Candeli A, Mastrandrea V, Cenci G, de Bartolomeo A
Ann Sclavo. 1975 Jan-Feb;17(1):102-14.
The previously postulated hypothesis, according to which different species of the genus Bacillus show strictly similar morphological and biological properties when the same variants are considered, has been confirmed by the present research. The "S" (smooth) variants of the five studied species (B. anthracis, B. subtilis, B. cereus, B. megaterium, B. mesentericus) are all lethal, at the experimented dose, for mice, whereas the "R" (rough, "star-shaped" colonies) variant of the same strains of the same species are all not pathogenic for the same animals. Likewise the "S" variants of three species tested in guinea pigs showed to be pathogenic; particularly B. anthracis and B. subtilis were lethal, whereas B. cereus caused a black eschar like that one described in the cutaneous anthrax. The "RS" variant ("medusae head" surface colonies) is not pathogenic for mice and guinea pigs (even B. anthracis) if the tested strains are cultivated for years in ordinary solid nutrient media; the same morphological variants are strongly pathogenic (also B. subtilis), when the strains are recently isolated from infected animals. The similarity between the same "S" variants of different species is proved also by the protection given by anti-anthrax serum to animals infected by B. subtilis.
先前提出的假说，即当考虑相同变体时，芽孢杆菌属的不同物种表现出严格相似的形态和生物学特性，已被本研究证实。所研究的五个物种（炭疽芽孢杆菌、枯草芽孢杆菌、蜡样芽孢杆菌、巨大芽孢杆菌、肠系膜芽孢杆菌）的“S”（光滑）变体，在实验剂量下，对小鼠均具有致死性，而同一物种相同菌株的“R”（粗糙、“星形”菌落）变体对相同动物均无致病性。同样，在豚鼠中测试的三个物种的“S”变体显示具有致病性；特别是炭疽芽孢杆菌和枯草芽孢杆菌具有致死性，而蜡样芽孢杆菌会引起一种类似于皮肤炭疽中描述的黑色焦痂。如果测试菌株在普通固体营养培养基中培养数年，“RS”变体（“美杜莎头”表面菌落）对小鼠和豚鼠（甚至炭疽芽孢杆菌）无致病性；当菌株最近从感染动物中分离出来时，相同的形态变体具有很强的致病性（枯草芽孢杆菌也是如此）。抗炭疽血清对感染枯草芽孢杆菌的动物的保护作用也证明了不同物种相同“S”变体之间的相似性。
