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Yalkut K, Ben Ali Hassine S, Basaran E, Kula C, Ozcan A, Avci FG, Keskin O, Sariyar Akbulut B, Ozbek P. Attenuation of Type IV pili activity by natural products. J Biomol Struct Dyn 2024:1-11. [PMID: 38305801 DOI: 10.1080/07391102.2024.2310781] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2023] [Accepted: 01/20/2024] [Indexed: 02/03/2024]
Abstract
The virulence factor Type IV pili (T4P) are surface appendages used by the opportunistic pathogen Pseudomonas aeruginosa for twitching motility and adhesion in the environment and during infection. Additionally, the use of these appendages by P. aeruginosa for biofilm formation increases its virulence and drug resistance. Therefore, attenuation of the activity of T4P would be desirable to control P. aeruginosa infections. Here, a computational approach has been pursued to screen natural products that can be used for this purpose. PilB, the elongation ATPase of the T4P machinery in P. aeruginosa, has been selected as the target subunit and virtual screening of FDA-approved drugs has been conducted. Screening identified two natural compounds, ergoloid and irinotecan, as potential candidates for inhibiting this T4P-associated ATPase in P. aeruginosa. These candidate compounds underwent further rigorous evaluation through molecular dynamics (MD) simulations and then through in vitro twitching motility and biofilm inhibition assays. Notably, ergoloid emerged as a particularly promising candidate for weakening the T4P activity by inhibiting the elongation ATPases associated with T4P. This repurposing study paves the way for the timely discovery of antivirulence drugs as an alternative to classical antibiotic treatments to help combat infections caused by P. aeruginosa and related pathogens.Communicated by Ramaswamy H. Sarma.
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Affiliation(s)
- Kerem Yalkut
- Department of Bioengineering, Faculty of Engineering, Marmara University, Istanbul, Turkey
| | - Soumaya Ben Ali Hassine
- Department of Bioengineering, Faculty of Engineering, Marmara University, Istanbul, Turkey
- Department of Bioengineering, Faculty of Engineering and Natural Sciences, Uskudar University, Istanbul, Turkey
| | - Esra Basaran
- Graduate School of Sciences and Engineering, Koc University, Istanbul, Turkey
| | - Ceyda Kula
- Department of Bioengineering, Faculty of Engineering, Marmara University, Istanbul, Turkey
| | - Aslıhan Ozcan
- Department of Bioengineering, Faculty of Engineering, Marmara University, Istanbul, Turkey
| | - Fatma Gizem Avci
- Department of Bioengineering, Faculty of Engineering and Natural Sciences, Uskudar University, Istanbul, Turkey
| | - Ozlem Keskin
- Graduate School of Sciences and Engineering, Koc University, Istanbul, Turkey
| | - Berna Sariyar Akbulut
- Department of Bioengineering, Faculty of Engineering, Marmara University, Istanbul, Turkey
| | - Pemra Ozbek
- Department of Bioengineering, Faculty of Engineering, Marmara University, Istanbul, Turkey
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Bhuyan S, Dutta L, Begum S, Giri SJ, Jain M, Mandal M, Ray SK. A study on twitching motility dynamics in Ralstonia solanacearum microcolonies by live imaging. J Basic Microbiol 2024; 64:42-49. [PMID: 37612794 DOI: 10.1002/jobm.202300272] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2023] [Revised: 07/15/2023] [Accepted: 08/13/2023] [Indexed: 08/25/2023]
Abstract
Ralstonia solanacearum is a rod-shaped phytopathogenic bacterium that causes lethal wilt disease in many plants. On solid agar growth medium, in the early hour of the growth of the bacterial colony, the type IV pili-mediated twitching motility, which is important for its virulence and biofilm formation, is prominently observed under the microscope. In this study, we have done a detailed observation of twitching motility in R. solanacearum colony. In the beginning, twitching motility in the microcolonies was observed as a density-dependent phenomenon that influences the shape of the microcolonies. No such phenomenon was observed in Escherichia coli, where twitching motility is absent. In the early phase of colony growth, twitching motility exhibited by the cells at the peripheral region of the colony was more prominent than the cells toward the center of the colony. Using time-lapse photography and merging the obtained photomicrographs into a video, twitching motility was observed as an intermittent phenomenon that progresses in layers in all directions as finger-like projections at the peripheral region of a bacterial colony. Each layer of bacteria twitches on top of the other and produces a multilayered film-like appearance. We found that the duration between the emergence of each layer diminishes progressively as the colony becomes older. This study on twitching motility demonstrates distinctly heterogeneity among the cells within a colony regarding their dynamics and the influence of microcolonies on each other regarding their morphology.
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Affiliation(s)
- Shuvam Bhuyan
- Department of Molecular Biology and Biotechnology, Tezpur University, Tezpur, Assam, India
| | - Lukapriya Dutta
- Department of Molecular Biology and Biotechnology, Tezpur University, Tezpur, Assam, India
| | - Shuhada Begum
- Department of Molecular Biology and Biotechnology, Tezpur University, Tezpur, Assam, India
| | - Shubhra J Giri
- Department of Molecular Biology and Biotechnology, Tezpur University, Tezpur, Assam, India
| | - Monika Jain
- Department of Molecular Biology and Biotechnology, Tezpur University, Tezpur, Assam, India
| | - Manabendra Mandal
- Department of Molecular Biology and Biotechnology, Tezpur University, Tezpur, Assam, India
| | - Suvendra K Ray
- Department of Molecular Biology and Biotechnology, Tezpur University, Tezpur, Assam, India
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Tapia-Rodriguez MR, Cantu-Soto EU, Vazquez-Armenta FJ, Bernal-Mercado AT, Ayala-Zavala JF. Inhibition of Acinetobacter baumannii Biofilm Formation by Terpenes from Oregano ( Lippia graveolens) Essential Oil. Antibiotics (Basel) 2023; 12:1539. [PMID: 37887240 PMCID: PMC10604308 DOI: 10.3390/antibiotics12101539] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2023] [Revised: 10/11/2023] [Accepted: 10/12/2023] [Indexed: 10/28/2023] Open
Abstract
Acinetobacter baumannii is a nosocomial pathogen known for its ability to form biofilms, leading to persistent infections and antibiotic resistance. The limited effective antibiotics have encouraged the development of innovative strategies such as using essential oils and their constituents. This study evaluated the efficacy of oregano (Lippia graveolens) essential oil (OEO) and its terpene compounds, carvacrol and thymol, in inhibiting A. baumannii biofilms. These treatments showed a minimum inhibitory concentration of 0.6, 0.3, and 2.5 mg/mL and a minimum bactericidal concentration of 1.2, 0.6, and 5 mg/mL, respectively. Sub-inhibitory doses of each treatment and the OEO significantly reduced biofilm biomass and the covered area of A. baumannii biofilms as measured by fluorescence microscopy. Carvacrol at 0.15 mg/mL exhibited the most potent efficacy, achieving a remarkable 95% reduction. Sub-inhibitory concentrations of carvacrol significantly reduced the biofilm formation of A. baumannii in stainless steel surfaces by up to 1.15 log CFU/cm2 compared to untreated bacteria. The OEO and thymol exhibited reductions of 0.6 log CFU/cm2 and 0.4 log CFU/cm2, respectively, without affecting cell viability. Moreover, the terpenes inhibited twitching motility, a crucial step in biofilm establishment, with carvacrol exhibiting the highest inhibition, followed by OEO and thymol. The study provides valuable insights into the potential of terpenes as effective agents against A. baumannii biofilms, offering promising avenues for developing novel strategies to prevent persistent infections and overcome antibiotic resistance.
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Affiliation(s)
- Melvin Roberto Tapia-Rodriguez
- Departamento de Biotecnología y Ciencias Alimentarias, Instituto Tecnológico de Sonora, 5 de Febrero 818 Sur, Col. Centro, Ciudad Obregón 85000, Mexico;
| | - Ernesto Uriel Cantu-Soto
- Departamento de Biotecnología y Ciencias Alimentarias, Instituto Tecnológico de Sonora, 5 de Febrero 818 Sur, Col. Centro, Ciudad Obregón 85000, Mexico;
| | - Francisco Javier Vazquez-Armenta
- Departamento de Ciencias Químico Biológicas, Universidad de Sonora, México Blvd. Luis Encinas y Rosales S/N, Col. Centro, Hermosillo 83000, Mexico;
| | - Ariadna Thalia Bernal-Mercado
- Departamento de Investigación y Posgrado en Alimentos, Universidad de Sonora, México Blvd. Luis Encinas y Rosales S/N, Col. Centro, Hermosillo 83000, Mexico;
| | - Jesus Fernando Ayala-Zavala
- Centro de Investigación en Alimentación y Desarrollo, A.C. Carretera Gustavo Enrique Astiazarán Rosas 46, Hermosillo 83304, Mexico;
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Yang Y, Fei N, Ji W, Qiao P, Yang L, Liu D, Guan W, Zhao T. pilA Gene Contributes to Virulence, Motility, Biofilm Formation, and Interspecific Competition of Bacteria in Acidovorax citrulli. Microorganisms 2023; 11:1806. [PMID: 37512977 PMCID: PMC10385852 DOI: 10.3390/microorganisms11071806] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2023] [Revised: 06/30/2023] [Accepted: 07/12/2023] [Indexed: 07/30/2023] Open
Abstract
Acidovorax citrulli, the causative agent of bacterial fruit blotch, can be divided into two main groups based on factors such as pathogenicity and host species preference. PilA is an important structural and functional component of type IV pili (T4P). Previous studies have found significant differences in pilA DNA sequences between group I and group II strains of A. citrulli. In this study, we characterized pilA in the group I strain pslb65 and the group II strain Aac5. pilA mutants, complementation strains, and cross-complementation strains were generated, and their biological phenotypes were analyzed to identify functional differences between pilA in the two groups. pilA deletion mutants (pslb65-ΔpilA and Aac5-ΔpilA) showed significantly reduced pathogenicity compared with the wild-type (WT) strains; pslb65-ΔpilA also completely lost twitching motility, whereas Aac5-ΔpilA only partially lost motility. In King's B medium, there were no significant differences in biofilm formation between pslb65-ΔpilA and WT pslb65, but Aac5-ΔpilA showed significantly reduced biofilm formation compared to WT Aac5. In M9 minimal medium, both mutants showed significantly lower biofilm formation compared to the corresponding WT strains, although biofilm formation was recovered in the complementation strains. The biofilm formation capacity was somewhat recovered in the cross-complementation strains but remained significantly lower than in the WT strains. The interspecies competitive abilities of pslb65-ΔpilA and Aac5-ΔpilA were significantly lower than in the WT strains; Aac5-ΔpilA was more strongly competitive than pslb65-ΔpilA, and the complementation strains recovered competitiveness to WT levels. Furthermore, the cross-complementation strains showed stronger competitive abilities than the corresponding WT strains. The relative expression levels of genes related to T4P and the type VI secretion system were then assessed in the pilA mutants via quantitative PCR. The results showed significant differences in the relative expression levels of multiple genes in pslb65-ΔpilA and Aac5-ΔpilA compared to the corresponding WT stains. This indicated the presence of specific differences in pilA function between the two A. citrulli groups, but the regulatory mechanisms involved require further study.
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Affiliation(s)
- Yuwen Yang
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China
- National Nanfan Research Institute (Sanya), Chinese Academy of Agricultural Sciences, Sanya 572024, China
| | - Nuoya Fei
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China
- College of Life Sciences, Jilin Normal University, Siping 136000, China
| | - Weiqin Ji
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Pei Qiao
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Linlin Yang
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China
- Department of Plant Pathology, Plant Protection College, Shenyang Agricultural University, Shenyang 110866, China
| | - Dehua Liu
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China
- College of Plant Protection, Jilin Agricultural University, Changchun 130118, China
| | - Wei Guan
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Tingchang Zhao
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China
- National Nanfan Research Institute (Sanya), Chinese Academy of Agricultural Sciences, Sanya 572024, China
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Kühn MJ, Macmillan H, Talà L, Inclan Y, Patino R, Pierrat X, Al‐Mayyah Z, Engel JN, Persat A. Two antagonistic response regulators control Pseudomonas aeruginosa polarization during mechanotaxis. EMBO J 2023; 42:e112165. [PMID: 36795017 PMCID: PMC10519157 DOI: 10.15252/embj.2022112165] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2022] [Revised: 01/24/2023] [Accepted: 01/30/2023] [Indexed: 02/17/2023] Open
Abstract
The opportunistic pathogen Pseudomonas aeruginosa adapts to solid surfaces to enhance virulence and infect its host. Type IV pili (T4P), long and thin filaments that power surface-specific twitching motility, allow single cells to sense surfaces and control their direction of movement. T4P distribution is polarized to the sensing pole by the chemotaxis-like Chp system via a local positive feedback loop. However, how the initial spatially resolved mechanical signal is translated into T4P polarity is incompletely understood. Here, we demonstrate that the two Chp response regulators PilG and PilH enable dynamic cell polarization by antagonistically regulating T4P extension. By precisely quantifying the localization of fluorescent protein fusions, we show that phosphorylation of PilG by the histidine kinase ChpA controls PilG polarization. Although PilH is not strictly required for twitching reversals, it becomes activated upon phosphorylation and breaks the local positive feedback mechanism established by PilG, allowing forward-twitching cells to reverse. Chp thus uses a main output response regulator, PilG, to resolve mechanical signals in space and employs a second regulator, PilH, to break and respond when the signal changes. By identifying the molecular functions of two response regulators that dynamically control cell polarization, our work provides a rationale for the diversity of architectures often found in non-canonical chemotaxis systems.
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Affiliation(s)
- Marco J Kühn
- Institute of Bioengineering and Global Health Institute, School of Life Sciences, Ecole Polytechnique Fédérale de LausanneLausanneSwitzerland
| | | | - Lorenzo Talà
- Institute of Bioengineering and Global Health Institute, School of Life Sciences, Ecole Polytechnique Fédérale de LausanneLausanneSwitzerland
| | - Yuki Inclan
- Department of MedicineUniversity of CaliforniaSan FranciscoCAUSA
| | - Ramiro Patino
- Department of MedicineUniversity of CaliforniaSan FranciscoCAUSA
| | - Xavier Pierrat
- Institute of Bioengineering and Global Health Institute, School of Life Sciences, Ecole Polytechnique Fédérale de LausanneLausanneSwitzerland
| | - Zainebe Al‐Mayyah
- Institute of Bioengineering and Global Health Institute, School of Life Sciences, Ecole Polytechnique Fédérale de LausanneLausanneSwitzerland
| | - Joanne N Engel
- Department of MedicineUniversity of CaliforniaSan FranciscoCAUSA
- Department of Microbiology and ImmunologyUniversity of CaliforniaSan FranciscoCAUSA
| | - Alexandre Persat
- Institute of Bioengineering and Global Health Institute, School of Life Sciences, Ecole Polytechnique Fédérale de LausanneLausanneSwitzerland
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Zhu M, Li Y, Chen DP, Li CP, Ouyang GP, Wang ZC. Allicin-inspired disulfide derivatives containing quinazolin-4(3H)-one as a bacteriostat against Xanthomonas oryzae pv. oryzae. Pest Manag Sci 2023; 79:537-547. [PMID: 36193761 DOI: 10.1002/ps.7221] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/17/2022] [Revised: 08/29/2022] [Accepted: 10/04/2022] [Indexed: 06/16/2023]
Abstract
BACKGROUND Plant bacterial diseases have seriously affected the yield and quality of crops, among which rice bacterial leaf blight (BLB), caused by Xanthomonas oryzae pv. oryzae has seriously affected the yield of rice. As plant-pathogenic bacteria gradually become resistant to existing bactericides, it is necessary to find effective bactericides with novel structures. RESULTS Herein, a series of compounds containing quinazolin-4(3H)-one and disulfide moieties were designed and synthesized using a facile synthetic method. The bioassay results revealed that most target compounds possessed noticeable antibacterial activity against Xanthomonas oryzae pv. oryzae. Particularly, compound 2-(butyldisulfanyl) quinazolin-4(3H)-one (1) exhibited remarkable antibacterial activity with the half effective concentration (EC50 ) of 0.52 μg mL-1 . Additionally, compound 1 was confirmed to inhibit the growth of the bacteria, change the bacterial morphology, and increase the level of reactive oxygen species. Proteomics, and RT-qPCR analysis results indicated that compound 1 could downregulate the expression of Pil-Chp histidine kinase chpA encoded by the pilL gene, and the potting experiments proved that compound 1 exhibits significant protective activity against BLB. CONCLUSIONS Compound 1 may weaken the pathogenicity of Xanthomonas oryzae pv. oryzae by inhibiting the bacterial growth and blocking the pili-mediated twitching motility without inducing the bacterial apoptosis. This study indicates that such derivatives could be a promising scaffold to develop a bacteriostat to control BLB. © 2022 Society of Chemical Industry.
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Affiliation(s)
- Mei Zhu
- State Key Laboratory Breeding Base of Green Pesticide and Agricultural Bioengineering, Key Laboratory of Green Pesticide and Agricultural Bioengineering, Ministry of Education, Center for Research and Development of Fine Chemicals of Guizhou University, Guiyang, China
| | - Yan Li
- College of Pharmacy, Guizhou University, Guiyang, China
| | - Dan-Ping Chen
- College of Pharmacy, Guizhou University, Guiyang, China
| | - Cheng-Peng Li
- College of Pharmacy, Guizhou University, Guiyang, China
| | - Gui-Ping Ouyang
- State Key Laboratory Breeding Base of Green Pesticide and Agricultural Bioengineering, Key Laboratory of Green Pesticide and Agricultural Bioengineering, Ministry of Education, Center for Research and Development of Fine Chemicals of Guizhou University, Guiyang, China
- College of Pharmacy, Guizhou University, Guiyang, China
| | - Zhen-Chao Wang
- State Key Laboratory Breeding Base of Green Pesticide and Agricultural Bioengineering, Key Laboratory of Green Pesticide and Agricultural Bioengineering, Ministry of Education, Center for Research and Development of Fine Chemicals of Guizhou University, Guiyang, China
- College of Pharmacy, Guizhou University, Guiyang, China
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Sacharok AL, Porsch EA, St Geme JW 3rd. The Kingella kingae PilC1 MIDAS Motif Is Essential for Type IV Pilus Adhesive Activity and Twitching Motility. Infect Immun 2023; 91:e0033822. [PMID: 36537792 DOI: 10.1128/iai.00338-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Kingella kingae is an emerging pathogen that has recently been identified as a leading cause of osteoarticular infections in young children. Colonization with K. kingae is common, with approximately 10% of young children carrying this organism in the oropharynx at any given time. Adherence to epithelial cells represents the first step in K. kingae colonization of the oropharynx, a prerequisite for invasive disease. Type IV pili and the pilus-associated PilC1 and PilC2 proteins have been shown to mediate K. kingae adherence to epithelial cells, but the molecular mechanism of this adhesion has remained unknown. Metal ion-dependent adhesion site (MIDAS) motifs are commonly found in integrins, where they function to promote an adhesive interaction with a ligand. In this study, we identified a potential MIDAS motif in K. kingae PilC1 which we hypothesized was directly involved in mediating type IV pilus adhesive interactions. We found that the K. kingae PilC1 MIDAS motif was required for bacterial adherence to epithelial cell monolayers and extracellular matrix proteins and for twitching motility. Our results demonstrate that K. kingae has co-opted a eukaryotic adhesive motif for promoting adherence to host structures and facilitating colonization.
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Tajuelo A, Terrón MC, López-Siles M, McConnell MJ. Role of peptidoglycan recycling enzymes AmpD and AnmK in Acinetobacter baumannii virulence features. Front Cell Infect Microbiol 2023; 12:1064053. [PMID: 36710969 PMCID: PMC9880065 DOI: 10.3389/fcimb.2022.1064053] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2022] [Accepted: 12/13/2022] [Indexed: 01/15/2023] Open
Abstract
Acinetobacter baumannii is an important causative agent of hospital acquired infections. In addition to acquired resistance to many currently-available antibiotics, it is intrinsically resistant to fosfomycin. It has previously been shown that AmpD and AnmK contribute to intrinsic fosfomycin resistance in A. baumannii due to their involvement in the peptidoglycan recycling pathway. However, the role that these two enzymes play in the fitness and virulence of A. baumannii has not been studied. The aim of this study was to characterize several virulence-related phenotypic traits in A. baumannii mutants lacking AmpD and AnmK. Specifically, cell morphology, peptidoglycan thickness, membrane permeability, growth under iron-limiting conditions, fitness, resistance to disinfectants and antimicrobial agents, twitching motility and biofilm formation of the mutant strains A. baumannii ATCC 17978 ΔampD::Kan and ΔanmK::Kan were compared to the wild type strain. Our results demonstrate that bacterial growth and fitness of both mutants were compromised, especially in the ΔampD::Kan mutant. In addition, biofilm formation was decreased by up to 69%, whereas twitching movement was reduced by about 80% in both mutants. These results demonstrate that, in addition to increased susceptibility to fosfomycin, alteration of the peptidoglycan recycling pathway affects multiple aspects related to virulence. Inhibition of these enzymes could be explored as a strategy to develop novel treatments for A. baumannii in the future. Furthermore, this study establishes a link between intrinsic fosfomycin resistance mechanisms and bacterial fitness and virulence traits.
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Affiliation(s)
- Ana Tajuelo
- Intrahospital Infections Laboratory, Instituto de Salud Carlos III (ISCIII), National Centre for Microbiology, Madrid, Spain,Universidad Nacional de Educación a Distancia (UNED), Madrid, Spain
| | - María C. Terrón
- Electron Microscopy Unit, Scientific-Technical Central Units, Instituto de Salud Carlos III (ISCIII), Madrid, Spain
| | - Mireia López-Siles
- Intrahospital Infections Laboratory, Instituto de Salud Carlos III (ISCIII), National Centre for Microbiology, Madrid, Spain,Serra Húnter Fellow, Microbiology of Intestinal Diseases, Biology Department, Universitat de Girona, Girona, Spain,*Correspondence: Mireia López-Siles,
| | - Michael J. McConnell
- Intrahospital Infections Laboratory, Instituto de Salud Carlos III (ISCIII), National Centre for Microbiology, Madrid, Spain
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Martínez-Servat S, Pinyol-Escala L, Daura-Pich O, Almazán M, Hernández I, López-García B, Fernández C. Characterization of Lysobacter enzymogenes B25, a potential biological control agent of plant-parasitic nematodes, and its mode of action. AIMS Microbiol 2023; 9:151-176. [PMID: 36891531 PMCID: PMC9988411 DOI: 10.3934/microbiol.2023010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2022] [Revised: 02/16/2023] [Accepted: 02/22/2023] [Indexed: 03/05/2023] Open
Abstract
It is certainly difficult to estimate productivity losses due to the action of phytopathogenic nematodes but it might be about 12 % of world agricultural production. Although there are numerous tools to reduce the effect of these nematodes, there is growing concern about their environmental impact. Lysobacter enzymogenes B25 is an effective biological control agent against plant-parasitic nematodes, showing control over root-knot nematodes (RKN) such as Meloidogyne incognita and Meloidogyne javanica. In this paper, the efficacy of B25 to control RKN infestation in tomato plants (Solanum lycopersicum cv. Durinta) is described. The bacterium was applied 4 times at an average of concentration around 108 CFU/mL showing an efficacy of 50-95 % depending on the population and the pressure of the pathogen. Furthermore, the control activity of B25 was comparable to that of the reference chemical used. L. enzymogenes B25 is hereby characterized, and its mode of action studied, focusing on different mechanisms that include motility, the production of lytic enzymes and secondary metabolites and the induction of plant defenses. The presence of M. incognita increased the twitching motility of B25. In addition, cell-free supernatants obtained after growing B25, in both poor and rich media, showed efficacy in inhibiting RKN egg hatching in vitro. This nematicidal activity was sensitive to high temperatures, suggesting that it is mainly due to extracellular lytic enzymes. The secondary metabolites heat-stable antifungal factor and alteramide A/B were identified in the culture filtrate and their contribution to the nematicidal activity of B25 is discussed. This study points out L. enzymogenes B25 as a promising biocontrol microorganism against nematode infestation of plants and a good candidate to develop a sustainable nematicidal product.
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Affiliation(s)
| | | | | | - Marta Almazán
- Futureco Bioscience, S.A, Olèrdola, Barcelona, Spain
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Chen YM, Wang HY, Wu CH, Lin YJ, Chiu CH. Prevalence of Type IV Pili-Mediated Twitching Motility in Streptococcus sanguinis Strains and Its Impact on Biofilm Formation and Host Adherence. Appl Environ Microbiol 2022; 88:e0140322. [PMID: 36094177 DOI: 10.1128/aem.01403-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Type IV pili (Tfp) are known to mediate several biological activities, including surface-dependent twitching motility. Although a pil gene cluster for Tfp biosynthesis is found in all sequenced Streptococcus sanguinis strains, Tfp-mediated twitching motility is less commonly detected. Upon examining 81 clinical strains, 39 strains generated twitching zones on blood agar plates (BAP), while 27 strains displayed twitching on Todd-Hewitt (TH) agar. Although BAP appears to be more suitable for the development of twitching zones, 5 strains exhibited twitching motility only on TH agar, indicating that twitching motility is not only strain specific but also sensitive to growth media. Furthermore, different twitching phenotypes were observed in strains expressing comparable levels of pilT, encoding the retraction ATPase, suggesting that the twitching phenotype on agar plates is regulated by multiple factors. By using a PilT-null and a pilin protein-null derivative (CHW02) of twitching-active S. sanguinis CGMH010, we found that Tfp retraction was essential for biofilm stability. Further, biofilm growth was amplified in CHW02 in the absence of shearing force, indicating that S. sanguinis may utilize other ligands for biofilm formation in the absence of Tfp. Similar to SK36, Tfp from CGMH010 were required for colonization of host cells, but PilT only marginally affected adherence and only in the twitching-active strain. Taken together, the results suggest that Tfp participates in host cell adherence and that Tfp retraction facilitates biofilm stability. IMPORTANCE Although the gene clusters encoding Tfp are commonly present in Streptococcus sanguinis, not all strains express surface-dependent twitching motility on agar surfaces. Regardless of whether the Tfp could drive motility, Tfp can serve as a ligand for the colonization of host cells. Though many S. sanguinis strains lack twitching activity, motility can enhance biofilm stability in a twitching-active strain; thus, perhaps motility provides little or no advantage to the survival of bacteria within dental plaque. Rather, Tfp retraction could provide additional advantages for the bacteria to establish infections outside the oral cavity.
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Patel H, Gajjar D. Cell adhesion and twitching motility influence strong biofilm formation in Pseudomonas aeruginosa. Biofouling 2022; 38:235-249. [PMID: 35345952 DOI: 10.1080/08927014.2022.2054703] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/03/2021] [Revised: 03/11/2022] [Accepted: 03/14/2022] [Indexed: 06/14/2023]
Abstract
In the present study, biofilm formation was quantified in UTI isolates of Pseudomonas aeruginosa (n = 22) using the crystal violet assay and was categorized into; strong (n = 16), weak (n = 4), and moderate (n = 2) biofilm producers. Further experiments were done using strong (n = 4) and weak (n = 4) biofilm producers. Biofilm formation was greater in Luria broth followed by natural urine and artificial urine on silicone and silicone-coated latex. Cell adhesion and twitching motility were greater in strong biofilm producers. The presence of thick biofilm with an increased number of dead and total number of cells of strong biofilm producers was observed using CLSM. The concentrations of exopolymeric substances (eDNA, protein, and pel polysaccharide) were high in strong biofilm producers. FEG-SEM visualization of biofilm produced by strong biofilm producers showed more cells encased in thick biofilm matrix than weak ones. Overall results provide evidence for increased cell adhesion and twitching motility in strong biofilm producers.
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Affiliation(s)
- Hiral Patel
- Department of Microbiology and Biotechnology Centre, Faculty of Science, The Maharaja Sayajirao University of Baroda, Vadodara, Gujarat, India
| | - Devarshi Gajjar
- Department of Microbiology and Biotechnology Centre, Faculty of Science, The Maharaja Sayajirao University of Baroda, Vadodara, Gujarat, India
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12
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Schmidt AK, Fitzpatrick AD, Schwartzkopf CM, Faith DR, Jennings LK, Coluccio A, Hunt DJ, Michaels LA, Hargil A, Chen Q, Bollyky PL, Dorward DW, Wachter J, Rosa PA, Maxwell KL, Secor PR. A Filamentous Bacteriophage Protein Inhibits Type IV Pili To Prevent Superinfection of Pseudomonas aeruginosa. mBio 2022; 13:e0244121. [PMID: 35038902 DOI: 10.1128/mbio.02441-21] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Pseudomonas aeruginosa is an opportunistic pathogen that causes infections in a variety of settings. Many P. aeruginosa isolates are infected by filamentous Pf bacteriophage integrated into the bacterial chromosome as a prophage. Pf virions can be produced without lysing P. aeruginosa. However, cell lysis can occur during superinfection, which occurs when Pf virions successfully infect a host lysogenized by a Pf prophage. Temperate phages typically encode superinfection exclusion mechanisms to prevent host lysis by virions of the same or similar species. In this study, we sought to elucidate the superinfection exclusion mechanism of Pf phage. Initially, we observed that P. aeruginosa that survive Pf superinfection are transiently resistant to Pf-induced plaquing and are deficient in twitching motility, which is mediated by type IV pili (T4P). Pf utilize T4P as a cell surface receptor, suggesting that T4P are suppressed in bacteria that survive superinfection. We tested the hypothesis that a Pf-encoded protein suppresses T4P to mediate superinfection exclusion by expressing Pf proteins in P. aeruginosa and measuring plaquing and twitching motility. We found that the Pf protein PA0721, which we termed Pf superinfection exclusion (PfsE), promoted resistance to Pf infection and suppressed twitching motility by binding the T4P protein PilC. Because T4P play key roles in biofilm formation and virulence, the ability of Pf phage to modulate T4P via PfsE has implications in the ability of P. aeruginosa to persist at sites of infection. IMPORTANCE Pf bacteriophage (phage) are filamentous viruses that infect Pseudomonas aeruginosa and enhance its virulence potential. Pf virions can lyse and kill P. aeruginosa through superinfection, which occurs when an already infected cell is infected by the same or similar phage. Here, we show that a small, highly conserved Pf phage protein (PA0721, PfsE) provides resistance to superinfection by phages that use the type IV pilus as a cell surface receptor. PfsE does this by inhibiting assembly of the type IV pilus via an interaction with PilC. As the type IV pilus plays important roles in virulence, the ability of Pf phage to modulate its assembly has implications for P. aeruginosa pathogenesis.
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13
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Vesel N, Blokesch M. Pilus Production in Acinetobacter baumannii Is Growth Phase Dependent and Essential for Natural Transformation. J Bacteriol 2021; 203:e00034-21. [PMID: 33495250 DOI: 10.1128/JB.00034-21] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2021] [Accepted: 01/19/2021] [Indexed: 12/17/2022] Open
Abstract
Rapid bacterial evolution has alarming negative impacts on animal and human health which can occur when pathogens acquire antimicrobial resistance traits. As a major cause of antibiotic-resistant opportunistic infections, A. baumannii is a high-priority health threat which has motivated renewed interest in studying how this pathogen acquires new, dangerous traits. Acinetobacter baumannii is a severe threat to human health as a frequently multidrug-resistant hospital-acquired pathogen. Part of the danger from this bacterium comes from its genome plasticity and ability to evolve quickly by taking up and recombining external DNA into its own genome in a process called natural competence for transformation. This mode of horizontal gene transfer is one of the major ways that bacteria can acquire new antimicrobial resistances and toxic traits. Because these processes in A. baumannii are not well studied, we herein characterized new aspects of natural transformability in this species that include the species’ competence window. We uncovered a strong correlation with a growth phase-dependent synthesis of a type IV pilus (TFP), which constitutes the central part of competence-induced DNA uptake machinery. We used bacterial genetics and microscopy to demonstrate that the TFP is essential for the natural transformability and surface motility of A. baumannii, whereas pilus-unrelated proteins of the DNA uptake complex do not affect the motility phenotype. Furthermore, TFP biogenesis and assembly is subject to input from two regulatory systems that are homologous to Pseudomonas aeruginosa, namely, the PilSR two-component system and the Pil-Chp chemosensory system. We demonstrated that these systems affect not only the piliation status of cells but also their ability to take up DNA for transformation. Importantly, we report on discrepancies between TFP biogenesis and natural transformability within the same genus by comparing data for our work on A. baumannii to data reported for Acinetobacter baylyi, the latter of which served for decades as a model for natural competence. IMPORTANCE Rapid bacterial evolution has alarming negative impacts on animal and human health which can occur when pathogens acquire antimicrobial resistance traits. As a major cause of antibiotic-resistant opportunistic infections, A. baumannii is a high-priority health threat which has motivated renewed interest in studying how this pathogen acquires new, dangerous traits. In this study, we deciphered a specific time window in which these bacteria can acquire new DNA and correlated that with its ability to produce the external appendages that contribute to the DNA acquisition process. These cell appendages function doubly for motility on surfaces and for DNA uptake. Collectively, we showed that A. baumannii is similar in its TFP production to Pseudomonas aeruginosa, though it differs from the well-studied species A. baylyi.
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14
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Carabelli A, Isgró M, Sanni O, Figueredo GP, Winkler DA, Burroughs L, Blok AJ, Dubern JF, Pappalardo F, Hook AL, Williams P, Alexander MR. Single-Cell Tracking on Polymer Microarrays Reveals the Impact of Surface Chemistry on Pseudomonas aeruginosa Twitching Speed and Biofilm Development. ACS Appl Bio Mater 2020; 3:8471-8480. [PMID: 34308271 PMCID: PMC8291582 DOI: 10.1021/acsabm.0c00849] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2020] [Accepted: 10/22/2020] [Indexed: 12/02/2022]
Abstract
Bacterial biofilms exhibit up to 1000 times greater resistance to antibiotic or host immune clearance than planktonic cells. Pseudomonas aeruginosa produces retractable type IV pili (T4P) that facilitate twitching motility on surfaces. The deployment of pili is one of the first responses of bacteria to surface interactions and because of their ability to contribute to cell surface adhesion and biofilm formation, this has relevance to medical device-associated infections. While polymer chemistry is known to influence biofilm development, its impact on twitching motility is not understood. Here, we combine a polymer microarray format with time-lapse automated microscopy to simultaneously assess P. aeruginosa twitching motility on 30 different methacrylate/acrylate polymers over 60 min post inoculation using a high-throughput system. During this critical initial period where the decision to form a biofilm is thought to occur, similar numbers of bacterial cells accumulate on each polymer. Twitching motility is observed on all polymers irrespective of their chemistry and physical surface properties, in contrast to the differential biofilm formation noted after 24 h of incubation. However, on the microarray polymers, P. aeruginosa cells twitch at significantly different speeds, ranging from 5 to ∼13 nm/s, associated with crawling or walking and are distinguishable from the different cell surface tilt angles observed. Chemometric analysis using partial least-squares (PLS) regression identifies correlations between surface chemistry, as measured by time-of-flight secondary ion mass spectrometry (ToF-SIMS), and both biofilm formation and single-cell twitching speed. The relationships between surface chemistry and these two responses are different for each process. There is no correlation between polymer surface stiffness and roughness as determined by atomic force measurement (AFM), or water contact angle (WCA), and twitching speed or biofilm formation. This reinforces the dominant and distinct contributions of material surface chemistry to twitching speed and biofilm formation.
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Affiliation(s)
- Alessandro
M. Carabelli
- Advanced
Materials and Healthcare Technologies, School of Pharmacy, University of Nottingham, Nottingham NG7 2RD, U.K.
| | - Marco Isgró
- Advanced
Materials and Healthcare Technologies, School of Pharmacy, University of Nottingham, Nottingham NG7 2RD, U.K.
| | - Olutoba Sanni
- Advanced
Materials and Healthcare Technologies, School of Pharmacy, University of Nottingham, Nottingham NG7 2RD, U.K.
| | | | - David A. Winkler
- Advanced
Materials and Healthcare Technologies, School of Pharmacy, University of Nottingham, Nottingham NG7 2RD, U.K.
- Monash
Institute of Pharmaceutical Sciences, Monash
University, Parkville 3052, Australia
- La Trobe
Institute for Molecular Science, la Trobe
University, Bundoora 3083, Australia
- CSIRO
Data61, Pullenvale 4069, Australia
| | - Laurence Burroughs
- Advanced
Materials and Healthcare Technologies, School of Pharmacy, University of Nottingham, Nottingham NG7 2RD, U.K.
| | - Andrew J. Blok
- Division
of Molecular Therapeutics and Formulation, School of Pharmacy, University of Nottingham, Nottingham, NG7 2RD, U.K.
| | - Jean-Frédéric Dubern
- Biodiscovery
Institute and School of Life Sciences, University
of Nottingham, Nottingham NG7 2RD, U.K.
| | - Francesco Pappalardo
- Advanced
Materials and Healthcare Technologies, School of Pharmacy, University of Nottingham, Nottingham NG7 2RD, U.K.
| | - Andrew L. Hook
- Advanced
Materials and Healthcare Technologies, School of Pharmacy, University of Nottingham, Nottingham NG7 2RD, U.K.
| | - Paul Williams
- Biodiscovery
Institute and School of Life Sciences, University
of Nottingham, Nottingham NG7 2RD, U.K.
| | - Morgan R. Alexander
- Advanced
Materials and Healthcare Technologies, School of Pharmacy, University of Nottingham, Nottingham NG7 2RD, U.K.
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15
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V. K, Neela VK. Twitching motility of Stenotrophomonas maltophilia under iron limitation: In-silico, phenotypic and proteomic approaches. Virulence 2020; 11:104-112. [PMID: 31957553 PMCID: PMC6984648 DOI: 10.1080/21505594.2020.1713649] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2019] [Revised: 11/18/2019] [Accepted: 12/02/2019] [Indexed: 10/26/2022] Open
Abstract
This study investigates the twitching ability of 28 clinical and five environmental strains of S. maltophilia grown under iron-depleted condition through in-silico, phenotypic and proteomics approaches. Rapid Annotations using Subsystem Technology (RAST) analysis revealed the presence of 21 targets of type IV pilus shared across S. maltophilia strains K279a, R551-3, D457 and JV3. The macroscopic twitching assay showed that only clinical isolates produced a zone of twitching with a mean of 22.00 mm under normal and 25.00 mm under iron-depleted conditions. (p = 0.002). Environmental isolates did not show any significant twitching activity in both conditions tested. Isobaric Tags for Relative and Absolute Quantification (ITRAQ) analysis showed altered expression of twitching motility protein PilT (99.08-fold change), flagellar biosynthesis protein FliC (20.14-fold change), and fimbrial protein (0.70-fold change) in response to iron-depleted condition. Most of the strains that have the ability to twitch under the normal condition, exhibit enhanced twitching during iron limitation.
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Affiliation(s)
- Kalidasan V.
- Department of Medical Microbiology and Parasitology, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, Serdang, Malaysia
| | - Vasantha Kumari Neela
- Department of Medical Microbiology and Parasitology, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, Serdang, Malaysia
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16
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D'Attoma G, Morelli M, De La Fuente L, Cobine PA, Saponari M, de Souza AA, De Stradis A, Saldarelli P. Phenotypic Characterization and Transformation Attempts Reveal Peculiar Traits of Xylella fastidiosa Subspecies pauca Strain De Donno. Microorganisms 2020; 8:E1832. [PMID: 33233703 DOI: 10.3390/microorganisms8111832] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2020] [Revised: 11/17/2020] [Accepted: 11/18/2020] [Indexed: 12/19/2022] Open
Abstract
Xylella fastidiosa subsp. pauca strain De Donno has been recently identified as the causal agent of a severe disease affecting olive trees in a wide area of the Apulia Region (Italy). While insights on the genetics and epidemiology of this virulent strain have been gained, its phenotypic and biological traits remained to be explored. We investigated in vitro behavior of the strain and compare its relevant biological features (growth rate, biofilm formation, cell-cell aggregation, and twitching motility) with those of the type strain Temecula1. The experiments clearly showed that the strain De Donno did not show fringe on the agar plates, produced larger amounts of biofilm and had a more aggregative behavior than the strain Temecula1. Repeated attempts to transform, by natural competence, the strain De Donno failed to produce a GFP-expressing and a knockout mutant for the rpfF gene. Computational prediction allowed us to identify potentially deleterious sequence variations most likely affecting the natural competence and the lack of fringe formation. GFP and rpfF- mutants were successfully obtained by co-electroporation in the presence of an inhibitor of the type I restriction-modification system. The availability of De Donno mutant strains will open for new explorations of its interactions with hosts and insect vectors.
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Fulano AM, Shen D, Kinoshita M, Chou SH, Qian G. The Homologous Components of Flagellar Type III Protein Apparatus Have Acquired a Novel Function to Control Twitching Motility in a Non-Flagellated Biocontrol Bacterium. Biomolecules 2020; 10:E733. [PMID: 32392834 DOI: 10.3390/biom10050733] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2020] [Revised: 04/30/2020] [Accepted: 05/05/2020] [Indexed: 01/07/2023] Open
Abstract
The bacterial flagellum is one of the best-studied surface-attached appendages in bacteria. Flagellar assembly in vivo is promoted by its own protein export apparatus, a type III secretion system (T3SS) in pathogenic bacteria. Lysobacter enzymogenes OH11 is a non-flagellated soil bacterium that utilizes type IV pilus (T4P)-driven twitching motility to prey upon nearby fungi for food. Interestingly, the strain OH11 encodes components homologous to the flagellar type III protein apparatus (FT3SS) on its genome, but it remains unknown whether this FT3SS-like system is functional. Here, we report that, despite the absence of flagella, the FT3SS homologous genes are responsible not only for the export of the heterologous flagellin in strain OH11 but also for twitching motility. Blocking the FT3SS-like system by in-frame deletion mutations in either flhB or fliI abolished the secretion of heterologous flagellin molecules into the culture medium, indicating that the FT3SS is functional in strain OH11. A deletion of flhA, flhB, fliI, or fliR inhibited T4P-driven twitching motility, whereas neither that of fliP nor fliQ did, suggesting that FlhA, FlhB, FliI, and FliR may obtain a novel function to modulate the twitching motility. The flagellar FliI ATPase was required for the secretion of the major pilus subunit, PilA, suggesting that FliI would have evolved to act as a PilB-like pilus ATPase. These observations lead to a plausible hypothesis that the non-flagellated L. enzymogenes OH11 could preserve FT3SS-like genes for acquiring a distinct function to regulate twitching motility associated with its predatory behavior.
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18
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Feng T, Han Y, Li B, Li Z, Yu Y, Sun Q, Li X, Du L, Zhang XH, Wang Y. Interspecies and Intraspecies Signals Synergistically Regulate Lysobacter enzymogenes Twitching Motility. Appl Environ Microbiol 2019; 85:e01742-19. [PMID: 31540995 DOI: 10.1128/AEM.01742-19] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2019] [Accepted: 09/18/2019] [Indexed: 12/24/2022] Open
Abstract
The twitching motility of bacteria is closely related to environmental adaptability and pathogenic behaviors. Lysobacter is a good genus in which to study twitching motility because of the complex social activities and distinct movement patterns of its members. Regardless, the mechanism that induces twitching motility is largely unknown. In this study, we found that the interspecies signal indole caused Lysobacter to have irregular, random twitching motility with significantly enhanced speed. Deletion of qseC or qseB from the two-component system for indole signaling perception resulted in the disappearance of rapid, random movements and significantly decreased twitching activity. Indole-induced, rapid, random twitching was achieved through upregulation of expression of gene cluster pilE1-pilY11-pilX1-pilW1-pilV1-fimT1 In addition, under conditions of extremely low bacterial density, individual Lysobacter cells grew and divided in a stable manner in situ without any movement. The intraspecies quorum-sensing signaling factor 13-methyltetradecanoic acid, designated L. enzymogenes diffusible signaling factor (LeDSF), was essential for Lysobacter to produce twitching motility through indirect regulation of gene clusters pilM-pilN-pilO-pilP-pilQ and pilS1-pilR-pilA-pilB-pilC These results demonstrate that the motility of Lysobacter is induced and regulated by indole and LeDSF, which reveals a novel theory for future studies of the mechanisms of bacterial twitching activities.IMPORTANCE The mechanism underlying bacterial twitching motility is an important research area because it is closely related to social and pathogenic behaviors. The mechanism mediating cell-to-cell perception of twitching motility is largely unknown. Using Lysobacter as a model, we found in this study that the interspecies signal indole caused Lysobacter to exhibit irregular, random twitching motility via activation of gene cluster pilE1-pilY11-pilX1-pilW1-pilV1-fimT1 In addition, population-dependent behavior induced by 13-methyltetradecanoic acid, a quorum-sensing signaling molecule designated LeDSF, was involved in twitching motility by indirectly regulating gene clusters pilM-pilN-pilO-pilP-pilQ and pilS1-pilR-pilA-pilB-pilC The results demonstrate that the twitching motility of Lysobacter is regulated by these two signaling molecules, offering novel clues for exploring the mechanisms of twitching motility and population-dependent behaviors of bacteria.
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19
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Zöllner R, Cronenberg T, Maier B. Motor Properties of PilT-Independent Type 4 Pilus Retraction in Gonococci. J Bacteriol 2019; 201:e00778-18. [PMID: 30692169 PMCID: PMC6707916 DOI: 10.1128/jb.00778-18] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2018] [Accepted: 01/17/2019] [Indexed: 01/25/2023] Open
Abstract
Bacterial type 4 pili (T4P) belong to the strongest molecular machines. The gonococcal T4P retraction ATPase PilT supports forces exceeding 100 pN during T4P retraction. Here, we address the question of whether gonococcal T4P retract in the absence of PilT. We show that pilT deletion strains indeed retract their T4P, but the maximum force is reduced to 5 pN. Similarly, the speed of T4P retraction is lower by orders of magnitude compared to that of T4P retraction driven by PilT. Deleting the pilT paralogue pilT2 further reduces the speed of T4P retraction, yet T4P retraction is detectable in the absence of all three pilT paralogues. Furthermore, we show that depletion of proton motive force (PMF) slows but does not inhibit pilT-independent T4P retraction. We conclude that the retraction ATPase is not essential for gonococcal T4P retraction. However, the force generated in the absence of PilT is too low to support important functions of T4P, including twitching motility, fluidization of colonies, and induction of host cell response.IMPORTANCE Bacterial type 4 pili (T4P) have been termed the "Swiss Army knives" of bacteria because they perform numerous functions, including host cell interaction, twitching motility, colony formation, DNA uptake, protein secretion, and surface sensing. The pilus fiber continuously elongates or retracts, and these dynamics are functionally important. Curiously, only a subset of T4P systems employ T4P retraction ATPases to power T4P retraction. Here, we show that one of the strongest T4P machines, the gonococcal T4P, retracts without a retraction ATPase. Biophysical characterization reveals strongly reduced force and speed compared to retraction with ATPase. We propose that bacteria encode retraction ATPases when T4P have to generate high-force-supporting functions like twitching motility, triggering host cell response, or fluidizing colonies.
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Affiliation(s)
- Robert Zöllner
- University of Cologne, Institute for Biological Physics, Cologne, Germany
| | - Tom Cronenberg
- University of Cologne, Institute for Biological Physics, Cologne, Germany
| | - Berenike Maier
- University of Cologne, Institute for Biological Physics, Cologne, Germany
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20
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Nieto V, Kroken AR, Grosser MR, Smith BE, Metruccio MME, Hagan P, Hallsten ME, Evans DJ, Fleiszig SMJ. Type IV Pili Can Mediate Bacterial Motility within Epithelial Cells. mBio 2019; 10:e02880-18. [PMID: 31431558 PMCID: PMC6703432 DOI: 10.1128/mbio.02880-18] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2018] [Accepted: 07/31/2019] [Indexed: 02/07/2023] Open
Abstract
Pseudomonas aeruginosa is among bacterial pathogens capable of twitching motility, a form of surface-associated movement dependent on type IV pili (T4P). Previously, we showed that T4P and twitching were required for P. aeruginosa to cause disease in a murine model of corneal infection, to traverse human corneal epithelial multilayers, and to efficiently exit invaded epithelial cells. Here, we used live wide-field fluorescent imaging combined with quantitative image analysis to explore how twitching contributes to epithelial cell egress. Results using time-lapse imaging of cells infected with wild-type PAO1 showed that cytoplasmic bacteria slowly disseminated throughout the cytosol at a median speed of >0.05 μm s-1 while dividing intracellularly. Similar results were obtained with flagellin (fliC) and flagellum assembly (flhA) mutants, thereby excluding swimming, swarming, and sliding as mechanisms. In contrast, pilA mutants (lacking T4P) and pilT mutants (twitching motility defective) appeared stationary and accumulated in expanding aggregates during intracellular division. Transmission electron microscopy confirmed that these mutants were not trapped within membrane-bound cytosolic compartments. For the wild type, dissemination in the cytosol was not prevented by the depolymerization of actin filaments using latrunculin A and/or the disruption of microtubules using nocodazole. Together, these findings illustrate a novel form of intracellular bacterial motility differing from previously described mechanisms in being directly driven by bacterial motility appendages (T4P) and not depending on polymerized host actin or microtubules.IMPORTANCE Host cell invasion can contribute to disease pathogenesis by the opportunistic pathogen Pseudomonas aeruginosa Previously, we showed that the type III secretion system (T3SS) of invasive P. aeruginosa strains modulates cell entry and subsequent escape from vacuolar trafficking to host lysosomes. However, we also showed that mutants lacking either type IV pili (T4P) or T4P-dependent twitching motility (i) were defective in traversing cell multilayers, (ii) caused less pathology in vivo, and (iii) had a reduced capacity to exit invaded cells. Here, we report that after vacuolar escape, intracellular P. aeruginosa can use T4P-dependent twitching motility to disseminate throughout the host cell cytoplasm. We further show that this strategy for intracellular dissemination does not depend on flagellin and resists both host actin and host microtubule disruption. This differs from mechanisms used by previously studied pathogens that utilize either host actin or microtubules for intracellular dissemination independently of microbe motility appendages.
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Affiliation(s)
- Vincent Nieto
- School of Optometry, University of California, Berkeley, California, USA
| | - Abby R Kroken
- School of Optometry, University of California, Berkeley, California, USA
| | - Melinda R Grosser
- School of Optometry, University of California, Berkeley, California, USA
| | - Benjamin E Smith
- Vision Science Program, University of California, Berkeley, California, USA
| | | | - Patrick Hagan
- Undergraduate Research Apprentice Program, University of California, Berkeley, California, USA
| | - Mary E Hallsten
- Undergraduate Research Apprentice Program, University of California, Berkeley, California, USA
| | - David J Evans
- School of Optometry, University of California, Berkeley, California, USA
- College of Pharmacy, Touro University California, Vallejo, California, USA
| | - Suzanne M J Fleiszig
- School of Optometry, University of California, Berkeley, California, USA
- Vision Science Program, University of California, Berkeley, California, USA
- Graduate Group in Microbiology, University of California, Berkeley, California, USA
- Graduate Group in Infectious Diseases and Immunity, University of California, Berkeley, California, USA
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21
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Nelson CE, Huang W, Brewer LK, Nguyen AT, Kane MA, Wilks A, Oglesby-Sherrouse AG. Proteomic Analysis of the Pseudomonas aeruginosa Iron Starvation Response Reveals PrrF Small Regulatory RNA-Dependent Iron Regulation of Twitching Motility, Amino Acid Metabolism, and Zinc Homeostasis Proteins. J Bacteriol 2019; 201:e00754-18. [PMID: 30962354 DOI: 10.1128/JB.00754-18] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2018] [Accepted: 03/31/2019] [Indexed: 12/16/2022] Open
Abstract
Iron is a critical nutrient for most microbial pathogens, and the immune system exploits this requirement by sequestering iron. The opportunistic pathogen Pseudomonas aeruginosa exhibits a high requirement for iron yet an exquisite ability to overcome iron deprivation during infection. Upon iron starvation, P. aeruginosa induces the expression of several high-affinity iron acquisition systems, as well as the PrrF small regulatory RNAs (sRNAs) that mediate an iron-sparing response. Here, we used liquid chromatography-tandem mass spectrometry to conduct proteomics of the iron starvation response of P. aeruginosa Iron starvation increased levels of multiple proteins involved in amino acid catabolism, providing the capacity for iron-independent entry of carbons into the tricarboxylic acid (TCA) cycle. Proteins involved in sulfur assimilation and cysteine biosynthesis were reduced upon iron starvation, while proteins involved in iron-sulfur cluster biogenesis were increased, highlighting the central role of iron in P. aeruginosa metabolism. Iron starvation also resulted in changes in the expression of several zinc-responsive proteins and increased levels of twitching motility proteins. Subsequent analyses provided evidence for the regulation of many of these proteins via posttranscriptional regulatory events, some of which are dependent upon the PrrF sRNAs. Moreover, we showed that iron-regulated twitching motility is partially dependent upon the prrF locus, highlighting a novel link between the PrrF sRNAs and motility. These findings add to the known impacts of iron starvation in P. aeruginosa and outline potentially novel roles for the PrrF sRNAs in iron homeostasis and pathogenesis.IMPORTANCE Iron is central for growth and metabolism of almost all microbial pathogens, and as such, this element is sequestered by the host innate immune system to restrict microbial growth. Here, we used label-free proteomics to investigate the Pseudomonas aeruginosa iron starvation response, revealing a broad landscape of metabolic and metal homeostasis changes that have not previously been described. We further provide evidence that many of these processes, including twitching motility, are regulated through the iron-responsive PrrF small regulatory RNAs. As such, this study demonstrates the power of proteomics for defining stress responses of microbial pathogens.
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Daum B, Gold V. Twitch or swim: towards the understanding of prokaryotic motion based on the type IV pilus blueprint. Biol Chem 2019; 399:799-808. [PMID: 29894297 DOI: 10.1515/hsz-2018-0157] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2018] [Accepted: 05/05/2018] [Indexed: 01/02/2023]
Abstract
Bacteria and archaea are evolutionarily distinct prokaryotes that diverged from a common ancestor billions of years ago. However, both bacteria and archaea assemble long, helical protein filaments on their surface through a machinery that is conserved at its core. In both domains of life, the filaments are required for a diverse array of important cellular processes including cell motility, adhesion, communication and biofilm formation. In this review, we highlight the recent structures of both the type IV pilus machinery and the archaellum determined in situ. We describe the current level of functional understanding and discuss how this relates to the pressures facing bacteria and archaea throughout evolution.
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Affiliation(s)
- Bertram Daum
- Living Systems Institute, University of Exeter, Stocker Road, Exeter EX4 4QD, UK.,College of Engineering, Mathematics and Physical Sciences, University of Exeter, Stocker Road, Exeter EX4 4QD, UK
| | - Vicki Gold
- Living Systems Institute, University of Exeter, Stocker Road, Exeter EX4 4QD, UK.,College of Life and Environmental Sciences, Geoffrey Pope, University of Exeter, Stocker Road, Exeter EX4 4QD, UK
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23
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Berry JL, Gurung I, Anonsen JH, Spielman I, Harper E, Hall AMJ, Goosens VJ, Raynaud C, Koomey M, Biais N, Matthews S, Pelicic V. Global biochemical and structural analysis of the type IV pilus from the Gram-positive bacterium Streptococcus sanguinis. J Biol Chem 2019; 294:6796-6808. [PMID: 30837269 PMCID: PMC6497953 DOI: 10.1074/jbc.ra118.006917] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2018] [Revised: 02/27/2019] [Indexed: 11/06/2022] Open
Abstract
Type IV pili (Tfp) are functionally versatile filaments, widespread in prokaryotes, that belong to a large class of filamentous nanomachines known as type IV filaments (Tff). Although Tfp have been extensively studied in several Gram-negative pathogens where they function as key virulence factors, many aspects of their biology remain poorly understood. Here, we performed a global biochemical and structural analysis of Tfp in a recently emerged Gram-positive model, Streptococcus sanguinis In particular, we focused on the five pilins and pilin-like proteins involved in Tfp biology in S. sanguinis We found that the two major pilins, PilE1 and PilE2, (i) follow widely conserved principles for processing by the prepilin peptidase PilD and for assembly into filaments; (ii) display only one of the post-translational modifications frequently found in pilins, i.e. a methylated N terminus; (iii) are found in the same heteropolymeric filaments; and (iv) are not functionally equivalent. The 3D structure of PilE1, solved by NMR, revealed a classical pilin-fold with a highly unusual flexible C terminus. Intriguingly, PilE1 more closely resembles pseudopilins forming shorter Tff than bona fide Tfp-forming major pilins, underlining the evolutionary relatedness among different Tff. Finally, we show that S. sanguinis Tfp contain a low abundance of three additional proteins processed by PilD, the minor pilins PilA, PilB, and PilC. These findings provide the first global biochemical and structural picture of a Gram-positive Tfp and have fundamental implications for our understanding of a widespread class of filamentous nanomachines.
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Affiliation(s)
- Jamie-Lee Berry
- From the Medical Research Council Centre for Molecular Bacteriology and Infection, Imperial College London, London SW7 2AZ, United Kingdom
| | - Ishwori Gurung
- From the Medical Research Council Centre for Molecular Bacteriology and Infection, Imperial College London, London SW7 2AZ, United Kingdom
| | - Jan Haug Anonsen
- the Department of Biological Sciences, Proteomics and Mass Spectrometry Unit, University of Oslo, 0371 Oslo, Norway.,the Department of Biological Sciences, Center for Integrative Microbial Evolution, University of Oslo, 0371 Oslo, Norway
| | - Ingrid Spielman
- the Department of Biology, Brooklyn College of the City University of New York, New York, New York 11210.,The Graduate Center of the City University of New York, New York, New York 10016, and
| | - Elliot Harper
- From the Medical Research Council Centre for Molecular Bacteriology and Infection, Imperial College London, London SW7 2AZ, United Kingdom
| | - Alexander M J Hall
- From the Medical Research Council Centre for Molecular Bacteriology and Infection, Imperial College London, London SW7 2AZ, United Kingdom
| | - Vivianne J Goosens
- From the Medical Research Council Centre for Molecular Bacteriology and Infection, Imperial College London, London SW7 2AZ, United Kingdom
| | - Claire Raynaud
- From the Medical Research Council Centre for Molecular Bacteriology and Infection, Imperial College London, London SW7 2AZ, United Kingdom
| | - Michael Koomey
- the Department of Biological Sciences, Center for Integrative Microbial Evolution, University of Oslo, 0371 Oslo, Norway
| | - Nicolas Biais
- the Department of Biology, Brooklyn College of the City University of New York, New York, New York 11210.,The Graduate Center of the City University of New York, New York, New York 10016, and
| | - Steve Matthews
- the Centre for Structural Biology, Imperial College London, London SW7 2AZ, United Kingdom
| | - Vladimir Pelicic
- From the Medical Research Council Centre for Molecular Bacteriology and Infection, Imperial College London, London SW7 2AZ, United Kingdom,
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24
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Ronish LA, Lillehoj E, Fields JK, Sundberg EJ, Piepenbrink KH. The structure of PilA from Acinetobacter baumannii AB5075 suggests a mechanism for functional specialization in Acinetobacter type IV pili. J Biol Chem 2018; 294:218-230. [PMID: 30413536 DOI: 10.1074/jbc.ra118.005814] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2018] [Revised: 10/19/2018] [Indexed: 11/06/2022] Open
Abstract
Type IV pili (T4P) are bacterial appendages composed of protein subunits, called pilins, noncovalently assembled into helical fibers. T4P are essential, in many bacterial species, for processes as diverse as twitching motility, natural competence, biofilm or microcolony formation, and host cell adhesion. The genes encoding type IV pili are found universally in the Gram-negative, aerobic, nonflagellated, and pathogenic coccobacillus Acinetobacter baumannii, but there is considerable variation in PilA, the major protein subunit, both in amino acid sequence and in glycosylation patterns. Here we report the X-ray crystal structure of PilA from AB5075, a recently characterized, highly virulent isolate, at 1.9 Å resolution and compare it to homologues from A. baumannii strains ACICU and BIDMC57, which are C-terminally glycosylated. These structural comparisons revealed that PilAAB5075 exhibits a distinctly electronegative surface chemistry. To understand the functional consequences of this change in surface electrostatics, we complemented a ΔpilA knockout strain with divergent pilA genes from ACICU, BIDMC57, and AB5075. The resulting transgenic strains showed differential twitching motility and biofilm formation while maintaining the ability to adhere to epithelial cells. PilAAB5075 and PilAACICU, although structurally similar, promote different characteristics, favoring twitching motility and biofilm formation, respectively. These results support a model in which differences in pilus electrostatics affect the equilibrium of microcolony formation, which in turn alters the balance between motility and biofilm formation in Acinetobacter.
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Affiliation(s)
- Leslie A Ronish
- Department of Biochemistry, University of Nebraska-Lincoln, Lincoln, Nebraska 68588
| | - Erik Lillehoj
- Department of Pediatrics, University of Maryland School of Medicine, Baltimore, Maryland 21201
| | - James K Fields
- Institute of Human Virology, University of Maryland School of Medicine, Baltimore, Maryland 21201
| | - Eric J Sundberg
- Institute of Human Virology, University of Maryland School of Medicine, Baltimore, Maryland 21201; Department of Medicine, University of Maryland School of Medicine, Baltimore, Maryland 21201; Departments of Microbiology and Immunology, University of Maryland School of Medicine, Baltimore, Maryland 21201
| | - Kurt H Piepenbrink
- Department of Biochemistry, University of Nebraska-Lincoln, Lincoln, Nebraska 68588; Departments of Food Science and Technology, University of Nebraska-Lincoln, Lincoln, Nebraska 68588; Nebraska Food for Health Center, University of Nebraska-Lincoln, Lincoln, Nebraska 68588; Center for Integrated Biomolecular Communication, University of Nebraska-Lincoln, Lincoln, Nebraska 68588.
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25
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Nolan LM, Whitchurch CB, Barquist L, Katrib M, Boinett CJ, Mayho M, Goulding D, Charles IG, Filloux A, Parkhill J, Cain AK. A global genomic approach uncovers novel components for twitching motility-mediated biofilm expansion in Pseudomonas aeruginosa. Microb Genom 2018; 4. [PMID: 30383525 PMCID: PMC6321873 DOI: 10.1099/mgen.0.000229] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Pseudomonas aeruginosa is an extremely successful pathogen able to cause both acute and chronic infections in a range of hosts, utilizing a diverse arsenal of cell-associated and secreted virulence factors. A major cell-associated virulence factor, the Type IV pilus (T4P), is required for epithelial cell adherence and mediates a form of surface translocation termed twitching motility, which is necessary to establish a mature biofilm and actively expand these biofilms. P. aeruginosa twitching motility-mediated biofilm expansion is a coordinated, multicellular behaviour, allowing cells to rapidly colonize surfaces, including implanted medical devices. Although at least 44 proteins are known to be involved in the biogenesis, assembly and regulation of the T4P, with additional regulatory components and pathways implicated, it is unclear how these components and pathways interact to control these processes. In the current study, we used a global genomics-based random-mutagenesis technique, transposon directed insertion-site sequencing (TraDIS), coupled with a physical segregation approach, to identify all genes implicated in twitching motility-mediated biofilm expansion in P. aeruginosa. Our approach allowed identification of both known and novel genes, providing new insight into the complex molecular network that regulates this process in P. aeruginosa. Additionally, our data suggest that the flagellum-associated gene products have a differential effect on twitching motility, based on whether components are intra- or extracellular. Overall the success of our TraDIS approach supports the use of this global genomic technique for investigating virulence genes in bacterial pathogens.
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Affiliation(s)
- Laura M Nolan
- 1MRC Centre for Molecular Bacteriology and Infection (CMBI), Department of Life Sciences, Imperial College London, London SW7 2AZ, UK
| | - Cynthia B Whitchurch
- 2The ithree Institute, University of Technology Sydney, Ultimo, NSW 2007, Australia
| | - Lars Barquist
- 3Institute for Molecular Infection Biology, University of Würzburg, Würzburg D-97080, Germany.,4Helmholtz Institute for RNA-based Infection Research (HIRI), Würzburg, Germany
| | - Marilyn Katrib
- 2The ithree Institute, University of Technology Sydney, Ultimo, NSW 2007, Australia
| | - Christine J Boinett
- 5Wellcome Sanger Institute, Wellcome Genome Campus, Hinxton, Cambridge, UK.,†Present address: Hospital for Tropical Diseases, Wellcome Trust Major Overseas Programme, Oxford University Clinical Research Unit, Ho Chi Minh City, Vietnam
| | - Matthew Mayho
- 5Wellcome Sanger Institute, Wellcome Genome Campus, Hinxton, Cambridge, UK
| | - David Goulding
- 5Wellcome Sanger Institute, Wellcome Genome Campus, Hinxton, Cambridge, UK
| | - Ian G Charles
- 6Quadram Institute of Bioscience, Norwich Research Park, Norwich, Norfolk NR4 7UA, UK
| | - Alain Filloux
- 1MRC Centre for Molecular Bacteriology and Infection (CMBI), Department of Life Sciences, Imperial College London, London SW7 2AZ, UK
| | - Julian Parkhill
- 5Wellcome Sanger Institute, Wellcome Genome Campus, Hinxton, Cambridge, UK
| | - Amy K Cain
- 5Wellcome Sanger Institute, Wellcome Genome Campus, Hinxton, Cambridge, UK.,‡Present address: Chemical and Biomolecular Sciences, Macquarie University, Sydney, NSW, Australia
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26
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Song WY, Zang SS, Li ZK, Dai GZ, Liu K, Chen M, Qiu BS. Sycrp2 Is Essential for Twitching Motility in the Cyanobacterium Synechocystis sp. Strain PCC 6803. J Bacteriol 2018; 200:e00436-18. [PMID: 30104238 DOI: 10.1128/JB.00436-18] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2018] [Accepted: 08/10/2018] [Indexed: 01/13/2023] Open
Abstract
Two cAMP receptor proteins (CRPs), Sycrp1 (encoded by sll1371) and Sycrp2 (encoded by sll1924), exist in the cyanobacterium Synechocystis sp. strain PCC 6803. Previous studies have demonstrated that Sycrp1 has binding affinity for cAMP and is involved in motility by regulating the formation of pili. However, the function of Sycrp2 remains unknown. Here, we report that sycrp2 disruption results in the loss of motility of Synechocystis sp. PCC 6803, and that the phenotype can be recovered by reintroducing the sycrp2 gene into the genome of sycrp2-disrupted mutants. Electron microscopy showed that the sycrp2-disrupted mutant lost the pilus apparatus on the cell surface, resulting in a lack of cell motility. Furthermore, the transcript level of the pilA9-pilA11 operon (essential for cell motility and regulated by the cAMP receptor protein Sycrp1) was markedly decreased in sycrp2-disrupted mutants compared with the wild-type strain. Moreover, yeast two-hybrid analysis and a pulldown assay demonstrated that Sycrp2 interacted with Sycrp1 to form a heterodimer and that Sycrp1 and Sycrp2 interacted with themselves to form homodimers. Gel mobility shift assays revealed that Sycrp1 specifically binds to the upstream region of pilA9 Together, these findings indicate that in Synechocystis sp. PCC 6803, Sycrp2 regulates the formation of pili and cell motility by interacting with Sycrp1.IMPORTANCE cAMP receptor proteins (CRPs) are widely distributed in cyanobacteria and play important roles in regulating gene expression. Although many cyanobacterial species have two cAMP receptor-like proteins, the functional links between them are unknown. Here, we found that Sycrp2 in the cyanobacterium Synechocystis sp. strain PCC 6803 is essential for twitching motility and that it interacts with Sycrp1, a known cAMP receptor protein involved with twitching motility. Our findings indicate that the two cAMP receptor-like proteins in cyanobacteria do not have functional redundancy but rather work together.
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27
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De Silva PM, Chong P, Fernando DM, Westmacott G, Kumar A. Effect of Incubation Temperature on Antibiotic Resistance and Virulence Factors of Acinetobacter baumannii ATCC 17978. Antimicrob Agents Chemother 2018; 62:e01514-17. [PMID: 29061747 DOI: 10.1128/AAC.01514-17] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2017] [Accepted: 10/16/2017] [Indexed: 01/27/2023] Open
Abstract
Acinetobacter baumannii is a notorious opportunistic pathogen that is prevalent mainly in hospital settings. The ability of A. baumannii to adapt and to survive in a range of environments has been a key factor for its persistence and success as an opportunistic pathogen. In this study, we investigated the effect of temperature on the clinically relevant phenotypes displayed by A. baumannii at 37°C and 28°C. Surface-associated motility was significantly reduced at 28°C, while biofilm formation on plastic surfaces was increased at 28°C. Decreased susceptibility to aztreonam and increased susceptibility to trimethoprim-sulfamethoxazole were observed at 28°C. No differences in virulence, as assayed in a Galleria mellonella model, were observed. Proteomic analysis showed differential expression of 629 proteins, of which 366 were upregulated and 263 were downregulated at 28°C. Upregulation of the Csu and iron uptake proteins at 28°C was a key finding for understanding some of the phenotypes displayed by A. baumannii at 28°C.
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28
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Ni L, Jin Z, Yang S, Jin F. [Single-cell analysis method for twitching motility of Pseudomonas aeruginosa]. Sheng Wu Gong Cheng Xue Bao 2017; 33:1611-1624. [PMID: 28956405 DOI: 10.13345/j.cjb.170131] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Twitching motility is very important for Pseudomonas aeruginosa in the adaptation of surface environment and in the 3-D structure formation of mature biofilm. To quantitatively characterize twitching motility in situ, we developed a method by combining high-throughput data acquisition, automatic image processing and database establishment. This method is based on single cell analysis and big data visualization. A periodic relaxation of 0.9 second was resolved during slingshot motility analysis. Twitching motilities of bacteria under addition of two quorum sensing signaling molecules were studied, cells moved faster after signal addition. This method may help understand the molecular mechanism and regulatory circuits of twitching motility.
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Affiliation(s)
- Lei Ni
- Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei 230026, Anhui, China
| | - Zhenyu Jin
- Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei 230026, Anhui, China
| | - Shuai Yang
- Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei 230026, Anhui, China
| | - Fan Jin
- Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei 230026, Anhui, China.,CAS Key Laboratory of Soft Matter Chemistry, University of Science and Technology of China, Hefei 230026, Anhui, China
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29
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Buensuceso RNC, Daniel-Ivad M, Kilmury SLN, Leighton TL, Harvey H, Howell PL, Burrows LL. Cyclic AMP-Independent Control of Twitching Motility in Pseudomonas aeruginosa. J Bacteriol 2017; 199:e00188-17. [PMID: 28583947 DOI: 10.1128/JB.00188-17] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2017] [Accepted: 05/23/2017] [Indexed: 01/05/2023] Open
Abstract
FimV is a Pseudomonas aeruginosa inner membrane hub protein that modulates levels of the second messenger, cyclic AMP (cAMP), through the activation of adenylate cyclase CyaB. Although type IVa pilus (T4aP)-dependent twitching motility is modulated by cAMP levels, mutants lacking FimV are twitching impaired, even when exogenous cAMP is provided. Here we further define FimV's cAMP-dependent and -independent regulation of twitching. We confirmed that the response regulator of the T4aP-associated Chp chemotaxis system, PilG, requires both FimV and the CyaB regulator, FimL, to activate CyaB. However, in cAMP-replete backgrounds-lacking the cAMP phosphodiesterase CpdA or the CheY-like protein PilH or expressing constitutively active CyaB-pilG and fimV mutants failed to twitch. Both cytoplasmic and periplasmic domains of FimV were important for its cAMP-dependent and -independent roles, while its septal peptidoglycan-targeting LysM motif was required only for twitching motility. Polar localization of the sensor kinase PilS, a key regulator of transcription of the major pilin, was FimV dependent. However, unlike its homologues in other species that localize flagellar system components, FimV was not required for swimming motility. These data provide further evidence to support FimV's role as a key hub protein that coordinates the polar localization and function of multiple structural and regulatory proteins involved in P. aeruginosa twitching motility.IMPORTANCEPseudomonas aeruginosa is a serious opportunistic pathogen. Type IVa pili (T4aP) are important for its virulence, because they mediate dissemination and invasion via twitching motility and are involved in surface sensing, which modulates pathogenicity via changes in cAMP levels. Here we show that the hub protein FimV and the response regulator of the Chp system, PilG, regulate twitching independently of their roles in the modulation of cAMP synthesis. These functions do not require the putative scaffold protein FimL, proposed to link PilG with FimV. PilG may regulate asymmetric functioning of the T4aP system to allow for directional movement, while FimV appears to localize both structural and regulatory elements-including the PilSR two-component system-to cell poles for optimal function.
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30
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Sun Y, Sun F, Feng W, Qiu X, Liu Y, Yang B, Chen Y, Xia P. Hyperoside inhibits biofilm formation of Pseudomonas aeruginosa. Exp Ther Med 2017; 14:1647-1652. [PMID: 28810631 DOI: 10.3892/etm.2017.4641] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2015] [Accepted: 10/21/2016] [Indexed: 11/06/2022] Open
Abstract
Pseudomonas aeruginosa (P. aeruginosa) is a common pathogen in hospital-acquired infection and is readily able to form biofilms. Due to its high antibiotic resistance, traditional antibacterial treatments exert a limited effect on P. aeruginosa biofilm infections. It has been indicated that hyperoside inhibits P. aeruginosa PAO1 (PAO1) biofilm formation without affecting growth. Therefore, the current study examined the biofilm formation and quorum sensing (QS) system of PAO1 in the presence of hyperoside. Confocal laser scanning microscopy analysis demonstrated that hyperoside significantly inhibited biofilm formation. It was also observed that hyperoside inhibited twitching motility in addition to adhesion. Data from reverse transcription-quantitative polymerase chain reaction indicated that hyperoside inhibited the expression of lasR, lasI, rhlR and rhlI genes. These results suggest that the QS-inhibiting effect of hyperoside may lead to a reduction in biofilm formation. However, the precise mechanism of hyperoside on P. aeruginosa pathogenicity remains unclear and requires elucidation in additional studies.
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Affiliation(s)
- Yixuan Sun
- Department of Pharmacy, Southwest Hospital, Third Military Medical University, Chongqing 400038, P.R. China
| | - Fengjun Sun
- Department of Pharmacy, Southwest Hospital, Third Military Medical University, Chongqing 400038, P.R. China
| | - Wei Feng
- Department of Pharmacy, Southwest Hospital, Third Military Medical University, Chongqing 400038, P.R. China
| | - Xuewen Qiu
- Department of Pharmacy, Southwest Hospital, Third Military Medical University, Chongqing 400038, P.R. China
| | - Yao Liu
- Department of Pharmacy, Southwest Hospital, Third Military Medical University, Chongqing 400038, P.R. China
| | - Bo Yang
- Department of Pharmacy, Southwest Hospital, Third Military Medical University, Chongqing 400038, P.R. China
| | - Yongchuan Chen
- Department of Pharmacy, Southwest Hospital, Third Military Medical University, Chongqing 400038, P.R. China
| | - Peiyuan Xia
- Department of Pharmacy, Southwest Hospital, Third Military Medical University, Chongqing 400038, P.R. China
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31
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Zhao Y, Qian G, Chen Y, Du L, Liu F. Transcriptional and Antagonistic Responses of Biocontrol Strain Lysobacter enzymogenes OH11 to the Plant Pathogenic Oomycete Pythium aphanidermatum. Front Microbiol 2017. [PMID: 28634478 PMCID: PMC5459918 DOI: 10.3389/fmicb.2017.01025] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Lysobacter enzymogenes is a ubiquitous, beneficial, plant-associated bacterium emerging as a novel biological control agent. It has the potential to become a new source of antimicrobial secondary metabolites such as the Heat-Stable Antifungal Factor (HSAF), which is a broad-spectrum antimycotic with a novel mode of action. However, very little information about how L. enzymogenes detects and responds to fungi or oomycetes has been reported. An in vitro confrontation bioassay between the pathogenic oomycete Pythium aphanidermatum and the biocontrol bacterial strain L. enzymogenes OH11 was used to analyze the transcriptional changes in the bacteria that were induced by the oomycetes. Analysis was performed at three time points of the interaction, starting before inhibition zone formation until inhibition zone formation. A L. enzymogenes OH11 DNA microarray was constructed for the analysis. Microarray analysis indicated that a wide range of genes belonging to 14 diverse functions in L. enzymogenes were affected by P. aphanidermatum as critical antagonistic effects occurred. L. enzymogenes detected and responded to the presence of P. aphanidermatum early, but alteration of gene expression typically occurred after inhibition zone formation. The presence of P. aphanidermatum increased the twitching motility and HSAF production in L. enzymogenes. We also performed a contact interaction between L. enzymogenes and P. aphanidermatum, and found that HSAF played a critical role in the interaction. Our experiments demonstrated that L. enzymogenes displayed transcriptional and antagonistic responses to P. aphanidermatum in order to gain advantages in the competition with this oomycete. This study revealed new insights into the interactions between bacteria and oomycete.
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Affiliation(s)
- Yangyang Zhao
- Institute of Plant Protection, Jiangsu Academy of Agricultural SciencesNanjing, China
| | - Guoliang Qian
- Key Laboratory of Integrated Management of Crop Diseases and Pests, College of Plant Protection, Nanjing Agricultural University, Ministry of EducationNanjing, China
| | - Yuan Chen
- Key Laboratory of Integrated Management of Crop Diseases and Pests, College of Plant Protection, Nanjing Agricultural University, Ministry of EducationNanjing, China
| | - Liangcheng Du
- Department of Chemistry, University of Nebraska-LincolnLincoln, NE, United States
| | - Fengquan Liu
- Institute of Plant Protection, Jiangsu Academy of Agricultural SciencesNanjing, China
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32
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Nakane D, Nishizaka T. Asymmetric distribution of type IV pili triggered by directional light in unicellular cyanobacteria. Proc Natl Acad Sci U S A 2017; 114:6593-8. [PMID: 28584115 DOI: 10.1073/pnas.1702395114] [Citation(s) in RCA: 46] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
The type IV pili (T4P) system is a supermolecular machine observed in prokaryotes. Cells repeat the cycle of T4P extension, surface attachment, and retraction to drive twitching motility. Although the properties of T4P as a motor have been scrutinized with biophysics techniques, the mechanism of regulation remains unclear. Here we provided the framework of the T4P dynamics at the single-cell level in Synechocystis sp. PCC6803, which can recognize light direction. We demonstrated that the dynamics was detected by fluorescent beads under an optical microscope and controlled by blue light that induces negative phototaxis; extension and retraction of T4P was activated at the forward side of lateral illumination to move away from the light source. Additionally, we directly visualized each pilus by fluorescent labeling, allowing us to quantify their asymmetric distribution. Finally, quantitative analyses of cell tracking indicated that T4P was generated uniformly within 0.2 min after blue-light exposure, and within the next 1 min the activation became asymmetric along the light axis to achieve directional cell motility; this process was mediated by the photo-sensing protein, PixD. This sequential process provides clues toward a general regulation mechanism of T4P system, which might be essentially common between archaella and other secretion apparatuses.
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33
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Hoppe J, Ünal CM, Thiem S, Grimpe L, Goldmann T, Gaßler N, Richter M, Shevchuk O, Steinert M. PilY1 Promotes Legionella pneumophila Infection of Human Lung Tissue Explants and Contributes to Bacterial Adhesion, Host Cell Invasion, and Twitching Motility. Front Cell Infect Microbiol 2017; 7:63. [PMID: 28326293 PMCID: PMC5339237 DOI: 10.3389/fcimb.2017.00063] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2016] [Accepted: 02/20/2017] [Indexed: 11/13/2022] Open
Abstract
Legionnaires' disease is an acute fibrinopurulent pneumonia. During infection Legionella pneumophila adheres to the alveolar lining and replicates intracellularly within recruited macrophages. Here we provide a sequence and domain composition analysis of the L. pneumophila PilY1 protein, which has a high homology to PilY1 of Pseudomonas aeruginosa. PilY1 proteins of both pathogens contain a von Willebrand factor A (vWFa) and a C-terminal PilY domain. Using cellular fractionation, we assigned the L. pneumophila PilY1 as an outer membrane protein that is only expressed during the transmissive stationary growth phase. PilY1 contributes to infection of human lung tissue explants (HLTEs). A detailed analysis using THP-1 macrophages and A549 lung epithelial cells revealed that this contribution is due to multiple effects depending on host cell type. Deletion of PilY1 resulted in a lower replication rate in THP-1 macrophages but not in A549 cells. Further on, adhesion to THP-1 macrophages and A549 epithelial cells was decreased. Additionally, the invasion into non-phagocytic A549 epithelial cells was drastically reduced when PilY1 was absent. Complementation variants of a PilY1-negative mutant revealed that the C-terminal PilY domain is essential for restoring the wild type phenotype in adhesion, while the putatively mechanosensitive vWFa domain facilitates invasion into non-phagocytic cells. Since PilY1 also promotes twitching motility of L. pneumophila, we discuss the putative contribution of this newly described virulence factor for bacterial dissemination within infected lung tissue.
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Affiliation(s)
- Julia Hoppe
- Institut für Mikrobiologie, Technische Universität Braunschweig Braunschweig, Germany
| | - Can M Ünal
- Institut für Mikrobiologie, Technische Universität Braunschweig Braunschweig, Germany
| | - Stefanie Thiem
- Institut für Mikrobiologie, Technische Universität Braunschweig Braunschweig, Germany
| | - Louisa Grimpe
- Institut für Mikrobiologie, Technische Universität Braunschweig Braunschweig, Germany
| | - Torsten Goldmann
- Pathology of the University Hospital of Lübeck and the Leibniz Research CenterBorstel, Germany; Airway Research Center North (ARCN), Member of the German Center for Lung ResearchBorstel, Germany
| | - Nikolaus Gaßler
- Institut für Pathologie, Klinikum Braunschweig Braunschweig, Germany
| | | | - Olga Shevchuk
- Center for Proteomics, University of Rijeka Rijeka, Croatia
| | - Michael Steinert
- Institut für Mikrobiologie, Technische Universität BraunschweigBraunschweig, Germany; Helmholtz Center for Infection ResearchBraunschweig, Germany
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34
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Gloag ES, Elbadawi C, Zachreson CJ, Aharonovich I, Toth M, Charles IG, Turnbull L, Whitchurch CB. Micro-Patterned Surfaces That Exploit Stigmergy to Inhibit Biofilm Expansion. Front Microbiol 2017; 7:2157. [PMID: 28167929 PMCID: PMC5253354 DOI: 10.3389/fmicb.2016.02157] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2016] [Accepted: 12/21/2016] [Indexed: 11/13/2022] Open
Abstract
Twitching motility is a mode of surface translocation that is mediated by the extension and retraction of type IV pili and which, depending on the conditions, enables migration of individual cells or can manifest as a complex multicellular collective behavior that leads to biofilm expansion. When twitching motility occurs at the interface of an abiotic surface and solidified nutrient media, it can lead to the emergence of extensive self-organized patterns of interconnected trails that form as a consequence of the actively migrating bacteria forging a furrow network in the substratum beneath the expanding biofilm. These furrows appear to direct bacterial movements much in the same way that roads and footpaths coordinate motor vehicle and human pedestrian traffic. Self-organizing systems such as these can be accounted for by the concept of stigmergy which describes self-organization that emerges through indirect communication via persistent signals within the environment. Many bacterial communities are able to actively migrate across solid and semi-solid surfaces through complex multicellular collective behaviors such as twitching motility and flagella-mediated swarming motility. Here, we have examined the potential of exploiting the stigmergic behavior of furrow-mediated trail following as a means of controlling bacterial biofilm expansion along abiotic surfaces. We found that incorporation of a series of parallel micro-fabricated furrows significantly impeded active biofilm expansion by Pseudomonas aeruginosa and Proteus vulgaris. We observed that in both cases bacterial movements tended to be directed along the furrows. We also observed that narrow furrows were most effective at disrupting biofilm expansion as they impeded the ability of cells to self-organize into multicellular assemblies required for escape from the furrows and migration into new territory. Our results suggest that the implementation of micro-fabricated furrows that exploit stigmergy may be a novel approach to impeding active biofilm expansion across abiotic surfaces such as those used in medical and industrial settings.
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Affiliation(s)
- Erin S Gloag
- The ithree institute, University of Technology Sydney Ultimo, NSW, Australia
| | - Christopher Elbadawi
- School of Mathematical and Physical Sciences, University of Technology Sydney Ultimo, NSW, Australia
| | - Cameron J Zachreson
- School of Mathematical and Physical Sciences, University of Technology Sydney Ultimo, NSW, Australia
| | - Igor Aharonovich
- School of Mathematical and Physical Sciences, University of Technology Sydney Ultimo, NSW, Australia
| | - Milos Toth
- School of Mathematical and Physical Sciences, University of Technology Sydney Ultimo, NSW, Australia
| | - Ian G Charles
- The ithree institute, University of Technology Sydney Ultimo, NSW, Australia
| | - Lynne Turnbull
- The ithree institute, University of Technology Sydney Ultimo, NSW, Australia
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Leighton TL, Yong DH, Howell PL, Burrows LL. Type IV Pilus Alignment Subcomplex Proteins PilN and PilO Form Homo- and Heterodimers in Vivo. J Biol Chem 2016; 291:19923-38. [PMID: 27474743 DOI: 10.1074/jbc.m116.738377] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2016] [Indexed: 11/06/2022] Open
Abstract
Pseudomonas aeruginosa is a leading cause of hospital-acquired infections and is resistant to many antibiotics. Type IV pili (T4P) are among the key virulence factors used by P. aeruginosa for host cell attachment, biofilm formation, and twitching motility, making this system a promising target for novel therapeutics. Point mutations in the conserved PilMNOP alignment subcomplex were previously shown to have distinct effects on assembly and disassembly of T4P, suggesting that it may function in a dynamic manner. We introduced mutations encoding Cys substitutions into pilN and/or pilO on the chromosome to maintain normal stoichiometry and expression levels and captured covalent PilNO heterodimers, as well as PilN and PilO homodimers, in vivo Most covalent PilN or PilO homodimers had minimal functional impact in P. aeruginosa, suggesting that homodimers are a physiologically relevant state. However, certain covalent homo- or heterodimers eliminated twitching motility, suggesting that specific PilNO configurations are essential for T4P function. These data were verified using soluble N-terminal truncated fragments of PilN and PilO Cys mutants, which purified as a mixture of homo- and heterodimers at volumes consistent with a tetramer. Deletion of genes encoding alignment subcomplex components, PilM or PilP, but not other T4P components, including the motor ATPases PilB or PilT, blocked in vivo formation of disulfide-bonded PilNO heterodimers, suggesting that both PilM and PilP influence the heterodimer interface. Combined, our data suggest that T4P function depends on rearrangements at PilN and PilO interfaces.
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Affiliation(s)
- Tiffany L Leighton
- From the Department of Biochemistry and Biomedical Sciences and the Michael G. DeGroote Institute for Infectious Disease Research, McMaster University, Hamilton, Ontario L8S 4K1 and
| | - Daniel H Yong
- From the Department of Biochemistry and Biomedical Sciences and the Michael G. DeGroote Institute for Infectious Disease Research, McMaster University, Hamilton, Ontario L8S 4K1 and
| | - P Lynne Howell
- the Program in Molecular Structure and Function, The Hospital for Sick Children and Department of Biochemistry, University of Toronto, Toronto M5G 0A4 Ontario, Canada
| | - Lori L Burrows
- From the Department of Biochemistry and Biomedical Sciences and the Michael G. DeGroote Institute for Infectious Disease Research, McMaster University, Hamilton, Ontario L8S 4K1 and
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36
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Abstract
Bacteria form surface-attached communities, known as biofilms, which are central to bacterial biology and how they affect us. Although surface-attached bacteria often experience strong chemical gradients, it remains unclear whether single cells can effectively perform chemotaxis on surfaces. Here we use microfluidic chemical gradients and massively parallel automated tracking to study the behavior of the pathogen Pseudomonas aeruginosa during early biofilm development. We show that individual cells can efficiently move toward chemoattractants using pili-based "twitching" motility and the Chp chemosensory system. Moreover, we discovered the behavioral mechanism underlying this surface chemotaxis: Cells reverse direction more frequently when moving away from chemoattractant sources. These corrective maneuvers are triggered rapidly, typically before a wayward cell has ventured a fraction of a micron. Our work shows that single bacteria can direct their motion with submicron precision and reveals the hidden potential for chemotaxis within bacterial biofilms.
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37
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Jansari VH, Potharla VY, Riddell GT, Bardy SL. Twitching motility and cAMP levels: signal transduction through a single methyl-accepting chemotaxis protein. FEMS Microbiol Lett 2016; 363:fnw119. [PMID: 27190147 DOI: 10.1093/femsle/fnw119] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/29/2016] [Indexed: 12/17/2022] Open
Abstract
The Pseudomonas aeruginosa Chp chemosensory system regulates twitching motility, intracellular adenosine 3('') 5(')-cyclic monophosphate (cAMP) levels and is postulated to be involved in directional twitching towards phosphatidylethanolamine (PE). Because PilJ is the only methyl-accepting chemotaxis protein (MCP) identified in the Chp system, we determined the role of PilJ in mediating signal transduction for the distinct outputs of this system. Mutants that lack the periplasmic domain of PilJ (pilJΔ74-273) showed lower levels of cAMP but retained directional twitching towards PE. While initial studies revealed reduced twitching motility by PilJΔ74-273, this was due to decreased cAMP levels. Our data illustrate the importance of the periplasmic domain of PilJ in regulating cAMP. This is the first time a defined domain within PilJ has been identified as having a distinct role in signal transduction.
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Affiliation(s)
- Vibhuti H Jansari
- Department of Biological Sciences, University of Wisconsin-Milwaukee, Milwaukee, WI 53211, USA
| | - Vishwakanth Y Potharla
- Department of Biological Sciences, University of Wisconsin-Milwaukee, Milwaukee, WI 53211, USA
| | - Geoff T Riddell
- Department of Biological Sciences, University of Wisconsin-Milwaukee, Milwaukee, WI 53211, USA
| | - Sonia L Bardy
- Department of Biological Sciences, University of Wisconsin-Milwaukee, Milwaukee, WI 53211, USA
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Nguyen Y, Harvey H, Sugiman-Marangos S, Bell SD, Buensuceso RNC, Junop MS, Burrows LL. Structural and functional studies of the Pseudomonas aeruginosa minor pilin, PilE. J Biol Chem 2015; 290:26856-65. [PMID: 26359492 PMCID: PMC4646338 DOI: 10.1074/jbc.m115.683334] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2015] [Revised: 09/04/2015] [Indexed: 11/06/2022] Open
Abstract
Many bacterial pathogens, including Pseudomonas aeruginosa, use type IVa pili (T4aP) for attachment and twitching motility. T4aP are composed primarily of major pilin subunits, which are repeatedly assembled and disassembled to mediate function. A group of pilin-like proteins, the minor pilins FimU and PilVWXE, prime pilus assembly and are incorporated into the pilus. We showed previously that minor pilin PilE depends on the putative priming subcomplex PilVWX and the non-pilin protein PilY1 for incorporation into pili, and that with FimU, PilE may couple the priming subcomplex to the major pilin PilA, allowing for efficient pilus assembly. Here we provide further support for this model, showing interaction of PilE with other minor pilins and the major pilin. A 1.25 Å crystal structure of PilEΔ1-28 shows a typical type IV pilin fold, demonstrating how it may be incorporated into the pilus. Despite limited sequence identity, PilE is structurally similar to Neisseria meningitidis minor pilins PilXNm and PilVNm, recently suggested via characterization of mCherry fusions to modulate pilus assembly from within the periplasm. A P. aeruginosa PilE-mCherry fusion failed to complement twitching motility or piliation of a pilE mutant. However, in a retraction-deficient strain where surface piliation depends solely on PilE, the fusion construct restored some surface piliation. PilE-mCherry was present in sheared surface fractions, suggesting that it was incorporated into pili. Together, these data provide evidence that PilE, the sole P. aeruginosa equivalent of PilXNm and PilVNm, likely connects a priming subcomplex to the major pilin, promoting efficient assembly of T4aP.
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Affiliation(s)
- Ylan Nguyen
- From the Department of Biochemistry and Biomedical Sciences and the Michael G. DeGroote Institute for Infectious Disease Research, McMaster University, Hamilton, Ontario L8S 4K1 and
| | - Hanjeong Harvey
- From the Department of Biochemistry and Biomedical Sciences and the Michael G. DeGroote Institute for Infectious Disease Research, McMaster University, Hamilton, Ontario L8S 4K1 and
| | - Seiji Sugiman-Marangos
- From the Department of Biochemistry and Biomedical Sciences and the Michael G. DeGroote Institute for Infectious Disease Research, McMaster University, Hamilton, Ontario L8S 4K1 and
| | - Stephanie D Bell
- From the Department of Biochemistry and Biomedical Sciences and the Michael G. DeGroote Institute for Infectious Disease Research, McMaster University, Hamilton, Ontario L8S 4K1 and
| | - Ryan N C Buensuceso
- From the Department of Biochemistry and Biomedical Sciences and the Michael G. DeGroote Institute for Infectious Disease Research, McMaster University, Hamilton, Ontario L8S 4K1 and
| | - Murray S Junop
- the Department of Biochemistry, Western University, London, Ontario N6A 3K7, Canada
| | - Lori L Burrows
- From the Department of Biochemistry and Biomedical Sciences and the Michael G. DeGroote Institute for Infectious Disease Research, McMaster University, Hamilton, Ontario L8S 4K1 and
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39
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Abstract
The bacterial type IV pilus (T4P) is a versatile molecular machine with a broad range of functions. Recent advances revealed that the molecular components and the biophysical properties of the machine are well conserved among phylogenetically distant bacterial species. However, its functions are diverse, and include adhesion, motility, and horizontal gene transfer. This review focusses on the role of T4P in surface motility and bacterial interactions. Different species have evolved distinct mechanisms for intracellular coordination of multiple pili and of pili with other motility machines, ranging from physical coordination to biochemical clocks. Coordinated behavior between multiple bacteria on a surface is achieved by active manipulation of surfaces and modulation of pilus-pilus interactions. An emerging picture is that the T4P actively senses and responds to environmental conditions.
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Affiliation(s)
- Berenike Maier
- Department of Physics, University of Cologne, Zülpicher Str. 77, 50937 Köln, Germany.
| | - Gerard C L Wong
- Department of Bioengineering, Department of Chemistry & Biochemistry, California Nano Systems Institute, University of California, Los Angeles, CA 90095-1600, USA
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40
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Okkotsu Y, Little AS, Schurr MJ. The Pseudomonas aeruginosa AlgZR two-component system coordinates multiple phenotypes. Front Cell Infect Microbiol 2014; 4:82. [PMID: 24999454 PMCID: PMC4064291 DOI: 10.3389/fcimb.2014.00082] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2014] [Accepted: 06/02/2014] [Indexed: 01/28/2023] Open
Abstract
Pseudomonas aeruginosa is an opportunistic pathogen that causes a multitude of infections. These infections can occur at almost any site in the body and are usually associated with a breach of the innate immune system. One of the prominent sites where P. aeruginosa causes chronic infections is within the lungs of cystic fibrosis patients. P. aeruginosa uses two-component systems that sense environmental changes to differentially express virulence factors that cause both acute and chronic infections. The P. aeruginosa AlgZR two component system is one of its global regulatory systems that affects the organism's fitness in a broad manner. This two-component system is absolutely required for two P. aeruginosa phenotypes: twitching motility and alginate production, indicating its importance in both chronic and acute infections. Additionally, global transcriptome analyses indicate that it regulates the expression of many different genes, including those associated with quorum sensing, type IV pili, type III secretion system, anaerobic metabolism, cyanide and rhamnolipid production. This review examines the complex AlgZR regulatory network, what is known about the structure and function of each protein, and how it relates to the organism's ability to cause infections.
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Affiliation(s)
- Yuta Okkotsu
- Department of Microbiology, University of Colorado School of Medicine Aurora, CO, USA
| | - Alexander S Little
- Department of Microbiology, University of Colorado School of Medicine Aurora, CO, USA
| | - Michael J Schurr
- Department of Microbiology, University of Colorado School of Medicine Aurora, CO, USA
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41
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Gloag ES, Javed MA, Wang H, Gee ML, Wade SA, Turnbull L, Whitchurch CB. Stigmergy: A key driver of self-organization in bacterial biofilms. Commun Integr Biol 2013; 6:e27331. [PMID: 24753789 PMCID: PMC3984292 DOI: 10.4161/cib.27331] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2013] [Accepted: 11/25/2013] [Indexed: 11/19/2022] Open
Abstract
Bacterial biofilms are complex multicellular communities that are often associated with the emergence of large-scale patterns across the biofilm. How bacteria self-organize to form these structured communities is an area of active research. We have recently determined that the emergence of an intricate network of trails that forms during the twitching motility mediated expansion of Pseudomonas aeruginosa biofilms is attributed to an interconnected furrow system that is forged in the solidified nutrient media by aggregates of cells as they migrate across the media surface. This network acts as a means for self-organization of collective behavior during biofilm expansion as the cells following these vanguard aggregates were preferentially confined within the furrow network resulting in the formation of an intricate network of trails of cells. Here we further explore the process by which the intricate network of trails emerges. We have determined that the formation of the intricate network of furrows is associated with significant remodeling of the sub-stratum underlying the biofilm. The concept of stigmergy has been used to describe a variety of self-organization processes observed in higher organisms and abiotic systems that involve indirect communication via persistent cues in the environment left by individuals that influence the behavior of other individuals of the group at a later point in time. We propose that the concept of stigmergy can also be applied to describe self-organization of bacterial biofilms and can be included in the repertoire of systems used by bacteria to coordinate complex multicellular behaviors.
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Affiliation(s)
- Erin S Gloag
- The ithree institute; University of Technology Sydney; Ultimo, NSW Australia
| | - Muhammad A Javed
- Faculty of Engineering and Industrial Sciences; Biotactical Engineering; IRIS; Swinburne University of Technology; Hawthorn, VIC Australia
| | - Huabin Wang
- School of Chemistry; University of Melbourne; Parkville, VIC Australia
| | - Michelle L Gee
- School of Chemistry; University of Melbourne; Parkville, VIC Australia
| | - Scott A Wade
- Faculty of Engineering and Industrial Sciences; Biotactical Engineering; IRIS; Swinburne University of Technology; Hawthorn, VIC Australia
| | - Lynne Turnbull
- The ithree institute; University of Technology Sydney; Ultimo, NSW Australia
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42
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Cai Y, Wang R, An MM, Liang BB. Iron-Depletion prevents biofilm formation in Pseudomonas Aeruginosa through twitching mobility and quorum sensing. Braz J Microbiol 2010; 41:37-41. [PMID: 24031461 PMCID: PMC3768596 DOI: 10.1590/s1517-83822010000100008] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2008] [Revised: 05/06/2009] [Accepted: 07/22/2009] [Indexed: 12/02/2022] Open
Abstract
Influence of iron-depletion on twitching motility and quorum sensing (QS) system in P. aeruginosa was evaluated. The results demonstrated iron-depletion can retard biofilm formation and increase the twitching motility and expression of QS-related genes, suggesting a potential interaction between twitching motility and QS system in P. aeruginosa biofilm formation.
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Affiliation(s)
- Yun Cai
- Department of Clinical Pharmacology, the PLA General Hospital , Beijing 100853 , People's Republic of China
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