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Vadakkan K, Sathishkumar K, Kuttiyachan Urumbil S, Ponnenkunnathu Govindankutty S, Kumar Ngangbam A, Devi Nongmaithem B. A review of chemical signaling mechanisms underlying quorum sensing and its inhibition in Staphylococcus aureus. Bioorg Chem 2024; 148:107465. [PMID: 38761705 DOI: 10.1016/j.bioorg.2024.107465] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2024] [Revised: 04/29/2024] [Accepted: 05/14/2024] [Indexed: 05/20/2024]
Abstract
Staphylococcus aureus is a significant bacterium responsible for multiple infections and is a primary cause of fatalities among patients in hospital environments. The advent of pathogenic bacteria such as methicillin-resistant S. aureus revealed the shortcomings of employing antibiotics to treat bacterial infectious diseases. Quorum sensing enhances S. aureus's survivability through signaling processes. Targeting the key components of quorum sensing has drawn much interest nowadays as a promising strategy for combating infections caused by bacteria. Concentrating on the accessory gene regulator quorum-sensing mechanism is the most commonly suggested anti-virulence approach for S.aureus. Quorum quenching is a common strategy for controlling illnesses triggered by microorganisms since it reduces the pathogenicity of bacteria and improves bacterial biofilm susceptibility to antibiotics, thus providing an intriguing prospect for drug discovery. Quorum sensing inhibition reduces selective stresses and constrains the emergence of antibiotic resistance while limiting bacterial pathogenicity. This review examines the quorum sensing mechanisms involved in S. aureus, quorum sensing targets and gene regulation, environmental factors affecting quorum sensing, quorum sensing inhibition, natural products as quorum sensing inhibitory agents and novel therapeutical strategies to target quorum sensing in S. aureus as drug developing technique to augment conventional antibiotic approaches.
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Affiliation(s)
- Kayeen Vadakkan
- Department of Biotechnology, St. Mary's College (Autonomous), Thrissur, Kerala 680020, India; Manipur International University, Imphal, Manipur 795140, India.
| | - Kuppusamy Sathishkumar
- Center for Global Health Research, Saveetha Medical College and Hospitals, Saveetha Institute of Medical and Technical Sciences (SIMATS), Saveetha University, Thandalam, Chennai, Tamil Nadu 602105, India
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Sabino YNV, de Araújo Domingues KC, O'Connor PM, Marques PH, Santos EH, Tótola MR, Abreu LM, de Queiroz MV, Cotter PD, Mantovani HC. Bacillus velezensis iturins inhibit the hemolytic activity of Staphylococcus aureus. Sci Rep 2024; 14:9469. [PMID: 38658583 PMCID: PMC11043418 DOI: 10.1038/s41598-024-58973-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2023] [Accepted: 04/05/2024] [Indexed: 04/26/2024] Open
Abstract
Bovine mastitis caused by S. aureus has a major economic impact on the dairy sector. With the crucial need for new therapies, anti-virulence strategies have gained attention as alternatives to antibiotics. Here we aimed to identify novel compounds that inhibit the production/activity of hemolysins, a virulence factor of S. aureus associated with mastitis severity. We screened Bacillus strains obtained from diverse sources for compounds showing anti-hemolytic activity. Our results demonstrate that lipopeptides produced by Bacillus spp. completely prevented the hemolytic activity of S. aureus at certain concentrations. Following purification, both iturins, fengycins, and surfactins were able to reduce hemolysis caused by S. aureus, with iturins showing the highest anti-hemolytic activity (up to 76% reduction). The lipopeptides showed an effect at the post-translational level. Molecular docking simulations demonstrated that these compounds can bind to hemolysin, possibly interfering with enzyme action. Lastly, molecular dynamics analysis indicated general stability of important residues for hemolysin activity as well as the presence of hydrogen bonds between iturins and these residues, with longevous interactions. Our data reveals, for the first time, an anti-hemolytic activity of lipopeptides and highlights the potential application of iturins as an anti-virulence therapy to control bovine mastitis caused by S. aureus.
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Affiliation(s)
| | | | | | - Pedro Henrique Marques
- Department of Microbiology, Immunology and Parasitology, Federal University of Triângulo Mineiro, Uberaba, MG, Brazil
| | - Eduardo Horta Santos
- Department of Biochemistry and Immunology, Institute of Biological Sciences, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil
| | | | | | | | - Paul D Cotter
- Teagasc Food Research Centre, Moorepark, Fermoy, Co. Cork, Cork, Ireland
- APC Microbiome Ireland, Cork, Ireland
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Dos Santos TB, Dos Santos Gomes D, Dos Santos Neto AG, do Amorim Costa Gaspar LM, Droppa-Almeida D. Botanical Extracts and Compounds of Castanea Plants and Methods of Use: US20190125818A1 - The United States Patent Evaluation. Recent Pat Biotechnol 2024; 18:152-161. [PMID: 38282444 DOI: 10.2174/1872208317666230420105000] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2022] [Revised: 02/16/2023] [Accepted: 02/27/2023] [Indexed: 01/30/2024]
Abstract
BACKGROUND Bacterial infections are increasingly difficult to combat, which makes them a threat to public health on a global level. Staphylococcus aureus is considered one of the main causes of infections in hospitals, as it has a variety of virulence factors, as well as is able to produce bacterial biofilms, which, consequently, bring numerous damages to public health as a result of increased resistance to conventional antibiotics and a longer hospital stay. Therefore, the use of compounds extracted from medicinal plants is a potential pharmaceutically acceptable target, as they do not have toxicity and the potential to disrupt biofilms produced by Staphylococcus aureus already evidenced, thus revealing their relevance to our study. OBJECTIVE The objective of this work was to perform a critical analysis of a patent with natural extracts against bacterial biofilms found in the United States Patent and Trademark Office (USPTO) database, to map the possible bioactive compounds that may serve as potential future antimicrobial drugs. METHODS A technological survey was carried out to verify existing patents using natural extracts with anti-biofilm potential. For this, it was searched with the keywords: Botanical extracts AND biofilms; which were performed in the United States Patent and Trademark Office (USPTO) database. Thus, the selected patent used a non-aqueous extract partitioned and vacuum-contracted, subsequently lyophilized for assays with antimicrobial potential. Because of this, a patent was analyzed regarding its chemistry, and biological activity, followed by a critical analysis of the technology proposed in the invention. RESULTS When using the keywords Botanical extracts AND biofilms in the USPTO, it was possible to find twenty-two inventions; however, only four patents in the USPTO were in agreement with the proposal of the natural extract having antimicrobial activity and an anti-biofilm potential, of which two belonged to the same applicant with similar proposals. The key point of this invention was to enable the compounds of the Castanea sativa plant and its methods of obtaining the extract to present a significant antimicrobial action associated or not with antibiotics, promoting the development of new therapies against bacterial infections capable of disrupting biofilms. The invention developed a methodology for extracting Castanea sativa, in which pentacyclic triterpene compounds were found mostly in its leaves. Whereas for the extraction, the crude methanol extracts called extracts 224 from the ground leaves were made by maceration, filtered, combined, concentrated under pressure in rotary evaporators, and lyophilized. After that, they were resuspended in water and partitioned in succession with hexane, ethyl acetate, and butanol. The most active refined partition was the 224C extract with the solvent ethyl acetate, which was subjected to further fractionation using silica column chromatography. Resulting in the most refined extract, which was 224C-F2, capable of acting directly on the quorum sensing of bacteria, mainly Staphylococcus aureus, blocking the translation of RNAIII, including a series of exotoxins. Regarding the antimicrobial capacity against Staphylococcus aureus, it presented Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) of 1.56 μg/mL-1 and > 100 μg/mL -1, respectively. CONCLUSION Given the analyzed patent, it was possible to verify the importance of alternatives to reduce the impact of bacterial biofilms, which causes damage to industries in general and to health. From this, the invention analyzed has a promising proposal with antimicrobial potential focusing on the great impact of bacterial biofilms. Therefore, natural extracts with antibiofilmic potential can help to minimize the economic losses caused to health due to these multidrug-resistant microorganisms with different virulence mechanisms.
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Schilcher K, Severn MM, Jenul C, Avina YSC, Keogh RA, Horswill AR. The Staphylococcus aureus CamS lipoprotein is a repressor of toxin production that shapes host-pathogen interaction. PLoS Biol 2024; 22:e3002451. [PMID: 38180978 PMCID: PMC10769083 DOI: 10.1371/journal.pbio.3002451] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2023] [Accepted: 11/27/2023] [Indexed: 01/07/2024] Open
Abstract
Lipoproteins of the opportunistic pathogen Staphylococcus aureus play a crucial role in various cellular processes and host interactions. Consisting of a protein and a lipid moiety, they support nutrient acquisition and anchor the protein to the bacterial membrane. Recently, we identified several processed and secreted small linear peptides that derive from the secretion signal sequence of S. aureus lipoproteins. Here, we show, for the first time, that the protein moiety of the S. aureus lipoprotein CamS has a biological role that is distinct from its associated linear peptide staph-cAM373. The small peptide was shown to be involved in interspecies horizontal gene transfer, the primary mechanism for the dissemination of antibiotic resistance among bacteria. We provide evidence that the CamS protein moiety is a potent repressor of cytotoxins, such as α-toxin and leukocidins. The CamS-mediated suppression of toxin transcription was reflected by altered disease severity in in vivo infection models involving skin and soft tissue, as well as bloodstream infections. Collectively, we have uncovered the role of the protein moiety of the staphylococcal lipoprotein CamS as a previously uncharacterized repressor of S. aureus toxin production, which consequently regulates virulence and disease outcomes. Notably, the camS gene is conserved in S. aureus, and we also demonstrated the muted transcriptional response of cytotoxins in 2 different S. aureus lineages. Our findings provide the first evidence of distinct biological functions of the protein moiety and its associated linear peptide for a specific lipoprotein. Therefore, lipoproteins in S. aureus consist of 3 functional components: a lipid moiety, a protein moiety, and a small linear peptide, with putative different biological roles that might not only determine the outcome of host-pathogen interactions but also drive the acquisition of antibiotic resistance determinants.
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Affiliation(s)
- Katrin Schilcher
- Department of Immunology and Microbiology, School of Medicine, University of Colorado, Anschutz Medical Campus, Aurora, Colorado, United States of America
- Department of Genetics and Genome Biology, University of Leicester, Leicester, United Kingdom
| | - Morgan M. Severn
- Department of Immunology and Microbiology, School of Medicine, University of Colorado, Anschutz Medical Campus, Aurora, Colorado, United States of America
| | - Christian Jenul
- Department of Immunology and Microbiology, School of Medicine, University of Colorado, Anschutz Medical Campus, Aurora, Colorado, United States of America
- Department of Genetics and Genome Biology, University of Leicester, Leicester, United Kingdom
| | - Young-Saeng C. Avina
- Department of Immunology and Microbiology, School of Medicine, University of Colorado, Anschutz Medical Campus, Aurora, Colorado, United States of America
| | - Rebecca A. Keogh
- Department of Immunology and Microbiology, School of Medicine, University of Colorado, Anschutz Medical Campus, Aurora, Colorado, United States of America
| | - Alexander R. Horswill
- Department of Immunology and Microbiology, School of Medicine, University of Colorado, Anschutz Medical Campus, Aurora, Colorado, United States of America
- Department of Veterans Affairs, Eastern Colorado Health Care System, Aurora, Colorado, United States of America
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Sabino YNV, Araújo Domingues KCD, Mathur H, Gómez-Mascaraque LG, Drouin G, Martínez-Abad A, Tótola MR, Abreu LM, Cotter PD, Mantovani HC. Exopolysaccharides produced by Bacillus spp. inhibit biofilm formation by Staphylococcus aureus strains associated with bovine mastitis. Int J Biol Macromol 2023; 253:126689. [PMID: 37678679 DOI: 10.1016/j.ijbiomac.2023.126689] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2023] [Revised: 08/22/2023] [Accepted: 09/02/2023] [Indexed: 09/09/2023]
Abstract
Bovine mastitis is a costly disease in the dairy sector worldwide. Here the objective was to identify and characterize anti-biofilm compounds produced by Bacillus spp. against S. aureus associated with bovine mastitis. Results showed that cell-free supernatants of three Bacillus strains (out of 33 analysed) reduced S. aureus biofilm formation by approximately 40 % without affecting bacterial growth. The anti-biofilm activity was associated with exopolysaccharides (EPS) secreted by Bacillus spp. The EPS decreased S. aureus biofilm formation in a dose-dependent manner, inhibiting biofilm formation by 83 % at 1 mg/mL. The EPS also showed some biofilm disruption activity (up to 36.4 %), which may be partially mediated by increased expression of the aur gene. The characterization of EPS produced by Bacillus velezensis 87 and B. velezensis TR47II revealed macromolecules with molecular weights of 31.2 and 33.7 kDa, respectively. These macromolecules were composed mainly of glucose (mean = 218.5 μg/mg) and mannose (mean = 241.5 μg/mg) and had similar functional groups (pyranose ring, beta-type glycosidic linkage, and alkynes) as revealed by FT-IR. In conclusion, this study shows the potential applications of EPS produced by B. velezensis as an anti-biofilm compound that could contribute to the treatment of bovine mastitis caused by S. aureus.
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Affiliation(s)
| | | | - Harsh Mathur
- Teagasc Food Research Centre, Moorepark, Fermoy, Co. Cork, Ireland
| | | | - Gaetan Drouin
- Teagasc Food Research Centre, Moorepark, Fermoy, Co. Cork, Ireland
| | | | - Marcos Rogério Tótola
- Department of Microbiology, Universidade Federal de Viçosa, Viçosa, Minas Gerais, Brazil
| | - Lucas Magalhães Abreu
- Department of Phytopathology, Universidade Federal de Viçosa, Viçosa, Minas Gerais, Brazil
| | - Paul D Cotter
- Teagasc Food Research Centre, Moorepark, Fermoy, Co. Cork, Ireland; APC Microbiome Ireland, Cork, Ireland
| | - Hilario Cuquetto Mantovani
- Department of Microbiology, Universidade Federal de Viçosa, Viçosa, Minas Gerais, Brazil; Department of Animal and Dairy Sciences, University of Wisconsin-Madison, Madison, WI, USA.
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Hassan RM, Abd El-Maksoud MS, Ghannam IAY, El-Azzouny AAS, Aboul-Enein MN. Synthetic non-toxic anti-biofilm agents as a strategy in combating bacterial resistance. Eur J Med Chem 2023; 262:115867. [PMID: 37866335 DOI: 10.1016/j.ejmech.2023.115867] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2023] [Revised: 09/26/2023] [Accepted: 10/09/2023] [Indexed: 10/24/2023]
Abstract
The tremendous increase in the bacterial resistance to the available antibiotics is a serious problem for the treatment of various infections. Biofilm formation in bacteria significantly contributes to the bacterial survival in host cells, and is considered as an crucial factor, responsible for bacterial resistance. The response of the bacterial cells in the biofilm to antibiotics is completely different from that of the free floating planktonic cells of the same strain. The anti-biofilm agents that could inhibit the biofilm production without affecting the bacterial growth, apply less selective pressure over the bacterial strains than the traditional antibiotics; thus the development of bacterial resistance would be of low incidence. Many attempts have been performed to discover novel agents capable of interfering with the bacterial biofilm life cycle, and several compounds have shown promising activities in suppressing the biofilm production or in dispersing mature existing biofilms. This review describes the different chemical classes that have anti-biofilm effects against different Gram-positive and Gram-negative bacteria without affecting the bacterial growth.
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Affiliation(s)
- Rasha Mohamed Hassan
- Medicinal and Pharmaceutical Chemistry Department, Pharmaceutical and Drug Industries Research Institute, National Research Centre (ID: 60014618), P.O. 12622, Dokki, Giza, Egypt.
| | - Mohamed Samir Abd El-Maksoud
- Medicinal and Pharmaceutical Chemistry Department, Pharmaceutical and Drug Industries Research Institute, National Research Centre (ID: 60014618), P.O. 12622, Dokki, Giza, Egypt
| | - Iman Ahmed Youssef Ghannam
- Chemistry of Natural and Microbial Products Department, Pharmaceutical and Drug Industries Research Institute, National Research Centre, Dokki, Cairo, 12622, Egypt
| | - Aida Abdel-Sattar El-Azzouny
- Medicinal and Pharmaceutical Chemistry Department, Pharmaceutical and Drug Industries Research Institute, National Research Centre (ID: 60014618), P.O. 12622, Dokki, Giza, Egypt
| | - Mohamed Nabil Aboul-Enein
- Medicinal and Pharmaceutical Chemistry Department, Pharmaceutical and Drug Industries Research Institute, National Research Centre (ID: 60014618), P.O. 12622, Dokki, Giza, Egypt.
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Goc A, Sumera W, Rath M, Niedzwiecki A. Inhibition of α-hemolysin activity of Staphylococcus aureus by theaflavin 3,3'-digallate. PLoS One 2023; 18:e0290904. [PMID: 37651426 PMCID: PMC10470925 DOI: 10.1371/journal.pone.0290904] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2023] [Accepted: 08/17/2023] [Indexed: 09/02/2023] Open
Abstract
The ongoing rise in antibiotic resistance, and a waning of the introduction of new antibiotics, has resulted in limited treatment options for bacterial infections, including these caused by methicillin-resistant Staphylococcus aureus, leaving the world in a post-antibiotic era. Here, we set out to examine mechanisms by which theaflavin 3,3'-digallate (TF3) might act as an anti-hemolytic compound. In the presented study, we found that TF3 has weak bacteriostatic and bactericidal effects on Staphylococcus aureus, and strong inhibitory effect towards the hemolytic activity of its α-hemolysin (Hla) including its production and secretion. A supportive SPR assay reinforced these results and further revealed binding of TF3 to Hla with KD = 4.57×10-5 M. Interestingly, TF3 was also able to protect human primary keratinocytes from Hla-induced cell death, being at the same time non-toxic for them. Further analysis of TF3 properties revealed that TF3 blocked Hla-prompting immune reaction by inhibiting production and secretion of IL1β, IL6, and TNFα in vitro and in vivo, through affecting NFκB activity. Additionally, we observed that TF3 also markedly attenuated S. aureus-induced barrier disruption, by inhibiting Hla-triggered E-cadherin and ZO-1 impairment. Overall, by blocking activity of Hla, TF3 subsequently subdued the inflammation and protected the epithelial barrier, which is considered as beneficial to relieving skin injury.
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Affiliation(s)
- Anna Goc
- Department of Infectious Diseases, Dr. Rath Research Institute, San Jose, California, United States of America
| | - Waldemar Sumera
- Department of Infectious Diseases, Dr. Rath Research Institute, San Jose, California, United States of America
| | - Matthias Rath
- Department of Infectious Diseases, Dr. Rath Research Institute, San Jose, California, United States of America
| | - Aleksandra Niedzwiecki
- Department of Infectious Diseases, Dr. Rath Research Institute, San Jose, California, United States of America
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Jenkins CH, Scott AE, O’Neill PA, Norville IH, Prior JL, Ireland PM. The Arabinose 5-Phosphate Isomerase KdsD Is Required for Virulence in Burkholderia pseudomallei. J Bacteriol 2023; 205:e0003423. [PMID: 37458584 PMCID: PMC10448790 DOI: 10.1128/jb.00034-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2023] [Accepted: 06/06/2023] [Indexed: 08/25/2023] Open
Abstract
Burkholderia pseudomallei is the causative agent of melioidosis, which is endemic primarily in Southeast Asia and northern Australia but is increasingly being seen in other tropical and subtropical regions of the world. Melioidosis is associated with high morbidity and mortality rates, which is mediated by the wide range of virulence factors encoded by B. pseudomallei. These virulence determinants include surface polysaccharides such as lipopolysaccharide (LPS) and capsular polysaccharides (CPS). Here, we investigated a predicted arabinose-5-phosphate isomerase (API) similar to KdsD in B. pseudomallei strain K96243. KdsD is required for the production of the highly conserved 3-deoxy-d-manno-octulosonic acid (Kdo), a key sugar in the core region of LPS. Recombinant KdsD was expressed and purified, and API activity was determined. Although a putative API paralogue (KpsF) is also predicted to be encoded, the deletion of kdsD resulted in growth defects, loss of motility, reduced survival in RAW 264.7 murine macrophages, and attenuation in a BALB/c mouse model of melioidosis. Suppressor mutations were observed during a phenotypic screen for motility, revealing single nucleotide polymorphisms or indels located in the poorly understood CPS type IV cluster. Crucially, suppressor mutations did not result in reversion of attenuation in vivo. This study demonstrates the importance of KdsD for B. pseudomallei virulence and highlights further the complex nature of the polysaccharides it produces. IMPORTANCE The intrinsic resistance of B. pseudomallei to many antibiotics complicates treatment. This opportunistic pathogen possesses a wide range of virulence factors, resulting in severe and potentially fatal disease. Virulence factors as targets for drug development offer an alternative approach to combat pathogenic bacteria. Prior to initiating early drug discovery approaches, it is important to demonstrate that disruption of the target gene will prevent the development of disease. This study highlights the fact that KdsD is crucial for virulence of B. pseudomallei in an animal model of infection and provides supportive phenotypic characterization that builds a foundation for future therapeutic development.
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Affiliation(s)
- Christopher H. Jenkins
- Chemical, Biological and Radiological Division, Defence Science and Technology Laboratory, Salisbury, Wiltshire, United Kingdom
| | - Andrew E. Scott
- Chemical, Biological and Radiological Division, Defence Science and Technology Laboratory, Salisbury, Wiltshire, United Kingdom
| | - Paul A. O’Neill
- University of Exeter Sequencing Service, Exeter, United Kingdom
| | - Isobel H. Norville
- Chemical, Biological and Radiological Division, Defence Science and Technology Laboratory, Salisbury, Wiltshire, United Kingdom
- Biosciences Department, University of Exeter, Exeter, United Kingdom
| | - Joann L. Prior
- Chemical, Biological and Radiological Division, Defence Science and Technology Laboratory, Salisbury, Wiltshire, United Kingdom
- Biosciences Department, University of Exeter, Exeter, United Kingdom
- Southampton General Hospital, Southampton, United Kingdom
| | - Philip M. Ireland
- Chemical, Biological and Radiological Division, Defence Science and Technology Laboratory, Salisbury, Wiltshire, United Kingdom
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Sabino YNV, Cotter PD, Mantovani HC. Anti-virulence compounds against Staphylococcus aureus associated with bovine mastitis: A new therapeutic option? Microbiol Res 2023; 271:127345. [PMID: 36889204 DOI: 10.1016/j.micres.2023.127345] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2022] [Revised: 02/22/2023] [Accepted: 02/26/2023] [Indexed: 03/05/2023]
Abstract
Bovine mastitis represents a major economic burden faced by the dairy industry. S. aureus is an important and prevalent bovine mastitis-associated pathogen in dairy farms worldwide. The pathogenicity and persistence of S. aureus in the bovine mammary gland are associated with the expression of a range of virulence factors involved in biofilm formation and the production of several toxins. The traditional therapeutic approach to treating bovine mastitis includes the use of antibiotics, but the emergence of antibiotic-resistant strains has caused therapeutic failure. New therapeutic approaches targeting virulence factors of S. aureus rather than cell viability can have several advantages including lower selective pressure towards the development of resistance and little impact on the host commensal microbiota. This review summarizes the potential of anti-virulence therapies to control S. aureus associated with bovine mastitis focusing on anti-toxin, anti-biofilm, and anti-quorum sensing compounds. It also points to potential sources of new anti-virulence inhibitors and presents screening strategies for identifying these compounds.
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Affiliation(s)
| | | | - Hilario C Mantovani
- Department of Animal and Dairy Sciences, University of Wisconsin-Madison, Madison, WI, USA.
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Bai YB, Yang XR, Li B, Zhou XZ, Wang WW, Cheng FS, Zhang JY. Virtual Screening and In Vitro Experimental Verification of LuxS Inhibitors for Escherichia coli O157:H7. Microbiol Spectr 2023; 11:e0350222. [PMID: 36809060 PMCID: PMC10100900 DOI: 10.1128/spectrum.03502-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2022] [Accepted: 02/02/2023] [Indexed: 02/23/2023] Open
Abstract
Enterohemorrhagic Escherichia coli O157:H7 is an important foodborne pathogen that forms biofilms. In this study, three quorum-sensing (QS) inhibitors (M414-3326, 3254-3286, and L413-0180) were obtained through virtual screening, and their in vitro antibiofilm activities were validated. Briefly, the three-dimensional structure model of LuxS was constructed and characterized using the SWISS-MODEL. High-affinity inhibitors were screened from the ChemDiv database (1,535,478 compounds) using LuxS as a ligand. Five compounds (L449-1159, L368-0079, M414-3326, 3254-3286, and L413-0180) with a good inhibitory effect (50% inhibitory concentration <10 μM) on type II QS signal molecule autoinducer-2 (AI-2) were obtained using a AI-2 bioluminescence assay. The absorption, distribution, metabolism, excretion, and toxicity (ADMET) properties predicated that the five compounds had high intestinal absorption levels (high) and plasma protein binding (absorbent strong) and did not inhibit the metabolism of CYP2D6 metabolic enzymes. In addition, molecular dynamics simulation showed that compounds L449-1159 and L368-0079 could not stably bind with LuxS. Thus, these compounds were excluded. Furthermore, surface plasmon resonance results showed that the three compounds could specifically bind to LuxS. IN addition, the three compounds could effectively inhibit the biofilm formation without affecting the growth and metabolism of the bacteria. Finally, the reverse transcription-quantitative PCR results showed that the three compounds downregulated the expression of the LuxS gene. Overall, these results revealed that the three compounds obtained through virtual screening could inhibit biofilm formation of E. coli O157:H7 and are potential LuxS inhibitors that can be used to treat E. coli O157:H7 infections. IMPORTANCE E. coli O157:H7 is a foodborne pathogen of public health importance. Quorum sensing (QS) is a form of bacterial communication that can regulate various group behaviors, including biofilm formation. Here, we identified three QS AI-2 inhibitors (M414-3326, 3254-3286, and L413-0180) that can stably and specifically bind to LuxS protein. The three QS AI-2 inhibitors inhibited biofilm formation without affecting the growth and metabolic activity of E. coli O157:H7. The three QS AI-2 inhibitors are promising agents for treating E. coli O157:H7 infections. Further studies to identify the mechanism of the three QS AI-2 inhibitors are needed to develop new drugs to overcome antibiotic resistance.
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Affiliation(s)
- Yu-Bin Bai
- Key Laboratory of New Animal Drug Project of Gansu Province, Lanzhou, Gansu, People’s Republic of China
- Key Laboratory of Veterinary Pharmaceutical Development, Ministry of Agriculture, Lanzhou, Gansu, People’s Republic of China
- Lanzhou Institute of Husbandry and Pharmaceutical Sciences, Chinese Academy of Agricultural Sciences, Lanzhou, Gansu, People’s Republic of China
| | - Xiao-Rong Yang
- Key Laboratory of New Animal Drug Project of Gansu Province, Lanzhou, Gansu, People’s Republic of China
- Key Laboratory of Veterinary Pharmaceutical Development, Ministry of Agriculture, Lanzhou, Gansu, People’s Republic of China
- Lanzhou Institute of Husbandry and Pharmaceutical Sciences, Chinese Academy of Agricultural Sciences, Lanzhou, Gansu, People’s Republic of China
| | - Bing Li
- Key Laboratory of New Animal Drug Project of Gansu Province, Lanzhou, Gansu, People’s Republic of China
- Key Laboratory of Veterinary Pharmaceutical Development, Ministry of Agriculture, Lanzhou, Gansu, People’s Republic of China
- Lanzhou Institute of Husbandry and Pharmaceutical Sciences, Chinese Academy of Agricultural Sciences, Lanzhou, Gansu, People’s Republic of China
| | - Xu-Zheng Zhou
- Key Laboratory of New Animal Drug Project of Gansu Province, Lanzhou, Gansu, People’s Republic of China
- Key Laboratory of Veterinary Pharmaceutical Development, Ministry of Agriculture, Lanzhou, Gansu, People’s Republic of China
- Lanzhou Institute of Husbandry and Pharmaceutical Sciences, Chinese Academy of Agricultural Sciences, Lanzhou, Gansu, People’s Republic of China
| | - Wei-Wei Wang
- Key Laboratory of New Animal Drug Project of Gansu Province, Lanzhou, Gansu, People’s Republic of China
- Key Laboratory of Veterinary Pharmaceutical Development, Ministry of Agriculture, Lanzhou, Gansu, People’s Republic of China
| | - Fu-Sheng Cheng
- Key Laboratory of New Animal Drug Project of Gansu Province, Lanzhou, Gansu, People’s Republic of China
- Key Laboratory of Veterinary Pharmaceutical Development, Ministry of Agriculture, Lanzhou, Gansu, People’s Republic of China
- Lanzhou Institute of Husbandry and Pharmaceutical Sciences, Chinese Academy of Agricultural Sciences, Lanzhou, Gansu, People’s Republic of China
| | - Ji-Yu Zhang
- Key Laboratory of New Animal Drug Project of Gansu Province, Lanzhou, Gansu, People’s Republic of China
- Key Laboratory of Veterinary Pharmaceutical Development, Ministry of Agriculture, Lanzhou, Gansu, People’s Republic of China
- Lanzhou Institute of Husbandry and Pharmaceutical Sciences, Chinese Academy of Agricultural Sciences, Lanzhou, Gansu, People’s Republic of China
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Otto M. Critical Assessment of the Prospects of Quorum-Quenching Therapy for Staphylococcus aureus Infection. Int J Mol Sci 2023; 24:ijms24044025. [PMID: 36835436 PMCID: PMC9958572 DOI: 10.3390/ijms24044025] [Citation(s) in RCA: 13] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2023] [Revised: 02/04/2023] [Accepted: 02/08/2023] [Indexed: 02/19/2023] Open
Abstract
Staphylococcus aureus is an important pathogen that causes a high number of infections and is one of the leading causes of death in hospitalized patients. Widespread antibiotic resistance such as in methicillin-resistant S. aureus (MRSA) has prompted research into potential anti-virulence-targeted approaches. Targeting the S. aureus accessory gene regulator (Agr) quorum-sensing system, a master regulator of virulence, is the most frequently proposed anti-virulence strategy for S. aureus. While much effort has been put into the discovery and screening for Agr inhibitory compounds, in vivo analysis of their efficacy in animal infection models is still rare and reveals various shortcomings and problems. These include (i) an almost exclusive focus on topical skin infection models, (ii) technical problems that leave doubt as to whether observed in vivo effects are due to quorum-quenching, and (iii) the discovery of counterproductive biofilm-increasing effects. Furthermore, potentially because of the latter, invasive S. aureus infection is associated with Agr dysfunctionality. Altogether, the potential of Agr inhibitory drugs is nowadays seen with low enthusiasm given the failure to provide sufficient in vivo evidence for their potential after more than two decades since the initiation of such efforts. However, current Agr inhibition-based probiotic approaches may lead to a new application of Agr inhibition strategies in preventing S. aureus infections by targeting colonization or for otherwise difficult-to-treat skin infections such as atopic dermatitis.
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Affiliation(s)
- Michael Otto
- Pathogen Molecular Genetics Section, Laboratory of Bacteriology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20814, USA
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12
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Genetic and Environmental Investigation of a Novel Phenylamino Acetamide Inhibitor of the Pseudomonas aeruginosa Type III Secretion System. Appl Environ Microbiol 2023; 89:e0175222. [PMID: 36519869 PMCID: PMC9888221 DOI: 10.1128/aem.01752-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Traditional antibiotics target essential cellular components or metabolic pathways conserved in both pathogenic and nonpathogenic bacteria. Unfortunately, long-term antibiotic use often leads to antibiotic resistance and disruption of the overall microbiota. In this work, we identified a phenylamino acetamide compound, named 187R, that strongly inhibited the expression of the type III secretion system (T3SS) encoding genes and the secretion of the T3SS effector proteins in Pseudomonas aeruginosa. T3SS is an important virulence factor, as T3SS-deficient strains of P. aeruginosa are greatly attenuated in virulence. We further showed that 187R had no effect on bacterial growth, implying a reduced selective pressure for the development of resistance. 187R-mediated repression of T3SS was dependent on ExsA, the master regulator of T3SS in P. aeruginosa. The impact of 187R on the host-associated microbial community was also tested using the Arabidopsis thaliana phyllosphere as a model. Both culture-independent (Illumina sequencing) and culture-dependent (Biolog) methods showed that the application of 187R had little impact on the composition and function of microbial community compared to the antibiotic streptomycin. Together, these results suggested that compounds that target virulence factors could serve as an alternative strategy for disease management caused by bacterial pathogens. IMPORTANCE New antimicrobial therapies are urgently needed, since antibiotic resistance in human pathogens has become one of the world's most urgent public health problems. Antivirulence therapy has been considered a promising alternative for the management of infectious diseases, as antivirulence compounds target only the virulence factors instead of the growth of bacteria, and they are therefore unlikely to affect commensal microorganisms. However, the impacts of antivirulence compounds on the host microbiota are not well understood. We report a potent synthetic inhibitor of the P. aeruginosa T3SS, 187R, and its effect on the host microbiota of Arabidopsis. Both culture-independent (Illumina sequencing) and culture-dependent (Biolog) methods showed that the impacts of the antivirulence compound on the composition and function of host microbiota were limited. These results suggest that antivirulence compounds can be a potential alternative method to antibiotics.
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13
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Lyagin I, Stepanov N, Presnov D, Trifonov A, Efremenko E. Self-Assembling Enzymatic Nanocomplexes with Polypeptides and Low-Weight Organic Compounds: Preparation, Characterization, and Application of New Antibacterials. Int J Mol Sci 2023; 24:ijms24031831. [PMID: 36768158 PMCID: PMC9915939 DOI: 10.3390/ijms24031831] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2022] [Revised: 01/12/2023] [Accepted: 01/15/2023] [Indexed: 01/18/2023] Open
Abstract
The self-assembling of nanosized materials is a promising field for research and development. Multiple approaches are applied to obtain inorganic, organic and composite nanomaterials with different functionality. In the present work, self-assembling nanocomplexes (NCs) were prepared on the basis of enzymes and polypeptides followed by the investigation of the influence of low-molecular weight biologically active compounds on the properties of the NCs. For that, the initially possible formation of catalytically active self-assembling NCs of four hydrolytic enzymes with nine effectors was screened via molecular modeling. It allowed the selection of two enzymes (hexahistidine-tagged organophosphorus hydrolase and penicillin acylase) and two compounds (emodin and naringenin) having biological activity. Further, such NCs based on surface-modified enzymes were characterized by a batch of physical and biochemical methods. At least three NCs containing emodin and enzyme (His6-OPH and/or penicillin acylase) have been shown to significantly improve the antibacterial activity of colistin and, to a lesser extent, polymyxin B towards both Gram-positive bacteria (Bacillus subtilis) and Gram-negative bacteria (Escherichia coli).
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Affiliation(s)
- Ilya Lyagin
- Faculty of Chemistry, Lomonosov Moscow State University, 119991 Moscow, Russia
| | - Nikolay Stepanov
- Faculty of Chemistry, Lomonosov Moscow State University, 119991 Moscow, Russia
| | - Denis Presnov
- Skobeltsyn Institute of Nuclear Physics, Lomonosov Moscow State University, 119991 Moscow, Russia
| | - Artem Trifonov
- Faculty of Physics, Lomonosov Moscow State University, 119991 Moscow, Russia
| | - Elena Efremenko
- Faculty of Chemistry, Lomonosov Moscow State University, 119991 Moscow, Russia
- Correspondence: ; Tel.: +7-495-939-3170; Fax: +7-495-939-5417
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14
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Formato M, Vastolo A, Piccolella S, Calabrò S, Cutrignelli MI, Zidorn C, Pacifico S. Castanea sativa Mill. Leaf: UHPLC-HR MS/MS Analysis and Effects on In Vitro Rumen Fermentation and Methanogenesis. MOLECULES (BASEL, SWITZERLAND) 2022; 27:molecules27248662. [PMID: 36557796 PMCID: PMC9785889 DOI: 10.3390/molecules27248662] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/23/2022] [Revised: 12/02/2022] [Accepted: 12/02/2022] [Indexed: 12/14/2022]
Abstract
Castanea sativa Mill. (Fagaceae) is a deciduous tree grown for its wood and edible fruits. Chestnut processing produces residues (burs, shells, and leaves) exploitable for their diversity in bioactive compounds in animal nutrition. In fact, plant-specialized metabolites likely act as rumen modifiers. Thus, the recovery of residual plant parts as feed ingredients is an evaluable strategy. In this context, European chestnut leaves from northern Germany have been investigated, proving to be a good source of flavonoids as well as gallo- and ellagitannins. To this purpose, an alcoholic extract was obtained and an untargeted profiling carried out, mainly by means of ultra-high-performance liquid chromatography/high-resolution tandem mass spectrometry (UHPLC-HR MS/MS) techniques. To better unravel the polyphenol constituents, fractionation strategies were employed to obtain a lipophilic fraction and a polar one. This latter was highly responsive to total phenolic and flavonoid content analyses, as well as to antiradical (DPPH● and ABTS+●) and reducing activity (PFRAP) assays. The effect of the alcoholic extract and its fractions on rumen liquor was also evaluated in vitro in terms of fermentative parameter changes and impact on methanogenesis. The data acquired confirm that chestnut leaf extract and the fractions therefrom promote an increase in total volatile fatty acids, while decreasing acetate/propionate ratio and CH4 production.
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Affiliation(s)
- Marialuisa Formato
- Department of Environmental, Biological and Pharmaceutical Sciences and Technologies, University of Campania ‘Luigi Vanvitelli’, Via Vivaldi 43, 81100 Caserta, Italy
| | - Alessandro Vastolo
- Department of Veterinary Medicine and Animal Production, University of Naples Federico II, Via Federico Delpino 1, 80137 Napoli, Italy
| | - Simona Piccolella
- Department of Environmental, Biological and Pharmaceutical Sciences and Technologies, University of Campania ‘Luigi Vanvitelli’, Via Vivaldi 43, 81100 Caserta, Italy
| | - Serena Calabrò
- Department of Veterinary Medicine and Animal Production, University of Naples Federico II, Via Federico Delpino 1, 80137 Napoli, Italy
| | - Monica Isabella Cutrignelli
- Department of Veterinary Medicine and Animal Production, University of Naples Federico II, Via Federico Delpino 1, 80137 Napoli, Italy
| | - Christian Zidorn
- Pharmazeutisches Institut, Abteilung Pharmazeutische Biologie, Christian-Albrechts-Universität zu Kiel, Gutenbergstraße 76, 24118 Kiel, Germany
| | - Severina Pacifico
- Department of Environmental, Biological and Pharmaceutical Sciences and Technologies, University of Campania ‘Luigi Vanvitelli’, Via Vivaldi 43, 81100 Caserta, Italy
- Correspondence:
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15
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Gupta DS, Kumar MS. The implications of quorum sensing inhibition in bacterial antibiotic resistance- with a special focus on aquaculture. J Microbiol Methods 2022; 203:106602. [PMID: 36270462 DOI: 10.1016/j.mimet.2022.106602] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2022] [Revised: 10/06/2022] [Accepted: 10/13/2022] [Indexed: 11/06/2022]
Abstract
The aquaculture industry is an expanding and demanding industry and due to an increase in urbanization, with rise in income of developing countries population, it offers to provide a sustainable food supply. However, the industry is facing a number of challenges, out of which few needs to be tackled immediately to maximise the productivity. An upcoming problem is the emergence of antibiotic resistant pathogens due to the unchecked use of antibiotics in aquaculture and human clinical practices. A wide variety of aquatic pathogens such as Edwardsiella, Vibrio, and Aeromonas spp. use quorum sensing (QS) systems, a regulatory process involving cell communication via signalling molecules for the collective function of pathogens which regulates the genes expression including virulent genes. Quorum sensing results in bacterial biofilms formation, which leads to their reduced susceptibility towards antimicrobial agents. The usage of quorum sensing inhibitors (QSIs) has been proposed as an attractive strategy to tackle this problem. Due to the modulation of virulence genes expression, QSIs can be used as novel and viable approach to overcome antibiotic resistance in aquaculture. In this review, we direct our attention to the quorum sensing phenomenon and its viability as a target pathway for tackling the ever-growing problem of antimicrobial resistance in aquaculture. This review also provides a concise compilation of the currently available QSIs and investigates possible natural sources for quorum quenching.
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Affiliation(s)
- Dhruv S Gupta
- Shobhaben Pratapbhai Patel School of Pharmacy and Technology Management, SVKM'(S) NMIMS, Vile Parle (w), Mumbai 400056, India
| | - Maushmi S Kumar
- Shobhaben Pratapbhai Patel School of Pharmacy and Technology Management, SVKM'(S) NMIMS, Vile Parle (w), Mumbai 400056, India.
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16
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Bai YB, Shi MY, Wang WW, Wu LY, Bai YT, Li B, Zhou XZ, Zhang JY. Novel quorum sensing inhibitor Echinatin as an antibacterial synergist against Escherichia coli. Front Microbiol 2022; 13:1003692. [PMID: 36386683 PMCID: PMC9663819 DOI: 10.3389/fmicb.2022.1003692] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2022] [Accepted: 10/14/2022] [Indexed: 12/05/2022] Open
Abstract
A new antibacterial strategy based on inhibiting bacterial quorum sensing (QS) has emerged as a promising method of attenuating bacterial pathogenicity and preventing bacterial resistance to antibiotics. In this study, we screened Echinatin (Ech) with high-efficiency anti-QS from 13 flavonoids through the AI-2 bioluminescence assay. Additionally, crystal violet (CV) staining combined with confocal laser scanning microscopy (CLSM) was used to evaluate the effect of anti-biofilm against Escherichia coli (E. coli). Further, the antibacterial synergistic effect of Ech and marketed antibiotics were measured by broth dilution and Alamar Blue Assay. It was found that Ech interfered with the phenotype of QS, including biofilm formation, exopolysaccharide (EPS) production, and motility, without affecting bacterial growth and metabolic activity. Moreover, qRT-PCR exhibited that Ech significantly reduced the expression of QS-regulated genes (luxS, pfs, lsrB, lsrK, lsrR, flhC, flhD, fliC, csgD, and stx2). More important, Ech with currently marketed colistin antibiotics (including colistin B and colistin E) showed significantly synergistically increased antibacterial activity in overcoming antibiotic resistance of E. coli. In summary, these results suggested the potent anti-QS and novel antibacterial synergist candidate of Ech for treating E. coli infections.
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Affiliation(s)
- Yu-Bin Bai
- Key Laboratory of New Animal Drug Project of Gansu Province, Lanzhou, China,Key Laboratory of Veterinary Pharmaceutical Development, Ministry of Agriculture, Lanzhou, China,Lanzhou Institute of Husbandry and Pharmaceutical Sciences, Chinese Academy of Agricultural Sciences, Lanzhou, China
| | - Meng-Yan Shi
- Key Laboratory of New Animal Drug Project of Gansu Province, Lanzhou, China,Key Laboratory of Veterinary Pharmaceutical Development, Ministry of Agriculture, Lanzhou, China,Lanzhou Institute of Husbandry and Pharmaceutical Sciences, Chinese Academy of Agricultural Sciences, Lanzhou, China
| | - Wei-Wei Wang
- Key Laboratory of New Animal Drug Project of Gansu Province, Lanzhou, China,Key Laboratory of Veterinary Pharmaceutical Development, Ministry of Agriculture, Lanzhou, China,Lanzhou Institute of Husbandry and Pharmaceutical Sciences, Chinese Academy of Agricultural Sciences, Lanzhou, China
| | - Ling-Yu Wu
- Key Laboratory of New Animal Drug Project of Gansu Province, Lanzhou, China,Key Laboratory of Veterinary Pharmaceutical Development, Ministry of Agriculture, Lanzhou, China,Lanzhou Institute of Husbandry and Pharmaceutical Sciences, Chinese Academy of Agricultural Sciences, Lanzhou, China
| | - Yu-Ting Bai
- Key Laboratory of New Animal Drug Project of Gansu Province, Lanzhou, China,Key Laboratory of Veterinary Pharmaceutical Development, Ministry of Agriculture, Lanzhou, China,Lanzhou Institute of Husbandry and Pharmaceutical Sciences, Chinese Academy of Agricultural Sciences, Lanzhou, China
| | - Bing Li
- Key Laboratory of New Animal Drug Project of Gansu Province, Lanzhou, China,Key Laboratory of Veterinary Pharmaceutical Development, Ministry of Agriculture, Lanzhou, China,Lanzhou Institute of Husbandry and Pharmaceutical Sciences, Chinese Academy of Agricultural Sciences, Lanzhou, China
| | - Xu-Zheng Zhou
- Key Laboratory of New Animal Drug Project of Gansu Province, Lanzhou, China,Key Laboratory of Veterinary Pharmaceutical Development, Ministry of Agriculture, Lanzhou, China,Lanzhou Institute of Husbandry and Pharmaceutical Sciences, Chinese Academy of Agricultural Sciences, Lanzhou, China
| | - Ji-Yu Zhang
- Key Laboratory of New Animal Drug Project of Gansu Province, Lanzhou, China,Key Laboratory of Veterinary Pharmaceutical Development, Ministry of Agriculture, Lanzhou, China,Lanzhou Institute of Husbandry and Pharmaceutical Sciences, Chinese Academy of Agricultural Sciences, Lanzhou, China,*Correspondence: Ji-Yu Zhang,
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17
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Jordan SC, Hall PR, Daly SM. Nonconformity of biofilm formation in vivo and in vitro based on Staphylococcus aureus accessory gene regulator status. Sci Rep 2022; 12:1251. [PMID: 35075262 PMCID: PMC8786897 DOI: 10.1038/s41598-022-05382-w] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2021] [Accepted: 01/07/2022] [Indexed: 12/27/2022] Open
Abstract
Staphylococcus aureus is an opportunistic, pathogenic bacteria that causes significant morbidity and mortality. As antibiotic resistance by S. aureus continues to be a serious concern, developing novel drug therapies to combat these infections is vital. Quorum sensing inhibitors (QSI) dampen S. aureus virulence and facilitate clearance by the host immune system by blocking quorum sensing signaling that promotes upregulation of virulence genes controlled by the accessory gene regulator (agr) operon. While QSIs have shown therapeutic promise in mouse models of S. aureus skin infection, their further development has been hampered by the suggestion that agr inhibition promotes biofilm formation. In these studies, we investigated the relationship between agr function and biofilm growth across various S. aureus strains and experimental conditions, including in a mouse model of implant-associated infection. We found that agr deletion was associated with the presence of increased biofilm only under narrow in vitro conditions and, crucially, was not associated with enhanced biofilm development or enhanced morbidity in vivo.
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Affiliation(s)
- S Caroline Jordan
- Department of Pharmaceutical Sciences, University of New Mexico College of Pharmacy, Albuquerque, NM, 87131, USA
| | - Pamela R Hall
- Department of Pharmaceutical Sciences, University of New Mexico College of Pharmacy, Albuquerque, NM, 87131, USA
| | - Seth M Daly
- Department of Pharmaceutical Sciences, University of New Mexico College of Pharmacy, Albuquerque, NM, 87131, USA.
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18
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Ali F, Cai Q, Hu J, Zhang L, Hoare R, Monaghan SJ, Pang H. In silico analysis of AhyI protein and AI-1 inhibition using N-cis-octadec-9z-enoyl-l-homoserine lactone inhibitor in Aeromonas hydrophila. Microb Pathog 2021; 162:105356. [PMID: 34915138 DOI: 10.1016/j.micpath.2021.105356] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2021] [Revised: 11/26/2021] [Accepted: 12/07/2021] [Indexed: 10/19/2022]
Abstract
AhyI is homologous to the protein LuxI and is conserved throughout bacterial species including Aeromonas hydrophila. A. hydrophila causes opportunistic infections in fish and other aquatic organisms. Furthermore, this pathogennot only poses a great risk for the aquaculture industry, but also for human public health. AhyI (expressing acylhomoserine lactone) is responsible for the biosynthesis of autoinducer-1 (AI-1), commonly referred to as a quorum sensing (QS) signaling molecule, which plays an essential role in bacterial communication. Studying protein structure is essential for understanding molecular mechanisms of pathogenicity in microbes. Here, we have deduced a predicted structure of AhyI protein and characterized its function using in silico methods to aid the development of new treatments for controlling A.hydrophila infections. In addition to modeling AhyI, an appropriate inhibitor molecule was identified via high throughput virtual screening (HTVS) using mcule drug-like databases.The AhyI-inhibitor N-cis-octadec-9Z-enoyl-l-Homoserine lactone was selected withthe best drug score. In order to understand the pocket sites (ligand binding sites) and their interaction with the selected inhibitor, docking (predicted protein binding complex) servers were used and the selected ligand was docked with the predicted AhyI protein model. Remarkably, N-cis-octadec-9Z-enoyl-l-Homoserine lactone established interfaces with the protein via16 residues (V24, R27, F28, R31, W34, V36, D45, M77, F82, T101, R102, L103, 104, V143, S145, and V168), which are involved with regulating mechanisms of inhibition. These proposed predictions suggest that this inhibitor molecule may be used as a novel drug candidate for the inhibition of auto-inducer-1 (AI-1) activity.The N-cis-octadec-9Z-enoyl-l-Homoserine lactone inhibitor molecule was studied on cultured bacteria to validate its potency against AI-1 production. At a concentration of 40 μM, optimal inhibition efficiency of AI-1 was observedin bacterial culture media.These results suggest that the inhibitor molecule N-cis-octadec-9Z-enoyl-l-Homoserine lactone is a competitive inhibitor of AI-1 biosynthesis.
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Affiliation(s)
- Farman Ali
- Fujian Provincial Key Laboratory of Agro Ecological Processing and Safety Monitoring, College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, 35002, China; Key Laboratory of Crop Ecology and Molecular Physiology (Fujian Agriculture and Forestry University) Fujian Province University, Fuzhou, 35002, China
| | - Qilan Cai
- Fujian Provincial Key Laboratory of Agro Ecological Processing and Safety Monitoring, College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, 35002, China; Key Laboratory of Crop Ecology and Molecular Physiology (Fujian Agriculture and Forestry University) Fujian Province University, Fuzhou, 35002, China
| | - Jialing Hu
- College of Fisheries, Guangdong Ocean University, Zhanjiang, 524025, China; Guangdong Provincial Key Laboratory of Pathogenic Biology and Epidemiology for Aquatic Economic Animal, Key Laboratory of Control for Disease of Aquatic Animals of Guangdong Higher Education Institutes, Zhanjiang, 524025, China
| | - Lishan Zhang
- Fujian Provincial Key Laboratory of Agro Ecological Processing and Safety Monitoring, College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, 35002, China; Key Laboratory of Crop Ecology and Molecular Physiology (Fujian Agriculture and Forestry University) Fujian Province University, Fuzhou, 35002, China
| | - Rowena Hoare
- Institute of Aquaculture, University of Stirling, Stirling, FK9 4LA, Scotland, UK
| | - Sean J Monaghan
- Institute of Aquaculture, University of Stirling, Stirling, FK9 4LA, Scotland, UK
| | - Huanying Pang
- College of Fisheries, Guangdong Ocean University, Zhanjiang, 524025, China; Guangdong Provincial Key Laboratory of Pathogenic Biology and Epidemiology for Aquatic Economic Animal, Key Laboratory of Control for Disease of Aquatic Animals of Guangdong Higher Education Institutes, Zhanjiang, 524025, China.
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19
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Díaz-Núñez JL, Pérez-López M, Espinosa N, Campos-Hernández N, García-Contreras R, Díaz-Guerrero M, Cortes-López H, Vázquez-Sánchez M, Quezada H, Martínez-Vázquez M, Soto-Hernández RM, Burgos-Hernández M, González-Pedrajo B, Castillo-Juárez I. Anti-Virulence Properties of Plant Species: Correlation between In Vitro Activity and Efficacy in a Murine Model of Bacterial Infection. Microorganisms 2021; 9:2424. [PMID: 34946027 PMCID: PMC8706108 DOI: 10.3390/microorganisms9122424] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2021] [Revised: 11/13/2021] [Accepted: 11/15/2021] [Indexed: 11/17/2022] Open
Abstract
Several plant extracts exhibit anti-virulence properties due to the interruption of bacterial quorum sensing (QS). However, studies on their effects at the preclinical level are scarce. Here, we used a murine model of abscess/necrosis induced by Pseudomonas aeruginosa to evaluate the anti-pathogenic efficacy of 24 plant extracts at a sub-inhibitory concentration. We analyzed their ability to inhibit QS-regulated virulence factors such as swarming, pyocyanin production, and secretion of the ExoU toxin via the type III secretion system (T3SS). Five of the seven extracts with the best anti-pathogenic activity reduced ExoU secretion, and the extracts of Diphysa americana and Hibiscus sabdariffa were identified as the most active. Therefore, the abscess/necrosis model allows identification of plant extracts that have the capacity to reduce pathogenicity of P. aeruginosa. Furthermore, we evaluated the activity of the plant extracts on Chromobacterium violaceum. T3SS (ΔescU) and QS (ΔcviI) mutant strains were assessed in both the abscess/necrosis and sepsis models. Only the ΔescU strain had lower pathogenicity in the animal models, although no activity of plant extracts was observed. These results demonstrate differences between the anti-virulence activity recorded in vitro and pathogenicity in vivo and between the roles of QS and T3S systems as virulence determinants.
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Affiliation(s)
- José Luis Díaz-Núñez
- Laboratorio de Fitoquímica, Posgrado de Botánica, Colegio de Postgraduados, Texcoco 56230, Mexico; (J.L.D.-N.); (M.P.-L.); (N.C.-H.); (H.C.-L.); (M.V.-S.); (R.M.S.-H.); (M.B.-H.)
| | - Macrina Pérez-López
- Laboratorio de Fitoquímica, Posgrado de Botánica, Colegio de Postgraduados, Texcoco 56230, Mexico; (J.L.D.-N.); (M.P.-L.); (N.C.-H.); (H.C.-L.); (M.V.-S.); (R.M.S.-H.); (M.B.-H.)
| | - Norma Espinosa
- Departamento de Genética Molecular, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, Ciudad de México 04510, Mexico; (N.E.); (M.D.-G.)
| | - Nayelli Campos-Hernández
- Laboratorio de Fitoquímica, Posgrado de Botánica, Colegio de Postgraduados, Texcoco 56230, Mexico; (J.L.D.-N.); (M.P.-L.); (N.C.-H.); (H.C.-L.); (M.V.-S.); (R.M.S.-H.); (M.B.-H.)
| | - Rodolfo García-Contreras
- Departamento de Microbiología y Parasitología, Facultad de Medicina, Universidad Nacional Autónoma de México, Ciudad de México 04510, Mexico;
| | - Miguel Díaz-Guerrero
- Departamento de Genética Molecular, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, Ciudad de México 04510, Mexico; (N.E.); (M.D.-G.)
| | - Humberto Cortes-López
- Laboratorio de Fitoquímica, Posgrado de Botánica, Colegio de Postgraduados, Texcoco 56230, Mexico; (J.L.D.-N.); (M.P.-L.); (N.C.-H.); (H.C.-L.); (M.V.-S.); (R.M.S.-H.); (M.B.-H.)
| | - Monserrat Vázquez-Sánchez
- Laboratorio de Fitoquímica, Posgrado de Botánica, Colegio de Postgraduados, Texcoco 56230, Mexico; (J.L.D.-N.); (M.P.-L.); (N.C.-H.); (H.C.-L.); (M.V.-S.); (R.M.S.-H.); (M.B.-H.)
| | - Héctor Quezada
- Laboratorio de Investigación en Inmunología y Proteómica, Hospital Infantil de México Federico Gómez, Ciudad de México 06720, Mexico;
| | - Mariano Martínez-Vázquez
- Departamento de Productos Naturales, Instituto de Química, Universidad Nacional Autόnoma de México, Ciudad de México 04510, Mexico;
| | - Ramón Marcos Soto-Hernández
- Laboratorio de Fitoquímica, Posgrado de Botánica, Colegio de Postgraduados, Texcoco 56230, Mexico; (J.L.D.-N.); (M.P.-L.); (N.C.-H.); (H.C.-L.); (M.V.-S.); (R.M.S.-H.); (M.B.-H.)
| | - Mireya Burgos-Hernández
- Laboratorio de Fitoquímica, Posgrado de Botánica, Colegio de Postgraduados, Texcoco 56230, Mexico; (J.L.D.-N.); (M.P.-L.); (N.C.-H.); (H.C.-L.); (M.V.-S.); (R.M.S.-H.); (M.B.-H.)
| | - Bertha González-Pedrajo
- Departamento de Genética Molecular, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, Ciudad de México 04510, Mexico; (N.E.); (M.D.-G.)
| | - Israel Castillo-Juárez
- Laboratorio de Fitoquímica, Posgrado de Botánica, Colegio de Postgraduados, Texcoco 56230, Mexico; (J.L.D.-N.); (M.P.-L.); (N.C.-H.); (H.C.-L.); (M.V.-S.); (R.M.S.-H.); (M.B.-H.)
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Wang S, Feng Y, Han X, Cai X, Yang L, Liu C, Shen L. Inhibition of Virulence Factors and Biofilm Formation by Wogonin Attenuates Pathogenicity of Pseudomonas aeruginosa PAO1 via Targeting pqs Quorum-Sensing System. Int J Mol Sci 2021; 22:ijms222312699. [PMID: 34884499 PMCID: PMC8657757 DOI: 10.3390/ijms222312699] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Revised: 11/17/2021] [Accepted: 11/22/2021] [Indexed: 02/06/2023] Open
Abstract
Pseudomonas aeruginosa, an important opportunistic pathogen, is capable of producing various virulence factors and forming biofilm that are regulated by quorum sensing (QS). It is known that targeting virulence factor production and biofilm formation instead of exerting selective pressure on growth such as conventional antibiotics can reduce multidrug resistance in bacteria. Therefore, many quorum-sensing inhibitors (QSIs) have been developed to prevent or treat this bacterial infection. In this study, wogonin, as an active ingredient from Agrimonia pilosa, was found to be able to inhibit QS system of P. aeruginosa PAO1. Wogonin downregulated the expression of QS-related genes and reduced the production of many virulence factors, such as elastase, pyocyanin, and proteolytic enzyme. In addition, wogonin decreased the extracellular polysaccharide synthesis and inhibited twitching, swimming, and swarming motilities and biofilm formation. The attenuation of pathogenicity in P. aeruginosa PAO1 by wogonin application was further validated in vivo by cabbage infection and fruit fly and nematode survival experiments. Further molecular docking analysis, pathogenicity examination of various QS-related mutants, and PQS signal molecule detection revealed that wogonin could interfere with PQS signal molecular synthesis by affecting pqsA and pqsR. Taken together, the results indicated that wogonin might be used as an anti-QS candidate drug to attenuate the infection caused by P. aeruginosa.
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Affiliation(s)
- Shiwei Wang
- Key Laboratory of Resources Biology and Biotechnology in Western China, Ministry of Education, The College of Life Sciences, Northwest University, Xi’an 710069, China; (S.W.); (Y.F.); (X.H.); (X.C.); (L.Y.)
- Provincial Key Laboratory of Biotechnology of Shaanxi Province, The College of Life Sciences, Northwest University, Xi’an 710069, China
| | - Yuqi Feng
- Key Laboratory of Resources Biology and Biotechnology in Western China, Ministry of Education, The College of Life Sciences, Northwest University, Xi’an 710069, China; (S.W.); (Y.F.); (X.H.); (X.C.); (L.Y.)
| | - Xiaofeng Han
- Key Laboratory of Resources Biology and Biotechnology in Western China, Ministry of Education, The College of Life Sciences, Northwest University, Xi’an 710069, China; (S.W.); (Y.F.); (X.H.); (X.C.); (L.Y.)
| | - Xinyu Cai
- Key Laboratory of Resources Biology and Biotechnology in Western China, Ministry of Education, The College of Life Sciences, Northwest University, Xi’an 710069, China; (S.W.); (Y.F.); (X.H.); (X.C.); (L.Y.)
| | - Liu Yang
- Key Laboratory of Resources Biology and Biotechnology in Western China, Ministry of Education, The College of Life Sciences, Northwest University, Xi’an 710069, China; (S.W.); (Y.F.); (X.H.); (X.C.); (L.Y.)
| | - Chaolan Liu
- Antibiotics Research and Re-Evaluation Key Laboratory of Sichuan Province, Sichuan Industrial Institute of Antibiotics, Chengdu University, No. 168, Huaguan Road, Chengdu 610052, China;
| | - Lixin Shen
- Key Laboratory of Resources Biology and Biotechnology in Western China, Ministry of Education, The College of Life Sciences, Northwest University, Xi’an 710069, China; (S.W.); (Y.F.); (X.H.); (X.C.); (L.Y.)
- Correspondence:
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21
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Bhosale H, Ramakrishnan V, Jayaraman VK. Support vector machine-based prediction of pore-forming toxins (PFT) using distributed representation of reduced alphabets. J Bioinform Comput Biol 2021; 19:2150028. [PMID: 34693886 DOI: 10.1142/s0219720021500281] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Bacterial virulence can be attributed to a wide variety of factors including toxins that harm the host. Pore-forming toxins are one class of toxins that confer virulence to the bacteria and are one of the promising targets for therapeutic intervention. In this work, we develop a sequence-based machine learning framework for the prediction of pore-forming toxins. For this, we have used distributed representation of the protein sequence encoded by reduced alphabet schemes based on conformational similarity and hydropathy index as input features to Support Vector Machines (SVMs). The choice of conformational similarity and hydropathy indices is based on the functional mechanism of pore-forming toxins. Our methodology achieves about 81% accuracy indicating that conformational similarity, an indicator of the flexibility of amino acids, along with hydrophobic index can capture the intrinsic features of pore-forming toxins that distinguish it from other types of transporter proteins. Increased understanding of the mechanisms of pore-forming toxins can further contribute to the use of such "mechanism-informed" features that may increase the prediction accuracy further.
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Affiliation(s)
- Hrushikesh Bhosale
- Department of Computer Science, FLAME University, Pune, Maharashtra, India
| | - Vigneshwar Ramakrishnan
- School of Chemical & Biotechnology, SASTRA Deemed-to-be University, Thanjavur, Tamilnadu, India
| | - Valadi K Jayaraman
- Department of Computer Science, FLAME University, Pune, Maharashtra, India
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22
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Salam AM, Porras G, Cho YSK, Brown MM, Risener CJ, Marquez L, Lyles JT, Bacsa J, Horswill AR, Quave CL. Castaneroxy A From the Leaves of Castanea sativa Inhibits Virulence in Staphylococcus aureus. Front Pharmacol 2021; 12:640179. [PMID: 34262448 PMCID: PMC8274328 DOI: 10.3389/fphar.2021.640179] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2020] [Accepted: 06/01/2021] [Indexed: 01/05/2023] Open
Abstract
Methicillin-resistant Staphylococcus aureus (MRSA) represents one of the most serious infectious disease concerns worldwide, with the CDC labeling it a "serious threat" in 2019. The current arsenal of antibiotics works by targeting bacterial growth and survival, which exerts great selective pressure for the development of resistance. The development of novel anti-infectives that inhibit quorum sensing and thus virulence in MRSA has been recurrently proposed as a promising therapeutic approach. In a follow-up of a study examining the MRSA quorum sensing inhibitory activity of extracts of Italian plants used in local traditional medicine, 224C-F2 was reported as a bioactive fraction of a Castanea sativa (European chestnut) leaf extract. The fraction demonstrated high activity in vitro and effective attenuation of MRSA pathogenicity in a mouse model of skin infection. Through further bioassay-guided fractionation using reverse-phase high performance liquid chromatography, a novel hydroperoxy cycloartane triterpenoid, castaneroxy A (1), was isolated. Its structure was established by nuclear magnetic resonance, mass spectrometry and X-ray diffraction analyses. Isomers of 1 were also detected in an adjacent fraction. In a series of assays assessing inhibition of markers of MRSA virulence, 1 exerted activities in the low micromolar range. It inhibited agr::P3 activation (IC50 = 31.72 µM), δ-toxin production (IC50 = 31.72 µM in NRS385), supernatant cytotoxicity to HaCaT human keratinocytes (IC50 = 7.93 µM in NRS385), and rabbit erythrocyte hemolytic activity (IC50 = 7.93 µM in LAC). Compound 1 did not inhibit biofilm production, and at high concentrations it exerted cytotoxicity against human keratinocytes greater than that of 224C-F2. Finally, 1 reduced dermonecrosis in a murine model of MRSA infection. The results establish 1 as a promising antivirulence candidate for development against MRSA.
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Affiliation(s)
- Akram M Salam
- Program in Molecular and Systems Pharmacology, Laney Graduate School, Emory University, Atlanta, GA, United States
| | - Gina Porras
- Center for the Study of Human Health, Emory University, Atlanta, GA, United States
| | - Young-Saeng K Cho
- Department of Immunology and Microbiology, University of Colorado Anschutz Medical Campus, Aurora, CO, United States
| | - Morgan M Brown
- Department of Immunology and Microbiology, University of Colorado Anschutz Medical Campus, Aurora, CO, United States
| | - Caitlin J Risener
- Program in Molecular and Systems Pharmacology, Laney Graduate School, Emory University, Atlanta, GA, United States
| | - Lewis Marquez
- Program in Molecular and Systems Pharmacology, Laney Graduate School, Emory University, Atlanta, GA, United States
| | - James T Lyles
- Center for the Study of Human Health, Emory University, Atlanta, GA, United States
| | - John Bacsa
- Department of Chemistry, Emory University, Atlanta, GA, United States
| | - Alexander R Horswill
- Department of Immunology and Microbiology, University of Colorado Anschutz Medical Campus, Aurora, CO, United States
| | - Cassandra L Quave
- Center for the Study of Human Health, Emory University, Atlanta, GA, United States.,Department of Dermatology, Emory University School of Medicine, Atlanta, GA, United States.,Antibiotic Resistance Center, Emory University, Atlanta, GA, United States
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23
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Hao S, Yang D, Zhao L, Shi F, Ye G, Fu H, Lin J, Guo H, He R, Li J, Chen H, Khan MF, Li Y, Tang H. EGCG-Mediated Potential Inhibition of Biofilm Development and Quorum Sensing in Pseudomonas aeruginosa. Int J Mol Sci 2021; 22:ijms22094946. [PMID: 34066609 PMCID: PMC8125375 DOI: 10.3390/ijms22094946] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2021] [Revised: 04/25/2021] [Accepted: 04/27/2021] [Indexed: 12/13/2022] Open
Abstract
Pseudomonas aeruginosa (P. aeruginosa), one of the dangerous multidrug resistance pathogens, orchestrates virulence factors production through quorum sensing (QS). Since the exploration of QS inhibitors, targeting virulence to circumvent bacterial pathogenesis without causing significant growth inhibition is a promising approach to treat P. aeruginosa infections. The present study has evaluated the anti-QS and anti-infective activity of epigallocatechin-3-gallate (EGCG), a bioactive ingredient of the traditional green tea, against P. aeruginosa. EGCG showed significant inhibitory effects on the development of biofilm, protease, elastase activity, swimming, and swarming motility, which was positively related to the production of C4-AHL. The expression of QS-related and QS-regulated virulence factors genes was also evaluated. Quantitative PCR analysis showed that EGCG significantly reduced the expression of las, rhl, and PQS genes and was highly correlated with the alterations of C4-AHL production. In-vivo experiments demonstrated that EGCG treatment reduced P. aeruginosa pathogenicity in Caenorhabditis elegans (C. elegans). EGCG increased the survival of C. elegans by 23.25%, 30.04%, and 36.35% in a dose-dependent manner. The findings of this study strongly suggest that EGCG could be a potential candidate for QS inhibition as an anti-virulence compound against bacterial infection.
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Affiliation(s)
- Suqi Hao
- College of Veterinary Medicine, Sichuan Agricultural University, No. 211 Huimin Road, Wenjiang District, Chengdu 611130, China; (S.H.); (D.Y.); (L.Z.); (F.S.); (G.Y.); (H.F.); (J.L.); (H.G.); (R.H.)
| | - Dan Yang
- College of Veterinary Medicine, Sichuan Agricultural University, No. 211 Huimin Road, Wenjiang District, Chengdu 611130, China; (S.H.); (D.Y.); (L.Z.); (F.S.); (G.Y.); (H.F.); (J.L.); (H.G.); (R.H.)
| | - Ling Zhao
- College of Veterinary Medicine, Sichuan Agricultural University, No. 211 Huimin Road, Wenjiang District, Chengdu 611130, China; (S.H.); (D.Y.); (L.Z.); (F.S.); (G.Y.); (H.F.); (J.L.); (H.G.); (R.H.)
| | - Fei Shi
- College of Veterinary Medicine, Sichuan Agricultural University, No. 211 Huimin Road, Wenjiang District, Chengdu 611130, China; (S.H.); (D.Y.); (L.Z.); (F.S.); (G.Y.); (H.F.); (J.L.); (H.G.); (R.H.)
| | - Gang Ye
- College of Veterinary Medicine, Sichuan Agricultural University, No. 211 Huimin Road, Wenjiang District, Chengdu 611130, China; (S.H.); (D.Y.); (L.Z.); (F.S.); (G.Y.); (H.F.); (J.L.); (H.G.); (R.H.)
| | - Hualin Fu
- College of Veterinary Medicine, Sichuan Agricultural University, No. 211 Huimin Road, Wenjiang District, Chengdu 611130, China; (S.H.); (D.Y.); (L.Z.); (F.S.); (G.Y.); (H.F.); (J.L.); (H.G.); (R.H.)
| | - Juchun Lin
- College of Veterinary Medicine, Sichuan Agricultural University, No. 211 Huimin Road, Wenjiang District, Chengdu 611130, China; (S.H.); (D.Y.); (L.Z.); (F.S.); (G.Y.); (H.F.); (J.L.); (H.G.); (R.H.)
| | - Hongrui Guo
- College of Veterinary Medicine, Sichuan Agricultural University, No. 211 Huimin Road, Wenjiang District, Chengdu 611130, China; (S.H.); (D.Y.); (L.Z.); (F.S.); (G.Y.); (H.F.); (J.L.); (H.G.); (R.H.)
| | - Ran He
- College of Veterinary Medicine, Sichuan Agricultural University, No. 211 Huimin Road, Wenjiang District, Chengdu 611130, China; (S.H.); (D.Y.); (L.Z.); (F.S.); (G.Y.); (H.F.); (J.L.); (H.G.); (R.H.)
| | - Jianlong Li
- College of Food Science, Sichuan Agricultural University, Chengdu 611130, China;
| | - Hongwei Chen
- College of Veterinary Medicine, Southwest University, Chongqing 402460, China;
| | - Muhammad Faraz Khan
- Department of Botany, Faculty of Basic and Applied Sciences, University of Poonch Rawalakot, Rawalakot 12350, Pakistan;
| | - Yinglun Li
- College of Veterinary Medicine, Sichuan Agricultural University, No. 211 Huimin Road, Wenjiang District, Chengdu 611130, China; (S.H.); (D.Y.); (L.Z.); (F.S.); (G.Y.); (H.F.); (J.L.); (H.G.); (R.H.)
- Correspondence: (Y.L.); (H.T.)
| | - Huaqiao Tang
- College of Veterinary Medicine, Sichuan Agricultural University, No. 211 Huimin Road, Wenjiang District, Chengdu 611130, China; (S.H.); (D.Y.); (L.Z.); (F.S.); (G.Y.); (H.F.); (J.L.); (H.G.); (R.H.)
- Correspondence: (Y.L.); (H.T.)
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24
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Stoica C, Cox G. Old problems and new solutions: antibiotic alternatives in food animal production. Can J Microbiol 2021; 67:427-444. [PMID: 33606564 DOI: 10.1139/cjm-2020-0601] [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] [Indexed: 12/26/2022]
Abstract
The antimicrobial resistance crisis is a Global Health challenge that impacts humans, animals, and the environment alike. In response to increased demands for animal protein and by-products, there has been a substantial increase in the use of antimicrobial agents in the animal industry. Indeed, they are extensively used to prevent, control, and (or) treat disease in animals. In addition to infection control, in-feed supplementation with antimicrobials became common practice for growth promotion of livestock. Unfortunately, the global overuse of antimicrobials has contributed to the emergence and spread of resistance. As such, many countries have implemented policies and approaches to eliminate the use of antimicrobials as growth promoters in food animals, which necessitates the need for alternate and One Health strategies to maintain animal health and welfare. This review summarizes the antimicrobial resistance crisis from Global Health and One Health perspectives. In addition, we outline examples of potential alternate strategies to circumvent antimicrobial use in animal husbandry practices, including antivirulence agents, bacteriophages, and nutritional measures to control bacterial pathogens. Overall, these alternate strategies require further research and development efforts, including assessment of efficacy and the associated development, manufacturing, and labor costs.
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Affiliation(s)
- Celine Stoica
- Department of Molecular and Cellular Biology, College of Biological Sciences, University of Guelph, 50 Stone Road East, Guelph, ON N1G 2W1, Canada.,Department of Molecular and Cellular Biology, College of Biological Sciences, University of Guelph, 50 Stone Road East, Guelph, ON N1G 2W1, Canada
| | - Georgina Cox
- Department of Molecular and Cellular Biology, College of Biological Sciences, University of Guelph, 50 Stone Road East, Guelph, ON N1G 2W1, Canada.,Department of Molecular and Cellular Biology, College of Biological Sciences, University of Guelph, 50 Stone Road East, Guelph, ON N1G 2W1, Canada
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25
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Assessment of the anti-virulence potential of extracts from four plants used in traditional Chinese medicine against multidrug-resistant pathogens. BMC Complement Med Ther 2020; 20:318. [PMID: 33076882 PMCID: PMC7574281 DOI: 10.1186/s12906-020-03114-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2020] [Accepted: 10/09/2020] [Indexed: 12/14/2022] Open
Abstract
BACKGROUND Multidrug-resistant pathogens are resistant to many antibiotics and associated with serious infections. Amomum tsaoko Crevost et Lemaire, Sanguisorba officinalis, Terminalia chebula Retz and Salvia miltiorrhiza Bge, are all used in Traditional Chinese Medicine (TCM) against multidrug-resistant pathogens, and the purpose of this study was to evaluate the antibacterial and anti-virulence activity of extracts derived from them. METHODS The antibacterial activity of ethanol and aqueous extracts from these four plants was examined against several multi-drug resistant bacterial strains, and their anti-virulence potential (including quorum quenching activity, biofilm inhibition, and blocking production of virulence factor δ-toxin) was assessed against different S. aureus strains. The chemical composition of the most effective extract was determined by LC-FTMS. RESULTS Only extracts from S. officinalis and A. tsaoko were shown to exhibit limited growth inhibition activity at a dose of 256 μg·mL-1. The S. officinalis ethanol extract, the ethanol and aqueous extract of A. tsaoko, and the aqueous extract of S. miltiorrhiza all demonstrated quorum quenching activity, but didn't significantly inhibit bacterial growth. The ethanol extract of S. officinalis inhibited bacterial toxin production and biofilm formation at low concentrations. Chemical composition analysis of the most effective extract of S. officinalis showed that it mainly contained saponins. CONCLUSIONS The most active extract tested in this study was the ethanol root extract of S. officinalis. It inhibited δ-toxin production and biofilm formation at low concentrations and saponins may be its key active components. While the four plants showed no direct antibacterial effects, their anti-virulence properties may be key to fighting bacterial infections.
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26
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Van Doan H, Hoseinifar SH, Hung TQ, Lumsangkul C, Jaturasitha S, Paolucci M. Dietary inclusion of chestnut (Castanea sativa) polyphenols to Nile tilapia reared in biofloc technology: Impacts on growth, immunity, and disease resistance against Streptococcus agalactiae. FISH & SHELLFISH IMMUNOLOGY 2020; 105:319-326. [PMID: 32702475 DOI: 10.1016/j.fsi.2020.07.010] [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: 04/15/2020] [Revised: 07/02/2020] [Accepted: 07/05/2020] [Indexed: 06/11/2023]
Abstract
A feeding trial was carried out to examine the effects of adding chestnut (Castanea sativa) polyphenols (CSP) on the growth, skin mucus and serum immune parameters of Nile tilapia (Oreochromis niloticus). Five experimental diets with inclusion levels of 0, 1, 2, 4, and 8 g kg-1 of CSP were fed to Nile tilapia fingerlings (12.77 ± 0.17 g fish-1) during an eight-week trial. Fish were analyzed on the fourth and eighth week to determine the influences of CSP on growth, skin mucus, and serum immune parameters. Challenging test versus Streptococcus agalactiae was evaluated at the end of the trial. Fish fed with CSP enriched diets displayed a significant increase (P ≤ 0.05) in growth and a decline in feed conversion ratio (P ≤ 0.05). Similarly, skin mucus and serum immune parameters were significantly increased (P ≤ 0.05) in fish fed CSP with respect to the control. The effects were already evident four weeks after the CSP administration. The disease protection test displayed that the fish's survival rate was significantly higher (P < 0.05) in CSP diets over the control. The relative percentage of survival (RSP) was 62.5, 75.0, 58.3, and 37.5 in fish fed diets contained 1, 2, 4, and 8 g kg-1 CSP, respectively. The best effect on growth, immune response, and disease resistance were shown in Nile tilapia fed with a diet supplementation of 2 g kg-1 CSP.
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Affiliation(s)
- Hien Van Doan
- Department of Animal and Aquatic Sciences, Faculty of Agriculture, Chiang Mai University, Chiang Mai, 50200, Thailand; Science and Technology Research Institute, Chiang Mai University, 239 Huay Keaw Rd., Suthep, Muang, Chiang Mai, 50200, Thailand.
| | - Seyed Hossein Hoseinifar
- Department of Fisheries Gorgan University of Agricultural Sciences and Natural Resources, Gorgan, Iran
| | - Tran Quang Hung
- University of South Bohemia in Ceske Budejovice, Faculty of Fisheries and Protection of Waters, South Bohemian Research Center of Aquaculture and Biodiversity of Hydrocenoses, Institute of Aquaculture and Protection of Waters, Na Sádkách 1780, 370 05, České Budějovice, Czech Republic
| | - Chompunut Lumsangkul
- Department of Animal and Aquatic Sciences, Faculty of Agriculture, Chiang Mai University, Chiang Mai, 50200, Thailand
| | - Sanchai Jaturasitha
- Department of Animal and Aquatic Sciences, Faculty of Agriculture, Chiang Mai University, Chiang Mai, 50200, Thailand; Science and Technology Research Institute, Chiang Mai University, 239 Huay Keaw Rd., Suthep, Muang, Chiang Mai, 50200, Thailand
| | - Marina Paolucci
- Department of Sciences and Technologies, University of Sannio, Benevento, 82100, Italy
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27
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Dettweiler M, Marquez L, Lin M, Sweeney-Jones AM, Chhetri BK, Zurawski DV, Kubanek J, Quave CL. Pentagalloyl glucose from Schinus terebinthifolia inhibits growth of carbapenem-resistant Acinetobacter baumannii. Sci Rep 2020; 10:15340. [PMID: 32948818 PMCID: PMC7501240 DOI: 10.1038/s41598-020-72331-w] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2020] [Accepted: 08/28/2020] [Indexed: 01/29/2023] Open
Abstract
The rise of antibiotic resistance has necessitated a search for new antimicrobials with potent activity against multidrug-resistant gram-negative pathogens, such as carbapenem-resistant Acinetobacter baumannii (CRAB). In this study, a library of botanical extracts generated from plants used to treat infections in traditional medicine was screened for growth inhibition of CRAB. A crude extract of Schinus terebinthifolia leaves exhibited 80% inhibition at 256 µg/mL and underwent bioassay-guided fractionation, leading to the isolation of pentagalloyl glucose (PGG), a bioactive gallotannin. PGG inhibited growth of both CRAB and susceptible A. baumannii (MIC 64-256 µg/mL), and also exhibited activity against Pseudomonas aeruginosa (MIC 16 µg/mL) and Staphylococcus aureus (MIC 64 µg/mL). A mammalian cytotoxicity assay with human keratinocytes (HaCaTs) yielded an IC50 for PGG of 256 µg/mL. Mechanistic experiments revealed iron chelation as a possible mode of action for PGG's activity against CRAB. Passaging assays for resistance did not produce any resistant mutants over a period of 21 days. In conclusion, PGG exhibits antimicrobial activity against CRAB, but due to known pharmacological restrictions in delivery, translation as a therapeutic may be limited to topical applications such as wound rinses and dressings.
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Affiliation(s)
- Micah Dettweiler
- Department of Dermatology, Emory University School of Medicine, Atlanta, GA, USA
| | - Lewis Marquez
- Molecular and Systems Pharmacology Program, Emory University, Atlanta, GA, USA
| | - Michelle Lin
- Center for the Study of Human Health, Emory University, Atlanta, GA, USA
| | - Anne M Sweeney-Jones
- School of Chemistry and Biochemistry, Center for Microbial Dynamics and Infection, Institute for Bioengineering and Bioscience, Georgia Institute of Technology, Atlanta, GA, USA
| | - Bhuwan Khatri Chhetri
- School of Chemistry and Biochemistry, Center for Microbial Dynamics and Infection, Institute for Bioengineering and Bioscience, Georgia Institute of Technology, Atlanta, GA, USA
| | - Daniel V Zurawski
- Wound Infections Department, Bacterial Diseases Branch, Center for Infectious Disease Research, Walter Reed Army Institute of Research (WRAIR), Silver Spring, Maryland, USA
| | - Julia Kubanek
- School of Chemistry and Biochemistry, Center for Microbial Dynamics and Infection, Institute for Bioengineering and Bioscience, Georgia Institute of Technology, Atlanta, GA, USA
| | - Cassandra L Quave
- Department of Dermatology, Emory University School of Medicine, Atlanta, GA, USA.
- Center for the Study of Human Health, Emory University, Atlanta, GA, USA.
- Emory University Herbarium, Atlanta, GA, USA.
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28
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Schilcher K, Horswill AR. Staphylococcal Biofilm Development: Structure, Regulation, and Treatment Strategies. Microbiol Mol Biol Rev 2020; 84:e00026-19. [PMID: 32792334 PMCID: PMC7430342 DOI: 10.1128/mmbr.00026-19] [Citation(s) in RCA: 302] [Impact Index Per Article: 75.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
In many natural and clinical settings, bacteria are associated with some type of biotic or abiotic surface that enables them to form biofilms, a multicellular lifestyle with bacteria embedded in an extracellular matrix. Staphylococcus aureus and Staphylococcus epidermidis, the most frequent causes of biofilm-associated infections on indwelling medical devices, can switch between an existence as single free-floating cells and multicellular biofilms. During biofilm formation, cells first attach to a surface and then multiply to form microcolonies. They subsequently produce the extracellular matrix, a hallmark of biofilm formation, which consists of polysaccharides, proteins, and extracellular DNA. After biofilm maturation into three-dimensional structures, the biofilm community undergoes a disassembly process that leads to the dissemination of staphylococcal cells. As biofilms are dynamic and complex biological systems, staphylococci have evolved a vast network of regulatory mechanisms to modify and fine-tune biofilm development upon changes in environmental conditions. Thus, biofilm formation is used as a strategy for survival and persistence in the human host and can serve as a reservoir for spreading to new infection sites. Moreover, staphylococcal biofilms provide enhanced resilience toward antibiotics and the immune response and impose remarkable therapeutic challenges in clinics worldwide. This review provides an overview and an updated perspective on staphylococcal biofilms, describing the characteristic features of biofilm formation, the structural and functional properties of the biofilm matrix, and the most important mechanisms involved in the regulation of staphylococcal biofilm formation. Finally, we highlight promising strategies and technologies, including multitargeted or combinational therapies, to eradicate staphylococcal biofilms.
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Affiliation(s)
- Katrin Schilcher
- Department of Immunology and Microbiology, University of Colorado School of Medicine, Aurora, Colorado, USA
| | - Alexander R Horswill
- Department of Immunology and Microbiology, University of Colorado School of Medicine, Aurora, Colorado, USA
- Department of Veterans Affairs Eastern Colorado Health Care System, Denver, Colorado, USA
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29
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Schilcher K, Horswill AR. Staphylococcal Biofilm Development: Structure, Regulation, and Treatment Strategies. Microbiol Mol Biol Rev 2020. [PMID: 32792334 DOI: 10.1128/mmbr.00026-19/asset/e] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/15/2023] Open
Abstract
In many natural and clinical settings, bacteria are associated with some type of biotic or abiotic surface that enables them to form biofilms, a multicellular lifestyle with bacteria embedded in an extracellular matrix. Staphylococcus aureus and Staphylococcus epidermidis, the most frequent causes of biofilm-associated infections on indwelling medical devices, can switch between an existence as single free-floating cells and multicellular biofilms. During biofilm formation, cells first attach to a surface and then multiply to form microcolonies. They subsequently produce the extracellular matrix, a hallmark of biofilm formation, which consists of polysaccharides, proteins, and extracellular DNA. After biofilm maturation into three-dimensional structures, the biofilm community undergoes a disassembly process that leads to the dissemination of staphylococcal cells. As biofilms are dynamic and complex biological systems, staphylococci have evolved a vast network of regulatory mechanisms to modify and fine-tune biofilm development upon changes in environmental conditions. Thus, biofilm formation is used as a strategy for survival and persistence in the human host and can serve as a reservoir for spreading to new infection sites. Moreover, staphylococcal biofilms provide enhanced resilience toward antibiotics and the immune response and impose remarkable therapeutic challenges in clinics worldwide. This review provides an overview and an updated perspective on staphylococcal biofilms, describing the characteristic features of biofilm formation, the structural and functional properties of the biofilm matrix, and the most important mechanisms involved in the regulation of staphylococcal biofilm formation. Finally, we highlight promising strategies and technologies, including multitargeted or combinational therapies, to eradicate staphylococcal biofilms.
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Affiliation(s)
- Katrin Schilcher
- Department of Immunology and Microbiology, University of Colorado School of Medicine, Aurora, Colorado, USA
| | - Alexander R Horswill
- Department of Immunology and Microbiology, University of Colorado School of Medicine, Aurora, Colorado, USA
- Department of Veterans Affairs Eastern Colorado Health Care System, Denver, Colorado, USA
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Targeting ESKAPE pathogens with anti-infective medicinal plants from the Greater Mpigi region in Uganda. Sci Rep 2020; 10:11935. [PMID: 32686689 PMCID: PMC7371678 DOI: 10.1038/s41598-020-67572-8] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2020] [Accepted: 05/22/2020] [Indexed: 12/13/2022] Open
Abstract
Antibiotic resistance poses one of the greatest threats to global health today; conventional drug therapies are becoming increasingly inefficacious and limited. We identified 16 medicinal plant species used by traditional healers for the treatment of infectious and inflammatory diseases in the Greater Mpigi region of Uganda. Extracts were evaluated for their ability to inhibit growth of clinical isolates of multidrug-resistant ESKAPE pathogens. Extracts were also screened for quorum quenching activity against S. aureus, including direct protein output assessment (δ-toxin), and cytotoxicity against human keratinocytes (HaCaT). Putative matches of compounds were elucidated via LC–FTMS for the best-performing extracts. These were extracts of Zanthoxylum chalybeum (Staphylococcus aureus: MIC: 16 μg/mL; Enterococcus faecium: MIC: 32 μg/mL) and Harungana madagascariensis (S. aureus: MIC: 32 μg/mL; E. faecium: MIC: 32 μg/mL) stem bark. Extracts of Solanum aculeastrum root bark and Sesamum calycinum subsp. angustifolium leaves exhibited strong quorum sensing inhibition activity against all S. aureus accessory gene regulator (agr) alleles in absence of growth inhibition (IC50 values: 1–64 μg/mL). The study provided scientific evidence for the potential therapeutic efficacy of these medicinal plants in the Greater Mpigi region used for infections and wounds, with 13 out of 16 species tested being validated with in vitro studies.
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Dettweiler M, Melander RJ, Porras G, Risener C, Marquez L, Samarakoon T, Melander C, Quave CL. A Clerodane Diterpene from Callicarpa americana Resensitizes Methicillin-Resistant Staphylococcus aureus to β-Lactam Antibiotics. ACS Infect Dis 2020; 6:1667-1673. [PMID: 32579326 DOI: 10.1021/acsinfecdis.0c00307] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
The rise of antibiotic resistance presents a significant healthcare challenge and precludes the use of many otherwise valuable antibiotics. One potential solution to this problem is the use of antibiotics in combination with resistance-modifying agents, compounds that act synergistically with existing antibiotics to resensitize previously resistant bacteria. In this study, 12(S),16ξ-dihydroxycleroda-3,13-dien-15,16-olide, a clerodane diterpene isolated from the medicinal plant Callicarpa americana, was found to synergize with oxacillin against methicillin-resistant Staphylococcus aureus. This synergy was confirmed by checkerboard (fractional inhibitory concentration index (FICI) = 0.125) and time-kill assays, with a subinhibitory dose of 12(S),16ξ-dihydroxycleroda-3,13-dien-15,16-olide causing the effective concentration of oxacillin to fall below the susceptibility breakpoint for S. aureus, a >32-fold decrease in both cases.
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Affiliation(s)
- Micah Dettweiler
- Emory University, Department of Dermatology, 615 Michael Street, Whitehead 105L, Atlanta, Georgia 30322, United States
| | - Roberta J. Melander
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556, United States
| | - Gina Porras
- Emory University, Center for the Study of Human Health, 1557 Dickey Drive, Anthropology 306, Atlanta, Georgia 30322, United States
| | - Caitlin Risener
- Emory University, Molecular and Systems Pharmacology Program, 615 Michael Street, Whitehead 115, Atlanta, Georgia 30322, United States
| | - Lewis Marquez
- Emory University, Molecular and Systems Pharmacology Program, 615 Michael Street, Whitehead 115, Atlanta, Georgia 30322, United States
| | - Tharanga Samarakoon
- Emory University Herbarium, 1462 Clifton Road, Atlanta, Georgia 30322, United States
| | - Christian Melander
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556, United States
| | - Cassandra L. Quave
- Emory University, Department of Dermatology, 615 Michael Street, Whitehead 105L, Atlanta, Georgia 30322, United States
- Emory University, Center for the Study of Human Health, 1557 Dickey Drive, Anthropology 306, Atlanta, Georgia 30322, United States
- Emory University, Molecular and Systems Pharmacology Program, 615 Michael Street, Whitehead 115, Atlanta, Georgia 30322, United States
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Effects of Natural Products on Bacterial Communication and Network-Quorum Sensing. BIOMED RESEARCH INTERNATIONAL 2020; 2020:8638103. [PMID: 32596389 PMCID: PMC7273434 DOI: 10.1155/2020/8638103] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/09/2020] [Revised: 03/29/2020] [Accepted: 04/18/2020] [Indexed: 12/20/2022]
Abstract
Quorum sensing (QS) has emerged as a research hotspot in microbiology and medicine. QS is a regulatory cell communication system used by bacterial flora to signal to the external environment. QS influences bacterial growth, proliferation, biofilm formation, virulence factor production, antibiotic synthesis, and environmental adaptation. Through the QS system, natural products can regulate the growth of harmful bacteria and enhance the growth of beneficial bacteria, thereby improving human health. Herein, we review advances in the discovery of natural products that regulate bacterial QS systems.
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Novel Peptide from Commensal Staphylococcus simulans Blocks Methicillin-Resistant Staphylococcus aureus Quorum Sensing and Protects Host Skin from Damage. Antimicrob Agents Chemother 2020; 64:AAC.00172-20. [PMID: 32253213 DOI: 10.1128/aac.00172-20] [Citation(s) in RCA: 42] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2020] [Accepted: 03/29/2020] [Indexed: 12/21/2022] Open
Abstract
Recent studies highlight the abundance of commensal coagulase-negative staphylococci (CoNS) on healthy skin. Evidence suggests that CoNS actively shape the skin immunological and microbial milieu to resist colonization or infection by opportunistic pathogens, including methicillin-resistant Staphylococcus aureus (MRSA), in a variety of mechanisms collectively termed colonization resistance. One potential colonization resistance mechanism is the application of quorum sensing, also called the accessory gene regulator (agr) system, which is ubiquitous among staphylococci. Common and rare CoNS make autoinducing peptides (AIPs) that function as MRSA agr inhibitors, protecting the host from invasive infection. In a screen of CoNS spent media, we found that Staphylococcus simulans, a rare human skin colonizer and frequent livestock colonizer, released potent inhibitors of all classes of MRSA agr signaling. We identified three S. simulans agr classes and have shown intraspecies cross talk between noncognate S. simulans agr types for the first time. The S. simulans AIP-I structure was confirmed, and the novel AIP-II and AIP-III structures were solved via mass spectrometry. Synthetic S. simulans AIPs inhibited MRSA agr signaling with nanomolar potency. S. simulans in competition with MRSA reduced dermonecrotic and epicutaneous skin injury in murine models. The addition of synthetic AIP-I also effectively reduced MRSA dermonecrosis and epicutaneous skin injury in murine models. These results demonstrate potent anti-MRSA quorum sensing inhibition by a rare human skin commensal and suggest that cross talk between CoNS and MRSA may be important in maintaining healthy skin homeostasis and preventing MRSA skin damage during colonization or acute infection.
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Tang H, Porras G, Brown MM, Chassagne F, Lyles JT, Bacsa J, Horswill AR, Quave CL. Triterpenoid acids isolated from Schinus terebinthifolia fruits reduce Staphylococcus aureus virulence and abate dermonecrosis. Sci Rep 2020; 10:8046. [PMID: 32415287 PMCID: PMC7229044 DOI: 10.1038/s41598-020-65080-3] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2019] [Accepted: 04/28/2020] [Indexed: 02/06/2023] Open
Abstract
Staphylococcus aureus relies on quorum sensing to exert virulence to establish and maintain infection. Prior research demonstrated the potent quorum sensing inhibition effects of "430D-F5", a refined extract derived from the fruits of Schinus terebinthifolia, a medicinal plant used for the traditional treatment of skin and soft tissue infections. We report the isolation and identification of three compounds from 430D-F5 that reduce virulence and abate dermonecrosis: 3-oxo-olean-12-en-28-oic acid (1), 3-oxotirucalla-7,24Z-dien-26-oic acid (2) and 3α-hydroxytirucalla-7,24 Z-dien-27-oic acid (3). Each compound inhibits all S. aureus accessory gene regulator (agr) alleles (IC50 2-70 μM). Dose-dependent responses were also observed in agr-regulated reporters for leucocidin A (lukA, IC50 0.4-25 μM) and glycerol ester hydrolase or lipase (gehB, IC50 1.5-25 μM). Surprisingly, dose-dependent activity against the nuclease reporter (nuc), which is under the control of the sae two-component system, was also observed (IC50 0.4-12.5 μM). Compounds 1-3 exhibited little to no effect on the agr-independent mgrA P2 reporter (a constitutive promoter from the mgrA two-component system) and the esxA reporter (under control of mgrA). Compounds 1-3 inhibited δ-toxin production in vitro and reduced dermonecrosis in a murine in vivo model. This is the first report of triterpenoid acids with potent anti-virulence effects against S. aureus.
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Affiliation(s)
- Huaqiao Tang
- Center for the Study of Human Health, Emory University College of Arts and Sciences, 30322, Atlanta, Georgia, USA
- Department of Pharmacy, Sichuan Agricultural University, Chengdu, Sichuan, China
| | - Gina Porras
- Center for the Study of Human Health, Emory University College of Arts and Sciences, 30322, Atlanta, Georgia, USA
| | - Morgan M Brown
- Department of Immunology and Microbiology, University of Colorado School of Medicine, Aurora, CO, 80045, USA
| | - Francois Chassagne
- Center for the Study of Human Health, Emory University College of Arts and Sciences, 30322, Atlanta, Georgia, USA
| | - James T Lyles
- Center for the Study of Human Health, Emory University College of Arts and Sciences, 30322, Atlanta, Georgia, USA
| | - John Bacsa
- X-ray Crystallography Center, Emory University College of Arts and Sciences, Atlanta, GA, 30322, USA
| | - Alexander R Horswill
- Department of Immunology and Microbiology, University of Colorado School of Medicine, Aurora, CO, 80045, USA
| | - Cassandra L Quave
- Center for the Study of Human Health, Emory University College of Arts and Sciences, 30322, Atlanta, Georgia, USA.
- Department of Dermatology, Emory University School of Medicine, Atlanta, 30322, GA, USA.
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Gatta V, Tomašič T, Ilaš J, Zidar N, Peterlin Mašič L, Barančoková M, Frlan R, Anderluh M, Kikelj D, Tammela P. A New Cell-Based AI-2-Mediated Quorum Sensing Interference Assay in Screening of LsrK-Targeted Inhibitors. Chembiochem 2020; 21:1918-1922. [PMID: 32026533 DOI: 10.1002/cbic.201900773] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2019] [Indexed: 01/06/2023]
Abstract
Quorum sensing (QS), a bacterial communication strategy, has been recognized as one of the control mechanisms of virulence in bacteria. Thus, targeting QS offers an interesting opportunity to impair bacterial pathogenicity and develop antivirulence agents. Aiming to enhance the discovery of QS inhibitors, we developed a bioreporter Escherichia coli JW5505 pET-Plsrlux and set up a cell-based assay for identifying inhibitors of autoinducer-2 (AI-2)-mediated QS. A comparative study on the performance of target- versus cell-based assays was performed, and 91 compounds selected with the potential to target the ATP binding pocket of LsrK, a key enzyme in AI-2 processing, were tested in an LsrK inhibition assay, providing 36 hits. The same set of compounds was tested by the AI-2-mediated QS interference assay, resulting in 24 active compounds. Among those, six were also found to be active against LsrK, whereas 18 might target other components of the pathway. Thus, this AI-2-mediated QS interference cell-based assay is an effective tool for complementing target-based assays, yet also stands as an independent assay for primary screening.
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Affiliation(s)
- Viviana Gatta
- Drug Research Program, Division of Pharmaceutical Biosciences, Faculty of Pharmacy, University of Helsinki, Viikinkaari 5 E (PO Box 56), 00014, Helsinki, Finland
| | - Tihomir Tomašič
- University of Ljubljana, Faculty of Pharmacy, Aškerčeva 7, 1000, Ljubljana, Slovenia
| | - Janez Ilaš
- University of Ljubljana, Faculty of Pharmacy, Aškerčeva 7, 1000, Ljubljana, Slovenia
| | - Nace Zidar
- University of Ljubljana, Faculty of Pharmacy, Aškerčeva 7, 1000, Ljubljana, Slovenia
| | - Lucija Peterlin Mašič
- University of Ljubljana, Faculty of Pharmacy, Aškerčeva 7, 1000, Ljubljana, Slovenia
| | - Michaela Barančoková
- University of Ljubljana, Faculty of Pharmacy, Aškerčeva 7, 1000, Ljubljana, Slovenia
| | - Rok Frlan
- University of Ljubljana, Faculty of Pharmacy, Aškerčeva 7, 1000, Ljubljana, Slovenia
| | - Marko Anderluh
- University of Ljubljana, Faculty of Pharmacy, Aškerčeva 7, 1000, Ljubljana, Slovenia
| | - Danijel Kikelj
- University of Ljubljana, Faculty of Pharmacy, Aškerčeva 7, 1000, Ljubljana, Slovenia
| | - Päivi Tammela
- Drug Research Program, Division of Pharmaceutical Biosciences, Faculty of Pharmacy, University of Helsinki, Viikinkaari 5 E (PO Box 56), 00014, Helsinki, Finland
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Mok N, Chan SY, Liu SY, Chua SL. Vanillin inhibits PqsR-mediated virulence in Pseudomonas aeruginosa. Food Funct 2020; 11:6496-6508. [DOI: 10.1039/d0fo00046a] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Vanillin, a natural phenolic aldehyde from vanilla bean, has been reported to inhibit pqs quorum sensing in Pseudomonas aeruginosa, with potential applications in combinatorial antimicrobial therapy against biofilm infections.
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Affiliation(s)
- Nicholas Mok
- Department of Biology
- University of Waterloo
- Waterloo
- Canada
| | - Shepherd Yuen Chan
- Department of Applied Biology and Chemical Technology
- The Hong Kong Polytechnic University
- Kowloon
- China
| | - Sylvia Yang Liu
- Department of Applied Biology and Chemical Technology
- The Hong Kong Polytechnic University
- Kowloon
- China
| | - Song Lin Chua
- Department of Applied Biology and Chemical Technology
- The Hong Kong Polytechnic University
- Kowloon
- China
- State Key Laboratory of Chemical Biology and Drug Discovery
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Antioxidant Effect of the Castanea sativa Mill. Leaf Extract on Oxidative Stress Induced upon Human Spermatozoa. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2019; 2019:8926075. [PMID: 31934271 PMCID: PMC6942883 DOI: 10.1155/2019/8926075] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/11/2019] [Revised: 11/25/2019] [Accepted: 11/29/2019] [Indexed: 02/07/2023]
Abstract
This study was aimed at evaluating in vitro the effects of a 75% v/v ethanolic extract of leaves of Castanea sativa Mill. (var. Bastarda Rossa, Mount Amiata, Tuscany, Italy) on ejaculated human sperm. Total polyphenols and total flavonoids contained in the extract were determined by a colorimetric assay and HPLC-DAD. The DPPH test and electrochemistry were utilized to study the antioxidant activity of the extract. Swim-up-selected sperm from 8 healthy men were treated with the C. sativa leaf extract at different dilutions (1 : 100, 1 : 200, and 1 : 500), and sperm motility was assessed following the WHO guidelines. Swim-up-selected spermatozoa were incubated with 100 μM H2O2 to induce lipid peroxidation (LPO) and with H2O2 and the leaf extract (1 : 100, 1 : 200, and 1 : 500) to test the antioxidant activity of the extract. The levels of LPO were determined by measuring malondialdehyde (MDA) concentrations. The treated samples were also analyzed by transmission electron microscopy (TEM) for ultrastructural evaluation. The chemical analysis showed that one-third ca. of the polyphenols in the C. sativa extract were made up of flavonoids, with hyperoside present in high concentration. A good antioxidant activity was demonstrated by both the DPPH test and electrochemical analysis. The C. sativa leaf extract did not decrease sperm motility at all tested dilutions. Treatment with H2O2 alone caused a significant increment in MDA levels (P = 0.006993), while the treatment with H2O2 plus C. sativa extract diluted to 1 : 100 and 1 : 200 significantly reduced MDA levels (P = 0.01476 and P = 0.01571, respectively), with respect to H2O2 alone. TEM analysis confirmed the protective effect of the extract on damage induced by LPO, in particular that occurring at the plasma membrane level. The C. sativa leaf extract could be used in human and farm animal protocols for gamete handling, such as techniques of assisted reproduction and cryopreservation of semen, all conditions in which oxidative stress is exacerbated.
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Dupas C, Métoyer B, El Hatmi H, Adt I, Mahgoub SA, Dumas E. Plants: A natural solution to enhance raw milk cheese preservation? Food Res Int 2019; 130:108883. [PMID: 32156345 DOI: 10.1016/j.foodres.2019.108883] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2019] [Revised: 11/29/2019] [Accepted: 12/01/2019] [Indexed: 01/18/2023]
Abstract
Plants have been traditionnally used for centuries in cheese manufacturing, either for their aromatic properties or as technological auxiliaries (e.g. milk-clotting enzyme preparations, cheese wrappers). Some of these plants are known to have antimicrobial and/or antioxidant properties and could also act as natural preservatives for raw milk and derived dairy products. This review examined the traditional uses of plants in dairy processing, and then focuses on known antimicrobial and antioxidant properties of their extracts (e.g. maceration, decoction, essential oil). Known effects of theses plants on technological flora (starter cultures and microorganisms implicated in cheese ripening) were also summarized, and the potential for plant extracts used in combination with hurdle technologies was explored. Then, legal restriction and bioactivity variations from a culture media to a food matrix was reviewed: non-toxic bioactive molecules found in plants, extract preparation modes suitable with foodgrade processing restrictions, the role of the food matrix as a hindrance to the efficiency of bioactive compounds, and a review of food legislation. Finally, some commercial plant extracts for milk preservation were discussed.
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Affiliation(s)
- Coralie Dupas
- Univ Lyon, Université Claude Bernard Lyon 1, ISARA Lyon, BioDyMIA - Equipe Mixte d'Accueil n°3733, rue Henri de Boissieu, F-01000 Bourg en Bresse, France.
| | - Benjamin Métoyer
- Univ Lyon, Université Claude Bernard Lyon 1, ISARA Lyon, BioDyMIA - Equipe Mixte d'Accueil n°3733, rue Henri de Boissieu, F-01000 Bourg en Bresse, France.
| | - Halima El Hatmi
- Institut des Régions Arides (IRA), Km 22.5, route du Djorf, 4119 Medenine, Tunisia.
| | - Isabelle Adt
- Univ Lyon, Université Claude Bernard Lyon 1, ISARA Lyon, BioDyMIA - Equipe Mixte d'Accueil n°3733, rue Henri de Boissieu, F-01000 Bourg en Bresse, France.
| | - Samir A Mahgoub
- Department of Agricultural Microbiology, Faculty of Agriculture, Zagazig University, 44511, Egypt.
| | - Emilie Dumas
- Univ Lyon, Université Claude Bernard Lyon 1, ISARA Lyon, BioDyMIA - Equipe Mixte d'Accueil n°3733, rue Henri de Boissieu, F-01000 Bourg en Bresse, France.
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Horswill AR, Gordon CP. Structure-Activity Relationship Studies of Small Molecule Modulators of the Staphylococcal Accessory Gene Regulator. J Med Chem 2019; 63:2705-2730. [PMID: 31658413 DOI: 10.1021/acs.jmedchem.9b00798] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
The accessory gene regulator (agr) quorum-sensing system is arguably the most important regulator of Staphylococcus virulence. The agr-system serves a crucial role in pathogenesis by triggering substantive gene expression alterations to up-regulate the production of a wide variety of virulence determinants such as exoenzymes (proteases, lipases, nucleases) and downregulate the expression of surface binding proteins. Accordingly, the agr-system represents a compelling target for the development of antivirulence therapeutics as potential adjuncts, or alternatives, to conventional bactericidal and bacteriostatic antibiotics. Despite this potential, to date, no agr-system inhibitors have progressed to the clinic; however, several promising lead compounds have been identified through screens of synthetic and natural product libraries. On the basis of the molecular components within the agr-system, the current contingent of regulating compounds can be clustered into three broad groups, AgrA-P3 activation inhibitors, AgrB-AgrD processing inhibitors, and AgrC-AIP interaction inhibitors. This review aims to provide an overview of the development, structure-activity-relationships, and limitations of compounds within each of these groups in addition to the current opportunities for developing next-generation anologs.
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Affiliation(s)
- Alexander R Horswill
- Veterans Affairs Eastern Colorado Health Care System, Aurora, Colorado 80045, United States.,Department of Immunology and Microbiology, University of Colorado Anschutz Medical Campus, Aurora, Colorado 80045, United States
| | - Christopher P Gordon
- School of Science and Health, Western Sydney University, Locked Bag 1797, Penrith South DC, NSW 2751, Australia.,Molecular Medicine Research Group, School of Medicine, Westerm Sydney University, Building 30, Campbelltown, NSW 2560, Australia
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Pineau RM, Hanson SE, Lyles JT, Quave CL. Growth Inhibitory Activity of Callicarpa americana Leaf Extracts Against Cutibacterium acnes. Front Pharmacol 2019; 10:1206. [PMID: 31680977 PMCID: PMC6803531 DOI: 10.3389/fphar.2019.01206] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2019] [Accepted: 09/19/2019] [Indexed: 11/16/2022] Open
Abstract
Acne vulgaris is a common skin disease affecting adolescents and young adults of all ethnic groups, negatively impacting self-esteem, self-confidence, and social life. The Gram-positive bacteria Cutibacterium acnes colonizes the sebum-rich follicle and contributes to inflammation of the pilosebaceous gland. Long-term antibiotic therapies targeting C. acnes lead to the development of antimicrobial resistance, and novel acne vulgaris therapies are needed. This study investigated the C. acnes inhibitory activity of Callicarpa americana leaves, a native Southeastern United States shrub historically used by Native Americans to treat fever, stomachache, and pruritis. Flash chromatography fractions of the ethyl acetate-soluble C. americana ethanol leaf extract (649C-F9 and 649C-F13) exhibited MICs ranging from 16 to 32 µg ml-1 and IC50 range of 4-32 μg ml-1 against a panel of 10 distinct C. acnes isolates. Cytotoxicity against an immortalized human keratinocyte cell line (HaCaTs) skin was detected at more than eight times the dose required for growth inhibitory activity (IC50 of 256 μg ml-1 for 649C-F9 and IC50 of >512 μg ml-1 for 649C-F13). This work highlights the potential of C. americana leaf extracts as a cosmeceutical ingredient for the management of acne vulgaris. Further research is necessary to assess its mechanism of action and in vivo efficacy.
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Affiliation(s)
- Rozenn M. Pineau
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA, United States
| | - Sarah E. Hanson
- Center for the Study of Human Health, Emory College of Arts and Sciences, Atlanta, GA, United States
| | - James T. Lyles
- Center for the Study of Human Health, Emory College of Arts and Sciences, Atlanta, GA, United States
| | - Cassandra L. Quave
- Center for the Study of Human Health, Emory College of Arts and Sciences, Atlanta, GA, United States
- Department of Dermatology, Emory University School of Medicine, Atlanta, GA, United States
- Emory University Herbarium, Atlanta, GA, United States
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Quorum Sensing, Virulence, and Antibiotic Resistance of USA100 Methicillin-Resistant Staphylococcus aureus Isolates. mSphere 2019; 4:4/4/e00553-19. [PMID: 31413175 PMCID: PMC6695519 DOI: 10.1128/msphere.00553-19] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Methicillin-resistant Staphylococcus aureus (MRSA) infections impact all patient populations both in the community and in health care settings. Despite advances in our knowledge of MRSA virulence, little is known about the regulatory mechanisms of USA100 health care-associated MRSA isolates, which are the second most frequently identified MRSA isolates found in all infections. This work focused on the contribution of the USA100 agr type II quorum-sensing system to virulence and antibiotic resistance. From a MRSA strain collection, we selected 16 representative USA100 isolates, constructed mutants with Δagr mutations, and characterized selected strain pairs for virulence factor expression, murine skin infection, and antibiotic resistance. For each strain pair, hemolysis and extracellular protease expression were significantly greater in the wild-type (WT) strains than in the Δagr mutants. Similarly, mice challenged with the WT strains had larger areas of dermonecrosis and greater weight loss than those challenged with the Δagr mutants, demonstrating that the USA100 agr system regulates virulence. Although USA100 isolates exhibit a high level of antibiotic resistance, the WT and Δagr strain pairs showed no difference in MICs by MIC testing. However, in the presence of a sub-MIC of vancomycin, most of the USA100 Δagr mutants exhibited slower growth than the WT isolates, and a couple of the Δagr mutants also grew more slowly in the presence of a sub-MIC of cefoxitin. Altogether, our findings demonstrate that the USA100 agr system is a critical regulator of virulence, and it may have a contribution to the optimal survival of these MRSA strains in the presence of antibiotics.IMPORTANCE USA100 health care-associated MRSA isolates are highly antibiotic resistant and can cause invasive disease across all patient populations. Even though USA100 strains are some of the most frequently identified causes of infections, little is known about virulence regulation in these isolates. Our study demonstrates that the USA100 agr quorum-sensing system is important for the control of toxin and exoenzyme production and that the agr system has a key role in skin infection. In some USA100 isolates, the agr system is important for growth in the presence of low levels of antibiotics. Altogether, our findings demonstrate that the USA100 agr system is a critical regulator of virulence and that it may make a contribution to the optimal survival of these MRSA strains in the presence of antibiotics.
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Khatri Chhetri B, Lavoie S, Sweeney-Jones AM, Mojib N, Raghavan V, Gagaring K, Dale B, McNamara CW, Soapi K, Quave CL, Polavarapu PL, Kubanek J. Peyssonnosides A-B, Unusual Diterpene Glycosides with a Sterically Encumbered Cyclopropane Motif: Structure Elucidation Using an Integrated Spectroscopic and Computational Workflow. J Org Chem 2019; 84:8531-8541. [PMID: 31244158 PMCID: PMC6614789 DOI: 10.1021/acs.joc.9b00884] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2019] [Indexed: 11/30/2022]
Abstract
Two sulfated diterpene glycosides featuring a highly substituted and sterically encumbered cyclopropane ring have been isolated from the marine red alga Peyssonnelia sp. Combination of a wide array of 2D NMR spectroscopic experiments, in a systematic structure elucidation workflow, revealed that peyssonnosides A-B (1-2) represent a new class of diterpene glycosides with a tetracyclo [7.5.0.01,10.05,9] tetradecane architecture. A salient feature of this workflow is the unique application of quantitative interproton distances obtained from the rotating frame Overhauser effect spectroscopy (ROESY) NMR experiment, wherein the β-d-glucose moiety of 1 was used as an internal probe to unequivocally determine the absolute configuration, which was also supported by optical rotatory dispersion (ORD). Peyssonnoside A (1) exhibited promising activity against liver stage Plasmodium berghei and moderate antimethicillin-resistant Staphylococcus aureus (MRSA) activity, with no cytotoxicity against human keratinocytes. Additionally, 1 showed strong growth inhibition of the marine fungus Dendryphiella salina indicating an antifungal ecological role in its natural environment. The high natural abundance and novel carbon skeleton of 1 suggests a rare terpene cyclase machinery, exemplifying the chemical diversity in this phylogenetically distinct marine red alga.
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Affiliation(s)
- Bhuwan Khatri Chhetri
- School
of Chemistry and Biochemistry, Aquatic Chemical Ecology Center, and School of Biological
Sciences, Georgia Institute of Technology, Atlanta, Georgia 30332, United States
| | - Serge Lavoie
- School
of Chemistry and Biochemistry, Aquatic Chemical Ecology Center, and School of Biological
Sciences, Georgia Institute of Technology, Atlanta, Georgia 30332, United States
- Institut
des Sciences de la Forêt Tempérée, Université du Québec en Outaouais, 58, rue Principale, Ripon, Québec J0V 1V0, Canada
| | - Anne Marie Sweeney-Jones
- School
of Chemistry and Biochemistry, Aquatic Chemical Ecology Center, and School of Biological
Sciences, Georgia Institute of Technology, Atlanta, Georgia 30332, United States
| | - Nazia Mojib
- School
of Chemistry and Biochemistry, Aquatic Chemical Ecology Center, and School of Biological
Sciences, Georgia Institute of Technology, Atlanta, Georgia 30332, United States
| | - Vijay Raghavan
- Department
of Chemistry, Vanderbilt University, Nashville, Tennessee 37235, United States
| | - Kerstin Gagaring
- Calibr
at
The Scripps Research Institute, La Jolla, California 92037, United States
| | - Brandon Dale
- Department
of Dermatology, Center for the Study of Human Health, and Antibiotic
Resistance Center, Emory University, Atlanta, Georgia 30322, United States
| | - Case W. McNamara
- Calibr
at
The Scripps Research Institute, La Jolla, California 92037, United States
| | - Katy Soapi
- Institute
of Applied Sciences, University of South
Pacific, Suva, Fiji
| | - Cassandra L. Quave
- Department
of Dermatology, Center for the Study of Human Health, and Antibiotic
Resistance Center, Emory University, Atlanta, Georgia 30322, United States
| | - Prasad L. Polavarapu
- Department
of Chemistry, Vanderbilt University, Nashville, Tennessee 37235, United States
| | - Julia Kubanek
- School
of Chemistry and Biochemistry, Aquatic Chemical Ecology Center, and School of Biological
Sciences, Georgia Institute of Technology, Atlanta, Georgia 30332, United States
- Parker
H. Petit Institute for Bioengineering and Bioscience, Georgia Institute of Technology, Atlanta, Georgia 30332, United States
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44
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Staphylococcus aureus Toxins: From Their Pathogenic Roles to Anti-virulence Therapy Using Natural Products. BIOTECHNOL BIOPROC E 2019. [DOI: 10.1007/s12257-019-0059-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
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45
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American Civil War plant medicines inhibit growth, biofilm formation, and quorum sensing by multidrug-resistant bacteria. Sci Rep 2019; 9:7692. [PMID: 31118466 PMCID: PMC6531439 DOI: 10.1038/s41598-019-44242-y] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2019] [Accepted: 05/13/2019] [Indexed: 11/21/2022] Open
Abstract
A shortage of conventional medicine during the American Civil War (1861–1865) spurred Confederate physicians to use preparations of native plants as medicines. In 1863, botanist Francis Porcher compiled a book of medicinal plants native to the southern United States, including plants used in Native American traditional medicine. In this study, we consulted Porcher’s book and collected samples from three species that were indicated for the formulation of antiseptics: Liriodendron tulipifera, Aralia spinosa, and Quercus alba. Extracts of these species were tested for the ability to inhibit growth in three species of multidrug-resistant pathogenic bacteria associated with wound infections: Staphylococcus aureus, Klebsiella pneumoniae, and Acinetobacter baumannii. Extracts were also tested for biofilm and quorum sensing inhibition against S. aureus. Q. alba extracts inhibited growth in all three species of bacteria (IC50 64, 32, and 32 µg/mL, respectively), and inhibited biofilm formation (IC50 1 µg/mL) in S. aureus. L. tulipifera extracts inhibited biofilm formation (IC50 32 µg/mL) in S. aureus. A. spinosa extracts inhibited biofilm formation (IC50 2 µg/mL) and quorum sensing (IC50 8 µg/mL) in S. aureus. These results support that this selection of plants exhibited some antiseptic properties in the prevention and management of wound infections during the conflict.
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46
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Bezar IF, Mashruwala AA, Boyd JM, Stock AM. Drug-like Fragments Inhibit agr-Mediated Virulence Expression in Staphylococcus aureus. Sci Rep 2019; 9:6786. [PMID: 31043623 PMCID: PMC6494831 DOI: 10.1038/s41598-019-42853-z] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2017] [Accepted: 04/01/2019] [Indexed: 11/23/2022] Open
Abstract
In response to the increasingly problematic emergence of antibiotic resistance, novel strategies for combating pathogenic bacteria are being investigated. Targeting the agr quorum sensing system, which regulates expression of virulence in Staphylococcus aureus, is one potentially useful approach for combating drug-resistant pathogens that has not yet been fully explored. A previously published study of a fragment screen resulted in the identification of five compound fragments that interact with the DNA-binding domain of the response regulator AgrA from S. aureus. We have analyzed the ability of these compounds to affect agr-mediated virulence gene expression in cultured S. aureus cells. Three of the compounds demonstrated the ability to reduce agr-driven transcription at the P2 and P3 promoters of the agr operon and increase biofilm formation, and two of these compounds also showed the ability to reduce levels of secreted toxins. The finding that the compounds tested were able to reduce agr activity suggests that they could be useful tools for probing the effects of agr inhibition. Furthermore, the characteristics of compound fragments make them good starting materials for the development of compound libraries to iteratively improve the inhibitors.
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Affiliation(s)
- Ian F Bezar
- Department of Biochemistry and Molecular Biology, Center for Advanced Biotechnology and Medicine, Rutgers-Robert Wood Johnson Medical School, Piscataway, New Jersey, 08854, USA
- Graduate School of Biomedical Sciences at Robert Wood Johnson Medical School, Piscataway, New Jersey, 08854, USA
| | - Ameya A Mashruwala
- Department of Biochemistry and Microbiology, Rutgers University, New Brunswick, New Jersey, 08901, USA
- Graduate School-New Brunswick, Rutgers University, New Brunswick, New Jersey, 08901, USA
- Department of Molecular Biology, Princeton University, Princeton, 08544, New Jersey, USA
| | - Jeffrey M Boyd
- Department of Biochemistry and Microbiology, Rutgers University, New Brunswick, New Jersey, 08901, USA
| | - Ann M Stock
- Department of Biochemistry and Molecular Biology, Center for Advanced Biotechnology and Medicine, Rutgers-Robert Wood Johnson Medical School, Piscataway, New Jersey, 08854, USA.
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47
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Abstract
Staphylococcus aureus is a Gram-positive opportunistic pathogen that has evolved a complex regulatory network to control virulence. One of the main functions of this interconnected network is to sense various environmental cues and respond by altering the production of virulence factors necessary for survival in the host, including cell surface adhesins and extracellular enzymes and toxins. Of these S. aureus regulatory systems, one of the best studied is the accessory gene regulator (agr), which is a quorum-sensing system that senses the local concentration of a cyclic peptide signaling molecule. This system allows S. aureus to sense its own population density and translate this information into a specific gene expression pattern. Besides agr, this pathogen uses other two-component systems to sense specific cues and coordinates responses with cytoplasmic regulators of the SarA protein family and alternative sigma factors. These divergent regulatory systems integrate the various environmental and host-derived signals into a network that ensures optimal pathogen response to the changing conditions. This article gives an overview of the most important and best-studied S. aureus regulatory systems and summarizes the functions of these regulators during host interactions. The regulatory systems discussed include the agr quorum-sensing system; the SaeRS, SrrAB, and ArlRS two-component systems, the cytoplasmic SarA-family regulators (SarA, Rot, and MgrA); and the alternative sigma factors (SigB and SigH).
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48
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Chassagne F, Huang X, Lyles JT, Quave CL. Validation of a 16th Century Traditional Chinese Medicine Use of Ginkgo biloba as a Topical Antimicrobial. Front Microbiol 2019; 10:775. [PMID: 31057504 PMCID: PMC6478001 DOI: 10.3389/fmicb.2019.00775] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2018] [Accepted: 03/26/2019] [Indexed: 12/31/2022] Open
Abstract
In the search for new therapeutic solutions to address an increasing number of multidrug-resistant bacterial pathogens, secondary metabolites from plants have proven to be a rich source of antimicrobial compounds. Ginkgo biloba, a tree native to China, has been spread around the world as an ornamental tree. Its seeds have been used as snacks and medical materials in Traditional Chinese Medicine (TCM), while over the last century its leaf extracts emerged as a source of rising pharmaceutical commerce related to brain health in Western medicine. Besides studies on the neuro-protective effects of Ginkgo, its antibacterial activities have gained more attention from researchers in the past decades, though its leaves were the main focus. We reviewed a 16th-century Chinese text, the Ben Cao Gang Mu by Li Shi-Zhen, to investigate the ancient prescription of Ginkgo seeds for skin infections. We performed antibacterial assays on various Ginkgo seed extracts against pathogens (Staphylococcus aureus, Cutibacterium acnes, Klebsiella pneumoniae, Acinetobacter baumannii, Streptococcus pyogenes) relevant to skin and soft tissue infections (SSTIs). We demonstrate here that Ginkgo seed coats and immature seeds exhibit antibacterial activity against Gram-positive skin pathogens (C. acnes, S. aureus, and S. pyogenes), and thus validated its use in TCM. We also identified one compound tied to the antibacterial activity observed, ginkgolic acid C15:1, and examine its toxicity to human keratinocytes. These results highlight the relevance of ancient medical texts as leads for the discovery of natural products with antimicrobial activities.
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Affiliation(s)
- François Chassagne
- Center for the Study of Human Health, Emory University, Atlanta, GA, United States
| | - Xinyi Huang
- Center for the Study of Human Health, Emory University, Atlanta, GA, United States
| | - James T Lyles
- Center for the Study of Human Health, Emory University, Atlanta, GA, United States
| | - Cassandra L Quave
- Center for the Study of Human Health, Emory University, Atlanta, GA, United States.,Department of Dermatology, Emory University, Atlanta, GA, United States
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49
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Quorum Sensing as Antivirulence Target in Cystic Fibrosis Pathogens. Int J Mol Sci 2019; 20:ijms20081838. [PMID: 31013936 PMCID: PMC6515091 DOI: 10.3390/ijms20081838] [Citation(s) in RCA: 50] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2019] [Revised: 04/11/2019] [Accepted: 04/11/2019] [Indexed: 12/17/2022] Open
Abstract
Cystic fibrosis (CF) is an autosomal recessive genetic disorder which leads to the secretion of a viscous mucus layer on the respiratory epithelium that facilitates colonization by various bacterial pathogens. The problem of drug resistance has been reported for all the species able to colonize the lung of CF patients, so alternative treatments are urgently needed. In this context, a valid approach is to investigate new natural and synthetic molecules for their ability to counteract alternative pathways, such as virulence regulating quorum sensing (QS). In this review we describe the pathogens most commonly associated with CF lung infections: Staphylococcus aureus, Pseudomonas aeruginosa, species of the Burkholderia cepacia complex and the emerging pathogens Stenotrophomonas maltophilia, Haemophilus influenzae and non-tuberculous Mycobacteria. For each bacterium, the QS system(s) and the molecules targeting the different components of this pathway are described. The amount of investigations published in the last five years clearly indicate the interest and the expectations on antivirulence therapy as an alternative to classical antibiotics.
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50
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Lavoie S, Sweeney-Jones AM, Mojib N, Dale B, Gagaring K, McNamara CW, Quave CL, Soapi K, Kubanek J. Antibacterial Oligomeric Polyphenols from the Green Alga Cladophora socialis. J Org Chem 2019; 84:5035-5045. [PMID: 30908914 PMCID: PMC6503470 DOI: 10.1021/acs.joc.8b03218] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
![]()
A series of oligomeric phenols including
the known natural product
3,4,3′,4′-tetrahydroxy-1,1′-biphenyl (3), the previously synthesized 2,3,8,9-tetrahydroxybenzo[c]chromen-6-one (4), and eight new related natural products,
cladophorols B–I (5–12), were
isolated from the Fijian green alga Cladophora socialis and identified by a combination of NMR spectroscopy, mass spectrometric
analysis, and computational modeling using DFT calculations. J-resolved spectroscopy and line width reduction by picric
acid addition aided in resolving the heavily overlapped aromatic signals.
A panel of Gram-positive and Gram-negative pathogens used to evaluate
pharmacological potential led to the determination that cladophorol
C (6) exhibits potent antibiotic activity selective toward
methicillin-resistant Staphylococcus aureus (MRSA)
with an MIC of 1.4 μg/mL. Cladophorols B (5) and
D–H (7–11) had more modest
but also selective antibiotic potency. Activities of cladophorols
A–I (4–12) were also assessed
against the asexual blood stages of Plasmodium falciparum and revealed cladophorols A (4) and B (5) to have modest activity with EC50 values of 0.7 and
1.9 μg/mL, respectively.
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Affiliation(s)
- Serge Lavoie
- Aquatic Chemical Ecology Center , Georgia Institute of Technology , Atlanta , Georgia 30332 , United States.,Institut des Sciences de la Forêt tempérée , Université du Québec en Outaouais , 58, rue Principale , Ripon , Québec J0V 1V0 , Canada
| | - Anne Marie Sweeney-Jones
- Aquatic Chemical Ecology Center , Georgia Institute of Technology , Atlanta , Georgia 30332 , United States
| | - Nazia Mojib
- Aquatic Chemical Ecology Center , Georgia Institute of Technology , Atlanta , Georgia 30332 , United States
| | - Brandon Dale
- Department of Dermatology, Center for the Study of Human Health, and Antibiotic Resistance Center , Emory University , Atlanta , Georgia 30322 , United States
| | - Kerstin Gagaring
- Calibr at The Scripps Research Institute , La Jolla , California 92037 , United States
| | - Case W McNamara
- Calibr at The Scripps Research Institute , La Jolla , California 92037 , United States
| | - Cassandra L Quave
- Department of Dermatology, Center for the Study of Human Health, and Antibiotic Resistance Center , Emory University , Atlanta , Georgia 30322 , United States
| | - Katy Soapi
- Institute of Applied Sciences , University of South Pacific , Suva , Fiji
| | - Julia Kubanek
- Aquatic Chemical Ecology Center , Georgia Institute of Technology , Atlanta , Georgia 30332 , United States.,Parker H. Petit Institute for Bioengineering and Bioscience , Georgia Institute of Technology , Atlanta , Georgia 30332 , United States
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