Complete Genome Sequence of Exfoliative Toxin-Producing Staphylococcus aureus Strain MSSA_SSSS_01, Obtained from a Case of Staphylococcal Scalded-Skin Syndrome.
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ABSTRACT:
SUBMITTER: Cella E
PROVIDER: S-EPMC7883837 | biostudies-literature | 2021 Feb
REPOSITORIES: biostudies-literature
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Complete Genome Sequence of Exfoliative Toxin-Producing Staphylococcus aureus Strain MSSA_SSSS_01, Obtained from a Case of Staphylococcal Scalded-Skin Syndrome.
Cella Eleonora E David Michael Z MZ Jubair Mohammad M Baines Sarah L SL Pegues David A DA Azarian Taj T
Microbiology resource announcements 20210211 6
Here, we announce the complete genome sequence of an exfoliative toxin-producing strain of <i>Staphylococcus aureus</i> sequence type 582 (ST582), isolated from a case of staphylococcal scalded-skin syndrome. The genome consists of a single circularized unitig with a total length of 2,792,190 bp carrying 2,699 genes. The genome is the basis for future epidemiological and genomic studies. ...[more]
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Project description:Staphylococcus aureus is a human and animal pathogen as well as a commensal bacterium. It can be a causative agent of severe, life-threatening infections with high mortality, e.g., toxic shock syndrome, septic shock, and multi-organ failure. S. aureus strains secrete a number of toxins. Exotoxins/enterotoxins are considered important in the pathogenesis of the above-mentioned conditions. Exotoxins, e.g., superantigen toxins, cause uncontrolled and polyclonal T cell activation and unregulated activation of inflammatory cytokines. Here we show the importance of genomic analysis of infectious strains in order to identify disease-causing exotoxins. Further, we show through functional analysis of superantigenic properties of staphylococcal exotoxins that even very small amounts of a putative superantigenic contaminant can have a significant mitogenic effect. The results show expression and production of two distinct staphylococcal exotoxins, SEC and SEL, in several strains from clinical isolates. Antibodies against both toxins are required to neutralise the superantigenic activity of staphylococcal supernatants and purified staphylococcal toxins.
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| S-EPMC8895341 | biostudies-literature
Project description:Staphylococcal scalded-skin syndrome is an exfoliative dermatitis characterized by the separation of the epidermis at the stratum granulosum. This disruption is mediated by one of two Staphylococcus aureus exotoxins, exfoliative toxins A and B (ETA and ETB). Both ETA and ETB have been reported to be bacterial superantigens. A controversy exists, however, as other data indicate that these exotoxins are not superantigens. Here we demonstrate that recombinant exfoliative toxins produced in Escherichia coli do not act as T-cell mitogens and thus are not bacterial superantigens. These data fit the clinical profile of the disease, which is not associated with the classic symptoms of a superantigen-mediated syndrome.
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Project description:BackgroundPatients with atopic dermatitis (AD) with a history of eczema herpeticum have increased staphylococcal colonization and infections. However, whether Staphylococcus aureus alters the outcome of skin viral infection has not been determined.ObjectiveWe investigated whether S aureus toxins modulated host response to herpes simplex virus (HSV) 1 and vaccinia virus (VV) infections in normal human keratinocytes (NHKs) and in murine infection models.MethodsNHKs were treated with S aureus toxins before incubation of viruses. BALB/c mice were inoculated with S aureus 2 days before VV scarification. Viral loads of HSV-1 and VV were evaluated by using real-time PCR, a viral plaque-forming assay, and immunofluorescence staining. Small interfering RNA duplexes were used to knockdown the gene expression of the cellular receptor of ?-toxin, a disintegrin and metalloprotease 10 (ADAM10). ADAM10 protein and ?-toxin heptamers were detected by using Western blot assays.ResultsWe demonstrate that sublytic staphylococcal ?-toxin increases viral loads of HSV-1 and VV in NHKs. Furthermore, we demonstrate in vivo that the VV load is significantly greater (P < .05) in murine skin inoculated with an ?-toxin-producing S aureus strain compared with murine skin inoculated with the isogenic ?-toxin-deleted strain. The viral enhancing effect of ?-toxin is mediated by ADAM10 and is associated with its pore-forming property. Moreover, we demonstrate that ?-toxin promotes viral entry in NHKs.ConclusionThe current study introduces the novel concept that staphylococcal ?-toxin promotes viral skin infection and provides a mechanism by which S aureus infection might predispose the host toward disseminated viral infections.
| S-EPMC3594992 | biostudies-literature