Chester W. Emmons

Entomophthora Coronata, the Etiologic Agent of a Phycomycosis of Horses

Mycologists are generally acquainted with species of Entomophthora as parasites of insects. In a separate paper (1) we are reporting four cases of a chronic granulomatous disease of the nasal mucosa and the lips of horses caused by Entomophthora coronata (Costantin) Kevorkian (4). Germination of conidia of this fungus may be by a single hypha, by multiple hyphae, by replication of a single conidium on a short conidiophore, or by replication of many conidia on many short conidiophores. In many cultures all conidia are covered by hair-like appendages. The versatility of this fungus, the taxonomic significance of this variability, and the proof that E. coronata can parasitize mammalian tissues should be of interest to mycologists. The fungus was easily demonstrated in the tissues of the host where it grew as a coenocytic mycelium. In culture E. coronata grows rapidly. A subculture on glucoseneopeptone agar incubated at 30°C begins to discharge spores in 10-15 hours and the colony reaches a diameter of 6 cm within 48 hours. The colony is colorless to yellowish white. It is at first flat and glabrous but it quickly produces radial and irregular folds and a white bloom on the surface which represents surface hyphae and short conidiophores (FIG. 1). The colony remains membranous without deep penetration of the agar substratum and without production of a conspicuous aerial mycelium. In a petri dish incubated in an inverted position and in agar slants incubated vertically, the glass surface opposite the colony is covered in 24-36 hours by a film of conidia which have been discharged forcibly from the tips of conidiophores and which germinate by production of hyphae or reproduce by replication on the nonnutritive glass surface (FIGS. 2-7). Hyphae vary in dimensions between 6 and 15 ,x. They contain droplets and granules of varying size which apparently are fat, glycogen and other metabolites. Many germinated spores and older hyphae appear

Cryptococcus neoformans Strains from a Severe Outbreak of Bovine Mastitis.

Cryptococcus neoformans was isolated from a severe outbreak of bovine mastitis. A comparison of 62 strains revealed considerable variation in color, acid production in sugars, and amount of capsular material. During the course of the study, the origin of 10 mucoid mutants was noted. The strains were compared with strains of the same species isolated from human cryptococcosis, from soil, and with the originalSanfelice strain. They are typical of the speciesC. neoformans in colony characteristics, morphology, temperature tolerance, acid production in sugars and pathogenicity for mice.

The Jekyll-Hydes of mycology.

Sectorial mutation, loss of ability to produce spores and the multiplicity of species, attest to the lability of the fungi. The size and morphological complexity of fungi reveal at once to the observer many overt aspects of variability and the physiologist easily detects other mutants which are masked by a common phenotype. The consequences and potentialities of the lability of fungi in didactic mycology, in use of fungi as research tools, in plant pathology, and in industrial mycology, are too many and varied to enumerate before an audience already familiar with them. I shall discuss those aspects of the adaptability of fungi which enable them, under appropriate conditions, to turn immediately from a saprophytic existence to parasitism of animal tissues. I submit that this aspect of the adaptability of the fungi places upon mycologists a responsibility which has been only partially acknowledged. Medical mycology should be the concern of mycologists generally and not a subspecialty of medical bacteriology or medicine. Specialization and complexity among the fungi are spectacularly mnanifested by those molds and yeasts which flourish under generally inhospitable environmental conditions, grow on substrates unavailable to most microorganisms or play sometimes beneficial, sometimes lethal roles in the economy of nature. Many of the fungi which are found in unusual habitats are now fixed in their present relationships. Some require special substrates, some are obligate parasites which require for survival