Molecular analysis of pyrogenic exotoxins from Streptococcus pyogenes isolates associated with toxic shock-like syndrome.
Toxic shock-like syndrome (TSLS) is characterized by hypotension or shock, fever, multiorgan system involvement, and a concurrent group A streptococcal infection. We analyzed 34 streptococcal strains isolated from patients with clinically well-documented TSLS for their pyrogenic toxin profiles and M-protein types. Although strains of nine different M types were represented in the sample, 74% of the isolates were of either M type 1 or 3. It was determined that 53% produced streptococcal pyrogenic exotoxin type A under in vitro growth conditions and that 85% contained the gene encoding this toxin. These values are in contrast to the published value of 15% for the incidence of this gene in a sample of general group A streptococcal isolates. As has been found with all group A streptococci examined to date, regardless of disease association, 100% of TSLS-associated isolates contained the gene encoding pyrogenic exotoxin type B. This toxin was detectably produced by 59% of isolates. The gene encoding pyrogenic toxin type C was found in only 21% of isolates. We conclude that the pyrogenic exotoxin type A gene is associated with group A streptococcal strains isolated from patients with TSLS and may play a causative role in this illness. However, other factors are also likely to be important, since not all strains from patients with TSLS contained the A toxin gene.
Department of Microbiology, University of Minnesota, Minneapolis 55455.
A R
AR
Hauser
D L
DL
Stevens
E L
EL
Kaplan
P M
PM
Schlievert
D000942:Antigens, Bacterial / Q000032:analysis / Q000235:genetics; D001425:Bacterial Outer Membrane Proteins; D001426:Bacterial Proteins / Q000032:analysis / Q000235:genetics; D002352:Carrier Proteins; D004247:DNA / Q000302:isolation & purification; D015342:DNA Probes / Q000235:genetics; D004587:Electrophoresis, Agar Gel; D005098:Exotoxins / Q000737:chemistry* / Q000235:genetics; D005838:Genotype; D005779:Immunodiffusion; D008565:Membrane Proteins; D009693:Nucleic Acid Hybridization; D010641:Phenotype; D012150:Polymorphism, Restriction Fragment Length; D015183:Restriction Mapping; D012772:Shock, Septic / Q000382:microbiology*; D013297:Streptococcus pyogenes / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*
D000942:Antigens, Bacterial; D001425:Bacterial Outer Membrane Proteins; D001426:Bacterial Proteins; D002352:Carrier Proteins; D015342:DNA Probes; D005098:Exotoxins; D008565:Membrane Proteins; C117980:SpeA protein, Streptococcus pyogenes; C027951:erythrogenic toxin; C014689:streptococcal M protein; D004247:DNA