Malinverni R, Bille J, Glauser M P
J Infect Dis. 1987 Jul;156(1):151-7. doi: 10.1093/infdis/156.1.151.
In rats challenged with viridans streptococci poorly susceptible to antibiotic killing, single doses of antibiotics only prevent endocarditis induced by bacterial inoculum sizes that produce disease in 90% of control animals (ID90): additional doses are required to protect against inocula exceeding the ID90. We investigated whether single-dose rifampin would extend the efficacy of single-dose prophylaxis to inocula exceeding the ID90. We used two strains of viridans streptococci highly susceptible to killing by rifampin and two resistant strains. All rats were injected with 10-1,000 times the ID90 of the four strains. Single-dose rifampin successfully prevented endocarditis due to all four strains. A few prophylaxis failures were observed after challenge with the two poorly susceptible strains, but in vivo emergence of resistant variants did not account for these failures. Thus, rifampin was the first antibiotic given as a single dose that successfully prevented experimental streptococcus endocarditis after challenge with high bacterial inocula.
在用对抗生素杀伤作用敏感性较差的草绿色链球菌攻击的大鼠中，单剂量抗生素仅能预防由在90%的对照动物中引发疾病的细菌接种量（ID90）所诱导的心内膜炎：需要额外剂量来预防超过ID90的接种量。我们研究了单剂量利福平是否会将单剂量预防的效果扩展至超过ID90的接种量。我们使用了两种对利福平杀伤作用高度敏感的草绿色链球菌菌株和两种耐药菌株。所有大鼠均注射了四种菌株ID90的10至1000倍。单剂量利福平成功预防了由所有四种菌株引起的心内膜炎。在用两种敏感性较差的菌株攻击后观察到了一些预防失败的情况，但体内耐药变异株的出现并不能解释这些失败。因此，利福平是第一种单剂量给药后能成功预防高细菌接种量攻击后实验性链球菌心内膜炎的抗生素。
