Sequence Variability in Staphylococcal Enterotoxin Genes seb, sec, and sed.
Ingestion of staphylococcal enterotoxins preformed by Staphylococcus aureus in food leads to staphylococcal food poisoning, the most prevalent foodborne intoxication worldwide. There are five major staphylococcal enterotoxins: SEA, SEB, SEC, SED, and SEE. While variants of these toxins have been described and were linked to specific hosts or levels or enterotoxin production, data on sequence variation is still limited. In this study, we aim to extend the knowledge on promoter and gene variants of the major enterotoxins SEB, SEC, and SED. To this end, we determined seb, sec, and sed promoter and gene sequences of a well-characterized set of enterotoxigenic Staphylococcus aureus strains originating from foodborne outbreaks, human infections, human nasal colonization, rabbits, and cattle. New nucleotide sequence variants were detected for all three enterotoxins and a novel amino acid sequence variant of SED was detected in a strain associated with human nasal colonization. While the seb promoter and gene sequences exhibited a high degree of variability, the sec and sed promoter and gene were more conserved. Interestingly, a truncated variant of sed was detected in all tested sed harboring rabbit strains. The generated data represents a further step towards improved understanding of strain-specific differences in enterotoxin expression and host-specific variation in enterotoxin sequences.
['Johler|Sophia|S|', 'Sihto|Henna-Maria|HM|', 'Macori|Guerrino|G|', 'Stephan|Roger|R|']
D000595:Amino Acid Sequence D000818:Animals D001427:Bacterial Toxins D001483:Base Sequence D002417:Cattle D004269:DNA, Bacterial D004768:Enterotoxins D005798:Genes, Bacterial D006801:Humans D009297:Nasal Mucosa D011401:Promoter Regions, Genetic D011817:Rabbits D013211:Staphylococcus aureus
enterotoxin seb sec sed Staphylococcus aureus sequence variation promoter