While investigating the virulence traits of Staphylococcus aureus adhering to the skin of atopic-dermatitis (AD) patients, we identified a novel open reading frame (ORF) with structural similarity to a superantigen from genome sequence data of an isolate from AD skin. Concurrently, the same ORF was identified in a bovine isolate of S. aureus and designated SElY (H. K. Ono, Y. Sato’o, K. Narita, I. Naito, et al., Appl Environ Microbiol 81:7034–7040, 2015, https://doi.org/10.1128/AEM.01873-15). Recombinant SElYbov had superantigen activity in human peripheral blood mononuclear cells. It further demonstrated emetic activity in a primate animal model, and it was proposed that SElY be renamed SEY (H. K. Ono, S. Hirose, K. Narita, M. Sugiyama, et al., PLoS Pathog 15:e1007803, 2019, https://doi.org/10.1371/journal.ppat.1007803). Here, we investigated the prevalence of the sey gene in 270 human clinical isolates of various origins in Japan. Forty-two strains were positive for the sey gene, and the positive isolates were from patients with the skin diseases atopic dermatitis and impetigo/staphylococcal scalded skin syndrome (SSSS), with a detection rate of ∼17 to 22%. There were three variants of SEY (SEY1, SEY2, and SEY3), and isolates producing SEY variants formed three distinct clusters corresponding to clonal complexes (CCs) 121, 59, and 20, respectively. Most sey+ isolates produced SEY in broth culture. Unlike SEYbov, the three recombinant SEY variants exhibited stability against heat treatment. SEY predominantly activated human T cells with a particular T-cell receptor (TCR) Vα profile, a unique observation since most staphylococcal enterotoxins exert their superantigenic activities through activating T cells with specific TCR Vβ profiles. SEY may act to induce localized inflammation via skin-resident T-cell activation, facilitating the pathogenesis of S. aureus infection in disrupted epithelial barriers.

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Atopic dermatitis (AD) is an itchy, chronic form of eczema with multiple pathogenic factors, including skin barrier dysfunction and immune response dysregulation. Type 2 inflammation, characterized by the accumulation of Th2 cells, ILC2, and type 2 cytokines (interleukin (IL)-4, IL-5, and IL-13), plays a crucial role in the pathophysiology of AD, although other cytokines derived from Th1, Th17 and Th22 are also involved in the formation of AD skin lesions. 1,2 Skin barrier dysfunction is also linked to inflammation of the skin and vice versa. Skin barrier dysfunction enhances transepidermal allergen exposure and triggers type 2 inflammation. The type 2 cytokines IL-4, IL-13, IL-31, and IL-22, which are produced by Th22, decrease the production of filaggrin (FLG), loricrin, and involucrin in epidermal keratinocytes, resulting in skin barrier dysfunction.

Penentuan jenis kelamin pada beberapa spesies burung cukup sulit dilakukan dikarenakan jantan dan betina memiliki ciri morfologi yang sama (monomorfik), salah satunya famili Columbidae. Teknik penentuan jenis kelamin burung secara molekuler yang populer adalah metode Polymerase Chain Reaction (PCR) dengan gen target Chromo Helicase DNA-binding (CHD), namun keberhasilan amplifikasi gen target pada PCR tersebut dipengaruhi salah satunya kesesuaian DNA template dengan primer yang digunakan. Penelitian ini bertujuan untuk mengevaluasi 5 jenis primer PCR P2/P8, 2550F/2718R, CHD1F/CHD1R, 1237L/1272H dan CHD1LF/CHD1LR untuk menentukan jenis kelamin famili Columbidae. Penelitian ini dilakukan dengan menguji 5 jenis primer tersebut di atas pada sampel DNA tiap pasang jantan dan betina dari burung merpati, balam jambi, punai, derkuku, dan perkutut. Hasil penelitian diketahui primer CHD1LF/CHD1LR menunjukkan hasil terbaik dan direkomendasikan untuk menentukan jenis kelamin famili Columbidae.