Chen Chang-Hua
Department of Internal Medicine, Changhua Christian Hospital, Taiwan.
Heart Surg Forum. 2018 Jan 16;21(1):E023-E025. doi: 10.1532/hsf.1751.
There is no clear relationship between the serum inhibition test and clinical outcome for Streptococcus mitis (S. mitis) endocarditis. We report an 84-year-old male with endocarditis caused by penicillin-tolerant S. mitis. The results for the serum inhibitory test (SIT) and serum bactericidal test (SBT) showed a trough level of SIT = 1:256 and SBT = 1:4 and a peak level of SIT ≥ 1:1024 and SBT = 1:16. In addition, the SIT/SBT ratio was 64 at peak level and more than 64 at trough level, which is compatible with penicillin-tolerant S. mitis. Following a 42-day high-dose penicillin treatment (24 M IU/day, via a continuous drip), the patient made a good recovery. In vitro inhibitory and bactericidal test results were not a valid predictor of medical treatment failure. Physicians need to continue to evaluate the surgical indications when treating patients with S. mitis endocarditis.
对于缓症链球菌心内膜炎,血清抑制试验与临床结果之间没有明确的关系。我们报告了一名84岁因耐青霉素缓症链球菌导致心内膜炎的男性患者。血清抑制试验(SIT)和血清杀菌试验(SBT)结果显示,谷值水平为SIT = 1:256、SBT = 1:4,峰值水平为SIT≥1:1024、SBT = 1:16。此外,峰值水平时SIT/SBT比值为64,谷值水平时大于64,这与耐青霉素缓症链球菌相符。经过42天的高剂量青霉素治疗(2400万国际单位/天,持续静脉滴注),患者恢复良好。体外抑制和杀菌试验结果并不能有效预测治疗失败。治疗缓症链球菌心内膜炎患者时,医生需要持续评估手术指征。