A combination of osmium tetroxide and several heavy metals is a good fixative for hyphal pellets of Trichophyton mentagrophytes, and staining them after sectioning is effective for enhancing the contrast in the sections. Permanganate fixation, however, is not a reliable fixative for the hyphae of a dermatophyte. The hyphal cells of the fungus show a complicated construction similar to that of other fungi or higher plant cells.
A small spherical electron-dense granule, called a peripheral (or septal) body, is found in most sections at the peripheral ends of the fungal cells located near the septal wall. This body may be a special structural component of dermatophytes which is different from a lipid storage granule, but it serves some other functions.
A nucleus-like structure with a nuclear membrane and nucleolus, which is believed to correspond to that demonstrated in yeast or animal cells, can be seen in a well prepared sectioned hyphae. However, the absence of a discrete nucleus or a nuclear apparatus in certain dermatophytes has been suggested by some workers.
The other important architectures, usually seen in yeast cells or filamentous fungi as cell wall, cytoplasmic membrane, mitochondrion, storage granule, internal double membrane, and vacuole, are also recognizable in most sections of the hyphae of a dermatophyte.

View full abstract

A modified method of slide agglutination test using red blood cells on Vibrio comma was described. All strains of El Tor vibrio were hemagglutinative, but all newly isolated strains of Asiatic cholera vibrio were negative for this reaction. Hemagglutinative strains of Asiatic cholera vibrio were also found in the stock cultures. The number of positive cultures seemed to have some relation to the years in which they were isolated. Accordingly, the application of this test for the differentiation of vibrios should be limited only to the newly isolated strains.
The hemagglutinating capacity of these vibrios was easily destroyed by heat and some chemicals. Its possible relationship to the surface structure was suggested.

View full abstract

1. The mode of action of isoniazid was studied using Mycobacterium "Jucho" as the test organism.
2. Isoniazid inhibited markedly the incorporation of sulfate-³⁵S into the protein fraction, although the incorporation to the TCA-soluble fraction was not inhibited.
3. Isoniazid did not inhibit the formation of glutamic acid from radioactive acetate, but the incorporation of glutamic acid thus formed into the protein fraction was inhibited by isoniazid.
4. The incorporation of leucine-1-¹⁴C into the protein fraction was not inhibited by isoniazid. The effect of isoniazid on the incorporation of amino acids does not appear to be uniform.

View full abstract