1,721,058 research outputs found
Exoantigen test for identification of Petriellidium boydii cultures
Full text linkCultures of Petriellidium boydii were serologically identified by detection of their exoantigens with an immunodiffusion procedure. The technique, which is specific and sensitive, allowed the rapid identification and differentiation of 12 isolates of P. boydii from numerous other morphologically similar Hyphomycetes. The antigen-antiserum reference system and the production, by two different techniques, of exoantigens used in the identification of P. boydii are described
Killer systems and pathogenic fungi
No full textOur own studies on the yeast killer phenomenon have been concentrated on its application for the differentiation of opportunistic pathogenic yeast isolates within the same species and its use as an epidemiological marker in nosocomial infections caused by yeasts. Our most recent investigations have led us to reevaluate the potential uses of this phenomenon, since it is now apparent that other microorganisms, unrelated to yeasts, are susceptible to the effects of these toxins. The yeast killer phenomenon can theoretically be used to study epidemiological aspects of any pathogenic microorganism, especially when other systems are not available. Monoclonal antibodies produced against a crude toxic extract of a killer yeast (Pichia anomala UCSC 25F) active against a large number of microorganisms were used to carry out a serological study on metabolic products of various yeasts with known and unknown genetic determinants of their killer characteristics. The extract itself had demonstrated a therapeutic effect in vivo when applied topically. Anti-idiotypic antibodies against these monoclonal antibodies were raised in rabbits. In vitro, these anti-Ids mimicked the action of the killer toxin used as immunogen in the production of monoclonal antibodies. The perspectives of investigations on yeast killer phenomenon are discussed
In vitro tests : how do they influence therapeutic choices?
No full textIn an era in which invasive opportunistic fungal infections, especially aspergillosis and candidiasis, have become one of the major causes of morbidity and mortality in patients with hematological disorders and malignancies, clinicians can benefit from the growing role that laboratories play in the early diagnosis and therapeutic management of such infections. In particular, in vitro testing results, if the methods used are reliable and reproducible, can be useful either for specific therapeutic approaches or for detecting antifungal drug resistance. Although the title of our review implies answers to the question on how in vitro tests can influence the therapeutic choice of an antifungal drug, we prefer that the reader forms his own judgement. To help readers to form their judgement, this review will be focused on: descriptions of the current available methods for in vitro antifungal susceptibility testing of yeasts and moulds; summary on what has been done in the correlation of in vitro susceptibility results with the clinical outcome of human or experimental fungal infections following specific therapy with a defined antifungal drug; discussion on the appropriateness of the routine use of in vitro antifungal susceptibility testing, the potential clinical application of its results; and, finally, assessment of the clinical relevance of in vitro detection of antifungal drug resistance
Serological analysis of dermatophyte isolates with monoclonal antibodies produced against Microsporum canis
Full text linkHybridoma cells produced by fusing myeloma cells with spleen cells from mice immunized with a soluble antigen of Microsporum canis yielded 30 antibody-producing clones. Six of these clones, propagated as ascites tumors in mice, showed two different types of monoclonal antibodies. The type 1 monoclonal antibody reacted with 17 heterologous and 10 homologous dermatophyte antigens. Type 2 monoclonal antibodies were unable to precipitate three antigens from different isolates of M. canis, thus suggesting the occurrence of different serotypes within the species
Voriconazole activity against clinical yeast isolates : a multicentre Italian study
No full textThe activity of voriconazole was tested in vitro against 1996 clinical yeast isolates collected in 20 Italian microbiology laboratories. Voriconazole susceptibility testing was carried out with the broth microdilution (NCCLS M27-A2), Etest and disk diffusion methods. The minimum inhibitory concentrations at which 90% of the isolates were inhibited (MIC90) obtained with the NCCLS method were 0.03 mg/L for Candida albicans, 0.5 mg/L for Candida non-albicans and 0.25 mg/L for other genera; those obtained with Etesting were, respectively, 0.032 mg/L, 0.125 mg/L and 0.125 mg/L. With the disk diffusion method, the majority of isolates (92.3%) showed inhibition zone diameters between 21 mm and 40 mm. Using a tentative MIC cut-off of 1mg/L as indicative of in vitro susceptibility, 98.1% of the isolates tested in our study would be classified as susceptible, and only 28 (1.4%) of the isolates, with MICs higher than 2mg/L, would be classified as resistant to the drug. Our findings confirm the broad-spectrum in vitro activity of voriconazole against yeasts, including Candida species that are generally less susceptible to other azoles
Antigenic characterization of Microsporum canis, M. distortum, M. equinum, M. ferrugineum and Trichophyton soudanense cultures
No full textThe authors investigated the antigenic properties of a group of closely related dermatophytes whose components may be morphologically confused with one another: Microsporum canis, M. distortum, M. equinum, M. ferrugineum and Trichophyton soudanense. By using reference antigens and adsorbed monospecific antisera, it was possible to serologically distinguish the reference strains by the exoantigen technique. Their common and specific antigenic determinants were visualized by cross-immunoelectrophoresis tests with intermediate gel
A microautomated dilution method for susceptibility testing with antifungal drugs
No full textThe authors perfected, for standardization purposes, a microautomated system (Dynatech MIC 2000 Inoculator) to obtain the accurate quantitative results, i.e., determination of minimum inhibitory (MIC) and fungicidal (MFC) concentrations, avoiding the work and time consuming procedure of the classic broth dilution method in tubes. The spectrum of activity of seven antifungal antibiotics against 204 yeast isolates of six different species, in two different media comparatively, is described
Dermatophyte carriers among school children
No full textTrichophyton mentagrophytes and Microsporum canis were isolated from apparently healthy scalps of schoolboys during an epidemiological study of dermatophyte carriers. Various other keratinophilic fungi were also isolated
Preliminary studies on the carcinogenic effects of Penicillium roqueforti toxin (PR toxin) on rats
No full textPreliminary results on the carcinogenic activity of a mycotoxin of Penicillium roqueforti (PR toxin) are reported. A squamous epithelioma and a uterine sarcoma were histologically confirmed in 2 of 10 albino rats fed PR toxin in a relatively short time (449 and 551 days respectively). Only an adenocarcinoma was histologically proven within a control group of 10 rats in a significantly longer (931 days) time span
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