Bracegirdle P, West A A, Lever M S, Fitzgeorge R B, Baskerville A
Division of Pathology, Public Health Laboratory Service, Salisbury, Wiltshire.
Epidemiol Infect. 1994 Feb;112(1):69-79. doi: 10.1017/s0950268800057435.
Aerosol infection (AI) of Porton outbred mice with Listeria species, exhibiting varying degrees of virulence, was compared with gastric intubation (GI) on the basis of numbers of deaths, 50% lethal dose (LD50) and pattern of listerial infection. The AI route appeared to be more sensitive, efficient and consistent than GI in that it required 10(5) fewer micro-organisms to obtain infection and death then ensued within 4 days, with GI deaths usually occurring on day 7. All the virulent strains tested caused 100% mortality by AI, while virulent and avirulent strains were indistinguishable by GI. Bacterial counts in the livers and spleens of infected mice were consistent with the relative virulence of the infectious agent using AI but not in GI mice. There were higher numbers of micro-organisms and more widespread lesions in the organs of AI mice than in GI. Results indicate that AI is an accurate in vivo indicator of virulence in listeria and using AI, bacterial counts in the liver and spleen could replace LD50 tests, thereby reducing the number of animals required for in vivo virulence testing.
将不同毒力的李斯特菌属对波顿远交群小鼠进行气溶胶感染（AI），并根据死亡数量、半数致死剂量（LD50）和李斯特菌感染模式，与胃插管感染（GI）进行比较。气溶胶感染途径似乎比胃插管感染更敏感、有效且一致，因为它所需的微生物数量少10⁵就能引发感染，随后在4天内出现死亡，而胃插管感染导致的死亡通常发生在第7天。所有测试的强毒株通过气溶胶感染均导致100%的死亡率，而强毒株和无毒株通过胃插管感染则无法区分。感染小鼠肝脏和脾脏中的细菌计数与使用气溶胶感染时病原体的相对毒力一致，但胃插管感染的小鼠则不然。与胃插管感染的小鼠相比，气溶胶感染小鼠器官中的微生物数量更多，病变范围更广。结果表明，气溶胶感染是李斯特菌毒力的一种准确的体内指标，使用气溶胶感染时，肝脏和脾脏中的细菌计数可以替代LD50测试，从而减少体内毒力测试所需的动物数量。
