How is Aeromonas hydrophila primarily transmitted?

Aeromonas hydrophila is primarily transmitted through horizontal transmission, which occurs when the bacteria are spread from one organism to another through direct contact or the environment. This transmission often involves water as a vehicle, as Aeromonas species are commonly found in freshwater environments, including lakes, rivers, and aquaculture systems. They can spread through contaminated water, which can infect fish and other aquatic organisms, leading to various health issues.

Soil contamination can be a secondary source of bacteria, but it is not the primary mode of transmission for Aeromonas hydrophila. Airborne particles are also not significant for this pathogen since it is primarily aquatic and does not typically spread through the air. Vertical transmission can occur but is not the main route for most cases involving Aeromonas hydrophila; it is more relevant in different bacterial species or contexts. Therefore, horizontal transmission best describes how this bacterium propagates in various environments, particularly in aquatic settings.