Staphylococcal and Streptococcal Pyrogenic Toxins Involved in Toxic Shock Syndrome and Related Illnesses

Abstract

Toxic-shock syndrome (TSS) is an acute onset, multiorgan illness which resembles severe scarlet fever. The illness is caused by Staphylococcus aureus strains that express TSS toxin-1 (TSST-1), enterotoxin B, or enterotoxin C. TSST-1 is associated with menstrual TSS and approximately one-half of nonmenstrual cases; the other two toxins cause nonmenstrual cases, 47% and 3%, respectively. The three toxins are expressed in culture media under similar environmental conditions. These conditions may explain the association of certain tampons with menstrual TSS. Biochemically, the toxins are all relatively low molecular weight and fairly heat and protease stable. Enterotoxins B and C, share nearly 50% sequence homology with streptococcal scarlet fever toxin A; they share no homology with TSST-1 despite sharing numerous biological properties. Numerous animal models for development of TSS have suggested mechanisms of toxin action, though the exact molecular action is not known. The toxins are all potent pyrogens, induce T lymphocyte proliferation, requiring interleukin 1 release from macrophages, suppress immunoglobulin production, enhance endotoxin shock, and enhance hypersensitivity skin reactions. The genetic control of the toxins has been studied and suggests the exotoxins are variable traits. Some additional properties of TSS S. aureus which facilitate disease causation have been clarified.

Factors enhancing adherence of toxigenicStaphylococcus aureusto epithelial cells and their possible role in sudden infant death syndrome

“…been demonstrated in the renal tubular cells of some SIDS infants but not in a comparison group of infants who were not cot death victims [32]. The pyrogenic toxins of S. aureus and group A streptococci are powerful 'superantigens' that can induce release of cytokines that might trigger a cascade of events leading to shock or damage to the respiratory or cardiac systems [17].…”

“…The pyrogenic toxins are produced between 37-40°C; and they are produced in greater quantities at the higher temperatures [17]. Three factors associated with SIDS might increase the infant's temperature and thereby enhance toxin production: respiratory infection; overwrapping with clothing or bedding; and the prone sleeping position.…”

“…These are 'superantigens' that have significant physiological effects such as induction of fever (> 38°C), possibly by direct action on the hypothalamus or by their induction of tumor necrosis factor (TNF) and interleukin-t by monocytes [17]. S. aureis was isolated from a higher proportion of SIDS infants (41P3 %), compared with a control population (28-3 %) [18].…”

The Staphylococcal Enterotoxins

“…aureus toxin, designated as toxic shock syndrome toxin 1 (TSST-1), was shown to be associated with TSS in menstruating women and in nonmenstrual cases (Dinges etal., 2000). Pyrogenic exotoxins of Strep, pyogenes may also cause TSS (Bohach et al, 1990). These toxins share structural and biological properties with SEs, such as enhancement of endotoxic shock, but only SEs induce vomiting.…”

Comparison of the Prevalence of Genes Coding for Enterotoxins, Exfoliatins, Panton-Valentine Leukocidin and TSST-1 Between Methicillin-Resistant and Methicillin-Susceptible Isolates of Staphylococcus Aureus at the University Hospital in Olomouc

“…The ability of S. aureus to cause various infections and intoxication, results from the production of different extracellular and surface virulence factors with adhesive properties to a range of molecules (MSCRAMMs) 2,3 . The extracellular products include especially toxins with superantigenic properties, namely enterotoxins A-E, G-K, M-O and Q (sea-seq genes), exfoliative toxins A and B (eta, etb), toxic shock syndrome toxin-1 (TSST-1, tst) as well as, for example, Panton-Valentine leukocidin (pvl) [4][5][6][7] .…”