An LT-B-ST (LT-B/ST) fusion peptide was constructed by genetically joining the 5' terminus of a synthetic gene coding for the heat-stable enterotoxin (ST) of Escherichia coli to the 3' terminus of the gene coding for the binding subunit of the heat-labile enterotoxin (LT-B) of E. coli. An eight-amino-acid, proline-containing linker was included between the LT-B and ST moieties. An aroA mutant o...

In contrast to Bacillus subtilis, the role of the two-component regulatory system ResDE has not yet been investigated in the facultative anaerobe Bacillus cereus. We examined the role of ResDE in the food-borne pathogen B. cereus F4430/73 by constructing resDE and resE mutants. Growth performances, glucose metabolism, and expression of hemolysin BL (Hbl) and nonhemolytic enterotoxin (Nhe) were ...

BACKGROUND About 20 different types of staphylococcal enterotoxins are produced by Staphylococcus aureus, in which type A is more common in food poisoning syndrome. Also staphylococcal enterotoxin A superantigen is a potent inducer of cytotoxic T lymphocyte activity and cytokine production and could stimulate T cells containing T-cell receptor beta chain domains when binding to major histocompa...

The biosynthesis of enterotoxin A by replicating and nonreplicating cells was investigated. Unlike enterotoxin B, a secondary metabolite, enterotoxin A secretion resembled that of a primary metabolite by being secreted during the exponential phase of growth. The amount of toxin produced per unit of growth was not influenced by NaCl, NaNO(2), or NaNO(3). Several surfactants increased toxin secre...

background rheumatoid arthritis (ra) is the most common chronic inflammatory disease of unknown etiology. in this regard, the role of bacterial superantigens (as an effective agent) were considered. objectives this study aimed to assess staphylococcal enterotoxin e in the blood of patients with rheumatoid arthritis. patients and methods a total of 83 blood samples of patients with ra were studi...

OBJECTIVES To investigate the prevalence and toxin production characteristics of non-emetic and emetic Bacillus cereus strains isolated via the laboratory surveillance system in Korea. METHODS A total of 667 B. cereus strains were collected by the Korea National Research Institute of Health laboratory surveillance system from 2012 to 2014. The collected strains were analyzed by geographical r...

Nine strains belonging to Bacillus cereus group has been isolated from food and environmental samples. Their taxonomic position was confirmed by RFLP analysis of 16S rRNA gene digested with TaqI. The detection of DNA sequences encoding the hemolysin BL complex and enterotoxin NHE, was studied in Bacillus sp. isolates. Set of primers was used to amplify fragment of hblD gene by PCR. For the dete...

Staphylococcus(S.) aureus produces different extra-cellular protein toxins and virulence factors. One of the most important extra-cellular proteins is an enterotoxin which causes staphylococcal food poisoning (SFP) due to their enterotoxins. Different methods have been used to detect this toxin, each of which has advantages and disadvantages. DNA amplification methods, however, can show the pre...

Previous studies indicated that enterotoxin B production by staphylococci was strongly inhibited by slight reductions in water activity (a(w)) levels. Similar studies reported herein, employing an enterotoxin A-producing strain, indicated that this organism was capable of producing enterotoxin at a much lower a(w) level than that required for enterotoxin B production. Staphylococcal growth rate...