Metabolism of mannitol by Coccidioides immitis

Lones, George W. (National Institute of Allergy and Infectious Diseases, U.S. Public Health Service, Bethesda, Md.), and Carl Peacock. Metabolism of mannitol by Coccidioides immitis. J. Bacteriol. 87:1114-1117. 1964.-Strain M-11 of Coccidioides immitis was found to utilize mannitol for growth in the mycelial form but not in the spherule form. Cell-free extracts of both forms, grown on glucose, were capable of reducing nicotinamide adenine dinucleotide with mannitol-1-PO(4) but not with mannitol. The extracts accomplished a rapid oxidation of reduced nicotinamide adenine dinucleotide by fructose-6-PO(4), the expected product of mannitol-1-PO(4) oxidation. Fructose was inactive. Paper electrophoresis and chromatography with several solvent systems demonstrated a substance in extracts of both mycelium and spherules having a migration consistent with that of mannitol.     

Unusual Reducing Sugar from Coccidioides immitis

Documentation is offered for the identification of 3-O-methyl-mannose as one of several neutral sugars found in defatted arthrospore and mycelial cell walls of Coccidioides immitis.     

Solid-phase immunoenzyme analysis of Coccidioides immitis antigens

A highly effective and specific solid-phase enzyme immunoassay system has been developed. The enzyme immunoassay is a highly sensitive technique for the detection and identification of C. immitis cellular and metabolic antigens. This technique is suitable for the study of strain differences in the antigenic composition of C. immitis, rendered harmless by different methods. The expediency of the preliminary sonification of cell suspensions of C. immitis, the causative agent of coccidioidomycosis, has been experimentally confirmed.     

Estudios sobre el Coccidioides immitis Rixford et Gilchrist

Summary Seven cases of coccidioidomycosis have been reported until now in Argentina, 2 of which are not yet published. Mycological characters of the 3 Argentine strains are identical with those of the North-American strains. Colonies are velvety or floccose, white, zonate or hemizonate. Vegetative mycelium forms: chlamydospores (intercalary or terminal), racket mycelium, appressoria, funicula, vegetative anastomosis and rudimentary sclerotia.Fertile mycelium develops as branches of the aereal mycelium and leads to the formation of entospores (thallospores) separated by empty cells which function as disjunctors. They utilize monosaccharides and sodium acetate better than other carbon sources. Ammonium chloride is the simplest nitrogen source which provides a good growth ofC. immitis. Argentine strains are proteolytic and one of them hemolize rabbit's red blood corpuscles.

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Resumé On a rapporté jusqu'à present 7 cas de eoccidioidomycose dans l'Argentine, dont deux sont encore inédits. L'étude mycologique de 3 souches nous a révélé qu'elles sont identiques aux souches nord-americaines. Les colonies sont véloutées ou laineuses, blanches, zonées ou hémizonées.Le mycélium végétatif forme des chlamydospores, mycélium en raquette, appressorium, funiculus, des anastomoses vegetatives et, dans les milieux avec 1% de graisse, des sclérotes rudimentaires. Le mycélium de fructification naît du mycélium aérien et consiste dans la formation d'entospores (thallospores) separés par des cellules vides qui fonctionnent comme des disjoncteurs.Elles utilisent mieux les monosaccharides et l'acétate de sodium que les autres sources de carbone. Le ClNH₄ est la source d azote plus simple qui fournit un bon developpement duC. immitis. Les souches étudiées sont protéolytiques et quelques unes hemolisent le sang du lapin.

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Agradecemos muy sinceramente a los Drs.Ignacio Basombrid yJulian Prado los datos gentilmente suministrados de los casos N 6 y 7.     

Soil Ecology of Coccidioides immitis at Amerindian Middens in California

Outbreaks of coccidioidomycosis and isolation of Coccidioides immitis have been reported from Amerindian middens. This study was undertaken to determine the most important ecological component(s) for the occurrence of C. immitis at archeological sites. Soils from 10 former Indian villages with no prior history of coccidioidal infection were collected and cultured. The physicochemical properties of the midden soils were compared with nonmidden soils and positive soils. The following theories for the sporadic distribution of the pathogen in the soil of the Lower Sonoran Life Zone were considered: (i) the Larrea tridentata (creosote bush) association, (ii) the preference for saline soils, (iii) isolation near rodent burrows, and (iv) animals as possible agents of dispersal. Results showed that a high percentage of the midden soils contained C. immitis, whereas none of the adjacent, nonmidden soils yielded the fungus. Physicochemical analyses revealed that the dark color and alkaline pH of the midden soils were due to past organic contamination. Repeated isolations were made from soils with low to moderate alkalinity. Alkalinity and sandy texture were consistent features of all soils in this study. However, the lack of any reports of nonsandy infested soils possibly indicates that the sandy texture and alkalinity may be factors in the distribution of this fungus. The organic content, soil parent material, and color were not important in the soil ecology. L. tridentata was not significant in the macroflora at the infested sites surveyed. Samples collected without reference to rodent burrows yielded a high percentage of recoveries. Animals, although not the major natural reservoir, cannot be ignored as possible factors in the ecology of C. immitis.     

Serological Comparison of Spherules and Arthrospores of Coccidioides immitis

Spherule and arthrospore cellular preparations were sonic-treated and separated into their respective supernatant and sediment components. Complement-fixation tests with antispherule and antiarthrospore pooled rabbit sera revealed that the soluble antigens exhibited more serological activity than the sediment preparations. After autoclaving, an arthrospore cellular antigen exhibited increased activity with either antisera, whereas autoclaved spherules exhibited increased activity only with antispherule serum. Complement-fixation tests with coccicioidin and spherule culture supernatant preparations revealed quantitative or qualitative differences in antigenic determinants between these two morphological phases of Coccidioides immitis.     

Morphogenesis throughout saprobic and parasitic cycles of Coccidioides immitis

The fungus, Coccidioides immitis, differs from other dimorphic pathogens in that its parasitic stage is a complex morphogenic cycle, raising the question that changes in structure and composition during morphogenesis might influence host responses. As a prelude to examining the interaction of fungal morphogenesis and host responses, the life cycle of this fungus has been examined in greater detail than previously accomplished. During saprobic development, alternating enterothallic arthroconidia are formed as infectious propagules. The outer wall is broken and loosely adherent. Under in vitro conditions supporting the parasitic cycle, multinucleate arthroconidia transform into uninucleate round cells. Rapid, synchronous, nuclear replication is initiated, accompanied by increase in cell mass and deposition of new cell wall substance. As karyokinesis ceases, morphologic differentiation begins with invagination of the inner layers of the spherule wall and then is progressive, eventually segmenting the protoplasm into uninucleate endospores grouped in clusters within a hyaline membrane. Endospores, escaping through a break in the spherule wall, are held in aggregates by fibrils which are stretched and broken as endospores separate. It would seem that rapid production of hundreds of progeny from an original single cell, protected during development by an enclosing spherule wall and then released in clusters, should favor establishment of the fungus in a host, and dynamic changes in the cell wall during morphogenesis should influence the host response.     

Isolation and identification of Coccidioides immitis from natural sources

The review of media and techniques that have been developed to date appears to provide more than adequate choice for investigators in endemic areas to perform ecological studies of this organism. The final identification of this organism still lies in the demonstration of itsin vivo morphology.Paper read at the Eighth International Congresses for Tropical Medicine and Malaria, September 1968, Teheran (Iran).