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https://www.readbyqxmd.com/read/28442219/virulence-potential-of-staphylococcus-aureus-isolates-from-buruli-ulcer-patients
#1
Nana Ama Amissah, Monika A Chlebowicz, Anthony Ablordey, Caitlin S Tetteh, Isaac Prah, Tjip S van der Werf, Alex W Friedrich, Jan Maarten van Dijl, Ymkje Stienstra, John W Rossen
Buruli ulcer (BU) is a necrotizing infection of the skin and subcutaneous tissue caused by Mycobacterium ulcerans. BU wounds may also be colonized with other microorganisms including Staphylococcus aureus. This study aimed to characterize the virulence factors of S. aureus isolated from BU patients. Previously sequenced genomes of 21 S. aureus isolates from BU patients were screened for the presence of virulence genes. The results show that all S. aureus isolates harbored on their core genomes genes for known virulence factors like α-hemolysin, and the α- and β-phenol soluble modulins...
April 19, 2017: International Journal of Medical Microbiology: IJMM
https://www.readbyqxmd.com/read/28434738/relationships-among-superantigen-toxin-gene-profiles-genotypes-and-pathogenic-characteristics-of-staphylococcus-aureus-isolates-from-bovine-mastitis
#2
Dong Wang, Limei Zhang, Changfu Yong, Mingliang Shen, Tariq Ali, Muhammad Shahid, Kun Han, Xuezhang Zhou, Bo Han
Staphylococcus aureus is one of the major etiological agents of bovine mastitis, harboring a wide variety of staphylococcal superantigen (SAg) toxin genes. The SAg toxin genes are reported to be closely associated with the pathogenicity of the Staph. aureus causing the bovine mastitis. This study was conducted to investigate SAg toxin gene profiles and to assess the relationships among SAg toxin genes, genotypes of Staph. aureus, and their pathogenic properties. A total of 327 quarter milk samples were collected from bovine mastitis cases for isolation and identification of pathogens...
April 20, 2017: Journal of Dairy Science
https://www.readbyqxmd.com/read/28428772/molecular-characterization-of-staphylococcus-aureus-isolated-from-bovine-mastitis-and-close-human-contacts-in-south-african-dairy-herds-genetic-diversity-and-inter-species-host-transmission
#3
Tracy Schmidt, Marleen M Kock, Marthie M Ehlers
Staphylococcus aureus is one of the most common etiological agents of contagious bovine mastitis worldwide. The purpose of this study was to genetically characterize a collection of S. aureus isolates (bovine = 146, human = 12) recovered from cases of bovine mastitis and nasal swabs of close human contacts in the dairy environment. Isolates were screened for a combination of clinically significant antimicrobial and virulence gene markers whilst the molecular epidemiology of these isolates and possible inter-species host transmission was investigated using a combination of genotyping techniques...
2017: Frontiers in Microbiology
https://www.readbyqxmd.com/read/28401320/the-virulence-factors-of-group-a-streptococcus-strains-isolated-from-invasive-and-non-invasive-infections-in-polish-and-german-centres-2009-2011
#4
M Strus, P B Heczko, E Golińska, A Tomusiak, A Chmielarczyk, M Dorycka, M van der Linden, A Samet, A Piórkowska
Streptococcus pyogenes (GAS) is one of the major human pathogenic bacteria that cause a wide range of diseases. Currently, increased incidence of streptococcal invasive infections is observed worldwide. In this study, we focused on the prevalence of genes encoding superantigens and type M proteins in the population of GAS strains from invasive versus non-invasive infections. We tested 253 GAS strains: 48 strains from patients with invasive infections (18 from wound/deep skin localization, 30 from women in labour) and 205 strains from non-invasive forms (147 from common infections of the upper respiratory, 49 from the vagina of females with genital tract infections and 9 from non-invasive wound and superficial skin infections)...
April 11, 2017: European Journal of Clinical Microbiology & Infectious Diseases
https://www.readbyqxmd.com/read/28375567/biological-characteristics-of-staphylococcal-enterotoxin-q-and-its-potential-risk-for-food-poisoning
#5
D-L Hu, H K Ono, S Isayama, R Okada, M Okamura, L C Lei, Z S Liu, X-C Zhang, M Y Liu, J C Cui, A Nakane
AIMS: To elucidate the biological characteristics and stability of a newly identified staphylococcal enterotoxin Q (SEQ) against heating and digestive enzymes, and evaluate the risk of seq-harboring S. aureus in food poisoning. METHODS AND RESULTS: Purified SEQ was treated with heating, pepsin and trypsin that are related to food cooking, stomach and intestine conditions. Superantigenic activity of SEQ was assessed by determining the ability of IL-2 induction in mouse spleen cells...
April 4, 2017: Journal of Applied Microbiology
https://www.readbyqxmd.com/read/28362113/staphylococcal-enterotoxins-and-enterotoxin-like-toxins-with-special-reference-to-dairy-products-an-overview
#6
Noreddine Benkerroum
Staphylococcal enterotoxins (SEs) have been raising health concerns for food safety due to their association with Staphylococcal Food Poisoning (SFP). As superantigens, they also cause the life threatening Toxic Shock Syndrome (TSS), the transmission of which via food cannot be ruled out despite the lack of epidemiological evidence. To date, at least 23 of these exotoxins are known and separated into SEs and staphylococcal enterotoxin-like (SEl) depending on whether or not they invoke emesis. This work presents an up-to-date overview on the presently known SEs/SEls from the perspective of their classification, pathogenesis, and genetic organisation...
March 31, 2017: Critical Reviews in Food Science and Nutrition
https://www.readbyqxmd.com/read/28359755/a-novel-staphylococcal-enterotoxin-b-subunit-vaccine-candidate-elicits-protective-immune-response-in-a-mouse-model
#7
Jun Young Choi, Sungho Shin, Na Young Kim, Woo Sung Son, Tae Jin Kang, Dong Hyun Song, Chi Ho Yu, Gyeung Haeng Hur, Seong Tae Jeong, Young Kee Shin
Staphylococcal enterotoxin B (SEB), produced by the gram-positive bacterium Staphylococcus aureus, is responsible for food poisoning and toxic shock syndrome, and is considered a potential bioterrorism agent. Unfortunately, still now no approved vaccines are available against SEB. In this study, we constructed a series of nontoxic SEB mutants (mSEBs) and examined whether these mSEBs provide protective immunity against SEB challenge. These mSEB vaccine candidates did not demonstrate superantigen activity in mouse splenocyte cultures...
March 27, 2017: Toxicon: Official Journal of the International Society on Toxinology
https://www.readbyqxmd.com/read/28320831/interference-of-the-t-cell-and-antigen-presenting-cell-costimulatory-pathway-using-ctla4-ig-abatacept-prevents-staphylococcal-enterotoxin-b-pathology
#8
Sarah J C Whitfield, Chris Taylor, Jane E Risdall, Gareth D Griffiths, James T A Jones, E Diane Williamson, Sjoerd Rijpkema, Luisa Saraiva, Sandrine Vessillier, A Christopher Green, Alun J Carter
Staphylococcal enterotoxin B (SEB) is a bacterial superantigen that binds the receptors in the APC/T cell synapse and causes increased proliferation of T cells and a cytokine storm syndrome in vivo. Exposure to the toxin can be lethal and cause significant pathology in humans. The lack of effective therapies for SEB exposure remains an area of concern, particularly in scenarios of acute mass casualties. We hypothesized that blockade of the T cell costimulatory signal by the CTLA4-Ig synthetic protein (abatacept) could prevent SEB-dependent pathology...
March 20, 2017: Journal of Immunology: Official Journal of the American Association of Immunologists
https://www.readbyqxmd.com/read/28286804/bacterial-superantigen-toxins-induce-a-lethal-cytokine-storm-by-enhancing-b7-2-cd28-costimulatory-receptor-engagement-a-critical-immune-checkpoint
#9
Raymond Kaempfer, Andrey Popugailo, Revital Levy, Gila Arad, Dalia Hillman, Ziv Rotfogel
Formation of the costimulatory axis between the B7-2 and CD28 coreceptors is critical for T-cell activation. Superantigens, Gram-positive bacterial virulence factors, cause toxic shock and sepsis by hyperinducing inflammatory cytokines. We report a novel role for costimulatory receptors CD28 and B7-2 as obligatory receptors for superantigens, rendering them therapeutic targets. We show that by engaging not only CD28 but also its coligand B7-2 directly, superantigens potently enhance the interaction between B7-2 and CD28, inducing thereby T-cell hyperactivation...
2017: Receptors & Clinical Investigation
https://www.readbyqxmd.com/read/28274699/members-of-a-new-subgroup-of-streptococcus-anginosus-harbor-virulence-related-genes-previously-observed-in-streptococcus-pyogenes
#10
Anshu Babbar, Venkatesan Naveen Kumar, René Bergmann, Israel Barrantes, Dietmar H Pieper, Andreas Itzek, D Patric Nitsche-Schmitz
Conventionally categorized as commensals, the Streptococci of the species S. anginosus are facultative human pathogens that are difficult to diagnose and often overlooked. Furthermore, detailed investigation and diagnosis of S. anginosus infections is hampered by unexplored taxonomy and widely elusive molecular pathogenesis. To explore their pathogenic potential, S. anginosus isolates collected from patients of two geographical locations (Vellore, India and Leipzig, Germany) were subjected to multi-locus sequence analysis (MLSA)...
April 2017: International Journal of Medical Microbiology: IJMM
https://www.readbyqxmd.com/read/28260936/microbiome-in-atopic-dermatitis
#11
REVIEW
Uwe Wollina
Atopic dermatitis (AD) is a common chronic inflammatory skin disease affecting ~10-20% of the general population. AD is characterized by disturbances in epidermal barrier function and hyperactive immune response. Recently, changes in the skin and intestinal microbiome have been analyzed in more detail. The available data suggest a link between disturbed skin microbiome and course of the disease. Flares of the disease are associated with an expansion of Staphylococcus aureus on lesional skin and a substantial loss of biodiversity in skin microbiome...
2017: Clinical, Cosmetic and Investigational Dermatology
https://www.readbyqxmd.com/read/28241767/multiple-sclerosis-an-example-of-pathogenic-viral-interaction
#12
REVIEW
Walter Fierz
A hypothesis is formulated on viral interaction between HHV-6A and EBV as a pathogenic mechanism in Multiple Sclerosis (MS). Evidence of molecular and genetic mechanisms suggests a link between HHV-6A infection and EBV activation in the brain of MS patients leading to intrathecal B-cell transformation. Consequent T-cell immune response against the EBV-infected cells is postulated as a pathogenic basis for inflammatory lesion formation in the brain of susceptible individuals. A further link between HHV-6A and EBV involves their induction of expression of the human endogenous retrovirus HERV-K18-encoded superantigen...
February 28, 2017: Virology Journal
https://www.readbyqxmd.com/read/28235987/staphylococcus-enterotoxin-profile-of-china-isolates-and-the-superantigenicity-of-some-novel-enterotoxins
#13
Menglu Shen, Yi Li, Linlin Zhang, Songbao Dai, Jiashun Wang, Yongqing Li, Lei Zhang, Jinhai Huang
The genus of staphylococcus widely distributes in environments and contributes to a variety of animal and human diseases. The enterotoxins (SEs) secreted by this type of pathogen have been the leading cause of bacterial toxic shock syndrome and food poisoning, and thus present a substantial concern to public health. In this study, we analyzed the superantigen profile of 122 staphylococcus strains isolated from diverse sources. When screened for the presence and prevalence of 17 known se or se-like (sel) genes, except selj, all other genes were detected in these isolates...
February 24, 2017: Archives of Microbiology
https://www.readbyqxmd.com/read/28219889/rapid-and-rigorous-il-17a-production-by-a-distinct-subpopulation-of-effector-memory-t-lymphocytes-constitutes-a-novel-mechanism-of-toxic-shock-syndrome-immunopathology
#14
Peter A Szabo, Ankur Goswami, Delfina M Mazzuca, Kyoungok Kim, David B O'Gorman, David A Hess, Ian D Welch, Howard A Young, Bhagirath Singh, John K McCormick, S M Mansour Haeryfar
Toxic shock syndrome (TSS) is caused by staphylococcal and streptococcal superantigens (SAgs) that provoke a swift hyperinflammatory response typified by a cytokine storm. The precipitous decline in the host's clinical status and the lack of targeted therapies for TSS emphasize the need to identify key players of the storm's initial wave. Using a humanized mouse model of TSS and human cells, we herein demonstrate that SAgs elicit in vitro and in vivo IL-17A responses within hours. SAg-triggered human IL-17A production was characterized by remarkably high mRNA stability for this cytokine...
April 1, 2017: Journal of Immunology: Official Journal of the American Association of Immunologists
https://www.readbyqxmd.com/read/28218671/human-scfvs-that-counteract-bioactivities-of-staphylococcus-aureus-tsst-1
#15
Thunchanok Rukkawattanakul, Nitat Sookrung, Watee Seesuay, Nattawat Onlamoon, Pornphan Diraphat, Wanpen Chaicumpa, Nitaya Indrawattana
Some Staphylococcus aureus isolates produced toxic shock syndrome toxin-1 (TSST-1) which is a pyrogenic toxin superantigen (PTSAg). The toxin activates a large fraction of peripheral blood T lymphocytes causing the cells to proliferate and release massive amounts of pro-inflammatory cytokines leading to a life-threatening multisystem disorder: toxic shock syndrome (TSS). PTSAg-mediated-T cell stimulation circumvents the conventional antigenic peptide presentation to T cell receptor (TCR) by the antigen-presenting cell (APC)...
February 17, 2017: Toxins
https://www.readbyqxmd.com/read/28205241/septic-transfusion-case-caused-by-a-platelet-pool-with-visible-clotting-due-to-contamination-with-staphylococcus-aureus
#16
Maria Loza-Correa, Yuntong Kou, Mariam Taha, Miloslav Kalab, Jennifer Ronholm, Patrick M Schlievert, Michael P Cahill, Robert Skeate, Christine Cserti-Gazdewich, Sandra Ramirez-Arcos
BACKGROUND: Contamination of platelet concentrates (PCs) with Staphylococcus aureus is one of the most significant ongoing transfusion safety risks in developed countries. CASE REPORT: This report describes a transfusion reaction in an elderly patient diagnosed with acute myeloid leukemia, transfused with a 4-day-old buffy coat PC through a central venous catheter. The transfusion was interrupted when a large fibrous clot in the PC obstructed infusion pump flow...
May 2017: Transfusion
https://www.readbyqxmd.com/read/28193526/identification-of-the-blood-coagulation-factor-interacting-sequences-in-staphylococcal-superantigen-like-protein-10
#17
Saotomo Itoh, Takemasa Takii, Kikuo Onozaki, Tsutomu Tsuji, Shigeaki Hida
Staphylococcal superantigen-like proteins (SSLs) are a family of exoproteins of Staphylococcus aureus. We have shown that SSL10 binds to vitamin K-dependent coagulation factors and inhibits blood coagulation induced by recalcification of citrated plasma. SSL10 was revealed to bind to coagulation factors via their γ-carboxyglutamic acid (Gla) domain. In this study we attempted to identify the responsible sequence of SSL10 for the interaction with coagulation factors. We prepared a series of domain swap mutants between SSL10 and its paralog SSL7 that does not interact with coagulation factors, and examined their binding activity to immobilized prothrombin using ELISA-like binding assay...
March 25, 2017: Biochemical and Biophysical Research Communications
https://www.readbyqxmd.com/read/28128856/experimental-arthritis-in-the-rat-induced-by-the-superantigen-staphylococcal-enterotoxin-a
#18
K Gerlach, C Tomuschat, R Finke, M S Staege, C Brütting, J Brandt, B Jordan, R Schwesig, A Rosemeier, K-S Delank, M E Kornhuber, A Emmer
The pathogenesis of rheumatoid arthritis (RA) is incompletely understood. Human endogenous retroviruses (HERVs) and their superantigenic envelope protein (env) have been implicated in the pathogenesis of RA. In the present investigation, the arthritogenic potential of the superantigen staphylococcal enterotoxin A (SEA) has been investigated. In the present investigation, the bacterial superantigen staphylococcal enterotoxin A (SEA) was injected into the right knee joint of 15 Lewis rats. Further nine animals received saline...
March 2017: Scandinavian Journal of Immunology
https://www.readbyqxmd.com/read/28123509/different-roles-of-staphylococcus-aureus-enterotoxin-in-different-subtypes-of-nasal-polyps
#19
Ke-Jia Cheng, Shen-Qing Wang, Ying-Ying Xu
Chronic rhinosinusitis with nasal polyps (CRSwNP) is a multifactorial disease. The pathogenesis of CRSwNP remains unclear. This study was designed to investigate the role of inflammation and Staphylococcus aureus enterotoxin (SE) in this disease. The study included a total of 74 patients with CRSwNP and 6 controls. A serum Phadiatop assay was conducted to detect atopy status, and serum eosinophil cationic protein (ECP) and total immunoglobulin (Ig)E levels were determined using ELISA. SEA, SEB, total IgE, ECP and myeloperoxidase (MPO) levels in nasal tissue supernatant were measured using ELISA...
January 2017: Experimental and Therapeutic Medicine
https://www.readbyqxmd.com/read/28122962/staphylococcus-aureus-downregulates-ip-10-production-and-prevents-th1-cell-recruitment
#20
Zhigang Li, Benoît Levast, Joaquín Madrenas
Staphylococcal superantigens cause toxic shock syndrome, which is characterized by massive T cell activation and a predominant Th1 profile of cytokine production. However, superantigen-producing Staphylococcus aureus strains are often part of the human nasal microbiome, and this carrier state has often been associated with some type 2 immune responses such as chronic sinusitis with polyps and atopic dermatitis. We have previously reported that the S. aureus cell wall downregulates the human T cell response to superantigens through a TLR2-dependent, IL-10-mediated mechanism...
March 1, 2017: Journal of Immunology: Official Journal of the American Association of Immunologists
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