Zhang S, Iandolo J J, Stewart G C
Department of Diagnostic Medicine/Pathobiology, College of Veterinary Medicine, Kansas State University, Manhattan 66506, USA.
FEMS Microbiol Lett. 1998 Nov 15;168(2):227-33. doi: 10.1111/j.1574-6968.1998.tb13278.x.
Staphylococcus aureus enterotoxin D is one of the serotypes most commonly associated with food poisoning. Further characterization of the enterotoxin D-encoding plasmid revealed the presence of an open reading frame which encodes a previously unidentified enterotoxin, designated staphylococcal enterotoxin J (SEJ). SEJ is a protein of 269 amino acid residues which has substantial sequence similarity to the staphylococcal A, E, D family of enterotoxins. The enterotoxin D and J open reading frames are transcribed in opposite directions and are separated by an 895 nucleotide intergenic region which contains a perfect inverted repeat, with each arm of the repeat having a length of 21 nucleotides. Chloramphenicol acetyl transferase (cat) transcriptional fusions were used to quantify expression from the enterotoxin gene promoters. Both enterotoxin genes are expressed in S. aureus. However, only sed is regulated by the agr virulence gene signal transduction pathway. Western blot analyses utilizing anti-enterotoxin antisera have confirmed the results obtained with the cat reporter system. PCR amplification studies suggest that the sej determinant may be present on all sed-encoding plasmids.
金黄色葡萄球菌肠毒素D是最常与食物中毒相关的血清型之一。对编码肠毒素D的质粒进行进一步鉴定发现，存在一个开放阅读框，该阅读框编码一种以前未鉴定的肠毒素，命名为葡萄球菌肠毒素J（SEJ）。SEJ是一种由269个氨基酸残基组成的蛋白质，与葡萄球菌A、E、D家族的肠毒素具有显著的序列相似性。肠毒素D和J的开放阅读框以相反方向转录，并由一个895个核苷酸的基因间区域隔开，该区域包含一个完美的反向重复序列，重复序列的每个臂长度为21个核苷酸。氯霉素乙酰转移酶（cat）转录融合用于定量肠毒素基因启动子的表达。两种肠毒素基因均在金黄色葡萄球菌中表达。然而，只有sed受agr毒力基因信号转导途径调控。利用抗肠毒素抗血清进行的蛋白质印迹分析证实了用cat报告系统获得的结果。PCR扩增研究表明，sej决定簇可能存在于所有编码sed的质粒上。
