The genus Aeromonas includes at least 13 species, among which is the motile, mesophilic Aeromonas hydrophila. The mesophilic species have been associated with a wide range of infections in humans that have been isolated frequently from various food products, and from patients with diarrhea. Drinking water and food are reservoirs of A. hydrophila and therefore may be important sources of human infections, leading to intestinal and non-intestinal
diseases. Epidemiological studies implicated Aeromonas species in causing water and food-borne outbreaks and traveler's diarrhea that are increasingly recognized by researchers as a cause of various clinical syndromes. The presence of Y. enterocolitica and A. hydrophila in food products is of a special concern since those organisms are capable of growth at refrigerator temperatures.