South Kensington Campus, Imperial College London, London, SW72AZ, UK
| | - X. M. Matanza
- Department of Life Sciences, South Kensington Campus, Imperial College London, London, SW72AZ, UK
| | - B. Roche
- Universite de Strasbourg, Institut de Biologie Moléculaire et Cellulaire, CNRS UPR9002, F-67000 Strasbourg, France
| | - K. P. Ha
- Department of Life Sciences, South Kensington Campus, Imperial College London, London, SW72AZ, UK
| | - H. C. Cheung
- Department of Life Sciences, South Kensington Campus, Imperial College London, London, SW72AZ, UK
| | - S. Appleyard
- Department of Life Sciences, South Kensington Campus, Imperial College London, London, SW72AZ, UK
| | - T. Collins
- Department of Life Sciences, South Kensington Campus, Imperial College London, London, SW72AZ, UK
| | - O. Flanagan
- Department of Life Sciences, South Kensington Campus, Imperial College London, London, SW72AZ, UK
| | - B. S. Marteyn
- Universite de Strasbourg, Institut de Biologie Moléculaire et Cellulaire, CNRS UPR9002, F-67000 Strasbourg, France
- University of Strasbourg Institute for Advanced Study (USIAS), F-67000 Strasbourg, France
- Institut Pasteur, Université de Paris, Inserm U1225, Unité de Pathogenèse des Infections Vasculaires, F-75015 Paris, France
| | - A. Clements
- Department of Life Sciences, South Kensington Campus, Imperial College London, London, SW72AZ, UK
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6
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Randall JR, Groover KE, O'Donnell AC, Garza JM, Cole TJ, Davies BW. Adapting antibacterial display to identify serum-active macrocyclic peptide antibiotics. PNAS NEXUS 2023; 2:pgad270. [PMID: 37637199 PMCID: PMC10449418 DOI: 10.1093/pnasnexus/pgad270] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/30/2023] [Accepted: 08/09/2023] [Indexed: 08/29/2023]
Abstract
The lack of available treatments for many antimicrobial-resistant infections highlights the critical need for antibiotic discovery innovation. Peptides are an underappreciated antibiotic scaffold because they often suffer from proteolytic instability and toxicity toward human cells, making in vivo use challenging. To investigate sequence factors related to serum activity, we adapt an antibacterial display technology to screen a library of peptide macrocycles for antibacterial potential directly in human serum. We identify dozens of new macrocyclic peptide antibiotic sequences and find that serum activity within our library is influenced by peptide length, cationic charge, and the number of disulfide bonds present. Interestingly, an optimized version of our most active lead peptide permeates the outer membrane of Gram-negative bacteria without strong inner-membrane disruption and kills bacteria slowly while causing cell elongation. This contrasts with traditional cationic antimicrobial peptides, which kill rapidly via lysis of both bacterial membranes. Notably, this optimized variant is not toxic to mammalian cells and retains its function in vivo, suggesting therapeutic promise. Our results support the use of more physiologically relevant conditions when screening peptides for antimicrobial activity which retain in vivo functionality.
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Affiliation(s)
- Justin R Randall
- Department of Molecular Biosciences, University of Texas at Austin, Austin, TX 78712, USA
| | - Kyra E Groover
- Department of Molecular Biosciences, University of Texas at Austin, Austin, TX 78712, USA
| | - Angela C O'Donnell
- Department of Molecular Biosciences, University of Texas at Austin, Austin, TX 78712, USA
| | - Joseph M Garza
- Department of Molecular Biosciences, University of Texas at Austin, Austin, TX 78712, USA
| | - T Jeffrey Cole
- Department of Molecular Biosciences, University of Texas at Austin, Austin, TX 78712, USA
| | - Bryan W Davies
- Department of Molecular Biosciences, University of Texas at Austin, Austin, TX 78712, USA
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7
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Randall JR, Groover KE, O’Donnell AC, Garza JM, Cole TJ, Davies BW. Adapting antibacterial display to identify serum active macrocyclic peptide antibiotics. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.07.28.550711. [PMID: 37546850 PMCID: PMC10402130 DOI: 10.1101/2023.07.28.550711] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/08/2023]
Abstract
The lack of available treatments for many antimicrobial resistant infections highlights the critical need for antibiotic discovery innovation. Peptides are an underappreciated antibiotic scaffold because they often suffer from proteolytic instability and toxicity towards human cells, making in vivo use challenging. To investigate sequence factors related to serum activity, we adapt an antibacterial display technology to screen a library of peptide macrocycles for antibacterial potential directly in human serum. We identify dozens of new macrocyclic peptide antibiotic sequences and find that serum activity within our library is influenced by peptide length, cationic charge, and the number of disulfide bonds present. Interestingly, an optimized version of our most active lead peptide permeates the outer membrane of gram-negative bacteria without strong inner membrane disruption and kills bacteria slowly while causing cell elongation. This contrasts with traditional cationic antimicrobial peptides, which kill rapidly via lysis of both bacterial membranes. Notably, this optimized variant is not toxic to mammalian cells and retains its function in vivo , suggesting therapeutic promise. Our results support the use of more physiologically relevant conditions when screening peptides for antimicrobial activity which retain in vivo functionality. Significance Traditional methods of natural antibiotic discovery are low throughput and cannot keep pace with the development of antimicrobial resistance. Synthetic peptide display technologies offer a high-throughput means of screening drug candidates, but rarely consider functionality beyond simple target binding and do not consider retention of function in vivo . Here, we adapt a function-based, antibacterial display technology to screen a large library of peptide macrocycles directly for bacterial growth inhibition in human serum. This screen identifies an optimized non-toxic macrocyclic peptide antibiotic retaining in vivo function, suggesting this advancement could increase clinical antibiotic discovery efficiency.
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Affiliation(s)
- Justin R. Randall
- Department of Molecular Biosciences, University of Texas at Austin, Austin, Texas 78712
| | - Kyra E. Groover
- Department of Molecular Biosciences, University of Texas at Austin, Austin, Texas 78712
| | - Angela C. O’Donnell
- Department of Molecular Biosciences, University of Texas at Austin, Austin, Texas 78712
| | - Joseph M. Garza
- Department of Molecular Biosciences, University of Texas at Austin, Austin, Texas 78712
| | - T. Jeffrey Cole
- Department of Molecular Biosciences, University of Texas at Austin, Austin, Texas 78712
| | - Bryan W. Davies
- Department of Molecular Biosciences, University of Texas at Austin, Austin, Texas 78712
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8
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Boero E, Gorham RD, Francis EA, Brand J, Teng LH, Doorduijn DJ, Ruyken M, Muts RM, Lehmann C, Verschoor A, van Kessel KPM, Heinrich V, Rooijakkers SHM. Purified complement C3b triggers phagocytosis and activation of human neutrophils via complement receptor 1. Sci Rep 2023; 13:274. [PMID: 36609665 PMCID: PMC9822988 DOI: 10.1038/s41598-022-27279-4] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2022] [Accepted: 12/29/2022] [Indexed: 01/07/2023] Open
Abstract
The complement system provides vital immune protection against infectious agents by labeling them with complement fragments that enhance phagocytosis by immune cells. Many details of complement-mediated phagocytosis remain elusive, partly because it is difficult to study the role of individual complement proteins on target surfaces. Here, we employ serum-free methods to couple purified complement C3b onto E. coli bacteria and beads and then expose human neutrophils to these C3b-coated targets. We examine the neutrophil response using a combination of flow cytometry, confocal microscopy, luminometry, single-live-cell/single-target manipulation, and dynamic analysis of neutrophil spreading on opsonin-coated surfaces. We show that purified C3b can potently trigger phagocytosis and killing of bacterial cells via Complement receptor 1. Comparison of neutrophil phagocytosis of C3b- versus antibody-coated beads with single-bead/single-target analysis exposes a similar cell morphology during engulfment. However, bulk phagocytosis assays of C3b-beads combined with DNA-based quenching reveal that these are poorly internalized compared to their IgG1 counterparts. Similarly, neutrophils spread slower on C3b-coated compared to IgG-coated surfaces. These observations support the requirement of multiple stimulations for efficient C3b-mediated uptake. Together, our results establish the existence of a direct pathway of phagocytic uptake of C3b-coated targets and present methodologies to study this process.
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Affiliation(s)
- Elena Boero
- grid.5477.10000000120346234Department of Medical Microbiology, University Medical Center Utrecht, Utrecht University, Heidelberglaan 100, 3584 CX Utrecht, The Netherlands ,grid.425088.3GSK, 53100 Siena, Italy
| | - Ronald D. Gorham
- grid.5477.10000000120346234Department of Medical Microbiology, University Medical Center Utrecht, Utrecht University, Heidelberglaan 100, 3584 CX Utrecht, The Netherlands ,grid.417555.70000 0000 8814 392XSanofi, Waltham, MA 02451 USA
| | - Emmet A. Francis
- grid.27860.3b0000 0004 1936 9684Department of Biomedical Engineering, University of California Davis, Davis, CA 95616 USA
| | - Jonathan Brand
- grid.27860.3b0000 0004 1936 9684Department of Biomedical Engineering, University of California Davis, Davis, CA 95616 USA
| | - Lay Heng Teng
- grid.27860.3b0000 0004 1936 9684Department of Biomedical Engineering, University of California Davis, Davis, CA 95616 USA
| | - Dennis J. Doorduijn
- grid.5477.10000000120346234Department of Medical Microbiology, University Medical Center Utrecht, Utrecht University, Heidelberglaan 100, 3584 CX Utrecht, The Netherlands
| | - Maartje Ruyken
- grid.5477.10000000120346234Department of Medical Microbiology, University Medical Center Utrecht, Utrecht University, Heidelberglaan 100, 3584 CX Utrecht, The Netherlands
| | - Remy M. Muts
- grid.5477.10000000120346234Department of Medical Microbiology, University Medical Center Utrecht, Utrecht University, Heidelberglaan 100, 3584 CX Utrecht, The Netherlands
| | - Christian Lehmann
- grid.5330.50000 0001 2107 3311Laboratory of Dendritic Cell Biology, Department of Dermatology, University Hospital of Erlangen, Friedrich-Alexander-Universität (FAU) Erlangen-Nürnberg, 91052 Erlangen, Germany
| | - Admar Verschoor
- grid.15474.330000 0004 0477 2438Department of Otorhinolaryngology, Technische Universität München and Klinikum Rechts der Isar, 81675 Munich, Germany
| | - Kok P. M. van Kessel
- grid.5477.10000000120346234Department of Medical Microbiology, University Medical Center Utrecht, Utrecht University, Heidelberglaan 100, 3584 CX Utrecht, The Netherlands
| | - Volkmar Heinrich
- grid.27860.3b0000 0004 1936 9684Department of Biomedical Engineering, University of California Davis, Davis, CA 95616 USA
| | - Suzan H. M. Rooijakkers
- grid.5477.10000000120346234Department of Medical Microbiology, University Medical Center Utrecht, Utrecht University, Heidelberglaan 100, 3584 CX Utrecht, The Netherlands
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9
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Prashar A, Gimenez MC, Moussaoui S, Khan IS, Terebiznik MR. Filamentous Bacteria as Targets to Study Phagocytosis. Methods Mol Biol 2023; 2692:91-107. [PMID: 37365463 DOI: 10.1007/978-1-0716-3338-0_7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/28/2023]
Abstract
Filamentous targets are internalized via phagocytic cups that last for several minutes before closing to form a phagosome. This characteristic offers the possibility to study key events in phagocytosis with greater spatial and temporal resolution than is possible to achieve using spherical particles, for which the transition from a phagocytic cup to an enclosed phagosome occurs within a few seconds after particle attachment. In this chapter, we provide methodologies to prepare filamentous bacteria and describe how they can be used as targets to study different aspects of phagocytosis.
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Affiliation(s)
- Akriti Prashar
- Program in Cell Biology, Peter Gilgan Centre of Research and Learning, The Hospital for Sick Children, Toronto, ON, Canada
| | - Maria Cecilia Gimenez
- Department of Biological Sciences, University of Toronto at Scarborough, Toronto, ON, Canada
| | - Serene Moussaoui
- Department of Biological Sciences, University of Toronto at Scarborough, Toronto, ON, Canada
- Department of Cell and Systems Biology, University of Toronto, Toronto, ON, Canada
| | - Iram Sobia Khan
- Department of Biological Sciences, University of Toronto at Scarborough, Toronto, ON, Canada
- Department of Cell and Systems Biology, University of Toronto, Toronto, ON, Canada
| | - Mauricio R Terebiznik
- Department of Biological Sciences, University of Toronto at Scarborough, Toronto, ON, Canada.
- Department of Cell and Systems Biology, University of Toronto, Toronto, ON, Canada.
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10
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Furniss RCD, Kaderabkova N, Barker D, Bernal P, Maslova E, Antwi AA, McNeil HE, Pugh HL, Dortet L, Blair JM, Larrouy-Maumus GJ, McCarthy RR, Gonzalez D, Mavridou DA. Breaking antimicrobial resistance by disrupting extracytoplasmic protein folding. eLife 2022; 11:57974. [PMID: 35025730 PMCID: PMC8863373 DOI: 10.7554/elife.57974] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2020] [Accepted: 01/11/2022] [Indexed: 11/24/2022] Open
Abstract
Antimicrobial resistance in Gram-negative bacteria is one of the greatest threats to global health. New antibacterial strategies are urgently needed, and the development of antibiotic adjuvants that either neutralize resistance proteins or compromise the integrity of the cell envelope is of ever-growing interest. Most available adjuvants are only effective against specific resistance proteins. Here, we demonstrate that disruption of cell envelope protein homeostasis simultaneously compromises several classes of resistance determinants. In particular, we find that impairing DsbA-mediated disulfide bond formation incapacitates diverse β-lactamases and destabilizes mobile colistin resistance enzymes. Furthermore, we show that chemical inhibition of DsbA sensitizes multidrug-resistant clinical isolates to existing antibiotics and that the absence of DsbA, in combination with antibiotic treatment, substantially increases the survival of Galleria mellonella larvae infected with multidrug-resistant Pseudomonas aeruginosa. This work lays the foundation for the development of novel antibiotic adjuvants that function as broad-acting resistance breakers. Antibiotics, like penicillin, are the foundation of modern medicine, but bacteria are evolving to resist their effects. Some of the most harmful pathogens belong to a group called the 'Gram-negative bacteria', which have an outer layer – called the cell envelope – that acts as a drug barrier. This envelope contains antibiotic resistance proteins that can deactivate or repel antibiotics or even pump them out of the cell once they get in. One way to tackle antibiotic resistance could be to stop these proteins from working. Proteins are long chains of building blocks called amino acids that fold into specific shapes. In order for a protein to perform its role correctly, it must fold in the right way. In bacteria, a protein called DsbA helps other proteins fold correctly by holding them in place and inserting links called disulfide bonds. It was unclear whether DsbA plays a role in the folding of antibiotic resistance proteins, but if it did, it might open up new ways to treat antibiotic resistant infections. To find out more, Furniss, Kaderabkova et al. collected the genes that code for several antibiotic resistance proteins and put them into Escherichia coli bacteria, which made the bacteria resistant to antibiotics. Furniss, Kaderabkova et al. then stopped the modified E. coli from making DsbA, which led to the antibiotic resistance proteins becoming unstable and breaking down because they could not fold correctly. Further experiments showed that blocking DsbA with a chemical inhibitor in other pathogenic species of Gram-negative bacteria made these bacteria more sensitive to antibiotics that they would normally resist. To demonstrate that using this approach could work to stop infections by these bacteria, Furniss, Kaderabkova et al. used Gram-negative bacteria that produced antibiotic resistance proteins but could not make DsbA to infect insect larvae. The larvae were then treated with antibiotics, which increased their survival rate, indicating that blocking DsbA may be a good approach to tackling antibiotic resistant bacteria. According to the World Health Organization, developing new treatments against Gram-negative bacteria is of critical importance, but the discovery of new drugs has ground to a halt. One way around this is to develop ways to make existing drugs work better. Making drugs that block DsbA could offer a way to treat resistant infections using existing antibiotics in the future.
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Affiliation(s)
| | - Nikol Kaderabkova
- Department of Molecular Biosciences, The University of Texas at Austin, Austin, United States
| | - Declan Barker
- Department of Life Sciences, Imperial College London, London, United Kingdom
| | - Patricia Bernal
- Department of Microbiology, Universidad de Sevilla, Seville, Spain
| | - Evgenia Maslova
- Department of Life Sciences, Brunel University London, London, United Kingdom
| | - Amanda Aa Antwi
- Department of Life Sciences, Imperial College London, London, United Kingdom
| | - Helen E McNeil
- Institute of Microbiology and Infection, University of Birmingham, Birmingham, United Kingdom
| | - Hannah L Pugh
- Institute of Microbiology and Infection, University of Birmingham, Birmingham, United Kingdom
| | - Laurent Dortet
- Department of Bacteriology-Hygiene, Paris-Sud University, Paris, France
| | - Jessica Ma Blair
- Institute of Microbiology and Infection, University of Birmingham, Birmingham, United Kingdom
| | | | - Ronan R McCarthy
- Department of Life Sciences, Brunel University London, London, United Kingdom
| | - Diego Gonzalez
- Department of Biology, University of Neuchatel, Neuchatel, Switzerland
| | - Despoina Ai Mavridou
- Department of Molecular Biosciences, The University of Texas at Austin, Austin, United States
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11
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Akinsola RO, Adewoyin M, Lee CW, Sim EUH, Narayanan K. RFP-based method for real-time tracking of invasive bacteria in a heterogeneous population of cells. Anal Biochem 2021; 634:114432. [PMID: 34695391 DOI: 10.1016/j.ab.2021.114432] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2021] [Revised: 09/02/2021] [Accepted: 10/19/2021] [Indexed: 10/20/2022]
Abstract
Quantification of bacterial invasion into eukaryotic cells is a prerequisite to unfold the molecular mechanisms of this vector's function to obtain insights for improving its efficiency. Invasion is traditionally quantified by antibiotic protection assays that require dilution plating and counting of colony-forming units rescued from infected cells. However, to differentiate between attached and internalized bacteria vector, this assay requires supplementation by a time-consuming and tedious immunofluorescence staining, making it laborious and reduces its reliability and reproducibility. Here we describe a new red fluorescent protein (RFP)-based high-throughput and inexpensive method for tracking bacterial adherence and internalization through flow cytometry to provide a convenient and real-time quantification of bacterial invasiveness in a heterogeneous population of cells. We invaded MCF-7, A549, and HEK-293 cells with the E. coli vector and measured RFP using imaging flow cytometry. We found high cellular infection of up to 70.47% in MCF-7 compared to 27.4% and 26.2% in A549 and HEK-293 cells, respectively. The quantitative evaluation of internalized E. coli is rapid and cell-dependent, and it distinctively differentiates between attached and cytosolic bacteria while showing the degree of cellular invasiveness. This imaging flow cytometry approach can be applied broadly to study host-bacteria interaction.
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Affiliation(s)
- Rasaq Olajide Akinsola
- School of Science, Monash University Malaysia, Bandar Sunway 47500, Selangor Darul Ehsan, Malaysia
| | - Malik Adewoyin
- Faculty of Dentistry, Universiti Kebangsaan Malaysia Jalan Muda Abdul Aziz, 50300, Kuala Lumpur, Malaysia
| | - Choon-Weng Lee
- Institute of Biological Sciences, University of Malaya, 50603, Kuala Lumpur, Malaysia
| | - Edmund Ui-Hang Sim
- Faculty of Resource Science and Technology, Universiti Malaysia Sarawak, 94300, Sarawak, Malaysia
| | - Kumaran Narayanan
- School of Science, Monash University Malaysia, Bandar Sunway 47500, Selangor Darul Ehsan, Malaysia.
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12
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Abstract
The gut microbiota plays a crucial role in susceptibility to enteric pathogens, including Citrobacter rodentium, a model extracellular mouse pathogen that colonizes the colonic mucosa. C. rodentium infection outcomes vary between mouse strains, with C57BL/6 and C3H/HeN mice clearing and succumbing to the infection, respectively. Kanamycin (Kan) treatment at the peak of C57BL/6 mouse infection with Kan-resistant C. rodentium resulted in relocalization of the pathogen from the colonic mucosa and cecum to solely the cecal luminal contents; cessation of the Kan treatment resulted in rapid clearance of the pathogen. We now show that in C3H/HeN mice, following Kan-induced displacement of C. rodentium to the cecum, the pathogen stably colonizes the cecal lumens of 65% of the mice in the absence of continued antibiotic treatment, a phenomenon that we term antibiotic-induced bacterial commensalization (AIBC). AIBC C. rodentium was well tolerated by the host, which showed few signs of inflammation; passaged AIBC C. rodentium robustly infected naive C3H/HeN mice, suggesting that the AIBC state is transient and did not select for genetically avirulent C. rodentium mutants. Following withdrawal of antibiotic treatment, 35% of C3H/HeN mice were able to prevent C. rodentium commensalization in the gut lumen. These mice presented a bloom of a commensal species, Citrobacter amalonaticus, which inhibited the growth of C. rodentiumin vitro in a contact-dependent manner and the luminal growth of AIBC C. rodentiumin vivo. Overall, our data suggest that commensal species can confer colonization resistance to closely related pathogenic species.
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13
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Reuter A, Hilpert C, Dedieu-Berne A, Lematre S, Gueguen E, Launay G, Bigot S, Lesterlin C. Targeted-antibacterial-plasmids (TAPs) combining conjugation and CRISPR/Cas systems achieve strain-specific antibacterial activity. Nucleic Acids Res 2021; 49:3584-3598. [PMID: 33660775 PMCID: PMC8034655 DOI: 10.1093/nar/gkab126] [Citation(s) in RCA: 36] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2020] [Revised: 02/10/2021] [Accepted: 02/16/2021] [Indexed: 12/25/2022] Open
Abstract
The global emergence of drug-resistant bacteria leads to the loss of efficacy of our antibiotics arsenal and severely limits the success of currently available treatments. Here, we developed an innovative strategy based on targeted-antibacterial-plasmids (TAPs) that use bacterial conjugation to deliver CRISPR/Cas systems exerting a strain-specific antibacterial activity. TAPs are highly versatile as they can be directed against any specific genomic or plasmid DNA using the custom algorithm (CSTB) that identifies appropriate targeting spacer sequences. We demonstrate the ability of TAPs to induce strain-selective killing by introducing lethal double strand breaks (DSBs) into the targeted genomes. TAPs directed against a plasmid-born carbapenem resistance gene efficiently resensitise the strain to the drug. This work represents an essential step toward the development of an alternative to antibiotic treatments, which could be used for in situ microbiota modification to eradicate targeted resistant and/or pathogenic bacteria without affecting other non-targeted bacterial species.
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Affiliation(s)
- Audrey Reuter
- Microbiologie Moléculaire et Biochimie Structurale (MMSB), Université Lyon 1, CNRS, Inserm, UMR5086, 69007 Lyon, France
| | - Cécile Hilpert
- Microbiologie Moléculaire et Biochimie Structurale (MMSB), Université Lyon 1, CNRS, Inserm, UMR5086, 69007 Lyon, France
| | - Annick Dedieu-Berne
- Microbiologie Moléculaire et Biochimie Structurale (MMSB), Université Lyon 1, CNRS, Inserm, UMR5086, 69007 Lyon, France
| | - Sophie Lematre
- Microbiologie Moléculaire et Biochimie Structurale (MMSB), Université Lyon 1, CNRS, Inserm, UMR5086, 69007 Lyon, France
| | - Erwan Gueguen
- University of Lyon, Université Lyon 1, INSA de Lyon, CNRS UMR 5240 Microbiologie Adaptation et Pathogénie, 69622 Villeurbanne, France
| | - Guillaume Launay
- Microbiologie Moléculaire et Biochimie Structurale (MMSB), Université Lyon 1, CNRS, Inserm, UMR5086, 69007 Lyon, France
| | - Sarah Bigot
- Microbiologie Moléculaire et Biochimie Structurale (MMSB), Université Lyon 1, CNRS, Inserm, UMR5086, 69007 Lyon, France
| | - Christian Lesterlin
- Microbiologie Moléculaire et Biochimie Structurale (MMSB), Université Lyon 1, CNRS, Inserm, UMR5086, 69007 Lyon, France
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14
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Miryala S, Nair VG, Chandramohan S, Srinandan CS. Matrix inhibition by Salmonella excludes uropathogenic E. coli from biofilm. FEMS Microbiol Ecol 2021; 97:5924450. [PMID: 33059364 DOI: 10.1093/femsec/fiaa214] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2020] [Accepted: 10/13/2020] [Indexed: 11/15/2022] Open
Abstract
Biofilm is a predominant lifestyle of bacteria that comprises of cells as collectives enmeshed in a polymeric matrix. Biofilm formation is vital for bacterial species as it provides access to nutrients and protects the cells from environmental stresses. Here we show that interference in biofilm matrix production is a strategy by the competing bacterial species to reduce the ability of the other species to colonize a surface. Escherichia coli colonies that differ in matrix production display different morphologies on Congo red agar media, which we exploited for screening bacterial isolates capable of inhibiting the matrix. The cell-free supernatants from growth culture of the screened isolates impaired uropathogenic E. coli (UPEC) UTI89 strain's biofilm. A physicochemical analysis suggested that the compound could be a glycopeptide or a polysaccharide. Isolates that inhibited matrix production belonged to species of the family Enterobacteriaceae such as Shigella, Escherichia, Enterobacter and Salmonella. Competition experiments between the isolates and the UPEC strain resulted in mutual inhibition, particularly during biofilm formation causing significant reduction in productivity and fitness. Furthermore, we show that Salmonella strains competitively excluded the UPEC strain in the biofilm by inhibiting its matrix production, highlighting the role of interference competition.
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Affiliation(s)
- Sandeep Miryala
- Biofilm Biology Lab, Centre for Research in Infectious Diseases, School of Chemical and Biotechnology,Thanjavur, Tamil Nadu, India
| | - Veena G Nair
- Biofilm Biology Lab, Centre for Research in Infectious Diseases, School of Chemical and Biotechnology,Thanjavur, Tamil Nadu, India
| | - S Chandramohan
- Biofilm Biology Lab, Centre for Research in Infectious Diseases, School of Chemical and Biotechnology,Thanjavur, Tamil Nadu, India
| | - C S Srinandan
- Biofilm Biology Lab, Centre for Research in Infectious Diseases, School of Chemical and Biotechnology,Thanjavur, Tamil Nadu, India
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15
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Visualization of Bacteria-Mediated Gene Delivery Using High-Resolution Electron and Confocal Microscopy. Methods Mol Biol 2020. [PMID: 33336268 DOI: 10.1007/978-1-0716-0943-9_3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
Abstract
Visual analysis of the gene delivery process when using invasive bacteria as a vector has been conventionally performed using standard light and fluorescence microscopy. These microscopes can provide basic information on the invasiveness of the bacterial vector including the ability of the vector to successfully adhere to the cell membrane. Standard microscopy techniques however fall short when finer details including membrane attachment as well as internalization into the cytoplasm are desired. High-resolution visual analysis of bacteria-mediated gene delivery can allow accurate measurement of the adherence and internalization capabilities of engineered vectors. Here, we describe the use of scanning electron microscopy (SEM) to directly quantify vectors when they are external to the cell wall, and confocal microscopy to evaluate the vectors when they have internalized into the cytoplasm. By performing the invasion procedure on microscope coverslips, cells can be easily prepared for analysis using electron or confocal microscopes. Imaging the invasion complexes in high resolution can provide important insights into the behavior of bacterial vectors including E. coli, Listeria, and Salmonella when invading their target cells to deliver DNA and other molecules.
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16
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Jégouzo SAF, Nelson C, Hardwick T, Wong STA, Lau NKK, Neoh GKE, Castellanos-Rueda R, Huang Z, Mignot B, Hirdaramani A, Howitt A, Frewin K, Shen Z, Fox RJ, Wong R, Ando M, Emony L, Zhu H, Holder A, Werling D, Krishnan N, Robertson BD, Clements A, Taylor ME, Drickamer K. Mammalian lectin arrays for screening host-microbe interactions. J Biol Chem 2020; 295:4541-4555. [PMID: 32094229 PMCID: PMC7135977 DOI: 10.1074/jbc.ra120.012783] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2020] [Revised: 02/14/2020] [Indexed: 12/22/2022] Open
Abstract
Many members of the C-type lectin family of glycan-binding receptors have been ascribed roles in the recognition of microorganisms and serve as key receptors in the innate immune response to pathogens. Other mammalian receptors have become targets through which pathogens enter target cells. These receptor roles have often been documented with binding studies involving individual pairs of receptors and microorganisms. To provide a systematic overview of interactions between microbes and the large complement of C-type lectins, here we developed a lectin array and suitable protocols for labeling of microbes that could be used to probe this array. The array contains C-type lectins from cow, chosen as a model organism of agricultural interest for which the relevant pathogen–receptor interactions have not been previously investigated in detail. Screening with yeast cells and various strains of both Gram-positive and -negative bacteria revealed distinct binding patterns, which in some cases could be explained by binding to lipopolysaccharides or capsular polysaccharides, but in other cases they suggested the presence of novel glycan targets on many of the microorganisms. These results are consistent with interactions previously ascribed to the receptors, but they also highlight binding to additional sugar targets that have not previously been recognized. Our findings indicate that mammalian lectin arrays represent unique discovery tools for identifying both novel ligands and new receptor functions.
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Affiliation(s)
- Sabine A F Jégouzo
- Department of Life Sciences, Imperial College London, London SW7 2AZ, United Kingdom
| | - Conor Nelson
- Department of Life Sciences, Imperial College London, London SW7 2AZ, United Kingdom
| | - Thomas Hardwick
- Department of Life Sciences, Imperial College London, London SW7 2AZ, United Kingdom
| | - S T Angel Wong
- Department of Life Sciences, Imperial College London, London SW7 2AZ, United Kingdom
| | - Noel Kuan Kiat Lau
- Department of Life Sciences, Imperial College London, London SW7 2AZ, United Kingdom
| | - Gaik Kin Emily Neoh
- Department of Life Sciences, Imperial College London, London SW7 2AZ, United Kingdom
| | | | - Zhiyao Huang
- Department of Life Sciences, Imperial College London, London SW7 2AZ, United Kingdom
| | - Benjamin Mignot
- Department of Life Sciences, Imperial College London, London SW7 2AZ, United Kingdom
| | - Aanya Hirdaramani
- Department of Life Sciences, Imperial College London, London SW7 2AZ, United Kingdom
| | - Annie Howitt
- Department of Life Sciences, Imperial College London, London SW7 2AZ, United Kingdom
| | - Kathryn Frewin
- Department of Life Sciences, Imperial College London, London SW7 2AZ, United Kingdom
| | - Zheng Shen
- Department of Life Sciences, Imperial College London, London SW7 2AZ, United Kingdom
| | - Rhys J Fox
- Department of Life Sciences, Imperial College London, London SW7 2AZ, United Kingdom
| | - Rachel Wong
- Department of Life Sciences, Imperial College London, London SW7 2AZ, United Kingdom
| | - Momoko Ando
- Department of Life Sciences, Imperial College London, London SW7 2AZ, United Kingdom
| | - Lauren Emony
- Department of Life Sciences, Imperial College London, London SW7 2AZ, United Kingdom
| | - Henderson Zhu
- Department of Life Sciences, Imperial College London, London SW7 2AZ, United Kingdom
| | - Angela Holder
- Department of Pathobiology and Population Sciences, Royal Veterinary College, North Mymms, Hatfield, Hertfordshire AL9 7TA, United Kingdom
| | - Dirk Werling
- Department of Pathobiology and Population Sciences, Royal Veterinary College, North Mymms, Hatfield, Hertfordshire AL9 7TA, United Kingdom
| | - Nitya Krishnan
- Department of Infectious Disease and MRC Centre for Molecular Bacteriology and Infection, Imperial College London, London SW7 2AZ, United Kingdom
| | - Brian D Robertson
- Department of Infectious Disease and MRC Centre for Molecular Bacteriology and Infection, Imperial College London, London SW7 2AZ, United Kingdom
| | - Abigail Clements
- Department of Life Sciences and MRC Centre for Molecular Bacteriology and Infection, Imperial College London, London SW7 2AZ, United Kingdom
| | - Maureen E Taylor
- Department of Life Sciences, Imperial College London, London SW7 2AZ, United Kingdom
| | - Kurt Drickamer
- Department of Life Sciences, Imperial College London, London SW7 2AZ, United Kingdom
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17
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Shigella sonnei Does Not Use Amoebae as Protective Hosts. Appl Environ Microbiol 2018; 84:AEM.02679-17. [PMID: 29475870 PMCID: PMC5930310 DOI: 10.1128/aem.02679-17] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2017] [Accepted: 02/15/2018] [Indexed: 01/25/2023] Open
Abstract
Shigella flexneri and Shigella sonnei bacteria cause the majority of all shigellosis cases worldwide. However, their distributions differ, with S. sonnei predominating in middle- and high-income countries and S. flexneri predominating in low-income countries. One proposed explanation for the continued range expansion of S. sonnei is that it can survive in amoebae, which could provide a protective environment for the bacteria. In this study, we demonstrate that while both S. sonnei and S. flexneri can survive coculture with the free-living amoebae Acanthamoebae castellanii, bacterial growth is predominantly extracellular. All isolates of Shigella were degraded following phagocytosis by A. castellanii, unlike those of Legionella pneumophila, which can replicate intracellularly. Our data suggest that S. sonnei is not able to use amoebae as a protective host to enhance environmental survival. Therefore, alternative explanations for S. sonnei emergence need to be considered. IMPORTANCE The distribution of Shigella species closely mirrors a country's socioeconomic conditions. With the transition of many populous nations from low- to middle-income countries, S. sonnei infections have emerged as a major public health issue. Understanding why S. sonnei infections are resistant to improvements in living conditions is key to developing methods to reduce exposure to this pathogen. We show that free-living amoebae are not likely to be environmental hosts of S. sonnei, as all Shigella strains tested were phagocytosed and degraded by amoebae. Therefore, alternative scenarios are required to explain the emergence and persistence of S. sonnei infections.
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18
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Mavridou DAI, Gonzalez D, Kim W, West SA, Foster KR. Bacteria Use Collective Behavior to Generate Diverse Combat Strategies. Curr Biol 2018; 28:345-355.e4. [PMID: 29395918 DOI: 10.1016/j.cub.2017.12.030] [Citation(s) in RCA: 66] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2017] [Revised: 11/06/2017] [Accepted: 12/14/2017] [Indexed: 01/06/2023]
Abstract
Animals have evolved a wide diversity of aggressive behavior often based upon the careful monitoring of other individuals. Bacteria are also capable of aggression, with many species using toxins to kill or inhibit their competitors. Like animals, bacteria also have systems to monitor others during antagonistic encounters, but how this translates into behavior remains poorly understood. Here, we use colonies of Escherichia coli carrying colicin-encoding plasmids as a model for studying antagonistic behavior. We show that in the absence of threat, dispersed cells with low reproductive value produce colicin toxins spontaneously, generating efficient pre-emptive attacks. Cells can also respond conditionally to toxins released by clonemates via autoinduction or other genotypes via competition sensing. The strength of both pre-emptive and responsive attacks varies widely between strains. We demonstrate that this variability occurs easily through mutation by rationally engineering strains to recapitulate the diversity in naturally occurring strategies. Finally, we discover that strains that can detect both competitors and clonemates are capable of massive coordinated attacks on competing colonies. This collective behavior protects established colonies from competitors, mirroring the evolution of alarm calling in the animal world.
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Affiliation(s)
- Despoina A I Mavridou
- Department of Zoology, University of Oxford, Oxford OX1 3PS, UK; Calleva Research Centre for Evolution and Human Sciences, Magdalen College, Oxford OX1 4AU, UK; MRC Centre for Molecular Bacteriology and Infection, Department of Life Sciences, Imperial College London, Kensington, London SW7 2DD, UK
| | - Diego Gonzalez
- Department of Zoology, University of Oxford, Oxford OX1 3PS, UK; Calleva Research Centre for Evolution and Human Sciences, Magdalen College, Oxford OX1 4AU, UK
| | - Wook Kim
- Department of Zoology, University of Oxford, Oxford OX1 3PS, UK
| | - Stuart A West
- Department of Zoology, University of Oxford, Oxford OX1 3PS, UK; Calleva Research Centre for Evolution and Human Sciences, Magdalen College, Oxford OX1 4AU, UK
| | - Kevin R Foster
- Department of Zoology, University of Oxford, Oxford OX1 3PS, UK; Calleva Research Centre for Evolution and Human Sciences, Magdalen College, Oxford OX1 4AU, UK.
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