1
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Singh S, Singh S, Trivedi M, Dwivedi M. An insight into MDR Acinetobacter baumannii infection and its pathogenesis: Potential therapeutic targets and challenges. Microb Pathog 2024; 192:106674. [PMID: 38714263 DOI: 10.1016/j.micpath.2024.106674] [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: 10/19/2023] [Revised: 04/22/2024] [Accepted: 05/01/2024] [Indexed: 05/09/2024]
Abstract
Acinetobacter baumannii is observed as a common species of Gram-negative bacteria that exist in soil and water. Despite being accepted as a typical component of human skin flora, it has become an important opportunistic pathogen, especially in healthcare settings. The pathogenicity of A. baumannii is attributed to its virulence factors, which include adhesins, pili, lipopolysaccharides, outer membrane proteins, iron uptake systems, autotransporter, secretion systems, phospholipases etc. These elements provide the bacterium the ability to cling to and penetrate host cells, get past the host immune system, and destroy tissue. Its infection is a major contributor to human pathophysiological conditions including pneumonia, bloodstream infections, urinary tract infections, and surgical site infections. It is challenging to treat infections brought on by this pathogen since this bacterium has evolved to withstand numerous drugs and further emergence of drug-resistant A. baumannii results in higher rates of morbidity and mortality. The long-term survival of this bacterium on surfaces of medical supplies and hospital furniture facilitates its frequent spread in humans from one habitat to another. There is a need for urgent investigations to find effective drug targets for A. baumannii as well as designing novel drugs to reduce the survival and spread of infection. In the current review, we represent the specific features, pathogenesis, and molecular intricacies of crucial drug targets of A. baumannii. This would also assist in proposing strategies and alternative therapies for the prevention and treatment of A. baumannii infections and their spread.
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Affiliation(s)
- Sukriti Singh
- Amity Institute of Biotechnology, Amity University Uttar Pradesh, Lucknow, 226028, India
| | - Sushmita Singh
- Amity Institute of Biotechnology, Amity University Uttar Pradesh, Lucknow, 226028, India
| | - Mala Trivedi
- Amity Institute of Biotechnology, Amity University Uttar Pradesh, Lucknow, 226028, India
| | - Manish Dwivedi
- Amity Institute of Biotechnology, Amity University Uttar Pradesh, Lucknow, 226028, India; Research Cell, Amity University Uttar Pradesh, Lucknow, 226028, India.
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2
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Brychcy M, Nguyen B, Tierney GA, Casula P, Kokodynski A, Godoy VG. The metabolite vanillic acid regulates Acinetobacter baumannii surface attachment. Mol Microbiol 2024; 121:833-849. [PMID: 38308563 DOI: 10.1111/mmi.15234] [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: 10/20/2023] [Revised: 01/17/2024] [Accepted: 01/19/2024] [Indexed: 02/05/2024]
Abstract
The nosocomial bacterium Acinetobacter baumannii is protected from antibiotic treatment by acquiring antibiotic resistances and by forming biofilms. Cell attachment, one of the first steps in biofilm formation, is normally induced by environmental metabolites. We hypothesized that vanillic acid (VA), the oxidized form of vanillin and a widely available metabolite, may play a role in A. baumannii cell attachment. We first discovered that A. baumannii actively breaks down VA through the evolutionarily conserved vanABKP genes. These genes are under the control of the repressor VanR, which we show binds directly to VanR binding sites within the vanABKP genes bidirectional promoter. VA in turn counteracts VanR inhibition. We identified a VanR binding site and searched for it throughout the genome, especially in pili encoding promoter genes. We found a VanR binding site in the pilus encoding csu operon promoter and showed that VanR binds specifically to it. As expected, a strain lacking VanR overproduces Csu pili and makes robust biofilms. Our study uncovers the role that VA plays in facilitating the attachment of A. baumannii cells to surfaces, a crucial step in biofilm formation. These findings provide valuable insights into a previously obscure catabolic pathway with significant clinical implications.
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Affiliation(s)
- Merlin Brychcy
- Department of Biology, Northeastern University, Boston, Massachusetts, USA
| | - Brian Nguyen
- Department of Biology, Northeastern University, Boston, Massachusetts, USA
| | | | - Pranav Casula
- Department of Biology, Northeastern University, Boston, Massachusetts, USA
| | - Alexis Kokodynski
- Department of Biology, Northeastern University, Boston, Massachusetts, USA
| | - Veronica G Godoy
- Department of Biology, Northeastern University, Boston, Massachusetts, USA
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3
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Böhning J, Tarafder AK, Bharat TA. The role of filamentous matrix molecules in shaping the architecture and emergent properties of bacterial biofilms. Biochem J 2024; 481:245-263. [PMID: 38358118 PMCID: PMC10903470 DOI: 10.1042/bcj20210301] [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: 09/18/2023] [Revised: 01/29/2024] [Accepted: 01/31/2024] [Indexed: 02/16/2024]
Abstract
Numerous bacteria naturally occur within spatially organised, multicellular communities called biofilms. Moreover, most bacterial infections proceed with biofilm formation, posing major challenges to human health. Within biofilms, bacterial cells are embedded in a primarily self-produced extracellular matrix, which is a defining feature of all biofilms. The biofilm matrix is a complex, viscous mixture primarily composed of polymeric substances such as polysaccharides, filamentous protein fibres, and extracellular DNA. The structured arrangement of the matrix bestows bacteria with beneficial emergent properties that are not displayed by planktonic cells, conferring protection against physical and chemical stresses, including antibiotic treatment. However, a lack of multi-scale information at the molecular level has prevented a better understanding of this matrix and its properties. Here, we review recent progress on the molecular characterisation of filamentous biofilm matrix components and their three-dimensional spatial organisation within biofilms.
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Affiliation(s)
- Jan Böhning
- Structural Studies Division, MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH, U.K
| | - Abul K. Tarafder
- Structural Studies Division, MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH, U.K
| | - Tanmay A.M. Bharat
- Structural Studies Division, MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH, U.K
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4
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Ahmad I, Nadeem A, Mushtaq F, Zlatkov N, Shahzad M, Zavialov AV, Wai SN, Uhlin BE. Csu pili dependent biofilm formation and virulence of Acinetobacter baumannii. NPJ Biofilms Microbiomes 2023; 9:101. [PMID: 38097635 PMCID: PMC10721868 DOI: 10.1038/s41522-023-00465-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2023] [Accepted: 11/23/2023] [Indexed: 12/17/2023] Open
Abstract
Acinetobacter baumannii has emerged as one of the most common extensive drug-resistant nosocomial bacterial pathogens. Not only can the bacteria survive in hospital settings for long periods, but they are also able to resist adverse conditions. However, underlying regulatory mechanisms that allow A. baumannii to cope with these conditions and mediate its virulence are poorly understood. Here, we show that bi-stable expression of the Csu pili, along with the production of poly-N-acetyl glucosamine, regulates the formation of Mountain-like biofilm-patches on glass surfaces to protect bacteria from the bactericidal effect of colistin. Csu pilus assembly is found to be an essential component of mature biofilms formed on glass surfaces and of pellicles. By using several microscopic techniques, we show that clinical isolates of A. baumannii carrying abundant Csu pili mediate adherence to epithelial cells. In addition, Csu pili suppressed surface-associated motility but enhanced colonization of bacteria into the lungs, spleen, and liver in a mouse model of systemic infection. The screening of c-di-GMP metabolizing protein mutants of A. baumannii 17978 for the capability to adhere to epithelial cells led us to identify GGDEF/EAL protein AIS_2337, here denoted PdeB, as a major regulator of Csu pili-mediated virulence and biofilm formation. Moreover, PdeB was found to be involved in the type IV pili-regulated robustness of surface-associated motility. Our findings suggest that the Csu pilus is not only a functional component of mature A. baumannii biofilms but also a major virulence factor promoting the initiation of disease progression by mediating bacterial adherence to epithelial cells.
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Affiliation(s)
- Irfan Ahmad
- Department of Molecular Biology and Umeå Centre for Microbial Research (UCMR), Umeå University, SE-90187, Umeå, Sweden.
- Institute of Biomedical and Allied Health Sciences, University of Health Sciences, Lahore, Pakistan.
| | - Aftab Nadeem
- Department of Molecular Biology and Umeå Centre for Microbial Research (UCMR), Umeå University, SE-90187, Umeå, Sweden
| | - Fizza Mushtaq
- Department of Molecular Biology and Umeå Centre for Microbial Research (UCMR), Umeå University, SE-90187, Umeå, Sweden
- Institute of Biomedical and Allied Health Sciences, University of Health Sciences, Lahore, Pakistan
| | - Nikola Zlatkov
- Department of Molecular Biology and Umeå Centre for Microbial Research (UCMR), Umeå University, SE-90187, Umeå, Sweden
| | - Muhammad Shahzad
- Department of Pharmacology, University of Health Sciences, Lahore, Pakistan
| | - Anton V Zavialov
- Department of Biochemistry, University of Turku, Tykistökatu 6A, 20520, Turku, Finland
| | - Sun Nyunt Wai
- Department of Molecular Biology and Umeå Centre for Microbial Research (UCMR), Umeå University, SE-90187, Umeå, Sweden
- The Laboratory for Molecular Infection Medicine Sweden (MIMS), Umeå University, SE-90187, Umeå, Sweden
| | - Bernt Eric Uhlin
- Department of Molecular Biology and Umeå Centre for Microbial Research (UCMR), Umeå University, SE-90187, Umeå, Sweden
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Giese C, Puorger C, Ignatov O, Bečárová Z, Weber ME, Schärer MA, Capitani G, Glockshuber R. Stochastic chain termination in bacterial pilus assembly. Nat Commun 2023; 14:7718. [PMID: 38001074 PMCID: PMC10673952 DOI: 10.1038/s41467-023-43449-y] [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: 10/14/2022] [Accepted: 11/09/2023] [Indexed: 11/26/2023] Open
Abstract
Adhesive type 1 pili from uropathogenic Escherichia coli strains are filamentous, supramolecular protein complexes consisting of a short tip fibrillum and a long, helical rod formed by up to several thousand copies of the major pilus subunit FimA. Here, we reconstituted the entire type 1 pilus rod assembly reaction in vitro, using all constituent protein subunits in the presence of the assembly platform FimD, and identified the so-far uncharacterized subunit FimI as an irreversible assembly terminator. We provide a complete, quantitative model of pilus rod assembly kinetics based on the measured rate constants of FimD-catalyzed subunit incorporation. The model reliably predicts the length distribution of assembled pilus rods as a function of the ratio between FimI and the main pilus subunit FimA and is fully consistent with the length distribution of membrane-anchored pili assembled in vivo. The results show that the natural length distribution of adhesive pili formed via the chaperone-usher pathway results from a stochastic chain termination reaction. In addition, we demonstrate that FimI contributes to anchoring the pilus to the outer membrane and report the crystal structures of (i) FimI in complex with the assembly chaperone FimC, (ii) the FimI-FimC complex bound to the N-terminal domain of FimD, and (iii) a ternary complex between FimI, FimA and FimC that provides structural insights on pilus assembly termination and pilus anchoring by FimI.
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Affiliation(s)
- Christoph Giese
- Institute of Molecular Biology and Biophysics, Department of Biology, ETH Zurich, 8093, Zurich, Switzerland.
| | - Chasper Puorger
- Institute of Molecular Biology and Biophysics, Department of Biology, ETH Zurich, 8093, Zurich, Switzerland
- Institute for Chemistry and Bioanalytics, University of Applied Sciences and Arts Northwestern Switzerland, 4132, Muttenz, Switzerland
| | - Oleksandr Ignatov
- Institute of Molecular Biology and Biophysics, Department of Biology, ETH Zurich, 8093, Zurich, Switzerland
- V.I. Grishchenko Clinic of Reproductive Medicine, Blahovishchenska st.25, 61052, Kharkiv, Ukraine
| | - Zuzana Bečárová
- Institute of Molecular Biology and Biophysics, Department of Biology, ETH Zurich, 8093, Zurich, Switzerland
| | - Marco E Weber
- Institute of Molecular Biology and Biophysics, Department of Biology, ETH Zurich, 8093, Zurich, Switzerland
- Laboratory of Physical Chemistry, Department of Chemistry and Applied Biosciences, ETH Zurich, 8093, Zurich, Switzerland
| | - Martin A Schärer
- Institute of Molecular Biology and Biophysics, Department of Biology, ETH Zurich, 8093, Zurich, Switzerland
- Laboratory of Biomolecular Research, Paul Scherrer Institute, 5232, Villigen, Switzerland
| | - Guido Capitani
- Laboratory of Biomolecular Research, Paul Scherrer Institute, 5232, Villigen, Switzerland
| | - Rudi Glockshuber
- Institute of Molecular Biology and Biophysics, Department of Biology, ETH Zurich, 8093, Zurich, Switzerland
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6
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Li L, Short FL, Hassan KA, Naidu V, Pokhrel A, Nagy SS, Prity FT, Shah BS, Afrin N, Baker S, Parkhill J, Cain AK, Paulsen IT. Systematic analyses identify modes of action of ten clinically relevant biocides and antibiotic antagonism in Acinetobacter baumannii. Nat Microbiol 2023; 8:1995-2005. [PMID: 37814070 DOI: 10.1038/s41564-023-01474-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2019] [Accepted: 08/11/2023] [Indexed: 10/11/2023]
Abstract
Concerns exist that widespread use of antiseptic or disinfectant biocides could contribute to the emergence and spread of multidrug-resistant bacteria. To investigate this, we performed transposon-directed insertion-site sequencing (TraDIS) on the multidrug-resistant pathogen, Acinetobacter baumannii, exposed to a panel of ten structurally diverse and clinically relevant biocides. Multiple gene targets encoding cell envelope or cytoplasmic proteins involved in processes including fatty acid biogenesis, multidrug efflux, the tricarboxylic acid cycle, cell respiration and cell division, were identified to have effects on bacterial fitness upon biocide exposure, suggesting that these compounds may have intracellular targets in addition to their known effects on the cell envelope. As cell respiration genes are required for A. baumannii fitness in biocides, we confirmed that sub-inhibitory concentrations of the biocides that dissipate membrane potential can promote A. baumannii tolerance to antibiotics that act intracellularly. Our results support the concern that residual biocides might promote antibiotic resistance in pathogenic bacteria.
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Affiliation(s)
- Liping Li
- ARC Centre of Excellence in Synthetic Biology, Macquarie University, Sydney, New South Wales, Australia
- School of Natural Sciences, Macquarie University, Sydney, New South Wales, Australia
| | - Francesca L Short
- ARC Centre of Excellence in Synthetic Biology, Macquarie University, Sydney, New South Wales, Australia
- Infection Program and Department of Microbiology, Biomedicine Discovery Institute, Monash University, Clayton, Victoria, Australia
| | - Karl A Hassan
- ARC Centre of Excellence in Synthetic Biology, Macquarie University, Sydney, New South Wales, Australia
- School of Natural Sciences, Macquarie University, Sydney, New South Wales, Australia
- School of Environmental and Life Sciences, University of Newcastle, Callaghan, New South Wales, Australia
| | - Varsha Naidu
- ARC Centre of Excellence in Synthetic Biology, Macquarie University, Sydney, New South Wales, Australia
- School of Natural Sciences, Macquarie University, Sydney, New South Wales, Australia
- School of Environmental and Life Sciences, University of Newcastle, Callaghan, New South Wales, Australia
| | - Alaska Pokhrel
- ARC Centre of Excellence in Synthetic Biology, Macquarie University, Sydney, New South Wales, Australia
- Australian Institute for Microbiology and Infection (AIMI), University of Technology, Sydney, New South Wales, Australia
| | - Stephanie S Nagy
- School of Natural Sciences, Macquarie University, Sydney, New South Wales, Australia
| | - Farzana T Prity
- ARC Centre of Excellence in Synthetic Biology, Macquarie University, Sydney, New South Wales, Australia
- School of Natural Sciences, Macquarie University, Sydney, New South Wales, Australia
| | - Bhumika S Shah
- ARC Centre of Excellence in Synthetic Biology, Macquarie University, Sydney, New South Wales, Australia
- School of Natural Sciences, Macquarie University, Sydney, New South Wales, Australia
| | - Nusrat Afrin
- School of Natural Sciences, Macquarie University, Sydney, New South Wales, Australia
| | - Stephen Baker
- Cambridge Institute of Therapeutic Immunology and Infectious Disease (CITIID), University of Cambridge, Cambridge, UK
| | - Julian Parkhill
- The Wellcome Sanger Institute, Wellcome Genome Campus, Hinxton, Cambridge, UK
- Department of Veterinary Medicine, University of Cambridge, Cambridge, UK
| | - Amy K Cain
- ARC Centre of Excellence in Synthetic Biology, Macquarie University, Sydney, New South Wales, Australia.
- School of Natural Sciences, Macquarie University, Sydney, New South Wales, Australia.
| | - Ian T Paulsen
- ARC Centre of Excellence in Synthetic Biology, Macquarie University, Sydney, New South Wales, Australia.
- School of Natural Sciences, Macquarie University, Sydney, New South Wales, Australia.
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7
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Liu X, Chang Y, Xu Q, Zhang W, Huang Z, Zhang L, Weng S, Leptihn S, Jiang Y, Yu Y, Hua X. Mutation in the two-component regulator BaeSR mediates cefiderocol resistance and enhances virulence in Acinetobacter baumannii. mSystems 2023; 8:e0129122. [PMID: 37345941 PMCID: PMC10469669 DOI: 10.1128/msystems.01291-22] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2023] [Accepted: 05/04/2023] [Indexed: 06/23/2023] Open
Abstract
Acinetobacter baumannii has become one of the most challenging pathogens in many countries with limited treatment options available. Cefiderocol, a novel siderophore-conjugated cephalosporin, shows potent in vitro activity against A. baumannii, including isolates resistant to carbapenems. To date, few reports on the mechanisms of cefiderocol resistance are available. In order to investigate potential mechanisms of cefiderocol resistance in A. baumannii, we performed in vitro evolution experiments at sub-lethal concentrations of the antibiotic. All four cefiderocol-resistant strains obtained harbored mutations in two-component system BaeS-BaeR. When we engineered the mutations of BaeS (D89V) and BaeR (S104N) into the genome of ATCC 17978, these mutations increased cefiderocol minimum inhibitory concentrations (MICs) by 8-fold to 16-fold. Transcriptome analyses showed that the expression of MacAB-TolC and MFS transporters was up-regulated in BaeSR mutants. Strains over-expressing MFS transporter and MacAB-TolC displayed higher MICs and higher median inhibition concentration (IC50) values, while MICs and IC50 decreased when efflux pump genes were knocked out. In a BaeR mutant with up-regulated csu operon, we observed a higher number of pili, enhanced surface motility, and increased biofilm formation compared to wild-type ATCC 17978. Using the Galleria mellonella infection model, we found that the BaeS mutant in which paa operon was up-regulated exhibited increased virulence. In conclusion, the mutations in BaeSR decreased cefiderocol susceptibility of A. baumannii through up-regulating efflux pumps gene expression. BaeS or BaeR also controls the expression of csu and paa, influencing biofilm formation, surface motility, and virulence in A. baumannii. IMPORTANCE The widespread prevalence of multi-drug-resistant A. baumannii (MDRAB) poses a significant therapeutic challenge. Cefiderocol is considered a promising antibiotic for the treatment of MDRAB infections. Therefore, it is necessary to study the potential resistance mechanisms of cefiderocol to delay the development of bacterial resistance. Here, we demonstrated that mutations in baeS and baeR reduced the susceptibility of A. baumannii to cefiderocol by up-regulating the expression of the MFS family efflux pump and MacAB-TolC efflux pump. We propose that BaeS mutants increase bacterial virulence by up-regulating the expression of the paa operon. This also reports the regulatory effect of BaeSR on csu operon for the first time. This study provides further insights into the role of BaeSR in developing cefiderocol resistance and virulence in A. baumannii.
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Affiliation(s)
- Xiaochen Liu
- Department of Infectious Diseases, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
- Key Laboratory of Microbial Technology and Bioinformatics of Zhejiang Province, Hangzhou, Zhejiang, China
- Regional Medical Center for National Institute of Respiratory Diseases, Sir Run Run Shaw Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang, China
| | - Yunjie Chang
- Department of Infectious Diseases, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
- Center of Cryo Electron Microscopy, Zhejiang University, Hangzhou, Zhejiang, China
- Department of Biophysics, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
| | - Qingye Xu
- Zhejiang Provincial People's Hospital, People's Hospital of Hangzhou Medical College, Hangzhou, Zhejiang, China
| | - Wang Zhang
- Department of Infectious Diseases, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
- Key Laboratory of Microbial Technology and Bioinformatics of Zhejiang Province, Hangzhou, Zhejiang, China
- Regional Medical Center for National Institute of Respiratory Diseases, Sir Run Run Shaw Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang, China
| | - Zhen Huang
- College of Agriculture and Biotechnology, Zhejiang University, Hangzhou, Zhejiang, China
| | - Linyue Zhang
- Department of Infectious Diseases, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
- Key Laboratory of Microbial Technology and Bioinformatics of Zhejiang Province, Hangzhou, Zhejiang, China
- Regional Medical Center for National Institute of Respiratory Diseases, Sir Run Run Shaw Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang, China
| | - Shanshan Weng
- Department of Infectious Diseases, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
- Key Laboratory of Microbial Technology and Bioinformatics of Zhejiang Province, Hangzhou, Zhejiang, China
- Regional Medical Center for National Institute of Respiratory Diseases, Sir Run Run Shaw Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang, China
| | - Sebastian Leptihn
- Department of Infectious Diseases, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
- Zhejiang University-University of Edinburgh Institute, Zhejiang University, Haining, Zhejiang, China
- University of Edinburgh Medical School, Biomedical Sciences, College of Medicine and Veterinary Medicine, The University of Edinburgh, Edinburgh, United Kingdom
| | - Yan Jiang
- Department of Infectious Diseases, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
- Key Laboratory of Microbial Technology and Bioinformatics of Zhejiang Province, Hangzhou, Zhejiang, China
- Regional Medical Center for National Institute of Respiratory Diseases, Sir Run Run Shaw Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang, China
| | - Yunsong Yu
- Department of Infectious Diseases, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
- Key Laboratory of Microbial Technology and Bioinformatics of Zhejiang Province, Hangzhou, Zhejiang, China
- Regional Medical Center for National Institute of Respiratory Diseases, Sir Run Run Shaw Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang, China
| | - Xiaoting Hua
- Department of Infectious Diseases, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
- Key Laboratory of Microbial Technology and Bioinformatics of Zhejiang Province, Hangzhou, Zhejiang, China
- Regional Medical Center for National Institute of Respiratory Diseases, Sir Run Run Shaw Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang, China
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8
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Iruegas R, Pfefferle K, Göttig S, Averhoff B, Ebersberger I. Feature architecture aware phylogenetic profiling indicates a functional diversification of type IVa pili in the nosocomial pathogen Acinetobacter baumannii. PLoS Genet 2023; 19:e1010646. [PMID: 37498819 PMCID: PMC10374093 DOI: 10.1371/journal.pgen.1010646] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2023] [Accepted: 06/06/2023] [Indexed: 07/29/2023] Open
Abstract
The Gram-negative bacterial pathogen Acinetobacter baumannii is a major cause of hospital-acquired opportunistic infections. The increasing spread of pan-drug resistant strains makes A. baumannii top-ranking among the ESKAPE pathogens for which novel routes of treatment are urgently needed. Comparative genomics approaches have successfully identified genetic changes coinciding with the emergence of pathogenicity in Acinetobacter. Genes that are prevalent both in pathogenic and a-pathogenic Acinetobacter species were not considered ignoring that virulence factors may emerge by the modification of evolutionarily old and widespread proteins. Here, we increased the resolution of comparative genomics analyses to also include lineage-specific changes in protein feature architectures. Using type IVa pili (T4aP) as an example, we show that three pilus components, among them the pilus tip adhesin ComC, vary in their Pfam domain annotation within the genus Acinetobacter. In most pathogenic Acinetobacter isolates, ComC displays a von Willebrand Factor type A domain harboring a finger-like protrusion, and we provide experimental evidence that this finger conveys virulence-related functions in A. baumannii. All three genes are part of an evolutionary cassette, which has been replaced at least twice during A. baumannii diversification. The resulting strain-specific differences in T4aP layout suggests differences in the way how individual strains interact with their host. Our study underpins the hypothesis that A. baumannii uses T4aP for host infection as it was shown previously for other pathogens. It also indicates that many more functional complexes may exist whose precise functions have been adjusted by modifying individual components on the domain level.
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Affiliation(s)
- Ruben Iruegas
- Applied Bioinformatics Group, Inst of Cell Biology and Neuroscience, Goethe University Frankfurt, Frankfurt am Main, Germany
| | - Katharina Pfefferle
- Molecular Microbiology & Bioenergetics, Institute of Molecular Biosciences, Goethe University Frankfurt, Frankfurt am Main, Germany
| | - Stephan Göttig
- Institute for Medical Microbiology and Infection Control, University Hospital, Goethe University, Frankfurt, Germany
| | - Beate Averhoff
- Molecular Microbiology & Bioenergetics, Institute of Molecular Biosciences, Goethe University Frankfurt, Frankfurt am Main, Germany
| | - Ingo Ebersberger
- Applied Bioinformatics Group, Inst of Cell Biology and Neuroscience, Goethe University Frankfurt, Frankfurt am Main, Germany
- Senckenberg Biodiversity and Climate Research Centre (S-BIK-F), Frankfurt am Main, Germany
- LOEWE Centre for Translational Biodiversity Genomics (TBG), Frankfurt am Main, Germany
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9
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Lei EK, Ryan S, van Faassen H, Foss M, Robotham A, Baltat I, Fulton K, Henry KA, Chen W, Hussack G. Isolation and characterization of a VHH targeting the Acinetobacter baumannii cell surface protein CsuA/B. Appl Microbiol Biotechnol 2023:10.1007/s00253-023-12594-1. [PMID: 37284893 DOI: 10.1007/s00253-023-12594-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2023] [Revised: 04/18/2023] [Accepted: 05/15/2023] [Indexed: 06/08/2023]
Abstract
Acinetobacter baumannii is a Gram-negative bacterial pathogen that exhibits high intrinsic resistance to antimicrobials, with treatment often requiring the use of last-resort antibiotics. Antibiotic-resistant strains have become increasingly prevalent, underscoring a need for new therapeutic interventions. The aim of this study was to use A. baumannii outer membrane vesicles as immunogens to generate single-domain antibodies (VHHs) against bacterial cell surface targets. Llama immunization with the outer membrane vesicle preparations from four A. baumannii strains (ATCC 19606, ATCC 17961, ATCC 17975, and LAC-4) elicited a strong heavy-chain IgG response, and VHHs were selected against cell surface and/or extracellular targets. For one VHH, OMV81, the target antigen was identified using a combination of gel electrophoresis, mass spectrometry, and binding studies. Using these techniques, OMV81 was shown to specifically recognize CsuA/B, a protein subunit of the Csu pilus, with an equilibrium dissociation constant of 17 nM. OMV81 specifically bound to intact A. baumannii cells, highlighting its potential use as a targeting agent. We anticipate the ability to generate antigen-specific antibodies against cell surface A. baumannii targets could provide tools for further study and treatment of this pathogen. KEY POINTS: •Llama immunization with bacterial OMV preparations for VHH generation •A. baumannii CsuA/B, a pilus subunit, identified by mass spectrometry as VHH target •High-affinity and specific VHH binding to CsuA/B and A. baumannii cells.
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Affiliation(s)
- Eric K Lei
- Human Health Therapeutics Research Centre, National Research Council Canada, Ottawa, Ontario, Canada
| | - Shannon Ryan
- Human Health Therapeutics Research Centre, National Research Council Canada, Ottawa, Ontario, Canada
| | - Henk van Faassen
- Human Health Therapeutics Research Centre, National Research Council Canada, Ottawa, Ontario, Canada
| | - Mary Foss
- Human Health Therapeutics Research Centre, National Research Council Canada, Ottawa, Ontario, Canada
| | - Anna Robotham
- Human Health Therapeutics Research Centre, National Research Council Canada, Ottawa, Ontario, Canada
| | - Isabel Baltat
- Human Health Therapeutics Research Centre, National Research Council Canada, Ottawa, Ontario, Canada
| | - Kelly Fulton
- Human Health Therapeutics Research Centre, National Research Council Canada, Ottawa, Ontario, Canada
| | - Kevin A Henry
- Human Health Therapeutics Research Centre, National Research Council Canada, Ottawa, Ontario, Canada
- Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, Ontario, Canada
| | - Wangxue Chen
- Human Health Therapeutics Research Centre, National Research Council Canada, Ottawa, Ontario, Canada
- Department of Biology, Brock University, St. Catharines, Ontario, Canada
| | - Greg Hussack
- Human Health Therapeutics Research Centre, National Research Council Canada, Ottawa, Ontario, Canada.
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10
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Böhning J, Dobbelstein AW, Sulkowski N, Eilers K, von Kügelgen A, Tarafder AK, Peak-Chew SY, Skehel M, Alva V, Filloux A, Bharat TAM. Architecture of the biofilm-associated archaic Chaperone-Usher pilus CupE from Pseudomonas aeruginosa. PLoS Pathog 2023; 19:e1011177. [PMID: 37058467 PMCID: PMC10104325 DOI: 10.1371/journal.ppat.1011177] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2022] [Accepted: 02/03/2023] [Indexed: 04/15/2023] Open
Abstract
Chaperone-Usher Pathway (CUP) pili are major adhesins in Gram-negative bacteria, mediating bacterial adherence to biotic and abiotic surfaces. While classical CUP pili have been extensively characterized, little is known about so-called archaic CUP pili, which are phylogenetically widespread and promote biofilm formation by several human pathogens. In this study, we present the electron cryomicroscopy structure of the archaic CupE pilus from the opportunistic human pathogen Pseudomonas aeruginosa. We show that CupE1 subunits within the pilus are arranged in a zigzag architecture, containing an N-terminal donor β-strand extending from each subunit into the next, where it is anchored by hydrophobic interactions, with comparatively weaker interactions at the rest of the inter-subunit interface. Imaging CupE pili on the surface of P. aeruginosa cells using electron cryotomography shows that CupE pili adopt variable curvatures in response to their environment, which might facilitate their role in promoting cellular attachment. Finally, bioinformatic analysis shows the widespread abundance of cupE genes in isolates of P. aeruginosa and the co-occurrence of cupE with other cup clusters, suggesting interdependence of cup pili in regulating bacterial adherence within biofilms. Taken together, our study provides insights into the architecture of archaic CUP pili, providing a structural basis for understanding their role in promoting cellular adhesion and biofilm formation in P. aeruginosa.
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Affiliation(s)
- Jan Böhning
- Sir William Dunn School of Pathology, University of Oxford, Oxford, United Kingdom
| | - Adrian W. Dobbelstein
- Department of Protein Evolution, Max Planck Institute for Biology Tübingen, Tübingen, Germany
| | - Nina Sulkowski
- Sir William Dunn School of Pathology, University of Oxford, Oxford, United Kingdom
| | - Kira Eilers
- Department of Life Sciences, MRC Centre for Molecular Bacteriology and Infection, Imperial College London, London, United Kingdom
| | - Andriko von Kügelgen
- Sir William Dunn School of Pathology, University of Oxford, Oxford, United Kingdom
| | - Abul K. Tarafder
- Sir William Dunn School of Pathology, University of Oxford, Oxford, United Kingdom
| | - Sew-Yeu Peak-Chew
- Cell Biology Division, MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge, United Kingdom
| | - Mark Skehel
- Proteomics Science Technology Platform, The Francis Crick Institute, London, United Kingdom
| | - Vikram Alva
- Department of Protein Evolution, Max Planck Institute for Biology Tübingen, Tübingen, Germany
| | - Alain Filloux
- Department of Life Sciences, MRC Centre for Molecular Bacteriology and Infection, Imperial College London, London, United Kingdom
| | - Tanmay A. M. Bharat
- Sir William Dunn School of Pathology, University of Oxford, Oxford, United Kingdom
- Structural Studies Division, MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge, United Kingdom
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11
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Shadan A, Pathak A, Ma Y, Pathania R, Singh RP. Deciphering the virulence factors, regulation, and immune response to Acinetobacter baumannii infection. Front Cell Infect Microbiol 2023; 13:1053968. [PMID: 36968113 PMCID: PMC10038080 DOI: 10.3389/fcimb.2023.1053968] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2022] [Accepted: 02/06/2023] [Indexed: 02/25/2023] Open
Abstract
Deciphering the virulence factors, regulation, and immune response to Acinetobacter baumannii infectionAcinetobacter baumannii is a gram-negative multidrug-resistant nosocomial pathogen and a major cause of hospital acquired infetions. Carbapenem resistant A. baumannii has been categorised as a Priority1 critial pathogen by the World Health Organisation. A. baumannii is responsible for infections in hospital settings, clinical sectors, ventilator-associated pneumonia, and bloodstream infections with a mortality rates up to 35%. With the development of advanced genome sequencing, molecular mechanisms of manipulating bacterial genomes, and animal infection studies, it has become more convenient to identify the factors that play a major role in A. baumannii infection and its persistence. In the present review, we have explored the mechanism of infection, virulence factors, and various other factors associated with the pathogenesis of this organism. Additionally, the role of the innate and adaptive immune response, and the current progress in the development of innovative strategies to combat this multidrug-resistant pathogen is also discussed.
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Affiliation(s)
- Afreen Shadan
- Department of Microbiology, Dr. Shyama Prasad Mukherjee University, Ranchi, Jharkhand, India
| | - Avik Pathak
- Department of Biosciences and Bioengineering, Indian Institute of Technology, Roorkee, India
| | - Ying Ma
- College of Resources and Environment, Southwest University, Chongqing, China
- *Correspondence: Ying Ma, ; Ranjana Pathania, ; Rajnish Prakash Singh,
| | - Ranjana Pathania
- Department of Biosciences and Bioengineering, Indian Institute of Technology, Roorkee, India
- *Correspondence: Ying Ma, ; Ranjana Pathania, ; Rajnish Prakash Singh,
| | - Rajnish Prakash Singh
- Department of Bioengineering and Biotechnology, Birla Institute of Technology, Ranchi, Jharkhand, India
- *Correspondence: Ying Ma, ; Ranjana Pathania, ; Rajnish Prakash Singh,
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12
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Yang N, Jin X, Zhu C, Gao F, Weng Z, Du X, Feng G. Subunit vaccines for Acinetobacter baumannii. Front Immunol 2023; 13:1088130. [PMID: 36713441 PMCID: PMC9878323 DOI: 10.3389/fimmu.2022.1088130] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2022] [Accepted: 12/22/2022] [Indexed: 01/15/2023] Open
Abstract
Acinetobacter baumannii is a gram-negative bacterium and a crucial opportunistic pathogen in hospitals. A. baumannii infection has become a challenging problem in clinical practice due to the increasing number of multidrug-resistant strains and their prevalence worldwide. Vaccines are effective tools to prevent and control A. baumannii infection. Many researchers are studying subunit vaccines against A. baumannii. Subunit vaccines have the advantages of high purity, safety, and stability, ease of production, and highly targeted induced immune responses. To date, no A. baumannii subunit vaccine candidate has entered clinical trials. This may be related to the easy degradation of subunit vaccines in vivo and weak immunogenicity. Using adjuvants or delivery vehicles to prepare subunit vaccines can slow down degradation and improve immunogenicity. The common immunization routes include intramuscular injection, subcutaneous injection, intraperitoneal injection and mucosal vaccination. The appropriate immunization method can also enhance the immune effect of subunit vaccines. Therefore, selecting an appropriate adjuvant and immunization method is essential for subunit vaccine research. This review summarizes the past exploration of A. baumannii subunit vaccines, hoping to guide current and future research on these vaccines.
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Affiliation(s)
- Ning Yang
- Department of Respiratory and Critical Care Medicine, The Second Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu, China
| | - Xiao Jin
- Department of Respiratory and Critical Care Medicine, The Second Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu, China
| | - Chenghua Zhu
- Department of Respiratory and Critical Care Medicine, The Second Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu, China
| | - Fenglin Gao
- Department of Respiratory and Critical Care Medicine, The Second Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu, China
| | - Zheqi Weng
- The Second Clinical Medical School of Nanjing Medical University, Nanjing, Jiangsu, China
| | - Xingran Du
- Department of Infectious Disease, The Second Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu, China,*Correspondence: Xingran Du, ; Ganzhu Feng,
| | - Ganzhu Feng
- Department of Respiratory and Critical Care Medicine, The Second Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu, China,*Correspondence: Xingran Du, ; Ganzhu Feng,
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13
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Dolma KG, Khati R, Paul AK, Rahmatullah M, de Lourdes Pereira M, Wilairatana P, Khandelwal B, Gupta C, Gautam D, Gupta M, Goyal RK, Wiart C, Nissapatorn V. Virulence Characteristics and Emerging Therapies for Biofilm-Forming Acinetobacter baumannii: A Review. BIOLOGY 2022; 11:biology11091343. [PMID: 36138822 PMCID: PMC9495682 DOI: 10.3390/biology11091343] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/18/2022] [Revised: 09/04/2022] [Accepted: 09/08/2022] [Indexed: 11/20/2022]
Abstract
Simple Summary Acinetobacter baumannii (A. baumannii) is one of the ESKAPE organisms and has the competency to build biofilms. These biofilms account for the most nosocomial infections all over the world. This review reflects on the various physicochemical and environmental factors such as adhesion, pili expression, growth surfaces, drug-resistant genes, and virulence factors that profoundly affect its resistant forte. Emerging drug-resistant issues and limitations to newer drugs are other factors affecting the hospital environment. Here, we discuss newer and alternative methods that can significantly enhance the susceptibility to Acinetobacter spp. Many new antibiotics are under trials, such as GSK-3342830, The Cefiderocol (S-649266), Fimsbactin, and similar. On the other hand, we can also see the impact of traditional medicine and the secondary metabolites of these natural products’ application in searching for new treatments. The field of nanoparticles has demonstrated effective antimicrobial actions and has exhibited encouraging results in the field of nanomedicine. The use of various phages such as vWUPSU and phage ISTD as an alternative treatment for its specificity and effectiveness is being investigated. Cathelicidins obtained synthetically or from natural sources can effectively produce antimicrobial activity in the micromolar range. Radioimmunotherapy and photodynamic therapy have boundless prospects if explored as a therapeutic antimicrobial strategy. Abstract Acinetobacter species is one of the most prevailing nosocomial pathogens with a potent ability to develop antimicrobial resistance. It commonly causes infections where there is a prolonged utilization of medical devices such as CSF shunts, catheters, endotracheal tubes, and similar. There are several strains of Acinetobacter (A) species (spp), among which the majority are pathogenic to humans, but A. baumannii are entirely resistant to several clinically available antibiotics. The crucial mechanism that renders them a multidrug-resistant strain is their potent ability to synthesize biofilms. Biofilms provide ample opportunity for the microorganisms to withstand the harsh environment and further cause chronic infections. Several studies have enumerated multiple physiological and virulence factors responsible for the production and maintenance of biofilms. To further enhance our understanding of this pathogen, in this review, we discuss its taxonomy, pathogenesis, current treatment options, global resistance rates, mechanisms of its resistance against various groups of antimicrobials, and future therapeutics.
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Affiliation(s)
- Karma G. Dolma
- Department of Microbiology, Sikkim Manipal Institute of Medical Sciences, Sikkim Manipal University, Gangtok 737102, Sikkim, India
| | - Rachana Khati
- Department of Microbiology, Sikkim Manipal Institute of Medical Sciences, Sikkim Manipal University, Gangtok 737102, Sikkim, India
| | - Alok K. Paul
- School of Pharmacy and Pharmacology, University of Tasmania, Hobart, TAS 7001, Australia
| | - Mohammed Rahmatullah
- Department of Biotechnology & Genetic Engineering, University of Development Alternative, Lalmatia, Dhaka 1207, Bangladesh
| | - Maria de Lourdes Pereira
- CICECO-Aveiro Institute of Materials, University of Aveiro, 3810-193 Aveiro, Portugal
- Department of Medical Sciences, University of Aveiro, 3810-193 Aveiro, Portugal
| | - Polrat Wilairatana
- Department of Clinical Tropical Medicine, Faculty of Tropical Medicine, Mahidol University, Bangkok 10400, Thailand
- Correspondence: (P.W.); (V.N.)
| | - Bidita Khandelwal
- Department of Medicine, Sikkim Manipal Institute of Medical Sciences, Sikkim Manipal University, Gangtok 737102, Sikkim, India
| | - Chamma Gupta
- Department of Biotechnology, Sikkim Manipal Institute of Medical Sciences, Sikkim Manipal University, Gangtok 737102, Sikkim, India
| | - Deepan Gautam
- Department of Microbiology, Sikkim Manipal Institute of Medical Sciences, Sikkim Manipal University, Gangtok 737102, Sikkim, India
| | - Madhu Gupta
- Department of Pharmaceutics, Delhi Pharmaceutical Sciences and Research University, New Delhi 110017, India
| | - Ramesh K. Goyal
- Department of Pharmaceutics, Delhi Pharmaceutical Sciences and Research University, New Delhi 110017, India
| | - Christophe Wiart
- Institute for Tropical Biology and Conservation, Universiti Malaysia Sabah, Kota Kinabalu 88400, Malaysia
| | - Veeranoot Nissapatorn
- School of Allied Health Sciences and World Union for Herbal Drug Discovery (WUHeDD), Walailak University, Nakhon Si Thammarat 80160, Thailand
- Correspondence: (P.W.); (V.N.)
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14
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Pakharukova N, Malmi H, Tuittila M, Dahlberg T, Ghosal D, Chang YW, Myint SL, Paavilainen S, Knight SD, Lamminmäki U, Uhlin BE, Andersson M, Jensen G, Zavialov AV. Archaic chaperone-usher pili self-secrete into superelastic zigzag springs. Nature 2022; 609:335-340. [PMID: 35853476 PMCID: PMC9452303 DOI: 10.1038/s41586-022-05095-0] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2021] [Accepted: 07/08/2022] [Indexed: 11/23/2022]
Abstract
Adhesive pili assembled through the chaperone-usher pathway are hair-like appendages that mediate host tissue colonization and biofilm formation of Gram-negative bacteria1-3. Archaic chaperone-usher pathway pili, the most diverse and widespread chaperone-usher pathway adhesins, are promising vaccine and drug targets owing to their prevalence in the most troublesome multidrug-resistant pathogens1,4,5. However, their architecture and assembly-secretion process remain unknown. Here, we present the cryo-electron microscopy structure of the prototypical archaic Csu pilus that mediates biofilm formation of Acinetobacter baumannii-a notorious multidrug-resistant nosocomial pathogen. In contrast to the thick helical tubes of the classical type 1 and P pili, archaic pili assemble into an ultrathin zigzag architecture secured by an elegant clinch mechanism. The molecular clinch provides the pilus with high mechanical stability as well as superelasticity, a property observed for the first time, to our knowledge, in biomolecules, while enabling a more economical and faster pilus production. Furthermore, we demonstrate that clinch formation at the cell surface drives pilus secretion through the outer membrane. These findings suggest that clinch-formation inhibitors might represent a new strategy to fight multidrug-resistant bacterial infections.
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Affiliation(s)
- Natalia Pakharukova
- Joint Biotechnology Laboratory, MediCity, Faculty of Medicine, University of Turku, Turku, Finland
| | - Henri Malmi
- Joint Biotechnology Laboratory, MediCity, Faculty of Medicine, University of Turku, Turku, Finland
| | - Minna Tuittila
- Joint Biotechnology Laboratory, MediCity, Faculty of Medicine, University of Turku, Turku, Finland
| | - Tobias Dahlberg
- Department of Physics, Umeå Centre for Microbial Research (UCMR), Umeå University, Umeå, Sweden
| | - Debnath Ghosal
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA
- Division of Medicine, Dentistry and Health Sciences, University of Melbourne, Parkville, Victoria, Australia
| | - Yi-Wei Chang
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA
- Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Si Lhyam Myint
- Department of Molecular Biology, The Laboratory for Molecular Infection Medicine Sweden (MIMS), Umeå Centre for Microbial Research (UCMR), Umeå University, Umeå, Sweden
| | - Sari Paavilainen
- Joint Biotechnology Laboratory, MediCity, Faculty of Medicine, University of Turku, Turku, Finland
| | - Stefan David Knight
- Department of Cell and Molecular Biology, Biomedical Centre, Uppsala University, Uppsala, Sweden
| | - Urpo Lamminmäki
- Department of Life Technologies, University of Turku, Turku, Finland
| | - Bernt Eric Uhlin
- Department of Molecular Biology, The Laboratory for Molecular Infection Medicine Sweden (MIMS), Umeå Centre for Microbial Research (UCMR), Umeå University, Umeå, Sweden
| | - Magnus Andersson
- Department of Physics, Umeå Centre for Microbial Research (UCMR), Umeå University, Umeå, Sweden
| | - Grant Jensen
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA
| | - Anton V Zavialov
- Joint Biotechnology Laboratory, MediCity, Faculty of Medicine, University of Turku, Turku, Finland.
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15
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Murph M, Singh S, Schvarzstein M. A combined in silico and in vivo approach to the structure-function annotation of SPD-2 provides mechanistic insight into its functional diversity. Cell Cycle 2022; 21:1958-1979. [PMID: 35678569 PMCID: PMC9415446 DOI: 10.1080/15384101.2022.2078458] [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: 07/26/2021] [Revised: 04/10/2022] [Accepted: 05/04/2022] [Indexed: 11/03/2022] Open
Abstract
Centrosomes are organelles that function as hubs of microtubule nucleation and organization, with key roles in organelle positioning, asymmetric cell division, ciliogenesis, and signaling. Aberrant centrosome number, structure or function is linked to neurodegenerative diseases, developmental abnormalities, ciliopathies, and tumor development. A major regulator of centrosome biogenesis and function in C. elegans is the conserved Spindle-defective protein 2 (SPD-2), a homolog of the human CEP-192 protein. CeSPD-2 is required for centrosome maturation, centriole duplication, spindle assembly and possibly cell polarity establishment. Despite its importance, the specific molecular mechanism of CeSPD-2 regulation and function is poorly understood. Here, we combined computational analysis with cell biology approaches to uncover possible structure-function relationships of CeSPD-2 that may shed mechanistic light on its function. Domain prediction analysis corroborated and refined previously identified coiled-coils and ASH (Aspm-SPD-2 Hydin) domains and identified new domains: a GEF domain, an Ig-like domain, and a PDZ-like domain. In addition to these predicted structural features, CeSPD-2 is also predicted to be intrinsically disordered. Surface electrostatic maps identified a large basic region unique to the ASH domain of CeSPD-2. This basic region overlaps with most of the residues predicted to be involved in protein-protein interactions. In vivo, ASH::GFP localized to centrosomes and centrosome-associated microtubules. Our analysis groups ASH domains, PapD, Usher chaperone domains, and Major Sperm Protein (MSP) domains into a single superfold within the larger Immunoglobulin superfamily. This study lays the groundwork for designing rational hypothesis-based experiments to uncover the mechanisms of CeSPD-2 function in vivo.Abbreviations: AIR, Aurora kinase; ASH, Aspm-SPD-2 Hydin; ASP, Abnormal Spindle Protein; ASPM, Abnormal Spindle-like Microcephaly-associated Protein; CC, coiled-coil; CDK, Cyclin-dependent Kinase; Ce, Caenorhabditis elegans; CEP, Centrosomal Protein; CPAP, centrosomal P4.1-associated protein; D, Drosophila; GAP, GTPase activating protein; GEF, GTPase guanine nucleotide exchange factor; Hs, Homo sapiens/Human; Ig, Immunoglobulin; MAP, Microtubule associated Protein; MSP, Major Sperm Protein; MDP, Major Sperm Domain-Containing Protein; OCRL-1, Golgi endocytic trafficking protein Inositol polyphosphate 5-phosphatase; PAR, abnormal embryonic PARtitioning of the cytosol; PCM, Pericentriolar material; PCMD, pericentriolar matrix deficient; PDZ, PSD95/Dlg-1/zo-1; PLK, Polo like kinase; RMSD, Root Mean Square Deviation; SAS, Spindle assembly abnormal proteins; SPD, Spindle-defective protein; TRAPP, TRAnsport Protein Particle; Xe, Xenopus; ZYG, zygote defective protein.
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Affiliation(s)
- Mikaela Murph
- Department of Biology, City University of New York, Brooklyn College, New York, NY, USA
| | - Shaneen Singh
- Department of Biology, City University of New York, Brooklyn College, New York, NY, USA
- Department of Biology, The Graduate Center at City University of New York, New York, NY, USA
- Department Biochemistry, The Graduate Center at City University of New York, New York, NY, USA
| | - Mara Schvarzstein
- Department of Biology, City University of New York, Brooklyn College, New York, NY, USA
- Department of Biology, The Graduate Center at City University of New York, New York, NY, USA
- Department Biochemistry, The Graduate Center at City University of New York, New York, NY, USA
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16
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Massier S, Robin B, Mégroz M, Wright A, Harper M, Hayes B, Cosette P, Broutin I, Boyce JD, Dé E, Hardouin J. Phosphorylation of Extracellular Proteins in Acinetobacter baumannii in Sessile Mode of Growth. Front Microbiol 2021; 12:738780. [PMID: 34659171 PMCID: PMC8517400 DOI: 10.3389/fmicb.2021.738780] [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: 07/09/2021] [Accepted: 08/30/2021] [Indexed: 11/21/2022] Open
Abstract
Acinetobacter baumannii is a problematic nosocomial pathogen owing to its increasing resistance to antibiotics and its great ability to survive in the hospital environment, which is linked to its capacity to form biofilms. Structural and functional investigations of post-translational modifications, such as phosphorylations, may lead to identification of candidates for therapeutic targets against this pathogen. Here, we present the first S/T/Y phosphosecretome of two A. baumannii strains, the reference strain ATCC 17978 and the virulent multi-drug resistant strain AB0057, cultured in two modes of growth (planktonic and biofilm) using TiO2 chromatography followed by high resolution mass spectrometry. In ATCC 17978, we detected a total of 137 (97 phosphoproteins) and 52 (33 phosphoproteins) phosphosites in biofilm and planktonic modes of growth, respectively. Similarly, in AB0057, 155 (119 phosphoproteins) and 102 (74 phosphoproteins) phosphosites in biofilm and planktonic modes of growth were identified, respectively. Both strains in the biofilm mode of growth showed a higher number of phosphosites and phosphoproteins compared to planktonic growth. Several phosphorylated sites are localized in key regions of proteins involved in either drug resistance (β-lactamases), adhesion to host tissues (pilins), or protein secretion (Hcp). Site-directed mutagenesis of the Hcp protein, essential for type VI secretion system-mediated interbacterial competition, showed that four of the modified residues are essential for type VI secretion system activity.
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Affiliation(s)
- Sébastien Massier
- Normandie Univ., UNIROUEN, INSA Rouen, CNRS, Polymers, Biopolymers, Surfaces Laboratory, Rouen, France
- PISSARO Proteomic Facility, IRIB, Mont-Saint-Aignan, France
| | - Brandon Robin
- Normandie Univ., UNIROUEN, INSA Rouen, CNRS, Polymers, Biopolymers, Surfaces Laboratory, Rouen, France
| | - Marianne Mégroz
- Infection and Immunity Program, Department of Microbiology, Monash Biomedicine Discovery Institute, Monash University, Melbourne, VIC, Australia
| | - Amy Wright
- Infection and Immunity Program, Department of Microbiology, Monash Biomedicine Discovery Institute, Monash University, Melbourne, VIC, Australia
| | - Marina Harper
- Infection and Immunity Program, Department of Microbiology, Monash Biomedicine Discovery Institute, Monash University, Melbourne, VIC, Australia
| | - Brooke Hayes
- Infection and Immunity Program, Department of Microbiology, Monash Biomedicine Discovery Institute, Monash University, Melbourne, VIC, Australia
| | - Pascal Cosette
- Normandie Univ., UNIROUEN, INSA Rouen, CNRS, Polymers, Biopolymers, Surfaces Laboratory, Rouen, France
- PISSARO Proteomic Facility, IRIB, Mont-Saint-Aignan, France
| | | | - John D. Boyce
- Infection and Immunity Program, Department of Microbiology, Monash Biomedicine Discovery Institute, Monash University, Melbourne, VIC, Australia
| | - Emmanuelle Dé
- Normandie Univ., UNIROUEN, INSA Rouen, CNRS, Polymers, Biopolymers, Surfaces Laboratory, Rouen, France
| | - Julie Hardouin
- Normandie Univ., UNIROUEN, INSA Rouen, CNRS, Polymers, Biopolymers, Surfaces Laboratory, Rouen, France
- PISSARO Proteomic Facility, IRIB, Mont-Saint-Aignan, France
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17
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He LH, Wang H, Liu Y, Kang M, Li T, Li CC, Tong AP, Zhu YB, Song YJ, Savarino SJ, Prouty MG, Xia D, Bao R. Chaperone-tip adhesin complex is vital for synergistic activation of CFA/I fimbriae biogenesis. PLoS Pathog 2020; 16:e1008848. [PMID: 33007034 PMCID: PMC7531860 DOI: 10.1371/journal.ppat.1008848] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2019] [Accepted: 07/30/2020] [Indexed: 02/05/2023] Open
Abstract
Colonization factor CFA/I defines the major adhesive fimbriae of enterotoxigenic Escherichia coli and mediates bacterial attachment to host intestinal epithelial cells. The CFA/I fimbria consists of a tip-localized minor adhesive subunit, CfaE, and thousands of copies of the major subunit CfaB polymerized into an ordered helical rod. Biosynthesis of CFA/I fimbriae requires the assistance of the periplasmic chaperone CfaA and outer membrane usher CfaC. Although the CfaE subunit is proposed to initiate the assembly of CFA/I fimbriae, how it performs this function remains elusive. Here, we report the establishment of an in vitro assay for CFA/I fimbria assembly and show that stabilized CfaA-CfaB and CfaA-CfaE binary complexes together with CfaC are sufficient to drive fimbria formation. The presence of both CfaA-CfaE and CfaC accelerates fimbria formation, while the absence of either component leads to linearized CfaB polymers in vitro. We further report the crystal structure of the stabilized CfaA-CfaE complex, revealing features unique for biogenesis of Class 5 fimbriae.
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Affiliation(s)
- Li-hui He
- Center of Infectious Diseases, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu, China
| | - Hao Wang
- Henry M. Jackson Foundation for the Advancement of Military Medicine, Bethesda, MD, United States of America
- Enteric Diseases Department, Infectious Diseases Directorate, Naval Medical Research Center, Silver Spring, MD, United States of America
| | - Yang Liu
- Henry M. Jackson Foundation for the Advancement of Military Medicine, Bethesda, MD, United States of America
- Enteric Diseases Department, Infectious Diseases Directorate, Naval Medical Research Center, Silver Spring, MD, United States of America
| | - Mei Kang
- Department of Laboratory medicine, West China Hospital, Sichuan University, Chengdu, China
| | - Tao Li
- Center of Infectious Diseases, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu, China
| | - Chang-cheng Li
- Center of Infectious Diseases, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu, China
| | - Ai-ping Tong
- Center of Infectious Diseases, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu, China
| | - Yi-bo Zhu
- Center of Infectious Diseases, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu, China
| | - Ying-jie Song
- Center of Infectious Diseases, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu, China
| | - Stephen J. Savarino
- Enteric Diseases Department, Infectious Diseases Directorate, Naval Medical Research Center, Silver Spring, MD, United States of America
- Department of Pediatrics, Uniformed Services University of the Health Sciences, Bethesda, MD, United States of America
| | - Michael G. Prouty
- Enteric Diseases Department, Infectious Diseases Directorate, Naval Medical Research Center, Silver Spring, MD, United States of America
| | - Di Xia
- Laboratory of Cell Biology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD, United States of America
| | - Rui Bao
- Center of Infectious Diseases, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu, China
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18
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Ramezanalizadeh F, Owlia P, Rasooli I. Type I pili, CsuA/B and FimA induce a protective immune response against Acinetobacter baumannii. Vaccine 2020; 38:5436-5446. [DOI: 10.1016/j.vaccine.2020.06.052] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2019] [Revised: 06/02/2020] [Accepted: 06/18/2020] [Indexed: 12/13/2022]
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19
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Rehman T, Yin L, Latif MB, Chen J, Wang K, Geng Y, Huang X, Abaidullah M, Guo H, Ouyang P. Adhesive mechanism of different Salmonella fimbrial adhesins. Microb Pathog 2019; 137:103748. [PMID: 31521802 DOI: 10.1016/j.micpath.2019.103748] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2019] [Revised: 09/10/2019] [Accepted: 09/11/2019] [Indexed: 02/01/2023]
Abstract
Salmonellosis is a serious threat to human and animal health. Salmonella adhesion to the host cell is an initial and most crucial step in the pathogenesis of salmonellosis. Many factors are involved in the adhesion process of Salmonella infection. Fimbriae are one of the most important factors in the adhesion of Salmonella. The Salmonella fimbriae are assembled in three types of assembly pathways: chaperon-usher, nucleation-precipitation, and type IV fimbriae. These assembly pathways lead to multiple types of fimbriae. Salmonella fimbriae bind to host cell receptors to initiate adhesion. So far, many receptors have been identified, such as Toll-like receptors. However, several receptors that may be involved in the adhesive mechanism of Salmonella fimbriae are still un-identified. This review aimed to summarize the types of Salmonella fimbriae produced by different assembly pathways and their role in adhesion. It also enlisted previously discovered receptors involved in adhesion. This review might help readers to develop a comprehensive understanding of Salmonella fimbriae, their role in adhesion, and recently developed strategies to counter Salmonella infection.
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Affiliation(s)
- Tayyab Rehman
- Department of Basic Veterinary, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, 611130, Sichuan, China.
| | - Lizi Yin
- Department of Basic Veterinary, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, 611130, Sichuan, China.
| | - Muhammad Bilal Latif
- Department of Inflammation and Immunity, Lerner Research Institute, Cleveland Clinic Foundation, Cleveland, 44195, Ohio, USA.
| | - Jiehao Chen
- Department of Basic Veterinary, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, 611130, Sichuan, China.
| | - Kaiyu Wang
- Department of Basic Veterinary, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, 611130, Sichuan, China.
| | - Yi Geng
- Department of Basic Veterinary, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, 611130, Sichuan, China.
| | - Xiaoli Huang
- Department of Aquaculture, College of Animal Science and Technology, Sichuan Agricultural University, Chengdu, 611130, Sichuan, China.
| | - Muhammad Abaidullah
- Department of Basic Veterinary, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, 611130, Sichuan, China.
| | - Hongrui Guo
- Department of Basic Veterinary, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, 611130, Sichuan, China.
| | - Ping Ouyang
- Department of Basic Veterinary, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, 611130, Sichuan, China.
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20
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Classical chaperone-usher (CU) adhesive fimbriome: uropathogenic Escherichia coli (UPEC) and urinary tract infections (UTIs). Folia Microbiol (Praha) 2019; 65:45-65. [DOI: 10.1007/s12223-019-00719-x] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2018] [Accepted: 05/20/2019] [Indexed: 12/17/2022]
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21
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Pakharukova N, McKenna S, Tuittila M, Paavilainen S, Malmi H, Xu Y, Parilova O, Matthews S, Zavialov AV. Archaic and alternative chaperones preserve pilin folding energy by providing incomplete structural information. J Biol Chem 2018; 293:17070-17080. [PMID: 30228191 DOI: 10.1074/jbc.ra118.004170] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2018] [Revised: 09/14/2018] [Indexed: 11/06/2022] Open
Abstract
Adhesive pili are external component of fibrous adhesive organelles and help bacteria attach to biotic or abiotic surfaces. The biogenesis of adhesive pili via the chaperone-usher pathway (CUP) is independent of external energy sources. In the classical CUP, chaperones transport assembly-competent pilins in a folded but expanded conformation. During donor-strand exchange, pilins subsequently collapse, producing a tightly packed hydrophobic core and releasing the necessary free energy to drive fiber formation. Here, we show that pilus biogenesis in non-classical, archaic, and alternative CUPs uses a different source of conformational energy. High-resolution structures of the archaic Csu-pili system from Acinetobacter baumannii revealed that non-classical chaperones employ a short donor strand motif that is insufficient to fully complement the pilin fold. This results in chaperone-bound pilins being trapped in a substantially unfolded intermediate. The exchange of this short motif with the longer donor strand from adjacent pilin provides the full steric information essential for folding, and thereby induces a large unfolded-to-folded conformational transition to drive assembly. Our findings may inform the development of anti-adhesion drugs (pilicides) to combat bacterial infections.
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Affiliation(s)
- Natalia Pakharukova
- From the Department of Chemistry, University of Turku, Joint Biotechnology Laboratory (JBL), Arcanum, Vatselankatu 2, Turku FIN-20500, Finland and
| | - Sophie McKenna
- the Department of Life Sciences, Imperial College London, South Kensington Campus, London SW72AZ, United Kingdom
| | - Minna Tuittila
- From the Department of Chemistry, University of Turku, Joint Biotechnology Laboratory (JBL), Arcanum, Vatselankatu 2, Turku FIN-20500, Finland and
| | - Sari Paavilainen
- From the Department of Chemistry, University of Turku, Joint Biotechnology Laboratory (JBL), Arcanum, Vatselankatu 2, Turku FIN-20500, Finland and
| | - Henri Malmi
- From the Department of Chemistry, University of Turku, Joint Biotechnology Laboratory (JBL), Arcanum, Vatselankatu 2, Turku FIN-20500, Finland and
| | - Yingqi Xu
- the Department of Life Sciences, Imperial College London, South Kensington Campus, London SW72AZ, United Kingdom
| | - Olena Parilova
- From the Department of Chemistry, University of Turku, Joint Biotechnology Laboratory (JBL), Arcanum, Vatselankatu 2, Turku FIN-20500, Finland and
| | - Steve Matthews
- the Department of Life Sciences, Imperial College London, South Kensington Campus, London SW72AZ, United Kingdom
| | - Anton V Zavialov
- From the Department of Chemistry, University of Turku, Joint Biotechnology Laboratory (JBL), Arcanum, Vatselankatu 2, Turku FIN-20500, Finland and
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22
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Abstract
Nosocomial infections and infections of indwelling devices are major healthcare problems worldwide. These infections are strongly associated with the ability of pathogens to form biofilms on biotic and abiotic surfaces. Panantibiotic-resistant Acinetobacter baumannii is one of the most troublesome pathogens, capable of colonizing medical devices by means of Csu pili, an adhesive organelle that belongs to the widespread class of archaic chaperone–usher pili. Here, we report an atomic-resolution insight into the mechanism of bacterial attachment to abiotic surfaces. We show that archaic pili use a binding mechanism that enables bacterial adhesion to structurally variable substrates. The results suggest a simple and cheap solution to reduce infections of A. baumannii and related pathogens. Acinetobacter baumannii—a leading cause of nosocomial infections—has a remarkable capacity to persist in hospital environments and medical devices due to its ability to form biofilms. Biofilm formation is mediated by Csu pili, assembled via the “archaic” chaperone–usher pathway. The X-ray structure of the CsuC-CsuE chaperone–adhesin preassembly complex reveals the basis for bacterial attachment to abiotic surfaces. CsuE exposes three hydrophobic finger-like loops at the tip of the pilus. Decreasing the hydrophobicity of these abolishes bacterial attachment, suggesting that archaic pili use tip-fingers to detect and bind to hydrophobic cavities in substrates. Antitip antibody completely blocks biofilm formation, presenting a means to prevent the spread of the pathogen. The use of hydrophilic materials instead of hydrophobic plastics in medical devices may represent another simple and cheap solution to reduce pathogen spread. Phylogenetic analysis suggests that the tip-fingers binding mechanism is shared by all archaic pili carrying two-domain adhesins. The use of flexible fingers instead of classical receptor-binding cavities is presumably more advantageous for attachment to structurally variable substrates, such as abiotic surfaces.
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23
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Subinhibitory Concentrations of Trimethoprim and Sulfamethoxazole Prevent Biofilm Formation by Acinetobacter baumannii through Inhibition of Csu Pilus Expression. Antimicrob Agents Chemother 2017; 61:AAC.00778-17. [PMID: 28674047 DOI: 10.1128/aac.00778-17] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2017] [Accepted: 06/25/2017] [Indexed: 12/25/2022] Open
Abstract
Acinetobacter baumannii is emerging as a multidrug-resistant nosocomial pathogen of increasing threat to human health worldwide. Pili are important bacterial virulence factors, playing a role in attachment to host cells and biofilm formation. The Csu pilus, which is assembled via the chaperone-usher secretion system, has been studied in A. baumannii ATCC 19606. Here we show that, in opposition to previous reports, the common laboratory strain ATCC 17978 produces Csu pili. We found that, although ATCC 17978 was resistant to sulfamethoxazole (Smx) and trimethoprim (Tmp), subinhibitory concentrations of these antibiotics abolished the expression of Csu and consequently produced a dramatic reduction in biofilm formation by ATCC 17978. Smx and Tmp acted synergistically to inhibit the enzymatic systems involved in the bacterial synthesis of tetrahydrofolate (THF), which is required for the synthesis of nucleotides. The effects of these antibiotics were partially relieved by exogenous THF addition, indicating that Smx and Tmp turn off Csu assembly by inducing folate stress. We propose that, for Acinetobacter, nanomolar concentrations of Smx and Tmp represent a "danger signal." In response to this signal, Csu expression is repressed, allowing biofilm dispersal and escape from potentially inhibitory concentrations of antibiotics. The roles of antibiotics as signaling molecules are being increasingly acknowledged, with clear implications for both the treatment of bacterial diseases and the understanding of complex microbial interactions in the environment.
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24
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Pakharukova N, Tuittila M, Paavilainen S, Zavialov A. Methylation, crystallization and SAD phasing of the Csu pilus CsuC-CsuE chaperone-adhesin subunit pre-assembly complex from Acinetobacter baumannii. Acta Crystallogr F Struct Biol Commun 2017; 73:450-454. [PMID: 28777087 PMCID: PMC5544001 DOI: 10.1107/s2053230x17009566] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2017] [Accepted: 06/27/2017] [Indexed: 11/10/2022] Open
Abstract
Acinetobacter baumannii is one of the most difficult Gram-negative bacteria to control and treat. This pathogen forms biofilms on hospital surfaces and medical devices using Csu pili assembled via the archaic chaperone-usher pathway. To uncover the mechanism of bacterial attachment to abiotic surfaces, it was aimed to determine the crystal structure of the pilus tip adhesin CsuE. The CsuC-CsuE chaperone-subunit pre-assembly complex was purified from the periplasm of Escherichia coli overexpressing CsuC and CsuE. Despite the high purity of the complex, no crystals could be obtained. This challenge was solved by the methylation of lysine residues. The complex was crystallized in 0.1 M bis-tris pH 5.5, 17% PEG 3350 using the hanging-drop vapour-diffusion method. The crystals diffracted to a resolution of 2.31 Å and belonged to the triclinic space group P1, with unit-cell parameters a = 53.84, b = 63.85, c = 89.25 Å, α = 74.65, β = 79.65, γ = 69.07°. Initial phases were derived from a single anomalous diffraction experiment using a selenomethionine derivative.
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Affiliation(s)
- Natalia Pakharukova
- Department of Chemistry, University of Turku, Joint Biotechnology Laboratory, Arcanum, Vatselankatu 2, 20500 Turku, Finland
| | - Minna Tuittila
- Department of Chemistry, University of Turku, Joint Biotechnology Laboratory, Arcanum, Vatselankatu 2, 20500 Turku, Finland
| | - Sari Paavilainen
- Department of Chemistry, University of Turku, Joint Biotechnology Laboratory, Arcanum, Vatselankatu 2, 20500 Turku, Finland
| | - Anton Zavialov
- Department of Chemistry, University of Turku, Joint Biotechnology Laboratory, Arcanum, Vatselankatu 2, 20500 Turku, Finland
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25
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Bao R, Liu Y, Savarino SJ, Xia D. Off-pathway assembly of fimbria subunits is prevented by chaperone CfaA of CFA/I fimbriae from enterotoxigenic E. coli. Mol Microbiol 2016; 102:975-991. [PMID: 27627030 DOI: 10.1111/mmi.13530] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2016] [Revised: 09/10/2016] [Accepted: 09/12/2016] [Indexed: 11/29/2022]
Abstract
The assembly of the class 5 colonization factor antigen I (CFA/I) fimbriae of enterotoxigenic E. coli was proposed to proceed via the alternate chaperone-usher pathway. Here, we show that in the absence of the chaperone CfaA, CfaB, the major pilin subunit of CFA/I fimbriae, is able to spontaneously refold and polymerize into cyclic trimers. CfaA kinetically traps CfaB to form a metastable complex that can be stabilized by mutations. Crystal structure of the stabilized complex reveals distinctive interactions provided by CfaA to trap CfaB in an assembly competent state through donor-strand complementation (DSC) and cleft-mediated anchorage. Mutagenesis indicated that DSC controls the stability of the chaperone-subunit complex and the cleft-mediated anchorage of the subunit C-terminus additionally assist in subunit refolding. Surprisingly, over-stabilization of the chaperone-subunit complex led to delayed fimbria assembly, whereas destabilizing the complex resulted in no fimbriation. Thus, CfaA acts predominantly as a kinetic trap by stabilizing subunit to avoid its off-pathway self-polymerization that results in energetically favorable trimers and could serve as a driving force for CFA/I pilus assembly, representing an energetic landscape unique to class 5 fimbria assembly.
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Affiliation(s)
- Rui Bao
- Division of Infectious Diseases, National Key Laboratory of Biotherapy/Collaborative Innovation Center of Biotherapy, West China Hospitals, Sichuan University, Chengdu, 610041, China.,Laboratory of Cell Biology, Center for Cancer Research, National Cancer Institute, NIH, Bethesda, MD, 20892, USA
| | - Yang Liu
- Enteric Diseases Department, Infectious Diseases Directorate, Naval Medical Research Center, Silver Spring, MD, 20910-7500, USA
| | - Stephen J Savarino
- Enteric Diseases Department, Infectious Diseases Directorate, Naval Medical Research Center, Silver Spring, MD, 20910-7500, USA.,Department of Pediatrics, Uniformed Services University of the Health Sciences, Bethesda, MD, 20814-4799, USA
| | - Di Xia
- Laboratory of Cell Biology, Center for Cancer Research, National Cancer Institute, NIH, Bethesda, MD, 20892, USA
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26
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Pakharukova N, Roy S, Tuittila M, Rahman MM, Paavilainen S, Ingars AK, Skaldin M, Lamminmäki U, Härd T, Teneberg S, Zavialov AV. Structural basis for Myf and Psa fimbriae-mediated tropism of pathogenic strains of Yersinia for host tissues. Mol Microbiol 2016; 102:593-610. [PMID: 27507539 DOI: 10.1111/mmi.13481] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/09/2016] [Indexed: 02/06/2023]
Abstract
Three pathogenic species of the genus Yersinia assemble adhesive fimbriae via the FGL-chaperone/usher pathway. Closely related Y. pestis and Y. pseudotuberculosis elaborate the pH6 antigen (Psa), which mediates bacterial attachment to alveolar cells of the lung. Y. enterocolitica, instead, assembles the homologous fimbriae Myf of unknown function. Here, we discovered that Myf, like Psa, specifically recognizes β1-3- or β1-4-linked galactose in glycosphingolipids, but completely lacks affinity for phosphatidylcholine, the main receptor for Psa in alveolar cells. The crystal structure of a subunit of Psa (PsaA) complexed with choline together with mutagenesis experiments revealed that PsaA has four phosphatidylcholine binding pockets that enable super-high-avidity binding of Psa-fibres to cell membranes. The pockets are arranged as six tyrosine residues, which are all missing in the MyfA subunit of Myf. Conversely, the crystal structure of the MyfA-galactose complex revealed that the galactose-binding site is more extended in MyfA, enabling tighter binding to lactosyl moieties. Our results suggest that during evolution, Psa has acquired a tyrosine-rich surface that enables it to bind to phosphatidylcholine and mediate adhesion of Y. pestis/pseudotuberculosis to alveolar cells, whereas Myf has specialized as a carbohydrate-binding adhesin, facilitating the attachment of Y. enterocolitica to intestinal cells.
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Affiliation(s)
- Natalia Pakharukova
- Department of Chemistry, University of Turku, Turku, Joint Biotechnology Laboratory, Arcanum, Vatselankatu 2, Turku, 20500, Finland
| | - Saumendra Roy
- Department of Chemistry, University of Turku, Turku, Joint Biotechnology Laboratory, Arcanum, Vatselankatu 2, Turku, 20500, Finland.,Department of Chemistry and Biotechnology, Swedish University of Agricultural Sciences, Uppsala BioCentre, P.O. BOX 7016, Uppsala, 75007, Sweden
| | - Minna Tuittila
- Department of Chemistry, University of Turku, Turku, Joint Biotechnology Laboratory, Arcanum, Vatselankatu 2, Turku, 20500, Finland
| | - Mohammad M Rahman
- Department of Chemistry, University of Turku, Turku, Joint Biotechnology Laboratory, Arcanum, Vatselankatu 2, Turku, 20500, Finland
| | - Sari Paavilainen
- Department of Chemistry, University of Turku, Turku, Joint Biotechnology Laboratory, Arcanum, Vatselankatu 2, Turku, 20500, Finland
| | - Anna-Karin Ingars
- Department of Medical Biochemistry and Cell Biology, Institute of Biomedicine, The Sahlgrenska Academy, University of Gothenburg, P.O. BOX 440, Göteborg, 40530, Sweden
| | - Maksym Skaldin
- Department of Chemistry, University of Turku, Turku, Joint Biotechnology Laboratory, Arcanum, Vatselankatu 2, Turku, 20500, Finland.,Department of Biochemistry/Biotechnology, University of Turku, Tykistökatu 6A, Turku, 20014, Finland
| | - Urpo Lamminmäki
- Department of Biochemistry/Biotechnology, University of Turku, Tykistökatu 6A, Turku, 20014, Finland
| | - Torleif Härd
- Department of Chemistry and Biotechnology, Swedish University of Agricultural Sciences, Uppsala BioCentre, P.O. BOX 7016, Uppsala, 75007, Sweden
| | - Susann Teneberg
- Department of Medical Biochemistry and Cell Biology, Institute of Biomedicine, The Sahlgrenska Academy, University of Gothenburg, P.O. BOX 440, Göteborg, 40530, Sweden
| | - Anton V Zavialov
- Department of Chemistry, University of Turku, Turku, Joint Biotechnology Laboratory, Arcanum, Vatselankatu 2, Turku, 20500, Finland.,Department of Chemistry and Biotechnology, Swedish University of Agricultural Sciences, Uppsala BioCentre, P.O. BOX 7016, Uppsala, 75007, Sweden
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27
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Pérez-Llarena FJ, Bou G. Proteomics As a Tool for Studying Bacterial Virulence and Antimicrobial Resistance. Front Microbiol 2016; 7:410. [PMID: 27065974 PMCID: PMC4814472 DOI: 10.3389/fmicb.2016.00410] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2015] [Accepted: 03/14/2016] [Indexed: 12/31/2022] Open
Abstract
Proteomic studies have improved our understanding of the microbial world. The most recent advances in this field have helped us to explore aspects beyond genomics. For example, by studying proteins and their regulation, researchers now understand how some pathogenic bacteria have adapted to the lethal actions of antibiotics. Proteomics has also advanced our knowledge of mechanisms of bacterial virulence and some important aspects of how bacteria interact with human cells and, thus, of the pathogenesis of infectious diseases. This review article addresses these issues in some of the most important human pathogens. It also reports some applications of Matrix-Assisted Laser Desorption/Ionization-Time-Of-Flight (MALDI-TOF) mass spectrometry that may be important for the diagnosis of bacterial resistance in clinical laboratories in the future. The reported advances will enable new diagnostic and therapeutic strategies to be developed in the fight against some of the most lethal bacteria affecting humans.
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Affiliation(s)
| | - Germán Bou
- Servicio de Microbiología-INIBIC, Complejo Hospitalario Universitario A Coruña A Coruña, Spain
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