An Antiphagocytic Factor Associated with Group E Streptococcus
Year: 1973
Type: article
Abstract: Group E streptococci (GES) grown in Tryptose phosphate broth (TPB) were highly susceptible to nonspecific phagocytosis by porcine leukocytes, whereas GES grown in serum-supplemented TPB (STPB) were resistant to nonspecific phagocytosis. It was concluded that serum supplementation induced the elaboration of an antiphagocytic factor (APF). The APF was distinct from the group-specific and type-specific polysaccharide antigens, and it was destroyed by trypsin. Electron photomicrographs revealed that GES grown in STPB possessed a fimbriated surface component similar to M protein-positive stains of group A streptococcus. The surface component was absent when GES were propagated in unfortified TPB. The APF was neutralized specifically by sera from swine immune to streptococcic lymphadenitis (SLS), a disease caused by GES. It was hypothesized that the APF was associated with the pathogenicity of GES and that it was involved in the induction of protective immunity to SLS.
Source: Infection and Immunity
Authors: Raymond A. Daynes, Charles H. Armstrong
Institution: Purdue University West Lafayette
Language: English
Field: Medicine
Domain: Health Sciences
Open Access status: green
OpenAlex ID: W1953645504