Additive Attenuation of Virulence of Streptococcus pneumoniae by Mutation of the Genes Encoding Pneumolysin and Other Putative Pneumococcal Virulence Proteins

摘要: Although the polysaccharide capsule of Streptococcus pneumoniae has been recognized as a sine qua non virulence, much recent attention focused on role pneumococcal proteins in pathogenesis, particularly view their potential vaccine antigens. The individual contributions pneumolysin (Ply), major neuraminidase (NanA), autolysin (LytA), hyaluronidase (Hyl), surface protein A (PspA), and choline-binding (CbpA) have examined by specifically mutagenizing respective genes chromosome comparing impact virulence mouse intraperitoneal challenge model. Mutagenesis either ply, lytA, or pspA gene S. D39 significantly reduced relative to that wild-type strain, indicating products contribute pathogenesis. On other hand, mutations nanA, hyl, cbpA had no significant impact. derivatives carrying ply deletion mutation well an insertion-duplication one was also examined. nanA lytA did not result additional attenuation background. However, additive observed for strains with ply-hyl, ply-pspA, ply-cbpA double mutations.