title: Identification and characterization of two novel staphylococcal enterotoxins, types S and T.
abstract: In addition to two known staphylococcal enterotoxin-like genes (selj and selr), two novel genes coding for two superantigens, staphylococcal enterotoxins S and T (SES and SET), were identified in plasmid pF5, which is harbored by food poisoning-related Staphylococcus aureus strain Fukuoka 5. This strain was implicated in a food poisoning incident in Fukuoka City, Japan, in 1997. Recombinant SES (rSES) specifically stimulated human T cells in a T-cell receptor Vbeta9- and Vbeta16-specific manner in the presence of major histocompatibility complex (MHC) class II(+) antigen-presenting cells (APC). rSET also stimulated T cells in the presence of MHC class II(+) APC, although its Vbeta skewing was not found in reactive T cells. Subsequently, we examined the emetic activity of SES and SET. We also studied SElR to determine emetic activity in primates. This toxin was identified in previous studies but was not examined in terms of possession of emetic activity for primates. rSES induced emetic reactions in two of four monkeys at a dose of 100 microg/kg within 5 h of intragastric administration. In one monkey, rSET induced a delayed reaction (24 h postadministration) at a dose of 100 microg/kg, and in the other one, the reaction occurred 5 days postadministration. rSElR induced a reaction in two of six animals within 5 h at 100 microg/kg. On this basis, we speculate that the causative toxins of vomiting in the Fukuoka case are SES and SER. Additionally, SES, SER, and SET also induced emesis in house musk shrews as in the monkeys.
authors: Department of Veterinary Medicine, Faculty of Agriculture, Iwate University, Ueda 3-18-8, Morioka, Iwate 020-8550, Japan.
authors: Hisaya K
authors: HK
authors: Ono
authors: Katsuhiko
authors: K
authors: Omoe
authors: Ken'ichi
authors: K
authors: Imanishi
authors: Yoshihiro
authors: Y
authors: Iwakabe
authors: Dong-Liang
authors: DL
authors: Hu
authors: Hidehito
authors: H
authors: Kato
authors: Naoyuki
authors: N
authors: Saito
authors: Akio
authors: A
authors: Nakane
authors: Takehiko
authors: T
authors: Uchiyama
authors: Kunihiro
authors: K
authors: Shinagawa
mesh_terms: D000818:Animals; D001483:Base Sequence; D004768:Enterotoxins / Q000235:genetics*; D000949:Histocompatibility Antigens Class II; D006801:Humans; D008213:Lymphocyte Activation / Q000276:immunology; D008252:Macaca fascicularis; D008969:Molecular Sequence Data; D010802:Phylogeny; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012788:Shrews; D013202:Staphylococcal Food Poisoning / Q000276:immunology* / Q000382:microbiology; D013211:Staphylococcus aureus / Q000235:genetics* / Q000276:immunology*; D018089:Superantigens / Q000235:genetics*; D013601:T-Lymphocytes / Q000276:immunology / Q000382:microbiology
chemical_list: D004768:Enterotoxins; D000949:Histocompatibility Antigens Class II; D018089:Superantigens