Ultrastructural study of the interaction of the fungi Sporothrix schenckii and Ceratocystis stenoceras with bone-marrow-derived murine macrophages.

Bone-marrow-derived macrophages of C57BL/6 mice cultivated in vitro were infected with the yeast form of Sporothrix schenckii or Ceratocystis stenoceras. Observations made in light and electron microscopy showed that part of the S. schenckii-containing phagosomes rapidly fused with lysosomes and fungal cells were digested. Surviving fungal cells elongated very rapidly and were liberated into the culture medium after 48 h upon macrophage lysis. The cells of the non-pathogenic isolate C. stenoceras did not elongate and were almost all digested after 8 days, while macrophages were unaltered. Staining for acid phosphatase showed that this enzymatic activity increased soon after ingestion with both isolates. However, this increase was less pronounced with S. schenckii than with the non-pathogenic isolate. The search for a toxic substance produced by S. schenckii and responsible for the low content in acid phosphatase and subsequent macrophage lysis remained negative. It is thus probable that both phenomena essentially resulted from fungus filamentation which led to a dramatic distortion of phagosomes and host cells.

Disseminated infection with Conidiobolus incongruus.

The first fatal case of disseminated infection due to Conidiobolus incongruus is reported. The patient presented with a subcutaneous mass, febrility, weight loss, cough and hemoptysis. Histological examination of skin and subcutaneous tissue, lung, lymph nodes, esophagus, liver and jejunum showed a granulomatous reaction with bright eosinophilic amorphous material and broad hyphae. A fungus cultured from skin and subcutaneous tissue was identified as Conidiobolus incongruus.

[Toxicogenic fungi isolated from foodstuffs coming from the Far East]. / Champignons toxinogènes isolés d'une denrée alimentaire en provenance d'Extrême-Orient.

Acetonic extracts of filamentous fungi formerly isolated from asiatic foodstuff were studied for toxicity. Eight out of 19 isolates inhibited seed germination of Lepidium sativum. Fluorescence was light at 366 nm. The skin test on rabbit was negative.

[Pathogenicity of "Candida albicans" for normal mice and mice treated by the mycotoxin diacetoxyscirpenol (author's transl)]. / Pouvoir pathogène de Candida albicans pour la souris normale ou déprimée par une mycotoxine: le diacétoxyscirpénol.

The study of the action of diacetoxyscirpenol, a mycotoxin from Fusarium, was carried out on mice. It was found that a single dose of 1/2 DL50 (4.5 mg/kg) inoculated intraperitoneally, induced a transitory diminution of weight of the spleen and thymus and fall in the percentage of blood lymphocyte. The effect on the course of candidiasis was obvious: the mice challenged with C. albicans and treated by small repeated doses of mycotoxin died more rapidly than not treated but infected mice, emphasizing significantly the effect of the immunosuppressive processus on the development of the opportunistic fungus.

[Effects of diacetoxyscirpenol on experimental candidiasis of mice]. / Action du diacetoxyscirpénol sur la candidose expérimentale de la Souris.

A single injection of 4.5 mg/kg of diacetoxyscirpenol (a toxin synthesized by Fusarium) into Mice challenged by C. albicans, increases significantly the development of an experimental candidiasis. Suspensions of homogenized kidneys was spread on Sabouraud dextrose agar plates and the colonies of C. albicans were counted after 24 hrs incubation. The mean values were determined. Comparison of mean values calculated for kidneys from the Mice challenged with C. albicans and those challenged with C. albicans plus toxin gave highly significant results.

Perithecial ultrastructure and formation of ascospores of Ceratocystis stenoceras (Robak) C. Moreau.

Fine details of perithecial morphology and aspects of ascospore formation of Ceratocystis stenoceras (Robak) C. Moreau are shown in electron micrographs of ultrathin sections. The envelope of the perithecial body proper consisted of two zones of cells which differed morphologically one from another. Loose aggregates of small electron opaque particles were present at the outer wall surface which may be responsible for the characteristic pigmentation of the body and neck. Cells comprising the ostiolate neck may arise as modifications of spindle-shaped cells of the inner zone of the perithecial envelope. Cell walls of the neck and of zones 1 and 2 may be composed in part of periodic acid-reactive polysaccharide. The perithecial envelope and ascogenous cells were separated by a band of several parallel, double-layered membranes which may function in some manner with biosynthetic activities of ascospore production. In general, the mechanics of ascospore formation by C. stenoceras were in most ways in agreement with recent reports of ascospore outogeny in other ascomycetous fungi. Mature ascospores were somewhat lenticular in shape and the outer space wall was finely sculptured.

[Cerebral mucormycosis in the cat caused by Mucor pusillus]. / Mucormycose cérébrale du chat due à Mucor pusillus.

The pathologic examination of the brain of a pet cat, suspected of rabies, showed lesions of mucormycosis. The causal fungus, Mucor (Rhizomucor) pusillus was isolated and identified. The authors describe the lesions produced, the experimental pathogenicity for the rabbit and the morphologic and physiologic characteristics of the isolate.

[Study of the sugar composition of Conidiobolus strains saprophytic or pathogenic to man and animal]. / Etudes de la composition en sucres de souches de Conidiobolus saprophytes ou pathogènes pour l'homme et l'animal.

The composition in the cell wall sugars of 13 strains of Conidiobolus coronatus and 1 strain of Conidiobolus incongruus has been determined. Glucose and mannose were found to be the main sugars. The study of the ratio mannose/glucose has shown that there are 3 groups of strains. The first group which contains the strain of C. coronatus isolated from man or chimpanzee is characterized by a ratio lying between 0.92 and 1.3. The second group containing the strains of C. coronatus isolated from horse lesion or from soil is characterized by a ratio lying between 2.7 and 4.1. The last group which contains C. incongruus whose ratio mannose/glucose is 0.44. These results suggest the existence of two groups among the strains of C. coronatus. Lethal temperature of each strain and eventual presence of villosus spores are also mentioned.

[Kinetics of production of collagenase, esterase and elastase by human and soil strains of "Entomophthora coronata" (author's transl)]. / Collagénase, estérase et élastase de souches pathogène et saprophyte de Entomophthora coronata : cinétique de production.

A comparative study was made of the production of extracellular proteolytic enzymes, which were originated from two different strains, one pathogenic and one saprophytic, of E. coronata in stable culture at 30 degrees C. Quantitative differences were found: the maximal activity of the three enzymes (collagenase, esterase, elastase) produced by the strain isolated from soil was always lower than that observed with the human strain.

[Tropical entomophthoromycoses]. / Les entomophthoromycoses tropicales.

A review was made about human entomophthoromycosis observed in tropical areas due to fungi of the order Entomophthorales. Rhinophycomycosis is caused by Entomophthora coronata, a cosmopolitan fungus which is only pathogen in wet tropical and subtropical climates. The disease, a muco-cutaneous infection of the face, induces monstruous deformations. Basidiobolomycosis is caused by Basidiobolus meristosporus, a saprophyte of different amphibians and reptiles very often present in the family Agamidae. The disease interests the subcutaneous tissues and is mainly located at the trunk, shoulders and upper part of the limbs. The epidemiology, clinic and therapeutic were reported. Histopathological lesions and morphology of both fungi were studied. The etiology of the casual agents of these mycoses was discussed.

Ultrastructural observations of an unusual osmiophilic body in the hyphae of Sporothrix schenckii and Ceratocystis stenoceras.

Electron microscopy of 8 strains of Sporothrix schenckii and 1 strain each of Ceratocystis stenoceras, C. pluriannulata, C. ulmi, and C. minor revealed the presence of unusual osmiophilic structures (EOB) which appeared as normal organellar components of young cells of these fungi. In S. schenckii and C. stenoceras, these structures were markedly osmiophilic, reacted strongly with thiocarbohydrazide, could be partially solubilized with the lipid solvent sodium methoxide, and appeared to possess lipase activity. On subsequent cellular ageing, lipid bodies were commonly seen in intimate association with the EOB. Eventually, the EOB underwent degeneration and extensive vacuolization. It is suggested that these structures are composed in part of lipoidal material in possible association with a protein matrix, and may be in some manner involved with lipid metabolism of mechanisms of lipid storage.

[Experimental "per os" transmission of Entomophthora coronata to the mouse]. / Transmission expérimentale "per os" de "Entomophthora coronata" à la souris.

Mycelial fragments of E. coronata have been observed in the pus of abscesses of the neck and the shoulder of mice inoculated per os, far from the point of inoculation. However, the subcultures were negative; a positive subculture was obtained in only one instance from a lung taken off ten days after the inoculation by the fungus.

["Trypanosoma brucei gambiense", antigenic study. III. Hemagglutination reaction with specific antigenic fractions]. / "Trypanosoma brucie gambiense" étude antigénique III. --Réaction d'hémagglutination à l'aide de fractions antigéniques spécifiques

The tannic acid hemagglutination method was applied to experimentally infected rodents sera. The antigens were Trypanosoma gambiense fractions separated by gel filtration on Sephadex G 200. Two fractions, at least, showed specific activity.