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Vasina DV, Antonova NP, Shidlovskaya EV, Kuznetsova NA, Grishin AV, Akoulina EA, Trusova EA, Lendel AM, Mazunina EP, Kozlova SR, Dudun AA, Bonartsev AP, Lunin VG, Gushchin VA. Alginate Gel Encapsulated with Enzybiotics Cocktail Is Effective against Multispecies Biofilms. Gels 2024; 10:60. [PMID: 38247783 PMCID: PMC10815372 DOI: 10.3390/gels10010060] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2023] [Revised: 01/11/2024] [Accepted: 01/12/2024] [Indexed: 01/23/2024] Open
Abstract
The development of new and effective antibacterials for pharmaceutical or cosmetic skin care that have a low potential for the emergence and expansion of bacterial resistance is of high demand in scientific and applied research. Great hopes are placed on alternative agents such as bactericidal peptidoglycan hydrolases, depolymerases, etc. Enzybiotic-based preparations are being studied for the treatment of various infections and, among others, can be used as topical formulations and dressings with protein-polysaccharide complexes. Here, we investigate the antibiofilm properties of a novel enzybiotic cocktail of phage endolysin LysSi3 and bacteriocin lysostaphin, formulated in the alginate gel matrix and its ability to control the opportunistic skin-colonizing bacteria Staphylococcus aureus, Pseudomonas aeruginosa, and Klebsiella pneumoniae, as well as mixed-species biofilms. Our results propose that the application of SiL-gel affects different components of biofilm extracellular polymeric substances, disrupts the matrix, and eliminates the bacteria embedded in it. This composition is highly effective against biofilms composed of Gram-negative and Gram-positive species and does not possess significant cytotoxic effects. Our data form the basis for the development of antibacterial skin care products with a gentle but effective mode of action.
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Affiliation(s)
- Daria V. Vasina
- N.F. Gamaleya National Research Centre for Epidemiology and Microbiology, Ministry of Health of the Russian Federation, 123098 Moscow, Russia; (N.P.A.); (E.V.S.); (N.A.K.); (A.V.G.); (E.P.M.); (S.R.K.); (V.G.L.); (V.A.G.)
| | - Nataliia P. Antonova
- N.F. Gamaleya National Research Centre for Epidemiology and Microbiology, Ministry of Health of the Russian Federation, 123098 Moscow, Russia; (N.P.A.); (E.V.S.); (N.A.K.); (A.V.G.); (E.P.M.); (S.R.K.); (V.G.L.); (V.A.G.)
| | - Elena V. Shidlovskaya
- N.F. Gamaleya National Research Centre for Epidemiology and Microbiology, Ministry of Health of the Russian Federation, 123098 Moscow, Russia; (N.P.A.); (E.V.S.); (N.A.K.); (A.V.G.); (E.P.M.); (S.R.K.); (V.G.L.); (V.A.G.)
| | - Nadezhda A. Kuznetsova
- N.F. Gamaleya National Research Centre for Epidemiology and Microbiology, Ministry of Health of the Russian Federation, 123098 Moscow, Russia; (N.P.A.); (E.V.S.); (N.A.K.); (A.V.G.); (E.P.M.); (S.R.K.); (V.G.L.); (V.A.G.)
| | - Alexander V. Grishin
- N.F. Gamaleya National Research Centre for Epidemiology and Microbiology, Ministry of Health of the Russian Federation, 123098 Moscow, Russia; (N.P.A.); (E.V.S.); (N.A.K.); (A.V.G.); (E.P.M.); (S.R.K.); (V.G.L.); (V.A.G.)
- All-Russia Research Institute of Agricultural Biotechnology, 127550 Moscow, Russia
| | - Elizaveta A. Akoulina
- Faculty of Biology, MSU-BIT Shenzhen University, Shenzhen 518115, China;
- Faculty of Biology, M.V. Lomonosov Moscow State University, 119234 Moscow, Russia;
| | | | - Anastasiya M. Lendel
- N.F. Gamaleya National Research Centre for Epidemiology and Microbiology, Ministry of Health of the Russian Federation, 123098 Moscow, Russia; (N.P.A.); (E.V.S.); (N.A.K.); (A.V.G.); (E.P.M.); (S.R.K.); (V.G.L.); (V.A.G.)
| | - Elena P. Mazunina
- N.F. Gamaleya National Research Centre for Epidemiology and Microbiology, Ministry of Health of the Russian Federation, 123098 Moscow, Russia; (N.P.A.); (E.V.S.); (N.A.K.); (A.V.G.); (E.P.M.); (S.R.K.); (V.G.L.); (V.A.G.)
| | - Sofia R. Kozlova
- N.F. Gamaleya National Research Centre for Epidemiology and Microbiology, Ministry of Health of the Russian Federation, 123098 Moscow, Russia; (N.P.A.); (E.V.S.); (N.A.K.); (A.V.G.); (E.P.M.); (S.R.K.); (V.G.L.); (V.A.G.)
| | - Andrei A. Dudun
- Research Center of Biotechnology of the Russian Academy of Sciences Leninsky Ave, 33, Bld. 2, 119071 Moscow, Russia;
| | - Anton P. Bonartsev
- Faculty of Biology, M.V. Lomonosov Moscow State University, 119234 Moscow, Russia;
| | - Vladimir G. Lunin
- N.F. Gamaleya National Research Centre for Epidemiology and Microbiology, Ministry of Health of the Russian Federation, 123098 Moscow, Russia; (N.P.A.); (E.V.S.); (N.A.K.); (A.V.G.); (E.P.M.); (S.R.K.); (V.G.L.); (V.A.G.)
- All-Russia Research Institute of Agricultural Biotechnology, 127550 Moscow, Russia
| | - Vladimir A. Gushchin
- N.F. Gamaleya National Research Centre for Epidemiology and Microbiology, Ministry of Health of the Russian Federation, 123098 Moscow, Russia; (N.P.A.); (E.V.S.); (N.A.K.); (A.V.G.); (E.P.M.); (S.R.K.); (V.G.L.); (V.A.G.)
- Faculty of Biology, M.V. Lomonosov Moscow State University, 119234 Moscow, Russia;
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2
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Guo Y, Mao Z, Ran F, Sun J, Zhang J, Chai G, Wang J. Nanotechnology-Based Drug Delivery Systems to Control Bacterial-Biofilm-Associated Lung Infections. Pharmaceutics 2023; 15:2582. [PMID: 38004561 PMCID: PMC10674810 DOI: 10.3390/pharmaceutics15112582] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2023] [Revised: 10/09/2023] [Accepted: 10/17/2023] [Indexed: 11/26/2023] Open
Abstract
Airway mucus dysfunction and impaired immunological defenses are hallmarks of several lung diseases, including asthma, cystic fibrosis, and chronic obstructive pulmonary diseases, and are mostly causative factors in bacterial-biofilm-associated respiratory tract infections. Bacteria residing within the biofilm architecture pose a complex challenge in clinical settings due to their increased tolerance to currently available antibiotics and host immune responses, resulting in chronic infections with high recalcitrance and high rates of morbidity and mortality. To address these unmet clinical needs, potential anti-biofilm therapeutic strategies are being developed to effectively control bacterial biofilm. This review focuses on recent advances in the development and application of nanoparticulate drug delivery systems for the treatment of biofilm-associated respiratory tract infections, especially addressing the respiratory barriers of concern for biofilm accessibility and the various types of nanoparticles used to combat biofilms. Understanding the obstacles facing pulmonary drug delivery to bacterial biofilms and nanoparticle-based approaches to combatting biofilm may encourage researchers to explore promising treatment modalities for bacterial-biofilm-associated chronic lung infections.
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Affiliation(s)
- Yutong Guo
- School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou 510006, China
| | - Zeyuan Mao
- School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou 510006, China
| | - Fang Ran
- School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou 510006, China
| | - Jihong Sun
- Department of Radiology, Sir Run Run Shaw Hospital, School of Medicine, Zhejiang University, Hangzhou 310016, China
| | - Jingfeng Zhang
- The Key Laboratory of Diagnosis and Treatment of Digestive System Tumors of Zhejiang Province, Ningbo 315000, China
| | - Guihong Chai
- School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou 510006, China
| | - Jian Wang
- State Key Laboratory of Respiratory Disease, National Clinical Research Center for Respiratory Disease, Guangzhou Institute of Respiratory Health, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou 510180, China
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3
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Gheorghita AA, Wozniak DJ, Parsek MR, Howell PL. Pseudomonas aeruginosa biofilm exopolysaccharides: assembly, function, and degradation. FEMS Microbiol Rev 2023; 47:fuad060. [PMID: 37884397 PMCID: PMC10644985 DOI: 10.1093/femsre/fuad060] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2023] [Revised: 10/04/2023] [Accepted: 10/25/2023] [Indexed: 10/28/2023] Open
Abstract
The biofilm matrix is a fortress; sheltering bacteria in a protective and nourishing barrier that allows for growth and adaptation to various surroundings. A variety of different components are found within the matrix including water, lipids, proteins, extracellular DNA, RNA, membrane vesicles, phages, and exopolysaccharides. As part of its biofilm matrix, Pseudomonas aeruginosa is genetically capable of producing three chemically distinct exopolysaccharides - alginate, Pel, and Psl - each of which has a distinct role in biofilm formation and immune evasion during infection. The polymers are produced by highly conserved mechanisms of secretion, involving many proteins that span both the inner and outer bacterial membranes. Experimentally determined structures, predictive modelling of proteins whose structures are yet to be solved, and structural homology comparisons give us insight into the molecular mechanisms of these secretion systems, from polymer synthesis to modification and export. Here, we review recent advances that enhance our understanding of P. aeruginosa multiprotein exopolysaccharide biosynthetic complexes, and how the glycoside hydrolases/lyases within these systems have been commandeered for antimicrobial applications.
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Affiliation(s)
- Andreea A Gheorghita
- Program in Molecular Medicine, Peter Gilgan Centre for Research and Learning, The Hospital for Sick Children, 686 Bay St, Toronto, ON M5G 0A4, Canada
- Department of Biochemistry, University of Toronto, Medical Science Building, 1 King's College Cir, Toronto, ON M5S 1A8, Canada
| | - Daniel J Wozniak
- Department of Microbial Infection and Immunity, The Ohio State University College of Medicine, 776 Biomedical Research Tower, 460 W 12th Ave, Columbus, OH 43210, United States
- Department of Microbiology, The Ohio State University College, Biological Sciences Bldg, 105, 484 W 12th Ave, Columbus, OH 43210, United States
| | - Matthew R Parsek
- Department of Microbiology, University of Washington, Health Sciences Bldg, 1705 NE Pacific St, Seattle, WA 98195-7735, United States
| | - P Lynne Howell
- Program in Molecular Medicine, Peter Gilgan Centre for Research and Learning, The Hospital for Sick Children, 686 Bay St, Toronto, ON M5G 0A4, Canada
- Department of Biochemistry, University of Toronto, Medical Science Building, 1 King's College Cir, Toronto, ON M5S 1A8, Canada
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4
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Zhang Y, Bhasme P, Reddy DS, Liu D, Yu Z, Zhao T, Zheng Y, Kumar A, Yu H, Ma LZ. Dual functions: A coumarin-chalcone conjugate inhibits cyclic-di-GMP and quorum-sensing signaling to reduce biofilm formation and virulence of pathogens. MLIFE 2023; 2:283-294. [PMID: 38817812 PMCID: PMC10989777 DOI: 10.1002/mlf2.12087] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/20/2023] [Accepted: 08/01/2023] [Indexed: 06/01/2024]
Abstract
Antibiotic resistance or tolerance of pathogens is one of the most serious global public health threats. Bacteria in biofilms show extreme tolerance to almost all antibiotic classes. Thus, use of antibiofilm drugs without bacterial-killing effects is one of the strategies to combat antibiotic tolerance. In this study, we discovered a coumarin-chalcone conjugate C9, which can inhibit the biofilm formation of three common pathogens that cause nosocomial infections, namely, Pseudomonas aeruginosa, Staphylococcus aureus, and Escherichia coli, with the best antibiofilm activity against P. aeruginosa. Further investigations indicate that C9 decreases the synthesis of the key biofilm matrix exopolysaccharide Psl and bacterial second messenger cyclic-di-GMP. Meanwhile, C9 can interfere with the regulation of the quorum sensing (QS) system to reduce the virulence of P. aeruginosa. C9 treatment enhances the sensitivity of biofilm to several antibiotics and reduces the survival rate of P. aeruginosa under starvation or oxidative stress conditions, indicating its excellent potential for use as an antibiofilm-forming and anti-QS drug.
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Affiliation(s)
- Yu Zhang
- State Key Laboratory of Microbial Resources, Institute of MicrobiologyChinese Academy of SciencesBeijingChina
| | - Pramod Bhasme
- State Key Laboratory of Microbial Resources, Institute of MicrobiologyChinese Academy of SciencesBeijingChina
- University of Chinese Academy of SciencesBeijingChina
| | - Dinesh S. Reddy
- Centre for Nano and Material SciencesJain UniversityBangaloreKarnatakaIndia
| | - Dejian Liu
- State Key Laboratory of Microbial Resources, Institute of MicrobiologyChinese Academy of SciencesBeijingChina
- University of Chinese Academy of SciencesBeijingChina
| | - Zhaoxiao Yu
- State Key Laboratory of Microbial Resources, Institute of MicrobiologyChinese Academy of SciencesBeijingChina
| | - Tianhu Zhao
- State Key Laboratory of Microbial Resources, Institute of MicrobiologyChinese Academy of SciencesBeijingChina
| | - Yaqian Zheng
- State Key Laboratory of Microbial Resources, Institute of MicrobiologyChinese Academy of SciencesBeijingChina
- University of Chinese Academy of SciencesBeijingChina
| | - Amit Kumar
- Centre for Nano and Material SciencesJain UniversityBangaloreKarnatakaIndia
| | - Haiying Yu
- State Key Laboratory of Microbial Resources, Institute of MicrobiologyChinese Academy of SciencesBeijingChina
| | - Luyan Z. Ma
- State Key Laboratory of Microbial Resources, Institute of MicrobiologyChinese Academy of SciencesBeijingChina
- University of Chinese Academy of SciencesBeijingChina
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5
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Tran TMT, Addison RS, Davis RA, Rehm BHA. Bromotyrosine-Derived Metabolites from a Marine Sponge Inhibit Pseudomonas aeruginosa Biofilms. Int J Mol Sci 2023; 24:10204. [PMID: 37373352 DOI: 10.3390/ijms241210204] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2023] [Revised: 06/06/2023] [Accepted: 06/06/2023] [Indexed: 06/29/2023] Open
Abstract
Pseudomonas aeruginosa forms stable biofilms, providing a major barrier for multiple classes of antibiotics and severely impairing treatment of infected patients. The biofilm matrix of this Gram-negative bacterium is primarily composed of three major exopolysaccharides: alginate, Psl, and Pel. Here, we studied the antibiofilm properties of sponge-derived natural products ianthelliformisamines A-C and their combinations with clinically used antibiotics. Wild-type P. aeruginosa strain and its isogenic exopolysaccharide-deficient mutants were employed to determine the interference of the compounds with biofilm matrix components. We identified that ianthelliformisamines A and B worked synergistically with ciprofloxacin to kill planktonic and biofilm cells. Ianthelliformisamines A and B reduced the minimum inhibitory concentration (MIC) of ciprofloxacin to 1/3 and 1/4 MICs, respectively. In contrast, ianthelliformisamine C (MIC = 53.1 µg/mL) alone exhibited bactericidal effects dose-dependently on both free-living and biofilm populations of wild-type PAO1, PAO1ΔpslA (Psl deficient), PDO300 (alginate overproducing and mimicking clinical isolates), and PDO300Δalg8 (alginate deficient). Interestingly, the biofilm of the clinically relevant mucoid variant PDO300 was more susceptible to ianthelliformisamine C than strains with impaired polysaccharide synthesis. Ianthelliformisamines exhibited low cytotoxicity towards HEK293 cells in the resazurin viability assay. Mechanism of action studies showed that ianthelliformisamine C inhibited the efflux pump of P. aeruginosa. Metabolic stability analyses indicated that ianthelliformisamine C is stable and ianthelliformisamines A and B are rapidly degraded. Overall, these findings suggest that the ianthelliformisamine chemotype could be a promising candidate for the treatment of P. aeruginosa biofilms.
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Affiliation(s)
- Tam M T Tran
- Centre for Cell Factories and Biopolymers, Griffith Institute for Drug Discovery, Griffith University, Nathan, QLD 4111, Australia
| | - Russell S Addison
- Preclinical ADME/PK, Griffith Institute for Drug Discovery, Griffith University, Nathan, QLD 4111, Australia
| | - Rohan A Davis
- NatureBank, Griffith Institute for Drug Discovery, Griffith University, Nathan, QLD 4111, Australia
- School of Environment and Science, Griffith University, Nathan, QLD 4111, Australia
| | - Bernd H A Rehm
- Centre for Cell Factories and Biopolymers, Griffith Institute for Drug Discovery, Griffith University, Nathan, QLD 4111, Australia
- Menzies Health Institute Queensland, Griffith University, Gold Coast, QLD 4222, Australia
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6
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Ambreetha S, Singh V. Genetic and environmental determinants of surface adaptations in Pseudomonas aeruginosa. MICROBIOLOGY (READING, ENGLAND) 2023; 169. [PMID: 37276014 DOI: 10.1099/mic.0.001335] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Pseudomonas aeruginosa
is a well-studied Gram-negative opportunistic bacterium that thrives in markedly varied environments. It is a nutritionally versatile microbe that can colonize a host as well as exist in the environment. Unicellular, planktonic cells of
P. aeruginosa
can come together to perform a coordinated swarming movement or turn into a sessile, surface-adhered population called biofilm. These collective behaviours produce strikingly different outcomes. While swarming motility rapidly disseminates the bacterial population, biofilm collectively protects the population from environmental stresses such as heat, drought, toxic chemicals, grazing by predators, and attack by host immune cells and antibiotics. The ubiquitous nature of
P. aeruginosa
is likely to be supported by the timely transition between planktonic, swarming and biofilm lifestyles. The social behaviours of this bacteria viz biofilm and swarm modes are controlled by signals from quorum-sensing networks, LasI-LasR, RhlI-RhlR and PQS-MvfR, and several other sensory kinases and response regulators. A combination of environmental and genetic cues regulates the transition of the
P. aeruginosa
population to specific states. The current review is aimed at discussing key factors that promote physiologically distinct transitioning of the
P. aeruginosa
population.
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Affiliation(s)
- Sakthivel Ambreetha
- Department of Developmental Biology and Genetics, Indian Institute of Science, Bengaluru, Karnataka - 560012, India
| | - Varsha Singh
- Department of Developmental Biology and Genetics, Indian Institute of Science, Bengaluru, Karnataka - 560012, India
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7
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Zammuto V, Spanò A, Agostino E, Macrì A, De Pasquale C, Ferlazzo G, Rizzo MG, Nicolò MS, Guglielmino S, Gugliandolo C. Anti-Bacterial Adhesion on Abiotic and Biotic Surfaces of the Exopolysaccharide from the Marine Bacillus licheniformis B3-15. Mar Drugs 2023; 21:md21050313. [PMID: 37233507 DOI: 10.3390/md21050313] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2023] [Revised: 05/05/2023] [Accepted: 05/18/2023] [Indexed: 05/27/2023] Open
Abstract
The eradication of bacterial biofilm represents a crucial strategy to prevent a clinical problem associated with microbial persistent infection. In this study we evaluated the ability of the exopolysaccharide (EPS) B3-15, produced by the marine Bacillus licheniformis B3-15, to prevent the adhesion and biofilm formation of Pseudomonas aeruginosa ATCC 27853 and Staphylococcus aureus ATCC 29213 on polystyrene and polyvinyl chloride surfaces. The EPS was added at different times (0, 2, 4 and 8 h), corresponding to the initial, reversible and irreversible attachment, and after the biofilm development (24 or 48 h). The EPS (300 µg/mL) impaired the initial phase, preventing bacterial adhesion even when added after 2 h of incubation, but had no effects on mature biofilms. Without exerting any antibiotic activity, the antibiofilm mechanisms of the EPS were related to the modification of the (i) abiotic surface properties, (ii) cell-surface charges and hydrophobicity, and iii) cell-to-cell aggregation. The addition of EPS downregulated the expression of genes (lecA and pslA of P. aeruginosa and clfA of S. aureus) involved in the bacterial adhesion. Moreover, the EPS reduced the adhesion of P. aeruginosa (five logs-scale) and S. aureus (one log) on human nasal epithelial cells. The EPS could represent a promising tool for the prevention of biofilm-related infections.
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Affiliation(s)
- Vincenzo Zammuto
- Department of Chemical, Biological, Pharmaceutical and Environmental Sciences, University of Messina, Viale Ferdinando Stagno D'Alcontres 31, 98166 Messina, Italy
- Research Centre for Extreme Environments and Extremophiles, Department of Chemical, Biological, Pharmaceutical and Environmental Sciences, University of Messina, Viale Ferdinando Stagno D'Alcontres 31, 98166 Messina, Italy
| | - Antonio Spanò
- Department of Chemical, Biological, Pharmaceutical and Environmental Sciences, University of Messina, Viale Ferdinando Stagno D'Alcontres 31, 98166 Messina, Italy
- Research Centre for Extreme Environments and Extremophiles, Department of Chemical, Biological, Pharmaceutical and Environmental Sciences, University of Messina, Viale Ferdinando Stagno D'Alcontres 31, 98166 Messina, Italy
| | - Eleonora Agostino
- Department of Chemical, Biological, Pharmaceutical and Environmental Sciences, University of Messina, Viale Ferdinando Stagno D'Alcontres 31, 98166 Messina, Italy
| | - Angela Macrì
- Department of Chemical, Biological, Pharmaceutical and Environmental Sciences, University of Messina, Viale Ferdinando Stagno D'Alcontres 31, 98166 Messina, Italy
| | - Claudia De Pasquale
- Laboratory of Immunology and Biotherapy, Department of Human Pathology, University of Messina, Via Consolare Valeria, 1, 98124 Messina, Italy
| | - Guido Ferlazzo
- Department of Experimental Medicine (DIMES), University of Genoa and IRCCS Ospedale Policlinico San Martino, 16132 Genoa, Italy
| | - Maria Giovanna Rizzo
- Department of Chemical, Biological, Pharmaceutical and Environmental Sciences, University of Messina, Viale Ferdinando Stagno D'Alcontres 31, 98166 Messina, Italy
- Research Centre for Extreme Environments and Extremophiles, Department of Chemical, Biological, Pharmaceutical and Environmental Sciences, University of Messina, Viale Ferdinando Stagno D'Alcontres 31, 98166 Messina, Italy
| | - Marco Sebastiano Nicolò
- Department of Chemical, Biological, Pharmaceutical and Environmental Sciences, University of Messina, Viale Ferdinando Stagno D'Alcontres 31, 98166 Messina, Italy
- Research Centre for Extreme Environments and Extremophiles, Department of Chemical, Biological, Pharmaceutical and Environmental Sciences, University of Messina, Viale Ferdinando Stagno D'Alcontres 31, 98166 Messina, Italy
| | - Salvatore Guglielmino
- Department of Chemical, Biological, Pharmaceutical and Environmental Sciences, University of Messina, Viale Ferdinando Stagno D'Alcontres 31, 98166 Messina, Italy
- Research Centre for Extreme Environments and Extremophiles, Department of Chemical, Biological, Pharmaceutical and Environmental Sciences, University of Messina, Viale Ferdinando Stagno D'Alcontres 31, 98166 Messina, Italy
| | - Concetta Gugliandolo
- Department of Chemical, Biological, Pharmaceutical and Environmental Sciences, University of Messina, Viale Ferdinando Stagno D'Alcontres 31, 98166 Messina, Italy
- Research Centre for Extreme Environments and Extremophiles, Department of Chemical, Biological, Pharmaceutical and Environmental Sciences, University of Messina, Viale Ferdinando Stagno D'Alcontres 31, 98166 Messina, Italy
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Chung J, Eisha S, Park S, Morris AJ, Martin I. How Three Self-Secreted Biofilm Exopolysaccharides of Pseudomonas aeruginosa, Psl, Pel, and Alginate, Can Each Be Exploited for Antibiotic Adjuvant Effects in Cystic Fibrosis Lung Infection. Int J Mol Sci 2023; 24:ijms24108709. [PMID: 37240055 DOI: 10.3390/ijms24108709] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2023] [Revised: 04/29/2023] [Accepted: 05/10/2023] [Indexed: 05/28/2023] Open
Abstract
In cystic fibrosis (CF), pulmonary infection with Pseudomonas aeruginosa is a cause of increased morbidity and mortality, especially in patients for whom infection becomes chronic and there is reliance on long-term suppressive therapies. Current antimicrobials, though varied mechanistically and by mode of delivery, are inadequate not only due to their failure to eradicate infection but also because they do not halt the progression of lung function decline over time. One of the reasons for this failure is thought to be the biofilm mode of growth of P. aeruginosa, wherein self-secreted exopolysaccharides (EPSs) provide physical protection against antibiotics and an array of niches with resulting metabolic and phenotypic heterogeneity. The three biofilm-associated EPSs secreted by P. aeruginosa (alginate, Psl, and Pel) are each under investigation and are being exploited in ways that potentiate antibiotics. In this review, we describe the development and structure of P. aeruginosa biofilms before examining each EPS as a potential therapeutic target for combating pulmonary infection with P. aeruginosa in CF, with a particular focus on the current evidence for these emerging therapies and barriers to bringing these therapies into clinic.
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Affiliation(s)
- Jonathan Chung
- Department of Translational Medicine, Research Institute, The Hospital for Sick Children, University of Toronto, 686 Bay Street, Toronto, ON M5G 0A4, Canada
| | - Shafinaz Eisha
- Department of Translational Medicine, Research Institute, The Hospital for Sick Children, University of Toronto, 686 Bay Street, Toronto, ON M5G 0A4, Canada
| | - Subin Park
- Department of Translational Medicine, Research Institute, The Hospital for Sick Children, University of Toronto, 686 Bay Street, Toronto, ON M5G 0A4, Canada
| | - Amanda J Morris
- Department of Translational Medicine, Research Institute, The Hospital for Sick Children, University of Toronto, 686 Bay Street, Toronto, ON M5G 0A4, Canada
| | - Isaac Martin
- Department of Translational Medicine, Research Institute, The Hospital for Sick Children, University of Toronto, 686 Bay Street, Toronto, ON M5G 0A4, Canada
- Division of Respiratory Medicine, Department of Paediatrics, The Hospital for Sick Children, University of Toronto, 555 University Avenue, Toronto, ON M5G 1X8, Canada
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9
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Liu YJ, Li ZH, He YT, Yuan L, Sheng GP. Antibiotic resistomes in face-mask biofilm along an urban river: Multiple drivers and co-occurrence with human opportunistic pathogens. JOURNAL OF HAZARDOUS MATERIALS 2023; 455:131587. [PMID: 37172383 PMCID: PMC10162859 DOI: 10.1016/j.jhazmat.2023.131587] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/01/2023] [Revised: 04/26/2023] [Accepted: 05/04/2023] [Indexed: 05/14/2023]
Abstract
Discarded face masks from the global COVID-19 pandemic have contributed significantly to plastic pollution in surface water, whereas their potential as a reservoir for aquatic pollutants is not well understood. Herein, we conducted a field experiment along a human-impacted urban river, investigating the variations of antibiotic resistance genes (ARGs), pathogens, and water-borne contaminants in commonly-used face masks. Results showed that high-biomass biofilms formed on face masks selectively enriched more ARGs than stone biofilm (0.08-0.22 vs 0.07-0.15 copies/16 S rRNA gene copies) from bulk water, which mainly due to unique microbial communities, enhanced horizontal gene transfer, and selective pressure of accumulated contaminants based on redundancy analysis and variation partitioning analysis. Several human opportunistic pathogens (e.g., Acinetobacter, Escherichia-Shigella, Bacillus, and Klebsiella), which are considered potential ARG carriers, were also greatly concentrated in face-mask biofilms, imposing a potential threat to aquatic ecological environment and human health. Moreover, wastewater treatment plant effluents, as an important source of pollutants to urban rivers, further aggravated the abundances of ARGs and opportunistic pathogens in face-mask biofilms. Our findings demonstrated that discarded face masks provide a hotspot for the proliferation and spread of ARGs and pathogens in urban water, highlighting the urgent requirement for implementing stricter regulations in face mask disposal.
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Affiliation(s)
- Yan-Jun Liu
- CAS Key Laboratory of Urban Pollutant Conversion, Department of Environmental Science and Engineering, University of Science and Technology of China, Hefei 230026, China
| | - Zheng-Hao Li
- CAS Key Laboratory of Urban Pollutant Conversion, Department of Environmental Science and Engineering, University of Science and Technology of China, Hefei 230026, China.
| | - Yun-Tian He
- CAS Key Laboratory of Urban Pollutant Conversion, Department of Environmental Science and Engineering, University of Science and Technology of China, Hefei 230026, China
| | - Li Yuan
- CAS Key Laboratory of Urban Pollutant Conversion, Department of Environmental Science and Engineering, University of Science and Technology of China, Hefei 230026, China.
| | - Guo-Ping Sheng
- CAS Key Laboratory of Urban Pollutant Conversion, Department of Environmental Science and Engineering, University of Science and Technology of China, Hefei 230026, China
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10
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Balducci E, Papi F, Capialbi DE, Del Bino L. Polysaccharides' Structures and Functions in Biofilm Architecture of Antimicrobial-Resistant (AMR) Pathogens. Int J Mol Sci 2023; 24:ijms24044030. [PMID: 36835442 PMCID: PMC9965654 DOI: 10.3390/ijms24044030] [Citation(s) in RCA: 18] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2023] [Revised: 02/13/2023] [Accepted: 02/14/2023] [Indexed: 02/19/2023] Open
Abstract
Bacteria and fungi have developed resistance to the existing therapies such as antibiotics and antifungal drugs, and multiple mechanisms are mediating this resistance. Among these, the formation of an extracellular matrix embedding different bacterial cells, called biofilm, is an effective strategy through which bacterial and fungal cells are establishing a relationship in a unique environment. The biofilm provides them the possibility to transfer genes conferring resistance, to prevent them from desiccation and to impede the penetration of antibiotics or antifungal drugs. Biofilms are formed of several constituents including extracellular DNA, proteins and polysaccharides. Depending on the bacteria, different polysaccharides form the biofilm matrix in different microorganisms, some of them involved in the first stage of cells' attachment to surfaces and to each other, and some responsible for giving the biofilm structure resistance and stability. In this review, we describe the structure and the role of different polysaccharides in bacterial and fungal biofilms, we revise the analytical methods to characterize them quantitatively and qualitatively and finally we provide an overview of potential new antimicrobial therapies able to inhibit biofilm formation by targeting exopolysaccharides.
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Affiliation(s)
| | | | - Daniela Eloisa Capialbi
- GSK, 53100 Siena, Italy
- Department of Biotechnology, Chemistry and Pharmacy, University of Siena, 53100 Siena, Italy
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11
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Yin R, Cheng J, Wang J, Li P, Lin J. Treatment of Pseudomonas aeruginosa infectious biofilms: Challenges and strategies. Front Microbiol 2022; 13:955286. [PMID: 36090087 PMCID: PMC9459144 DOI: 10.3389/fmicb.2022.955286] [Citation(s) in RCA: 23] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2022] [Accepted: 08/09/2022] [Indexed: 01/10/2023] Open
Abstract
Pseudomonas aeruginosa, a Gram-negative bacterium, is one of the major pathogens implicated in human opportunistic infection and a common cause of clinically persistent infections such as cystic fibrosis, urinary tract infections, and burn infections. The main reason for the persistence of P. aeruginosa infections is due to the ability of P. aeruginosa to secrete extracellular polymeric substances such as exopolysaccharides, matrix proteins, and extracellular DNA during invasion. These substances adhere to and wrap around bacterial cells to form a biofilm. Biofilm formation leads to multiple antibiotic resistance in P. aeruginosa, posing a significant challenge to conventional single antibiotic therapeutic approaches. It has therefore become particularly important to develop anti-biofilm drugs. In recent years, a number of new alternative drugs have been developed to treat P. aeruginosa infectious biofilms, including antimicrobial peptides, quorum-sensing inhibitors, bacteriophage therapy, and antimicrobial photodynamic therapy. This article briefly introduces the process and regulation of P. aeruginosa biofilm formation and reviews several developed anti-biofilm treatment technologies to provide new directions for the treatment of P. aeruginosa biofilm infection.
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12
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Ma X, Liu Q, Song F, Huang Y. Differentially Expressed Genes of Pseudomonas aeruginosa Isolates from Eyes with Keratitis and Healthy Conjunctival Sacs. Infect Drug Resist 2022; 15:4495-4506. [PMID: 35983295 PMCID: PMC9380828 DOI: 10.2147/idr.s374335] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2022] [Accepted: 08/06/2022] [Indexed: 11/23/2022] Open
Abstract
Background Pseudomonas aeruginosa (P. aeruginosa) is the second-most common commensal bacterium in healthy conjunctival sacs. When the corneal epithelial barrier is damaged, P. aeruginosa in a healthy conjunctival sac can cause infectious keratitis, which can result in the loss of vision. This study was designed to investigate the differentially expressed genes (DEGs) of P. aeruginosa isolates from eyes with keratitis and from healthy conjunctival sacs to predict their functions and pathways through Illumina high-throughput RNA sequencing (RNA-seq). Methods P. aeruginosa isolates from keratitis and healthy conjunctival sacs were obtained. The transcriptome profile of P. aeruginosa was characterized by a high throughput RNA-seq strategy using the Illumina HiSeq 2500 platform. The DEGs were analyzed with DESeq and validated through quantitative real-time polymerase chain reaction (PCR) and with experimental mice. GO enrichment and the KEGG pathway were also analyzed. Results In genome-wide transcriptional analysis, 557 genes (332 upregulated and 225 downregulated) were found to be differentially expressed (fold change ≥ 2, p ≤ 0.05) in the strains from keratitis. GO enrichment analysis suggested that DEGs tended to be associated with cellular and metabolic processes. KEGG pathway analysis revealed the DEGs were typically associated with the pathways of the bacterial secretion system and pyoverdine metabolism. Eleven DEGs were validated using quantitative reverse-transcription PCR and verified with experimental mice. The results were consistent with those obtained in RNA-seq. Conclusion The DEGs related to pilin, T2SS, T3SS, and pyoverdine metabolisms were significantly altered in the strains from keratitis. The findings may be helpful for further investigations on genes or pathways related to the pathogenesis of and therapeutic targets for P. aeruginosa keratitis.
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Affiliation(s)
- Xiubin Ma
- Department of Ophthalmology, Eye Institute of Shandong First Medical University, Qingdao Eye Hospital of Shandong First Medical University, Qingdao, People's Republic of China.,State Key Laboratory Cultivation Base, Shandong Provincial Key Laboratory of Ophthalmology, Shandong Eye Institute, Qingdao, People's Republic of China.,Department of Ophthalmology, School of Ophthalmology, Shandong First Medical University, Qingdao, People's Republic of China
| | - Qing Liu
- Department of Ophthalmology, Eye Institute of Shandong First Medical University, Qingdao Eye Hospital of Shandong First Medical University, Qingdao, People's Republic of China.,State Key Laboratory Cultivation Base, Shandong Provincial Key Laboratory of Ophthalmology, Shandong Eye Institute, Qingdao, People's Republic of China.,Department of Ophthalmology, School of Ophthalmology, Shandong First Medical University, Qingdao, People's Republic of China
| | - Fangying Song
- Department of Ophthalmology, Eye Institute of Shandong First Medical University, Qingdao Eye Hospital of Shandong First Medical University, Qingdao, People's Republic of China.,State Key Laboratory Cultivation Base, Shandong Provincial Key Laboratory of Ophthalmology, Shandong Eye Institute, Qingdao, People's Republic of China.,Department of Ophthalmology, School of Ophthalmology, Shandong First Medical University, Qingdao, People's Republic of China
| | - Yusen Huang
- Department of Ophthalmology, Eye Institute of Shandong First Medical University, Qingdao Eye Hospital of Shandong First Medical University, Qingdao, People's Republic of China.,State Key Laboratory Cultivation Base, Shandong Provincial Key Laboratory of Ophthalmology, Shandong Eye Institute, Qingdao, People's Republic of China.,Department of Ophthalmology, School of Ophthalmology, Shandong First Medical University, Qingdao, People's Republic of China
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13
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Pseudomonas aeruginosa polysaccharide Psl supports airway microbial community development. THE ISME JOURNAL 2022; 16:1730-1739. [PMID: 35338335 PMCID: PMC9213427 DOI: 10.1038/s41396-022-01221-y] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/15/2021] [Revised: 02/24/2022] [Accepted: 03/08/2022] [Indexed: 01/01/2023]
Abstract
Pseudomonas aeruginosa dominates the complex polymicrobial cystic fibrosis (CF) airway and is a leading cause of death in persons with CF. Oral streptococcal colonization has been associated with stable CF lung function. However, no studies have demonstrated how Streptococcus salivarius, the most abundant streptococcal species found in individuals with stable CF lung disease, potentially improves lung function or becomes incorporated into the CF airway biofilm. By utilizing a two-species biofilm model to probe interactions between S. salivarius and P. aeruginosa, we discovered that the P. aeruginosa exopolysaccharide Psl promoted S. salivarius biofilm formation. Further, we identified a S. salivarius maltose-binding protein (MalE) that is required for promotion of biofilm formation both in vitro and in a Drosophila melanogaster co-infection model. Finally, we demonstrate that promotion of dual biofilm formation with S. salivarius is common among environmental and clinical P. aeruginosa isolates. Overall, our data supports a model in which S. salivarius uses a sugar-binding protein to interact with P. aeruginosa exopolysaccharide, which may be a strategy by which S. salivarius establishes itself within the CF airway microbial community.
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14
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Ma LZ, Wang D, Liu Y, Zhang Z, Wozniak DJ. Regulation of Biofilm Exopolysaccharide Biosynthesis and Degradation in Pseudomonas aeruginosa. Annu Rev Microbiol 2022; 76:413-433. [DOI: 10.1146/annurev-micro-041320-111355] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Microbial communities enmeshed in a matrix of macromolecules, termed as biofilms, are the natural setting of bacteria. Exopolysaccharide is a critical matrix component of biofilms. Here, we focus on biofilm matrix exopolysaccharides in Pseudomonas aeruginosa. This opportunistic pathogen can adapt to a wide range of environments and can form biofilms or aggregates in a variety of surfaces or environments, such as the lungs of people with cystic fibrosis, catheters, wounds, and contact lenses. The ability to synthesize multiple exopolysaccharides is one of the advantages that facilitate bacterial survival in different environments. P. aeruginosa can produce several exopolysaccharides, including alginate, Psl, Pel, and lipopolysaccharide. In this review, we highlight the roles of each exopolysaccharide in P. aeruginosa biofilm development and how bacteria coordinate the biosynthesis of multiple exopolysaccharides and bacterial motility. In addition, we present advances in antibiofilm strategies targeting matrix exopolysaccharides, with a focus on glycoside hydrolases. Expected final online publication date for the Annual Review of Microbiology, Volume 76 is September 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.
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Affiliation(s)
- Luyan Z. Ma
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
| | - Di Wang
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
| | - Yiwei Liu
- Department of Microbial Infection and Immunity and Department of Microbiology, Ohio State University, Columbus, Ohio, USA
| | - Zhenyu Zhang
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
| | - Daniel J. Wozniak
- Department of Microbial Infection and Immunity and Department of Microbiology, Ohio State University, Columbus, Ohio, USA
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15
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Del Bino L, Østerlid KE, Wu DY, Nonne F, Romano MR, Codée J, Adamo R. Synthetic Glycans to Improve Current Glycoconjugate Vaccines and Fight Antimicrobial Resistance. Chem Rev 2022; 122:15672-15716. [PMID: 35608633 PMCID: PMC9614730 DOI: 10.1021/acs.chemrev.2c00021] [Citation(s) in RCA: 50] [Impact Index Per Article: 25.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Antimicrobial resistance (AMR) is emerging as the next potential pandemic. Different microorganisms, including the bacteria Acinetobacter baumannii, Clostridioides difficile, Escherichia coli, Enterococcus faecium, Klebsiella pneumoniae, Neisseria gonorrhoeae, Pseudomonas aeruginosa, non-typhoidal Salmonella, and Staphylococcus aureus, and the fungus Candida auris, have been identified by the WHO and CDC as urgent or serious AMR threats. Others, such as group A and B Streptococci, are classified as concerning threats. Glycoconjugate vaccines have been demonstrated to be an efficacious and cost-effective measure to combat infections against Haemophilus influenzae, Neisseria meningitis, Streptococcus pneumoniae, and, more recently, Salmonella typhi. Recent times have seen enormous progress in methodologies for the assembly of complex glycans and glycoconjugates, with developments in synthetic, chemoenzymatic, and glycoengineering methodologies. This review analyzes the advancement of glycoconjugate vaccines based on synthetic carbohydrates to improve existing vaccines and identify novel candidates to combat AMR. Through this literature survey we built an overview of structure-immunogenicity relationships from available data and identify gaps and areas for further research to better exploit the peculiar role of carbohydrates as vaccine targets and create the next generation of synthetic carbohydrate-based vaccines.
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Affiliation(s)
| | - Kitt Emilie Østerlid
- Leiden Institute of Chemistry, Leiden University, 2300 RA Leiden, The Netherlands
| | - Dung-Yeh Wu
- Leiden Institute of Chemistry, Leiden University, 2300 RA Leiden, The Netherlands
| | | | | | - Jeroen Codée
- Leiden Institute of Chemistry, Leiden University, 2300 RA Leiden, The Netherlands
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16
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Mucoid Pseudomonas aeruginosa Can Produce Calcium-Gelled Biofilms Independent of the Matrix Components Psl and CdrA. J Bacteriol 2022; 204:e0056821. [PMID: 35416688 PMCID: PMC9112934 DOI: 10.1128/jb.00568-21] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Biofilms are aggregates of microorganisms embedded in an extracellular matrix comprised largely of exopolysaccharides (EPSs), nucleic acids, and proteins. Pseudomonas aeruginosa is an opportunistic human pathogen that is also a model organism for studying biofilms in the laboratory. Here, we define a novel program of biofilm development used by mucoid (alginate-overproducing) P. aeruginosa in the presence of elevated calcium. Calcium cations cross-link negatively charged alginate polymers, resulting in individual cells being suspended in an alginate gel. The formation of this type of structurally distinct biofilm is not reliant on the canonical biofilm EPS components Psl and Pel or the matrix protein CdrA. We also observed that mucoid P. aeruginosa biofilm cells do not have the typical elevated levels of the secondary messenger cyclic di-GMP (c-di-GMP), as expected of biofilm cells, nor does the overproduction of alginate rely on high c-di-GMP. This contrasts with nonmucoid biofilms in which the production of the matrix components Psl, Pel, and CdrA is positively regulated by elevated c-di-GMP. We further demonstrate that calcium-gelled alginate biofilms impede the penetration of the antibiotic tobramycin, thus protecting the biofilm community from antibiotic-mediated killing. Finally, we show that bacterial aggregates with a dispersed cell arrangement like laboratory-grown calcium-alginate biofilm structures are present in explanted cystic fibrosis (CF) lung samples. Our findings illustrate the diverse nature of biofilm formation and structure in P. aeruginosa. IMPORTANCE The opportunistic pathogen Pseudomonas aeruginosa produces a complex biofilm matrix comprised of exopolysaccharides (EPSs), nucleic acids, and proteins. P. aeruginosa biofilm formation canonically depends on a variable combination of the exopolysaccharides Psl and Pel and the matrix protein CdrA. We demonstrate that mucoid P. aeruginosa, which overproduces the EPS alginate, possesses an entirely alternate and calcium-dependent method of biofilm formation. These mucoid biofilm structures do not require Psl, Pel, or CdrA, and they display a unique organization of individually suspended cells similar to bacterial aggregates observed in cystic fibrosis airways. Furthermore, calcium-gelled mucoid biofilms impede the penetration and killing action of the antibiotic tobramycin, illustrating their potential clinical significance. Our findings highlight the compositional and structural variety of P. aeruginosa biofilm aggregates.
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Divyashree M, Mani MK, Karunasagar I. Association of exopolysaccharide genes in biofilm developing antibiotic-resistant Pseudomonas aeruginosa from hospital wastewater. JOURNAL OF WATER AND HEALTH 2022; 20:176-184. [PMID: 35100165 DOI: 10.2166/wh.2021.223] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
The study aimed to examine the relationship between antibiotic resistance, biofilm formation and genes responsible for biofilm formation. Sixty-six Pseudomonas aeruginosa isolates were obtained from hospital wastewater and analyzed for their antibiotic resistance. Biofilm production among the isolates was tested by indirect quantification method crystal violet assay. Biofilm-associated genes among these isolates psl, alg, and pel were also checked. The maximum resistance was observed for ampicillins (88.24%) followed by nalidixic (83.82%), and nitrofurantoin (64.71%), respectively. Biofilm phenotypes are distributed in the following categories: high 39.39% (n = 26); moderate 57.57% (n = 38), and weak 3.0% (n = 2). Among the total isolates, biofilm-associated genes were detected in 84.84% (n = 56) of isolates and the remaining isolates 15.15% (n = 10) did not harbor any genes. In this study, pslB was the most predominant gene observed (71.21%, n = 47) followed by pslA (57.57%, n = 38), pelA (45.45%, n = 30), algD (43.93%, n = 29), and pelD (27.27%, n = 18), respectively. The present study reveals that the majority of the isolates are multidrug resistant being moderate and high biofilm formers. The study implies that biofilm acts as a machinery for bacteria to survive in the hospital effluent which is an antibiotic stress environment.
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Affiliation(s)
- M Divyashree
- Department of Biomedical Sciences, Nitte University Center for Science Education and Research (NUCSER), NITTE (Deemed to be University), Paneer Campus, Kotekar-Beeri Road, Deralakatte, Mangalore 575018, India E-mail:
| | - Madhu K Mani
- Department of Biomedical Sciences, Nitte University Center for Science Education and Research (NUCSER), NITTE (Deemed to be University), Paneer Campus, Kotekar-Beeri Road, Deralakatte, Mangalore 575018, India E-mail:
| | - Indrani Karunasagar
- DST-TEC, NITTE (DU), Paneer Campus, Kotekar-Beeri Road, Deralakatte, Mangaluru 575018, Karnataka, India
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18
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Characterizations of the viability and gene expression of dispersal cells from Pseudomonas aeruginosa biofilms released by alginate lyase and tobramycin. PLoS One 2021; 16:e0258950. [PMID: 34695148 PMCID: PMC8544826 DOI: 10.1371/journal.pone.0258950] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2021] [Accepted: 10/08/2021] [Indexed: 11/19/2022] Open
Abstract
Biofilm infections are hard to manage using conventional antibiotic treatment regimens because biofilm structures discourage antibiotics from reaching the entire bacterial community and allow pathogen cells to persistently colonize and develop a plethora of tolerance mechanisms towards antibiotics. Moreover, the dispersed cells from biofilms can cause further complications by colonizing different sites and establishing new cycles of biofilms. Previously, we showed that alginate lyase enzyme (AlyP1400), purified from a marine Pseudoalteromonas bacterium, reduced Pseudomonas aeruginosa biofilm biomass and boosted bactericidal activity of tobramycin by degrading alginate within the biofilm extracellular polymeric substances matrix. In this work, we used a flow cytometry-based assay to analyze collected dispersal cells and demonstrated the synergy between tobramycin with AlyP1400 in enhancing the release of both live and dead biofilm cells from a mucoid P. aeruginosa strain CF27, which is a clinical isolate from cystic fibrosis (CF) patients. Interestingly, this enhanced dispersal was only observed when AlyP1400 was combined with tobramycin and administered simultaneously but not when AlyP1400 was added in advance of tobramycin in a sequential manner. Moreover, neither the combined nor sequential treatment altered the dispersal of the biofilms from a non-mucoid P. aeruginosa laboratory strain PAK. We then carried out the gene expression and tobramycin survival analyses to further characterize the impacts of the combined treatment on the CF27 dispersal cells. Gene expression analysis indicated that CF27 dispersal cells had increased expression in virulence- and antibiotic resistance-related genes, including algR, bdlA, lasB, mexF, mexY, and ndvB. In the CF27 dispersal cell population, the combinational treatment of AlyP1400 with tobramycin further induced bdlA, mexF, mexY, and ndvB genes more than non-treated and tobramycin-treated dispersal cells, suggesting an exacerbated bacterial stress response to the combinational treatment. Simultaneous to the gene expression analysis, the survival ability of the same batch of biofilm dispersal cells to a subsequent tobramycin challenge displayed a significantly higher tobramycin tolerant fraction of cells (~60%) upon the combinational treatment of AlyP1400 and tobramycin than non-treated and tobramycin-treated dispersal cells, as well as the planktonic cells (all below 10%). These results generate new knowledge about the gene expression and antibiotic resistance profiles of dispersed cells from biofilm. This information can guide the design of safer and more efficient therapeutic strategies for the combinational use of alginate lyase and tobramycin to treat P. aeruginosa biofilm-related infections in CF lungs.
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O-Specific Antigen-Dependent Surface Hydrophobicity Mediates Aggregate Assembly Type in Pseudomonas aeruginosa. mBio 2021; 12:e0086021. [PMID: 34372703 PMCID: PMC8406328 DOI: 10.1128/mbio.00860-21] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
Bacteria live in spatially organized aggregates during chronic infections, where they adapt to the host environment, evade immune responses, and resist therapeutic interventions. Although it is known that environmental factors such as polymers influence bacterial aggregation, it is not clear how bacterial adaptation during chronic infection impacts the formation and spatial organization of aggregates in the presence of polymers. Here, we show that in an in vitro model of cystic fibrosis (CF) containing the polymers extracellular DNA (eDNA) and mucin, O-specific antigen is a major factor determining the formation of two distinct aggregate assembly types of Pseudomonas aeruginosa due to alterations in cell surface hydrophobicity. Our findings suggest that during chronic infection, the interplay between cell surface properties and polymers in the environment may influence the formation and structure of bacterial aggregates, which would shed new light on the fitness costs and benefits of O-antigen production in environments such as CF lungs.
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Craig K, Johnson BR, Grunden A. Leveraging Pseudomonas Stress Response Mechanisms for Industrial Applications. Front Microbiol 2021; 12:660134. [PMID: 34040596 PMCID: PMC8141521 DOI: 10.3389/fmicb.2021.660134] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2021] [Accepted: 04/12/2021] [Indexed: 12/25/2022] Open
Abstract
Members of the genus Pseudomonas are metabolically versatile and capable of adapting to a wide variety of environments. Stress physiology of Pseudomonas strains has been extensively studied because of their biotechnological potential in agriculture as well as their medical importance with regards to pathogenicity and antibiotic resistance. This versatility and scientific relevance led to a substantial amount of information regarding the stress response of a diverse set of species such as Pseudomonas chlororaphis, P. fluorescens, P. putida, P. aeruginosa, and P. syringae. In this review, environmental and industrial stressors including desiccation, heat, and cold stress, are cataloged along with their corresponding mechanisms of survival in Pseudomonas. Mechanisms of survival are grouped by the type of inducing stress with a focus on adaptations such as synthesis of protective substances, biofilm formation, entering a non-culturable state, enlisting chaperones, transcription and translation regulation, and altering membrane composition. The strategies Pseudomonas strains utilize for survival can be leveraged during the development of beneficial strains to increase viability and product efficacy.
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Affiliation(s)
- Kelly Craig
- AgBiome Inc., Research Triangle Park, NC, United States
| | | | - Amy Grunden
- Department of Plant and Microbial Biology, North Carolina State University, Raleigh, NC, United States
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21
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Cendra MDM, Torrents E. Pseudomonas aeruginosa biofilms and their partners in crime. Biotechnol Adv 2021; 49:107734. [PMID: 33785375 DOI: 10.1016/j.biotechadv.2021.107734] [Citation(s) in RCA: 55] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2020] [Revised: 03/15/2021] [Accepted: 03/18/2021] [Indexed: 12/24/2022]
Abstract
Pseudomonas aeruginosa biofilms and the capacity of the bacterium to coexist and interact with a broad range of microorganisms have a substantial clinical impact. This review focuses on the main traits of P. aeruginosa biofilms, such as the structural composition and regulatory networks involved, placing particular emphasis on the clinical challenges they represent in terms of antimicrobial susceptibility and biofilm infection clearance. Furthermore, the ability of P. aeruginosa to grow together with other microorganisms is a significant pathogenic attribute with clinical relevance; hence, the main microbial interactions of Pseudomonas are especially highlighted and detailed throughout this review. This article also explores the infections caused by single and polymicrobial biofilms of P. aeruginosa and the current models used to recreate them under laboratory conditions. Finally, the antimicrobial and antibiofilm strategies developed against P. aeruginosa mono and multispecies biofilms are detailed at the end of this review.
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Affiliation(s)
- Maria Del Mar Cendra
- Bacterial Infections and Antimicrobial therapies Group, Institute for Bioengineering of Catalonia (IBEC), The Barcelona Institute of Science and Technology, Baldiri Reixac 15-21, 08028 Barcelona, Spain.
| | - Eduard Torrents
- Bacterial Infections and Antimicrobial therapies Group, Institute for Bioengineering of Catalonia (IBEC), The Barcelona Institute of Science and Technology, Baldiri Reixac 15-21, 08028 Barcelona, Spain; Microbiology Section, Department of Genetics, Microbiology and Statistics, Faculty of Biology, University of Barcelona, 643 Diagonal Ave., 08028 Barcelona, Spain.
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22
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Beyond the Wall: Exopolysaccharides in the Biofilm Lifestyle of Pathogenic and Beneficial Plant-Associated Pseudomonas. Microorganisms 2021; 9:microorganisms9020445. [PMID: 33670010 PMCID: PMC7926942 DOI: 10.3390/microorganisms9020445] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2021] [Revised: 02/12/2021] [Accepted: 02/18/2021] [Indexed: 11/16/2022] Open
Abstract
The formation of biofilms results from a multicellular mode of growth, in which bacteria remain enwrapped by an extracellular matrix of their own production. Many different bacteria form biofilms, but among the most studied species are those that belong to the Pseudomonas genus due to the metabolic versatility, ubiquity, and ecological significance of members of this group of microorganisms. Within the Pseudomonas genus, biofilm studies have mainly focused on the opportunistic human pathogen Pseudomonas aeruginosa due to its clinical importance. The extracellular matrix of P. aeruginosa is mainly composed of exopolysaccharides, which have been shown to be important for the biofilm architecture and pathogenic features of this bacterium. Notably, some of the exopolysaccharides recurrently used by P. aeruginosa during biofilm formation, such as the alginate and polysaccharide synthesis loci (Psl) polysaccharides, are also used by pathogenic and beneficial plant-associated Pseudomonas during their interaction with plants. Interestingly, their functions are multifaceted and seem to be highly dependent on the bacterial lifestyle and genetic context of production. This paper reviews the functions and significance of the exopolysaccharides produced by plant-associated Pseudomonas, particularly the alginate, Psl, and cellulose polysaccharides, focusing on their equivalents produced in P. aeruginosa within the context of pathogenic and beneficial interactions.
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The Extracellular Polysaccharide Matrix of Pseudomonas aeruginosa Biofilms Is a Determinant of Polymorphonuclear Leukocyte Responses. Infect Immun 2020; 89:IAI.00631-20. [PMID: 33077623 DOI: 10.1128/iai.00631-20] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2020] [Accepted: 10/09/2020] [Indexed: 01/04/2023] Open
Abstract
Bacterial biofilms may cause chronic infections due to their ability to evade clearance by the immune system and antibiotics. The persistent biofilms induce a hyperinflammatory state that damages the surrounding host tissue. Knowledge about the components of biofilms that are responsible for provoking the harmful but inefficient immune response is limited. Flagella are known to stimulate the response of polymorphonuclear leukocytes (PMNs) to planktonic solitary bacteria. However, we provide evidence that flagella are not a prerequisite for the response of PMNs to Pseudomonas aeruginosa biofilms. Instead, we found that extracellular matrix polysaccharides in P. aeruginosa biofilms play a role in the response of PMNs toward biofilms. Using a set of P. aeruginosa mutants with the ability to produce a subset of matrix exopolysaccharides, we found that P. aeruginosa biofilms with distinct exopolysaccharide matrix components elicit distinct PMN responses. In particular, the PMNs respond aggressively toward a biofilm matrix consisting of both Psl and alginate exopolysaccharides. These findings are relevant for therapeutic strategies aimed at dampening the collateral damage associated with biofilm-based infections.
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Thi MTT, Wibowo D, Rehm BH. Pseudomonas aeruginosa Biofilms. Int J Mol Sci 2020; 21:ijms21228671. [PMID: 33212950 PMCID: PMC7698413 DOI: 10.3390/ijms21228671] [Citation(s) in RCA: 283] [Impact Index Per Article: 70.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2020] [Revised: 11/09/2020] [Accepted: 11/13/2020] [Indexed: 12/17/2022] Open
Abstract
Pseudomonas aeruginosa is an opportunistic human pathogen causing devastating acute and chronic infections in individuals with compromised immune systems. Its highly notorious persistence in clinical settings is attributed to its ability to form antibiotic-resistant biofilms. Biofilm is an architecture built mostly by autogenic extracellular polymeric substances which function as a scaffold to encase the bacteria together on surfaces, and to protect them from environmental stresses, impedes phagocytosis and thereby conferring the capacity for colonization and long-term persistence. Here we review the current knowledge on P. aeruginosa biofilms, its development stages, and molecular mechanisms of invasion and persistence conferred by biofilms. Explosive cell lysis within bacterial biofilm to produce essential communal materials, and interspecies biofilms of P. aeruginosa and commensal Streptococcus which impedes P. aeruginosa virulence and possibly improves disease conditions will also be discussed. Recent research on diagnostics of P. aeruginosa infections will be investigated. Finally, therapeutic strategies for the treatment of P. aeruginosa biofilms along with their advantages and limitations will be compiled.
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Zhang Y, Pan X, Wang L, Chen L. Iron metabolism in Pseudomonas aeruginosa biofilm and the involved iron-targeted anti-biofilm strategies. J Drug Target 2020; 29:249-258. [PMID: 32969723 DOI: 10.1080/1061186x.2020.1824235] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
Pseudomonas aeruginosa is a gram-negative bacterium that exists in various ecosystems, causing severe infections in patients with AIDS or cystic fibrosis. P. aeruginosa can form biofilm on a variety of surfaces, whereby the bacteria produce defensive substances and enhance antibiotic-resistance, making themselves more adaptable to hostile environments. P. aeruginosa resistance represents one of the main causes of infection-related morbidity and mortality at a global level. Iron is required for the growth of P. aeruginosa biofilm. This review summarises how the iron metabolism contributes to develop biofilm, and more importantly, it may provide some references for the clinic to achieve novel anti-biofilm therapeutics by targeting iron activities.
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Affiliation(s)
- Yapeng Zhang
- Department of Medical Microbiology, School of Basic Medical Sciences, Central South University, Changsha, China
| | - Xuanhe Pan
- Department of Medical Microbiology, School of Basic Medical Sciences, Central South University, Changsha, China
| | - Linqian Wang
- Department of Clinical Laboratory, Hunan Cancer Hospital, the Affiliated Cancer Hospital of Xiangya School of Medicine, Central South University, Changsha, China
| | - Liyu Chen
- Department of Medical Microbiology, School of Basic Medical Sciences, Central South University, Changsha, China
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Geddes-McAlister J, Kugadas A, Gadjeva M. Tasked with a Challenging Objective: Why Do Neutrophils Fail to Battle Pseudomonas aeruginosa Biofilms. Pathogens 2019; 8:pathogens8040283. [PMID: 31817091 PMCID: PMC6963930 DOI: 10.3390/pathogens8040283] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2019] [Revised: 11/26/2019] [Accepted: 12/02/2019] [Indexed: 01/28/2023] Open
Abstract
Multidrug-resistant (MDR) bacterial infections are a leading cause of mortality, affecting approximately 250,000 people in Canada and over 2 million people in the United States, annually. The lack of efficacy of antibiotic-based treatments is often caused by inability of the drug to penetrate bacterial biofilms in sufficient concentrations, posing a major therapeutic challenge. Here, we review the most recent information about the architecture of Pseudomonas aeruginosa biofilms in vivo and describe how advances in imaging and mass spectroscopy analysis bring about novel therapeutic options and challenge existing dogmas.
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Affiliation(s)
| | - Abirami Kugadas
- Division of Infectious Diseases, Department of Medicine, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA 02115, USA;
| | - Mihaela Gadjeva
- Division of Infectious Diseases, Department of Medicine, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA 02115, USA;
- Correspondence: ; Tel.: +1-617-525-2268; Fax: +1-617-525-2510
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27
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Zhang Z, Weng Y, Ding Y, Qian S. Use of Genetically Modified Bacteria to Repair Cracks in Concrete. MATERIALS 2019; 12:ma12233912. [PMID: 31779264 PMCID: PMC6926745 DOI: 10.3390/ma12233912] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/22/2019] [Revised: 11/13/2019] [Accepted: 11/22/2019] [Indexed: 12/21/2022]
Abstract
In this paper, we studied the crack-repair by spraying bacteria-based liquid around the cracks in concrete. To enhance the repair efficiency and speed up the repair process, the transposon mutagenesis method was employed to modify the genes of Bacillus halodurans and create a mutant bacterial strain with higher efficiency of calcium carbonate productivity by catalyzing the combination of carbonate and calcium ion. The efficiency of crack-repairing in concrete by spraying two kinds of bacterial liquid was evaluated via image analysis, X-ray computed tomography (X-CT) scanning technology and the sorptivity test. The results show that the crack-repair efficiency was enhanced very evidently by spraying genetically modified bacterial-liquid as no microbiologically induced calcite precipitation (MICP) was found within the cracks for concrete samples sprayed using wild type bacterial-liquid. In addition, the crack-repair process was also shortened significantly in the case of genetically modified bacteria.
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Affiliation(s)
- Zhigang Zhang
- Key Laboratory of New Technology for Construction of Cities in Mountain Area, Chongqing University, Ministry of Education, Chongqing 400045, China;
- School of Civil and Environmental Engineering, Nanyang Technological University, Singapore 637551, Singapore; (Y.W.); (Y.D.)
| | - Yiwei Weng
- School of Civil and Environmental Engineering, Nanyang Technological University, Singapore 637551, Singapore; (Y.W.); (Y.D.)
- Singapore Centre for 3D Printing, School of Mechanical and Aerospace Engineering, Singapore 639798, Singapore
| | - Yuanzhao Ding
- School of Civil and Environmental Engineering, Nanyang Technological University, Singapore 637551, Singapore; (Y.W.); (Y.D.)
| | - Shunzhi Qian
- School of Civil and Environmental Engineering, Nanyang Technological University, Singapore 637551, Singapore; (Y.W.); (Y.D.)
- Correspondence:
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28
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El-Helow ER, Atalla RG, Sabra WA, Lotfy WA. Kinetic studies on the expression of alginate and extracellular proteins by Pseudomonas aeruginosa FRD1 and PAO1. J GEN APPL MICROBIOL 2019; 66:15-23. [PMID: 31366850 DOI: 10.2323/jgam.2019.04.003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Pseudomonas aeruginosa is characterized by its capability to produce extracellular virulence proteins and to establish biofilm-based infections that do not respond easily to conventional treatments. However, the physiological conditions that decrease the fitness of such a persistent pathogen would assist the host to defend itself and reduce the infection prevalence. Therefore, developing treatments against P. aeruginosa requires a quantitative understanding of the relationship between bacterial growth kinetics and secretion of alginate and proteins, in addition to the ecological factors that control their synthesis. For this purpose, we examined various environmental factors that affect the specific product yield coefficients (expressed as g product/OD600) of alginate and extracellular proteins using a mucoid (FRD1) and a non-mucoid (PAO1) clinical isolate of P. aeruginosa, respectively. The results suggested magnesium sulfate, trace elements and hydrogen peroxide as significant variables that positively affect alginate synthesis by the FRD1 cells. However, the production of extracellular proteins by PAO1 was negatively affected by the concentration of ferrous sulfate. For understanding the kinetics of expressing alginate and extracellular proteins by the cells, a well-controlled 5 L tank bioreactor was used. The results suggested that under the bioreactor controlled conditions, both alginate and extracellular proteins are expressed parallel to biomass increase in the cells of P. aeruginosa.
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Affiliation(s)
- Ehab R El-Helow
- Department of Botany and Microbiology, Faculty of Science, Alexandria University
| | - Ramy G Atalla
- Department of Botany and Microbiology, Faculty of Science, Alexandria University
| | - Wael A Sabra
- Department of Botany and Microbiology, Faculty of Science, Alexandria University
| | - Walid A Lotfy
- Microbiology Department, Faculty of Dentistry, Pharos University in Alexandria
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29
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Thanabalasuriar A, Scott BNV, Peiseler M, Willson ME, Zeng Z, Warrener P, Keller AE, Surewaard BGJ, Dozier EA, Korhonen JT, Cheng LIT, Gadjeva M, Stover CK, DiGiandomenico A, Kubes P. Neutrophil Extracellular Traps Confine Pseudomonas aeruginosa Ocular Biofilms and Restrict Brain Invasion. Cell Host Microbe 2019; 25:526-536.e4. [PMID: 30930127 DOI: 10.1016/j.chom.2019.02.007] [Citation(s) in RCA: 112] [Impact Index Per Article: 22.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2018] [Revised: 11/30/2018] [Accepted: 02/21/2019] [Indexed: 12/17/2022]
Abstract
Bacterial biofilm infections are difficult to eradicate because of antibiotic insusceptibility and high recurrence rates. Biofilm formation by Pseudomonas aeruginosa, a leading cause of bacterial keratitis, is facilitated by the bacterial Psl exopolysaccharide and associated with heightened virulence. Using intravital microscopy, we observed that neutrophilic recruitment to corneal infections limits P. aeruginosa biofilms to the outer eye surface, preventing bacterial dissemination. Neutrophils moved to the base of forming biofilms, where they underwent neutrophil extracellular trap formation (NETosis) in response to high expression of the bacterial type-3 secretion system (T3SS). NETs formed a barrier "dead zone," confining bacteria to the external corneal environment and inhibiting bacterial dissemination into the brain. Once formed, ocular biofilms were resistant to antibiotics and neutrophil killing, advancing eye pathology. However, blocking both Psl and T3SS together with antibiotic treatment broke down the biofilm and reversed keratitis, suggesting future therapeutic strategies for this intractable infection.
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Affiliation(s)
- Ajitha Thanabalasuriar
- University of Calgary, Department of Physiology and Pharmacology, Calvin Phoebe & Joan Snyder Institute for Chronic Diseases, Cumming School of Medicine, Calgary, AB, Canada; Microbial Sciences, MedImmune/AstraZeneca LLC, Gaithersburg, MD, USA
| | - Brittney Noelle Vivian Scott
- University of Calgary, Department of Physiology and Pharmacology, Calvin Phoebe & Joan Snyder Institute for Chronic Diseases, Cumming School of Medicine, Calgary, AB, Canada
| | - Moritz Peiseler
- University of Calgary, Department of Physiology and Pharmacology, Calvin Phoebe & Joan Snyder Institute for Chronic Diseases, Cumming School of Medicine, Calgary, AB, Canada
| | - Michelle Elizabeth Willson
- University of Calgary, Department of Physiology and Pharmacology, Calvin Phoebe & Joan Snyder Institute for Chronic Diseases, Cumming School of Medicine, Calgary, AB, Canada
| | - Zhutian Zeng
- University of Calgary, Department of Physiology and Pharmacology, Calvin Phoebe & Joan Snyder Institute for Chronic Diseases, Cumming School of Medicine, Calgary, AB, Canada
| | - Paul Warrener
- Microbial Sciences, MedImmune/AstraZeneca LLC, Gaithersburg, MD, USA
| | | | - Bas Gerardus Johannes Surewaard
- University of Calgary, Department of Physiology and Pharmacology, Calvin Phoebe & Joan Snyder Institute for Chronic Diseases, Cumming School of Medicine, Calgary, AB, Canada
| | | | - Juha Tapio Korhonen
- University of Calgary, Department of Physiology and Pharmacology, Calvin Phoebe & Joan Snyder Institute for Chronic Diseases, Cumming School of Medicine, Calgary, AB, Canada
| | - Lily I-Ting Cheng
- Microbial Sciences, MedImmune/AstraZeneca LLC, Gaithersburg, MD, USA
| | - Mihaela Gadjeva
- Department of Medicine, Division of Infectious Diseases, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - C Kendall Stover
- Microbial Sciences, MedImmune/AstraZeneca LLC, Gaithersburg, MD, USA
| | | | - Paul Kubes
- University of Calgary, Department of Physiology and Pharmacology, Calvin Phoebe & Joan Snyder Institute for Chronic Diseases, Cumming School of Medicine, Calgary, AB, Canada.
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Colombo C, Pitirollo O, Lay L. Recent Advances in the Synthesis of Glycoconjugates for Vaccine Development. Molecules 2018; 23:molecules23071712. [PMID: 30011851 PMCID: PMC6099631 DOI: 10.3390/molecules23071712] [Citation(s) in RCA: 57] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2018] [Revised: 07/09/2018] [Accepted: 07/11/2018] [Indexed: 12/25/2022] Open
Abstract
During the last decade there has been a growing interest in glycoimmunology, a relatively new research field dealing with the specific interactions of carbohydrates with the immune system. Pathogens’ cell surfaces are covered by a thick layer of oligo- and polysaccharides that are crucial virulence factors, as they mediate receptors binding on host cells for initial adhesion and organism invasion. Since in most cases these saccharide structures are uniquely exposed on the pathogen surface, they represent attractive targets for vaccine design. Polysaccharides isolated from cell walls of microorganisms and chemically conjugated to immunogenic proteins have been used as antigens for vaccine development for a range of infectious diseases. However, several challenges are associated with carbohydrate antigens purified from natural sources, such as their difficult characterization and heterogeneous composition. Consequently, glycoconjugates with chemically well-defined structures, that are able to confer highly reproducible biological properties and a better safety profile, are at the forefront of vaccine development. Following on from our previous review on the subject, in the present account we specifically focus on the most recent advances in the synthesis and preliminary immunological evaluation of next generation glycoconjugate vaccines designed to target bacterial and fungal infections that have been reported in the literature since 2011.
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Affiliation(s)
- Cinzia Colombo
- Dipartimento di Chimica, Universita' degli Studi di Milano, via Golgi 19, 20133 Milano, Italy.
| | - Olimpia Pitirollo
- Dipartimento di Chimica, Universita' degli Studi di Milano, via Golgi 19, 20133 Milano, Italy.
| | - Luigi Lay
- Dipartimento di Chimica, Universita' degli Studi di Milano, via Golgi 19, 20133 Milano, Italy.
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Polymorphonuclear Leukocytes or Hydrogen Peroxide Enhance Biofilm Development of Mucoid Pseudomonas aeruginosa. Mediators Inflamm 2018; 2018:8151362. [PMID: 30116152 PMCID: PMC6079396 DOI: 10.1155/2018/8151362] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2018] [Revised: 03/13/2018] [Accepted: 04/16/2018] [Indexed: 01/05/2023] Open
Abstract
Pseudomonas aeruginosa is an opportunistic pathogenic bacterium involved in many human infections, including pneumonia, diabetic foot ulcers, and ventilator-associated pneumonia. P. aeruginosa cells usually undergo mucoid conversion during chronic lung infection in patients with cystic fibrosis (CF) and resist destruction by polymorphonuclear leukocytes (PMNs), which release free oxygen radicals (ROS), such as H2O2. PMNs are the main leucocytes in the CF sputum of patients who are infected with P. aeruginosa, which usually forms biofilms. Here, we report that PMNs or H2O2 can promote biofilm formation by mucoid P. aeruginosa FRD1 with the use of the hanging-peg method. The mucoid strain infecting CF patients overproduces alginate. In this study, PMNs and H2O2 promoted alginate production, and biofilms treated with PMNs or H2O2 exhibited higher expression of alginate genes. Additionally, PMNs increased the activity of GDP-mannose dehydrogenase, which is the key enzyme in alginate biosynthesis. Our results demonstrate that PMNs or H2O2 can enhance mucoid P. aeruginosa biofilms.
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32
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Powell LC, Pritchard MF, Ferguson EL, Powell KA, Patel SU, Rye PD, Sakellakou SM, Buurma NJ, Brilliant CD, Copping JM, Menzies GE, Lewis PD, Hill KE, Thomas DW. Targeted disruption of the extracellular polymeric network of Pseudomonas aeruginosa biofilms by alginate oligosaccharides. NPJ Biofilms Microbiomes 2018; 4:13. [PMID: 29977590 PMCID: PMC6026129 DOI: 10.1038/s41522-018-0056-3] [Citation(s) in RCA: 110] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2017] [Revised: 05/20/2018] [Accepted: 06/06/2018] [Indexed: 11/29/2022] Open
Abstract
Acquisition of a mucoid phenotype by Pseudomonas sp. in the lungs of cystic fibrosis (CF) patients, with subsequent over-production of extracellular polymeric substance (EPS), plays an important role in mediating the persistence of multi-drug resistant (MDR) infections. The ability of a low molecular weight (Mn = 3200 g mol−1) alginate oligomer (OligoG CF-5/20) to modify biofilm structure of mucoid Pseudomonas aeruginosa (NH57388A) was studied in vitro using scanning electron microscopy (SEM), confocal laser scanning microscopy (CLSM) with Texas Red (TxRd®)-labelled OligoG and EPS histochemical staining. Structural changes in treated biofilms were quantified using COMSTAT image-analysis software of CLSM z-stack images, and nanoparticle diffusion. Interactions between the oligomers, Ca2+ and DNA were studied using molecular dynamics (MD) simulations, Fourier transform infrared spectroscopy (FTIR) and isothermal titration calorimetry (ITC). Imaging demonstrated that OligoG treatment (≥0.5%) inhibited biofilm formation, revealing a significant reduction in both biomass and biofilm height (P < 0.05). TxRd®-labelled oligomers readily diffused into established (24 h) biofilms. OligoG treatment (≥2%) induced alterations in the EPS of established biofilms; significantly reducing the structural quantities of EPS polysaccharides, and extracellular (e)DNA (P < 0.05) with a corresponding increase in nanoparticle diffusion (P < 0.05) and antibiotic efficacy against established biofilms. ITC demonstrated an absence of rapid complex formation between DNA and OligoG and confirmed the interactions of OligoG with Ca2+ evident in FTIR and MD modelling. The ability of OligoG to diffuse into biofilms, potentiate antibiotic activity, disrupt DNA-Ca2+-DNA bridges and biofilm EPS matrix highlights its potential for the treatment of biofilm-related infections. Small carbohydrate molecules derived from marine algae show potential for inhibiting biofilm formation in multi-drug resistant infections. A research team led by Lydia Powell at Cardiff University, UK, investigated the action of carbohydrates called alginate oligosaccharides, composed of a small number of linked sugar molecules. The oligosaccharides modified and disrupted the structure of cultured biofilms of Pseudomonas aeruginosa, the cause of many serious drug resistant infections. This effect significantly inhibited the formation and maintenance of the biofilm state, which is known to be a crucial factor allowing the bacteria to resist drug treatment. Antibiotics proved more effective following the oligosaccharide intervention. The researchers uncovered key molecular details involved in the ability of the oligosaccharides to diffuse into and disrupt biofilms. The therapeutic potential of these small carbohydrates is currently being investigated in clinical trials.
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Affiliation(s)
- Lydia C Powell
- 1Advanced Therapies Group, Cardiff University School of Dentistry, Heath Park, Cardiff, CF14 4XY UK
| | - Manon F Pritchard
- 1Advanced Therapies Group, Cardiff University School of Dentistry, Heath Park, Cardiff, CF14 4XY UK
| | - Elaine L Ferguson
- 1Advanced Therapies Group, Cardiff University School of Dentistry, Heath Park, Cardiff, CF14 4XY UK
| | - Kate A Powell
- 1Advanced Therapies Group, Cardiff University School of Dentistry, Heath Park, Cardiff, CF14 4XY UK
| | - Shree U Patel
- 1Advanced Therapies Group, Cardiff University School of Dentistry, Heath Park, Cardiff, CF14 4XY UK
| | | | | | - Niklaas J Buurma
- 3Physical Organic Chemistry Centre, School of Chemistry, Cardiff University, Cardiff, UK
| | | | - Jack M Copping
- 4Respiratory Diagnostics Group, Swansea University, Swansea, UK
| | | | - Paul D Lewis
- 4Respiratory Diagnostics Group, Swansea University, Swansea, UK
| | - Katja E Hill
- 1Advanced Therapies Group, Cardiff University School of Dentistry, Heath Park, Cardiff, CF14 4XY UK
| | - David W Thomas
- 1Advanced Therapies Group, Cardiff University School of Dentistry, Heath Park, Cardiff, CF14 4XY UK
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33
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Lotfy WA, Atalla RG, Sabra WA, El-Helow ER. Expression of extracellular polysaccharides and proteins by clinical isolates of Pseudomonas aeruginosa in response to environmental conditions. Int Microbiol 2018; 21:129-142. [PMID: 30810953 DOI: 10.1007/s10123-018-0010-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2018] [Revised: 05/13/2018] [Accepted: 05/14/2018] [Indexed: 11/25/2022]
Abstract
The opportunistic pathogen Pseudomonas aeruginosa causes chronic respiratory infections in patients with cystic fibrosis (CF). Persistence of this bacterium is attributed to its ability to form biofilms which rely on an extracellular polymeric substance matrix. Extracellular polysaccharides (EPS) and secreted proteins are key matrix components of P. aeruginosa biofilms. Recently, nebulized magnesium sulfate has been reported as a significant bronchodilator for asthmatic patients including CF. However, the impact of magnesium sulfate on the virulence effect of P. aeruginosa is lacking. In this report, we investigated the influence of magnesium sulfate and other environmental factors on the synthesis of alginate and secretion of proteins by a mucoid and a non-mucoid strain of P. aeruginosa, respectively. By applying the Plackett-Burman and Box-Behnken experimental designs, we found that phosphates (6.0 g/l), ammonium sulfate (4.0 g/l), and trace elements (0.6 mg/l) markedly supported alginate production by the mucoid strain. However, ferrous sulfate (0.3 mg/l), magnesium sulfate (0.02 g/l), and phosphates (6.0 g/l) reinforced the secretion of proteins by the non-mucoid strain.
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Affiliation(s)
- Walid A Lotfy
- Microbiology Department, Faculty of Dentistry, Pharos University in Alexandria, Alexandria, Egypt.
| | - Ramy G Atalla
- Department of Botany and Microbiology, Faculty of Science, Alexandria University, Alexandria, Egypt
| | - Wael A Sabra
- Department of Botany and Microbiology, Faculty of Science, Alexandria University, Alexandria, Egypt
| | - Ehab R El-Helow
- Department of Botany and Microbiology, Faculty of Science, Alexandria University, Alexandria, Egypt
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Ray VA, Hill PJ, Stover CK, Roy S, Sen CK, Yu L, Wozniak DJ, DiGiandomenico A. Anti-Psl Targeting of Pseudomonas aeruginosa Biofilms for Neutrophil-Mediated Disruption. Sci Rep 2017; 7:16065. [PMID: 29167572 PMCID: PMC5700069 DOI: 10.1038/s41598-017-16215-6] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2017] [Accepted: 11/08/2017] [Indexed: 01/05/2023] Open
Abstract
Bacterial biofilms are recalcitrant to antibiotic therapy and a major cause of persistent and recurrent infections. New antibody-based therapies may offer potential to target biofilm specific components for host-cell mediated bacterial clearance. For Pseudomonas aeruginosa, human monoclonal antibodies (mAbs) targeting the Psl biofilm exopolysaccharide exhibit protective activity against planktonic bacteria in acute infection models. However, anti-Psl mAb activity against P. aeruginosa biofilms is unknown. Here, we demonstrate that anti-Psl mAbs targeting three distinct Psl epitopes exhibit stratified binding in mature in vitro biofilms and bind Psl within the context of a chronic biofilm infection. These mAbs also exhibit differential abilities to inhibit early biofilm events and reduce biomass from mature biofilms in the presence of neutrophils. Importantly, a mAb mixture with neutrophils exhibited the greatest biomass reduction, which was further enhanced when combined with meropenem, a common anti-Pseudomonal carbapenem antibiotic. Moreover, neutrophil-mediated killing of biofilm bacteria correlated with the evident mAb epitope stratification within the biofilm. Overall, our results suggest that anti-Psl mAbs might be promising candidates for adjunctive use with antibiotics to inhibit/disrupt P. aeruginosa biofilms as a result of chronic infection.
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Affiliation(s)
- Valerie A Ray
- Center for Microbial Interface Biology, Departments of Microbial Infection and Immunity, Microbiology, Ohio State University, Columbus, OH, 43210, USA
| | - Preston J Hill
- Center for Microbial Interface Biology, Departments of Microbial Infection and Immunity, Microbiology, Ohio State University, Columbus, OH, 43210, USA
| | - C Kendall Stover
- Department of Infectious Diseases, MedImmune, LLC, Gaithersburg, MD, 20878, USA
| | - Sashwati Roy
- Comprehensive Wound Center, Davis Heart and Lung Research Institute, Center for Regenerative Medicine and Cell Based Therapies, Ohio State University Medical Center, Columbus, OH, 43210, USA.,Department of Surgery, College of Veterinary Medicine, Ohio State University, Columbus, OH, 43210, USA
| | - Chandan K Sen
- Comprehensive Wound Center, Davis Heart and Lung Research Institute, Center for Regenerative Medicine and Cell Based Therapies, Ohio State University Medical Center, Columbus, OH, 43210, USA.,Department of Surgery, College of Veterinary Medicine, Ohio State University, Columbus, OH, 43210, USA
| | - Li Yu
- Translational Sciences, MedImmune, LLC, Gaithersburg, MD, 20878, USA
| | - Daniel J Wozniak
- Center for Microbial Interface Biology, Departments of Microbial Infection and Immunity, Microbiology, Ohio State University, Columbus, OH, 43210, USA
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35
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Ferrando D, Ziemba C, Herzberg M. Revisiting interrelated effects of extracellular polysaccharides during biofouling of reverse osmosis membranes: Viscoelastic properties and biofilm enhanced osmotic pressure. J Memb Sci 2017. [DOI: 10.1016/j.memsci.2016.08.071] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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36
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A Survival Strategy for Pseudomonas aeruginosa That Uses Exopolysaccharides To Sequester and Store Iron To Stimulate Psl-Dependent Biofilm Formation. Appl Environ Microbiol 2016; 82:6403-6413. [PMID: 27565622 DOI: 10.1128/aem.01307-16] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2016] [Accepted: 08/16/2016] [Indexed: 01/20/2023] Open
Abstract
Exopolysaccharide Psl is a critical biofilm matrix component in Pseudomonas aeruginosa, which forms a fiber-like matrix to enmesh bacterial communities. Iron is important for P. aeruginosa biofilm development, yet it is not clearly understood how iron contributes to biofilm development. Here, we showed that iron promoted biofilm formation via elevating Psl production in P. aeruginosa The high level of iron stimulated the synthesis of Psl by reducing rhamnolipid biosynthesis and inhibiting the expression of AmrZ, a repressor of psl genes. Iron-stimulated Psl biosynthesis and biofilm formation held true in mucoid P. aeruginosa strains. Subsequent experiments indicated that iron bound with Psl in vitro and in biofilms, which suggested that Psl fibers functioned as an iron storage channel in P. aeruginosa biofilms. Moreover, among three matrix exopolysaccharides of P. aeruginosa, Psl is the only exopolysaccharide that can bind with both ferrous and ferric ion, yet with higher affinity for ferrous iron. Our data suggest a survival strategy of P. aeruginosa that uses exopolysaccharide to sequester and store iron to stimulate Psl-dependent biofilm formation. IMPORTANCE Pseudomonas aeruginosa is an environmental microorganism which is also an opportunistic pathogen that can cause severe infections in immunocompromised individuals. It is the predominant airway pathogen causing morbidity and mortality in individuals affected by the genetic disease cystic fibrosis (CF). Increased airway iron and biofilm formation have been proposed to be the potential factors involved in the persistence of P. aeruginosa in CF patients. Here, we showed that a high level of iron enhanced the production of the key biofilm matrix exopolysaccharide Psl to stimulate Psl-dependent biofilm formation. Our results not only make the link between biofilm formation and iron concentration in CF, but also could guide the administration or use of iron chelators to interfere with biofilm formation in P. aeruginosa in CF patients. Furthermore, our data also imply a survival strategy of P. aeruginosa under high-iron environmental conditions.
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Baker P, Hill PJ, Snarr BD, Alnabelseya N, Pestrak MJ, Lee MJ, Jennings LK, Tam J, Melnyk RA, Parsek MR, Sheppard DC, Wozniak DJ, Howell PL. Exopolysaccharide biosynthetic glycoside hydrolases can be utilized to disrupt and prevent Pseudomonas aeruginosa biofilms. SCIENCE ADVANCES 2016; 2:e1501632. [PMID: 27386527 PMCID: PMC4928890 DOI: 10.1126/sciadv.1501632] [Citation(s) in RCA: 164] [Impact Index Per Article: 20.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/12/2015] [Accepted: 04/26/2016] [Indexed: 05/11/2023]
Abstract
Bacterial biofilms present a significant medical challenge because they are recalcitrant to current therapeutic regimes. A key component of biofilm formation in the opportunistic human pathogen Pseudomonas aeruginosa is the biosynthesis of the exopolysaccharides Pel and Psl, which are involved in the formation and maintenance of the structural biofilm scaffold and protection against antimicrobials and host defenses. Given that the glycoside hydrolases PelAh and PslGh encoded in the pel and psl biosynthetic operons, respectively, are utilized for in vivo exopolysaccharide processing, we reasoned that these would provide specificity to target P. aeruginosa biofilms. Evaluating these enzymes as potential therapeutics, we demonstrate that these glycoside hydrolases selectively target and degrade the exopolysaccharide component of the biofilm matrix. PelAh and PslGh inhibit biofilm formation over a 24-hour period with a half maximal effective concentration (EC50) of 69.3 ± 1.2 and 4.1 ± 1.1 nM, respectively, and are capable of disrupting preexisting biofilms in 1 hour with EC50 of 35.7 ± 1.1 and 12.9 ± 1.1 nM, respectively. This treatment was effective against clinical and environmental P. aeruginosa isolates and reduced biofilm biomass by 58 to 94%. These noncytotoxic enzymes potentiated antibiotics because the addition of either enzyme to a sublethal concentration of colistin reduced viable bacterial counts by 2.5 orders of magnitude when used either prophylactically or on established 24-hour biofilms. In addition, PelAh was able to increase neutrophil killing by ~50%. This work illustrates the feasibility and benefits of using bacterial exopolysaccharide biosynthetic glycoside hydrolases to develop novel antibiofilm therapeutics.
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Affiliation(s)
- Perrin Baker
- Program in Molecular Structure & Function, Research Institute, The Hospital for Sick Children, Toronto, Ontario M5G 1X8, Canada
| | - Preston J. Hill
- Departments of Microbial Infection and Immunity, Microbiology, Center for Microbial Interface Biology, Ohio State University, Columbus, OH 43210, USA
| | - Brendan D. Snarr
- Departments of Medicine, Microbiology, and Immunology, McGill University, Montréal, Québec H3A 2B4, Canada
- Infectious Diseases and Immunity in Global Health Program, Centre for Translational Biology, McGill University Health Centre, Montréal, Québec H4A 3J1, Canada
| | - Noor Alnabelseya
- Program in Molecular Structure & Function, Research Institute, The Hospital for Sick Children, Toronto, Ontario M5G 1X8, Canada
- Department of Biochemistry, University of Toronto, Toronto, Ontario M5S 1A8, Canada
| | - Matthew J. Pestrak
- Departments of Microbial Infection and Immunity, Microbiology, Center for Microbial Interface Biology, Ohio State University, Columbus, OH 43210, USA
| | - Mark J. Lee
- Departments of Medicine, Microbiology, and Immunology, McGill University, Montréal, Québec H3A 2B4, Canada
- Infectious Diseases and Immunity in Global Health Program, Centre for Translational Biology, McGill University Health Centre, Montréal, Québec H4A 3J1, Canada
| | - Laura K. Jennings
- Department of Microbiology, University of Washington, Seattle, WA 98195, USA
| | - John Tam
- Program in Molecular Structure & Function, Research Institute, The Hospital for Sick Children, Toronto, Ontario M5G 1X8, Canada
| | - Roman A. Melnyk
- Program in Molecular Structure & Function, Research Institute, The Hospital for Sick Children, Toronto, Ontario M5G 1X8, Canada
- Department of Biochemistry, University of Toronto, Toronto, Ontario M5S 1A8, Canada
| | - Matthew R. Parsek
- Department of Microbiology, University of Washington, Seattle, WA 98195, USA
| | - Donald C. Sheppard
- Departments of Medicine, Microbiology, and Immunology, McGill University, Montréal, Québec H3A 2B4, Canada
- Infectious Diseases and Immunity in Global Health Program, Centre for Translational Biology, McGill University Health Centre, Montréal, Québec H4A 3J1, Canada
| | - Daniel J. Wozniak
- Departments of Microbial Infection and Immunity, Microbiology, Center for Microbial Interface Biology, Ohio State University, Columbus, OH 43210, USA
| | - P. Lynne Howell
- Program in Molecular Structure & Function, Research Institute, The Hospital for Sick Children, Toronto, Ontario M5G 1X8, Canada
- Department of Biochemistry, University of Toronto, Toronto, Ontario M5S 1A8, Canada
- Corresponding author.
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Mathee K, Silver LL, Tatke G. 70th Anniversary Collection for the Microbiology Society: Journal of Medical Microbiology. J Med Microbiol 2015; 64:1457-1461. [PMID: 26689963 DOI: 10.1099/jmm.0.000186] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
In the last 70 years, we have seen a radical change in our perception and understanding of the microbial world. During this period, we learned from Woese and Fox there exists a third kingdom called 'Archea' based on the phylogenetic studies of the 16S rRNA that revolutionized microbiology (Woese & Fox, 1977; Woese et al., 1978). Furthermore, we were forced to reckon with the fact that Koch and Pasteur's way of growing cells in test-tubes or flasks planktonically does not necessarily translate to the real-life scenario of bacterial lifestyle, where they prefer to live and function as a closely knit microbial community called biofilm. Thanks are due to Costerton, who led the crusade on the concept of biofilms and expanded its scope of inquiry, which forced scientists and clinicians worldwide to rethink how we evaluate and apply the data. Then progressively, disbelief turned into belief, and now it is universally accepted that the micro-organisms hobnob with the members of their community to communicate and coordinate their behaviour, especially in regard to growth patterns and virulence traits via signalling molecules. Just when we thought that we were losing the battle against bacteria, antimicrobials were discovered. We then witnessed the rise and fall of antibiotics and the development of antibiotic resistance. Due to space and choice limitation, we will focus on the three areas that caused this major paradigm shift (i) antimicrobial resistance (AMR), (ii) biofilm and (iii) quorum sensing (QS), and how the Journal of Medical Microbiology played a major role in advancing the shift.
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Affiliation(s)
- Kalai Mathee
- Global Health Consortium, Florida International University, Miami, FL, USA.,Department of Human and Molecular Genetics, Herbert Wertheim College of Medicine, Florida International University, Miami, FL, USA.,Biomolecular Sciences Institute, Florida International University, Miami, FL, USA
| | | | - Gorakh Tatke
- Department of Human and Molecular Genetics, Herbert Wertheim College of Medicine, Florida International University, Miami, FL, USA.,Department of Biological Sciences, College of Arts & Sciences, Florida International University, Miami, FL, USA
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Yu S, Su T, Wu H, Liu S, Wang D, Zhao T, Jin Z, Du W, Zhu MJ, Chua SL, Yang L, Zhu D, Gu L, Ma LZ. PslG, a self-produced glycosyl hydrolase, triggers biofilm disassembly by disrupting exopolysaccharide matrix. Cell Res 2015; 25:1352-67. [PMID: 26611635 PMCID: PMC4670989 DOI: 10.1038/cr.2015.129] [Citation(s) in RCA: 100] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2015] [Revised: 10/10/2015] [Accepted: 10/10/2015] [Indexed: 01/07/2023] Open
Abstract
Biofilms are surface-associated communities of microorganism embedded in extracellular matrix. Exopolysaccharide is a critical component in the extracellular matrix that maintains biofilm architecture and protects resident biofilm bacteria from antimicrobials and host immune attack. However, self-produced factors that target the matrix exopolysaccharides, are still poorly understood. Here, we show that PslG, a protein involved in the synthesis of a key biofilm matrix exopolysaccharide Psl in Pseudomonas aeruginosa, prevents biofilm formation and disassembles existing biofilms within minutes at nanomolar concentrations when supplied exogenously. The crystal structure of PslG indicates the typical features of an endoglycosidase. PslG mainly disrupts the Psl matrix to disperse bacteria from biofilms. PslG treatment markedly enhances biofilm sensitivity to antibiotics and macrophage cells, resulting in improved biofilm clearance in a mouse implant infection model. Furthermore, PslG shows biofilm inhibition and disassembly activity against a wide range of Pseudomonas species, indicating its great potential in combating biofilm-related complications.
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Affiliation(s)
- Shan Yu
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China,University of the Chinese Academy of Sciences, Beijing 100049, China
| | - Tiantian Su
- State Key Laboratory of Microbial Technology, School of Life Sciences, Shandong University, Jinan, Shandong 250100, China
| | - Huijun Wu
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China,University of the Chinese Academy of Sciences, Beijing 100049, China
| | - Shiheng Liu
- State Key Laboratory of Microbial Technology, School of Life Sciences, Shandong University, Jinan, Shandong 250100, China
| | - Di Wang
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China
| | - Tianhu Zhao
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China,University of the Chinese Academy of Sciences, Beijing 100049, China
| | - Zengjun Jin
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China,University of the Chinese Academy of Sciences, Beijing 100049, China
| | - Wenbin Du
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China
| | - Mei-Jun Zhu
- School of Food Science, Washington State University, Pullman, WA 99164-6120, USA
| | - Song Lin Chua
- Singapore Centre on Environmental Life Sciences Engineering (SCELSE), Nanyang Technological University, Singapore 637551
| | - Liang Yang
- Singapore Centre on Environmental Life Sciences Engineering (SCELSE), Nanyang Technological University, Singapore 637551
| | - Deyu Zhu
- State Key Laboratory of Microbial Technology, School of Life Sciences, Shandong University, Jinan, Shandong 250100, China
| | - Lichuan Gu
- State Key Laboratory of Microbial Technology, School of Life Sciences, Shandong University, Jinan, Shandong 250100, China,E-mail:
| | - Luyan Z Ma
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China,E-mail:
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40
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Gnanadhas DP, Elango M, Datey A, Chakravortty D. Chronic lung infection by Pseudomonas aeruginosa biofilm is cured by L-Methionine in combination with antibiotic therapy. Sci Rep 2015; 5:16043. [PMID: 26521707 PMCID: PMC4629202 DOI: 10.1038/srep16043] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2015] [Accepted: 10/07/2015] [Indexed: 01/29/2023] Open
Abstract
Bacterial biofilms are associated with 80-90% of infections. Within the biofilm, bacteria are refractile to antibiotics, requiring concentrations >1,000 times the minimum inhibitory concentration. Proteins, carbohydrates and DNA are the major components of biofilm matrix. Pseudomonas aeruginosa (PA) biofilms, which are majorly associated with chronic lung infection, contain extracellular DNA (eDNA) as a major component. Herein, we report for the first time that L-Methionine (L-Met) at 0.5 μM inhibits Pseudomonas aeruginosa (PA) biofilm formation and disassembles established PA biofilm by inducing DNase expression. Four DNase genes (sbcB, endA, eddB and recJ) were highly up-regulated upon L-Met treatment along with increased DNase activity in the culture supernatant. Since eDNA plays a major role in establishing and maintaining the PA biofilm, DNase activity is effective in disrupting the biofilm. Upon treatment with L-Met, the otherwise recalcitrant PA biofilm now shows susceptibility to ciprofloxacin. This was reflected in vivo, in the murine chronic PA lung infection model. Mice treated with L-Met responded better to antibiotic treatment, leading to enhanced survival as compared to mice treated with ciprofloxacin alone. These results clearly demonstrate that L-Met can be used along with antibiotic as an effective therapeutic against chronic PA biofilm infection.
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Affiliation(s)
- Divya Prakash Gnanadhas
- Department of Microbiology and Cell Biology, Indian Institute of Science, Bangalore, India
- Department of Aerospace Engineering, Indian Institute of Science, Bangalore, India
| | - Monalisha Elango
- Department of Microbiology and Cell Biology, Indian Institute of Science, Bangalore, India
| | - Akshay Datey
- Department of Microbiology and Cell Biology, Indian Institute of Science, Bangalore, India
- Department of Aerospace Engineering, Indian Institute of Science, Bangalore, India
- The Bioengineering Program, Indian Institute of Science, Bangalore, India
| | - Dipshikha Chakravortty
- Department of Microbiology and Cell Biology, Indian Institute of Science, Bangalore, India
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41
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Rybtke M, Hultqvist LD, Givskov M, Tolker-Nielsen T. Pseudomonas aeruginosa Biofilm Infections: Community Structure, Antimicrobial Tolerance and Immune Response. J Mol Biol 2015; 427:3628-45. [DOI: 10.1016/j.jmb.2015.08.016] [Citation(s) in RCA: 132] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2015] [Revised: 08/18/2015] [Accepted: 08/20/2015] [Indexed: 02/07/2023]
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Baker P, Whitfield GB, Hill PJ, Little DJ, Pestrak MJ, Robinson H, Wozniak DJ, Howell PL. Characterization of the Pseudomonas aeruginosa Glycoside Hydrolase PslG Reveals That Its Levels Are Critical for Psl Polysaccharide Biosynthesis and Biofilm Formation. J Biol Chem 2015; 290:28374-28387. [PMID: 26424791 DOI: 10.1074/jbc.m115.674929] [Citation(s) in RCA: 56] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2015] [Indexed: 01/04/2023] Open
Abstract
A key component of colonization, biofilm formation, and protection of the opportunistic human pathogen Pseudomonas aeruginosa is the biosynthesis of the exopolysaccharide Psl. Composed of a pentameric repeating unit of mannose, glucose, and rhamnose, the biosynthesis of Psl is proposed to occur via a Wzx/Wzy-dependent mechanism. Previous genetic studies have shown that the putative glycoside hydrolase PslG is essential for Psl biosynthesis. To understand the function of this protein, the apo-structure of the periplasmic domain of PslG (PslG(31-442)) and its complex with mannose were determined to 2.0 and 1.9 Å resolution, respectively. Despite a domain architecture and positioning of catalytic residues similar to those of other family 39 glycoside hydrolases, PslG(31-442) exhibits a unique 32-Å-long active site groove that is distinct from other structurally characterized family members. PslG formed a complex with two mannose monosaccharides in this groove, consistent with binding data obtained from intrinsic tryptophan fluorescence. PslG was able to catalyze the hydrolysis of surface-associated Psl, and this activity was abolished in a E165Q/E276Q double catalytic variant. Surprisingly, P. aeruginosa variants with these chromosomal mutations as well as a pslG deletion mutant were still capable of forming Psl biofilms. However, overexpression of PslG in a pslG deletion background impaired biofilm formation and resulted in less surface-associated Psl, suggesting that regulation of this enzyme is important during polysaccharide biosynthesis.
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Affiliation(s)
- Perrin Baker
- Program in Molecular Structure and Function, Research Institute, The Hospital for Sick Children, Toronto, Ontario M5G 1X8, Canada
| | - Gregory B Whitfield
- Program in Molecular Structure and Function, Research Institute, The Hospital for Sick Children, Toronto, Ontario M5G 1X8, Canada; Department of Biochemistry, University of Toronto, Toronto, Ontario M5S 1A8, Canada
| | - Preston J Hill
- Division of Infectious Disease, Center for Microbial Interface Biology, Ohio State University, Columbus, Ohio 43210
| | - Dustin J Little
- Program in Molecular Structure and Function, Research Institute, The Hospital for Sick Children, Toronto, Ontario M5G 1X8, Canada; Department of Biochemistry, University of Toronto, Toronto, Ontario M5S 1A8, Canada
| | - Matthew J Pestrak
- Division of Infectious Disease, Center for Microbial Interface Biology, Ohio State University, Columbus, Ohio 43210
| | - Howard Robinson
- Photon Sciences Division, Brookhaven National Laboratory, Upton, New York 11973-5000
| | - Daniel J Wozniak
- Division of Infectious Disease, Center for Microbial Interface Biology, Ohio State University, Columbus, Ohio 43210.
| | - P Lynne Howell
- Program in Molecular Structure and Function, Research Institute, The Hospital for Sick Children, Toronto, Ontario M5G 1X8, Canada; Department of Biochemistry, University of Toronto, Toronto, Ontario M5S 1A8, Canada
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43
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Liposomal antibiotic formulations for targeting the lungs in the treatment of Pseudomonas aeruginosa. Ther Deliv 2014; 5:409-27. [PMID: 24856168 DOI: 10.4155/tde.14.13] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
Pseudomonas aeruginosa is a Gram-negative bacterium that causes serious lung infections in cystic fibrosis, non-cystic fibrosis bronchiectasis, immunocompromised, and mechanically ventilated patients. The arsenal of conventional antipseudomonal antibiotic drugs include the extended-spectrum penicillins, cephalosporins, carbapenems, monobactams, polymyxins, fluoroquinolones, and aminoglycosides but their toxicity and/or increasing antibiotic resistance are of particular concern. Improvement of existing therapies against Pseudomonas aeruginosa infections involves the use of liposomes - artificial phospholipid vesicles that are biocompatible, biodegradable, and nontoxic and able to entrap and carry hydrophilic, hydrophobic, and amphiphilic molecules to the site of action. The goal of developing liposomal antibiotic formulations is to improve their therapeutic efficacy by reducing drug toxicity and/or by enhancing the delivery and retention of antibiotics at the site of infection. The focus of this review is to appraise the current progress of the development and application of liposomal antibiotic delivery systems for the treatment pulmonary infections caused by P. aeruginosa.
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44
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Coordination of swarming motility, biosurfactant synthesis, and biofilm matrix exopolysaccharide production in Pseudomonas aeruginosa. Appl Environ Microbiol 2014; 80:6724-32. [PMID: 25172852 DOI: 10.1128/aem.01237-14] [Citation(s) in RCA: 74] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Biofilm formation is a complex process in which many factors are involved. Bacterial swarming motility and exopolysaccharides both contribute to biofilm formation, yet it is unclear how bacteria coordinate swarming motility and exopolysaccharide production. Psl and Pel are two key biofilm matrix exopolysaccharides in Pseudomonas aeruginosa. This opportunistic pathogen has three types of motility, swimming, twitching, and swarming. In this study, we found that elevated Psl and/or Pel production reduced the swarming motility of P. aeruginosa but had little effect on swimming and twitching. The reduction was due to decreased rhamnolipid production with no relation to the transcription of rhlAB, two key genes involved in the biosynthesis of rhamnolipids. Rhamnolipid-negative rhlR and rhlAB mutants synthesized more Psl, whereas exopolysaccharide-deficient strains exhibited a hyperswarming phenotype. These results suggest that competition for common sugar precursors catalyzed by AlgC could be a tactic for P. aeruginosa to balance the synthesis of exopolysaccharides and rhamnolipids and to control bacterial motility and biofilm formation inversely because the biosynthesis of rhamnolipids, Psl, and Pel requires AlgC to provide the sugar precursors and an additional algC gene enhances the biosynthesis of Psl and rhamnolipids. In addition, our data indicate that the increase in RhlI/RhlR expression attenuated Psl production. This implied that the quorum-sensing signals could regulate exopolysaccharide biosynthesis indirectly in bacterial communities. In summary, this study represents a mechanism that bacteria utilize to coordinate swarming motility, biosurfactant synthesis, and biofilm matrix exopolysaccharide production, which is critical for biofilm formation and bacterial survival in the environment.
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45
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Rogers GB, van der Gast CJ, Serisier DJ. Predominant pathogen competition and core microbiota divergence in chronic airway infection. ISME JOURNAL 2014; 9:217-25. [PMID: 25036925 DOI: 10.1038/ismej.2014.124] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/11/2014] [Revised: 06/10/2014] [Accepted: 06/13/2014] [Indexed: 01/11/2023]
Abstract
Chronic bacterial lung infections associated with non-cystic fibrosis bronchiectasis represent a substantial and growing health-care burden. Where Pseudomonas aeruginosa is the numerically dominant species within these infections, prognosis is significantly worse. However, in many individuals, Haemophilus influenzae predominates, a scenario associated with less severe disease. The mechanisms that determine which pathogen is most abundant are not known. We hypothesised that the distribution of H. influenzae and P. aeruginosa would be consistent with strong interspecific competition effects. Further, we hypothesised that where P. aeruginosa is predominant, it is associated with a distinct 'accessory microbiota' that reflects a significant interaction between this pathogen and the wider bacterial community. To test these hypotheses, we analysed 16S rRNA gene pyrosequencing data generated previously from 60 adult bronchiectasis patients, whose airway microbiota was dominated by either P. aeruginosa or H. influenzae. The relative abundances of the two dominant species in their respective groups were not significantly different, and when present in the opposite pathogen group the two species were found to be in very low abundance, if at all. These findings are consistent with strong competition effects, moving towards competitive exclusion. Ordination analysis indicated that the distribution of the core microbiota associated with each pathogen, readjusted after removal of the dominant species, was significantly divergent (analysis of similarity (ANOSIM), R=0.07, P=0.019). Taken together, these findings suggest that both interspecific competition and also direct and/or indirect interactions between the predominant species and the wider bacterial community may contribute to the predominance of P. aeruginosa in a subset of bronchiectasis lung infections.
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Affiliation(s)
- Geraint B Rogers
- 1] SAHMRI Infection and Immunity Theme, School of Medicine, Flinders University, Adelaide, South Australia, Australia [2] Immunity, Infection, and Inflammation Program, Mater Research Institute, University of Queensland, Translational Research Institute, Woolloongabba, Queensland, Australia
| | | | - David J Serisier
- 1] Immunity, Infection, and Inflammation Program, Mater Research Institute, University of Queensland, Translational Research Institute, Woolloongabba, Queensland, Australia [2] Department of Respiratory Medicine, Mater Adult Hospital, South Brisbane, Queensland, Australia
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46
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Exopolysaccharide quantification. Methods Mol Biol 2014. [PMID: 24818919 DOI: 10.1007/978-1-4939-0473-0_29] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
Abstract
The extracellular (EC) matrix is a key feature of mature P. aeruginosa biofilms. Exopolysaccharides are considered as major components of this biofilm matrix. They include alginate, LPS, glucans, and psl- and pel-dependent products. Here, we describe a method of quantification of the psl-dependent mannose-rich exopolysaccharide, based on the quantification of mannose in carbohydrate-enriched cell-associated extracts and growth media. Mannose is quantified by GC or GC-MS with an internal standard, after acid hydrolysis and conversion into volatile alditol acetates.
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Gupta K, Liao J, Petrova OE, Cherny KE, Sauer K. Elevated levels of the second messenger c-di-GMP contribute to antimicrobial resistance of Pseudomonas aeruginosa. Mol Microbiol 2014; 92:488-506. [PMID: 24655293 DOI: 10.1111/mmi.12587] [Citation(s) in RCA: 54] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/18/2014] [Indexed: 01/25/2023]
Abstract
Biofilms are highly structured, surface-associated communities. A hallmark of biofilms is their extraordinary resistance to antimicrobial agents that is activated during early biofilm development of Pseudomonas aeruginosa and requires the regulatory hybrid SagS and BrlR, a member of the MerR family of multidrug efflux pump activators. However, little is known about the mechanism by which SagS contributes to BrlR activation or drug resistance. Here, we demonstrate that ΔsagS biofilm cells harbour the secondary messenger c-di-GMP at reduced levels similar to those observed in wild-type cells grown planktonically rather than as biofilms. Restoring c-di-GMP levels to wild-type biofilm-like levels restored brlR expression, DNA binding by BrlR, and recalcitrance to killing by antimicrobial agents of ΔsagS biofilm cells. We likewise found that increasing c-di-GMP levels present in planktonic cells to biofilm-like levels (≥ 55 pmol mg(-1) ) resulted in planktonic cells being significantly more resistant to antimicrobial agents, with increased resistance correlating with increased brlR, mexA, and mexE expression and BrlR production. In contrast, reducing cellular c-di-GMP levels of biofilm cells to ≤ 40 pmol mg(-1) correlated with increased susceptibility and reduced brlR expression. Our findings suggest that a signalling pathway involving a specific c-di-GMP pool regulated by SagS contributes to the resistance of P. aeruginosa biofilms.
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Affiliation(s)
- Kajal Gupta
- Department of Biological Sciences, Binghamton University, Binghamton, NY, 13902, USA
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48
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Friedman A, Hu B, Xue C. On a multiphase multicomponent model of biofilm growth. ARCHIVE FOR RATIONAL MECHANICS AND ANALYSIS 2014; 211:257-300. [PMID: 24729628 PMCID: PMC3979576 DOI: 10.1007/s00205-013-0665-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Biofilms are formed when free-floating bacteria attach to a surface and secrete polysaccharide to form an extracellular polymeric matrix (EPS). A general model of biofilm growth needs to include the bacteria, the EPS, and the solvent within the biofilm region Ω(t), and the solvent in the surrounding region D(t). The interface between the two regions, Γ(t), is a free boundary. In this paper, we consider a mathematical model, which consists of a Stokes equation for the EPS with bacteria attached to it, and a Stokes equation for the solvent in Ω(t) and a different one for the solvent in D(t). The volume fraction of the EPS is another unknown satisfying a reaction-diffusion equation. The entire system is coupled nonlinearly within Ω(t), and across the free surface Γ(t). We prove the existence and uniqueness of solution, with a smooth surface Γ(t), for a small time interval.
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Affiliation(s)
- A. Friedman
- Mathematical Biosciences Institute, and Department of Mathematics, Ohio State University, Columbus, Ohio 43210
| | - Bei Hu
- Department of Applied and Computational Mathematics and Statistics, University of Notre Dame, IN 46556
| | - Chuan Xue
- Mathematical Biosciences Institute, and Department of Mathematics, Ohio State University, Columbus, Ohio 43210
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49
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Huse HK, Kwon T, Zlosnik JEA, Speert DP, Marcotte EM, Whiteley M. Pseudomonas aeruginosa enhances production of a non-alginate exopolysaccharide during long-term colonization of the cystic fibrosis lung. PLoS One 2013; 8:e82621. [PMID: 24324811 PMCID: PMC3855792 DOI: 10.1371/journal.pone.0082621] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2013] [Accepted: 10/25/2013] [Indexed: 01/31/2023] Open
Abstract
The gram-negative opportunistic pathogen Pseudomonas aeruginosa is the primary cause of chronic respiratory infections in individuals with the heritable disease cystic fibrosis (CF). These infections can last for decades, during which time P. aeruginosa has been proposed to acquire beneficial traits via adaptive evolution. Because CF lacks an animal model that can acquire chronic P. aeruginosa infections, identifying genes important for long-term in vivo fitness remains difficult. However, since clonal, chronological samples can be obtained from chronically infected individuals, traits undergoing adaptive evolution can be identified. Recently we identified 24 P. aeruginosa gene expression traits undergoing parallel evolution in vivo in multiple individuals, suggesting they are beneficial to the bacterium. The goal of this study was to determine if these genes impact P. aeruginosa phenotypes important for survival in the CF lung. By using a gain-of-function genetic screen, we found that 4 genes and 2 operons undergoing parallel evolution in vivo promote P. aeruginosa biofilm formation. These genes/operons promote biofilm formation by increasing levels of the non-alginate exopolysaccharide Psl. One of these genes, phaF, enhances Psl production via a post-transcriptional mechanism, while the other 5 genes/operons do not act on either psl transcription or translation. Together, these data demonstrate that P. aeruginosa has evolved at least two pathways to over-produce a non-alginate exopolysaccharide during long-term colonization of the CF lung. More broadly, this approach allowed us to attribute a biological significance to genes with unknown function, demonstrating the power of using evolution as a guide for targeted genetic studies.
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Affiliation(s)
- Holly K. Huse
- Section of Molecular Genetics and Microbiology, University of Texas at Austin, Austin, Texas, United States of America
- Institute of Cellular and Molecular Biology and Center for Systems and Synthetic Biology, University of Texas at Austin, Austin, Texas, United States of America
| | - Taejoon Kwon
- Institute of Cellular and Molecular Biology and Center for Systems and Synthetic Biology, University of Texas at Austin, Austin, Texas, United States of America
| | - James E. A. Zlosnik
- Department of Pediatrics and Center for Understanding and Preventing Infection in Children, The University of British Columbia, Vancouver, British Columbia, Canada
| | - David P. Speert
- Department of Pediatrics and Center for Understanding and Preventing Infection in Children, The University of British Columbia, Vancouver, British Columbia, Canada
| | - Edward M. Marcotte
- Institute of Cellular and Molecular Biology and Center for Systems and Synthetic Biology, University of Texas at Austin, Austin, Texas, United States of America
| | - Marvin Whiteley
- Section of Molecular Genetics and Microbiology, University of Texas at Austin, Austin, Texas, United States of America
- Institute of Cellular and Molecular Biology and Center for Systems and Synthetic Biology, University of Texas at Austin, Austin, Texas, United States of America
- * E-mail:
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50
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Wei Q, Ma LZ. Biofilm matrix and its regulation in Pseudomonas aeruginosa. Int J Mol Sci 2013; 14:20983-1005. [PMID: 24145749 PMCID: PMC3821654 DOI: 10.3390/ijms141020983] [Citation(s) in RCA: 193] [Impact Index Per Article: 17.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2013] [Revised: 09/29/2013] [Accepted: 10/09/2013] [Indexed: 01/25/2023] Open
Abstract
Biofilms are communities of microorganisms embedded in extracellular polymeric substances (EPS) matrix. Bacteria in biofilms demonstrate distinct features from their free-living planktonic counterparts, such as different physiology and high resistance to immune system and antibiotics that render biofilm a source of chronic and persistent infections. A deeper understanding of biofilms will ultimately provide insights into the development of alternative treatment for biofilm infections. The opportunistic pathogen Pseudomonas aeruginosa, a model bacterium for biofilm research, is notorious for its ability to cause chronic infections by its high level of drug resistance involving the formation of biofilms. In this review, we summarize recent advances in biofilm formation, focusing on the biofilm matrix and its regulation in P. aeruginosa, aiming to provide resources for the understanding and control of bacterial biofilms.
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Affiliation(s)
- Qing Wei
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, No.3, 1st Beichen West Road, Chaoyang District, Beijing 100101, China.
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