Mycoplasma is a genus of wall-less bacteria in the class Mollicutes, characterized by the smallest genomes of any self-replicating organisms (~580–1,350 kb). The lack of a cell wall makes them intrinsically resistant to beta-lactam antibiotics and undetectable by Gram staining. Key human-pathogenic species include M. pneumoniae (atypical pneumonia), M. genitalium (STI), and M. hominis (urogenital infections).
Like ureaplasma (a fellow Mollicute), Mycoplasma species are parasitic, depending on host cells for nutrients they cannot synthesize — including cholesterol for membrane stability.
Reproductive Tract Associations
- Prostatitis: M. hominis and M. genitalium detected in prostatic secretions of chronic prostatitis patients [1].
- Male infertility: Mycoplasma colonization of seminal fluid associated with reduced sperm quality [2].
- Endometriosis: Part of vaginal microbiome shifts in endometriosis patients [3].
Gut and Systemic Associations
- Multiple sclerosis: Mycoplasma detected in gut microbiome studies of MS patients [4].
- Crohn's disease: Part of gut microbiome shifts during Crohn's remission/relapse cycles [5].
- Oral microbiome: Affected by common medications [6].
Cross-References
- ureaplasma — sister Mollicute genus; shares wall-less biology and urogenital niche
- endometriosis — vaginal microbiome associations
- propionic acid — some Mycoplasma species produce propionate