岡山医学会Acta Medica Okayama0030-1558867-81974黄色ブドウ球菌の耐塩機構における細菌表層の役割 特にフリーズ・エッチング法による形態学的検討299307ENKen-ichiTomochikaKatsukoSasaiYasuhiroKanemasaThe role of cell surface in a haloresistant mechanism of S. aureus was analyzed by free-ze-etching method. Our comparative studies were carried out on S. aureus cultivated in 0.5% NaCl containing medium (Normal-Staph) and in 10% NaCl containing medium (10% -Staph), as they were or were treated with L-11 enzyme (cell wall lytic enzyme obtained from Flabobacterium sp.). 1. As shown in photographs of non-treated and enzyme-treated cells, both the cell size and cell wall thickness of 10% -Staph increased to about 1.5 times Normal-Staph. 2. When Normal-Staph was exposed to L-11 enzyme, there occurred a gradual decrease in the OD. In the case of 10% -Staph, the OD showed a down-slope with a shoulder which rose in OD once at about 10 minutes after incubation. 3. The surface pattern of plasma membrane of Normal-Staph appeared to be made up of closely arranged spherical subunits. But in the case of 10% -Staph, the spherical subunits were indistinct and appeared to be sparsely located.No potential conflict of interest relevant to this article was reported.岡山医学会Acta Medica Okayama0030-1558859-101973細菌細胞中のカチオン測定法に関する検討481486ENTakeshiKatayamaKen-ichiTomochikaChiekoTakatsuYasuhiroKanemasaJutaroTawaraThe precise mensuration of the intracellular cation content is very significant from the biological point of view. When a salt concentration is medium is higher than in bacterial cells, it is very difficult to measure the intracellular cation content because of extracellular high contamination. In such a case, there is no other way except repeated washing for elimination of the outer contaminants. With the repeated washing method, authors attempted to measure accurately the intracellular cation content of Staph. aureus 209 P, cultivated in the medium of the various degrees of salt concentration, by flame photometory and atomic absorption spectrophotometory. The results were as follows. 1. When univalent cation concentration in cells is lower than in medium, it is necessary to wash the cells several times. The washing effect on extracellular contaminants could agree with the theoretical equation of washing that the contaminant decreased exponentially. The successive decrease of assay values by an easy grade must show a leakage of the intracellular Na. The reflective point could be considerated to show the Na content. 2. As in general potassium concentration in cells is higher than in medium, the accurate value was decided by extrapolation of the linear analytical quantity vs. washing time to zero time. 3. In spite of the extreme variation of sodium salt concentration in culture medium, the univalent cation content in Staph. aureus 209 P had hardly any shifts. 4. Bivalent cations, Mg and Ca, were not affected by the washing.No potential conflict of interest relevant to this article was reported.岡山医学会Acta Medica Okayama0030-1558915-61979パケット形成突然変異株を用いての黄色ブドウ球菌分裂様式の研究763774ENKen-ichiTomochikaYoshikazuHiraiAkinobuOkabeAkiraKumodeYasuhiroKanemasaIn order to study the process of cell division in Staphylococcus aureus which usually forms irregular cell clusters, a mutant which forms regularly arranged cell packets was isolated. The morphological characteristics of this mutant were studied by electron microscopy. The packets of this mutant were made by the appearance of thickened cell wall like substance which surrounded a group of cells. The formation of regularly arranged cell packets originated in the disturbance of cell segregation.No potential conflict of interest relevant to this article was reported.岡山医学会Acta Medica Okayama0030-1558955-61983大腸菌のペニシリン誘導フィラメント細胞におけるアミノ酸能動輸送能変化575581ENNobuakiNaitoKen-ichiTomochikaAkiraKumodeJunjiShiodeYasuhiroKanemasa最少発育阻止濃度以下のぺニシリンGにより誘導した大腸菌フィラメント細胞のアミノ酸能動輸送能の測定を行った.各種アミノ酸の能動輸送能は細胞の伸長に伴い低下したが,特にosmotic shock resistant基質においてその低下が著しかった.α-MGやTPMP(+)の取り込み能は,ぺニシリン処理の影響をほとんど受けなかった.このことから,アミノ酸能動輸送能の低下は,そのエネルギー源の消失によるのではなく,原形質膜中のアミノ酸能動輸送担体の分布またはその量的変化に起因することが示唆された.No potential conflict of interest relevant to this article was reported.岡山医学会Acta Medica Okayama0030-15589711-121985ブドウ球菌における耐塩機構 ―浸透圧調節に寄与するプロリンの動態―937946ENEikoNagamachiKen-ichiTomochikaYoshikazuHiraiTakashiMaruyamaAkinobuOkabeYasuhiroKanemasaS. aureus can grow in high salinity condition by a salt-tolerance mechanism. We have shown that S. aureus accumulated a large amount of proline in cytoplasm for the osmoregulation in high osmotic condition. In this study, we tried to elucidate the dynamics of proline by altering the salt concentration and supplementing proline in semisynthetic or synthetic media. S. aureus required only 20μM of proline as an essential amino acid under the normal condition, but 700μM to accumulate proline as an osmoregulator under the 10% NaCl condition. When the supplementary proline was not enough, S. aureus accumulated glutamine to compensate the osmoregulation by proline.No potential conflict of interest relevant to this article was reported.