Specificity of the collagenolytic enzyme from the fungus Entomophthora coronata: comparison with the bacterial collagenase from Achromobacter iophagus.
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Biomedical subjects
Publications and source records attributed to H Fromentin.
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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.
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.
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.
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.
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.
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.
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.
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.