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Biomedical subjects

C H Armstrong

Publications and source records attributed to C H Armstrong.

27 records · Page 2Linked to original sources
PubMed1971

The distribution of group E streptococcus among lymph nodes of experimentally infected swine.

Lymph nodes, spleens, and tonsils from swine infected experimentally with Group E Streptococcus (GES, the causative agent of jowl abscess) were examined grossly and bacteriologically. Forty-two abscessed lymph nodes were seen among 14 infected swine. Pure cultures of GES were recovered from each abscess. Approximately half of 112 pools of grossly normal lymph nodes yielded GES as did half of 14 tonsils and 14 spleens. All GES recovered were morphologically and serologically identical to the strain used to create the experimental infection.

Abscess↗
PubMed1970

Somatic antigens of Streptococcus group E. I. Comparison of extraction techniques.

Eleven Streptococcus group E strains, representing serotypes I, II, III, IV, V, and "untypable" isolates, were extracted by formamide, trichloroacetic acid, and hydrochloric acid under various conditions in an effort to determine the best method for recovering maximum amounts of group and type antigens. The group antigen was found to be relatively stable, and adequate amounts for identification purposes were recovered by a wide spectrum of conditions. Type-specific antigens were relatively labile, and were destroyed at low pH in acid hydrolysis or by prolonged heating in formamide hydrolysis. The best single procedure for recovering both type and group antigens from Streptococcus group E was formamide hydrolysis for 30 min at 180 C.

Animals↗
PubMed1970

Somatic antigens of Streptococcus group E. II. Separation and a partial physicochemical characterization.

Antigenic extracts of Streptococcus group E (SGE) were subjected to fractional ethanol precipitation, block (preparative) electrophoresis, and gel filtration for the purpose of separating the type antigen from the group antigen. Ethanol precipitation was ineffective in separating the substances. Block electrophoresis yielded serologically pure group antigen and a mixture of type and group antigen. Serologically pure type antigen was obtained by gel filtration. In some cases, pure group antigen was also recovered; in others, it was contaminated with type antigen. Gel filtration column effluents of antigenic extracts of SGE serotypes, I, II, III, IV, V and "untypable" isolates, collected from the region in which type antigen was eluted, were studied by paper chromatography and infrared spectrophotometry in an effort to develop a nonserological means of detecting type antigen. Hydrolysates of type antigens or suspect type antigens of serotypes I through V contained l-rhamnose, d-glucose, and several unidentified substances. d-Galactose also was present in hydrolysates of serotypes III and V. Untypable isolates and negative controls contained traces of d-glucose only. The data suggested that serotypes I through V contained a type antigen and that the untypable isolates were devoid of type antigen. Infrared absorbance spectra seemed to support the paper chromatography data.

Animals↗