H. B. Levine

Miconazole in coccidioidomycosis: II. Therapeutic and pharmacologic studies in man

Fourteen patients with chronic coccidioidomycosis, many of whom had complicating concurrent diseases and/or had failed to respond to amphotericin therapy, were treated with intravenous miconazole, a synthetic imidazole drug previously shown to be effective in experimental murine coccidioidomycosis. Up to 3.6 g/day was given for up to three months. 7inimal inhibitory concentrations of mycelial and endospore phases of all clinical isolates of C. immitis were less than 2.0 mug/ml. Peak concentrations in the blood of up to 7.5 mug/ml (by assay against C. immitis in vitro) were achieved. Doses above 9 mg/kg or 350 mg/m2 were more efficacious in producing blood levels over 1 mug/ml. Serum protein binding, determined by several methods, was approximately 90 per cent. The disappearance of bioactive drug from blood after infusion has a rapid initial phase (t1/2 approximately 30 minutes) and a final plateau (t1/2 approximately 20 hours). Eight patients had objective evidence of response, three had slight or equivocal responses, two could not be evaluated, and one was a treatment failure. Side effects were generally uncommon, minor and transient except for phlebitis. Infusion into central venous catheters appears to circumvent this problem. Miconazole is a potentially useful drug in the treatment of coccidioidomycosis.

Saccharomyces cerevisiae as a vaccine against coccidioidomycosis

Disseminated coccidioidomycosis is a life-threatening infection. In these studies, we examined protection against systemic murine coccidioidomycosis by vaccination with heat-killed Saccharomyces cerevisiae (HKY). CD-1 mice received HKY subcutaneously or by oral gavage with or without adjuvants once weekly beginning 3 or 4 weeks prior to infection; oral live Saccharomyces was also studied. All HKY sc regimens were equivalent, prolonging survival (P<or=0.005) and reducing fungal burden versus controls. Oral live Saccharomyces, but not HKY, prolonged survival (P=0.03), but did not reduce fungal burden. Survival of mice given HKY was equivalent to vaccination with formalin-killed spherules, but inferior in reduction of fungal burden. HKY was superior to a successful recombinant vaccine, PRA plus adjuvant. This novel heterologous protection afforded by HKY vaccination offers a new approach to a vaccine against coccidioidomycosis.

Expert Opinion: What To Do When There Is Coccidioides Exposure in a Laboratory

Inadvertent exposure to Coccidioides species by laboratory staff and others as a result of a mishap is not an uncommon cause of infection in clinical microbiology laboratories. These types of infection may occur in laboratories outside the endemic areas, because the etiologic agent is unexpected in the submitted specimens and because personnel may be unfamiliar with the hazards of dealing with Coccidioides species in the laboratory. Coccidioidal infections are often difficult to treat, and outcomes can be poor. Here, we emphasize prevention and an approach to a laboratory accident that minimizes the risk of exposure to laboratory staff and staff in adjacent areas. On the basis of an artificially large exposure to arthroconidia that may occur as a result of a laboratory accident, a conservative approach of close observation and early treatment of exposed staff is discussed.

Cellular immunity to Coccidioides immitis: In vitro lymphocyte response to spherules, arthrospores, and endospores

Abstract In vitro stimulation of incorporation of tritiated thymidine by human peripheral lymphocytes in response to two soluble antigens and three different intact but nonviable fungal forms of Coccidioides immitis was studied. Lymphocytes were obtained from three groups of subjects: healthy skin test positive, healthy skin test negative, and disseminated disease. Dose-response relationships to the intact forms (endospores, arthrospores, and spherules) were determined. Responses of lymphocytes from healthy skin test-positive subjects and subjects with disseminated disease were similar. Ranking of antigens by “potency” gave the following results: endospores = spherulin > mycelial filtrate > arthrospores = spherules. Endospores were the most potent of the intact forms in 10 of 11 subjects. The clear superiority of endospores over spherules is not due to differences in the total particle surface area available for presentation to the leukocytes. All antigens tested except spherules could discriminate between skin test-positive and skin test-negative subjects in this in vitro system. A T-cell-enriched, B-cell- and mono-cyte-depleted cell population demonstrated an active response to spherulin and to endospores. The variance of these finding with animal studies demonstrating spherules to be immunogenically superior when compared to endospores is discussed. This may have importance in future studies in humans of vaccines to C. immitis .