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Characterization of Human Type C Enterotoxin Produced by Clinical S. epidermidis Isolates. Toxins (Basel) 2018; 10:toxins10040139. [PMID: 29584685 PMCID: PMC5923305 DOI: 10.3390/toxins10040139] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2018] [Revised: 03/19/2018] [Accepted: 03/20/2018] [Indexed: 11/17/2022] Open
Abstract
Staphylococcal Enterotoxins (SEs) are superantigens (SAg) originally produced by S. aureus, but their presence in coagulase negative staphylococci (CNS) has long been suspected. This study aims to better characterize a novel C-like enterotoxin expressed by clinical S. epidermidis strains, called SECepi. We isolated and characterized SECepi for its molecular and functional properties. The toxin was structurally modeled according to its significant similarity with S. aureus SEC3. Most of SEC amino acid residues important for the formation of the trimolecular Major Histocompatibility Complex II MHCII-SEC-T Cell Receptor TCR complex are conserved in SECepi. The functional properties of SECepi were estimated after cloning, expression in E. coli, and purification. The recombinant SECepi toxin exhibits biological characteristics of a SAg including stimulation of human T-cell mitogenicity, inducing and releasing high cytokines levels: IL-2, -4, -6, -8, -10, IFN-γ, TNF-α and GM-CSF at a dose as low as 3.7 pM. Compared to SECaureus, the production of pro-sepsis cytokine IL-6 is significantly higher with SECepi-activated lymphocytes. Furthermore, SECepi is stable to heat, pepsin or trypsin hydrolysis. The SECepi superantigen produced by CNS is functionally very close to that of S. aureus, possibly inducing a systemic inflammatory response at least comparable to that of SECaureus, and may account for S. epidermidis pathogenicity.
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52
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Fisher EL, Otto M, Cheung GYC. Basis of Virulence in Enterotoxin-Mediated Staphylococcal Food Poisoning. Front Microbiol 2018; 9:436. [PMID: 29662470 PMCID: PMC5890119 DOI: 10.3389/fmicb.2018.00436] [Citation(s) in RCA: 145] [Impact Index Per Article: 24.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2017] [Accepted: 02/26/2018] [Indexed: 12/17/2022] Open
Abstract
The Staphylococcus aureus enterotoxins are a superfamily of secreted virulence factors that share structural and functional similarities and possess potent superantigenic activity causing disruptions in adaptive immunity. The enterotoxins can be separated into two groups; the classical (SEA-SEE) and the newer (SEG-SElY and counting) enterotoxin groups. Many members from both these groups contribute to the pathogenesis of several serious human diseases, including toxic shock syndrome, pneumonia, and sepsis-related infections. Additionally, many members demonstrate emetic activity and are frequently responsible for food poisoning outbreaks. Due to their robust tolerance to denaturing, the enterotoxins retain activity in food contaminated previously with S. aureus. The genes encoding the enterotoxins are found mostly on a variety of different mobile genetic elements. Therefore, the presence of enterotoxins can vary widely among different S. aureus isolates. Additionally, the enterotoxins are regulated by multiple, and often overlapping, regulatory pathways, which are influenced by environmental factors. In this review, we also will focus on the newer enterotoxins (SEG-SElY), which matter for the role of S. aureus as an enteropathogen, and summarize our current knowledge on their prevalence in recent food poisoning outbreaks. Finally, we will review the current literature regarding the key elements that govern the complex regulation of enterotoxins, the molecular mechanisms underlying their enterotoxigenic, superantigenic, and immunomodulatory functions, and discuss how these activities may collectively contribute to the overall manifestation of staphylococcal food poisoning.
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Affiliation(s)
- Emilie L Fisher
- Pathogen Molecular Genetics Section, Laboratory of Bacteriology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, United States
| | - Michael Otto
- Pathogen Molecular Genetics Section, Laboratory of Bacteriology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, United States
| | - Gordon Y C Cheung
- Pathogen Molecular Genetics Section, Laboratory of Bacteriology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, United States
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53
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Zhang DF, Yang XY, Zhang J, Qin X, Huang X, Cui Y, Zhou M, Shi C, French NP, Shi X. Identification and characterization of two novel superantigens among Staphylococcus aureus complex. Int J Med Microbiol 2018; 308:438-446. [PMID: 29574061 DOI: 10.1016/j.ijmm.2018.03.002] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2018] [Revised: 02/19/2018] [Accepted: 03/05/2018] [Indexed: 01/13/2023] Open
Abstract
Staphylococcal enterotoxins (SEs), also known as superantigens, play a very important role in infections and food poisoning caused by Staphylococcus aureus. Recently, S. argenteus and S. schweitzeri were recognized as novel species closely related to S. aureus. In this study of these three species, it was found that two putative SE genes were located upstream of some vSaβ pathogenicity islands and the deduced amino acid sequences showed < 65.3% identity with those of known SEs. The related proteins, designated staphylococcal enterotoxin-like toxin 26 (SEl26) and 27 (SEl27), were identified and characterized among the three species. The mRNAs encoding SEl26 and SEl27 were expressed during all the growth phases. Recombinant SEl26 and SEl27 exhibited superantigenic activity in human peripheral blood mononuclear cells and mouse splenocytes by examining cell proliferation and cytokine production. Interestingly, these two genes were present universally in S. argenteus sequence type 2250 with clinical importance. Meanwhile, SEl27 variants from different species showed differential sensitivity to human peripheral blood mononuclear cells, which corresponded to the primary bacterial species hosts. It was demonstrated from these results that SEl26 and SEl27 were characterized to be two novel SE toxins and some SEs evolved along with the bacteria when the organisms adapted the hosts' immune systems.
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Affiliation(s)
- Dao-Feng Zhang
- MOST-USDA Joint Research Center for Food Safety, School of Agriculture and Biology & State Key Laboratory of Microbial Metabolism, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Xin-Yi Yang
- Zhuhai Biori Biotechnology Co. Ltd, Zhuhai, 519015, China
| | - Jing Zhang
- MOST-USDA Joint Research Center for Food Safety, School of Agriculture and Biology & State Key Laboratory of Microbial Metabolism, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Xiaojie Qin
- MOST-USDA Joint Research Center for Food Safety, School of Agriculture and Biology & State Key Laboratory of Microbial Metabolism, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Xiaozhen Huang
- MOST-USDA Joint Research Center for Food Safety, School of Agriculture and Biology & State Key Laboratory of Microbial Metabolism, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Yan Cui
- MOST-USDA Joint Research Center for Food Safety, School of Agriculture and Biology & State Key Laboratory of Microbial Metabolism, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Min Zhou
- School of Food Science and Engineering, Wuhan Polytechnic University, Wuhan, 430023, Hubei, China
| | - Chunlei Shi
- MOST-USDA Joint Research Center for Food Safety, School of Agriculture and Biology & State Key Laboratory of Microbial Metabolism, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Nigel P French
- Infectious Disease Research Centre, Institute of Veterinary, Animal and Biomedical Sciences, Massey University, Palmerston North, 4442, New Zealand
| | - Xianming Shi
- MOST-USDA Joint Research Center for Food Safety, School of Agriculture and Biology & State Key Laboratory of Microbial Metabolism, Shanghai Jiao Tong University, Shanghai, 200240, China.
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54
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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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55
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Denayer S, Delbrassinne L, Nia Y, Botteldoorn N. Food-Borne Outbreak Investigation and Molecular Typing: High Diversity of Staphylococcus aureus Strains and Importance of Toxin Detection. Toxins (Basel) 2017; 9:E407. [PMID: 29261162 PMCID: PMC5744127 DOI: 10.3390/toxins9120407] [Citation(s) in RCA: 54] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2017] [Revised: 12/15/2017] [Accepted: 12/16/2017] [Indexed: 02/03/2023] Open
Abstract
Staphylococcus aureus is an important aetiological agent of food intoxications in the European Union as it can cause gastro-enteritis through the production of various staphylococcal enterotoxins (SEs) in foods. Reported enterotoxin dose levels causing food-borne illness are scarce and varying. Three food poisoning outbreaks due to enterotoxin-producing S. aureus strains which occurred in 2013 in Belgium are described. The outbreaks occurred in an elderly home, at a barbecue event and in a kindergarten and involved 28, 18, and six cases, respectively. Various food leftovers contained coagulase positive staphylococci (CPS). Low levels of staphylococcal enterotoxins ranging between 0.015 ng/g and 0.019 ng/g for enterotoxin A (SEA), and corresponding to 0.132 ng/g for SEC were quantified in the food leftovers for two of the reported outbreaks. Molecular typing of human and food isolates using pulsed-field gel electrophoresis (PFGE) and enterotoxin gene typing, confirmed the link between patients and the suspected foodstuffs. This also demonstrated the high diversity of CPS isolates both in the cases and in healthy persons carrying enterotoxin genes encoding emetic SEs for which no detection methods currently exist. For one outbreak, the investigation pointed out to the food handler who transmitted the outbreak strain to the food. Tools to improve staphylococcal food poisoning (SFP) investigations are presented.
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Affiliation(s)
- Sarah Denayer
- Scientific Service of Food borne Pathogens, Scientific Institute of Public Health (WIV-ISP), 1050 Brussels, Belgium.
| | - Laurence Delbrassinne
- Scientific Service of Food borne Pathogens, Scientific Institute of Public Health (WIV-ISP), 1050 Brussels, Belgium.
| | - Yacine Nia
- Laboratory for Food Safety, Anses, Université Paris-Est, 94701 Maisons-Alfort, France.
| | - Nadine Botteldoorn
- Scientific Service of Food borne Pathogens, Scientific Institute of Public Health (WIV-ISP), 1050 Brussels, Belgium.
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56
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Ferreira-Duarte AP, Pinheiro-Torres AS, Anhê GF, Condino-Neto A, Antunes E, DeSouza IA. MHC Class II Activation and Interferon-γ Mediate the Inhibition of Neutrophils and Eosinophils by Staphylococcal Enterotoxin Type A (SEA). Front Cell Infect Microbiol 2017; 7:518. [PMID: 29322036 PMCID: PMC5733477 DOI: 10.3389/fcimb.2017.00518] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2017] [Accepted: 12/04/2017] [Indexed: 12/30/2022] Open
Abstract
Staphylococcal enterotoxins are classified as superantigens that act by linking T-cell receptor with MHC class II molecules, which are expressed on classical antigen-presenting cells (APC). Evidence shows that MHC class II is also expressed in neutrophils and eosinophils. This study aimed to investigate the role of MHC class II and IFN-γ on chemotactic and adhesion properties of neutrophils and eosinophils after incubation with SEA. Bone marrow (BM) cells obtained from BALB/c mice were resuspended in culture medium, and incubated with SEA (3–30 ng/ml; 1–4 h), after which chemotaxis and adhesion were evaluated. Incubation with SEA significantly reduced the chemotactic and adhesive responses in BM neutrophils activated with IL-8 (200 ng/ml). Likewise, SEA significantly reduced the chemotactic and adhesive responses of BM eosinophils activated with eotaxin (300 ng/ml). The inhibitory effects of SEA on cell chemotaxis and adhesion were fully prevented by prior incubation with an anti-MHC class II blocking antibody (2 μg/ml). SEA also significantly reduced the intracellular Ca2+ levels in IL-8- and eotaxin-activated BM cells. No alterations of MAC-1, VLA4, and LFA-1α expressions were observed after SEA incubation. In addition, SEA elevated by 3.5-fold (P < 0.05) the INF-γ levels in BM cells. Incubation of BM leukocytes with IFN-γ (10 ng/ml, 2 h) reduced both neutrophil and eosinophil chemotaxis and adhesion, which were prevented by prior incubation with anti-MHC class II antibody (2 μg/ml). In conclusion, SEA inhibits neutrophil and eosinophil by MHC class II-dependent mechanism, which may be modulated by concomitant release of IFN-γ.
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Affiliation(s)
- Ana P Ferreira-Duarte
- Department of Biology and Physiology, Faculty of Medicine of Jundiai, Jundiai, Brazil
| | | | - Gabriel F Anhê
- Department of Pharmacology, State University of Campinas, Campinas, Brazil
| | - Antônio Condino-Neto
- Department of Immunology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
| | - Edson Antunes
- Department of Pharmacology, State University of Campinas, Campinas, Brazil
| | - Ivani A DeSouza
- Department of Biology and Physiology, Faculty of Medicine of Jundiai, Jundiai, Brazil
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57
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Wakabayashi Y, Umeda K, Yonogi S, Nakamura H, Yamamoto K, Kumeda Y, Kawatsu K. Staphylococcal food poisoning caused by Staphylococcus argenteus harboring staphylococcal enterotoxin genes. Int J Food Microbiol 2017; 265:23-29. [PMID: 29112896 DOI: 10.1016/j.ijfoodmicro.2017.10.022] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2017] [Revised: 10/16/2017] [Accepted: 10/18/2017] [Indexed: 10/18/2022]
Abstract
Staphylococcal food poisoning (SFP) is caused by staphylococcal enterotoxins (SEs) preformed in food materials. SE genes are encoded on mobile genetic elements and are widely found across Staphylococcus species including S. argenteus, although most SFP cases are caused by S. aureus. S. argenteus, recently discriminated from S. aureus as a novel species, are non-pigmented staphylococci phenotypically related to S. aureus. In 2014 and 2015, two independent food poisoning cases occurred in Osaka, Japan, in which non-pigmented staphylococci were predominantly isolated. Several enterotoxin genes (seb, seg, sei, sem, sen, seo, and selu2) were found in their genome and the production of SEB was confirmed by reverse passive agglutination tests. The non-pigmented isolates from patients, food handlers, food, and cooking utensils all produced the same pulsed-field gel electrophoresis pattern. These non-pigmented isolates were coagulase-positive and biochemically identical to S. aureus. We performed further genetic analysis using nucA sequencing and multi-locus sequence typing, and identified these isolates as S. argenteus. We also found that seb was encoded on the Staphylococcus aureus pathogenicity island, while seg, sei, sem, sen, seo, and selu2 were encoded on the enterotoxin gene cluster. From these results, we concluded that the two food poisoning outbreaks were SFP cases caused by S. argenteus harboring SE genes.
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Affiliation(s)
- Yuki Wakabayashi
- Bacteriology Section, Division of Microbiology, Osaka Institute of Public Health Morinomiya Center, Higashinari-ku, Osaka, Japan
| | - Kaoru Umeda
- Microbiology Section, Division of Microbiology, Osaka Institute of Public Health Tennoji Center, Tennoji-ku, Osaka, Japan
| | - Shinya Yonogi
- Bacteriology Section, Division of Microbiology, Osaka Institute of Public Health Morinomiya Center, Higashinari-ku, Osaka, Japan.
| | - Hiromi Nakamura
- Microbiology Section, Division of Microbiology, Osaka Institute of Public Health Tennoji Center, Tennoji-ku, Osaka, Japan
| | - Kaori Yamamoto
- Microbiology Section, Division of Microbiology, Osaka Institute of Public Health Tennoji Center, Tennoji-ku, Osaka, Japan
| | - Yuko Kumeda
- Research Organization for the 21st Century, Osaka Prefecture University, Naka-ku, Sakai, Japan
| | - Kentaro Kawatsu
- Bacteriology Section, Division of Microbiology, Osaka Institute of Public Health Morinomiya Center, Higashinari-ku, Osaka, Japan
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58
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Langley RJ, Ting YT, Clow F, Young PG, Radcliff FJ, Choi JM, Sequeira RP, Holtfreter S, Baker H, Fraser JD. Staphylococcal enterotoxin-like X (SElX) is a unique superantigen with functional features of two major families of staphylococcal virulence factors. PLoS Pathog 2017; 13:e1006549. [PMID: 28880913 PMCID: PMC5589262 DOI: 10.1371/journal.ppat.1006549] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2017] [Accepted: 07/24/2017] [Indexed: 11/23/2022] Open
Abstract
Staphylococcus aureus is an opportunistic pathogen that produces many virulence factors. Two major families of which are the staphylococcal superantigens (SAgs) and the Staphylococcal Superantigen-Like (SSL) exoproteins. The former are immunomodulatory toxins that induce a Vβ-specific activation of T cells, while the latter are immune evasion molecules that interfere with a wide range of innate immune defences. The superantigenic properties of Staphylococcal enterotoxin-like X (SElX) have recently been established. We now reveal that SElX also possesses functional characteristics of the SSLs. A region of SElX displays high homology to the sialyl-lactosamine (sLacNac)-specific binding site present in a sub-family of SSLs. By analysing the interaction of SElX with sLacNac-containing glycans we show that SElX has an equivalent specificity and host cell binding range to the SSLs. Mutation of key amino acids in this conserved region affects the ability of SElX to bind to cells of myeloid origin and significantly reduces its ability to protect S. aureus from destruction in a whole blood killing (WBK) assay. Like the SSLs, SElX is up-regulated early during infection and is under the control of the S. aureus exotoxin expression (Sae) two component gene regulatory system. Additionally, the structure of SElX in complex with the sLacNac-containing tetrasaccharide sialyl Lewis X (sLeX) reveals that SElX is a unique single-domain SAg. In summary, SElX is an ‘SSL-like’ SAg. The ability of Staphylococcus aureus to cause disease can be attributed to the wide range of toxins and immune evasion molecules it produces. The 25-member superantigen (SAg) family of toxins disrupts adaptive immunity by activating large proportions of T cells. In contrast, the structurally-related 14-member Staphylococcal Superantigen-Like (SSL) family inhibits a wide range of innate immune functions. We have discovered that the SAg staphylococcal enterotoxin-like X (SElX) has the sialylated-glycan-dependent active site found in a sub-family of SSLs. Through this site it possesses the ability to affect host innate immunity defences. By solving the X-ray crystal structure of SElX we have also discovered that SElX is a unique single-domain SAg. While it retains a typical β-grasp domain, it lacks the OB-fold domain that is present in all other staphylococcal SAgs.
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Affiliation(s)
- Ries J. Langley
- School of Medical Sciences, and The Maurice Wilkins Centre for Molecular Biodiscovery, the University of Auckland, Auckland, New Zealand
- * E-mail:
| | - Yi Tian Ting
- School of Biological Sciences, and The Maurice Wilkins Centre for Molecular Biodiscovery, the University of Auckland, Auckland, New Zealand
| | - Fiona Clow
- School of Medical Sciences, and The Maurice Wilkins Centre for Molecular Biodiscovery, the University of Auckland, Auckland, New Zealand
| | - Paul G. Young
- School of Biological Sciences, and The Maurice Wilkins Centre for Molecular Biodiscovery, the University of Auckland, Auckland, New Zealand
| | - Fiona J. Radcliff
- School of Medical Sciences, and The Maurice Wilkins Centre for Molecular Biodiscovery, the University of Auckland, Auckland, New Zealand
| | - Jeong Min Choi
- School of Medical Sciences, and The Maurice Wilkins Centre for Molecular Biodiscovery, the University of Auckland, Auckland, New Zealand
| | - Richard P. Sequeira
- School of Medical Sciences, and The Maurice Wilkins Centre for Molecular Biodiscovery, the University of Auckland, Auckland, New Zealand
| | - Silva Holtfreter
- School of Medical Sciences, and The Maurice Wilkins Centre for Molecular Biodiscovery, the University of Auckland, Auckland, New Zealand
| | - Heather Baker
- School of Biological Sciences, and The Maurice Wilkins Centre for Molecular Biodiscovery, the University of Auckland, Auckland, New Zealand
| | - John D. Fraser
- School of Medical Sciences, and The Maurice Wilkins Centre for Molecular Biodiscovery, the University of Auckland, Auckland, New Zealand
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59
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Tuffs SW, James DBA, Bestebroer J, Richards AC, Goncheva MI, O’Shea M, Wee BA, Seo KS, Schlievert PM, Lengeling A, van Strijp JA, Torres VJ, Fitzgerald JR. The Staphylococcus aureus superantigen SElX is a bifunctional toxin that inhibits neutrophil function. PLoS Pathog 2017; 13:e1006461. [PMID: 28880920 PMCID: PMC5589267 DOI: 10.1371/journal.ppat.1006461] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2017] [Accepted: 06/09/2017] [Indexed: 12/29/2022] Open
Abstract
Bacterial superantigens (SAgs) cause Vβ-dependent T-cell proliferation leading to immune dysregulation associated with the pathogenesis of life-threatening infections such as toxic shock syndrome, and necrotizing pneumonia. Previously, we demonstrated that staphylococcal enterotoxin-like toxin X (SElX) from Staphylococcus aureus is a classical superantigen that exhibits T-cell activation in a Vβ-specific manner, and contributes to the pathogenesis of necrotizing pneumonia. Here, we discovered that SElX can also bind to neutrophils from human and other mammalian species and disrupt IgG-mediated phagocytosis. Site-directed mutagenesis of the conserved sialic acid-binding motif of SElX abolished neutrophil binding and phagocytic killing, and revealed multiple glycosylated neutrophil receptors for SElX binding. Furthermore, the neutrophil binding-deficient mutant of SElX retained its capacity for T-cell activation demonstrating that SElX exhibits mechanistically independent activities on distinct cell populations associated with acquired and innate immunity, respectively. Finally, we demonstrated that the neutrophil-binding activity rather than superantigenicity is responsible for the SElX-dependent virulence observed in a necrotizing pneumonia rabbit model of infection. Taken together, we report the first example of a SAg, that can manipulate both the innate and adaptive arms of the human immune system during S. aureus pathogenesis. Staphylococcus aureus is a bacterial pathogen responsible for an array of disease types in healthcare and community settings. One of the keys to the success of this pathogen is its ability to subvert the immune system of the host. Here we demonstrate that the superantigen (SAg) staphylococcal enterotoxin-like toxin X (SElX) contributes to immune evasion by inducing unregulated T-cell proliferation, and by inhibition of phagocytosis by neutrophils. We observed that the capacity to bind neutrophils appears to be central to the SElX-dependent toxicity observed in a necrotising pneumonia infection model in rabbits. We report the first example of a staphylococcal SAg with two independent immunomodulatory functions acting on distinct immune cell types.
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Affiliation(s)
- Stephen W. Tuffs
- The Roslin Institute, University of Edinburgh, Easter Bush Campus, Midlothian, Scotland, United States of America
| | - David B. A. James
- Department of Microbiology, New York University School of Medicine, New York, NY, United Kingdom
| | - Jovanka Bestebroer
- Department Medical Microbiology, UMC Utrecht, Heidelberglaan 100, 3584 CX Utrecht, The Netherlands
| | - Amy C. Richards
- The Roslin Institute, University of Edinburgh, Easter Bush Campus, Midlothian, Scotland, United States of America
| | - Mariya I. Goncheva
- The Roslin Institute, University of Edinburgh, Easter Bush Campus, Midlothian, Scotland, United States of America
| | - Marie O’Shea
- The Roslin Institute, University of Edinburgh, Easter Bush Campus, Midlothian, Scotland, United States of America
| | - Bryan A. Wee
- The Roslin Institute, University of Edinburgh, Easter Bush Campus, Midlothian, Scotland, United States of America
| | - Keun Seok Seo
- Department of Basic Sciences, College of Veterinary Medicine, Mississippi State University, Starkville, MS, United States
| | - Patrick M. Schlievert
- Department of Microbiology, University of Iowa, Carver College of Medicine, Iowa City, Iowa, United States of America
| | - Andreas Lengeling
- The Roslin Institute, University of Edinburgh, Easter Bush Campus, Midlothian, Scotland, United States of America
| | - Jos A. van Strijp
- Department Medical Microbiology, UMC Utrecht, Heidelberglaan 100, 3584 CX Utrecht, The Netherlands
| | - Victor J. Torres
- Department of Microbiology, New York University School of Medicine, New York, NY, United Kingdom
| | - J. Ross Fitzgerald
- The Roslin Institute, University of Edinburgh, Easter Bush Campus, Midlothian, Scotland, United States of America
- * E-mail:
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60
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Susilo YB, Sihto HM, Rådström P, Stephan R, Johler S, Schelin J. Reduced Enterotoxin D Formation on Boiled Ham in Staphylococcus Aureus Δagr Mutant. Toxins (Basel) 2017; 9:E263. [PMID: 28841182 PMCID: PMC5618196 DOI: 10.3390/toxins9090263] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2017] [Revised: 08/21/2017] [Accepted: 08/24/2017] [Indexed: 11/16/2022] Open
Abstract
Staphylococcal food poisoning (SFP) is a common cause of foodborne illness worldwide, and enterotoxin D (SED) is one of the most frequent Staphylococcus aureus enterotoxins associated with it. It has been reported that the expression and formation of SED in S. aureus is regulated by the quorum sensing Agr system. In this study, the effect of agr deletion on sed expression in S. aureus grown on boiled ham was investigated. Growth, sed mRNA and SED protein levels in an S. aureus wild type strain and its isogenic Δagr mutant were monitored for 14 days at 22 °C. The results showed that although deletion of the agr gene did not affect the growth rate or maximum cell density of S. aureus on boiled ham, it had a pronounced effect on SED formation during the first 5 days of incubation. The SED concentration was not reflected in the amount of preceding sed transcripts, suggesting that sed transcription levels may not always reflect SED formation. The expression of RNAIII transcript, the regulatory signal of the Agr system, was also monitored. Similar transcription patterns were observed for RNAIII and sed. Surprisingly, in the Δagr mutant, sed expression was comparable to that in the wild type strain, and was thus unaffected by deletion of the Agr system. These results demonstrate that the Agr system appears to only partially affect SED formation, even in a real food environment.
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Affiliation(s)
- Yusak Budi Susilo
- Applied Microbiology, Department of Chemistry, Lund University, SE-221 00 Lund, Sweden.
| | - Henna-Maria Sihto
- Institute for Food Safety and Hygiene, University of Zurich, CH-8057 Zurich, Switzerland.
| | - Peter Rådström
- Applied Microbiology, Department of Chemistry, Lund University, SE-221 00 Lund, Sweden.
| | - Roger Stephan
- Institute for Food Safety and Hygiene, University of Zurich, CH-8057 Zurich, Switzerland.
| | - Sophia Johler
- Institute for Food Safety and Hygiene, University of Zurich, CH-8057 Zurich, Switzerland.
| | - Jenny Schelin
- Applied Microbiology, Department of Chemistry, Lund University, SE-221 00 Lund, Sweden.
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61
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Prevalence and Genetic Characteristics of Staphylococcus aureus and Staphylococcus argenteus Isolates Harboring Panton-Valentine Leukocidin, Enterotoxins, and TSST-1 Genes from Food Handlers in Myanmar. Toxins (Basel) 2017; 9:toxins9080241. [PMID: 28777321 PMCID: PMC5577575 DOI: 10.3390/toxins9080241] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2017] [Revised: 07/26/2017] [Accepted: 08/02/2017] [Indexed: 11/17/2022] Open
Abstract
Asymptomatic carriers of toxigenic Staphylococcus aureus are potential source of diseases, including food poisoning. Toxigenic potential and genetic traits of colonizing S. aureus were investigated for 563 healthy food handlers in Myanmar. Carriage of S. aureus was found in 110 individuals (19.5%), and a total of 144 S. aureus isolates were recovered from nasal cavities (110 isolates) and hands (34 isolates). Panton-Valentine leucocidin genes (pvl) were detected in 18 isolates (12.5%), among which 11 isolates were classified into coa-VIa, agr type III, and ST1930 (CC96) that had been also detected in pvl-positive clinical isolates in Myanmar. A pvl-positive, ST2250 nasal isolate was identified as S. argenteus, a novel coagulase-positive staphylococcus species. Toxic shock syndrome toxin-1 (TSST-1) gene was detected in five pvl-negative isolates. All of the 144 isolates harbored at least one of the 21 enterotoxin(-like) gene(s). The most prevalent enterotoxin(-like) gene was selw (98%), followed by selx (97%), sei (28%), sely (28%), sem (26%), sel (24%), and sea and sec (22% each). Considerable genetic diversity with five groups was detected for selw. The present study revealed the relatively high rate of pvl, as well as the wide distribution of enterotoxin(-like) genes among colonizing S. aureus in Myanmar.
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62
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Rodríguez-Lázaro D, Oniciuc EA, García PG, Gallego D, Fernández-Natal I, Dominguez-Gil M, Eiros-Bouza JM, Wagner M, Nicolau AI, Hernández M. Detection and Characterization of Staphylococcus aureus and Methicillin-Resistant S. aureus in Foods Confiscated in EU Borders. Front Microbiol 2017; 8:1344. [PMID: 28785245 PMCID: PMC5519621 DOI: 10.3389/fmicb.2017.01344] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2017] [Accepted: 07/03/2017] [Indexed: 11/22/2022] Open
Abstract
The aim of the study was to evaluate the potential role of the illegal entry of food in UE in the Methicillin-resistant S. aureus (MRSA) spread. We studied the prevalence and characteristics of Staphylococcus aureus and MRSA isolated from foods of animal origin confiscated from passengers on flights from 45 non-EU countries from 2012 to 2015 by the Border Authorities at Bilbao International Airport (Spain) and Vienna International Airport (Austria), as well as foods from open markets close to EU land borders. Of 868 food samples tested (diverse meat samples including antelope, duck, guinea pig, pork, rodents, turkey, dairy products, and eggs), 136 (15.7%) were positive for S. aureus and 26 (3.0%) for MRSA. All MRSA strains were mecA-positive. The prevalence of S. aureus-positive dairy samples among food confiscated at Bilbao International Airport was 64.6%, and this airport also had the highest value (11.8%) for MRSA-positive samples. The predominant sequence type was ST5 (30.8%), followed by ST8, ST1649, ST1, and other lineages were found to a lesser extent (ST7, ST22, ST72, ST97, and ST398). Six isolates tested positive for luk-PVL genes (SCCmec IV subtypes IVc and IVe). Enterotoxin profiling revealed that 19 MRSA strains were enterotoxigenic, harboring one or more se genes. The MRSA isolates positive for luk-PVL genes were not enterotoxigenic, and none of the isolates tested positive for enterotoxin E. We found 14 resistance profiles, and more than 69% of the MRSA isolates were resistant to three or more types of antimicrobial agents. This finding reveals both the wide diversity of the antimicrobial resistance found in the strains and the capacity to resist not only to beta-lactam drugs. One MRSA strain showed unusual characteristics: it was oxacillin-susceptible, harbored SCCmec V, and was positive for sed, seg, and sej but negative for PVL virulence factors. This study shows the presence of enterotoxigenic HA-, CA-, and LA-MRSA in foods illegally entering the EU, and highlights illegal importation of food as route of enterotoxigenic MRSA spread. Uncontrolled entry of food stuffs into the EU can be a relevant neglected route of MRSA dissemination.
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Affiliation(s)
- David Rodríguez-Lázaro
- Microbiology Division, Department of Biotechnology and Food Science, Faculty of Science, University of BurgosBurgos, Spain
| | - Elena-Alexandra Oniciuc
- Microbiology Division, Department of Biotechnology and Food Science, Faculty of Science, University of BurgosBurgos, Spain
- Faculty of Food Science and Engineering, Dunarea de Jos University of GalatiGalati, Romania
| | - Patricia G. García
- Laboratory of Molecular Biology and Microbiology, Instituto Tecnológico Agrario de Castilla y LeónValladolid, Spain
| | - David Gallego
- Dependencia de Sanidad de Vizcaya, Delegación del Gobierno en el País VascoBilbao, Spain
| | - Isabel Fernández-Natal
- Department of Clinical Microbiology, Complejo Asistencial Universitario de LeónLeón, Spain
- Institute of Biomedicine, University of LeónLeón, Spain
| | - Marta Dominguez-Gil
- Department of Clinical Microbiology, University Hospital Rio HortegaValladolid, Spain
| | - José M. Eiros-Bouza
- Department of Clinical Microbiology, University Hospital Rio HortegaValladolid, Spain
| | - Martin Wagner
- Institute for Milk Hygiene, Milk Technology and Food Science, University of Veterinary Medicine ViennaVienna, Austria
| | - Anca I. Nicolau
- Faculty of Food Science and Engineering, Dunarea de Jos University of GalatiGalati, Romania
| | - Marta Hernández
- Laboratory of Molecular Biology and Microbiology, Instituto Tecnológico Agrario de Castilla y LeónValladolid, Spain
- Departamento de Ingeniería Agrícola y Forestal, Tecnología de los Alimentos, Escuela Técnica Superior de Ingenierías Agrarias, Universidad de ValladolidPalencia, Spain
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63
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Characterization of Enterotoxigenic Bacillus cereus sensu lato and Staphylococcus aureus Isolates and Associated Enterotoxin Production Dynamics in Milk or Meat-Based Broth. Toxins (Basel) 2017; 9:toxins9070225. [PMID: 28714887 PMCID: PMC5535172 DOI: 10.3390/toxins9070225] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2017] [Revised: 07/13/2017] [Accepted: 07/13/2017] [Indexed: 02/05/2023] Open
Abstract
Bacillus cereus sensu lato species, as well as Staphylococcus aureus, are important pathogenic bacteria which can cause foodborne illness through the production of enterotoxins. This study characterised enterotoxin genes of these species and examined growth and enterotoxin production dynamics of isolates when grown in milk or meat-based broth. All B. cereus s. l. isolates harboured nheA, hblA and entFM toxin genes, with lower prevalence of bceT and hlyII. When grown at 16 °C, toxin production by individual B. cereus s. l. isolates varied depending on the food matrix; toxin was detected at cell densities below 5 log10(CFU/mL). At 16 °C no staphylococcal enterotoxin C (SEC) production was detected by S. aureus isolates, although low levels of SED production was noted. At 30 °C all S. aureus isolates produced detectable enterotoxin in the simulated meat matrix, whereas SEC production was significantly reduced in milk. Relative to B. cereus s. l. toxin production, S. aureus typically required reaching higher cell numbers to produce detectable levels of enterotoxin. Phylogenetic analysis of the sec and sel genes suggested population evolution which correlated with animal host adaptation, with subgroups of bovine isolates or caprine/ovine isolates noted, which were distinct from human isolates. Taken together, this study highlights the marked differences in the production of enterotoxins both associated with different growth matrices themselves, but also in the behaviour of individual strains when exposed to different food matrices.
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64
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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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65
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Ono HK, Hirose S, Naito I, Sato'o Y, Asano K, Hu DL, Omoe K, Nakane A. The emetic activity of staphylococcal enterotoxins, SEK, SEL, SEM, SEN and SEO in a small emetic animal model, the house musk shrew. Microbiol Immunol 2017; 61:12-16. [PMID: 28042656 DOI: 10.1111/1348-0421.12460] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2016] [Revised: 12/18/2016] [Accepted: 12/20/2016] [Indexed: 11/30/2022]
Abstract
Staphylococcal enterotoxins (SEs) produced by Staphylococcus aureus are the most recognizable causative agents of emetic food poisoning in humans. New types of SEs and SE-like (SEl) toxins have been reported. Several epidemiological investigations have shown that the SEs and SEl genes, particularly, SEK, SEL, SEM, SEN and SEO genes, are frequently detected in strains isolated from patients with food poisoning. The purpose of the present study was to evaluate the emetic activity of recently identified SEs using a small emetic animal model, the house musk shrew. The emetic activity of these SEs in house musk shrews was evaluated by intraperitoneal administration and emetic responses, including the number of shrews that vomited, emetic frequency and latency of vomiting were documented. It was found that SEs induce emetic responses in these animals. This is the first time to demonstrate that SEK, SEL, SEM, SEN and SEO possess emetic activity in the house musk shrew.
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Affiliation(s)
- Hisaya K Ono
- Department of Microbiology and Immunology, Hirosaki University Graduate School of Medicine, 5 Zaifu-cho, Hirosaki 036-8562.,Laboratory of Zoonoses, Kitasato University School of Veterinary Medicine, 35-1 Higashi-23-ban-cho, Towada, Aomori 034-8628
| | - Shouhei Hirose
- Department of Microbiology and Immunology, Hirosaki University Graduate School of Medicine, 5 Zaifu-cho, Hirosaki 036-8562
| | - Ikunori Naito
- Department of Veterinary Medicine, Faculty of Agriculture, Iwate University, Ueda 3-18-8, Morioka, Iwate 020-8550
| | - Yusuke Sato'o
- Division of Bacteriology, Department of Infection and Immunity, School of Medicine, Jichi Medical University, 3311-1 Yakushiji, Shimotsuke, Tochigi 329-0498, Japan
| | - Krisana Asano
- Department of Microbiology and Immunology, Hirosaki University Graduate School of Medicine, 5 Zaifu-cho, Hirosaki 036-8562
| | - Dong-Liang Hu
- Laboratory of Zoonoses, Kitasato University School of Veterinary Medicine, 35-1 Higashi-23-ban-cho, Towada, Aomori 034-8628
| | - Katsuhiko Omoe
- Department of Veterinary Medicine, Faculty of Agriculture, Iwate University, Ueda 3-18-8, Morioka, Iwate 020-8550
| | - Akio Nakane
- Department of Microbiology and Immunology, Hirosaki University Graduate School of Medicine, 5 Zaifu-cho, Hirosaki 036-8562
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66
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Ercoli L, Gallina S, Nia Y, Auvray F, Primavilla S, Guidi F, Pierucci B, Graziotti C, Decastelli L, Scuota S. Investigation of a Staphylococcal Food Poisoning Outbreak from a Chantilly Cream Dessert, in Umbria (Italy). Foodborne Pathog Dis 2017; 14:407-413. [PMID: 28402712 PMCID: PMC5512467 DOI: 10.1089/fpd.2016.2267] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
On August 28, 2015, a staphylococcal food poisoning outbreak occurred in Umbria, Italy, affecting 24 of the 42 customers who had dinner at a local restaurant. About 3 h after ingesting a variety of foods, the customers manifested gastrointestinal symptoms. Within 24 h of notification from the hospital emergency department, Sanitary Inspectors of the local Public Health Unit performed an epidemiological investigation. A retrospective cohort study was conducted among the customers. Food and environmental samples were collected. Due to the rapid onset of symptoms (vomiting, diarrhea), the food samples were analyzed for the presence of toxigenic bacteria and their toxins; nasopharyngeal swabs were collected from the waiters and cooks. Among the food tested, high levels of coagulase-positive staphylococci (CPS) (3.4 × 108 CFU/g) and staphylococcal enterotoxins (2.12 ng SEA/g) were only detected in the Chantilly cream dessert. CPS were also detected on the surface of a kitchen table (10 CFU/swab), and five food handlers were positive for Staphylococcus aureus. In total, five enterotoxigenic S. aureus isolates were recovered from three food handlers, a kitchen surface, and the Chantilly cream dessert. These isolates were further characterized by biotyping, pulsed-field gel electrophoresis, and multiplex polymerase chain reaction assays for the detection of eleven enterotoxin encoding genes (sea, seb, sec, sed, see, seg, seh, sei, sej, sep, and ser) and three genes involved in antibiotic resistance (mecA, mecC, and mupA). Three sea-positive strains, isolated from the dessert, environment, and one of the cooks, had the same pulsed-field gel electrophoresis profile and belonged to the human biotype, suggesting that the contamination causing the outbreak most likely originated from a food handler. Moreover, improper storage of the dessert, at room temperature for about 5 h, permitted microbial growth and SEA production. This study underlines the importance of both laboratory evidence and epidemiological data for outbreak investigation.
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Affiliation(s)
- Laura Ercoli
- 1 Istituto Zooprofilattico Sperimentale Umbria e Marche , Perugia, Italy
| | - Silvia Gallina
- 2 National Reference Laboratory Stafilococchi coagulasi positivi-Istituto Zooprofilattico Sperimentale del Piemonte , Liguria e Valle d'Aosta, Torino, Italy
| | - Yacine Nia
- 3 Laboratory for Food Safety, Anses, Université Paris-Est , Maisons-Alfort, France
| | - Frédéric Auvray
- 3 Laboratory for Food Safety, Anses, Université Paris-Est , Maisons-Alfort, France
| | - Sara Primavilla
- 1 Istituto Zooprofilattico Sperimentale Umbria e Marche , Perugia, Italy
| | - Fabrizia Guidi
- 1 Istituto Zooprofilattico Sperimentale Umbria e Marche , Perugia, Italy
| | - Benedetta Pierucci
- 4 Dipartimento Prevenzione Servizio Igiene Alimenti e Nutrizione, USL Umbria 1, Piazza Giovanni XXIII, Citta' di Castello, Italy
| | - Catia Graziotti
- 4 Dipartimento Prevenzione Servizio Igiene Alimenti e Nutrizione, USL Umbria 1, Piazza Giovanni XXIII, Citta' di Castello, Italy
| | - Lucia Decastelli
- 2 National Reference Laboratory Stafilococchi coagulasi positivi-Istituto Zooprofilattico Sperimentale del Piemonte , Liguria e Valle d'Aosta, Torino, Italy
| | - Stefania Scuota
- 1 Istituto Zooprofilattico Sperimentale Umbria e Marche , Perugia, Italy
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67
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Nunes MM, Caldas ED. Preliminary Quantitative Microbial Risk Assessment for Staphylococcus enterotoxins in fresh Minas cheese, a popular food in Brazil. Food Control 2017. [DOI: 10.1016/j.foodcont.2016.08.046] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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68
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Fox A, Pichon B, Wilkinson H, Doumith M, Hill R, McLauchlin J, Kearns A. Detection and molecular characterization of Livestock-Associated MRSA in raw meat on retail sale in North West England. Lett Appl Microbiol 2017; 64:239-245. [DOI: 10.1111/lam.12709] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2016] [Revised: 12/23/2016] [Accepted: 12/24/2016] [Indexed: 11/29/2022]
Affiliation(s)
- A. Fox
- Public Health England; Food Water and Environmental Microbiology Services; Preston Laboratory; Preston UK
| | - B. Pichon
- Antimicrobial Resistance and Healthcare Infections Reference Unit; National Infection Service; Public Health England; London UK
| | - H. Wilkinson
- Public Health England; Food Water and Environmental Microbiology Services; Preston Laboratory; Preston UK
| | - M. Doumith
- Antimicrobial Resistance and Healthcare Infections Reference Unit; National Infection Service; Public Health England; London UK
| | - R.L.R. Hill
- Antimicrobial Resistance and Healthcare Infections Reference Unit; National Infection Service; Public Health England; London UK
| | - J. McLauchlin
- Public Health England Food Water and Environmental Microbiology Services; London UK
- Institute of Infection and Global Health; University of Liverpool; Liverpool UK
| | - A.M. Kearns
- Antimicrobial Resistance and Healthcare Infections Reference Unit; National Infection Service; Public Health England; London UK
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69
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Comparative Effects of Food Preservatives on the Production of Staphylococcal Enterotoxin I from Staphylococcus aureus Isolate. J FOOD QUALITY 2017. [DOI: 10.1155/2017/9495314] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Staphylococcal enterotoxin I (SEI) is associated with staphylococcal food poisoning, but little is known about different food preservatives on the production of SEI. In this study, the effect of different food preservatives (sodium nitrite, polylysine, chitosan, and tea catechin) on the bacteria growth, sei gene expression, and extracellular SEI production of Staphylococcus aureus isolate H4 was detected in tryptone soya broth (TSB) culture. Our results showed that all of these preservatives depressed S. aureus H4 growth and the order of inhibitory effect was 0.8 g/L tea catechin > 6 g/L chitosan > 0.25 g/L polylysine > 0.4 g/L tea catechin > 0.15 g/L sodium nitrite. Furthermore, 0.25 g/L polylysine or 0.15 g/L sodium nitrite did not significantly alter sei gene transcription, while 6 g/L chitosan obviously increased the relative mRNA level of sei gene expression. 0.4 g/L tea catechin remarkably inhibited sei gene transcription. In addition, 0.15 g/L sodium nitrite and 6 g/L chitosan significantly enhanced SEI secretion. 0.25 g/L polylysine, especially 0.4 g/L tea catechin, sharply inhibited the level of SEI secretion. The results indicated that tea catechin not only suppressed Staphylococcus aureus growth, but also inhibited SEI production and secretion, suggesting that tea catechin may be better than sodium nitrite, polylysine, or chitosan for keeping the food from the contamination of SEI. These investigations would be useful for food industry to provide safer food products due to S. aureus enterotoxins-related control strategy.
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70
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Biological toxins of potential bioterrorism risk: Current status of detection and identification technology. Trends Analyt Chem 2016. [DOI: 10.1016/j.trac.2016.05.024] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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71
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Nagaraj S, Ramlal S, Kingston J, Batra HV. Development of IgY based sandwich ELISA for the detection of staphylococcal enterotoxin G (SEG), an egc toxin. Int J Food Microbiol 2016; 237:136-141. [DOI: 10.1016/j.ijfoodmicro.2016.08.009] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2016] [Revised: 08/05/2016] [Accepted: 08/08/2016] [Indexed: 11/30/2022]
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72
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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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73
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Review Over a 3-Year Period of European Union Proficiency Tests for Detection of Staphylococcal Enterotoxins in Food Matrices. Toxins (Basel) 2016; 8:107. [PMID: 27089364 PMCID: PMC4848633 DOI: 10.3390/toxins8040107] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2016] [Revised: 03/30/2016] [Accepted: 04/06/2016] [Indexed: 11/18/2022] Open
Abstract
Staphylococcal food poisoning outbreaks are a major cause of foodborne illnesses in Europe and their notifications have been mandatory since 2005. Even though the European regulation on microbiological criteria for food defines a criterion on staphylococcal enterotoxin (SE) only in cheese and dairy products, European Food Safety Authority (EFSA) data reported that various types of food matrices are involved in staphylococcal food poisoning outbreaks. The European Screening Method (ESM) of European Union Reference Laboratory for Coagulase Positive Staphylococci (EURL CPS) was validated in 2011 for SE detection in food matrices and is currently the official method used for screening purposes in Europe. In this context, EURLCPS is annually organizing Inter-Laboratory Proficiency Testing Trials (ILPT) to evaluate the competency of the European countries’ National Reference Laboratories (NRLs) to analyse SE content in food matrices. A total of 31 NRLs representing 93% of European countries participated in these ILPTs. Eight food matrices were used for ILPT over the period 2013–2015, including cheese, freeze-dried cheese, tuna, mackerel, roasted chicken, ready-to-eat food, milk, and pastry. Food samples were spiked with four SE types (i.e., SEA, SEC, SED, and SEE) at various concentrations. Homogeneity and stability studies showed that ILPT samples were both homogeneous and stable. The analysis of results obtained by participants for a total of 155 blank and 620 contaminated samples allowed for evaluation of trueness (>98%) and specificity (100%) of ESM. Further to the validation study of ESM carried out in 2011, these three ILPTs allowed for the assessment of the proficiency of the NRL network and the performance of ESM on a large variety of food matrices and samples. The ILPT design presented here will be helpful for the organization of ILPT on SE detection by NRLs or other expert laboratories.
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74
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Marton M. Staphylococcal Toxic Shock Syndrome Caused by an Intravaginal Product. A Case Report. ACTA ACUST UNITED AC 2016; 2:51-55. [PMID: 29967837 DOI: 10.1515/jccm-2016-0003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2015] [Accepted: 12/15/2015] [Indexed: 11/15/2022]
Abstract
Staphylococcal toxic shock syndrome (STSS) represents a potentially lethal disease, and survival depends primarily on the early initiation of appropriate treatment. As the clinical picture at presentation is usually common, frequently this could lead to misdiagnosis and delays in the initiation of the proper therapy. The case of a 43-years old female who developed a staphylococcal septic shock syndrome caused by a forgotten intravaginal tampon is reported.
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Affiliation(s)
- Monica Marton
- Swedish Medical Center, Department of Anesthesiology and Critical Care, Seattle, USA
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75
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Koymans KJ, Vrieling M, Gorham RD, van Strijp JAG. Staphylococcal Immune Evasion Proteins: Structure, Function, and Host Adaptation. Curr Top Microbiol Immunol 2015; 409:441-489. [PMID: 26919864 DOI: 10.1007/82_2015_5017] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Staphylococcus aureus is a successful human and animal pathogen. Its pathogenicity is linked to its ability to secrete a large amount of virulence factors. These secreted proteins interfere with many critical components of the immune system, both innate and adaptive, and hamper proper immune functioning. In recent years, numerous studies have been conducted in order to understand the molecular mechanism underlying the interaction of evasion molecules with the host immune system. Structural studies have fundamentally contributed to our understanding of the mechanisms of action of the individual factors. Furthermore, such studies revealed one of the most striking characteristics of the secreted immune evasion molecules: their conserved structure. Despite high-sequence variability, most immune evasion molecules belong to a small number of structural categories. Another remarkable characteristic is that S. aureus carries most of these virulence factors on mobile genetic elements (MGE) or ex-MGE in its accessory genome. Coevolution of pathogen and host has resulted in immune evasion molecules with a highly host-specific function and prevalence. In this review, we explore how these shared structures and genomic locations relate to function and host specificity. This is discussed in the context of therapeutic options for these immune evasion molecules in infectious as well as in inflammatory diseases.
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Affiliation(s)
- Kirsten J Koymans
- Department of Medical Microbiology, University Medical Center Utrecht, G04-614, Heidelberglaan 100, 3584 CX, Utrecht, The Netherlands.
| | - Manouk Vrieling
- Department of Medical Microbiology, University Medical Center Utrecht, G04-614, Heidelberglaan 100, 3584 CX, Utrecht, The Netherlands
| | - Ronald D Gorham
- Department of Medical Microbiology, University Medical Center Utrecht, G04-614, Heidelberglaan 100, 3584 CX, Utrecht, The Netherlands
| | - Jos A G van Strijp
- Department of Medical Microbiology, University Medical Center Utrecht, G04-614, Heidelberglaan 100, 3584 CX, Utrecht, The Netherlands
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