Definition of rickettsia in English:



  • Any 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.

    • ‘These diseases result from a variety of infectious agents including bacteria, rickettsia, viruses and protozoa, or they may be caused by substances produced by the tick.’
    • ‘Typhus is caused by rickettsia, bacteria-like microorganisms transmitted through blood-sucking insects such as fleas, lice, and ticks.’
    • ‘It usually takes several hours of attachment and feeding before the rickettsiae are transmitted to the host.’
    • ‘Biological weapons can come in a variety of forms, including viruses, bacteria, and rickettsia (bacteria that can live inside host cells like viruses).’
    • ‘It was interesting to note that neither the viruses nor the rickettsiae multiplied in this cell line.’


Modern Latin, named after Howard Taylor Ricketts (1871–1910), American pathologist.