<prompt> Which of the following statements is true about endemic typhus:ls caused by R. rickettsiils transmitted by bites of fleasHas no Mammalian reservoirCan be cultured in chemical defined culture medium  <response>: Option 1, 2, 3 Endemic typhus: Causative agent- R. typhi Vector - Flea, Rats are the reservoir Option 4 Rickettsiae cannot be cultivated in cell free media. Isolation can be done by cell lines Vero, primary chick embryo, WI-38, HeLa, egg yolk sac inoculation, or animal inoculation guinea pig. 