Immunoelectrophoretic studies of sera from rabbits exprimentally infected with Histoplasma capsulatum.

Adamson, David M. (University of Oklahoma, Norman), and George C. Cozad. Immunoelectrophoretic studies of sera from rabbits experimentally infected with Histoplasma capsulatum. J. Bacteriol. 92:887-891. 1966.-In a study involving 24 mature Dutch rabbits inoculated intravenously with 2.6 x 10(8)Histoplasma capsulatum yeast cells per kg of body weight, all rabbits were shown to develop precipitins by the end of the 5th week. Precipitins were demonstrated both by the micro-Ouchterlony method and microimmunoelectrophoresis with the use of concentrated histoplasmin as the antigen. The latter technique proved to be the more sensitive. The 10 x concentrate of histoplasmin gave better precipitin patterns than did the 5 x concentrate. Agglutinins were formed by 90% of the rabbits by the end of the 4th week, as shown by the capillary tube agglutination test. Three precipitin bands, arbitrarily designated A, B, and C, were demonstrated by immunoelectrophoresis with use of the sera of the test animals. Band A occurred between the 1st and 2nd weeks after inoculation and was, for a period, present in 100% of the sera of the test animals. Band A occurred separately or in conjunction with band B or B and C, and it persisted longer than these other two bands. Bands B and C appeared between the 3rd and 4th weeks and were found, by the end of the 5th week, in 35 and 15%, respectively, of the sera tested. They were never seen separately or together without the presence of band A. Band C disappeared by the end of the 6th week, and band B, by the 10th week, but band A was still present in 19% of the sera at the end of 10 weeks.