著者

山田 喜紹

出版者

日本ウイルス学会

雑誌

ウイルス (ISSN:00426857)

巻号頁・発行日

vol.23, no.3, pp.205-220, 1973

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Morphological change of a goat pneumonitis (GP) strain of <i>Chlamydia psittaci</i> in L cell monolayers induced by penicillin were investigated by electron microscopy. When the drug was added simultaneously with GP to the cell culture, its minimal inhibitory dose was estimated to be 1&mu;g (1.6 units) per ml of medium. Penicillin interefered with the growth cycle of the psittacosis organism at a concentration higher than 1&mu;g/ml by producing enlarged initial bodies 3 to 5&mu; in diameter. The abnormally enlarged initial bodies did multiply as such to some extent, but did not develop in to infective elementary bodies in the presence of an inhibitory dose of penicillin.<br>In the presence of a small dose of penicillin, ranging from 0.05 to 0.1&mu;g/ml, an excessive cytoplasmic membrane was formed within the enlarged initial bodies 15 hours or more after the onset of infection. At that time were produced a number of irregular-shaped &ldquo;miniature initial bodies&rdquo; and small empty vesicles. The miniature initial bodies had been liberated from the initial bodies by a buddinglike process.<br>Free miniature initial bodies did not develop further. In the presence of a smaller dose of penicillin, ranging from 0.025 to 0.5&mu;g/ml, clusters of electron-dense granules were formed within the maturing intermediate forms of the psittacosis organism. They were never found in the control intermediate forms grown in penicillin-free medium. The biochemical nature of those granules is not known at the moment.