We don't have synonyms for Rickettsiae yet — it may be a rare, specialized, newly coined, or misspelled word. The closest thesaurus entries we have are rickettsia, rickettsial and rickettsias.
(n) :
Any of a group of gram-negative bacteria, of the genus Rickettsia, carried as parasites by ticks, fleas and lice, that cause typhus and other diseases.
(n) :
(informal) Any bacterium of the order Rickettsiales.
(n) :
Any of a group of gram-negative bacteria, of the genus Rickettsia, carried as parasites by ticks, fleas and lice, that cause typhus and other diseases.
(n) :
(informal) Any bacterium of the order Rickettsiales.