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Kungwani NA, Panda J, Mishra AK, Chavda N, Shukla S, Vikhe K, Sharma G, Mohanta YK, Sharifi-Rad M. Combating bacterial biofilms and related drug resistance: Role of phyto-derived adjuvant and nanomaterials. Microb Pathog 2024; 195:106874. [PMID: 39181190 DOI: 10.1016/j.micpath.2024.106874] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2024] [Revised: 08/16/2024] [Accepted: 08/19/2024] [Indexed: 08/27/2024]
Abstract
The emergence of antimicrobial resistance (AMR) in clinical microbes has led to a search for novel antibiotics for combating bacterial infections. The treatment of bacterial infections becomes more challenging with the onset of biofilm formation. AMR is further accelerated by biofilm physiology and differential gene expression in bacteria with an inherent resistance to conventional antibiotics. In the search for innovative strategies to control the spread of AMR in clinical isolates, plant-derived therapeutic metabolites can be repurposed to control biofilm-associated drug resistance. Unlike antibiotics, designed to act on a single cellular process, phytochemicals can simultaneously target multiple cellular components. Furthermore, they can disrupt biofilm formation and inhibit quorum sensing, offering a comprehensive approach to combat bacterial infections. In bacterial biofilms, the first line of AMR is due to biofilms associated with the extracellular matrix, diffusion barriers, quorum sensing, and persister cells. These extracellular barriers can be overcome using phytochemical-based antibiotic adjuvants to increase the efficacy of antibiotic treatment and restrict the spread of AMR. Furthermore, phytochemicals can be used to target bacterial intracellular machinery such as DNA replication, protein synthesis, efflux pumps, and degrading enzymes. In parallel with pristine phytochemicals, phyto-derived nanomaterials have emerged as an effective means of fighting bacterial biofilms. These nanomaterials can be formulated to cross the biofilm barriers and function on cellular targets. This review focuses on the synergistic effects of phytochemicals and phyto-derived nanomaterials in controlling the progression of biofilm-related AMR. IT provides comprehensive insights into recent advancements and the underlying mechanisms of the use of phyto-derived adjuvants and nanomaterials.
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Affiliation(s)
- Neelam Amit Kungwani
- Department of Environmental Biotechnology, Gujarat Biotechnology University, Gandhinagar, Gujarat, 382355, India.
| | - Jibanjyoti Panda
- Nano-biotechnology and Translational Knowledge Laboratory, Department of Applied Biology, School of Biological Sciences, University of Science and Technology Meghalaya, Techno City, 9th Mile, Baridua, Ri-Bhoi, 793101, Meghalaya, India
| | - Awdhesh Kumar Mishra
- Department of Biotechnology, Yeungnam University, Gyeongsan, Gyeongbuk, 38541, Republic of Korea
| | | | - Sudhir Shukla
- Homi Bhabha National Institute, Biofouling and Biofilm Processes Section, WSCD, Chemistry Group, Bhabha Atomic Research Centre, Kalpakkam, Tamilnadu, 603102, India
| | - Kalyani Vikhe
- Department of Environmental Biotechnology, Gujarat Biotechnology University, Gandhinagar, Gujarat, 382355, India
| | - Gunjan Sharma
- Department of Plant Biotechnology, Gujarat Biotechnology University, Gandhinagar, Gujarat, 382355, India
| | - Yugal Kishore Mohanta
- Nano-biotechnology and Translational Knowledge Laboratory, Department of Applied Biology, School of Biological Sciences, University of Science and Technology Meghalaya, Techno City, 9th Mile, Baridua, Ri-Bhoi, 793101, Meghalaya, India; Centre for Herbal Pharmacology and Environmental Sustainability, Chettinad Hospital and Research Institute, Chettinad Academy of Research and Education, Kelambakkam, 603103, Tamil Nadu, India.
| | - Majid Sharifi-Rad
- Department of Range and Watershed Management, Faculty of Water and Soil, University of Zabol, Zabol, 98613-35856, Iran.
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Li Y, Liang X, Chen N, Yuan X, Wang J, Wu Q, Ding Y. The promotion of biofilm dispersion: a new strategy for eliminating foodborne pathogens in the food industry. Crit Rev Food Sci Nutr 2024:1-25. [PMID: 39054781 DOI: 10.1080/10408398.2024.2354524] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/27/2024]
Abstract
Food safety is a critical global concern due to its direct impact on human health and overall well-being. In the food processing environment, biofilm formation by foodborne pathogens poses a significant problem as it leads to persistent and high levels of food contamination, thereby compromising the quality and safety of food. Therefore, it is imperative to effectively remove biofilms from the food processing environment to ensure food safety. Unfortunately, conventional cleaning methods fall short of adequately removing biofilms, and they may even contribute to further contamination of both equipment and food. It is necessary to develop alternative approaches that can address this challenge in food industry. One promising strategy in tackling biofilm-related issues is biofilm dispersion, which represents the final step in biofilm development. Here, we discuss the biofilm dispersion mechanism of foodborne pathogens and elucidate how biofilm dispersion can be employed to control and mitigate biofilm-related problems. By shedding light on these aspects, we aim to provide valuable insights and solutions for effectively addressing biofilm contamination issues in food industry, thus enhancing food safety and ensuring the well-being of consumers.
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Affiliation(s)
- Yangfu Li
- State Key Laboratory of Applied Microbiology Southern China, National Health Commission Science and Technology Innovation Platform for Nutrition and Safety of Microbial Food, Guangdong Provincial Key Laboratory of Microbial Safety and Health, Institute of Microbiology, Guangdong Academy of Sciences, Guangzhou, China
| | - Xinmin Liang
- State Key Laboratory of Applied Microbiology Southern China, National Health Commission Science and Technology Innovation Platform for Nutrition and Safety of Microbial Food, Guangdong Provincial Key Laboratory of Microbial Safety and Health, Institute of Microbiology, Guangdong Academy of Sciences, Guangzhou, China
- Department of Food Science & Engineering, College of Life Science and Technology, Jinan University, Guangzhou, China
| | - Nuo Chen
- State Key Laboratory of Applied Microbiology Southern China, National Health Commission Science and Technology Innovation Platform for Nutrition and Safety of Microbial Food, Guangdong Provincial Key Laboratory of Microbial Safety and Health, Institute of Microbiology, Guangdong Academy of Sciences, Guangzhou, China
| | - Xiaoming Yuan
- State Key Laboratory of Applied Microbiology Southern China, National Health Commission Science and Technology Innovation Platform for Nutrition and Safety of Microbial Food, Guangdong Provincial Key Laboratory of Microbial Safety and Health, Institute of Microbiology, Guangdong Academy of Sciences, Guangzhou, China
- Department of Food Science & Engineering, College of Life Science and Technology, Jinan University, Guangzhou, China
| | - Juan Wang
- College of Food Science, South China Agricultural University, Guangzhou, China
| | - Qingping Wu
- State Key Laboratory of Applied Microbiology Southern China, National Health Commission Science and Technology Innovation Platform for Nutrition and Safety of Microbial Food, Guangdong Provincial Key Laboratory of Microbial Safety and Health, Institute of Microbiology, Guangdong Academy of Sciences, Guangzhou, China
| | - Yu Ding
- Department of Food Science & Engineering, College of Life Science and Technology, Jinan University, Guangzhou, China
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3
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David A, Tahrioui A, Tareau AS, Forge A, Gonzalez M, Bouffartigues E, Lesouhaitier O, Chevalier S. Pseudomonas aeruginosa Biofilm Lifecycle: Involvement of Mechanical Constraints and Timeline of Matrix Production. Antibiotics (Basel) 2024; 13:688. [PMID: 39199987 PMCID: PMC11350761 DOI: 10.3390/antibiotics13080688] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2024] [Revised: 07/22/2024] [Accepted: 07/23/2024] [Indexed: 09/01/2024] Open
Abstract
Pseudomonas aeruginosa is an opportunistic pathogen causing acute and chronic infections, especially in immunocompromised patients. Its remarkable adaptability and resistance to various antimicrobial treatments make it difficult to eradicate. Its persistence is enabled by its ability to form a biofilm. Biofilm is a community of sessile micro-organisms in a self-produced extracellular matrix, which forms a scaffold facilitating cohesion, cell attachment, and micro- and macro-colony formation. This lifestyle provides protection against environmental stresses, the immune system, and antimicrobial treatments, and confers the capacity for colonization and long-term persistence, often characterizing chronic infections. In this review, we retrace the events of the life cycle of P. aeruginosa biofilm, from surface perception/contact to cell spreading. We focus on the importance of extracellular appendages, mechanical constraints, and the kinetics of matrix component production in each step of the biofilm life cycle.
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Affiliation(s)
| | | | | | | | | | | | | | - Sylvie Chevalier
- Univ Rouen Normandie, Univ Caen Normandie, Normandie Univ, CBSA UR 4312, F-76000 Rouen, France
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4
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Kalia M, Amari D, Davies DG, Sauer K. cis-DA-dependent dispersion by Pseudomonas aeruginosa biofilm and identification of cis-DA-sensory protein DspS. mBio 2023; 14:e0257023. [PMID: 38014955 PMCID: PMC10746223 DOI: 10.1128/mbio.02570-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2023] [Accepted: 10/11/2023] [Indexed: 11/29/2023] Open
Abstract
IMPORTANCE Dispersion is an essential stage of the biofilm life cycle resulting in the release of bacteria from a biofilm into the surrounding environment. Dispersion contributes to bacterial survival by relieving overcrowding within a biofilm and allowing dissemination of cells into new habitats for colonization. Thus, dispersion can contribute to biofilm survival as well as disease progression and transmission. Cells dispersed from a biofilm rapidly lose their recalcitrant antimicrobial-tolerant biofilm phenotype and transition to a state that is susceptible to antibiotics. However, much of what is known about this biofilm developmental stage has been inferred from exogenously induced dispersion. Our findings provide the first evidence that native dispersion is coincident with reduced cyclic dimeric guanosine monophosphate levels, while also relying on at least some of the same factors that are central to the environmentally induced dispersion response, namely, BdlA, DipA, RbdA, and AmrZ. Additionally, we demonstrate for the first time that cis-DA signaling to induce dispersion is attributed to the two-component sensor/response regulator DspS, a homolog of the DSF sensor RpfC. Our findings also provide a path toward manipulating the native dispersion response as a novel and highly promising therapeutic intervention.
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Affiliation(s)
- Manmohit Kalia
- Department of Biological Sciences, Binghamton University, Binghamton, New York, USA
- Binghamton Biofilm Research Center, Binghamton University, Binghamton, New York, USA
| | - Diana Amari
- Department of Biological Sciences, Binghamton University, Binghamton, New York, USA
- Binghamton Biofilm Research Center, Binghamton University, Binghamton, New York, USA
| | - David G. Davies
- Department of Biological Sciences, Binghamton University, Binghamton, New York, USA
- Binghamton Biofilm Research Center, Binghamton University, Binghamton, New York, USA
| | - Karin Sauer
- Department of Biological Sciences, Binghamton University, Binghamton, New York, USA
- Binghamton Biofilm Research Center, Binghamton University, Binghamton, New York, USA
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Wang X, Liu M, Yu C, Li J, Zhou X. Biofilm formation: mechanistic insights and therapeutic targets. MOLECULAR BIOMEDICINE 2023; 4:49. [PMID: 38097907 PMCID: PMC10721784 DOI: 10.1186/s43556-023-00164-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2023] [Accepted: 12/06/2023] [Indexed: 12/18/2023] Open
Abstract
Biofilms are complex multicellular communities formed by bacteria, and their extracellular polymeric substances are observed as surface-attached or non-surface-attached aggregates. Many types of bacterial species found in living hosts or environments can form biofilms. These include pathogenic bacteria such as Pseudomonas, which can act as persistent infectious hosts and are responsible for a wide range of chronic diseases as well as the emergence of antibiotic resistance, thereby making them difficult to eliminate. Pseudomonas aeruginosa has emerged as a model organism for studying biofilm formation. In addition, other Pseudomonas utilize biofilm formation in plant colonization and environmental persistence. Biofilms are effective in aiding bacterial colonization, enhancing bacterial resistance to antimicrobial substances and host immune responses, and facilitating cell‒cell signalling exchanges between community bacteria. The lack of antibiotics targeting biofilms in the drug discovery process indicates the need to design new biofilm inhibitors as antimicrobial drugs using various strategies and targeting different stages of biofilm formation. Growing strategies that have been developed to combat biofilm formation include targeting bacterial enzymes, as well as those involved in the quorum sensing and adhesion pathways. In this review, with Pseudomonas as the primary subject of study, we review and discuss the mechanisms of bacterial biofilm formation and current therapeutic approaches, emphasizing the clinical issues associated with biofilm infections and focusing on current and emerging antibiotic biofilm strategies.
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Affiliation(s)
- Xinyu Wang
- Department of Biotherapy, Cancer Center and State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu, 610041, China
- State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, Chinese Academy of Medical Sciences Research Unit of Oral Carcinogenesis and Management, West China Hospital of Stomatology, Sichuan University, Chengdu, 610041, Sichuan, China
| | - Ming Liu
- State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, Chinese Academy of Medical Sciences Research Unit of Oral Carcinogenesis and Management, West China Hospital of Stomatology, Sichuan University, Chengdu, 610041, Sichuan, China
| | - Chuanjiang Yu
- Institute for Cancer Genetics, Columbia University, New York, NY, 10032, USA
| | - Jing Li
- State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, Chinese Academy of Medical Sciences Research Unit of Oral Carcinogenesis and Management, West China Hospital of Stomatology, Sichuan University, Chengdu, 610041, Sichuan, China.
| | - Xikun Zhou
- Department of Biotherapy, Cancer Center and State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu, 610041, China.
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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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7
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Zemke AC, D'Amico EJ, Torres AM, Carreno-Florez GP, Keeley P, DuPont M, Kasturiarachi N, Bomberger JM. Bacterial respiratory inhibition triggers dispersal of Pseudomonas aeruginosa biofilms. Appl Environ Microbiol 2023; 89:e0110123. [PMID: 37728340 PMCID: PMC10617509 DOI: 10.1128/aem.01101-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2023] [Accepted: 07/14/2023] [Indexed: 09/21/2023] Open
Abstract
Pseudomonas aeruginosa grows as a biofilm under many environmental conditions, and the bacterium can disperse from biofilms via highly regulated, dynamic processes. However, physiologic triggers of biofilm dispersal remain poorly understood. Based on prior literature describing dispersal triggered by forms of starvation, we tested bacterial respiratory inhibitors for biofilm dispersal in two models resembling chronic airway infections. Our underlying hypothesis was that respiratory inhibitors could serve as a model for the downstream effects of starvation. We used two experimental conditions. In the first condition, biofilms were grown and dispersed from the surface of airway epithelial cells, and the second condition was a model where biofilms were grown on glass in cell culture media supplemented with host-relevant iron sources. In both biofilm models, the respiratory inhibitors potassium cyanide and sodium azide each triggered biofilm dispersal. We hypothesized that cyanide-induced dispersal was due to respiratory inhibition rather than signaling via an alternative mechanism, and, indeed, if respiration was supported by overexpression of cyanide-insensitive oxidase, dispersal was prevented. Dispersal required the activity of the cyclic-di-GMP regulated protease LapG, reinforcing the role of matrix degradation in dispersal. Finally, we examined the roles of individual phosphodiesterases, previously implicated in dispersal to specific triggers, and found signaling to be highly redundant. Combined deletion of the phosphodiesterases dipA, bifA, and rbdA was required to attenuate the dispersal phenotype. In summary, this work adds insight into the physiology of biofilm dispersal under environmental conditions in which bacterial respiration is abruptly limited. IMPORTANCE The bacterium Pseudomonas aeruginosa grows in biofilm communities that are very difficult to treat in human infections. Growing as a biofilm can protect bacteria from antibiotics and the immune system. Bacteria can leave a biofilm through a process called "dispersal." Dispersed bacteria seed new growth areas and are more susceptible to killing by antibiotics. The triggers for biofilm dispersal are not well understood, and if we understood dispersal better it might lead to the development of new treatments for infection. In this paper, we find that inhibiting P. aeurginosa's ability to respire (generate energy) can trigger dispersal from a biofilm grown in association with human respiratory epithelial cells in culture. The dispersal process requires a protease which is previously known to degrade the biofilm matrix. These findings give us a better understanding of how the biofilm dispersal process works so that future research can discover better ways of clearing bacteria growing in biofilms.
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Affiliation(s)
- Anna C. Zemke
- Division of Pulmonary, Allergy and Critical Care Medicine, Department of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Emily J. D'Amico
- Division of Pulmonary, Allergy and Critical Care Medicine, Department of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Angela M. Torres
- Division of Pulmonary, Allergy and Critical Care Medicine, Department of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Grace P. Carreno-Florez
- Division of Pulmonary, Allergy and Critical Care Medicine, Department of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Patrick Keeley
- Division of Pulmonary, Allergy and Critical Care Medicine, Department of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Matt DuPont
- Division of Pulmonary, Allergy and Critical Care Medicine, Department of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Naomi Kasturiarachi
- Division of Pulmonary, Allergy and Critical Care Medicine, Department of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Jennifer M. Bomberger
- Department of Microbiology and Molecular Genetics, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
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8
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Wang S, Zhao Y, Breslawec AP, Liang T, Deng Z, Kuperman LL, Yu Q. Strategy to combat biofilms: a focus on biofilm dispersal enzymes. NPJ Biofilms Microbiomes 2023; 9:63. [PMID: 37679355 PMCID: PMC10485009 DOI: 10.1038/s41522-023-00427-y] [Citation(s) in RCA: 17] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2023] [Accepted: 08/15/2023] [Indexed: 09/09/2023] Open
Abstract
Bacterial biofilms, which consist of three-dimensional extracellular polymeric substance (EPS), not only function as signaling networks, provide nutritional support, and facilitate surface adhesion, but also serve as a protective shield for the residing bacterial inhabitants against external stress, such as antibiotics, antimicrobials, and host immune responses. Biofilm-associated infections account for 65-80% of all human microbial infections that lead to serious mortality and morbidity. Tremendous effort has been spent to address the problem by developing biofilm-dispersing agents to discharge colonized microbial cells to a more vulnerable planktonic state. Here, we discuss the recent progress of enzymatic eradicating strategies against medical biofilms, with a focus on dispersal mechanisms. Particularly, we review three enzyme classes that have been extensively investigated, namely glycoside hydrolases, proteases, and deoxyribonucleases.
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Affiliation(s)
- Shaochi Wang
- Otorhinolaryngology Hospital, The First Affiliated Hospital of Zhengzhou University, 450052, Zhengzhou, China
- Translational Medicine Center, The First Affiliated Hospital of Zhengzhou University, 450052, Zhengzhou, China
| | - Yanteng Zhao
- Translational Medicine Center, The First Affiliated Hospital of Zhengzhou University, 450052, Zhengzhou, China
| | - Alexandra P Breslawec
- Department of Chemistry and Biochemistry, University of Maryland, College Park, MD, 20740, USA
| | - Tingting Liang
- Key Laboratory of Natural Medicine and Immune-Engineering of Henan Province, Henan University Jinming Campus, 475004, Kaifeng, Henan, China
| | - Zhifen Deng
- Translational Medicine Center, The First Affiliated Hospital of Zhengzhou University, 450052, Zhengzhou, China
| | - Laura L Kuperman
- Department of Chemistry and Biochemistry, University of Maryland, College Park, MD, 20740, USA.
- Mirimus Inc., 760 Parkside Avenue, Brooklyn, NY, 11226, USA.
| | - Qiuning Yu
- Otorhinolaryngology Hospital, The First Affiliated Hospital of Zhengzhou University, 450052, Zhengzhou, China.
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Ghosh M, Raghav S, Ghosh P, Maity S, Mohela K, Jain D. Structural analysis of novel drug targets for mitigation of Pseudomonas aeruginosa biofilms. FEMS Microbiol Rev 2023; 47:fuad054. [PMID: 37771093 DOI: 10.1093/femsre/fuad054] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2023] [Revised: 09/20/2023] [Accepted: 09/27/2023] [Indexed: 09/30/2023] Open
Abstract
Pseudomonas aeruginosa is an opportunistic human pathogen responsible for acute and chronic, hard to treat infections. Persistence of P. aeruginosa is due to its ability to develop into biofilms, which are sessile bacterial communities adhered to substratum and encapsulated in layers of self-produced exopolysaccharides. These biofilms provide enhanced protection from the host immune system and resilience towards antibiotics, which poses a challenge for treatment. Various strategies have been expended for combating biofilms, which involve inhibiting biofilm formation or promoting their dispersal. The current remediation approaches offer some hope for clinical usage, however, treatment and eradication of preformed biofilms is still a challenge. Thus, identifying novel targets and understanding the detailed mechanism of biofilm regulation becomes imperative. Structure-based drug discovery (SBDD) provides a powerful tool that exploits the knowledge of atomic resolution details of the targets to search for high affinity ligands. This review describes the available structural information on the putative target protein structures that can be utilized for high throughput in silico drug discovery against P. aeruginosa biofilms. Integrating available structural information on the target proteins in readily accessible format will accelerate the process of drug discovery.
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Affiliation(s)
- Moumita Ghosh
- Transcription Regulation Lab, Regional Centre for Biotechnology, NCR Biotech Science Cluster, 3rd Milestone, Faridabad-Gurugram Expressway, Faridabad, Haryana-121001, India
| | - Shikha Raghav
- Transcription Regulation Lab, Regional Centre for Biotechnology, NCR Biotech Science Cluster, 3rd Milestone, Faridabad-Gurugram Expressway, Faridabad, Haryana-121001, India
| | - Puja Ghosh
- Transcription Regulation Lab, Regional Centre for Biotechnology, NCR Biotech Science Cluster, 3rd Milestone, Faridabad-Gurugram Expressway, Faridabad, Haryana-121001, India
| | - Swagatam Maity
- Transcription Regulation Lab, Regional Centre for Biotechnology, NCR Biotech Science Cluster, 3rd Milestone, Faridabad-Gurugram Expressway, Faridabad, Haryana-121001, India
| | - Kavery Mohela
- Transcription Regulation Lab, Regional Centre for Biotechnology, NCR Biotech Science Cluster, 3rd Milestone, Faridabad-Gurugram Expressway, Faridabad, Haryana-121001, India
| | - Deepti Jain
- Transcription Regulation Lab, Regional Centre for Biotechnology, NCR Biotech Science Cluster, 3rd Milestone, Faridabad-Gurugram Expressway, Faridabad, Haryana-121001, India
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10
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Trouillon J, Attrée I, Elsen S. The regulation of bacterial two-partner secretion systems. Mol Microbiol 2023; 120:159-177. [PMID: 37340956 DOI: 10.1111/mmi.15112] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2022] [Revised: 06/01/2023] [Accepted: 06/07/2023] [Indexed: 06/22/2023]
Abstract
Two-partner secretion (TPS) systems, also known as Type Vb secretion systems, allow the translocation of effector proteins across the outer membrane of Gram-negative bacteria. By secreting different classes of effectors, including cytolysins and adhesins, TPS systems play important roles in bacterial pathogenesis and host interactions. Here, we review the current knowledge on TPS systems regulation and highlight specific and common regulatory mechanisms across TPS functional classes. We discuss in detail the specific regulatory networks identified in various bacterial species and emphasize the importance of understanding the context-dependent regulation of TPS systems. Several regulatory cues reflecting host environment during infection, such as temperature and iron availability, are common determinants of expression for TPS systems, even across relatively distant species. These common regulatory pathways often affect TPS systems across subfamilies with different effector functions, representing conserved global infection-related regulatory mechanisms.
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Affiliation(s)
- Julian Trouillon
- Université Grenoble Alpes, CNRS, CEA, IBS UMR 5075, Team Bacterial Pathogenesis and Cellular Responses, Grenoble, France
| | - Ina Attrée
- Université Grenoble Alpes, CNRS, CEA, IBS UMR 5075, Team Bacterial Pathogenesis and Cellular Responses, Grenoble, France
| | - Sylvie Elsen
- Université Grenoble Alpes, CNRS, CEA, IBS UMR 5075, Team Bacterial Pathogenesis and Cellular Responses, Grenoble, France
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11
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Park S, Dingemans J, Sauer K. Manganese Acts as an Environmental Inhibitor of Pseudomonas aeruginosa Biofilm Development by Inducing Dispersion and Modulating c-di-GMP and Exopolysaccharide Production via RbdA. J Bacteriol 2023; 205:e0000323. [PMID: 37199658 PMCID: PMC10294637 DOI: 10.1128/jb.00003-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2023] [Accepted: 04/27/2023] [Indexed: 05/19/2023] Open
Abstract
The opportunistic human pathogen Pseudomonas aeruginosa causes chronic infections that involve multicellular aggregates called biofilms. Biofilm formation is modulated by the host environment and the presence of cues and/or signals, likely affecting the pool of the bacterial second messenger cyclic diguanylate monophosphate (c-di-GMP). The manganese ion Mn2+ is a divalent metal cation that is essential for pathogenic bacterial survival and replication during the infection in a host organism. In this study, we investigated how Mn2+ alters P. aeruginosa biofilm formation via the regulation of c-di-GMP levels. Exposure to Mn2+ was found to temporally enhance attachment but impair subsequent biofilm development, apparent by reduced biofilm biomass accumulation and lack of microcolony formation due to the induction of dispersion. Moreover, exposure to Mn2+ coincided with reduced production of the exopolysaccharides Psl and Pel, decreased transcriptional abundance of pel and psl, and decreased levels of c-di-GMP. To determine whether the effect of Mn2+ was linked to the activation of phosphodiesterases (PDEs), we screened several PDE mutants for Mn2+-dependent phenotypes (attachment and polysaccharide production) as well as PDE activity. The screen revealed that the PDE RbdA is activated by Mn2+ and is responsible for Mn2+-dependent attachment, inhibition of Psl production, and dispersion. Taken together, our findings suggest Mn2+ is an environmental inhibitor of P. aeruginosa biofilm development that acts through the PDE RbdA to modulate c-di-GMP levels, thereby impeding polysaccharide production and biofilm formation but enhancing dispersion. IMPORTANCE While diverse environmental conditions such as the availability of metal ions have been shown to affect biofilm development, little is known about the mechanism. Here, we demonstrate that Mn2+ affects Pseudomonas aeruginosa biofilm development by stimulating phosphodiesterase RbdA activity to reduce the signaling molecule c-di-GMP levels, thereby hindering polysaccharide production and biofilm formation but enhancing dispersion. Our findings demonstrate that Mn2+ acts as an environmental inhibitor of P. aeruginosa biofilms, further suggesting manganese to be a promising new antibiofilm factor.
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Affiliation(s)
- Soyoung Park
- Department of Biological Sciences, Binghamton University, Binghamton, New York, USA
- Binghamton Biofilm Research Center, Binghamton University, Binghamton, New York, USA
| | - Jozef Dingemans
- Department of Biological Sciences, Binghamton University, Binghamton, New York, USA
- Binghamton Biofilm Research Center, Binghamton University, Binghamton, New York, USA
| | - Karin Sauer
- Department of Biological Sciences, Binghamton University, Binghamton, New York, USA
- Binghamton Biofilm Research Center, Binghamton University, Binghamton, New York, USA
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12
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Bhattacharyya A, Mavrodi O, Bhowmik N, Weller D, Thomashow L, Mavrodi D. Bacterial biofilms as an essential component of rhizosphere plant-microbe interactions. METHODS IN MICROBIOLOGY 2023; 53:3-48. [PMID: 38415193 PMCID: PMC10898258 DOI: 10.1016/bs.mim.2023.05.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/29/2024]
Affiliation(s)
- Ankita Bhattacharyya
- School of Biological, Environmental and Earth Sciences, The University of Southern Mississippi, Hattiesburg, MS, United States
| | - Olga Mavrodi
- School of Biological, Environmental and Earth Sciences, The University of Southern Mississippi, Hattiesburg, MS, United States
| | - Niladri Bhowmik
- School of Biological, Environmental and Earth Sciences, The University of Southern Mississippi, Hattiesburg, MS, United States
| | - David Weller
- USDA-ARS Wheat Health, Genetics and Quality Research Unit, Pullman, WA, United States
| | - Linda Thomashow
- USDA-ARS Wheat Health, Genetics and Quality Research Unit, Pullman, WA, United States
| | - Dmitri Mavrodi
- School of Biological, Environmental and Earth Sciences, The University of Southern Mississippi, Hattiesburg, MS, United States
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13
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He J, Gao X, Huang H, Hao J. Proposal and Verification of the Theory of Layer-by-Layer Elimination of Biofilm in Listeria monocytogenes. Foods 2023; 12:foods12071361. [PMID: 37048183 PMCID: PMC10093742 DOI: 10.3390/foods12071361] [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: 03/11/2023] [Accepted: 03/21/2023] [Indexed: 04/14/2023] Open
Abstract
Biofilms are microbial communities that represent a high abundance of microbial life forms on Earth. Within biofilms, structural changes during clearance processes occur in three spatial and temporal dimensions; therefore, microscopy and quantitative image analysis are essential in elucidating their function. Here, we present confocal laser scanning microscopy (CLSM) in conjunction with ISA-2 software analysis for the automated and high-throughput quantification, analysis, and visualisation of biofilm interiors and overall biofilm properties in three spatial and temporal dimensions. This paper discusses the removal process of Listeria monocytogenes (LM) biofilms using slightly acidic electrolytic water, non-electrolytic hypochlorite water, and alternating the use of strongly acidic and strongly alkaline electrolytic water. The results show that the biofilm gradually thins and gutters from the initial viscous dense and thick morphology under the action of either biocide. This process is consistent with first-level kinetics. After CLSM filming to observe the biofilm structure, analysis software was used to process and quantify the biovolume, average biofilm thickness, biofilm roughness and other indicators; fluorescence enzyme markers were used to verify the remaining amount of extracellular nucleic acid. In this study, we proposed and validated the theory of layer-by-layer elimination of LM biofilm.
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Affiliation(s)
- Jialin He
- College of Food Science and Biology, Hebei University of Science and Technology, No. 26 Yuxiang Street, Shijiazhuang 050018, China
| | - Xiangyu Gao
- College of Food Science and Biology, Hebei University of Science and Technology, No. 26 Yuxiang Street, Shijiazhuang 050018, China
| | - Hanbing Huang
- College of Food Science and Biology, Hebei University of Science and Technology, No. 26 Yuxiang Street, Shijiazhuang 050018, China
| | - Jianxiong Hao
- College of Food Science and Biology, Hebei University of Science and Technology, No. 26 Yuxiang Street, Shijiazhuang 050018, China
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14
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Razvi E, Whitfield GB, Reichhardt C, Dreifus JE, Willis AR, Gluscencova OB, Gloag ES, Awad TS, Rich JD, da Silva DP, Bond W, Le Mauff F, Sheppard DC, Hatton BD, Stoodley P, Reinke AW, Boulianne GL, Wozniak DJ, Harrison JJ, Parsek MR, Howell PL. Glycoside hydrolase processing of the Pel polysaccharide alters biofilm biomechanics and Pseudomonas aeruginosa virulence. NPJ Biofilms Microbiomes 2023; 9:7. [PMID: 36732330 PMCID: PMC9894940 DOI: 10.1038/s41522-023-00375-7] [Citation(s) in RCA: 13] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2022] [Accepted: 01/16/2023] [Indexed: 02/04/2023] Open
Abstract
Pel exopolysaccharide biosynthetic loci are phylogenetically widespread biofilm matrix determinants in bacteria. In Pseudomonas aeruginosa, Pel is crucial for cell-to-cell interactions and reducing susceptibility to antibiotic and mucolytic treatments. While genes encoding glycoside hydrolases have long been linked to biofilm exopolysaccharide biosynthesis, their physiological role in biofilm development is unclear. Here we demonstrate that the glycoside hydrolase activity of P. aeruginosa PelA decreases adherent biofilm biomass and is responsible for generating the low molecular weight secreted form of the Pel exopolysaccharide. We show that the generation of secreted Pel contributes to the biomechanical properties of the biofilm and decreases the virulence of P. aeruginosa in Caenorhabditis elegans and Drosophila melanogaster. Our results reveal that glycoside hydrolases found in exopolysaccharide biosynthetic systems can help shape the soft matter attributes of a biofilm and propose that secreted matrix components be referred to as matrix associated to better reflect their influence.
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Affiliation(s)
- Erum Razvi
- Program in Molecular Medicine, The Hospital for Sick Children, Toronto, ON, Canada
- Department of Biochemistry, University of Toronto, Toronto, ON, Canada
| | - Gregory B Whitfield
- Program in Molecular Medicine, The Hospital for Sick Children, Toronto, ON, Canada
- Department of Biochemistry, University of Toronto, Toronto, ON, Canada
- Département de Microbiologie, Infectiologie, et Immunologie, Faculté de Médecine Université de Montréal, Montréal, QC, Canada
| | - Courtney Reichhardt
- Department of Microbiology, University of Washington, Seattle, WA, USA
- Department of Chemistry, Washington University, St. Louis, MO, USA
| | - Julia E Dreifus
- Department of Microbiology, University of Washington, Seattle, WA, USA
| | - Alexandra R Willis
- Department of Molecular Genetics, University of Toronto, Toronto, ON, Canada
| | - Oxana B Gluscencova
- Program in Developmental and Stem Cell Biology, The Hospital for Sick Children, Toronto, ON, Canada
| | - Erin S Gloag
- Department of Microbial Infection and Immunity, The Ohio State University, Columbus, OH, 43210, USA
- Department of Biomedical Sciences and Pathobiology, VA-MD College of Veterinary Medicine, Virginia Tech, VA, 24061, USA
| | - Tarek S Awad
- Department of Materials Science and Engineering, University of Toronto, Toronto, ON, Canada
| | - Jacquelyn D Rich
- Department of Biological Sciences, University of Calgary, Calgary, AB, Canada
| | - Daniel Passos da Silva
- Department of Microbiology, University of Washington, Seattle, WA, USA
- BioVectra Inc. 11 Aviation, Charlottetown, PE, Canada
| | - Whitney Bond
- Department of Microbiology, University of Washington, Seattle, WA, USA
| | - François Le Mauff
- Department of Microbiology and Immunology, Faculty of Medicine, McGill University, Montreal, QC, Canada
- Infectious Disease and Immunity in Global Health, Research Institute of the McGill University Health Centre, Montreal, QC, Canada
- McGill Interdisciplinary Initiative in Infection and Immunity, Montreal, QC, Canada
| | - Donald C Sheppard
- Department of Microbiology and Immunology, Faculty of Medicine, McGill University, Montreal, QC, Canada
- Infectious Disease and Immunity in Global Health, Research Institute of the McGill University Health Centre, Montreal, QC, Canada
- McGill Interdisciplinary Initiative in Infection and Immunity, Montreal, QC, Canada
| | - Benjamin D Hatton
- Department of Materials Science and Engineering, University of Toronto, Toronto, ON, Canada
| | - Paul Stoodley
- Department of Microbial Infection and Immunity, The Ohio State University, Columbus, OH, 43210, USA
- Department of Orthopedics, The Ohio State University, Columbus, OH, 43210, USA
- National Biofilm Innovation Centre (NBIC) and National Centre for Advanced Tribology at Southampton (nCATS), University of Southampton, Southampton, SO17 1BJ, UK
- Department of Microbiology, The Ohio State University, Columbus, OH, 43210, USA
| | - Aaron W Reinke
- Department of Molecular Genetics, University of Toronto, Toronto, ON, Canada
| | - Gabrielle L Boulianne
- Department of Molecular Genetics, University of Toronto, Toronto, ON, Canada
- Program in Developmental and Stem Cell Biology, The Hospital for Sick Children, Toronto, ON, Canada
| | - Daniel J Wozniak
- Department of Microbial Infection and Immunity, The Ohio State University, Columbus, OH, 43210, USA
- Department of Microbiology, The Ohio State University, Columbus, OH, 43210, USA
| | - Joe J Harrison
- Department of Biological Sciences, University of Calgary, Calgary, AB, Canada
| | - Matthew R Parsek
- Department of Microbiology, University of Washington, Seattle, WA, USA
| | - P Lynne Howell
- Program in Molecular Medicine, The Hospital for Sick Children, Toronto, ON, Canada.
- Department of Biochemistry, University of Toronto, Toronto, ON, Canada.
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15
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Flemming HC, van Hullebusch ED, Neu TR, Nielsen PH, Seviour T, Stoodley P, Wingender J, Wuertz S. The biofilm matrix: multitasking in a shared space. Nat Rev Microbiol 2023; 21:70-86. [PMID: 36127518 DOI: 10.1038/s41579-022-00791-0] [Citation(s) in RCA: 173] [Impact Index Per Article: 173.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/04/2022] [Indexed: 01/20/2023]
Abstract
The biofilm matrix can be considered to be a shared space for the encased microbial cells, comprising a wide variety of extracellular polymeric substances (EPS), such as polysaccharides, proteins, amyloids, lipids and extracellular DNA (eDNA), as well as membrane vesicles and humic-like microbially derived refractory substances. EPS are dynamic in space and time and their components interact in complex ways, fulfilling various functions: to stabilize the matrix, acquire nutrients, retain and protect eDNA or exoenzymes, or offer sorption sites for ions and hydrophobic substances. The retention of exoenzymes effectively renders the biofilm matrix an external digestion system influencing the global turnover of biopolymers, considering the ubiquitous relevance of biofilms. Physico-chemical and biological interactions and environmental conditions enable biofilm systems to morph into films, microcolonies and macrocolonies, films, ridges, ripples, columns, pellicles, bubbles, mushrooms and suspended aggregates - in response to the very diverse conditions confronting a particular biofilm community. Assembly and dynamics of the matrix are mostly coordinated by secondary messengers, signalling molecules or small RNAs, in both medically relevant and environmental biofilms. Fully deciphering how bacteria provide structure to the matrix, and thus facilitate and benefit from extracellular reactions, remains the challenge for future biofilm research.
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Affiliation(s)
- Hans-Curt Flemming
- Singapore Centre for Environmental Life Sciences Engineering, Nanyang Technological University, Singapore, Singapore.
| | | | - Thomas R Neu
- Department of River Ecology, Helmholtz Centre for Environmental Research - UFZ, Magdeburg, Germany
| | - Per H Nielsen
- Center for Microbial Communities, Department of Chemistry and Bioscience, Aalborg University, Aalborg, Denmark
| | - Thomas Seviour
- Aarhus University Centre for Water Technology, Department of Biological and Chemical Engineering, Aarhus University, Aarhus, Denmark
| | - Paul Stoodley
- Department of Microbial Infection and Immunity, The Ohio State University, Columbus, OH, USA.,Department of Orthopaedics, The Ohio State University, Columbus, OH, USA
| | - Jost Wingender
- University of Duisburg-Essen, Biofilm Centre, Department of Aquatic Microbiology, Essen, Germany
| | - Stefan Wuertz
- Singapore Centre for Environmental Life Sciences Engineering, Nanyang Technological University, Singapore, Singapore
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16
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The Alginate and Motility Regulator AmrZ is Essential for the Regulation of the Dispersion Response by Pseudomonas aeruginosa Biofilms. mSphere 2022; 7:e0050522. [PMID: 36374041 PMCID: PMC9769550 DOI: 10.1128/msphere.00505-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Dispersion is an active process exhibited by Pseudomonas aeruginosa during the late stages of biofilm development or in response to various cues, including nitric oxide and glutamate. Upon cue sensing, biofilm cells employ enzymes that actively degrade the extracellular matrix, thereby allowing individual cells to become liberated. While the mechanism by which P. aeruginosa senses and relays dispersion cues has been characterized, little is known about how dispersion cue sensing mechanisms result in matrix degradation. Considering that the alginate and motility regulator AmrZ has been reported to regulate genes that play a role in dispersion, including those affecting virulence, c-di-GMP levels, Pel and Psl abundance, and motility, we asked whether AmrZ contributes to the regulation of dispersion. amrZ was found to be significantly increased in transcript abundance under dispersion-inducing conditions, with the inactivation of amrZ impairing dispersion by P. aeruginosa biofilms in response to glutamate and nitric oxide. While the overexpression of genes encoding matrix-degrading enzymes pelA, pslG, and/or endA resulted in the dispersion of wild-type biofilms, similar conditions failed to disperse biofilms formed by dtamrZ. Likewise, the inactivation of amrZ abrogated the hyperdispersive phenotype of PAO1/pJN-bdlA_G31A biofilms, with dtamrZ-impaired dispersion being independent of the expression, production, and activation of BdlA. Instead, dispersion was found to require the AmrZ-target genes napB and PA1891. Our findings indicate that AmrZ is essential for the regulation of dispersion by P. aeruginosa biofilms, functions downstream of BdlA postdispersion cue sensing, and regulates the expression of genes contributing to biofilm matrix degradation as well as napB and PA1891. IMPORTANCE In P. aeruginosa, biofilm dispersion has been well-characterized with respect to dispersion cue perception, matrix degradation, and the consequences of dispersion. While the intracellular signaling molecule c-di-GMP has been linked to many of the phenotypic changes ascribed to dispersion, including the modulation of motility and matrix production, little is known about the regulatory mechanisms leading to matrix degradation and cells actively leaving the biofilm. In this study, we report for the first time an essential role of the transcriptional regulator AmrZ and two AmrZ-dependent genes, napB, and PA1891, in the dispersion response, thereby linking dispersion cue sensing via BdlA to the regulation of matrix degradation and to the ultimate liberation of bacterial cells from the biofilm.
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17
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Pseudomonas aeruginosa Can Diversify after Host Cell Invasion to Establish Multiple Intracellular Niches. mBio 2022; 13:e0274222. [PMID: 36374039 PMCID: PMC9765609 DOI: 10.1128/mbio.02742-22] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Within epithelial cells, Pseudomonas aeruginosa depends on its type III secretion system (T3SS) to escape vacuoles and replicate rapidly in the cytosol. Previously, it was assumed that intracellular subpopulations remaining T3SS-negative (and therefore in vacuoles) were destined for degradation in lysosomes, supported by data showing vacuole acidification. Here, we report in both corneal and bronchial human epithelial cells that vacuole-associated bacteria can persist, sometimes in the same cells as cytosolic bacteria. Using a combination of phase-contrast, confocal, and correlative light-electron microscopy (CLEM), we also found they can demonstrate biofilm-associated markers: cdrA and cyclic-di-GMP (c-di-GMP). Vacuolar-associated bacteria, but not their cytosolic counterparts, tolerated the cell-permeable antibiotic ofloxacin. Surprisingly, use of mutants showed that both persistence in vacuoles and ofloxacin tolerance were independent of the biofilm-associated protein CdrA or exopolysaccharides (Psl, Pel, alginate). A T3SS mutant (ΔexsA) unable to escape vacuoles phenocopied vacuole-associated subpopulations in wild-type PAO1-infected cells, with results revealing that epithelial cell death depended upon bacterial viability. Intravital confocal imaging of infected mouse corneas confirmed that P. aeruginosa formed similar intracellular subpopulations within epithelial cells in vivo. Together, these results show that P. aeruginosa differs from other pathogens by diversifying intracellularly into vacuolar and cytosolic subpopulations that both contribute to pathogenesis. Their different gene expression and behavior (e.g., rapid replication versus slow replication/persistence) suggest cooperation favoring both short- and long-term interests and another potential pathway to treatment failure. How this intracellular diversification relates to previously described "acute versus chronic" virulence gene-expression phenotypes of P. aeruginosa remains to be determined. IMPORTANCE Pseudomonas aeruginosa can cause sight- and life-threatening opportunistic infections, and its evolving antibiotic resistance is a growing concern. Most P. aeruginosa strains can invade host cells, presenting a challenge to therapies that do not penetrate host cell membranes. Previously, we showed that the P. aeruginosa type III secretion system (T3SS) plays a pivotal role in survival within epithelial cells, allowing escape from vacuoles, rapid replication in the cytoplasm, and suppression of host cell death. Here, we report the discovery of a novel T3SS-negative subpopulation of intracellular P. aeruginosa within epithelial cells that persist in vacuoles rather than the cytoplasm and that tolerate a cell-permeable antibiotic (ofloxacin) that is able to kill cytosolic bacteria. Classical biofilm-associated markers, although demonstrated by this subpopulation, are not required for vacuolar persistence or antibiotic tolerance. These findings advance our understanding of how P. aeruginosa hijacks host cells, showing that it diversifies into multiple populations with T3SS-negative members enabling persistence while rapid replication is accomplished by more vulnerable T3SS-positive siblings. Intracellular P. aeruginosa persisting and tolerating antibiotics independently of the T3SS or biofilm-associated factors could present additional challenges to development of more effective therapeutics.
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18
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Low Temperature Plasma Strategies for Xylella fastidiosa Inactivation. APPLIED SCIENCES-BASEL 2022. [DOI: 10.3390/app12094711] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
The quarantine bacterium Xylella fastidiosa was first detected in Salento (Apulia, Italy) in 2013 and caused severe symptoms in olives, leading to plant death. The disease, named Olive Quick Decline Syndrome (OQDS), is caused by the strain “De Donno” ST53 of the subspecies pauca of this bacterium (XfDD), which is spread by the insect Philaenus spumarius. The epidemic poses a serious threat to the agricultural economy and the landscape, as X. fastidiosa infects several plant species and there is yet no recognized solution. Research on OQDS is focused on finding strategies to control its spread or mitigate its symptoms. As a perspective solution, we investigated the efficacy of the low-temperature plasma and plasma-activated water to kill bacterial cells. Experiments were conducted in vitro to test the biocidal effect of the direct application of a Surface Dielectric Barrier Discharge (SDBD) plasma on bacteria cells and Plasma Activated Water (PAW). PAW activity was tested as a possible biocidal agent that can move freely in the xylem network paving the way to test the strategy on infected plants. The results showed a high decontamination rate even for cells of XfDD embedded in biofilms grown on solid media and complete inactivation in liquid culture medium.
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19
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Nadar S, Khan T, Patching SG, Omri A. Development of Antibiofilm Therapeutics Strategies to Overcome Antimicrobial Drug Resistance. Microorganisms 2022; 10:microorganisms10020303. [PMID: 35208758 PMCID: PMC8879831 DOI: 10.3390/microorganisms10020303] [Citation(s) in RCA: 34] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2021] [Revised: 01/19/2022] [Accepted: 01/25/2022] [Indexed: 02/04/2023] Open
Abstract
A biofilm is a community of stable microorganisms encapsulated in an extracellular matrix produced by themselves. Many types of microorganisms that are found on living hosts or in the environment can form biofilms. These include pathogenic bacteria that can serve as a reservoir for persistent infections, and are culpable for leading to a broad spectrum of chronic illnesses and emergence of antibiotic resistance making them difficult to be treated. The absence of biofilm-targeting antibiotics in the drug discovery pipeline indicates an unmet opportunity for designing new biofilm inhibitors as antimicrobial agents using various strategies and targeting distinct stages of biofilm formation. The strategies available to control biofilm formation include targeting the enzymes and proteins specific to the microorganism and those involved in the adhesion pathways leading to formation of resistant biofilms. This review primarily focuses on the recent strategies and advances responsible for identifying a myriad of antibiofilm agents and their mechanism of biofilm inhibition, including extracellular polymeric substance synthesis inhibitors, adhesion inhibitors, quorum sensing inhibitors, efflux pump inhibitors, and cyclic diguanylate inhibitors. Furthermore, we present the structure–activity relationships (SAR) of these agents, including recently discovered biofilm inhibitors, nature-derived bioactive scaffolds, synthetic small molecules, antimicrobial peptides, bioactive compounds isolated from fungi, non-proteinogenic amino acids and antibiotics. We hope to fuel interest and focus research efforts on the development of agents targeting the uniquely complex, physical and chemical heterogeneous biofilms through a multipronged approach and combinatorial therapeutics for a more effective control and management of biofilms across diseases.
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Affiliation(s)
- Sahaya Nadar
- Department of Pharmaceutical Chemistry, St. John Institute of Pharmacy and Research, Mumbai 400056, India;
| | - Tabassum Khan
- Department of Pharmaceutical Chemistry & Quality Assurance, SVKM’s Dr. Bhanuben Nanavati College of Pharmacy, Mumbai 400056, India;
| | - Simon G. Patching
- School of Biomedical Sciences and Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds LS2 9JT, UK
- Correspondence: or (S.G.P.); (A.O.)
| | - Abdelwahab Omri
- The Novel Drug & Vaccine Delivery Systems Facility, Department of Chemistry and Biochemistry, Laurentian University, Sudbury, ON P3E 2C6, Canada
- Correspondence: or (S.G.P.); (A.O.)
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20
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Fischer S, Klockgether J, Gonzalez Sorribes M, Dorda M, Wiehlmann L, Tümmler B. Sequence diversity of the Pseudomonas aeruginosa population in loci that undergo microevolution in cystic fibrosis airways. Access Microbiol 2022; 3:000286. [PMID: 35024551 PMCID: PMC8749138 DOI: 10.1099/acmi.0.000286] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2021] [Accepted: 10/04/2021] [Indexed: 12/23/2022] Open
Abstract
Five hundred and thirty-four unrelated Pseudomonas aeruginosa isolates from inanimate habitats, patients with cystic fibrosis (CF) and other human infections were sequenced in 19 genes that had been identified previously as the hot spots of genomic within-host evolution in serial isolates from 12 CF lungs. Amplicon sequencing confirmed a significantly higher sequence diversity of the 19 loci in P. aeruginosa isolates from CF patients compared to those from other habitats, but this overrepresentation was mainly due to the larger share of synonymous substitutions. Correspondingly, non-synonymous substitutions were either rare (gltT, lepA, ptsP) or benign (nuoL, fleR, pelF) in some loci. Other loci, however, showed an accumulation of non-neutral coding variants. Strains from the CF habitat were often mutated at evolutionarily conserved positions in the elements of stringent response (RelA, SpoT), LPS (PagL), polyamine transport (SpuE, SpuF) and alginate biosynthesis (AlgG, AlgU). The strongest skew towards the CF lung habitat was seen for amino acid sequence variants in AlgG that clustered in the carbohydrate-binding/sugar hydrolysis domain. The master regulators of quorum sensing lasR and rhlR were frequent targets for coding variants in isolates from chronic and acute human infections. Unique variants in lasR showed strong evidence of positive selection indicated by d N/d S values of ~4. The pelA gene that encodes a multidomain enzyme involved in both the formation and dispersion of Pel biofilms carried the highest number of single-nucleotide variants among the 19 genes and was the only gene with a higher frequency of missense mutations in P. aeruginosa strains from non-CF habitats than in isolates from CF airways. PelA protein variants are widely distributed in the P. aeruginosa population. In conclusion, coding variants in a subset of the examined loci are indeed characteristic for the adaptation of P. aeruginosa to the CF airways, but for other loci the elevated mutation rate is more indicative of infections in human habitats (lasR, rhlR) or global diversifying selection (pelA).
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Affiliation(s)
- Sebastian Fischer
- Clinical Research Group 'Molecular Pathology of Cystic Fibrosis', Department for Paediatric Pneumology, Allergology and Neonatology, Hannover Medical School, Hannover, Germany
| | - Jens Klockgether
- Clinical Research Group 'Molecular Pathology of Cystic Fibrosis', Department for Paediatric Pneumology, Allergology and Neonatology, Hannover Medical School, Hannover, Germany
| | - Marina Gonzalez Sorribes
- Clinical Research Group 'Molecular Pathology of Cystic Fibrosis', Department for Paediatric Pneumology, Allergology and Neonatology, Hannover Medical School, Hannover, Germany.,Facultat de Biologia, Universitat de Barcelona, Barcelona, Spain
| | - Marie Dorda
- Clinical Research Group 'Molecular Pathology of Cystic Fibrosis', Department for Paediatric Pneumology, Allergology and Neonatology, Hannover Medical School, Hannover, Germany.,Research Core Unit Genomics, Hannover Medical School, Hannover, Germany
| | - Lutz Wiehlmann
- Clinical Research Group 'Molecular Pathology of Cystic Fibrosis', Department for Paediatric Pneumology, Allergology and Neonatology, Hannover Medical School, Hannover, Germany.,Research Core Unit Genomics, Hannover Medical School, Hannover, Germany
| | - Burkhard Tümmler
- Clinical Research Group 'Molecular Pathology of Cystic Fibrosis', Department for Paediatric Pneumology, Allergology and Neonatology, Hannover Medical School, Hannover, Germany.,Biomedical Research in Endstage and Obstructive Lung Disease Hannover (BREATH), German Center for Lung Research, Hannover Medical School, Germany
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21
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Pseudomonas aeruginosa
Oligoribonuclease Controls Susceptibility to Polymyxin B by Regulating Pel Exopolysaccharide Production. Antimicrob Agents Chemother 2022; 66:e0207221. [DOI: 10.1128/aac.02072-21] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Polymyxins are considered as the last resort antibiotics to treat infections caused by multidrug-resistant Gram negative pathogens.
Pseudomonas aeruginosa
is an opportunistic pathogen that causes various infections in humans. Proteins involved in lipopolysaccharide modification and maintaining inner and outer membrane integrities have been found to contribute to the bacterial resistance to polymyxins. Oligoribonuclease (Orn) is an exonuclease that regulates the homeostasis of intracellular (3'-5')-cyclic dimeric guanosine monophosphate (c-di-GMP), thereby regulating the production of extracellular polysaccharide in
P. aeruginosa
. Previously, we demonstrated that Orn affects the bacterial resistance to fluoroquinolone, β-lactam and aminoglycoside antibiotics. In this study, we found that mutation of
orn
increased the bacterial survival following polymyxin B treatment in a wild type
P. aeruginosa
strain PA14. Overexpression of c-di-GMP degradation enzymes in the
orn
mutant reduced the bacterial survival. By using a fluorescence labeled polymyxin B, we found that mutation of
orn
increased the bacterial surface bound polymyxin B. Deletion of the Pel synthesis genes or treatment with a Pel hydrolase reduced the surface bound polymyxin B and bacterial survival. We further demonstrated that Pel binds to extracellular DNA (eDNA), which traps polymyxin B and thus protects the bacterial cells. Collectively, our results revealed a novel defense mechanism against polymyxin in
P. aeruginosa
.
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22
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Park S, Sauer K. Controlling Biofilm Development Through Cyclic di-GMP Signaling. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2022; 1386:69-94. [PMID: 36258069 PMCID: PMC9891824 DOI: 10.1007/978-3-031-08491-1_3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
The cyclic di-GMP (c-di-GMP) second messenger represents a signaling system that regulates many bacterial behaviors and is of key importance for driving the lifestyle switch between motile loner cells and biofilm formers. This review provides an up-to-date summary of c-di-GMP pathways connected to biofilm formation by the opportunistic pathogen P. aeruginosa. Emphasis will be on the timing of c-di-GMP production over the course of biofilm formation, to highlight non-uniform and hierarchical increases in c-di-GMP levels, as well as biofilm growth conditions that do not conform with our current model of c-di-GMP.
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Affiliation(s)
- Soyoung Park
- Department of Biological Sciences, Binghamton University, Binghamton, NY, USA
- Binghamton Biofilm Research Center (BBRC), Binghamton University, Binghamton, NY, USA
| | - Karin Sauer
- Department of Biological Sciences, Binghamton University, Binghamton, NY, USA.
- Binghamton Biofilm Research Center (BBRC), Binghamton University, Binghamton, NY, USA.
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23
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Asimakopoulou E, Εkonomou SΙ, Papakonstantinou P, Doran O, Stratakos AC. Inhibition of corrosion causing Pseudomonas aeruginosa using plasma-activated water. J Appl Microbiol 2021; 132:2781-2794. [PMID: 34846774 DOI: 10.1111/jam.15391] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2021] [Revised: 11/24/2021] [Accepted: 11/28/2021] [Indexed: 12/28/2022]
Abstract
AIMS The cost of Microbiologically Influenced Corrosion (MIC) significantly affects a wide range of sectors. This study aims to assess the efficiency of a novel technology based on the use of plasma-activated water (PAW) in inhibiting corrosion caused by bacteria. METHODS AND RESULTS This study evaluated the effectiveness of PAW, produced by a plasma bubble reactor, in reducing corrosion causing Pseudomonas aeruginosa planktonic cells in tap water and biofilms were grown onto stainless steel (SS) coupons. Planktonic cells and biofilms were treated with PAW at different discharge frequencies (500-1500 Hz) and exposure times (0-20 min). P. aeruginosa cells in tap water were significantly reduced after treatment, with higher exposure times and discharge frequencies achieving higher reductions. Also, PAW treatment led to a gradual reduction for young and mature biofilms, achieving >4-Log reductions after 20 min. Results were also used to develop two predictive inactivation models. CONCLUSIONS This work presents evidence that PAW can be used to inactivate both planktonic cells and biofilms of P. aeruginosa. Experimental and theoretical results also demonstrate that reduction is dependent on discharge frequency and exposure time. SIGNIFICANCE AND IMPACT OF THE STUDY This work demonstrates the potential of using PAW as means to control MIC.
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Affiliation(s)
| | - Sotiriοs Ι Εkonomou
- Faculty of Health and Applied Sciences (HAS), Centre for Research in Biosciences, University of the West of England, Bristol, UK
| | | | - Olena Doran
- Faculty of Health and Applied Sciences (HAS), University of the West of England, Coldharbour Ln, Bristol, UK
| | - Alexandros Ch Stratakos
- Centre for Research in Biosciences, Faculty of Health and Applied Sciences (HAS), University of the West of England, Bristol, UK
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24
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Extracellular DNA (eDNA). A Major Ubiquitous Element of the Bacterial Biofilm Architecture. Int J Mol Sci 2021; 22:ijms22169100. [PMID: 34445806 PMCID: PMC8396552 DOI: 10.3390/ijms22169100] [Citation(s) in RCA: 64] [Impact Index Per Article: 21.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2021] [Revised: 08/19/2021] [Accepted: 08/20/2021] [Indexed: 12/22/2022] Open
Abstract
After the first ancient studies on microbial slime (the name by which the biofilm matrix was initially indicated), multitudes of studies on the morphology, composition and physiology of biofilms have arisen. The emergence of the role that biofilms play in the pathogenesis of recalcitrant and persistent clinical infections, such as periprosthetic orthopedic infections, has reinforced scientific interest. Extracellular DNA (eDNA) is a recently uncovered component that is proving to be almost omnipresent in the extracellular polymeric substance (EPS) of biofilm. This macromolecule is eliciting unprecedented consideration for the critical impact on the pathogenesis of chronic clinical infections. After a systematic review of the literature, an updated description of eDNA in biofilms is presented, with a special focus on the latest findings regarding its fundamental structural role and the contribution it makes to the complex architecture of bacterial biofilms through interactions with a variety of other molecular components of the biofilm matrix.
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25
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Andersen JB, Hultqvist LD, Jansen CU, Jakobsen TH, Nilsson M, Rybtke M, Uhd J, Fritz BG, Seifert R, Berthelsen J, Nielsen TE, Qvortrup K, Givskov M, Tolker-Nielsen T. Identification of small molecules that interfere with c-di-GMP signaling and induce dispersal of Pseudomonas aeruginosa biofilms. NPJ Biofilms Microbiomes 2021; 7:59. [PMID: 34244523 PMCID: PMC8271024 DOI: 10.1038/s41522-021-00225-4] [Citation(s) in RCA: 34] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2021] [Accepted: 06/11/2021] [Indexed: 12/29/2022] Open
Abstract
Microbial biofilms are involved in a number of infections that cannot be cured, as microbes in biofilms resist host immune defenses and antibiotic therapies. With no strict biofilm-antibiotic in the current pipelines, there is an unmet need for drug candidates that enable the current antibiotics to eradicate bacteria in biofilms. We used high-throughput screening to identify chemical compounds that reduce the intracellular c-di-GMP content in Pseudomonas aeruginosa. This led to the identification of a small molecule that efficiently depletes P. aeruginosa for c-di-GMP, inhibits biofilm formation, and disperses established biofilm. A combination of our lead compound with standard of care antibiotics showed improved eradication of an implant-associated infection established in mice. Genetic analyses provided evidence that the anti-biofilm compound stimulates the activity of the c-di-GMP phosphodiesterase BifA in P. aeruginosa. Our work constitutes a proof of concept for c-di-GMP phosphodiesterase-activating drugs administered in combination with antibiotics as a viable treatment strategy for otherwise recalcitrant infections.
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Affiliation(s)
- Jens Bo Andersen
- Costerton Biofilm Center. Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Louise Dahl Hultqvist
- Costerton Biofilm Center. Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | | | - Tim Holm Jakobsen
- Costerton Biofilm Center. Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Martin Nilsson
- Costerton Biofilm Center. Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Morten Rybtke
- Costerton Biofilm Center. Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Jesper Uhd
- Department of Chemistry, Technical University of Denmark, Lyngby, Denmark
| | - Blaine Gabriel Fritz
- Costerton Biofilm Center. Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Roland Seifert
- Institute of Pharmacology and Research Core Unit Metabolomics, Hannover Medical School Carl-Neuberg-Straße 1, Hannover, Germany
| | - Jens Berthelsen
- Costerton Biofilm Center. Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Thomas Eiland Nielsen
- Costerton Biofilm Center. Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.,Singapore Centre for Environmental Life Sciences Engineering, Nanyang Technological University, Singapore, Singapore
| | - Katrine Qvortrup
- Department of Chemistry, Technical University of Denmark, Lyngby, Denmark
| | - Michael Givskov
- Costerton Biofilm Center. Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark. .,Singapore Centre for Environmental Life Sciences Engineering, Nanyang Technological University, Singapore, Singapore.
| | - Tim Tolker-Nielsen
- Costerton Biofilm Center. Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.
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26
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Bharti S, Maurya RK, Venugopal U, Singh R, Akhtar MS, Krishnan MY. Rv1717 Is a Cell Wall - Associated β-Galactosidase of Mycobacterium tuberculosis That Is Involved in Biofilm Dispersion. Front Microbiol 2021; 11:611122. [PMID: 33584576 PMCID: PMC7873859 DOI: 10.3389/fmicb.2020.611122] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2020] [Accepted: 12/16/2020] [Indexed: 01/12/2023] Open
Abstract
Understanding the function of conserved hypothetical protein (CHP)s expressed by a pathogen in the infected host can lead to better understanding of its pathogenesis. The present work describes the functional characterization of a CHP, Rv1717 of Mycobacterium tuberculosis (Mtb). Rv1717 has been previously reported to be upregulated in TB patient lungs. Rv1717 belongs to the cupin superfamily of functionally diverse proteins, several of them being carbohydrate handling proteins. Bioinformatic analysis of the amino acid sequence revealed similarity to glycosyl hydrolases. Enzymatic studies with recombinant Rv1717 purified from Escherichia coli showed that the protein is a β-D-galactosidase specific for pyranose form rather than the furanose form. We expressed the protein in Mycobacterium smegmatis (Msm), which lacks its ortholog. In MsmRv1717, the protein was found to localize to the cell wall (CW) with a preference to the poles. MsmRv1717 showed significant changes in colony morphology and cell surface properties. Most striking observation was its unusual Congo red colony morphotype, reduced ability to form biofilms, pellicles and autoagglutinate. Exogenous Rv1717 not only prevented biofilm formation in Msm, but also degraded preformed biofilms, suggesting that its substrate likely exists in the exopolysaccharides of the biofilm matrix. Presence of galactose in the extracellular polymeric substance (EPS) has not been reported before and hence we used the galactose-specific Wisteria floribunda lectin (WFL) to test the same. The lectin extensively bound to Msm and Mtb EPS, but not the bacterium per se. Purified Rv1717 also hydrolyzed exopolysaccharides extracted from Msm biofilm. Eventually, to decipher its role in Mtb, we downregulated its expression and demonstrate that the strain is unable to disperse from in vitro biofilms, unlike the wild type. Biofilms exposed to carbon starvation showed a sudden upregulation of Rv1717 transcripts supporting the potential role of Rv1717 in Mtb dispersing from a deteriorating biofilm.
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Affiliation(s)
- Suman Bharti
- Microbiology Division, CSIR-Central Drug Research Institute, Lucknow, India
| | - Rahul Kumar Maurya
- Microbiology Division, CSIR-Central Drug Research Institute, Lucknow, India
| | | | - Radhika Singh
- Toxicology and Health Risk Assessment Division, CSIR-Indian Institute of Toxicology Research, Lucknow, India
| | - Md Sohail Akhtar
- Molecular and Structural Biology Division, CSIR-Central Drug Research Institute, Lucknow, India
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27
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Whitfield GB, Howell PL. The Matrix Revisited: Opening Night for the Pel Polysaccharide Across Eubacterial Kingdoms. Microbiol Insights 2021; 14:1178636120988588. [PMID: 33642867 PMCID: PMC7890745 DOI: 10.1177/1178636120988588] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2020] [Accepted: 12/16/2020] [Indexed: 01/29/2023] Open
Abstract
Bacteria synthesize and export adhesive macromolecules to enable biofilm formation. These macromolecules, collectively called the biofilm matrix, are structurally varied and often unique to specific bacterial species or subspecies. This heterogeneity in matrix utilization makes it difficult to facilitate direct comparison between biofilm formation mechanisms of different bacterial species. Despite this, some matrix components, in particular the polysaccharides poly-β-1,6-N-acetyl-glucosamine (PNAG) and bacterial cellulose, are utilized by many Gram-negative species for biofilm formation. However, there is a very narrow distribution of these components across Gram-positive organisms, whose biofilm matrix determinants remain largely undiscovered. We found that a genetic locus required for the production of a biofilm matrix component of P. aeruginosa, the Pel polysaccharide, is widespread in Gram-negative bacteria and that there is a variant form of this cluster present in many Gram-positive bacterial species. We demonstrated that this locus is required for biofilm formation by Bacillus cereus ATCC 10987, produces a polysaccharide that is similar to Pel, and is post-translationally regulated by cyclic-3′,5′-dimeric-guanosine monophosphate (c-di-GMP) in a manner identical to P. aeruginosa. However, while the proposed mechanism for Pel production appears remarkably similar between B. cereus and P. aeruginosa, we identified several key differences between Gram-negative and Gram-positive Pel biosynthetic components in other monoderms. In particular, 4 different architectural subtypes of the c-di-GMP-binding component PelD were identified, including 1 found only in Streptococci that has entirely lost the c-di-GMP recognition domain. These observations highlight how existing multi-component bacterial machines can be subtly tweaked to adapt to the unique physiology and regulatory mechanisms of Gram-positive organisms. Collectively, our analyses suggest that the Pel biosynthetic locus is one of the most phylogenetically widespread biofilm matrix determinants in bacteria, and that its mechanism of production and regulation is extraordinarily conserved across the majority of organisms that possess it.
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Affiliation(s)
- Gregory B Whitfield
- Program in Molecular Medicine, The Hospital for Sick Children, Toronto, ON, Canada.,Department of Biochemistry, University of Toronto, ON, Canada.,Département de Microbiologie, Infectiologie, et Immunologie, Université de Montréal, QC, Canada
| | - P Lynne Howell
- Program in Molecular Medicine, The Hospital for Sick Children, Toronto, ON, Canada.,Department of Biochemistry, University of Toronto, ON, Canada
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28
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Mai-Prochnow A, Zhou R, Zhang T, Ostrikov K(K, Mugunthan S, Rice SA, Cullen PJ. Interactions of plasma-activated water with biofilms: inactivation, dispersal effects and mechanisms of action. NPJ Biofilms Microbiomes 2021; 7:11. [PMID: 33504802 PMCID: PMC7841176 DOI: 10.1038/s41522-020-00180-6] [Citation(s) in RCA: 53] [Impact Index Per Article: 17.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2020] [Accepted: 12/11/2020] [Indexed: 01/30/2023] Open
Abstract
Biofilms have several characteristics that ensure their survival in a range of adverse environmental conditions, including high cell numbers, close cell proximity to allow easy genetic exchange (e.g., for resistance genes), cell communication and protection through the production of an exopolysaccharide matrix. Together, these characteristics make it difficult to kill undesirable biofilms, despite the many studies aimed at improving the removal of biofilms. An elimination method that is safe, easy to deliver in physically complex environments and not prone to microbial resistance is highly desired. Cold atmospheric plasma, a lightning-like state generated from air or other gases with a high voltage can be used to make plasma-activated water (PAW) that contains many active species and radicals that have antimicrobial activity. Recent studies have shown the potential for PAW to be used for biofilm elimination without causing the bacteria to develop significant resistance. However, the precise mode of action is still the subject of debate. This review discusses the formation of PAW generated species and their impacts on biofilms. A focus is placed on the diffusion of reactive species into biofilms, the formation of gradients and the resulting interaction with the biofilm matrix and specific biofilm components. Such an understanding will provide significant benefits for tackling the ubiquitous problem of biofilm contamination in food, water and medical areas.
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Affiliation(s)
- Anne Mai-Prochnow
- grid.1013.30000 0004 1936 834XSchool of Chemical and Biomolecular Engineering, The University of Sydney, Darlington, NSW 2006 Australia
| | - Renwu Zhou
- grid.1013.30000 0004 1936 834XSchool of Chemical and Biomolecular Engineering, The University of Sydney, Darlington, NSW 2006 Australia
| | - Tianqi Zhang
- grid.1013.30000 0004 1936 834XSchool of Chemical and Biomolecular Engineering, The University of Sydney, Darlington, NSW 2006 Australia
| | - Kostya (Ken) Ostrikov
- grid.1024.70000000089150953School of Chemistry and Physics, Queensland University of Technology, Brisbane, QLD 4000 Australia
| | - Sudarsan Mugunthan
- grid.59025.3b0000 0001 2224 0361The Singapore Centre for Environmental Life Sciences Engineering, Nanyang Technological University, Singapore, 639798 Singapore
| | - Scott A. Rice
- grid.59025.3b0000 0001 2224 0361The Singapore Centre for Environmental Life Sciences Engineering, Nanyang Technological University, Singapore, 639798 Singapore ,grid.59025.3b0000 0001 2224 0361The School of Biological Sciences, Nanyang Technological University, Singapore, 639798 Singapore ,grid.117476.20000 0004 1936 7611The ithree Institute, The University of Technology Sydney, Sydney, NSW 2007 Australia
| | - Patrick J. Cullen
- grid.1013.30000 0004 1936 834XSchool of Chemical and Biomolecular Engineering, The University of Sydney, Darlington, NSW 2006 Australia
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29
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Irmscher T, Roske Y, Gayk I, Dunsing V, Chiantia S, Heinemann U, Barbirz S. Pantoea stewartii WceF is a glycan biofilm-modifying enzyme with a bacteriophage tailspike-like fold. J Biol Chem 2021; 296:100286. [PMID: 33450228 PMCID: PMC7949094 DOI: 10.1016/j.jbc.2021.100286] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2020] [Revised: 12/22/2020] [Accepted: 01/11/2021] [Indexed: 11/19/2022] Open
Abstract
Pathogenic microorganisms often reside in glycan-based biofilms. Concentration and chain length distribution of these mostly anionic exopolysaccharides (EPS) determine the overall biophysical properties of a biofilm and result in a highly viscous environment. Bacterial communities regulate this biofilm state via intracellular small-molecule signaling to initiate EPS synthesis. Reorganization or degradation of this glycan matrix, however, requires the action of extracellular glycosidases. So far, these were mainly described for bacteriophages that must degrade biofilms for gaining access to host bacteria. The plant pathogen Pantoea stewartii (P. stewartii) encodes the protein WceF within its EPS synthesis cluster. WceF has homologs in various biofilm forming plant pathogens of the Erwinia family. In this work, we show that WceF is a glycosidase active on stewartan, the main P. stewartii EPS biofilm component. WceF has remarkable structural similarity with bacteriophage tailspike proteins (TSPs). Crystal structure analysis showed a native trimer of right-handed parallel β-helices. Despite its similar fold, WceF lacks the high stability found in bacteriophage TSPs. WceF is a stewartan hydrolase and produces oligosaccharides, corresponding to single stewartan repeat units. However, compared with a stewartan-specific glycan hydrolase of bacteriophage origin, WceF showed lectin-like autoagglutination with stewartan, resulting in notably slower EPS cleavage velocities. This emphasizes that the bacterial enzyme WceF has a role in P. stewartii biofilm glycan matrix reorganization clearly different from that of a bacteriophage exopolysaccharide depolymerase.
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Affiliation(s)
- Tobias Irmscher
- Physikalische Biochemie, Universität Potsdam, Potsdam, Germany; Department Theory and Bio-Systems, Max Planck Institute of Colloids and Interfaces, Potsdam, Germany
| | - Yvette Roske
- Crystallography, Max-Delbrück-Centrum für Molekulare Medizin, Berlin, Germany
| | - Igor Gayk
- Physikalische Biochemie, Universität Potsdam, Potsdam, Germany
| | - Valentin Dunsing
- Physikalische Zellbiochemie, Universität Potsdam, Potsdam, Germany
| | | | - Udo Heinemann
- Crystallography, Max-Delbrück-Centrum für Molekulare Medizin, Berlin, Germany; Institut für Chemie und Biochemie, Freie Universität, Berlin, Germany.
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30
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Wille J, Coenye T. Biofilm dispersion: The key to biofilm eradication or opening Pandora's box? Biofilm 2020; 2:100027. [PMID: 33447812 PMCID: PMC7798462 DOI: 10.1016/j.bioflm.2020.100027] [Citation(s) in RCA: 60] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2019] [Revised: 05/28/2020] [Accepted: 05/28/2020] [Indexed: 12/16/2022] Open
Abstract
Biofilms are extremely difficult to eradicate due to their decreased antibiotic susceptibility. Inducing biofilm dispersion could be a potential strategy to help combat biofilm-related infections. Mechanisms of biofilm dispersion can basically be divided into two groups, i.e. active and passive dispersion. Active dispersion depends on a decrease in the intracellular c-di-GMP levels, leading to the production of enzymes that degrade the biofilm matrix and promote dispersion. In contrast, passive dispersion relies on triggers that directly release cells from the biofilm. In the present review, several active and passive dispersion strategies are discussed. In addition, the disadvantages and possible consequences of using dispersion as a treatment approach for biofilm-related infections are also reviewed.
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Affiliation(s)
- Jasper Wille
- Laboratory of Pharmaceutical Microbiology, Ghent University, Ghent, Belgium
| | - Tom Coenye
- Laboratory of Pharmaceutical Microbiology, Ghent University, Ghent, Belgium
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31
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Abstract
The formation of microbial biofilms enables single planktonic cells to assume a multicellular mode of growth. During dispersion, the final step of the biofilm life cycle, single cells egress from the biofilm to resume a planktonic lifestyle. As the planktonic state is considered to be more vulnerable to antimicrobial agents and immune responses, dispersion is being considered a promising avenue for biofilm control. In this Review, we discuss conditions that lead to dispersion and the mechanisms by which native and environmental cues contribute to dispersion. We also explore recent findings on the role of matrix degradation in the dispersion process, and the distinct phenotype of dispersed cells. Last, we discuss the translational and therapeutic potential of dispersing bacteria during infection.
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Affiliation(s)
- Kendra P Rumbaugh
- Department of Surgery, Texas Tech University Health Sciences Center, Lubbock, TX, USA
- Department of Immunology and Molecular Microbiology, Texas Tech University Health Sciences Center, Lubbock, TX, USA
- Department of the TTUHSC Surgery Burn Center of Research Excellence, Texas Tech University Health Sciences Center, Lubbock, TX, USA
| | - Karin Sauer
- Department of Biological Sciences, Binghamton University, Binghamton, NY, USA.
- Binghamton Biofilm Research Center, Binghamton University, Binghamton, NY, USA.
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32
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Abstract
During chronic lung infections, Pseudomonas aeruginosa grows in highly antibiotic-tolerant communities called biofilms that are difficult for the host to clear. We have developed models for studying P. aeruginosa biofilm dispersal in environments that replicate key features of the airway. We found that mechanisms of biofilm dispersal in these models may employ alternative or additional signaling mechanisms, highlighting the importance of the growth environment in dispersal events. We have adapted the models to accommodate apical fluid flow, bacterial clinical isolates, antibiotics, and primary human airway epithelial cells, all of which are relevant to understanding bacterial behaviors in the context of human disease. We also examined dispersal agents in combination with commonly used antipseudomonal antibiotics and saw improved clearance when nitrite was combined with the antibiotic aztreonam. Pseudomonas aeruginosa grows in highly antibiotic-tolerant biofilms during chronic airway infections. Dispersal of bacteria from biofilms may restore antibiotic susceptibility or improve host clearance. We describe models to study biofilm dispersal in the nutritionally complex environment of the human airway. P. aeruginosa was cocultured in the apical surface of airway epithelial cells (AECs) in a perfusion chamber. Dispersal, triggered by sodium nitrite, a nitric oxide (NO) donor, was tracked by live cell microscopy. Next, a static model was developed in which biofilms were grown on polarized AECs without flow. We observed that NO-triggered biofilm dispersal was an energy-dependent process. From the existing literature, NO-mediated biofilm dispersal is regulated by DipA, NbdA, RbdA, and MucR. Interestingly, altered signaling pathways appear to be used in this model, as deletion of these genes failed to block NO-induced biofilm dispersal. Similar results were observed using biofilms grown in an abiotic model on glass with iron-supplemented cell culture medium. In cystic fibrosis, airway mucus contributes to the growth environment, and a wide range of bacterial phenotypes are observed; therefore, we tested biofilm dispersal in a panel of late cystic fibrosis clinical isolates cocultured in the mucus overlying primary human AECs. Finally, we examined dispersal in combination with the clinically used antibiotics ciprofloxacin, aztreonam and tobramycin. In summary, we have validated models to study biofilm dispersal in environments that recapitulate key features of the airway and identified combinations of currently used antibiotics that may enhance the therapeutic effect of biofilm dispersal. IMPORTANCE During chronic lung infections, Pseudomonas aeruginosa grows in highly antibiotic-tolerant communities called biofilms that are difficult for the host to clear. We have developed models for studying P. aeruginosa biofilm dispersal in environments that replicate key features of the airway. We found that mechanisms of biofilm dispersal in these models may employ alternative or additional signaling mechanisms, highlighting the importance of the growth environment in dispersal events. We have adapted the models to accommodate apical fluid flow, bacterial clinical isolates, antibiotics, and primary human airway epithelial cells, all of which are relevant to understanding bacterial behaviors in the context of human disease. We also examined dispersal agents in combination with commonly used antipseudomonal antibiotics and saw improved clearance when nitrite was combined with the antibiotic aztreonam.
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