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Li H, Li C, Shi C, Sameeh MY, Al-Asmari F, Cui H, Lin L. Transcriptome analysis reveals the inhibitory mechanism of phloretin on virulence expression of Staphylococcus aureus and its application in cooked chicken. Int J Food Microbiol 2024; 415:110647. [PMID: 38422678 DOI: 10.1016/j.ijfoodmicro.2024.110647] [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: 09/04/2023] [Revised: 02/10/2024] [Accepted: 02/26/2024] [Indexed: 03/02/2024]
Abstract
Staphylococcus aureus (S. aureus) enterotoxins have aroused great concern to food safety owing to its increased risk of food poisoning. The current research aimed to investigate the anti-virulence mechanisms of phloretin against S. aureus in terms of toxin activity and gene expression. The results indicated that phloretin could effectively inhibit the production of hemolysins and enterotoxins, and its anti-virulence effect was exerted in a concentration-dependent manner. Transcriptome results indicated that phloretin could downregulate the transcription level of majority virulence factors related genes (68 %) of S. aureus, including the quorum sensing-related genes (agrB, agrC, agrA, sspA, splF, splD and others) and bacterial secretion system-related genes (secDF, secY2, and yidC). In addition, it was speculated that phloretin was most likely to bind to the AgrA DNA binding domain, thereby affecting the expression of downstream virulence genes (hla, seb, spa, rot, geh, etc) based on molecular docking. Finally, the application in cooked chicken indicated that phloretin could effectively decrease the content of enterotoxins and improve the storage quality of cooked chicken. These findings not only evidenced the feasible anti-virulence activity of phloretin, but also provided a new strategy to prevent S. aureus food poisoning in cooked meat preservation.
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Affiliation(s)
- Hong Li
- School of Food and Biological Engineering, Jiangsu University, Zhenjiang 212013, China
| | - Changzhu Li
- State Key Laboratory of Utilization of Woody Oil Resource, Hunan Academy of Forestry, Changsha 410007, China
| | - Ce Shi
- School of Food and Biological Engineering, Jiangsu University, Zhenjiang 212013, China
| | - Manal Y Sameeh
- Department of Chemistry, Al-Leith University College, Umm Al Qura University, Makkah 25100, Saudi Arabia
| | - Fahad Al-Asmari
- Department of Food and Nutrition Sciences, College of Agricultural and Food Sciences, King Faisal University, Al Ahsa 31982, Saudi Arabia
| | - Haiying Cui
- School of Food and Biological Engineering, Jiangsu University, Zhenjiang 212013, China.
| | - Lin Lin
- School of Food and Biological Engineering, Jiangsu University, Zhenjiang 212013, China; State Key Laboratory of Utilization of Woody Oil Resource, Hunan Academy of Forestry, Changsha 410007, China.
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2
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Lu L, Wang J, Wang C, Zhu J, Wang H, Liao L, Zhao Y, Wang X, Yang C, He Z, Li M. Plant-derived virulence arresting drugs as novel antimicrobial agents: Discovery, perspective, and challenges in clinical use. Phytother Res 2024; 38:727-754. [PMID: 38014754 DOI: 10.1002/ptr.8072] [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: 06/21/2023] [Revised: 09/23/2023] [Accepted: 11/05/2023] [Indexed: 11/29/2023]
Abstract
Antimicrobial resistance (AMR) emerges as a severe crisis to public health and requires global action. The occurrence of bacterial pathogens with multi-drug resistance appeals to exploring alternative therapeutic strategies. Antivirulence treatment has been a positive substitute in seeking to circumvent AMR, which aims to target virulence factors directly to combat bacterial infections. Accumulated evidence suggests that plant-derived natural products, which have been utilized to treat infectious diseases for centuries, can be abundant sources for screening potential virulence-arresting drugs (VADs) to develop advanced therapeutics for infectious diseases. This review sums up some virulence factors and their actions in various species of bacteria, as well as recent advances pertaining to plant-derived natural products as VAD candidates. Furthermore, we also discuss natural VAD-related clinical trials and patents, the perspective of VAD-based advanced therapeutics for infectious diseases and critical challenges hampering clinical use of VADs, and genomics-guided identification for VAD therapeutic. These newly discovered natural VADs will be encouraging and optimistic candidates that may sustainably combat AMR.
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Affiliation(s)
- Lan Lu
- Key Laboratory of Medicinal and Edible Plants Resources Development of Sichuan Education Department, Sichuan Industrial Institute of Antibiotics, School of Pharmacy, Chengdu University, Chengdu, Sichuan, P.R. China
| | - Jingya Wang
- Key Laboratory of Medicinal and Edible Plants Resources Development of Sichuan Education Department, Sichuan Industrial Institute of Antibiotics, School of Pharmacy, Chengdu University, Chengdu, Sichuan, P.R. China
| | - Chongrui Wang
- Faculty of Chinese Medicine, Shandong University of Traditional Chinese Medicine, Jinan, Shandong, P.R. China
| | - Jie Zhu
- Key Laboratory of Medicinal and Edible Plants Resources Development of Sichuan Education Department, Sichuan Industrial Institute of Antibiotics, School of Pharmacy, Chengdu University, Chengdu, Sichuan, P.R. China
| | - Hongping Wang
- Safety Evaluation Center, Sichuan Institute for Drug Control (Sichuan Testing Center of Medical Devices), Chengdu, Sichuan, P.R. China
| | - Li Liao
- Key Laboratory of Medicinal and Edible Plants Resources Development of Sichuan Education Department, Sichuan Industrial Institute of Antibiotics, School of Pharmacy, Chengdu University, Chengdu, Sichuan, P.R. China
| | - Yuting Zhao
- Key Laboratory of Medicinal and Edible Plants Resources Development of Sichuan Education Department, Sichuan Industrial Institute of Antibiotics, School of Pharmacy, Chengdu University, Chengdu, Sichuan, P.R. China
| | - Xiaobo Wang
- Department of Hepatobiliary Surgery, Langzhong People's Hospital, Langzhong, Sichuan, P.R. China
| | - Chen Yang
- Key Laboratory of Medicinal and Edible Plants Resources Development of Sichuan Education Department, Sichuan Industrial Institute of Antibiotics, School of Pharmacy, Chengdu University, Chengdu, Sichuan, P.R. China
| | - Zhengyou He
- Key Laboratory of Medicinal and Edible Plants Resources Development of Sichuan Education Department, Sichuan Industrial Institute of Antibiotics, School of Pharmacy, Chengdu University, Chengdu, Sichuan, P.R. China
| | - Mingxing Li
- Laboratory of Molecular Pharmacology, Department of Pharmacology, School of Pharmacy, Southwest Medical University, Luzhou, Sichuan, China
- Cell Therapy & Cell Drugs of Luzhou Key Laboratory, Luzhou, Sichuan, China
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Mehrabkhani M, Movahhed T, Arefnezhad M, Hamedi S, Faramarzian F. Antimicrobial effect of hydro-alcoholic extract of apple with and without zinc oxide nanoparticles on Streptococcus Mutans. Eur J Transl Myol 2023; 33:11623. [PMID: 37753783 PMCID: PMC10811637 DOI: 10.4081/ejtm.2023.11623] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2023] [Accepted: 08/10/2023] [Indexed: 09/28/2023] Open
Abstract
This study aimed to evaluate the antimicrobial effect of hydro-alcoholic extract of apple (Malus domestica Borkh. Vs.golab, with and without ZnO nanoparticles) on Streptococcus Mutans bacterium compared to 0.2% Chlorhexidine, Persica and suspension of ZnO nanoparticles. Study samples were examined in the groups of apple hydro-alcoholic extract with and without addition of ZnO nanoparticles, a positive control group (Chlorhexidine 0.2%, Persica and suspension of ZnO nanoparticles), and a negative control group (distilled water). In this experiment, a concentration of 500 PPM of ZnO nanoparticles with a diameter of 0.4 nm was used. Agar diffusion method was used to determine the Minimum Inhibitory Concentration (MIC) of apple hydro-alcoholic extract with and without adding ZnO nanoparticles. The concentrations used were 200, 100, 50 and 25 mg/ml. ANOVA statistical test was used to compare the average in the study groups. According to our results, hydro-alcoholic extract of apples alone had no effect on the target bacteria in any of the concentrations. In the group of apple hydro-alcoholic extract with ZnO nanoparticles, the mean inhibition zone was 13 mm at a concentration of 25 mg/ml. 0.2% Chlorhexidine, Persica and suspension of ZnO nanoparticles was observed with the mean inhibition zone of 20 mm, 16 mm and 15 mm, respectively. Hydro-alcoholic extract of apple with addition of ZnO nanoparticles in concentration of 25mg/ml, had growth inhibitory effect on Streptococcus Mutans, but it was not remarkably efficient in comparison with Chlorhexidine.
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Affiliation(s)
- Maryam Mehrabkhani
- Department of Pediatric Dentistry, School of Dentistry, Mashhad University of Medical Sciences, Mashhad.
| | - Taraneh Movahhed
- Department of Pediatric Dentistry, School of Dentistry, Mashhad University of Medical Sciences, Mashhad.
| | - Mohsen Arefnezhad
- Kashmar School of Nursing, Mashhad University of Medical Sciences, Mashhad.
| | - Shokouhsadat Hamedi
- Department of Clinical Persian Pharmacy, School of Persian and Complementary Medicine, Mashhad University of Medical Sciences, Mashhad.
| | - Farnaz Faramarzian
- Department of Endodontics, School of Dentistry, Zahedan University of Medical Sciences, Zahedan.
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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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Qi Y, Hou J, Zhao Y, Song W, Wang L, Chen H, Chen G. An inhibitory effect of schisandrone on α-hemolysin expression to combat methicillin-resistant staphylococcus aureus infections. World J Microbiol Biotechnol 2022; 39:3. [PMID: 36344903 DOI: 10.1007/s11274-022-03442-x] [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: 06/27/2022] [Accepted: 10/14/2022] [Indexed: 11/09/2022]
Abstract
Due to increasing antibiotic resistance, targeting bacterial virulence factors is now gaining further interest as an alternative strategy to develop novel classes of anti-infective agents. The critical role of α-hemolysin (Hla), an indispensable virulence determinant, in the pathogenicity of Staphylococcus aureus renders this virulence factor an appealing target for effective therapeutic applications. Herein, we identified a natural compound schisandraone, as an effective Hla inhibitor, which could inhibit Hla production and thus hemolytic activity in a dose-dependent manner without affecting the growth of S. aureus. We also found that the addition of schisandrone could down-regulate the transcriptional levels of the hla, agrA and RNAIII and significantly alleviated Hla-mediated injury of A549 cells co-cultured with S. aureus. In vivo studies further suggested that schisandrone combined with antibiotic ceftiofur exhibited a significant therapeutic effect on S. aureus infection. These findings revealed the role of schisandrone in inhibiting the activity of Hla and we believe that it is a promising anti-virulence candidate to combat MRSA pneumonia.
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Affiliation(s)
- Yingxin Qi
- College of Life Science, Key Laboratory of Straw Biology and Utilization of the Ministry of Education Jilin Agricultural University, Changchun, China.,School of Biological and Food Engineering, Jilin Engineering Normal University, Changchun, China
| | - Juan Hou
- College of Clinical Medicine, Changchun University of Chinese Medicine, Changchun, China
| | - Yicheng Zhao
- College of Clinical Medicine, Changchun University of Chinese Medicine, Changchun, China.,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
| | - Wu Song
- College of Clinical Medicine, Changchun University of Chinese Medicine, Changchun, China
| | - Li Wang
- College of Clinical Medicine, Changchun University of Chinese Medicine, Changchun, China
| | - Huan Chen
- Jilin Agricultural University, Changchun, China
| | - Guang Chen
- College of Life Science, Key Laboratory of Straw Biology and Utilization of the Ministry of Education Jilin Agricultural University, Changchun, China. .,School of Biological and Food Engineering, Jilin Engineering Normal University, Changchun, China.
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Xu L, Lu G, Zhan B, Wei L, Deng X, Zhang Q, Shen X, Wang J, Feng H. Uncovering the efficacy and mechanisms of Genkwa flos and bioactive ingredient genkwanin against L. monocytogenes infection. JOURNAL OF ETHNOPHARMACOLOGY 2022; 297:115571. [PMID: 35870686 DOI: 10.1016/j.jep.2022.115571] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/11/2022] [Revised: 07/14/2022] [Accepted: 07/17/2022] [Indexed: 06/15/2023]
Abstract
ETHNOPHARMACOLOGICAL RELEVANCE Genkwa flos (yuanhua in Chinese), the dried flower buds of the plant Daphne genkwa Siebold & Zucc., as a traditional herb widely used for the treatment of inflammation-related symptoms and diseases, with the efficacies of diuretic, phlegm-resolving and cough suppressant. AIM OF THE STUDY Traditional Chinese Medicine (TCM) is presumed to be of immense potential against pathogens infection. Whereas, the potential efficacy and mechanisms of Genkwa flos against L. monocytogenes infection has not been extensively explored. The present study aimed to identify the bioactive ingredients of Genkwa flos against L. monocytogenes infection and to delineate the underlying mechanisms of action. MATERIALS AND METHODS Bioinformatics approach at protein network level was employed to investigate the therapeutic mechanisms of Genkwa flos against L. monocytogenes infection. And hemolysis inhibition assay, cytoprotection test, western blotting, oligomerization assay and molecular docking analysis were applied to substantiate the multiple efficacies of Genkwa flos and the bioactive ingredient genkwanin. Histopathological analysis and biochemistry detection were conducted to evaluate the in vivo protective effect of genkwanin. RESULTS Network pharmacology and experimental validation revealed that Traditional Chinese Medicine (TCM) Genkwa flos exhibited anti-L. monocytogenes potency and was found to inhibit the hemolytic activity of LLO. Bioactive ingredient genkwanin interfered with the pore-forming activity of LLO by engaging the active residues Tyr414, Tyr98, Asn473, Val100, Tyr440 and Val438, and thereby attenuated LLO-mediated cytotoxicity. Consistent with the bioinformatics prediction, exposed to genkwanin could upregulate the Nrf2 level and promote the translocation of Nrf2. In vivo, genkwanin oral administration (80 mg/kg) significantly protected against systemic L. monocytogenes infection, as evidenced by reduced myeloperoxidase (MPO) and malondialdehyde (MDA) levels, increased mice survival rate by 30% and decreased pathogen colonization. CONCLUSION Our study demonstrated that Genkwa flos is a potential anti-L. monocytogenes TCM, highlighted the therapeutic potential of Genkwa flos active ingredient genkwanin by targeting the pore-forming cytolysin LLO and acting as a promising antioxidative candidate against L. monocytogenes infection.
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Affiliation(s)
- Lei Xu
- State Key Laboratory for Zoonotic Diseases, Key Laboratory for Zoonosis Research, Ministry of Education, College of Veterinary Medicine, Jilin University, Changchun, China.
| | - Gejin Lu
- State Key Laboratory for Zoonotic Diseases, Key Laboratory for Zoonosis Research, Ministry of Education, College of Veterinary Medicine, Jilin University, Changchun, China; Changchun Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Yujinxiang Street 573, Changchun, Jilin, 130122, China.
| | - Baihe Zhan
- State Key Laboratory for Zoonotic Diseases, Key Laboratory for Zoonosis Research, Ministry of Education, College of Veterinary Medicine, Jilin University, Changchun, China.
| | - Lijuan Wei
- State Key Laboratory for Zoonotic Diseases, Key Laboratory for Zoonosis Research, Ministry of Education, College of Veterinary Medicine, Jilin University, Changchun, China; Hebei Veterinary Medicine Technology Innovation Center, Shijiazhuang, 050041, Hebei, China.
| | - Xuming Deng
- State Key Laboratory for Zoonotic Diseases, Key Laboratory for Zoonosis Research, Ministry of Education, College of Veterinary Medicine, Jilin University, Changchun, China.
| | - Qiaoling Zhang
- State Key Laboratory for Zoonotic Diseases, Key Laboratory for Zoonosis Research, Ministry of Education, College of Veterinary Medicine, Jilin University, Changchun, China.
| | - Xue Shen
- Department of Food Science, College of Food Science and Engineering, Jilin University, Changchun, China.
| | - Jianfeng Wang
- State Key Laboratory for Zoonotic Diseases, Key Laboratory for Zoonosis Research, Ministry of Education, College of Veterinary Medicine, Jilin University, Changchun, China.
| | - Haihua Feng
- State Key Laboratory for Zoonotic Diseases, Key Laboratory for Zoonosis Research, Ministry of Education, College of Veterinary Medicine, Jilin University, Changchun, China.
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Pun M, Khazanov N, Galsurker O, Weitman M, Kerem Z, Senderowitz H, Yedidia I. Phloretin, an Apple Phytoalexin, Affects the Virulence and Fitness of Pectobacterium brasiliense by Interfering With Quorum-Sensing. FRONTIERS IN PLANT SCIENCE 2021; 12:671807. [PMID: 34249044 PMCID: PMC8270676 DOI: 10.3389/fpls.2021.671807] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/24/2021] [Accepted: 05/31/2021] [Indexed: 05/31/2023]
Abstract
The effects of phloretin a phytoalexin from apple, was tested on Pectobacterium brasiliense (Pb1692), an emerging soft-rot pathogen of potato. Exposure of Pb1692 to 0.2 mM phloretin a concentration that does not affect growth, or to 0.4 mM a 50% growth inhibiting concentration (50% MIC), reduced motility, biofilm formation, secretion of plant cell wall-degrading enzymes, production of acyl-homoserine lactone (AHL) signaling molecules and infection, phenotypes that are associated with bacterial population density-dependent system known as quorum sensing (QS). To analyze the effect of growth inhibition on QS, the activity of ciprofloxacin, an antibiotic that impairs cell division, was compared to that of phloretin at 50% MIC. Unlike phloretin, the antibiotic hardly affected the tested phenotypes. The use of DH5α, a QS-negative Escherichia coli strain, transformed with an AHL synthase (ExpI) from Pb1692, allowed to validate direct inhibition of AHL production by phloretin, as demonstrated by two biosensor strains, Chromobacterium violaceaum (CV026) and E. coli (pSB401). Expression analysis of virulence-related genes revealed downregulation of QS-regulated genes (expI, expR, luxS, rsmB), plant cell wall degrading enzymes genes (pel, peh and prt) and motility genes (motA, fim, fliA, flhC and flhD) following exposure to both phloretin concentrations. The results support the inhibition of ExpI activity by phloretin. Docking simulations were used to predict the molecular associations between phloretin and the active site of ExpI, to suggest a likely mode of action for the compound's inhibition of virulence.
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Affiliation(s)
- Manoj Pun
- The Institute of Plant Sciences, Volcani Center, Agricultural Research Organization (ARO), Rishon Lezion, Israel
- The Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Rehovot, Israel
| | - Netaly Khazanov
- Department of Chemistry, Bar-Ilan University, Ramat Gan, Israel
| | - Ortal Galsurker
- The Institute of Plant Sciences, Volcani Center, Agricultural Research Organization (ARO), Rishon Lezion, Israel
| | - Michal Weitman
- Department of Chemistry, Bar-Ilan University, Ramat Gan, Israel
| | - Zohar Kerem
- The Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Rehovot, Israel
| | | | - Iris Yedidia
- The Institute of Plant Sciences, Volcani Center, Agricultural Research Organization (ARO), Rishon Lezion, Israel
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Guzzo F, Scognamiglio M, Fiorentino A, Buommino E, D’Abrosca B. Plant Derived Natural Products against Pseudomonas aeruginosa and Staphylococcus aureus: Antibiofilm Activity and Molecular Mechanisms. Molecules 2020; 25:E5024. [PMID: 33138250 PMCID: PMC7663672 DOI: 10.3390/molecules25215024] [Citation(s) in RCA: 47] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2020] [Revised: 10/24/2020] [Accepted: 10/27/2020] [Indexed: 12/13/2022] Open
Abstract
Bacteria are social organisms able to build complex structures, such as biofilms, that are highly organized surface-associated communities of microorganisms, encased within a self- produced extracellular matrix. Biofilm is commonly associated with many health problems since its formation increases resistance to antibiotics and antimicrobial agents, as in the case of Pseudomonas aeruginosa and Staphylococcus aureus, two human pathogens causing major concern. P. aeruginosa is responsible for severe nosocomial infections, the most frequent of which is ventilator-associated pneumonia, while S. aureus causes several problems, like skin infections, septic arthritis, and endocarditis, to name just a few. Literature data suggest that natural products from plants, bacteria, fungi, and marine organisms have proven to be effective as anti-biofilm agents, inhibiting the formation of the polymer matrix, suppressing cell adhesion and attachment, and decreasing the virulence factors' production, thereby blocking the quorum sensing network. Here, we focus on plant derived chemicals, and provide an updated literature review on the anti-biofilm properties of terpenes, flavonoids, alkaloids, and phenolic compounds. Moreover, whenever information is available, we also report the mechanisms of action.
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Affiliation(s)
- Francesca Guzzo
- Dipartimento di Scienze e Tecnologie Ambientali Biologiche e Farmaceutiche–DiSTABiF, Università degli Studi della Campania “Luigi Vanvitelli”, via Vivaldi 43, I-81100 Caserta, Italy; (F.G.); (M.S.); (A.F.)
| | - Monica Scognamiglio
- Dipartimento di Scienze e Tecnologie Ambientali Biologiche e Farmaceutiche–DiSTABiF, Università degli Studi della Campania “Luigi Vanvitelli”, via Vivaldi 43, I-81100 Caserta, Italy; (F.G.); (M.S.); (A.F.)
| | - Antonio Fiorentino
- Dipartimento di Scienze e Tecnologie Ambientali Biologiche e Farmaceutiche–DiSTABiF, Università degli Studi della Campania “Luigi Vanvitelli”, via Vivaldi 43, I-81100 Caserta, Italy; (F.G.); (M.S.); (A.F.)
- Dipartimento di Biotecnologia Marina, Stazione Zoologica Anton Dohrn, Villa Comunale, 80121 Naples, Italy
| | - Elisabetta Buommino
- Dipartimento di Farmacia, Università degli Studi di Napoli “Federico II”, Via Domenico Montesano 49, 80131 Napoli, Italy;
| | - Brigida D’Abrosca
- Dipartimento di Scienze e Tecnologie Ambientali Biologiche e Farmaceutiche–DiSTABiF, Università degli Studi della Campania “Luigi Vanvitelli”, via Vivaldi 43, I-81100 Caserta, Italy; (F.G.); (M.S.); (A.F.)
- Dipartimento di Biotecnologia Marina, Stazione Zoologica Anton Dohrn, Villa Comunale, 80121 Naples, Italy
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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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Greenberg M, Kuo D, Jankowsky E, Long L, Hager C, Bandi K, Ma D, Manoharan D, Shoham Y, Harte W, Ghannoum MA, Shoham M. Small-molecule AgrA inhibitors F12 and F19 act as antivirulence agents against Gram-positive pathogens. Sci Rep 2018; 8:14578. [PMID: 30275455 PMCID: PMC6167350 DOI: 10.1038/s41598-018-32829-w] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2018] [Accepted: 09/17/2018] [Indexed: 01/20/2023] Open
Abstract
Small-molecule antivirulence agents represent a promising alternative or adjuvant to antibiotics. These compounds disarm pathogens of disease-causing toxins without killing them, thereby diminishing survival pressure to develop resistance. Here we show that the small-molecule antivirulence agents F12 and F19 block staphylococcal transcription factor AgrA from binding to its promoter. Consequently, toxin expression is inhibited, thus preventing host cell damage by Gram-positive pathogens. Broad spectrum efficacy against Gram-positive pathogens is due to the existence of AgrA homologs in many Gram-positive bacteria. F12 is more efficacious in vitro and F19 works better in vivo. In a murine MRSA bacteremia/sepsis model, F19 treatment alone resulted in 100% survival while untreated animals had 70% mortality. Furthermore, F19 enhances antibiotic efficacy in vivo. Notably, in a murine MRSA wound infection model, combination of F19 with antibiotics resulted in bacterial load reduction. Thus, F19 could be used alone or in combination with antibiotics to prevent and treat infections of Gram-positive pathogens.
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Affiliation(s)
- Michael Greenberg
- Department of Biochemistrty, Case Western Reserve University School of Medicine, Cleveland, OH, 44106, USA
| | - David Kuo
- Department of Biochemistrty, Case Western Reserve University School of Medicine, Cleveland, OH, 44106, USA
| | - Eckhard Jankowsky
- Center for RNA and Therapeutics, Case Western Reserve University, Cleveland, OH, 44106, USA
| | - Lisa Long
- Department of Dermatology, Case Western Reserve University School of Medicine, Cleveland, OH, 44106, USA
| | - Chris Hager
- Department of Dermatology, Case Western Reserve University School of Medicine, Cleveland, OH, 44106, USA
| | - Kiran Bandi
- Department of Biochemistrty, Case Western Reserve University School of Medicine, Cleveland, OH, 44106, USA.,University of Pittsburgh School of Medicine, Pittsburgh, USA
| | - Danyang Ma
- Department of Biochemistrty, Case Western Reserve University School of Medicine, Cleveland, OH, 44106, USA
| | - Divya Manoharan
- Department of Biochemistrty, Case Western Reserve University School of Medicine, Cleveland, OH, 44106, USA
| | | | - William Harte
- Case Western Reserve University, Cleveland, OH, 44106, USA
| | - Mahmoud A Ghannoum
- Department of Dermatology, Case Western Reserve University School of Medicine, Cleveland, OH, 44106, USA
| | - Menachem Shoham
- Department of Biochemistrty, Case Western Reserve University School of Medicine, Cleveland, OH, 44106, USA. .,Q2 Pharma, Ltd., Haifa, Israel.
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11
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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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12
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Zhou X, Zhang B, Cui Y, Chen S, Teng Z, Lu G, Wang J, Deng X. Curcumin Promotes the Clearance of Listeria monocytogenes both In Vitro and In Vivo by Reducing Listeriolysin O Oligomers. Front Immunol 2017; 8:574. [PMID: 28567044 PMCID: PMC5434164 DOI: 10.3389/fimmu.2017.00574] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2016] [Accepted: 04/28/2017] [Indexed: 01/28/2023] Open
Abstract
The pore-forming toxin listeriolysin O (LLO), an essential virulence factor that is secreted by Listeria monocytogenes (L. monocytogenes), is responsible for bacterial breaching at the phagosomal membranes and subsequent release into the cytoplasm; it cannot be recognized by the host immune system. The vital role that LLO plays in bacterial pathogenicity and evading host immune clearance makes this virulence a promising target for addressing L. monocytogenes infection. In this study, we hypothesized that curcumin, a polyphenol derived from turmeric that could effectively inhibit LLO pore-forming activity, might be useful in the prevention or treatment of L. monocytogenes infection. Thus, the in vitro protective effects of curcumin against L. monocytogenes infection by targeting LLO were assessed via hemolytic activity assays, cytotoxicity tests, intracellular growth assays, and confocal microscopy. Our results revealed that treating infected macrophages with curcumin can lead to a decrease in LLO-mediated bacteria phagosomal escape and limit the intracellular growth of L. monocytogenes. Moreover, results from animal experiments show that this natural compound effectively increases protection against bacterial infection and helps the host to clear the invading pathogen completely from an animal model, establishing it as a potent antagonist of L. monocytogenes. The results from our molecular modeling and mutational analysis demonstrated that curcumin directly engages with domains 2 and 4 of LLO, thereby decreasing the hemolytic activity of LLO by influencing its oligomerization. Taken together, these results suggest that, as an antitoxin agent, curcumin can be further developed into a novel therapy against L. monocytogenes infections by targeting LLO.
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Affiliation(s)
- Xuan Zhou
- Center of Infection and Immunity, The First Hospital, Jilin University, Changchun, China.,Key Laboratory of Zoonosis, Ministry of Education, College of Veterinary Medicine, Jilin University, Changchun, China
| | - Bing Zhang
- Key Laboratory of Zoonosis, Ministry of Education, College of Veterinary Medicine, Jilin University, Changchun, China
| | - Yumei Cui
- Key Laboratory of Zoonosis, Ministry of Education, College of Veterinary Medicine, Jilin University, Changchun, China
| | - Shuiye Chen
- Key Laboratory of Zoonosis, Ministry of Education, College of Veterinary Medicine, Jilin University, Changchun, China
| | - Zihao Teng
- Key Laboratory of Zoonosis, Ministry of Education, College of Veterinary Medicine, Jilin University, Changchun, China
| | - Gejin Lu
- Key Laboratory of Zoonosis, Ministry of Education, College of Veterinary Medicine, Jilin University, Changchun, China
| | - Jianfeng Wang
- Key Laboratory of Zoonosis, Ministry of Education, College of Veterinary Medicine, Jilin University, Changchun, China
| | - Xuming Deng
- Center of Infection and Immunity, The First Hospital, Jilin University, Changchun, China.,Key Laboratory of Zoonosis, Ministry of Education, College of Veterinary Medicine, Jilin University, Changchun, China
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13
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Shoham M, Greenberg M. Preventing the spread of infectious diseases: antivirulents versus antibiotics. Future Microbiol 2017; 12:365-368. [PMID: 28339290 DOI: 10.2217/fmb-2017-0011] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Affiliation(s)
- Menachem Shoham
- Department of Biochemistry, Case Western Reserve University, Cleveland, OH 44106, USA
| | - Michael Greenberg
- Department of Biochemistry, Case Western Reserve University, Cleveland, OH 44106, USA
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14
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Fontaine BM, Nelson K, Lyles JT, Jariwala PB, García-Rodriguez JM, Quave CL, Weinert EE. Identification of Ellagic Acid Rhamnoside as a Bioactive Component of a Complex Botanical Extract with Anti-biofilm Activity. Front Microbiol 2017; 8:496. [PMID: 28386254 PMCID: PMC5362615 DOI: 10.3389/fmicb.2017.00496] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2017] [Accepted: 03/10/2017] [Indexed: 12/29/2022] Open
Abstract
Staphylococcus aureus is a leading cause of hospital-acquired infections. It is listed among the top "serious threats" to human health in the USA, due in large part to rising rates of resistance. Many S. aureus infections are recalcitrant to antibiotic therapy due to their ability to form a biofilm, which acts not only as a physical barrier to antibiotics and the immune system, but results in differences in metabolism that further restricts antibiotic efficacy. Development of a modular strategy to synthesize a library of phenolic glycosides allowed for bioactivity testing and identification of anti-biofilm compounds within an extract of the elmleaf blackberry (Rubus ulmifolius). Two ellagic acid (EA) derivatives, EA xyloside and EA rhamnoside, have been identified as components of the Rubus extract. In addition, EA rhamnoside has been identified as an inhibitor of biofilm formation, with activity comparable to the complex extract 220D-F2 (composed of a mixture of EA glycosides), and confirmed by confocal laser scanning microscopy analyses.
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Affiliation(s)
| | - Kate Nelson
- Department of Dermatology, Emory University School of Medicine Atlanta, GA, USA
| | - James T Lyles
- Center for the Study of Human Health, Emory University Atlanta, GA, USA
| | - Parth B Jariwala
- Department of Chemistry, Emory UniversityAtlanta, GA, USA; Center for the Study of Human Health, Emory UniversityAtlanta, GA, USA
| | | | - Cassandra L Quave
- Department of Dermatology, Emory University School of MedicineAtlanta, GA, USA; Center for the Study of Human Health, Emory UniversityAtlanta, GA, USA
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15
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Liu Y, Shi D, Guo Y, Li M, Zha Y, Wang Q, Wang J. Dracorhodin Perochlorate attenuates Staphylococcus aureus USA300 virulence by decreasing α-toxin expression. World J Microbiol Biotechnol 2016; 33:17. [PMID: 27900629 DOI: 10.1007/s11274-016-2129-x] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2016] [Accepted: 08/14/2016] [Indexed: 01/08/2023]
Abstract
α-Toxin, a pore-forming toxin secreted by most Staphylococcus aureus, plays critical role in the pathogenesis associated with various infectious diseases. The USA300 which is a major international epidemic methicilin-resisrant S. aureus has spread rapidly to multiple countries and become an emerging public health concern. In this study, the in vitro efficacy of Dracorhodin Perochlorate (DP) against USA300 virulence was evaluated. Using susceptibility testing, immunoblots, rabbit blood haemolytic assay and real-time RT-PCR, we observed that the α-toxin production was decreased when USA300 was co-cultured with different sub-inhibitory concentration of DP. Further, the protective effect of DP against USA300-mediated injury of human alveolar epithelial cells (A549) and MH-S cells was evaluated by cytotoxicity assays, and the result revealed that DP, at final concentration of 16 µg/ml, is a potent antagonist for USA300-mediated cell damage. Importantly, those beneficial effects might partially correlate with hla and RNAIII suppression by DP, leading to the inhibition of α-toxin production in culture supernatant. Overall, these results suggest that DP could attenuate the virulence of USA300 by decreasing α-toxin production without inhibiting bacterial growth, and this compound may represent an ideal candidate for the development of anti-virulence agent combating S. aureus infection.
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Affiliation(s)
- Yumin Liu
- College of Animal Science and Technology, Jilin Agricultural University, Changchun, 130118, China.,College of Animal Science and Technology, Changchun University of Science and Technology, Changchun, 130600, China
| | - Dongxue Shi
- Key Laboratory of Zoonosis, Ministry of Education, Institute of Zoonosis, College of Veterinary Medicine, Jilin University, Changchun, 130062, China
| | - Yan Guo
- Key Laboratory of Zoonosis, Ministry of Education, Institute of Zoonosis, College of Veterinary Medicine, Jilin University, Changchun, 130062, China
| | - Meng Li
- Key Laboratory of Zoonosis, Ministry of Education, Institute of Zoonosis, College of Veterinary Medicine, Jilin University, Changchun, 130062, China
| | - Yonghong Zha
- Key Laboratory of Zoonosis, Ministry of Education, Institute of Zoonosis, College of Veterinary Medicine, Jilin University, Changchun, 130062, China
| | - Quankai Wang
- College of Animal Science and Technology, Jilin Agricultural University, Changchun, 130118, China.
| | - Jianfeng Wang
- Key Laboratory of Zoonosis, Ministry of Education, Institute of Zoonosis, College of Veterinary Medicine, Jilin University, Changchun, 130062, China.
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16
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The combination of osthole with baicalin protects mice from Staphylococcus aureus pneumonia. World J Microbiol Biotechnol 2016; 33:11. [PMID: 27878749 DOI: 10.1007/s11274-016-2162-9] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2016] [Accepted: 10/17/2016] [Indexed: 10/20/2022]
Abstract
We reported the inhibition of α-Hemolysin (Hla) production in methicillin-resistant Staphylococcus aureus USA300 by osthole and further investigated the combination of osthole and baicalin in the treatment of staphylococcal pneumonia. Using cytotoxicity assays and a mouse model of intranasal lung infection, we evaluated the effect of combined therapy. Our results suggest that the combination of osthole and baicalin alleviated S. aureus-mediated A549 cell injury and protected mice from S. aureus pneumonia.
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17
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Subinhibitory concentrations of phloretin repress the virulence of Salmonella typhimurium and protect against Salmonella typhimurium infection. Antonie van Leeuwenhoek 2016; 109:1503-1512. [PMID: 27549210 DOI: 10.1007/s10482-016-0752-z] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/21/2016] [Accepted: 08/06/2016] [Indexed: 10/21/2022]
Abstract
Phloretin, a natural component of many fruits, exhibits anti-virulence effects and provides a new alternative to counter bacterial infection. The aim of this study was to determine the effect of subinhibitory concentrations of phloretin on the virulence of Salmonella typhimurium. At concentrations where growth of Salmonella was not inhibited, phloretin significantly inhibited bacteria biofilm formation and motility. Subinhibitory concentrations of phloretin repressed eight genes involved in the Salmonella pathogenicity island 1 and 3 genes involved in flagella production. Furthermore, subinhibitory concentrations of phloretin inhibited the adhesion and invasion of Salmonella in IEC-6 cells and reduced the LDH levels of S. typhimurium-infected IEC-6 cells. Additionally, phloretin significantly decreased the cecum bacterial loads of the mice infected with live S. typhimurium containing subinhibitory concentrations of phloretin by gavage. These results suggested that subinhibitory concentrations of phloretin attenuate the virulence of S. typhimurium and protect against S. typhimurium infection.
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18
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Ouyang P, Chen J, Sun M, Yin Z, Lin J, Fu H, Shu G, He C, Lv C, Deng X, Wang K, Geng Y, Yin L. Imperatorin inhibits the expression of alpha-hemolysin in Staphylococcus aureus strain BAA-1717 (USA300). Antonie van Leeuwenhoek 2016; 109:915-22. [PMID: 27043440 DOI: 10.1007/s10482-016-0690-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/09/2016] [Accepted: 03/28/2016] [Indexed: 10/22/2022]
Abstract
Both community-associated and hospital-acquired infections with methicillin-resistant Staphylococcus aureus (MRSA) have been increasingly reported around the world in the past 20 years. In 2006, the Centers for Disease Control and Prevention reported that 64 % of MRSA isolates were of the USA300 clonal type in infected patients in USA. The aim of our study was to estimate the in vitro effect of imperatorin on MRSA strain BAA-1717 (USA300). The effects of imperatorin on alpha-hemolysin (Hla) production, when strain BAA-1717 was co-cultured with sub-inhibitory concentrations of imperatorin, were analysed using susceptibility testing, hemolysis assays, western blotting and real-time PCR. Live/Dead analysis and cytotoxicity assays were employed to examine the protective effect of imperatorin against the strain BAA-1717-mediated injury of human alveolar epithelial cells (A549). The results showed that imperatorin has no anti-S. aureus activity at the tested concentrations in vitro. However, imperatorin can observably inhibit the production of Hla in culture supernatants and reduce the transcriptional levels of hla (the gene encoding Hla) and arg (the accessory gene regulator). Imperatorin prevented Hla-mediated A549 epithelial cell injury in a co-culture system. In conclusion, our results suggested that imperatorin has the potential to be developed as a new anti-virulence drug candidate for managing S. aureus infection.
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Affiliation(s)
- Ping Ouyang
- College of Veterinary Medicine, Sichuan Agriculture University, Chengdu, China
| | - Junjie Chen
- College of Veterinary Medicine, Sichuan Agriculture University, Chengdu, China
| | - Mao Sun
- College of Veterinary Medicine, Sichuan Agriculture University, Chengdu, China
| | - Zhongqiong Yin
- College of Veterinary Medicine, Sichuan Agriculture University, Chengdu, China
| | - Juchun Lin
- College of Veterinary Medicine, Sichuan Agriculture University, Chengdu, China
| | - Hualin Fu
- College of Veterinary Medicine, Sichuan Agriculture University, Chengdu, China
| | - Gang Shu
- College of Veterinary Medicine, Sichuan Agriculture University, Chengdu, China
| | - Changliang He
- College of Veterinary Medicine, Sichuan Agriculture University, Chengdu, China
| | - Cheng Lv
- College of Veterinary Medicine, Sichuan Agriculture University, Chengdu, China
| | - Xuming Deng
- College of Veterinary Medicine, Jilin University, Changchun, China
| | - Kaiyu Wang
- College of Veterinary Medicine, Sichuan Agriculture University, Chengdu, China
| | - Yi Geng
- College of Veterinary Medicine, Sichuan Agriculture University, Chengdu, China
| | - Lizi Yin
- College of Veterinary Medicine, Sichuan Agriculture University, Chengdu, China.
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