Group B Streptococcal Toxic Shock-Like Syndrome: Report of a Case and Purification of an Associated Pyrogenic Toxin

A patient with streptococcal toxic shock-like syndrome (TSLS) caused by Streptococcus agalactiae (group B Streptococcus) is described. The patient had all of the defining criteria for toxic shock syndrome (TSS), including fever, hypotension, erythematous rash, desquamation, and involvement of multiple organs. Neither Staphylococcus aureus nor group A streptococci were recovered, but vaginal and urine cultures yielded group B streptococci. The group B streptococcal isolate gave negative results in antibody tests for the production of TSS toxin 1, staphylococcal enterotoxins, and streptococcal scarlet fever toxins. However, the strain produced a novel pyrogenic toxin. This toxin, purified from culture fluids by ethanol precipitation, isoelectric focusing, and reverse-phase high-pressure liquid chromatography, had a molecular weight of 12,000 and an isoelectric point of ∼7.0. The purified toxin was pyrogenic in rabbits, enhanced the susceptibility of the animals to lethal endotoxin shock, and caused the proliferation of rabbit splenocytes; these properties define pyrogenic toxins. When given to three rabbits via a subcutaneous miniosmotic pump, the toxin caused TSS-like symptoms ending in death. Three additional group B streptococcal strains from patients with TSLS were tested and were found to produce a toxin with similar properties.