K. Takayama1,2,3, Lynn Wang1,2,3, R. S. Merkal1,2,3
1Agricultural Research Service, National Animal Disease Laboratory, Ames, Iowa 50010
2Institute for Enzyme Research, University of Wisconsin, Madison, Wisconsin 53706
3Veterans Administration Hospital, Madison, Wisconsin 53705
Tóm tắt
The morphology of cells of the H37Ra strain of
Mycobacterium tuberculosis
exposed to 0.5 μg of isonicotinic acid hydrazide (isoniazid) per ml was examined by scanning electron microscopy (SEM). Cells that were exposed to isoniazid for 3 h showed no detectable change, whereas cells exposed to the drug for 24 h exhibited diverse morphological features. From our examination of these SEM pictures, we have reconstructed the probable sequence of morphological changes to be as follows: (i) the wrinkling of the cell surface was ascribed as the earliest observable change, (ii) the cell surface then became very rough and ragged, (iii) eventually the cytoplasmic material was extruded from the cell, (iv) this event produced a collapsed cell, (v) the cells began to fragment, (vi) the fragmented cells then coalesced to form an amorphous mass of cell debris.
