rickettsia

例句：

1. 1. The rickettsiae are responsible for causing diseasesin humans and animals.
   立克次体是导致人类和动物疾病的罪魁祸首。
2. 2. Rickettsiae are a groupof bacteria that cause diseases in humans andanimals.
   立克次体是一种细菌，能够引起人类和动物的疾病。
3. 3. Rickettsiae are found in the environment and canbe transmitted to humans through contaminatedfood or water.
   立克次体存在于环境中，可以通过受污染的食物或水传播给人类。