Fu H S, Hassett D J, Cohen M S
Department of Microbiology, University of North Carolina, Chapel Hill 27514.
Infect Immun. 1989 Jul;57(7):2173-8. doi: 10.1128/iai.57.7.2173-2178.1989.
Neisseria gonorrhoeae, an obligate human pathogen, is subjected to oxidant stress when attacked by O2 reduction products formed by neutrophils. In this study, exposure of gonococci to sublethal concentrations of superoxide and hydrogen peroxide (and related O-centered radicals) resulted in phenotypic resistance to oxidant stress. Adaptation required new protein formation but was not related to increases in superoxide dismutase or catalase. We have previously demonstrated that gonococci use phagocyte-derived L-(+)-lactate. Oxidant stress of greater magnitude than that required for adaptation led to a generalized increase in bacterial metabolism, particularly in L-(+)- and D-(-)-lactate utilization and lactate dehydrogenase activity. Increased lactate utilization required new protein synthesis. These results suggest the possibility that lactate metabolism is of importance to N. gonorrhoeae subjected to oxidant stress. Use of lct mutant organisms unable to use L-(+)-lactate should allow examination of this hypothesis.
淋病奈瑟菌是一种专性人体病原体，当受到中性粒细胞形成的氧还原产物攻击时会遭受氧化应激。在本研究中，将淋球菌暴露于亚致死浓度的超氧化物和过氧化氢（以及相关的以氧为中心的自由基）会导致其对氧化应激产生表型抗性。适应性变化需要新蛋白质的形成，但与超氧化物歧化酶或过氧化氢酶的增加无关。我们之前已经证明，淋球菌利用吞噬细胞衍生的L-(+)-乳酸。比适应性所需的更大程度的氧化应激导致细菌代谢普遍增加，特别是在L-(+)-和D-(-)-乳酸利用以及乳酸脱氢酶活性方面。乳酸利用增加需要新蛋白质的合成。这些结果表明，乳酸代谢对于遭受氧化应激的淋病奈瑟菌可能很重要。使用无法利用L-(+)-乳酸的lct突变体生物应该可以检验这一假设。
