Tyndall R L, Domingue E L
Appl Environ Microbiol. 1982 Oct;44(4):954-9. doi: 10.1128/aem.44.4.954-959.1982.
Studies of the interaction of Legionella pneumophila with free-living amoebae showed that Naegleria lovaniensis and Acanthamoeba royreba could use L. pneumophila as a sole food source. However, growth of the amoebae on nonnutrient agar plates seeded with L. pneumophila was slower than growth on nonnutrient agar plates seeded with Escherichia coli. On inoculation of L. pneumophila into axenic cultures of N. lovaniensis and A. royreba, 99.9% of the L. pneumophila was destroyed within 24 h. After several weeks, however, some amoeba cultures became chronically infected and supported the growth of L. pneumophila. Amoebae exposed to L. pneumophila and containing adhered L. pneumophila, L. pneumophila antigens, or both, showed no increased pathogenic potential on intranasal inoculation of weanling mice. Similarly, L. pneumophila propagated in chronically infected amoeba cultures showed no increase in virulence on intraperitoneal inoculation of guinea pigs relative to L. pneumophila grown in yeast extract broth.
嗜肺军团菌与自由生活变形虫相互作用的研究表明，洛万内格氏阿米巴和罗伊氏棘阿米巴可以将嗜肺军团菌作为唯一的食物来源。然而，在接种嗜肺军团菌的无营养琼脂平板上，变形虫的生长速度比接种大肠杆菌的无营养琼脂平板上的生长速度要慢。将嗜肺军团菌接种到洛万内格氏阿米巴和罗伊氏棘阿米巴的无菌培养物中后，99.9%的嗜肺军团菌在24小时内被破坏。然而，几周后，一些变形虫培养物会受到慢性感染，并支持嗜肺军团菌的生长。暴露于嗜肺军团菌并含有附着的嗜肺军团菌、嗜肺军团菌抗原或两者的变形虫，在对断奶小鼠进行鼻内接种时，并未表现出致病性增加。同样，相对于在酵母提取物肉汤中生长的嗜肺军团菌，在慢性感染变形虫培养物中繁殖的嗜肺军团菌在对豚鼠进行腹腔接种时，毒力也没有增加。
