Merida W. Castleberry

Comparison of serologic reactions in experimental canine and simian coccidioidomycosis

Three groups of monkeys and groups of dogs were each exposed by the respiratory route to graded inhaled doses of approximately 9,500, 2,500 and 325 dry arthrospores of Coccidioides immitis strain Silveira. In sera from infected dogs, the highest median agar gel precipitin titers occurred at five and nine weeks postexposure. Titers fell after these time periods in all dose groups. Agar gel precipitin titers in the medium and low dose groups of monkeys reached their highest median values at 14 weeks postexposure and then declined slightly. Agar gel precipitin titers in infected monkeys were consistently higher than thoee in infected dogs. Highest median titers for CF antibodies occurred at the five week test period in dogs of all dose groups. After this time period, the median titers in the sera of these dogs declined. In infected monkeys, maximum median titers of CF antibodies were observed at nine and 17 weeks postexposure. The median titers forming this plateau were higher than the highest median titers ...

Immunization against experimental lethal simian coccidioidomycosis using whole killed arthrospores and cell fraction.

Immunization against experimental coccidioidomycosis began with the use of a killed, whole-cell antigen. Negroni, Vivoli and Bonfiglioli (8) investigated the immune response in guinea pigs using dead material. Vogel and co-workers (14) at Duke University found that intramuscular immunization with a killed spherule-endospore suspension increased re? sistance of guinea pigs to pulmonary infection. The disease not only occurred less frequently but was less severe in the immunized than in the non-immunized control animals. Later Friedman (1) and Smith (2) reported that killed arthrospore vaccines administered subcutaneously protected mice against lethal disease but not against infection with Coccidioides immitis Rixf. & Gilchr. In the latter experiments the challenge dose was administered intraperitoneally. After Pappagianis and co-workers (10) observed that respiratory exposure appeared to be a more severe test of the resistance of immunized animals than challenge by parenteral inoculation, Levine et al. (5) adopted intranasal instillation as the method of challenge. Killed arthrospores, mycelial and spherule antigens introduced intramuscularly into mice all protected against lethal intranasal challenge. Mice that received the spherule-endospore vaccine appeared to have infections that were milder than mice immunized with other test vaccines. Extending his studies to larger animals, Levine et al (6) tested the efficacy of killed spherule vaccine in cynomolgous monkeys challenged with 200 air-borne organisms. A total dose of 9 mg (dry weight) of vaccine was used for immunizations that were given alternately subcu? taneously and intramuscularly at 1, 11, 28, and 54 days. The animals