1
|
Raptová P, Skočková V, Babica P, Sovadinová I, Sychrová E, Vídeňská P, Šplíchalová P, Vašíček O, Šindlerová L. Cyanobacterial bloom-associated lipopolysaccharides induce pro-inflammatory processes in keratinocytes in vitro. ENVIRONMENTAL TOXICOLOGY AND PHARMACOLOGY 2024; 105:104342. [PMID: 38092246 DOI: 10.1016/j.etap.2023.104342] [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: 06/26/2023] [Revised: 10/23/2023] [Accepted: 12/08/2023] [Indexed: 12/24/2023]
Abstract
Our previous studies have shown that CyanoHAB LPS (lipopolysaccharides) and LPS from cyanobacterial cultures induce pro-inflammatory effects on intestinal epithelial and immune cells in vitro. To expand our understanding, we investigated their impact on human keratinocytes, which are targeted during water recreational activities. LPS samples were isolated from CyanoHAB biomasses dominated by Microcystis, Aphanizomenon, Planktothrix, and Dolichospermum, or from axenic cultures of these genera. We identified two CyanoHAB biomasses containing a high proportion of Gram-negative bacteria, including potentially pathogenic genera. These biomasses showed the highest induction of interleukin (IL) 8, IL-6, C-C motif chemokine ligand (CCL) 2 (also known as MCP-1), and CCL20 production by HaCaT cells. Interestingly, all CyanoHAB-derived LPS and LPS from axenic cultures (except for Microcystis) accelerated cell proliferation and migration. Our findings highlight the role of G- bacteria composition and LPS structural disparities in influencing these effects, with implications for skin health during recreational activities.
Collapse
Affiliation(s)
- P Raptová
- Department of Biophysics of Immune System, Institute of Biophysics of the Czech Academy of Sciences, Brno 61200, Czech Republic; Department of Experimental Biology, Faculty of Science, Masaryk University, Brno 62500, Czech Republic.
| | - V Skočková
- Department of Biophysics of Immune System, Institute of Biophysics of the Czech Academy of Sciences, Brno 61200, Czech Republic; Department of Experimental Biology, Faculty of Science, Masaryk University, Brno 62500, Czech Republic.
| | - P Babica
- RECETOX, Faculty of Science, Masaryk University, Brno 62500, Czech Republic; Department of Experimental Phycology and Ecotoxicology, Institute of Botany of the Czech Academy of Sciences, Brno 60200, Czech Republic.
| | - I Sovadinová
- RECETOX, Faculty of Science, Masaryk University, Brno 62500, Czech Republic.
| | - E Sychrová
- RECETOX, Faculty of Science, Masaryk University, Brno 62500, Czech Republic.
| | - P Vídeňská
- RECETOX, Faculty of Science, Masaryk University, Brno 62500, Czech Republic.
| | - P Šplíchalová
- RECETOX, Faculty of Science, Masaryk University, Brno 62500, Czech Republic.
| | - O Vašíček
- Department of Biophysics of Immune System, Institute of Biophysics of the Czech Academy of Sciences, Brno 61200, Czech Republic.
| | - L Šindlerová
- Department of Biophysics of Immune System, Institute of Biophysics of the Czech Academy of Sciences, Brno 61200, Czech Republic.
| |
Collapse
|
2
|
Guo Q, Zhan Y, Zhang W, Wang J, Yan Y, Wang W, Lin M. Development and Regulation of the Extreme Biofilm Formation of Deinococcus radiodurans R1 under Extreme Environmental Conditions. Int J Mol Sci 2023; 25:421. [PMID: 38203592 PMCID: PMC10778927 DOI: 10.3390/ijms25010421] [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: 11/08/2023] [Revised: 12/22/2023] [Accepted: 12/24/2023] [Indexed: 01/12/2024] Open
Abstract
To grow in various harsh environments, extremophiles have developed extraordinary strategies such as biofilm formation, which is an extremely complex and progressive process. However, the genetic elements and exact mechanisms underlying extreme biofilm formation remain enigmatic. Here, we characterized the biofilm-forming ability of Deinococcus radiodurans in vitro under extreme environmental conditions and found that extremely high concentrations of NaCl or sorbitol could induce biofilm formation. Meantime, the survival ability of biofilm cells was superior to that of planktonic cells in different extreme conditions, such as hydrogen peroxide stress, sorbitol stress, and high UV radiation. Transcriptome profiles of D. radiodurans in four different biofilm development stages further revealed that only 13 matched genes, which are involved in environmental information processing, carbohydrate metabolism, or stress responses, share sequence homology with genes related to the biofilm formation of Escherichia coli, Pseudomonas aeruginosa, and Staphylococcus aureus. Overall, 64% of the differentially expressed genes are functionally unknown, indicating the specificity of the regulatory network of D. radiodurans. The mutation of the drRRA gene encoding a response regulator strongly impaired biofilm formation ability, implying that DrRRA is an essential component of the biofilm formation of D. radiodurans. Furthermore, transcripts from both the wild type and the drRRA mutant were compared, showing that the expression of drBON1 (Deinococcus radioduransBON domain-containing protein 1) significantly decreased in the drRRA mutant during biofilm development. Further analysis revealed that the drBON1 mutant lacked the ability to form biofilm and DrRRA, and as a facilitator of biofilm formation, could directly stimulate the transcription of the biofilm-related gene drBON1. Overall, our work highlights a molecular mechanism mediated by the response regulator DrRRA for controlling extreme biofilm formation and thus provides guidance for future studies to investigate novel mechanisms that are used by D. radiodurans to adapt to extreme environments.
Collapse
Affiliation(s)
- Qiannan Guo
- National Key Laboratory of Agricultural Microbiology, Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China; (Q.G.); (Y.Z.); (W.Z.); (J.W.); (Y.Y.); (W.W.)
- Key Laboratory of Agricultural Microbiome (MARA), Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Yuhua Zhan
- National Key Laboratory of Agricultural Microbiology, Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China; (Q.G.); (Y.Z.); (W.Z.); (J.W.); (Y.Y.); (W.W.)
- Key Laboratory of Agricultural Microbiome (MARA), Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Wei Zhang
- National Key Laboratory of Agricultural Microbiology, Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China; (Q.G.); (Y.Z.); (W.Z.); (J.W.); (Y.Y.); (W.W.)
- Key Laboratory of Agricultural Microbiome (MARA), Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Jin Wang
- National Key Laboratory of Agricultural Microbiology, Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China; (Q.G.); (Y.Z.); (W.Z.); (J.W.); (Y.Y.); (W.W.)
- Key Laboratory of Agricultural Microbiome (MARA), Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Yongliang Yan
- National Key Laboratory of Agricultural Microbiology, Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China; (Q.G.); (Y.Z.); (W.Z.); (J.W.); (Y.Y.); (W.W.)
- Key Laboratory of Agricultural Microbiome (MARA), Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Wenxiu Wang
- National Key Laboratory of Agricultural Microbiology, Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China; (Q.G.); (Y.Z.); (W.Z.); (J.W.); (Y.Y.); (W.W.)
- Key Laboratory of Agricultural Microbiome (MARA), Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Min Lin
- National Key Laboratory of Agricultural Microbiology, Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China; (Q.G.); (Y.Z.); (W.Z.); (J.W.); (Y.Y.); (W.W.)
- Key Laboratory of Agricultural Microbiome (MARA), Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| |
Collapse
|
3
|
Xiao M, Li G, Yang H. Microbe-host interactions: structure and functions of Gram-negative bacterial membrane vesicles. Front Microbiol 2023; 14:1225513. [PMID: 37720140 PMCID: PMC10500606 DOI: 10.3389/fmicb.2023.1225513] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2023] [Accepted: 08/17/2023] [Indexed: 09/19/2023] Open
Abstract
Bacteria-host interaction is a common, relevant, and intriguing biological phenomena. The host reacts actively or passively to the bacteria themselves, their products, debris, and so on, through various defense systems containing the immune system, the bacteria communicate with the local or distal tissues of the host via their own surface antigens, secreted products, nucleic acids, etc., resulting in relationships of attack and defense, adaptation, symbiosis, and even collaboration. The significance of bacterial membrane vesicles (MVs) as a powerful vehicle for the crosstalk mechanism between the two is growing. In the recent decade, the emergence of MVs in microbial interactions and a variety of bacterial infections, with multiple adhesions to host tissues, cell invasion and evasion of host defense mechanisms, have brought MVs to the forefront of bacterial pathogenesis research. Whereas MVs are a complex combination of molecules not yet fully understood, research into its effects, targeting and pathogenic components will advance its understanding and utilization. This review will summarize structural, extraction and penetration information on several classes of MVs and emphasize the role of MVs in transport and immune response activation. Finally, the potential of MVs as a therapeutic method will be highlighted, as will future research prospects.
Collapse
Affiliation(s)
- Min Xiao
- Yunnan Key Laboratory of Stomatology, Kunming Medical University, Kunming, Yunnan, China
- Department of Dental Research, The Affiliated Stomatology Hospital of Kunming Medical University, Kunming, Yunnan, China
| | - Guiding Li
- Yunnan Key Laboratory of Stomatology, Kunming Medical University, Kunming, Yunnan, China
- Department of Dental Research, The Affiliated Stomatology Hospital of Kunming Medical University, Kunming, Yunnan, China
| | - Hefeng Yang
- Yunnan Key Laboratory of Stomatology, Kunming Medical University, Kunming, Yunnan, China
- Department of Dental Research, The Affiliated Stomatology Hospital of Kunming Medical University, Kunming, Yunnan, China
| |
Collapse
|
4
|
Chan DK, Dykema K, Fatima M, Harvey H, Qaderi I, Burrows LL. Nutrient Limitation Sensitizes Pseudomonas aeruginosa to Vancomycin. ACS Infect Dis 2023; 9:1408-1423. [PMID: 37279282 PMCID: PMC10353551 DOI: 10.1021/acsinfecdis.3c00167] [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: 04/14/2023] [Indexed: 06/08/2023]
Abstract
Traditional antibacterial screens rely on growing bacteria in nutrient-replete conditions which are not representative of the natural environment or sites of infection. Instead, screening in more physiologically relevant conditions may reveal novel activity for existing antibiotics. Here, we screened a panel of antibiotics reported to lack activity against the opportunistic Gram-negative bacterium, Pseudomonas aeruginosa, under low-nutrient and low-iron conditions, and discovered that the glycopeptide vancomycin inhibited the growth of P. aeruginosa at low micromolar concentrations through its canonical mechanism of action, disruption of peptidoglycan crosslinking. Spontaneous vancomycin-resistant mutants underwent activating mutations in the sensor kinase of the two-component CpxSR system, which induced cross-resistance to almost all classes of β-lactams, including the siderophore antibiotic cefiderocol. Other mutations that conferred vancomycin resistance mapped to WapR, an α-1,3-rhamnosyltransferase involved in lipopolysaccharide core biosynthesis. A WapR P164T mutant had a modified LPS profile compared to wild type that was accompanied by increased susceptibility to select bacteriophages. We conclude that screening in nutrient-limited conditions can reveal novel activity for existing antibiotics and lead to discovery of new and impactful resistance mechanisms.
Collapse
Affiliation(s)
- Derek
C. K. Chan
- David Braley Center for Antibiotic
Discovery, Michael G. DeGroote Institute for Infectious Disease Research,
Department of Biochemistry and Biomedical Sciences, McMaster University, 1280 Main Street West, Hamilton, Ontario L8S 4K1, Canada
| | - Katherine Dykema
- David Braley Center for Antibiotic
Discovery, Michael G. DeGroote Institute for Infectious Disease Research,
Department of Biochemistry and Biomedical Sciences, McMaster University, 1280 Main Street West, Hamilton, Ontario L8S 4K1, Canada
| | - Mahrukh Fatima
- David Braley Center for Antibiotic
Discovery, Michael G. DeGroote Institute for Infectious Disease Research,
Department of Biochemistry and Biomedical Sciences, McMaster University, 1280 Main Street West, Hamilton, Ontario L8S 4K1, Canada
| | - Hanjeong Harvey
- David Braley Center for Antibiotic
Discovery, Michael G. DeGroote Institute for Infectious Disease Research,
Department of Biochemistry and Biomedical Sciences, McMaster University, 1280 Main Street West, Hamilton, Ontario L8S 4K1, Canada
| | - Ikram Qaderi
- David Braley Center for Antibiotic
Discovery, Michael G. DeGroote Institute for Infectious Disease Research,
Department of Biochemistry and Biomedical Sciences, McMaster University, 1280 Main Street West, Hamilton, Ontario L8S 4K1, Canada
| | - Lori L. Burrows
- David Braley Center for Antibiotic
Discovery, Michael G. DeGroote Institute for Infectious Disease Research,
Department of Biochemistry and Biomedical Sciences, McMaster University, 1280 Main Street West, Hamilton, Ontario L8S 4K1, Canada
| |
Collapse
|
5
|
Gong Z, Guo J, Li Q, Xie H. Molecular mechanism of lipopolysaccharide (LPS) in promoting biomineralization on bacterial surface. Biochim Biophys Acta Gen Subj 2023; 1867:130305. [PMID: 36621513 DOI: 10.1016/j.bbagen.2023.130305] [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: 10/28/2022] [Revised: 01/03/2023] [Accepted: 01/04/2023] [Indexed: 01/07/2023]
Abstract
Biomineralization on bacterial surface is affected by biomolecules of bacterial cell surface. Lipopolysaccharide (LPS) is the main and outermost component on the extracellular membrane of Gram-negative bacteria. In the present study, the molecular mechanism of LPS in affecting biomineralization of Ag+/Cl- colloids was investigated by taking advantages of two LPS structural deficient mutants of Escherichia coli. The two mutants were generated by impairing the expression of waaP or wbbH genes with CRISPR/Cas9 technology and it induced deficient polysaccharide chain of O-antigen (ΔwbbH) or phosphate groups of core oligosaccharide (ΔwaaP) in LPS structures. There were significant changes of the cell morphology and surface charge of the two mutants in comparing with that of wild type cells. LPS from ΔwaaP mutant showed increased ΔHITC upon interacting with free Ag+ ions than LPS from wild type cells or ΔwbbH mutant, implying the binding affinity of LPS to Ag+ ions is affected by the phosphate groups in core oligosaccharide. LPS from ΔwbbH mutant showed decreased endotherm (ΔQ) upon interacting with Ag+/Cl- colloids than LPS from wild type or ΔwaaP mutant cells, implying LPS polysaccharide chain structure is critical for stabilizing Ag+/Cl- colloids. Biomineralization of Ag+/Cl- colloids on ΔwbbH mutant cell surface showed distinctive morphology in comparison with that of wild type or ΔwaaP mutant cells, which confirmed the critical role of O-antigen of LPS in biomineralization. The present work provided molecular evidence of the relationship between LPS structure, ions, and ionic colloids in biomineralization on bacterial cell surface.
Collapse
Affiliation(s)
- Zechuan Gong
- Institute of Aix-marseille (AMU-WHU), Wuhan University of Technology, Wuhan 430070, China
| | - Junhui Guo
- School of Chemistry, Chemical Engineering and Life Sciences, Wuhan University of Technology, Wuhan 430070, China.
| | - Qichang Li
- School of Chemistry, Chemical Engineering and Life Sciences, Wuhan University of Technology, Wuhan 430070, China
| | - Hao Xie
- Institute of Aix-marseille (AMU-WHU), Wuhan University of Technology, Wuhan 430070, China; School of Chemistry, Chemical Engineering and Life Sciences, Wuhan University of Technology, Wuhan 430070, China.
| |
Collapse
|
6
|
Cyanobacterial Harmful Bloom Lipopolysaccharides Induce Pro-Inflammatory Effects in Immune and Intestinal Epithelial Cells In Vitro. Toxins (Basel) 2023; 15:toxins15030169. [PMID: 36977060 PMCID: PMC10058507 DOI: 10.3390/toxins15030169] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2022] [Revised: 02/02/2023] [Accepted: 02/20/2023] [Indexed: 02/24/2023] Open
Abstract
Freshwater cyanobacterial harmful blooms (CyanoHABs) produce a variety of toxic and bioactive compounds including lipopolysaccharides (LPSs). The gastrointestinal tract can be exposed to them via contaminated water even during recreational activities. However, there is no evidence of an effect of CyanoHAB LPSs on intestinal cells. We isolated LPSs of four CyanoHABs dominated by different cyanobacterial species and LPSs of four laboratory cultures representing the respective dominant cyanobacterial genera. Two intestinal and one macrophage cell lines were used to detect in vitro pro-inflammatory activity of the LPS. All LPSs isolated from CyanoHABs and laboratory cultures induced cytokines production in at least one in vitro model, except for LPSs from the Microcystis PCC7806 culture. LPSs isolated from cyanobacteria showed unique migration patterns in SDS-PAGE that were qualitatively distinct from those of endotoxins from Gram-negative bacteria. There was no clear relationship between the biological activity of the LPS and the share of genomic DNA of Gram-negative bacteria in the respective biomass. Thus, the total share of Gram-negative bacteria, or the presence of Escherichia coli-like LPSs, did not explain the observed pro-inflammatory activities. The pro-inflammatory properties of environmental mixtures of LPSs from CyanoHABs indicate their human health hazards, and further attention should be given to their assessment and monitoring.
Collapse
|
7
|
Ibrahim MM, Liu Y, Ure K, Hall CW, Mah TF, Abdelbary H. Establishment of a Novel Rat Model of Gram-Negative Periprosthetic Joint Infection Using Cementless Hip Hemiarthroplasty. J Bone Joint Surg Am 2023; 105:42-52. [PMID: 36598474 DOI: 10.2106/jbjs.22.00094] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
BACKGROUND Gram-negative periprosthetic joint infections (GN-PJIs) present unique challenges. Our aim was to establish a clinically representative GN-PJI model that recapitulates biofilm formation in vivo. We also hypothesized that biofilm formation on the implant surface would affect its ability to osseointegrate. METHODS Three-dimensionally-printed medical-grade titanium hip implants were used to replace the femoral heads of male Sprague-Dawley rats. GN-PJI was induced using 2 bioluminescent Pseudomonas aeruginosa strains: a reference strain (PA14-lux) and a mutant biofilm-defective strain (ΔflgK-lux). Infection was monitored in real time using an in vivo imaging system (IVIS) and magnetic resonance imaging (MRI). Bacterial loads were quantified utilizing the viable colony count. Biofilm formation at the bone-implant interface was visualized using field-emission scanning electron microscopy (FE-SEM). Implant stability, as an outcome, was directly assessed by quantifying osseointegration using microcomputed tomography, and indirectly assessed by identifying gait-pattern changes. RESULTS Bioluminescence detected by the IVIS was focused on the hip region and demonstrated localized infection, with greater ability of PA14-lux to persist in the model compared with the ΔflgK-lux strain, which is defective in biofilm formation. This was corroborated by MRI, as PA14-lux induced relatively larger implant-related abscesses. Biofilm formation at the bone-implant interface induced by PA14-lux was visualized using FE-SEM versus defective-biofilm formation by ΔflgK-lux. Quantitatively, the average viable colony count of the sonicated implants, in colony-forming units/mL, was 3.77 × 108 for PA14-lux versus 3.65 × 103 for ΔflgK-lux, with a 95% confidence interval around the difference of 1.45 × 108 to 6.08 × 108 (p = 0.0025). This difference in the ability to persist in the model was reflected significantly on implant osseointegration, with a mean intersection surface of 4.1 × 106 ± 1.99 × 106 μm2 for PA14-lux versus 6.44 × 106 ± 2.53 × 106 μm2 for ΔflgK-lux and 7.08 × 106 ± 1.55 × 106 μm2 for the noninfected control (p = 0.048). CONCLUSIONS To our knowledge, this proposed, novel in vivo biofilm-based model is the most clinically representative for GN-PJI to date, since animals can bear weight on the implant, poor osseointegration was associated with biofilm formation, and localized PJI was assessed by various modalities. CLINICAL RELEVANCE This model will allow for more reliable testing of novel biofilm-targeting therapeutics.
Collapse
Affiliation(s)
- Mazen M Ibrahim
- Department of Biochemistry, Microbiology and Immunology, Faculty of Medicine, University of Ottawa, Ottawa, Ontario, Canada.,Department of Surgery, Faculty of Medicine, University of Ottawa, Ottawa, Ontario, Canada.,The Ottawa Hospital, Ottawa, Ontario, Canada.,Department of Orthopaedic Surgery, Faculty of Medicine, Helwan University, Cairo, Egypt
| | - Yun Liu
- Materials Characterization Core Facility, Centre for Advanced Materials Research (CAMaR), University of Ottawa, Ottawa, Ontario, Canada
| | - Kerstin Ure
- Animal Behavior and Physiology Core, Faculty of Medicine, University of Ottawa, Ottawa, Ontario, Canada
| | - Clayton W Hall
- Department of Biochemistry, Microbiology and Immunology, Faculty of Medicine, University of Ottawa, Ottawa, Ontario, Canada.,Division of Medical Microbiology, Department of Pathology and Molecular Medicine, McMaster University, Hamilton, Ontario, Canada
| | - Thien-Fah Mah
- Department of Biochemistry, Microbiology and Immunology, Faculty of Medicine, University of Ottawa, Ottawa, Ontario, Canada
| | - Hesham Abdelbary
- Department of Surgery, Faculty of Medicine, University of Ottawa, Ottawa, Ontario, Canada.,The Ottawa Hospital, Ottawa, Ontario, Canada
| |
Collapse
|
8
|
Grace A, Sahu R, Owen DR, Dennis VA. Pseudomonas aeruginosa reference strains PAO1 and PA14: A genomic, phenotypic, and therapeutic review. Front Microbiol 2022; 13:1023523. [PMID: 36312971 PMCID: PMC9607943 DOI: 10.3389/fmicb.2022.1023523] [Citation(s) in RCA: 31] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2022] [Accepted: 09/28/2022] [Indexed: 11/25/2022] Open
Abstract
Pseudomonas aeruginosa is a ubiquitous, motile, gram-negative bacterium that has been recently identified as a multi-drug resistant pathogen in critical need of novel therapeutics. Of the approximately 5,000 strains, PAO1 and PA14 are common laboratory reference strains, modeling moderately and hyper-virulent phenotypes, respectively. PAO1 and PA14 have been instrumental in facilitating the discovery of novel drug targets, testing novel therapeutics, and supplying critical genomic information on the bacterium. While the two strains have contributed to a wide breadth of knowledge on the natural behaviors and therapeutic susceptibilities of P. aeruginosa, they have demonstrated significant deviations from observations in human infections. Many of these deviations are related to experimental inconsistencies in laboratory strain environment that complicate and, at times, terminate translation from laboratory results to clinical applications. This review aims to provide a comparative analysis of the two strains and potential methods to improve their clinical relevance.
Collapse
Affiliation(s)
- Amber Grace
- Department of Biological Sciences, Alabama State University, Montgomery, AL, United States
| | - Rajnish Sahu
- Department of Biological Sciences, Alabama State University, Montgomery, AL, United States
| | | | - Vida A. Dennis
- Department of Biological Sciences, Alabama State University, Montgomery, AL, United States
- *Correspondence: Vida A. Dennis,
| |
Collapse
|
9
|
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.
Collapse
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
| |
Collapse
|
10
|
Wang C, Ye Q, Ding Y, Zhang J, Gu Q, Pang R, Zhao H, Wang J, Wu Q. Detection of Pseudomonas aeruginosa Serogroup G Using Real-Time PCR for Novel Target Genes Identified Through Comparative Genomics. Front Microbiol 2022; 13:928154. [PMID: 35814691 PMCID: PMC9263582 DOI: 10.3389/fmicb.2022.928154] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2022] [Accepted: 06/07/2022] [Indexed: 11/20/2022] Open
Abstract
Accurate serotyping is essential for effective infection control. Pseudomonas aeruginosa serogroup G is one of the most common serogroups found in water. Conventional serotyping methods are not standardized and have several shortcomings. Therefore, a robust method for rapidly identifying P. aeruginosa serotypes is required. This study established a real-time PCR method for identifying P. aeruginosa serogroup G strains using novel target gene primers based on comparative genomic analysis. A total of 343 genome sequences, including 16 P. aeruginosa serogroups and 67 other species, were analyzed. Target genes identified were amplified using real-time PCR for detecting P. aeruginosa serogroup G strains. Eight serogroup G genes, PA59_01276, PA59_01887, PA59_01888, PA59_01891, PA59_01894, PA59_04268, PA59_01892, and PA59_01896, were analyzed to determine specific targets. A real-time fluorescence quantitative PCR method, based on the novel target PA59_01276, was established to detect and identify serogroup G strains. The specificity of this method was confirmed using P. aeruginosa serogroups and non-P. aeruginosa species. The sensitivity of this real-time PCR method was 4 × 102 CFU/mL, and it could differentiate and detect P. aeruginosa serogroup G in the range of 4.0 × 103–4.0 × 108 CFU/mL in artificially contaminated drinking water samples without enrichment. The sensitivity of these detection limits was higher by 1–3 folds compared to that of the previously reported PCR methods. In addition, the G serum group was accurately detected using this real-time PCR method without interference by high concentrations of artificially contaminated serum groups F and D. These results indicate that this method has high sensitivity and accuracy and is promising for identifying and rapidly detecting P. aeruginosa serogroup G in water samples. Moreover, this research will contribute to the development of effective vaccines and therapies for infections caused by multidrug-resistant P. aeruginosa.
Collapse
Affiliation(s)
- Chufang Wang
- College of Food Science, South China Agricultural University, Guangzhou, China
- Guangdong Provincial Key Laboratory of Microbial Safety and Health, State Key Laboratory of Applied Microbiology Southern China, Institute of Microbiology, Guangdong Academy of Sciences, Guangzhou, China
- Key Laboratory of Agricultural Microbiomics and Precision Application, Ministry of Agriculture and Rural Affairs, Guangdong Academy of Sciences, Guangzhou, China
| | - Qinghua Ye
- Guangdong Provincial Key Laboratory of Microbial Safety and Health, State Key Laboratory of Applied Microbiology Southern China, Institute of Microbiology, Guangdong Academy of Sciences, Guangzhou, China
- Key Laboratory of Agricultural Microbiomics and Precision Application, Ministry of Agriculture and Rural Affairs, Guangdong Academy of Sciences, Guangzhou, China
| | - Yu Ding
- Guangdong Provincial Key Laboratory of Microbial Safety and Health, State Key Laboratory of Applied Microbiology Southern China, Institute of Microbiology, Guangdong Academy of Sciences, Guangzhou, China
- Key Laboratory of Agricultural Microbiomics and Precision Application, Ministry of Agriculture and Rural Affairs, Guangdong Academy of Sciences, Guangzhou, China
| | - Jumei Zhang
- Guangdong Provincial Key Laboratory of Microbial Safety and Health, State Key Laboratory of Applied Microbiology Southern China, Institute of Microbiology, Guangdong Academy of Sciences, Guangzhou, China
- Key Laboratory of Agricultural Microbiomics and Precision Application, Ministry of Agriculture and Rural Affairs, Guangdong Academy of Sciences, Guangzhou, China
| | - Qihui Gu
- Guangdong Provincial Key Laboratory of Microbial Safety and Health, State Key Laboratory of Applied Microbiology Southern China, Institute of Microbiology, Guangdong Academy of Sciences, Guangzhou, China
- Key Laboratory of Agricultural Microbiomics and Precision Application, Ministry of Agriculture and Rural Affairs, Guangdong Academy of Sciences, Guangzhou, China
| | - Rui Pang
- Guangdong Provincial Key Laboratory of Microbial Safety and Health, State Key Laboratory of Applied Microbiology Southern China, Institute of Microbiology, Guangdong Academy of Sciences, Guangzhou, China
- Key Laboratory of Agricultural Microbiomics and Precision Application, Ministry of Agriculture and Rural Affairs, Guangdong Academy of Sciences, Guangzhou, China
| | - Hui Zhao
- Guangdong Provincial Key Laboratory of Microbial Safety and Health, State Key Laboratory of Applied Microbiology Southern China, Institute of Microbiology, Guangdong Academy of Sciences, Guangzhou, China
- Key Laboratory of Agricultural Microbiomics and Precision Application, Ministry of Agriculture and Rural Affairs, Guangdong Academy of Sciences, Guangzhou, China
| | - Juan Wang
- College of Food Science, South China Agricultural University, Guangzhou, China
- Guangdong Provincial Key Laboratory of Microbial Safety and Health, State Key Laboratory of Applied Microbiology Southern China, Institute of Microbiology, Guangdong Academy of Sciences, Guangzhou, China
- Key Laboratory of Agricultural Microbiomics and Precision Application, Ministry of Agriculture and Rural Affairs, Guangdong Academy of Sciences, Guangzhou, China
- *Correspondence: Juan Wang,
| | - Qingping Wu
- College of Food Science, South China Agricultural University, Guangzhou, China
- Guangdong Provincial Key Laboratory of Microbial Safety and Health, State Key Laboratory of Applied Microbiology Southern China, Institute of Microbiology, Guangdong Academy of Sciences, Guangzhou, China
- Key Laboratory of Agricultural Microbiomics and Precision Application, Ministry of Agriculture and Rural Affairs, Guangdong Academy of Sciences, Guangzhou, China
- Qingping Wu,
| |
Collapse
|
11
|
Biosynthesis of the Pseudomonas aeruginosa common polysaccharide antigen by D-Rhamnosyltransferases WbpX and WbpY. Glycoconj J 2022; 39:393-411. [PMID: 35166992 PMCID: PMC8853325 DOI: 10.1007/s10719-022-10040-4] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2021] [Revised: 11/28/2021] [Accepted: 01/12/2022] [Indexed: 12/28/2022]
Abstract
The Gram-negative bacterium Pseudomonas aeruginosa simultaneously expresses two O-antigenic glycoforms. While the O-specific antigen (OSA) is variable in composition, the common polysaccharide antigen (CPA) is highly conserved and is composed of a homopolymer of D-rhamnose (D-Rha) in trisaccharide repeating units [D-Rhaα1-2-D-Rhaα1-3-D-Rhaɑ1-3]n. We have previously reported that α3-D-Rha-transferase WbpZ transfers a D-Rha residue from GDP-D-Rha to D-GlcNAcα-O-PO3-PO3-(CH2)11-O-phenyl. Genes encoding two more D-Rha-transferases are found in the O antigen gene cluster (wbpX and wbpY). In this study we showed that WbpX and WbpY recombinantly expressed in E. coli differ in their donor and acceptor specificities and have properties of GT-B folded enzymes of the GT4 glycosyltransferase family. NMR spectroscopic analysis of the WbpY reaction product showed that WbpY transferred one D-Rha residue in α1-3 linkage to synthetic D-Rhaα1-3-D-GlcNAcα-O-PO3-PO3-(CH2)11-O-phenyl acceptor. WbpX synthesized several products that contained D-Rha in both α1-2 and α1-3 linkages. Mass spectrometry indicated that the mixture of WbpX and WbpY efficiently catalyzed the synthesis of D-Rha oligomers in a non-processive mechanism. Since O antigens are virulence factors, these findings open the door to advancing technology for antibacterial drug discovery and vaccine development.
Collapse
|
12
|
The Basis for Natural Multiresistance to Phage in Pseudomonas aeruginosa. Antibiotics (Basel) 2020; 9:antibiotics9060339. [PMID: 32570896 PMCID: PMC7344871 DOI: 10.3390/antibiotics9060339] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2020] [Revised: 06/01/2020] [Accepted: 06/16/2020] [Indexed: 01/21/2023] Open
Abstract
Pseudomonas aeruginosa is responsible for long-term infections and is particularly resistant to treatments when hiding inside the extracellular matrix or biofilms. Phage therapy might represent an alternative to antibiotic treatment, but up to 10% of clinical strains appear to resist multiple phages. We investigated the characteristics of P. aeruginosa clinical strains naturally resistant to phages and compared them to highly susceptible strains. The phage-resistant strains were defective in lipopolysaccharide (LPS) biosynthesis, were nonmotile and displayed an important degree of autolysis, releasing phages and pyocins. Complete genome sequencing of three resistant strains showed the existence of a large accessory genome made of multiple insertion elements, genomic islands, pyocins and prophages, including two phages performing lateral transduction. Mutations were found in genes responsible for the synthesis of LPS and/or type IV pilus, the major receptors for most phages. CRISPR-Cas systems appeared to be absent or inactive in phage-resistant strains, confirming that they do not play a role in the resistance to lytic phages but control the insertion of exogenous sequences. We show that, despite their apparent weakness, the multiphage-resistant strains described in this study displayed selective advantages through the possession of various functions, including weapons to eliminate other strains of the same or closely related species.
Collapse
|
13
|
A Screen for Antibiotic Resistance Determinants Reveals a Fitness Cost of the Flagellum in Pseudomonas aeruginosa. J Bacteriol 2020; 202:JB.00682-19. [PMID: 31871033 DOI: 10.1128/jb.00682-19] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2019] [Accepted: 12/18/2019] [Indexed: 01/09/2023] Open
Abstract
The intrinsic resistance of Pseudomonas aeruginosa to many antibiotics limits treatment options for pseudomonal infections. P. aeruginosa's outer membrane is highly impermeable and decreases antibiotic entry into the cell. We used an unbiased high-throughput approach to examine mechanisms underlying outer membrane-mediated antibiotic exclusion. Insertion sequencing (INSeq) identified genes that altered fitness in the presence of linezolid, rifampin, and vancomycin, antibiotics to which P. aeruginosa is intrinsically resistant. We reasoned that resistance to at least one of these antibiotics would depend on outer membrane barrier function, as previously demonstrated in Escherichia coli and Vibrio cholerae This approach demonstrated a critical role of the outer membrane barrier in vancomycin fitness, while efflux pumps were primary contributors to fitness in the presence of linezolid and rifampin. Disruption of flagellar assembly or function was sufficient to confer a fitness advantage to bacteria exposed to vancomycin. These findings clearly show that loss of flagellar function alone can confer a fitness advantage in the presence of an antibiotic.IMPORTANCE The cell envelopes of Gram-negative bacteria render them intrinsically resistant to many classes of antibiotics. We used insertion sequencing to identify genes whose disruption altered the fitness of a highly antibiotic-resistant pathogen, Pseudomonas aeruginosa, in the presence of antibiotics usually excluded by the cell envelope. This screen identified gene products involved in outer membrane biogenesis and homeostasis, respiration, and efflux as important contributors to fitness. An unanticipated fitness cost of flagellar assembly and function in the presence of the glycopeptide antibiotic vancomycin was further characterized. These findings have clinical relevance for individuals with cystic fibrosis who are infected with P. aeruginosa and undergo treatment with vancomycin for a concurrent Staphylococcus aureus infection.
Collapse
|
14
|
The Role of Pseudomonas aeruginosa Lipopolysaccharide in Bacterial Pathogenesis and Physiology. Pathogens 2019; 9:pathogens9010006. [PMID: 31861540 PMCID: PMC7168646 DOI: 10.3390/pathogens9010006] [Citation(s) in RCA: 88] [Impact Index Per Article: 17.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2019] [Revised: 12/15/2019] [Accepted: 12/17/2019] [Indexed: 12/13/2022] Open
Abstract
The major constituent of the outer membrane of Gram-negative bacteria is lipopolysaccharide (LPS), which is comprised of lipid A, core oligosaccharide, and O antigen, which is a long polysaccharide chain extending into the extracellular environment. Due to the localization of LPS, it is a key molecule on the bacterial cell wall that is recognized by the host to deploy an immune defence in order to neutralize invading pathogens. However, LPS also promotes bacterial survival in a host environment by protecting the bacteria from these threats. This review explores the relationship between the different LPS glycoforms of the opportunistic pathogen Pseudomonas aeruginosa and the ability of this organism to cause persistent infections, especially in the genetic disease cystic fibrosis. We also discuss the role of LPS in facilitating biofilm formation, antibiotic resistance, and how LPS may be targeted by new antimicrobial therapies.
Collapse
|
15
|
Treatment with the Pseudomonas aeruginosa Glycoside Hydrolase PslG Combats Wound Infection by Improving Antibiotic Efficacy and Host Innate Immune Activity. Antimicrob Agents Chemother 2019; 63:AAC.00234-19. [PMID: 30988141 DOI: 10.1128/aac.00234-19] [Citation(s) in RCA: 53] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2019] [Accepted: 04/04/2019] [Indexed: 12/25/2022] Open
Abstract
Pseudomonas aeruginosa is an opportunistic, nosocomial bacterial pathogen that forms persistent infections due to the formation of protective communities, known as biofilms. Once the biofilm is formed, the bacteria embedded within it are recalcitrant to antimicrobial treatment and host immune defenses. Moreover, the presence of biofilms in wounds is correlated with chronic infection and delayed healing. The current standard of care for chronic wound infections typically involves physical disruption of the biofilm via debridement and subsequent antimicrobial treatment. The glycoside hydrolases PelAh and PslGh have been demonstrated in vitro to disrupt biofilm integrity through degradation of the key biofilm matrix exopolysaccharides Pel and Psl, respectively. Herein, we demonstrate that PslGh hydrolase therapy is a promising strategy for controlling P. aeruginosa wound infections. Hydrolase treatment of P. aeruginosa biofilms resulted in increased antibiotic efficacy and penetration into the biofilm. PslGh treatment of P. aeruginosa biofilms also improved innate immune activity leading to greater complement deposition, neutrophil phagocytosis, and neutrophil reactive oxygen species production. Furthermore, when P. aeruginosa-infected wounds were treated with a combination of PslGh and tobramycin, we observed an additive effect leading to greater bacterial clearance than treatments of tobramycin or PslGh alone. This study demonstrates that PelAh and PslGh have promising therapeutic potential and that PslGh may aid in the treatment of P. aeruginosa wound infections.
Collapse
|
16
|
Shi X, Wei W, Wang N. Tremella polysaccharides inhibit cellular apoptosis and autophagy induced by Pseudomonas aeruginosa lipopolysaccharide in A549 cells through sirtuin 1 activation. Oncol Lett 2018; 15:9609-9616. [PMID: 29805682 PMCID: PMC5958729 DOI: 10.3892/ol.2018.8554] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2017] [Accepted: 07/20/2017] [Indexed: 12/14/2022] Open
Abstract
In the present study, the role of Tremella polysaccharides in cellular apoptosis and autophagy induced by Pseudomonas aeruginosa lipopolysaccharide (LPS) in human epithelial A549 lung-cancer cells was investigated. Initially, it was demonstrated that LPS attenuated A549 cell viability in a time- and dose-dependent manner. Furthermore, LPS induced apoptotic cell death and autophagy in A549 cells and increased reactive oxygen species (ROS) production in a time-dependent manner. In addition, LPS treatment was demonstrated to markedly suppress sirtuin 1 (SIRT1) protein expression in A549 cells. Notably, it was demonstrated that Tremella polysaccharides activate SIRT1, leading to increased p62 expression, decreased p53 acetylation and B-cell lymphoma 2-associated X protein expression, and subsequently attenuate LPS-induced apoptotic cell death and autophagy. The results of the present study demonstrated that Tremella polysaccharides activate SIRT1 and inhibit LPS-induced ROS production, apoptosis and autophagy. This may have critical implications for the treatment of Pseudomonas aeruginosa infection.
Collapse
Affiliation(s)
- Xiaolan Shi
- Department of Respiratory and Asthma, Xi'an Children's Hospital, Xi'an, Shanxi 710043, P.R. China
| | - Wenfeng Wei
- Department of Paediatrics, Xianyang Central Hospital, Xi'an, Shanxi 712000, P.R. China
| | - Ning Wang
- Department of Respiratory and Asthma, Xi'an Children's Hospital, Xi'an, Shanxi 710043, P.R. China
| |
Collapse
|
17
|
Latino L, Caroff M, Pourcel C. Fine structure analysis of lipopolysaccharides in bacteriophage-resistant Pseudomonas aeruginosa PAO1 mutants. Microbiology (Reading) 2017; 163:848-855. [DOI: 10.1099/mic.0.000476] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Affiliation(s)
- Libera Latino
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Univ Paris-Sud, Université Paris-Saclay, 91198 Gif-sur-Yvette cedex, France
| | - Martine Caroff
- LPS-BioSciences, Bât 409, I2BC, Université Paris-Sud, 91405 Orsay, France
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Univ Paris-Sud, Université Paris-Saclay, 91198 Gif-sur-Yvette cedex, France
| | - Christine Pourcel
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Univ Paris-Sud, Université Paris-Saclay, 91198 Gif-sur-Yvette cedex, France
| |
Collapse
|
18
|
Tognon M, Köhler T, Gdaniec BG, Hao Y, Lam JS, Beaume M, Luscher A, Buckling A, van Delden C. Co-evolution with Staphylococcus aureus leads to lipopolysaccharide alterations in Pseudomonas aeruginosa. ISME JOURNAL 2017; 11:2233-2243. [PMID: 28548661 DOI: 10.1038/ismej.2017.83] [Citation(s) in RCA: 56] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/05/2016] [Revised: 03/24/2017] [Accepted: 04/19/2017] [Indexed: 02/07/2023]
Abstract
Detrimental and beneficial interactions between co-colonizing bacteria may influence the course of infections. In cystic fibrosis (CF) airways, Staphylococcus aureus prevails in childhood, whereas Pseudomonas aeruginosa progressively predominates thereafter. While a range of interactions has been identified, it is unclear if these represent specific adaptations or correlated responses to other aspects of the environment. Here, we investigate how P. aeruginosa adapts to S. aureus by evolving P. aeruginosa in the presence and absence of S. aureus. P. aeruginosa populations that evolved for 150 generations were sequenced and compared to the ancestor strain. Mutations in the Wsp signaling system were identified in both treatments and likely occurred because of low oxygen availability. Despite showing increased killing activity, wsp mutants were less fit in the presence of S. aureus. In contrast, mutations in lipopolysaccharide (LPS) biosynthesis occurred exclusively in co-cultures with S. aureus and conferred a fitness gain in its presence. Moreover, they increased resistance towards beta-lactam antibiotics. Strikingly, both mutations in wsp and LPS genes are observed in clinical isolates from CF-patients. Our results suggest that P. aeruginosa LPS mutations are a direct consequence of S. aureus imposed selection in vitro.
Collapse
Affiliation(s)
- Mikael Tognon
- Transplant Infectious Diseases Unit, University Hospitals of Geneva, Genève, Switzerland.,Department of Microbiology and Molecular Medicine, University of Geneva, Genève, Switzerland
| | - Thilo Köhler
- Transplant Infectious Diseases Unit, University Hospitals of Geneva, Genève, Switzerland.,Department of Microbiology and Molecular Medicine, University of Geneva, Genève, Switzerland
| | - Bartosz G Gdaniec
- Transplant Infectious Diseases Unit, University Hospitals of Geneva, Genève, Switzerland.,Department of Microbiology and Molecular Medicine, University of Geneva, Genève, Switzerland
| | - Youai Hao
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, ON, Canada
| | - Joseph S Lam
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, ON, Canada
| | - Marie Beaume
- Transplant Infectious Diseases Unit, University Hospitals of Geneva, Genève, Switzerland.,Department of Microbiology and Molecular Medicine, University of Geneva, Genève, Switzerland
| | - Alexandre Luscher
- Transplant Infectious Diseases Unit, University Hospitals of Geneva, Genève, Switzerland.,Department of Microbiology and Molecular Medicine, University of Geneva, Genève, Switzerland
| | - Angus Buckling
- Environment and Sustainability Institute, University of Exeter, Penryn, UK
| | - Christian van Delden
- Transplant Infectious Diseases Unit, University Hospitals of Geneva, Genève, Switzerland.,Department of Microbiology and Molecular Medicine, University of Geneva, Genève, Switzerland
| |
Collapse
|
19
|
Cyclic-di-GMP regulates lipopolysaccharide modification and contributes to Pseudomonas aeruginosa immune evasion. Nat Microbiol 2017; 2:17027. [PMID: 28263305 PMCID: PMC5341770 DOI: 10.1038/nmicrobiol.2017.27] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2016] [Accepted: 01/31/2017] [Indexed: 11/18/2022]
Abstract
Pseudomonas aeruginosa is a Gram-negative bacterial pathogen associated with acute and chronic infections. The universal c-di-GMP second messenger is instrumental in the switch from a motile lifestyle to resilient biofilm as in the cystic fibrosis lung. The SadC diguanylate cyclase is associated with this patho-adaptive transition. Here we identified an unrecognized SadC partner, WarA, which we show is a methyltransferase in complex with a putative kinase WarB. We established that WarA binds to c-di-GMP, which potentiates its methyltransferase activity. Together, WarA and WarB have structural similarities with the bi-functional Escherichia coli LPS O antigen regulator WbdD. Strikingly, WarA influences P. aeruginosa O antigen modal distribution and interacts with the LPS biogenesis machinery. LPS is known to modulate the immune response in the host, and by using a zebrafish infection model, we implicate WarA in the ability of P. aeruginosa to evade detection by the host.
Collapse
|
20
|
Hong TP, Carter MQ, Struffi P, Casonato S, Hao Y, Lam JS, Lory S, Jousson O. Conjugative type IVb pilus recognizes lipopolysaccharide of recipient cells to initiate PAPI-1 pathogenicity island transfer in Pseudomonas aeruginosa. BMC Microbiol 2017; 17:31. [PMID: 28173753 PMCID: PMC5297154 DOI: 10.1186/s12866-017-0943-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2016] [Accepted: 02/03/2017] [Indexed: 12/31/2022] Open
Abstract
Background Pseudomonas aeruginosa pathogenicity island 1 (PAPI-1) is one of the largest genomic islands of this important opportunistic human pathogen. Previous studies have shown that PAPI-1 encodes several putative virulence factors, including a major regulator of biofilm formation and antibiotic-resistance traits. PAPI-1 is horizontally transferable into recipient strains lacking this island via conjugation mediated by the specialized type IV pilus. The PAPI-1 encodes a cluster of ten genes associated with the synthesis and assembly of the type IV pilus. The PAPI-1 acquisition mechanism is currently not well understood. Results In this study, we performed a series of conjugation experiments and identified determinants of PAPI-1 acquisition by analyzing transfer efficiency between the donor and a series of mutant recipient strains. Our data show that common polysaccharide antigen (CPA) lipopolysaccharide (LPS), a homopolymer of D-rhamnose, is required for initiating PAPI-1 transfer, suggesting that this structure acts as a receptor for conjugative type IV pilus in recipient strains. These results were substantiated by experimental evidence from PAPI-1 transfer assay experiments, in which outer membrane or LPS preparations from well-defined LPS mutants were added to the transfer mix to assess the role of P. aeruginosa LPS in PAPI-1 transfer and in vitro binding experiments between pilin fusion protein GST-pilV2’ and immobilized LPS molecules were performed. Our data also showed that P. aeruginosa strains that had already acquired a copy of PAPI-1 were unable to import additional copies of the island, and that such strains produced proportionally lower amounts of CPA LPS compared to the strains lacking PAPI-1. Conclusions These results suggest that a PAPI-1 exclusion mechanism exists in P. aeruginosa that might serve to regulate the avoidance of uncontrolled expansions of the bacterial genome. Electronic supplementary material The online version of this article (doi:10.1186/s12866-017-0943-4) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Toan Phuoc Hong
- Centre for Integrative Biology, University of Trento, 38123, Trento, Italy
| | - Michelle Q Carter
- Department of Microbiology and Immunobiology, Harvard Medical School, Boston, MA, 02115, USA
| | - Paolo Struffi
- Centre for Integrative Biology, University of Trento, 38123, Trento, Italy
| | - Stefano Casonato
- Centre for Integrative Biology, University of Trento, 38123, Trento, Italy
| | - Youai Hao
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, ON, N1G 2W1, Canada
| | - Joseph S Lam
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, ON, N1G 2W1, Canada
| | - Stephen Lory
- Department of Microbiology and Immunobiology, Harvard Medical School, Boston, MA, 02115, USA
| | - Olivier Jousson
- Centre for Integrative Biology, University of Trento, 38123, Trento, Italy.
| |
Collapse
|