Immunogenic capacity of ribosomes of Salmonella typhi interfered with by a flagellin-like material contaminant

The double-immunodiffusion technique and sodium dodecyl-polyacryl-amide electrophoresis were used to demonstrate the presence of flagellin-like material strongly attached to ribosomes of Salmonella typhi Ty 2. This flagellinlike material contaminating the ribosome preparation interferes with the induction of antiribosome serum, promoting the formation of antisera reacting either only with flagellin or in some cases with flagellin and ribosomes, but giving a very weak reaction with the latter. The interference is also observed when purified ribosomes from a nonflagellated mutant of S. typhi (S. typhi O-901) mixed with purified S. typhi Ty 2 flagellin are utilized as antigens. The antiribosome sera obtained with ribosomes from S. typhi O-901 have a considerably higher titer than those that are interfered with. These sera were able to react with ribosomes obtained from several related species and did not react with flagella-derived flagellin of S. typhi Ty 2.