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Gadaime NK, Haddadin RN, Shehabi AA, Omran IN. Antimicrobial resistance and carbapenemase dissemination in Pseudomonas aeruginosa isolates from Libyan hospitals: a call for surveillance and intervention. Libyan J Med 2024; 19:2344320. [PMID: 38643488 PMCID: PMC11034451 DOI: 10.1080/19932820.2024.2344320] [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: 02/05/2024] [Accepted: 04/15/2024] [Indexed: 04/23/2024] Open
Abstract
Pseudomonas aeruginosa is a multidrug-resistant bacterium capable of forming biofilms. This study aimed to assess resistance of clinical isolates from Libyan hospitals to antipseudomonal antibiotics, the prevalence of selected extended-spectrum β-lactamases and carbapenemase genes among these isolates, and the microorganisms' capacity for alginate and biofilm production. Forty-five isolates were collected from four hospitals in Benghazi and Derna, Libya. Antimicrobial susceptibility was determined using agar disc diffusion. The presence of resistance genes (blaCTXM, blaTEM, blaSHV-1, blaGES-1, blaKPC, and blaNDM) was screened using PCR. Biofilm formation was quantified via the crystal violet assay, while alginate production was measured spectrophotometrically. Resistance to antipseudomonal antibiotics ranged from 48.9% to 75.6%. The most prevalent resistance gene was blaNDM (26.7%), followed by blaGES-1 (17.8%). Moreover, all isolates demonstrated varying degrees of biofilm-forming ability and alginate production. No statistically significant correlation was found between biofilm formation and alginate production. The dissemination of resistant genes in P. aeruginosa, particularly carbapenemases, is of great concern. This issue is compounded by the bacteria's biofilm-forming capability. Urgent intervention and continuous surveillance are imperative to prevent further deterioration and the catastrophic spread of resistance among these formidable bacteria.
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Affiliation(s)
- Nasrin K. Gadaime
- School of Medicine, The University of Jordan, Amman, Jordan
- Department of Lab Medicine, Faculty of Medical Technology-Derna, National Board for technical and Vocational Education, Derna, Libya
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2
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Østergaard MZ, Nielsen FD, Meinfeldt MH, Kirkpatrick CL. The uncharacterized PA3040-3042 operon is part of the cell envelope stress response and a tobramycin resistance determinant in a clinical isolate of Pseudomonas aeruginosa. Microbiol Spectr 2024; 12:e0387523. [PMID: 38949386 PMCID: PMC11302039 DOI: 10.1128/spectrum.03875-23] [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: 11/09/2023] [Accepted: 05/22/2024] [Indexed: 07/02/2024] Open
Abstract
Bacteriophages (hereafter "phages") are ubiquitous predators of bacteria in the natural world, but interest is growing in their development into antibacterial therapy as complement or replacement for antibiotics. However, bacteria have evolved a huge variety of antiphage defense systems allowing them to resist phage lysis to a greater or lesser extent. In addition to dedicated phage defense systems, some aspects of the general stress response also impact phage susceptibility, but the details of this are not well known. In order to elucidate these factors in the opportunistic pathogen Pseudomonas aeruginosa, we used the laboratory-conditioned strain PAO1 as host for phage infection experiments as it is naturally poor in dedicated phage defense systems. Screening by transposon insertion sequencing indicated that the uncharacterized operon PA3040-PA3042 was potentially associated with resistance to lytic phages. However, we found that its primary role appeared to be in regulating biofilm formation, particularly in a clinical isolate of P. aeruginosa in which it also altered tobramycin resistance. Its expression was highly growth-phase dependent and responsive to phage infection and cell envelope stress. Our results suggest that this operon may be a cryptic but important locus for P. aeruginosa stress tolerance. IMPORTANCE An important category of bacterial stress response systems is bacteriophage defense, where systems are triggered by bacteriophage infection and activate a response which may either destroy the phage genome or destroy the infected cell so that the rest of the population survives. In some bacteria, the cell envelope stress response is activated by bacteriophage infection, but it is unknown whether this contributes to the survival of the infection. We have found that a conserved uncharacterized operon (PA3040-PA3042) of the cell envelope stress regulon in Pseudomonas aeruginosa, which has very few dedicated phage defense systems, responds to phage infection and stationary phase as well as envelope stress and is important for growth and biofilm formation in a clinical isolate of P. aeruginosa, even in the absence of phages. As homologs of these genes are found in other bacteria, they may be a novel component of the general stress response.
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Affiliation(s)
- Magnus Z. Østergaard
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, Odense, Denmark
| | - Flemming D. Nielsen
- Department of Clinical Microbiology, Odense University Hospital, Odense, Denmark
| | - Mette H. Meinfeldt
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, Odense, Denmark
| | - Clare L. Kirkpatrick
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, Odense, Denmark
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3
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David A, Tahrioui A, Tareau AS, Forge A, Gonzalez M, Bouffartigues E, Lesouhaitier O, Chevalier S. Pseudomonas aeruginosa Biofilm Lifecycle: Involvement of Mechanical Constraints and Timeline of Matrix Production. Antibiotics (Basel) 2024; 13:688. [PMID: 39199987 PMCID: PMC11350761 DOI: 10.3390/antibiotics13080688] [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: 07/01/2024] [Revised: 07/22/2024] [Accepted: 07/23/2024] [Indexed: 09/01/2024] Open
Abstract
Pseudomonas aeruginosa is an opportunistic pathogen causing acute and chronic infections, especially in immunocompromised patients. Its remarkable adaptability and resistance to various antimicrobial treatments make it difficult to eradicate. Its persistence is enabled by its ability to form a biofilm. Biofilm is a community of sessile micro-organisms in a self-produced extracellular matrix, which forms a scaffold facilitating cohesion, cell attachment, and micro- and macro-colony formation. This lifestyle provides protection against environmental stresses, the immune system, and antimicrobial treatments, and confers the capacity for colonization and long-term persistence, often characterizing chronic infections. In this review, we retrace the events of the life cycle of P. aeruginosa biofilm, from surface perception/contact to cell spreading. We focus on the importance of extracellular appendages, mechanical constraints, and the kinetics of matrix component production in each step of the biofilm life cycle.
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Affiliation(s)
| | | | | | | | | | | | | | - Sylvie Chevalier
- Univ Rouen Normandie, Univ Caen Normandie, Normandie Univ, CBSA UR 4312, F-76000 Rouen, France
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4
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Edvardsen PKT, Askarian F, Zurich R, Nizet V, Vaaje-Kolstad G. Exploring roles of the chitinase ChiC in modulating Pseudomonas aeruginosa virulence phenotypes. Microbiol Spectr 2024; 12:e0054624. [PMID: 38819151 PMCID: PMC11218509 DOI: 10.1128/spectrum.00546-24] [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: 02/29/2024] [Accepted: 04/23/2024] [Indexed: 06/01/2024] Open
Abstract
Chitinases are ubiquitous enzymes involved in biomass degradation and chitin turnover in nature. Pseudomonas aeruginosa (PA), an opportunistic human pathogen, expresses ChiC, a secreted glycoside hydrolase 18 family chitinase. Despite speculation about ChiC's role in PA disease pathogenesis, there is scant evidence supporting this hypothesis. Since PA cannot catabolize chitin, we investigated the potential function(s) of ChiC in PA pathophysiology. Our findings show that ChiC exhibits activity against both insoluble (α- and β-chitin) and soluble chitooligosaccharides. Enzyme kinetics toward (GlcNAc)4 revealed a kcat of 6.50 s-1 and a KM of 1.38 mM, the latter remarkably high for a canonical chitinase. In our label-free proteomics investigation, ChiC was among the most abundant proteins in the Pel biofilm, suggesting a potential contribution to PA biofilm formation. Using an intratracheal challenge model of PA pneumonia, the chiC::ISphoA/hah transposon insertion mutant paradoxically showed slightly increased virulence compared to the wild-type parent strain. Our results indicate that ChiC is a genuine chitinase that contributes to a PA pathoadaptive pathway.IMPORTANCEIn addition to performing chitin degradation, chitinases from the glycoside hydrolase 18 family have been found to play important roles during pathogenic bacterial infection. Pseudomonas aeruginosa is an opportunistic pathogen capable of causing pneumonia in immunocompromised individuals. Despite not being able to grow on chitin, the bacterium produces a chitinase (ChiC) with hitherto unknown function. This study describes an in-depth characterization of ChiC, focusing on its potential contribution to the bacterium's disease-causing ability. We demonstrate that ChiC can degrade both polymeric chitin and chitooligosaccharides, and proteomic analysis of Pseudomonas aeruginosa biofilm revealed an abundance of ChiC, hinting at a potential role in biofilm formation. Surprisingly, a mutant strain incapable of ChiC production showed higher virulence than the wild-type strain. While ChiC appears to be a genuine chitinase, further investigation is required to fully elucidate its contribution to Pseudomonas aeruginosa virulence, an important task given the evident health risk posed by this bacterium.
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Affiliation(s)
| | - Fatemeh Askarian
- Division of Host-Microbe Systems & Therapeutics, Department of Pediatrics, UC San Diego School of Medicine, La Jolla, California, USA
| | - Raymond Zurich
- Division of Host-Microbe Systems & Therapeutics, Department of Pediatrics, UC San Diego School of Medicine, La Jolla, California, USA
| | - Victor Nizet
- Division of Host-Microbe Systems & Therapeutics, Department of Pediatrics, UC San Diego School of Medicine, La Jolla, California, USA
- Skaggs School of Pharmacy and Pharmaceutical Sciences, UC San Diego, La Jolla, California, USA
| | - Gustav Vaaje-Kolstad
- Faculty of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences, Ås, Norway
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5
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Okurowska K, Monk PN, Karunakaran E. Increased tolerance to commonly used antibiotics in a Pseudomonas aeruginosa ex vivo porcine keratitis model. MICROBIOLOGY (READING, ENGLAND) 2024; 170:001459. [PMID: 38739119 PMCID: PMC11165664 DOI: 10.1099/mic.0.001459] [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: 11/22/2023] [Accepted: 04/26/2024] [Indexed: 05/14/2024]
Abstract
Introduction. Bacterial keratitis, particularly caused by Pseudomonas aeruginosa, is challenging to treat because of multi-drug tolerance, often associated with the formation of biofilms. Antibiotics in development are typically evaluated against planktonic bacteria in a culture medium, which may not accurately represent the complexity of infections in vivo.Hypothesis/Gap Statement. Developing a reliable, economic ex vivo keratitis model that replicates some complexity of tissue infections could facilitate a deeper understanding of antibiotic efficacy, thus aiding in the optimization of treatment strategies for bacterial keratitis.Methodology. Here we investigated the efficacy of three commonly used antibiotics (gentamicin, ciprofloxacin and meropenem) against Pseudomonas aeruginosa cytotoxic strain PA14 and invasive strain PA01 using an ex vivo porcine keratitis model.Results. Both strains of P. aeruginosa were susceptible to the MIC of the three tested antibiotics. However, significantly higher concentrations were necessary to inhibit bacterial growth in the minimum biofilm eradication concentration (MBEC) assay, with both strains tolerating concentrations greater than 512 mg l-1 of meropenem. When MIC and higher concentrations than MBEC (1024 mg l-1) of antibiotics were applied, ciprofloxacin exhibited the highest potency against both P. aeruginosa strains, followed by meropenem, while gentamicin showed the least potency. Despite this, none of the antibiotic concentrations used effectively cleared the infection, even after 18 h of continuous exposure.Conclusions. Further exploration of antibiotic concentrations and aligning dosing with clinical studies to validate the model is needed. Nonetheless, our ex vivo porcine keratitis model could be a valuable tool for assessing antibiotic efficacy.
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Affiliation(s)
- Katarzyna Okurowska
- Department of Chemical and Biological Engineering, University of Sheffield, Sheffield S10 2TN, UK
- National Institute for Health and Care Research, University of Leeds, Leeds LS2 9JT, UK
| | - Peter N. Monk
- Department of Infection, Immunity and Cardiovascular Disease, University of Sheffield, Sheffield S10 2TN, UK
| | - Esther Karunakaran
- Department of Chemical and Biological Engineering, University of Sheffield, Sheffield S10 2TN, UK
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6
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Mallick S, Das S. Treatment of low-pH rubber wastewater using ureolytic bacteria and the production of calcium carbonate precipitate for soil stabilization. CHEMOSPHERE 2024; 356:141913. [PMID: 38582164 DOI: 10.1016/j.chemosphere.2024.141913] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/04/2023] [Revised: 03/22/2024] [Accepted: 04/04/2024] [Indexed: 04/08/2024]
Abstract
Rubber wastewater contains variable low pH with a high load of nutrients such as nitrogen, phosphorous, suspended solids, high biological oxygen demand (BOD), and chemical oxygen demand (COD). Ureolytic and biofilm-forming bacterial strains Bacillus sp. OS26, Bacillus cereus OS36, Lysinibacillus macroides ST13, and Burkholderia multivorans DF12 were isolated from rubber processing centres showed high urease activity. Microscopic analyses evaluated the structural organization of biofilm. Extracellular polymeric substances (EPS) matrix of the biofilm of the strains showed the higher abundance of polysaccharides and lipids which help in the attachment and absorption of nutrients. The functional groups of polysaccharides, proteins, and lipids present in EPS were revealed by ATR-FTIR and 1H NMR. A consortium composed of B. cereus OS36, L. macroides ST13, and B. multivorans DF12 showed the highest biofilm formation, and efficiently reduced 62% NH3, 72% total nitrogen, and 66% PO43-. This consortium also reduced 76% BOD, 61% COD, and 68% TDS. After bioremediation, the pH of the remediated wastewater increased to 11.19. To reduce the alkalinity of discharged wastewater, CaCl2 and urea were added for calcite reaction. The highest CaCO3 precipitate was obtained at 24.6 mM of CaCl2, 2% urea, and 0.0852 mM of nickel (Ni2+) as a co-factor which reduced the pH to 7.4. The elemental composition of CaCO3 precipitate was analyzed by SEM-EDX. XRD analysis of the bacterially-induced precipitate revealed a crystallinity index of 0.66. The resulting CaCO3 precipitate was used as soil stabilizer. The precipitate filled the void spaces of the treated soil, reduced the permeability by 80 times, and increased the compression by 8.56 times than untreated soil. Thus, CaCO3 precipitated by ureolytic and biofilm-forming bacterial consortium through ureolysis can be considered a promising approach for neutralization of rubber wastewater and soil stabilization.
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Affiliation(s)
- Souradip Mallick
- Laboratory of Environmental Microbiology and Ecology (LEnME), Department of Life Science, National Institute of Technology, Rourkela, 769 008, Odisha, India
| | - Surajit Das
- Laboratory of Environmental Microbiology and Ecology (LEnME), Department of Life Science, National Institute of Technology, Rourkela, 769 008, Odisha, India.
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7
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Deiss-Yehiely E, Dzordzorme AE, Loiselle ME, Yonker LM, Hammond PT. Carboxylated Nanoparticle Surfaces Enhance Association with Mucoid Pseudomonas aeruginosa Biofilms. ACS APPLIED MATERIALS & INTERFACES 2024; 16:14573-14582. [PMID: 38484043 PMCID: PMC10982939 DOI: 10.1021/acsami.3c18656] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/29/2023] [Revised: 01/05/2024] [Accepted: 01/08/2024] [Indexed: 04/04/2024]
Abstract
Pseudomonas aeruginosa biofilms comprise three main polysaccharides: alginate, psl, and pel, which all imbue tolerance against exogenous antimicrobials. Nanoparticles (NPs) are an exciting new strategy to overcome the biofilm matrix for therapeutic delivery applications; however, zero existing FDA approvals for biofilm-specific NP formulations can be attributed to the complex interplay of physiochemical forces at the biofilm-NP interface. Here, we leverage a set of inducible, polysaccharide-specific, expressing isogenic P. aeruginosa mutants coupled with an assembled layer-by-layer NP (LbL NP) panel to characterize biofilm-NP interactions. When investigating these interactions using confocal microscopy, alginate-layered NPs associated more than dextran-sulfate-layered NPs with biofilms that had increased alginate production, including biofilms produced by mucoid P. aeruginosa isolates from people with cystic fibrosis. These differences were further confirmed in LbL NPs layered with polysaccharide- or hydrocarbon-based polymers with pendent carboxylate or sulfate functional groups. These data suggest carboxylated NP surfaces have enhanced interactions specifically with mucoid biofilms as compared to sulfated surfaces and lay the foundation for their inclusion as a design element for increasing biofilm-NP interactions and efficacious drug delivery.
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Affiliation(s)
- Elad Deiss-Yehiely
- Department
of Materials Science and Engineering, Massachusetts
Institute of Technology, Cambridge, Massachusetts 02139, United States
- Koch
Institute for Integrative Cancer Research, Massachusetts Institute
of Technology, Cambridge, Massachusetts 02139, United States
| | - Abigail E. Dzordzorme
- Department
of Biological Engineering, Massachusetts
Institute of Technology, Cambridge, Massachusetts 02139, United States
| | - Maggie Elizabeth Loiselle
- Mucosal
Immunology and Biology Research Center, Division of Infectious Disease, Massachusetts General Hospital, Boston, Massachusetts 02114, United States
- Department
of Pediatrics, Division of Infectious Disease, Massachusetts General Hospital, Boston, Massachusetts 02114, United States
| | - Lael M. Yonker
- Mucosal
Immunology and Biology Research Center, Division of Infectious Disease, Massachusetts General Hospital, Boston, Massachusetts 02114, United States
- Department
of Pediatrics, Division of Infectious Disease, Massachusetts General Hospital, Boston, Massachusetts 02114, United States
- Harvard
Medical School, Boston, Massachusetts 02115, United States
| | - Paula T. Hammond
- Koch
Institute for Integrative Cancer Research, Massachusetts Institute
of Technology, Cambridge, Massachusetts 02139, United States
- Institute
for Soldier Nanotechnologies, Massachusetts
Institute of Technology, Cambridge, Massachusetts 02139, United States
- Department
of Chemical Engineering, Massachusetts Institute
of Technology, Cambridge, Massachusetts 02139, United States
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8
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Yaeger LN, Ranieri MRM, Chee J, Karabelas-Pittman S, Rudolph M, Giovannoni AM, Harvey H, Burrows LL. A genetic screen identifies a role for oprF in Pseudomonas aeruginosa biofilm stimulation by subinhibitory antibiotics. NPJ Biofilms Microbiomes 2024; 10:30. [PMID: 38521769 PMCID: PMC10960818 DOI: 10.1038/s41522-024-00496-7] [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: 09/06/2023] [Accepted: 03/05/2024] [Indexed: 03/25/2024] Open
Abstract
Biofilms are surface-associated communities of bacteria that grow in a self-produced matrix of polysaccharides, proteins, and extracellular DNA (eDNA). Sub-minimal inhibitory concentrations (sub-MIC) of antibiotics induce biofilm formation, potentially as a defensive response to antibiotic stress. However, the mechanisms behind sub-MIC antibiotic-induced biofilm formation are unclear. We show that treatment of Pseudomonas aeruginosa with multiple classes of sub-MIC antibiotics with distinct targets induces biofilm formation. Further, addition of exogenous eDNA or cell lysate failed to increase biofilm formation to the same extent as antibiotics, suggesting that the release of cellular contents by antibiotic-driven bacteriolysis is insufficient. Using a genetic screen for stimulation-deficient mutants, we identified the outer membrane porin OprF and the ECF sigma factor SigX as important. Similarly, loss of OmpA - the Escherichia coli OprF homolog - prevented sub-MIC antibiotic stimulation of E. coli biofilms. Our screen also identified the periplasmic disulfide bond-forming enzyme DsbA and a predicted cyclic-di-GMP phosphodiesterase encoded by PA2200 as essential for biofilm stimulation. The phosphodiesterase activity of PA2200 is likely controlled by a disulfide bond in its regulatory domain, and folding of OprF is influenced by disulfide bond formation, connecting the mutant phenotypes. Addition of reducing agent dithiothreitol prevented sub-MIC antibiotic biofilm stimulation. Finally, activation of a c-di-GMP-responsive promoter follows treatment with sub-MIC antibiotics in the wild-type but not an oprF mutant. Together, these results show that antibiotic-induced biofilm formation is likely driven by a signaling pathway that translates changes in periplasmic redox state into elevated biofilm formation through increases in c-di-GMP.
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Affiliation(s)
- Luke N Yaeger
- Biochemistry and Biomedical Sciences and the Michael G. DeGroote Centre for Infectious Disease Research, McMaster University, Hamilton, ON, Canada
| | - Michael R M Ranieri
- Biochemistry and Biomedical Sciences and the Michael G. DeGroote Centre for Infectious Disease Research, McMaster University, Hamilton, ON, Canada
| | - Jessica Chee
- Biochemistry and Biomedical Sciences and the Michael G. DeGroote Centre for Infectious Disease Research, McMaster University, Hamilton, ON, Canada
| | - Sawyer Karabelas-Pittman
- Biochemistry and Biomedical Sciences and the Michael G. DeGroote Centre for Infectious Disease Research, McMaster University, Hamilton, ON, Canada
| | - Madeleine Rudolph
- Biochemistry and Biomedical Sciences and the Michael G. DeGroote Centre for Infectious Disease Research, McMaster University, Hamilton, ON, Canada
| | - Alessio M Giovannoni
- Biochemistry and Biomedical Sciences and the Michael G. DeGroote Centre for Infectious Disease Research, McMaster University, Hamilton, ON, Canada
| | - Hanjeong Harvey
- Biochemistry and Biomedical Sciences and the Michael G. DeGroote Centre for Infectious Disease Research, McMaster University, Hamilton, ON, Canada
| | - Lori L Burrows
- Biochemistry and Biomedical Sciences and the Michael G. DeGroote Centre for Infectious Disease Research, McMaster University, Hamilton, ON, Canada.
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9
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Oladosu VI, Park S, Sauer K. Flip the switch: the role of FleQ in modulating the transition between the free-living and sessile mode of growth in Pseudomonas aeruginosa. J Bacteriol 2024; 206:e0036523. [PMID: 38436566 PMCID: PMC10955856 DOI: 10.1128/jb.00365-23] [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: 03/05/2024] Open
Abstract
Pseudomonas aeruginosa is a Gram-negative, opportunistic pathogen causing chronic infections that are associated with the sessile/biofilm mode of growth rather than the free-living/planktonic mode of growth. The transcriptional regulator FleQ contributes to both modes of growth by functioning both as an activator and repressor and inversely regulating flagella genes associated with the planktonic mode of growth and genes contributing to the biofilm mode of growth. Here, we review findings that enhance our understanding of the molecular mechanism by which FleQ enables the transition between the two modes of growth. We also explore recent advances in the mechanism of action of FleQ to both activate and repress gene expression from a single promoter. Emphasis will be on the role of sigma factors, cyclic di-GMP, and the transcriptional regulator AmrZ in inversely regulating flagella and biofilm-associated genes and converting FleQ from a repressor to an activator.
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Affiliation(s)
- Victoria I. Oladosu
- Department of Biological Sciences, Binghamton University, Binghamton, New York, USA
| | - Soyoung Park
- Binghamton Biofilm Research Center, Binghamton University, Binghamton, New York, USA
| | - Karin Sauer
- Department of Biological Sciences, Binghamton University, Binghamton, New York, USA
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10
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Blanco-Romero E, Garrido-Sanz D, Durán D, Rybtke M, Tolker-Nielsen T, Redondo-Nieto M, Rivilla R, Martín M. Role of extracellular matrix components in biofilm formation and adaptation of Pseudomonas ogarae F113 to the rhizosphere environment. Front Microbiol 2024; 15:1341728. [PMID: 38333580 PMCID: PMC10850567 DOI: 10.3389/fmicb.2024.1341728] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2023] [Accepted: 01/11/2024] [Indexed: 02/10/2024] Open
Abstract
Regulating the transition of bacteria from motile to sessile lifestyles is crucial for their ability to compete effectively in the rhizosphere environment. Pseudomonas are known to rely on extracellular matrix (ECM) components for microcolony and biofilm formation, allowing them to adapt to a sessile lifestyle. Pseudomonas ogarae F113 possesses eight gene clusters responsible for the production of ECM components. These gene clusters are tightly regulated by AmrZ, a major transcriptional regulator that influences the cellular levels of c-di-GMP. The AmrZ-mediated transcriptional regulation of ECM components is primarily mediated by the signaling molecule c-di-GMP and the flagella master regulator FleQ. To investigate the functional role of these ECM components in P. ogarae F113, we performed phenotypic analyses using mutants in genes encoding these ECM components. These analyses included assessments of colony morphology, dye-staining, static attachment to abiotic surfaces, dynamic biofilm formation on abiotic surfaces, swimming motility, and competitive colonization assays of the rhizosphere. Our results revealed that alginate and PNAG polysaccharides, along with PsmE and the fimbrial low molecular weight protein/tight adherence (Flp/Tad) pilus, are the major ECM components contributing to biofilm formation. Additionally, we found that the majority of these components and MapA are needed for a competitive colonization of the rhizosphere in P. ogarae F113.
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Affiliation(s)
- Esther Blanco-Romero
- Departamento de Biología, Facultad de Ciencias, Universidad Autónoma de Madrid, Madrid, Spain
| | - Daniel Garrido-Sanz
- Departamento de Biología, Facultad de Ciencias, Universidad Autónoma de Madrid, Madrid, Spain
- Department of Fundamental Microbiology, University of Lausanne, Lausanne, Switzerland
| | - David Durán
- Departamento de Biología, Facultad de Ciencias, Universidad Autónoma de Madrid, Madrid, Spain
| | - Morten Rybtke
- Costerton Biofilm Center, Department of Immunology and Microbiology, University of Copenhagen, Copenhagen, Denmark
| | - Tim Tolker-Nielsen
- Costerton Biofilm Center, Department of Immunology and Microbiology, University of Copenhagen, Copenhagen, Denmark
| | - Miguel Redondo-Nieto
- Departamento de Biología, Facultad de Ciencias, Universidad Autónoma de Madrid, Madrid, Spain
| | - Rafael Rivilla
- Departamento de Biología, Facultad de Ciencias, Universidad Autónoma de Madrid, Madrid, Spain
| | - Marta Martín
- Departamento de Biología, Facultad de Ciencias, Universidad Autónoma de Madrid, Madrid, Spain
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11
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Ferguson DL, Gloag ES, Parsek MR, Wozniak DJ. Extracellular DNA enhances biofilm integrity and mechanical properties of mucoid Pseudomonas aeruginosa. J Bacteriol 2023; 205:e0023823. [PMID: 37791754 PMCID: PMC10601617 DOI: 10.1128/jb.00238-23] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2023] [Accepted: 08/31/2023] [Indexed: 10/05/2023] Open
Abstract
Pseudomonas aeruginosa is one of the most common biofilm-forming pathogens responsible for lung infections of individuals with cystic fibrosis (CF). P. aeruginosa becomes tolerant to antimicrobials in the biofilm state and is difficult to treat. Production of extracellular polymeric substances (EPS), such as alginate and extracellular DNA (eDNA), can allow adherence to abiotic and biotic surfaces, antimicrobial evasion, and resilience to environmental pressures. Alginate-producing mucoid variants of P. aeruginosa are frequently isolated from CF airway samples and are associated with worsening patient outcomes. While eDNA is a major structural component of nonmucoid P. aeruginosa biofilms, the potential role of eDNA in mucoid biofilms is unclear. Here, we investigate how eDNA contributes to clinical mucoid biofilm physiology and integrity. We predicted that eDNA plays a structural and mechanical role in mucoid biofilms. To test this, we quantified biofilm eDNA in mucoid biofilms and used microscopy and rheology to visualize eDNA and detect changes in biofilm structure and mechanics upon DNaseI treatment. We showed that biofilm eDNA abundance is diverse across clinical mucoid strains and observed a temporal increase in foci of eDNA within intact mucoid biofilms. Increased cell dispersal and reduced biomass were also observed following DNaseI treatment of mucoid biofilms. Degradation of eDNA also impacted the mechanical integrity of mucoid biofilms by increasing the stiffness and decreasing the cohesion of the biofilm. These findings advance our understanding of clinical mucoid P. aeruginosa biofilms and facilitate the development of new approaches to target biofilms by exploiting the functions of EPS components. IMPORTANCE Understanding the role of eDNA in mucoid Pseudomonas aeruginosa biofilms will lead to therapeutic strategies that combat the biophysical and structural function of EPS for the eradication of bacteria in mucoid biofilms during chronic infections. This knowledge can be used to further identify unknown matrix component interactions within pathogenic biofilm-forming clinical isolates.
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Affiliation(s)
- Danielle L. Ferguson
- Department of Microbial Infection and Immunity, Microbiology, The Ohio State University, Columbus, Ohio, USA
| | - Erin S. Gloag
- Department of Biomedical Sciences and Pathobiology, Virginia-Maryland College of Veterinary Medicine, Virginia Tech, Blacksburg, Virginia, USA
| | - Matthew R. Parsek
- Department of Microbiology, University of Washington, Seattle, Washington, USA
| | - Daniel J. Wozniak
- Department of Microbial Infection and Immunity, Microbiology, The Ohio State University, Columbus, Ohio, USA
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12
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Qun T, Zhou T, Hao J, Wang C, Zhang K, Xu J, Wang X, Zhou W. Antibacterial activities of anthraquinones: structure-activity relationships and action mechanisms. RSC Med Chem 2023; 14:1446-1471. [PMID: 37593578 PMCID: PMC10429894 DOI: 10.1039/d3md00116d] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2023] [Accepted: 05/24/2023] [Indexed: 08/19/2023] Open
Abstract
With the increasing prevalence of untreatable infections caused by antibiotic-resistant bacteria, the discovery of new drugs from natural products has become a hot research topic. The antibacterial activity of anthraquinones widely distributed in traditional Chinese medicine has attracted much attention. Herein, the structure and activity relationships (SARs) of anthraquinones as bacteriostatic agents are reviewed and elucidated. The substituents of anthraquinone and its derivatives are closely related to their antibacterial activities. The stronger the polarity of anthraquinone substituents is, the more potent the antibacterial effects appear. The presence of hydroxyl groups is not necessary for the antibacterial activity of hydroxyanthraquinone derivatives. Substitution of di-isopentenyl groups can improve the antibacterial activity of anthraquinone derivatives. The rigid plane structure of anthraquinone lowers its water solubility and results in the reduced activity. Meanwhile, the antibacterial mechanisms of anthraquinone and its analogs are explored, mainly including biofilm formation inhibition, destruction of the cell wall, endotoxin inhibition, inhibition of nucleic acid and protein synthesis, and blockage of energy metabolism and other substances.
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Affiliation(s)
- Tang Qun
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences 200241 Shanghai China
| | - Tiantian Zhou
- School of Chinese Materia Medica, Guangdong Pharmaceutical University 440113 Guangzhou China
| | - Jiongkai Hao
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences 200241 Shanghai China
| | - Chunmei Wang
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences 200241 Shanghai China
- Key laboratory of Veterinary Chemical Drugs and Pharmaceutics, Ministry of Agriculture and Rural Affairs, Shanghai Research Institute, Chinese Academy of Agricultural Sciences Shanghai 200241 China
| | - Keyu Zhang
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences 200241 Shanghai China
- Key laboratory of Veterinary Chemical Drugs and Pharmaceutics, Ministry of Agriculture and Rural Affairs, Shanghai Research Institute, Chinese Academy of Agricultural Sciences Shanghai 200241 China
| | - Jing Xu
- Huanghua Agricultural and Rural Development Bureau Bohai New Area 061100 Hebei China
| | - Xiaoyang Wang
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences 200241 Shanghai China
- Key laboratory of Veterinary Chemical Drugs and Pharmaceutics, Ministry of Agriculture and Rural Affairs, Shanghai Research Institute, Chinese Academy of Agricultural Sciences Shanghai 200241 China
| | - Wen Zhou
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences 200241 Shanghai China
- Key laboratory of Veterinary Chemical Drugs and Pharmaceutics, Ministry of Agriculture and Rural Affairs, Shanghai Research Institute, Chinese Academy of Agricultural Sciences Shanghai 200241 China
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13
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Ahmad Ansari F, Ahmad I, Pichtel J. Synergistic effects of biofilm-producing PGPR strains on wheat plant colonization, growth and soil resilience under drought stress. Saudi J Biol Sci 2023; 30:103664. [PMID: 37213696 PMCID: PMC10193011 DOI: 10.1016/j.sjbs.2023.103664] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2023] [Revised: 04/03/2023] [Accepted: 04/21/2023] [Indexed: 05/23/2023] Open
Abstract
Drought stress substantially impedes crop productivity throughout the world. Microbial based approaches have been considered a potential possibility and are under study. Based on our prior screening examination, two distinct and novel biofilm-forming PGPR strains namely Bacillus subtilis-FAB1 and Pseudomonas azotoformans-FAP3 are encompassed in this research. Bacterial biofilm development on glass surface, microtiter plate and seedling roots were assessed and characterized quantitatively and qualitatively by light and scanning electron microscopy. Above two isolates were further evaluated for their consistent performance by inoculating on wheat plants in a pot-soil system under water stresses. Bacterial moderate tolerance to ten-day drought was recorded on the application of individual strains with wheat plants; however, the FAB1 + FAP3 consortium expressively improved wheat survival during drought. The strains FAB1 and FAP3 displayed distinct and multifunctional plant growth stimulating attributes as well as effective roots and rhizosphere colonization in combination which could provide sustained wheat growth during drought. FAB1 and FAP3-induced alterations cooperatively conferred improved plant drought tolerance by controlling physiological traits (gs, Ci, E, iWUE and PN), stress indicators (SOD, CAT, GR, proline and MDA content) and also maintained physico-chemical attributes and hydrolytic enzymes including DHA, urease, ALP, protease, ACP and β glucosidase in the soil. Our findings could support future efforts to enhance plant drought tolerance by engineering the rhizobacterial biofilms and associated attributes which requires in-depth exploration and exploiting potential native strains for local agricultural application.
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Affiliation(s)
- Firoz Ahmad Ansari
- Biofilm Research Lab., Department of Agricultural Microbiology, Faculty of Agricultural Sciences, Aligarh Muslim University, Aligarh 202002, India
- Corresponding author at: Department of Agricultural Microbiology Faculty of Agricultural Sciences AMU, Aligarh, India.
| | - Iqbal Ahmad
- Biofilm Research Lab., Department of Agricultural Microbiology, Faculty of Agricultural Sciences, Aligarh Muslim University, Aligarh 202002, India
| | - John Pichtel
- Department of Environment, Geology and Natural Resources, Ball State University, Muncie, IN 47306, USA
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14
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Chung J, Eisha S, Park S, Morris AJ, Martin I. How Three Self-Secreted Biofilm Exopolysaccharides of Pseudomonas aeruginosa, Psl, Pel, and Alginate, Can Each Be Exploited for Antibiotic Adjuvant Effects in Cystic Fibrosis Lung Infection. Int J Mol Sci 2023; 24:ijms24108709. [PMID: 37240055 DOI: 10.3390/ijms24108709] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2023] [Revised: 04/29/2023] [Accepted: 05/10/2023] [Indexed: 05/28/2023] Open
Abstract
In cystic fibrosis (CF), pulmonary infection with Pseudomonas aeruginosa is a cause of increased morbidity and mortality, especially in patients for whom infection becomes chronic and there is reliance on long-term suppressive therapies. Current antimicrobials, though varied mechanistically and by mode of delivery, are inadequate not only due to their failure to eradicate infection but also because they do not halt the progression of lung function decline over time. One of the reasons for this failure is thought to be the biofilm mode of growth of P. aeruginosa, wherein self-secreted exopolysaccharides (EPSs) provide physical protection against antibiotics and an array of niches with resulting metabolic and phenotypic heterogeneity. The three biofilm-associated EPSs secreted by P. aeruginosa (alginate, Psl, and Pel) are each under investigation and are being exploited in ways that potentiate antibiotics. In this review, we describe the development and structure of P. aeruginosa biofilms before examining each EPS as a potential therapeutic target for combating pulmonary infection with P. aeruginosa in CF, with a particular focus on the current evidence for these emerging therapies and barriers to bringing these therapies into clinic.
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Affiliation(s)
- Jonathan Chung
- Department of Translational Medicine, Research Institute, The Hospital for Sick Children, University of Toronto, 686 Bay Street, Toronto, ON M5G 0A4, Canada
| | - Shafinaz Eisha
- Department of Translational Medicine, Research Institute, The Hospital for Sick Children, University of Toronto, 686 Bay Street, Toronto, ON M5G 0A4, Canada
| | - Subin Park
- Department of Translational Medicine, Research Institute, The Hospital for Sick Children, University of Toronto, 686 Bay Street, Toronto, ON M5G 0A4, Canada
| | - Amanda J Morris
- Department of Translational Medicine, Research Institute, The Hospital for Sick Children, University of Toronto, 686 Bay Street, Toronto, ON M5G 0A4, Canada
| | - Isaac Martin
- Department of Translational Medicine, Research Institute, The Hospital for Sick Children, University of Toronto, 686 Bay Street, Toronto, ON M5G 0A4, Canada
- Division of Respiratory Medicine, Department of Paediatrics, The Hospital for Sick Children, University of Toronto, 555 University Avenue, Toronto, ON M5G 1X8, Canada
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15
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Khateb H, Hook AL, Kern S, Watts JA, Singh S, Jackson D, Marinez-Pomares L, Williams P, Alexander MR. Identification of Pseudomonas aeruginosa exopolysaccharide Psl in biofilms using 3D OrbiSIMS. Biointerphases 2023; 18:031007. [PMID: 37255378 PMCID: PMC10234676 DOI: 10.1116/6.0002604] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2023] [Revised: 04/29/2023] [Accepted: 05/09/2023] [Indexed: 06/01/2023] Open
Abstract
Secondary ion mass spectrometry (SIMS) offers advantages over both liquid extraction mass spectrometry and matrix assisted laser desorption mass spectrometry in that it provides the direct in situ analysis of molecules and has the potential to preserve the 3D location of an analyte in a sample. Polysaccharides are recognized as challenging analytes in the mass spectrometry of liquids and are also difficult to identify and assign using SIMS. Psl is an exopolysaccharide produced by Pseudomonas aeruginosa, which plays a key role in biofilm formation and maturation. In this Letter, we describe the use of the OrbiTrap analyzer with SIMS (3D OrbiSIMS) for the label-free mass spectrometry of Psl, taking advantage of its high mass resolving power for accurate secondary ion assignment. We study a P. aeruginosa biofilm and compare it with purified Psl to enable the assignment of secondary ions specific to the Psl structure. This resulted in the identification of 17 peaks that could confidently be ascribed to Psl fragments within the biofilm matrix. The complementary approach of the following neutral loss sequences is also shown to identify multiple oligosaccharide fragments without the requirement of a biological reference sample.
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Affiliation(s)
- Heba Khateb
- Advanced Materials and Healthcare Technologies Division, School of Pharmacy, University of Nottingham, Nottingham, United Kingdom
- National Biofilms Innovation Centre, Biodiscovery Institute and School of Life Sciences, University of Nottingham, Nottingham, United Kingdom
| | - Andrew L Hook
- Advanced Materials and Healthcare Technologies Division, School of Pharmacy, University of Nottingham, Nottingham, United Kingdom
| | - Stefanie Kern
- Nanoscale and Microscale Research Centre, University of Nottingham, Nottingham, United Kingdom
| | - Julie A Watts
- Nanoscale and Microscale Research Centre, University of Nottingham, Nottingham, United Kingdom
| | - Sonali Singh
- National Biofilms Innovation Centre and School of Life Sciences, University of Nottingham, Nottingham, United Kingdom
| | - Darryl Jackson
- National Biofilms Innovation Centre and School of Life Sciences, University of Nottingham, Nottingham, United Kingdom
| | - Luisa Marinez-Pomares
- National Biofilms Innovation Centre and School of Life Sciences, University of Nottingham, Nottingham, United Kingdom
| | - Paul Williams
- National Biofilms Innovation Centre, Biodiscovery Institute and School of Life Sciences, University of Nottingham, Nottingham, United Kingdom
| | - Morgan R Alexander
- Advanced Materials and Healthcare Technologies Division, School of Pharmacy, University of Nottingham, Nottingham, United Kingdom
- National Biofilms Innovation Centre, Biodiscovery Institute and School of Life Sciences, University of Nottingham, Nottingham, United Kingdom
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16
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Balducci E, Papi F, Capialbi DE, Del Bino L. Polysaccharides' Structures and Functions in Biofilm Architecture of Antimicrobial-Resistant (AMR) Pathogens. Int J Mol Sci 2023; 24:ijms24044030. [PMID: 36835442 PMCID: PMC9965654 DOI: 10.3390/ijms24044030] [Citation(s) in RCA: 19] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2023] [Revised: 02/13/2023] [Accepted: 02/14/2023] [Indexed: 02/19/2023] Open
Abstract
Bacteria and fungi have developed resistance to the existing therapies such as antibiotics and antifungal drugs, and multiple mechanisms are mediating this resistance. Among these, the formation of an extracellular matrix embedding different bacterial cells, called biofilm, is an effective strategy through which bacterial and fungal cells are establishing a relationship in a unique environment. The biofilm provides them the possibility to transfer genes conferring resistance, to prevent them from desiccation and to impede the penetration of antibiotics or antifungal drugs. Biofilms are formed of several constituents including extracellular DNA, proteins and polysaccharides. Depending on the bacteria, different polysaccharides form the biofilm matrix in different microorganisms, some of them involved in the first stage of cells' attachment to surfaces and to each other, and some responsible for giving the biofilm structure resistance and stability. In this review, we describe the structure and the role of different polysaccharides in bacterial and fungal biofilms, we revise the analytical methods to characterize them quantitatively and qualitatively and finally we provide an overview of potential new antimicrobial therapies able to inhibit biofilm formation by targeting exopolysaccharides.
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Affiliation(s)
| | | | - Daniela Eloisa Capialbi
- GSK, 53100 Siena, Italy
- Department of Biotechnology, Chemistry and Pharmacy, University of Siena, 53100 Siena, Italy
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17
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Razvi E, Whitfield GB, Reichhardt C, Dreifus JE, Willis AR, Gluscencova OB, Gloag ES, Awad TS, Rich JD, da Silva DP, Bond W, Le Mauff F, Sheppard DC, Hatton BD, Stoodley P, Reinke AW, Boulianne GL, Wozniak DJ, Harrison JJ, Parsek MR, Howell PL. Glycoside hydrolase processing of the Pel polysaccharide alters biofilm biomechanics and Pseudomonas aeruginosa virulence. NPJ Biofilms Microbiomes 2023; 9:7. [PMID: 36732330 PMCID: PMC9894940 DOI: 10.1038/s41522-023-00375-7] [Citation(s) in RCA: 13] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2022] [Accepted: 01/16/2023] [Indexed: 02/04/2023] Open
Abstract
Pel exopolysaccharide biosynthetic loci are phylogenetically widespread biofilm matrix determinants in bacteria. In Pseudomonas aeruginosa, Pel is crucial for cell-to-cell interactions and reducing susceptibility to antibiotic and mucolytic treatments. While genes encoding glycoside hydrolases have long been linked to biofilm exopolysaccharide biosynthesis, their physiological role in biofilm development is unclear. Here we demonstrate that the glycoside hydrolase activity of P. aeruginosa PelA decreases adherent biofilm biomass and is responsible for generating the low molecular weight secreted form of the Pel exopolysaccharide. We show that the generation of secreted Pel contributes to the biomechanical properties of the biofilm and decreases the virulence of P. aeruginosa in Caenorhabditis elegans and Drosophila melanogaster. Our results reveal that glycoside hydrolases found in exopolysaccharide biosynthetic systems can help shape the soft matter attributes of a biofilm and propose that secreted matrix components be referred to as matrix associated to better reflect their influence.
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Affiliation(s)
- Erum Razvi
- Program in Molecular Medicine, The Hospital for Sick Children, Toronto, ON, Canada
- Department of Biochemistry, University of Toronto, Toronto, ON, Canada
| | - Gregory B Whitfield
- Program in Molecular Medicine, The Hospital for Sick Children, Toronto, ON, Canada
- Department of Biochemistry, University of Toronto, Toronto, ON, Canada
- Département de Microbiologie, Infectiologie, et Immunologie, Faculté de Médecine Université de Montréal, Montréal, QC, Canada
| | - Courtney Reichhardt
- Department of Microbiology, University of Washington, Seattle, WA, USA
- Department of Chemistry, Washington University, St. Louis, MO, USA
| | - Julia E Dreifus
- Department of Microbiology, University of Washington, Seattle, WA, USA
| | - Alexandra R Willis
- Department of Molecular Genetics, University of Toronto, Toronto, ON, Canada
| | - Oxana B Gluscencova
- Program in Developmental and Stem Cell Biology, The Hospital for Sick Children, Toronto, ON, Canada
| | - Erin S Gloag
- Department of Microbial Infection and Immunity, The Ohio State University, Columbus, OH, 43210, USA
- Department of Biomedical Sciences and Pathobiology, VA-MD College of Veterinary Medicine, Virginia Tech, VA, 24061, USA
| | - Tarek S Awad
- Department of Materials Science and Engineering, University of Toronto, Toronto, ON, Canada
| | - Jacquelyn D Rich
- Department of Biological Sciences, University of Calgary, Calgary, AB, Canada
| | - Daniel Passos da Silva
- Department of Microbiology, University of Washington, Seattle, WA, USA
- BioVectra Inc. 11 Aviation, Charlottetown, PE, Canada
| | - Whitney Bond
- Department of Microbiology, University of Washington, Seattle, WA, USA
| | - François Le Mauff
- Department of Microbiology and Immunology, Faculty of Medicine, McGill University, Montreal, QC, Canada
- Infectious Disease and Immunity in Global Health, Research Institute of the McGill University Health Centre, Montreal, QC, Canada
- McGill Interdisciplinary Initiative in Infection and Immunity, Montreal, QC, Canada
| | - Donald C Sheppard
- Department of Microbiology and Immunology, Faculty of Medicine, McGill University, Montreal, QC, Canada
- Infectious Disease and Immunity in Global Health, Research Institute of the McGill University Health Centre, Montreal, QC, Canada
- McGill Interdisciplinary Initiative in Infection and Immunity, Montreal, QC, Canada
| | - Benjamin D Hatton
- Department of Materials Science and Engineering, University of Toronto, Toronto, ON, Canada
| | - Paul Stoodley
- Department of Microbial Infection and Immunity, The Ohio State University, Columbus, OH, 43210, USA
- Department of Orthopedics, The Ohio State University, Columbus, OH, 43210, USA
- National Biofilm Innovation Centre (NBIC) and National Centre for Advanced Tribology at Southampton (nCATS), University of Southampton, Southampton, SO17 1BJ, UK
- Department of Microbiology, The Ohio State University, Columbus, OH, 43210, USA
| | - Aaron W Reinke
- Department of Molecular Genetics, University of Toronto, Toronto, ON, Canada
| | - Gabrielle L Boulianne
- Department of Molecular Genetics, University of Toronto, Toronto, ON, Canada
- Program in Developmental and Stem Cell Biology, The Hospital for Sick Children, Toronto, ON, Canada
| | - Daniel J Wozniak
- Department of Microbial Infection and Immunity, The Ohio State University, Columbus, OH, 43210, USA
- Department of Microbiology, The Ohio State University, Columbus, OH, 43210, USA
| | - Joe J Harrison
- Department of Biological Sciences, University of Calgary, Calgary, AB, Canada
| | - Matthew R Parsek
- Department of Microbiology, University of Washington, Seattle, WA, USA
| | - P Lynne Howell
- Program in Molecular Medicine, The Hospital for Sick Children, Toronto, ON, Canada.
- Department of Biochemistry, University of Toronto, Toronto, ON, Canada.
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18
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Grossich R, Lemos Vilches M, Costa CS, Pezzoni M. Role of Pel and Psl polysaccharides in the response of Pseudomonas aeruginosa to environmental challenges: oxidative stress agents (UVA, H 2O 2, sodium hypochlorite) and its competitor Staphylococcus aureus. MICROBIOLOGY (READING, ENGLAND) 2023; 169. [PMID: 36757866 DOI: 10.1099/mic.0.001301] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/10/2023]
Abstract
Pseudomonas aeruginosa is a versatile bacterium capable of adapting to a wide range of stress factors, including solar UVA radiation (400-315 nm). High UVA doses produce lethal effects due to the action of reactive oxygen species. Sublethal UVA doses also induces oxidative damage, but, in addition, it triggers a variety of adaptive responses, including the overexpression of pelA and pslA genes in P. aeruginosa. These genes encode the synthesis of Pel and Psl, which are essential polysaccharides in biofilm formation. The present study analysed the role of Pel and Psl in the adaptive responses generated by exposure to low UVA doses, and their importance in the response to lethal doses of UVA, hydrogen peroxide (H2O2), and sodium hypochlorite, in both planktonic cells and submerged and air-liquid interface (ALI) biofilms. It also studied the roles of Pel and Psl in P. aeruginosa-Staphylococcus aureus interaction. The results demonstrate that the capacity of sublethal UVA exposure to increase cell hydrophobicity and cell attachment and generate cross-protection phenomena in P. aeruginosa depends on the presence of Pel and Psl. The study also shows that Pel and Psl have a key role in the tolerance to lethal doses of UVA radiation, sodium hypochlorite and H2O2, in both biofilms and planktonic cells. Finally, co-culture assays showed total inhibition of S. aureus growth in presence of P. aeruginosa. This phenomenon depends, at least in part, on the simultaneous presence of Pel and Psl in planktonic cells and biofilms, suggesting a relevant role of these polysaccharides in the interaction between these species.
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Affiliation(s)
- Romina Grossich
- Departamento de Radiobiología, Comision Nacional de Energía Atómica, San Martín, Buenos Aires, Argentina
| | - Martín Lemos Vilches
- Departamento de Radiobiología, Comision Nacional de Energía Atómica, San Martín, Buenos Aires, Argentina
| | - Cristina S Costa
- Departamento de Radiobiología, Comision Nacional de Energía Atómica, San Martín, Buenos Aires, Argentina
| | - Magdalena Pezzoni
- Departamento de Radiobiología, Comision Nacional de Energía Atómica, San Martín, Buenos Aires, Argentina
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19
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Genome-wide screen in human plasma identifies multifaceted complement evasion of Pseudomonas aeruginosa. PLoS Pathog 2023; 19:e1011023. [PMID: 36696456 PMCID: PMC9901815 DOI: 10.1371/journal.ppat.1011023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2022] [Revised: 02/06/2023] [Accepted: 11/23/2022] [Indexed: 01/26/2023] Open
Abstract
Pseudomonas aeruginosa, an opportunistic Gram-negative pathogen, is a leading cause of bacteremia with a high mortality rate. We recently reported that P. aeruginosa forms a persister-like sub-population of evaders in human plasma. Here, using a gain-of-function transposon sequencing (Tn-seq) screen in plasma, we identified and validated previously unknown factors affecting bacterial persistence in plasma. Among them, we identified a small periplasmic protein, named SrgA, whose expression leads to up to a 100-fold increase in resistance to killing. Additionally, mutants in pur and bio genes displayed higher tolerance and persistence, respectively. Analysis of several steps of the complement cascade and exposure to an outer-membrane-impermeable drug, nisin, suggested that the mutants impede membrane attack complex (MAC) activity per se. Electron microscopy combined with energy-dispersive X-ray spectroscopy (EDX) revealed the formation of polyphosphate (polyP) granules upon incubation in plasma of different size in purD and wild-type strains, implying the bacterial response to a stress signal. Indeed, inactivation of ppk genes encoding polyP-generating enzymes lead to significant elimination of persisting bacteria from plasma. Through this study, we shed light on a complex P. aeruginosa response to the plasma conditions and discovered the multifactorial origin of bacterial resilience to MAC-induced killing.
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20
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Ellis JR, Bull JJ, Rowley PA. Fungal Glycoside Hydrolases Display Unique Specificities for Polysaccharides and Staphylococcus aureus Biofilms. Microorganisms 2023; 11:microorganisms11020293. [PMID: 36838258 PMCID: PMC9964650 DOI: 10.3390/microorganisms11020293] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2022] [Revised: 01/14/2023] [Accepted: 01/16/2023] [Indexed: 01/26/2023] Open
Abstract
Commercially available cellulases and amylases can disperse the pathogenic bacteria embedded in biofilms. This suggests that polysaccharide-degrading enzymes would be useful as antibacterial therapies to aid the treatment of biofilm-associated bacteria, e.g., in chronic wounds. Using a published enzyme library, we explored the capacity of 76 diverse recombinant glycoside hydrolases to disperse Staphylococcus aureus biofilms. Four of the 76 recombinant glycoside hydrolases digested purified cellulose, amylose, or pectin. However, these enzymes did not disperse biofilms, indicating that anti-biofilm activity is not general to all glycoside hydrolases and that biofilm activity cannot be predicted from the activity on pure substrates. Only one of the 76 recombinant enzymes was detectably active in biofilm dispersion, an α-xylosidase from Aspergillus nidulans. An α-xylosidase cloned subsequently from Aspergillus thermomutatus likewise demonstrated antibiofilm activity, suggesting that α-xylosidases, in general, can disperse Staphylococcus biofilms. Surprisingly, neither of the two β-xylosidases in the library degraded biofilms. Commercial preparations of amylase and cellulase that are known to be effective in the dispersion of Staphylococcus biofilms were also analyzed. The commercial cellulase contained contaminating proteins with multiple enzymes exhibiting biofilm-dispersing activity. Successfully prospecting for additional antibiofilm enzymes may thus require large libraries and may benefit from purified enzymes. The complexity of biofilms and the diversity of glycoside hydrolases continue to make it difficult to predict or understand the enzymes that could have future therapeutic applications.
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Affiliation(s)
- Jeremy R. Ellis
- Department of Biological Sciences, University of Idaho, Moscow, ID 83844, USA
- The Johns Hopkins University School of Medicine, Johns Hopkins University, Baltimore, MD 21205, USA
| | - James J. Bull
- Department of Biological Sciences, University of Idaho, Moscow, ID 83844, USA
| | - Paul A. Rowley
- Department of Biological Sciences, University of Idaho, Moscow, ID 83844, USA
- Correspondence:
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21
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Coppola D, Buonocore C, Palisse M, Tedesco P, de Pascale D. Exploring Oceans for Curative Compounds: Potential New Antimicrobial and Anti-Virulence Molecules against Pseudomonas aeruginosa. Mar Drugs 2022; 21:9. [PMID: 36662182 PMCID: PMC9865402 DOI: 10.3390/md21010009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2022] [Revised: 12/16/2022] [Accepted: 12/20/2022] [Indexed: 12/28/2022] Open
Abstract
Although several antibiotics are already widely used against a large number of pathogens, the discovery of new antimicrobial compounds with new mechanisms of action is critical today in order to overcome the spreading of antimicrobial resistance among pathogen bacteria. In this regard, marine organisms represent a potential source of a wide diversity of unique secondary metabolites produced as an adaptation strategy to survive in competitive and hostile environments. Among the multidrug-resistant Gram-negative bacteria, Pseudomonas aeruginosa is undoubtedly one of the most important species due to its high intrinsic resistance to different classes of antibiotics on the market and its ability to cause serious therapeutic problems. In the present review, we first discuss the general mechanisms involved in the antibiotic resistance of P. aeruginosa. Subsequently, we list the marine molecules identified up until now showing activity against P. aeruginosa, dividing them according to whether they act as antimicrobial or anti-virulence compounds.
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Affiliation(s)
- Daniela Coppola
- Department of Ecosustainable Marine Biotechnology, Stazione Zoologica Anton Dohrn, Via Ammiraglio Ferdinando Acton 55, 80133 Naples, Italy
| | - Carmine Buonocore
- Department of Ecosustainable Marine Biotechnology, Stazione Zoologica Anton Dohrn, Via Ammiraglio Ferdinando Acton 55, 80133 Naples, Italy
| | - Morgan Palisse
- Département des Sciences de la Vie et de la Terre, Université de Caen Normandie, Boulevard Maréchal Juin CS, CEDEX, 14032 Caen, France
| | - Pietro Tedesco
- Department of Ecosustainable Marine Biotechnology, Stazione Zoologica Anton Dohrn, Via Ammiraglio Ferdinando Acton 55, 80133 Naples, Italy
| | - Donatella de Pascale
- Department of Ecosustainable Marine Biotechnology, Stazione Zoologica Anton Dohrn, Via Ammiraglio Ferdinando Acton 55, 80133 Naples, Italy
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22
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Illuminating the signalomics of microbial biofilm on plant surfaces. BIOCATALYSIS AND AGRICULTURAL BIOTECHNOLOGY 2022. [DOI: 10.1016/j.bcab.2022.102537] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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23
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Role of Exopolysaccharides of Pseudomonas in Heavy Metal Removal and Other Remediation Strategies. Polymers (Basel) 2022; 14:polym14204253. [PMID: 36297831 PMCID: PMC9609410 DOI: 10.3390/polym14204253] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2022] [Revised: 10/05/2022] [Accepted: 10/07/2022] [Indexed: 11/30/2022] Open
Abstract
Pseudomonas biofilms have been studied intensively for several decades and research outcomes have been successfully implemented in various medical and agricultural applications. Research on biofilm synthesis and composition has also overlapped with the objectives of environmental sciences, since biofilm components show exceptional physicochemical properties applicable to remediation techniques. Especially, exopolysaccharides (ExPs) have been at the center of scientific interest, indicating their potential in solving the environmental issues of heavy metal land and water contamination via sorptive interactions and flocculation. Since exposure to heavy metal via contaminated water or soil poses an imminent risk to the environment and human health, ExPs provide an interesting and viable solution to this issue, alongside other effective and green remedial techniques (e.g., phytostabilization, implementation of biosolids, and biosorption using agricultural wastes) aiming to restore contaminated sites to their natural, pollution-free state, or to ameliorate the negative impact of heavy metals on the environment. Thus, we discuss the plausible role and performance of Pseudomonas ExPs in remediation techniques, aiming to provide the relevant available and comprehensive information on ExPs’ biosynthesis and their usage in heavy metal remediation or other environmental applications, such as wastewater treatment via bioflocculation and soil remediation.
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Planet PJ. Adaptation and Evolution of Pathogens in the Cystic Fibrosis Lung. J Pediatric Infect Dis Soc 2022; 11:S23-S31. [PMID: 36069898 PMCID: PMC9451014 DOI: 10.1093/jpids/piac073] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/24/2022] [Accepted: 07/11/2022] [Indexed: 02/05/2023]
Abstract
As opposed to acute respiratory infections, the persistent bacterial infections of the lung that characterize cystic fibrosis (CF) provide ample time for bacteria to evolve and adapt. The process of adaptation is recorded in mutations that accumulate over time in the genomes of the infecting bacteria. Some of these mutations lead to obvious phenotypic differences such as antibiotic resistance or the well-known mucoid phenotype of Pseudomonas aeruginosa. Other mutations may be just as important but harder to detect such as increased mutation rates, cell surface changes, and shifts in metabolism and nutrient acquisition. Remarkably, many of the adaptations occur again and again in different patients, signaling that bacteria are adapting to solve specific challenges in the CF respiratory tract. This parallel evolution even extends across distinct bacterial species. This review addresses the bacterial systems that are known to change in long-term CF infections with a special emphasis on cross-species comparisons. Consideration is given to how adaptation may impact health in CF, and the possible evolutionary mechanisms that lead to the repeated parallel adaptations.
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Affiliation(s)
- Paul J Planet
- Corresponding Author: Paul J. Planet, MD, PhD, 3615 Civic Center Blvd, Philadelphia, PA 19104. E-mail:
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Phuengmaung P, Mekjaroen J, Saisorn W, Chatsuwan T, Somparn P, Leelahavanichkul A. Rapid Synergistic Biofilm Production of Pseudomonas and Candida on the Pulmonary Cell Surface and in Mice, a Possible Cause of Chronic Mixed Organismal Lung Lesions. Int J Mol Sci 2022; 23:ijms23169202. [PMID: 36012475 PMCID: PMC9409386 DOI: 10.3390/ijms23169202] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2022] [Revised: 08/12/2022] [Accepted: 08/15/2022] [Indexed: 11/16/2022] Open
Abstract
Due to the possible co-presence of Pseudomonas aeruginosa and Candida albicans (the most common nosocomial pathogens) in lungs, rapid interkingdom biofilm production is possible. As such, PA+CA produced more dominant biofilms on the pulmonary epithelial surface (NCI-H292) (confocal fluorescent extracellular matrix staining) with dominant psl upregulation, as demonstrated by polymerase chain reaction (PCR), after 8 h of experiments than PA alone. With a proteomic analysis, rhamnosyltransferase RhlB protein (Psl-associated quorum-sensing protein) was found to be among the high-abundance proteins in PA+CA than in PA biofilms, supporting psl-mediated biofilms in PA+CA on the cell surface. Additionally, PA+CA increased supernatant cytokines (IL-8 and IL-13, but not TNF-α, IL-6, and IL-10) with a similar upregulation of TLR-4, TLR-5, and TLR-9 (by PCR) compared with PA-stimulated cells. The intratracheal administration of PA+CA induced a greater severity of sepsis (serum creatinine, alanine transaminase, serum cytokines, and histology score) and prominent biofilms (fluorescent staining) with psl upregulation (PCR). In comparison with PA+CA biofilms on glass slides, PA+CA biofilms on biotic surfaces were more prominent (fluorescent staining). In conclusion, PA+CA induced Psl-predominant biofilms on the pulmonary cell surface and in mice with acute pneumonia, and these biofilms were more prominent than those induced by PA alone, highlighting the impact of Candida on rapid interkingdom biofilm production.
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Affiliation(s)
- Pornpimol Phuengmaung
- Department of Microbiology, Faculty of Medicine, Chulalongkorn University, Bangkok 10330, Thailand
- Center of Excellence on Translational Research in Inflammation and Immunology (CETRII), Department of Microbiology, Faculty of Medicine, Chulalongkorn University, Bangkok 10330, Thailand
| | - Jiradej Mekjaroen
- Center of Excellence in Systems Biology, Research Affairs, Faculty of Medicine, Chulalongkorn University, Bangkok 10330, Thailand
| | - Wilasinee Saisorn
- Department of Microbiology, Faculty of Medicine, Chulalongkorn University, Bangkok 10330, Thailand
- Center of Excellence on Translational Research in Inflammation and Immunology (CETRII), Department of Microbiology, Faculty of Medicine, Chulalongkorn University, Bangkok 10330, Thailand
| | - Tanittha Chatsuwan
- Department of Microbiology, Faculty of Medicine, Chulalongkorn University, Bangkok 10330, Thailand
| | - Poorichaya Somparn
- Center of Excellence in Systems Biology, Research Affairs, Faculty of Medicine, Chulalongkorn University, Bangkok 10330, Thailand
- Correspondence: (P.S.); (A.L.); Tel.: +66-2-256-4251 (P.S. & A.L.); Fax: +66-2-252-6920 (P.S. & A.L.)
| | - Asada Leelahavanichkul
- Department of Microbiology, Faculty of Medicine, Chulalongkorn University, Bangkok 10330, Thailand
- Center of Excellence on Translational Research in Inflammation and Immunology (CETRII), Department of Microbiology, Faculty of Medicine, Chulalongkorn University, Bangkok 10330, Thailand
- Correspondence: (P.S.); (A.L.); Tel.: +66-2-256-4251 (P.S. & A.L.); Fax: +66-2-252-6920 (P.S. & A.L.)
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Preclinical Evaluation of Recombinant Microbial Glycoside Hydrolases as Antibiofilm Agents in Acute Pulmonary Pseudomonas aeruginosa Infection. Antimicrob Agents Chemother 2022; 66:e0005222. [PMID: 35862738 PMCID: PMC9380554 DOI: 10.1128/aac.00052-22] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
The bacterium Pseudomonas aeruginosa can colonize the airways of patients with chronic lung disease. Within the lung, P. aeruginosa forms biofilms that can enhance resistance to antibiotics and immune defenses. P. aeruginosa biofilm formation is dependent on the secretion of matrix exopolysaccharides, including Pel and Psl. In this study, recombinant glycoside hydrolases (GHs) that degrade Pel and Psl were evaluated alone and in combination with antibiotics in a mouse model of P. aeruginosa infection. Intratracheal GH administration was well tolerated by mice. Pharmacokinetic analysis revealed that, although GHs have short half-lives, administration of two GHs in combination resulted in increased GH persistence. Combining GH prophylaxis and treatment with the antibiotic ciprofloxacin resulted in greater reduction in pulmonary bacterial burden than that with either agent alone. This study lays the foundation for further exploration of GH therapy in bacterial infections.
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Shahid M, Al-Khattaf FS, Danish M, Zeyad MT, Atef Hatamleh A, Mohamed A, Ali S. PGPR Kosakonia Radicincitans KR-17 Increases the Salt Tolerance of Radish by Regulating Ion-Homeostasis, Photosynthetic Molecules, Redox Potential, and Stressor Metabolites. FRONTIERS IN PLANT SCIENCE 2022; 13:919696. [PMID: 35979076 PMCID: PMC9376370 DOI: 10.3389/fpls.2022.919696] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/13/2022] [Accepted: 06/10/2022] [Indexed: 05/10/2023]
Abstract
Among abiotic stresses, salinity is a significant limiting factor affecting agricultural productivity, survival, and production, resulting in significant economic losses. Considering the salinity problem, the goal of this study was to identify a halotolerant beneficial soil bacterium to circumvent salinity-induced phytotoxicity. Here, strain KR-17 (having an irregular margin; a mucoid colony; Gm-ve short rod; optimum temperature, 30°C; pH 7.0; no any pigmentation; showed a positive response to citrate utilization, catalase, starch, sucrose, lactose, and dextrose, etc.) recovered from rhizosphere soils of the potato-cultivating field, tolerated surprisingly a high (18% NaCl; 3.-M concentration) level of salt and identified as Kosakonia radicincitans (Accession No. OM348535). This strain was discovered to be metabolically active, synthesized essential PGP bioactive molecules like indole-3-acetic acid (IAA), siderophore (iron-chelating compounds), ACC deaminase, and ammonia, the quantity of which, however, increased with increasing NaCl concentrations. Here, Raphanus sativus L. (radish) was taken as a model crop to evaluate the adverse impact of NaCl, as well as salinity alleviation by halotolerant K. radicincitans. Salinity-induced toxicity to R. sativus was increased in a dose-dependent way, as observed both in vitro and in vivo conditions. Maximum NaCl levels (15%) demonstrated more extreme harm and considerably reduced the plant's biological features. However, membrane damage, relative leaf water content (RLWC), stressor metabolites, and antioxidant enzymes were increased as NaCl concentration increased. In contrast, halotolerant K. radicincitans KR-17 relieved salinity stress and enhanced the overall performance of R. sativus (L.) by increasing germination efficiency, dry biomass, and leaf pigments even in salt-challenged conditions. Additionally, KR-17 inoculation significantly (p ≤ 0.05) improved plant mineral nutrients (Na, K, Ca, Mg, Zn, Fe, Cu, P, and N). Following inoculation, strain KR-17 enhanced the protein, carbohydrates, root pigments, amino acids (AsA and Lys), lipids, and root alkaloids in R. sativus (L.). Besides these, due to PGPR seed priming in NaCl-stressed/non-stressed conditions, membrane damage, RLWC, stressor metabolites, and antioxidant defense enzymes were dramatically reduced. The strong biofilm-forming capacity of K. radicincitans could result in both in vitro and in vivo colonization under NaCl stress. Conclusively, halotolerant K. radicincitans KR-17 may probably be investigated affordably as the greatest way to increase the production of radish under salinity-stressed soils.
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Affiliation(s)
- Mohammad Shahid
- Department of Agricultural Microbiology, Faculty of Agricultural Sciences, Aligarh Muslim University, Aligarh, India
| | - Fatimah S. Al-Khattaf
- Department of Botany and Microbiology, College of Sciences, King Saud University, Riyadh, Saudi Arabia
| | - Mohammad Danish
- Section of Plant Pathology and Nematology, Department of Botany, Aligarh Muslim University, Aligarh, India
| | | | - Ashraf Atef Hatamleh
- Department of Botany and Microbiology, College of Sciences, King Saud University, Riyadh, Saudi Arabia
| | | | - Sajad Ali
- Department of Biotechnology, Yeungnam University, Gyeongsan, South Korea
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Singkham-In U, Phuengmaung P, Makjaroen J, Saisorn W, Bhunyakarnjanarat T, Chatsuwan T, Chirathaworn C, Chancharoenthana W, Leelahavanichkul A. Chlorhexidine Promotes Psl Expression in Pseudomonas aeruginosa That Enhances Cell Aggregation with Preserved Pathogenicity Demonstrates an Adaptation against Antiseptic. Int J Mol Sci 2022; 23:ijms23158308. [PMID: 35955437 PMCID: PMC9368580 DOI: 10.3390/ijms23158308] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2022] [Revised: 07/20/2022] [Accepted: 07/25/2022] [Indexed: 11/16/2022] Open
Abstract
Because Pseudomonas aeruginosa is frequently in contact with Chlorhexidine (a regular antiseptic), bacterial adaptations are possible. In comparison with the parent strain, the Chlorhexidine-adapted strain formed smaller colonies with metabolic downregulation (proteomic analysis) with the cross-resistance against colistin (an antibiotic for several antibiotic-resistant bacteria), partly through the modification of L-Ara4N in the lipopolysaccharide at the outer membrane. Chlorhexidine-adapted strain formed dense liquid–solid interface biofilms with enhanced cell aggregation partly due to the Chlorhexidine-induced overexpression of psl (exopolysaccharide-encoded gene) through the LadS/GacSA pathway (c-di-GMP-independence) in 12 h biofilms and maintained the aggregation with SiaD-mediated c-di-GMP dependence in 24 h biofilms as evaluated by polymerase chain reaction (PCR). The addition of Ca2+ in the Chlorhexidine-adapted strain facilitated several Psl-associated genes, indicating an impact of Ca2+ in Psl production. The activation by Chlorhexidine-treated sessile bacteria demonstrated a lower expression of IL-6 and IL-8 on fibroblasts and macrophages than the activation by the parent strain, indicating the less inflammatory reactions from Chlorhexidine-exposed bacteria. However, the 14-day severity of the wounds in mouse caused by Chlorhexidine-treated bacteria versus the parent strain was similar, as indicated by wound diameters and bacterial burdens. In conclusion, Chlorhexidine induced psl over-expression and colistin cross-resistance that might be clinically important.
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Affiliation(s)
- Uthaibhorn Singkham-In
- Department of Microbiology, Faculty of Medicine, Chulalongkorn University, 1873 Rama 4 Road, Pathumwan, Bangkok 10330, Thailand; (U.S.-I.); (P.P.); (C.C.)
| | - Pornpimol Phuengmaung
- Department of Microbiology, Faculty of Medicine, Chulalongkorn University, 1873 Rama 4 Road, Pathumwan, Bangkok 10330, Thailand; (U.S.-I.); (P.P.); (C.C.)
| | - Jiradej Makjaroen
- Center of Excellence in Systems Biology, Faculty of Medicine, Chulalongkorn University, 1873 Rama 4 Road, Pathumwan, Bangkok 10330, Thailand;
| | - Wilasinee Saisorn
- Translational Research in Inflammation and Immunology Research Unit (TRIRU), Department of Microbiology, Faculty of Medicine, Chulalongkorn University, 1873 Rama 4 Road, Pathumwan, Bangkok 10330, Thailand; (W.S.); (T.B.)
| | - Thansita Bhunyakarnjanarat
- Translational Research in Inflammation and Immunology Research Unit (TRIRU), Department of Microbiology, Faculty of Medicine, Chulalongkorn University, 1873 Rama 4 Road, Pathumwan, Bangkok 10330, Thailand; (W.S.); (T.B.)
| | - Tanittha Chatsuwan
- Antimicrobial Resistance and Stewardship Research Unit, Department of Microbiology, Faculty of Medicine, Chulalongkorn University, 1873 Rama 4 Road, Pathumwan, Bangkok 10330, Thailand;
| | - Chintana Chirathaworn
- Department of Microbiology, Faculty of Medicine, Chulalongkorn University, 1873 Rama 4 Road, Pathumwan, Bangkok 10330, Thailand; (U.S.-I.); (P.P.); (C.C.)
| | - Wiwat Chancharoenthana
- Tropical Nephrology Research Unit, Department of Clinical Tropical Medicine, Faculty of Tropical Medicine, Mahidol University, Bangkok 10400, Thailand
- Correspondence: (W.C.); (A.L.); Tel.: +66-2-306-9130 (W.C.); +66-2-256-4251 (A.L.); Fax: +66-2-354-9150 (W.C.); +66-2-252-6920 (A.L.)
| | - Asada Leelahavanichkul
- Translational Research in Inflammation and Immunology Research Unit (TRIRU), Department of Microbiology, Faculty of Medicine, Chulalongkorn University, 1873 Rama 4 Road, Pathumwan, Bangkok 10330, Thailand; (W.S.); (T.B.)
- Correspondence: (W.C.); (A.L.); Tel.: +66-2-306-9130 (W.C.); +66-2-256-4251 (A.L.); Fax: +66-2-354-9150 (W.C.); +66-2-252-6920 (A.L.)
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29
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McSorley JC, MacFadyen AC, Kerr L, Tucker NP. Host lysolipid differentially modulates virulence factor expression and antimicrobial susceptibility in Pseudomonas aeruginosa. MICROBIOLOGY (READING, ENGLAND) 2022; 168. [PMID: 35796718 DOI: 10.1099/mic.0.001179] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Lysophosphatidic acid (LPA) occurs naturally in inflammatory exudates and has previously been shown to increase the susceptibility of Pseudomonas aeruginosa to β-lactam antibiotics whilst concomitantly reducing accumulation of the virulence factors pyoverdine and elastase. Here it is demonstrated that LPA can also exert inhibitory effects upon pyocyanin production in P. aeruginosa, as well as influencing susceptibility to a wide range of chemically diverse non β-lactam antimicrobials. Most strikingly, LPA markedly antagonizes the effect of the polycationic antibiotics colistin and tobramycin at a concentration of 250 µg ml-1 whilst conversely enhancing their efficacy at the lower concentration of 8.65 µg ml-1, approximating the maximal physiological concentrations found in inflammatory exudates. Transcriptomic responses of the virulent strain UCBPP-PA14 to LPA were analysed using RNA-sequencing along with BioLog phenoarrays and whole cell assays in attempts to delineate possible mechanisms underlying these effects. The results strongly suggest involvement of LPA-induced carbon catabolite repression together with outer-membrane (OM) stress responses whilst raising questions about the effect of LPA upon other P. aeruginosa virulence factors including type III secretion. This could have clinical relevance as it suggests that endogenous LPA may, at concentrations found in vivo, differentially modulate antibiotic susceptibility of P. aeruginosa whilst simultaneously regulating expression of virulence factors, thereby influencing host-pathogen interactions during infection. The possibility of applying exogenous LPA locally as an enhancer of select antibiotics merits further investigation.
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Affiliation(s)
- James C McSorley
- Strathclyde Institute of Pharmacy and Biomedical Sciences, University of Strathclyde, Glasgow, UK
| | - Alison C MacFadyen
- Institute of Biodiversity, Animal Health & Comparative Medicine, Graham Kerr Building, University of Glasgow, Glasgow, G12 8QQ, UK
| | - Leena Kerr
- Institute of Life and Earth Sciences, School of Energy, Geoscience, Infrastructure and Society, Heriot-Watt University, Riccarton, Edinburgh EH14 4AS, UK
| | - Nicholas Peter Tucker
- Strathclyde Institute of Pharmacy and Biomedical Sciences, University of Strathclyde, Glasgow, UK
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Dias BB, Carreño F, Helfer VE, Garzella PMB, de Lima DMF, Barreto F, de Araújo BV, Dalla Costa T. Probability of Target Attainment of Tobramycin Treatment in Acute and Chronic Pseudomonas aeruginosa Lung Infection Based on Preclinical Population Pharmacokinetic Modeling. Pharmaceutics 2022; 14:pharmaceutics14061237. [PMID: 35745809 PMCID: PMC9228144 DOI: 10.3390/pharmaceutics14061237] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2022] [Revised: 05/27/2022] [Accepted: 06/06/2022] [Indexed: 02/01/2023] Open
Abstract
Biofilms and infectious process may alter free antimicrobial concentrations at the site of infection. Tobramycin (TOB), an aminoglycoside used to treat lung infections caused by Pseudomonas aeruginosa, binds to alginate present in biofilm extracellular matrix increasing its minimum inhibitory concentration (MIC). This work aimed to investigate the impact of biofilm-forming P. aeruginosa infection on TOB lung and epithelial lining fluid (ELF) penetration, using microdialysis, and to develop a population pharmacokinetic (popPK) model to evaluate the probability of therapeutic target attainment of current dosing regimens employed in fibrocystic and non-fibrocystic patients. The popPK model developed has three compartments including the lung. The ELF concentrations were described by a penetration factor derived from the lung compartment. Infection was a covariate in lung volume (V3) and only chronic infection was a covariate in central volume (V1) and total clearance (CL). Simulations of the recommended treatments for acute and chronic infection achieved >90% probability of target attainment (PTA) in the lung with 4.5 mg/kg q24h and 11 mg/kg q24h, respectively, for the most prevalent P. aeruginosa MIC (0.5 mg/mL). The popPK model was successfully applied to evaluate the PTA of current TOB dosing regimens used in the clinic, indicating the need to investigate alternative posology.
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Affiliation(s)
- Bruna Bernar Dias
- Pharmaceutical Sciences Graduate Program, Federal University of Rio Grande do Sul–UFRGS, Porto Alegre 90610-000, Brazil; (B.B.D.); (V.E.H.); (P.M.B.G.); (D.M.F.d.L.); (B.V.d.A.)
| | - Fernando Carreño
- Eshelman School of Pharmacy, University of North Carolina, Chapel Hill, NC 27599, USA;
| | - Victória Etges Helfer
- Pharmaceutical Sciences Graduate Program, Federal University of Rio Grande do Sul–UFRGS, Porto Alegre 90610-000, Brazil; (B.B.D.); (V.E.H.); (P.M.B.G.); (D.M.F.d.L.); (B.V.d.A.)
| | - Priscila Martini Bernardi Garzella
- Pharmaceutical Sciences Graduate Program, Federal University of Rio Grande do Sul–UFRGS, Porto Alegre 90610-000, Brazil; (B.B.D.); (V.E.H.); (P.M.B.G.); (D.M.F.d.L.); (B.V.d.A.)
| | - Daiane Maria Fonseca de Lima
- Pharmaceutical Sciences Graduate Program, Federal University of Rio Grande do Sul–UFRGS, Porto Alegre 90610-000, Brazil; (B.B.D.); (V.E.H.); (P.M.B.G.); (D.M.F.d.L.); (B.V.d.A.)
| | - Fabiano Barreto
- Federal Laboratory of Animal and Plant Health and Inspection–LFDA/RS, Porto Alegre 90610-000, Brazil;
| | - Bibiana Verlindo de Araújo
- Pharmaceutical Sciences Graduate Program, Federal University of Rio Grande do Sul–UFRGS, Porto Alegre 90610-000, Brazil; (B.B.D.); (V.E.H.); (P.M.B.G.); (D.M.F.d.L.); (B.V.d.A.)
| | - Teresa Dalla Costa
- Pharmaceutical Sciences Graduate Program, Federal University of Rio Grande do Sul–UFRGS, Porto Alegre 90610-000, Brazil; (B.B.D.); (V.E.H.); (P.M.B.G.); (D.M.F.d.L.); (B.V.d.A.)
- Correspondence:
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UVA as environmental signal for alginate production in Pseudomonas aeruginosa: role of this polysaccharide in the protection of planktonic cells and biofilms against lethal UVA doses. Photochem Photobiol Sci 2022; 21:1459-1472. [PMID: 35551642 DOI: 10.1007/s43630-022-00236-w] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2022] [Accepted: 04/19/2022] [Indexed: 10/18/2022]
Abstract
Pseudomonas aeruginosa is an extremely versatile microorganism that survives in a wide variety of niches. It is capable to respond rapidly to changes in the environment by producing secondary metabolites and virulence factors, including alginate. Alginate is an extracellular polysaccharide that protects the bacteria from antibiotics and oxidative agents, and enhances cell adhesion to solid surfaces in the process of biofilm formation. In the present study, we analyzed the role of alginate in the response of P. aeruginosa to lethal doses of ultraviolet-A (UVA) radiation, the major fraction of solar UV radiation reaching the Earth's surface. We also studied the role of alginate in the context of the adaptive responses generated when P. aeruginosa is exposed to sublethal doses of UVA radiation. The survival studies demonstrated that alginate has a key role in the resistance of P. aeruginosa to the oxidative stress generated by lethal UVA doses, both in planktonic cells and in static biofilms. In addition, the presence of alginate proved to be essential in the occurrence of adaptive responses such as induction of biofilm formation and cross-protection against hydrogen peroxide and sodium hypochlorite, both generated by exposure to low UVA doses. Finally, we demonstrated that the increase of biofilm formation is accompanied by an increase in alginate concentration in the biofilm matrix, possibly through the ppGpp-dependent induction of genes related to alginate regulation (algR and algU) and biosynthesis (algD operon). Given the importance of alginate in biofilm formation and its protective roles, better understanding of the mechanisms associated to its functions and synthesis is relevant, given the normal exposure of P. aeruginosa to UVA radiation and other types of oxidative stresses.
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Danish M, Shahid M, Zeyad MT, Bukhari NA, Al-Khattaf FS, Hatamleh AA, Ali S. Bacillus mojavensis, a Metal-Tolerant Plant Growth-Promoting Bacterium, Improves Growth, Photosynthetic Attributes, Gas Exchange Parameters, and Alkalo-Polyphenol Contents in Silver Nanoparticle (Ag-NP)-Treated Withania somnifera L. (Ashwagandha). ACS OMEGA 2022; 7:13878-13893. [PMID: 35559145 PMCID: PMC9088912 DOI: 10.1021/acsomega.2c00262] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/13/2022] [Accepted: 03/22/2022] [Indexed: 05/19/2023]
Abstract
Discharge of nanoparticles (NPs) into aquatic and terrestrial ecosystems during manufacturing processes and from various commercial goods has become a significant ecotoxicological concern. After reaching soil systems, NPs cause deleterious effects on soil fertility, microbial activity, and crop productivity. Taking into consideration the medicinal importance of Withania somnifera (L.) (ashwagandha), the present study assessed the potential hazards of silver nanoparticles (Ag-NPs) and the toxicity amelioration by a metal-tolerant plant growth-promoting rhizobacterium (PGPR). Bacillus mojavensis BZ-13 (NCBI accession number MZ950923) recovered from metal-polluted rhizosphere soil, tolerated an exceptionally high level of Ag-NPs. The growth-regulating substances synthesized by B. mojavensis were increased with increasing concentrations (0-1000 μg mL-1) of Ag-NPs. Also, strain BZ-13 had the ability to form biofilm, produce alginate and exopolysaccharides (EPSs), as well maintain swimming and swarming motilities in the presence of Ag-NPs. Soil application of varying concentrations of Ag-NPs resulted in a dose-related reduction in growth and biochemical features of ashwagandha. In contrast, following soil inoculation, B. mojavensis relieved the Ag-NPs-induced phytotoxicity and improved plant productivity. Root, shoot length, dry biomass, and leaf area increased by 13, 17, 37, 25%, respectively, when B. mojavensis was applied with 25 mg/kg Ag-NPs when compared to noninoculated controls. Furthermore, the soil plant analysis development (SPAD) index, photosystem efficiency (Fv/Fm), PS II quantum yield (FPS II), photochemical quenching (qP), non-photochemical quenching (NpQ), and total chlorophyll and carotenoid content of BZ-13-inoculated plants in the presence of 25 mg Ag-NPs/kg increased by 33, 29, 41, 47, 35, 26, and 25%, respectively, when compared to noninoculated controls that were exposed to the same amounts of NPs. In addition, a significant (p ≤ 0.05) increase in 48, 18, 21, and 19% in withaferin-A (alkaloids), flavonoids, phenols, and tannin content, respectively, was recorded when plants were detached from bacterized and Ag-NP-treated plants. Leaf gas exchange parameters were also modulated in the case of inoculated plants. Furthermore, bacterial inoculation significantly decreased proline, lipid peroxidation, antioxidant enzymes, and Ag-NP's absorption and build-up in phyto-organs. In conclusion, soil inoculation with B. mojavensis may possibly be used as an alternative to protect W. somnifera plants in soil contaminated with nanoparticles. Therefore, phytohormone and other biomolecule-synthesizing and NP-tolerant PGPR strains like B. mojavensis might serve as an agronomically significant and cost-effective remediation agent for augmenting the yield and productivity of medicinally important plants like ashwagandha raised in soil contaminated with nanoparticles in general and Ag-NPs in particular.
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Affiliation(s)
- Mohammad Danish
- Section
of Plant Pathology and Nematology, Department of Botany, Aligarh Muslim University, Aligarh202002, Uttar Pradesh, India
| | - Mohammad Shahid
- Department
of Agricultural Microbiology, Faculty of Agricultural Sciences, Aligarh Muslim University, Aligarh 202002, Uttar Pradesh, India
| | - Mohammad Tarique Zeyad
- ICAR-National
Bureau of Agriculturally Important Microorganisms (NBAIM), Mau, 275101, Uttar Pradesh, India
| | - Najat A. Bukhari
- Department
of Botany and Microbiology, College of Science, King Saud University, P.O. Box 2455, Riyadh 11451, Saudi Arabia
| | - Fatimah S. Al-Khattaf
- Department
of Botany and Microbiology, College of Science, King Saud University, P.O. Box 2455, Riyadh 11451, Saudi Arabia
| | - Ashraf Atef Hatamleh
- Department
of Botany and Microbiology, College of Science, King Saud University, P.O. Box 2455, Riyadh 11451, Saudi Arabia
| | - Sajad Ali
- Department
of Biotechnology, Yeungnam University, Gyeongsan 38541, South Korea
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Fleming D, Niese B, Redman W, Vanderpool E, Gordon V, Rumbaugh KP. Contribution of Pseudomonas aeruginosa Exopolysaccharides Pel and Psl to Wound Infections. Front Cell Infect Microbiol 2022; 12:835754. [PMID: 35463635 PMCID: PMC9021892 DOI: 10.3389/fcimb.2022.835754] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2021] [Accepted: 03/01/2022] [Indexed: 11/24/2022] Open
Abstract
Biofilms are the cause of most chronic bacterial infections. Living within the biofilm matrix, which is made of extracellular substances, including polysaccharides, proteins, eDNA, lipids and other molecules, provides microorganisms protection from antimicrobials and the host immune response. Exopolysaccharides are major structural components of bacterial biofilms and are thought to be vital to numerous aspects of biofilm formation and persistence, including adherence to surfaces, coherence with other biofilm-associated cells, mechanical stability, protection against desiccation, binding of enzymes, and nutrient acquisition and storage, as well as protection against antimicrobials, host immune cells and molecules, and environmental stressors. However, the contribution of specific exopolysaccharide types to the pathogenesis of biofilm infection is not well understood. In this study we examined whether the absence of the two main exopolysaccharides produced by the biofilm former Pseudomonas aeruginosa would affect wound infection in a mouse model. Using P. aeruginosa mutants that do not produce the exopolysaccharides Pel and/or Psl we observed that the severity of wound infections was not grossly affected; both the bacterial load in the wounds and the wound closure rates were unchanged. However, the size and spatial distribution of biofilm aggregates in the wound tissue were significantly different when Pel and Psl were not produced, and the ability of the mutants to survive antibiotic treatment was also impaired. Taken together, our data suggest that while the production of Pel and Psl do not appear to affect P. aeruginosa pathogenesis in mouse wound infections, they may have an important implication for bacterial persistence in vivo.
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Affiliation(s)
- Derek Fleming
- Department of Surgery, Texas Tech University Health Sciences, Lubbock, TX, United States
| | - Brandon Niese
- Department of Physics, Center for Nonlinear Dynamics, The University of Texas at Austin, Austin TX, United States
| | - Whitni Redman
- Department of Surgery, Texas Tech University Health Sciences, Lubbock, TX, United States
| | - Emily Vanderpool
- Department of Surgery, Texas Tech University Health Sciences, Lubbock, TX, United States
| | - Vernita Gordon
- Department of Physics, Center for Nonlinear Dynamics, The University of Texas at Austin, Austin TX, United States
- Interdisciplinary Life Sciences Graduate Programs, LaMontagne Center for Infectious Disease, The University of Texas at Austin, Austin, TX, United States
| | - Kendra P. Rumbaugh
- Department of Surgery, Texas Tech University Health Sciences, Lubbock, TX, United States
- Burn Center for Research Excellence, Texas Tech University Health Sciences, Lubbock, TX, United States
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Krishna PS, Woodcock SD, Pfeilmeier S, Bornemann S, Zipfel C, Malone JG. Pseudomonas syringae addresses distinct environmental challenges during plant infection through the coordinated deployment of polysaccharides. JOURNAL OF EXPERIMENTAL BOTANY 2022; 73:2206-2221. [PMID: 34905021 PMCID: PMC8982409 DOI: 10.1093/jxb/erab550] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/20/2021] [Accepted: 12/13/2021] [Indexed: 06/14/2023]
Abstract
Prior to infection, phytopathogenic bacteria face a challenging environment on the plant surface, where they are exposed to nutrient starvation and abiotic stresses. Pathways enabling surface adhesion, stress tolerance, and epiphytic survival are important for successful plant pathogenesis. Understanding the roles and regulation of these pathways is therefore crucial to fully understand bacterial plant infections. The phytopathogen Pseudomonas syringae pv. tomato (Pst) encodes multiple polysaccharides that are implicated in biofilm formation, stress survival, and virulence in other microbes. To examine how these polysaccharides impact Pst epiphytic survival and pathogenesis, we analysed mutants in multiple polysaccharide loci to determine their intersecting contributions to epiphytic survival and infection. In parallel, we used qRT-PCR to analyse the regulation of each pathway. Pst polysaccharides are tightly coordinated by multiple environmental signals. Nutrient availability, temperature, and surface association strongly affect the expression of different polysaccharides under the control of the signalling protein genes ladS and cbrB and the second messenger cyclic-di-GMP. Furthermore, functionally redundant, combinatorial phenotypes were observed for several polysaccharides. Exopolysaccharides play a role in mediating leaf adhesion, while α-glucan and alginate together confer desiccation tolerance. Our results suggest that polysaccharides play important roles in overcoming environmental challenges to Pst during plant infection.
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Affiliation(s)
- Pilla Sankara Krishna
- Department of Molecular Microbiology, John Innes Centre, Norwich Research Park, Norwich NR4 7UH, UK
| | - Stuart Daniel Woodcock
- Department of Molecular Microbiology, John Innes Centre, Norwich Research Park, Norwich NR4 7UH, UK
| | - Sebastian Pfeilmeier
- Department of Molecular Microbiology, John Innes Centre, Norwich Research Park, Norwich NR4 7UH, UK
- The Sainsbury Laboratory, University of East Anglia, Norwich Research Park, Norwich NR4 7UH, UK
| | - Stephen Bornemann
- The Sainsbury Laboratory, University of East Anglia, Norwich Research Park, Norwich NR4 7UH, UK
- Department of Biological Chemistry, John Innes Centre, Norwich Research Park, Norwich NR4 7UH, UK
| | - Cyril Zipfel
- The Sainsbury Laboratory, University of East Anglia, Norwich Research Park, Norwich NR4 7UH, UK
| | - Jacob George Malone
- Department of Molecular Microbiology, John Innes Centre, Norwich Research Park, Norwich NR4 7UH, UK
- University of East Anglia, Norwich Research Park, Norwich NR4 7TJ, UK
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35
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Secchi E, Savorana G, Vitale A, Eberl L, Stocker R, Rusconi R. The structural role of bacterial eDNA in the formation of biofilm streamers. Proc Natl Acad Sci U S A 2022; 119:e2113723119. [PMID: 35290120 PMCID: PMC8944759 DOI: 10.1073/pnas.2113723119] [Citation(s) in RCA: 27] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2021] [Accepted: 02/01/2022] [Indexed: 12/23/2022] Open
Abstract
Across diverse habitats, bacteria are mainly found as biofilms, surface-attached communities embedded in a self-secreted matrix of extracellular polymeric substances (EPS), which enhance bacterial recalcitrance to antimicrobial treatment and mechanical stresses. In the presence of flow and geometric constraints such as corners or constrictions, biofilms can take the form of long, suspended filaments (streamers), which bear important consequences in industrial and clinical settings by causing clogging and fouling. The formation of streamers is thought to be driven by the viscoelastic nature of the biofilm matrix. Yet, little is known about the structural composition of streamers and how it affects their mechanical properties. Here, using a microfluidic platform that allows growing and precisely examining biofilm streamers, we show that extracellular DNA (eDNA) constitutes the backbone and is essential for the mechanical stability of Pseudomonas aeruginosa streamers. This finding is supported by the observations that DNA-degrading enzymes prevent the formation of streamers and clear already formed ones and that the antibiotic ciprofloxacin promotes their formation by increasing the release of eDNA. Furthermore, using mutants for the production of the exopolysaccharide Pel, an important component of P. aeruginosa EPS, we reveal an concurring role of Pel in tuning the mechanical properties of the streamers. Taken together, these results highlight the importance of eDNA and of its interplay with Pel in determining the mechanical properties of P. aeruginosa streamers and suggest that targeting the composition of streamers can be an effective approach to control the formation of these biofilm structures.
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Affiliation(s)
- Eleonora Secchi
- Institute of Environmental Engineering, Department of Civil, Environmental and Geomatic Engineering, ETH Zürich, 8093 Zürich, Switzerland
| | - Giovanni Savorana
- Institute of Environmental Engineering, Department of Civil, Environmental and Geomatic Engineering, ETH Zürich, 8093 Zürich, Switzerland
| | - Alessandra Vitale
- Department of Plant and Microbial Biology, University of Zürich, 8008 Zürich, Switzerland
| | - Leo Eberl
- Department of Plant and Microbial Biology, University of Zürich, 8008 Zürich, Switzerland
| | - Roman Stocker
- Institute of Environmental Engineering, Department of Civil, Environmental and Geomatic Engineering, ETH Zürich, 8093 Zürich, Switzerland
| | - Roberto Rusconi
- Department of Biomedical Sciences, Humanitas University, 20072 Pieve Emanuele, Italy
- IRCCS Humanitas Research Hospital, 20089 Rozzano, Italy
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Kin selection for cooperation in natural bacterial populations. Proc Natl Acad Sci U S A 2022; 119:2119070119. [PMID: 35193981 PMCID: PMC8892524 DOI: 10.1073/pnas.2119070119] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/06/2021] [Indexed: 01/03/2023] Open
Abstract
Bacteria secrete many molecules outside the cell, where they provide benefits to other cells. One potential reason for producing these “public goods” is that they benefit closely related cells that share the gene for cooperation (kin selection). While many laboratory studies have supported this hypothesis, there is a lack of evidence that kin selection favors cooperation in natural populations. We examined bacterial genomes from the environment and used population genetics theory to analyze the DNA sequences. Our analyses suggest that public goods cooperation has indeed been favored by kin selection in natural populations. Bacteria produce a range of molecules that are secreted from the cell and can provide a benefit to the local population of cells. Laboratory experiments have suggested that these “public goods” molecules represent a form of cooperation, favored because they benefit closely related cells (kin selection). However, there is a relative lack of data demonstrating kin selection for cooperation in natural populations of bacteria. We used molecular population genetics to test for signatures of kin selection at the genomic level in natural populations of the opportunistic pathogen Pseudomonas aeruginosa. We found consistent evidence from multiple traits that genes controlling putatively cooperative traits have higher polymorphism and greater divergence and are more likely to harbor deleterious mutations relative to genes controlling putatively private traits, which are expressed at similar rates. These patterns suggest that cooperative traits are controlled by kin selection, and we estimate that the relatedness for social interactions in P. aeruginosa is r = 0.84. More generally, our results demonstrate how molecular population genetics can be used to study the evolution of cooperation in natural populations.
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N-acyl Homoserine Lactone Mediated Quorum Sensing Exhibiting Plant Growth-promoting and Abiotic Stress Tolerant Bacteria Demonstrates Drought Stress Amelioration. JOURNAL OF PURE AND APPLIED MICROBIOLOGY 2022. [DOI: 10.22207/jpam.16.1.69] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Multiple plant growth-promoting attributes with N-acyl homoserine lactone (AHL)-mediated quorum sensing exhibiting bacterial strains can help plants to withstand varying abiotic and biotic stress conditions for improving the plant health and productivity. In total, 306 bacterial isolates were isolated from diverse locations and sites. In our exploration, bacterial isolates were screened based on AHL production, plant growth-promoting attributes, abiotic stress tolerance, and antagonistic activity against phytopathogenic fungi. Among the screened 306 isolates, 4 (11VPKHP4, 7VP51.8, P51.10, NBRI N7) were selected based on their efficiency in AHL production, biofilm formation, enduring different abiotic stress conditions, exhibiting plant growth-promoting attributes, and antagonistic activity. Based on 16S rRNA gene sequencing analyses of the selected 4 isolates belong to Pseudomonas genera. Selected isolates 11VPKHP4, 7VP51.8, P51.10, and NBRI N7 were also proficient in biosurfactant production, emulsification, suggesting that all isolates fabricate emulsifiers. The plant growth promotion potential of selected 4 bacterial isolates showed significant growth enhancement in all the vegetative parameters of Zea mays under control as well as drought stress condition. Biochemical parameters and defense enzymes under drought stress conditions were also modulated in the PGPR treated plants as compared to their uninoculated respective controls. With quorum sensing, multiple PGPR attributes, stress tolerance, biofilm formation, and EPS production the selected isolates have the potential to facilitate enhanced plant growth, rhizosphere colonization, maintenance of soil moisture content under normal and diverse stresses.
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38
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Nadar S, Khan T, Patching SG, Omri A. Development of Antibiofilm Therapeutics Strategies to Overcome Antimicrobial Drug Resistance. Microorganisms 2022; 10:microorganisms10020303. [PMID: 35208758 PMCID: PMC8879831 DOI: 10.3390/microorganisms10020303] [Citation(s) in RCA: 34] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2021] [Revised: 01/19/2022] [Accepted: 01/25/2022] [Indexed: 02/04/2023] Open
Abstract
A biofilm is a community of stable microorganisms encapsulated in an extracellular matrix produced by themselves. Many types of microorganisms that are found on living hosts or in the environment can form biofilms. These include pathogenic bacteria that can serve as a reservoir for persistent infections, and are culpable for leading to a broad spectrum of chronic illnesses and emergence of antibiotic resistance making them difficult to be treated. The absence of biofilm-targeting antibiotics in the drug discovery pipeline indicates an unmet opportunity for designing new biofilm inhibitors as antimicrobial agents using various strategies and targeting distinct stages of biofilm formation. The strategies available to control biofilm formation include targeting the enzymes and proteins specific to the microorganism and those involved in the adhesion pathways leading to formation of resistant biofilms. This review primarily focuses on the recent strategies and advances responsible for identifying a myriad of antibiofilm agents and their mechanism of biofilm inhibition, including extracellular polymeric substance synthesis inhibitors, adhesion inhibitors, quorum sensing inhibitors, efflux pump inhibitors, and cyclic diguanylate inhibitors. Furthermore, we present the structure–activity relationships (SAR) of these agents, including recently discovered biofilm inhibitors, nature-derived bioactive scaffolds, synthetic small molecules, antimicrobial peptides, bioactive compounds isolated from fungi, non-proteinogenic amino acids and antibiotics. We hope to fuel interest and focus research efforts on the development of agents targeting the uniquely complex, physical and chemical heterogeneous biofilms through a multipronged approach and combinatorial therapeutics for a more effective control and management of biofilms across diseases.
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Affiliation(s)
- Sahaya Nadar
- Department of Pharmaceutical Chemistry, St. John Institute of Pharmacy and Research, Mumbai 400056, India;
| | - Tabassum Khan
- Department of Pharmaceutical Chemistry & Quality Assurance, SVKM’s Dr. Bhanuben Nanavati College of Pharmacy, Mumbai 400056, India;
| | - Simon G. Patching
- School of Biomedical Sciences and Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds LS2 9JT, UK
- Correspondence: or (S.G.P.); (A.O.)
| | - Abdelwahab Omri
- The Novel Drug & Vaccine Delivery Systems Facility, Department of Chemistry and Biochemistry, Laurentian University, Sudbury, ON P3E 2C6, Canada
- Correspondence: or (S.G.P.); (A.O.)
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39
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Balmuri SR, Phandanouvong-Lozano V, House SD, Yang JC, Niepa TH. Mucoid Coating Provides a Growth Advantage to Pseudomonas aeruginosa at Oil–Water Interfaces. ACS APPLIED BIO MATERIALS 2022; 5:1868-1878. [DOI: 10.1021/acsabm.1c01198] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
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40
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Luo A, Wang F, Sun D, Liu X, Xin B. Formation, Development, and Cross-Species Interactions in Biofilms. Front Microbiol 2022; 12:757327. [PMID: 35058893 PMCID: PMC8764401 DOI: 10.3389/fmicb.2021.757327] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2021] [Accepted: 11/29/2021] [Indexed: 12/25/2022] Open
Abstract
Biofilms, which are essential vectors of bacterial survival, protect microbes from antibiotics and host immune attack and are one of the leading causes that maintain drug-resistant chronic infections. In nature, compared with monomicrobial biofilms, polymicrobial biofilms composed of multispecies bacteria predominate, which means that it is significant to explore the interactions between microorganisms from different kingdoms, species, and strains. Cross-microbial interactions exist during biofilm development, either synergistically or antagonistically. Although research into cross-species biofilms remains at an early stage, in this review, the important mechanisms that are involved in biofilm formation are delineated. Then, recent studies that investigated cross-species cooperation or synergy, competition or antagonism in biofilms, and various components that mediate those interactions will be elaborated. To determine approaches that minimize the harmful effects of biofilms, it is important to understand the interactions between microbial species. The knowledge gained from these investigations has the potential to guide studies into microbial sociality in natural settings and to help in the design of new medicines and therapies to treat bacterial infections.
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Affiliation(s)
- Aihua Luo
- Department of Stomatology, Guizhou Provincial People's Hospital, Guiyang, China
| | - Fang Wang
- Department of Pharmacy, Qingdao Stomatological Hospital Affiliated to Qingdao University, Qingdao, China
| | - Degang Sun
- Department of Cariology and Endodontology, Qingdao Stomatological Hospital Affiliated to Qingdao University, Qingdao, China
| | - Xueyu Liu
- Department of Cariology and Endodontology, Qingdao Stomatological Hospital Affiliated to Qingdao University, Qingdao, China.,Central Laboratory, Qingdao Stomatological Hospital Affiliated to Qingdao University, Qingdao, China
| | - Bingchang Xin
- Department of Cariology and Endodontology, Qingdao Stomatological Hospital Affiliated to Qingdao University, Qingdao, China.,Central Laboratory, Qingdao Stomatological Hospital Affiliated to Qingdao University, Qingdao, China
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41
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Redman WK, Welch GS, Williams AC, Damron AJ, Northcut WO, Rumbaugh KP. Efficacy and safety of biofilm dispersal by glycoside hydrolases in wounds. Biofilm 2021; 3:100061. [PMID: 34825176 PMCID: PMC8605310 DOI: 10.1016/j.bioflm.2021.100061] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2021] [Revised: 11/04/2021] [Accepted: 11/05/2021] [Indexed: 12/20/2022] Open
Abstract
Novel anti-biofilm and dispersal agents are currently being investigated in an attempt to combat biofilm-associated wound infections. Glycoside hydrolases (GHs) are enzymes that hydrolyze the glycosidic bonds between sugars, such as those found within the exopolysaccharides of the biofilm matrix. Previous studies have shown that GHs can weaken the matrix, inducing bacterial dispersal, and improving antibiotic clearance. Yet, the number of GH enzymes that have been examined for potential therapeutic effects is limited. In this study, we screened sixteen GHs for their ability to disperse mono-microbial and polymicrobial biofilms grown in different environments. Six GHs, α-amylase (source: A. oryzae), alginate lyase (source: various algae), pectinase (source: Rhizopus sp.), amyloglucosidase (source: A. niger), inulinase (source: A. niger), and xylanase (source: A. oryzae), exhibited the highest dispersal efficacy in vitro. Two GHs, α-amylase (source: Bacillus sp.) and cellulase (source: A. niger), used in conjunction with meropenem demonstrated infection clearing ability in a mouse wound model. GHs were also effective in improving antibiotic clearance in diabetic mice. To examine their safety, we screened the GHs for toxicity in cell culture. Overall, there was an inverse relationship between enzyme exposure time and cellular toxicity, with twelve out of sixteen GHs demonstrating some level of toxicity in cell culture. However, only one GH exhibited harmful effects in mice. These results further support the ability of GHs to improve antibiotic clearance of biofilm-associated infections and help lay a foundation for establishing GHs as therapeutic agents for chronic wound infections.
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Affiliation(s)
- Whitni K Redman
- Department of Surgery, Texas Tech University Health Sciences Center, Lubbock, TX, USA.,Immunology and Molecular Microbiology, Texas Tech University Health Sciences Center, Lubbock, TX, USA
| | - Garrett S Welch
- Department of Surgery, Texas Tech University Health Sciences Center, Lubbock, TX, USA.,TTUHSC Surgery Burn Center of Research Excellence, Texas Tech University Health Sciences Center, Lubbock, TX, USA
| | - Avery C Williams
- Department of Surgery, Texas Tech University Health Sciences Center, Lubbock, TX, USA
| | - Addyson J Damron
- Department of Surgery, Texas Tech University Health Sciences Center, Lubbock, TX, USA
| | | | - Kendra P Rumbaugh
- Department of Surgery, Texas Tech University Health Sciences Center, Lubbock, TX, USA.,Immunology and Molecular Microbiology, Texas Tech University Health Sciences Center, Lubbock, TX, USA.,TTUHSC Surgery Burn Center of Research Excellence, Texas Tech University Health Sciences Center, Lubbock, TX, USA
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42
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Differential Surface Competition and Biofilm Invasion Strategies of Pseudomonas aeruginosa PA14 and PAO1. J Bacteriol 2021; 203:e0026521. [PMID: 34516283 DOI: 10.1128/jb.00265-21] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
Pseudomonas aeruginosa strains PA14 and PAO1 are among the two best-characterized model organisms used to study the mechanisms of biofilm formation while also representing two distinct lineages of P. aeruginosa. Previous work has shown that PA14 and PAO1 use different strategies for surface colonization; they also have different extracellular matrix composition and different propensities to disperse from biofilms back into the planktonic phase surrounding them. We expand on this work here by exploring the consequences of these different biofilm production strategies during direct competition. Using differentially labeled strains and microfluidic culture methods, we show that PAO1 can outcompete PA14 in direct competition during early colonization and subsequent biofilm growth, that they can do so in constant and perturbed environments, and that this advantage is specific to biofilm growth and requires production of the Psl polysaccharide. In contrast, P. aeruginosa PA14 is better able to invade preformed biofilms and is more inclined to remain surface-associated under starvation conditions. These data together suggest that while P. aeruginosa PAO1 and PA14 are both able to effectively colonize surfaces, they do so in different ways that are advantageous under different environmental settings. IMPORTANCE Recent studies indicate that P. aeruginosa PAO1 and PA14 use distinct strategies to initiate biofilm formation. We investigated whether their respective colonization and matrix secretion strategies impact their ability to compete under different biofilm-forming regimes. Our work shows that these different strategies do indeed impact how these strains fair in direct competition: PAO1 dominates during colonization of a naive surface, while PA14 is more effective in colonizing a preformed biofilm. These data suggest that even for very similar microbes there can be distinct strategies to successfully colonize and persist on surfaces during the biofilm life cycle.
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43
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Rahman MU, Fleming DF, Sinha I, Rumbaugh KP, Gordon VD, Christopher GF. Effect of collagen and EPS components on the viscoelasticity of Pseudomonas aeruginosa biofilms. SOFT MATTER 2021; 17:6225-6237. [PMID: 34109345 PMCID: PMC8283923 DOI: 10.1039/d1sm00463h] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Pseudomonas aeruginosa is an opportunistic pathogen that causes thousands of deaths every year in part due to its ability to form biofilms composed of bacteria embedded in a matrix of self-secreted extracellular polysaccharides (EPS), e-DNA, and proteins. In chronic wounds, biofilms are exposed to the host extracellular matrix, of which collagen is a major component. How bacterial EPS interacts with host collagen and whether this interaction affects biofilm viscoelasticity is not well understood. Since physical disruption of biofilms is often used in their removal, knowledge of collagen's effects on biofilm viscoelasticity may enable new treatment strategies that are better tuned to biofilms growing in host environments. In this work, biofilms are grown in the presence of different concentrations of collagen that mimic in vivo conditions. In order to explore collagen's interaction with EPS, nine strains of P. aeruginosa with different patterns of EPS production were used to grow biofilms. Particle tracking microrheology was used to characterize the mechanical development of biofilms over two days. Collagen is found to decrease biofilm compliance and increase relative elasticity regardless of the EPS present in the system. However, this effect is minimized when biofilms overproduce EPS. Collagen appears to become a de facto component of the EPS, through binding to bacteria or physical entanglement.
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Affiliation(s)
- Minhaz Ur Rahman
- Department of Mechanical Engineering, Whitacre College of Engineering, Texas Tech University, Lubbock, TX, USA.
| | - Derek F Fleming
- Department of Surgery, Texas Tech Health Sciences, Lubbock, TX, USA
| | - Indranil Sinha
- Department of Mechanical Engineering, Whitacre College of Engineering, Texas Tech University, Lubbock, TX, USA.
| | | | - Vernita D Gordon
- Department of Physics, Center for Nonlinear Dynamics, Interdisciplinary Life Sciences Graduate Programs, LaMontagne Center for Infectious Disease, The University of Texas at Austin, Austin, TX, USA
| | - Gordon F Christopher
- Department of Mechanical Engineering, Whitacre College of Engineering, Texas Tech University, Lubbock, TX, USA.
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44
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Zhao Z, Li H, Tao X, Xie Y, Yang L, Mao ZW, Xia W. Light-Triggered Nitric Oxide Release by a Photosensitizer to Combat Bacterial Biofilm Infections. Chemistry 2021; 27:5453-5460. [PMID: 33220013 DOI: 10.1002/chem.202004698] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2020] [Revised: 11/18/2020] [Indexed: 01/09/2023]
Abstract
Bacterial biofilms are a serious global health concern, often responsible for persistent infections. New strategies to prevent and treat bacterial infections by eradication of the biofilms are urgently needed. A novel ruthenium-based compound is reported in this study that functions as both a boronic acid-decorated photosensitizer (PS) and a light-triggered nitric oxide (NO) releasing agent. The compound can selectively attach to the bacterial membrane and biofilms and it is highly potent at eradicating Pseudomonas aeruginosa biofilms through the simultaneous release of NO and reactive oxygen species (ROS). The compound, which is more effective than clinical antibiotic tobramycin, also has excellent bacterial specificity and shows no significant cytotoxicity to human cells. The results reveal potential applications of this innovative dual-functional photoactivated ruthenium compound to combat bacterial biofilm infections.
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Affiliation(s)
- Zhennan Zhao
- MOE Key Laboratory of Bioinorganic and Synthetic Chemistry, School of Chemistry, Sun Yat-Sen University, Guangzhou, 510275, China
| | - Huinan Li
- MOE Key Laboratory of Bioinorganic and Synthetic Chemistry, School of Chemistry, Sun Yat-Sen University, Guangzhou, 510275, China
| | - Xuan Tao
- MOE Key Laboratory of Bioinorganic and Synthetic Chemistry, School of Chemistry, Sun Yat-Sen University, Guangzhou, 510275, China
| | - Yanxuan Xie
- MOE Key Laboratory of Bioinorganic and Synthetic Chemistry, School of Chemistry, Sun Yat-Sen University, Guangzhou, 510275, China
| | - Liang Yang
- School of Medicine, Southern University of Science and Technology, Shenzhen, 518055, China
| | - Zong-Wan Mao
- MOE Key Laboratory of Bioinorganic and Synthetic Chemistry, School of Chemistry, Sun Yat-Sen University, Guangzhou, 510275, China
| | - Wei Xia
- MOE Key Laboratory of Bioinorganic and Synthetic Chemistry, School of Chemistry, Sun Yat-Sen University, Guangzhou, 510275, China
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45
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Beyond the Wall: Exopolysaccharides in the Biofilm Lifestyle of Pathogenic and Beneficial Plant-Associated Pseudomonas. Microorganisms 2021; 9:microorganisms9020445. [PMID: 33670010 PMCID: PMC7926942 DOI: 10.3390/microorganisms9020445] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2021] [Revised: 02/12/2021] [Accepted: 02/18/2021] [Indexed: 11/16/2022] Open
Abstract
The formation of biofilms results from a multicellular mode of growth, in which bacteria remain enwrapped by an extracellular matrix of their own production. Many different bacteria form biofilms, but among the most studied species are those that belong to the Pseudomonas genus due to the metabolic versatility, ubiquity, and ecological significance of members of this group of microorganisms. Within the Pseudomonas genus, biofilm studies have mainly focused on the opportunistic human pathogen Pseudomonas aeruginosa due to its clinical importance. The extracellular matrix of P. aeruginosa is mainly composed of exopolysaccharides, which have been shown to be important for the biofilm architecture and pathogenic features of this bacterium. Notably, some of the exopolysaccharides recurrently used by P. aeruginosa during biofilm formation, such as the alginate and polysaccharide synthesis loci (Psl) polysaccharides, are also used by pathogenic and beneficial plant-associated Pseudomonas during their interaction with plants. Interestingly, their functions are multifaceted and seem to be highly dependent on the bacterial lifestyle and genetic context of production. This paper reviews the functions and significance of the exopolysaccharides produced by plant-associated Pseudomonas, particularly the alginate, Psl, and cellulose polysaccharides, focusing on their equivalents produced in P. aeruginosa within the context of pathogenic and beneficial interactions.
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46
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Whitfield GB, Howell PL. The Matrix Revisited: Opening Night for the Pel Polysaccharide Across Eubacterial Kingdoms. Microbiol Insights 2021; 14:1178636120988588. [PMID: 33642867 PMCID: PMC7890745 DOI: 10.1177/1178636120988588] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2020] [Accepted: 12/16/2020] [Indexed: 01/29/2023] Open
Abstract
Bacteria synthesize and export adhesive macromolecules to enable biofilm formation. These macromolecules, collectively called the biofilm matrix, are structurally varied and often unique to specific bacterial species or subspecies. This heterogeneity in matrix utilization makes it difficult to facilitate direct comparison between biofilm formation mechanisms of different bacterial species. Despite this, some matrix components, in particular the polysaccharides poly-β-1,6-N-acetyl-glucosamine (PNAG) and bacterial cellulose, are utilized by many Gram-negative species for biofilm formation. However, there is a very narrow distribution of these components across Gram-positive organisms, whose biofilm matrix determinants remain largely undiscovered. We found that a genetic locus required for the production of a biofilm matrix component of P. aeruginosa, the Pel polysaccharide, is widespread in Gram-negative bacteria and that there is a variant form of this cluster present in many Gram-positive bacterial species. We demonstrated that this locus is required for biofilm formation by Bacillus cereus ATCC 10987, produces a polysaccharide that is similar to Pel, and is post-translationally regulated by cyclic-3′,5′-dimeric-guanosine monophosphate (c-di-GMP) in a manner identical to P. aeruginosa. However, while the proposed mechanism for Pel production appears remarkably similar between B. cereus and P. aeruginosa, we identified several key differences between Gram-negative and Gram-positive Pel biosynthetic components in other monoderms. In particular, 4 different architectural subtypes of the c-di-GMP-binding component PelD were identified, including 1 found only in Streptococci that has entirely lost the c-di-GMP recognition domain. These observations highlight how existing multi-component bacterial machines can be subtly tweaked to adapt to the unique physiology and regulatory mechanisms of Gram-positive organisms. Collectively, our analyses suggest that the Pel biosynthetic locus is one of the most phylogenetically widespread biofilm matrix determinants in bacteria, and that its mechanism of production and regulation is extraordinarily conserved across the majority of organisms that possess it.
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Affiliation(s)
- Gregory B Whitfield
- Program in Molecular Medicine, The Hospital for Sick Children, Toronto, ON, Canada.,Department of Biochemistry, University of Toronto, ON, Canada.,Département de Microbiologie, Infectiologie, et Immunologie, Université de Montréal, QC, Canada
| | - P Lynne Howell
- Program in Molecular Medicine, The Hospital for Sick Children, Toronto, ON, Canada.,Department of Biochemistry, University of Toronto, ON, Canada
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Schulze A, Mitterer F, Pombo JP, Schild S. Biofilms by bacterial human pathogens: Clinical relevance - development, composition and regulation - therapeutical strategies. MICROBIAL CELL (GRAZ, AUSTRIA) 2021; 8:28-56. [PMID: 33553418 PMCID: PMC7841849 DOI: 10.15698/mic2021.02.741] [Citation(s) in RCA: 83] [Impact Index Per Article: 27.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/08/2020] [Revised: 01/08/2021] [Accepted: 01/12/2021] [Indexed: 12/19/2022]
Abstract
Notably, bacterial biofilm formation is increasingly recognized as a passive virulence factor facilitating many infectious disease processes. In this review we will focus on bacterial biofilms formed by human pathogens and highlight their relevance for diverse diseases. Along biofilm composition and regulation emphasis is laid on the intensively studied biofilms of Vibrio cholerae, Pseudomonas aeruginosa and Staphylococcus spp., which are commonly used as biofilm model organisms and therefore contribute to our general understanding of bacterial biofilm (patho-)physiology. Finally, therapeutical intervention strategies targeting biofilms will be discussed.
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Affiliation(s)
- Adina Schulze
- Institute of Molecular Biosciences, University of Graz, Humboldtstrasse 50, 8010 Graz, Austria
- A.S. and F.M. contributed equally to this work
| | - Fabian Mitterer
- Institute of Molecular Biosciences, University of Graz, Humboldtstrasse 50, 8010 Graz, Austria
- A.S. and F.M. contributed equally to this work
| | - Joao P. Pombo
- Institute of Molecular Biosciences, University of Graz, Humboldtstrasse 50, 8010 Graz, Austria
| | - Stefan Schild
- Institute of Molecular Biosciences, University of Graz, Humboldtstrasse 50, 8010 Graz, Austria
- BioTechMed Graz, Austria
- Field of Excellence Biohealth – University of Graz, Graz, Austria
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Heredia-Ponce Z, Gutiérrez-Barranquero JA, Purtschert-Montenegro G, Eberl L, de Vicente A, Cazorla FM. Role of extracellular matrix components in the formation of biofilms and their contribution to the biocontrol activity of Pseudomonas chlororaphis PCL1606. Environ Microbiol 2020; 23:2086-2101. [PMID: 33314481 DOI: 10.1111/1462-2920.15355] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2020] [Revised: 12/09/2020] [Accepted: 12/10/2020] [Indexed: 12/15/2022]
Abstract
Pseudomonas chlororaphis PCL1606 (PcPCL1606) displays plant-colonizing features and exhibits antagonistic traits against soil-borne phytopathogenic fungi. Biofilm formation could be relevant for the PcPCL1606 lifestyle, and in this study the role of some putative extracellular matrix components (EMC; Fap-like fibre, alginate and Psl-like polysaccharides) in the biofilm architecture and biocontrol activity of this bacterium were determined. EMC such as the Fap-like fibre and alginate polysaccharide play secondary roles in biofilm formation in PcPCL1606, because they are not fundamental to its biofilm architecture in flow cell chamber, but synergistically they have shown to favour bacterial competition during biofilm formation. Conversely, studies on Psl-like polysaccharide have revealed that it may contain mannose, and that it is strongly involved in the PcPCL1606 biofilm architecture and niche competition. Furthermore, the Fap-like fibre and Psl-like exopolysaccharide play roles in early surface attachment and contribute to biocontrol activity against the white root rot disease caused by Rosellinia necatrix in avocado plants. These results constitute the first report regarding the study of the extracellular matrix of the PcPCL1606 strain and highlight the importance of a putative Fap-like fibre and Psl-like exopolysaccharide produced by PcPCL1606 in the biofilm formation process and interactions with the host plant root.
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Affiliation(s)
- Zaira Heredia-Ponce
- Instituto de Hortofruticultura Subtropical y Mediterránea "La Mayora" (IHSM-UMA-CSIC) - Departamento de Microbiología, Universidad de Málaga, Bulevar Louis Pasteur, 31 (Campus Universitario de Teatinos), Málaga, 29071, Spain
| | - José Antonio Gutiérrez-Barranquero
- Instituto de Hortofruticultura Subtropical y Mediterránea "La Mayora" (IHSM-UMA-CSIC) - Departamento de Microbiología, Universidad de Málaga, Bulevar Louis Pasteur, 31 (Campus Universitario de Teatinos), Málaga, 29071, Spain
| | | | - Leo Eberl
- Department of Plant and Microbial Biology, University of Zurich, Zollikerstrasse 107, Zurich, CH-8008, Switzerland
| | - Antonio de Vicente
- Instituto de Hortofruticultura Subtropical y Mediterránea "La Mayora" (IHSM-UMA-CSIC) - Departamento de Microbiología, Universidad de Málaga, Bulevar Louis Pasteur, 31 (Campus Universitario de Teatinos), Málaga, 29071, Spain
| | - Francisco M Cazorla
- Instituto de Hortofruticultura Subtropical y Mediterránea "La Mayora" (IHSM-UMA-CSIC) - Departamento de Microbiología, Universidad de Málaga, Bulevar Louis Pasteur, 31 (Campus Universitario de Teatinos), Málaga, 29071, Spain
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The Extracellular Polysaccharide Matrix of Pseudomonas aeruginosa Biofilms Is a Determinant of Polymorphonuclear Leukocyte Responses. Infect Immun 2020; 89:IAI.00631-20. [PMID: 33077623 DOI: 10.1128/iai.00631-20] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2020] [Accepted: 10/09/2020] [Indexed: 01/04/2023] Open
Abstract
Bacterial biofilms may cause chronic infections due to their ability to evade clearance by the immune system and antibiotics. The persistent biofilms induce a hyperinflammatory state that damages the surrounding host tissue. Knowledge about the components of biofilms that are responsible for provoking the harmful but inefficient immune response is limited. Flagella are known to stimulate the response of polymorphonuclear leukocytes (PMNs) to planktonic solitary bacteria. However, we provide evidence that flagella are not a prerequisite for the response of PMNs to Pseudomonas aeruginosa biofilms. Instead, we found that extracellular matrix polysaccharides in P. aeruginosa biofilms play a role in the response of PMNs toward biofilms. Using a set of P. aeruginosa mutants with the ability to produce a subset of matrix exopolysaccharides, we found that P. aeruginosa biofilms with distinct exopolysaccharide matrix components elicit distinct PMN responses. In particular, the PMNs respond aggressively toward a biofilm matrix consisting of both Psl and alginate exopolysaccharides. These findings are relevant for therapeutic strategies aimed at dampening the collateral damage associated with biofilm-based infections.
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Blanco-Romero E, Garrido-Sanz D, Rivilla R, Redondo-Nieto M, Martín M. In Silico Characterization and Phylogenetic Distribution of Extracellular Matrix Components in the Model Rhizobacteria Pseudomonas fluorescens F113 and Other Pseudomonads. Microorganisms 2020; 8:E1740. [PMID: 33171989 PMCID: PMC7716237 DOI: 10.3390/microorganisms8111740] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2020] [Revised: 11/01/2020] [Accepted: 11/04/2020] [Indexed: 12/23/2022] Open
Abstract
Biofilms are complex structures that are crucial during host-bacteria interaction and colonization. Bacteria within biofilms are surrounded by an extracellular matrix (ECM) typically composed of proteins, polysaccharides, lipids, and DNA. Pseudomonads contain a variety of ECM components, some of which have been extensively characterized. However, neither the ECM composition of plant-associated pseudomonads nor their phylogenetic distribution within the genus has been so thoroughly studied. In this work, we use in silico methods to describe the ECM composition of Pseudomonas fluorescens F113, a plant growth-promoting rhizobacteria and model for rhizosphere colonization. These components include the polysaccharides alginate, poly-N-acetyl-glucosamine (PNAG) and levan; the adhesins LapA, MapA and PsmE; and the functional amyloids in Pseudomonas. Interestingly, we identified novel components: the Pseudomonas acidic polysaccharide (Pap), whose presence is limited within the genus; and a novel type of Flp/Tad pilus, partially different from the one described in P. aeruginosa. Furthermore, we explored the phylogenetic distribution of the most relevant ECM components in nearly 600 complete Pseudomonas genomes. Our analyses show that Pseudomonas populations contain a diverse set of gene/gene clusters potentially involved in the formation of their ECMs, showing certain commensal versus pathogen lifestyle specialization.
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Affiliation(s)
| | | | | | | | - Marta Martín
- Departamento de Biología, Facultad de Ciencias, Universidad Autónoma de Madrid, c/Darwin 2, 28049 Madrid, Spain; (E.B.-R.); (D.G.-S.); (R.R.); (M.R.-N.)
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