Serological procedures to detect dermatophyte antigens.
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Animals↗
Biomedical subjects
L Polonelli
Publications and source records attributed to L Polonelli.
Killer systems and pathogenic fungi.
Our 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.
Animals↗
Biotyping of aerobic actinomycetes by modified killer system.
Forty-four yeasts belonging to the genera Pichia, Candida, Saccharomyces and Kluyveromyces were tested for their potential killer effect on 13 aerobic actinomycetes (6 Nocardia asteroides, 1 N. brasiliensis, 1 N. caviae and 5 Actinomadura madurae). Only a few yeast strains did not display any killer activity against the aerobic actinomycetes studied, thus confirming that the killer phenomenon is widespread among microorganisms. For epidemiological purposes, a killer system was developed. According to their susceptibility to the 9 killer yeasts chosen, it was possible to differentiate the Nocardia and Actinomadura isolates into biotypes. Fitting conditions of the killer system to potential sensitive microorganisms with different characteristics of growth are also discussed.
Actinomycetaceae↗
Antigenic studies on Rhizopus microsporus, Rh. rhizopodiformis, progeny and intermediates (Rh. chinensis).
Fourteen isolates belonging to Rhizopus microsporus, Rh. rhizopodiformis, the progeny of Rh. microsporus x Rh. rhizopodiformis and an intermediate species, Rh. chinensis, were serologically tested either by a modification of the exoantigen technique of Kaufman & Standard (1978) or by the more analytical cross immunoelectrophoresis technique with intermediate gel. Common antigenic determinants in the isolates studied indicated that the species, their progeny and the intermediate species Rh. chinensis, are antigenically very closely related. Through absorptions, a specific reference antiserum for Rh. microsporus was obtained. With this adsorbed monospecific antiserum, using the exoantigen test, the identity of the isolates in study, determined after their general morphology as Rh. microsporus, was confirmed. For comparative purposes, the use of reversed phase high performance liquid chromatography for the investigation of fungal isolates is also reported.
Antigens, Fungal↗
Yeast killer toxin-like anti-idiotypic antibodies.
Anti-idiotypic antibodies (anti-Ids) were raised in a rabbit against a murine monoclonal antibody (MAb) neutralizing the yeast killer toxin produced by a strain of Pichia (Hansenula) anomala. In an immunodiffusion test, the anti-Ids produced in the rabbit recognized the antigen-binding site of the MAb used as the immunogen (KT4) but not that of another heterologous MAb. The absence of any significant cross-reactivity among the anti-Ids raised in a rabbit for a heterologous MAb suggested that the anti-Ids were highly specific for unique variable-region determinants. Furthermore, the P. anomala killer toxin proved to be competing with anti-Ids for the binding site of MAb KT4. Anti-Ids against the MAb to yeast killer toxin inhibited the growth of Candida albicans, thereby mimicking the effect of the yeast killer toxin. These results suggest that, in some cases, anti-Ids might be useful tools for elucidating structure-function relationships for sensitive cell receptors.
Animals↗
Biotyping of micelial fungus cultures by the killer system.
Based on the occurrence of the yeast killer phenomenon in hyphomycetes, the toxic effect of 37 selected killer yeasts was studied on eleven strains of Pseudallescheria boydii, six strains of Aspergillus niger, 18 strains of Penicillium camemberti and nine strains of Sporothrix schenckii. The demonstration of different biotypes within the species of P. boydii and P. camemberti proves that the killer system also is a practical and effective method for epidemiological studies among hyphomycetes. Based on the system used, it was not possible to observe markedly different biotypes among the A. niger and S. schenckii strains studied. The first evidence that an isolated, concentrated (50X) and partially purified yeast killer toxin may display a lethal activity against mycelial fungus cultures is also given in this paper.
Mitosporic Fungi↗
Electron microscopy studies of human intestinal spirochetes.
The ultrastructure of twenty human intestinal spirochetes was analyzed using the electron microscope. Negatively stained cells were generally found to be loosely and irregularly waved. The isolates had cell dimensions ranging from 0.18-0.35 micron in width and from 3.9-14.2 micron in length. Twin bundles of flagella were present in the space between the cytoplasmic membrane and the outer membrane. The majority of isolates had five flagella inserted sub-terminally at each cell end. Human intestinal spirochetes divide by binary fission. They are morphologically similar to swine intestinal treponemes, both pathogenic (Treponema hyodysenteriae) and non pathogenic (Treponema innocens), and different from Treponema pallidum, Treponema phagedenis and Borrelia burgdorferi. Following treatment with sodium deoxycolate, no bundles of cytoplasmic microtubules were observed in cells obtained from cultures of human and swine intestinal spirochetes or from cells of B. burgdorferi, while these structures were present in similarly treated cells of T. pallidum and T. phagedenis.
Animals↗
Antigenic characterization of Penicillium camemberti and related common cheese contaminants.
Twenty-four isolates of Penicillium (including a green-spored mutant from a French Brie cheese, Penicillium camemberti) with a proposed relationship to the white cheese mold P. camemberti were investigated by immunological procedures. These penicillia, which are representative of species that have caused considerable taxonomic confusion, had common micromorphology (terverticillate penicilli with rough and smooth stipes and smooth ellipsoidal to subglobose [(3 to 5) X 2 1/2 to 4 1/2 microns] conidia); growth rates; good growth on creatine sucrose agar, cheese, and other products with a high amount of protein and lipid as a primary habitat; production (with the exception of Penicillium solitum) of cyclopiazonic acid; and the ability to grow at low temperatures and water activities. The isolates that were investigated proved to be strictly antigenically related. Absorbed antiserum of the green-spored mutant of P. camemberti showed a specific precipitin band when tested by immunodiffusion either with its homologous reference antigen or with the exoantigens obtained from different isolates. The precipitin band was not present in any P. camemberti starter culture but in many unwanted cheese contaminants. The precipitin band can be used in the purity control of P. camemberti starter culture spore preparations. Analysis of the exoantigens of all the cultures by reversed phase high-performance liquid chromatography allowed us to subdivide these penicillia into nine groups below the species level. The results indicate that P. commune Thom is the wild-type ancestor of P. camemberti.
Antigens, Bacterial↗
Production and characterization of yeast killer toxin monoclonal antibodies.
Monoclonal antibodies were obtained after fusion of mouse myeloma cells with spleen cells isolated from mice primed with a crude extract of yeast killer toxin produced by a strain of Hansenula anomala. Hybridomas were selected by specific immunoassay reaction of their fluid with crude yeast killer toxin extract. Among the monoclonal antibodies, which were characterized by the Western blot technique, one (designated KT4) proved to have precipitating properties, thus permitting the neutralization of the killer activity of the toxin. Experiments in double immunodiffusion showed that monoclonal antibody KT4 produced homologous precipitin bands by reacting with either the crude toxin used as immunogen or a toxic extract of Hansenula mrakii. It is suggested that these monoclonal antibodies will be useful for the purification, characterization, and understanding of the bioactions of yeast killer toxins.
Animals↗
Potential therapeutic effect of yeast killer toxin.
Experimental infections were produced in guinea pigs, rabbits and dogs with lesions similar to those seen in human seborrheic dermatitis and otitis externa by cutaneous application of cultures of Malassezia furfur and M. pachydermatis. Infected animals were treated by topical application of a concentrated yeast killer toxin (Hansenula anomala UCSC 25F). Clinical recovery as well as negative mycological test cultures of infected animals proved to the clearly associated with the treatment by the killer toxin.
Administration, Topical↗
Serotyping of fungal isolates by precipitating monoclonal antibodies.
Ascites fluid from hybridoma cell lines producing monoclonal antibodies to an exoantigen of Microsporum canis was assayed for its precipitating properties. Three types of monoclonal antibodies were used for serological analysis of heterologous mycelial cultures. Based on specific antigenic determinants, the fungal strains showed different immunodiffusion reactivity within the species. The monoclonal antibodies also proved to be effective reagents for serotyping heterogeneous species. They may also have potential applications in epidemiology.
Animals↗
Specific and common antigenic determinants of Candida albicans isolates detected by monoclonal antibody.
We isolated a hybridoma cell line which produced monoclonal antibody to one determinant of an exoantigen of Candida albicans. The immunoglobulin G antibody product was characterized by using a Western blot technique and was used for a serological analysis of numerous homologous and heterologous yeast isolates. Based on specific immunologic determinants, C. albicans strains were identified and clustered into five groups. The monoclonal antibodies were effective reagents for identifying and serotyping our C. albicans isolates; they have potential application in the epidemiology of yeast infections.
Animals↗
Identification and serotyping of Microsporum canis isolates by monoclonal antibodies.
Hybridoma cells were produced by fusing mouse myeloma cells with spleen cells from mice primed with an exoantigen of Microsporum canis. Three clones produced antibodies which were examined by the Western blot technique for their potential usefulness in the identification of M. canis isolates and differentiation of strains within the species. Based on reactions with immunological determinants, all of the M. canis isolates tested presented either species- or strain-specific domains. Monoclonal antibodies proved to be useful reagents for the identification of M. canis isolates and for the differentiation of strains within the species. A purified antigen depleted of common antigenic determinants was obtained in affinity chromatography by using monoclonal antibody.
Animals↗
Reevaluation of the yeast killer phenomenon.
The killer effect of 36 Hansenula, Pichia, Saccharomyces, and Candida species on 26 hyphomycetes isolates, 1 isolate of the achlorophyllous microorganism Prototheca, 4 isolates of the lipophilic yeast Malassezia, 1 isolate of the aerobic actinomycete Nocardia, and 19 isolates of bacteria was studied. The killer phenomenon, which was previously considered to be restricted to yeasts, was found to occur among unrelated microorganisms.
Antibiosis↗
Paracoccidioidomycosis (South American blastomycosis): a report of an imported case previously diagnosed as tuberculosis.
A case of paracoccidioidomycosis, previously treated for tuberculosis for two years, is reported. Combined treatment with oral ketoconazole and sulfamethoxypyridazine was successful. The problem of a low index of suspicion among physicians for tropical mycoses, which are very rarely observed in Italy, is discussed.
Adult↗
Imported paracoccidioidomycosis: a public health problem in non-endemic areas.
Diagnosis of paracoccidioidomycosis in an immigrant who had returned to Italy following a long sojourn in Venezuela prompted a review of imported cases of this Latin American disease in nonendemic countries. Forty-two such instances of well-documented paracoccidioidomycosis were complied. Among these, eleven individuals had arrived in nonendemic countries with active symptomatic infections, fifteen others were first suspected of having tuberculosis, and four each were considered to have blastomycosis caused by Blastomyces dermatitidis and carcinomas. Three individuals were considered to have Wegener's granulomatosis or blastomycosis. Two other patients were treated for syphilis before being diagnosed as having paracoccidioidomycosis. A striking feature of most of these cases was the long asymptomatic period following initial infection. The dormant periods ranged form four months to 60 years with an average duration of 14 years. The need to question patients about travel to or residency in foreign countries is emphasized, along with the necessity to include the mycoses in differential diagnoses. Three reported cases, all from Africa with no history of travel to the endemic areas of the New World, were considered to be doubtful. In one of these, Russell bodies apparently had been mistaken for the tissue-form cells of Paracoccidioides brasiliensis.(ABSTRACT TRUNCATED AT 250 WORDS)
Diagnosis, Differential↗
Antigenic characterization of Microsporum canis, M. distortum, M. equinum, M. ferrugineum and Trichophyton soudanense cultures.
The 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.
Antigens, Fungal↗
Use of killer toxins for computer-aided differentiation of Candida albicans strains.
Killer toxins were isolated from eight selected killer yeasts. Their activity on 100 Candida albicans isolates of human and animal origin was studied. A computer aided system for differentiating C. albicans strains was developed. By using this system, it was possible to differentiate 14 biotypes of C. albicans isolates based on their susceptibility to the killer toxins.
Candida albicans↗