Chlamydia are obligate intracellular parasites (they are unable to synthesize ATP), which are larger than viruses and form their own cell walls like bacteria. They contain DNA and RNA and are considered bacterial. Like bacteria they are sensitive to wide spectrum antibiotics but not the penicillins.
There are two significant species:
It should be noted that the different serotypes of C. trachomatis cause different diseases.
Last reviewed 01/2018