Clinical aspects of staphylococcal and streptococcal toxinic diseases

Staphylococcus aureus and Streptococcus pyogenes produce a lot of toxins, s ome of them responsible for specific diseases. Staphylococcal food poisonni ng is due to ingestion of enterotoxin containing food. Seven toxins have be en isolated so far. Generalized exfoliative syndrome is related to exfo-lia tin. Young children are particulary affected. The disease consists in a cut aneous exfoliation usually limited with a favourable outcome. The mucus mem branes are not involved. The nose or pharynx are the most usual portal of e ntry. Staphylococcus aureus is not grown from the bullae. Severe extensive forms have been observed particulary in neonates (Ritter's disease). Bullou s impetigo is also due to exfoliatin. It consists in the presence of a rest ricted number of cloudy bullae, from wich staphylococcus can be grown. It i s a mild disease with a favourable outcome within a few days. Scarlet fever is related to the streptococcal erythrogenic toxins. The classic form of t he disease is presently rare. This disease may be related to staphylococcus as a complication of arthritis, osteomyelitis or wound superinfection. Bac teremia is usual. Staphylococcal scarlet fever is not related to exfoliatin as previously believed, but to enterotoxins or TSST-1, so it seems to be a n abortive form of toxic shook syndrome. Toxic shock syndrome is defined as a multi organ failure syndrome with a rapid onset, fever, rash followed by desquamation, vomiting and diarrhea, hypotension, conjunctivitis and straw berry tongue. The disease is related to an infection or colonisation with a toxin (TSST-1) producing strain of Staphylococus aureus. Enterotoxins (mai nly C) may be involved. The disease may occur in childhood, sometimes after superinfection of varicella. The mortality is low (5%) and mainly due to A RDS or cardiac problems. Erythrogenic toxins produced by Streptococcus pyog enes are involved in a streptococcal form of toxic shock syndrome with a qu ite similar presentation. In most cases however, a cutaneous or soft tissue infection is at the origin. Necrotizing fasciitis complicating varicella i s a classic cause in children. Bacteremia is often observed. The mortality, rate is as high as 60%. The streptococcal strains involved in north americ a use to produce the toxin erythrogenic A, the european cases seem to be mo re related to strains secreting the B toxin with a dysregulation of the mec anisms wich control the secretion of the toxin. Staphylococcus strains prod ucing the Panton and Valentine leucocidin are responsible for chronic or re lapsing furonculosis and above all for a very severe necrotizing pneumonia observed in children and young adults presenting as an acute respiratory di stress syndrome with leucopenia, hemoptysis and shock carying a heavy morta lity rate. Besides these specific diseases, staphylococcal and streptococca l toxins may be involved in some syndromes of unknown origin, in wich the i ntervention of superantigens seems very likely. Kawasaki syndrome is among them as strains producing staphylococcal and streptococcal toxins have been grown from patients with Kawasaki syndrome. In the same way, the intervent ion of toxins is suspected in the determination of sudden infant death synd rome and atopic eczema. (C) 2001 Editions scientifiques et medicales Elsevi er SAS.