RESPONSE OF PSEUDOMONAS-AERUGINOSA TO PYOCYANIN - MECHANISMS OF RESISTANCE, ANTIOXIDANT DEFENSES, AND DEMONSTRATION OF A MANGANESE-COFACTORED SUPEROXIDE-DISMUTASE
RESPONSE OF PSEUDOMONAS-AERUGINOSA TO PYOCYANIN - MECHANISMS OF RESISTANCE, ANTIOXIDANT DEFENSES, AND DEMONSTRATION OF A MANGANESE-COFACTORED SUPEROXIDE-DISMUTASE
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DOI：
10.1128/iai.60.2.328-336.1992
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发表时间：
1992-02-01
影响因子：
3.1
通讯作者：
COHEN, MS
中科院分区：
文献类型：
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作者：
HASSETT, DJ;CHARNIGA, L;COHEN, MS
绿脓杆菌产生一种蓝色色素，绿脓菌素。绿脓菌素是一种氧化还原活性吩嗪化合物，通过产生活性氧中间体杀死哺乳动物和细菌细胞。我们研究了铜绿假单胞菌抵抗绿脓菌素的机制。[C-14]绿脓菌素被大肠杆菌和铜绿假单胞菌吸收，但后者吸收较慢。作为细胞内超氧化物和/或过氧化氢产生的指示剂的氰化物不敏感呼吸，在绿脓菌素处理的铜绿假单胞菌中比在大肠杆菌中低50倍。杆菌铜绿假单胞菌的氰化物不敏感呼吸作用比大肠杆菌弱。大肠杆菌暴露于其他氧化还原活性化合物（百草枯，链黑菌素，和白花丹）。电子顺磁共振谱和自旋捕集表明，铜绿假单胞菌产生的绿脓菌素自由基和超氧阴离子比大肠杆菌少。杆菌E.大肠杆菌含有NADPH：绿脓菌素氧化还原酶，其增加绿脓菌素被NADPH还原的速率。相反，铜绿假单胞菌的细胞提取物不含NADPH：绿脓菌素氧化还原酶活性，实际上降低了绿脓菌素介导的NADPH氧化速率。抗氧化防御也可以降低铜绿假单胞菌对绿脓菌素的敏感性。在限磷培养条件下，绿脓菌素产量和过氧化氢酶活性均得到提高。超氧化物歧化酶活性也增加低磷条件下。当细胞在高磷酸盐琥珀酸盐培养基中生长时，铜绿假单胞菌形成了先前描述的铁超氧化物歧化酶和锰辅因子超氧化物歧化酶。这些结果表明，铜绿假单胞菌抵抗绿脓菌素，因为该化合物的有限的氧化还原循环，并且在有利于绿脓菌素产生的条件下，过氧化氢酶和超氧化物歧化酶活性增加。
Pseudomonas aeruginosa produces a blue pigment, pyocyanin. Pyocyanin is a redox-active phenazine compound that kills mammalian and bacterial cells through the generation of reactive oxygen intermediates. We examined the mechanisms by which P. aeruginosa resists pyocyanin. [C-14]pyocyanin was taken up by both Escherichia coli and P. aeruginosa, though more slowly by the latter. Cyanide-insensitive respiration, used as an indicator of intracellular superoxide and/or hydrogen peroxide production, was 50-fold less in pyocyanin-treated P. aeruginosa than in E. coli. P. aeruginosa showed less cyanide-insensitive respiration than E. coli upon exposure to other redox-active compounds (paraquat, streptonigrin, and plumbagin). Electron paramagnetic resonance spectrometry and spin trapping showed that P. aeruginosa generated less pyocyanin radical and superoxide than E. coli. Cell extracts from E. coli contained an NADPH:pyocyanin oxidoreductase which increased the rate of reduction of pyocyanin by NADPH. Conversely, cell extracts from P. aeruginosa contained no NADPH:pyocyanin oxidoreductase activity and actually decreased the rate of pyocyanin-mediated NADPH oxidation. Antioxidant defenses could also reduce the sensitivity of P. aeruginosa to pyocyanin. Under culture conditions of limited phosphate, both pyocyanin production and catalase activity were enhanced. Superoxide dismutase activity was also increased under low-phosphate conditions. When cells were grown in a high-phosphate succinate medium, P. aeruginosa formed a previously described iron-superoxide dismutase as well as a manganese-cofactored superoxide dismutase. These results demonstrate that P. aeruginosa resists pyocyanin because of limited redox cycling of this compound and that under conditions favoring pyocyanin production, catalase and superoxide dismutase activities increase.