Like other mycoplasmas M. fermentans is characterized by the absence of a peptidoglycan cell wall and resulting resistance to many antibacterial agents.

Investigations have focused on a possible link to it being a cofactor in HIV infection[3] as well as fibromyalgia, Gulf War syndrome and Chronic fatigue syndrome, however the belief that M. fermentans is pathogenic in such conditions has largely been disregarded after the failure of several large scale studies to find a link.

Mycoplasma fermentans was first described by Ruiter and Wentholt in 1952 from isolate of a human genital infection, which led to the initial name G-strain.

[5] In 1955 Edward proposed a new naming structure renaming his human type 3 strain and Ruiter and Wentholt's G-strain to M. fermentans due to its believed unique ability amongst the group to ferment multiple sugars.

This new mycoplasma, dubbed M. incognitus was concerning as it could either be an opportunistic co-infection or a sexually transmitted infectious cofactor to the HIV disease process.