Of 124 staphylococcal strains isolated from sheep milk, 78 produced enterotoxin A, B, C, or D when evaluated by an enzyme-linked immunosorbent assay. Enterotoxins A and D, elaborated by 44 and 43 strains, respectively, showed the highest incidence. Enterotoxin production by coagulase-negative strains (one Staphylococcus cohnii, three S. epidermidis, five S. haemolyticus, and four S. xylosus) wa...

Aeromonas hydrophila secretes several extracellular proteins including enterotoxin, hemolysin and aerolysin that are associated with the bacterial virulence. Previous studies have shown that two hemolytic toxins, hemolysin A and aerolysin A contribute to the virulence of Aeromonas hydrophila. In the current study, a total of 50 strains of Aeromonas hydrophila, including 28 (56%) strains isolate...

Immunologic cross-reactivity between Streptococcus pyogenes type A exotoxin (erythrogenic toxin) and Staphylococcus aureus enterotoxins B and C1 was demonstrated by Ouchterlony double diffusion, Western immunoblot, and immunodot analyses. Specific antiserum to type A streptococcal exotoxin reacted more strongly with staphylococcal enterotoxin B than with enterotoxin C1. The reactivity of type A...

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...

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...

Mouse thymocytes were used to compare mechanisms by which Vibrio cholerae and heat-labile Escherichia coli enterotoxins activate the adenylate cyclase-cyclic adenosine monophosphate (AMP) system. Both enterotoxins had their time-delayed increase in cyclic AMP neutralized by antisera to V. cholerae or E. coli enterotoxin, blocked by low concentrations of ganglioside G(M1), and destroyed by prior...

Out of 321 strains of Bacillus cereus from several sources and isolated in four different countries, 239 (74%) produced cytotoxins. Only 127 (53%) of the cytotoxic strains were positive for the B-component gene of the haemolysin BL (enterotoxin) by polymerase chain reaction (PCR). Western blots using antiserum produced against enterotoxin(s) gave positive results for 199 (83%) of the cytotoxic ...

Clostridium perfringens enterotoxin, when inoculated into the ligated intestinal loop of mice, caused marked distension due to fluid accumulation. The increase in weight of the intestinal loop was proportional to the log dose of enterotoxin within a range from 1 to 16 micrograms. The fluid accumulation was arrested by washing the loop with saline or by injection of the specific anti-enterotoxin...

A sensitive and specific monoclonal antibody-based sandwich enzyme-linked immunosorbent assay (ELISA) was established and validated for the detection of staphylococcal enterotoxin A (SEA). After routine fusion and selection, 10 monoclonal antibodies showed high affinity for SEA. An optimal pair for sandwich ELISA was selected by pairwise interaction analysis. After optimization, the limit of de...

A total of 249 strains of mesophilic Aeromonas including 179 A. hydrophila and 70 A. caviae were tested for production of cholera-like enterotoxin by reversed passive latex agglutination (RPLA) assay. A cholera-like enterotoxin neutralized with cholera antitoxin was demonstrated in the culture filtrates from eight (4.5%) of the 179 A. hydrophila strains, while none of A. caviae strains revealed...