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Egge SL, Rizvi SA, Simar SR, Alcalde M, Martinez JRW, Hanson BM, Dinh AQ, Baptista RP, Tran TT, Shelburne SA, Munita JM, Arias CA, Hakki M, Miller WR. Cefiderocol heteroresistance associated with mutations in TonB-dependent receptor genes in Pseudomonas aeruginosa of clinical origin. Antimicrob Agents Chemother 2024; 68:e0012724. [PMID: 38995033 PMCID: PMC11304687 DOI: 10.1128/aac.00127-24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2024] [Accepted: 06/01/2024] [Indexed: 07/13/2024] Open
Abstract
The siderophore-cephalosporin cefiderocol (FDC) presents a promising treatment option for carbapenem-resistant (CR) P. aeruginosa (PA). FDC circumvents traditional porin and efflux-mediated resistance by utilizing TonB-dependent receptors (TBDRs) to access the periplasmic space. Emerging FDC resistance has been associated with loss of function mutations within TBDR genes or the regulatory genes controlling TBDR expression. Further, difficulties with antimicrobial susceptibility testing (AST) and unexpected negative clinical treatment outcomes have prompted concerns for heteroresistance, where a single lineage isolate contains resistant subpopulations not detectable by standard AST. This study aimed to evaluate the prevalence of TBDR mutations among clinical isolates of P. aeruginosa and the phenotypic effect on FDC susceptibility and heteroresistance. We evaluated the sequence of pirR, pirS, pirA, piuA, or piuD from 498 unique isolates collected before the introduction of FDC from four clinical sites in Portland, OR (1), Houston, TX (2), and Santiago, Chile (1). At some clinical sites, TBDR mutations were seen in up to 25% of isolates, and insertion, deletion, or frameshift mutations were predicted to impair protein function were seen in 3% of all isolates (n = 15). Using population analysis profile testing, we found that P. aeruginosa with major TBDR mutations were enriched for a heteroresistant phenotype and undergo a shift in the susceptibility distribution of the population as compared to susceptible strains with wild-type TBDR genes. Our results indicate that mutations in TBDR genes predate the clinical introduction of FDC, and these mutations may predispose to the emergence of FDC resistance.
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Affiliation(s)
- Stephanie L. Egge
- Division of Infectious Diseases, Houston Methodist Hospital, Houston, Texas, USA
- Center for Infectious Diseases, Houston Methodist Research Institute, Houston, Texas, USA
- Department of Medicine, Division of Infectious Diseases, Oregon Health and Science University, Portland, Oregon, USA
| | - Samie A. Rizvi
- Division of Infectious Diseases, Houston Methodist Hospital, Houston, Texas, USA
- Center for Infectious Diseases, Houston Methodist Research Institute, Houston, Texas, USA
| | - Shelby R. Simar
- UTHealth Houston School of Public Health, University of Texas Health Science Center, Houston, Texas, USA
| | - Manuel Alcalde
- Instituto de Ciencias e Innovación en Medicina (ICIM), Facultad de Medicina Clinica Alemana, Universidad del Desarrollo and Multidisciplinary Initiative for Collaborative Research On Bacterial Resistance (MICROB-R), Santiago, Chile
- Instituto de Biomedicina de Sevilla (IBiS), Hospital Universitario Virgen Macarena, CSIC, Universidad de Sevilla, Seville, Spain
| | - Jose R. W. Martinez
- Instituto de Ciencias e Innovación en Medicina (ICIM), Facultad de Medicina Clinica Alemana, Universidad del Desarrollo and Multidisciplinary Initiative for Collaborative Research On Bacterial Resistance (MICROB-R), Santiago, Chile
| | - Blake M. Hanson
- UTHealth Houston School of Public Health, University of Texas Health Science Center, Houston, Texas, USA
| | - An Q. Dinh
- Division of Infectious Diseases, Houston Methodist Hospital, Houston, Texas, USA
- Center for Infectious Diseases, Houston Methodist Research Institute, Houston, Texas, USA
| | - Rodrigo P. Baptista
- Division of Infectious Diseases, Houston Methodist Hospital, Houston, Texas, USA
- Center for Infectious Diseases, Houston Methodist Research Institute, Houston, Texas, USA
- Department of Medicine, Weill Cornell Medical College, New York, New York, USA
| | - Truc T. Tran
- Division of Infectious Diseases, Houston Methodist Hospital, Houston, Texas, USA
- Center for Infectious Diseases, Houston Methodist Research Institute, Houston, Texas, USA
- Department of Medicine, Weill Cornell Medical College, New York, New York, USA
| | - Samuel A. Shelburne
- Department of Infectious Diseases, Infection Control, and Employee Health, University of Texas M.D. Anderson Cancer Center, Houston, Texas, USA
| | - Jose M. Munita
- Instituto de Ciencias e Innovación en Medicina (ICIM), Facultad de Medicina Clinica Alemana, Universidad del Desarrollo and Multidisciplinary Initiative for Collaborative Research On Bacterial Resistance (MICROB-R), Santiago, Chile
| | - Cesar A. Arias
- Division of Infectious Diseases, Houston Methodist Hospital, Houston, Texas, USA
- Center for Infectious Diseases, Houston Methodist Research Institute, Houston, Texas, USA
- Department of Medicine, Weill Cornell Medical College, New York, New York, USA
| | - Morgan Hakki
- Department of Medicine, Division of Infectious Diseases, Oregon Health and Science University, Portland, Oregon, USA
| | - William R. Miller
- Division of Infectious Diseases, Houston Methodist Hospital, Houston, Texas, USA
- Center for Infectious Diseases, Houston Methodist Research Institute, Houston, Texas, USA
- Department of Medicine, Weill Cornell Medical College, New York, New York, USA
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Burch-Konda J, Kayastha BB, Kubo A, Achour M, Hull M, Braga R, Winton L, Rogers RR, McCoy J, Lutter EI, Patrauchan MA. EF-Hand Calcium Sensor, EfhP, Controls Transcriptional Regulation of Iron Uptake by Calcium in Pseudomonas aeruginosa. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.01.09.574892. [PMID: 38260268 PMCID: PMC10802428 DOI: 10.1101/2024.01.09.574892] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/24/2024]
Abstract
The human pathogen Pseudomonas aeruginosa poses a major risk for a range of severe infections, particularly lung infections in patients suffering from cystic fibrosis (CF). As previously reported, the virulent behavior of this pathogen is enhanced by elevated levels of Ca 2+ that are commonly present in CF nasal and lung fluids. In addition, a Ca 2+ -binding EF-hand protein, EfhP (PA4107), was partially characterized and shown to be critical for the Ca 2+ -regulated virulence in P. aeruginosa . Here we describe the rapid (10 min, 60 min), and adaptive (12 h) transcriptional responses of PAO1 to elevated Ca 2+ detected by genome-wide RNA sequencing and show that efhP deletion significantly hindered both rapid and adaptive Ca 2+ regulation. The most differentially regulated genes included multiple Fe sequestering mechanisms, a large number of extracytoplasmic function sigma factors (ECFσ) and several virulence factors, such as production of pyocins. The Ca 2+ regulation of Fe uptake was also observed in CF clinical isolates and appeared to involve the global regulator Fur. In addition, we showed that the efhP transcription is controlled by Ca 2+ and Fe, and this regulation required Ca 2+ -dependent two-component regulatory system CarSR. Furthermore, the efhP expression is significantly increased in CF clinical isolates and upon pathogen internalization into epithelial cells. Overall, the results established for the first time that Ca 2+ controls Fe sequestering mechanisms in P. aeruginosa and that EfhP plays a key role in the regulatory interconnectedness between Ca 2+ and Fe signaling pathways, the two distinct and important signaling pathways that guide the pathogen's adaptation to host. IMPORTANCE Pseudomonas aeruginosa ( Pa ) poses a major risk for severe infections, particularly in patients suffering from cystic fibrosis (CF). For the first time, kinetic RNA sequencing analysis identified Pa rapid and adaptive transcriptional responses to Ca 2+ levels consistent with those present in CF respiratory fluids. The most highly upregulated processes include iron sequestering, iron starvation sigma factors, and self-lysis factors pyocins. An EF-hand Ca 2+ sensor, EfhP, is required for at least 1/3 of the Ca 2+ response, including all the iron uptake mechanisms and production of pyocins. Transcription of efhP itself is regulated by Ca 2+ , Fe, and increases during interactions with host epithelial cells, suggesting the protein's important role in Pa infections. The findings establish the regulatory interconnectedness between Ca 2+ and iron signaling pathways that shape Pa transcriptional responses. Therefore, understanding Pa's transcriptional response to Ca 2+ and associated regulatory mechanisms will serve the development of future therapeutics targeting Pa dangerous infections.
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Jung S, Schultz G, Mafiz AI, Bevels E, Jaskula K, Brownell K, Lantz E, Strickland A. Antimicrobial effects of a borate-based bioactive glass wound matrix on wound-relevant pathogens. J Wound Care 2023; 32:763-772. [PMID: 38060418 DOI: 10.12968/jowc.2023.32.12.763] [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] [Indexed: 12/18/2023]
Abstract
OBJECTIVE The antimicrobial effects of a borate-based bioactive glass matrix (BBBGM) on clinically relevant microorganisms was investigated for up to seven days in vitro. METHOD A total of 19 wound-relevant pathogens were studied using the in vitro AATCC 100 test method. RESULTS The reduction of viable Gram-negative and Gram-positive bacteria and yeasts at days 4 and 7 post-culture on the BBBGM was significant (> 4log10) in most cases. Mould counts were reduced (<2log10) during the seven-day assessment, indicating that mould viability and reproduction was inhibited. The cell count of each organism was reduced at seven days indicating that the BBBGM not only reduced the viable cell count, but that the cell count did not recover during the seven-day period, indicating a sustained reduction in pathogenic activity. CONCLUSION Based on the present results, the use of a BBBGM as a pathogenic barrier should be considered as a tool for combating pathogenic colonisation and infection in acute and hard-to-heal (chronic) wounds.
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Kolodkin-Gal I, Parsek MR, Patrauchan MA. The roles of calcium signaling and calcium deposition in microbial multicellularity. Trends Microbiol 2023; 31:1225-1237. [PMID: 37429751 PMCID: PMC10772221 DOI: 10.1016/j.tim.2023.06.005] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2023] [Revised: 06/07/2023] [Accepted: 06/12/2023] [Indexed: 07/12/2023]
Abstract
Calcium signaling is an essential mediator of signal-controlling gene expression in most developmental systems. In addition, calcium has established extracellular functions as a structural component of biogenic minerals found in complex tissues. In bacteria, the formation of calcium carbonate structures is associated with complex colony morphology. Genes promoting the formation of biogenic minerals are essential for proper biofilm development and protection against antimicrobial solutes and toxins. Here we review recent findings on the role of calcium and calcium signaling as emerging regulators of biofilm formation in beneficial bacteria, as well as essential mediators of biofilm formation and virulence in human pathogens. The presented analysis concludes that the new understanding of calcium signaling may help to improve the performance of beneficial strains for sustainable agriculture, microbiome manipulation, and sustainable construction. Unraveling the roles of calcium may also promote the development of novel therapies against biofilm infections that target calcium uptake, calcium sensors, and calcium carbonate deposition.
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Affiliation(s)
- Ilana Kolodkin-Gal
- Department of Plant Pathology and Microbiology, Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Rehovot, Israel.
| | - Matthew R Parsek
- Department of Microbiology, University of Washington, Seattle, WA, USA.
| | - Marianna A Patrauchan
- Department of Microbiology and Molecular Genetics, Oklahoma State University, Stillwater, OK, USA.
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Agaras BC, Grossi CEM, Ulloa RM. Unveiling the Secrets of Calcium-Dependent Proteins in Plant Growth-Promoting Rhizobacteria: An Abundance of Discoveries Awaits. PLANTS (BASEL, SWITZERLAND) 2023; 12:3398. [PMID: 37836138 PMCID: PMC10574481 DOI: 10.3390/plants12193398] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/05/2023] [Revised: 09/20/2023] [Accepted: 09/22/2023] [Indexed: 10/15/2023]
Abstract
The role of Calcium ions (Ca2+) is extensively documented and comprehensively understood in eukaryotic organisms. Nevertheless, emerging insights, primarily derived from studies on human pathogenic bacteria, suggest that this ion also plays a pivotal role in prokaryotes. In this review, our primary focus will be on unraveling the intricate Ca2+ toolkit within prokaryotic organisms, with particular emphasis on its implications for plant growth-promoting rhizobacteria (PGPR). We undertook an in silico exploration to pinpoint and identify some of the proteins described in the existing literature, including prokaryotic Ca2+ channels, pumps, and exchangers that are responsible for regulating intracellular Calcium concentration ([Ca2+]i), along with the Calcium-binding proteins (CaBPs) that play a pivotal role in sensing and transducing this essential cation. These investigations were conducted in four distinct PGPR strains: Pseudomonas chlororaphis subsp. aurantiaca SMMP3, P. donghuensis SVBP6, Pseudomonas sp. BP01, and Methylobacterium sp. 2A, which have been isolated and characterized within our research laboratories. We also present preliminary experimental data to evaluate the influence of exogenous Ca2+ concentrations ([Ca2+]ex) on the growth dynamics of these strains.
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Affiliation(s)
- Betina Cecilia Agaras
- Laboratory of Physiology and Genetics of Plant Probiotic Bacteria (LFGBBP), Centre of Biochemistry and Microbiology of Soils, National University of Quilmes, Bernal B1876BXD, Argentina
- National Scientific and Technical Research Council (CONICET), Buenos Aires C1425FQB, Argentina;
| | - Cecilia Eugenia María Grossi
- National Scientific and Technical Research Council (CONICET), Buenos Aires C1425FQB, Argentina;
- Laboratory of Plant Signal Transduction, Institute of Genetic Engineering and Molecular Biology (INGEBI), National Scientific and Technical Research Council (CONICET), Buenos Aires C1425FQB, Argentina
| | - Rita María Ulloa
- National Scientific and Technical Research Council (CONICET), Buenos Aires C1425FQB, Argentina;
- Laboratory of Plant Signal Transduction, Institute of Genetic Engineering and Molecular Biology (INGEBI), National Scientific and Technical Research Council (CONICET), Buenos Aires C1425FQB, Argentina
- Biochemistry Department, Faculty of Exact and Natural Sciences, University of Buenos Aires (FCEN-UBA), Buenos Aires C1428EGA, Argentina
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Gehlert FO, Sauerwein T, Weidenbach K, Repnik U, Hallack D, Förstner KU, Schmitz RA. Dual-RNAseq Analysis Unravels Virus-Host Interactions of MetSV and Methanosarcina mazei. Viruses 2022; 14:2585. [PMID: 36423194 PMCID: PMC9694453 DOI: 10.3390/v14112585] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2022] [Revised: 11/05/2022] [Accepted: 11/19/2022] [Indexed: 11/23/2022] Open
Abstract
Methanosarcina spherical virus (MetSV), infecting Methanosarcina species, encodes 22 genes, but their role in the infection process in combination with host genes has remained unknown. To study the infection process in detail, infected and uninfected M. mazei cultures were compared using dual-RNAseq, qRT-PCRs, and transmission electron microscopy (TEM). The transcriptome analysis strongly indicates a combined role of virus and host genes in replication, virus assembly, and lysis. Thereby, 285 host and virus genes were significantly regulated. Within these 285 regulated genes, a network of the viral polymerase, MetSVORF6, MetSVORF5, MetSVORF2, and the host genes encoding NrdD, NrdG, a CDC48 family protein, and a SSB protein with a role in viral replication was postulated. Ultrastructural analysis at 180 min p.i. revealed many infected cells with virus particles randomly scattered throughout the cytoplasm or attached at the cell surface, and membrane fragments indicating cell lysis. Dual-RNAseq and qRT-PCR analyses suggested a multifactorial lysis reaction in potential connection to the regulation of a cysteine proteinase, a pirin-like protein and a HicB-solo protein. Our study's results led to the first preliminary infection model of MetSV infecting M. mazei, summarizing the key infection steps as follows: replication, assembly, and host cell lysis.
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Affiliation(s)
- Finn O. Gehlert
- Institute for General Microbiology, Christian Albrechts University, 24118 Kiel, Germany
| | - Till Sauerwein
- ZB MED, Information Centre for Life Sciences, 50931 Cologne, Germany
| | - Katrin Weidenbach
- Institute for General Microbiology, Christian Albrechts University, 24118 Kiel, Germany
| | - Urska Repnik
- Central Microscopy, Christian Albrechts University, 24118 Kiel, Germany
| | - Daniela Hallack
- Institute for General Microbiology, Christian Albrechts University, 24118 Kiel, Germany
| | | | - Ruth A. Schmitz
- Institute for General Microbiology, Christian Albrechts University, 24118 Kiel, Germany
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Kayastha BB, Kubo A, Burch-Konda J, Dohmen RL, McCoy JL, Rogers RR, Mares S, Bevere J, Huckaby A, Witt W, Peng S, Chaudhary B, Mohanty S, Barbier M, Cook G, Deng J, Patrauchan MA. EF-hand protein, EfhP, specifically binds Ca 2+ and mediates Ca 2+ regulation of virulence in a human pathogen Pseudomonas aeruginosa. Sci Rep 2022; 12:8791. [PMID: 35614085 PMCID: PMC9132961 DOI: 10.1038/s41598-022-12584-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2022] [Accepted: 05/09/2022] [Indexed: 11/30/2022] Open
Abstract
Calcium (Ca2+) is well known as a second messenger in eukaryotes, where Ca2+ signaling controls life-sustaining cellular processes. Although bacteria produce the components required for Ca2+ signaling, little is known about the mechanisms of bacterial Ca2+ signaling. Previously, we have identified a putative Ca2+-binding protein EfhP (PA4107) with two canonical EF-hand motifs and reported that EfhP mediates Ca2+ regulation of virulence factors production and infectivity in Pseudomonas aeruginosa, a human pathogen causing life-threatening infections. Here, we show that EfhP selectively binds Ca2+ with 13.7 µM affinity, and that mutations at the +X and -Z positions within each or both EF-hand motifs abolished Ca2+ binding. We also show that the hydrophobicity of EfhP increased in a Ca2+-dependent manner, however no such response was detected in the mutated proteins. 15 N-NMR showed Ca2+-dependent chemical shifts in EfhP confirming Ca2+-binding triggered structural rearrangements in the protein. Deletion of efhP impaired P. aeruginosa survival in macrophages and virulence in vivo. Disabling EfhP Ca2+ binding abolished Ca2+ induction of pyocyanin production in vitro. These data confirm that EfhP selectively binds Ca2+, which triggers its structural changes required for the Ca2+ regulation of P. aeruginosa virulence, thus establishing the role of EfhP as a Ca2+ sensor.
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Affiliation(s)
- Biraj B Kayastha
- Department of Microbiology and Molecular Genetics, Oklahoma State University, Stillwater, OK, 74078, USA
| | - Aya Kubo
- Department of Microbiology and Molecular Genetics, Oklahoma State University, Stillwater, OK, 74078, USA
| | - Jacob Burch-Konda
- Department of Microbiology and Molecular Genetics, Oklahoma State University, Stillwater, OK, 74078, USA
| | - Rosalie L Dohmen
- Department of Microbiology and Molecular Genetics, Oklahoma State University, Stillwater, OK, 74078, USA
| | - Jacee L McCoy
- Department of Microbiology and Molecular Genetics, Oklahoma State University, Stillwater, OK, 74078, USA
| | - Rendi R Rogers
- Department of Microbiology and Molecular Genetics, Oklahoma State University, Stillwater, OK, 74078, USA
| | - Sergio Mares
- Department of Microbiology and Molecular Genetics, Oklahoma State University, Stillwater, OK, 74078, USA
| | - Justin Bevere
- Vaccine Development Center at West Virginia University, Morgantown, WV, 26506, USA
- Department of Microbiology, Immunology and Cell Biology, West Virginia University, Morgantown, WV, 26506, USA
| | - Annalisa Huckaby
- Vaccine Development Center at West Virginia University, Morgantown, WV, 26506, USA
- Department of Microbiology, Immunology and Cell Biology, West Virginia University, Morgantown, WV, 26506, USA
| | - William Witt
- Vaccine Development Center at West Virginia University, Morgantown, WV, 26506, USA
- Department of Microbiology, Immunology and Cell Biology, West Virginia University, Morgantown, WV, 26506, USA
| | - Shuxia Peng
- Department of Biochemistry and Molecular Biology, Oklahoma State University, Stillwater, OK, 74078, USA
| | - Bharat Chaudhary
- Department of Chemistry, Oklahoma State University, Stillwater, OK, 74078, USA
| | - Smita Mohanty
- Department of Chemistry, Oklahoma State University, Stillwater, OK, 74078, USA
| | - Mariette Barbier
- Vaccine Development Center at West Virginia University, Morgantown, WV, 26506, USA
- Department of Microbiology, Immunology and Cell Biology, West Virginia University, Morgantown, WV, 26506, USA
| | - Gabriel Cook
- Department of Chemistry, Oklahoma State University, Stillwater, OK, 74078, USA
| | - Junpeng Deng
- Department of Biochemistry and Molecular Biology, Oklahoma State University, Stillwater, OK, 74078, USA
| | - Marianna A Patrauchan
- Department of Microbiology and Molecular Genetics, Oklahoma State University, Stillwater, OK, 74078, USA.
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Zhao Y, Wee CY, Zhang H, Yang Z, Wang WEJ, Thian ES. Silver-substituted hydroxyapatite inhibits Pseudomonas aeruginosa outer membrane protein F: A potential antibacterial mechanism. MATERIALS SCIENCE & ENGINEERING. C, MATERIALS FOR BIOLOGICAL APPLICATIONS 2022; 134:112713. [DOI: 10.1016/j.msec.2022.112713] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/16/2021] [Revised: 01/06/2022] [Accepted: 02/09/2022] [Indexed: 12/20/2022]
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9
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Waschulin V, Borsetto C, James R, Newsham KK, Donadio S, Corre C, Wellington E. Biosynthetic potential of uncultured Antarctic soil bacteria revealed through long-read metagenomic sequencing. THE ISME JOURNAL 2022; 16:101-111. [PMID: 34253854 PMCID: PMC8692599 DOI: 10.1038/s41396-021-01052-3] [Citation(s) in RCA: 44] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/21/2021] [Revised: 06/17/2021] [Accepted: 06/28/2021] [Indexed: 12/31/2022]
Abstract
The growing problem of antibiotic resistance has led to the exploration of uncultured bacteria as potential sources of new antimicrobials. PCR amplicon analyses and short-read sequencing studies of samples from different environments have reported evidence of high biosynthetic gene cluster (BGC) diversity in metagenomes, indicating their potential for producing novel and useful compounds. However, recovering full-length BGC sequences from uncultivated bacteria remains a challenge due to the technological restraints of short-read sequencing, thus making assessment of BGC diversity difficult. Here, long-read sequencing and genome mining were used to recover >1400 mostly full-length BGCs that demonstrate the rich diversity of BGCs from uncultivated lineages present in soil from Mars Oasis, Antarctica. A large number of highly divergent BGCs were not only found in the phyla Acidobacteriota, Verrucomicrobiota and Gemmatimonadota but also in the actinobacterial classes Acidimicrobiia and Thermoleophilia and the gammaproteobacterial order UBA7966. The latter furthermore contained a potential novel family of RiPPs. Our findings underline the biosynthetic potential of underexplored phyla as well as unexplored lineages within seemingly well-studied producer phyla. They also showcase long-read metagenomic sequencing as a promising way to access the untapped genetic reservoir of specialised metabolite gene clusters of the uncultured majority of microbes.
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Affiliation(s)
| | - Chiara Borsetto
- School of Life Sciences, University of Warwick, Coventry, UK
| | | | | | | | - Christophe Corre
- School of Life Sciences, University of Warwick, Coventry, UK
- Department of Chemistry, University of Warwick, Coventry, UK
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10
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Pacheco-Moreno A, Stefanato FL, Ford JJ, Trippel C, Uszkoreit S, Ferrafiat L, Grenga L, Dickens R, Kelly N, Kingdon AD, Ambrosetti L, Nepogodiev SA, Findlay KC, Cheema J, Trick M, Chandra G, Tomalin G, Malone JG, Truman AW. Pan-genome analysis identifies intersecting roles for Pseudomonas specialized metabolites in potato pathogen inhibition. eLife 2021; 10:71900. [PMID: 34792466 PMCID: PMC8719888 DOI: 10.7554/elife.71900] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2021] [Accepted: 11/16/2021] [Indexed: 11/29/2022] Open
Abstract
Agricultural soil harbors a diverse microbiome that can form beneficial relationships with plants, including the inhibition of plant pathogens. Pseudomonas spp. are one of the most abundant bacterial genera in the soil and rhizosphere and play important roles in promoting plant health. However, the genetic determinants of this beneficial activity are only partially understood. Here, we genetically and phenotypically characterize the Pseudomonas fluorescens population in a commercial potato field, where we identify strong correlations between specialized metabolite biosynthesis and antagonism of the potato pathogens Streptomyces scabies and Phytophthora infestans. Genetic and chemical analyses identified hydrogen cyanide and cyclic lipopeptides as key specialized metabolites associated with S. scabies inhibition, which was supported by in planta biocontrol experiments. We show that a single potato field contains a hugely diverse and dynamic population of Pseudomonas bacteria, whose capacity to produce specialized metabolites is shaped both by plant colonization and defined environmental inputs. Potato scab and blight are two major diseases which can cause heavy crop losses. They are caused, respectively, by the bacterium Streptomyces scabies and an oomycete (a fungus-like organism) known as Phytophthora infestans. Fighting these disease-causing microorganisms can involve crop management techniques – for example, ensuring that a field is well irrigated helps to keep S. scabies at bay. Harnessing biological control agents can also offer ways to control disease while respecting the environment. Biocontrol bacteria, such as Pseudomonas, can produce compounds that keep S. scabies and P. infestans in check. However, the identity of these molecules and how irrigation can influence Pseudomonas population remains unknown. To examine these questions, Pacheco-Moreno et al. sampled and isolated hundreds of Pseudomonas strains from a commercial potato field, closely examining the genomes of 69 of these. Comparing the genetic information of strains based on whether they could control the growth of S. scabies revealed that compounds known as cyclic lipopeptides are key to controlling the growth of S. scabies and P. infestans. Whether the field was irrigated also had a large impact on the strains forming the Pseudomonas population. Working out how Pseudomonas bacteria block disease could speed up the search for biological control agents. The approach developed by Pacheco-Moreno et al. could help to predict which strains might be most effective based on their genetic features. Similar experiments could also work for other combinations of plants and diseases.
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Affiliation(s)
- Alba Pacheco-Moreno
- Department of Molecular Microbiology, John Innes Centre, Norwich, United Kingdom
| | | | - Jonathan J Ford
- Department of Molecular Microbiology, John Innes Centre, Norwich, United Kingdom
| | - Christine Trippel
- Department of Molecular Microbiology, John Innes Centre, Norwich, United Kingdom
| | - Simon Uszkoreit
- Department of Molecular Microbiology, John Innes Centre, Norwich, United Kingdom
| | - Laura Ferrafiat
- Department of Molecular Microbiology, John Innes Centre, Norwich, United Kingdom
| | - Lucia Grenga
- Department of Molecular Microbiology, John Innes Centre, Norwich, United Kingdom
| | - Ruth Dickens
- Department of Molecular Microbiology, John Innes Centre, Norwich, United Kingdom
| | - Nathan Kelly
- Department of Molecular Microbiology, John Innes Centre, Norwich, United Kingdom
| | - Alexander Dh Kingdon
- Department of Molecular Microbiology, John Innes Centre, Norwich, United Kingdom
| | - Liana Ambrosetti
- Department of Molecular Microbiology, John Innes Centre, Norwich, United Kingdom
| | - Sergey A Nepogodiev
- Department of Biochemistry and Metabolism, John Innes Centre, Norwich, United Kingdom
| | - Kim C Findlay
- Department of Cell and Developmental Biology, John Innes Centre, Norwich, United Kingdom
| | - Jitender Cheema
- Department of Computational and Systems Biology, John Innes Centre, Norwich, United Kingdom
| | - Martin Trick
- Computational and Systems Biology, John Innes Centre, Norwich, United Kingdom
| | - Govind Chandra
- Department of Molecular Microbiology, John Innes Centre, Norwich, United Kingdom
| | | | - Jacob G Malone
- Department of Molecular Microbiology, John Innes Centre, Norwich, United Kingdom
| | - Andrew W Truman
- Department of Molecular Microbiology, John Innes Centre, Norwich, United Kingdom
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11
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Goodyear MC, Garnier N, Krieger JR, Geddes-McAlister J, Khursigara CM. Label-free quantitative proteomics identifies unique proteomes of clinical isolates of the Liverpool Epidemic Strain of Pseudomonas aeruginosa and laboratory strain PAO1. Proteomics Clin Appl 2021; 15:e2100062. [PMID: 34510773 DOI: 10.1002/prca.202100062] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2021] [Accepted: 09/09/2021] [Indexed: 11/11/2022]
Abstract
PURPOSE Comparative genomics and phenotypic assays have shown that antibiotic resistance profiles differ among clinical isolates of Pseudomonas aeruginosa and that genotype-phenotype associations are difficult to establish for resistance phenotypes based on these comparisons alone. EXPERIMENTAL DESIGN Here, we used label-free quantitative proteomics to compare two isolates of the Liverpool Epidemic Strain (LES) of P. aeruginosa, LESlike1 and LESB58, and the common laboratory strain P. aeruginosa PAO1 to more accurately predict functional differences between strains. RESULTS Our results show that the proteomes of the LES isolates are more similar to each other than to PAO1; however, a number of differences were observed in the abundance of proteins involved in quorum sensing, virulence, and antibiotic resistance, including in the comparison of LESlike1 and LESB58. Additionally, the proteomic data revealed a higher abundance of proteins involved in polymyxin and aminoglycoside resistance in LESlike1. Minimum inhibitory concentration assays showed that LESlike1 had up to 128-fold higher resistance to antibiotics from these classes. CONCLUSIONS These findings provide an example of the ability of proteomic data to complement genotypic and phenotypic studies to understand resistance in clinical isolates. CLINICAL RELEVANCE P. aeruginosa is a predominant pathogen in chronic lung infections in individuals with cystic fibrosis (CF). LES isolates are capable of transferring between CF patients and have been associated with increased hospital visits and antibiotic treatments.
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Affiliation(s)
- Mara C Goodyear
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, Ontario, Canada
| | - Nicole Garnier
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, Ontario, Canada
| | | | | | - Cezar M Khursigara
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, Ontario, Canada
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12
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King M, Kubo A, Kafer L, Braga R, McLeod D, Khanam S, Conway T, Patrauchan MA. Calcium-Regulated Protein CarP Responds to Multiple Host Signals and Mediates Regulation of Pseudomonas aeruginosa Virulence by Calcium. Appl Environ Microbiol 2021; 87:e00061-21. [PMID: 33674436 PMCID: PMC8117776 DOI: 10.1128/aem.00061-21] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2021] [Accepted: 02/27/2021] [Indexed: 11/20/2022] Open
Abstract
Pseudomonas aeruginosa is an opportunistic pathogen causing life-threatening infections. Previously, we showed that elevated calcium (Ca2+) levels increase the production of virulence factors in P. aeruginosa In an effort to characterize the Ca2+ regulatory network, we identified a Ca2+-regulated β-propeller protein, CarP, and showed that expression of the encoding gene is controlled by the Ca2+-regulated two-component system CarSR. Here, by using a Galleria melonella model, we showed that CarP plays a role in regulating P. aeruginosa virulence. By using transcriptome sequencing (RNA-Seq), reverse transcription (RT)-PCR, quantitative RT-PCR (RT-qPCR), and promoter fusions, we determined that carP is transcribed into at least two transcripts and regulated by several bacterial and host factors. The transcription of carP is elevated in response to Ca2+ in P. aeruginosa cystic fibrosis isolates and PAO1 laboratory strain. Elevated Fe2+ also induces carP The simultaneous addition of Ca2+ and Fe2+ increased the carP promoter activity synergistically, which requires the presence of CarR. In silico analysis of the intergenic sequence upstream of carP predicted recognition sites of RhlR/LasR, OxyR, and LexA, suggesting regulation by quorum sensing (QS) and oxidative stress. In agreement, the carP promoter was activated in response to stationary-phase PAO1 supernatant and required the presence of elevated Ca2+ and CarR but remained silent in the triple mutant lacking rhlI, lasI, and pqsA synthases. We also showed that carP transcription is regulated by oxidative stress and that CarP contributes to P. aeruginosa Ca2+-dependent H2O2 tolerance. The multifactorial regulation of carP suggests that CarP plays an important role in P. aeruginosa adaptations to host environments.IMPORTANCEP. aeruginosa is a human pathogen causing life-threatening infections. It is particularly notorious for its ability to adapt to diverse environments within the host. Understanding the signals and the signaling pathways enabling P. aeruginosa adaptation is imperative for developing effective therapies to treat infections caused by this organism. One host signal of particular importance is calcium. Previously, we identified a component of the P. aeruginosa calcium-signaling network, CarP, whose expression is induced by elevated levels of calcium. Here, we show that carP plays an important role in P. aeruginosa virulence and is upregulated in P. aeruginosa strains isolated from sputa of patients with cystic fibrosis. We also identified several bacterial and host factors that regulate the transcription of carP Such multifactorial regulation highlights the interconnectedness between regulatory circuits and, together with the pleotropic effect of CarP on virulence, suggests the importance of this protein in P. aeruginosa adaptations to the host.
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Affiliation(s)
- Michelle King
- Department of Microbiology and Molecular Genetics, Oklahoma State University, Stillwater, Oklahoma, USA
| | - Aya Kubo
- Department of Microbiology and Molecular Genetics, Oklahoma State University, Stillwater, Oklahoma, USA
| | - Leah Kafer
- Department of Microbiology and Molecular Genetics, Oklahoma State University, Stillwater, Oklahoma, USA
| | - Reygan Braga
- Department of Microbiology and Molecular Genetics, Oklahoma State University, Stillwater, Oklahoma, USA
| | - Daniel McLeod
- Department of Microbiology and Molecular Genetics, Oklahoma State University, Stillwater, Oklahoma, USA
| | - Sharmily Khanam
- Department of Microbiology and Molecular Genetics, Oklahoma State University, Stillwater, Oklahoma, USA
| | - Tyrrell Conway
- Department of Microbiology and Molecular Genetics, Oklahoma State University, Stillwater, Oklahoma, USA
| | - Marianna A Patrauchan
- Department of Microbiology and Molecular Genetics, Oklahoma State University, Stillwater, Oklahoma, USA
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13
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Fan K, Cao Q, Lan L. Genome-Wide Mapping Reveals Complex Regulatory Activities of BfmR in Pseudomonas aeruginosa. Microorganisms 2021; 9:485. [PMID: 33668961 PMCID: PMC8025907 DOI: 10.3390/microorganisms9030485] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2021] [Revised: 02/09/2021] [Accepted: 02/22/2021] [Indexed: 01/04/2023] Open
Abstract
BfmR is a response regulator that modulates diverse pathogenic phenotypes and induces an acute-to-chronic virulence switch in Pseudomonas aeruginosa, an important human pathogen causing serious nosocomial infections. However, the mechanisms of action of BfmR remain largely unknown. Here, using chromatin immunoprecipitation followed by high-throughput sequencing (ChIP-seq), we showed that 174 chromosomal regions of P. aeruginosa MPAO1 genome were highly enriched by coimmunoprecipitation with a C-terminal Flag-tagged BfmR. Integration of these data with global transcriptome analyses revealed that 172 genes in 106 predicted transcription units are potential targets for BfmR. We determined that BfmR binds to and modulates the promoter activity of genes encoding transcriptional regulators CzcR, ExsA, and PhoB. Intriguingly, BfmR bound to the promoters of a number of genes belong to either CzcR or PhoB regulon, or both, indicating that CzcRS and PhoBR two-component systems (TCSs) deeply feed into the BfmR-mediated regulatory network. In addition, we demonstrated that phoB is required for BfmR to promote the biofilm formation by P. aeruginosa. These results delineate the direct BfmR regulon and exemplify the complexity of BfmR-mediated regulation of cellular functions in P. aeruginosa.
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Affiliation(s)
- Ke Fan
- University of Chinese Academy of Sciences, No. 19A Yuquan Road, Beijing 100049, China;
- State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China;
| | - Qiao Cao
- State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China;
| | - Lefu Lan
- University of Chinese Academy of Sciences, No. 19A Yuquan Road, Beijing 100049, China;
- State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China;
- School of Pharmaceutical Science and Technology, Hangzhou Institute for Advanced Study, UCAS, Hangzhou 310024, China
- NMPA Key Laboratory for Testing Technology of Pharmaceutical Microbiology, Shanghai Institute for Food and Drug Control, Shanghai 201203, China
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14
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Nava AR, Mauricio N, Sanca AJ, Domínguez DC. Evidence of Calcium Signaling and Modulation of the LmrS Multidrug Resistant Efflux Pump Activity by Ca 2 + Ions in S. aureus. Front Microbiol 2020; 11:573388. [PMID: 33193178 PMCID: PMC7642317 DOI: 10.3389/fmicb.2020.573388] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2020] [Accepted: 09/14/2020] [Indexed: 12/19/2022] Open
Abstract
Calcium ions (Ca2+) play a pivotal role in eukaryote cell signaling and regulate many physiological functions. Although a similar role for Ca2+ in prokaryotes has been difficult to demonstrate, there is increasing evidence for Ca2+ as a cell regulator in bacteria. The purpose of this study was to investigate Ca2+ signaling and the effect of Ca2+ on the Staphylococcus aureus multidrug resistant efflux pump LmrS. We hypothesized that antibiotics act by increasing Ca2+ concentrations, which in turn enhance the efflux activity of LmrS. These Ca2+ transients were measured by luminometry in response to various antibiotics by using the photoprotein aequorin reconstituted within live bacterial cells. Efflux associated with LmrS was measured by the increase in fluorescence due to the loss of ethidium bromide (EtBr) from both S. aureus cells and from E. coli cells in which the lmrs gene of S. aureus was expressed. We found that addition of antibiotics to cells generated unique cytosolic Ca2+ transients and that addition of CaCl2 to cells enhanced EtBr efflux whereas addition of Ca2+ chelators or efflux pump inhibitors significantly decreased EtBr efflux from cells. We conclude that antibiotics induce a Ca2+ mediated response through transients in cytosolic Ca2+, which then stimulates LmrS efflux pump.
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Affiliation(s)
- Amy R Nava
- Department of Interdisciplinary Health Sciences, The University of Texas at El Paso, El Paso, TX, United States
| | - Natalia Mauricio
- Biology Department, El Paso Community College, El Paso, TX, United States
| | - Angel J Sanca
- Biological Sciences Department, The University of Texas at El Paso, El Paso, TX, United States
| | - Delfina C Domínguez
- Department of Interdisciplinary Health Sciences, The University of Texas at El Paso, El Paso, TX, United States.,Clinical Laboratory Science Program/Department of Public Health Sciences, The University of Texas at El Paso, El Paso, TX, United States
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15
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García JFM, Rojas L, Zenteno E, Cruz CV, Abascal EN. Characterization of Actinobacillus seminis biofilm formation. Antonie Van Leeuwenhoek 2020; 113:1371-1383. [PMID: 32671613 DOI: 10.1007/s10482-020-01447-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2020] [Accepted: 07/08/2020] [Indexed: 11/27/2022]
Abstract
Actinobacillus seminis is an autochthonous gram-negative bacterium that affects reproductive organs, causing epididymitis, low fertility, and occasional abortions in ovine and goats. The virulence factors and the pathogenicity mechanisms of A. seminis have not been clearly elucidated yet. In this work, biofilm production by A. seminis in in vitro assays is described and characterized. After 48-h incubation at 37 °C in trypticase soy broth, A. seminis formed biofilms containing an extracellular matrix comprised mainly of fibrillar material. Microaerophilia or the presence of calcium diminished biofilm formation in approximately 50% and 70%, respectively, but low iron concentrations increased it 40%. Through enzymatic digestion, it was found that proteins were the main component of these biofilms. Structural observations through scanning electron microscopy indicated the presence of a high amount of fibrillar material in which bacteria were immersed. Antibodies against different bacterial surface proteins, such as anti-biofilm matrix and anti-adhesin, diminished biofilm formation in 70% and 25%, respectively; whereas furanone C-30 and LED-209, compounds described as quorum-sensing inhibitors, completely inhibited biofilm formation. In conclusion, environmental conditions can influence strongly biofilm formation in A. seminis, and this could be an advantageous strategy that allows bacteria to persist inside a host.
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Affiliation(s)
- J Fernando Montes García
- Carrera de Biología, Facultad de Estudios Superiores Iztacala, Universidad Nacional Autónoma de México (UNAM), Av. de los Barrios #1, Los Reyes Iztacala, 54090, Tlalnepantla, State of Mexico, Mexico.,Licenciatura en Nutrición, Unidad Académica Profesional Acolman, Universidad Autónoma del Estado de Mexico, Acolman, Estado de Mexico, Mexico
| | - Lourdes Rojas
- Laboratorio Nacional de Servicios Experimentales, Centro de Investigación y de Estudios Avanzados del IPN, Av. IPN 2508, Zacatenco, 07360, Mexico City, Mexico
| | - Edgar Zenteno
- Departamento de Bioquímica, Facultad de Medicina, Universidad Nacional Autónoma de México, Mexico City, Mexico
| | - Candelario Vazquez Cruz
- Centro de Investigaciones en Ciencias Microbiológicas, BUAP, Apdo. Postal 1622, 72560, Puebla, Puebla, Mexico
| | - Erasmo Negrete Abascal
- Carrera de Biología, Facultad de Estudios Superiores Iztacala, Universidad Nacional Autónoma de México (UNAM), Av. de los Barrios #1, Los Reyes Iztacala, 54090, Tlalnepantla, State of Mexico, Mexico.
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16
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King MM, Kayastha BB, Franklin MJ, Patrauchan MA. Calcium Regulation of Bacterial Virulence. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2020; 1131:827-855. [PMID: 31646536 DOI: 10.1007/978-3-030-12457-1_33] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Calcium (Ca2+) is a universal signaling ion, whose major informational role shaped the evolution of signaling pathways, enabling cellular communications and responsiveness to both the intracellular and extracellular environments. Elaborate Ca2+ regulatory networks have been well characterized in eukaryotic cells, where Ca2+ regulates a number of essential cellular processes, ranging from cell division, transport and motility, to apoptosis and pathogenesis. However, in bacteria, the knowledge on Ca2+ signaling is still fragmentary. This is complicated by the large variability of environments that bacteria inhabit with diverse levels of Ca2+. Yet another complication arises when bacterial pathogens invade a host and become exposed to different levels of Ca2+ that (1) are tightly regulated by the host, (2) control host defenses including immune responses to bacterial infections, and (3) become impaired during diseases. The invading pathogens evolved to recognize and respond to the host Ca2+, triggering the molecular mechanisms of adhesion, biofilm formation, host cellular damage, and host-defense resistance, processes enabling the development of persistent infections. In this review, we discuss: (1) Ca2+ as a determinant of a host environment for invading bacterial pathogens, (2) the role of Ca2+ in regulating main events of host colonization and bacterial virulence, and (3) the molecular mechanisms of Ca2+ signaling in bacterial pathogens.
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Affiliation(s)
- Michelle M King
- Department of Microbiology and Molecular Genetics, Oklahoma State University, Stillwater, OK, USA
| | - Biraj B Kayastha
- Department of Microbiology and Molecular Genetics, Oklahoma State University, Stillwater, OK, USA
| | - Michael J Franklin
- Department of Microbiology and Center for Biofilm Engineering, Montana State University, Bozeman, MT, USA
| | - Marianna A Patrauchan
- Department of Microbiology and Molecular Genetics, Oklahoma State University, Stillwater, OK, USA.
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17
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Lotlikar SR, Kayastha BB, Vullo D, Khanam SS, Braga RE, Murray AB, McKenna R, Supuran CT, Patrauchan MA. Pseudomonas aeruginosa β-carbonic anhydrase, psCA1, is required for calcium deposition and contributes to virulence. Cell Calcium 2019; 84:102080. [PMID: 31589941 DOI: 10.1016/j.ceca.2019.102080] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2019] [Revised: 08/16/2019] [Accepted: 09/07/2019] [Indexed: 01/07/2023]
Abstract
Calcification of soft tissue leads to serious diseases and has been associated with bacterial chronic infections. However, the origin and the molecular mechanisms of calcification remain unclear. Here we hypothesized that a human pathogen Pseudomonas aeruginosa deposits extracellular calcium, a process requiring carbonic anhydrases (CAs). Transmission electron microscopy confirmed the formation of 0.1-0.2 μm deposits by P. aeruginosa PAO1 growing at 5 mM CaCl2, and X-ray elemental analysis confirmed they contain calcium. Quantitative analysis of deposited calcium showed that PAO1 deposits 0.35 and 0.75 mM calcium/mg protein when grown at 5 mM and 10 mM CaCl2, correspondingly. Fluorescent microscopy indicated that deposition initiates at the cell surface. We have previously characterized three PAO1 β-class CAs: psCA1, psCA2, and psCA3 that hydrate CO2 to HCO3-, among which psCA1 showed the highest catalytic activity (Lotlikar et. al. 2013). According to immunoblot and RT-qPCR, growth at elevated calcium levels increases the expression of psCA1. Analyses of the deletion mutants lacking one, two or all three psCA genes, determined that psCA1 plays a major role in calcium deposition and contributes to the pathogen's virulence. In-silico modeling of the PAO1 β-class CAs identified four amino acids that differ in psCA1 compared to psCA2, and psCA3 (T59, A61A, A101, and A108), and these differences may play a role in catalytic rate and thus calcium deposition. A series of inhibitors were tested against the recombinant psCA1, among which aminobenzene sulfonamide (ABS) and acetazolamide (AAZ), which inhibited psCA1 catalytic activity with KIs of 19 nM and 37 nM, correspondingly. The addition of ABS and AAZ to growing PAO1 reduced calcium deposition by 41 and 78, respectively. Hence, for the first time, we showed that the β-CA psCA1 in P. aeruginosa contributes to virulence likely by enabling calcium salt deposition, which can be partially controlled by inhibiting its catalytic activity.
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Affiliation(s)
- Shalaka R Lotlikar
- Department of Microbiology and Molecular Genetics, Oklahoma State University, Stillwater, OK 74078, USA
| | - Biraj B Kayastha
- Department of Microbiology and Molecular Genetics, Oklahoma State University, Stillwater, OK 74078, USA
| | - Daniela Vullo
- Università degli Studi di Firenze, Polo Scientifico, Laboratorio di Chimica Bioinorganica, Rm. 188, Via della Lastruccia 3, 50019 Sesto Fiorentino, Florence, Italy
| | - Sharmily S Khanam
- Department of Microbiology and Molecular Genetics, Oklahoma State University, Stillwater, OK 74078, USA
| | - Reygan E Braga
- Department of Microbiology and Molecular Genetics, Oklahoma State University, Stillwater, OK 74078, USA
| | - Akilah B Murray
- Department of Biochemistry and Molecular Biology, College of Medicine, University of Florida, Gainesville, FL 32610, USA
| | - Robert McKenna
- Department of Biochemistry and Molecular Biology, College of Medicine, University of Florida, Gainesville, FL 32610, USA
| | - Claudiu T Supuran
- Università degli Studi di Firenze, Polo Scientifico, Dipartimento Neurofarba, Sezione di Scienze Farmaceutiche, Via Ugo Schiff 6, 50019 Sesto Fiorentino, Florence, Italy
| | - Marianna A Patrauchan
- Department of Microbiology and Molecular Genetics, Oklahoma State University, Stillwater, OK 74078, USA.
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18
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Moretti C, Trabalza S, Granieri L, Caballo‐Ponce E, Devescovi G, Del Pino AM, Ramos C, Venturi V, van den Burg HA, Buonaurio R, Palmerini CA. A Na + /Ca 2+ exchanger of the olive pathogen Pseudomonas savastanoi pv. savastanoi is critical for its virulence. MOLECULAR PLANT PATHOLOGY 2019; 20:716-730. [PMID: 30912619 PMCID: PMC6637891 DOI: 10.1111/mpp.12787] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
In a number of compatible plant-bacterium interactions, a rise in apoplastic Ca2+ levels is observed, suggesting that Ca2+ represents an important environmental clue, as reported for bacteria infecting mammalians. We demonstrate that Ca2+ entry in Pseudomonas savastanoi pv. savastanoi (Psav) strain DAPP-PG 722 is mediated by a Na+ /Ca2+ exchanger critical for virulence. Using the fluorescent Ca2+ probe Fura 2-AM, we demonstrate that Ca2+ enters Psav cells foremost when they experience low levels of energy, a situation mimicking the apoplastic fluid. In fact, Ca2+ entry was suppressed in the presence of high concentrations of glucose, fructose, sucrose or adenosine triphosphate (ATP). Since Ca2+ entry was inhibited by nifedipine and LiCl, we conclude that the channel for Ca2+ entry is a Na+ /Ca2+ exchanger. In silico analysis of the Psav DAPP-PG 722 genome revealed the presence of a single gene coding for a Na+ /Ca2+ exchanger (cneA), which is a widely conserved and ancestral gene within the P. syringae complex based on gene phylogeny. Mutation of cneA compromised not only Ca2+ entry, but also compromised the Hypersensitive response (HR) in tobacco leaves and blocked the ability to induce knots in olive stems. The expression of both pathogenicity (hrpL, hrpA and iaaM) and virulence (ptz) genes was reduced in this Psav-cneA mutant. Complementation of the Psav-cneA mutation restored both Ca2+ entry and pathogenicity in olive plants, but failed to restore the HR in tobacco leaves. In conclusion, Ca2+ entry acts as a 'host signal' that allows and promotes Psav pathogenicity on olive plants.
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Affiliation(s)
- Chiaraluce Moretti
- Department of Agricultural, Food and Environmental ScienceUniversity of PerugiaBorgo XX Giugno 74, Perugia06121Italy
| | - Simone Trabalza
- Department of Agricultural, Food and Environmental ScienceUniversity of PerugiaBorgo XX Giugno 74, Perugia06121Italy
| | - Letizia Granieri
- Department of Agricultural, Food and Environmental ScienceUniversity of PerugiaBorgo XX Giugno 74, Perugia06121Italy
| | - Eloy Caballo‐Ponce
- Instituto de Hortofruticultura Subtropical y Mediterránea La MayoraUniversidad de Málaga‐Consejo Superior de Investigaciones Científicas (IHSM‐UMACSIC)Área de GenéticaMálagaSpain
| | - Giulia Devescovi
- Bacteriology Group, International Centre for Genetic Engineering and BiotechnologyTriesteItaly
| | - Alberto Marco Del Pino
- Department of Agricultural, Food and Environmental ScienceUniversity of PerugiaBorgo XX Giugno 74, Perugia06121Italy
| | - Cayo Ramos
- Bacteriology Group, International Centre for Genetic Engineering and BiotechnologyTriesteItaly
| | - Vittorio Venturi
- Bacteriology Group, International Centre for Genetic Engineering and BiotechnologyTriesteItaly
| | - Harrold A. van den Burg
- Molecular Plant Pathology, Swammerdam Institute for Life Sciences (SILS)University of AmsterdamAmsterdamNetherlands
| | - Roberto Buonaurio
- Department of Agricultural, Food and Environmental ScienceUniversity of PerugiaBorgo XX Giugno 74, Perugia06121Italy
| | - Carlo Alberto Palmerini
- Department of Agricultural, Food and Environmental ScienceUniversity of PerugiaBorgo XX Giugno 74, Perugia06121Italy
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19
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Gulyuk AV, LaJeunesse DR, Collazo R, Ivanisevic A. Characterization of Pseudomonas aeruginosa Films on Different Inorganic Surfaces before and after UV Light Exposure. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2018; 34:10806-10815. [PMID: 30122052 DOI: 10.1021/acs.langmuir.8b02079] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
The changes of the surface properties of Au, GaN, and SiO x after UV light irradiation were used to actively influence the process of formation of Pseudomonas aeruginosa films. The interfacial properties of the substrates were characterized by X-ray photoelectron spectroscopy and atomic force microscopy. The changes in the P. aeruginosa film properties were accessed by analyzing adhesion force maps and quantifying the intracellular Ca2+ concentration. The collected analysis indicates that the alteration of the inorganic materials' surface chemistry can lead to differences in biofilm formation and variable response from P. aeruginosa cells.
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Affiliation(s)
- Alexey V Gulyuk
- Department of Materials Science and Engineering , North Carolina State University , Raleigh , North Carolina 27695 , United States
| | - Dennis R LaJeunesse
- Joint School of Nanoscience and Nanoengineering , University of North Carolina-Greensboro and North Carolina A&T State University , Greensboro , North Carolina 27401 , United States
| | - Ramon Collazo
- Department of Materials Science and Engineering , North Carolina State University , Raleigh , North Carolina 27695 , United States
| | - Albena Ivanisevic
- Department of Materials Science and Engineering , North Carolina State University , Raleigh , North Carolina 27695 , United States
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20
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Chen H, Kandel PP, Cruz LF, Cobine PA, De La Fuente L. The Major Outer Membrane Protein MopB Is Required for Twitching Movement and Affects Biofilm Formation and Virulence in Two Xylella fastidiosa strains. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2017; 30:896-905. [PMID: 28800709 DOI: 10.1094/mpmi-07-17-0161-r] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
MopB is a major outer membrane protein (OMP) in Xylella fastidiosa, a bacterial plant pathogen that causes losses on many economically important crops. Based on in silico analysis, the uncharacterized MopB protein of X. fastidiosa contains a β-barrel structure with an OmpA-like domain and a predicted calcium-binding motif. Here, MopB function was studied by mutational analysis taking advantage of the natural competence of X. fastidiosa. Mutants of mopB were constructed in two different X. fastidiosa strains, the type strain Temecula and the more virulent WM1-1. Deletion of the mopB gene impaired cell-to-cell aggregation, surface attachment, and biofilm formation in both strains. Interestingly, mopB deletion completely abolished twitching motility. Electron microscopy of the bacterial cell surface revealed that mopB deletion eliminated type IV and type I pili formation, potentially caused by destabilization of the outer membrane. Both mopB mutants showed reduced virulence using tobacco (Nicotiana tabacum) as a host under greenhouse conditions. These results suggest that MopB has pleiotropic functions in biofilm formation and twitching motility and is important for virulence of X. fastidiosa.
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Affiliation(s)
- Hongyu Chen
- 1 Department of Entomology and Plant Pathology, Auburn University, Auburn, AL 36849, U.S.A.; and
| | - Prem P Kandel
- 1 Department of Entomology and Plant Pathology, Auburn University, Auburn, AL 36849, U.S.A.; and
| | - Luisa F Cruz
- 1 Department of Entomology and Plant Pathology, Auburn University, Auburn, AL 36849, U.S.A.; and
| | - Paul A Cobine
- 2 Department of Biological Sciences, Auburn University
| | - Leonardo De La Fuente
- 1 Department of Entomology and Plant Pathology, Auburn University, Auburn, AL 36849, U.S.A.; and
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21
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A Novel Calcium Uptake Transporter of Uncharacterized P-Type ATPase Family Supplies Calcium for Cell Surface Integrity in Mycobacterium smegmatis. mBio 2017; 8:mBio.01388-17. [PMID: 28951477 PMCID: PMC5615198 DOI: 10.1128/mbio.01388-17] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Ca2+ plays an important role in the physiology of bacteria. Intracellular Ca2+ concentrations are tightly maintained in the nanomolar range. Molecular mechanisms of Ca2+ uptake in bacteria remain elusive. Here we show that CtpE is responsible for Ca2+ uptake in Mycobacterium smegmatis. It represents a previously uncharacterized P-type ATPase family in bacteria. Disruption of ctpE in M. smegmatis resulted in a mutant with impaired growth under Ca2+-deficient conditions. The growth defect of the mutant could be rescued by Ca2+ or by ectopic expression of ctpE from M. smegmatis or the orthologous gene (Rv0908) from Mycobacterium tuberculosis H37Rv. Radioactive transport assays revealed that CtpE is a Ca2+-specific transporter. Ca2+ deficiency increased expression of ctpE, resulting in increased 45Ca2+ accumulation in cells. ctpE is a gene that is part of an operon, which is negatively regulated by Ca2+. The ctpE mutant also showed hypersensitivity to polymyxin B, increased biofilm formation, and higher cell aggregation, indicating cell envelope defects. Our work establishes, for the first time, the presence of Ca2+ uptake pumps of the energy-dependent P-type ATPase superfamily in bacteria and also implicates that intracellular Ca2+ is essential for growth and cell envelope integrity in M. smegmatis. Ca2+ is essential for gene regulation, enzymatic activity, and maintenance of structural integrity of cell walls in bacteria. Bacteria maintain intracellular calcium concentrations in a narrow range, creating a gradient with low cytoplasmic calcium concentration and high extracellular calcium concentration. Due to this steep gradient, active pumps belonging to family 2 of P-type ATPases and antiporters are used for Ca2+ efflux, whereas Ca2+ uptake is usually carried out by channels. Molecular mechanisms of Ca2+ uptake in bacteria are still elusive and are mainly limited to a nonproteinaceous channel in Escherichia coli and a pH-dependent channel protein from Bacillus subtilis. Energy-dependent active transporters are not reported for Ca2+ uptake from any organism. Here we show that CtpE belonging to a family of previously uncharacterized bacterial P-type ATPases is involved in specific uptake of Ca2+ into Mycobacterium smegmatis. We also demonstrate that intracellular Ca2+ obtained through CtpE is essential for growth and maintenance of cell surface properties under Ca2+-deficient conditions.
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Kathera C, Dulla EL, Chinahadri VP, Ramesh TSM, Basavaraju S, Jasti P. Proteomic characterization and bio-informatic analysis of differentially expressed E. coli Nissle 1917 proteins with response to cocoti wine stress. 3 Biotech 2017; 7:151. [PMID: 28597165 DOI: 10.1007/s13205-017-0787-5] [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: 12/03/2016] [Accepted: 03/21/2017] [Indexed: 10/19/2022] Open
Abstract
The present study emphases the comparative proteomic analysis of Escherichia coli Nissle 1917 under cocoti palm wine stress and identified differentially expressed proteins. Protein samples were analyzed by 2-D, MALDI-TOF combined with MS access. In 2-D electrophoresis, eight differentially expressed proteins were identified: five up-regulated, two down-regulated and one newly expressed protein. Protein spots were digested with trypsin for MALDI-TOF-MS analysis; protein sequences were obtained from MASCOT search. Sequences were aligned with template using Swiss Model server. Phyre-2 was used to predict homology modeling, RasMol was used to analyze the modeling structures, PSVS server was utilized to validate the protein structure by Ramachandran's plot analysis, physical and chemical properties were analyzed using ProtParam server, Phylogenetic tree was constructed by Mega4. UniProt search helps to find protein functional information of differentially expressed proteins, involved in catalytic activities, regulation mechanisms, DNA damage stimulus, anti-termination and termination process, protein binding, electron transport mechanism, and cell signaling process functions. A detailed exploration of the proteins under cocoti palm wine stress have provided the composition, structure and functions of the expressed proteins for further investigation.
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Quorum sensing by farnesol revisited. Curr Genet 2017; 63:791-797. [DOI: 10.1007/s00294-017-0683-x] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2017] [Revised: 02/01/2017] [Accepted: 02/07/2017] [Indexed: 12/18/2022]
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Khanam S, Guragain M, Lenaburg DL, Kubat R, Patrauchan MA. Calcium induces tobramycin resistance in Pseudomonas aeruginosa by regulating RND efflux pumps. Cell Calcium 2016; 61:32-43. [PMID: 28034459 DOI: 10.1016/j.ceca.2016.11.004] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2016] [Revised: 10/27/2016] [Accepted: 11/17/2016] [Indexed: 11/24/2022]
Abstract
Pseudomonas aeruginosa is an opportunistic multidrug resistant pathogen causing severe chronic infections. Our previous studies showed that elevated calcium (Ca2+) enhances production of several virulence factors and plant infectivity of the pathogen. Here we show that Ca2+ increases resistance of P. aeruginosa PAO1 to tobramycin, antibiotic commonly used to treat Pseudomonas infections. LC-MS/MS-based comparative analysis of the membrane proteomes of P aeruginosa grown at elevated versus not added Ca2+, determined that the abundances of two RND (resistance-nodulation-cell division) efflux pumps, MexAB-OprM and MexVW-OprM, were increased in the presence of elevated Ca2+. Analysis of twelve transposon mutants with disrupted RND efflux pumps showed that six of them (mexB, muxC, mexY, mexJ, czcB, and mexE) contribute to Ca2+-induced tobramycin resistance. Transcriptional analyses by promoter activity and RT-qPCR showed that the expression of mexAB, muxABC, mexXY, mexJK, czcCBA, and mexVW is increased by elevated Ca2+. Disruption of mexJ, mexC, mexI, and triA significantly decreased Ca2+-induced plant infectivity of the pathogen. Earlier, our group showed that PAO1 maintains intracellular Ca2+ (Ca2+in) homeostasis, which mediates Ca2+ regulation of P. aeruginosa virulence, and identified four putative Ca2+ transporters involved in this process (Guragain et al., 2013). Here we show that three of these transporters (PA2435, PA2092, PA4614) play role in Ca2+-induced tobramycin resistance and one of them (PA2435) contributes to Ca2+ regulation of mexAB-oprM promoter activity. Furthermore, mexJ, czcB, and mexE contribute to the maintenance of Ca2+in homeostasis. This provides the first evidence that Ca2+in homeostasis mediates Ca2+ regulation of RND transport systems, which contribute to Ca2+-enhanced tobramycin resistance and plant infectivity in P. aeruginosa.
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Affiliation(s)
- Sharmily Khanam
- Department of Microbiology and Molecular Genetics, Oklahoma State University, Stillwater, OK, United States
| | - Manita Guragain
- Department of Microbiology and Molecular Genetics, Oklahoma State University, Stillwater, OK, United States
| | - Dirk L Lenaburg
- Department of Microbiology and Molecular Genetics, Oklahoma State University, Stillwater, OK, United States
| | - Ryan Kubat
- Department of Microbiology and Molecular Genetics, Oklahoma State University, Stillwater, OK, United States
| | - Marianna A Patrauchan
- Department of Microbiology and Molecular Genetics, Oklahoma State University, Stillwater, OK, United States.
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LadS is a calcium-responsive kinase that induces acute-to-chronic virulence switch in Pseudomonas aeruginosa. Nat Microbiol 2016; 2:16184. [DOI: 10.1038/nmicrobiol.2016.184] [Citation(s) in RCA: 65] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2016] [Accepted: 08/30/2016] [Indexed: 11/08/2022]
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Within-Host Evolution of the Dutch High-Prevalent Pseudomonas aeruginosa Clone ST406 during Chronic Colonization of a Patient with Cystic Fibrosis. PLoS One 2016; 11:e0158106. [PMID: 27337151 PMCID: PMC4918941 DOI: 10.1371/journal.pone.0158106] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2016] [Accepted: 06/12/2016] [Indexed: 01/01/2023] Open
Abstract
This study investigates adaptation of ST406, a prevalent P. aeruginosa clone, present in 15% of chronically infected cystic fibrosis (CF) patients in the Netherlands, in a newly infected CF patient during three years using whole genome sequencing (WGS), transcriptomics, and phenotypic assays, including biofilm formation. WGS-based phylogeny demonstrates that ST406 is genetically distinct from other reported CF related strains or epidemic clones. Comparative genomic analysis of the early (S1) and late (S2) isolate yielded 42 single nucleotide polymorphisms (SNPs) and 10 indels and a single 7 kb genomic fragment only found in S2. Most SNPs and differentially expressed genes encoded proteins involved in metabolism, secretion and signal transduction or transcription. SNPs were identified in regulator genes mexT and exsA and coincided with differential gene expression of mexE and mexF, encoding the MexE/F efflux pump, genes encoding the type six secretion system (T6SS) and type three secretion system (T3SS), which have also been previously implicated in adaptation of other P. aeruginosa strains during chronic infection of CF lungs. The observation that genetically different strains from different patients have accumulated similar genetic adaptations supports the concept of adaptive parallel evolution of P. aeruginosa in chronically infected CF patients. Phenotypically, there was loss of biofilm maturation coinciding with a significant lower level of transcription of both bfmR and bfmS during chronic colonization. These data suggest that the high-prevalent Dutch CF clone ST406 displays adaptation to the CF lung niche, which involves a limited number of mutations affecting regulators controlling biofilm formation and secretion and genes involved in metabolism. These genes could provide good targets for anti-pseudomonal therapy.
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The Pseudomonas aeruginosa PAO1 Two-Component Regulator CarSR Regulates Calcium Homeostasis and Calcium-Induced Virulence Factor Production through Its Regulatory Targets CarO and CarP. J Bacteriol 2016; 198:951-63. [PMID: 26755627 DOI: 10.1128/jb.00963-15] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2015] [Accepted: 12/31/2015] [Indexed: 02/02/2023] Open
Abstract
UNLABELLED Pseudomonas aeruginosa is an opportunistic human pathogen that causes severe, life-threatening infections in patients with cystic fibrosis (CF), endocarditis, wounds, or artificial implants. During CF pulmonary infections, P. aeruginosa often encounters environments where the levels of calcium (Ca(2+)) are elevated. Previously, we showed that P. aeruginosa responds to externally added Ca(2+) through enhanced biofilm formation, increased production of several secreted virulence factors, and by developing a transient increase in the intracellular Ca(2+) level, followed by its removal to the basal submicromolar level. However, the molecular mechanisms responsible for regulating Ca(2+)-induced virulence factor production and Ca(2+) homeostasis are not known. Here, we characterized the genome-wide transcriptional response of P. aeruginosa to elevated [Ca(2+)] in both planktonic cultures and biofilms. Among the genes induced by CaCl2 in strain PAO1 was an operon containing the two-component regulator PA2656-PA2657 (here called carS and carR), while the closely related two-component regulators phoPQ and pmrAB were repressed by CaCl2 addition. To identify the regulatory targets of CarSR, we constructed a deletion mutant of carR and performed transcriptome analysis of the mutant strain at low and high [Ca(2+)]. Among the genes regulated by CarSR in response to CaCl2 are the predicted periplasmic OB-fold protein, PA0320 (here called carO), and the inner membrane-anchored five-bladed β-propeller protein, PA0327 (here called carP). Mutations in both carO and carP affected Ca(2+) homeostasis, reducing the ability of P. aeruginosa to export excess Ca(2+). In addition, a mutation in carP had a pleotropic effect in a Ca(2+)-dependent manner, altering swarming motility, pyocyanin production, and tobramycin sensitivity. Overall, the results indicate that the two-component system CarSR is responsible for sensing high levels of external Ca(2+) and responding through its regulatory targets that modulate Ca(2+) homeostasis, surface-associated motility, and the production of the virulence factor pyocyanin. IMPORTANCE During infectious disease, Pseudomonas aeruginosa encounters environments with high calcium (Ca(2+)) concentrations, yet the cells maintain intracellular Ca(2+) at levels that are orders of magnitude less than that of the external environment. In addition, Ca(2+) signals P. aeruginosa to induce the production of several virulence factors. Compared to eukaryotes, little is known about how bacteria maintain Ca(2+) homeostasis or how Ca(2+) acts as a signal. In this study, we identified a two-component regulatory system in P. aeruginosa PAO1, termed CarRS, that is induced at elevated Ca(2+) levels. CarRS modulates Ca(2+) signaling and Ca(2+) homeostasis through its regulatory targets, CarO and CarP. The results demonstrate that P. aeruginosa uses a two-component regulatory system to sense external Ca(2+) and relays that information for Ca(2+)-dependent cellular processes.
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Guragain M, Campbell A, Patrauchan M. Measurement of Intracellular Calcium Concentration in Pseudomonas aeruginosa. Bio Protoc 2016. [DOI: 10.21769/bioprotoc.2041] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022] Open
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Castillo-Juárez I, Maeda T, Mandujano-Tinoco EA, Tomás M, Pérez-Eretza B, García-Contreras SJ, Wood TK, García-Contreras R. Role of quorum sensing in bacterial infections. World J Clin Cases 2015; 3:575-598. [PMID: 26244150 PMCID: PMC4517333 DOI: 10.12998/wjcc.v3.i7.575] [Citation(s) in RCA: 120] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/09/2014] [Revised: 11/30/2014] [Accepted: 04/20/2015] [Indexed: 02/05/2023] Open
Abstract
Quorum sensing (QS) is cell communication that is widely used by bacterial pathogens to coordinate the expression of several collective traits, including the production of multiple virulence factors, biofilm formation, and swarming motility once a population threshold is reached. Several lines of evidence indicate that QS enhances virulence of bacterial pathogens in animal models as well as in human infections; however, its relative importance for bacterial pathogenesis is still incomplete. In this review, we discuss the present evidence from in vitro and in vivo experiments in animal models, as well as from clinical studies, that link QS systems with human infections. We focus on two major QS bacterial models, the opportunistic Gram negative bacteria Pseudomonas aeruginosa and the Gram positive Staphylococcus aureus, which are also two of the main agents responsible of nosocomial and wound infections. In addition, QS communication systems in other bacterial, eukaryotic pathogens, and even immune and cancer cells are also reviewed, and finally, the new approaches proposed to combat bacterial infections by the attenuation of their QS communication systems and virulence are also discussed.
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Calcium binding proteins and calcium signaling in prokaryotes. Cell Calcium 2014; 57:151-65. [PMID: 25555683 DOI: 10.1016/j.ceca.2014.12.006] [Citation(s) in RCA: 136] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2014] [Revised: 12/08/2014] [Accepted: 12/09/2014] [Indexed: 11/20/2022]
Abstract
With the continued increase of genomic information and computational analyses during the recent years, the number of newly discovered calcium binding proteins (CaBPs) in prokaryotic organisms has increased dramatically. These proteins contain sequences that closely resemble a variety of eukaryotic calcium (Ca(2+)) binding motifs including the canonical and pseudo EF-hand motifs, Ca(2+)-binding β-roll, Greek key motif and a novel putative Ca(2+)-binding domain, called the Big domain. Prokaryotic CaBPs have been implicated in diverse cellular activities such as division, development, motility, homeostasis, stress response, secretion, transport, signaling and host-pathogen interactions. However, the majority of these proteins are hypothetical, and only few of them have been studied functionally. The finding of many diverse CaBPs in prokaryotic genomes opens an exciting area of research to explore and define the role of Ca(2+) in organisms other than eukaryotes. This review presents the most recent developments in the field of CaBPs and novel advancements in the role of Ca(2+) in prokaryotes.
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