Mycoplasma are single celled organisms which are usually considered to be bacteria. They have no cell wall, but they are able to grow on cell free media. Thus they are procaryotic cells bound by a single membrane.
There are a number of different Mycoplasma species; the most commonly encountered in day to day practice is Mycoplasma pneumoniae which is the only species causing respiratory pathology - specifically pneumonia - in humans. It may also result in myocarditis and in Stevens-Johnson disease.
Last reviewed 01/2018