1.C.128.  The  Staphylococcus Pyogenic Enterotoxin (SPE) Family

Staphylococcal enterotoxin-like W (SElW) is a widely prevalent enterotoxin-like protein that functions as a classical staphylococcal superantigen (SAg) and has been shown to exacerbate infections caused by the S. aureus epidemic clone CC398.  Enterotoxin-producing Staphylococcus aureus is a common cause of staphylococcal food poisoning (al Bustan et al. 1996).  The presence of genes encoding staphylococcal enterotoxins (SEs), including the classical enterotoxins (sea-see), non-classical enterotoxins (seg-seu), exfoliative toxins (eta-etd) and toxic shock syndrome toxin-1 (tst-1) have been investigated (Wiśniewski et al. 2023). Enterotoxin F may play a role in toxic shock syndrome.(Notermans et al. 1983). Only 5 (SEA to SEE) out of 27 known staphylococcal enterotoxins can be analyzed using commercially available kits. Six genes (seg, sei, sem, sen, seo, and seu), encoding putative and undetectable enterotoxins, are located on the enterotoxin gene cluster (egc), which is part of the Staphylococcus aureus genomic island vSaβ. These enterotoxins are likely involved in staphylococcal food-poisoning outbreaks (Schwendimann et al. 2021).  Staphylococcal enterotoxins promote virulence in bacterial keratitis (Johnson et al. 2023).  A comprehensive review of toxin diversity, molecular mechanisms, and clinical implications has appeared. This review examines the pathogenic mechanisms of Staphylococcus aureus, emphasizing its toxin-driven virulence factors, including pore-forming toxins, exfoliative toxins, and superantigens. (Di Bella et al. 2025).


 

References:

al Bustan, M.A., E.E. Udo, and T.D. Chugh. (1996). Nasal carriage of enterotoxin-producing Staphylococcus aureus among restaurant workers in Kuwait City. Epidemiol Infect 116: 319-322.

Di Bella, S., B. Marini, G. Stroffolini, N. Geremia, D.R. Giacobbe, F. Campanile, M. Bartoletti, G. Alloisio, L. Di Risio, G. Viglietti, L. Principe, V. Costantino, M. Busetti, V. Zerbato, F. Mearelli, G. Biolo, A. Nunnari, C.M. Cafiero, and A. di Masi. (2025). The virulence toolkit of Staphylococcus aureus: a comprehensive review of toxin diversity, molecular mechanisms, and clinical implications. Eur J Clin Microbiol Infect Dis 44: 1797-1816.

Johnson, W.L., M. Sohn, C.F. Woeller, and R.A.F. Wozniak. (2023). Staphylococcal Enterotoxins Promote Virulence in Bacterial Keratitis. Invest Ophthalmol Vis Sci 64: 5.

Notermans, S., W.J. van Leeuwen, J. Dufrenne, and P.D. Tips. (1983). Serum antibodies to enterotoxins produced by Staphylococcus aureus with special reference to enterotoxin F and toxic shock syndrome. J Clin Microbiol 18: 1055-1060.

Schwendimann, L., D. Merda, T. Berger, S. Denayer, C. Feraudet-Tarisse, A.J. Kläui, S. Messio, M.Y. Mistou, Y. Nia, J.A. Hennekinne, and H.U. Graber. (2021). Staphylococcal Enterotoxin Gene Cluster: Prediction of Enterotoxin (SEG and SEI) Production and of the Source of Food Poisoning on the Basis of Saβ Typing. Appl. Environ. Microbiol. 87: e0266220.

Wiśniewski, P., J. Gajewska, A. Zadernowska, and W. Chajęcka-Wierzchowska. (2023). Identification of the Enterotoxigenic Potential of spp. from Raw Milk and Raw Milk Cheeses. Toxins (Basel) 16:.

Examples:

TC#NameOrganismal TypeExample
1.C.128.1.1

Enterotoxin type S of 257 aas and 1 N-terminal TMS.

Enterotoxin type S of Staphylococcus aureus

 
1.C.128.1.2

Enterotoxin OB of 258 aas and 1 N-terminal TMS.

Enterotoxin OB of Staphylococcus pseudintermedius

 
1.C.128.1.3

Exotoxin beta-grasp domain-containing protein of 275 aas and 1 N-terminal TMS of Staphylococcus aureus.

Exotoxin β-grasp of Staphylococcus aureus.

 
1.C.128.1.4

Staphylococcal enterotoxin type K of 246 aas and 1 N-terminal TMS.

Enterotoxin K of Staphylococcus aureus