Bacteriology mnemonic

Obligate intracellular bacteria

The mnemonic

Rickettsia, Chlamydia, Coxiella, Ehrlichia

What each word stands for

  • RickettsiaSpotted fever and typhus groups
  • ChlamydiaTrachomatis and psittaci
  • CoxiellaQ fever
  • EhrlichiaTick-borne ehrlichiosis

Why it matters clinically

These cannot be grown on cell-free media, so diagnosis uses serology, PCR or cell culture.

Where it stops being reliable

Orientia and Anaplasma are also obligate intracellular; this lists names only.

Teaching aid, still awaiting independent review. Confirm facts in a standard source.

More mnemonics

Common questions

What is the Bacteriology mnemonic?

Rickettsia, Chlamydia, Coxiella, Ehrlichia. It helps you recall: Obligate intracellular bacteria.

What does "Rickettsia" stand for?

Spotted fever and typhus groups

What does "Chlamydia" stand for?

Trachomatis and psittaci

What does "Coxiella" stand for?

Q fever

What are all the parts of the Rickettsia, Chlamydia, Coxiella, Ehrlichia mnemonic?

Rickettsia: Spotted fever and typhus groups; Chlamydia: Trachomatis and psittaci; Coxiella: Q fever; Ehrlichia: Tick-borne ehrlichiosis.

Which topic does this mnemonic belong to?

It belongs to Bacteriology in Microbiology.

Where does this mnemonic stop being reliable?

Orientia and Anaplasma are also obligate intracellular; this lists names only.

How is this useful clinically?

These cannot be grown on cell-free media, so diagnosis uses serology, PCR or cell culture.

How do I make this mnemonic stick?

Say it aloud, write it from memory tomorrow, then again in a week. Then test yourself on a Microbiology question about Bacteriology.

Is this a standard mnemonic?

It is a teaching aid written or adapted by our team. Some resemble ones students share informally. Check any fact that matters in a standard source.