Pyrogenic Responses to Staphylococcal Enterotoxins A and B in Cats

Abstract

Pyrogenic responses, ranging up to 4.8 F, were induced in cats by oral administration of highly purified staphylococcal enterotoxin B in doses from 10 to 100 jig/kg. Fever was a more sensitive indicator of intoxication than was emesis. Highly purified preparations of enterotoxin A, whether administered intravenously (0.01 to 1.0 jAg/kg), orally (10 to 25 jig/kg), or into the cerebral ventricles (0.005 to 0.020 ,g in 0.20 ml), were also pyrogenic in cats. Tolerance to the pyrogenic activity was produced by repeated intravenous injection of a given dose of enterotoxin A but not by repeated intracerebroventricular injection. Enterotoxin A was more potent than enterotoxin B after intravenous injection in causing both fever and emesis. Crosstolerance could not be demonstrated between enterotoxin A and enterotoxin B or Salmonella typhosa endotoxin. This lack of cross-tolerance plus the inability of large oral doses (100 to 4,700 pg/kg) of endotoxin to cause fever or emesis indicate that the reported responses were attributable to the specific toxins administered and not to contamination by other pyrogens.

Staphylococcal enterotoxin A-induced fever is associated with increased circulating levels of cytokines in rabbits

“…In addition, intravenous (i.v.) injection of very small doses of SEA or SEB into rabbits, cats, and monkeys produces lethargy, fever, shock, and death (6,9,16,23,31,32). It has been postulated that SEB may exert its toxicity by damaging the capillary endothelium in the large intestine and thereby permitting absorption of bacterial lipopolysaccharide (LPS) into the circulation (41).…”

Pyrogenic Specificity of Streptococcal Exotoxins, Staphylococcal Enterotoxin, and Gram-Negative Endotoxin

“…Preliminary work indicates that a fourth SPE may also be distinguished by this method (17). Specificity has been observed for at least two different types of SET when injected into cats (3). With SET-A, a depressed pyrogenic response was obtained after repeated administration by the intravenous but not by the intraventricular (cerebral) route.…”

“…For SET-A, amounts of' 1.0 ,tg/kg administered intravenously to the rabbit produce fever consistently. Smaller doses are effective in cats, and the measure of pyrogenicity has been suggested as a more sensitive alternative to the emetic dose response in such animals (3). The MPD-3 for endotoxins is generally about I to 10 ng (9); this compares favorably with amounts needed for complete coagulation in the limulus lysate test (4).…”

Bindings of Toxic Shock Syndrome Toxin‐1 and Staphylococcal Enterotoxins A, B, and C to Rabbit Spleen Cells

“…Some investigators reported that staphylococcal enterotoxins (SE) might be also responsible for TSS (7), especially for non-menstrual TSS (8,22). TSST-1 and SE share some biological properties including pyrogenicity (2,6,10,23), the capacity to enhance host susceptibility to lethal endotoxin shock (10,23,24) and further immunological aspects such as mitogenic effect on lymphocytes (4,13,17,18,29) and stimulation of interleukin (IL) 1 production (11). We have already confirmed that TSST-1 induces proliferative response and IL 2 production by T cells of murine lymphocytes (27) and human peripheral blood mononuclear cells (28).…”