The production of pyrogenic exotoxins by group A streptococci

Lancefield group A streptococci isolated from recent outbreaks and sporadic cases of scarlet fever were restricted to the following M types 1, 3, 4, 6, 12, 18, 22 and 66. These strains were examined for the presence of streptococcal pyrogenic exotoxins (SPE) types A, B and C by isoelectric focusing in polyacrylamide gels and by immunoprecipitation in agar gels. SPE B was produced by 70% of the strains and SPE C by 40%. SPE A could not be detected in these strains. In contrast, SPE type A was found in 4 of 10 strains, held by the NCTC, that had been isolated before 1940 from patients with scarlet fever. Nine of 12 recent isolates from patients with sore throat uncomplicated by a rash produced SPE C and 4 of these also produced SPE B.

[Microbiology of streptococcal infections]

Since the discovery of streptococci by the surgeon of Vienna, Theodor Billroth, more than 100 years ago, they have proved to be a bacterial group of great medical and epidemiological importance. The classification in growth-characteristics on blood culture mediums (alpha-, beta- and gamma-hemolysis) has been detached by the evidence of group specific cell wall antigens. The antigene extraction described by Lancefield can distinguish at least 21 serogroups (A-T). They have also taken over the historical names (S. pyogenes, S. agalactiae etc.). In addition to group relationship the antigen structure of the streptococci cell wall (carbohydrates, peptidoglycanes, M-T-R-proteins and others) is responsible for antigenetic and pathogenetic conditions. Some species of streptococci do also excrete exotoxines (streptolysin, hyaluronidase, bacteriocines, erythrogenic toxins) with antigenetic and pathogenetic significance. Infections with streptococci of the serogroup A, B, D and H are numerously and medically significant. There is a great interest in infections due to A streptococci (pharygitis, impetigo, erysipel, scarlatin fever). The known non-purulent diseases following A streptococci infections (acute rheumatoid fever, acute glomerulonephritis) are streptococcal specific reactions for the individual. Some antigens of the cell wall and also some exotoxines react in human beings as autoantigenes. Human beings are the most important reservoir for streptococci. Nearly 20% of a population have A streptococci in their upper respiratory tract.(ABSTRACT TRUNCATED AT 250 WORDS)

The incidence of scarlet fever

This study attempted to find the incidence of scarlet fever in the Oxford region, including the proportion of patients from whom Streptococcus pyogenes could be isolated. General practitioners collected throat swabs from patients with suspected scarlet fever. The swabs were examined for viral and bacterial pathogens. Children admitted to hospital were used as controls. Twenty-five of 105 patients with suspected scarlet fever grew Str. pyogenes; M type 4 was the commonest type. The clinical diagnosis of scarlet fever was not always confirmed by throat culture. The annual incidence of scarlet fever was estimated to be 0.3 cases per 1000 per year.

Scarlet fever, Toxic-shock syndrome and the Staphylococcus

A case of scarlet fever studied in 1959 and caused by Staphylococcus aureus, phage type 52/52a/80 infection of a surgical burn is reported. The literature is reviewed and data are presented which indicate the distinct antigenicity of the erythrogenic toxins of staphylococci and group A streptococci. The patient developed neutralizing antibodies to staphylococcal toxin which disappeared ten months after infection. The similarity of the rashes and desquamation of the skin of several diseases caused by staphylococci indicate at least one common toxin.

Staphylococcal scarlet fever: role of pyrogenic exotoxins

Staphylococcal pyrogenic exotoxin (PE) types A and B were tested for their role in production of a scarlatiniform rash. The PEs elicited minimal skin reactions after intracutaneous injection into animals not presensitized to the toxins. In contrast, erythematous injection into animals not presensitized to the toxins. In contrast, erythematous and edematous rashes were produced after administration of either PE to animals presensitized to homologous toxin. After 3 to 4 days, the erythematous areas showed membranous desquamation. Staphylococcal PEs also enhanced delayed and Arthus hypersensitivity skin reactions developed against unrelated proteins; the reactions subsequently desquamated. In addition, animals previously sensitized to either staphylococcal PE type developed scarlatiniform rashes after challenged with heterologous staphylococcal or any group A streptococcal PE. The data suggest that staphylococcal PEs produce scarlet fever-like rashes comparable to group A streptococcal PEs and that all PE types contain a common core moiety against which delayed hypersensitivity may be developed.

Effect of scarlet fever toxin on the phagocytic activity of the reticuloendothelial system

In normal rabbits and mice, one i.v. injection of scarlet fever toxin (ET) (30 000 STD per kg of rabbit weight or 20-g mouse) elicited a similar biphasic change in carbon clearance rate - early depression followed by a stimulating phase - as has been described for Gram-negative endotoxins. Prolonged depression without a subsequent stimulation phase was obtained in mice by raising the ET dose. The reasons of the discrepancy between these findings and those of Hanna and Watson (1965b) are discussed. Pyrogenic tolerance to ET is not accompanied by accelerated carbon clearance and is not impaired by RES blockade. A possible mechanism of ET tolerance is suggested.

Influence of antilymphocyte and antipolymorphonuclear sera on the pyrogenic effect of scarlet fever toxin

The role played by lymphocytes in the pyretic response to scarlet fever toxin (ET) was studied in vivo using antilymphocyte serum (ALS). Two i.v. injections of ALS inhibited the pyretic response to a subsequent ET injection in rabbits. The course of endotoxin fever remained uninfluenced by ALS. Antipolymorphonuclear serum had no effect on the pyretic response to either of the toxins. Pretreatment with ALS also inhibited the skin reaction after i.d. injection of ET. These findings are further evidence a mediating role of lymphocytes in the biological effects of ET, among other things in the release of endogenous pyrogen.