Hamon C B, Klebanoff S J
J Exp Med. 1973 Feb 1;137(2):438-50. doi: 10.1084/jem.137.2.438.
H(2)O(2) formation by Streptococcus mitis was measured by the catalase-dependent conversion of [(14)C]formate to (14)CO(2) ; it was optimal at pH 6.0-6.5 and required glucose. The H(2)O(2) formed by S. mitis could be employed as a component of an antimicrobial system that also included lactoperoxidase (LPO) and either iodide or thiocyanate ions in the concentrations present in saliva. The antimicrobial effect of the LPO-iodide-S. mitis system was measured by the decrease in the viable cell count of the target organisms (Escherichia coli, Staphylococcus aureus, Candida tropicalis). The antimicrobial effect of the LPO-thiocyanate-S. mitis system was measured by the decrease in the rate of growth or the rate of uptake of [(14)C]valine by the target organisms (E. coli, S. aureus). Mixed or parotid saliva could replace LPO and thiocyanate ions in the S. mitis-dependent inhibition of bacterial growth and valine uptake. The presence in saliva of a peroxidase-mediated, antimicrobial system dependent on microbial metabolism for H(2)O(2) and its role as a natural host defense mechanism are considered.
通过过氧化氢酶介导的[(14)C]甲酸向(14)CO(2)的转化来测定缓症链球菌形成H(2)O(2)的情况；其在pH 6.0 - 6.5时最为适宜且需要葡萄糖。缓症链球菌形成的H(2)O(2)可用作抗菌系统的一个组成部分，该系统还包括唾液中存在的浓度的乳过氧化物酶（LPO）以及碘离子或硫氰酸根离子。通过靶标微生物（大肠杆菌、金黄色葡萄球菌、热带假丝酵母）活菌数的减少来测定LPO - 碘 - 缓症链球菌系统的抗菌效果。通过靶标微生物（大肠杆菌、金黄色葡萄球菌）生长速率或[(14)C]缬氨酸摄取速率的降低来测定LPO - 硫氰酸根 - 缓症链球菌系统的抗菌效果。混合唾液或腮腺唾液可替代LPO和硫氰酸根离子，在缓症链球菌依赖的细菌生长抑制和缬氨酸摄取抑制中发挥作用。文中考虑了唾液中存在的一种依赖微生物代谢产生H(2)O(2)的过氧化物酶介导的抗菌系统及其作为天然宿主防御机制的作用。
