Streptococcal pyrogenic exotoxin B enhances tissue damage initiated by other Streptococcus pyogenes products.
This study compared the pathology and infection pattern of streptococcal pyrogenic exotoxin B-positive (SpeB(+)) and SpeB-negative (SpeB(-)) isogenic variants of an M1 isolate of Streptococcus pyogenes in a mouse skin air sac model. SpeB(+) strains resulted in severe local tissue damage that extended from the epidermis through the subcutaneous layers, whereas isogenic SpeB(-) variants had reduced gross pathology. At the histologic level, differences in necrosis and host responses to each variant were apparent. Injection of purified SpeB alone into a skin air sac failed to induce any significant tissue damage; however, coinjection of the enzyme with either the wild-type or the speB mutant resulted in increased and accelerated tissue necrosis. Surprisingly, coinjection of the enzyme with the spleen-recovered SpeB(-) variant failed to induce a lesion.
Saouda
M
M
Department of Microbiology and Immunology, Medical College of Ohio, Toledo, USA. msaouda@mco.edu
Wu
W
W
Conran
P
P
Boyle
M D
MD
D000818:Animals; D001426:Bacterial Proteins; D015152:Blotting, Northern; D004817:Epidermis / Q000187:drug effects / Q000473:pathology; D005098:Exotoxins / Q000235:genetics / Q000302:isolation & purification / Q000633:toxicity*; D015964:Gene Expression Regulation, Bacterial; D008565:Membrane Proteins; D051379:Mice; D018482:Muscle, Skeletal / Q000187:drug effects / Q000473:pathology; D010641:Phenotype; D012867:Skin / Q000187:drug effects / Q000382:microbiology / Q000473:pathology*; D013290:Streptococcal Infections / Q000473:pathology*; D013297:Streptococcus pyogenes / Q000235:genetics*; D013997:Time Factors
D001426:Bacterial Proteins; D005098:Exotoxins; D008565:Membrane Proteins; C117980:SpeA protein, Streptococcus pyogenes; C027951:erythrogenic toxin