<unk>  of symbionts is the transfer of a microbial symbiont from the parent directly to the offspring. Many metazoan species carry symbiotic bacteria which play a mutualistic, commensal, or parasitic role. A symbiont is acquired by a host via horizontal,<unk> , or mixed<unk> .
Vertical transmission
Horizontal transmission
Airborne transmission
Human-to-human transmission
Sylvatic cycle
Epizootic
Social contagion
Natural reservoir