State Key Laboratory of Agrobiotechnology, and Ministry of Agriculture, College of Veterinary Medicine, China Agricultural University, Beijing, China.
PLoS One. 2011;6(7):e23145. doi: 10.1371/journal.pone.0023145. Epub 2011 Jul 29.
Staphylococcus sciuri (S. sciuri) is a rare pathogen in humans, but it can cause a wide array of human infections. Recently a S. sciuri isolate (HBXX06) was reported to cause fatal exudative epidermitis (EE) in piglets and thus considered as a potential zoonotic agent. To investigate the pathogenicity of this bacterium, we cloned exfoliative toxin C (ExhC), a major toxin of the S. sciuri isolate and performed functional analysis of the recombinant ExhC-his (rExhC) protein using in vitro cell cultures and newborn mice as models. We found that rExhC could induce necrosis in multiple cell lines and peritoneal macrophages as well as skin lesions in newborn mice, and that the rExhC-induced necrosis in cells or skin lesions in newborn mice could be completely abolished if amino acids 79-128 of rExhC were deleted or blocked with a monoclonal antibody (3E4), indicating aa 79-128 portion as an essential necrosis-inducing domain. This information contributes to further understandings of the mechanisms underlying S. sciuri infection.
松鼠葡萄球菌（S. sciuri）是人畜共患的罕见病原体，可引起多种人类感染。最近有报道称松鼠葡萄球菌分离株（HBXX06）可引起仔猪致命性渗出性皮炎（EE），因此被认为是一种潜在的人畜共患病原体。为了研究该细菌的致病性，我们克隆了其脱落毒素 C（ExhC），并使用体外细胞培养和新生小鼠模型对重组 ExhC-his（rExhC）蛋白进行了功能分析。结果发现，rExhC 可诱导多种细胞系和腹腔巨噬细胞坏死，并可诱导新生小鼠皮肤损伤，若缺失 rExhC 的 79-128 位氨基酸或用单克隆抗体（3E4）封闭该区域，rExhC 诱导的细胞或新生小鼠皮肤损伤可完全被阻断，表明 aa 79-128 位氨基酸是诱导坏死的必需结构域。该研究结果有助于进一步阐明松鼠葡萄球菌感染的机制。
