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Abstract: Heat-killed Saccharomyces cerevisiae (HKY) used as a vaccine protects mice against systemic aspergillosis and coccidioidomycosis. Little is known about the immune response induced by HKY vaccination, consequently our goal was to do an analysis of HKY-induced immune responses involved in protection. BALB/c mice were vaccinated subcutaneously 3 times with HKY, a protective reagent, and bronchoalveolar lavage fluid, spleen, lymph nodes, and serum collected 2–5 weeks later. Cultured spleen or lymph node cells were stimulated with HKY. Proliferation of HKY-stimulated spleen or lymph node cells was tested by Alamar Blue reduction and flow cytometry. Cytokines from lymphocyte supernatants and antibody to glycans in serum collected from HKY-vaccinated mice were measured by ELISA. The results show that HKY promoted spleen cell and lymph node cell proliferation from HKY-vaccinated mice but not from PBS-vaccinated control mice (all P <0.05). Cytokine measurement showed HKY significantly promoted IFNγ, IL-6 and IL-17A production by spleen cells and lymph node cells (all P <0.05 and P <0.01, respectively). Cytokine production by HKY-stimulated cells from PBS-vaccinated mice was lower than those from HKY-vaccinated (P <0.05). Cytokines in BAL from HKY-vaccinated were higher, 1.7-fold for IFNγ and 2.1-fold for TNFα, than in BAL from PBS-vaccinated. Flow cytometry of lymphocytes from HKY-vaccinated showed 52% of CD3+ or 56% of CD8+ cells exhibited cell division after stimulation with HKY, compared to non-stimulated controls (26 or 23%, respectively) or HKY-stimulated cells from PBS-vaccinated (31 or 34%). HKY also induced antibody against Saccharomyces glucan and mannan with titers 4- or 2-fold, respectively, above that in unvaccinated. Taken together, the results suggested that HKY vaccination induces significant and specific Th1 type cellular immune responses and antibodies to glucan and mannan. [Copyright &y& Elsevier]

Abstract: Saccharomyces cerevisiae is increasingly recognized clinically, and repeated isolations from patients on a hematology unit in Turku, Finland, led to an epidemiologic investigation. Isolates were recovered from multiple body sites of 23 patients (n = 180) from 1994 to 1995 and from 29 patients (n = 45) from 1997 to 2002; these plus 2 from the hospital kitchen were identified as S. cerevisiae. Isolates were genotyped by restriction fragment length polymorphism (RFLP) of genomic DNA after EcoR1 digestion. Of 108 isolates, 97 (95 patient isolates and 2 from the hospital kitchen) were DNA group B and identical in RFLP pattern. The remaining 11 isolates were DNA group A; 2 patients that shared a room had identical group A isolates, both converted to DNA group B type colonization within 2 months. In almost all patients, S. cerevisiae was first recovered after admission. These data suggest an endemic source of colonizing organisms, possibly from the hospital food preparation area. [Copyright &y& Elsevier]

Abstract: 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 ≤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. [Copyright &y& Elsevier]

Abstract: Candida parapsilosis family has 3 proposed species: C. parapsilosis sensu stricto, Candida orthopsilosis, and Candida metapsilosis. C. parapsilosis sensu stricto had significantly higher caspofungin (CAS) and anidulafungin MICs than C. orthopsilosis or C. metapsilosis; C. metapsilosis was least susceptible to fluconazole. C. parapsilosis sensu stricto more frequently displayed (37%) paradoxical growth in CAS (P ≤ 0.02). These species susceptibility differences could affect therapeutic choices. [Copyright &y& Elsevier]

Abstract: Mannose binding lectin (MBL) is a protein of the collectin family that appears important in resistance to invasive pulmonary aspergillosis. We assessed the role of MBL in experimental systemic aspergillosis. MBL-sufficient C57BL/6 (WT) mice and B6.129S4 – Mb11tm1Kata Mb12tm1Kata/J MBL A and C gene-knockout (KO) mice were infected intravenously with different inocula of Aspergillus fumigatus conidia. WT and KO mice were dose-responsively susceptible. In no instance were the KO mice more susceptible than WT. At the highest inoculum, all WT and 90% of KO mice died on day 4 (P >0.05). Reduction of the inoculum to 5.5×106 conidia was lethal, but comparison showed KO mice less susceptible to lethal infection (P <0.015). At the lowest inoculum used, deaths of KO mice were delayed, but survival was not significantly different than WT (P >0.05). These results suggest MBL may play a deleterious role in systemic aspergillosis. [Copyright &y& Elsevier]

Highlights: [•] HKY vaccine protects against DKA/steroid treated mice with pulmonary mucormycosis. [•] This is the first illustration of HKY efficacy in classically immunosuppressed mice. [•] HKY induces antibodies that react with Rhizopus oryzae cell wall antigens. [•] Our results broaden the HKY efficacy spectrum to a fifth mycosis. [•] Our data warrant the future development of HKY as a pan-fungal vaccine. [ABSTRACT FROM AUTHOR]

Abstract: A new real-time polymerase chain reaction (RT-PCR) assay based on a Coccidioides genus–specific molecular beacon probe was developed for the detection of coccidioidomycosis and validated with tissues from animal models and clinical samples. The assay showed high analytic reproducibility (r2 > 0.99) and specificity for cultured strains (100%); the lower limit of detection was 1 fg of genomic DNA/μL of reaction. Fungal burdens in the organs of mice infected with Coccidioides posadasii strain Silveira were more accurately quantified by RT-PCR compared to colony-forming unit for all tissues. The RT-PCR assay was positive for 97.7% of spleen and 100% of liver or lung. Progression of infection in all organs was similar by both methods (P > 0.05). The sensitivity of the assay also was 100% for paraffin-embedded samples and samples from patients with positive cultures. Our RT-PCR assay is effective for the diagnosis and monitoring of Coccidioides infection, and its use also avoids the biohazard and time delay of identifying cultures in the clinical setting. [Copyright &y& Elsevier]

Abstract: Current diagnostic techniques for fungal diseases could be improved with respect to sensitivity, specificity, and timeliness. To address this clinical need, we adapted a non–amplification-based nucleic acid detection technology to identify fungal pathogens. We demonstrate a high-specificity, detection sensitivity, reproducibility, and multiplex capacity for detecting fungal strains. [Copyright &y& Elsevier]

Abstract: Microsatellite typing of 25 Candida parapsilosis isolates from a described outbreak in a neonatal intensive care showed 2 large groups of blood isolates that were related to hand isolates from specific hospital staff, not infant-colonizing isolates. These results demonstrate the power of this typing tool in clarifying epidemiologic associations. [Copyright &y& Elsevier]

Two isolates of Candida dubliniensis were identified from a collection of 30 examined from Israel in a molecular epidemiology study. The 30 isolates were tentatively identified as Candida albicans. The new species, C. dubliniensis, is being reported from new geographic locales. These two isolates, from an Arab and a Druze patient, are the first to be reported from the Middle East. [ABSTRACT FROM AUTHOR]

Summary: In a screen of drugs previously tested in humans we identified itraconazole, a systemic antifungal, as a potent antagonist of the Hedgehog (Hh) signaling pathway that acts by a mechanism distinct from its inhibitory effect on fungal sterol biosynthesis. Systemically administered itraconazole, like other Hh pathway antagonists, can suppress Hh pathway activity and the growth of medulloblastoma in a mouse allograft model and does so at serum levels comparable to those in patients undergoing antifungal therapy. Mechanistically, itraconazole appears to act on the essential Hh pathway component Smoothened (SMO) by a mechanism distinct from that of cyclopamine and other known SMO antagonists, and prevents the ciliary accumulation of SMO normally caused by Hh stimulation. [Copyright &y& Elsevier]