Answer: rickettsias

AnswerCrossword Clue
rickettsiasAny of a group of very small bacteria that includes the causative agents of typhus and various other febrile diseases in humans. Like viruses, many of them can only grow inside living cells, and they are frequently transmitted by mites, ticks, or lice
rickettsiasRICKETTSIA, a genus of bacteria that cause typhus and Rocky Mountain spotted fever