An Arcanobacterium (Actinomyces) pyogenes Mutant Deficient in Production of the Pore-Forming Cytolysin Pyolysin Has Reduced Virulence
AUTOR(ES)
Jost, B. H.
FONTE
American Society for Microbiology
RESUMO
Pyolysin (PLO), the hemolytic exotoxin expressed by Arcanobacterium (Actinomyces) pyogenes, is a member of the thiol-activated cytolysin family of bacterial toxins. Insertional inactivation of the plo gene results in loss of expression of PLO with a concomitant loss in hemolytic activity. The plo mutant, PLO-1, has an approximately 1.8-log10 reduction in the 50% infectious dose compared to that for wild-type A. pyogenes in a mouse intraperitoneal infection model. Studies involving cochallenge of wild-type and PLO-1 bacteria resulted in recovery of similar numbers of both strains, suggesting that PLO production is required for survival in vivo. Recombinant, His-tagged PLO (His-PLO) is cytotoxic for mouse peritoneal macrophages and J774 cells in a dose-dependent manner. Protection against challenge with A. pyogenes could be afforded by vaccination with formalin-inactivated His-PLO, suggesting that PLO is a host-protective antigen, as well as a virulence determinant.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=96520Documentos Relacionados
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