OBJECTIVE To evaluate enterotoxin production, enterotoxin gene distribution, and genetic diversity of Staphylococcus aureus in milk obtained from cows with subclinical mastitis. SAMPLE Milk samples obtained from 350 cows (1,354 mammary glands) on 11 Wisconsin dairy farms. PROCEDURES Of 252 S aureus isolates obtained from 146 cows, 83 isolates (from 66 cows with subclinical mastitis) were co...

the aim of this study was to determine the frequency of enterotoxigenic and enteroaggregative strains ofescherichia coli in chicken carcasses by polymerase chain reaction (pcr). in this study 63 strains of e. coliwere isolated from 110 samples of chicken carcasses during processing after chilling in the poultry slaughterhouse of shahrekord. polymerase chain reaction assays were used to detect t...

We purified and sequenced the heat-stable enterotoxin produced by Citrobacter freundii. The toxin was detected during purification by reaction with monoclonal antibody to Escherichia coli heat-stable enterotoxin. The C. freundii toxin amino acid sequence was identical to that of the 18-amino-acid heat-stable enterotoxin (STa) produced by toxigenic E. coli.

Conditions for detection and quantitation of Clostridium perfringens enterotoxin by counterimmunoelectrophoresis are described. As little as 0.2 microgram of enterotoxin per ml could be detected. The test was found to be rapid, sensitive, specific and easy for the detection and quantitation of enterotoxin.

The effect of pH on the thermal inactivation of staphylococcal enterotoxin A was investigated. Analysis of heated toxin by immunodiffusion in gel indicated that enterotoxin A in beef bouillon was inactivated faster at pH 5.3 than at pH 6.2. The z values (slopes) for the heat inactivation curves at pH 6.2 and 5.3 were 49.5 and 55 F (about 27 and 30 C), respectively. Enterotoxin produced and heat...

Heat-labile enterotoxin preparations obtained from two enteropathogenic strains of Escherichia coli of porcine and human origin were shown to stimulate adenylate cyclase activity of human embryonic intestinal epithelial cells in culture. Comparable results were also obtained when cholera toxin was used. The degree of enzyme stimulation was proportional to the concentration of enterotoxin. Simil...

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 aim of this study was to determine the frequency of enterotoxigenic and enteroaggregative strains ofEscherichia coli in chicken carcasses by polymerase chain reaction (PCR). In this study 63 strains of E. coliwere isolated from 110 samples of chicken carcasses during processing after chilling in the poultry slaughterhouse of Shahrekord. Polymerase chain reaction assays were used to detect t...

Up to approximately 50 mug of staphylococcal enterotoxin A per plate was produced by cellophane-over-agar cultures. Enterotoxin was determined by a latex agglutination technique.