Carey R B, Brause B D, Roberts R B
Ann Intern Med. 1977 Aug;87(2):150-4. doi: 10.7326/0003-4819-87-2-150.
Vitamin B6-dependent viridans streptococci were isolated from two patients with microbial endocarditis. Because of their unique requirement for pyridoxal hydrochloride, these organisms did not grow normally in the media usually used in diagnostic laboratories. When tested in supplemented media, both strains were resistant to penicillin G and relatively sensitive to streptomycin. Penicillin-streptomycin synergy was demonstrated in vitro as well as in experimental endocarditis. These laboratory findings confirmed the clinical observations in these two patients that penicillin-streptomycin therapy should be used in vitamin B6-dependent streptococcal endocarditis. Nutritionally varient streptococci may be important pathogens in microbial endocarditis and must be considered in patients with suggestive clinical findings but negative blood cultures.
从两名患有微生物性心内膜炎的患者中分离出了依赖维生素B6的草绿色链球菌。由于它们对盐酸吡哆醛有独特需求，这些微生物在诊断实验室通常使用的培养基中不能正常生长。在添加了营养成分的培养基中进行测试时，两种菌株均对青霉素G耐药，而对链霉素相对敏感。在体外以及实验性心内膜炎中均证实了青霉素 - 链霉素的协同作用。这些实验室结果证实了这两名患者的临床观察结果，即对于依赖维生素B6的链球菌性心内膜炎应采用青霉素 - 链霉素治疗。营养变异型链球菌可能是微生物性心内膜炎中的重要病原体，对于有提示性临床发现但血培养阴性的患者必须予以考虑。
