Mycoplasmal

Mycoplasmal is an adjective relating to the genus Mycoplasma, a group of very small bacteria within the class Mollicutes. Mycoplasmas are among the smallest free-living organisms and are notable for lacking a cell wall. Their membranes contain sterols, and they exhibit pleomorphism and slow growth in culture. The absence of a cell wall renders them intrinsically resistant to beta-lactam antibiotics.

They colonize mucosal surfaces in humans and animals, often as part of the normal microbiota but also as pathogens. Notable human pathogens include Mycoplasma pneumoniae, which causes atypical pneumonia and pharyngitis, and Mycoplasma genitalium, linked to nongonococcal urethritis and pelvic inflammatory disease. Other species such as M. hominis and M. fermentans are associated with various urogenital and systemic infections.

Pathogenesis involves adherence to host cells via a specialized attachment organelle, leading to inflammation and tissue damage. Because they lack a cell wall, they are not stained well by Gram stain and require specialized culture conditions or molecular assays for detection. They often cause persistent, slow-onset symptoms.

Diagnosis commonly relies on nucleic acid amplification tests and serology; culture is slow and technically demanding, using rich media such as PPLO broth or agar. Treatment relies on antibiotics that inhibit protein synthesis or DNA replication, such as macrolides, tetracyclines, and fluoroquinolones. Beta-lactam antibiotics are ineffective against mycoplasmas.

Public health considerations include rising antibiotic resistance in several mycoplasmal species, particularly M. genitalium. Prevention focuses on safe sexual practices where relevant, accurate diagnosis, and appropriate antimicrobial stewardship to limit resistance.