Motile Aeromonas Septicemia (MAS)

▪️  The motile aeromonads are small Gram-negative bacilli or coccobacilli rods (~0.5 x 1µm) (fig 1), and non-spore-forming bacteria.

▪️  It can thrive and flourish in a wide range of temperatures, reaching as high as 37 ºC.

▪️  The virulence factors of A. hydrophila include haemolysin, aerolysin, cytosine, gelatinase, enterotoxin, and antimicrobial peptides.

▪️  MAS outbreaks are usually associated with environmental stressors that have diminished fish immunity to resist pathogen. These factors include temperature stress, stressful water quality conditions (low dissolved oxygen, high ammonia, high organic load, pollution), overcrowding, poor nutritional condition, physical injury, and infection with another bacteria, virus, parasites, or fungi (Harikrishnan & Balasundaram, 2005).