title: Toxic shock syndrome toxin 1-producing Staphylococcus aureus isolates contain the staphylococcal enterotoxin B genetic element but do not express staphylococcal enterotoxin B.
abstract: Toxic shock syndrome toxin 1 (TSST-1) and staphylococcal enterotoxin B (SEB) are two examples of variable genetic traits produced by Staphylococcus aureus. Regarding phenotypes, most investigations have reported that SEB and TSST-1 are not coproduced in S. aureus. However, it is unclear whether genotypically SEB (entB) and TSST-1 (tst) genes are found within the same isolate. Gene probes specific for entB and tst showed that both genes were present within 8 TSST-1+ isolates analyzed. However, SEB was not produced by any of these isolates. In contrast, none of 9 SEB-producing S. aureus isolates contained the TSST-1 genetic element DNA. Hybridization of restriction fragments with TSST-1 and SEB genetic element probes and tryptophan auxotyping suggested that tst and entB are located in close proximity on the chromosome. The entB locus may be a preferred site of insertion for the TSST-1 genetic element, and such insertion may interfere with the expression of SEB.
authors.affiliation: Department of Medicine, University of British Columbia, Vancouver, Canada.
authors.forename: M L
authors.initials: ML
authors.lastname: De Boer
authors.forename: A W
authors.initials: AW
authors.lastname: Chow
mesh_terms: D001427:Bacterial Toxins; D015139:Blotting, Southern; D002876:Chromosomes, Bacterial; D004269:DNA, Bacterial / Q000032:analysis; D004768:Enterotoxins / Q000096:biosynthesis*; D015870:Gene Expression; D006801:Humans; D010957:Plasmids; D016133:Polymerase Chain Reaction; D015183:Restriction Mapping; D012772:Shock, Septic / Q000382:microbiology; D013203:Staphylococcal Infections / Q000382:microbiology; D013211:Staphylococcus aureus / Q000235:genetics / Q000302:isolation & purification* / Q000502:physiology*; D018089:Superantigens
chemical_list: D001427:Bacterial Toxins; D004269:DNA, Bacterial; D004768:Enterotoxins; D018089:Superantigens; C030107:enterotoxin F, Staphylococcal; C031818:enterotoxin B, staphylococcal