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Geiger CJ, Wong GCL, O'Toole GA. A bacterial sense of touch: T4P retraction motor as a means of surface sensing by Pseudomonas aeruginosa PA14. J Bacteriol 2024; 206:e0044223. [PMID: 38832786 PMCID: PMC11270903 DOI: 10.1128/jb.00442-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/05/2024] Open
Abstract
Most microbial cells found in nature exist in matrix-covered, surface-attached communities known as biofilms. This mode of growth is initiated by the ability of the microbe to sense a surface on which to grow. The opportunistic pathogen Pseudomonas aeruginosa (Pa) PA14 utilizes a single polar flagellum and type 4 pili (T4P) to sense surfaces. For Pa, T4P-dependent "twitching" motility is characterized by effectively pulling the cell across a surface through a complex process of cooperative binding, pulling, and unbinding. T4P retraction is powered by hexameric ATPases. Pa cells that have engaged a surface increase production of the second messenger cyclic AMP (cAMP) over multiple generations via the Pil-Chp system. This rise in cAMP allows cells and their progeny to become better adapted for surface attachment and activates virulence pathways through the cAMP-binding transcription factor Vfr. While many studies have focused on mechanisms of T4P twitching and regulation of T4P production and function by the Pil-Chp system, the mechanism by which Pa senses and relays a surface-engagement signal to the cell is still an open question. Here we review the current state of the surface sensing literature for Pa, with a focus on T4P, and propose an integrated model of surface sensing whereby the retraction motor PilT senses and relays the signal to the Pil-Chp system via PilJ to drive cAMP production and adaptation to a surface lifestyle.
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Affiliation(s)
- C. J. Geiger
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire, USA
| | - G. C. L. Wong
- Department of Bioengineering, University of California, Los Angeles, Los Angeles, California, USA
- Department of Chemistry and Biochemistry, University of California, Los Angeles, Los Angeles, California, USA
- California NanoSystems Institute, University of California, Los Angeles, Los Angeles, California, USA
| | - G. A. O'Toole
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire, USA
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Ábrahám Á, Dér L, Csákvári E, Vizsnyiczai G, Pap I, Lukács R, Varga-Zsíros V, Nagy K, Galajda P. Single-cell level LasR-mediated quorum sensing response of Pseudomonas aeruginosa to pulses of signal molecules. Sci Rep 2024; 14:16181. [PMID: 39003361 PMCID: PMC11246452 DOI: 10.1038/s41598-024-66706-6] [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: 09/04/2023] [Accepted: 07/03/2024] [Indexed: 07/15/2024] Open
Abstract
Quorum sensing (QS) is a communication form between bacteria via small signal molecules that enables global gene regulation as a function of cell density. We applied a microfluidic mother machine to study the kinetics of the QS response of Pseudomonas aeruginosa bacteria to additions and withdrawals of signal molecules. We traced the fast buildup and the subsequent considerably slower decay of a population-level and single-cell-level QS response. We applied a mathematical model to explain the results quantitatively. We found significant heterogeneity in QS on the single-cell level, which may result from variations in quorum-controlled gene expression and protein degradation. Heterogeneity correlates with cell lineage history, too. We used single-cell data to define and quantitatively characterize the population-level quorum state. We found that the population-level QS response is well-defined. The buildup of the quorum is fast upon signal molecule addition. At the same time, its decay is much slower following signal withdrawal, and the quorum may be maintained for several hours in the absence of the signal. Furthermore, the quorum sensing response of the population was largely repeatable in subsequent pulses of signal molecules.
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Affiliation(s)
- Ágnes Ábrahám
- HUN-REN Biological Research Centre, Institute of Biophysics, Temesvári Krt. 62, Szeged, 6726, Hungary
- Doctoral School of Multidisciplinary Medical Sciences, University of Szeged, Dóm Tér 9, Szeged, 6720, Hungary
| | - László Dér
- HUN-REN Biological Research Centre, Institute of Biophysics, Temesvári Krt. 62, Szeged, 6726, Hungary
| | - Eszter Csákvári
- HUN-REN Biological Research Centre, Institute of Biophysics, Temesvári Krt. 62, Szeged, 6726, Hungary
- Division for Biotechnology, Bay Zoltán Nonprofit Ltd. for Applied Research, Derkovits Fasor 2., Szeged, 6726, Hungary
| | - Gaszton Vizsnyiczai
- HUN-REN Biological Research Centre, Institute of Biophysics, Temesvári Krt. 62, Szeged, 6726, Hungary
| | - Imre Pap
- HUN-REN Biological Research Centre, Institute of Biophysics, Temesvári Krt. 62, Szeged, 6726, Hungary
- Doctoral School of Multidisciplinary Medical Sciences, University of Szeged, Dóm Tér 9, Szeged, 6720, Hungary
| | - Rebeka Lukács
- HUN-REN Biological Research Centre, Institute of Biophysics, Temesvári Krt. 62, Szeged, 6726, Hungary
| | - Vanda Varga-Zsíros
- HUN-REN Biological Research Centre, Institute of Biophysics, Temesvári Krt. 62, Szeged, 6726, Hungary
- HUN-REN Biological Research Centre, Institute of Biochemistry, Temesvári Krt. 62, Szeged, 6726, Hungary
| | - Krisztina Nagy
- HUN-REN Biological Research Centre, Institute of Biophysics, Temesvári Krt. 62, Szeged, 6726, Hungary.
| | - Péter Galajda
- HUN-REN Biological Research Centre, Institute of Biophysics, Temesvári Krt. 62, Szeged, 6726, Hungary.
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Zhang Y, Zhao X, Wang J, Liao L, Qin H, Zhang R, Li C, He Y, Huang S. VmsR, a LuxR-Type Regulator, Contributes to Virulence, Cell Motility, Extracellular Polysaccharide Production and Biofilm Formation in Xanthomonas oryzae pv. oryzicola. Int J Mol Sci 2024; 25:7595. [PMID: 39062838 PMCID: PMC11277528 DOI: 10.3390/ijms25147595] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2024] [Revised: 07/05/2024] [Accepted: 07/06/2024] [Indexed: 07/28/2024] Open
Abstract
LuxR-type regulators play pivotal roles in regulating numerous bacterial processes, including bacterial motility and virulence, thereby exerting a significant influence on bacterial behavior and pathogenicity. Xanthomonas oryzae pv. oryzicola, a rice pathogen, causes bacterial leaf streak. Our research has identified VmsR, which is a response regulator of the two-component system (TCS) that belongs to the LuxR family. These findings of the experiment reveal that VmsR plays a crucial role in regulating pathogenicity, motility, biofilm formation, and the production of extracellular polysaccharides (EPSs) in Xoc GX01. Notably, our study shows that the vmsR mutant exhibits a reduced swimming motility but an enhanced swarming motility. Furthermore, this mutant displays decreased virulence while significantly increasing EPS production and biofilm formation. We have uncovered that VmsR directly interacts with the promoter regions of fliC and fliS, promoting their expression. In contrast, VmsR specifically binds to the promoter of gumB, resulting in its downregulation. These findings indicate that the knockout of vmsR has profound effects on virulence, motility, biofilm formation, and EPS production in Xoc GX01, providing insights into the intricate regulatory network of Xoc.
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Affiliation(s)
- Yaqi Zhang
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, College of Life Science and Technology, Guangxi University, Nanning 530004, China; (Y.Z.); (X.Z.); (J.W.); (L.L.); (H.Q.); (R.Z.); (C.L.)
| | - Xiyao Zhao
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, College of Life Science and Technology, Guangxi University, Nanning 530004, China; (Y.Z.); (X.Z.); (J.W.); (L.L.); (H.Q.); (R.Z.); (C.L.)
| | - Jiuxiang Wang
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, College of Life Science and Technology, Guangxi University, Nanning 530004, China; (Y.Z.); (X.Z.); (J.W.); (L.L.); (H.Q.); (R.Z.); (C.L.)
| | - Lindong Liao
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, College of Life Science and Technology, Guangxi University, Nanning 530004, China; (Y.Z.); (X.Z.); (J.W.); (L.L.); (H.Q.); (R.Z.); (C.L.)
| | - Huajun Qin
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, College of Life Science and Technology, Guangxi University, Nanning 530004, China; (Y.Z.); (X.Z.); (J.W.); (L.L.); (H.Q.); (R.Z.); (C.L.)
| | - Rongbo Zhang
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, College of Life Science and Technology, Guangxi University, Nanning 530004, China; (Y.Z.); (X.Z.); (J.W.); (L.L.); (H.Q.); (R.Z.); (C.L.)
| | - Changyu Li
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, College of Life Science and Technology, Guangxi University, Nanning 530004, China; (Y.Z.); (X.Z.); (J.W.); (L.L.); (H.Q.); (R.Z.); (C.L.)
| | - Yongqiang He
- College of Agronomy, Guangxi University, Nanning 530004, China
| | - Sheng Huang
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, College of Life Science and Technology, Guangxi University, Nanning 530004, China; (Y.Z.); (X.Z.); (J.W.); (L.L.); (H.Q.); (R.Z.); (C.L.)
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4
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Çevikbaş H, Ulusoy S, Kaya Kinaytürk N. Exploring rose absolute and phenylethyl alcohol as novel quorum sensing inhibitors in Pseudomonas aeruginosa and Chromobacterium violaceum. Sci Rep 2024; 14:15666. [PMID: 38977845 PMCID: PMC11231148 DOI: 10.1038/s41598-024-66888-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2024] [Accepted: 07/05/2024] [Indexed: 07/10/2024] Open
Abstract
Inter-cellular signaling, referred to as quorum sensing (QS), regulates the production of virulence factors in numerous gram-negative bacteria, such as the human pathogens Pseudomonas aeruginosa and Chromobacterium violaceum. QS inhibition may provide an opportunity for the treatment of bacterial infections. This represents the initial study to examine the antibiofilm and antivirulence capabilities of rose absolute and its primary component, phenylethyl alcohol. QS inhibition was assessed by examining extracellular exopolysaccharide synthesis, biofilm development, and swarming motility in P. aeruginosa PAO1, along with violacein production in C. violaceum ATCC 12472. Molecular docking analysis was conducted to explore the mechanism by which PEA inhibits QS. Our results indicate that rose absolute and PEA caused decrease in EPS production (60.5-33.5%), swarming motility (94.7-64.5%), and biofilm formation (98.53-55.5%) in the human pathogen P. aeruginosa PAO1. Violacein production decreased by 98.1% and 62.5% with an absolute (0.5 v/v %) and PEA (2 mM). Moreover, the molecular docking analysis revealed a promising competitive interaction between PEA and AHLs. Consequently, this study offers valuable insights into the potential of rose absolute and PEA as inhibitors of QS in P. aeruginosa and C. violaceum.
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Affiliation(s)
- Halime Çevikbaş
- Faculty of Engineering and Natural Sciences, Biology Department, Süleyman Demirel University, Isparta, 32260, Turkey
| | - Seyhan Ulusoy
- Faculty of Engineering and Natural Sciences, Biology Department, Süleyman Demirel University, Isparta, 32260, Turkey.
| | - Neslihan Kaya Kinaytürk
- Faculty of Arts and Science, Nanoscience and Nanotechnology Department, Mehmet Akif Ersoy University, Burdur, 15100, Turkey
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Cianciulli Sesso A, Resch A, Moll I, Bläsi U, Sonnleitner E. The FinO/ProQ-like protein PA2582 impacts antimicrobial resistance in Pseudomonas aeruginosa. Front Microbiol 2024; 15:1422742. [PMID: 39011145 PMCID: PMC11247311 DOI: 10.3389/fmicb.2024.1422742] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2024] [Accepted: 06/03/2024] [Indexed: 07/17/2024] Open
Abstract
Bacteria employ small regulatory RNAs (sRNA) and/or RNA binding proteins (RBPs) to respond to environmental cues. In Enterobacteriaceae, the FinO-domain containing RBP ProQ associates with numerous sRNAs and mRNAs, impacts sRNA-mediated riboregulation or mRNA stability by binding to 5'- or 3'-untranslated regions as well as to internal stem loop structures. Global RNA-protein interaction studies and sequence comparisons identified a ProQ-like homolog (PA2582/ProQ Pae ) in Pseudomonas aeruginosa (Pae). To address the function of ProQ Pae , at first a comparative transcriptome analysis of the Pae strains PAO1 and PAO1ΔproQ was performed. This study revealed more than 100 differentially abundant transcripts, affecting a variety of cellular functions. Among these transcripts were pprA and pprB, encoding the PprA/PprB two component system, psrA, encoding a transcriptional activator of pprB, and oprI, encoding the outer membrane protein OprI. RNA co-purification experiments with Strep-tagged Pae ProQ protein corroborated an association of ProQ Pae with these transcripts. In accordance with the up-regulation of the psrA, pprA, and pprB genes in strain PAO1ΔproQ a phenotypic analysis revealed an increased susceptibility toward the aminoglycosides tobramycin and gentamicin in biofilms. Conversely, the observed down-regulation of the oprI gene in PAO1ΔproQ could be reconciled with a decreased susceptibility toward the synthetic cationic antimicrobial peptide GW-Q6. Taken together, these studies revealed that ProQ Pae is an RBP that impacts antimicrobial resistance in Pae.
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Affiliation(s)
- Anastasia Cianciulli Sesso
- Department of Microbiology, Immunobiology and Genetics, Max Perutz Labs, Center of Molecular Biology, Vienna Biocenter, University of Vienna, Vienna, Austria
- Vienna BioCenter PhD Program, a Doctoral School of the University of Vienna and the Medical University of Vienna, Max Perutz Labs, Vienna Biocenter, University of Vienna, Vienna, Austria
| | - Armin Resch
- Department of Microbiology, Immunobiology and Genetics, Max Perutz Labs, Center of Molecular Biology, Vienna Biocenter, University of Vienna, Vienna, Austria
| | - Isabella Moll
- Department of Microbiology, Immunobiology and Genetics, Max Perutz Labs, Center of Molecular Biology, Vienna Biocenter, University of Vienna, Vienna, Austria
| | - Udo Bläsi
- Department of Microbiology, Immunobiology and Genetics, Max Perutz Labs, Center of Molecular Biology, Vienna Biocenter, University of Vienna, Vienna, Austria
| | - Elisabeth Sonnleitner
- Department of Microbiology, Immunobiology and Genetics, Max Perutz Labs, Center of Molecular Biology, Vienna Biocenter, University of Vienna, Vienna, Austria
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6
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Kok LC, Tsai CC, Liao YH, Lo YL, Cheng NW, Lin CT, Chang HY. Roles of transcriptional factor PsrA in the regulation of quorum sensing in Pseudomonas aeruginosa PAO1. Front Microbiol 2024; 15:1424330. [PMID: 38989021 PMCID: PMC11233452 DOI: 10.3389/fmicb.2024.1424330] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2024] [Accepted: 06/14/2024] [Indexed: 07/12/2024] Open
Abstract
The transcription factor PsrA regulates fatty acid metabolism, the type III secretion system, and quinolone signaling quorum sensing system in Pseudomonas aeruginosa. To explore additional roles of PsrA in P. aeruginosa, this study engineered a P. aeruginosa PAO1 strain to carry a recombinant plasmid with the psrA gene (pMMBpsrA) and examined the impact of elevated psrA expression to the bacterium. Transcriptomic analysis revealed that PsrA significantly downregulated genes encoding the master quorum-sensing regulators, RhlR and LasR, and influenced many quorum-sensing-associated genes. The role of PsrA in quorum sensing was further corroborated by testing autoinducer synthesis in PAO1 [pMMBpsrA] using two reporter bacteria strains Chromobacterium violaceum CV026 and Escherichia coli [pSB1075], which respond to short- and long-chain acyl homoserine lactones, respectively. Phenotypic comparisons of isogenic ΔpsrA, ΔlasR, and ΔpsrAΔlasR mutants revealed that the reduced elastase, caseinase, and swarming activity in PAO1 [pMMBpsrA] were likely mediated through LasR. Additionally, electrophoretic mobility shift assays demonstrated that recombinant PsrA could bind to the lasR promoter at a 5'-AAACGTTTGCTT-3' sequence, which displays moderate similarity to the previously reported consensus PsrA binding motif. Furthermore, the PsrA effector molecule oleic acid inhibited PsrA binding to the lasR promoter and restored several quorum sensing-related phenotypes to wild-type levels. These findings suggest that PsrA regulates certain quorum-sensing phenotypes by negatively regulating lasR expression, with oleic acid acting as a crucial signaling molecule.
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Affiliation(s)
- Li-Ching Kok
- Institute of Molecular Medicine, National Tsing Hua University, Hsinchu City, Taiwan
| | - Chia-Chun Tsai
- Institute of Molecular Medicine, National Tsing Hua University, Hsinchu City, Taiwan
| | - Yu-Hsuan Liao
- Institute of Molecular Medicine, National Tsing Hua University, Hsinchu City, Taiwan
| | - Yi-Ling Lo
- Institute of Molecular Medicine, National Tsing Hua University, Hsinchu City, Taiwan
| | - Nai-Wei Cheng
- Institute of Molecular Medicine, National Tsing Hua University, Hsinchu City, Taiwan
| | - Ching-Ting Lin
- School of Chinese Medicine, China Medical University, Taichung City, Taiwan
| | - Hwan-You Chang
- Institute of Molecular Medicine, National Tsing Hua University, Hsinchu City, Taiwan
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Maršík D, Maťátková O, Kolková A, Masák J. Exploring the antimicrobial potential of chitosan nanoparticles: synthesis, characterization and impact on Pseudomonas aeruginosa virulence factors. NANOSCALE ADVANCES 2024; 6:3093-3105. [PMID: 38868829 PMCID: PMC11166115 DOI: 10.1039/d4na00064a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/23/2024] [Accepted: 04/21/2024] [Indexed: 06/14/2024]
Abstract
The escalating antibiotic resistance observed in bacteria poses a significant threat to society, with the global prevalence of resistant strains of Pseudomonas aeruginosa on the rise. Addressing this challenge necessitates exploring strategies that would complement existing antimicrobial agents, e.g. by substances mitigating bacterial virulence without eliciting selective pressure for resistance emergence. In this respect, free-form chitosan has demonstrated promising efficacy, prompting our investigation into reinforcing its effects through nanoparticle formulations. Our study focuses on the preparation of chitosan nanoparticles under suitable conditions while emphasizing the challenges associated with stability that can affect biological activity. These challenges are mitigated by introducing quaternized chitosan, which ensures colloidal stability in the culture media. Our approach led to the production of trimethylchitosan nanoparticles with a median size of 103 nm, circularity of 0.967, and a charge of 14.9 ± 3.1 mV, stable within a one-month period in a water stock solution, showing promising attributes for further valorization. Furthermore, the study delves into the antimicrobial activity of trimethylchitosan nanoparticles on Pseudomonas aeruginosa and confirms the benefits of both nanoformulation and modification of chitosan, as our prepared nanoparticles inhibit 50% of the bacterial population at concentration ≥160 mg L-1 within tested strains. Additionally, we identified a concentration of 5 mg L-1 that no longer impedes bacterial growth, allowing reliable verification of the effect of the prepared nanoparticles on Pseudomonas aeruginosa virulence factors, including motility, protease activity, hemolytic activity, rhamnolipids, pyocyanin, and biofilm production. Although trimethylchitosan nanoparticles exhibit promise as an effective antibiofilm agent (reducing biofilm development by 50% at concentrations ranging from 80 to 160 mg L-1) their impact on virulence manifestation is likely not directly associated with quorum sensing. Instead, it can probably be attributed to non-specific interactions with the bacterial surface. This exploration provides valuable insights into the potential of quaternized chitosan nanoparticles in addressing Pseudomonas aeruginosa infections and underscores the multifaceted nature of their antimicrobial effects.
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Affiliation(s)
- Dominik Maršík
- Department of Biotechnology, University of Chemistry and Technology Technická 5, Prague 6 Prague 166 28 Czechia
| | - Olga Maťátková
- Department of Biotechnology, University of Chemistry and Technology Technická 5, Prague 6 Prague 166 28 Czechia
| | - Anna Kolková
- Department of Biotechnology, University of Chemistry and Technology Technická 5, Prague 6 Prague 166 28 Czechia
| | - Jan Masák
- Department of Biotechnology, University of Chemistry and Technology Technická 5, Prague 6 Prague 166 28 Czechia
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Pastora AB, Rzasa KM, O’Toole GA. Multiple pathways impact the swarming motility of Pseudomonas fluorescens Pf0-1. Microbiol Spectr 2024; 12:e0016624. [PMID: 38687073 PMCID: PMC11237744 DOI: 10.1128/spectrum.00166-24] [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: 01/17/2024] [Accepted: 04/20/2024] [Indexed: 05/02/2024] Open
Abstract
Swarming motility in pseudomonads typically requires both a functional flagellum and the production/secretion of a biosurfactant. Published work has shown that the wild-type Pseudomonas fluorescens Pf0-1 is swarming deficient due to a point mutation in the gacA gene, which until recently was thought to inactivate rather than attenuate the Gac/Rsm pathway. As a result, little is known about the underlying mechanisms that regulate swarming motility by P. fluorescens Pf0-1. Here, we demonstrate that a ΔrsmA ΔrsmE ΔrsmI mutant, which phenotypically mimics Gac/Rsm pathway overstimulation, is proficient at swarming motility. RsmA and RsmE appear to play a key role in this regulation. Transposon mutagenesis of the ΔrsmA ΔrsmE ΔrsmI mutant identified multiple factors that impact swarming motility, including pathways involved in flagellar synthesis and biosurfactant production/secretion. We find that loss of genes linked to biosurfactant Gacamide A biosynthesis or secretion impacts swarming motility, as does loss of the alternative sigma factor FliA, which results in a defect in flagellar function. Collectively, these findings provide evidence that P. fluorescens Pf0-1 can swarm if the Gac/Rsm pathway is activated, highlight the regulatory complexity of swarming motility in this strain, and demonstrate that the cyclic lipopeptide Gacamide A is utilized as a biosurfactant for swarming motility.IMPORTANCESwarming motility is a coordinated process that allows communities of bacteria to collectively move across a surface. For P. fluorescens Pf0-1, this phenotype is notably absent in the parental strain, and to date, little is known about the regulation of swarming in this strain. Here, we identify RsmA and RsmE as key repressors of swarming motility via modulating the levels of biosurfactant production/secretion. Using transposon mutagenesis and subsequent genetic analyses, we further identify potential regulatory mechanisms of swarming motility and link Gacamide A biosynthesis and transport machinery to swarming motility.
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Affiliation(s)
- Alexander B. Pastora
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire, USA
| | - Kara M. Rzasa
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire, USA
- Thayer School of Engineering at Dartmouth, Hanover, New Hampshire, USA
| | - George A. O’Toole
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire, USA
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Sakka K, Kihira M, Kuhara W, Mochida A, Ogawa S, Kimura T, Sakka M. Unique behavioral patterns of wandering colonies of Brevibacillus thermoruber on agar plates. J Basic Microbiol 2024; 64:e2400091. [PMID: 38651780 DOI: 10.1002/jobm.202400091] [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: 02/20/2024] [Revised: 03/27/2024] [Accepted: 04/10/2024] [Indexed: 04/25/2024]
Abstract
Brevibacillus thermoruber strain Nabari cells grow as widely spreading dendritic colonies on reasoner's 2A-agar (1.5%) plates at around 55°C but as small motile colonies at 37°C. Motile colonies can be divided into colonies that move in straight or curved lines over long distances (wandering colonies), and colonies that rotate at a fixed location (rotating colonies). The addition of surfactant to the agar medium greatly increased the frequency of wandering colonies and facilitated the study of such colonies. The morphology of the wandering colonies varied: circular at the tip and pointed at the back, lemon-shaped with pointed ends, crescent-shaped, bullet-shaped, fish-like, and so on. A single colony may split into multiple colonies as it moves, or multiple colonies may merge into a single colony. The most surprising aspect of the movement of wandering colonies was that when a moving colony collides with another colony, it sometimes does not make a U-turn, but instead retreats straight back, as if bouncing back. The migration mechanisms of wandering colonies are discussed based on optical microscopic observations of swimming patterns of single cells in water and scanning electron microscopy of the arrangement of bacterial cells in wandering colonies.
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Affiliation(s)
- Kazuo Sakka
- Graduate School of Bioresources, Mie University, Tsu, Japan
| | | | | | | | - Satoru Ogawa
- Graduate School of Medicine, Mie University, Tsu, Japan
| | - Tetsuya Kimura
- Graduate School of Bioresources, Mie University, Tsu, Japan
| | - Makiko Sakka
- Graduate School of Bioresources, Mie University, Tsu, Japan
- Kinki Kankyo Service Co., Ltd., Nabari, Japan
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Lee DH, Kim SB. Quorum Quenching Potential of Reyranella sp. Isolated from Riverside Soil and Description of Reyranella humidisoli sp. nov. J Microbiol 2024; 62:449-461. [PMID: 38814538 DOI: 10.1007/s12275-024-00131-2] [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: 10/10/2023] [Revised: 01/13/2024] [Accepted: 02/27/2024] [Indexed: 05/31/2024]
Abstract
Quorum quenching refers to any mechanism that inhibits quorum sensing processes. In this study, quorum quenching activity among bacteria inhabiting riverside soil was screened, and a novel Gram-stain-negative, rod shaped bacterial strain designated MMS21-HV4-11T, which showed the highest level of quorum quenching activity, was isolated and subjected to further analysis. Strain MMS21-HV4-11T could be assigned to the genus Reyranella of Alphaproteobacteria based on the 16S rRNA gene sequence, as the strain shared 98.74% sequence similarity with Reyranella aquatilis seoho-37T, and then 97.87% and 97.80% sequence similarity with Reyranella soli KIS14-15T and Reyranella massiliensis 521T, respectively. The decomposed N-acyl homoserine lactone was restored at high concentrations under acidic conditions, implying that lactonase and other enzyme(s) are responsible for quorum quenching. The genome analysis indicated that strain MMS21-HV4-11T had two candidate genes for lactonase and one for acylase, and expected protein structures were confirmed. In the quorum sensing inhibition assay using a plant pathogen Pectobacterium carotovorum KACC 14888, development of soft rot was significantly inhibited by strain MMS21-HV4-11T. Besides, the swarming motility by Pseudomonas aeruginosa PA14 was significantly inhibited in the presence of strain MMS21-HV4-11T. Since the isolate did not display direct antibacterial activity against either of these species, the inhibition was certainly due to quorum quenching activity. In an extended study with the type strains of all known species of Reyranella, all strains were capable of degrading N-acyl homoserine lactones (AHLs), thus showing quorum quenching potential at the genus level. This is the first study on the quorum quenching potential and enzymes responsible in Reyranella. In addition, MMS21-HV4-11T could be recognized as a new species through taxonomic characterization, for which the name Reyranella humidisoli sp. nov. is proposed (type strain = MMS21-HV4-11 T = KCTC 82780 T = LMG 32365T).
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Affiliation(s)
- Dong Hyeon Lee
- Department of Microbiology and Molecular Biology, College of Bioscience and Biotechnology, Chungnam National University, Daejeon, 34134, Republic of Korea
| | - Seung Bum Kim
- Department of Microbiology and Molecular Biology, College of Bioscience and Biotechnology, Chungnam National University, Daejeon, 34134, Republic of Korea.
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Liu D, Liu J, Ran L, Yang Z, He Y, Yang H, Yu Y, Fu L, Zhu M, Chen H. Oleanolic Acid Promotes the Formation of Probiotic Escherichia coli Nissle 1917 (EcN) Biofilm by Inhibiting Bacterial Motility. Microorganisms 2024; 12:1097. [PMID: 38930479 PMCID: PMC11205495 DOI: 10.3390/microorganisms12061097] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2024] [Revised: 05/15/2024] [Accepted: 05/22/2024] [Indexed: 06/28/2024] Open
Abstract
Probiotic biofilms have been beneficial in the fight against infections, restoring the equilibrium of the host's gut microbiota, and enhancing host health. They are considered a novel strategy for probiotic gut colonization. In this case, we evaluated the effects of various active substances from traditional Chinese medicine on Escherichia coli Nissle 1917 (EcN) to determine if they promote biofilm formation. It was shown that 8-64 μg/mL of oleanolic acid increased the development of EcN biofilm. Additionally, we observed that oleanolic acid can effectively suppress biofilm formation in pathogenic bacteria such as Salmonella and Staphylococcus aureus. Next, we assessed the amount of EcN extracellular polysaccharides, the number of live bacteria, their metabolic activity, the hydrophobicity of their surface, and the shape of their biofilms using laser confocal microscopy. Through transcriptome analysis, a total of 349 differentially expressed genes were identified, comprising 134 upregulated and 215 downregulated genes. GO functional enrichment analysis and KEGG pathway enrichment analysis revealed that oleanolic acid functions are through the regulation of bacterial motility, the iron absorption system, the two-component system, and adhesion pathways. These findings suggest that the main effects of oleanolic acid are to prevent bacterial motility, increase initial adhesion, and encourage the development of EcN biofilms. In addition, oleanolic acid interacts with iron absorption to cooperatively control the production of EcN biofilms within an optimal concentration range. Taking these results together, this study suggests that oleanolic acid may enhance probiotic biofilm formation in the intestines, presenting new avenues for probiotic product development.
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Affiliation(s)
- Dan Liu
- College of Veterinary Medicine, Southwest University, Chongqing 402460, China; (D.L.); (J.L.); (L.R.); (Z.Y.); (Y.H.); (H.Y.)
| | - Jingjing Liu
- College of Veterinary Medicine, Southwest University, Chongqing 402460, China; (D.L.); (J.L.); (L.R.); (Z.Y.); (Y.H.); (H.Y.)
| | - Lei Ran
- College of Veterinary Medicine, Southwest University, Chongqing 402460, China; (D.L.); (J.L.); (L.R.); (Z.Y.); (Y.H.); (H.Y.)
| | - Zhuo Yang
- College of Veterinary Medicine, Southwest University, Chongqing 402460, China; (D.L.); (J.L.); (L.R.); (Z.Y.); (Y.H.); (H.Y.)
| | - Yuzhang He
- College of Veterinary Medicine, Southwest University, Chongqing 402460, China; (D.L.); (J.L.); (L.R.); (Z.Y.); (Y.H.); (H.Y.)
| | - Hongzao Yang
- College of Veterinary Medicine, Southwest University, Chongqing 402460, China; (D.L.); (J.L.); (L.R.); (Z.Y.); (Y.H.); (H.Y.)
- National Center of Technology Innovation for Pigs, Chongqing 402460, China; (Y.Y.); (L.F.); (M.Z.)
| | - Yuandi Yu
- National Center of Technology Innovation for Pigs, Chongqing 402460, China; (Y.Y.); (L.F.); (M.Z.)
- Chongqing Academy of Animal Sciences, Chongqing 402460, China
| | - Lizhi Fu
- National Center of Technology Innovation for Pigs, Chongqing 402460, China; (Y.Y.); (L.F.); (M.Z.)
- Chongqing Academy of Animal Sciences, Chongqing 402460, China
| | - Maixun Zhu
- National Center of Technology Innovation for Pigs, Chongqing 402460, China; (Y.Y.); (L.F.); (M.Z.)
- Chongqing Academy of Animal Sciences, Chongqing 402460, China
| | - Hongwei Chen
- College of Veterinary Medicine, Southwest University, Chongqing 402460, China; (D.L.); (J.L.); (L.R.); (Z.Y.); (Y.H.); (H.Y.)
- National Center of Technology Innovation for Pigs, Chongqing 402460, China; (Y.Y.); (L.F.); (M.Z.)
- Traditional Chinese Veterinary Research Institute, Southwest University, Chongqing 402460, China
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12
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Warrell DL, Zarrella TM, Machalek C, Khare A. Interspecies surfactants serve as public goods enabling surface motility in Pseudomonas aeruginosa. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.01.03.573969. [PMID: 38260674 PMCID: PMC10802355 DOI: 10.1101/2024.01.03.573969] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/24/2024]
Abstract
In most natural environments, bacteria live in polymicrobial communities where secreted molecules from neighboring species alter bacterial behaviors including motility, but such interactions are understudied. Pseudomonas aeruginosa is a motile opportunistic pathogen that exists in diverse multispecies environments such as the soil and is frequently found in human wound and respiratory tract co-infections with other bacteria including Staphylococcus aureus. Here we show that P. aeruginosa can co-opt secreted surfactants from other species for flagellar-based surface motility. We found that exogenous surfactants from S. aureus, other bacteria, and interkingdom species enabled P. aeruginosa to switch from swarming to an alternative surface spreading motility on semi-solid surfaces and allowed for the emergence of surface motility on hard agar where P. aeruginosa was otherwise unable to move. This motility was distinct from the response of other motile bacteria in the presence of exogenous surfactants. Mutant analysis indicated that this P. aeruginosa motility was similar to a previously described mucin-based motility, 'surfing', albeit with divergent regulation. Thus, our study demonstrates that secreted surfactants from the host as well as neighboring bacterial and interkingdom species act as public goods facilitating P. aeruginosa flagella-mediated surfing-like surface motility, thereby allowing it to access different environmental niches.
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Affiliation(s)
- Delayna L Warrell
- Laboratory of Molecular Biology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA
| | - Tiffany M Zarrella
- Laboratory of Molecular Biology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA
- Postdoctoral Research Associate Training Program, National Institute of General Medical Sciences, National Institutes of Health, Bethesda, MD, USA
- Current address: Department of Biology, Georgetown University, Washington, DC, USA
| | - Christopher Machalek
- Laboratory of Molecular Biology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA
| | - Anupama Khare
- Laboratory of Molecular Biology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA
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Mahavy CE, Razanatseheno AJ, Mol A, Ngezahayo J, Duez P, El Jaziri M, Baucher M, Rasamiravaka T. Edible Medicinal Guava Fruit ( Psidium guajava L.) Are a Source of Anti-Biofilm Compounds against Pseudomonas aeruginosa. PLANTS (BASEL, SWITZERLAND) 2024; 13:1122. [PMID: 38674531 PMCID: PMC11054768 DOI: 10.3390/plants13081122] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/15/2024] [Revised: 04/12/2024] [Accepted: 04/15/2024] [Indexed: 04/28/2024]
Abstract
Psidium guajava is one of the most common edible medicinal plants frequently used in Malagasy traditional medicine to treat gastrointestinal infections. In order to evaluate their probable antibacterial activities, three organic extracts (successive extractions by hexane, dichloromethane, and ethanol) of ripe guava fruits were assessed for their bactericidal and anti-virulence properties against P. aeruginosa PAO1. Although these three extracts have shown no direct antibacterial activity (MIC of 1000 µg/mL) and, at the non-bactericidal concentration of 100 µg/mL, no impact on the production of major P. aeruginosa PAO1 virulence factors (pyocyanin and rhamnolipids), the hexane and dichloromethane extracts showed significant anti-biofilm properties and the dichloromethane extract disrupted the P. aeruginosa PAO1 swarming motility. Bioguided fractionation of the dichloromethane extract led to the isolation and identification of lycopene and β-sitosterol-β-D-glucoside as major anti-biofilm compounds. Interestingly, both compounds disrupt P. aeruginosa PAO1 biofilm formation and maintenance with IC50 of 1383 µM and 131 µM, respectively. More interestingly, both compounds displayed a synergistic effect with tobramycin with a two-fold increase in its effectiveness in killing biofilm-encapsulated P. aeruginosa PAO1. The present study validates the traditional uses of this edible medicinal plant, indicating the therapeutic effectiveness of guava fruits plausibly through the presence of these tri- and tetraterpenoids, which deserve to be tested against pathogens generally implicated in diarrhea.
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Affiliation(s)
- Christian Emmanuel Mahavy
- Laboratory of Biotechnology and Microbiology, University of Antananarivo, BP 906, Antananarivo 101, Madagascar
| | | | - Adeline Mol
- Laboratory of Plant Biotechnology, Université Libre de Bruxelles, B-1050 Brussels, Belgium
| | - Jeremie Ngezahayo
- Centre de Recherche en Sciences Naturelles et de l'Environnement (CRSNE), Université du Burundi, Bujumbura BP 2700, Burundi
| | - Pierre Duez
- Unit of Therapeutic Chemistry and Pharmacognosy, University of Mons, B-7000 Mons, Belgium
| | - Mondher El Jaziri
- Laboratory of Plant Biotechnology, Université Libre de Bruxelles, B-1050 Brussels, Belgium
| | - Marie Baucher
- Laboratory of Plant Biotechnology, Université Libre de Bruxelles, B-1050 Brussels, Belgium
| | - Tsiry Rasamiravaka
- Laboratory of Biotechnology and Microbiology, University of Antananarivo, BP 906, Antananarivo 101, Madagascar
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14
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Padaga SG, Bhatt H, Ch S, Paul M, Itoo AM, Ghosh B, Roy S, Biswas S. Glycol Chitosan-Poly(lactic acid) Conjugate Nanoparticles Encapsulating Ciprofloxacin: A Mucoadhesive, Antiquorum-Sensing, and Biofilm-Disrupting Treatment Modality for Bacterial Keratitis. ACS APPLIED MATERIALS & INTERFACES 2024; 16:18360-18385. [PMID: 38573741 DOI: 10.1021/acsami.3c18061] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/05/2024]
Abstract
Bacterial keratitis (BK) causes visual morbidity/blindness if not treated effectively. Here, ciprofloxacin (CIP)-loaded nanoparticles (NPs) using glycol chitosan (GC) and poly(lactic acid) (PLA) conjugate at three different ratios (CIP@GC(PLA) NPs (1:1,5,15)) were fabricated. CIP@GC(PLA) NPs (1:1) were more effective than other tested ratios, indicating the importance of optimal hydrophobic/hydrophilic balance for corneal penetration and preventing bacterial invasion. The CIP@GC(PLA) (NPs) (1:1) realized the highest association with human corneal epithelial cells, which were nonirritant to the hen's egg-chorioallantoic membrane test (HET-CAM test) and demonstrated significant antibacterial response in the in vitro minimum inhibitory, bactericidal, live-dead cells, zone of inhibition, and biofilm inhibition assays against the keratitis-inducing pathogen Pseudomonas aeruginosa. The antiquorum sensing activity of GC has been explored for the first time. The NPs disrupted the bacterial quorum sensing by inhibiting the production of virulence factors, including acyl homoserine lactones, pyocyanin, and motility, and caused significant downregulation of quorum sensing associated genes. In the in vivo studies, CIP@GC(PLA) NPs (1:1) displayed ocular retention in vivo (∼6 h) and decreased the opacity and the bacterial load effectively. Overall, the CIP@GC(PLA) NP (1:1) is a biofilm-disrupting antiquorum sensing treatment regimen with clinical translation potential in BK.
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Affiliation(s)
- Sri Ganga Padaga
- Nanomedicine Research Laboratory, Department of Pharmacy, Birla Institute of Technology & Science-Pilani, Hyderabad Campus, Hyderabad, Telangana 500078, India
| | - Himanshu Bhatt
- Nanomedicine Research Laboratory, Department of Pharmacy, Birla Institute of Technology & Science-Pilani, Hyderabad Campus, Hyderabad, Telangana 500078, India
| | - Sanjay Ch
- Nanomedicine Research Laboratory, Department of Pharmacy, Birla Institute of Technology & Science-Pilani, Hyderabad Campus, Hyderabad, Telangana 500078, India
| | - Milan Paul
- Nanomedicine Research Laboratory, Department of Pharmacy, Birla Institute of Technology & Science-Pilani, Hyderabad Campus, Hyderabad, Telangana 500078, India
| | - Asif Mohd Itoo
- Nanomedicine Research Laboratory, Department of Pharmacy, Birla Institute of Technology & Science-Pilani, Hyderabad Campus, Hyderabad, Telangana 500078, India
| | - Balaram Ghosh
- Nanomedicine Research Laboratory, Department of Pharmacy, Birla Institute of Technology & Science-Pilani, Hyderabad Campus, Hyderabad, Telangana 500078, India
| | - Sanhita Roy
- Prof. Brien Holden Eye Research Centre, Kallam Anji Reddy Campus, L. V. Prasad Eye Institute, Hyderabad, Telangana 500034, India
| | - Swati Biswas
- Nanomedicine Research Laboratory, Department of Pharmacy, Birla Institute of Technology & Science-Pilani, Hyderabad Campus, Hyderabad, Telangana 500078, India
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15
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Magkiriadou S, Stepp WL, Newman DK, Manley S, Racki LR. Polyphosphate affects cytoplasmic and chromosomal dynamics in nitrogen-starved Pseudomonas aeruginosa. Proc Natl Acad Sci U S A 2024; 121:e2313004121. [PMID: 38564631 PMCID: PMC11009631 DOI: 10.1073/pnas.2313004121] [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: 08/21/2023] [Accepted: 01/26/2024] [Indexed: 04/04/2024] Open
Abstract
Polyphosphate (polyP) synthesis is a ubiquitous stress and starvation response in bacteria. In diverse species, mutants unable to make polyP have a wide variety of physiological defects, but the mechanisms by which this simple polyanion exerts its effects remain unclear. One possibility is that polyP's many functions stem from global effects on the biophysical properties of the cell. We characterize the effect of polyphosphate on cytoplasmic mobility under nitrogen-starvation conditions in the opportunistic pathogen Pseudomonas aeruginosa. Using fluorescence microscopy and particle tracking, we quantify the motion of chromosomal loci and cytoplasmic tracer particles. In the absence of polyP and upon starvation, we observe a 2- to 10-fold increase in mean cytoplasmic diffusivity. Tracer particles reveal that polyP also modulates the partitioning between a "more mobile" and a "less mobile" population: Small particles in cells unable to make polyP are more likely to be "mobile" and explore more of the cytoplasm, particularly during starvation. Concomitant with this larger freedom of motion in polyP-deficient cells, we observe decompaction of the nucleoid and an increase in the steady-state concentration of ATP. The dramatic polyP-dependent effects we observe on cytoplasmic transport properties occur under nitrogen starvation, but not carbon starvation, suggesting that polyP may have distinct functions under different types of starvation.
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Affiliation(s)
- Sofia Magkiriadou
- Laboratory of Experimental Biophysics, Institute of Physics, École Polytechnique Fédérale de Lausanne, LausanneCH-1015, Switzerland
| | - Willi L. Stepp
- Laboratory of Experimental Biophysics, Institute of Physics, École Polytechnique Fédérale de Lausanne, LausanneCH-1015, Switzerland
| | - Dianne K. Newman
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA91125
- Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA91125
| | - Suliana Manley
- Laboratory of Experimental Biophysics, Institute of Physics, École Polytechnique Fédérale de Lausanne, LausanneCH-1015, Switzerland
| | - Lisa R. Racki
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, San Diego, CA92037
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16
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Kar A, Mukherjee SK, Barik S, Hossain ST. Antimicrobial Activity of Trigonelline Hydrochloride Against Pseudomonas aeruginosa and Its Quorum-Sensing Regulated Molecular Mechanisms on Biofilm Formation and Virulence. ACS Infect Dis 2024; 10:746-762. [PMID: 38232080 DOI: 10.1021/acsinfecdis.3c00617] [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: 01/19/2024]
Abstract
Pseudomonas aeruginosa, a vivid biofilm-producing bacterium, is considered a dreadful opportunistic pathogen, and thus, management of biofilm-associated infections due to multidrug resistant strains by traditional drugs currently is of great concern. This study was aimed to assess the impact of trigonelline hydrochloride, a pyridine alkaloid, on P. aeruginosa PAO1, in search of an alternative therapeutant. The effect of trigonelline on colony morphology and motility was studied along with its role on biofilm and expression virulence factors. Trigonelline influenced the colony structure, motility, biofilm architecture, and the production of virulence factors in a dose-dependent manner. Alterations in quorum sending (QS)-regulated gene expression after treatment and molecular docking analysis for certain regulator proteins confirmed its effect on the QS-system network by affecting Las, Rhl, and Pqs signaling pathways and as possible molecular targets. Thus, trigonelline might be considered as a potential chemical lead to manage biofilm-associated pathogenesis or to develop other analogues with enhanced pharmacokinetic actions.
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Affiliation(s)
- Amiya Kar
- Department of Microbiology, University of Kalyani, Kalyani 741235, India
| | | | - Subhasis Barik
- Department of In Vitro Carcinogenesis and Cellular Chemotherapy, Chittaranjan National Cancer Institute, Kolkata, West Bengal 700026, India
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17
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Pastora AB, Rzasa KM, O’Toole GA. Multiple Pathways Impact Swarming Motility of Pseudomonas fluorescens Pf0-1. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.01.17.576057. [PMID: 38293239 PMCID: PMC10827169 DOI: 10.1101/2024.01.17.576057] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/01/2024]
Abstract
Swarming motility in pseudomonads typically requires both a functional flagellum and production/secretion of a biosurfactant. Published work has shown that the wild-type Pseudomonas fluorescens Pf0-1 is swarming-deficient due to a point mutation in the gacA gene, which until recently, was thought to inactivate rather than attenuate the Gac/Rsm pathway. As a result, little is known about the underlying mechanisms that regulate swarming motility by P. fluorescens Pf0-1. Here, we demonstrate that a ΔrsmA ΔrsmE ΔrsmI mutant, which phenotypically mimics Gac/Rsm pathway overstimulation, is proficient at swarming motility. RsmA and RsmE appear to play a key role in this regulation. Transposon mutagenesis of the ΔrsmA ΔrsmE ΔrsmI mutant identified multiple factors that impact swarming motility, including pathways involved in flagellar synthesis and biosurfactant production/secretion. We find that loss of genes linked to biosurfactant Gacamide A biosynthesis or secretion impact swarming motility, as does loss of the alternative sigma factor FliA, which results in a defect in flagellar function. Collectively, these findings provide evidence that P. fluorescens Pf0-1 can swarm if the Gac/Rsm pathway is activated, highlight the regulatory complexity of swarming motility in this strain, and demonstrate that the cyclic lipopeptide Gacamide A is utilized as a biosurfactant for swarming motility.
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Affiliation(s)
- Alexander B. Pastora
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire, USA
| | - Kara M. Rzasa
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire, USA
- Thayer School of Engineering at Dartmouth, Hanover, New Hampshire, USA
| | - George A. O’Toole
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire, USA
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18
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Krajnc M, Fei C, Košmrlj A, Kalin M, Stopar D. Mechanical constraints to unbound expansion of B. subtilis on semi-solid surfaces. Microbiol Spectr 2024; 12:e0274023. [PMID: 38047692 PMCID: PMC10783106 DOI: 10.1128/spectrum.02740-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2023] [Accepted: 10/13/2023] [Indexed: 12/05/2023] Open
Abstract
IMPORTANCE How bacterial cells colonize new territory is a problem of fundamental microbiological and biophysical interest and is key to the emergence of several phenomena of biological, ecological, and medical relevance. Here, we demonstrate how bacteria stuck in a colony of finite size can resume exploration of new territory by aquaplaning and how they fine tune biofilm viscoelasticity to surface material properties that allows them differential mobility. We show how changing local interfacial forces and colony viscosity results in a plethora of bacterial morphologies on surfaces with different physical and mechanical properties.
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Affiliation(s)
- Mojca Krajnc
- Biotechnical Faculty, Department of Microbiology, University of Ljubljana, Ljubljana, Slovenia
| | - Chenyi Fei
- Lewis-Sigler Institute for Integrative Genomics, Carl C. Icahn Laboratory, Princeton University, Princeton, New Jersey, USA
| | - Andrej Košmrlj
- Department of Mechanical and Aerospace Engineering, Princeton University, Princeton, New Jersey, USA
- Princeton Materials Institute, Princeton University, Princeton, New Jersey, USA
| | - Mitjan Kalin
- Faculty of Mechanical Engineering, University of Ljubljana, Ljubljana, Slovenia
| | - David Stopar
- Biotechnical Faculty, Department of Microbiology, University of Ljubljana, Ljubljana, Slovenia
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Sagar PK, Sharma P, Singh R. Anti-Quorum Sensing and Anti-Biofilm Activity of Ginger ( Zingiber officinale) Rhizomes against Multidrug-Resistant Clinical Isolates of Pseudomonas aeruginosa. Avicenna J Med Biotechnol 2024; 16:49-56. [PMID: 38605736 PMCID: PMC11005393 DOI: 10.18502/ajmb.v16i1.14171] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2023] [Accepted: 08/19/2023] [Indexed: 04/13/2024] Open
Abstract
Background The aim of this study was to determination of Anti-Quorum Sensing (AQS) and anti-biofilm potential of the methanol extract of ginger (Zingiber officinale) rhizomes against multidrug-resistant clinical isolates of Pseudomonas aeruginosa (P. aeruginosa). Methods The AQS activity of ginger was determined against Chromobacterium violaceum (C. violaceum) ATCC 12472 (CV12472), a biosensor strain, in qualitative manner using the agar well diffusion method. The violacein pigment inhibition was assessed to confirm AQS activity of ginger. The AQS potential of sub-minimum Inhibitory Concentrations (sub-MICs) of the ginger extract was determined by targeting different QS regulated virulence factors, including swarming motility (using swarm diameter measurement method), pyocyanin pigment (using chloroform extraction method), Exopolysaccharide (EPS) (using phenol-sulphuric acid method), and biofilm formation (using microtiter plate assay), against clinical isolates (CIs 2, 3, and 4) and standard reference strain of P. aeruginosa (PA01). Results The AQS activity of methanol extract of ginger was confirmed against C. violaceum (CV12472) as inhibition of violacein pigment formation without effecting the growth of CIs and PA01 of P. aeruginosa. The ginger extract exhibited concentration-dependent inhibition of virulence factors and biofilm formation. The maximum reduction was found in swarming motility, pyocyanin, EPS and biofilm formation against PA01 (51.38%), CI3 (57.91%), PA01 (63.29%) and CI2 (64.37%), respectively at 1/2 MIC of ginger extract. Conclusion The results of present study revealed the effective AQS and anti-biofilm potential of Zingiber officinale rhizome methanol extract at a reduced dose (sub-MICs). The extract may be explored as an agent of antimicrobial compounds having AQS and anti-biofilm activity for controlling microbial infection and also for reducing the chances of emergence of resistance in P. aeruginosa.
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Affiliation(s)
- Pankaj Kumar Sagar
- Department of Microbiology, Bundelkhand University, Jhansi-284128, Uttar Pradesh, India
| | - Poonam Sharma
- Department of Zoology, Indira Gandhi National Tribal University (A Central University), Amarkantak-484886, Madhya Pradesh, India
| | - Rambir Singh
- Department of Horticulture, Aromatic and Medicinal Plants, Mizoram University (A Central University), Aizawl-796004, Mizoram, India
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20
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Rayamajhee B, Willcox M, Henriquez FL, Vijay AK, Petsoglou C, Shrestha GS, Peguda HK, Carnt N. The role of naturally acquired intracellular Pseudomonas aeruginosa in the development of Acanthamoeba keratitis in an animal model. PLoS Negl Trop Dis 2024; 18:e0011878. [PMID: 38166139 PMCID: PMC10795995 DOI: 10.1371/journal.pntd.0011878] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2023] [Revised: 01/18/2024] [Accepted: 12/21/2023] [Indexed: 01/04/2024] Open
Abstract
BACKGROUND Acanthamoeba is an environmental host for various microorganisms. Acanthamoeba is also becoming an increasingly important pathogen as a cause of keratitis. In Acanthamoeba keratitis (AK), coinfections involving pathogenic bacteria have been reported, potentially attributed to the carriage of microbes by Acanthamoeba. This study assessed the presence of intracellular bacteria in Acanthamoeba species recovered from domestic tap water and corneas of two different AK patients and examined the impact of naturally occurring intracellular bacteria within Acanthamoeba on the severity of corneal infections in rats. METHODOLOGY/PRINCIPAL FINDINGS Household water and corneal swabs were collected from AK patients. Acanthamoeba strains and genotypes were confirmed by sequencing. Acanthamoeba isolates were assessed for the presence of intracellular bacteria using sequencing, fluorescence in situ hybridization (FISH), and electron microscopy. The viability of the bacteria in Acanthamoeba was assessed by labelling with alkyne-functionalized D-alanine (alkDala). Primary human macrophages were used to compare the intracellular survival and replication of the endosymbiotic Pseudomonas aeruginosa and a wild type strain. Eyes of rats were challenged intrastromally with Acanthamoeba containing or devoid of P. aeruginosa and evaluated for the clinical response. Domestic water and corneal swabs were positive for Acanthamoeba. Both strains belonged to genotype T4F. One of the Acanthamoeba isolates harboured P. aeruginosa which was seen throughout the Acanthamoeba's cytoplasm. It was metabolically active and could be seen undergoing binary fission. This motile strain was able to replicate in macrophage to a greater degree than strain PAO1 (p<0.05). Inoculation of Acanthamoeba containing the intracellular P. aeruginosa in rats eyes resulted in a severe keratitis with increased neutrophil response. Acanthamoeba alone induced milder keratitis. CONCLUSIONS/SIGNIFICANCE Our findings indicate the presence of live intracellular bacteria in Acanthamoeba can increase the severity of acute keratitis in vivo. As P. aeruginosa is a common cause of keratitis, this may indicate the potential for these intracellular bacteria in Acanthamoeba to lead to severe polymicrobial keratitis.
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Affiliation(s)
- Binod Rayamajhee
- School of Optometry and Vision Science, Faculty of Medicine and Health, UNSW, Sydney, Australia
| | - Mark Willcox
- School of Optometry and Vision Science, Faculty of Medicine and Health, UNSW, Sydney, Australia
| | - Fiona L. Henriquez
- School of Health and Life Sciences, University of the West of Scotland, Blantyre, Scotland, United Kingdom
| | - Ajay Kumar Vijay
- School of Optometry and Vision Science, Faculty of Medicine and Health, UNSW, Sydney, Australia
| | - Constantinos Petsoglou
- Sydney and Sydney Eye Hospital, Southeastern Sydney Local Health District, Sydney, Australia
- Save Sight Institute, University of Sydney, Sydney, Australia
| | - Gauri Shankar Shrestha
- School of Optometry and Vision Science, Faculty of Medicine and Health, UNSW, Sydney, Australia
| | - Hari Kumar Peguda
- School of Optometry and Vision Science, Faculty of Medicine and Health, UNSW, Sydney, Australia
| | - Nicole Carnt
- School of Optometry and Vision Science, Faculty of Medicine and Health, UNSW, Sydney, Australia
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21
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Fan W, Xiao Y, Dong J, Xing J, Tang F, Shi F. Variety-driven rhizosphere microbiome bestows differential salt tolerance to alfalfa for coping with salinity stress. FRONTIERS IN PLANT SCIENCE 2023; 14:1324333. [PMID: 38179479 PMCID: PMC10766110 DOI: 10.3389/fpls.2023.1324333] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/19/2023] [Accepted: 11/28/2023] [Indexed: 01/06/2024]
Abstract
Soil salinization is a global environmental issue and a significant abiotic stress that threatens crop production. Root-associated rhizosphere microbiota play a pivotal role in enhancing plant tolerance to abiotic stresses. However, limited information is available concerning the specific variations in rhizosphere microbiota driven by different plant genotypes (varieties) in response to varying levels of salinity stress. In this study, we compared the growth performance of three alfalfa varieties with varying salt tolerance levels in soils with different degrees of salinization. High-throughput 16S rRNA and ITS sequencing were employed to analyze the rhizosphere microbial communities. Undoubtedly, the increasing salinity significantly inhibited alfalfa growth and reduced rhizosphere microbial diversity. However, intriguingly, salt-tolerant varieties exhibited relatively lower susceptibility to salinity, maintaining more stable rhizosphere bacterial community structure, whereas the reverse was observed for salt-sensitive varieties. Bacillus emerged as the dominant species in alfalfa's adaptation to salinity stress, constituting 21.20% of the shared bacterial genera among the three varieties. The higher abundance of Bacillus, Ensifer, and Pseudomonas in the rhizosphere of salt-tolerant alfalfa varieties is crucial in determining their elevated salt tolerance. As salinity levels increased, salt-sensitive varieties gradually accumulated a substantial population of pathogenic fungi, such as Fusarium and Rhizoctonia. Furthermore, rhizosphere bacteria of salt-tolerant varieties exhibited increased activity in various metabolic pathways, including biosynthesis of secondary metabolites, carbon metabolism, and biosynthesis of amino acids. It is suggested that salt-tolerant alfalfa varieties can provide more carbon sources to the rhizosphere, enriching more effective plant growth-promoting bacteria (PGPB) such as Pseudomonas to mitigate salinity stress. In conclusion, our results highlight the variety-mediated enrichment of rhizosphere microbiota in response to salinity stress, confirming that the high-abundance enrichment of specific dominant rhizosphere microbes and their vital roles play a significant role in conferring high salt adaptability to these varieties.
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Affiliation(s)
- Wenqiang Fan
- Key Laboratory of Grassland Resources of the Ministry of Education and Key Laboratory of Forage Cultivation, Processing and High-Efficiency Utilization of the Ministry of Agriculture, College of Grassland, Resources and Environment, Inner Mongolia Agricultural University, Hohhot, China
| | - Yanzi Xiao
- College of Agriculture and Forestry, Hulunbuir University, Hulunber, China
| | - Jiaqi Dong
- Key Laboratory of Grassland Resources of the Ministry of Education and Key Laboratory of Forage Cultivation, Processing and High-Efficiency Utilization of the Ministry of Agriculture, College of Grassland, Resources and Environment, Inner Mongolia Agricultural University, Hohhot, China
| | - Jing Xing
- Key Laboratory of Grassland Resources of the Ministry of Education and Key Laboratory of Forage Cultivation, Processing and High-Efficiency Utilization of the Ministry of Agriculture, College of Grassland, Resources and Environment, Inner Mongolia Agricultural University, Hohhot, China
| | - Fang Tang
- Key Laboratory of Grassland Resources of the Ministry of Education and Key Laboratory of Forage Cultivation, Processing and High-Efficiency Utilization of the Ministry of Agriculture, College of Grassland, Resources and Environment, Inner Mongolia Agricultural University, Hohhot, China
| | - Fengling Shi
- Key Laboratory of Grassland Resources of the Ministry of Education and Key Laboratory of Forage Cultivation, Processing and High-Efficiency Utilization of the Ministry of Agriculture, College of Grassland, Resources and Environment, Inner Mongolia Agricultural University, Hohhot, China
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22
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Mi Y, He Y, Mi J, Huang Y, Fan H, Song L, An X, Xu S, Li M, Tong Y. Genetic and Phenotypic Analysis of Phage-Resistant Mutant Fitness Triggered by Phage-Host Interactions. Int J Mol Sci 2023; 24:15594. [PMID: 37958578 PMCID: PMC10648725 DOI: 10.3390/ijms242115594] [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: 09/28/2023] [Revised: 10/16/2023] [Accepted: 10/19/2023] [Indexed: 11/15/2023] Open
Abstract
The emergence of phage-resistant bacterial strains is one of the biggest challenges for phage therapy. However, the emerging phage-resistant bacteria are often accompanied by adaptive trade-offs, which supports a therapeutic strategy called "phage steering". The key to phage steering is to guide the bacterial population toward an evolutionary direction that is favorable for treatment. Thus, it is important to systematically investigate the impacts of phages targeting different bacterial receptors on the fitness of the bacterial population. Herein, we employed 20 different phages to impose strong evolutionary pressure on the host Pseudomonas aeruginosa PAO1 and examined the genetic and phenotypic responses of their phage-resistant mutants. Among these strains with impaired adsorptions, four types of mutations associated with bacterial receptors were identified, namely, lipopolysaccharides (LPSs), type IV pili (T4Ps), outer membrane proteins (OMPs), and exopolysaccharides (EPSs). PAO1, responding to LPS- and EPS-dependent phage infections, mostly showed significant growth impairment and virulence attenuation. Most mutants with T4P-related mutations exhibited a significant decrease in motility and biofilm formation ability, while the mutants with OMP-related mutations required the lowest fitness cost out of the bacterial populations. Apart from fitness costs, PAO1 strains might lose their resistance to antibiotics when counteracting with phages, such as the presence of large-fragment mutants in this study, which may inspire the usage of phage-antibiotic combination strategies. This work provides methods that leverage the merits of phage resistance relative to obtaining therapeutically beneficial outcomes with respect to phage-steering strategies.
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Affiliation(s)
- Yanze Mi
- College of Life Science and Technology, Beijing University of Chemical Technology, Beijing 100029, China; (Y.M.); (Y.H.); (J.M.); (Y.H.); (H.F.); (L.S.); (X.A.); (S.X.)
| | - Yile He
- College of Life Science and Technology, Beijing University of Chemical Technology, Beijing 100029, China; (Y.M.); (Y.H.); (J.M.); (Y.H.); (H.F.); (L.S.); (X.A.); (S.X.)
| | - Jinhui Mi
- College of Life Science and Technology, Beijing University of Chemical Technology, Beijing 100029, China; (Y.M.); (Y.H.); (J.M.); (Y.H.); (H.F.); (L.S.); (X.A.); (S.X.)
| | - Yunfei Huang
- College of Life Science and Technology, Beijing University of Chemical Technology, Beijing 100029, China; (Y.M.); (Y.H.); (J.M.); (Y.H.); (H.F.); (L.S.); (X.A.); (S.X.)
| | - Huahao Fan
- College of Life Science and Technology, Beijing University of Chemical Technology, Beijing 100029, China; (Y.M.); (Y.H.); (J.M.); (Y.H.); (H.F.); (L.S.); (X.A.); (S.X.)
| | - Lihua Song
- College of Life Science and Technology, Beijing University of Chemical Technology, Beijing 100029, China; (Y.M.); (Y.H.); (J.M.); (Y.H.); (H.F.); (L.S.); (X.A.); (S.X.)
| | - Xiaoping An
- College of Life Science and Technology, Beijing University of Chemical Technology, Beijing 100029, China; (Y.M.); (Y.H.); (J.M.); (Y.H.); (H.F.); (L.S.); (X.A.); (S.X.)
| | - Shan Xu
- College of Life Science and Technology, Beijing University of Chemical Technology, Beijing 100029, China; (Y.M.); (Y.H.); (J.M.); (Y.H.); (H.F.); (L.S.); (X.A.); (S.X.)
| | - Mengzhe Li
- College of Life Science and Technology, Beijing University of Chemical Technology, Beijing 100029, China; (Y.M.); (Y.H.); (J.M.); (Y.H.); (H.F.); (L.S.); (X.A.); (S.X.)
| | - Yigang Tong
- College of Life Science and Technology, Beijing University of Chemical Technology, Beijing 100029, China; (Y.M.); (Y.H.); (J.M.); (Y.H.); (H.F.); (L.S.); (X.A.); (S.X.)
- Beijing Advanced Innovation Center for Soft Matter Science and Engineering (BAIC-SM), Beijing University of Chemical Technology, Beijing 100029, China
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23
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Guadarrama-Orozco KD, Perez-Gonzalez C, Kota K, Cocotl-Yañez M, Jiménez-Cortés JG, Díaz-Guerrero M, Hernández-Garnica M, Munson J, Cadet F, López-Jácome LE, Estrada-Velasco ÁY, Fernández-Presas AM, García-Contreras R. To cheat or not to cheat: cheatable and non-cheatable virulence factors in Pseudomonas aeruginosa. FEMS Microbiol Ecol 2023; 99:fiad128. [PMID: 37827541 DOI: 10.1093/femsec/fiad128] [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: 07/23/2023] [Revised: 08/30/2023] [Accepted: 10/11/2023] [Indexed: 10/14/2023] Open
Abstract
Important bacterial pathogens such as Pseudomonas aeruginosa produce several exoproducts such as siderophores, degradative enzymes, biosurfactants, and exopolysaccharides that are used extracellularly, benefiting all members of the population, hence being public goods. Since the production of public goods is a cooperative trait, it is in principle susceptible to cheating by individuals in the population who do not invest in their production, but use their benefits, hence increasing their fitness at the expense of the cooperators' fitness. Among the most studied virulence factors susceptible to cheating are siderophores and exoproteases, with several studies in vitro and some in animal infection models. In addition to these two well-known examples, cheating with other virulence factors such as exopolysaccharides, biosurfactants, eDNA production, secretion systems, and biofilm formation has also been studied. In this review, we discuss the evidence of the susceptibility of each of those virulence factors to cheating, as well as the mechanisms that counteract this behavior and the possible consequences for bacterial virulence.
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Affiliation(s)
- Katya Dafne Guadarrama-Orozco
- Departamento de Microbiología y Parasitología, Facultad de Medicina, Universidad Nacional Autónoma de México, 04360 Mexico City,Mexico
| | - Caleb Perez-Gonzalez
- Departamento de Microbiología y Parasitología, Facultad de Medicina, Universidad Nacional Autónoma de México, 04360 Mexico City,Mexico
| | - Kokila Kota
- Ramapo College of New Jersey, Biology Department, Mahwah, NJ 07430, USA
| | - Miguel Cocotl-Yañez
- Departamento de Microbiología y Parasitología, Facultad de Medicina, Universidad Nacional Autónoma de México, 04360 Mexico City,Mexico
| | - Jesús Guillermo Jiménez-Cortés
- Departamento de Microbiología y Parasitología, Facultad de Medicina, Universidad Nacional Autónoma de México, 04360 Mexico City,Mexico
| | - Miguel Díaz-Guerrero
- Departamento de Microbiología y Parasitología, Facultad de Medicina, Universidad Nacional Autónoma de México, 04360 Mexico City,Mexico
| | - Mariel Hernández-Garnica
- Departamento de Microbiología y Parasitología, Facultad de Medicina, Universidad Nacional Autónoma de México, 04360 Mexico City,Mexico
| | - Julia Munson
- Ramapo College of New Jersey, Biology Department, Mahwah, NJ 07430, USA
| | - Frederic Cadet
- PEACCEL, Artificial Intelligence Department, AI for Biologics, Paris, 75013, France
| | - Luis Esaú López-Jácome
- Laboratorio de Microbiología Clínica, División de Infectología, Instituto Nacional de Rehabilitación Luis Guillermo Ibarra Ibarra, 14389 Mexico City, Mexico
| | - Ángel Yahir Estrada-Velasco
- Departamento de Microbiología y Parasitología, Facultad de Medicina, Universidad Nacional Autónoma de México, 04360 Mexico City,Mexico
| | - Ana María Fernández-Presas
- Departamento de Microbiología y Parasitología, Facultad de Medicina, Universidad Nacional Autónoma de México, 04360 Mexico City,Mexico
| | - Rodolfo García-Contreras
- Departamento de Microbiología y Parasitología, Facultad de Medicina, Universidad Nacional Autónoma de México, 04360 Mexico City,Mexico
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24
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Elumalai L, Palaniyandi S, Anbazhagan GK, Mohanam N, Munusamy S, G K SR, Pudukadu Munusamy A, Chinnasamy M, Ramasamy B. Synthesis of biogenic cadmium sulfide nanoparticles (MR03-CdSNPs) using marine Streptomyces kunmingensis - MR03 for in-vitro biological determinations and in silico analysis on biofilm virulence proteins: A novel approach. ENVIRONMENTAL RESEARCH 2023; 235:116698. [PMID: 37474092 DOI: 10.1016/j.envres.2023.116698] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/07/2023] [Revised: 07/11/2023] [Accepted: 07/17/2023] [Indexed: 07/22/2023]
Affiliation(s)
- Lokesh Elumalai
- Actinobacterial Research Laboratory, Department of Microbiology, Periyar University, Salem, Tamil Nadu, 636011, India
| | - Sankarganesh Palaniyandi
- Department of Food Technology, Hindustan Institute of Technology and Science, Padur, OMR, Chennai, Tamil Nadu, 603103, India
| | - Ganesh Kumar Anbazhagan
- Centre for Research and Development, Department of Microbiology, Hindustan College of Arts & Science, Padur, OMR, Chennai, Tamil Nadu, 603103, India
| | - Nithyalakshmi Mohanam
- Actinobacterial Research Laboratory, Department of Microbiology, Periyar University, Salem, Tamil Nadu, 636011, India
| | - Santhakumar Munusamy
- Actinobacterial Research Laboratory, Department of Microbiology, Periyar University, Salem, Tamil Nadu, 636011, India
| | - Sri Ragavi G K
- Actinobacterial Research Laboratory, Department of Microbiology, Periyar University, Salem, Tamil Nadu, 636011, India
| | - Ayyasamy Pudukadu Munusamy
- Bioremediation Laboratory, Department of Microbiology, Periyar University, Salem, Tamil Nadu, 636011, India
| | - Muthusamy Chinnasamy
- Department of Biotechnology, Srinivasan College of Arts and Science, (Affiliated to Bharathidasan University), Perambalur, Tamil Nadu, 621212, India
| | - Balagurunathan Ramasamy
- Actinobacterial Research Laboratory, Department of Microbiology, Periyar University, Salem, Tamil Nadu, 636011, India.
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25
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Poh WH, Ruhazat NS, Yang LK, Shivhare D, Lim PK, Kanagasundaram Y, Rice SA, Mutwil M. Transcriptomic and metabolomic characterization of antibacterial activity of Melastoma dodecandrum. FRONTIERS IN PLANT SCIENCE 2023; 14:1205725. [PMID: 37771487 PMCID: PMC10525717 DOI: 10.3389/fpls.2023.1205725] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/14/2023] [Accepted: 08/21/2023] [Indexed: 09/30/2023]
Abstract
Antibacterial resistance poses a significant global threat, necessitating the discovery of new therapeutic agents. Plants are a valuable source of secondary metabolites with demonstrated anticancer and antibacterial properties. In this study, we reveal that Melastoma dodecandrum exhibits both bacteriostatic and bactericidal effects against Pseudomonas aeruginosa and Staphylococcus aureus. Treatment with plant extracts results in membrane damage and a reduction in P.aeruginosa swimming and swarming motility. A comparative analysis of bacterial transcriptomes exposed to M.dodecandrum extracts and four distinct antibiotics indicates that the extracts may trigger similar transcriptomic responses as triclosan, a fatty acid synthesis inhibitor. Activity-guided fractionation suggests that the antibacterial activity is not attributable to hydrolyzable tannins, but to unidentified minor compounds. Additionally, we identified 104 specialized metabolic pathways and demonstrated a high level of transcriptional coordination between these biosynthetic pathways and phytohormones, highlighting potential regulatory mechanisms of antibacterial metabolites in M.dodecandrum.
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Affiliation(s)
- Wee Han Poh
- Singapore Centre for Environmental Life Sciences Engineering, Nanyang Technological University, Singapore, Singapore
- School of Biological Sciences, Nanyang Technological University, Singapore, Singapore
| | - Nur Syahirah Ruhazat
- School of Biological Sciences, Nanyang Technological University, Singapore, Singapore
| | - Lay Kien Yang
- Shared Analytics, Singapore Institute of Food and Biotechnology Innovation (SIFBI), Agency for Science, Technology, and Research (A*STAR), Singapore, Singapore
| | - Devendra Shivhare
- School of Biological Sciences, Nanyang Technological University, Singapore, Singapore
- AAVACC PTE LTD, Singapore, Singapore
| | - Peng Ken Lim
- School of Biological Sciences, Nanyang Technological University, Singapore, Singapore
| | - Yoganathan Kanagasundaram
- Shared Analytics, Singapore Institute of Food and Biotechnology Innovation (SIFBI), Agency for Science, Technology, and Research (A*STAR), Singapore, Singapore
| | - Scott A. Rice
- Singapore Centre for Environmental Life Sciences Engineering, Nanyang Technological University, Singapore, Singapore
- Agriculture and Food, Microbiomes for One Systems Health, Commonwealth Scientific and Industrial Research Organisation (CSIRO), Canberra, ACT, Australia
| | - Marek Mutwil
- School of Biological Sciences, Nanyang Technological University, Singapore, Singapore
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26
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Bru JL, Kasallis SJ, Zhuo Q, Høyland-Kroghsbo NM, Siryaporn A. Swarming of P. aeruginosa: Through the lens of biophysics. BIOPHYSICS REVIEWS 2023; 4:031305. [PMID: 37781002 PMCID: PMC10540860 DOI: 10.1063/5.0128140] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/26/2022] [Accepted: 08/29/2023] [Indexed: 10/03/2023]
Abstract
Swarming is a collective flagella-dependent movement of bacteria across a surface that is observed across many species of bacteria. Due to the prevalence and diversity of this motility modality, multiple models of swarming have been proposed, but a consensus on a general mechanism for swarming is still lacking. Here, we focus on swarming by Pseudomonas aeruginosa due to the abundance of experimental data and multiple models for this species, including interpretations that are rooted in biology and biophysics. In this review, we address three outstanding questions about P. aeruginosa swarming: what drives the outward expansion of a swarm, what causes the formation of dendritic patterns (tendrils), and what are the roles of flagella? We review models that propose biologically active mechanisms including surfactant sensing as well as fluid mechanics-based models that consider swarms as thin liquid films. Finally, we reconcile recent observations of P. aeruginosa swarms with early definitions of swarming. This analysis suggests that mechanisms associated with sliding motility have a critical role in P. aeruginosa swarm formation.
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Affiliation(s)
- Jean-Louis Bru
- Department of Molecular Biology and Biochemistry, University of California Irvine, Irvine, California 92697, USA
| | - Summer J. Kasallis
- Department of Physics and Astronomy, University of California Irvine, Irvine, California 92697, USA
| | - Quantum Zhuo
- Department of Physics and Astronomy, University of California Irvine, Irvine, California 92697, USA
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27
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Ruhal R, Ghosh M, Kumar V, Jain D. Mutation of putative glycosyl transferases PslC and PslI confers susceptibility to antibiotics and leads to drastic reduction in biofilm formation in Pseudomonas aeruginosa. MICROBIOLOGY (READING, ENGLAND) 2023; 169:001392. [PMID: 37702709 PMCID: PMC10569066 DOI: 10.1099/mic.0.001392] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/17/2023] [Accepted: 08/31/2023] [Indexed: 09/14/2023]
Abstract
Pseudomonas aeruginosa is an opportunistic, multidrug-resistant pathogen capable of adapting to numerous environmental conditions and causing fatal infections in immunocompromised patients. The predominant lifestyle of P. aeruginosa is in the form of biofilms, which are structured communities of bacteria encapsulated in a matrix containing exopolysaccharides, extracellular DNA (eDNA) and proteins. The matrix is impervious to antibiotics, rendering the bacteria tolerant to antimicrobials. P. aeruginosa also produces a plethora of virulence factors such as pyocyanin, rhamnolipids and lipopolysaccharides among others. In this study we present the molecular characterization of pslC and pslI genes, of the exopolysaccharide operon, that code for putative glycosyltransferases. PslC is a 303 amino acid containing putative GT2 glycosyltrasferase, whereas PslI is a 367 aa long protein, possibly functioning as a GT4 glycosyltransferase. Mutation in either of these two genes results in a significant reduction in biofilm biomass with concomitant decline in c-di-GMP levels in the bacterial cells. Moreover, mutation in pslC and pslI dramatically increased susceptibility of P. aeruginosa to tobramycin, colistin and ciprofloxacin. Additionally, these mutations also resulted in an increase in rhamnolipids and pyocyanin formation. We demonstrate that elevated rhamnolipids promote a swarming phenotype in the mutant strains. Together these results highlight the importance of PslC and PslI in the biogenesis of biofilms and their potential as targets for increased antibiotic susceptibility and biofilm inhibition.
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Affiliation(s)
- Rohit Ruhal
- Transcription Regulation Lab, Regional Centre for Biotechnology, NCR Biotech Science Cluster, 3rd Milestone, Faridabad-Gurgaon Expressway, Faridabad, 121001, India
| | - Moumita Ghosh
- Transcription Regulation Lab, Regional Centre for Biotechnology, NCR Biotech Science Cluster, 3rd Milestone, Faridabad-Gurgaon Expressway, Faridabad, 121001, India
| | - Vineet Kumar
- Transcription Regulation Lab, Regional Centre for Biotechnology, NCR Biotech Science Cluster, 3rd Milestone, Faridabad-Gurgaon Expressway, Faridabad, 121001, India
| | - Deepti Jain
- Transcription Regulation Lab, Regional Centre for Biotechnology, NCR Biotech Science Cluster, 3rd Milestone, Faridabad-Gurgaon Expressway, Faridabad, 121001, India
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28
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McWilliam KR. Cell-cell communication in African trypanosomes. MICROBIOLOGY (READING, ENGLAND) 2023; 169:001388. [PMID: 37643128 PMCID: PMC10482365 DOI: 10.1099/mic.0.001388] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/25/2023] [Accepted: 08/15/2023] [Indexed: 08/31/2023]
Abstract
Years of research have shown us that unicellular organisms do not exist entirely in isolation, but rather that they are capable of an altogether far more sociable way of living. Single cells produce, receive and interpret signals, coordinating and changing their behaviour according to the information received. Although this cell-cell communication has long been considered the norm in the bacterial world, an increasing body of knowledge is demonstrating that single-celled eukaryotic parasites also maintain active social lives. This communication can drive parasite development, facilitate the invasion of new niches and, ultimately, influence infection outcome. In this review, I present the evidence for cell-cell communication during the life cycle of the African trypanosomes, from their mammalian hosts to their insect vectors, and reflect on the many remaining unanswered questions in this fascinating field.
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Affiliation(s)
- K. R. McWilliam
- Institute for Immunology and Infection Research, School of Biological Sciences, King’s Buildings, University of Edinburgh, Charlotte Auerbach Road, Edinburgh, EH9 3FL, UK
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29
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Geiger CJ, O’Toole GA. Evidence for the Type IV Pilus Retraction Motor PilT as a Component of the Surface Sensing System in Pseudomonas aeruginosa. J Bacteriol 2023; 205:e0017923. [PMID: 37382531 PMCID: PMC10367593 DOI: 10.1128/jb.00179-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2023] [Accepted: 06/07/2023] [Indexed: 06/30/2023] Open
Abstract
Biofilm formation begins when bacteria contacting a surface induce cellular changes to become better adapted for surface growth. One of the first changes to occur for Pseudomonas aeruginosa after surface contact is an increase in the nucleotide second messenger 3',5'-cyclic AMP (cAMP). It has been demonstrated that this increase in intracellular cAMP is dependent on functional type IV pili (T4P) relaying a signal to the Pil-Chp system, but the mechanism by which this signal is transduced remains poorly understood. Here, we investigate the role of the type IV pilus retraction motor PilT in sensing a surface and relaying that signal to cAMP production. We show that mutations in PilT, and in particular those impacting the ATPase activity of this motor protein, reduce surface-dependent cAMP production. We identify a novel interaction between PilT and PilJ, a member of the Pil-Chp system, and propose a new model whereby P. aeruginosa uses its PilT retraction motor to sense a surface and to relay that signal via PilJ to increased production of cAMP. We discuss these findings in light of current T4P-dependent surface sensing models for P. aeruginosa. IMPORTANCE T4P are cellular appendages that allow P. aeruginosa to sense a surface, leading to the production of cAMP. This second messenger not only activates virulence pathways but leads to further surface adaptation and irreversible attachment of cells. Here, we demonstrate the importance of the retraction motor PilT in surface sensing. We also present a new surface sensing model in P. aeruginosa whereby the T4P retraction motor PilT senses and transmits the surface signal, likely via its ATPase domain and interaction with PilJ, to mediate production of the second messenger cAMP.
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Affiliation(s)
- C. J. Geiger
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire, USA
| | - G. A. O’Toole
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire, USA
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30
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Doshi A, Shaw M, Tonea R, Moon S, Minyety R, Doshi A, Laine A, Guo J, Danino T. Engineered bacterial swarm patterns as spatial records of environmental inputs. Nat Chem Biol 2023; 19:878-886. [PMID: 37142806 DOI: 10.1038/s41589-023-01325-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2022] [Accepted: 04/06/2023] [Indexed: 05/06/2023]
Abstract
A diverse array of bacteria species naturally self-organize into durable macroscale patterns on solid surfaces via swarming motility-a highly coordinated and rapid movement of bacteria powered by flagella. Engineering swarming is an untapped opportunity to increase the scale and robustness of coordinated synthetic microbial systems. Here we engineer Proteus mirabilis, which natively forms centimeter-scale bullseye swarm patterns, to 'write' external inputs into visible spatial records. Specifically, we engineer tunable expression of swarming-related genes that modify pattern features, and we develop quantitative approaches to decoding. Next, we develop a dual-input system that modulates two swarming-related genes simultaneously, and we separately show that growing colonies can record dynamic environmental changes. We decode the resulting multicondition patterns with deep classification and segmentation models. Finally, we engineer a strain that records the presence of aqueous copper. This work creates an approach for building macroscale bacterial recorders, expanding the framework for engineering emergent microbial behaviors.
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Affiliation(s)
- Anjali Doshi
- Department of Biomedical Engineering, Columbia University, New York City, NY, USA
| | - Marian Shaw
- Department of Biomedical Engineering, Columbia University, New York City, NY, USA
| | - Ruxandra Tonea
- Department of Biomedical Engineering, Columbia University, New York City, NY, USA
| | - Soonhee Moon
- Department of Biomedical Engineering, Columbia University, New York City, NY, USA
| | - Rosalía Minyety
- Department of Biomedical Engineering, Columbia University, New York City, NY, USA
| | - Anish Doshi
- Department of Electrical Engineering and Computer Sciences, University of California, Berkeley, CA, USA
| | - Andrew Laine
- Department of Biomedical Engineering, Columbia University, New York City, NY, USA
| | - Jia Guo
- Department of Psychiatry, Columbia University, New York City, NY, USA
- Mortimer B. Zuckerman Mind Brain Behavior Institute, Columbia University, New York City, NY, USA
| | - Tal Danino
- Department of Biomedical Engineering, Columbia University, New York City, NY, USA.
- Herbert Irving Comprehensive Cancer Center, Columbia University, New York City, NY, USA.
- Data Science Institute, Columbia University, New York City, NY, USA.
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31
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Zhang JJ, Feng YM, Zhang JR, Xiao WL, Liu SS, Zhou X, Zhang H, Wang PY, Liu LW, Yang S. Resistance-driven innovations in the discovery of bactericides: novel triclosan derivatives decorating isopropanolamine moiety as promising anti-biofilm agents against destructive plant bacterial diseases. PEST MANAGEMENT SCIENCE 2023; 79:2443-2455. [PMID: 36810950 DOI: 10.1002/ps.7419] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/27/2022] [Revised: 02/07/2023] [Accepted: 02/21/2023] [Indexed: 06/02/2023]
Abstract
BACKGROUND Controlling bacterial infections in plants is a major challenge owing to the appearance of resistant strains. As a physical barrier, the bacterial biofilm helps bacterial infections acquire drug resistance by enabling bacteria to accommodate complex and volatile environmental conditions and avoid bactericidal effects. Thus, developing new antibacterial agents with antibiofilm potency is imperative. RESULTS A series of simple triclosan derivatives containing isopropanolamine moiety were elaborately designed and assessed for their antibacterial behavior. Bioassay results showed that some title compounds had excellent bioactivity against three destructive bacteria Xanthomonas oryzae pv. oryzae (Xoo), Xanthomonas axonopodis pv. citri (Xac) and Pseudomonas syringae pv. actinidiae (Psa). Notably, compound C8 displayed high bioactivities toward Xoo and Xac, with EC50 values were 0.34 and 2.11 μg mL-1 , respectively. In vivo trials revealed that compound C8 exhibited excellent protective activities against rice bacterial blight and citrus bacterial canker at 200 μg mL-1 , with control effectivenesses of 49.57% and 85.60%, respectively. Compound A4 had remarkably inhibitory activity toward Psa, with an EC50 value of 2.63 μg mL-1 , and demonstrated outstanding protective activity with a value of 77.23% against Psa in vivo. Antibacterial mechanisms indicated that compound C8 dose-dependently prevented biofilm formation and extracellular polysaccharide production. C8 also significantly weakened the motility and pathogenicity of Xoo. CONCLUSION This study contributes to the development and excavation of novel bactericidal candidates with broad-spectrum antibacterial activity by targeting bacterial biofilm to control refractory plant bacterial diseases. © 2023 Society of Chemical Industry.
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Affiliation(s)
- Jiao-Jiao Zhang
- National Key Laboratory of Green Pesticide, Key Laboratory of Green Pesticide and Agricultural Bioengineering, Ministry of Education, Center for R&D of Fine Chemicals of Guizhou University, Guiyang, China
| | - Yu-Mei Feng
- National Key Laboratory of Green Pesticide, Key Laboratory of Green Pesticide and Agricultural Bioengineering, Ministry of Education, Center for R&D of Fine Chemicals of Guizhou University, Guiyang, China
| | - Jun-Rong Zhang
- National Key Laboratory of Green Pesticide, Key Laboratory of Green Pesticide and Agricultural Bioengineering, Ministry of Education, Center for R&D of Fine Chemicals of Guizhou University, Guiyang, China
| | - Wan-Lin Xiao
- National Key Laboratory of Green Pesticide, Key Laboratory of Green Pesticide and Agricultural Bioengineering, Ministry of Education, Center for R&D of Fine Chemicals of Guizhou University, Guiyang, China
| | - Shuai-Shuai Liu
- National Key Laboratory of Green Pesticide, Key Laboratory of Green Pesticide and Agricultural Bioengineering, Ministry of Education, Center for R&D of Fine Chemicals of Guizhou University, Guiyang, China
| | - Xiang Zhou
- National Key Laboratory of Green Pesticide, Key Laboratory of Green Pesticide and Agricultural Bioengineering, Ministry of Education, Center for R&D of Fine Chemicals of Guizhou University, Guiyang, China
| | - Heng Zhang
- National Key Laboratory of Green Pesticide, Key Laboratory of Green Pesticide and Agricultural Bioengineering, Ministry of Education, Center for R&D of Fine Chemicals of Guizhou University, Guiyang, China
| | - Pei-Yi Wang
- National Key Laboratory of Green Pesticide, Key Laboratory of Green Pesticide and Agricultural Bioengineering, Ministry of Education, Center for R&D of Fine Chemicals of Guizhou University, Guiyang, China
| | - Li-Wei Liu
- National Key Laboratory of Green Pesticide, Key Laboratory of Green Pesticide and Agricultural Bioengineering, Ministry of Education, Center for R&D of Fine Chemicals of Guizhou University, Guiyang, China
| | - Song Yang
- National Key Laboratory of Green Pesticide, Key Laboratory of Green Pesticide and Agricultural Bioengineering, Ministry of Education, Center for R&D of Fine Chemicals of Guizhou University, Guiyang, China
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Köhler T, Luscher A, Falconnet L, Resch G, McBride R, Mai QA, Simonin JL, Chanson M, Maco B, Galiotto R, Riat A, McCallin S, Chan B, van Delden C. Personalized aerosolised bacteriophage treatment of a chronic lung infection due to multidrug-resistant Pseudomonas aeruginosa. Nat Commun 2023; 14:3629. [PMID: 37369702 PMCID: PMC10300124 DOI: 10.1038/s41467-023-39370-z] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2023] [Accepted: 06/09/2023] [Indexed: 06/29/2023] Open
Abstract
Bacteriophage therapy has been suggested as an alternative or complementary strategy for the treatment of multidrug resistant (MDR) bacterial infections. Here, we report the favourable clinical evolution of a 41-year-old male patient with a Kartagener syndrome complicated by a life-threatening chronic MDR Pseudomonas aeruginosa infection, who is treated successfully with iterative aerosolized phage treatments specifically directed against the patient's isolate. We follow the longitudinal evolution of both phage and bacterial loads during and after phage administration in respiratory samples. Phage titres in consecutive sputum samples indicate in patient phage replication. Phenotypic analysis and whole genome sequencing of sequential bacterial isolates reveals a clonal, but phenotypically diverse population of hypermutator strains. The MDR phenotype in the collected isolates is multifactorial and mainly due to spontaneous chromosomal mutations. All isolates recovered after phage treatment remain phage susceptible. These results demonstrate that clinically significant improvement is achievable by personalised phage therapy even in the absence of complete eradication of P. aeruginosa lung colonization.
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Affiliation(s)
- Thilo Köhler
- Service of Infectious Diseases, Geneva University Hospitals, Geneva, Switzerland.
- Department of Microbiology and Molecular Medicine, University of Geneva, Geneva, Switzerland.
| | - Alexandre Luscher
- Service of Infectious Diseases, Geneva University Hospitals, Geneva, Switzerland
- Department of Microbiology and Molecular Medicine, University of Geneva, Geneva, Switzerland
| | - Léna Falconnet
- Service of Infectious Diseases, Geneva University Hospitals, Geneva, Switzerland
- Department of Microbiology and Molecular Medicine, University of Geneva, Geneva, Switzerland
| | - Grégory Resch
- Center for Research and Innovation in Clinical Pharmaceutical Sciences (CRISP), Lausanne University Hospital (CHUV), Lausanne, Switzerland
| | | | | | - Juliette L Simonin
- Department of Cell Physiology and Metabolism, University of Geneva, Geneva, Switzerland
| | - Marc Chanson
- Department of Cell Physiology and Metabolism, University of Geneva, Geneva, Switzerland
| | - Bohumil Maco
- Department of Microbiology and Molecular Medicine, University of Geneva, Geneva, Switzerland
| | - Raphaël Galiotto
- Department of Microbiology and Molecular Medicine, University of Geneva, Geneva, Switzerland
| | - Arnaud Riat
- Diagnostic Bacteriology Laboratory, Geneva University Hospitals, Geneva, Switzerland
| | - Shawna McCallin
- Department of Neuro-Urology Balgrist Hospital, Zurich, Switzerland
| | | | - Christian van Delden
- Service of Infectious Diseases, Geneva University Hospitals, Geneva, Switzerland
- Department of Microbiology and Molecular Medicine, University of Geneva, Geneva, Switzerland
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Ambreetha S, Singh V. Genetic and environmental determinants of surface adaptations in Pseudomonas aeruginosa. MICROBIOLOGY (READING, ENGLAND) 2023; 169. [PMID: 37276014 DOI: 10.1099/mic.0.001335] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Pseudomonas aeruginosa
is a well-studied Gram-negative opportunistic bacterium that thrives in markedly varied environments. It is a nutritionally versatile microbe that can colonize a host as well as exist in the environment. Unicellular, planktonic cells of
P. aeruginosa
can come together to perform a coordinated swarming movement or turn into a sessile, surface-adhered population called biofilm. These collective behaviours produce strikingly different outcomes. While swarming motility rapidly disseminates the bacterial population, biofilm collectively protects the population from environmental stresses such as heat, drought, toxic chemicals, grazing by predators, and attack by host immune cells and antibiotics. The ubiquitous nature of
P. aeruginosa
is likely to be supported by the timely transition between planktonic, swarming and biofilm lifestyles. The social behaviours of this bacteria viz biofilm and swarm modes are controlled by signals from quorum-sensing networks, LasI-LasR, RhlI-RhlR and PQS-MvfR, and several other sensory kinases and response regulators. A combination of environmental and genetic cues regulates the transition of the
P. aeruginosa
population to specific states. The current review is aimed at discussing key factors that promote physiologically distinct transitioning of the
P. aeruginosa
population.
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Affiliation(s)
- Sakthivel Ambreetha
- Department of Developmental Biology and Genetics, Indian Institute of Science, Bengaluru, Karnataka - 560012, India
| | - Varsha Singh
- Department of Developmental Biology and Genetics, Indian Institute of Science, Bengaluru, Karnataka - 560012, India
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Kasallis S, Bru JL, Chang R, Zhuo Q, Siryaporn A. Understanding how bacterial collectives organize on surfaces by tracking surfactant flow. CURRENT OPINION IN SOLID STATE & MATERIALS SCIENCE 2023; 27:101080. [PMID: 37427092 PMCID: PMC10327653 DOI: 10.1016/j.cossms.2023.101080] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 07/11/2023]
Abstract
Swarming is a collective bacterial behavior in which a dense population of bacterial cells moves over a porous surface, resulting in the expansion of the population. This collective behavior can guide bacteria away from potential stressors such as antibiotics and bacterial viruses. However, the mechanisms responsible for the organization of swarms are not understood. Here, we briefly review models that are based on bacterial sensing and fluid mechanics that are proposed to guide swarming in the pathogenic bacterium Pseudomonas aeruginosa. To provide further insight into the role of fluid mechanics in P. aeruginosa swarms, we track the movement of tendrils and the flow of surfactant using a novel technique that we have developed, Imaging of Reflected Illuminated Structures (IRIS). Our measurements show that tendrils and surfactants form distinct layers that grow in lockstep with each other. The results raise new questions about existing swarming models and the possibility that the flow of surfactants impacts tendril development. These findings emphasize that swarm organization involves an interplay between biological processes and fluid mechanics.
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Affiliation(s)
- Summer Kasallis
- Department of Physics & Astronomy, University of California Irvine, Irvine, CA 92697, USA
| | - Jean-Louis Bru
- Department of Molecular Biology & Biochemistry, University of California Irvine, Irvine, CA 92697, USA
| | - Rendell Chang
- Department of Molecular Biology & Biochemistry, University of California Irvine, Irvine, CA 92697, USA
| | - Quantum Zhuo
- Department of Physics & Astronomy, University of California Irvine, Irvine, CA 92697, USA
| | - Albert Siryaporn
- Department of Physics & Astronomy, University of California Irvine, Irvine, CA 92697, USA
- Department of Molecular Biology & Biochemistry, University of California Irvine, Irvine, CA 92697, USA
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de Sousa T, Hébraud M, Alves O, Costa E, Maltez L, Pereira JE, Martins Â, Igrejas G, Poeta P. Study of Antimicrobial Resistance, Biofilm Formation, and Motility of Pseudomonas aeruginosa Derived from Urine Samples. Microorganisms 2023; 11:1345. [PMID: 37317319 DOI: 10.3390/microorganisms11051345] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2023] [Revised: 04/28/2023] [Accepted: 05/17/2023] [Indexed: 06/16/2023] Open
Abstract
Pseudomonas aeruginosa causes urinary tract infections associated with catheters by forming biofilms on the surface of indwelling catheters. Therefore, controlling the spread of the bacteria is crucial to preventing its transmission in hospitals and the environment. Thus, our objective was to determine the antibiotic susceptibility profiles of twenty-five P. aeruginosa isolates from UTIs at the Medical Center of Trás-os-Montes and Alto Douro (CHTMAD). Biofilm formation and motility are also virulence factors studied in this work. Out of the twenty-five P. aeruginosa isolates, 16% exhibited multidrug resistance, being resistant to at least three classes of antibiotics. However, the isolates showed a high prevalence of susceptibility to amikacin and tobramycin. Resistance to carbapenem antibiotics, essential for treating infections when other antibiotics fail, was low in this study, Notably, 92% of the isolates demonstrated intermediate sensitivity to ciprofloxacin, raising concerns about its efficacy in controlling the disease. Genotypic analysis revealed the presence of various β-lactamase genes, with class B metallo-β-lactamases (MBLs) being the most common. The blaNDM, blaSPM, and blaVIM-VIM2 genes were detected in 16%, 60%, and 12% of the strains, respectively. The presence of these genes highlights the emerging threat of MBL-mediated resistance. Additionally, virulence gene analysis showed varying prevalence rates among the strains. The exoU gene, associated with cytotoxicity, was found in only one isolate, while other genes such as exoS, exoA, exoY, and exoT had a high prevalence. The toxA and lasB genes were present in all isolates, whereas the lasA gene was absent. The presence of various virulence genes suggests the potential of these strains to cause severe infections. This pathogen demonstrated proficiency in producing biofilms, as 92% of the isolates were found to be capable of doing so. Currently, antibiotic resistance is one of the most serious public health problems, as options become inadequate with the continued emergence and spread of multidrug-resistant strains, combined with the high rate of biofilm production and the ease of dissemination. In conclusion, this study provides insights into the antibiotic resistance and virulence profiles of P. aeruginosa strains isolated from human urine infections, highlighting the need for continued surveillance and appropriate therapeutic approaches.
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Affiliation(s)
- Telma de Sousa
- Department of Genetics and Biotechnology, University of Trás-os-Montes and Alto Douro (UTAD), 5000-801 Vila Real, Portugal
- Microbiology and Antibiotic Resistance Team (MicroART), Department of Veterinary Sciences, University of Trás-os-Montes and Alto Douro (UTAD), 5000-801 Vila Real, Portugal
- Functional Genomics and Proteomics Unit, University of Trás-os-Montes and Alto Douro (UTAD), 5000-801 Vila Real, Portugal
- Associate Laboratory for Green Chemistry (LAQV), Chemistry Department, Faculty of Science and Technology, University Nova of Lisbon, 2829-516 Lisbon, Portugal
| | - Michel Hébraud
- Université Clermont Auvergne, INRAE, UMR Microbiologie Environnement Digestif Santé (MEDiS), 60122 Saint-Genès-Champanelle, France
| | - Olimpia Alves
- Medical Centre of Trás-os-Montes and Alto Douro, Clinical Pathology Department, 5000-801 Vila Real, Portugal
| | - Eliana Costa
- Medical Centre of Trás-os-Montes and Alto Douro, Clinical Pathology Department, 5000-801 Vila Real, Portugal
| | - Luís Maltez
- Veterinary and Animal Research Centre (CECAV), University of Trás-os-Montes and Alto Douro (UTAD), 5000-801 Vila Real, Portugal
- Department of Veterinary Sciences, University of Trás-os-Montes and Alto Douro (UTAD), 5000-801 Vila Real, Portugal
| | - José Eduardo Pereira
- Veterinary and Animal Research Centre (CECAV), University of Trás-os-Montes and Alto Douro (UTAD), 5000-801 Vila Real, Portugal
- Department of Veterinary Sciences, University of Trás-os-Montes and Alto Douro (UTAD), 5000-801 Vila Real, Portugal
| | - Ângela Martins
- Department of Veterinary Sciences, University of Trás-os-Montes and Alto Douro (UTAD), 5000-801 Vila Real, Portugal
- Department of Zootechnics, University of Trás-os-Montes and Alto Douro (UTAD), 5000-801 Vila Real, Portugal
| | - Gilberto Igrejas
- Department of Genetics and Biotechnology, University of Trás-os-Montes and Alto Douro (UTAD), 5000-801 Vila Real, Portugal
- Functional Genomics and Proteomics Unit, University of Trás-os-Montes and Alto Douro (UTAD), 5000-801 Vila Real, Portugal
- Associate Laboratory for Green Chemistry (LAQV), Chemistry Department, Faculty of Science and Technology, University Nova of Lisbon, 2829-516 Lisbon, Portugal
| | - Patricia Poeta
- Microbiology and Antibiotic Resistance Team (MicroART), Department of Veterinary Sciences, University of Trás-os-Montes and Alto Douro (UTAD), 5000-801 Vila Real, Portugal
- Associate Laboratory for Green Chemistry (LAQV), Chemistry Department, Faculty of Science and Technology, University Nova of Lisbon, 2829-516 Lisbon, Portugal
- Department of Veterinary Sciences, University of Trás-os-Montes and Alto Douro (UTAD), 5000-801 Vila Real, Portugal
- Associate Laboratory for Animal and Veterinary Sciences (AL4AnimalS), University of Trás-os-Montes and Alto Douro (UTAD), 5000-801 Vila Real, Portugal
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Li R, Peng J, Liu Q, Chang Z, Huang Y, Tang J, Lu G. Xanthomonas campestris VemR enhances the transcription of the T3SS key regulator HrpX via physical interaction with HrpG. MOLECULAR PLANT PATHOLOGY 2023; 24:232-247. [PMID: 36626275 PMCID: PMC9923393 DOI: 10.1111/mpp.13293] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/29/2022] [Revised: 11/28/2022] [Accepted: 12/09/2022] [Indexed: 06/17/2023]
Abstract
VemR is a response regulator of the two-component signalling systems (TCSs). It consists solely of a receiver domain. Previous studies have shown that VemR plays an important role in influencing the production of exopolysaccharides and exoenzymes, cell motility, and virulence of Xanthomonas campestris pv. campestris (Xcc). However, whether VemR is involved in the essential pathogenicity determinant type III secretion system (T3SS) is unclear. In this work, we found by transcriptome analysis that VemR modulates about 10% of Xcc genes, which are involved in various cellular processes including the T3SS. Further experiments revealed that VemR physically interacts with numerous proteins, including the TCS sensor kinases HpaS and RavA, and the TCS response regulator HrpG, which directly activates the transcription of HrpX, a key regulator controlling T3SS expression. It has been demonstrated previously that HpaS composes a TCS with HrpG or VemR to control the expression of T3SS or swimming motility, while RavA and VemR form a TCS to control the expression of flagellar genes. Mutation analysis and in vitro transcription assay revealed that phosphorylation might be essential for the function of VemR and phosphorylated VemR could significantly enhance the activation of hrpX transcription by HrpG. We infer that the binding of VemR to HrpG can modulate the activity of HrpG to the hrpX promoter, thereby enhancing hrpX transcription. Although further studies are required to validate this inference and explore the detailed functional mechanism of VemR, our findings provide some insights into the complex regulatory cascade of the HpaS/RavA-VemR/HrpG-HrpX signal transduction system in the control of T3SS.
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Affiliation(s)
- Rui‐Fang Li
- State Key Laboratory for Conservation and Utilization of Subtropical Agro‐BioresourcesCollege of Life Science and Technology, Guangxi UniversityNanningChina
- Guangxi Key Laboratory of Biology for Crop Diseases and Insect PestsPlant Protection Research Institute, Guangxi Academy of Agricultural SciencesNanningChina
| | - Jian‐Ling Peng
- State Key Laboratory for Conservation and Utilization of Subtropical Agro‐BioresourcesCollege of Life Science and Technology, Guangxi UniversityNanningChina
| | - Qian‐Qian Liu
- State Key Laboratory for Conservation and Utilization of Subtropical Agro‐BioresourcesCollege of Life Science and Technology, Guangxi UniversityNanningChina
| | - Zheng Chang
- State Key Laboratory for Conservation and Utilization of Subtropical Agro‐BioresourcesCollege of Life Science and Technology, Guangxi UniversityNanningChina
| | - Yi‐Xin Huang
- State Key Laboratory for Conservation and Utilization of Subtropical Agro‐BioresourcesCollege of Life Science and Technology, Guangxi UniversityNanningChina
| | - Ji‐Liang Tang
- State Key Laboratory for Conservation and Utilization of Subtropical Agro‐BioresourcesCollege of Life Science and Technology, Guangxi UniversityNanningChina
| | - Guang‐Tao Lu
- State Key Laboratory for Conservation and Utilization of Subtropical Agro‐BioresourcesCollege of Life Science and Technology, Guangxi UniversityNanningChina
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Wang YY, Zhang XY, Zhong XL, Huang YJ, Lin J, Chen WM. Design and Synthesis of 3-Hydroxy-pyridin-4(1 H)-ones-Ciprofloxacin Conjugates as Dual Antibacterial and Antibiofilm Agents against Pseudomonas aeruginosa. J Med Chem 2023; 66:2169-2193. [PMID: 36692083 DOI: 10.1021/acs.jmedchem.2c02044] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Pseudomonas aeruginosa infections are often complicated by the fact that it can easily form a biofilm that increases its resistance to antibiotics. Consequently, the development of novel antibacterial agents against biofilm-associated drug-resistant P. aeruginosa is urgently needed. Herein, we report a series of 3-hydroxy-pyridin-4(1H)-ones-ciprofloxacin conjugates that were designed and synthesized as dual antibacterial and antibiofilm agents against P. aeruginosa. A potential 2-substituted 3-hydroxy-1,6-dimethylpyridin-4(1H)-one-ciprofloxacin conjugate (5e) was identified and had the best minimum inhibitory concentrations of 0.86 and 0.43 μM against P. aeruginosa 27853 and PAO1 and reduced 78.3% of biofilm formation. In addition, 5e eradicates mature biofilms and kills living bacterial cells that are incorporated into the biofilm. Studies on the antibiofilm mechanism of conjugates showed that 5e interferes with iron uptake by bacteria, inhibits their motility, and reduces the production of virulence. These results demonstrate that 3-hydroxy-pyridin-4(1H)-ones-ciprofloxacin conjugates are potent in the treatment of biofilm-associated drug-resistant P. aeruginosa infections.
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Affiliation(s)
- Yuan-Yuan Wang
- International Cooperative Laboratory of Traditional Chinese Medicine Modernization and Innovative Drug Development of Chinese Ministry of Education (MOE), College of Pharmacy, Jinan University, #855 Xingye Avenue, Guangzhou 511400, China
| | - Xiao-Yi Zhang
- International Cooperative Laboratory of Traditional Chinese Medicine Modernization and Innovative Drug Development of Chinese Ministry of Education (MOE), College of Pharmacy, Jinan University, #855 Xingye Avenue, Guangzhou 511400, China
| | - Xiao-Lin Zhong
- International Cooperative Laboratory of Traditional Chinese Medicine Modernization and Innovative Drug Development of Chinese Ministry of Education (MOE), College of Pharmacy, Jinan University, #855 Xingye Avenue, Guangzhou 511400, China
| | - Yong-Jun Huang
- International Cooperative Laboratory of Traditional Chinese Medicine Modernization and Innovative Drug Development of Chinese Ministry of Education (MOE), College of Pharmacy, Jinan University, #855 Xingye Avenue, Guangzhou 511400, China
| | - Jing Lin
- International Cooperative Laboratory of Traditional Chinese Medicine Modernization and Innovative Drug Development of Chinese Ministry of Education (MOE), College of Pharmacy, Jinan University, #855 Xingye Avenue, Guangzhou 511400, China
| | - Wei-Min Chen
- International Cooperative Laboratory of Traditional Chinese Medicine Modernization and Innovative Drug Development of Chinese Ministry of Education (MOE), College of Pharmacy, Jinan University, #855 Xingye Avenue, Guangzhou 511400, China
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Li R, Ren P, Zhang D, Cui P, Zhu G, Xian X, Tang J, Lu G. HpaP divergently regulates the expression of hrp genes in Xanthomonas oryzae pathovars oryzae and oryzicola. MOLECULAR PLANT PATHOLOGY 2023; 24:44-58. [PMID: 36260328 PMCID: PMC9742497 DOI: 10.1111/mpp.13276] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/17/2022] [Revised: 09/26/2022] [Accepted: 09/29/2022] [Indexed: 06/16/2023]
Abstract
The bacterial pathogens Xanthomonas oryzae pathovars oryzae (Xoo) and oryzicola (Xoc) cause leaf blight and leaf streak diseases on rice, respectively. Pathogenesis is largely defined by the virulence genes harboured in the pathogen genome. Recently, we demonstrated that the protein HpaP of the crucifer pathogen Xanthomonas campestris pv. campestris is an enzyme with both ATPase and phosphatase activities, and is involved in regulating the synthesis of virulence factors and the induction of the hypersensitive response (HR). In this study, we investigated the role of HpaP homologues in Xoo and Xoc. We showed that HpaP is required for full virulence of Xoo and Xoc. Deletion of hpaP in Xoo and Xoc led to a reduction in virulence and alteration in the production of virulence factors, including extracellular polysaccharide and cell motility. Comparative transcriptomics and reverse transcription-quantitative PCR assays revealed that in XVM2 medium, a mimic medium of the plant environment, the expression levels of hrp genes (for HR and pathogenicity) were enhanced in the Xoo hpaP deletion mutant compared to the wild type. By contrast, in the same growth conditions, hrp gene expression was decreased in the Xoc hpaP deletion mutant compared to the wild type. However, an opposite expression pattern was observed when the pathogens grew in planta, where the expression of hrp genes was reduced in the Xoo hpaP mutant but increased in the Xoc hpaP mutant. These findings indicate that HpaP plays a divergent role in Xoo and Xoc, which may lead to the different infection strategies employed by these two pathogens.
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Affiliation(s)
- Rui‐Fang Li
- Plant Protection Research InstituteGuangxi Academy of Agricultural Science, Key Laboratory of Green Prevention and Control on Fruits and Vegetables in South China Ministry of Agriculture and Rural Affairs, Guangxi Key Laboratory of Biology for Crop Diseases and Insect PestsNanningGuangxiChina
| | - Pei‐Dong Ren
- State Key Laboratory for Conservation and Utilization of Subtropical Agro‐BioresourcesCollege of Life Science and Technology, Guangxi UniversityNanningChina
| | - Da‐Pei Zhang
- State Key Laboratory for Conservation and Utilization of Subtropical Agro‐BioresourcesCollege of Life Science and Technology, Guangxi UniversityNanningChina
| | - Ping Cui
- State Key Laboratory for Conservation and Utilization of Subtropical Agro‐BioresourcesCollege of Life Science and Technology, Guangxi UniversityNanningChina
| | - Gui‐Ning Zhu
- Plant Protection Research InstituteGuangxi Academy of Agricultural Science, Key Laboratory of Green Prevention and Control on Fruits and Vegetables in South China Ministry of Agriculture and Rural Affairs, Guangxi Key Laboratory of Biology for Crop Diseases and Insect PestsNanningGuangxiChina
| | - Xiao‐Yong Xian
- Plant Protection Research InstituteGuangxi Academy of Agricultural Science, Key Laboratory of Green Prevention and Control on Fruits and Vegetables in South China Ministry of Agriculture and Rural Affairs, Guangxi Key Laboratory of Biology for Crop Diseases and Insect PestsNanningGuangxiChina
| | - Ji‐Liang Tang
- State Key Laboratory for Conservation and Utilization of Subtropical Agro‐BioresourcesCollege of Life Science and Technology, Guangxi UniversityNanningChina
| | - Guang‐Tao Lu
- State Key Laboratory for Conservation and Utilization of Subtropical Agro‐BioresourcesCollege of Life Science and Technology, Guangxi UniversityNanningChina
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Feng L, Xu M, Zeng W, Zhang X, Wang S, Yao Z, Zhou T, Shi S, Cao J, Chen L. Evaluation of the antibacterial, antibiofilm, and anti-virulence effects of acetic acid and the related mechanisms on colistin-resistant Pseudomonas aeruginosa. BMC Microbiol 2022; 22:306. [PMID: 36529724 PMCID: PMC9762083 DOI: 10.1186/s12866-022-02716-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2022] [Accepted: 11/28/2022] [Indexed: 12/23/2022] Open
Abstract
BACKGROUND Pseudomonas aeruginosa (P. aeruginosa) has been majorly implicated in the infection of burns, wounds, skin, and respiratory tract. Colistin is considered the last line of defense against P. aeruginosa infections. However, colistin is becoming increasingly invalid in treating patients infected with colistin-resistant (COL-R) P. aeruginosa. As one of the disinfectants used for wound infections, acetic acid (AA) offers good antibacterial and antibiofilm activities against P. aeruginosa. This study investigated the effects of AA on COL-R P. aeruginosa in terms of its antibacterial, antibiofilm, and anti-virulence properties and the corresponding underlying mechanisms. RESULTS The antimicrobial susceptibility and growth curve data revealed that 0.078% (v/v) AA exhibited good antibacterial activity against COL-R P. aeruginosa. Subinhibitory concentrations of AA were ineffective in inhibiting biofilm formation, but 4 × and 8 × of the minimum inhibitory concentration (MIC) was effective in removing the preformed biofilms in biofilm-eradication assays. The virulence results illustrated that AA inhibited COL-R P. aeruginosa swimming, swarming, twitching, and pyocyanin and elastase production. The analysis of the potential antibacterial mechanisms of AA on COL-R P. aeruginosa revealed that AA acted by increasing the outer and inner membrane permeability, polarizing the membrane potential, and decreasing the reduction potential in a concentration-dependent manner. The qRT-PCR results revealed that AA may inhibit the virulence of COL-R P. aeruginosa by inhibiting the expression of T3SS-related and QS-related genes. CONCLUSIONS AA possesses antibacterial, antibiofilm, and anti-virulence properties that ultimately lead to the alteration of the bacterial membrane permeability, membrane potential, and reduction potential. Our findings indicated that AA is presently one of the effective treatment options for infections. A high concentration of AA (> 0.156% v/v) can be used to sterilize biofilm-prone surgical instruments, for hospital disinfection, and for treating the external wound, whereas a low concentration of AA (0.00975-0.039% v/v) may be used as an anti-virulence agent for adjuvant treatment of COL-R P. aeruginosa, thereby further improving the application value of AA in the treatment of infections.
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Affiliation(s)
- Luozhu Feng
- grid.414906.e0000 0004 1808 0918Department of Clinical Laboratory, The First Affiliated Hospital of Wenzhou Medical University; Key Laboratory of Clinical Laboratory Diagnosis and Translational Research of Zhejiang Province, Wenzhou, Zhejiang Province China ,grid.268099.c0000 0001 0348 3990Department of Medical Lab Science, School of Laboratory Medicine and Life Science, Wenzhou Medical University, Wenzhou, Zhejiang Province China
| | - Mengxin Xu
- grid.414906.e0000 0004 1808 0918Department of Clinical Laboratory, The First Affiliated Hospital of Wenzhou Medical University; Key Laboratory of Clinical Laboratory Diagnosis and Translational Research of Zhejiang Province, Wenzhou, Zhejiang Province China
| | - Weiliang Zeng
- grid.414906.e0000 0004 1808 0918Department of Clinical Laboratory, The First Affiliated Hospital of Wenzhou Medical University; Key Laboratory of Clinical Laboratory Diagnosis and Translational Research of Zhejiang Province, Wenzhou, Zhejiang Province China
| | - Xiaodong Zhang
- grid.414906.e0000 0004 1808 0918Department of Clinical Laboratory, The First Affiliated Hospital of Wenzhou Medical University; Key Laboratory of Clinical Laboratory Diagnosis and Translational Research of Zhejiang Province, Wenzhou, Zhejiang Province China
| | - Sipei Wang
- grid.414906.e0000 0004 1808 0918Department of Clinical Laboratory, The First Affiliated Hospital of Wenzhou Medical University; Key Laboratory of Clinical Laboratory Diagnosis and Translational Research of Zhejiang Province, Wenzhou, Zhejiang Province China
| | - Zhuocheng Yao
- grid.268099.c0000 0001 0348 3990Department of Medical Lab Science, School of Laboratory Medicine and Life Science, Wenzhou Medical University, Wenzhou, Zhejiang Province China
| | - Tieli Zhou
- grid.414906.e0000 0004 1808 0918Department of Clinical Laboratory, The First Affiliated Hospital of Wenzhou Medical University; Key Laboratory of Clinical Laboratory Diagnosis and Translational Research of Zhejiang Province, Wenzhou, Zhejiang Province China
| | - Shiyi Shi
- grid.414906.e0000 0004 1808 0918Department of Clinical Laboratory, The First Affiliated Hospital of Wenzhou Medical University; Key Laboratory of Clinical Laboratory Diagnosis and Translational Research of Zhejiang Province, Wenzhou, Zhejiang Province China
| | - Jianming Cao
- grid.268099.c0000 0001 0348 3990Department of Medical Lab Science, School of Laboratory Medicine and Life Science, Wenzhou Medical University, Wenzhou, Zhejiang Province China
| | - Lijiang Chen
- grid.414906.e0000 0004 1808 0918Department of Clinical Laboratory, The First Affiliated Hospital of Wenzhou Medical University; Key Laboratory of Clinical Laboratory Diagnosis and Translational Research of Zhejiang Province, Wenzhou, Zhejiang Province China
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Characterization of Multiple Alginate Lyases in a Highly Efficient Alginate-Degrading Vibrio Strain and Its Degradation Strategy. Appl Environ Microbiol 2022; 88:e0138922. [PMID: 36409133 PMCID: PMC9746302 DOI: 10.1128/aem.01389-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Alginate is an important polysaccharide in the ocean that supports the growth of marine microorganisms. Many widespread Vibrio species possess alginate lyases and can utilize alginate as a carbon source, but the detailed alginate degradation mechanism in Vibrio remains to be further explored. In this study, we obtained a highly efficient alginate-degrading strain, Vibrio pelagius WXL662, with 11 alginate lyases (VpAly-I to -XI) and further elucidated its molecular mechanism of alginate degradation. Three alginate utilization loci (AUL) were identified in different parts of WXL662's genome, comprising six alginate lyases (VpAly-I, -II, -VIII, -IX, -X, and -XI) and other genes related to alginate degradation. Most of the alginate-degrading genes are strongly induced when alginate is provided as the sole carbon source. Ten alginate lyases (VpAly-I to -X) had been purified and characterized, including six from polysaccharide lyase family 7 (PL7), three from PL17, and one from PL6. These recombinant alginate lyases existing in different cellular locations were active at a wide temperature (10 to 50°C) and pH (4.0 to 9.0) range, with different substrate preferences and diverse degradation products, enabling WXL662 to efficiently utilize alginate in a changing marine environment. Importantly, outer membrane vesicles (OMVs) can act as vectors for alginate lyases (VpAly-II, -V, and -VI) in WXL662. Further investigations of public Vibrio genomes revealed that most alginate-degrading vibrios possess one AUL instead of previously reported "scattered" system. These results emphasize the specific alginate degradation strategy in Vibrio pelagius WXL662, which can be used as a model strain to study the ecological importance of effective alginate-degrading vibrios in the ocean. IMPORTANCE Alginate is an important carbon source in the marine environment, and vibrios are major alginate utilizers. Previous studies focused only on the characteristics of individual alginate lyases in vibrios, but few of them discussed the comprehensive alginate-degrading strategy. Here, we depicted the alginate utilization mechanism and its ecological implications of a highly efficient alginate-degrading Vibrio strain, WXL662, which contained 11 alginate lyases with distinct enzymatic characteristics. Importantly, unlike other vibrios with only one alginate utilization locus (AUL) or the previously reported "scattered" system, three AUL were identified in WXL662. Additionally, the involvement of outer membrane vesicles (OMVs) in the secretion of alginate lyases is proposed for the first time.
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Høyland‐Kroghsbo NM. Collaborations Between Microbes and those who Love Them. Isr J Chem 2022. [DOI: 10.1002/ijch.202200082] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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42
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Shilpha J, Meyappan V, Sakthivel N. Bioinspired synthesis of gold nanoparticles from Hemidesmus indicus L. root extract and their antibiofilm efficacy against Pseudomonas aeruginosa. Process Biochem 2022. [DOI: 10.1016/j.procbio.2022.10.018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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Low Ciprofloxacin Concentrations Select Multidrug-Resistant Mutants Overproducing Efflux Pumps in Clinical Isolates of Pseudomonas aeruginosa. Microbiol Spectr 2022; 10:e0072322. [PMID: 36000896 PMCID: PMC9603996 DOI: 10.1128/spectrum.00723-22] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Low antibiotic concentrations present in natural environments are a severe and often neglected threat to public health. Even if they are present below their MICs, they may select for antibiotic-resistant pathogens. Notably, the minimal subinhibitory concentrations that select resistant bacteria, and define the respective sub-MIC selective windows, differ between antibiotics. The establishment of these selective concentrations is needed for risk-assessment studies regarding the presence of antibiotics in different habitats. Using short-term evolution experiments in a set of 12 Pseudomonas aeruginosa clinical isolates (including high-risk clones with ubiquitous distribution), we have determined that ciprofloxacin sub-MIC selective windows are strain specific and resistome dependent. Nonetheless, in all cases, clinically relevant multidrug-resistant (MDR) mutants emerged upon exposure to low ciprofloxacin concentrations, with these concentrations being below the levels reported in ciprofloxacin-polluted natural habitats where P. aeruginosa can be present. This feature expands the conditions and habitats where clinically relevant quinolone-resistant mutants can emerge. In addition, we established the lowest concentration threshold beyond which P. aeruginosa, regardless of the strain, becomes resistant to ciprofloxacin. Three days of exposure under this sub-MIC "risk concentration" led to the selection of MDR mutants that displayed resistance mechanisms usually ascribed to high selective pressures, i.e., the overproduction of the efflux pumps MexCD-OprJ and MexEF-OprN. From a One-Health viewpoint, these data stress the transcendent role of low drug concentrations, which can be encountered in natural ecosystems, in aggravating the antibiotic resistance problem, especially when it comes to pathogens of environmental origin. IMPORTANCE It has been established that antibiotic concentrations below MICs can select antibiotic-resistant pathogens, a feature of relevance for analyzing the role of nonclinical ecosystems in antibiotic resistance evolution. The range of concentrations where this selection occurs defines the sub-MIC selective window, whose width depends on the antibiotic. Herein, we have determined the ciprofloxacin sub-MIC selective windows of a set of Pseudomonas aeruginosa clinical isolates (including high-risk clones with worldwide distribution) and established the lowest concentration threshold, notably an amount reported to be present in natural ecosystems, beyond which this pathogen acquires resistance. Importantly, our results show that this ciprofloxacin sub-MIC selects for multidrug-resistant mutants overproducing clinically relevant efflux pumps. From a One-Health angle, this information supports that low antimicrobial concentrations, present in natural environments, may have a relevant role in worsening the antibiotic resistance crisis, particularly regarding pathogens with environmental niches, such as P. aeruginosa.
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Coelho RCV, Araújo NAM, Telo da Gama MM. Dispersion of activity at an active-passive nematic interface. SOFT MATTER 2022; 18:7642-7653. [PMID: 36169262 DOI: 10.1039/d2sm00988a] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
Efficient nutrient mixing is crucial for the survival of bacterial colonies and other living systems known as active nematics. However, the dynamics of this mixing is non-trivial as there is a coupling between nutrients concentration and velocity field. To address this question, we solve the hydrodynamic equation for active nematics to model the bacterial swarms coupled to an advection-diffusion equation for the activity field, which is proportional to the concentration of nutrients. At the interface between active and passive nematics the activity field is transported by the interfacial flows and in turn it modifies them through the generation of active stresses. We find that the dispersion of this conserved activity field is subdiffusive due to the emergence of a barrier of negative defects at the active-passive interface, which hinders the propagation of the motile positive defects.
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Affiliation(s)
- Rodrigo C V Coelho
- Centro de Física Teórica e Computacional, Faculdade de Ciências, Universidade de Lisboa, P-1749-016 Lisboa, Portugal.
- Departamento de Física, Faculdade de Ciências, Universidade de Lisboa, P-1749-016 Lisboa, Portugal
| | - Nuno A M Araújo
- Centro de Física Teórica e Computacional, Faculdade de Ciências, Universidade de Lisboa, P-1749-016 Lisboa, Portugal.
- Departamento de Física, Faculdade de Ciências, Universidade de Lisboa, P-1749-016 Lisboa, Portugal
| | - Margarida M Telo da Gama
- Centro de Física Teórica e Computacional, Faculdade de Ciências, Universidade de Lisboa, P-1749-016 Lisboa, Portugal.
- Departamento de Física, Faculdade de Ciências, Universidade de Lisboa, P-1749-016 Lisboa, Portugal
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Sakka K, Kihira M, Kuhara W, Mochida A, Kimura T, Sakka M. Swarming behavior of a novel strain of Brevibacillus thermoruber. J Basic Microbiol 2022; 62:1475-1486. [PMID: 36190013 DOI: 10.1002/jobm.202200445] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2022] [Revised: 08/23/2022] [Accepted: 09/10/2022] [Indexed: 11/11/2022]
Abstract
Brevibacillus thermoruber strain Nabari was isolated from compost and identified based on 16 S rRNA gene sequencing and DNA-DNA hybridization using B. thermoruber DSM 7064 T as the standard, despite some differences in their physiological and structural characteristics. When B. thermoruber Nabari was cultivated on various solid media containing 1.5% agar at 60°C, it rapidly propagated over the entire plate. In particular, on R2A-agar medium, it formed fine dendritic colonies. Macroscopic and microscopic observations of peripheral regions of the colonies indicated that the dendritic patterns were formed by bacterial swarming of some of the cells; large flows of bacterial cell populations were observed in the peripheral regions of the dendritic colonies. The cells were highly flagellated, but no extreme elongation of cells was observed. When B. thermoruber Nabari cells were cultivated at 37°C on R2A-agar plates, most colonies were nonmotile, but some colonies were motile. For example, a wandering colony moved on the plate and split into two, and then they collided to become one again. Additionally, a simple incubation system was devised to record the movement of colonies at high temperatures in this study while protecting the cameras from thermal damage.
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Affiliation(s)
- Kazuo Sakka
- Graduate School of Bioresources, Mie University, Tsu, Japan.,Iga Research Center, Mie University, Iga, Japan
| | | | | | | | - Tetsuya Kimura
- Graduate School of Bioresources, Mie University, Tsu, Japan
| | - Makiko Sakka
- Graduate School of Bioresources, Mie University, Tsu, Japan.,Kinki Kankyo Service Co. Ltd., Nabari, Japan
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Unravelling the Distinctive Virulence Traits and Clonal Relationship among the Pseudomonas aeruginosa Isolates from Diabetic Patients. JOURNAL OF PURE AND APPLIED MICROBIOLOGY 2022. [DOI: 10.22207/jpam.16.3.37] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Infections with P. aeruginosa are three times more common in people with diabetes than in non-diabetic individuals. Investigations disclosing the distinguishing traits of P. aeruginosa strains to cause respiratory and wound infection in diabetics is limited. Wound swab and sputum from infected diabetic patients were used for the isolation of P. aeruginosa. The confirmed isolates were evaluated for their virulence factor production, antibiotic susceptibility, and clonal relationship. The study confirmed the increased virulence of sputum isolates characterized by their multidrug resistant nature, strong biofilm formation at 72h [(p<0.05) =0.003)] and 96h [(p<0.05) =0.002)] and elaboration of proteolytic enzymes (40.0%). Albeit the fact that wound isolates were less virulent than the sputum isolates, there was an increased siderophore production (77.0%). Nearly 90.0% of the isolates including sputum and wound were resistant to colistin. Random Amplified Polymorphic DNA analysis showed no distinct lineages of wound and sputum isolates. The study disclosed the higher prevalence of virulent P. aeruginosa in causing infection in the diabetics. No distinct lineages of the wound and sputum isolates indicated their ability to adapt to different host environments. To the best of our knowledge, this is the first study to show the difference in virulence traits among the P. aeruginosa strains isolated from sputum and wound of diabetic patients. Our study distinctly reveals the significance of periodic examination of antibiotic resistance and virulence factors of P. aeruginosa in order to recognize the possible co-regulatory mechanism involved in their expression.
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Dubern JF, Romero M, Mai-Prochnow A, Messina M, Trampari E, Gijzel HNV, Chan KG, Carabelli AM, Barraud N, Lazenby J, Chen Y, Robertson S, Malone JG, Williams P, Heeb S, Cámara M. ToxR is a c-di-GMP binding protein that modulates surface-associated behaviour in Pseudomonas aeruginosa. NPJ Biofilms Microbiomes 2022; 8:64. [PMID: 35982053 PMCID: PMC9388670 DOI: 10.1038/s41522-022-00325-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2022] [Accepted: 07/26/2022] [Indexed: 11/09/2022] Open
Abstract
Pseudomonas aeruginosa uses multiple protein regulators that work in tandem to control the production of a wide range of virulence factors and facilitate rapid adaptation to diverse environmental conditions. In this opportunistic pathogen, ToxR was known to positively regulate the production of the major virulence factor exotoxin A and now, through analysis of genetic changes between two sublines of P. aeruginosa PAO1 and functional complementation of swarming, we have identified a previously unknown role of ToxR in surface-associated motility in P. aeruginosa. Further analysis revealed that ToxR had an impact on swarming motility by regulating the Rhl quorum sensing system and subsequent production of rhamnolipid surfactants. Additionally, ToxR was found to tightly bind cyclic diguanylate (c-di-GMP) and negatively affect traits controlled by this second messenger including reducing biofilm formation and the expression of Psl and Pel exopolysaccharides, necessary for attachment and sessile communities matrix scaffolding, in P. aeruginosa. Moreover, a link between the post-transcriptional regulator RsmA and toxR expression via the alternative sigma factor PvdS, induced under iron-limiting conditions, is established. This study reveals the importance of ToxR in a sophisticated regulation of free-living and biofilm-associated lifestyles, appropriate for establishing acute or chronic P. aeruginosa infections.
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Affiliation(s)
- Jean-Frédéric Dubern
- National Biofilms Innovation Centre, Biodiscovery Institute and School of Life Sciences, University of Nottingham, Nottingham, UK
| | - Manuel Romero
- National Biofilms Innovation Centre, Biodiscovery Institute and School of Life Sciences, University of Nottingham, Nottingham, UK
| | - Anne Mai-Prochnow
- National Biofilms Innovation Centre, Biodiscovery Institute and School of Life Sciences, University of Nottingham, Nottingham, UK
- School of Chemical and Biomolecular Engineering, University of Sydney, Sydney, Australia
| | - Marco Messina
- National Biofilms Innovation Centre, Biodiscovery Institute and School of Life Sciences, University of Nottingham, Nottingham, UK
- Department of Science, University Roma Tre, Rome, Italy
| | - Eleftheria Trampari
- Department of Molecular Microbiology, John Innes Centre, Norwich, UK
- Quadram Institute Bioscience, Norwich Research Park, Norwich, UK
| | - Hardeep Naghra-van Gijzel
- National Biofilms Innovation Centre, Biodiscovery Institute and School of Life Sciences, University of Nottingham, Nottingham, UK
- Genomic Sciences, GlaxoSmithKline Research and Development, Stevenage, UK
| | - Kok-Gan Chan
- Institute of Biological Sciences, Faculty of Science, University of Malaya, Kuala Lumpur, Malaysia
- International Genome Centre, Jiangsu University, Zhenjiang, China
| | - Alessandro M Carabelli
- School of Pharmacy, Boots Science Building, University of Nottingham, Nottingham, UK
- Department of Medicine, University of Cambridge, Cambridge, UK
| | - Nicolas Barraud
- Centre for Marine Bio-Innovation, School of Biotechnology and Biomolecular Science, University of New South Wales, Sydney, Australia
- Genetics of Biofilms Unit, Institut Pasteur, Paris, France
| | - James Lazenby
- National Biofilms Innovation Centre, Biodiscovery Institute and School of Life Sciences, University of Nottingham, Nottingham, UK
- Quadram Institute Bioscience, Norwich Research Park, Norwich, UK
| | - Ye Chen
- National Biofilms Innovation Centre, Biodiscovery Institute and School of Life Sciences, University of Nottingham, Nottingham, UK
- Q Squared Solutions, Crystal Plaza, Pudong, Shanghai, China
| | - Shaun Robertson
- National Biofilms Innovation Centre, Biodiscovery Institute and School of Life Sciences, University of Nottingham, Nottingham, UK
| | - Jacob G Malone
- Department of Molecular Microbiology, John Innes Centre, Norwich, UK
- School of Biological Sciences, University of East Anglia, Norwich, UK
| | - Paul Williams
- National Biofilms Innovation Centre, Biodiscovery Institute and School of Life Sciences, University of Nottingham, Nottingham, UK
| | - Stephan Heeb
- National Biofilms Innovation Centre, Biodiscovery Institute and School of Life Sciences, University of Nottingham, Nottingham, UK
| | - Miguel Cámara
- National Biofilms Innovation Centre, Biodiscovery Institute and School of Life Sciences, University of Nottingham, Nottingham, UK.
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Lin Y, Mi D, Hou Y, Lin M, Xie Q, Niu X, Chen Y, He C, Tao J, Li C. Systematic analysis of the roles of c-di-GMP signaling in Xanthomonas oryzae pv. oryzae virulence. FEMS Microbiol Lett 2022; 369:6650349. [PMID: 35883214 DOI: 10.1093/femsle/fnac068] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2022] [Revised: 06/09/2022] [Accepted: 07/22/2022] [Indexed: 11/14/2022] Open
Abstract
Cyclic di-guanosine monophosphate (c-di-GMP) is a ubiquitous second messenger that is essential to bacterial adaptation to environments. Cellular c-di-GMP level is regulated by the diguanylate cyclases and the phosphodiesterases, and the signal transduction depends on its receptors. In Xanthomonas oryzae pv. oryzae strain PXO99A, 37 genes were predicted to encode GGDEF, EAL, GGDEF/EAL, HD-GYP, FleQ, MshE, PilZ, CuxR, Clp, YajQ proteins that may be involved in c-di-GMP turnover or function as c-di-GMP receptors. Although the functions of some of these genes have been studied, but the rest have not been extensively studied. Here, we deleted these 37 genes from PXO99A and analyzed the virulence, motility, biofilm and EPS production of these mutants. Our results show that most of these genes are required for PXO99A virulence, motility, biofilm formation or exopolysaccharide production. Although some of them have been reported in previous studies, we found four novel genes (gedpX8, gdpX11, pliZX4 and yajQ) are implicated in X. oryzae pv. oryzae virulence. Our data demonstrate that c-di-GMP signaling is vital for X. oryzae pv. oryzae virulence and some virulence-related factors production, but there is no positive correlation between them in most cases. Taken together, our systematic research provides a new light to understand the c-di-GMP signaling network in X. oryzae pv. oryzae.
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Affiliation(s)
- Yunuan Lin
- Hainan Key Laboratory for Sustainable Utilization of Tropical Bioresources.,School of Life Sciences
| | - Duo Mi
- Hainan Key Laboratory for Sustainable Utilization of Tropical Bioresources.,College of Tropical Crops, Hainan University, Haikou 570228, China
| | - Yunyu Hou
- Hainan Key Laboratory for Sustainable Utilization of Tropical Bioresources.,School of Life Sciences
| | - Maojuan Lin
- Hainan Key Laboratory for Sustainable Utilization of Tropical Bioresources.,College of Tropical Crops, Hainan University, Haikou 570228, China
| | - Qingbiao Xie
- Hainan Key Laboratory for Sustainable Utilization of Tropical Bioresources.,School of Life Sciences
| | - Xiaolei Niu
- Hainan Key Laboratory for Sustainable Utilization of Tropical Bioresources.,College of Tropical Crops, Hainan University, Haikou 570228, China
| | - Yinhua Chen
- Hainan Key Laboratory for Sustainable Utilization of Tropical Bioresources.,School of Life Sciences
| | - Chaozu He
- Hainan Key Laboratory for Sustainable Utilization of Tropical Bioresources.,College of Tropical Crops, Hainan University, Haikou 570228, China
| | - Jun Tao
- Hainan Key Laboratory for Sustainable Utilization of Tropical Bioresources.,College of Tropical Crops, Hainan University, Haikou 570228, China
| | - Chunxia Li
- Hainan Key Laboratory for Sustainable Utilization of Tropical Bioresources.,College of Tropical Crops, Hainan University, Haikou 570228, China
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Surface Motility Favors Codependent Interaction between Pseudomonas aeruginosa and Burkholderia cenocepacia. mSphere 2022; 7:e0015322. [PMID: 35862793 PMCID: PMC9429929 DOI: 10.1128/msphere.00153-22] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Interactions between different bacterial species shape bacterial communities and their environments. The opportunistic pathogens Pseudomonas aeruginosa and Burkholderia cenocepacia both can colonize the lungs of individuals affected by cystic fibrosis. Using the social surface behavior called swarming motility as a study model, we noticed intricate interactions between B. cenocepacia K56-2 and P. aeruginosa PA14. While strain K56-2 does not swarm under P. aeruginosa favorable swarming conditions, co-inoculation with a nonmotile PA14 flagellum-less ΔfliC mutant restored spreading for both strains. We show that P. aeruginosa provides the wetting agent rhamnolipids allowing K56-2 to perform swarming motility, while aflagellated PA14 appears to “hitchhike” along with K56-2 cells in the swarming colony. IMPORTANCEPseudomonas aeruginosa and Burkholderia cenocepacia are important opportunistic pathogens often found together in the airways of persons with cystic fibrosis. Laboratory cocultures of both species often ends with one taking over the other. We used a surface motility assay to study the social interactions between populations of these bacterial species. Under our conditions, B. cenocepacia cannot swarm without supplementation of the wetting agent produced by P. aeruginosa. In a mixed colony of both species, an aflagellated mutant of P. aeruginosa provides the necessary wetting agent to B. cenocepacia, allowing both bacteria to swarm and colonize a surface. We highlight this peculiar interaction where both bacteria set aside their antagonistic tendencies to travel together.
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The Xanthophyll Carotenoid Lutein Reduces the Invasive Potential of Pseudomonas aeruginosa and Increases Its Susceptibility to Tobramycin. Int J Mol Sci 2022; 23:ijms23137199. [PMID: 35806201 PMCID: PMC9266958 DOI: 10.3390/ijms23137199] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2022] [Revised: 06/24/2022] [Accepted: 06/27/2022] [Indexed: 11/16/2022] Open
Abstract
Recently, the xanthophyll carotenoid lutein has been qualified as a potential quorum sensing (QS) and biofilm inhibitor against Pseudomonas aeruginosa. To address the potential of this xanthophyll compound as a relevant antivirulence agent, we investigated in depth its impact on the invasion capabilities and aggressiveness of P. aeruginosa PAO1, which rely on the bacterial ability to build and maintain protective barriers, use different types of motilities and release myriad virulence factors, leading to host cell and tissue damages. Our data, obtained on the PAO1 strain, indicate that all-trans lutein (Lut; 22 µM) disrupts biofilm formation and disorganizes established biofilm structure without affecting bacterial viability, while improving the bactericidal activity of tobramycin against biofilm-encapsulated PAO1 cells. Furthermore, this xanthophyll affects PAO1 twitching and swarming motilities while reducing the production of the extracellular virulence factors pyocyanin, elastase and rhamnolipids as well as the expression of the QS-regulated lasB and rhlA genes without inhibiting the QS-independent aceA gene. Interestingly, the expression of the QS regulators rhlR/I and lasR/I is significantly reduced as well as that of the global virulence factor regulator vfr, which is suggested to be a major target of Lut. Finally, an oxidative metabolite of Lut, 3′-dehydrolutein, induces a similar inhibition phenotype. Taken together, lutein-type compounds represent potential agents to control the invasive ability and antibiotic resistance of P. aeruginosa.
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