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Su X, Yu H, Wang X, Zhang C, Wang H, Kong X, Qu Y, Luan Y, Meng Y, Guan J, Song G, Wang L, Song W, Zhao Y. Cyanidin chloride protects mice from methicillin-resistant Staphylococcus aureus-induced pneumonia by targeting Sortase A. Virulence 2022; 13:1434-1445. [PMID: 35983964 PMCID: PMC9397467 DOI: 10.1080/21505594.2022.2112831] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Methicillin-resistant Staphylococcus aureus (MRSA) has been developing rapidly in recent years. It poses a severe peril to global health care, and the new strategies to against the MRSA is urgently needed. Sortase A (SrtA) regulates the anchoring of many surface proteins. Compounds repress Staphylococcus aureus (S. aureus) cysteine transpeptidase SrtA are considered adequate potent virulence inhibitors. Then, we describe the identification of an effective SrtA inhibitor, cyanidin chloride, a bioflavonoid compound isolated from various plants. It has a reversible inhibitory effect on SrtA activity at an IC50 of 21.91 μg/mL. As a SrtA inhibitor, cyanidin chloride antagonizes SrtA-related virulence phenotypes due to its breadth and specificity, including fibrinogen adhesion, A549 cell invasion, biofilm formation, and surface protein (SpA) anchoring. Subsequently, molecular docking and fluorescence quenching revealed that SrtA and cyanidin chloride had robust mutual affinity. Further mechanistic studies revealed that Arg-197, Gly-167, and Sep-116 were the key-binding sites mediating the interaction between SrtA and cyanidin chloride. Notably, a significant therapeutic effect of cyanidin chloride in vivo was also observed on the mouse pneumonia model induced by MRSA. In conclusion, our study indicates that cyanidin chloride potentially represents a new candidate SrtA inhibitor for S. aureus and potentially be developed as a new antivirulence agent.
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Affiliation(s)
- Xin Su
- College of Clinical Medicine, Changchun University of Chinese Medicine, Changchun, China
| | - Hangqian Yu
- Center for Pathogen Biology and Infectious Diseases, Key Laboratory of Organ Regeneration and Transplantation of the Ministry of Education, The First Hospital of Jilin University, Changchun, China
| | - Xingye Wang
- College of Clinical Medicine, Changchun University of Chinese Medicine, Changchun, China
| | - Chi Zhang
- College of Clinical Medicine, Changchun University of Chinese Medicine, Changchun, China
| | - Heming Wang
- Department of Gastroenterology, Zhongshan Hospital of Fudan University, Shanghai, China
| | - Xiangri Kong
- College of Clinical Medicine, Changchun University of Chinese Medicine, Changchun, China,College of Animal Science, Jilin University, Changchun, China
| | - Yishen Qu
- Endocrinology Department, Affiliated Hospital to Changchun University of Chinese Medicine, Changchun, China
| | - Yanhe Luan
- College of Animal Science, Jilin University, Changchun, China
| | - Ying Meng
- College of Clinical Medicine, Changchun University of Chinese Medicine, Changchun, China
| | - Jiyu Guan
- Department of Anesthesiology, Peking University Third Hospital, Beijing, China
| | - Guangqi Song
- Department of Gastroenterology, Zhongshan Hospital of Fudan University, Shanghai, China
| | - Li Wang
- College of Clinical Medicine, Changchun University of Chinese Medicine, Changchun, China,CONTACT Li Wang
| | - Wu Song
- College of Clinical Medicine, Changchun University of Chinese Medicine, Changchun, China,Wu Song
| | - Yicheng Zhao
- College of Clinical Medicine, Changchun University of Chinese Medicine, Changchun, China,Key Laboratory of Zoonosis, Ministry of Education, College of Veterinary Medicine, Jilin University, Changchun, China,Yicheng Zhao
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Jing W, Guo D, Ning Z, Yang Y, Liu T, Wang M, Gao H. New polyphenolic glycosides from the stems of Caesalpinia cucullata and their inhibitory effect on methicillin-resistant Staphylococcus aureus with different ways. Bioorg Chem 2022; 129:106193. [DOI: 10.1016/j.bioorg.2022.106193] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2022] [Revised: 10/02/2022] [Accepted: 10/03/2022] [Indexed: 11/27/2022]
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Punicalagin, an Inhibitor of Sortase A, Is a Promising Therapeutic Drug to Combat Methicillin-Resistant Staphylococcus aureus Infections. Antimicrob Agents Chemother 2022; 66:e0022422. [PMID: 35652646 DOI: 10.1128/aac.00224-22] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Antimicrobial resistance (AMR) poses a major threat to human health globally. Staphylococcus aureus is recognized as a cause of disease worldwide, especially methicillin-resistant S. aureus (MRSA) and vancomycin-resistant S. aureus (VRSA). The enzyme sortase A (SrtA), present on the cell surface of S. aureus, plays a key role in bacterial virulence without affecting the bacterial viability, and SrtA-deficient S. aureus strains do not affect the growth of bacteria. Here, we found that punicalagin, a natural compound, was able to inhibit SrtA activity with a very low half maximal inhibitory concentration (IC50) value of 4.23 μg/mL, and punicalagin is a reversible inhibitor of SrtA. Moreover, punicalagin has no distinct cytotoxicity toward A549, HEK293T, or HepG2 cells at a much higher concentration than the IC50 detected by MTT [3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide] assays. In addition, punicalagin visibly attenuated the virulence-related phenotype of SrtA in vitro by decreasing adhesion of S. aureus to fibrinogen, reducing the ability of protein A (SpA) displayed on the surface of the bacteria and biofilm formation. Fluorescence quenching elucidated the interaction between punicalagin and SrtA. Molecular docking further implied that the inhibitory activity lay in the bond between punicalagin and SrtA residues LYS190, TYR187, ALA104, and GLU106. In In vivo studies, we surprisingly found that punicalagin had a more effective curative effect combined with cefotaxime when mice were infected with pneumonia caused by MRSA. Essentially, punicalagin, a therapeutic compound targeting SrtA, demonstrates great potential for combating MRSA infections.
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Okba MM, Abdel Baki PM, Abu-Elghait M, Shehabeldine AM, El-Sherei MM, Khaleel AE, Salem MA. UPLC-ESI-MS/MS profiling of the underground parts of common Iris species in relation to their anti-virulence activities against Staphylococcusaureus. JOURNAL OF ETHNOPHARMACOLOGY 2022; 282:114658. [PMID: 34555449 DOI: 10.1016/j.jep.2021.114658] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/07/2021] [Revised: 09/03/2021] [Accepted: 09/16/2021] [Indexed: 06/13/2023]
Abstract
ETHNOPHARMACOLOGICAL RELEVANCE The use of plant extracts and their phytochemicals as candidates for targeting the microbial resistance inhibition is increasingly focused in last decades. In Mongolian traditional medicine, Irises were long used for the treatment of bacterial infections. Irises have been used since the Ancient Egyptians. AIM OF THE STUDY Chemical composition and virulence inhibition potential of both polar (PF) and non-polar fractions (NPF) of three common Iris species (I. confusa, I. pseudacorus and I. germanica) were explored. MATERIAL AND METHODS Secondary metabolites profiling was characterized by the UPLC-HRMS/MS technique. Multi-variate data analysis was performed using Metaboanalyst 3.0. Anti-virulence inhibitory activity was evaluated via anti-haemolytic assay and Quantitative biofilm inhibition assay. RESULTS I. pseudacorus PF exhibited the most potent effect against S. aureus haemolytic activity. All the tested fractions from all species, except I. pseudacorus NPF, have no significant inhibition on the biofilm formation of methicillin resistant and sensitive (MRSA and MSSA) S. aureus. I. pseudacorus NPF showed potent biofilm inhibitory potential of 71.4 and 85.8% against biofilm formation of MRSA and MSSA, respectively. Metabolite profiling of the investigated species revealed ninety and forty-five metabolites detected in the PFs and NPFs, respectively. Nigricin-type, tectorigenin-type isoflavonids and xanthones allowed the discrimination of I. pseudacorus PF from the other species, highlighting the importance of those metabolites in exerting its promising activity. On the other hand, triterpene acids, iridals, triacylglycerols and ceramides represented the metabolites detected in highest abundance in I. pseudacorus NPF. CONCLUSIONS This is the sole map represents the secondary metabolites profiling of the PFs and NPFs of common Iris species correlating them with the potent explored Staphylococcus aureus anti-virulence activity.
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Affiliation(s)
- Mona M Okba
- Department of Pharmacognosy, Faculty of Pharmacy, Cairo University, Cairo, Egypt.
| | - Passent M Abdel Baki
- Department of Pharmacognosy, Faculty of Pharmacy, Cairo University, Cairo, Egypt.
| | - Mohammed Abu-Elghait
- Department of Botany and Microbiology, Faculty of Science, Al-Azhar University, 11884, Nasr City, Cairo, Egypt.
| | - Amr M Shehabeldine
- Department of Botany and Microbiology, Faculty of Science, Al-Azhar University, 11884, Nasr City, Cairo, Egypt.
| | - Moshera M El-Sherei
- Department of Pharmacognosy, Faculty of Pharmacy, Cairo University, Cairo, Egypt.
| | - Amal E Khaleel
- Department of Pharmacognosy, Faculty of Pharmacy, Cairo University, Cairo, Egypt.
| | - Mohamed A Salem
- Department of Pharmacognosy, Faculty of Pharmacy, Menoufia University, Gamal Abd El Nasr st., Shibin Elkom, 32511, Menoufia, Egypt.
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Identification of Novel Antistaphylococcal Hit Compounds Targeting Sortase A. Molecules 2021; 26:molecules26237095. [PMID: 34885677 PMCID: PMC8658998 DOI: 10.3390/molecules26237095] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2021] [Revised: 11/23/2021] [Accepted: 11/23/2021] [Indexed: 12/04/2022] Open
Abstract
Staphylococcus aureus (S. aureus) is a causative agent of many hospital- and community-acquired infections with the tendency to develop resistance to all known antibiotics. Therefore, the development of novel antistaphylococcal agents is of urgent need. Sortase A is considered a promising molecular target for the development of antistaphylococcal agents. The main aim of this study was to identify novel sortase A inhibitors. In order to find novel antistaphylococcal agents, we performed phenotypic screening of a library containing 15512 compounds against S. aureus ATCC43300. The molecular docking of hits was performed using the DOCK program and 10 compounds were selected for in vitro enzymatic activity inhibition assay. Two inhibitors were identified, N,N-diethyl-N′-(5-nitro-2-(quinazolin-2-yl)phenyl)propane-1,3-diamine (1) and acridin-9-yl-(1H-benzoimidazol-5-yl)-amine (2), which decrease sortase A activity with IC50 values of 160.3 µM and 207.01 µM, respectively. It was found that compounds 1 and 2 possess antibacterial activity toward 29 tested multidrug resistant S. aureus strains with MIC values ranging from 78.12 to 312.5 mg/L. These compounds can be used for further structural optimization and biological research.
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Sapra R, Rajora AK, Kumar P, Maurya GP, Pant N, Haridas V. Chemical Biology of Sortase A Inhibition: A Gateway to Anti-infective Therapeutic Agents. J Med Chem 2021; 64:13097-13130. [PMID: 34516107 DOI: 10.1021/acs.jmedchem.1c00386] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Staphylococcus aureus is the leading cause of hospital-acquired infections. The enzyme sortase A, present on the cell surface of S. aureus, plays a key role in bacterial virulence without affecting the bacterial viability. Inhibition of sortase A activity offers a powerful but clinically less explored therapeutic strategy, as it offers the possibility of not inducing any selective pressure on the bacteria to evolve drug-resistant strains. In this Perspective, we offer a chemical space narrative for the design of sortase A inhibitors, as delineated into three broad domains: peptidomimetics, natural products, and synthetic small molecules. This provides immense opportunities for medicinal chemists to alleviate the ever-growing crisis of antibiotic resistance.
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Affiliation(s)
- Rachit Sapra
- Department of Chemistry, Indian Institute of Technology Delhi, New Delhi-110016, India
| | - Amit K Rajora
- Department of Chemistry, Indian Institute of Technology Delhi, New Delhi-110016, India
| | - Pushpendra Kumar
- Department of Chemistry, Indian Institute of Technology Delhi, New Delhi-110016, India
| | - Govind P Maurya
- Department of Chemistry, Indian Institute of Technology Delhi, New Delhi-110016, India
| | - Nalin Pant
- Department of Chemistry, Indian Institute of Technology Delhi, New Delhi-110016, India
| | - V Haridas
- Department of Chemistry, Indian Institute of Technology Delhi, New Delhi-110016, India
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Alharthi S, Alavi SE, Moyle PM, Ziora ZM. Sortase A (SrtA) inhibitors as an alternative treatment for superbug infections. Drug Discov Today 2021; 26:2164-2172. [PMID: 33781954 DOI: 10.1016/j.drudis.2021.03.019] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2021] [Revised: 03/01/2021] [Accepted: 03/19/2021] [Indexed: 12/28/2022]
Abstract
Virulence factor, sortase A (SrtA), has crucial roles in the pathogenesis of Gram-positive superbugs. SrtA is a bacterial cell membrane enzyme that anchors crucial virulence factors to the cell wall surface of Gram-positive bacteria. SrtA is not necessary for bacterial growth and viability and is conveniently accessible in the cell membrane; therefore, it is an ideal target for antivirulence drug development. In this review, we focus on antimicrobial resistance (AMR)-expressing bacteria and SrtA as a potential target for overcoming AMR. The mechanism of action of SrtA and its inhibition by various types of inhibitors, such as synthetic small molecules, peptides, and natural products, are provided. Future SrtA research perspectives for alternative drug development to antibiotics are also proposed.
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Affiliation(s)
- Sitah Alharthi
- School of Pharmacy, The University of Queensland, Woolloongabba, Qld 4102, Australia; Department of Pharmaceutical Science, School of Pharmacy, Shaqra University, Riyadh, Saudi Arabia
| | - Seyed Ebrahim Alavi
- School of Pharmacy, The University of Queensland, Woolloongabba, Qld 4102, Australia
| | - Peter Michael Moyle
- School of Pharmacy, The University of Queensland, Woolloongabba, Qld 4102, Australia.
| | - Zyta Maria Ziora
- Institute for Molecular Bioscience, The University of Queensland, St Lucia, Qld 4067, Australia.
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Liu J, Sun Z, Zou Y, Li W, He F, Huang X, Lin C, Cai Q, Wisniewski M, Wu X. Pre- and postharvest measures used to control decay and mycotoxigenic fungi in potato ( Solanum tuberosum L.) during storage. Crit Rev Food Sci Nutr 2020; 62:415-428. [PMID: 32924541 DOI: 10.1080/10408398.2020.1818688] [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: 12/23/2022]
Abstract
Potato (Solanum tuberosum L.), a worldwide, staple food crop, is susceptible to postharvest rots caused by a variety of fungal pathogens, including Fusarium spp., Alternaria spp., Phytophthora infestans, Helminthosporium solani, Rhizoctonia solani, and Colletotrichum coccodes. Rots resulting from infections by these pathogens cause a significant reduction in potato quality and marketable yield. Importantly, some of these decay fungi also produce mycotoxins that represent a potential risk to human health. In the present review, an overview and discussion are provided on the epidemiology and pathogenesis of decay fungi, especially Fusarium spp., that include recent data derived from genomic and phylogenetic analyses. The biosynthesis and functional role of fungitoxic metabolites such as trichothecene mycotoxins and fusaric acid, produced in rotted potatoes are also reviewed. Advances in pre- and postharvest measures for rot management, especially eco-friendly methods including physical control, biological control, the use of natural compounds, and other agricultural management practices are also reviewed. Lastly, novel approaches to control potato dry rot such as the use of mycoviruses and CRISPR technology are highlighted.
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Affiliation(s)
- Jia Liu
- Chongqing Key Laboratory of Economic Plant Biotechnology, College of Landscape Architecture and Life Science/Institute of Special Plants, Chongqing University of Arts and Sciences, Yongchuan, Chongqing, China
| | - Zhiqiang Sun
- Yantai Lvyun Biotechnology Co., Ltd, Yantai, Shandong, China
| | - Yuping Zou
- Yantai Lvyun Biotechnology Co., Ltd, Yantai, Shandong, China
| | - Wenhua Li
- Yantai Lvyun Biotechnology Co., Ltd, Yantai, Shandong, China
| | - Fangyun He
- Chongqing Key Laboratory of Economic Plant Biotechnology, College of Landscape Architecture and Life Science/Institute of Special Plants, Chongqing University of Arts and Sciences, Yongchuan, Chongqing, China
| | - Xiaoya Huang
- Yantai Lvyun Biotechnology Co., Ltd, Yantai, Shandong, China
| | - Chenglin Lin
- Yantai Lvyun Biotechnology Co., Ltd, Yantai, Shandong, China
| | - Qingnian Cai
- College of Plant Protection, China Agricultural University, Beijing, China
| | - Michael Wisniewski
- Department of Biological Sciences, Virginia Polytechnic Institute and State University, Blacksburg, Virginia, USA
| | - Xuehong Wu
- College of Plant Protection, China Agricultural University, Beijing, China
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Phytochemical Composition and In Vitro Biological Activity of Iris spp. (Iridaceae): A New Source of Bioactive Constituents for the Inhibition of Oral Bacterial Biofilms. Antibiotics (Basel) 2020; 9:antibiotics9070403. [PMID: 32664528 PMCID: PMC7399867 DOI: 10.3390/antibiotics9070403] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2020] [Revised: 07/06/2020] [Accepted: 07/08/2020] [Indexed: 01/07/2023] Open
Abstract
The inhibition and eradication of oral biofilms is increasingly focused on the use of plant extracts as mouthwashes and toothpastes adjuvants. Here, we report on the chemical composition and the antibiofilm activity of 15 methanolic extracts of Iris species against both mono-(Pseudomonas aeruginosa, Staphylococcus aureus) and multi-species oral biofilms (Streptococcus gordonii, Veillonella parvula, Fusobacterium nucleatum subsp. nucleatum, and Actinomyces naeslundii). The phytochemical profiles of Iris pallida s.l., Iris versicolor L., Iris lactea Pall., Iris carthaliniae Fomin, and Iris germanica were determined by ultra-high performance liquid chromatography-high-resolution tandem mass spectroscopy (UHPLC-HRMS/MS) analysis, and a total of 180 compounds were identified among Iris species with (iso)flavonoid dominancy. I. pallida, I. versicolor, and I. germanica inhibited both the quorum sensing and adhesion during biofilm formation in a concentration-dependent manner. However, the extracts were less active against maturated biofilms. Of the five tested species, Iris pallida s.l. was the most effective at both inhibiting biofilm formation and disrupting existing biofilms, and the leaf extract exhibited the strongest inhibitory effect compared to the root and rhizome extracts. The cytotoxicity of the extracts was excluded in human fibroblasts. The inhibition of bacterial adhesion significantly correlated with myristic acid content, and quorum sensing inhibition correlated with the 7-β-hydroxystigmast-4-en-3-one content. These findings could be useful for establishing an effective tool for the control of oral biofilms and thus dental diseases.
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Wu SC, Liu F, Zhu K, Shen JZ. Natural Products That Target Virulence Factors in Antibiotic-Resistant Staphylococcus aureus. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2019; 67:13195-13211. [PMID: 31702908 DOI: 10.1021/acs.jafc.9b05595] [Citation(s) in RCA: 79] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
The increase in the incidence of antibiotic-resistant Staphylococcus aureus (S. aureus) associated infections necessitates the urgent development of novel therapeutic strategies and antibacterial drugs. Antivirulence strategy is an especially compelling alternative strategy due to its low selective pressure for the development of drug resistance in bacteria. Plants and microorganisms are not only important food and medicinal resources but also serve as sources for the discovery of natural products that target bacterial virulence factors. This review discusses the mechanisms of the major virulence factors of S. aureus, including the accessory gene regulator quorum-sensing system, bacterial biofilm formation, α-hemolysin, sortase A, and staphyloxanthin. We also provide an overview of natural products isolated from plants and microorganisms with activity against the major virulence factors of S. aureus and their adjuvant effects on existing antibiotics to overcome antibiotic-resistant S. aureus. Finally, the limitations and solutions of these antivirulence compounds are discussed, which will help in the development of novel antibacterial drugs against antibiotic-resistant S. aureus.
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Affiliation(s)
- Shuai-Cheng Wu
- Beijing Advanced Innovation Center for Food Nutrition and Human Health, College of Veterinary Medicine , China Agricultural University , No. 2 Yuanmingyuan West Road , Beijing 100193 , People's Republic of China
- College of Veterinary Medicine , Qingdao Agricultural University , No. 700 Changcheng Road , Qingdao , Shandong 266109 , People's Republic of China
| | - Fei Liu
- Beijing Advanced Innovation Center for Food Nutrition and Human Health, College of Veterinary Medicine , China Agricultural University , No. 2 Yuanmingyuan West Road , Beijing 100193 , People's Republic of China
| | - Kui Zhu
- Beijing Advanced Innovation Center for Food Nutrition and Human Health, College of Veterinary Medicine , China Agricultural University , No. 2 Yuanmingyuan West Road , Beijing 100193 , People's Republic of China
| | - Jian-Zhong Shen
- Beijing Advanced Innovation Center for Food Nutrition and Human Health, College of Veterinary Medicine , China Agricultural University , No. 2 Yuanmingyuan West Road , Beijing 100193 , People's Republic of China
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Zhang B, Teng Z, Li X, Lu G, Deng X, Niu X, Wang J. Chalcone Attenuates Staphylococcus aureus Virulence by Targeting Sortase A and Alpha-Hemolysin. Front Microbiol 2017; 8:1715. [PMID: 28932220 PMCID: PMC5592744 DOI: 10.3389/fmicb.2017.01715] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2017] [Accepted: 08/24/2017] [Indexed: 12/21/2022] Open
Abstract
Staphylococcus aureus (S.aureus) resistance, considered a dilemma for the clinical treatment of this bacterial infection, is becoming increasingly intractable. Novel anti-virulence strategies will undoubtedly provide a path forward in combating these resistant bacterial infections. Sortase A (SrtA), an enzyme responsible for anchoring virulence-related surface proteins, and alpha-hemolysin (Hla), a pore-forming cytotoxin, have aroused great scientific interest, as they have been regarded as targets for promising agents against S. aureus infection. In this study, we discovered that chalcone, a natural small compound with little anti-S. aureus activity, could significantly inhibit SrtA activity with an IC50 of 53.15 μM and Hla hemolysis activity with an IC50 of 17.63 μM using a fluorescence resonance energy transfer (FRET) assay and a hemolysis assay, respectively. In addition, chalcone was proven to reduce protein A (SpA) display in intact bacteria, binding to fibronectin, formation of biofilm and S. aureus invasion. Chalcone could down-regulate the transcriptional levels of the hla gene and the agrA gene, thus leading to a reduction in the expression of Hla and significant protection against Hla-mediated A549 cell injury; more importantly, chalcone could also reduce mortality in infected mice. Additionally, molecular dynamics simulations and mutagenesis assays were used to identify the mechanism of chalcone against SrtA, which implied that the inhibitory activity lies in the bond between chalcone and SrtA residues Val168, Ile182, and Arg197. Taken together, the in vivo and in vitro experiments suggest that chalcone is a potential novel therapeutic compound for S. aureus infection via targeting SrtA and Hla.
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Affiliation(s)
- Bing Zhang
- Key Laboratory of Zoonosis, Ministry of Education, College of Veterinary Medicine, Jilin UniversityChangchun, China.,Center of Infection and Immunity, The First Hospital, Jilin UniversityChangchun, China
| | - Zihao Teng
- Key Laboratory of Zoonosis, Ministry of Education, College of Veterinary Medicine, Jilin UniversityChangchun, China
| | - Xianhe Li
- Key Laboratory of Zoonosis, Ministry of Education, College of Veterinary Medicine, Jilin UniversityChangchun, China
| | - Gejin Lu
- Key Laboratory of Zoonosis, Ministry of Education, College of Veterinary Medicine, Jilin UniversityChangchun, China
| | - Xuming Deng
- Key Laboratory of Zoonosis, Ministry of Education, College of Veterinary Medicine, Jilin UniversityChangchun, China.,Center of Infection and Immunity, The First Hospital, Jilin UniversityChangchun, China
| | - Xiaodi Niu
- Key Laboratory of Zoonosis, Ministry of Education, College of Veterinary Medicine, Jilin UniversityChangchun, China
| | - Jianfeng Wang
- Key Laboratory of Zoonosis, Ministry of Education, College of Veterinary Medicine, Jilin UniversityChangchun, China.,Center of Infection and Immunity, The First Hospital, Jilin UniversityChangchun, China
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