Noun

(wikipedia rickettsia) (wikispecies) (en-noun)

Any of a group of gram-negative bacteria, of the genus Rickettsia , carried as parasites by ticks, fleas and lice; they cause typhus and other diseases

Noun

Any infectious bacterium of the genus Mycoplasma , often specifically

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*{{quote-magazine, date=2013-03

, author= , title=The Smallest Cell , volume=101, issue=2, page=83 , magazine= citation , passage=It is likely that the long evolutionary trajectory of Mycoplasma went from a reductive autotroph to oxidative heterotroph to a cell-wall–defective degenerate parasite. This evolutionary trajectory assumes the simplicity to complexity route of biogenesis, a point of view that is not universally accepted.}}