Dykhuizen R S, Frazer R, Duncan C, Smith C C, Golden M, Benjamin N, Leifert C
Infection Unit, Aberdeen Royal Infirmary, United Kingdom.
Antimicrob Agents Chemother. 1996 Jun;40(6):1422-5. doi: 10.1128/AAC.40.6.1422.
Dietary intake of nitrate generates salivary nitrite, which is acidified in the stomach, leading to a number of reactive intermediates of nitrogen, among which are the potentially carcinogenic N-nitrosamines. Acidified nitrite, however, also has antimicrobial activity which coincides with the formation of nitric oxide. The present study examines the antimicrobial effect in vitro of acidified nitrite on Salmonella enteritidis, Salmonella typhimurium, Yersinia enterocolitica, Shigella sonnei, and Escherichia coli O157. First-order regression plots showed a linear inverse relationship of log-transformed proton and nitrite concentrations with MICs and MBCs after 30 min, 2 h, and 24 h of exposure (P < 0.001 for all antibacterial activities). Susceptibility to the acidified nitrate solutions ranked as follows: Y. enterocolitica > S. enteritidis > S. typhimurium = Shigella sonnei > E. coli O157 (P < 0.05). Addition of SCN-, but not that of CI-, increased the antibacterial activity (paired t testing, P < 0.001). Generation of salivary nitrite from dietary nitrate may provide significant protection against gut pathogens in humans.
膳食中摄入的硝酸盐会产生唾液亚硝酸盐，其在胃中被酸化，从而产生多种氮的反应性中间体，其中包括潜在致癌的N-亚硝胺。然而，酸化的亚硝酸盐也具有抗菌活性，这与一氧化氮的形成同时发生。本研究检测了酸化亚硝酸盐对肠炎沙门氏菌、鼠伤寒沙门氏菌、小肠结肠炎耶尔森菌、宋内志贺菌和大肠杆菌O157的体外抗菌作用。一级回归图显示，在暴露30分钟、2小时和24小时后，对数转换后的质子和亚硝酸盐浓度与最低抑菌浓度（MIC）和最低杀菌浓度（MBC）呈线性反比关系（所有抗菌活性的P<0.001）。对酸化硝酸盐溶液的敏感性排序如下：小肠结肠炎耶尔森菌>肠炎沙门氏菌>鼠伤寒沙门氏菌=宋内志贺菌>大肠杆菌O157（P<0.05）。添加硫氰酸盐（SCN-）而非氯离子（Cl-）可增强抗菌活性（配对t检验，P<0.001）。膳食硝酸盐产生唾液亚硝酸盐可能为人类抵御肠道病原体提供重要保护。
