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Harnessing ultrasound-stimulated phase change contrast agents to improve antibiotic efficacy against methicillin-resistant Staphylococcus aureus biofilms. Biofilm 2021; 3:100049. [PMID: 34124645 PMCID: PMC8173270 DOI: 10.1016/j.bioflm.2021.100049] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2020] [Revised: 04/27/2021] [Accepted: 04/28/2021] [Indexed: 12/17/2022] Open
Abstract
Bacterial biofilms, often associated with chronic infections, respond poorly to antibiotic therapy and frequently require surgical intervention. Biofilms harbor persister cells, metabolically indolent cells, which are tolerant to most conventional antibiotics. In addition, the biofilm matrix can act as a physical barrier, impeding diffusion of antibiotics. Novel therapeutic approaches frequently improve biofilm killing, but usually fail to achieve eradication. Failure to eradicate the biofilm leads to chronic and relapsing infection, is associated with major financial healthcare costs and significant morbidity and mortality. We address this problem with a two-pronged strategy using 1) antibiotics that target persister cells and 2) ultrasound-stimulated phase-change contrast agents (US-PCCA), which improve antibiotic penetration. We previously demonstrated that rhamnolipids, produced by Pseudomonas aeruginosa, could induce aminoglycoside uptake in gram-positive organisms, leading to persister cell death. We have also shown that US-PCCA can transiently disrupt biological barriers to improve penetration of therapeutic macromolecules. We hypothesized that combining antibiotics which target persister cells with US-PCCA to improve drug penetration could improve treatment of methicillin resistant S. aureus (MRSA) biofilms. Aminoglycosides alone or in combination with US-PCCA displayed limited efficacy against MRSA biofilms. In contrast, the anti-persister combination of rhamnolipids and aminoglycosides combined with US-PCCA dramatically improved biofilm killing. This novel treatment strategy has the potential for rapid clinical translation as the PCCA formulation is a variant of FDA-approved ultrasound contrast agents that are already in clinical practice and the low-pressure ultrasound settings used in our study can be achieved with existing ultrasound hardware at pressures below the FDA set limits for diagnostic imaging.
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152
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Luk CH, Valenzuela C, Gil M, Swistak L, Bomme P, Chang YY, Mallet A, Enninga J. Salmonella enters a dormant state within human epithelial cells for persistent infection. PLoS Pathog 2021; 17:e1009550. [PMID: 33930101 PMCID: PMC8115778 DOI: 10.1371/journal.ppat.1009550] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2020] [Revised: 05/12/2021] [Accepted: 04/08/2021] [Indexed: 02/06/2023] Open
Abstract
Salmonella Typhimurium (S. Typhimurium) is an enteric bacterium capable of invading a wide range of hosts, including rodents and humans. It targets different host cell types showing different intracellular lifestyles. S. Typhimurium colonizes different intracellular niches and is able to either actively divide at various rates or remain dormant to persist. A comprehensive tool to determine these distinct S. Typhimurium lifestyles remains lacking. Here we developed a novel fluorescent reporter, Salmonella INtracellular Analyzer (SINA), compatible for fluorescence microscopy and flow cytometry in single-bacterium level quantification. This identified a S. Typhimurium subpopulation in infected epithelial cells that exhibits a unique phenotype in comparison to the previously documented vacuolar or cytosolic S. Typhimurium. This subpopulation entered a dormant state in a vesicular compartment distinct from the conventional Salmonella-containing vacuoles (SCV) as well as the previously reported niche of dormant S. Typhimurium in macrophages. The dormant S. Typhimurium inside enterocytes were viable and expressed Salmonella Pathogenicity Island 2 (SPI-2) virulence factors at later time points. We found that the formation of these dormant S. Typhimurium is not triggered by the loss of SPI-2 effector secretion but it is regulated by (p)ppGpp-mediated stringent response through RelA and SpoT. We predict that intraepithelial dormant S. Typhimurium represents an important pathogen niche and provides an alternative strategy for S. Typhimurium pathogenicity and its persistence. Salmonella Typhimurium is a clinically relevant bacterial pathogen that causes Salmonellosis. It can actively or passively invade various host cell types and reside in a Salmonella-containing vacuole (SCV) within host cells. The SCV can be remodeled into a replicative niche with the aid of Salmonella Type III Secretion System 2 (T3SS2) effectors or else, the SCV is ruptured for the access of the nutrient-rich host cytosol. Depending on the infected host cell type, S. Typhimurium undertake different lifestyles that are distinct by their subcellular localization, replication rate and metabolic rate. We present here a novel fluorescent reporter system that rapidly detects S. Typhimurium lifestyles using fluorescence microscopy and flow cytometry. We identified a dormant S. Typhimurium population within enterocyte that displays capacities in host cell persistence, dormancy exit and antibiotic tolerance. We deciphered the (p)ppGpp stringent response pathway that suppresses S. Typhimurium dormancy in enterocytes while promoting dormancy in macrophages, pinpointing a divergent physiological consequence regulated by the same set of S. Typhimurium molecular mediators. Altogether, our work demonstrated the potential of fluorescent reporters in facile bacterial characterization, and revealed a dormant S. Typhimurium population in human enterocytes that are phenotypically distinct from that observed in macrophages and fibroblasts.
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Affiliation(s)
- Chak Hon Luk
- Dynamics of Host-Pathogen Interactions Unit and UMR3691 CNRS, Institut Pasteur, Paris, France
- Université de Paris, Sorbonne Paris Cité, Paris, France
| | - Camila Valenzuela
- Dynamics of Host-Pathogen Interactions Unit and UMR3691 CNRS, Institut Pasteur, Paris, France
| | - Magdalena Gil
- Dynamics of Host-Pathogen Interactions Unit and UMR3691 CNRS, Institut Pasteur, Paris, France
| | - Léa Swistak
- Dynamics of Host-Pathogen Interactions Unit and UMR3691 CNRS, Institut Pasteur, Paris, France
- Université de Paris, Sorbonne Paris Cité, Paris, France
| | - Perrine Bomme
- Ultrastructural Bioimaging UTechS, C2RT, Institut Pasteur, Paris, France
| | - Yuen-Yan Chang
- Dynamics of Host-Pathogen Interactions Unit and UMR3691 CNRS, Institut Pasteur, Paris, France
| | - Adeline Mallet
- Ultrastructural Bioimaging UTechS, C2RT, Institut Pasteur, Paris, France
| | - Jost Enninga
- Dynamics of Host-Pathogen Interactions Unit and UMR3691 CNRS, Institut Pasteur, Paris, France
- Université de Paris, Sorbonne Paris Cité, Paris, France
- * E-mail:
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153
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Khan F, Park SK, Bamunuarachchi NI, Oh D, Kim YM. Caffeine-loaded gold nanoparticles: antibiofilm and anti-persister activities against pathogenic bacteria. Appl Microbiol Biotechnol 2021; 105:3717-3731. [PMID: 33900427 DOI: 10.1007/s00253-021-11300-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2020] [Revised: 03/31/2021] [Accepted: 04/17/2021] [Indexed: 01/18/2023]
Abstract
The formation of biofilms by bacterial pathogens and the presence of persister cells in biofilms have become major concerns in the health sector, owing to their antibiotic resistance and tolerance. The transformation of bacterial pathogens into persister cells, either stochastically or due to stressful environmental factors, results in recalcitrant and recurring infections. Here, we sought to prepare gold nanoparticles from naturally occurring caffeine and explore their inhibitory action against biofilm formation and persister cells. Fourier transform infrared spectroscopy, UV-visible absorption spectroscopy, field emission transmission electron microscopy, energy-dispersive X-ray diffraction, and dynamic light scattering were used to characterize the gold nanoparticles obtained from caffeine (Caff-AuNPs). The Caff-AuNPs were found to exhibit a number of properties, including the ability to prevent biofilm formation, disperse mature biofilms, and kill different types of persister of gram-positive (Staphylococcus aureus and Listeria monocytogenes) and gram-negative (Pseudomonas aeruginosa and Escherichia coli) pathogenic bacteria. Microscopic analysis of the aforementioned bacterial cells, treated with Caff-AuNPs, revealed the bactericidal effect of Caff-AuNPs, although the underlying mechanism remains unknown. Collectively, the Caff-AuNPs synthesized in this study may be used as potential drugs to combat chronic infections caused by biofilm-forming pathogenic bacteria. KEY POINTS: • Biofilm and persister cells are clinically relevant, as they either prolong or completely resist antibiotic treatments. • Caffeine is used in the green synthesis of Caff-AuNPs, which have antibacterial and antibiofilm properties. • Caff-AuNPs are effective against various pathogenic bacterial persister cells.
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Affiliation(s)
- Fazlurrahman Khan
- Research Center for Marine Integrated Bionics Technology, Pukyong National University, Busan, 48513, South Korea
| | - Seul-Ki Park
- Institute of Food Science, Pukyong National University, Busan, 48513, South Korea
| | | | - DoKyung Oh
- Department of Food Science and Technology, Pukyong National University, Busan, 48513, South Korea
| | - Young-Mog Kim
- Research Center for Marine Integrated Bionics Technology, Pukyong National University, Busan, 48513, South Korea. .,Institute of Food Science, Pukyong National University, Busan, 48513, South Korea. .,Department of Food Science and Technology, Pukyong National University, Busan, 48513, South Korea.
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154
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Abstract
Introduction: As a result of progress in medical care, a huge number of medical devices are used in the treatment of human diseases. In turn, biofilm-related infection has become a growing threat due to the tolerance of biofilms to antimicrobials, a problem magnified by the development of antimicrobial resistance worldwide. As a result, successful treatment of biofilm-disease using only antimicrobials is problematic.Areas covered: We summarize some alternative approaches to classic antimicrobials for the treatment of biofilm disease. This review is not intended to be exhaustive but to give a clinical picture of alternatives to antimicrobial agents to manage biofilm disease. We highlight those strategies that may be closer to application in clinical practice.Expert opinion: There are a number of outstanding challenges in the development of novel antibiofilm therapies. Screening for effective antibiofilm compounds requires models relevant to all clinical scenarios. Although in vitro research of anti-biofilm strategies has progressed significantly over the past decade, there is a lack of in vivo research. In addition, the complexity of biofilm biology makes it difficult to develop a compound that is likely to provide the single 'magic bullet'. The multifaceted nature of biofilms imposes the need for multi-targeted or combinatorial therapies.
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Affiliation(s)
- Jose L Del Pozo
- Infectious Diseases Division, Clínica Universidad De Navarra, Pamplona, Spain.,Department of Microbiology, Clínica Universidad De Navarra, Pamplona, Spain.,Laboratory of Microbial Biofilms, Clínica Universidad De Navarra, Pamplona, Spain
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155
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Targeting Superoxide dismutase confers enhanced Reactive Oxygen Species mediated eradication of Polymyxin B induced Acinetobacter baumannii persisters. Antimicrob Agents Chemother 2021; 95:AAC.02180-20. [PMID: 33593839 PMCID: PMC8092903 DOI: 10.1128/aac.02180-20] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Bacterial persisters represent non-inheritable drug tolerant population that are linked to recalcitrance of infections in healthcare settings. The rise of antibiotic resistance and depletion of new antibiotics in drug discovery pipeline has made the task of persister eradication more daunting. In the present study, we report that treatment of Acinetobacter baumannii with the last resort antibiotic polymyxin B displays continuous variation in tolerance among different clinical isolates. Mechanistically, Polymyxin B persisters exhibit disruption of proton motive force led delocalisation of cell division protein to attain a growth arrested phenotype. Tolerance studies on mutant strains revealed that superoxide dismutase (sodB) activity is a major contributor in tolerance of A. baumannii to polymyxin B. Using a dual fluorescence based persister detection system, screening of various antibiotics was performed to eradicate polymyxin B induced persisters of A. baumannii Rifampicin exhibited eradication of polymyxin B tolerant population by log reduction of 6 in magnitude against different clinical isolates of A. baumannii We establish that enhanced generation of ROS by rifampicin leads to clearance of these polymyxin B persisters. It was further demonstrated, as a proof of concept, that rifampicin potentiates the killing of polymyxin B persisters in murine wound infection model. We found that the effects were linked to significant down regulation of sodB by rifampicin, which contributes to higher generation of ROS in polymyxin B tolerant cells. In view of these results, we propose that the combination of polymyxin B and rifampicin is an effective antipersister strategy in clearing polymyxin B induced A. baumannii persisters.
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156
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Pandey S, Sahukhal GS, Elasri MO. The msaABCR Operon Regulates Persister Formation by Modulating Energy Metabolism in Staphylococcus aureus. Front Microbiol 2021; 12:657753. [PMID: 33936014 PMCID: PMC8079656 DOI: 10.3389/fmicb.2021.657753] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2021] [Accepted: 03/26/2021] [Indexed: 11/24/2022] Open
Abstract
Staphylococcus aureus is a major human pathogen that causes chronic, systemic infections, and the recalcitrance of these infections is mainly due to the presence of persister cells, which are a bacterial subpopulation that exhibits extreme, yet transient, antibiotic tolerance accompanied by a transient halt in growth. However, upon cessation of antibiotic treatment, a resumption in growth of persister cells causes recurrence of infections and treatment failure. Previously, we reported the involvement of msaABCR in several important staphylococcal phenotypes, including the formation of persister cells. Additionally, observations of the regulation of several metabolic genes by the msaABCR operon in transcriptomics and proteomics analyses have suggested its role in the metabolic activities of S. aureus. Given the importance of metabolism in persister formation as our starting point, in this study we demonstrated how the msaABCR operon regulates energy metabolism and subsequent antibiotic tolerance. We showed that deletion of the msaABCR operon results in increased tricarboxylic acid (TCA) cycle activity, accompanied by increased cellular ATP content and higher NADH content in S. aureus cells. We also showed that msaABCR (through MsaB) represses the ccpE and ndh2 genes, thereby regulating TCA cycle activity and the generation of membrane potential, respectively. Together, the observations from this study led to the conclusion that msaABCR operon deletion induces a metabolically hyperactive state, leading to decreased persister formation in S. aureus.
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Affiliation(s)
- Shanti Pandey
- Center for Molecular and Cellular Biosciences, The University of Southern Mississippi, Hattiesburg, MS, United States
| | - Gyan S Sahukhal
- Center for Molecular and Cellular Biosciences, The University of Southern Mississippi, Hattiesburg, MS, United States
| | - Mohamed O Elasri
- Center for Molecular and Cellular Biosciences, The University of Southern Mississippi, Hattiesburg, MS, United States
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157
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Ecology and evolution of antimicrobial resistance in bacterial communities. THE ISME JOURNAL 2021; 15:939-948. [PMID: 33219299 PMCID: PMC8115348 DOI: 10.1038/s41396-020-00832-7] [Citation(s) in RCA: 110] [Impact Index Per Article: 36.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/17/2020] [Revised: 10/29/2020] [Accepted: 11/03/2020] [Indexed: 02/07/2023]
Abstract
Accumulating evidence suggests that the response of bacteria to antibiotics is significantly affected by the presence of other interacting microbes. These interactions are not typically accounted for when determining pathogen sensitivity to antibiotics. In this perspective, we argue that resistance and evolutionary responses to antibiotic treatments should not be considered only a trait of an individual bacteria species but also an emergent property of the microbial community in which pathogens are embedded. We outline how interspecies interactions can affect the responses of individual species and communities to antibiotic treatment, and how these responses could affect the strength of selection, potentially changing the trajectory of resistance evolution. Finally, we identify key areas of future research which will allow for a more complete understanding of antibiotic resistance in bacterial communities. We emphasise that acknowledging the ecological context, i.e. the interactions that occur between pathogens and within communities, could help the development of more efficient and effective antibiotic treatments.
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158
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Khan J, Tarar SM, Gul I, Nawaz U, Arshad M. Challenges of antibiotic resistance biofilms and potential combating strategies: a review. 3 Biotech 2021; 11:169. [PMID: 33816046 DOI: 10.1007/s13205-021-02707-w] [Citation(s) in RCA: 58] [Impact Index Per Article: 19.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2020] [Accepted: 02/23/2021] [Indexed: 02/07/2023] Open
Abstract
In this modern era, medicine is facing many alarming challenges. Among different challenges, antibiotics are gaining importance. Recent years have seen unprecedented increase in knowledge and understanding of various factors that are root cause of the spread and development of resistance in microbes against antibiotics. The infection results in the formation of microbial colonies which are termed as biofilms. However, it has been found that a multiple factors contribute in the formation of antimicrobial resistance. Due to higher dose of Minimum Bactericidal Concentration (MBC) as well as of Minimum Inhibitory Concentration (MIC), a large batch of antibiotics available today are of no use as they are ineffective against infections. Therefore, to control infections, there is dire need to adopt alternative treatment for biofilm infection other than antibiotics. This review highlights the latest techniques that are being used to cure the menace of biofilm infections. A wide range of mechanisms has been examined with particular attention towards avenues which can be proved fruitful in the treatment of biofilms. Besides, newer strategies, i.e., matrix centered are also discussed as alternative therapeutic techniques including modulating microbial metabolism, matrix degrading enzyme, photodynamic therapy, natural compounds quorum sensing and nanotechnology which are being used to disrupt extra polymeric substances (EPS) matrix of desired bacterial biofilms.
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Affiliation(s)
- Javairia Khan
- Institute of Environmental Sciences and Engineering, School of Civil and Environmental Engineering, National University of Sciences and Technology (NUST), Islamabad, Pakistan
| | - Sumbal Mudassar Tarar
- Institute of Environmental Sciences and Engineering, School of Civil and Environmental Engineering, National University of Sciences and Technology (NUST), Islamabad, Pakistan
| | - Iram Gul
- Department of Earth and Environmental Sciences, Hazara University, Mansehra, Pakistan
| | - Uzam Nawaz
- Department of Statistics, The Women University Multan, Multan, Pakistan
| | - Muhammad Arshad
- Institute of Environmental Sciences and Engineering, School of Civil and Environmental Engineering, National University of Sciences and Technology (NUST), Islamabad, Pakistan
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159
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Deter HS, Hossain T, Butzin NC. Antibiotic tolerance is associated with a broad and complex transcriptional response in E. coli. Sci Rep 2021; 11:6112. [PMID: 33731833 PMCID: PMC7969968 DOI: 10.1038/s41598-021-85509-7] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2020] [Accepted: 03/02/2021] [Indexed: 02/06/2023] Open
Abstract
Antibiotic treatment kills a large portion of a population, while a small, tolerant subpopulation survives. Tolerant bacteria disrupt antibiotic efficacy and increase the likelihood that a population gains antibiotic resistance, a growing health concern. We examined how E. coli transcriptional networks changed in response to lethal ampicillin concentrations. We are the first to apply transcriptional regulatory network (TRN) analysis to antibiotic tolerance by leveraging existing knowledge and our transcriptional data. TRN analysis shows that gene expression changes specific to ampicillin treatment are likely caused by specific sigma and transcription factors typically regulated by proteolysis. These results demonstrate that to survive lethal concentration of ampicillin specific regulatory proteins change activity and cause a coordinated transcriptional response that leverages multiple gene systems.
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Affiliation(s)
- Heather S Deter
- Department of Bioengineering, University of Illinois Urbana-Champaign, Urbana, IL, 61801, USA
| | - Tahmina Hossain
- Department of Biology and Microbiology, South Dakota State University, Brookings, SD, 57006, USA
| | - Nicholas C Butzin
- Department of Biology and Microbiology, South Dakota State University, Brookings, SD, 57006, USA.
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160
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Bezrukov F, Prados J, Renzoni A, Panasenko OO. MazF toxin causes alterations in Staphylococcus aureus transcriptome, translatome and proteome that underlie bacterial dormancy. Nucleic Acids Res 2021; 49:2085-2101. [PMID: 33544858 PMCID: PMC7913683 DOI: 10.1093/nar/gkaa1292] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2020] [Revised: 12/07/2020] [Accepted: 12/28/2020] [Indexed: 12/23/2022] Open
Abstract
Antibiotic resistance is a serious problem which may be caused by bacterial dormancy. It has been suggested that bacterial toxin-antitoxin systems induce dormancy. We analyzed the genome-wide role of Staphylococcus aureus endoribonuclease toxin MazF using RNA-Seq, Ribo-Seq and quantitative proteomics. We characterized changes in transcriptome, translatome and proteome caused by MazF, and proposed that MazF decreases translation directly by cleaving mRNAs, and indirectly, by decreasing translation factors and by promoting ribosome hibernation. Important pathways affected during the early stage of MazF induction were identified: MazF increases cell wall thickness and decreases cell division; MazF activates SsrA-system which rescues stalled ribosomes, appearing as a result of MazF mRNA cleavage. These pathways may be promising targets for new antibacterial drugs that prevent bacteria dormancy. Finally, we described the overall impact of MazF on S. aureus cell physiology, and propose one of the mechanisms by which MazF might regulate cellular changes leading to dormancy.
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Affiliation(s)
- Fedor Bezrukov
- Department of Physics and Astronomy, The University of Manchester, Manchester M13 9PL, UK
| | - Julien Prados
- Department of Microbiology and Molecular Medicine, Faculty of Medicine, University of Geneva, Geneva 1211, Switzerland
| | - Adriana Renzoni
- Department of Microbiology and Molecular Medicine, Faculty of Medicine, University of Geneva, Geneva 1211, Switzerland.,Division of Infectious Diseases, Department of Medicine, Geneva University Hospitals and Medical School, Geneva 1211, Switzerland
| | - Olesya O Panasenko
- Department of Microbiology and Molecular Medicine, Faculty of Medicine, University of Geneva, Geneva 1211, Switzerland
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161
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Furusawa G, Diyana T, Lau NS. Metabolic strategies of dormancy of a marine bacterium Microbulbifer aggregans CCB-MM1: Its alternative electron transfer chain and sulfate-reducing pathway. Genomics 2021; 114:443-455. [PMID: 33689784 DOI: 10.1016/j.ygeno.2021.02.024] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2020] [Revised: 01/26/2021] [Accepted: 02/28/2021] [Indexed: 12/26/2022]
Abstract
Bacterial dormancy plays a crucial role in maintaining the functioning and diversity of microbial communities in natural environments. However, the metabolic regulations of the dormancy of bacteria in natural habitats, especially marine habitats, have remained largely unknown. A marine bacterium, Microbulbifer aggregans CCB-MM1 exhibits rod-to-coccus cell shape change during the dormant state. Therefore, to clarify the metabolic regulation of the dormancy, differential gene expression analysis based on RNA-Seq was performed between rod- (vegetative), intermediate, and coccus-shaped cells (dormancy). The RNA-Seq data revealed that one of two distinct electron transfer chains was upregulated in the dormancy. Dissimilatory sulfite reductase and soluble hydrogenase were also highly upregulated in the dormancy. In addition, induction of the dormancy of MM1 in the absence of MgSO4 was slower than that in the presence of MgSO4. These results indicate that the sulfate-reducing pathway plays an important role in entering the dormancy of MM1.
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Affiliation(s)
- Go Furusawa
- Centre for Chemical Biology, Universiti Sains Malaysia, 10 Persiaran Bukit Jambul, 11900 Bayan Lepas, Penang, Malaysia.
| | - Tarmizi Diyana
- Centre for Chemical Biology, Universiti Sains Malaysia, 10 Persiaran Bukit Jambul, 11900 Bayan Lepas, Penang, Malaysia
| | - Nyok-Sean Lau
- Centre for Chemical Biology, Universiti Sains Malaysia, 10 Persiaran Bukit Jambul, 11900 Bayan Lepas, Penang, Malaysia
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162
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Sulaiman JE, Lam H. Evolution of Bacterial Tolerance Under Antibiotic Treatment and Its Implications on the Development of Resistance. Front Microbiol 2021; 12:617412. [PMID: 33717007 PMCID: PMC7952611 DOI: 10.3389/fmicb.2021.617412] [Citation(s) in RCA: 43] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2020] [Accepted: 02/12/2021] [Indexed: 01/08/2023] Open
Abstract
Recent laboratory evolution studies have shown that upon repetitive antibiotic treatments, bacterial populations will adapt and eventually became tolerant and resistant to the drug. Drug tolerance rapidly evolves upon frequent, intermittent antibiotic treatments, and such emerging drug tolerance seems to be specific to the treatment conditions, complicating clinical practice. Moreover, it has been shown that tolerance often promotes the development of resistance, which further reinforces the need of clinical diagnostics for antibiotic tolerance to reduce the occurrence of acquired resistance. Here, we discuss the laboratory evolution studies that were performed to track the development of tolerance in bacterial populations, and highlight the urgency of developing a comprehensive knowledge base of various tolerance phenotypes and their detection in clinics. Finally, we propose future directions for basic research in this growing field.
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Affiliation(s)
- Jordy Evan Sulaiman
- Department of Chemical and Biological Engineering, The Hong Kong University of Science and Technology, Kowloon, Hong Kong
| | - Henry Lam
- Department of Chemical and Biological Engineering, The Hong Kong University of Science and Technology, Kowloon, Hong Kong
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163
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Eckstein S, Brehm J, Seidel M, Lechtenfeld M, Heermann R. Two novel XRE-like transcriptional regulators control phenotypic heterogeneity in Photorhabdus luminescens cell populations. BMC Microbiol 2021; 21:63. [PMID: 33627070 PMCID: PMC7905540 DOI: 10.1186/s12866-021-02116-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2020] [Accepted: 01/25/2021] [Indexed: 01/11/2023] Open
Abstract
BACKGROUND The insect pathogenic bacterium Photorhabdus luminescens exists in two phenotypically different forms, designated as primary (1°) and secondary (2°) cells. Upon yet unknown environmental stimuli up to 50% of the 1° cells convert to 2° cells. Among others, one important difference between the phenotypic forms is that 2° cells are unable to live in symbiosis with their partner nematodes, and therefore are not able to re-associate with them. As 100% switching of 1° to 2° cells of the population would lead to a break-down of the bacteria's life cycle the switching process must be tightly controlled. However, the regulation mechanism of phenotypic switching is still puzzling. RESULTS Here we describe two novel XRE family transcriptional regulators, XreR1 and XreR2, that play a major role in the phenotypic switching process of P. luminescens. Deletion of xreR1 in 1° or xreR2 in 2° cells as well as insertion of extra copies of xreR1 into 2° or xreR2 into 1° cells, respectively, induced the opposite phenotype in either 1° or 2° cells. Furthermore, both regulators specifically bind to different promoter regions putatively fulfilling a positive autoregulation. We found initial evidence that XreR1 and XreR2 constitute an epigenetic switch, whereby XreR1 represses xreR2 expression and XreR2 self-reinforces its own gene by binding to XreR1. CONCLUSION Regulation of gene expression by the two novel XRE-type regulators XreR1 and XreR2 as well as their interplay represents a major regulatory process in phenotypic switching of P. luminescens. A fine-tuning balance between both regulators might therefore define the fate of single cells to convert from the 1° to the 2° phenotype.
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Affiliation(s)
- Simone Eckstein
- Johannes-Gutenberg-Universität Mainz, Institut für Molekulare Physiologie, Biozentrum II, Mikrobiologie und Weinforschung, Hanns-Dieter-Hüsch-Weg 17, 55128, Mainz, Germany.,Ludwig-Maximilians-Universität München, Biozentrum, Bereich Mikrobiologie, Martinsried, Germany
| | - Jannis Brehm
- Johannes-Gutenberg-Universität Mainz, Institut für Molekulare Physiologie, Biozentrum II, Mikrobiologie und Weinforschung, Hanns-Dieter-Hüsch-Weg 17, 55128, Mainz, Germany
| | - Michael Seidel
- Ludwig-Maximilians-Universität München, Biozentrum, Bereich Mikrobiologie, Martinsried, Germany
| | - Mats Lechtenfeld
- Johannes-Gutenberg-Universität Mainz, Institut für Molekulare Physiologie, Biozentrum II, Mikrobiologie und Weinforschung, Hanns-Dieter-Hüsch-Weg 17, 55128, Mainz, Germany
| | - Ralf Heermann
- Johannes-Gutenberg-Universität Mainz, Institut für Molekulare Physiologie, Biozentrum II, Mikrobiologie und Weinforschung, Hanns-Dieter-Hüsch-Weg 17, 55128, Mainz, Germany.
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164
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Topka-Bielecka G, Dydecka A, Necel A, Bloch S, Nejman-Faleńczyk B, Węgrzyn G, Węgrzyn A. Bacteriophage-Derived Depolymerases against Bacterial Biofilm. Antibiotics (Basel) 2021; 10:175. [PMID: 33578658 PMCID: PMC7916357 DOI: 10.3390/antibiotics10020175] [Citation(s) in RCA: 44] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2020] [Revised: 02/03/2021] [Accepted: 02/06/2021] [Indexed: 12/11/2022] Open
Abstract
In addition to specific antibiotic resistance, the formation of bacterial biofilm causes another level of complications in attempts to eradicate pathogenic or harmful bacteria, including difficult penetration of drugs through biofilm structures to bacterial cells, impairment of immunological response of the host, and accumulation of various bioactive compounds (enzymes and others) affecting host physiology and changing local pH values, which further influence various biological functions. In this review article, we provide an overview on the formation of bacterial biofilm and its properties, and then we focus on the possible use of phage-derived depolymerases to combat bacterial cells included in this complex structure. On the basis of the literature review, we conclude that, although these bacteriophage-encoded enzymes may be effective in destroying specific compounds involved in the formation of biofilm, they are rarely sufficient to eradicate all bacterial cells. Nevertheless, a combined therapy, employing depolymerases together with antibiotics and/or other antibacterial agents or factors, may provide an effective approach to treat infections caused by bacteria able to form biofilms.
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Affiliation(s)
- Gracja Topka-Bielecka
- Department of Molecular Biology, Faculty of Biology, University of Gdańsk, Wita Stwosza 59, 80-308 Gdańsk, Poland; (G.T.-B.); (A.D.); (A.N.); (B.N.-F.); (G.W.)
| | - Aleksandra Dydecka
- Department of Molecular Biology, Faculty of Biology, University of Gdańsk, Wita Stwosza 59, 80-308 Gdańsk, Poland; (G.T.-B.); (A.D.); (A.N.); (B.N.-F.); (G.W.)
| | - Agnieszka Necel
- Department of Molecular Biology, Faculty of Biology, University of Gdańsk, Wita Stwosza 59, 80-308 Gdańsk, Poland; (G.T.-B.); (A.D.); (A.N.); (B.N.-F.); (G.W.)
| | - Sylwia Bloch
- Laboratory of Phage Therapy, Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Kładki 24, 80-822 Gdańsk, Poland;
| | - Bożena Nejman-Faleńczyk
- Department of Molecular Biology, Faculty of Biology, University of Gdańsk, Wita Stwosza 59, 80-308 Gdańsk, Poland; (G.T.-B.); (A.D.); (A.N.); (B.N.-F.); (G.W.)
| | - Grzegorz Węgrzyn
- Department of Molecular Biology, Faculty of Biology, University of Gdańsk, Wita Stwosza 59, 80-308 Gdańsk, Poland; (G.T.-B.); (A.D.); (A.N.); (B.N.-F.); (G.W.)
| | - Alicja Węgrzyn
- Laboratory of Phage Therapy, Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Kładki 24, 80-822 Gdańsk, Poland;
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165
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Mao Q, Liu J, Wiertzema JR, Chen D, Chen P, Baumler DJ, Ruan R, Chen C. Identification of Quinone Degradation as a Triggering Event for Intense Pulsed Light-Elicited Metabolic Changes in Escherichia coli by Metabolomic Fingerprinting. Metabolites 2021; 11:metabo11020102. [PMID: 33578995 PMCID: PMC7916761 DOI: 10.3390/metabo11020102] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2021] [Revised: 02/04/2021] [Accepted: 02/09/2021] [Indexed: 11/26/2022] Open
Abstract
Intense pulsed light (IPL) is becoming a new technical platform for disinfecting food against pathogenic bacteria. Metabolic changes are deemed to occur in bacteria as either the causes or the consequences of IPL-elicited bactericidal and bacteriostatic effects. However, little is known about the influences of IPL on bacterial metabolome. In this study, the IPL treatment was applied to E. coli K-12 for 0–20 s, leading to time- and dose-dependent reductions in colony-forming units (CFU) and morphological changes. Both membrane lipids and cytoplasmic metabolites of the control and IPL-treated E. coli were examined by the liquid chromatography-mass spectrometry (LC-MS)-based metabolomic fingerprinting. The results from multivariate modeling and marker identification indicate that the metabolites in electron transport chain (ETC), redox response, glycolysis, amino acid, and nucleotide metabolism were selectively affected by the IPL treatments. The time courses and scales of these metabolic changes, together with the biochemical connections among them, revealed a cascade of events that might be initiated by the degradation of quinone electron carriers and then followed by oxidative stress, disruption of intermediary metabolism, nucleotide degradation, and morphological changes. Therefore, the degradations of membrane quinones, especially the rapid depletion of menaquinone-8 (MK-8), can be considered as a triggering event in the IPL-elicited metabolic changes in E. coli.
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Affiliation(s)
- Qingqing Mao
- Department of Food Science and Nutrition, University of Minnesota, 1334 Eckles Ave, Saint Paul, MN 55108, USA; (Q.M.); (J.L.); (J.R.W.); (D.C.); (D.J.B.)
| | - Juer Liu
- Department of Food Science and Nutrition, University of Minnesota, 1334 Eckles Ave, Saint Paul, MN 55108, USA; (Q.M.); (J.L.); (J.R.W.); (D.C.); (D.J.B.)
| | - Justin R. Wiertzema
- Department of Food Science and Nutrition, University of Minnesota, 1334 Eckles Ave, Saint Paul, MN 55108, USA; (Q.M.); (J.L.); (J.R.W.); (D.C.); (D.J.B.)
| | - Dongjie Chen
- Department of Food Science and Nutrition, University of Minnesota, 1334 Eckles Ave, Saint Paul, MN 55108, USA; (Q.M.); (J.L.); (J.R.W.); (D.C.); (D.J.B.)
| | - Paul Chen
- Department of Bioproducts and Biosystems Engineering, University of Minnesota, 1390 Eckles Ave., Saint Paul, MN 55108, USA; (P.C.); (R.R.)
| | - David J. Baumler
- Department of Food Science and Nutrition, University of Minnesota, 1334 Eckles Ave, Saint Paul, MN 55108, USA; (Q.M.); (J.L.); (J.R.W.); (D.C.); (D.J.B.)
| | - Roger Ruan
- Department of Bioproducts and Biosystems Engineering, University of Minnesota, 1390 Eckles Ave., Saint Paul, MN 55108, USA; (P.C.); (R.R.)
| | - Chi Chen
- Department of Food Science and Nutrition, University of Minnesota, 1334 Eckles Ave, Saint Paul, MN 55108, USA; (Q.M.); (J.L.); (J.R.W.); (D.C.); (D.J.B.)
- Correspondence: ; Tel.: +1-612-624-7704; Fax: +1-612-625-5272
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166
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Song S, Wood TK. Are we really studying persister cells? ENVIRONMENTAL MICROBIOLOGY REPORTS 2021; 13:3-7. [PMID: 32363793 DOI: 10.1111/1758-2229.12849] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Affiliation(s)
- Sooyeon Song
- Department of Animal Science, JeonBuk National University, Jeonju-si, Jeollabuk-do, 54896, Republic of Korea
| | - Thomas K Wood
- Department of Chemical Engineering, Pennsylvania State University, University Park, PA, 16802-4400, USA
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167
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Aslan H, Petersen ME, De Berardinis A, Zacho Brunhede M, Khan N, Vergara A, Kallipolitis B, Meyer RL. Activation of the Two-Component System LisRK Promotes Cell Adhesion and High Ampicillin Tolerance in Listeria monocytogenes. Front Microbiol 2021; 12:618174. [PMID: 33584621 PMCID: PMC7873292 DOI: 10.3389/fmicb.2021.618174] [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: 10/16/2020] [Accepted: 01/06/2021] [Indexed: 11/13/2022] Open
Abstract
Listeria monocytogenes is a foodborne pathogen which can survive in harsh environmental conditions. It responds to external stimuli through an array of two-component systems (TCS) that sense external cues. Several TCS, including LisRK, have been linked to Listeria’s ability to grow at slightly elevated antibiotic levels. The aim of this study was to determine if the TCS LisRK is also involved in acquiring the high antibiotic tolerance that is characteristic of persister cells. LisRK activates a response that leads to remodeling of the cell envelope, and we therefore hypothesized that activation of LisRK could also increase in the cells’ adhesiveness and initiate the first step in biofilm formation. We used a ΔlisR mutant to study antibiotic tolerance in the presence and absence of LisRK, and a GFP reporter strain to visualize the activation of LisRK in L. monocytogenes LO28 at a single-cell level. LisRK was activated in most cells in stationary phase cultures. Antimicrobial susceptibility tests showed that LisRK was required for the generation of ampicillin tolerance under these conditions. The wildtype strain tolerated exposure to ampicillin at 1,000 × inhibitory levels for 24 h, and the fraction of surviving cells was 20,000-fold higher in the wildtype strain compared to the ΔlisR mutant. The same protection was not offered to other antibiotics (vancomycin, gentamicin, tetracycline), and the mechanism for antibiotic tolerance is thus highly specific. Furthermore, quantification of bacterial attachment rates and attachment force also revealed that the absence of a functional LisRK rendered the cells less adhesive. Hence, LisRK TCS promotes multiple protective mechanisms simultaneously.
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Affiliation(s)
- Hüsnü Aslan
- Faculty of Natural Sciences, Interdisciplinary Nanoscience Center, Aarhus University, Aarhus, Denmark
| | | | | | - Maja Zacho Brunhede
- Faculty of Natural Sciences, Interdisciplinary Nanoscience Center, Aarhus University, Aarhus, Denmark
| | - Nasar Khan
- Faculty of Natural Sciences, Interdisciplinary Nanoscience Center, Aarhus University, Aarhus, Denmark
| | - Alberto Vergara
- Faculty of Veterinary Medicine, University of Teramo, Teramo, Italy
| | - Birgitte Kallipolitis
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, Odense, Denmark
| | - Rikke Louise Meyer
- Faculty of Natural Sciences, Interdisciplinary Nanoscience Center, Aarhus University, Aarhus, Denmark.,Department of Biology, Faculty of Natural Sciences, Aarhus University, Aarhus, Denmark
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168
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Gao R, Liao X, Zhao X, Liu D, Ding T. The diagnostic tools for viable but nonculturable pathogens in the food industry: Current status and future prospects. Compr Rev Food Sci Food Saf 2021; 20:2146-2175. [PMID: 33484068 DOI: 10.1111/1541-4337.12695] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2020] [Revised: 12/21/2020] [Accepted: 12/28/2020] [Indexed: 12/21/2022]
Abstract
Viable but nonculturable (VBNC) microorganisms have been recognized as pathogenic contaminants in foods and environments. The failure of VBNC cells to form the visible colonies hinders the ability to use conventional media for their detection. Efficient and rapid detection of pathogens in the VBNC state is a prerequisite to ensure the food safety and public health. Despite their nonculturability, VBNC cells have distinct characteristics, such as morphology, metabolism, chemical composition, and gene and protein expression, that have been used as the basis for the development of abundant diagnostic tools. This review covers the current status and advances in various approaches for examining microorganisms in the VBNC state, including but not limited to the methodological aspects, advantages, and drawbacks of each technique. Existing methods, such as direct viable count, SYTO/PI dual staining, and propidium monoazide quantitative polymerase chain reaction (PCR), as well as some techniques with potential to be applied in the future, such as digital PCR, enhanced-surface Raman spectroscopy, and impedance-based techniques, are summarized in depth. Finally, future prospects for the one-step detection of VBNC bacteria are proposed and discussed. We believe that this review can provide more optional methods for researchers and promote the development of rapid, accurate detecting methods, and for inspectors, the diagnostic tools can provide data to undertake risk analysis of VBNC cells.
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Affiliation(s)
- Rui Gao
- Key Laboratory for Agro-Products Postharvest Handling of Ministry of Agriculture, Zhejiang Key Laboratory for Agro-Food Processing, Department of Food Science and Nutrition, Zhejiang University, Hangzhou, Zhejiang, China
| | - Xinyu Liao
- Key Laboratory for Agro-Products Postharvest Handling of Ministry of Agriculture, Zhejiang Key Laboratory for Agro-Food Processing, Department of Food Science and Nutrition, Zhejiang University, Hangzhou, Zhejiang, China
| | - Xihong Zhao
- Research Center for Environmental Ecology and Engineering, Key Laboratory for Green Chemical Process of Ministry of Education, Hubei Key Laboratory of Novel Reactor and Green Chemical Technology, School of Environmental Ecology and Biological Engineering, Wuhan Institute of Technology, Wuhan, China
| | - Donghong Liu
- Key Laboratory for Agro-Products Postharvest Handling of Ministry of Agriculture, Zhejiang Key Laboratory for Agro-Food Processing, Department of Food Science and Nutrition, Zhejiang University, Hangzhou, Zhejiang, China
| | - Tian Ding
- Key Laboratory for Agro-Products Postharvest Handling of Ministry of Agriculture, Zhejiang Key Laboratory for Agro-Food Processing, Department of Food Science and Nutrition, Zhejiang University, Hangzhou, Zhejiang, China
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169
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Smith OJ, Wicaksana A, Davidson D, Spratt D, Mosahebi A. An evaluation of the bacteriostatic effect of platelet-rich plasma. Int Wound J 2021; 18:448-456. [PMID: 33476481 PMCID: PMC8273594 DOI: 10.1111/iwj.13545] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2020] [Revised: 12/13/2020] [Accepted: 12/18/2020] [Indexed: 12/01/2022] Open
Abstract
Chronic wounds are a considerable health burden with high morbidity and poor rates of healing. Colonisation of chronic wounds by bacteria can be a significant factor in their poor healing rate. These bacteria can develop antibiotic resistance over time and can lead to wound infections, systemic illness, and occasionally amputation. When a large number of micro-organisms colonise wounds, they can lead to biofilm formation, which are self-perpetuating colonies of bacteria closed within an extracellular matrix, which are poorly penetrated by antibiotics. Platelet-rich plasma (PRP) is an autologous blood product rich in growth factors and cytokines that are involved in an inflammatory response. PRP can be injected or applied to a wound as a topical gel, and there is some interest regarding its antimicrobial properties and whether this can improve wound healing. This study aimed to evaluate the in vitro bacteriostatic effect of PRP. PRP was collected from healthy volunteers and processed into two preparations: activated PRP-activated with calcium chloride and ethanol; inactivated PRP. The activity of each preparation against Staphylococcus aureus and Staphylococcus epidermis was evaluated against a control by three experiments: bacterial kill assay to assess planktonic bacterial growth; plate colony assay to assess bacterial colony growth; and colony biofilm assay to assess biofilm growth. Compared with control, both preparations of PRP significantly inhibited growth of planktonic S aureus and S epidermis. Activated PRP reduced planktonic bacterial concentration more than inactivated PRP in both bacteria. Both PRP preparations significantly reduced bacterial colony counts for both bacteria when compared with control; however, there was no difference between the two. There was no difference found between biofilm growth in either PRP against control or against the other preparation. This study demonstrates that PRP does have an inhibitory effect on the growth of common wound pathogens. Activation may be an important factor in increasing the antimicrobial effect of PRP. However, we did not find evidence of an effect against more complex bacterial colonies.
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Affiliation(s)
- Oliver J Smith
- Department of Plastic Surgery, Royal Free Hospital, London, UK.,Division of Surgery and Interventional Science, University College London, London, UK
| | - Aditya Wicaksana
- Division of Surgery and Interventional Science, University College London, London, UK.,Division of Plastic Surgery, Faculty of Medicine Universitas Indonesia/Dr. Cipto Mangunkusumo National Hospital, Jakarta, Indonesia
| | - Donald Davidson
- Microbial Diseases, Eastman Dental Institute, Faculty of Medical Sciences, University College London, London, UK
| | - David Spratt
- Microbial Diseases, Eastman Dental Institute, Faculty of Medical Sciences, University College London, London, UK
| | - Ash Mosahebi
- Department of Plastic Surgery, Royal Free Hospital, London, UK.,Division of Surgery and Interventional Science, University College London, London, UK
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170
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Eisenreich W, Rudel T, Heesemann J, Goebel W. Persistence of Intracellular Bacterial Pathogens-With a Focus on the Metabolic Perspective. Front Cell Infect Microbiol 2021; 10:615450. [PMID: 33520740 PMCID: PMC7841308 DOI: 10.3389/fcimb.2020.615450] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2020] [Accepted: 11/30/2020] [Indexed: 12/19/2022] Open
Abstract
Persistence has evolved as a potent survival strategy to overcome adverse environmental conditions. This capability is common to almost all bacteria, including all human bacterial pathogens and likely connected to chronic infections caused by some of these pathogens. Although the majority of a bacterial cell population will be killed by the particular stressors, like antibiotics, oxygen and nitrogen radicals, nutrient starvation and others, a varying subpopulation (termed persisters) will withstand the stress situation and will be able to revive once the stress is removed. Several factors and pathways have been identified in the past that apparently favor the formation of persistence, such as various toxin/antitoxin modules or stringent response together with the alarmone (p)ppGpp. However, persistence can occur stochastically in few cells even of stress-free bacterial populations. Growth of these cells could then be induced by the stress conditions. In this review, we focus on the persister formation of human intracellular bacterial pathogens, some of which belong to the most successful persister producers but lack some or even all of the assumed persistence-triggering factors and pathways. We propose a mechanism for the persister formation of these bacterial pathogens which is based on their specific intracellular bipartite metabolism. We postulate that this mode of metabolism ultimately leads, under certain starvation conditions, to the stalling of DNA replication initiation which may be causative for the persister state.
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Affiliation(s)
- Wolfgang Eisenreich
- Department of Chemistry, Chair of Biochemistry, Technische Universität München, Garching, Germany
| | - Thomas Rudel
- Chair of Microbiology, Biocenter, University of Würzburg, Würzburg, Germany
| | - Jürgen Heesemann
- Max von Pettenkofer-Institute, Ludwig Maximilian University of Munich, München, Germany
| | - Werner Goebel
- Max von Pettenkofer-Institute, Ludwig Maximilian University of Munich, München, Germany
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171
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Yu K, Rodriguez M, Paul Z, Gordon E, Gu T, Rice K, Triplett EW, Keller-Wood M, Wood CE. Transfer of oral bacteria to the fetus during late gestation. Sci Rep 2021; 11:708. [PMID: 33436911 PMCID: PMC7804304 DOI: 10.1038/s41598-020-80653-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2020] [Accepted: 12/21/2020] [Indexed: 12/13/2022] Open
Abstract
The fetus develops in a privileged environment, as the placenta serves as both a gateway for nutrients and a barrier for pathogen transfer to the fetus. Regardless, recent evidence suggests the presence of bacterial DNA in both placenta and fetus, and we have reported that DNA and protein from small numbers of bacteria gain access to the fetus from the maternal bloodstream. Other routes of environmental bacterial transfer from the mother to fetus remain unknown, as well as the physiological relevance of their presence. In these experiments, we examine multiple routes by which bacterial cellular components can enter the fetus and the fetal response to influx of bacterial DNA and protein. We inoculated maternal sheep with genetically-labeled S. aureus (Staphylococcus aureus) using three routes: intravenously, orally, and intra-vaginally. The inoculum did not produce sepsis or fever in the ewes, therefore mimicking incidental exposure to bacteria during pregnancy. 3-5 days post inoculation, we assessed the presence of bacterial components in the fetal tissues and analyzed fetal brain tissue to identify any alterations in gene expression. Our results demonstrate that components of bacteria that were introduced into the maternal mouth were detected in the fetal brain and that they stimulated changes in gene expression. We conclude that an oral route of transmission is relevant for transfer of bacterial cellular components to the fetus.
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Affiliation(s)
- Kevin Yu
- Department of Physiology and Functional Genomics, University of Florida College of Medicine, 1345 Center Drive, Room M552, Gainesville, FL, 32610, USA
| | - Michelle Rodriguez
- Department of Microbiology and Cell Science, University of Florida Institute of Food and Agricultural Sciences, Gainesville, USA
| | - Zubin Paul
- Department of Physiology and Functional Genomics, University of Florida College of Medicine, 1345 Center Drive, Room M552, Gainesville, FL, 32610, USA
| | - Elizabeth Gordon
- Department of Physiology and Functional Genomics, University of Florida College of Medicine, 1345 Center Drive, Room M552, Gainesville, FL, 32610, USA
| | - Tongjun Gu
- Interdisciplinary Center for Biotechnology Research, University of Florida, Gainesville, USA
| | - Kelly Rice
- Department of Microbiology and Cell Science, University of Florida Institute of Food and Agricultural Sciences, Gainesville, USA
| | - Eric W Triplett
- Department of Microbiology and Cell Science, University of Florida Institute of Food and Agricultural Sciences, Gainesville, USA
| | - Maureen Keller-Wood
- Department of Pharmacodynamics, University of Florida College of Pharmacy, Gainesville, USA
| | - Charles E Wood
- Department of Physiology and Functional Genomics, University of Florida College of Medicine, 1345 Center Drive, Room M552, Gainesville, FL, 32610, USA.
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172
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Siddam AD, Zaslow SJ, Wang Y, Phillips KS, Silverman MD, Regan PM, Amarasinghe JJ. Characterization of Biofilm Formation by Mycobacterium chimaera on Medical Device Materials. Front Microbiol 2021; 11:586657. [PMID: 33505365 PMCID: PMC7829485 DOI: 10.3389/fmicb.2020.586657] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2020] [Accepted: 11/13/2020] [Indexed: 12/15/2022] Open
Abstract
Non-tuberculous mycobacteria (NTM) are widespread in the environment and are a public health concern due to their resistance to antimicrobial agents. The colonization of surgical heater-cooler devices (HCDs) by the slow-growing NTM species Mycobacterium chimaera has recently been linked to multiple invasive infections in patients worldwide. The resistance of M. chimaera to antimicrobials may be aided by a protective biofilm matrix of extracellular polymeric substances (EPS). This study explored the hypothesis that M. chimaera can form biofilms on medically relevant materials. Several M. chimaera strains, including two HCD isolates, were used to inoculate a panel of medical device materials. M. chimaera colonization of the surfaces was monitored for 6 weeks. M. chimaera formed a robust biofilm at the air-liquid interface of borosilicate glass tubes, which increased in mass over time. M. chimaera was observed by 3D Laser Scanning Microscopy to have motility during colonization, and form biofilms on stainless steel, titanium, silicone and polystyrene surfaces during the first week of inoculation. Scanning electron microscopy (SEM) of M. chimaera biofilms after 4 weeks of inoculation showed that M. chimaera cells were enclosed entirely in extracellular material, while cryo-preserved SEM samples further revealed that an ultrastructural component of the EPS matrix was a tangled mesh of 3D fiber-like projections connecting cells. Considering that slow-growing M. chimaera typically has culture times on the order of weeks, the microscopically observed ability to rapidly colonize stainless steel and titanium surfaces in as little as 24 h after inoculation is uncharacteristic. The insights that this study provides into M. chimaera colonization and biofilm formation of medical device materials are a significant advance in our fundamental understanding of M. chimaera surface interactions and have important implications for research into novel antimicrobial materials, designs and other approaches to help reduce the risk of infection.
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Affiliation(s)
- Archana D Siddam
- Winchester Engineering and Analytical Center, United States Food and Drug Administration, Winchester, MA, United States
| | - Shari J Zaslow
- Winchester Engineering and Analytical Center, United States Food and Drug Administration, Winchester, MA, United States
| | - Yi Wang
- Center for Devices and Radiological Health, Food and Drug Administration, Silver Spring, MD, United States
| | - K Scott Phillips
- Center for Devices and Radiological Health, Food and Drug Administration, Silver Spring, MD, United States
| | - Matthew D Silverman
- Winchester Engineering and Analytical Center, United States Food and Drug Administration, Winchester, MA, United States
| | - Patrick M Regan
- Winchester Engineering and Analytical Center, United States Food and Drug Administration, Winchester, MA, United States
| | - Jayaleka J Amarasinghe
- Winchester Engineering and Analytical Center, United States Food and Drug Administration, Winchester, MA, United States
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173
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Seyler TM, Moore C, Kim H, Ramachandran S, Agris PF. A New Promising Anti-Infective Agent Inhibits Biofilm Growth by Targeting Simultaneously a Conserved RNA Function That Controls Multiple Genes. Antibiotics (Basel) 2021; 10:41. [PMID: 33406640 PMCID: PMC7824582 DOI: 10.3390/antibiotics10010041] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2020] [Revised: 12/22/2020] [Accepted: 12/28/2020] [Indexed: 12/11/2022] Open
Abstract
Combating single and multi-drug-resistant infections in the form of biofilms is an immediate challenge. The challenge is to discover innovative targets and develop novel chemistries that combat biofilms and drug-resistant organisms, and thwart emergence of future resistant strains. An ideal novel target would control multiple genes, and can be inhibited by a single compound. We previously demonstrated success against Staphylococcus aureus biofilms by targeting the tRNA-dependent regulated T-box genes, not present in the human host. Present in Gram-positive bacteria, T-box genes attenuate transcription with a riboswitch-like element that regulates the expression of aminoacyl-tRNA synthetases and amino acid metabolism genes required for cell viability. PKZ18, the parent of a family of compounds selected in silico from 305,000 molecules, inhibits the function of the conserved T-box regulatory element and thus blocks growth of antibiotic-resistant S. aureus in biofilms. The PKZ18 analog PKZ18-22 was 10-fold more potent than vancomycin in inhibiting growth of S. aureus in biofilms. In addition, PKZ18-22 has a synergistic effect with existing antibiotics, e.g., gentamicin and rifampin. PKZ18-22 inhibits the T-box regulatory mechanism, halts the transcription of vital genes, and results in cell death. These effects are independent of the growth state, planktonic or biofilm, of the bacteria, and could inhibit emergent strains.
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Affiliation(s)
- Thorsten M. Seyler
- Department of Orthopaedic Surgery, Duke University School of Medicine, Durham, NC 277010, USA;
| | - Christina Moore
- Department of Orthopaedic Surgery, Duke University School of Medicine, Durham, NC 277010, USA;
| | - Haein Kim
- Department of Medicine, Duke University School of Medicine, Durham, NC 27710, USA; (H.K.); (S.R.)
| | - Sheetal Ramachandran
- Department of Medicine, Duke University School of Medicine, Durham, NC 27710, USA; (H.K.); (S.R.)
| | - Paul F. Agris
- Department of Medicine, Duke University School of Medicine, Durham, NC 27710, USA; (H.K.); (S.R.)
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174
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Sathyamoorthy R, Kushmaro Y, Rotem O, Matan O, Kadouri DE, Huppert A, Jurkevitch E. To hunt or to rest: prey depletion induces a novel starvation survival strategy in bacterial predators. THE ISME JOURNAL 2021; 15:109-123. [PMID: 32884113 PMCID: PMC7852544 DOI: 10.1038/s41396-020-00764-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/16/2020] [Revised: 08/12/2020] [Accepted: 08/25/2020] [Indexed: 02/06/2023]
Abstract
The small size of bacterial cells necessitates rapid adaption to sudden environmental changes. In Bdellovibrio bacteriovorus, an obligate predator of bacteria common in oligotrophic environments, the non-replicative, highly motile attack phase (AP) cell must invade a prey to ensure replication. AP cells swim fast and respire at high rates, rapidly consuming their own contents. How the predator survives in the absence of prey is unknown. We show that starvation for prey significantly alters swimming patterns and causes exponential decay in prey-searching cells over hours, until population-wide swim-arrest. Swim-arrest is accompanied by changes in energy metabolism, enabling rapid swim-reactivation upon introduction of prey or nutrients, and a sweeping change in gene expression and gene regulation that largely differs from those of the paradigmatic stationary phase. Swim-arrest is costly as it imposes a fitness penalty in the form of delayed growth. We track the control of the swim arrest-reactivation process to cyclic-di-GMP (CdG) effectors, including two motility brakes. CRISPRi transcriptional inactivation, and in situ localization of the brakes to the cell pole, demonstrated their essential role for effective survival under prey-induced starvation. Thus, obligate predators evolved a unique CdG-controlled survival strategy, enabling them to sustain their uncommon lifestyle under fluctuating prey supply.
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Affiliation(s)
- Rajesh Sathyamoorthy
- Department of Plant Pathology and Microbiology, Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, 76100, Rehovot, Israel
| | - Yuval Kushmaro
- Department of Plant Pathology and Microbiology, Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, 76100, Rehovot, Israel
| | - Or Rotem
- Department of Plant Pathology and Microbiology, Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, 76100, Rehovot, Israel
- Seed-x., Magshimim, Israel
| | - Ofra Matan
- Department of Plant Pathology and Microbiology, Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, 76100, Rehovot, Israel
| | - Daniel E Kadouri
- Department of Oral Biology, Rutgers School of Dental Medicine, Newark, NJ, USA
| | - Amit Huppert
- Bio-statistical Unit, The Gertner Institute for Epidemiology and Health Policy Research, Chaim Sheba Medical Center, Tel Hashomer, Israel
| | - Edouard Jurkevitch
- Department of Plant Pathology and Microbiology, Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, 76100, Rehovot, Israel.
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175
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Manoharan RK, Gangadaran P, Ayyaru S, Ahn BC, Ahn YH. Self-healing functionalization of sulfonated hafnium oxide and copper oxide nanocomposite for effective biocidal control of multidrug-resistant bacteria. NEW J CHEM 2021. [DOI: 10.1039/d1nj00323b] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
The combination of copper and sulfonated hafnium oxide nanoparticles could be used as an alternative antimicrobial agent to combat multidrug resistant bacteria and membrane biofouling.
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Affiliation(s)
| | - Prakash Gangadaran
- Department of Nuclear Medicine
- School of Medicine
- Kyungpook National University
- Kyungpook National University Hospital
- Daegu
| | - Sivasankaran Ayyaru
- Department of Civil Engineering
- Yeungnam University
- Gyeongsan
- Republic of Korea
| | - Byeong-Cheol Ahn
- Department of Nuclear Medicine
- School of Medicine
- Kyungpook National University
- Kyungpook National University Hospital
- Daegu
| | - Young-Ho Ahn
- Department of Civil Engineering
- Yeungnam University
- Gyeongsan
- Republic of Korea
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176
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Acinetobacter baumannii Targets Human Carcinoembryonic Antigen-Related Cell Adhesion Molecules (CEACAMs) for Invasion of Pneumocytes. mSystems 2020; 5:5/6/e00604-20. [PMID: 33361319 PMCID: PMC7762790 DOI: 10.1128/msystems.00604-20] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Multidrug-resistant Acinetobacter baumannii is regarded as a life-threatening pathogen mainly associated with nosocomial and community-acquired pneumonia. Here, we show that A. baumannii can bind the human carcinoembryonic antigen-related cell adhesion molecule (CEACAM) receptors CEACAM1, CEACAM5, and CEACAM6. This specific interaction enhances A. baumannii internalization in membrane-bound vacuoles, promptly decorated with Rab5, Rab7, and lipidated microtubule-associated protein light chain 3 (LC3). Dissecting intracellular signaling pathways revealed that infected pneumocytes trigger interleukin-8 (IL-8) secretion via the extracellular signal-regulated kinase (ERK)1/2 and nuclear factor-kappa B (NF-κB) signaling pathways for A. baumannii clearance. However, in CEACAM1-L-expressing cells, IL-8 secretion lasts only 24 h, possibly due to an A. baumannii-dependent effect on the CEACAM1-L intracellular domain. Conversely, the glycosylphosphatidylinositol-anchored CEACAM5 and CEACAM6 activate the c-Jun NH2-terminal kinase (JNK)1/2-Rubicon-NOX2 pathway, suggestive of LC3-associated phagocytosis. Overall, our data show for the first time novel mechanisms of adhesion to and invasion of pneumocytes by A. baumannii via CEACAM-dependent signaling pathways that eventually lead to bacterial killing. These findings suggest that CEACAM upregulation could put patients at increased risk of lower respiratory tract infection by A. baumannii IMPORTANCE This work shows for the first time that Acinetobacter baumannii binds to carcinoembryonic antigen-related cell adhesion molecule 1 (CEACAM1), CEACAM5, and CEACAM6. This binding significantly enhances A. baumannii internalization within alveolar host cell epithelia. Intracellular trafficking involves typical Rab5 and Rab7 vacuolar proteins as well as light chain 3 (LC3) and slowly progresses to bacterial killing by endosome acidification. CEACAM engagement by A. baumannii leads to distinct and specific downstream signaling pathways. The CEACAM1 pathway finely tunes interleukin-8 (IL-8) secretion, whereas CEACAM5 and CEACAM6 mediate LC3-associated phagocytosis. The present study provides new insights into A. baumannii-host interactions and could represent a promising therapeutic strategy to reduce pulmonary infections caused by this pathogen.
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177
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The Diverse Roles of the Global Transcriptional Regulator PhoP in the Lifecycle of Yersinia pestis. Pathogens 2020; 9:pathogens9121039. [PMID: 33322274 PMCID: PMC7764729 DOI: 10.3390/pathogens9121039] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2020] [Revised: 11/30/2020] [Accepted: 12/04/2020] [Indexed: 11/18/2022] Open
Abstract
Yersinia pestis, the causative agent of plague, has a complex infectious cycle that alternates between mammalian hosts (rodents and humans) and insect vectors (fleas). Consequently, it must adapt to a wide range of host environments to achieve successful propagation. Y. pestis PhoP is a response regulator of the PhoP/PhoQ two-component signal transduction system that plays a critical role in the pathogen’s adaptation to hostile conditions. PhoP is activated in response to various host-associated stress signals detected by the sensor kinase PhoQ and mediates changes in global gene expression profiles that lead to cellular responses. Y. pestis PhoP is required for resistance to antimicrobial peptides, as well as growth under low Mg2+ and other stress conditions, and controls a number of metabolic pathways, including an alternate carbon catabolism. Loss of phoP function in Y. pestis causes severe defects in survival inside mammalian macrophages and neutrophils in vitro, and a mild attenuation in murine plague models in vivo, suggesting its role in pathogenesis. A Y. pestisphoP mutant also exhibits reduced ability to form biofilm and to block fleas in vivo, indicating that the gene is also important for establishing a transmissible infection in this vector. Additionally, phoP promotes the survival of Y. pestis inside the soil-dwelling amoeba Acanthamoeba castellanii, a potential reservoir while the pathogen is quiescent. In this review, we summarize our current knowledge on the mechanisms of PhoP-mediated gene regulation in Y. pestis and examine the significance of the roles played by the PhoP regulon at each stage of the Y. pestis life cycle.
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178
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Lau WK, Dharmasena D, Horsley H, Jafari NV, Malone-Lee J, Stride E, Edirisinghe M, Rohn JL. Novel antibiotic-loaded particles conferring eradication of deep tissue bacterial reservoirs for the treatment of chronic urinary tract infection. J Control Release 2020; 328:490-502. [PMID: 32882271 DOI: 10.1016/j.jconrel.2020.08.048] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2020] [Revised: 07/09/2020] [Accepted: 08/24/2020] [Indexed: 11/24/2022]
Abstract
A significant proportion of urinary tract infection (UTI) patients experience recurrent episodes, due to deep tissue infection and treatment-resistant bacterial reservoirs. Direct bladder instillation of antibiotics has proved disappointing in treating UTI, likely due to the failure of infused antibiotics to penetrate the bladder epithelium and accumulate to high enough levels to kill intracellular bacteria. This work investigates the use of nitrofurantoin loaded poly(lactic-co-glycolic acid) (PLGA) particles to improve delivery to intracellular targets for the treatment of chronic UTI. Using electrohydrodynamic atomisation, we produced particles with an average diameter of 2.8 μm. In broth culture experiments, the biodegradable particles were effective against a number of UTI-relevant bacterial strains. Dye-loaded particles demonstrated that intracellular delivery was achieved in all cells in 2D cultures of a human bladder epithelial progenitor cell line in a dose-dependent manner, achieving far higher efficiency and concentration than equivalent quantities of free drug. Time-lapse video microscopy confirmed that delivery occurred within 30 min of administration, to 100% of cells. Moreover, the particles were able to deliver the drug to cells through multiple layers of a 3D human bladder organoid model causing minimal cell toxicity, displaying superior killing of bacterial reservoirs harboured within bladder cells compared with unencapsulated drug. The particles were also able to kill bacterial biofilms more effectively than the free drug. These results illustrate the potential for using antibiotic-loaded microparticles to effectively treat chronic UTIs. Such a delivery method could be extrapolated to other clinical indications where robust intracellular delivery is required, such as oncology and gene therapy.
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Affiliation(s)
- Wai K Lau
- Department of Mechanical Engineering, University College London, London, UK
| | - Dhanuson Dharmasena
- Department of Renal Medicine, Division of Medicine, University College London, London, UK
| | - Harry Horsley
- Department of Renal Medicine, Division of Medicine, University College London, London, UK
| | - Nazila V Jafari
- Department of Renal Medicine, Division of Medicine, University College London, London, UK
| | - James Malone-Lee
- Department of Renal Medicine, Division of Medicine, University College London, London, UK
| | - Eleanor Stride
- The Institute of Biomedical Engineering, University of Oxford, Oxford, UK
| | - Mohan Edirisinghe
- Department of Mechanical Engineering, University College London, London, UK
| | - Jennifer L Rohn
- Department of Renal Medicine, Division of Medicine, University College London, London, UK.
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179
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A Celecoxib Derivative Eradicates Antibiotic-Resistant Staphylococcus aureus and Biofilms by Targeting YidC2 Translocase. Int J Mol Sci 2020; 21:ijms21239312. [PMID: 33297331 PMCID: PMC7730571 DOI: 10.3390/ijms21239312] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2020] [Revised: 11/26/2020] [Accepted: 12/03/2020] [Indexed: 12/02/2022] Open
Abstract
The treatment of Staphylococcus aureus infections is impeded by the prevalence of MRSA and the formation of persisters and biofilms. Previously, we identified two celecoxib derivatives, Cpd36 and Cpd46, to eradicate MRSA and other staphylococci. Through whole-genome resequencing, we obtained several lines of evidence that these compounds might act by targeting the membrane protein translocase YidC2. Our data showed that ectopic expression of YidC2 in S. aureus decreased the bacterial susceptibility to Cpd36 and Cpd46, and that the YidC2-mediated tolerance to environmental stresses was suppressed by both compounds. Moreover, the membrane translocation of ATP synthase subunit c, a substrate of YidC2, was blocked by Cpd46, leading to a reduction in bacterial ATP production. Furthermore, we found that the thermal stability of bacterial YidC2 was enhanced, and introducing point mutations into the substrate-interacting cavity of YidC2 had a dramatic effect on Cpd36 binding via surface plasmon resonance assays. Finally, we demonstrated that these YidC2 inhibitors could effectively eradicate MRSA persisters and biofilms. Our findings highlight the potential of impeding YidC2-mediated translocation of membrane proteins as a new strategy for the treatment of bacterial infections.
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180
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A bacteriocin-based antimicrobial formulation to effectively disrupt the cell viability of methicillin-resistant Staphylococcus aureus (MRSA) biofilms. NPJ Biofilms Microbiomes 2020; 6:58. [PMID: 33268776 PMCID: PMC7710749 DOI: 10.1038/s41522-020-00166-4] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2020] [Accepted: 10/20/2020] [Indexed: 12/15/2022] Open
Abstract
Antibiotic-resistant and biofilm-associated infections brought about by methicillin-resistant Staphylococcus aureus (MRSA) strains is a pressing issue both inside as well as outside nosocomial environments worldwide. Here, we show that a combination of two bacteriocins with distinct structural and functional characteristics, garvicin KS, and micrococcin P1, showed a synergetic antibacterial activity against biofilms produced in vitro by S. aureus, including several MRSA strains. In addition, this bacteriocin-based antimicrobial combination showed the ability to restore the sensitivity of the highly resilient MRSA strain ATCC 33591 to the β-lactam antibiotic penicillin G. By using a combination of bacterial cell metabolic assays, confocal and scanning electron microscopy, we show that the combination between garvicin KS, micrococcin P1, and penicillin G potently inhibit cell viability within S. aureus biofilms by causing severe cell damage. Together these data indicate that bacteriocins can be valuable therapeutic tools in the fight against biofilm-associated MRSA infections.
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181
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Wilkinson MG, LaPointe G. Invited review: Starter lactic acid bacteria survival in cheese: New perspectives on cheese microbiology. J Dairy Sci 2020; 103:10963-10985. [DOI: 10.3168/jds.2020-18960] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2020] [Accepted: 07/21/2020] [Indexed: 11/19/2022]
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182
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Duraisamy S, Balakrishnan S, Ranjith S, Husain F, Sathyan A, Peter AS, Prahalathan C, Kumarasamy A. Bacteriocin-a potential antimicrobial peptide towards disrupting and preventing biofilm formation in the clinical and environmental locales. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2020; 27:44922-44936. [PMID: 33006097 DOI: 10.1007/s11356-020-10989-5] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/04/2020] [Accepted: 09/23/2020] [Indexed: 06/11/2023]
Abstract
Biofilm, a consortium of microbial cells, protected by extracellular polymeric matrix, is considered a global challenge due to the inherent antibiotic resistance conferred by its lifestyle. Besides, it poses environmental threats causing huge damage in food industries, fisheries, refineries, water systems, pharmaceutical industries, medical industries, etc. Living in a community of microbial populations is most critical in the clinical field, making it responsible for about 80% of severe and chronic microbial diseases. The necessity to find an alternative approach is the need of the hour to solve these crises. So far, many approaches have been attempted to disrupt the initial stage of biofilm formation, including adherence and maturation. Bacteriocins are a group of antimicrobial peptides, produced by bacteria having the potential to disrupt biofilm either by itself or in combination with other drugs than antibiotic counterparts. A clear understanding on mechanisms of bacterial biofilm formation, progression, and resistance will surely lead to the development of innovative, effective biofilm control strategies in pharmaceutical, health care industries and environmental locales.
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Affiliation(s)
- Senbagam Duraisamy
- Microbial Biotechnology Laboratory, Department of Marine Biotechnology, Bharathidasan University, Tiruchirappalli, Tamil Nadu, 620 024, India
| | - Senthilkumar Balakrishnan
- Department of Medical Microbiology, College of Health and Medical Sciences, Haramaya University, P.O. Box 235, Harar, Ethiopia
| | - Sukumar Ranjith
- Microbial Biotechnology Laboratory, Department of Marine Biotechnology, Bharathidasan University, Tiruchirappalli, Tamil Nadu, 620 024, India
| | - Fazal Husain
- Microbial Biotechnology Laboratory, Department of Marine Biotechnology, Bharathidasan University, Tiruchirappalli, Tamil Nadu, 620 024, India
| | - Aswathy Sathyan
- Microbial Biotechnology Laboratory, Department of Marine Biotechnology, Bharathidasan University, Tiruchirappalli, Tamil Nadu, 620 024, India
| | - Ansu Susan Peter
- Microbial Biotechnology Laboratory, Department of Marine Biotechnology, Bharathidasan University, Tiruchirappalli, Tamil Nadu, 620 024, India
| | - Chidambaram Prahalathan
- Department of Biochemistry, Bharathidasan University, Tiruchirappalli, Tamil Nadu, 620 024, India
| | - Anbarasu Kumarasamy
- Microbial Biotechnology Laboratory, Department of Marine Biotechnology, Bharathidasan University, Tiruchirappalli, Tamil Nadu, 620 024, India.
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183
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Bartell JA, Cameron DR, Mojsoska B, Haagensen JAJ, Pressler T, Sommer LM, Lewis K, Molin S, Johansen HK. Bacterial persisters in long-term infection: Emergence and fitness in a complex host environment. PLoS Pathog 2020; 16:e1009112. [PMID: 33315938 PMCID: PMC7769609 DOI: 10.1371/journal.ppat.1009112] [Citation(s) in RCA: 45] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2020] [Revised: 12/28/2020] [Accepted: 10/31/2020] [Indexed: 12/20/2022] Open
Abstract
Despite intensive antibiotic treatment, Pseudomonas aeruginosa often persists in the airways of cystic fibrosis (CF) patients for decades, and can do so without antibiotic resistance development. Using high-throughput screening assays of bacterial survival after treatment with high concentrations of ciprofloxacin, we have determined the prevalence of persisters in a large patient cohort using 460 longitudinal isolates of P. aeruginosa from 39 CF patients. Isolates were classed as high persister variants (Hip) if they regrew following antibiotic treatment in at least 75% of the experimental replicates. Strain genomic data, isolate phenotyping, and patient treatment records were integrated in a lineage-based analysis of persister formation and clinical impact. In total, 19% of the isolates were classified as Hip and Hip emergence increased over lineage colonization time within 22 Hip+ patients. Most Hip+ lineages produced multiple Hip isolates, but few Hip+ lineages were dominated by Hip. While we observed no strong signal of adaptive genetic convergence within Hip isolates, they generally emerged in parallel or following the development of ciprofloxacin resistance and slowed growth. Transient lineages were majority Hip-, while strains that persisted over a clinically diagnosed 'eradication' period were majority Hip+. Patients received indistinguishable treatment regimens before Hip emergence, but Hip+ patients overall were treated significantly more than Hip- patients, signaling repeated treatment failure. When subjected to in vivo-similar antibiotic dosing, a Hip isolate survived better than a non-Hip in a structured biofilm environment. In sum, the Hip phenotype appears to substantially contribute to long-term establishment of a lineage in the CF lung environment. Our results argue against the existence of a single dominant molecular mechanism underlying bacterial antibiotic persistence. We instead show that many routes, both phenotypic and genetic, are available for persister formation and consequent increases in strain fitness and treatment failure in CF airways.
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Affiliation(s)
- Jennifer A. Bartell
- The Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, Kgs. Lyngby, Denmark
| | - David R. Cameron
- Antimicrobial Discovery Center, Department of Biology, Northeastern University, Boston, Massachusetts, United States of America
- Department of Intensive Care Medicine, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
| | - Biljana Mojsoska
- Department of Clinical Microbiology, Rigshospitalet, Copenhagen, Denmark
| | - Janus Anders Juul Haagensen
- The Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, Kgs. Lyngby, Denmark
| | | | - Lea M. Sommer
- Department of Clinical Microbiology, Rigshospitalet, Copenhagen, Denmark
| | - Kim Lewis
- Antimicrobial Discovery Center, Department of Biology, Northeastern University, Boston, Massachusetts, United States of America
| | - Søren Molin
- The Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, Kgs. Lyngby, Denmark
| | - Helle Krogh Johansen
- Department of Clinical Microbiology, Rigshospitalet, Copenhagen, Denmark
- Department of Clinical Medicine, University of Copenhagen, Copenhagen, Denmark
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184
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Wood TK, Song S. Forming and waking dormant cells: The ppGpp ribosome dimerization persister model. Biofilm 2020; 2:100018. [PMID: 33447804 PMCID: PMC7798447 DOI: 10.1016/j.bioflm.2019.100018] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2019] [Revised: 12/20/2019] [Accepted: 12/23/2019] [Indexed: 02/07/2023] Open
Abstract
Procaryotes starve and face myriad stresses. The bulk population actively resists the stress, but a small population weathers the stress by entering a resting stage known as persistence. No mutations occur, and so persisters behave like wild-type cells upon removal of the stress and regrowth; hence, persisters are phenotypic variants. In contrast, resistant bacteria have mutations that allow cells to grow in the presence of antibiotics, and tolerant cells survive antibiotics better than actively-growing cells due to their slow growth (such as that of the stationary phase). In this review, we focus on the latest developments in studies related to the formation and resuscitation of persister cells and propose the guanosine pentaphosphate/tetraphosphate (henceforth ppGpp) ribosome dimerization persister (PRDP) model for entering and exiting the persister state.
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Affiliation(s)
- Thomas K. Wood
- Department of Chemical Engineering, Pennsylvania State University, University Park, PA, 16802-4400, USA
| | - Sooyeon Song
- Department of Chemical Engineering, Pennsylvania State University, University Park, PA, 16802-4400, USA
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185
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Browning AP, Sharp JA, Mapder T, Baker CM, Burrage K, Simpson MJ. Persistence as an Optimal Hedging Strategy. Biophys J 2020; 120:133-142. [PMID: 33253635 DOI: 10.1016/j.bpj.2020.11.2260] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2020] [Revised: 10/07/2020] [Accepted: 11/05/2020] [Indexed: 02/02/2023] Open
Abstract
Bacteria invest in a slow-growing subpopulation, called persisters, to ensure survival in the face of uncertainty. This hedging strategy is remarkably similar to financial hedging, where diversifying an investment portfolio protects against economic uncertainty. We provide a new, to our knowledge, theoretical foundation for understanding cellular hedging by unifying the study of biological population dynamics and the mathematics of financial risk management through optimal control theory. Motivated by the widely accepted role of volatility in the emergence of persistence, we consider several models of environmental volatility described by continuous-time stochastic processes. This allows us to study an emergent cellular hedging strategy that maximizes the expected per capita growth rate of the population. Analytical and simulation results probe the optimal persister strategy, revealing results that are consistent with experimental observations and suggest new opportunities for experimental investigation and design. Overall, we provide a new, to our knowledge, way of conceptualizing and modeling cellular decision making in volatile environments by explicitly unifying theory from mathematical biology and finance.
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Affiliation(s)
- Alexander P Browning
- School of Mathematical Sciences, Queensland University of Technology, Queensland, Australia; ARC Centre of Excellence for Mathematical and Statistical Frontiers, Queensland University of Technology, Queensland, Australia.
| | - Jesse A Sharp
- School of Mathematical Sciences, Queensland University of Technology, Queensland, Australia; ARC Centre of Excellence for Mathematical and Statistical Frontiers, Queensland University of Technology, Queensland, Australia
| | - Tarunendu Mapder
- School of Mathematical Sciences, Queensland University of Technology, Queensland, Australia; ARC Centre of Excellence for Mathematical and Statistical Frontiers, Queensland University of Technology, Queensland, Australia; Department of Medicine, Indiana University School of Medicine, Indianapolis, Indiana
| | - Christopher M Baker
- School of Mathematical Sciences, Queensland University of Technology, Queensland, Australia; ARC Centre of Excellence for Mathematical and Statistical Frontiers, Queensland University of Technology, Queensland, Australia; School of Mathematics and Statistics, University of Melbourne, Melbourne, Australia
| | - Kevin Burrage
- School of Mathematical Sciences, Queensland University of Technology, Queensland, Australia; ARC Centre of Excellence for Mathematical and Statistical Frontiers, Queensland University of Technology, Queensland, Australia; Department of Computer Science, University of Oxford, Oxford, United Kingdom
| | - Matthew J Simpson
- School of Mathematical Sciences, Queensland University of Technology, Queensland, Australia
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186
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Montrose K, López Cabezas RM, Paukštytė J, Saarikangas J. Winter is coming: Regulation of cellular metabolism by enzyme polymerization in dormancy and disease. Exp Cell Res 2020; 397:112383. [PMID: 33212148 DOI: 10.1016/j.yexcr.2020.112383] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2020] [Revised: 11/12/2020] [Accepted: 11/14/2020] [Indexed: 12/20/2022]
Abstract
Metabolism feeds growth. Accordingly, metabolism is regulated by nutrient-sensing pathways that converge growth promoting signals into biosynthesis by regulating the activity of metabolic enzymes. When the environment does not support growth, organisms invest in survival. For cells, this entails transitioning into a dormant, quiescent state (G0). In dormancy, the activity of biosynthetic pathways is dampened, and catabolic metabolism and stress tolerance pathways are activated. Recent work in yeast has demonstrated that dormancy is associated with alterations in the physicochemical properties of the cytoplasm, including changes in pH, viscosity and macromolecular crowding. Accompanying these changes, numerous metabolic enzymes transition from soluble to polymerized assemblies. These large-scale self-assemblies are dynamic and depolymerize when cells resume growth. Here we review how enzyme polymerization enables metabolic plasticity by tuning carbohydrate, nucleic acid, amino acid and lipid metabolic pathways, with particular focus on its potential adaptive value in cellular dormancy.
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Affiliation(s)
- Kristopher Montrose
- Helsinki Institute of Life Science, HiLIFE, University of Helsinki, Finland; Research Programme in Molecular and Integrative Biosciences, Faculty of Biological and Environmental Sciences, University of Helsinki, Finland
| | - Rosa María López Cabezas
- Helsinki Institute of Life Science, HiLIFE, University of Helsinki, Finland; Research Programme in Molecular and Integrative Biosciences, Faculty of Biological and Environmental Sciences, University of Helsinki, Finland
| | - Jurgita Paukštytė
- Helsinki Institute of Life Science, HiLIFE, University of Helsinki, Finland; Research Programme in Molecular and Integrative Biosciences, Faculty of Biological and Environmental Sciences, University of Helsinki, Finland
| | - Juha Saarikangas
- Helsinki Institute of Life Science, HiLIFE, University of Helsinki, Finland; Research Programme in Molecular and Integrative Biosciences, Faculty of Biological and Environmental Sciences, University of Helsinki, Finland; Neuroscience Center, University of Helsinki, Finland.
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187
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Melander RJ, Basak AK, Melander C. Natural products as inspiration for the development of bacterial antibiofilm agents. Nat Prod Rep 2020; 37:1454-1477. [PMID: 32608431 PMCID: PMC7677205 DOI: 10.1039/d0np00022a] [Citation(s) in RCA: 63] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Natural products have historically been a rich source of diverse chemical matter with numerous biological activities, and have played an important role in drug discovery in many areas including infectious disease. Synthetic and medicinal chemistry have been, and continue to be, important tools to realize the potential of natural products as therapeutics and as chemical probes. The formation of biofilms by bacteria in an infection setting is a significant factor in the recalcitrance of many bacterial infections, conferring increased tolerance to many antibiotics and to the host immune response, and as yet there are no approved therapeutics for combatting biofilm-based bacterial infections. Small molecules that interfere with the ability of bacteria to form and maintain biofilms can overcome antibiotic tolerance conferred by the biofilm phenotype, and have the potential to form combination therapies with conventional antibiotics. Many natural products with anti-biofilm activity have been identified from plants, microbes, and marine life, including: elligic acid glycosides, hamamelitannin, carolacton, skyllamycins, promysalin, phenazines, bromoageliferin, flustramine C, meridianin D, and brominated furanones. Total synthesis and medicinal chemistry programs have facilitated structure confirmation, identification of critical structural motifs, better understanding of mechanistic pathways, and the development of more potent, more accessible, or more pharmacologically favorable derivatives of anti-biofilm natural products.
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Affiliation(s)
- Roberta J Melander
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN 46556, USA.
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188
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Mechanisms controlling bacterial infection in myeloid cells under hypoxic conditions. Cell Mol Life Sci 2020; 78:1887-1907. [PMID: 33125509 PMCID: PMC7966188 DOI: 10.1007/s00018-020-03684-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2020] [Revised: 09/08/2020] [Accepted: 10/09/2020] [Indexed: 12/12/2022]
Abstract
Various factors of the tissue microenvironment such as the oxygen concentration influence the host-pathogen interaction. During the past decade, hypoxia-driven signaling via hypoxia-inducible factors (HIF) has emerged as an important factor that affects both the pathogen and the host. In this chapter, we will review the current knowledge of this complex interplay, with a particular emphasis given to the impact of hypoxia and HIF on the inflammatory and antimicrobial activity of myeloid cells, the bacterial responses to hypoxia and the containment of bacterial infections under oxygen-limited conditions. We will also summarize how low oxygen concentrations influence the metabolism of neutrophils, macrophages and dendritic cells. Finally, we will discuss the consequences of hypoxia and HIFα activation for the invading pathogen, with a focus on Pseudomonas aeruginosa, Mycobacterium tuberculosis, Coxiella burnetii, Salmonella enterica and Staphylococcus aureus. This includes a description of the mechanisms and microbial factors, which the pathogens use to sense and react to hypoxic conditions.
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189
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Chen H, Green A, Martz K, Wu X, Alzahrani A, Warriner K. The progress of type II persisters of Escherichia coli O157:H7 to a non-culturable state during prolonged exposure to antibiotic stress with revival being aided through acid-shock treatment and provision of methyl pyruvate. Can J Microbiol 2020; 67:518-528. [PMID: 33125853 DOI: 10.1139/cjm-2020-0339] [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] [Indexed: 11/22/2022]
Abstract
Persisters are a form of dormancy in bacteria that provide temporary resistance to antibiotics. The following reports on the formation of Escherichia coli O157:H7 E318 type II persisters from a protracted (8 days) challenge with ampicillin. Escherichia coli O157:H7 followed a multiphasic die-off pattern with an initial rapid decline (Phase I) of susceptible cells that transitioned to a slower rate representing tolerant cells (Phase II). After 24 h post-antibiotic challenge, the E. coli O157:H7 levels remained relatively constant at 2 log CFU/mL (Phase III), but became non-culturable within 8-days (Phase IV). The revival of persisters in Phase III could be achieved by the removal of antibiotic stress, although those in Phase IV required an extended incubation period or application of acid-shock. The carbon utilization profile of persister cells was less diverse compared with non-persisters, with only methyl pyruvate being utilized from the range tested. Inclusion of methyl pyruvate in tryptic soy agar revived non-cultural persisters, presumably by stimulating metabolism. The results suggest that persisters could be subdivided into culturable or non-culturable cells, with the former representing a transition state to the latter. The study provided insights into how to revive cells from dormancy to aid enumeration and control.
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Affiliation(s)
- Heather Chen
- Center of Public Health and Zoonosis, Department of Food Science, University of Guelph, Guelph, Ontario, Canada.,Center of Public Health and Zoonosis, Department of Food Science, University of Guelph, Guelph, Ontario, Canada
| | - Andrew Green
- Center of Public Health and Zoonosis, Department of Food Science, University of Guelph, Guelph, Ontario, Canada.,Center of Public Health and Zoonosis, Department of Food Science, University of Guelph, Guelph, Ontario, Canada
| | - Kailey Martz
- Center of Public Health and Zoonosis, Department of Food Science, University of Guelph, Guelph, Ontario, Canada.,Center of Public Health and Zoonosis, Department of Food Science, University of Guelph, Guelph, Ontario, Canada
| | - Xueyang Wu
- Center of Public Health and Zoonosis, Department of Food Science, University of Guelph, Guelph, Ontario, Canada.,Center of Public Health and Zoonosis, Department of Food Science, University of Guelph, Guelph, Ontario, Canada
| | - Abdulhakeem Alzahrani
- Center of Public Health and Zoonosis, Department of Food Science, University of Guelph, Guelph, Ontario, Canada.,Center of Public Health and Zoonosis, Department of Food Science, University of Guelph, Guelph, Ontario, Canada
| | - Keith Warriner
- Center of Public Health and Zoonosis, Department of Food Science, University of Guelph, Guelph, Ontario, Canada.,Center of Public Health and Zoonosis, Department of Food Science, University of Guelph, Guelph, Ontario, Canada
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190
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MazEF-rifampicin interaction suggests a mechanism for rifampicin induced inhibition of persisters. BMC Mol Cell Biol 2020; 21:73. [PMID: 33109090 PMCID: PMC7590665 DOI: 10.1186/s12860-020-00316-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2020] [Accepted: 10/11/2020] [Indexed: 12/15/2022] Open
Abstract
Background Persistence is a natural phenomenon whereby a subset of a population of isogenic bacteria either grow slow or become dormant conferring them with the ability to withstand various stresses including antibiotics. In a clinical setting bacterial persistence often leads to the recalcitrance of various infections increasing the treatment time and cost. Additionally, some studies also indicate that persistence can also pave way for the emergence of resistant strains. In a laboratory setting this persistent phenotype is enriched in nutritionally deprived environments. Consequently, in a batch culture the late stationary phase is enriched with persistent bacteria. The mechanism of persister cell formation and its regulation is not well understood. Toxin-antitoxin (TA) systems have been implicated to be responsible for bacterial persistence and rifampicin is used to treat highly persistent bacterial strains. The current study tries to explore a possible interaction between rifampicin and the MazEF TA system that furthers the former’s success rate in treating persistent bacteria. Results In the current study we found that the population of bacteria in the death phase of a batch culture consists of metabolically inactive live cells resembling persisters, which showed higher membrane depolarization as compared to the log phase bacteria. We also observed an increase in the expression of the MazEF TA modules in this phase. Since rifampicin is used to kill the persisters, we assessed the interaction of rifampicin with MazEF complex. We showed that rifampicin moderately interacts with MazEF complex with 1:1 stoichiometry. Conclusion Our study suggests that the interaction of rifampicin with MazEF complex might play an important role in inhibition of persisters. Supplementary information The online version contains supplementary material available at 10.1186/s12860-020-00316-8.
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191
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Wlodarski M, Mancini L, Raciti B, Sclavi B, Lagomarsino MC, Cicuta P. Cytosolic Crowding Drives the Dynamics of Both Genome and Cytosol in Escherichia coli Challenged with Sub-lethal Antibiotic Treatments. iScience 2020; 23:101560. [PMID: 33083729 PMCID: PMC7522891 DOI: 10.1016/j.isci.2020.101560] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2019] [Revised: 05/22/2020] [Accepted: 09/10/2020] [Indexed: 11/28/2022] Open
Abstract
In contrast to their molecular mode of action, the system-level effect of antibiotics on cells is only beginning to be quantified. Molecular crowding is expected to be a relevant global regulator, which we explore here through the dynamic response phenotypes in Escherichia coli, at single-cell resolution, under sub-lethal regimes of different classes of clinically relevant antibiotics, acting at very different levels in the cell. We measure chromosomal mobility through tracking of fast (<15 s timescale) fluctuations of fluorescently tagged chromosomal loci, and we probe the fluidity of the cytoplasm by tracking cytosolic aggregates. Measuring cellular density, we show how the overall levels of macromolecular crowding affect both quantities, regardless of antibiotic-specific effects. The dominant trend is a strong correlation between the effects in different parts of the chromosome and between the chromosome and cytosol, supporting the concept of an overall global role of molecular crowding in cellular physiology.
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Affiliation(s)
- Michal Wlodarski
- Biological and Soft Systems, Cavendish Laboratory, University of Cambridge, Cambridge, UK
- Dipartimento di Fisica and I.N.F.N., Università degli Studi di Milano, Via Celoria 16, 20133 Milano, Italy
| | - Leonardo Mancini
- Biological and Soft Systems, Cavendish Laboratory, University of Cambridge, Cambridge, UK
| | - Bianca Raciti
- Biological and Soft Systems, Cavendish Laboratory, University of Cambridge, Cambridge, UK
| | - Bianca Sclavi
- Laboratory of Biology and Applied Pharmacology (UMR 8113 CNRS), École Normale Supérieure, Paris-Saclay, France
| | | | - Pietro Cicuta
- IFOM Foundation FIRC Institute of Molecular Oncology Foundation, Milan 20139, Italy
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192
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I. Horowitz R, R. Freeman P. Efficacy of Double-Dose Dapsone Combination Therapy in the Treatment of Chronic Lyme Disease/Post-Treatment Lyme Disease Syndrome (PTLDS) and Associated Co-infections: A Report of Three Cases and Retrospective Chart Review. Antibiotics (Basel) 2020; 9:E725. [PMID: 33105645 PMCID: PMC7690415 DOI: 10.3390/antibiotics9110725] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2020] [Revised: 10/15/2020] [Accepted: 10/21/2020] [Indexed: 02/03/2023] Open
Abstract
Three patients with multi-year histories of relapsing and remitting Lyme disease and associated co-infections despite extended antibiotic therapy were each given double-dose dapsone combination therapy (DDD CT) for a total of 7-8 weeks. At the completion of therapy, all three patients' major Lyme symptoms remained in remission for a period of 25-30 months. A retrospective chart review of 37 additional patients undergoing DDD CT therapy (40 patients in total) was also performed, which demonstrated tick-borne symptom improvements in 98% of patients, with 45% remaining in remission for 1 year or longer. In conclusion, double-dose dapsone therapy could represent a novel and effective anti-infective strategy in chronic Lyme disease/ post-treatment Lyme disease syndrome (PTLDS), especially in those individuals who have failed regular dose dapsone combination therapy (DDS CT) or standard antibiotic protocols. A randomized, blinded, placebo-controlled trial is warranted to evaluate the efficacy of DDD CT in those individuals with chronic Lyme disease/PTLDS.
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Affiliation(s)
- Richard I. Horowitz
- HHS Babesia and Tick-borne Pathogens Subcommittee, Washington, DC 20201, USA
- Hudson Valley Healing Arts Center, Hyde Park, NY 12538, USA;
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193
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Chen S, Owolabi Y, Li A, Lo E, Robinson P, Janies D, Lee C, Dulin M. Patch dynamics modeling framework from pathogens' perspective: Unified and standardized approach for complicated epidemic systems. PLoS One 2020; 15:e0238186. [PMID: 33057348 PMCID: PMC7561140 DOI: 10.1371/journal.pone.0238186] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2020] [Accepted: 08/11/2020] [Indexed: 11/25/2022] Open
Abstract
Mathematical models are powerful tools to investigate, simulate, and evaluate potential interventions for infectious diseases dynamics. Much effort has focused on the Susceptible-Infected-Recovered (SIR)-type compartment models. These models consider host populations and measure change of each compartment. In this study, we propose an alternative patch dynamic modeling framework from pathogens' perspective. Each patch, the basic module of this modeling framework, has four standard mechanisms of pathogen population size change: birth (replication), death, inflow, and outflow. This framework naturally distinguishes between-host transmission process (inflow and outflow) and within-host infection process (replication) during the entire transmission-infection cycle. We demonstrate that the SIR-type model is actually a special cross-sectional and discretized case of our patch dynamics model in pathogens' viewpoint. In addition, this patch dynamics modeling framework is also an agent-based model from hosts' perspective by incorporating individual host's specific traits. We provide an operational standard to formulate this modular-designed patch dynamics model. Model parameterization is feasible with a wide range of sources, including genomics data, surveillance data, electronic health record, and from other emerging technologies such as multiomics. We then provide two proof-of-concept case studies to tackle some of the existing challenges of SIR-type models: sexually transmitted disease and healthcare acquired infections. This patch dynamics modeling framework not only provides theoretical explanations to known phenomena, but also generates novel insights of disease dynamics from a more holistic viewpoint. It is also able to simulate and handle more complicated scenarios across biological scales such as the current COVID-19 pandemic.
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Affiliation(s)
- Shi Chen
- Department of Public Health Sciences, University of North Carolina Charlotte, Charlotte, NC, United States of America
- School of Data Science, University of North Carolina Charlotte, Charlotte, NC, United States of America
| | - Yakubu Owolabi
- Department of Public Health Sciences, University of North Carolina Charlotte, Charlotte, NC, United States of America
- Division of HIV and TB, Centers for Disease Control and Prevention, Atlanta, GA, United States of America
| | - Ang Li
- State Key Laboratory of Vegetation and Environmental Change, Chinese Academy of Sciences, Beijing, China
| | - Eugenia Lo
- Department of Biological Sciences, University of North Carolina Charlotte, Charlotte, NC, United States of America
| | - Patrick Robinson
- Department of Public Health Sciences, University of North Carolina Charlotte, Charlotte, NC, United States of America
- Academy of Population Health Innovation, University of North Carolina Charlotte, Charlotte, NC, United States of America
| | - Daniel Janies
- Department of Bioinformatics, University of North Carolina Charlotte, Charlotte, NC, United States of America
| | - Chihoon Lee
- School of Business, Stevens Institute of Technology, Hoboken, NJ, United States of America
| | - Michael Dulin
- Department of Public Health Sciences, University of North Carolina Charlotte, Charlotte, NC, United States of America
- Academy of Population Health Innovation, University of North Carolina Charlotte, Charlotte, NC, United States of America
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194
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Lima WG, de Brito JCM, Cardoso VN, Fernandes SOA. In-depth characterization of antibacterial activity of melittin against Staphylococcus aureus and use in a model of non-surgical MRSA-infected skin wounds. Eur J Pharm Sci 2020; 156:105592. [PMID: 33049305 DOI: 10.1016/j.ejps.2020.105592] [Citation(s) in RCA: 36] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2020] [Revised: 10/07/2020] [Accepted: 10/08/2020] [Indexed: 12/12/2022]
Abstract
Skin infections caused by methicillin-resistant Staphylococcus aureus (MRSA) require the development of new and effective topical antibiotics. In this context, melittin, the main component of apitoxin, has a potent antibacterial effect. However, little is known regarding the anti-inflammatory potential this peptide in infection models, or its ability to induce clinically important resistance. Here, we aimed to conduct an in-depth characterization of the antibacterial potential of melittin in vitro and evaluate the pharmaceutical potential of an ointment containing melittin for the treatment of non-surgical infections induced by MRSA. The minimum inhibitory concentration of melittin varied from 0.12 to 4 μM. The antibacterial effect was mainly bactericidal and fast (approximately 0.5 h after incubation) and was maintained even in stationary cells and mature MRSA biofilms. Melittin interacts synergistically with beta-lactams and aminoglycosides, and its ability to form pores in the membrane reverses the resistance of vancomycin-intermediate Staphylococcus aureus (VISA) to amoxicillin, and vancomycin. Its ability to induce resistance in vitro was absent, and melittin was stable in several conditions often associated with infected wounds. In vivo, aointment containing melittin reduced bacterial load and the content of pro-inflammatory cytokines, such as tumor necrosis factor-α, interleukin-6 (IL-6), and IL-1 beta. Collectively, these data point to melittin as a potential candidate for topical formulations aimed at the treatment of non-surgical infections caused by MRSA.
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Affiliation(s)
- William Gustavo Lima
- Laboratório de Radioisótopos, Departamento de Análises Clinicas e Toxicológicas, Faculdade de Farmácia, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil
| | | | - Valbert Nascimento Cardoso
- Laboratório de Radioisótopos, Departamento de Análises Clinicas e Toxicológicas, Faculdade de Farmácia, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil
| | - Simone Odília Antunes Fernandes
- Laboratório de Radioisótopos, Departamento de Análises Clinicas e Toxicológicas, Faculdade de Farmácia, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil.
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195
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Talapko J, Škrlec I. The Principles, Mechanisms, and Benefits of Unconventional Agents in the Treatment of Biofilm Infection. Pharmaceuticals (Basel) 2020; 13:E299. [PMID: 33050521 PMCID: PMC7600518 DOI: 10.3390/ph13100299] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2020] [Revised: 10/08/2020] [Accepted: 10/09/2020] [Indexed: 02/06/2023] Open
Abstract
Today, researchers are looking at new ways to treat severe infections caused by resistance to standard antibiotic therapy. This is quite challenging due to the complex and interdependent relationships involved: the cause of infection-the patient-antimicrobial agents. The sessile biofilm form is essential in research to reduce resistance to very severe infections (such as ESKAPE pathogens: Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumanni, Pseudomonas aeruginosa, and Enterobacter spp). The purpose of this study is to elucidate the mechanisms of the occurrence, maintenance, and suppression of biofilm infections. One form of biofilm suppression is the efficient action of natural antagonists of bacteria-bacteriophages. Bacteriophages effectively penetrate the biofilm's causative cells. They infect those bacterial cells and either destroy them or prevent the infection spreading. In this process, bacteriophages are specific, relatively easy to apply, and harmless to the patient. Antimicrobial peptides (AMPs) support the mechanisms of bacteriophages' action. AMPs could also attack and destroy infectious agents on their own (even on biofilm). AMPs are simple, universal peptide molecules, mainly cationic peptides. Additional AMP research could help develop even more effective treatments of biofilm (bacteriophages, antibiotics, AMPs, nanoparticles). Here, we review recent unconventional agents, such as bacteriophages and AMPs, used for eradication of biofilm, providing an overview of potentially new biofilm treatment strategies.
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Affiliation(s)
| | - Ivana Škrlec
- Faculty of Dental Medicine and Health, Josip Juraj Strossmayer University of Osijek, HR-31000 Osijek, Croatia;
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196
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Seneviratne CJ, Suriyanarayanan T, Widyarman AS, Lee LS, Lau M, Ching J, Delaney C, Ramage G. Multi-omics tools for studying microbial biofilms: current perspectives and future directions. Crit Rev Microbiol 2020; 46:759-778. [PMID: 33030973 DOI: 10.1080/1040841x.2020.1828817] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The advent of omics technologies has greatly improved our understanding of microbial biology, particularly in the last two decades. The field of microbial biofilms is, however, relatively new, consolidated in the 1980s. The morphogenic switching by microbes from planktonic to biofilm phenotype confers numerous survival advantages such as resistance to desiccation, antibiotics, biocides, ultraviolet radiation, and host immune responses, thereby complicating treatment strategies for pathogenic microorganisms. Hence, understanding the mechanisms governing the biofilm phenotype can result in efficient treatment strategies directed specifically against molecular markers mediating this process. The application of omics technologies for studying microbial biofilms is relatively less explored and holds great promise in furthering our understanding of biofilm biology. In this review, we provide an overview of the application of omics tools such as transcriptomics, proteomics, and metabolomics as well as multi-omics approaches for studying microbial biofilms in the current literature. We also highlight how the use of omics tools directed at various stages of the biological information flow, from genes to metabolites, can be integrated via multi-omics platforms to provide a holistic view of biofilm biology. Following this, we propose a future artificial intelligence-based multi-omics platform that can predict the pathways associated with different biofilm phenotypes.
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Affiliation(s)
- Chaminda J Seneviratne
- Singapore Oral Microbiomics Initiative (SOMI), National Dental Research Institute Singapore, National Dental Centre, Singapore, Singapore.,Duke NUS Medical School, Singapore, Singapore
| | - Tanujaa Suriyanarayanan
- Singapore Oral Microbiomics Initiative (SOMI), National Dental Research Institute Singapore, National Dental Centre, Singapore, Singapore.,Duke NUS Medical School, Singapore, Singapore
| | - Armelia Sari Widyarman
- Department of Microbiology, Faculty of Dentistry, Trisakti University, Grogol, West Jakarta, Indonesia
| | - Lye Siang Lee
- Duke-NUS Medical School, Metabolomics Lab, Cardiovascular and Metabolic Disorders, Singapore, Singapore
| | - Matthew Lau
- Singapore Oral Microbiomics Initiative (SOMI), National Dental Research Institute Singapore, National Dental Centre, Singapore, Singapore
| | - Jianhong Ching
- Duke-NUS Medical School, Metabolomics Lab, Cardiovascular and Metabolic Disorders, Singapore, Singapore
| | - Christopher Delaney
- School of Medicine, Dentistry & Nursing, Glasgow Dental Hospital & School, University of Glasgow, Glasgow, UK
| | - Gordon Ramage
- School of Medicine, Dentistry & Nursing, Glasgow Dental Hospital & School, University of Glasgow, Glasgow, UK
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197
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Liu Y, Li R, Xiao X, Wang Z. Bacterial metabolism-inspired molecules to modulate antibiotic efficacy. J Antimicrob Chemother 2020; 74:3409-3417. [PMID: 31211378 DOI: 10.1093/jac/dkz230] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
The decreasing antibiotic susceptibility of bacterial pathogens calls for novel antimicrobial therapies. Traditional screening pathways based on drug-target interaction have gradually reached the stage of diminishing returns. Thus, novel strategies are urgently needed in the fight against antibiotic-refractory bacteria, particularly for tolerant bacteria. Recently, evidence has accumulated demonstrating that microbial changes caused by bacterial metabolic processes significantly modulate antibiotic killing. A better understanding of these bacterial metabolic processes is indicating a need to screen novel metabolic modulators as potential antibiotic adjuvants. In this review, we describe the state of our current knowledge about how these bacterial metabolism-inspired molecules affect antibiotic efficacy, including potentiation and inhibition activity. In addition, the challenges faced and prospects for bringing them into clinic are also discussed. These examples may provide candidates or targets for the development of novel antibiotic adjuvants.
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Affiliation(s)
- Yuan Liu
- Institute of Comparative Medicine, College of Veterinary Medicine, Yangzhou University, Yangzhou, Jiangsu, China.,Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou, Jiangsu, China
| | - Ruichao Li
- Institute of Comparative Medicine, College of Veterinary Medicine, Yangzhou University, Yangzhou, Jiangsu, China.,Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou, Jiangsu, China
| | - Xia Xiao
- Institute of Comparative Medicine, College of Veterinary Medicine, Yangzhou University, Yangzhou, Jiangsu, China.,Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou, Jiangsu, China
| | - Zhiqiang Wang
- Institute of Comparative Medicine, College of Veterinary Medicine, Yangzhou University, Yangzhou, Jiangsu, China.,Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou, Jiangsu, China
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198
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The Protective Effect of Staphylococcus epidermidis Biofilm Matrix against Phage Predation. Viruses 2020; 12:v12101076. [PMID: 32992766 PMCID: PMC7601396 DOI: 10.3390/v12101076] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2020] [Revised: 09/13/2020] [Accepted: 09/22/2020] [Indexed: 12/12/2022] Open
Abstract
Staphylococcus epidermidis is a major causative agent of nosocomial infections, mainly associated with the use of indwelling devices, on which this bacterium forms structures known as biofilms. Due to biofilms’ high tolerance to antibiotics, virulent bacteriophages were previously tested as novel therapeutic agents. However, several staphylococcal bacteriophages were shown to be inefficient against biofilms. In this study, the previously characterized S. epidermidis-specific Sepunavirus phiIBB-SEP1 (SEP1), which has a broad spectrum and high activity against planktonic cells, was evaluated concerning its efficacy against S. epidermidis biofilms. The in vitro biofilm killing assays demonstrated a reduced activity of the phage. To understand the underlying factors impairing SEP1 inefficacy against biofilms, this phage was tested against distinct planktonic and biofilm-derived bacterial populations. Interestingly, SEP1 was able to lyse planktonic cells in different physiological states, suggesting that the inefficacy for biofilm control resulted from the biofilm 3D structure and the protective effect of the matrix. To assess the impact of the biofilm architecture on phage predation, SEP1 was tested in disrupted biofilms resulting in a 2 orders-of-magnitude reduction in the number of viable cells after 6 h of infection. The interaction between SEP1 and the biofilm matrix was further assessed by the addition of matrix to phage particles. Results showed that the matrix did not inactivate phages nor affected phage adsorption. Moreover, confocal laser scanning microscopy data demonstrated that phage infected cells were less predominant in the biofilm regions where the matrix was more abundant. Our results provide compelling evidence indicating that the biofilm matrix can work as a barrier, allowing the bacteria to be hindered from phage infection.
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199
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(p)ppGpp and Its Role in Bacterial Persistence: New Challenges. Antimicrob Agents Chemother 2020; 64:AAC.01283-20. [PMID: 32718971 DOI: 10.1128/aac.01283-20] [Citation(s) in RCA: 59] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Antibiotic failure not only is due to the development of resistance by pathogens but can also often be explained by persistence and tolerance. Persistence and tolerance can be included in the "persistent phenotype," with high relevance for clinics. Two of the most important molecular mechanisms involved in tolerance and persistence are toxin-antitoxin (TA) modules and signaling via guanosine pentaphosphate/tetraphosphate [(p)ppGpp], also known as "magic spot." (p)ppGpp is a very important stress alarmone which orchestrates the stringent response in bacteria; hence, (p)ppGpp is produced during amino acid or fatty acid starvation by proteins belonging to the RelA/SpoT homolog family (RSH). However, (p)ppGpp levels can also accumulate in response to a wide range of signals, including oxygen variation, pH downshift, osmotic shock, temperature shift, or even exposure to darkness. Furthermore, the stringent response is not only involved in responses to environmental stresses (starvation for carbon sources, fatty acids, and phosphates or heat shock), but it is also used in bacterial pathogenesis, host invasion, and antibiotic tolerance and persistence. Given the exhaustive and contradictory literature surrounding the role of (p)ppGpp in bacterial persistence, and with the aim of summarizing what is known so far about the magic spot in this bacterial stage, this review provides new insights into the link between the stringent response and persistence. Moreover, we review some of the innovative treatments that have (p)ppGpp as a target, which are in the spotlight of the scientific community as candidates for effective antipersistence agents.
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200
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A strategy to control colonization of pathogens: embedding of lactic acid bacteria on the surface of urinary catheter. Appl Microbiol Biotechnol 2020; 104:9053-9066. [PMID: 32949279 DOI: 10.1007/s00253-020-10903-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2020] [Revised: 09/04/2020] [Accepted: 09/10/2020] [Indexed: 01/13/2023]
Abstract
Indwelling urinary catheterization is one of the major causes of urinary tract infection (UTI) in hospitalized patients worldwide. A catheter serves as a surface for the colonization and formation of biofilm by UTI-related pathogenic bacteria. To combat the biofilm formation on its surface, several strategies have already been employed such as coating it with antibiofilm and antimicrobial compounds. For instance, the application of lactic acid bacteria (LAB) offers a potential strategy for the treatment of biofilm formation on the surface of the urinary catheter due to its ability to kill the pathogenic bacteria. The killing of pathogenic bacteria by LAB occurs via the production of antimicrobial compounds such as lactic acid, bacteriocin, and hydrogen peroxide. LAB also displays a competitive exclusion mechanism to prevent the adhesion of pathogens on the surfaces. Hence, LAB has been extensively applied as a bacteriotherapy to combat infectious diseases. Several strategies have been employed to attach LAB to a surface, but its easy detachment during long time exposure becomes one of the drawbacks in its application. Here, we have proposed a novel strategy for its adhesion on the surface of the urinary catheter with the utilization of mannose-specific adhesin (Msa) protein in a way similar as uropathogenic bacteria interacts between Msa present on the tip of the type I fimbriae/pilus and the mannose moieties on the host epithelial cell surfaces. KEY POINTS: • Urinary tract infection (UTI) is one of the common hospital-acquired infections, which is associated with the application of an indwelling urinary catheter. • Based on the competitive exclusions properties of LAB, attachment of the LAB on the catheter surface would be a promising approach to control the formation of pathogenic biofilm. • The strategy employed for the adhesion of LAB is via a covalent interaction of its mannose-specific adhesin (Msa) protein to the mannose residues grafted on the catheter surface.
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