@article{oai:hsuh.repo.nii.ac.jp:00008345,
 author = {今村, 光孝 and 宮川, 博史 and 鈴木, 裕子 and 鎌口, 有秀 and 馬場, 久衞},
 issue = {1},
 journal = {東日本歯学雑誌},
 month = {Jun},
 note = {P(論文), Candida albicans(以下C.albicans)は,鵞口瘡やカンジダ膣炎や皮膚カンジダ症などを起こし,真菌の中でも病原性の強いもののひとつである。また生体内常在真菌として健康人の口腔,咽頭,腸管粘膜,膣などに存在しており通常は無害である。しかしながら,C.albicansはcompromised host,いわゆる宿主の抵抗性が減弱した人などに発症する日和見感染症の代表的起因菌でもあり,また近年,白血病,悪性腫瘍などで抗腫瘍剤や免疫抑制剤の投与により生体内微生物叢が変化する時にも菌交代現象としてCandida症は発症する。歯科領域においては,主に有床義歯装着患者に見られる義歯と接触する粘膜面の発赤,腫脹を主訴とする義歯性口内炎の原因菌としても考えられている。通常,C.albicansは2形性の真菌で,サブロー寒天培地を用いて37℃で培養すると,直径4～6μmの球状ないし卵形の酵母状となりその多くは,乳白色のクリーム様の集落を形成し分芽によって増殖する。一方,コーンミール寒天培地を用いて25℃ないし室温で培養すると,酵母細胞は発芽管が長く伸びて仮性菌糸を形成し,さらに各菌糸の接合部に多数の分芽胞子を形成すると共に,菌糸の末端に厚膜胞子を形成するのが本菌の特徴である。一般に,真菌の胞子は種の保存のために分散し,適当な条件下で発芽して増殖するための高度に特殊な分化をした細胞である。また,厚膜胞子は細菌における芽胞に相当する一種の耐久体ともみなされている。しかし,C.albicansの厚膜胞子は前述のように仮性菌糸の末端に形成され,分芽胞子に比べてその数は少なくかつ厚い細胞壁に覆われており,形成直後の厚膜胞子においては核やミトコンドリアが認められるが,成熟した厚膜胞子においては核やミトコンドリアが見られず,ほとんどが空胞とスポンジ様構造物で満たされている。そこで本研究においては,C.albicansの厚膜胞子が胞子としての重要な機能である増殖能と耐久性を兼ね備えたものであるか否かについて分芽胞子と比較検討した。, Candida albicans is a dimorphic fungus proliferating by budding with oval yeast when cultured with Sabouraud agar medium at 37℃ ; when cultured with Corn meal agar medium at 25℃ or room temperature, it forms pseudohyphae with many blastospores on the connections of each hyphae and chlamydospores on the ends. Spores of fungi differentiating highly specialized cells generally proliferate for preservation of the species to germinate under optimal conditions. However, much fewer chlamydospores than blastospores are formed on the ends of pseudohyphae and the chlamydospores also have thick cell walls. As a result, chlamydospores are considered to be persistent. However, mature chlamydospores do not show nucleus and mitochondria and are nearly filled by vacuoles and spongoid vacuoles. Therefore it is not certain that chlamydospores possess the functions of spores that their name indicates. This study compared chlamydospores and blastospores to examine whether chlamydospores possessed proliferative ability and persistence. Blastospores and chlamydospores formed by the C. albicans 2S2 strain were isolated and preserved in 0.3CMG medium at 6℃. The proliferative ability and persistence of the spores were examined with Sabouraud agar, BHI blood agar, Sabouraud liquid, and BHI liquid media. Further the ultrastructure of each spores was observed with transmission electron microscopy and the chromosomal DNA was analyzed by agarose gel electrophoresis. The results were as follows: 1. Blastospores and chlamydospores were isolated by stir and shake methods from pseudohyphae so the spore functions were not damaged. 2. Blastospores maintained proliferative ability and germinated even after preservation in 0.3CMG medium at 6℃ for 96 hours. 3. Some chlamydospores preserved for 24 hours germinated and proliferated, but after preservation for 48 hours or longer they did not proliferate and persistence was inferior to that of blastospores. 4. All blastospores formed within 24 hours had nucleus and organelles. However, a large number of chlamydospores had no nucleus. 5. There were mitochondria in chlamydospores after preservation for 24 hours, after 48 hours there were many spongoid vacuoles, after 72 hours there were only spongoid vacuoles, and after 96 hours there was separation of cell membrane from cell wall. 6. The chromosomal DNA of preserved chlamydospores showed more fragmentation of DNA than blastospores at all preservation times. The results suggested that chlamydospores were dying off and had no proliferative ability and were not persistent.},
 pages = {91--102},
 title = {<原著>Candida albicansの厚膜胞子の増殖能に関する研究},
 volume = {17},
 year = {1998}
}