results in total, 80 food samples suspected of seb contamination were assessed using the two methods. fifty-four samples were contaminated based on the pcr technique and twenty-six of those were confirmed using the strip assay. conclusions the sensitivity of the sandwich method was approximately 10 ng/ml and that of the competitive method was approximately 250 ng/ml. in the lfd, a highly specif...

Bacteroides fragilis constitutes about 1% of the bacterial flora in intestines of normal humans. Enterotoxigenic strains of B. fragilis have been associated with diarrheal diseases in humans and animals. The enterotoxin produced by these isolates induces fluid changes in ligated intestinal loops and an in vitro cytotoxic response in HT-29 cells. We developed a nested PCR to detect the enterotox...

OBJECTIVES To investigate the potential use of DNA techniques in epidemiological diagnosis of Bacillus cereus food poisoning. SUBJECTS Fifty six B. cereus isolates from milk were studied. DESIGN The 56 B. cereus isolates were characterised into enterotoxin positive (27 isolates) and enterotoxin negative (29 isolates) using reverse passive latex agglutination technique. SETTING Plasmid and...

The genes encoding for beta-lactamase (bla+) and resistance to metallic ions (cadmium, mercury, lead, arsenate, and arsenite) were located in a 56.2-kilobase plasmid, pZA10, isolated from a clinical strain, Staphylococcus aureus 6344. This strain produced enterotoxin B and enterotoxin C1. Elimination of pZA10 by either sodium dodecyl sulfate or heat treatment (43 degrees C) resulted in the loss...

AIMS   The aim of this study was to determine whether endophytic Bacillus cereus isolates from agronomic crops possessed genes for the nonhaemolytic enterotoxin (Nhe) and haemolysin BL (HBL) and, therefore, have the potential to cause diarrhoeal illness in humans. METHODS AND RESULTS   PCR followed by sequencing confirmed the presence of enterotoxin genes nheA, nheB, nheC, hblA, hblC, hblD in...

The epidemiological and bacteriological investigations on four foodborne outbreaks caused by a new type of enterotoxin-producing Clostridium perfringens are described. C. perfringens isolated from patients of these outbreaks did not produce any known enterotoxin and did not carry the C. perfringens enterotoxin gene. However, the culture filtrates of these isolates induced the accumulation of fl...

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...

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...

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...

Potentiometric and spectrophotometric titrations of staphylococcal enterotoxin B have been carried out in 0.16 M KC1 at 25”. Potentiometric titration results indicate that the titration curves are essentially reversible between pH 1.50 and 11.0. All of the ionizable groups in enterotoxin B found from the titration curves are consistent with the amino acid composition which has been reported in ...