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Suzuki Y, Ishitsuka T, Takagi M, Sasaki Y, Kakuda T, Kobayashi K, Kubota H, Ono HK, Kabeya H, Irie T, Andoh M, Asakura H, Takai S. Isolation and genetic characterization of Staphylococcus aureus from wild animal feces and game meats. Folia Microbiol (Praha) 2024; 69:347-360. [PMID: 37405631 DOI: 10.1007/s12223-023-01071-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2023] [Accepted: 06/12/2023] [Indexed: 07/06/2023]
Abstract
The populations of Japanese deer and boar have increased dramatically and have a serious impact on farming and mountain villages. Although the Japanese government promotes the use of captured wild animals, game meat is not subject to sanitary control considering that it is not subject to meat inspection or quality control. Here, we have attempted to isolate Staphylococcus aureus, a typical foodborne pathogen, as a part of an investigation of contamination in the meats of wild animals and their processing stages. We examined 390 samples of deer feces, 117 samples of wild boar feces, and 75 samples of disemboweled deer meat for isolation of S. aureus; ultimately, 30 (positive rate: 7.7%), 2 (1.7%), and 21 (28.0%) strains were isolated, respectively, from the samples. The genome sequences of these isolates were analyzed and were subjected to multilocus sequence typing. We identified 12 new sequence types (STs) and a dominant population of S. aureus with a characteristic genetic background in wild animals, namely, the ST groups derived from CC121 (number of strains = 39). These strains did not harbor the enterotoxin gene or only harbored egc-related enterotoxin, which is of low involvement in Staphylococcal food poisoning. However, one ST2449 strain, which produces causative enterotoxins, was isolated from a deer's feces. Since there are several common STs isolated from feces and dismembered meat and because fecal contamination during dismemberment is suspected, continuous monitoring and guidance for improving sanitary management conditions during processing and handling of the meat are highly warranted with immediate effect.
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Affiliation(s)
- Yasunori Suzuki
- Laboratory of Animal Hygiene, Kitasato University School of Veterinary Medicine, Higashi 23-35-1, Towada, Aomori, 034-8628, Japan.
| | - Toko Ishitsuka
- Laboratory of Animal Hygiene, Kitasato University School of Veterinary Medicine, Higashi 23-35-1, Towada, Aomori, 034-8628, Japan
| | - Miu Takagi
- Laboratory of Animal Hygiene, Kitasato University School of Veterinary Medicine, Higashi 23-35-1, Towada, Aomori, 034-8628, Japan
| | - Yukako Sasaki
- Laboratory of Animal Hygiene, Kitasato University School of Veterinary Medicine, Higashi 23-35-1, Towada, Aomori, 034-8628, Japan
| | - Tsutomu Kakuda
- Laboratory of Animal Hygiene, Kitasato University School of Veterinary Medicine, Higashi 23-35-1, Towada, Aomori, 034-8628, Japan
| | - Kai Kobayashi
- Department of Microbiology, Tokyo Metropolitan Institute of Public Health, 3-24-1 Hyakunin-Cho, Shinjuku-Ku, Tokyo, 169-0073, Japan
| | - Hiroaki Kubota
- Department of Microbiology, Tokyo Metropolitan Institute of Public Health, 3-24-1 Hyakunin-Cho, Shinjuku-Ku, Tokyo, 169-0073, Japan
| | - Hisaya K Ono
- Laboratory of Zoonoses, Kitasato University School of Veterinary Medicine, Higashi 23-35-1, Towada, Aomori, 034-8628, Japan
| | - Hidenori Kabeya
- Laboratory of Veterinary Food Hygiene, Department of Veterinary Medicine, College of Bioresource Sciences, Nihon University, 1866 Kameino, Fujisawa, Kanagawa, 252-0880, Japan
| | - Takao Irie
- Laboratory of Veterinary Parasitic Diseases, Department of Veterinary Sciences, Faculty of Agriculture, University of Miyazaki, 1-1 Gakuen-Kibanadai-Nishi, Miyazaki, 889-2192, Japan
| | - Masako Andoh
- Department of Pathogenetic and Preventive Veterinary Science, Joint Faculty of Veterinary Medicine, Kagoshima University, 1-21-24 Korimoto, Kagoshima, Kagoshima, 890-0065, Japan
| | - Hiroshi Asakura
- Division of Biomedical Food Research, National Institute of Health Sciences, 3-25-26, Tonomachi, Kawasaki-Ku, Kawasaki, Kanagawa, 210-9501, Japan
| | - Shinji Takai
- Laboratory of Animal Hygiene, Kitasato University School of Veterinary Medicine, Higashi 23-35-1, Towada, Aomori, 034-8628, Japan
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Liu A, Garrett S, Hong W, Zhang J. Staphylococcus aureus Infections and Human Intestinal Microbiota. Pathogens 2024; 13:276. [PMID: 38668232 PMCID: PMC11053856 DOI: 10.3390/pathogens13040276] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2024] [Revised: 03/18/2024] [Accepted: 03/23/2024] [Indexed: 04/29/2024] Open
Abstract
Staphylococcus aureus (S. aureus) is a common pathogen that can cause many human diseases, such as skin infection, food poisoning, endocarditis, and sepsis. These diseases can be minor infections or life-threatening, requiring complex medical management resulting in substantial healthcare costs. Meanwhile, as the critically ignored "organ," the intestinal microbiome greatly impacts physiological health, not only in gastrointestinal diseases but also in disorders beyond the gut. However, the correlation between S. aureus infection and intestinal microbial homeostasis is largely unknown. Here, we summarized the recent progress in understanding S. aureus infections and their interactions with the microbiome in the intestine. These summarizations will help us understand the mechanisms behind these infections and crosstalk and the challenges we are facing now, which could contribute to preventing S. aureus infections, effective treatment investigation, and vaccine development.
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Affiliation(s)
- Aotong Liu
- Department of Pharmacology & Regenerative Medicine, College of Medicine, University of Illinois Chicago, Chicago, IL 60612, USA;
| | - Shari Garrett
- Division of Gastroenterology and Hepatology, Department of Medicine, University of Illinois Chicago, Chicago, IL 60612, USA;
- Department of Microbiology and Immunology, University of Illinois Chicago, Chicago, IL 60612, USA
| | - Wanqing Hong
- Faculty of Science, University of Waterloo, Waterloo, ON N2L 3G1, Canada;
- School of Chemistry & Chemical Engineering and Materials Sciences, Shandong Normal University, Jinan 250061, China
| | - Jilei Zhang
- Department of Pharmacology & Regenerative Medicine, College of Medicine, University of Illinois Chicago, Chicago, IL 60612, USA;
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Sato'o Y, Hisatsune J, Aziz F, Tatsukawa N, Shibata-Nakagawa M, Ono HK, Naito I, Omoe K, Sugai M. Coordination of prophage and global regulator leads to high enterotoxin production in staphylococcal food poisoning-associated lineage. Microbiol Spectr 2024; 12:e0292723. [PMID: 38319074 PMCID: PMC10913437 DOI: 10.1128/spectrum.02927-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2023] [Accepted: 01/05/2024] [Indexed: 02/07/2024] Open
Abstract
Staphylococcus species in food produce Staphylococcal enterotoxins (SEs) that cause Staphylococcal food poisoning (SFP). More than 20 SE types have been reported, among which Staphylococcal enterotoxin A (SEA) has been recognized as one of the most important SEs associated with SFP. However, the regulatory mechanisms underlying its production remain unclear. Previously, we identified a major SFP clone in Japan, CC81 subtype-1, which exhibits high SEA production. In this study, we attempted to identify the factors contributing to this phenomenon. Thus, we demonstrated that the attenuation of the activity of endogenous regulator, Staphylococcal accessory regulator S (SarS), and the lysogenization of a high SEA-producing phage contributed to this phenomenon in CC81 subtype-1. Furthermore, our results indicated that SarS could directly bind to the promoter upstream of the sea gene and suppress SEA expression; this low SarS repression activity was identified as one of the reasons for the high SEA production observed. Therefore, we revealed that both exogenous and endogenous factors may probably contribute to the high SEA production. Our results confirmed that SE production is a fundamental and critical factor in SFP and clarified the associated production mechanism while enhancing our understanding as to why a specific clone frequently causes SFP. IMPORTANCE The importance of this study lies in its unveiling of a molecular regulatory mechanism associated with the most important food poisoning toxin and the evolution of Staphylococcal food poisoning (SFP)-associated clone. SFP is primarily caused by Staphylococcus aureus, with Staphylococcal enterotoxin A (SEA) being commonly involved in many cases. Thus, SEA has been recognized as a major toxin type. However, despite almost a century since its discovery, the complete mechanism of SEA production is as yet unknown. In this study, we analyzed an SEA-producing SFP clone isolated in East Asia and discovered that this strain, besides acquiring the high SEA-producing phage, exhibits remarkably high SEA production due to the low activity of SarS, an intrinsic regulatory factor. This is the first report documenting the evolution of the SFP clone through the coordinated action of exogenous mobile genetic factors and endogenous regulators on this notorious toxin.
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Affiliation(s)
- Yusuke Sato'o
- Department of Bacteriology, Hiroshima University Graduate School of Biomedical & Health Sciences, Hiroshima, Japan
| | - Junzo Hisatsune
- Department of Bacteriology, Hiroshima University Graduate School of Biomedical & Health Sciences, Hiroshima, Japan
- Antimicrobial Resistance Research Center, National Institute of Infectious Diseases (NIID), Tokyo, Japan
| | - Fatkhanuddin Aziz
- Department of Bacteriology, Hiroshima University Graduate School of Biomedical & Health Sciences, Hiroshima, Japan
| | - Nobuyuki Tatsukawa
- Department of Bacteriology, Hiroshima University Graduate School of Biomedical & Health Sciences, Hiroshima, Japan
| | - Mari Shibata-Nakagawa
- Department of Veterinary Medicine, Faculty of Agriculture, Iwate University, Morioka city, Japan
| | - Hisaya K. Ono
- Department of Veterinary Medicine, Faculty of Agriculture, Iwate University, Morioka city, Japan
- Laboratory of Zoonoses, Kitasato University School of Veterinary Medicine, Towada city, Japan
| | - Ikunori Naito
- Department of Veterinary Medicine, Faculty of Agriculture, Iwate University, Morioka city, Japan
| | - Katsuhiko Omoe
- Department of Veterinary Medicine, Faculty of Agriculture, Iwate University, Morioka city, Japan
| | - Motoyuki Sugai
- Department of Bacteriology, Hiroshima University Graduate School of Biomedical & Health Sciences, Hiroshima, Japan
- Antimicrobial Resistance Research Center, National Institute of Infectious Diseases (NIID), Tokyo, Japan
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Sheykhsaran E, Sadeghi J, Memar MY, Ghotaslou R, Baghi HB, Sharifi Y, Sefidan FY, Laghousi D, Abbasi A. Epidemiological characterization of clinical isolates of meticillin resistant Staphylococcus aureus through multilocus sequence typing and staphylococcal cassette chromosome mec typing in Northwest Iran. Mol Biol Rep 2024; 51:58. [PMID: 38165438 DOI: 10.1007/s11033-023-08951-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2023] [Accepted: 11/07/2023] [Indexed: 01/03/2024]
Abstract
BACKGROUND Methicillin-resistant Staphylococcus aureus (MRSA), is considered a potential and aggressive nosocomial pathogen. It accounts for 50% of S. aureus isolates in tertiary hospitals in Iran, however, there is no sufficient evolutionary and epidemiological investigation about this medically important bacterium. We aimed to study the lineage and evolution of MRSA in Northwest Iran during 2021-2022 based on the obtained phenotypic and genotypic characteristics. MATERIALS AND METHODS Seventy-two non-duplicate MRSA isolates were collected from 3 referral hospitals in Tabriz, Ardebil, and Urmia cities. The antimicrobial susceptibility patterns were determined by disk diffusion test and micro broth dilution methods. Thereafter 4 virulence genes (eta, etb, pvl, tst) and 5 types of staphylococcal cassette chromosome mec (SCCmec) were detected by PCR. In the final step, representative isolates were selected to be studied by Multilocus sequence typing (MLST). RESULTS The highest resistance was observed to erythromycin and clindamycin at a rate of 76.4%, followed by ciprofloxacin (61.1%), gentamicin (54.2%), rifampin (38.9%), and co-trimoxazole (27.8%). All isolates were susceptible to vancomycin. The virulence genes of etb, pvl, tst, and eta were detected in 50%, 29.2%, 21.8%, and 13.9% of isolates, respectively. SCCmec types III and I were the most prevalent types, followed by types IV, II, and V. MLST analysis revealed 6 sequence types: ST6854, ST5282, ST127, ST7804, ST1607, and ST7784. Two MLST-based clonal complexes (CC8, and CC97) were identified as well. CONCLUSION The ST numbers were non-repetitive. CC8 as a pandemic clone and an individual lineage and clinically significant clade was reported as the most prevalent clonal complex. It is essential periodic evaluations of antibiotic susceptibility patterns and study the evolutionary characteristics of medical-challenging microorganisms in particular MRSA to effectively treat and restrict the outbreaks.
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Affiliation(s)
- Elham Sheykhsaran
- Immunology Research Centre, Tabriz University of Medical Sciences, Tabriz, Iran
- Students' Research Committee, Tabriz University of Medical Sciences, Tabriz, Iran
- Department of Microbiology, Faculty of Medicine, Tabriz University of Medical Sciences, PO Box 5165665931, Tabriz, Iran
| | - Javid Sadeghi
- Immunology Research Centre, Tabriz University of Medical Sciences, Tabriz, Iran.
- Department of Microbiology, Faculty of Medicine, Tabriz University of Medical Sciences, PO Box 5165665931, Tabriz, Iran.
| | - Mohammad Yousef Memar
- Infectious and Tropical Diseases Research Center, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Reza Ghotaslou
- Department of Microbiology, Faculty of Medicine, Tabriz University of Medical Sciences, PO Box 5165665931, Tabriz, Iran
| | - Hossein Bannazadeh Baghi
- Immunology Research Centre, Tabriz University of Medical Sciences, Tabriz, Iran
- Infectious and Tropical Diseases Research Center, Tabriz University of Medical Sciences, Tabriz, Iran
- Department of Microbiology, Faculty of Medicine, Tabriz University of Medical Sciences, PO Box 5165665931, Tabriz, Iran
| | - Yaeghob Sharifi
- Department of Clinical Microbiology, School of Medicine, Urmia University of Medical Sciences, Urmia, Iran
| | - Fatemeh Yeganeh Sefidan
- Department of Microbiology, Faculty of Medicine, Tabriz University of Medical Sciences, PO Box 5165665931, Tabriz, Iran
| | - Delara Laghousi
- Social Determinants of Health Research Center, Health Management and Safety Promotion Research Institute, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Amin Abbasi
- Student Research Committee, Department of Food Sciences and Technology Research Institute, Faculty of Nutrition Sciences and Food Technology, Shahid Beheshti University of Medical Sciences, Tehran, Iran
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5
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Zhu Z, Hu Z, Li S, Fang R, Ono HK, Hu DL. Molecular Characteristics and Pathogenicity of Staphylococcus aureus Exotoxins. Int J Mol Sci 2023; 25:395. [PMID: 38203566 PMCID: PMC10778951 DOI: 10.3390/ijms25010395] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2023] [Revised: 12/24/2023] [Accepted: 12/26/2023] [Indexed: 01/12/2024] Open
Abstract
Staphylococcus aureus stands as one of the most pervasive pathogens given its morbidity and mortality worldwide due to its roles as an infectious agent that causes a wide variety of diseases ranging from moderately severe skin infections to fatal pneumonia and sepsis. S. aureus produces a variety of exotoxins that serve as important virulence factors in S. aureus-related infectious diseases and food poisoning in both humans and animals. For example, staphylococcal enterotoxins (SEs) produced by S. aureus induce staphylococcal foodborne poisoning; toxic shock syndrome toxin-1 (TSST-1), as a typical superantigen, induces toxic shock syndrome; hemolysins induce cell damage in erythrocytes and leukocytes; and exfoliative toxin induces staphylococcal skin scalded syndrome. Recently, Panton-Valentine leucocidin, a cytotoxin produced by community-associated methicillin-resistant S. aureus (CA-MRSA), has been reported, and new types of SEs and staphylococcal enterotoxin-like toxins (SEls) were discovered and reported successively. This review addresses the progress of and novel insights into the molecular structure, biological activities, and pathogenicity of both the classic and the newly identified exotoxins produced by S. aureus.
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Affiliation(s)
- Zhihao Zhu
- Department of Zoonoses, Kitasato University School of Veterinary Medicine, Towada 034-8628, Japan; (Z.Z.); (Z.H.); (H.K.O.)
- College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070, China;
| | - Zuo Hu
- Department of Zoonoses, Kitasato University School of Veterinary Medicine, Towada 034-8628, Japan; (Z.Z.); (Z.H.); (H.K.O.)
| | - Shaowen Li
- College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070, China;
| | - Rendong Fang
- Joint International Research Laboratory of Animal Health and Animal Food Safety, College of Veterinary Medicine, Southwest University, Chongqing 400715, China;
| | - Hisaya K. Ono
- Department of Zoonoses, Kitasato University School of Veterinary Medicine, Towada 034-8628, Japan; (Z.Z.); (Z.H.); (H.K.O.)
| | - Dong-Liang Hu
- Department of Zoonoses, Kitasato University School of Veterinary Medicine, Towada 034-8628, Japan; (Z.Z.); (Z.H.); (H.K.O.)
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6
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Yu S, Zhou Y, Feng D, Jiang Q, Li T, Jiang G, Zhou Z, Li H. Whole genome sequence-based characterization of virulence and antimicrobial resistance gene profiles of Staphylococcus aureus isolated from food poisoning incidents in eastern China. Front Microbiol 2023; 14:1225472. [PMID: 37795294 PMCID: PMC10546991 DOI: 10.3389/fmicb.2023.1225472] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2023] [Accepted: 09/04/2023] [Indexed: 10/06/2023] Open
Abstract
Staphylococcus aureus is an opportunistic foodborne pathogen occasionally isolated from diarrhea patients. In recent years, increasing studies have reported the detection of S. aureus in food poisoning incidents due to food contamination in the North and South of China. However, the epidemiology and genetic characteristics of S. aureus from food poisoning incidents in Eastern China remain unknown. The present study examined the genetic characteristics, antimicrobial resistance, and virulent factors of multidrug-resistant S. aureus isolated from 22 food poisoning incidents reported by the hospitals and health centers in Eastern China from 2011 to 2021. A total of 117 resistant and enterotoxigenic S. aureus isolates were collected and sequenced, among which 20 isolates were identified as methicillin resistant. Genetic analysis revealed 19 distinct CC/ST types, with CC6, CC22, CC59, CC88, and CC398 being the most frequent variants in methicillin-resistant S. aureus (MRSA). A considerable shift in CC types from CC1 to CC398 between 2011 and 2021 was observed in this study, indicating that CC398 may be the main epidemic strain circulating in the current food poisoning incidents. Additionally, genes for enterotoxins were detected in 55 isolates, with a prevalence of 27.8% (27/97) for methicillin-sensitive variants and 35.0% (7/20) for MRSA. The scn gene was detected in 59.0% of the isolates, demonstrating diverse contaminations of S. aureus among livestock-to-human transmission. Of the 117 isolates, only ten isolates displayed multi-drug resistance (MDR) to penicillin, tetracycline, and macrolides. None of the 117 foodborne S. aureus isolates tested positive for vanA in this study. Together, the present study provided phylogenetic characteristics of S. aureus from food poisoning incidents that emerged in Eastern China from 2011 to 2021. Our results suggested that these diarrhea episodes were hypotonic and merely transient low-MDR infections, however, further research for continued surveillance given the detection of virulence and antimicrobial resistance determinants is required to elucidate the genomic characteristics of pathogenic S. aureus in food poisoning incidents in the context of public health.
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7
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Guo Y, Yu X, Wang J, Hua D, You Y, Wu Q, Ji Q, Zhang J, Li L, Hu Y, Wu Z, Wei X, Jin L, Meng F, Yang Y, Hu X, Long L, Hu S, Qi H, Ma J, Bei W, Yan X, Wang H, He Z. A food poisoning caused by ST7 Staphylococcal aureus harboring sea gene in Hainan province, China. Front Microbiol 2023; 14:1110720. [PMID: 37007521 PMCID: PMC10060626 DOI: 10.3389/fmicb.2023.1110720] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2022] [Accepted: 02/27/2023] [Indexed: 03/18/2023] Open
Abstract
ST7 Staphylococcus aureus is highly prevalent in humans, pigs, as well as food in China; however, staphylococcal food poisoning (SFP) caused by this ST type has rarely been reported. On May 13, 2017, an SFP outbreak caused by ST7 S. aureus strains occurred in two campuses of a kindergarten in Hainan Province, China. We investigated the genomic characteristics and phylogenetic analysis of ST7 SFP strains combined with the 91 ST7 food-borne strains from 12 provinces in China by performing whole-genome sequencing (WGS). There was clear phylogenetic clustering of seven SFP isolates. Six antibiotic genes including blaZ, ANT (4′)-Ib, tetK, lnuA, norA, and lmrS were present in all SFP strains and also showed a higher prevalence rate in 91 food-borne strains. A multiple resistance plasmid pDC53285 was present in SFP strain DC53285. Among 27 enterotoxin genes, only sea and selx were found in all SFP strains. A ФSa3int prophage containing type A immune evasion cluster (sea, scn, sak, and chp) was identified in SFP strain. In conclusion, we concluded that this SFP event was caused by the contamination of cakes with ST7 S. aureus. This study indicated the potential risk of new emergencing ST7 clone for SFP.
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Affiliation(s)
- Yahui Guo
- Baotou Medical College, Inner Mongolia University of Science and Technology, Baotou, China
- Chinese Center for Disease Control and Prevention, National Institute for Communicable Disease Control and Prevention, Beijing, China
- Beijing Chaoyang District Center for Disease Control and Prevention, Beijing, China
| | - Xiaojie Yu
- Hainan Provincial Center for Disease Control and Prevention, Haikou, China
| | - Jixiao Wang
- Hainan Provincial Center for Disease Control and Prevention, Haikou, China
| | - De Hua
- Hainan Provincial Center for Disease Control and Prevention, Haikou, China
| | - Yuanhai You
- Chinese Center for Disease Control and Prevention, National Institute for Communicable Disease Control and Prevention, Beijing, China
| | - Qingbo Wu
- Hainan Provincial Center for Disease Control and Prevention, Haikou, China
| | - Qinglong Ji
- Chinese Academy of Inspection and Quarantine, Beijing, China
| | - Jianzhong Zhang
- Chinese Center for Disease Control and Prevention, National Institute for Communicable Disease Control and Prevention, Beijing, China
| | - Liefei Li
- Hainan Provincial Center for Disease Control and Prevention, Haikou, China
| | - Yuan Hu
- Chinese Center for Disease Control and Prevention, National Institute for Communicable Disease Control and Prevention, Beijing, China
| | - Zhonghui Wu
- Hainan Provincial Center for Disease Control and Prevention, Haikou, China
| | - Xiaoyue Wei
- Chinese Center for Disease Control and Prevention, National Institute for Communicable Disease Control and Prevention, Beijing, China
| | - Lianqun Jin
- Chinese PLA Center for Disease Control and Prevention, Beijing, China
| | - Fanliang Meng
- Chinese Center for Disease Control and Prevention, National Institute for Communicable Disease Control and Prevention, Beijing, China
| | - Yuhua Yang
- Chinese Center for Disease Control and Prevention, National Institute for Communicable Disease Control and Prevention, Beijing, China
| | - Xiaofeng Hu
- Chinese PLA Center for Disease Control and Prevention, Beijing, China
| | - Lijin Long
- Chinese Center for Disease Control and Prevention, National Institute for Communicable Disease Control and Prevention, Beijing, China
| | - Songnian Hu
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
| | - Heyuan Qi
- Microbial Resource and Big Data Center, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
| | - Juncai Ma
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
- Microbial Resource and Big Data Center, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
| | - Wenwen Bei
- Hainan Provincial Center for Disease Control and Prevention, Haikou, China
| | - Xiaomei Yan
- Chinese Center for Disease Control and Prevention, National Institute for Communicable Disease Control and Prevention, Beijing, China
- *Correspondence: Xiaomei Yan,
| | - Haibin Wang
- Baotou Medical College, Inner Mongolia University of Science and Technology, Baotou, China
- Beijing Chaoyang District Center for Disease Control and Prevention, Beijing, China
- Haibin Wang,
| | - Zilong He
- Beijing Advanced Innovation Center for Big Data-Based Precision Medicine, Interdisciplinary Innovation Institute of Medicine and Engineering, School of Engineering Medicine, Beihang University, Beijing, China
- Zilong He,
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8
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Yamamoto T, Taylor JN, Koseki S, Koyama K. Classification of food spoilage bacterial species and their sodium chloride, sodium acetate and glycine tolerance using chemometrics analysis and Raman spectroscopy. J Microbiol Methods 2021; 190:106326. [PMID: 34517040 DOI: 10.1016/j.mimet.2021.106326] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2021] [Revised: 08/07/2021] [Accepted: 09/07/2021] [Indexed: 10/20/2022]
Abstract
The purpose is classification of stress tolerances of spoilage bacteria using Raman spectra and chemometrics. We obtained Raman spectra of six spoilage bacteria. Classification models were constructed with support vector machine and classified food-related stress tolerance with 90% accuracy, which provides bacterial characteristics specific to environment reducing food spoilage.
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Affiliation(s)
- Takashi Yamamoto
- Graduate School of Agricultural Science, Hokkaido University, Kita-9, Nishi-9, Kita-ku, Sapporo 060-8589, Japan; Food Development Labs., Functional Food Division, Nippon Shinyaku Co., LTD., 14, Nishinosho-Monguchi-cho, Kisshoin, Minami-ku, Kyoto 601-8550, Japan.
| | - J Nicholas Taylor
- Research Institute for Electronic Science, Hokkaido University, Kita-20, Nishi-10, Kita-ku, Sapporo 001-0020, Japan.
| | - Shige Koseki
- Graduate School of Agricultural Science, Hokkaido University, Kita-9, Nishi-9, Kita-ku, Sapporo 060-8589, Japan.
| | - Kento Koyama
- Graduate School of Agricultural Science, Hokkaido University, Kita-9, Nishi-9, Kita-ku, Sapporo 060-8589, Japan.
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9
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Lv G, Jiang R, Zhang H, Wang L, Li L, Gao W, Zhang H, Pei Y, Wei X, Dong H, Qin L. Molecular Characteristics of Staphylococcus aureus From Food Samples and Food Poisoning Outbreaks in Shijiazhuang, China. Front Microbiol 2021; 12:652276. [PMID: 34239506 PMCID: PMC8258372 DOI: 10.3389/fmicb.2021.652276] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2021] [Accepted: 05/11/2021] [Indexed: 11/13/2022] Open
Abstract
As an opportunistic pathogen worldwide, Staphylococcus aureus can cause food poisoning and human infections. This study investigated the sequence typing, the penicillin (blaZ) and methicillin (mec) resistance profiles of S. aureus from food samples and food poisoning outbreaks in Shijiazhuang City, and the staphylococcal enterotoxin (SE) types of the S. aureus isolates from food poisoning. A total of 138 foodborne S. aureus isolates were distributed into 8 clonal complexes (CCs) and 12 singletons. CC1, CC5, CC8, CC15, CC97, CC59, CC398, CC88, and CC7 were the predominant CCs of foodborne S. aureus isolates. Moreover, CC59, CC15, and CC5 were the most prevalent CCs in food poisoning outbreaks. SEE was the most commonly detected SE in food poisoning isolates. One hundred thirty-three S. aureus isolates harbored the penicillin-resistant gene blaZ, and nine isolates carried the mec gene. The present study further explained the relationship between S. aureus and foods and food poisoning and indicated the potential risk of S. aureus infection.
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Affiliation(s)
- Guoping Lv
- Basic Medicine College, Hebei University of Chinese Medicine, Shijiazhuang, China
| | - Ruiping Jiang
- Shijiazhuang Center for Disease Control and Prevention, Shijiazhuang, China
| | - Han Zhang
- Basic Medicine College, Hebei University of Chinese Medicine, Shijiazhuang, China
| | - Lei Wang
- Shijiazhuang Center for Disease Control and Prevention, Shijiazhuang, China
| | - Lijie Li
- Shijiazhuang Center for Disease Control and Prevention, Shijiazhuang, China
| | - Weili Gao
- Shijiazhuang Center for Disease Control and Prevention, Shijiazhuang, China
| | - Hong Zhang
- Shijiazhuang Center for Disease Control and Prevention, Shijiazhuang, China
| | - Yantao Pei
- College of Life Science, Hebei Normal University, Shijiazhuang, China
| | - Xiuping Wei
- Shijiazhuang Center for Disease Control and Prevention, Shijiazhuang, China
| | - Hongyan Dong
- Basic Medicine College, Hebei University of Chinese Medicine, Shijiazhuang, China
| | - Liyun Qin
- Shijiazhuang Center for Disease Control and Prevention, Shijiazhuang, China
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10
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Sato'o Y, Omoe K, Aikawa Y, Kano M, Ono HK, Hu DL, Nakane A, Sugai M. Investigation of Staphylococcus aureus positive for Staphylococcal enterotoxin S and T genes. J Vet Med Sci 2021; 83:1120-1127. [PMID: 34039784 PMCID: PMC8349821 DOI: 10.1292/jvms.20-0662] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Staphylococcus aureus produces staphylococcal enterotoxins (SEs) and causes food poisoning. It is known that almost all SE-encoding genes are present on various types of mobile genetic elements and can mobilize among S. aureus populations. Further, plasmids comprise one of SE gene carriers. Previously, we reported novel SEs, SES and SET, harbored by the plasmid pF5 from Fukuoka5. In the present study, we analyzed the distribution of these SEs in various S. aureus isolates in Japan. We used 526 S. aureus strains and found 311 strains positive for at least one SE/SE-like toxin gene, but only two strains (Fukuoka5 and Hiroshima3) were positive for ses and set among the specimens. We analyzed two plasmids (pF5 and pH3) from these strains and found that they were different. Whereas these plasmids partially shared similar sequences involved in the ser/selj/set/ses gene cluster, other sequences were different. A comparison of these plasmids with those deposited in the NCBI database revealed that only one plasmid had the ser/selj/set/ses cluster with a stop mutation in set similar to that in pH3. In addition, the chromosomes of Fukuoka5 and Hiroshima3, positive for ses and set, were classified into different genotypes. Despite the low rate of gene positivity for these SEs, it is suggested that there is diversity in plasmids and strains carrying these two SEs. Consequently, regarding the entire feature of SE prevalence, we improved the multiplex PCR detection method for the SE superfamily to obtain further insight.
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Affiliation(s)
- Yusuke Sato'o
- Department of Bacteriology, Hiroshima University Graduate School of Biomedical & Health Sciences, Hiroshima-shi, Hiroshima 734-8551, Japan.,Department of Veterinary Medicine, Faculty of Agriculture, Iwate University, Ueda 3-18-8, Morioka, Iwate 020-8550, Japan.,The United Graduate School of Veterinary Sciences, Gifu University, Gifu, Gifu 501-1193, Japan.,Present address: Division of Bacteriology, Department of infection and immunity, School of Medicine, Jichi Medical University, Shimotsuke, Tochigi 323-0498, Japan
| | - Katsuhiko Omoe
- Department of Veterinary Medicine, Faculty of Agriculture, Iwate University, Ueda 3-18-8, Morioka, Iwate 020-8550, Japan.,The United Graduate School of Veterinary Sciences, Gifu University, Gifu, Gifu 501-1193, Japan
| | - Yasuko Aikawa
- Department of Veterinary Medicine, Faculty of Agriculture, Iwate University, Ueda 3-18-8, Morioka, Iwate 020-8550, Japan
| | - Mayuko Kano
- Department of Veterinary Medicine, Faculty of Agriculture, Iwate University, Ueda 3-18-8, Morioka, Iwate 020-8550, Japan
| | - Hisaya K Ono
- Department of Veterinary Medicine, Faculty of Agriculture, Iwate University, Ueda 3-18-8, Morioka, Iwate 020-8550, Japan.,The United Graduate School of Veterinary Sciences, Gifu University, Gifu, Gifu 501-1193, Japan.,Department of Microbiology and Immunology, Hirosaki University Graduate School of Medicine, 5 Zaifu-cho, Hirosaki, Aomori 036-8560, Japan.,Laboratory of Zoonoses, Kitasato University School of Veterinary Medicine, Towada, Aomori 034-8628, Japan
| | - Dong-Liang Hu
- Laboratory of Zoonoses, Kitasato University School of Veterinary Medicine, Towada, Aomori 034-8628, Japan
| | - Akio Nakane
- Department of Microbiology and Immunology, Hirosaki University Graduate School of Medicine, 5 Zaifu-cho, Hirosaki, Aomori 036-8560, Japan
| | - Motoyuki Sugai
- Department of Bacteriology, Hiroshima University Graduate School of Biomedical & Health Sciences, Hiroshima-shi, Hiroshima 734-8551, Japan.,Present address: Antimicrobial Resistance Research Center, National Institute of Infectious Diseases (NIID), Murayama, Tokyo 189-0002, Japan
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11
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Staphylococcal Enterotoxin Gene Cluster: Prediction of Enterotoxin (SEG and SEI) Production and of the Source of Food Poisoning on the Basis of vSaβ Typing. Appl Environ Microbiol 2021; 87:e0266220. [PMID: 33355100 PMCID: PMC8090894 DOI: 10.1128/aem.02662-20] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Besides the infection properties in human and animals, S. aureus can produce different enterotoxins in food. The enterotoxins can cause vomiting and diarrhea, often involving many people. Currently, only 5 (SEA to SEE) out of 27 known staphylococcal enterotoxins can be analyzed using commercially available kits. Six genes (seg, sei, sem, sen, seo, and seu), encoding putative and undetectable enterotoxins, are located on the enterotoxin gene cluster (egc), which is part of the Staphylococcus aureus genomic island vSaβ. These enterotoxins have been described as likely being involved in staphylococcal food-poisoning outbreaks. The aim of the present study was to determine if whole-genome data can be used for the prediction of staphylococcal egc enterotoxin production, particularly enterotoxin G (SEG) and enterotoxin I (SEI). For this purpose, whole-genome sequences of 75 Staphylococcus aureus strains from different origins (food-poisoning outbreaks, human, and animal) were investigated by applying bioinformatics methods (phylogenetic analysis using the core genome and different alignments). SEG and SEI expression was tested in vitro using a sandwich enzyme-linked immunosorbent assay method. Strains could be allocated to 14 different vSaβ types, each type being associated with a single clonal complex (CC). In addition, the vSaβ type and CC were associated with the origin of the strain (human or cattle derived). The amount of SEG and SEI produced also correlated with the vSaβ type and the CC of a strain. The present results show promising indications that the in vitro production of SEG and SEI can be predicted based on the vSaβ type or CC of a strain. IMPORTANCE Besides having infectious properties in human and animals, S. aureus can produce different enterotoxins in food. The enterotoxins can cause vomiting and diarrhea, often involving many people. Most of these outbreaks remain undiscovered, as detection methods for enterotoxins are only available for a few enterotoxins but not for the more recently discovered enterotoxins G (SEG) and I (SEI). In this study, we show promising results that in vitro production of SEG and SEI can be predicted based on the whole-genome sequencing data of a strain. In addition, these data could be used to find the source (human or cattle derived) of an outbreak strain, which is the key for a better understanding of the role SEG and SEI play in foodborne outbreaks caused by S. aureus.
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12
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Suzuki Y, Ono HK, Shimojima Y, Kubota H, Kato R, Kakuda T, Hirose S, Hu DL, Nakane A, Takai S, Sadamasu K. A novel staphylococcal enterotoxin SE02 involved in a staphylococcal food poisoning outbreak that occurred in Tokyo in 2004. Food Microbiol 2020; 92:103588. [PMID: 32950172 DOI: 10.1016/j.fm.2020.103588] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2019] [Revised: 05/22/2020] [Accepted: 06/24/2020] [Indexed: 02/04/2023]
Abstract
Staphylococcal enterotoxins (SEs) are extracellular proteins, produced mainly by Staphylococcus aureus, which cause staphylococcal food poisoning (SFP) when ingested. Here, a novel SE was identified from two strains, which were identified as the causative microbes of the SFP outbreak that occurred in Tokyo in 2004. Both strains harbored the SEA gene, but its production was lower than that of other SEA-producing SFP isolates. Whole-genome sequencing analysis demonstrated that both strains harbored a SE-like gene besides sea. Phylogenetic analysis revealed that the amino acid sequence deduced from the SE-like gene belonged to the SEB group. Therefore, this gene was presumed to be a novel SE gene and termed "SE02." The stability of SE02 against heating and proteolytic digestions was a little different from that of SEA. SE02 has both superantigenic and emetic bioactivities. Namely, SE02 activated mouse splenocytes and exhibited emetic activity in the common marmoset. SE02 mRNA was highly expressed in both isolates during the exponential phase of cultivation. In addition, SE02 protein was produced at 20 °C and 25 °C, which reflects the actual situation of SFP. SE02 appears to be a novel emetic toxin that was likely the causative toxin in combination with SEA in the SFP outbreak.
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Affiliation(s)
- Yasunori Suzuki
- Laboratory of Animal Hygiene, Kitasato University School of Veterinary Medicine, Higashi 23-35-1, Towada, Aomori, 034-8628, Japan; Department of Microbiology, Tokyo Metropolitan Institute of Public Health, Hyakunin-cho 3-24-1, Shinjuku, Tokyo, 169-0073, Japan.
| | - Hisaya K Ono
- Laboratory of Zoonoses, Kitasato University School of Veterinary Medicine, Higashi 23-35-1, Towada, Aomori, 034-8628, Japan
| | - Yukako Shimojima
- Department of Microbiology, Tokyo Metropolitan Institute of Public Health, Hyakunin-cho 3-24-1, Shinjuku, Tokyo, 169-0073, Japan
| | - Hiroaki Kubota
- Department of Microbiology, Tokyo Metropolitan Institute of Public Health, Hyakunin-cho 3-24-1, Shinjuku, Tokyo, 169-0073, Japan
| | - Rei Kato
- Department of Microbiology, Tokyo Metropolitan Institute of Public Health, Hyakunin-cho 3-24-1, Shinjuku, Tokyo, 169-0073, Japan
| | - Tsutomu Kakuda
- Laboratory of Animal Hygiene, Kitasato University School of Veterinary Medicine, Higashi 23-35-1, Towada, Aomori, 034-8628, Japan
| | - Shouhei Hirose
- Department of Microbiology and Immunology, Hirosaki University Graduate School of Medicine, Zaifu-cho 5, Hirosaki, Aomori, 036-8562, Japan
| | - Dong-Liang Hu
- Laboratory of Zoonoses, Kitasato University School of Veterinary Medicine, Higashi 23-35-1, Towada, Aomori, 034-8628, Japan
| | - Akio Nakane
- Department of Microbiology and Immunology, Hirosaki University Graduate School of Medicine, Zaifu-cho 5, Hirosaki, Aomori, 036-8562, Japan; Department of Biopolymer and Health Science, Hirosaki University Graduate School of Medicine, Zaifu-cho 5, Hirosaki, Aomori, 036-8562, Japan
| | - Shinji Takai
- Laboratory of Animal Hygiene, Kitasato University School of Veterinary Medicine, Higashi 23-35-1, Towada, Aomori, 034-8628, Japan
| | - Kenji Sadamasu
- Department of Microbiology, Tokyo Metropolitan Institute of Public Health, Hyakunin-cho 3-24-1, Shinjuku, Tokyo, 169-0073, Japan
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13
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Suzuki Y. Current Studies of Staphylococcal Food Poisoning. Food Hygiene and Safety Science (Shokuhin Eiseigaku Zasshi) 2019; 60:27-37. [DOI: 10.3358/shokueishi.60.27] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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14
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Chen Q, Xie S. Genotypes, Enterotoxin Gene Profiles, and Antimicrobial Resistance of Staphylococcus aureus Associated with Foodborne Outbreaks in Hangzhou, China. Toxins (Basel) 2019; 11:toxins11060307. [PMID: 31146460 PMCID: PMC6628443 DOI: 10.3390/toxins11060307] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2019] [Revised: 05/19/2019] [Accepted: 05/23/2019] [Indexed: 12/19/2022] Open
Abstract
Staphylococcal food poisoning is an illness caused by the consumption of food that contains sufficient amounts of one or more enterotoxins. In the present study, a total of 37 S. aureus isolates were recovered from leftover food, swabs from a kitchen environment, and patient feces associated with four foodborne outbreaks that occurred in Hangzhou, southeast China, and were characterized by multilocus sequence typing (MLST), spa typing, pulse-field gel electrophoresis (PFGE), and antimicrobial susceptibility. Classical enterotoxin and enterotoxin-like genes were profiled by PCR analysis. ST6-t304 was the most common clone (40.54%), followed by ST2315-t11687 (32.43%). Six clusters (A to F) were divided based on PFGE patterns, and Clusters A and C were the most common types, constituting 86.49% of all isolates. Moreover, sea was the most frequently identified enterotoxin gene (81.08%), followed by the combination of seg-sei-selm-seln-sleo-selu and sec-sell (each 48.65%). Five isolates also harbored the exotoxin cluster sed-selj-ser. In addition, resistance to penicillin (97.30%), erythromycin (37.85), tetracycline (32.43%), clindamycin, gentamicin, and sulfamethoxazole (each 10.81%) was observed. Our research demonstrated the link between leftover foods and patients by molecular typing and detecting the profiles of enterotoxin or enterotoxin-like genes in human and food isolates. S. aureus maintains an extensive repertoire of enterotoxins and drug resistance genes that could cause potential health threats to consumers.
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Affiliation(s)
- Qi Chen
- Department of Microbiology, Hangzhou Center for Disease Control and Prevention, Hangzhou 310021, China.
| | - Sangma Xie
- College of Life Information Science and Instrument Engineering, Hangzhou Dianzi University, Hangzhou 310018, China.
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15
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Käppeli N, Morach M, Corti S, Eicher C, Stephan R, Johler S. Staphylococcus aureus related to bovine mastitis in Switzerland: Clonal diversity, virulence gene profiles, and antimicrobial resistance of isolates collected throughout 2017. J Dairy Sci 2019; 102:3274-3281. [DOI: 10.3168/jds.2018-15317] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2018] [Accepted: 12/23/2018] [Indexed: 11/19/2022]
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16
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Zhang Y, Wang Y, Cai R, Shi L, Li C, Yan H. Prevalence of Enterotoxin Genes in Staphylococcus aureus Isolates from Pork Production. Foodborne Pathog Dis 2018; 15:437-443. [PMID: 29672171 DOI: 10.1089/fpd.2017.2408] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
In this study, 130 Staphylococcus aureus isolates from samples associated with pork production were tested for prevalence of 18 staphylococcal enterotoxin (SE) genes. Approximately 94.6% (123/130) of isolates from different stages of pork production harbored one or more SE genes forming 37 different enterotoxin gene profiles. Seb was present in 60.0% of the S. aureus isolates, the highest among the genes tested. The genes, sed, sej, seo, sep, ser, and seu, were not found. The five classical SE genes (including sea, seb, sec, sed, see) had lower prevalence than the egc gene cluster (seg, sei, sem, sen, seo, or seu). Notably, ∼6.9% (9/130) isolates harbored five SE genes. Classical SE genes were relatively higher in raw meat isolates than swine farm isolates, suggesting that raw meat isolates have a greater potential for classical staphylococcal food poisoning. Incomplete egc clusters were mainly distributed in swine farm isolates, and some of them coexisted with other classical SE genes (seb, sec), showing that swine farms could be potential sources of enterogenic S. aureus of food safety concern. Characterizing the distributions of enterotoxin genes among S. aureus may provide epidemiological information for the benefit of public health and food safety.
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Affiliation(s)
- Yang Zhang
- 1 School of Food Science and Engineering, South China University of Technology , Guangzhou, China
| | - Yage Wang
- 1 School of Food Science and Engineering, South China University of Technology , Guangzhou, China
| | - Rujian Cai
- 2 Institute of Animal Health Guangdong Academy of Agricultural Sciences , Guangzhou, China
| | - Lei Shi
- 3 Institute of Food Safety and Nutrition, Jinan University , Guangzhou, China .,4 State Key Laboratory of Food Safety Technology for Meat Products, Fujian, China
| | - Chunling Li
- 2 Institute of Animal Health Guangdong Academy of Agricultural Sciences , Guangzhou, China
| | - He Yan
- 1 School of Food Science and Engineering, South China University of Technology , Guangzhou, China .,4 State Key Laboratory of Food Safety Technology for Meat Products, Fujian, China
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17
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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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18
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Umeda K, Nakamura H, Yamamoto K, Nishina N, Yasufuku K, Hirai Y, Hirayama T, Goto K, Hase A, Ogasawara J. Molecular and epidemiological characterization of staphylococcal foodborne outbreak of Staphylococcus aureus harboring seg, sei, sem, sen, seo, and selu genes without production of classical enterotoxins. Int J Food Microbiol 2017; 256:30-35. [PMID: 28582663 DOI: 10.1016/j.ijfoodmicro.2017.05.023] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2017] [Revised: 05/26/2017] [Accepted: 05/29/2017] [Indexed: 10/19/2022]
Abstract
Staphylococcal food poisoning is the result of consumption of food contaminated with staphylococcal enterotoxins (SEs) produced by Staphylococcus aureus. To date, 23 SEs and SE-like enterotoxins (SEls) have been described in the literature. They are divided into classical SEs (SEA-SEE) and new SE/SEls (SEG-SElX). Some have proved to be foodborne-inducible, but others remain unidentified. In May 2016, at an elderly group home in Osaka city, Japan, an outbreak from foodborne pathogens occurred among lunch party participants. Within 2h 30min to 4h 40min, 15 of 53 participants presented gastrointestinal symptoms of vomiting, diarrhea, and nausea. A subsequent laboratory investigation detected S. aureus from most stool samples from patients, several left-over food items, a kitchen swab, and hand swabs from two food handlers. Classical SEs was not detected from S. aureus isolates or left-over food items. From examination for the presence of SE/SEl genes of 20 kinds by PCR, seg, sei, sem, sen, seo, and selu genes were detected in almost all isolates. These isolates exhibited identical or closely related types by coagulase type (type VII), Sma I digested pulsed-field gel electrophoresis analysis and multi-locus sequence typing (MLST-CC45 lineage). These results suggest that the foodborne outbreak was caused by S. aureus harboring seg, sei, sem, sen, seo, and selu genes without production of classical SEs. Additionally, some S. aureus isolates from human nasal swabs and healthy human feces harboring seg, sei, sem, sen, seo, and selu genes without production of classical SEs were classified into CC45 lineage using MLST. These findings suggest new SE/SEls as a potential cause of foodborne outbreaks.
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Affiliation(s)
- Kaoru Umeda
- Division of Microbiology, Osaka Institute of Public Health, 8-34, Tojo-cho, Tennoji-ku, Osaka 543-0026, Japan.
| | - Hiromi Nakamura
- Division of Microbiology, Osaka Institute of Public Health, 8-34, Tojo-cho, Tennoji-ku, Osaka 543-0026, Japan
| | - Kaori Yamamoto
- Division of Microbiology, Osaka Institute of Public Health, 8-34, Tojo-cho, Tennoji-ku, Osaka 543-0026, Japan
| | - Nobuko Nishina
- Osaka City Public Health Center, Southeast Living and Health Inspection Office, 1-2-7, Asahi-cho, Abeno-ku, Osaka 545-0051, Japan
| | - Kiyoshi Yasufuku
- Osaka City Public Health Center, Southeast Living and Health Inspection Office, 1-2-7, Asahi-cho, Abeno-ku, Osaka 545-0051, Japan
| | - Yuki Hirai
- Division of Microbiology, Osaka Institute of Public Health, 8-34, Tojo-cho, Tennoji-ku, Osaka 543-0026, Japan
| | - Teruo Hirayama
- Division of Microbiology, Osaka Institute of Public Health, 8-34, Tojo-cho, Tennoji-ku, Osaka 543-0026, Japan
| | - Kaoru Goto
- Division of Microbiology, Osaka Institute of Public Health, 8-34, Tojo-cho, Tennoji-ku, Osaka 543-0026, Japan
| | - Atsushi Hase
- Division of Microbiology, Osaka Institute of Public Health, 8-34, Tojo-cho, Tennoji-ku, Osaka 543-0026, Japan
| | - Jun Ogasawara
- Division of Microbiology, Osaka Institute of Public Health, 8-34, Tojo-cho, Tennoji-ku, Osaka 543-0026, Japan
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Hanis CL, Garrett KE, Essigmann HT, Robinson DA, Gunter SM, Nyitray AG, Brown EL. Household aggregation of Staphylococcus aureus by clonal complex and methicillin resistance profiles in Starr County, Texas. Eur J Clin Microbiol Infect Dis 2017; 36:1787-1793. [PMID: 28474178 DOI: 10.1007/s10096-017-2992-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2017] [Accepted: 04/17/2017] [Indexed: 02/08/2023]
Abstract
Staphylococcus aureus is one of the most common causes of skin and soft tissue infections in health-care and community settings, but transmission of S. aureus in community-based populations is incompletely understood. S. aureus carriage phenotypes (persistent, intermittent, and non-carriers) were determined for households from Starr County, TX. Nasal swabs were collected from a cohort of 901 residents and screened for the presence of S. aureus. Isolated strains were spa-typed and assigned to clonal complexes. Of the 901 participants there were 134 pairs, 28 trios, 11 quartets, 3 quintets and 1 septet residing in the same household. There was a significant increase in "ever" carriers (persistent and intermittent carriers combined) in these households over that expected based on population frequencies (p = 0.029). There were 42 ever carrier pairs of individuals with 21 concordant for clonal complex type whereas only 4.7 were expected to be so (p = 6.9E-11). These results demonstrated clear aggregation of S. aureus carriage and concordance for strain types within households. As antibiotic-resistant S. aureus strains increase in community settings, it is important to better understand risk factors for colonization, mechanisms of transmission, clonal complexes present, and the role of household concordance/transmission.
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Affiliation(s)
- C L Hanis
- Human Genetics Center, Division of Epidemiology, Human Genetics, and Environmental Sciences, University of Texas Health Science Center at Houston, Houston, TX, USA
| | - K E Garrett
- Center for Infectious Disease, Division of Epidemiology, Human Genetics, and Environmental Sciences, University of Texas Health Science Center, Houston, TX, USA
| | - H T Essigmann
- Center for Infectious Disease, Division of Epidemiology, Human Genetics, and Environmental Sciences, University of Texas Health Science Center, Houston, TX, USA
| | - D A Robinson
- Department of Microbiology, University of Mississippi Medical Center, Jackson, MS, USA
| | - S M Gunter
- Center for Infectious Disease, Division of Epidemiology, Human Genetics, and Environmental Sciences, University of Texas Health Science Center, Houston, TX, USA.,National School of Tropical Medicine, Section of Tropical Medicine, Baylor College of Medicine, Houston, TX, USA
| | - A G Nyitray
- Center for Infectious Disease, Division of Epidemiology, Human Genetics, and Environmental Sciences, University of Texas Health Science Center, Houston, TX, USA
| | - E L Brown
- Center for Infectious Disease, Division of Epidemiology, Human Genetics, and Environmental Sciences, University of Texas Health Science Center, Houston, TX, USA.
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20
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Cao H, Wang T, Yuan M, Yu J, Xu F. Growth and Modeling of Staphylococcus aureus in Flour Products under Isothermal and Nonisothermal Conditions. J Food Prot 2017; 80:523-531. [PMID: 28225295 DOI: 10.4315/0362-028x.jfp-16-248] [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] [Indexed: 11/11/2022]
Abstract
This study was conducted to investigate the growth of Staphylococcus aureus in traditional Chinese flour products under isothermal (10, 15, 20, 25, 30, and 37°C) and nonisothermal (10 to 20, 20 to 30, and 25 to 37°C) conditions. Then, models for the growth of S. aureus in flour products as a function of storage temperature, pH, and water activity (aw) were developed, and the goodness of fit of models was evaluated using the determination coefficient (R2), root mean square error (RMSE), bias factor (Bf), and accuracy factor (Af). Based on the above information, S. aureus growth in steamed bread under nonisothermal conditions was predicted from experiments performed under isothermal conditions. It was shown that different combinations of temperature and aw in flour products have a strong influence on the growth of S. aureus . The modified Gompertz model was found to be more suitable for describing the growth data of S. aureus in flour products, with an R2 of >0.99 and an RMSE of <0.37. The newly developed secondary models were validated, and for the specific growth rate and the lag time, the R2 values were 0.96 and 0.97, Af was 1.12 and 1.06, and Bf was 1.13 and 1.05, respectively. The predicted nonisothermal growth curves of S. aureus were in agreement with the reported experimental ones, with RMSE <0.29, Af value 1.02 to 1.09, and Bf value 0.92 to 0.99. These results indicated that the predictive models provided useful information for the establishment of safety standards and a risk assessment for S. aureus in flour products.
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Affiliation(s)
- Hui Cao
- School of Medical Instrument and Food Engineering, University of Shanghai for Science and Technology, P.O. Box 454, No. 516, Jungong Road, Shanghai 200093, People's Republic of China
| | - Tingting Wang
- School of Medical Instrument and Food Engineering, University of Shanghai for Science and Technology, P.O. Box 454, No. 516, Jungong Road, Shanghai 200093, People's Republic of China
| | - Min Yuan
- School of Medical Instrument and Food Engineering, University of Shanghai for Science and Technology, P.O. Box 454, No. 516, Jungong Road, Shanghai 200093, People's Republic of China
| | - Jingsong Yu
- School of Medical Instrument and Food Engineering, University of Shanghai for Science and Technology, P.O. Box 454, No. 516, Jungong Road, Shanghai 200093, People's Republic of China
| | - Fei Xu
- School of Medical Instrument and Food Engineering, University of Shanghai for Science and Technology, P.O. Box 454, No. 516, Jungong Road, Shanghai 200093, People's Republic of China
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Suzuki Y, Matsushita S, Kubota H, Kobayashi M, Murauchi K, Higuchi Y, Kato R, Hirai A, Sadamasu K. Identification and functional activity of a staphylocoagulase type XI variant originating from staphylococcal food poisoning isolates. Lett Appl Microbiol 2016; 63:172-7. [PMID: 27227969 DOI: 10.1111/lam.12595] [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: 02/25/2016] [Revised: 05/23/2016] [Accepted: 05/23/2016] [Indexed: 11/26/2022]
Abstract
UNLABELLED Staphylocoagulase, an extracellular protein secreted by Staphylococcus aureus, has been used as an epidemiological marker. At least 12 serotypes and 24 genotypes subdivided on the basis of nucleotide sequence have been reported to date. In this study, we identified a novel staphylocoagulase nucleotide sequence, coa310, from staphylococcal food poisoning isolates that had the ability to coagulate plasma, but could not be typed using the conventional method. The protein encoded by coa310 contained the six fundamental conserved domains of staphylocoagulase. The full-length nucleotide sequence of coa310 shared the highest similarity (77·5%) with that of staphylocoagulase-type (SCT) XIa. The sequence of the D1 region, which would be responsible for the determination of SCT, shared the highest similarity (91·8%) with that of SCT XIa. These results suggest that coa310 is a novel variant of SCT XI. Moreover, we demonstrated that coa310 encodes a functioning coagulase, by confirming the coagulating activity of the recombinant protein expressed from coa310. This is the first study to directly demonstrate that Coa310, a putative SCT XI, has coagulating activity. These findings may be useful for the improvement of the staphylocoagulase-typing method, including serotyping and genotyping. SIGNIFICANCE AND IMPACT OF THE STUDY This is the first study to identify a novel variant of staphylocoagulase type XI based on its nucleotide sequence and to demonstrate coagulating activity in the variant using a recombinant protein. Elucidation of the variety of staphylocoagulases will provide suggestions for further improvement of the staphylocoagulase-typing method and contribute to our understanding of the epidemiologic characterization of Staphylococcus aureus.
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Affiliation(s)
- Y Suzuki
- Department of Microbiology, Tokyo Metropolitan Institute of Public Health, Shinjuku-ku, Tokyo, Japan
| | - S Matsushita
- Department of Microbiology, Tokyo Metropolitan Institute of Public Health, Shinjuku-ku, Tokyo, Japan
| | - H Kubota
- Department of Microbiology, Tokyo Metropolitan Institute of Public Health, Shinjuku-ku, Tokyo, Japan
| | - M Kobayashi
- Department of Microbiology, Tokyo Metropolitan Institute of Public Health, Shinjuku-ku, Tokyo, Japan
| | - K Murauchi
- Department of Microbiology, Tokyo Metropolitan Institute of Public Health, Shinjuku-ku, Tokyo, Japan
| | - Y Higuchi
- Department of Microbiology, Tokyo Metropolitan Institute of Public Health, Shinjuku-ku, Tokyo, Japan
| | - R Kato
- Department of Microbiology, Tokyo Metropolitan Institute of Public Health, Shinjuku-ku, Tokyo, Japan
| | - A Hirai
- Department of Microbiology, Tokyo Metropolitan Institute of Public Health, Shinjuku-ku, Tokyo, Japan
| | - K Sadamasu
- Department of Microbiology, Tokyo Metropolitan Institute of Public Health, Shinjuku-ku, Tokyo, Japan
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22
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Positive Regulation of Staphylococcal Enterotoxin H by Rot (Repressor of Toxin) Protein and Its Importance in Clonal Complex 81 Subtype 1 Lineage-Related Food Poisoning. Appl Environ Microbiol 2015; 81:7782-90. [PMID: 26341202 DOI: 10.1128/aem.01936-15] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2015] [Accepted: 08/22/2015] [Indexed: 11/20/2022] Open
Abstract
We previously demonstrated the clonal complex 81 (CC81) subtype 1 lineage is the major staphylococcal food poisoning (SFP)-associated lineage in Japan (Y. Sato'o et al., J Clin Microbiol 52:2637-2640, 2014, http://dx.doi.org/10.1128/JCM.00661-14). Strains of this lineage produce staphylococcal enterotoxin H (SEH) in addition to SEA. However, an evaluation of the risk for the recently reported SEH has not been sufficiently conducted. We first searched for staphylococcal enterotoxin (SE) genes and SE proteins in milk samples that caused a large SFP outbreak in Japan. Only SEA and SEH were detected, while there were several SE genes detected in the samples. We next designed an experimental model using a meat product to assess the productivity of SEs and found that only SEA and SEH were detectably produced in situ. Therefore, we investigated the regulation of SEH production using a CC81 subtype 1 isolate. Through mutant analysis of global regulators, we found the repressor of toxin (Rot) functioned oppositely as a stimulator of SEH production. SEA production was not affected by Rot. seh mRNA expression correlated with rot both in media and on the meat product, and the Rot protein was shown to directly bind to the seh promoter. The seh promoter sequence was predicted to form a loop structure and to hide the RNA polymerase binding sequences. We propose Rot binds to the promoter sequence of seh and unfolds the secondary structure that may lead the RNA polymerase to bind the promoter, and then seh mRNA transcription begins. This alternative Rot regulation for SEH may contribute to sufficient toxin production by the CC81 subtype 1 lineage in foods to induce SFP.
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Li J, Yang J, Lu YW, Wu S, Wang MR, Zhu JM. Possible Role of Staphylococcal Enterotoxin B in the Pathogenesis of Autoimmune Diseases. Viral Immunol 2015; 28:354-9. [PMID: 26086678 DOI: 10.1089/vim.2015.0017] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022] Open
Abstract
As a member of superantigens (SAgs) produced by Staphylococcus aureus, staphylococcal enterotoxin B (SEB) is a exotoxin superantigen that can regulate the activity of immunomodulatory and pro-inflammatory cell types. In addition, SEB plays a critical role in the pathogenesis of autoimmune disorders either by initiating the autoimmune process or by inducing a relapse in an individual in clinical remission from an autoimmune disorder. SEB can directly activate T lymphocytes, leading to the release of cytokines, superoxides, or other mediators of inflammation either directly or indirectly, because of its unique ability to cross-link human major histocompatibility complex (MHC) class II and T cell receptors (TCR), forming a trimolecular complex. This review discusses the potential effects of SEB in the pathogenesis of autoimmune diseases such as multiple sclerosis, systemic lupus erythematosus, and rheumatoid arthritis, and explores some updated therapeutic medications to neutralize SEB.
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Affiliation(s)
- Jing Li
- 1 Department of Public Health and General Medicine, School of Integrated Traditional and Western Medicine, Anhui University of Chinese Medicine , Hefei, China
| | - Jie Yang
- 1 Department of Public Health and General Medicine, School of Integrated Traditional and Western Medicine, Anhui University of Chinese Medicine , Hefei, China
| | - Yu-wei Lu
- 2 Department of Information, The Second Hospital of Anhui Medical University , Hefei, China
| | - Song Wu
- 1 Department of Public Health and General Medicine, School of Integrated Traditional and Western Medicine, Anhui University of Chinese Medicine , Hefei, China
| | - Ming-rui Wang
- 1 Department of Public Health and General Medicine, School of Integrated Traditional and Western Medicine, Anhui University of Chinese Medicine , Hefei, China
| | - Ji-min Zhu
- 1 Department of Public Health and General Medicine, School of Integrated Traditional and Western Medicine, Anhui University of Chinese Medicine , Hefei, China
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24
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Suzuki Y, Kubota H, Sato'o Y, Ono H, Kato R, Sadamasu K, Kai A, Kamata Y. Identification and characterization of novel Staphylococcus aureus
pathogenicity islands encoding staphylococcal enterotoxins originating from staphylococcal food poisoning isolates. J Appl Microbiol 2015; 118:1507-20. [DOI: 10.1111/jam.12786] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2015] [Revised: 02/20/2015] [Accepted: 02/24/2015] [Indexed: 11/28/2022]
Affiliation(s)
- Y. Suzuki
- Department of Veterinary Medicine; Faculty of Agriculture; Iwate University; Morioka City Iwate Japan
- The United Graduate School of Veterinary Sciences; Gifu University; Gifu City Gifu Japan
- Department of Microbiology; Tokyo Metropolitan Institute of Public Health; Shinjuku-ku Tokyo Japan
| | - H. Kubota
- Department of Microbiology; Tokyo Metropolitan Institute of Public Health; Shinjuku-ku Tokyo Japan
| | - Y. Sato'o
- Department of Bacteriology; Hiroshima University Graduate School of Biomedical and Health Sciences; Hiroshima City Hiroshima Japan
| | - H.K. Ono
- Department of Microbiology and Immunology; Hirosaki University Graduate School of Medicine; Hirosaki City Aomori Japan
| | - R. Kato
- Department of Microbiology; Tokyo Metropolitan Institute of Public Health; Shinjuku-ku Tokyo Japan
| | - K. Sadamasu
- Department of Microbiology; Tokyo Metropolitan Institute of Public Health; Shinjuku-ku Tokyo Japan
| | - A. Kai
- Department of Microbiology; Tokyo Metropolitan Institute of Public Health; Shinjuku-ku Tokyo Japan
| | - Y. Kamata
- Department of Veterinary Medicine; Faculty of Agriculture; Iwate University; Morioka City Iwate Japan
- The United Graduate School of Veterinary Sciences; Gifu University; Gifu City Gifu Japan
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Li G, Wu S, Luo W, Su Y, Luan Y, Wang X. Staphylococcus aureus ST6-t701 isolates from food-poisoning outbreaks (2006-2013) in Xi'an, China. Foodborne Pathog Dis 2015; 12:203-6. [PMID: 25621506 DOI: 10.1089/fpd.2014.1850] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The aim of the study was to investigate the molecular epidemiologic of Staphylococcus aureus isolated from seven staphylococcal food-poisoning (SFP) outbreaks between 2006 and 2013 in Xi'an, northwest China. A total of seven S. aureus isolates associated with seven SFP outbreaks were obtained and characterized by determining the multilocus sequence typing, spa typing, pulsed-field gel electrophoresis (PFGE), antimicrobial susceptibility, toxin and resistant genes. The results showed that S. aureus ST6-t701 (71.4%) was the most predominant clone, followed by ST5-t002 and ST59-t172 (each 14.3%). Seven different PFGE patterns were obtained. Moreover, resistance was most frequently observed to trimethoprim and penicillin (each 71.4%), followed by erythromycin (28.6%), ampicillin, clindamycin, and tetracycline (each 14.3%). All strains were susceptible to chloramphenicol, cefoxitin, oxacillin, amikacin, and vancomycin. Three of seven strains displayed resistance to three or more antimicrobials. Resistance genes were found as follows: linA/linA' (100%), blaZ (85.7%), tet(K), ermC, ermT, and ermB (each 14.3%). Other resistant genes were not detected. In addition, the most frequently identified exotoxin genes were seu, lukED, hla, hlb, hld (each 100%), followed by hlg and hlgv (each 85.7%), lukPV (71.4%), sea (57.1%), see (42.9%), etd (28.6%), and seb, sec, sed, sej, and sek (each 14.3%). The results indicated that S. aureus ST6-t701, with a high prevalence in the northwest of China, exhibited multidrug resistance and harbored multiple toxin and resistance genes. Therefore, strict hygienic and preventative measures should be taken in order to avoid the contamination of food by S. aureus and toxin production in foods.
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Affiliation(s)
- Guanghui Li
- 1 College of Food Science and Engineering, Northwest A&F University , Yangling, Shaanxi, China
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