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Duracova M, Klimentova J, Fucikova A, Dresler J. Proteomic Methods of Detection and Quantification of Protein Toxins. Toxins (Basel) 2018; 10:toxins10030099. [PMID: 29495560 PMCID: PMC5869387 DOI: 10.3390/toxins10030099] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2018] [Revised: 02/21/2018] [Accepted: 02/23/2018] [Indexed: 12/11/2022] Open
Abstract
Biological toxins are a heterogeneous group of compounds that share commonalities with biological and chemical agents. Among them, protein toxins represent a considerable, diverse set. They cover a broad range of molecular weights from less than 1000 Da to more than 150 kDa. This review aims to compare conventional detection methods of protein toxins such as in vitro bioassays with proteomic methods, including immunoassays and mass spectrometry-based techniques and their combination. Special emphasis is given to toxins falling into a group of selected agents, according to the Centers for Disease Control and Prevention, such as Staphylococcal enterotoxins, Bacillus anthracis toxins, Clostridium botulinum toxins, Clostridium perfringens epsilon toxin, ricin from Ricinus communis, Abrin from Abrus precatorius or control of trade in dual-use items in the European Union, including lesser known protein toxins such as Viscumin from Viscum album. The analysis of protein toxins and monitoring for biological threats, i.e., the deliberate spread of infectious microorganisms or toxins through water, food, or the air, requires rapid and reliable methods for the early identification of these agents.
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Affiliation(s)
- Miloslava Duracova
- Faculty of Military Health Sciences, University of Defense in Brno, Třebešská 1575, CZ-500 01 Hradec Králové, Czech Republic.
| | - Jana Klimentova
- Faculty of Military Health Sciences, University of Defense in Brno, Třebešská 1575, CZ-500 01 Hradec Králové, Czech Republic.
| | - Alena Fucikova
- Faculty of Military Health Sciences, University of Defense in Brno, Třebešská 1575, CZ-500 01 Hradec Králové, Czech Republic.
| | - Jiri Dresler
- Military Health Institute, Military Medical Agency, Tychonova 1, CZ-160 00 Prague 6, Czech Republic.
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202
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Reta N, Saint CP, Michelmore A, Prieto-Simon B, Voelcker NH. Nanostructured Electrochemical Biosensors for Label-Free Detection of Water- and Food-Borne Pathogens. ACS APPLIED MATERIALS & INTERFACES 2018; 10:6055-6072. [PMID: 29369608 DOI: 10.1021/acsami.7b13943] [Citation(s) in RCA: 70] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
The emergence of nanostructured materials has opened new horizons in the development of next generation biosensors. Being able to control the design of the electrode interface at the nanoscale combined with the intrinsic characteristics of the nanomaterials engenders novel biosensing platforms with improved capabilities. The purpose of this review is to provide a comprehensive and critical overview of the latest trends in emerging nanostructured electrochemical biosensors. A detailed description and discussion of recent approaches to construct label-free electrochemical nanostructured electrodes is given with special focus on pathogen detection for environmental monitoring and food safety. This includes the use of nanoscale materials such as nanotubes, nanowires, nanoparticles, and nanosheets as well as porous nanostructured materials including nanoporous anodic alumina, mesoporous silica, porous silicon, and polystyrene nanochannels. These platforms may pave the way toward the development of point-of-care portable electronic devices for applications ranging from environmental analysis to biomedical diagnostics.
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Affiliation(s)
| | | | | | - Beatriz Prieto-Simon
- Monash Institute of Pharmaceutical Sciences, Monash University , Parkville, Victoria 3052, Australia
| | - Nicolas H Voelcker
- Monash Institute of Pharmaceutical Sciences, Monash University , Parkville, Victoria 3052, Australia
- Victorian Node of the Australian National Fabrication Facility, Melbourne Centre for Nanofabrication , Clayton, Victoria 3168, Australia
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203
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Lin Z, Zhang L, Zhang D, Huo G, Zhou X, Yang YW, Huo Y, Li B, Geng XC. A case report of spontaneous staphylococcal meningitis in a cynomolgus monkey. J Med Primatol 2018; 47:132-135. [PMID: 29399828 DOI: 10.1111/jmp.12330] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/20/2017] [Indexed: 12/23/2022]
Abstract
This report describes a suppurative meningitis in a young cynomolgus. The animal had neutrophil aggregation in the subarachnoid space and hemorrhage in bilateral adrenal glands. Staphylococcus was identified by FISH in brain. To our knowledge, this is the first case of staphylococcal meningitis with Waterhouse-Friderichsen syndrome in a cynomolgus monkey.
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Affiliation(s)
- Zhi Lin
- National Institute for Food and Drug Control, National Center for Safety Evaluation of Drugs, Beijing Key Lab for Pre-clinical Safety Evaluation of Drugs, Beijing, China
| | - Lu Zhang
- Key Laboratory of Digital Earth Science, Institute of Remote Sensing and Digital Earth, Chinese Academy of Sciences, Beijing, China
| | - Di Zhang
- National Institute for Food and Drug Control, National Center for Safety Evaluation of Drugs, Beijing Key Lab for Pre-clinical Safety Evaluation of Drugs, Beijing, China
| | - Guitao Huo
- National Institute for Food and Drug Control, National Center for Safety Evaluation of Drugs, Beijing Key Lab for Pre-clinical Safety Evaluation of Drugs, Beijing, China
| | - Xiaobing Zhou
- National Institute for Food and Drug Control, National Center for Safety Evaluation of Drugs, Beijing Key Lab for Pre-clinical Safety Evaluation of Drugs, Beijing, China
| | - Yan-Wei Yang
- National Institute for Food and Drug Control, National Center for Safety Evaluation of Drugs, Beijing Key Lab for Pre-clinical Safety Evaluation of Drugs, Beijing, China
| | - Yan Huo
- National Institute for Food and Drug Control, National Center for Safety Evaluation of Drugs, Beijing Key Lab for Pre-clinical Safety Evaluation of Drugs, Beijing, China
| | - Bo Li
- National Institute for Food and Drug Control, National Center for Safety Evaluation of Drugs, Beijing Key Lab for Pre-clinical Safety Evaluation of Drugs, Beijing, China
| | - Xing-Chao Geng
- National Institute for Food and Drug Control, National Center for Safety Evaluation of Drugs, Beijing Key Lab for Pre-clinical Safety Evaluation of Drugs, Beijing, China
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204
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Gu J, Liu T, Sadiq FA, Yang H, Yuan L, Zhang G, He G. Biogenic amines content and assessment of bacterial and fungal diversity in stinky tofu – A traditional fermented soy curd. Lebensm Wiss Technol 2018. [DOI: 10.1016/j.lwt.2017.08.085] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
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205
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Gonzalez AGM, Marques LMP, Gomes MDSA, Beltrão JCDC, Pinheiro MG, Esper LMR, Paula GRD, Teixeira LA, Aguiar-Alves F. Methicillin-resistant Staphylococcus aureus in minas frescal cheese: evaluation of classic enterotoxin genes, antimicrobial resistance and clonal diversity. FEMS Microbiol Lett 2018; 364:4584464. [PMID: 29099921 DOI: 10.1093/femsle/fnx232] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2017] [Accepted: 10/31/2017] [Indexed: 01/24/2023] Open
Abstract
This study aimed to investigate classical enterotoxin (sea to see) and mecA genes, by polymerase chain reaction and anitimicrobial susceptibility, by disk diffusion test of Staphylococcus aureus isolated from minas frescal cheese (MFC). All methicillin-resistant S. aureus (MRSA) isolates were investigated for the presence of Panton-Valentine leukocidin (PVL) genes and clonal diversity. Thirty-one S. aureus were isolated from four MFC samples. Seven (22.6%) S. aureus carried mecA gene and two of them carried enterotoxin genes seb/sec and sea/seb. Five (16.1%) S. aureus isolates showed induced resistance to clindamycin and nine (29%) were resistant to multiple -antibiotics (MDR), among these, six were MRSA. No MRSA isolates presented the PVL genes. Four MRSA were grouped into three clones and three isolates were not typable by pulsed field gel electrophoresis. MRSA isolates showed, by multilocus sequence typing, sequence types ST1, ST5, ST72 and ST4304 (new ST) and S. aureus protein A (spa type) t127, t568 and t2703. These data suggest that MFC may constitute a risk to the consumer because of its potential for staphylococcal food poisoning; however it might, also, become one of MRSA and MDR strains disseminator, including clones usually found in the hospital environment.
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Affiliation(s)
| | - Leila Márcia Peres Marques
- Departamento de Bromatologia, Faculdade de Farmácia, Universidade Federal Fluminense, Niterói, RJ 24241-000, Brasil
| | - Marcel da Silva Amorim Gomes
- Departamento de Bromatologia, Faculdade de Farmácia, Universidade Federal Fluminense, Niterói, RJ 24241-000, Brasil
| | | | - Marcos Gabriel Pinheiro
- Programa de Pós Graduacao em Patologia, Faculdade de Medicina, Universidade Federal Fluminense, Niterói, RJ 24033-900, Brasil
| | - Luciana Maria Ramires Esper
- Departamento de Bromatologia, Faculdade de Farmácia, Universidade Federal Fluminense, Niterói, RJ 24241-000, Brasil
| | - Geraldo Renato de Paula
- Departamento de Tecnologia de Medicamentos e Cosméticos, Faculdade de Farmácia, Universidade Federal Fluminense, Niterói, RJ 24241-000, Brasil
| | - Lenise Arneiro Teixeira
- Departamento de Tecnologia de Medicamentos e Cosméticos, Faculdade de Farmácia, Universidade Federal Fluminense, Niterói, RJ 24241-000, Brasil
| | - Fábio Aguiar-Alves
- Programa de Pós Graduacao em Patologia, Faculdade de Medicina, Universidade Federal Fluminense, Niterói, RJ 24033-900, Brasil
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206
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Shir A, Klein S, Sagiv-Barfi I, Geiger T, Zigler M, Langut Y, Edinger N, Levitzki A. S101, an Inhibitor of Proliferating T Cells, Rescues Mice From Superantigen-Induced Shock. J Infect Dis 2018; 217:288-297. [PMID: 29149330 DOI: 10.1093/infdis/jix576] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2016] [Accepted: 11/14/2017] [Indexed: 12/16/2022] Open
Abstract
Superantigens (SAgs) are extremely potent bacterial toxins, which evoke a virulent immune response, inducing nonspecific T-cell proliferation, rapid cytokine release, and lethal toxic shock, for which there is no effective treatment. We previously developed a small molecule, S101, which potently inhibits proliferating T cells. In a severe mouse model of toxic shock, a single injection of S101 given together with superantigen challenge rescued 100% of the mice. Even when given 2 hours after challenge, S101 rescued 40% of the mice. S101 targets the T-cell receptor, inflammatory response, and actin cytoskeleton pathways. S101 inhibits the aryl hydrocarbon receptor, a ligand-activated transcription factor that is involved in the differentiation of T-helper cells, especially Th17, and regulatory T cells. Our results provide the rationale for developing S101 to treat superantigen-induced toxic shock and other pathologies characterized by T-cell activation and proliferation.
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Affiliation(s)
- Alexei Shir
- Unit of Cellular Signaling, Silberman Life Sciences Institute, Hebrew University of Jerusalem, Safra Campus, Israel
| | - Shoshana Klein
- Unit of Cellular Signaling, Silberman Life Sciences Institute, Hebrew University of Jerusalem, Safra Campus, Israel
| | - Idit Sagiv-Barfi
- Unit of Cellular Signaling, Silberman Life Sciences Institute, Hebrew University of Jerusalem, Safra Campus, Israel
| | - Tamar Geiger
- Department of Proteomics and Signal Transduction, Max Planck Institute of Biochemistry, Martinsried, Germany
| | - Maya Zigler
- Unit of Cellular Signaling, Silberman Life Sciences Institute, Hebrew University of Jerusalem, Safra Campus, Israel
| | - Yael Langut
- Unit of Cellular Signaling, Silberman Life Sciences Institute, Hebrew University of Jerusalem, Safra Campus, Israel
| | - Nufar Edinger
- Unit of Cellular Signaling, Silberman Life Sciences Institute, Hebrew University of Jerusalem, Safra Campus, Israel
| | - Alexander Levitzki
- Unit of Cellular Signaling, Silberman Life Sciences Institute, Hebrew University of Jerusalem, Safra Campus, Israel
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207
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Computational Modeling of the Staphylococcal Enterotoxins and Their Interaction with Natural Antitoxin Compounds. Int J Mol Sci 2018; 19:ijms19010133. [PMID: 29301344 PMCID: PMC5796082 DOI: 10.3390/ijms19010133] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2017] [Revised: 12/26/2017] [Accepted: 12/27/2017] [Indexed: 01/08/2023] Open
Abstract
Staphylococcus aureus is an opportunistic bacterium that produces various types of toxins, resulting in serious food poisoning. Staphylococcal enterotoxins (SEs) are heat-stable and resistant to hydrolysis by digestive enzymes, representing a potential hazard for consumers worldwide. In the present study, we used amino-acid sequences encoding SEA and SEB-like to identify their respective template structure and build the three-dimensional (3-D) models using homology modeling method. Two natural compounds, Betulin and 28-Norolean-12-en-3-one, were selected for docking study on the basis of the criteria that they satisfied the Lipinski’s Rule-of-Five. A total of 14 and 13 amino-acid residues were present in the best binding site predicted in the SEA and SEB-like, respectively, using the Computer Atlas of Surface Topology of Proteins (CASTp). Among these residues, the docking study with natural compounds Betulin and 28-Norolean-12-en-3-one revealed that GLN43 and GLY227 in the binding site of the SEA, each formed a hydrogen-bond interaction with 28-Norolean-12-en-3-one; while GLY227 residue established a hydrogen bond with Betulin. In the case of SEB-like, the docking study demonstrated that ASN87 and TYR88 residues in its binding site formed hydrogen bonds with Betulin; whereas HIS59 in the binding site formed a hydrogen-bond interaction with 28-Norolean-12-en-3-one. Our results demonstrate that the toxic effects of these two SEs can be effectively treated with antitoxins like Betulin and 28-Norolean-12-en-3-one, which could provide an effective drug therapy for this pathogen.
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208
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209
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Hu DL, Ono HK, Isayama S, Okada R, Okamura M, Lei LC, Liu ZS, Zhang XC, Liu MY, Cui JC, Nakane A. Biological characteristics of staphylococcal enterotoxin Q and its potential risk for food poisoning. J Appl Microbiol 2017; 122:1672-1679. [PMID: 28375567 DOI: 10.1111/jam.13462] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2017] [Revised: 03/08/2017] [Accepted: 03/24/2017] [Indexed: 11/30/2022]
Abstract
AIMS To elucidate the biological characteristics and stability of a newly identified staphylococcal enterotoxin Q (SEQ) against heating and digestive enzymes and to evaluate the risk of seq-harbouring Staphylococcus aureus in food poisoning. METHODS AND RESULTS Purified SEQ was treated with heating, pepsin and trypsin which are related to food cooking, stomach and intestine conditions, respectively. Superantigenic activity of SEQ was assessed by determining the ability of IL-2 induction in mouse spleen cells. The emetic activity of SEQ was assessed using house musk shrew, a small emetic animal model. The results revealed that SEQ exhibits a remarkable resistance to heat treatment and pepsin digestion and has significant superantigenic and emetic activities. Furthermore, a sandwich ELISA for detection of SEQ production was developed, and the results showed that seq-harboring S. aureus isolates produce a large amount of SEQ. CONCLUSIONS The newly identified SEQ had remarkable stability to heat treatment and digestive enzyme degradation and exhibited significant superantigenic and emetic activities. In addition, seq-harbouring S. aureus isolated from food poisoning outbreaks produced a large amount of SEQ, suggesting that seq-harbouring S. aureus could potentially be a hazard for food safety. SIGNIFICANCE AND IMPACT OF THE STUDY This study found, for the first time, that SEQ, a nonclassical SE, had remarkable stability to heat treatment and enzyme degradation and exhibited significant emetic activity, indicating that SEQ is a high-risk toxin in food poisoning.
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Affiliation(s)
- D-L Hu
- College of Veterinary Medicine, Jilin University, Changchun, Jiling, China.,Department of Zoonoses, Kitasato University School of Veterinary Medicine, Towada, Aomori, Japan.,Department of Microbiology and Immunology, Hirosaki University Graduate School of Medicine, Hirosaki, Aomori, Japan
| | - H K Ono
- Department of Zoonoses, Kitasato University School of Veterinary Medicine, Towada, Aomori, Japan.,Department of Microbiology and Immunology, Hirosaki University Graduate School of Medicine, Hirosaki, Aomori, Japan
| | - S Isayama
- Department of Zoonoses, Kitasato University School of Veterinary Medicine, Towada, Aomori, Japan
| | - R Okada
- Department of Zoonoses, Kitasato University School of Veterinary Medicine, Towada, Aomori, Japan
| | - M Okamura
- Department of Zoonoses, Kitasato University School of Veterinary Medicine, Towada, Aomori, Japan
| | - L C Lei
- College of Veterinary Medicine, Jilin University, Changchun, Jiling, China
| | - Z S Liu
- College of Veterinary Medicine, Jilin University, Changchun, Jiling, China
| | - X-C Zhang
- College of Veterinary Medicine, Jilin University, Changchun, Jiling, China
| | - M Y Liu
- College of Veterinary Medicine, Jilin University, Changchun, Jiling, China
| | - J C Cui
- College of Life Science, Dalian Minzu University, Dalian, Liaoning, China
| | - A Nakane
- Department of Microbiology and Immunology, Hirosaki University Graduate School of Medicine, Hirosaki, Aomori, Japan
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210
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Bardet M, Unterreiner A, Malinverni C, Lafossas F, Vedrine C, Boesch D, Kolb Y, Kaiser D, Glück A, Schneider MA, Katopodis A, Renatus M, Simic O, Schlapbach A, Quancard J, Régnier CH, Bold G, Pissot-Soldermann C, Carballido JM, Kovarik J, Calzascia T, Bornancin F. The T-cell fingerprint of MALT1 paracaspase revealed by selective inhibition. Immunol Cell Biol 2017; 96:81-99. [DOI: 10.1111/imcb.1018] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2017] [Revised: 09/01/2017] [Accepted: 09/30/2017] [Indexed: 12/15/2022]
Affiliation(s)
- Maureen Bardet
- Novartis Institutes for BioMedical Research; Novartis Campus; Basel Switzerland
| | - Adeline Unterreiner
- Novartis Institutes for BioMedical Research; Novartis Campus; Basel Switzerland
| | - Claire Malinverni
- Novartis Institutes for BioMedical Research; Novartis Campus; Basel Switzerland
| | - Frédérique Lafossas
- Novartis Institutes for BioMedical Research; Novartis Campus; Basel Switzerland
| | - Corinne Vedrine
- Novartis Institutes for BioMedical Research; Novartis Campus; Basel Switzerland
| | - Danielle Boesch
- Novartis Institutes for BioMedical Research; Novartis Campus; Basel Switzerland
| | - Yeter Kolb
- Novartis Institutes for BioMedical Research; Novartis Campus; Basel Switzerland
| | - Daniel Kaiser
- Novartis Institutes for BioMedical Research; Novartis Campus; Basel Switzerland
| | - Anton Glück
- Novartis Institutes for BioMedical Research; Novartis Campus; Basel Switzerland
| | - Martin A Schneider
- Novartis Institutes for BioMedical Research; Novartis Campus; Basel Switzerland
| | - Andreas Katopodis
- Novartis Institutes for BioMedical Research; Novartis Campus; Basel Switzerland
| | - Martin Renatus
- Novartis Institutes for BioMedical Research; Novartis Campus; Basel Switzerland
| | - Oliver Simic
- Novartis Institutes for BioMedical Research; Novartis Campus; Basel Switzerland
| | - Achim Schlapbach
- Novartis Institutes for BioMedical Research; Novartis Campus; Basel Switzerland
| | - Jean Quancard
- Novartis Institutes for BioMedical Research; Novartis Campus; Basel Switzerland
| | - Catherine H Régnier
- Novartis Institutes for BioMedical Research; Novartis Campus; Basel Switzerland
| | - Guido Bold
- Novartis Institutes for BioMedical Research; Novartis Campus; Basel Switzerland
| | | | - José M Carballido
- Novartis Institutes for BioMedical Research; Novartis Campus; Basel Switzerland
| | - Jiri Kovarik
- Novartis Institutes for BioMedical Research; Novartis Campus; Basel Switzerland
| | - Thomas Calzascia
- Novartis Institutes for BioMedical Research; Novartis Campus; Basel Switzerland
| | - Frédéric Bornancin
- Novartis Institutes for BioMedical Research; Novartis Campus; Basel Switzerland
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211
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Zhang X, Hu X, Rao X. Apoptosis induced by Staphylococcus aureus toxins. Microbiol Res 2017; 205:19-24. [DOI: 10.1016/j.micres.2017.08.006] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2017] [Revised: 07/31/2017] [Accepted: 08/09/2017] [Indexed: 10/19/2022]
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212
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Vázquez-Sánchez D, Galvão JA, Oetterer M. Contamination sources, biofilm-forming ability and biocide resistance of Staphylococcus aureus in tilapia-processing facilities. FOOD SCI TECHNOL INT 2017; 24:209-222. [PMID: 29169268 DOI: 10.1177/1082013217742753] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
The major contamination sources, biofilm-forming ability and biocide resistance of Staphylococcus aureus in tilapia-processing plants were evaluated. Twenty-five processing control points were analysed twice in two factories, including whole tilapias, frozen fillets, water and food-contact surfaces. No final product was contaminated with S. aureus. However, high concentrations of S. aureus carrying enterotoxin ( se) genes were found in several processing points of both factories due to the application of inadequate hygienic and handling procedures, which generate a high risk of cross-contamination of the tilapia fillets with staphylococcal enterotoxins. Nine S. aureus strains were characterized by RAPD-PCR using primers AP-7, ERIC-2 and S. A wide diversity of se gene profiles was detected, most strains being multi- se-carriers. All S. aureus strains showed high biofilm-forming ability on stainless steel and polystyrene. Biofilm-forming ability was correlated with the presence of fliC H7 and the type of origin surface (metallic or plastic). A marked resistance of S. aureus to peracetic acid and sodium hypochlorite was also observed, required doses being higher than those recommended by manufacturers to be eradicated. Case-by-case approaches are thus recommended to determine the sources and degree of contamination present in each factory, which would allow applying precise responses that avoid, or at least reduce, the presence of bacterial pathogens and the emergence of antimicrobial resistance.
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Affiliation(s)
- Daniel Vázquez-Sánchez
- Department of Agri-Food Industry, Food and Nutrition, Laboratory of Freshwater Fish and Seafood Technology, 'Luiz de Queiroz' College of Agriculture (ESALQ), University of São Paulo (USP), Piracicaba, Brazil
| | - Juliana A Galvão
- Department of Agri-Food Industry, Food and Nutrition, Laboratory of Freshwater Fish and Seafood Technology, 'Luiz de Queiroz' College of Agriculture (ESALQ), University of São Paulo (USP), Piracicaba, Brazil
| | - Marília Oetterer
- Department of Agri-Food Industry, Food and Nutrition, Laboratory of Freshwater Fish and Seafood Technology, 'Luiz de Queiroz' College of Agriculture (ESALQ), University of São Paulo (USP), Piracicaba, Brazil
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213
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Dittmann KK, Chaul LT, Lee SHI, Corassin CH, Fernandes de Oliveira CA, Pereira De Martinis EC, Alves VF, Gram L, Oxaran V. Staphylococcus aureus in Some Brazilian Dairy Industries: Changes of Contamination and Diversity. Front Microbiol 2017; 8:2049. [PMID: 29123505 PMCID: PMC5662873 DOI: 10.3389/fmicb.2017.02049] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2016] [Accepted: 10/06/2017] [Indexed: 12/17/2022] Open
Abstract
Staphylococcus aureus, a major food-poisoning pathogen, is a common contaminant in dairy industries worldwide, including in Brazil. We determined the occurrence of S. aureus in five dairies in Brazil over 8 months. Of 421 samples, 31 (7.4%) were positive for S. aureus and prevalence varied from 0 to 63.3% between dairies. Sixty-six isolates from the 31 samples were typed by Multi-Locus Sequence Typing to determine if these isolates were persistent or continuously reintroduced. Seven known sequence types (STs), ST1, ST5, ST30, ST97, ST126, ST188 and ST398, and four new ST were identified, ST3531, ST3540, ST3562 and ST3534. Clonal complex (CC) 1 (including the four new ST), known as an epidemic clone, was the dominant CC. However, there were no indications of persistence of particular ST. The resistance toward 11 antibiotic compounds was assessed. Twelve profiles were generated with 75.8% of strains being sensitive to all antibiotic classes and no Methicillin-resistant S. aureus (MRSA) strains were found. The enterotoxin-encoding genes involved in food-poisoning, e.g., sea, sed, see, and seg were targeted by PCR. The two toxin-encoding genes, sed and see, were not detected. Only three strains (4.5%) harbored seg and two of these also harbored sea. Despite the isolates being Methicillin-sensitive S. aureus (MSSA), the presence of CC1 clones in the processing environment, including some harboring enterotoxin encoding genes, is of concern and hygiene must have high priority to reduce contamination.
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Affiliation(s)
- Karen K. Dittmann
- Department of Biotechnology and Biomedicine, Technical University of Denmark, Kongens Lyngby, Denmark
| | - Luíza T. Chaul
- Faculty of Pharmacy, Federal University of Goiás, Goiânia, Brazil
| | - Sarah H. I. Lee
- Faculty of Animal Science and Food Engineering, University of São Paulo, Ribeirão Preto, Brazil
| | - Carlos H. Corassin
- Faculty of Animal Science and Food Engineering, University of São Paulo, Ribeirão Preto, Brazil
| | | | | | | | - Lone Gram
- Department of Biotechnology and Biomedicine, Technical University of Denmark, Kongens Lyngby, Denmark
| | - Virginie Oxaran
- Department of Biotechnology and Biomedicine, Technical University of Denmark, Kongens Lyngby, Denmark
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214
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Elbashir S, Parveen S, Schwarz J, Rippen T, Jahncke M, DePaola A. Seafood pathogens and information on antimicrobial resistance: A review. Food Microbiol 2017; 70:85-93. [PMID: 29173644 DOI: 10.1016/j.fm.2017.09.011] [Citation(s) in RCA: 79] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2016] [Revised: 09/11/2017] [Accepted: 09/14/2017] [Indexed: 01/22/2023]
Abstract
Seafood-borne diseases are a major public health hazard in the United States and worldwide. Per capita, seafood consumption has increased globally during recent decades. Seafood importation and domestic aquaculture farming has also increased. Moreover, several recent outbreaks of human gastroenteritis have been linked to the consumption of contaminated seafood. Investigation of seafood-borne illnesses caused by norovirus, and Vibrio, and other bacteria and viruses require a concrete knowledge about the pathogenicity and virulence properties of the etiologic agents. This review explores pathogens that have been associated with seafood and resulting outbreaks in the U.S. and other countries as well as the presence of antimicrobial resistance in the reviewed pathogens. The spectrum of such resistance is widening due to the overuse, misuse, and sub-therapeutic application of antimicrobials in humans and animals.
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Affiliation(s)
- S Elbashir
- Food Science and Technology Ph.D. Program, Department of Agriculture, Food and Resource Sciences, University of Maryland Eastern Shore, 2116 Center for Food Science and Technology, Princess Anne, MD 21853, USA
| | - S Parveen
- Food Science and Technology Ph.D. Program, Department of Agriculture, Food and Resource Sciences, University of Maryland Eastern Shore, 2116 Center for Food Science and Technology, Princess Anne, MD 21853, USA.
| | - J Schwarz
- Food Science and Technology Ph.D. Program, Department of Agriculture, Food and Resource Sciences, University of Maryland Eastern Shore, 2116 Center for Food Science and Technology, Princess Anne, MD 21853, USA
| | - T Rippen
- Food Science and Technology Ph.D. Program, Department of Agriculture, Food and Resource Sciences, University of Maryland Eastern Shore, 2116 Center for Food Science and Technology, Princess Anne, MD 21853, USA
| | - M Jahncke
- Virginia Tech., Virginia Seafood Agricultural Research and Extension Center, 102 South King Street, Hampton, VA 23669, USA
| | - A DePaola
- Angelo DePaola Consulting, 12719 Dauphin Island Pkwy, Coden, AL 36523, USA
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215
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Goldmann O, Medina E. Staphylococcus aureus strategies to evade the host acquired immune response. Int J Med Microbiol 2017; 308:625-630. [PMID: 28939437 DOI: 10.1016/j.ijmm.2017.09.013] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2017] [Revised: 09/01/2017] [Accepted: 09/13/2017] [Indexed: 12/13/2022] Open
Abstract
Staphylococcus aureus poses a significant public-health problem. Infection caused by S. aureus can manifest as acute or long-lasting persistent diseases that are often refractory to antibiotic and are associated with significant morbidity and mortality. To develop more effective strategies for preventing or treating these infections, it is crucial to understand why the immune response is incapable to eradicate the bacterium. When S. aureus first infect the host, there is a robust activation of the host innate immune responses. Generally, S. aureus can survive this initial interaction due to the expression of a wide array of virulence factors that interfere with the host innate immune defenses. After this initial interaction the acquired immune response is the arm of the host defenses that will try to clear the pathogen. However, S. aureus is capable of maintaining infection in the host even in the presence of a robust antigen-specific immune response. Thus, understanding the mechanisms underlying the ability of S. aureus to escape immune surveillance by the acquired immune response will help uncover potentially important targets for the development of immune-based adjunctive therapies and more efficient vaccines. There are several lines of evidence that lead us to believe that S. aureus can directly or indirectly disable the acquired immune response. This review will discuss the different immune evasion strategies used by S. aureus to modulate the different components of the acquired immune defenses.
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Affiliation(s)
- Oliver Goldmann
- Infection Immunology Research Group, Helmholtz Centre for Infection Research, Inhoffenstrasse 7, 38124 Braunschweig, Germany.
| | - Eva Medina
- Infection Immunology Research Group, Helmholtz Centre for Infection Research, Inhoffenstrasse 7, 38124 Braunschweig, Germany.
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216
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Prevalence of methicillin-resistant Staphylococcus aureus (MRSA) in retail food in Singapore. Antimicrob Resist Infect Control 2017; 6:94. [PMID: 28904790 PMCID: PMC5591520 DOI: 10.1186/s13756-017-0255-3] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2017] [Accepted: 09/04/2017] [Indexed: 12/29/2022] Open
Abstract
We characterised 227 Staphylococcus aureus isolates from retail food and food handlers’ gloves samples obtained through food surveillance and risk assessment studies between 2011 and 2014. Of 227 isolates, five (2.2%) were methicillin-resistant and belonged to sequence types ST80 (n = 3) and ST6 (n = 2). All five isolates belonged to SCCmec type IV, were Panton-Valentine leukocidin (pvl)-negative and staphylococcal enterotoxin genes-positive. Resistance to azithromycin was found in ST80 isolates, in addition to resistance to beta-lactams. Our finding of two clinically relevant methicillin-resistant S. aureus (MRSA) strains (ST80 and ST6) in ready-to-eat food and food contact surfaces at retail in Singapore suggests food and food contact surfaces as potential environmental sources of MRSA in the community.
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217
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Singh M, Agrawal RK, Singh BR, Mendiratta SK, Agarwal RK, Singh MK, Kumar D. Development and Evaluation of Simple Dot-Blot Assays for Rapid Detection of Staphylococcal Enterotoxin-A in Food. Indian J Microbiol 2017; 57:507-511. [PMID: 29151654 DOI: 10.1007/s12088-017-0671-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2017] [Accepted: 09/02/2017] [Indexed: 01/06/2023] Open
Abstract
The present study was aimed to develop and evaluate dot-blot assays for rapid detection of staphylococcal enterotoxin-A (SEA) in food. Dot blots were developed in two formats, indirect and sandwich utilizing mouse monoclonal anti-SEA and rabbit polyclonal anti-SEA antibodies. In indirect dot-blot format, recombinant SEA was directly coated on NCM dot-blot strip and detection was carried out by anti-SEA antibodies. In sandwich dot-blot format, SEA was trapped between anti-SEA capture and detection antibodies. Both the dot-blot assays exhibited a sensitivity of ~48 ng ml-1 when tested in different food matrices. The developed assays were highly specific as no cross-reactivity was detected with other classical staphylococcal enterotoxins, toxigenic bacteria and foodborne pathogens. Sensitivity and specificity of developed indirect and sandwich dot-blot assays with respect to PCR was found to be 100 and 99%, respectively. The results shows that the developed dot-blot assays can be used as rapid preliminary screening tests for detection of SEA in food or determining the toxigenic potential of staphylococci, especially in resource-limited settings.
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Affiliation(s)
- Mamta Singh
- Division of Bacteriology and Mycology, Indian Veterinary Research Institute, Izatnagar, Bareilly, UP 243122 India
| | - Ravi Kant Agrawal
- Food Microbiology Laboratory, Division of Livestock Products Technology, Indian Veterinary Research Institute, Izatnagar, Bareilly, UP 243122 India
| | - Bhoj Raj Singh
- Division of Epidemiology, Indian Veterinary Research Institute, Izatnagar, Bareilly, UP 243122 India
| | - Sanjod Kumar Mendiratta
- Division of Livestock Products Technology, Indian Veterinary Research Institute, Izatnagar, Bareilly, UP 243122 India
| | - Rajesh Kumar Agarwal
- Division of Bacteriology and Mycology, Indian Veterinary Research Institute, Izatnagar, Bareilly, UP 243122 India
| | - Mithilesh Kumar Singh
- Immunology Section, Indian Veterinary Research Institute, Izatnagar, Bareilly, UP 243122 India
| | - Deepak Kumar
- Division of Veterinary Biotechnology, Indian Veterinary Research Institute, Izatnagar, Bareilly, UP 243122 India
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218
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Reen GK, Kumar A, Sharma P. In vitro and in silico evaluation of 2-(substituted phenyl) oxazolo[4,5-b]pyridine derivatives as potential antibacterial agents. Med Chem Res 2017. [DOI: 10.1007/s00044-017-2026-3] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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219
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Bastos CP, Bassani MT, Mata MM, Lopes GV, da Silva WP. Prevalence and expression of staphylococcal enterotoxin genes in Staphylococcus aureus isolated from food poisoning outbreaks. Can J Microbiol 2017; 63:834-840. [PMID: 28820948 DOI: 10.1139/cjm-2017-0316] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Staphylococcus aureus is an important pathogen of foodborne origin. The pathogen produces a variety of toxins that include the staphylococcal enterotoxins (SE). The present study aimed to evaluate the prevalence and expression of 5 SE genes (sea, seb, sec, sed, and see) in S. aureus isolated from outbreaks occurred in the state of Rio Grande do Sul, Brazil. All isolates, with the exception of 2, presented the same or higher transcriptional expression than the reference strains for at least 1 of these genes. The presence of SE genes combined with high levels of transcriptional expression suggests that 1 or more SEs were involved with the staphylococcal food poisoning outbreak analyzed in the present study.
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Affiliation(s)
- Caroline Peixoto Bastos
- Federal University of Pelotas (UFPel), Faculty of Agronomy Eliseu Maciel (FAEM), Department of Science and Food Technology, Pelotas, RS, Brazil.,Federal University of Pelotas (UFPel), Faculty of Agronomy Eliseu Maciel (FAEM), Department of Science and Food Technology, Pelotas, RS, Brazil
| | - Milena Tomasi Bassani
- Federal University of Pelotas (UFPel), Faculty of Agronomy Eliseu Maciel (FAEM), Department of Science and Food Technology, Pelotas, RS, Brazil.,Federal University of Pelotas (UFPel), Faculty of Agronomy Eliseu Maciel (FAEM), Department of Science and Food Technology, Pelotas, RS, Brazil
| | - Marcia Magalhães Mata
- Federal University of Pelotas (UFPel), Faculty of Agronomy Eliseu Maciel (FAEM), Department of Science and Food Technology, Pelotas, RS, Brazil.,Federal University of Pelotas (UFPel), Faculty of Agronomy Eliseu Maciel (FAEM), Department of Science and Food Technology, Pelotas, RS, Brazil
| | - Graciela Volz Lopes
- Federal University of Pelotas (UFPel), Faculty of Agronomy Eliseu Maciel (FAEM), Department of Science and Food Technology, Pelotas, RS, Brazil.,Federal University of Pelotas (UFPel), Faculty of Agronomy Eliseu Maciel (FAEM), Department of Science and Food Technology, Pelotas, RS, Brazil
| | - Wladimir Padilha da Silva
- Federal University of Pelotas (UFPel), Faculty of Agronomy Eliseu Maciel (FAEM), Department of Science and Food Technology, Pelotas, RS, Brazil.,Federal University of Pelotas (UFPel), Faculty of Agronomy Eliseu Maciel (FAEM), Department of Science and Food Technology, Pelotas, RS, Brazil
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220
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High prevalence of clonally diverse spa type t026 Staphylococcus aureus contaminating rural eggshells. J Med Microbiol 2017; 66:1196-1201. [DOI: 10.1099/jmm.0.000540] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
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221
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Use of Red Beet (Beta vulgaris L.) for Antimicrobial Applications—a Critical Review. FOOD BIOPROCESS TECH 2017. [DOI: 10.1007/s11947-017-1942-z] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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222
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Abstract
Local allergic inflammation (LAI) is recognized recently. 'entopy' was used to define LAI, which was positively correlated with allergen provocation testing, local sIgE up-regulation, inflammatory mediator secretion, and a lack of systemic allergy. The study of LAI is in its infancy and focuses mainly on the respiratory system. It is closely related to nasal inflammation and plays important roles in patients with nonallergic rhinitis (NAR), nonallergic chronic sinusitis with nasal polyps (CRSwNP), and nonallergic fungal rhinosinusitis (NAFRS). Based on studies using nasal allergen provocation testing, 40-57% of patients with NAR exhibited positive results and could be diagnosed as local allergic rhinitis. Total IgE and common airborne allergen-sIgE were up-regulated in eosinophilic CRSwNP patients compared to noneosinophilic CRSwNP patients and healthy controls, possibly due to local allergic inflammation. Some researchers also found that the level of local sIgE was increased in patients with NAFRS; they suggested that local allergic inflammation occurs in NAFRS. Studies of LAI will increase our understanding of nasal inflammation and help to establish novel treatments. However, the diagnosis of local allergic inflammation is complex due to the lack of convenient detection methods. The relationship between local allergic inflammation and systemic allergic inflammation is unclear, and an appropriate treatment for local allergic inflammation is required.
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Affiliation(s)
- Ke-Jia Cheng
- Department of Otolaryngology, The First Affiliated Hospital, College of Medicine, Zhejiang University, #79 Qingchun Road, Hangzhou, 310003, Zhejiang, People's Republic of China
| | - Min-Li Zhou
- Department of Otolaryngology, The First Affiliated Hospital, College of Medicine, Zhejiang University, #79 Qingchun Road, Hangzhou, 310003, Zhejiang, People's Republic of China
| | - Ying-Ying Xu
- Department of Otolaryngology, The First Affiliated Hospital, College of Medicine, Zhejiang University, #79 Qingchun Road, Hangzhou, 310003, Zhejiang, People's Republic of China
| | - Shui-Hong Zhou
- Department of Otolaryngology, The First Affiliated Hospital, College of Medicine, Zhejiang University, #79 Qingchun Road, Hangzhou, 310003, Zhejiang, People's Republic of China.
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223
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Bergevin M, Marion A, Farber D, Golding GR, Lévesque S. Severe MRSA Enterocolitis Caused by a Strain Harboring Enterotoxins D, G, and I. Emerg Infect Dis 2017; 23:865-867. [PMID: 28418301 PMCID: PMC5403038 DOI: 10.3201/eid2305.161644] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
We describe a case of methicillin-resistant Staphylococcus aureus (MRSA) enterocolitis in a healthy adult with previous antibiotic exposure. Colonoscopy revealed diffuse colitis and mild ileitis without ulceration. Stool cultures demonstrated abundant growth of MRSA and absent normal flora. Oral vancomycin treatment was effective and seems to be the consensus choice for therapy.
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224
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Benkerroum N. Staphylococcal enterotoxins and enterotoxin-like toxins with special reference to dairy products: An overview. Crit Rev Food Sci Nutr 2017; 58:1943-1970. [DOI: 10.1080/10408398.2017.1289149] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Affiliation(s)
- Noreddine Benkerroum
- Department of Food Science and Agricultural Chemistry, Macdonald-Stewart Building, McGill University, Macdonald Campus, Sainte-Anne-de-Bellevue, Canada
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225
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Hulme J. Recent advances in the detection of methicillin resistant Staphylococcus aureus (MRSA). BIOCHIP JOURNAL 2017. [DOI: 10.1007/s13206-016-1201-9] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
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226
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A novel staphylococcal enterotoxin B subunit vaccine candidate elicits protective immune response in a mouse model. Toxicon 2017; 131:68-77. [PMID: 28359755 DOI: 10.1016/j.toxicon.2017.03.012] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2016] [Revised: 03/21/2017] [Accepted: 03/22/2017] [Indexed: 11/20/2022]
Abstract
Staphylococcal enterotoxin B (SEB), produced by the gram-positive bacterium Staphylococcus aureus, is responsible for food poisoning and toxic shock syndrome, and is considered a potential bioterrorism agent. Unfortunately, still now no approved vaccines are available against SEB. In this study, we constructed a series of nontoxic SEB mutants (mSEBs) and examined whether these mSEBs provide protective immunity against SEB challenge. These mSEB vaccine candidates did not demonstrate superantigen activity in mouse splenocyte cultures. Immunization with the vaccine candidates triggered the production of IgG-antibodies with neutralizing activity. In addition, increased production of IgG1 and IgG3 was observed after immunization, which signifies both Th1- and Th2-induced immune responses. Among the vaccine candidates tested, S9, a double mutant (N23A and Y90A) and S19, a quadruple mutant (N23A, Y90A, R110A, and F177A), demonstrated complete protection against a lethal SEB challenge. Altogether, our results strongly suggest that these mSEBs could be an effective recombinant SEB vaccine candidates for further/future preclinical and clinical studies.
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227
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Zhao Y, Zhu A, Tang J, Tang C, Chen J, Liu J. Identification and measurement of staphylococcal enterotoxin-like protein I (SEll) secretion from Staphylococcus aureus clinical isolate. J Appl Microbiol 2017; 121:539-46. [PMID: 27187155 DOI: 10.1111/jam.13181] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2015] [Revised: 05/11/2016] [Accepted: 05/11/2016] [Indexed: 01/04/2023]
Abstract
AIMS Staphylococcus aureus (Staph. aureus) produces a wide variety of staphylococcal enterotoxins (SEs) and staphylococcal enterotoxin-like (SEl) proteins, which are the most causative agents of staphylococcal food poisoning. In contrast to classical SEs (SEA to SEE), the relationship between the novel SEs/SEls (SEG to SElX) and staphylococcal food poisoning is not elucidated. This study is aimed to establish a system to detect staphylococcal enterotoxin-like protein I (SElI) for analysis of staphylococcal food poisoning. METHODS AND RESULTS SElI was characterized in a Staph. aureus clinical isolate associated with food poisoning; there was an amino acid substitution Thr145Ala compared to previously identified SEI from Staph. aureus 04-02981. Subsequently, SElI was expressed, purified, and the poly- and monoclonal antibodies against it were prepared. Using these antibodies, a highly sensitive sandwich enzyme-linked immunosorbent assay (ELISA) that specifically detected and measured SElI secretion from the Staph. aureus clinical isolate in LB medium, milk and bloodstream was developed. CONCLUSIONS The ELISA system has been successfully applied for analysing SElI secretion in vivo and in vitro. SIGNIFICANCE AND IMPACT OF THE STUDY The highly sensitive ELISA should make it attractive for quantifying SElI in food hygiene supervision and clinical diagnosis in near future.
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Affiliation(s)
- Y Zhao
- College of Life Science and Technology, Southwest University for Nationalities, Chengdu, China
| | - A Zhu
- College of Life Science and Technology, Southwest University for Nationalities, Chengdu, China
| | - J Tang
- College of Life Science and Technology, Southwest University for Nationalities, Chengdu, China
| | - C Tang
- College of Life Science and Technology, Southwest University for Nationalities, Chengdu, China
| | - J Chen
- College of Life Science and Technology, Southwest University for Nationalities, Chengdu, China
| | - J Liu
- College of Life Science and Technology, Southwest University for Nationalities, Chengdu, China
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228
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PBMC activation via the ERK and STAT signaling pathways enhances the anti-tumor activity of Staphylococcal enterotoxin A. Mol Cell Biochem 2017; 434:75-87. [DOI: 10.1007/s11010-017-3038-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2017] [Accepted: 04/12/2017] [Indexed: 01/11/2023]
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229
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Rong D, Wu Q, Xu M, Zhang J, Yu S. Prevalence, Virulence Genes, Antimicrobial Susceptibility, and Genetic Diversity of Staphylococcus aureus from Retail Aquatic Products in China. Front Microbiol 2017; 8:714. [PMID: 28473827 PMCID: PMC5398012 DOI: 10.3389/fmicb.2017.00714] [Citation(s) in RCA: 52] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2016] [Accepted: 04/06/2017] [Indexed: 01/21/2023] Open
Abstract
Staphylococcus aureus is an important food-borne opportunistic pathogen that frequently causes severe blood and tissue infections or even fatal illnesses. Although S. aureus has been extensively studied in livestock and poultry foods in China, limited information has been reported in aquatic products. Accordingly, in this study, we aimed to characterize S. aureus in aquatic products purchased from retail markets in China. In total, 320 aquatic food samples were collected from 32 provincial capitals in China. The results showed that 119 samples (37.2%, 119/320) were positive for S. aureus by both qualitative and quantitative analyses. The contamination levels of 78.2% of samples ranged from 0.3 to 10 MPN/g, and six samples exceeded 110 MPN/g. A total of 119 S. aureus isolates from positive samples were selected to evaluate virulence factors, antibiotic resistance, and molecular characteristics. All S. aureus isolates were evaluated for the presence of 11 virulence genes by multiplex polymerase chain reaction, and α-hemolysin (hlα, 84.9%), fibronectin-binding protein A (fnbA, 79.0%), S. aureus enterotoxin E (see, 53.8%), and Panton-Valentine leucocidin (pvl, 50.4%) were identified as the major genes. These genes formed 56 different profiles, with the major profile identified as pvl-hlα-fnbA (28.6%). The antimicrobial susceptibility of all isolates was analyzed through the disk diffusion method, and the results showed high resistance to β-lactams, macrolides and tetracyclines, but susceptibility to linezolid and vancomycin. In addition, 26 sequence types (STs) were obtained via multilocus sequence typing, including seven novel STs, among which ST1 (20.2%), ST15 (18.5%), and ST188 (13.4%) were the most common STs. All the isolates were mecC negative, but nine isolates carrying mecA were evaluated by staphylococcal cassette chromosome mec (SCCmec) typing, all of which were SCCmecIII or SCCmecIV types. Isolates of SCCmecIII showed a high prevalence and were multidrug resistant. Our results showed that aquatic products could be a vehicle for transmission of virulence genes and multidrug-resistant S. aureus, representing a potential public health risk. The STs identified in this study indicated the genetic diversity of S. aureus, thereby providing important basic data for the dissemination of S. aureus in aquatic products.
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Affiliation(s)
- Dongli Rong
- Guangdong Institute of Microbiology, State Key Laboratory of Applied Microbiology Southern China and Guangdong Provincial Key Laboratory of Microbial Culture Collection and Application, Guangdong Open Laboratory of Applied MicrobiologyGuangzhou, China
- College of Life Science and Technology, Jinan UniversityGuangzhou, China
| | - Qingping Wu
- Guangdong Institute of Microbiology, State Key Laboratory of Applied Microbiology Southern China and Guangdong Provincial Key Laboratory of Microbial Culture Collection and Application, Guangdong Open Laboratory of Applied MicrobiologyGuangzhou, China
| | - Mingfang Xu
- College of Life Science and Technology, Jinan UniversityGuangzhou, China
| | - Jumei Zhang
- Guangdong Institute of Microbiology, State Key Laboratory of Applied Microbiology Southern China and Guangdong Provincial Key Laboratory of Microbial Culture Collection and Application, Guangdong Open Laboratory of Applied MicrobiologyGuangzhou, China
| | - Shubo Yu
- Guangdong Institute of Microbiology, State Key Laboratory of Applied Microbiology Southern China and Guangdong Provincial Key Laboratory of Microbial Culture Collection and Application, Guangdong Open Laboratory of Applied MicrobiologyGuangzhou, China
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230
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Whitfield SJC, Taylor C, Risdall JE, Griffiths GD, Jones JTA, Williamson ED, Rijpkema S, Saraiva L, Vessillier S, Green AC, Carter AJ. Interference of the T Cell and Antigen-Presenting Cell Costimulatory Pathway Using CTLA4-Ig (Abatacept) Prevents Staphylococcal Enterotoxin B Pathology. THE JOURNAL OF IMMUNOLOGY 2017; 198:3989-3998. [PMID: 28320831 DOI: 10.4049/jimmunol.1601525] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/06/2016] [Accepted: 02/11/2017] [Indexed: 12/20/2022]
Abstract
Staphylococcal enterotoxin B (SEB) is a bacterial superantigen that binds the receptors in the APC/T cell synapse and causes increased proliferation of T cells and a cytokine storm syndrome in vivo. Exposure to the toxin can be lethal and cause significant pathology in humans. The lack of effective therapies for SEB exposure remains an area of concern, particularly in scenarios of acute mass casualties. We hypothesized that blockade of the T cell costimulatory signal by the CTLA4-Ig synthetic protein (abatacept) could prevent SEB-dependent pathology. In this article, we demonstrate mice treated with a single dose of abatacept 8 h post SEB exposure had reduced pathology compared with control SEB-exposed mice. SEB-exposed mice showed significant reductions in body weight between days 4 and 9, whereas mice exposed to SEB and also treated with abatacept showed no weight loss for the duration of the study, suggesting therapeutic mitigation of SEB-induced morbidity. Histopathology and magnetic resonance imaging demonstrated that SEB mediated lung damage and edema, which were absent after treatment with abatacept. Analysis of plasma and lung tissues from SEB-exposed mice treated with abatacept demonstrated significantly lower levels of IL-6 and IFN-γ (p < 0.0001), which is likely to have resulted in less pathology. In addition, exposure of human and mouse PBMCs to SEB in vitro showed a significant reduction in levels of IL-2 (p < 0.0001) after treatment with abatacept, indicating that T cell proliferation is the main target for intervention. Our findings demonstrate that abatacept is a robust and potentially credible drug to prevent toxic effects from SEB exposure.
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Affiliation(s)
- Sarah J C Whitfield
- Department of Biomedical Sciences, Defence Science and Technology Laboratory, Salisbury, Wiltshire SP4 0JQ, United Kingdom;
| | - Chris Taylor
- Department of Biomedical Sciences, Defence Science and Technology Laboratory, Salisbury, Wiltshire SP4 0JQ, United Kingdom
| | - Jane E Risdall
- Department of Biomedical Sciences, Defence Science and Technology Laboratory, Salisbury, Wiltshire SP4 0JQ, United Kingdom.,Division of Anaesthesia, Department of Medicine, University of Cambridge, Cambridge CB2 0QQ, United Kingdom
| | - Gareth D Griffiths
- Department of Biomedical Sciences, Defence Science and Technology Laboratory, Salisbury, Wiltshire SP4 0JQ, United Kingdom
| | - James T A Jones
- Department of Biomedical Sciences, Defence Science and Technology Laboratory, Salisbury, Wiltshire SP4 0JQ, United Kingdom
| | - E Diane Williamson
- Department of Biomedical Sciences, Defence Science and Technology Laboratory, Salisbury, Wiltshire SP4 0JQ, United Kingdom
| | - Sjoerd Rijpkema
- Division of Bacteriology, National Institute for Biological Standards and Control, Potters Bar EN6 3QG, United Kingdom
| | - Luisa Saraiva
- Division of Biotherapeutics, National Institute for Biological Standards and Control, Potters Bar EN6 3QG, United Kingdom; and
| | - Sandrine Vessillier
- Division of Biotherapeutics, National Institute for Biological Standards and Control, Potters Bar EN6 3QG, United Kingdom; and
| | - A Christopher Green
- Department of Biomedical Sciences, Defence Science and Technology Laboratory, Salisbury, Wiltshire SP4 0JQ, United Kingdom
| | - Alun J Carter
- Department of Biomedical Sciences, Defence Science and Technology Laboratory, Salisbury, Wiltshire SP4 0JQ, United Kingdom.,Division of Oncology, Department of Medicine, Washington University School of Medicine, St. Louis, MO 63110
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231
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Yu CJ, Cui XY, Lu L, Yang J, Chen B, Zhu CW, Gao X. Effects of glucocorticoid on the expression and regulation of aquaporin 5 in the paranasal sinus of rats with chronic rhinosinusitis. Exp Ther Med 2017; 13:1753-1756. [PMID: 28565763 PMCID: PMC5443270 DOI: 10.3892/etm.2017.4215] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2016] [Accepted: 12/23/2016] [Indexed: 01/11/2023] Open
Abstract
Aquaporins (AQPs) are water-specific membrane channel proteins that regulate water homeostasis for cells and organisms. AQP5 serves an important role in the maintenance of mucosal water homeostasis, and potentially contributes to mucosal edema and inflammation formation in chronic rhinosinusitis (CRS). The aim of the present study was to explore the expression pattern of AQP5 and the effect of glucocorticoids on AQP5 expression in rats with CRS. The rats were randomly divided into three equal groups, as follows: CRS, dexamethasone (dexa) treatment and control groups. A polyvinyl acetal material containing Staphylococcus aureus was inserted into the left nasal cavity of each rat from the CRS and dexa groups. On the 90th post-operative day, the dexa group received dexamethasone (2 mg/kg/day) via intraperitoneal injection for 7 days. The controls did not receive any treatment. The expression of AQP5 in the sinonasal mucosa was determined using immunohistochemistry and quantitative PCR. The immunoreactivities of AQP5 were primarily noted in the epithelial lining and glandular cells, the vascular endothelium and in the goblet cells in the sinonasal mucosa. The AQP5 mRNA expression level was significantly higher in the dexa group than in the control and CRS groups (P=0.006 and P=0.014, respectively). However, no significant difference was indicated between the CRS and control groups (P=0.760). In conclusion, the current study suggests that glucocorticoids induce AQP5 expression in the sinonasal mucosa of CRS rats, which highlights AQP5 as a potential target in the diagnosis and treatment of CRS.
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Affiliation(s)
- Chen-Jie Yu
- Department of Otolaryngology, Drum Tower Clinical Medical School, Nanjing Medical University, Nanjing, Jiangsu 210008, P.R. China.,Department of Otolaryngology, Nanjing Drum Tower Hospital, Nanjing University School of Medicine, Nanjing, Jiangsu 210008, P.R. China
| | - Xin-Yan Cui
- Department of Otolaryngology, The First Affiliated Hospital, Nanjing Medical University, Nanjing, Jiangsu 210029, P.R. China
| | - Ling Lu
- Department of Otolaryngology, Nanjing Drum Tower Hospital, Nanjing University School of Medicine, Nanjing, Jiangsu 210008, P.R. China
| | - Jun Yang
- Department of Pathology, Nanjing Drum Tower Hospital, Nanjing University School of Medicine, Nanjing, Jiangsu 210008, P.R. China
| | - Bin Chen
- School of Medicine, Southeast University, Nanjing, Jiangsu 210009, P.R. China
| | - Cheng-Wen Zhu
- Department of Otolaryngology, Nanjing Drum Tower Hospital, Nanjing University School of Medicine, Nanjing, Jiangsu 210008, P.R. China
| | - Xia Gao
- Department of Otolaryngology, Drum Tower Clinical Medical School, Nanjing Medical University, Nanjing, Jiangsu 210008, P.R. China.,Department of Otolaryngology, Nanjing Drum Tower Hospital, Nanjing University School of Medicine, Nanjing, Jiangsu 210008, P.R. China
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232
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Regenthal P, Hansen JS, André I, Lindkvist-Petersson K. Thermal stability and structural changes in bacterial toxins responsible for food poisoning. PLoS One 2017; 12:e0172445. [PMID: 28207867 PMCID: PMC5313198 DOI: 10.1371/journal.pone.0172445] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2016] [Accepted: 02/03/2017] [Indexed: 11/17/2022] Open
Abstract
The staphylococcal enterotoxins (SEs) are secreted by the bacteria Staphylococcus aureus and are the most common causative agent in staphylococcal food poisoning. The staphylococcal enterotoxin A (SEA) has been associated with large staphylococcal food poisoning outbreaks, but newer identified SEs, like staphylococcal enterotoxin H (SEH) has recently been shown to be present at similar levels as SEA in food poisoning outbreaks. Thus, we set out to investigate the thermo-stability of the three-dimensional structures of SEA, SEH and staphylococcal enterotoxin E (SEE), since heat inactivation is a common method to inactivate toxins during food processing. Interestingly, the investigated toxins behaved distinctly different upon heating. SEA and SEE were more stable at slightly acidic pH values, while SEH adopted an extremely stable structure at neutral pH, with almost no effects on secondary structural elements upon heating to 95°C, and with reversible formation of tertiary structure upon subsequent cooling to room temperature. Taken together, the data suggests that the family of staphylococcal enterotoxins have different ability to withstand heat, and thus the exact profile of heat inactivation for all SEs causing food poisoning needs to be considered to improve food safety.
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Affiliation(s)
- Paulina Regenthal
- Department of Experimental Medical Science, Lund University, BMC, Lund, Sweden
| | - Jesper S Hansen
- Department of Experimental Medical Science, Lund University, BMC, Lund, Sweden
| | - Ingemar André
- Department of Biochemistry and Structural Biology, Lund University, Lund, Sweden
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233
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Al-Shabib NA, Husain FM, Ahmad I, Baig MH. Eugenol inhibits quorum sensing and biofilm of toxigenic MRSA strains isolated from food handlers employed in Saudi Arabia. BIOTECHNOL BIOTEC EQ 2017. [DOI: 10.1080/13102818.2017.1281761] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Affiliation(s)
- Nasser Abdulatif Al-Shabib
- Department of Food Science and Nutrition, College of Food and Agricultural Sciences, King Saud University, Riyadh, Saudi Arabia
| | - Fohad Mabood Husain
- Department of Food Science and Nutrition, College of Food and Agricultural Sciences, King Saud University, Riyadh, Saudi Arabia
- Department of Agricultural Microbiology, Aligarh Muslim University, Aligarh, India
| | - Iqbal Ahmad
- Department of Agricultural Microbiology, Aligarh Muslim University, Aligarh, India
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234
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Park KD, Pak SC, Park KK. The Pathogenetic Effect of Natural and Bacterial Toxins on Atopic Dermatitis. Toxins (Basel) 2016; 9:toxins9010003. [PMID: 28025545 PMCID: PMC5299398 DOI: 10.3390/toxins9010003] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2016] [Revised: 12/15/2016] [Accepted: 12/19/2016] [Indexed: 12/18/2022] Open
Abstract
Atopic dermatitis (AD) is a common allergic skin disease that is associated with chronic, recurrent eczematous and pruritic lesions at the flexural folds caused by interacting factors related to environmental and immune system changes. AD results in dry skin, and immunoglobulin E-mediated allergic reactions to foods and environmental allergens. While steroids and anti-histamines temporarily relieve the symptoms of AD, the possibility of side effects from pharmacological interventions remains. Despite intensive research, the underlying mechanisms for AD have not been clarified. A study of Staphylococcus aureus (S. aureus) established the role of its toxins in the pathogenesis of AD. Approximately 90% of patients with AD experience S. aureus colonization and up to 50%–60% of the colonizing S. aureus is toxin-producing. Any damage to the protective skin barrier allows for the entry of invading allergens and pathogens that further drive the pathogenesis of AD. Some natural toxins (or their components) that have therapeutic effects on AD have been studied. In addition, recent studies on inflammasomes as one component of the innate immune system have been carried out. Additionally, studies on the close relationship between the activation of inflammasomes and toxins in AD have been reported. This review highlights the literature that discusses the pathogenesis of AD, the role of toxins in AD, and the positive and negative effects of toxins on AD. Lastly, suggestions are made regarding the role of inflammasomes in AD.
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Affiliation(s)
- Kyung-Duck Park
- Department of Dermatology, College of Medicine, Catholic University of Daegu, 33, Duryugongwon-ro 17-gil, Nam-gu, Daegu 42472, Korea.
| | - Sok Cheon Pak
- School of Biomedical Sciences, Charles Sturt University, Panorama Avenue, Bathurst NSW 2795, Australia.
| | - Kwan-Kyu Park
- Department of Pathology, College of Medicine, Catholic University of Daegu, 33, Duryugongwon-ro 17-gil, Nam-gu, Daegu 42472, Korea.
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235
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Mun SH, Kong R, Seo YS, Zhou T, Kang OH, Shin DW, Kwon DY. Subinhibitory concentrations of punicalagin reduces expression of virulence-related exoproteins by Staphylococcus aureus. FEMS Microbiol Lett 2016; 363:fnw253. [PMID: 27974390 DOI: 10.1093/femsle/fnw253] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Revised: 04/27/2016] [Accepted: 11/08/2016] [Indexed: 02/01/2023] Open
Abstract
Staphylococcus aureus produces a number of virulence factors. The major virulence factors exhibited by S aureus include various antigens, enzymes, cytotoxins and exotoxins (e.g. hemolysins, enterotoxins and toxic shock syndrome toxin). In this report, we show the influence of punicalagin on the secretion of exoprotein from S aureus by western blotting, tumor necrosis factor (TNF) release assay and quantitative RT-PCR. When added to S aureus cultures at an OD600 of 0.9, graded subinhibitory concentrations of punicalagin reduced the production of α-toxin, SEA and SEB in methicillin-resistant Staphylococcus aureus in a dose-dependent manner. Consistently, punicalagin reduced TNF-inducing activity by S aureus culture supernatants. Here, the transcriptional level of agr (accessory gene regulator) in S aureus was inhibited by punicalagin, suggesting that the reduced transcription may affect the secretion of exotoxins. These findings suggest that the expression of α-toxin and enterotoxins in S aureus is sensitive to the action of punicalagin, which may be an advantageous candidate in the treatment of toxigenic staphylococcal disease.
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Affiliation(s)
- Su-Hyun Mun
- Department of Oriental Pharmacy, College of Pharmacy, Wonkwang Oriental Medicines Research Institute, Institute of Biotechnology, Wonkwang University, Iksan, Jeonbuk 570-749, Korea
| | - Ryong Kong
- Department of Oriental Medicine Resources, Sunchon National University, Suncheon, Jeonnam 540-742, Korea
| | - Yun-Soo Seo
- Department of Oriental Pharmacy, College of Pharmacy, Wonkwang Oriental Medicines Research Institute, Institute of Biotechnology, Wonkwang University, Iksan, Jeonbuk 570-749, Korea
| | - Tian Zhou
- Department of Oriental Pharmacy, College of Pharmacy, Wonkwang Oriental Medicines Research Institute, Institute of Biotechnology, Wonkwang University, Iksan, Jeonbuk 570-749, Korea
| | - Ok-Hwa Kang
- Department of Oriental Pharmacy, College of Pharmacy, Wonkwang Oriental Medicines Research Institute, Institute of Biotechnology, Wonkwang University, Iksan, Jeonbuk 570-749, Korea
| | - Dong-Won Shin
- Department of Oriental Medicine Resources, Sunchon National University, Suncheon, Jeonnam 540-742, Korea
| | - Dong-Yeul Kwon
- Department of Oriental Pharmacy, College of Pharmacy, Wonkwang Oriental Medicines Research Institute, Institute of Biotechnology, Wonkwang University, Iksan, Jeonbuk 570-749, Korea
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236
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The four-component aureocin A70 as a promising agent for food biopreservation. Int J Food Microbiol 2016; 237:39-46. [DOI: 10.1016/j.ijfoodmicro.2016.08.017] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2016] [Revised: 08/01/2016] [Accepted: 08/11/2016] [Indexed: 01/01/2023]
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237
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Arfatahery N, Davoodabadi A, Abedimohtasab T. Characterization of Toxin Genes and Antimicrobial Susceptibility of Staphylococcus aureus Isolates in Fishery Products in Iran. Sci Rep 2016; 6:34216. [PMID: 27694813 PMCID: PMC5046122 DOI: 10.1038/srep34216] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2015] [Accepted: 09/02/2016] [Indexed: 12/26/2022] Open
Abstract
Staphylococcus aureus is one of the most common causes of seafood-borne diseases worldwide, which are attributable to the contamination of food by preformed enterotoxins. In this study, a total of 206 (34.3%) Staphylococcus aureus strains were obtained from 600 fish and shrimp samples and were tested for their antimicrobial susceptibility. We assessed the prevalence of the genes responsible for the staphylococcal enterotoxins (SEA, SEB) and toxic shock syndrome toxin 1 (TSST-1) genes. The results indicated that 34% of aqua food samples were contaminated with S. aureus, and 23.8% of these isolates were mec-A-positive. Sixty-four percent of the strains isolated from contaminated seafood was enterotoxigenic S. aureus, and 28.2% of SEs were MRSA-positive. The most prevalent genotype was characterized by the presence of the sea gene (45.2%), followed by the seb gene (18.5%), and the tst gene encoding TSST-1 was found in eight strains (3.9%). Of the 206 S. aureus isolates, 189 strains (84.9%) were resistant to at least one antibiotic. Given the frequent outbreaks of enterotoxigenic MRSA, it is necessary to make revisions to mandatory programmes to facilitate improved hygiene practices during fishing, aquaculture, processing, and sales to prevent the contamination of fishery products in Iran.
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Affiliation(s)
- Noushin Arfatahery
- Dev of Microbiology, Dept of Pathobiology, School of Public Health and Institute of Public Health Research, Tehran University of Medical Sciences, Tehran, Iran
| | - Abolfazl Davoodabadi
- Dev of Microbiology, Dept of Pathobiology, School of Public Health and Institute of Public Health Research, Tehran University of Medical Sciences, Tehran, Iran
- Microbiology Department, Medical School, Babol University of Medical Science, Babol, Iran
| | - Taranehpeimaneh Abedimohtasab
- Dev of Microbiology, Dept of Pathobiology, School of Public Health and Institute of Public Health Research, Tehran University of Medical Sciences, Tehran, Iran
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238
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Zhang X, Shang W, Yuan J, Hu Z, Peng H, Zhu J, Hu Q, Yang Y, Liu H, Jiang B, Wang Y, Li S, Hu X, Rao X. Positive Feedback Cycle of TNFα Promotes Staphylococcal Enterotoxin B-Induced THP-1 Cell Apoptosis. Front Cell Infect Microbiol 2016; 6:109. [PMID: 27709104 PMCID: PMC5030291 DOI: 10.3389/fcimb.2016.00109] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2016] [Accepted: 09/05/2016] [Indexed: 11/13/2022] Open
Abstract
Staphylococcal enterotoxin B (SEB) has been demonstrated to be of importance in Staphylococcus aureus related diseases, such as atopic dermatitis (AD). Dysregulated apoptosis in AD is remarkable, and SEB can induce apoptosis of various cell types. However, the mechanisms by which SEB induces apoptosis and influences disease processes remain unclear. In this study, the recombinant SEB-induced THP-1 monocyte apoptosis was demonstrated in the absence of preliminary cell activation in a time- and dose-dependent manner. SEB could up-regulate the expression of tumor necrosis factor alpha (TNFα) in THP-1 cells and induce apoptosis via an extrinsic pathway. TNFα could in turn increase the expression of HLA-DRa, the SEB receptor on the cell surface. As a result, a positive feedback cycle of TNFα was established. TNFα expression and SEB-induced apoptosis were decreased by knocking down the expression of either HLA-DRa or TNFR1. Therefore, the feedback cycle of TNFα is crucial for SEB functions. This work provides insights into the mechanisms of SEB-induced monocyte apoptosis and emphasizes the major role of TNFα in future related studies.
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Affiliation(s)
- Xiaopeng Zhang
- Department of Microbiology, College of Basic Medical Sciences, Third Military Medical University Chongqing, China
| | - Weilong Shang
- Department of Microbiology, College of Basic Medical Sciences, Third Military Medical University Chongqing, China
| | - Jizhen Yuan
- Department of Microbiology, College of Basic Medical Sciences, Third Military Medical University Chongqing, China
| | - Zhen Hu
- Department of Microbiology, College of Basic Medical Sciences, Third Military Medical University Chongqing, China
| | - Huagang Peng
- Department of Microbiology, College of Basic Medical Sciences, Third Military Medical University Chongqing, China
| | - Junmin Zhu
- Department of Microbiology, College of Basic Medical Sciences, Third Military Medical University Chongqing, China
| | - Qiwen Hu
- Department of Microbiology, College of Basic Medical Sciences, Third Military Medical University Chongqing, China
| | - Yi Yang
- Department of Microbiology, College of Basic Medical Sciences, Third Military Medical University Chongqing, China
| | - Hui Liu
- Department of Microbiology, College of Basic Medical Sciences, Third Military Medical University Chongqing, China
| | - Bei Jiang
- Department of Microbiology, College of Basic Medical Sciences, Third Military Medical University Chongqing, China
| | - Yinan Wang
- Department of Microbiology, College of Basic Medical Sciences, Third Military Medical University Chongqing, China
| | - Shu Li
- Department of Microbiology, College of Basic Medical Sciences, Third Military Medical University Chongqing, China
| | - Xiaomei Hu
- Department of Microbiology, College of Basic Medical Sciences, Third Military Medical University Chongqing, China
| | - Xiancai Rao
- Department of Microbiology, College of Basic Medical Sciences, Third Military Medical University Chongqing, China
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239
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Hisatsune J, Sato'o Y, Yu L, Kutsuno S, Hayakawa Y, Sugai M. Efficient transformation of Staphylococcus aureus using multi-pulse electroporation. J Microbiol Methods 2016; 130:69-72. [PMID: 27567890 DOI: 10.1016/j.mimet.2016.08.012] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2016] [Revised: 08/17/2016] [Accepted: 08/17/2016] [Indexed: 12/23/2022]
Abstract
A new multi-pulse electroporation system was evaluated to transform Staphylococcus aureus. Compared to the conventional electroporation system, it yielded high transformation efficiency to obtain more than 3.9×105S. aureus RN4220 transformed cells/1μg plasmid DNA using a single electroporation by manipulating the poring pulse and transfer pulse.
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Affiliation(s)
- Junzo Hisatsune
- Department of Bacteriology, Hiroshima University Graduate School of Biomedical & Health Sciences, Hiroshima, Japan; Project Research Center for Nosocomial Infectious Diseases, Hiroshima University, Japan
| | - Yusuke Sato'o
- Department of Bacteriology, Hiroshima University Graduate School of Biomedical & Health Sciences, Hiroshima, Japan; Project Research Center for Nosocomial Infectious Diseases, Hiroshima University, Japan
| | - Liansheng Yu
- Department of Bacteriology, Hiroshima University Graduate School of Biomedical & Health Sciences, Hiroshima, Japan; Project Research Center for Nosocomial Infectious Diseases, Hiroshima University, Japan
| | - Shoko Kutsuno
- Department of Bacteriology, Hiroshima University Graduate School of Biomedical & Health Sciences, Hiroshima, Japan; Project Research Center for Nosocomial Infectious Diseases, Hiroshima University, Japan
| | | | - Motoyuki Sugai
- Department of Bacteriology, Hiroshima University Graduate School of Biomedical & Health Sciences, Hiroshima, Japan; Project Research Center for Nosocomial Infectious Diseases, Hiroshima University, Japan.
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240
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241
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Fagundes P, Farias F, Santos O, de Oliveira N, da Paz J, Ceotto-Vigoder H, Alviano D, Romanos M, Bastos M. The antimicrobial peptide aureocin A53 as an alternative agent for biopreservation of dairy products. J Appl Microbiol 2016; 121:435-44. [DOI: 10.1111/jam.13189] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2016] [Revised: 05/09/2016] [Accepted: 05/24/2016] [Indexed: 01/19/2023]
Affiliation(s)
- P.C. Fagundes
- Departamento de Microbiologia Geral; Instituto de Microbiologia Paulo de Góes; Universidade Federal do Rio de Janeiro; Rio de Janeiro Brazil
| | - F.M. Farias
- Departamento de Microbiologia Geral; Instituto de Microbiologia Paulo de Góes; Universidade Federal do Rio de Janeiro; Rio de Janeiro Brazil
| | - O.C.S. Santos
- Departamento de Microbiologia Geral; Instituto de Microbiologia Paulo de Góes; Universidade Federal do Rio de Janeiro; Rio de Janeiro Brazil
| | - N.E.M. de Oliveira
- Departamento de Microbiologia Geral; Instituto de Microbiologia Paulo de Góes; Universidade Federal do Rio de Janeiro; Rio de Janeiro Brazil
| | - J.A.S. da Paz
- Departamento de Microbiologia Geral; Instituto de Microbiologia Paulo de Góes; Universidade Federal do Rio de Janeiro; Rio de Janeiro Brazil
| | - H. Ceotto-Vigoder
- Departamento de Microbiologia Geral; Instituto de Microbiologia Paulo de Góes; Universidade Federal do Rio de Janeiro; Rio de Janeiro Brazil
| | - D.S. Alviano
- Departamento de Microbiologia Geral; Instituto de Microbiologia Paulo de Góes; Universidade Federal do Rio de Janeiro; Rio de Janeiro Brazil
| | - M.T.V. Romanos
- Departamento de Virologia; Instituto de Microbiologia Paulo de Góes; Universidade Federal do Rio de Janeiro; Rio de Janeiro Brazil
| | - M.C.F. Bastos
- Departamento de Microbiologia Geral; Instituto de Microbiologia Paulo de Góes; Universidade Federal do Rio de Janeiro; Rio de Janeiro Brazil
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242
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Fowoyo P, Ogunbanwo S. Virulence and toxigenicity of coagulase-negative staphylococci in Nigerian traditional fermented foods. Can J Microbiol 2016; 62:572-8. [DOI: 10.1139/cjm-2015-0752] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The incidence of coagulase-negative staphylococci (CoNS) may render food unsafe, as the clinical isolates have been reported to exude virulent traits. A total of 255 CoNS isolates from 6 traditional fermented foods (nono, kunu, wara, iru, ogi, and kindirmo) from North Central Nigeria, identified as Staphylococcus epidermidis, Staphylococcus simulans, Staphylococcus xylosus, Staphylococcus kloosii, and Staphylococcus caprae, were investigated for virulence traits. The strains were examined for biofilm formation and production of hyaluronidase, DNase, TNase, haemolysins, and superantigenic toxins (SEA, SEB, SEC, SED, and TSST-1) using standard and genotypic methods. The analysis of virulence factors revealed the production of slime in 200 isolates (78.4%); α-haemolysin in 136 (53.3%); β-haemolysin in 43 (16.9%); DNase in 199 (78.0%); TNase in 29 (11.4%); hyaluronidase in 125 (49.0%); TSST-1 in 119 (46.7%); and enterotoxin-producing isolates SEA, SEB, SEC, and SED in 61 (23.9%), 19 (7.5%), 9 (3.5%), and 8 (3.1%), respectively. PCR analysis detected tsst-1, sea, seb, and sec genes. The ability of these microorganisms to exhibit virulence evokes the potential to cause disease especially under determinate conditions or in immune-compromised patients. The occurrence of CoNS in food should not be ignored nor their pathogenic potential considered as insignificant, rather safety measures should be taken to reduce or totally eliminate their occurrence in foods.
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Affiliation(s)
- P.T. Fowoyo
- Department of Biosciences, Salem University, P.M.B. 1060, Lokoja, Nigeria
- Department of Microbiology, University of Ibadan, Ibadan, Nigeria
| | - S.T. Ogunbanwo
- Department of Biosciences, Salem University, P.M.B. 1060, Lokoja, Nigeria
- Department of Microbiology, University of Ibadan, Ibadan, Nigeria
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243
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Wu S, Duan N, Gu H, Hao L, Ye H, Gong W, Wang Z. A Review of the Methods for Detection of Staphylococcus aureus Enterotoxins. Toxins (Basel) 2016; 8:E176. [PMID: 27348003 PMCID: PMC4963824 DOI: 10.3390/toxins8070176] [Citation(s) in RCA: 91] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2016] [Accepted: 05/30/2016] [Indexed: 01/08/2023] Open
Abstract
Food safety has attracted extensive attention around the world, and food-borne diseases have become one of the major threats to health. Staphylococcus aureus is a major food-borne pathogen worldwide and a frequent contaminant of foodstuffs. Staphylococcal enterotoxins (SEs) produced by some S. aureus strains will lead to staphylococcal food poisoning (SFP) outbreaks. The most common symptoms caused by ingestion of SEs within food are nausea, vomiting, diarrhea and cramps. Children will suffer SFP by ingesting as little as 100 ng of SEs, and only a few micrograms of SEs are enough to cause SPF in vulnerable populations. Therefore, it is a great challenge and of urgent need to detect and identify SEs rapidly and accurately for governmental and non-governmental agencies, including the military, public health departments, and health care facilities. Herein, an overview of SE detection has been provided through a comprehensive literature survey.
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Affiliation(s)
- Shijia Wu
- State Key Laboratory of Food Science and Technology, Synergetic Innovation Center of Food Safety and Nutrition, School of Food Science and Technology, Jiangnan University, Wuxi 214122, China.
| | - Nuo Duan
- State Key Laboratory of Food Science and Technology, Synergetic Innovation Center of Food Safety and Nutrition, School of Food Science and Technology, Jiangnan University, Wuxi 214122, China.
| | - Huajie Gu
- State Key Laboratory of Food Science and Technology, Synergetic Innovation Center of Food Safety and Nutrition, School of Food Science and Technology, Jiangnan University, Wuxi 214122, China.
| | - Liling Hao
- State Key Laboratory of Food Science and Technology, Synergetic Innovation Center of Food Safety and Nutrition, School of Food Science and Technology, Jiangnan University, Wuxi 214122, China.
| | - Hua Ye
- State Key Laboratory of Food Science and Technology, Synergetic Innovation Center of Food Safety and Nutrition, School of Food Science and Technology, Jiangnan University, Wuxi 214122, China.
| | - Wenhui Gong
- State Key Laboratory of Food Science and Technology, Synergetic Innovation Center of Food Safety and Nutrition, School of Food Science and Technology, Jiangnan University, Wuxi 214122, China.
| | - Zhouping Wang
- State Key Laboratory of Food Science and Technology, Synergetic Innovation Center of Food Safety and Nutrition, School of Food Science and Technology, Jiangnan University, Wuxi 214122, China.
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244
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Wang W, Wang W, Liu L, Xu L, Kuang H, Zhu J, Xu C. Nanoshell-Enhanced Raman Spectroscopy on a Microplate for Staphylococcal Enterotoxin B Sensing. ACS APPLIED MATERIALS & INTERFACES 2016; 8:15591-15597. [PMID: 27193082 DOI: 10.1021/acsami.6b02905] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
A sensitive surface-enhanced Raman scattering (SERS) immunosensor based on the Au nanoparticle (Au NP) shell structure was developed to detect staphylococcal enterotoxin B (SEB) on a microplate. Au NPs modified with 4-nitrothiophenol (4-NTP) and coated with Ag shell of controlled thickness at 6.6 nm exhibited excellent SERS intensity and were used as signal reporters in the detection of SEB. The engaged 4-NTP allowed the significant electromagnetic enhancement between Au NPs and the Ag shell and prevented the dissociation of the Raman reporter. More importantly, 4-NTP-differentiated SERS signals between the sample and microplate. The SERS-based immunosensor had a limit of detection of 1.3 pg/mL SEB. Analysis of SEB-spiked milk samples revealed that the developed method had high accuracy. Therefore, the SERS-encoded Au@Ag core-shell structure-based immunosensor is promising for the detection of biotoxins, pathogens, and environmental pollutants.
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Affiliation(s)
| | - Weiwei Wang
- Cereals & Oils Nutrition Research Group, Academy of Science & Technology of State Administration of Grain , Beijing 100037, People's Republic of China
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245
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Antibacterial Activity of Juglone against Staphylococcus aureus: From Apparent to Proteomic. Int J Mol Sci 2016; 17:ijms17060965. [PMID: 27322260 PMCID: PMC4926497 DOI: 10.3390/ijms17060965] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2016] [Revised: 06/07/2016] [Accepted: 06/14/2016] [Indexed: 01/08/2023] Open
Abstract
The proportion of foodborne disease caused by pathogenic microorganisms is rising worldwide, with staphylococcal food poisoning being one of the main causes of this increase. Juglone is a plant-derived 1,4-naphthoquinone with confirmed antibacterial and antitumor activities. However, the specific mechanism underlying its antibacterial activity against Staphylococcus aureus remains unclear. To elucidate the mechanism underlying its antibacterial activity, isobaric tags for relative and absolute quantitation methods of quantitative proteomics were applied for analysis of the 53 proteins that were differentially expressed after treatment with juglone. Combined with verification experiments, such as detection of changes in DNA and RNA content and quantification of oxidative damage, our results suggested that juglone effectively increased the protein expression of oxidoreductase and created a peroxidative environment within the cell, significantly reducing cell wall formation and increasing membrane permeability. We hypothesize that juglone binds to DNA and reduces DNA transcription and replication directly. This is the first study to adopt a proteomic approach to investigate the antibacterial mechanism of juglone.
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246
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Wang J, Wang Z, Wu R, Jiang D, Bai B, Tan D, Yan T, Sun X, Zhang Q, Wu Z. Proteomic Analysis of the Antibacterial Mechanism of Action of Juglone against Staphylococcus aureus. Nat Prod Commun 2016. [DOI: 10.1177/1934578x1601100632] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Juglone is a plant-derived 1,4-naphthoquinone with confirmed antibacterial activity. However, the mechanism of action of juglone against Staphylococcus aureus remains unclear. Possible mechanisms were explored by a proteomic analysis of S. aureus proteins that are inhibited by juglone. Two-dimensional gel electrophoresis revealed that 21 protein spots were differentially expressed between juglone-treated and untreated cells of which 13 were identified. A bioinformatic analysis revealed that proteins participating in protein synthesis, the tricarboxylic acid cycle, as well as DNA and RNA synthesis were inhibited by juglone, thus leading to cell collapse. These findings provide clues regarding the mechanism of action of juglone, which can be effective for treating cases of S. aureus infection.
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Affiliation(s)
- Jiayi Wang
- College of Food Science, Shenyang Agricultural University, 120 Dongling Rd., Shenyang 110866, China
| | - Zixue Wang
- College of Food Science, Shenyang Agricultural University, 120 Dongling Rd., Shenyang 110866, China
| | - Rina Wu
- College of Food Science, Shenyang Agricultural University, 120 Dongling Rd., Shenyang 110866, China
| | - Donghua Jiang
- College of Food Science, Shenyang Agricultural University, 120 Dongling Rd., Shenyang 110866, China
| | - Bing Bai
- College of Food Science, Shenyang Agricultural University, 120 Dongling Rd., Shenyang 110866, China
| | - Dehong Tan
- College of Food Science, Shenyang Agricultural University, 120 Dongling Rd., Shenyang 110866, China
| | - Tingcai Yan
- College of Food Science, Shenyang Agricultural University, 120 Dongling Rd., Shenyang 110866, China
| | - Xiyun Sun
- College of Food Science, Shenyang Agricultural University, 120 Dongling Rd., Shenyang 110866, China
| | - Qi Zhang
- College of Food Science, Shenyang Agricultural University, 120 Dongling Rd., Shenyang 110866, China
| | - Zhaoxia Wu
- College of Food Science, Shenyang Agricultural University, 120 Dongling Rd., Shenyang 110866, China
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Larcombe S, Hutton ML, Lyras D. Involvement of Bacteria Other Than Clostridium difficile in Antibiotic-Associated Diarrhoea. Trends Microbiol 2016; 24:463-476. [DOI: 10.1016/j.tim.2016.02.001] [Citation(s) in RCA: 61] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2015] [Revised: 01/20/2016] [Accepted: 02/01/2016] [Indexed: 02/07/2023]
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248
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Certified reference materials for testing of the presence/absence of Staphylococcus aureus enterotoxin A (SEA) in cheese. Anal Bioanal Chem 2016; 408:5457-65. [PMID: 27220526 PMCID: PMC4939153 DOI: 10.1007/s00216-016-9642-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2016] [Revised: 04/27/2016] [Accepted: 05/14/2016] [Indexed: 11/30/2022]
Abstract
Staphylococcal enterotoxins (SEs) account for a substantial number of food-poisoning outbreaks. European legislation (Commission Regulation 1441/2007) stipulates the reference procedure for SE analysis in milk and dairy products, which is based on extraction, dialysis concentration and immunochemical detection using one of two approved assays (VIDAS® SET2, Ridascreen® SET Total). However, certified reference materials (CRMs) are lacking to support laboratories in performing reliable detection of Staphylococcus aureus enterotoxin A (SEA) in relevant matrices at sub-nanogram per gram levels. The certification of a set of three reference materials (blank and two SEA-containing materials) for testing of the presence/absence of SEA in cheese is described. The reference procedure was applied in an intercomparison with 15 laboratories, and results were reported in a qualitative manner (presence or absence of SEA in the sample). No false-negative or false-positive results were obtained. The certified values were stated as diagnostic specificity (blank material) or diagnostic sensitivity (SEA-containing materials) and were 100 % in all cases. Stability studies demonstrated suitable material stability when stored cooled or frozen. An in-house study on the recovery of SEA in the cheese materials using a double-sandwich enzyme-linked immunosorbent assay (ELISA) revealed comparable recovery values of around 45 % at the two spiking levels and in both the SEA-containing CRMs as well as blank CRM freshly spiked prior to analysis. The values were also comparable over time and among different analysts. The materials provide valuable support to laboratories for method validation and method performance verification and will increase the reliability of measuring SEA in cheese.
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249
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Staphylococcus aureus Phenol-Soluble Modulins Impair Interleukin Expression in Bovine Mammary Epithelial Cells. Infect Immun 2016; 84:1682-1692. [PMID: 27001539 DOI: 10.1128/iai.01330-15] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2015] [Accepted: 03/13/2016] [Indexed: 12/27/2022] Open
Abstract
The role of the recently described interleukin-32 (IL-32) in Staphylococcus aureus-induced mastitis, an inflammation of the mammary gland, is unclear. We determined expression of IL-32, IL-6, and IL-8 in S. aureus- and Escherichia coli-infected bovine mammary gland epithelial cells. Using live bacteria, we found that in S. aureus-infected cells, induction of IL-6 and IL-8 expression was less pronounced than in E. coli-infected cells. Notably, IL-32 expression was decreased in S. aureus-infected cells, while it was increased in E. coli-infected cells. We identified the staphylococcal phenol-soluble modulin (PSM) peptides as key contributors to these effects, as IL-32, IL-6, and IL-8 expression by epithelial cells exposed to psm mutant strains was significantly increased compared to that in cells exposed to the isogenic S. aureus wild-type strain, indicating that PSMs inhibit the production of these interleukins. The use of genetically complemented strains confirmed this observation. Inasmuch as the decreased expression of IL-32, which is involved in dendritic cell maturation, impairs immune responses, our results support a PSM-dependent mechanism that allows for the development of chronic S. aureus-related mastitis.
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250
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Two common structural motifs for TCR recognition by staphylococcal enterotoxins. Sci Rep 2016; 6:25796. [PMID: 27180909 PMCID: PMC4867771 DOI: 10.1038/srep25796] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2016] [Accepted: 04/18/2016] [Indexed: 12/29/2022] Open
Abstract
Superantigens are toxins produced by Staphylococcus aureus, called staphylococcal enterotoxins (abbreviated SEA to SEU). They can cross-link the T cell receptor (TCR) and major histocompatibility complex class II, triggering a massive T cell activation and hence disease. Due to high stability and toxicity, superantigens are potential agents of bioterrorism. Hence, antagonists may not only be useful in the treatment of disease but also serve as countermeasures to biological warfare. Of particular interest are inhibitors against SEA and SEB. SEA is the main cause of food poisoning, while SEB is a common toxin manufactured as a biological weapon. Here, we present the crystal structures of SEA in complex with TCR and SEE in complex with the same TCR, complemented with computational alanine-scanning mutagenesis of SEA, SEB, SEC3, SEE, and SEH. We have identified two common areas that contribute to the general TCR binding for these superantigens. This paves the way for design of single antagonists directed towards multiple toxins.
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