Aeromonas species: Pathogens of aquatic inhabitants with a human host range

Aeromonads are gram-negative, facultatively anaerobic, fermentative, oxidase-positive, nonsporeforming rods which, in contrast to vibrios, do not require added NaCl to complex media for growth and are resistant to the inhibitory action of the pteridine vibriostatic compound 0/129. In the fourth edition of Bergey's Manual of Determinative Bacteriology, they are assigned to the family Vibrionaceae within the genus Aeromonas, which comprises a single psychrophilic, nonmotile species, Aeromonas salmonicida, and three mesophilic polarly flagellated motile species Aeromonas hydrophila, Aeromonas sobria, and Aeromonas caviae. Recently three new mesophilic species, Aeromonas media, Aeromonas veronii, and Aeromonas schubertii have been recognized.