Krasemann C, Müller H E
Zentralbl Bakteriol Orig A. 1975;231(1-3):206-13.
We studied the virulence of 20 Erysipelothrix rhusiopathiae strains in albino mice and investigated the interdependence between virulence, growth rate, and neuraminidase production. The minimal number of germs, lethal to mice (LD100) varied among the strains between 10(1) and mor ethan 10(7) per animal. The course of the disease was also very different. Some strains killed the mice rapidly within 3 days. In other strains, however, even a very high number of bacteria caused death only 7 days after infection or later, in which cases the disease became manifest long in advance by ruffled fur and glutinous eyes. A significant correlation was found between the average neuraminidase production in different media and the virulence (p equal to 99%; Fig. 2). We found a less marked dependence between growth rate and virulence (Fig. 3). Neuraminidase activity and growth rate seem to influence virulence rather independently. This is concluded from the fact, that some virulent strains are characterized by quick growth and by producing either no neuraminidase or in small quantities only. On the other hand, neuraminidase production cannot be separated completely from growth rate. An induction of neuraminidas activity in vivo was not observed, even when the bacteria persisted in the mice over a long period of time. We therefore conclude that a short term enzyme induction is not probable.
我们研究了20株猪丹毒杆菌在白化小鼠中的毒力，并调查了毒力、生长速率和神经氨酸酶产生之间的相互关系。对小鼠致死的最小细菌数量（LD100）在各菌株间有所不同，每只动物为10(1)至超过10(7)个。疾病进程也差异很大。一些菌株在3天内迅速致小鼠死亡。然而，在其他菌株中，即使大量细菌也仅在感染7天后或更晚才导致死亡，在这些情况下，疾病早在出现之前就表现为毛发蓬松和眼睛黏糊。在不同培养基中平均神经氨酸酶产生与毒力之间发现了显著相关性（p等于99%；图2）。我们发现生长速率与毒力之间的相关性不太明显（图3）。神经氨酸酶活性和生长速率似乎相当独立地影响毒力。这是基于以下事实得出的结论：一些有毒力的菌株具有生长迅速的特点，要么不产生神经氨酸酶，要么仅产生少量神经氨酸酶。另一方面，神经氨酸酶的产生不能完全与生长速率分开。即使细菌在小鼠体内长期存在，也未观察到体内神经氨酸酶活性的诱导。因此我们得出结论，短期酶诱导不太可能。
