Growth and sporulation of a pyrimidine spore color mutant of Sordaria fimicola.

A nonautonomous spore color mutant of Sordaria fimicola is a pyrimidine auxotroph that produces hyaline nonviable ascospores. Uracil, uridine, and cytidine are more effective growth factors than cytosine and thymine and, in high concentrations, render the mutant self-fertile by inducing the ascospores to resume development and maturation. Crosses with the unlinked arginine non-autonomus spore color mutant st-59 yielded the double mutant st-59 pyr that requires both arginine and a pyrimidine for growth, which indicates a lack of suppression of the pyrimidine requirement by the arginine locus.

Life cycle and variation of Prototheca wickerhamii.

Prototheca wickerhamii is a yeastlike organism that resembles the green alga Chlorella. Nuclear division in coordination with cytoplasmic cleavage gives rise to uninucleate cytoplasmic segments, each of which acquires a delicate cell wall and develops into an autospore. The autospores in this species are spherical; but in a variant that presumably arose as a result of spontaneous mutation, the cytoplasmic cleavage is irregular, and the resultant autospores are ovoid to bacillary. When these variant autospores grow, they swell and round up before the nuclear division begins, producing spherical cells like those seen in wild-type cultures. In view of the fact that species concept in the genus is based on size and shape of cells, the variation limits in these morphological characteristics have significant bearing on species classification.

A case of coccidioidomycosis with unique clinical features.

Primary coccidioidomycosis, occurring in a microbiologist whose initial symptoms were cough, fever, night sweats, and chest pain, was unique, because for six months following infection his sera remained nonreactive, and his chest roentgenograms showed no lesions. Throughout this period, his sputa continued to yield Coccidioides immitis. His skin test, which showed negative results 12 days after the onset of symptoms, became positive for coccidioidomycosis eight months later. Spherule formation by C immitis cultures was demonstrated in human pleural fluid medium at 40 degrees C within four to six days and in the internal organs of a mouse inoculated with an arthrospore suspension. After six months of rest and without specific antibiotic treatment, the patient's sputa became negative and his clinical recovery was complete. We emphasize culture isolation and accurate identification of C immitis in diagnosis, and serology in the assessment of therapy.

Disseminated mucormycosis in a case of metastatic carcinoma.

A 50-year-old white woman who underwent bilateral mastectomy for fibrocystic disease of the breast in 1974 and laminectomy for lumbar disc fusion in 1979, was diagnosed early in 1980 at Roswell park Memorial Institute as a case of metastatic anaplastic carcinoma. She was started on platinum combination therapy, but in the course of her treatment she became increasingly jaundiced, then semi-comatose and died suddenly two months after the diagnosis of carcinoma. Histopathologic examinations revealed undifferentiated small-cell carcinoma in the lung, liver, lymph nodes, and bone. Mucormycosis, characterized by the presence of broad coenocytic hyphae associated with thrombosis, infarction, and necrosis, was unexpectedly discovered at postmortem examination in the brain, lung, and heart. The etiologic agent, Absidia corymbifera, was isolated from a lung specimen and was identified by its morphologic characteristics and by the formation of zygospores in crosses with a compatible tester strain of the mating type (-).

Coccidioidomycosis in a patient with lymphoma. Spherulation in human pleural fluid medium.

In a Caucasian woman who had had a giant follicular lymphoma for 21 months a small lesion developed in the upper lobe of the left lung. Excision, histologic study, and culture of the lesion were performed. Of the many stained sections, only one revealed endospore-containing spherules within the caseous necrosis of a granuloma, and only four spherules were identified. On agar medium the same tissue yielded a fast-growing fungus that produced arthrospores alternating with empty cells, typical of Coccidioides immitis. The arthrospore suspension was inoculated intraperitoneally into a mouse and into a medium of human pleural fluid at 40 C. Spherules containing endospores developed in the internal organs of the mouse and in the pleural fluid medium. The phylogeny of C. immitis is briefly discussed.