Dhople A M
Department of Biological Sciences, Florida Institute of Technology, Melbourne 32901-6988, USA.
Microbios. 1996;85(342):35-44.
In order to evaluate factors responsible for the failure of Mycobacterium leprae to multiply in cell-free cultures in vitro studies were undertaken to determine the possible poisoning of the organism by hydroxide and superoxide radicals produced in the growth medium. The superoxide dismutase activity was very low, 10% of the levels found in armadillo cells, while measured activity of catalase and glutathione peroxidase was negligible. Susceptibility of M. leprae to hydrogen peroxide was enhanced by potassium iodide but not by lactoperoxidase. The addition of high amounts of catalase completely prevented hydrogen peroxide-mediated killing of M. leprae. Superoxide generated by the action of xanthine oxidase on xanthine was lethal to M. leprae, but superoxide dismutase added to the reaction mixture gave significant protection. Thus superoxide radicals may be a major cause for the sudden termination of growth of M. leprae in primary cultures and also for failure of subcultures.
为了评估导致麻风分枝杆菌无法在无细胞培养中繁殖的因素，开展了体外研究，以确定生长培养基中产生的氢氧根和超氧阴离子自由基对该微生物可能产生的毒害作用。超氧化物歧化酶活性非常低，仅为犰狳细胞中所发现水平的10%，而过氧化氢酶和谷胱甘肽过氧化物酶的实测活性可忽略不计。碘化钾可增强麻风分枝杆菌对过氧化氢的敏感性，但乳过氧化物酶则无此作用。添加大量过氧化氢酶可完全防止过氧化氢介导的对麻风分枝杆菌的杀伤。黄嘌呤氧化酶作用于黄嘌呤产生的超氧阴离子对麻风分枝杆菌具有致死性，但向反应混合物中添加超氧化物歧化酶可提供显著的保护作用。因此，超氧阴离子自由基可能是原代培养中麻风分枝杆菌生长突然终止以及传代培养失败的主要原因。
