Papp-Szabò E, Firtel M, Josephy P D
Department of Chemistry and Biochemistry, Guelph-Waterloo, Centre for Graduate Work in Chemistry, University of Guelph, Ontario, Canada.
Infect Immun. 1994 Jul;62(7):2662-8. doi: 10.1128/iai.62.7.2662-2668.1994.
The respiratory burst of neutrophils is believed to kill bacteria by generating oxidative species, such as superoxide anion, hydrogen peroxide, and oxidized halogen species. The oxyR gene of Salmonella typhimurium controls a regulon induced by oxidative stress, such as exposure to hydrogen peroxide. Some researchers have suggested that oxyR may play a key role in bacterial survival following phagocytosis. We have tested this possibility by comparing the survival, following exposure to human neutrophils, of isogenic strains bearing different oxyR alleles. Neither inactivation of the oxyR gene nor constitutive overexpression of the oxyR-regulated proteins (oxyR1 allele) greatly alters bacterial resistance to neutrophils. The katG gene, encoding the oxyR-regulated enzyme hydroperoxidase I, was also without effect on survival following exposure to neutrophils. We conclude that the oxyR response does not play a significant role in the resistance of S. typhimurium to phagocytic killing in vitro.
中性粒细胞的呼吸爆发被认为是通过产生超氧阴离子、过氧化氢和氧化卤素等氧化物质来杀死细菌的。鼠伤寒沙门氏菌的oxyR基因控制着一个由氧化应激诱导的调节子，如暴露于过氧化氢。一些研究人员认为，oxyR可能在吞噬作用后细菌的存活中起关键作用。我们通过比较携带不同oxyR等位基因的同基因菌株在暴露于人类中性粒细胞后的存活率来测试这种可能性。oxyR基因的失活或oxyR调节蛋白的组成型过表达（oxyR1等位基因）都不会显著改变细菌对中性粒细胞的抗性。编码oxyR调节酶过氧化氢酶I的katG基因，在暴露于中性粒细胞后对存活率也没有影响。我们得出结论，oxyR反应在鼠伤寒沙门氏菌体外对吞噬杀伤的抗性中不起重要作用。
