Transmission refers to the method by which bacteria are transmitted to humans through air, water, food, or vectors. Modes of transmission may include contact, airborne, droplet, vectors, or vehicular.
Mollicutes transmission to humans occurs primarily through:
- Direct sexual contact
- Transplanted tissue (from donor to recipient)
- Childbirth or in utero (mother to fetus)
- Respiratory secretions (may be community-acquired, as with M. pneumoniae)
Thus, transmission occurs through human-to-human contact. Rare cases of transmission from animals to humans have been documented, but are not the norm. (M. pneumoniae bacteria are a human pathogen exclusively, and are primarily extracellular.)
Remember, many of these bacteria typically colonize mucosal and respiratory tract surfaces. They may already be present extracellularly - no additional human-to-human transmission is needed - when these bacteria invade an immunocompromised human host.
