Evaluation of the p-nitro-alpha-acetylamino-beta-hydroxypropiophenone differential test for identification of Mycobacterium tuberculosis complex.

The p-nitro-alpha-acetylamino-beta-hydroxypropiophenone (NAP) differential test for the identification of Mycobacterium tuberculosis recovered from clinical specimens was evaluated by two laboratories and found to be a rapid and accurate procedure with a specificity exceeding 99%.

Pathogenicity of the basidiospores of Filobasidiella neoformans.

The pathogenicity of the purified basidiospores of Filosbasidiella neoformans was determined. The basidiospores were purified by successive filtration and inoculated into white Swiss female mice via the intracranial and intravenous route. At autopsy, infection was seen with as few as fifty inoculated cells. The brain, liver and spleen were examined culturally and histologically to prove the pathogenicity of the purified basidiospores .

Pathogenicity of the hyphae of Filobasidiella neoformans.

The pathogenicity of the purified hyphae of Filobasidiella neoformans was determined. The hyphal particles were inoculated into white Swiss female mice via the intracranial and intravenous route. Upon autopsy, infection was seen with as few as 25 hyphal elements. The brain, liver, and spleen were examined culturally and the brain examined histologically to prove the pathogenicity of the purified hyphae.

Effects of time lapse between sputum collection and culturing on isolation of clinically significant fungi.

A retrospective study of 34,314 sputum specimens received by a reference laboratory over a 10-year period demonstrated that clinically significant fungi could be isolated even after long periods of delay between collecting and culturing. As a result of this study, it should be stressed that although immediate culturing for fungi is the ideal, specimens should not be rejected because of delays in transport.

Interactions between Histoplasma capsulatum and macrophages from normal and treated mice: comparison of the mycelial and yeast phases in alveolar and peritoneal macrophages.

Interactions between macrophages (alveolar and peritoneal) from normal, vaccinated (with heat-killed yeast cells), and Mycobacterium bovis BCG-treated mice and the mycelial and yeast phases of Histoplasma capsulatum were observed. Phagocytosis of microconidia, small hyphal fragments, and yeast cells occurred 4 to 6 h after the infection of macrophage cultures. Conversion to the yeast phase began at 6 to 7 h and was complete after a 72-h incubation at 37 degrees C. Macrophages surrounded and adhered to macroconidia and large hyphal elements. More macrophages (65 to 68%) from BCG-treated mice contained fungi at 24 h than did macrophages from normal or vaccinated mice. Although there was no increase in the number of fungi in macrophages from vaccinated mice, only the macrophages from BCG-treated mice contained fewer fungi after 48 h of infection with the mycelial phase of H. capsulatum. Fungal growth was not inhibited in any of the macrophage cultures when infected with the yeast phase. The macrophages infected with yeast cells were destroyed after 48 to 72 h in the culture. Only BCG-treated macrophages survived infection with the mycelial phase, whereas macrophages from normal and vaccinated mice were destroyed by the infection.

Technique for the purification of the hyphae of Filobasidiella neoformans.

A technique for the purification of the hyphae of Filobasidiella neoformans is described. Cultural conditions and strains for maximal hyphal production were determined. Blastospores were separated from hyphae by sonification of mycelial suspensions. Following this, the initial density ranges of all cell types were determined by isopycnic centrifugation, using Renografin-60 as a supporting medium. Based on these data, rate centrifugation with different density ranges was used to obtain cell separation. The final percentage of non-hyphal cells to total population was 0.007%. These were determined to be still viable at the end of separation.