Survival of Fish-Pathogenic Strains of Aeromonas hydrophila under Starvation

The survival of Aeromonas hydrophila under low-nutrient conditions was investigated in this study. The behavior of three strains isolated from Common Carp Cyprinus carpio (China) and Channel Catfish Ictalurus punctatus (USA) was compared when cells were starved at different temperatures (4, 15, 25, and 35 degrees C) over a 4-week period. Temperature played a major role in cell survival, and cell viability decreased rapidly at 4 degrees C. Conversely, cells stored at 15 degrees C did not lose viability over time. Warmer temperatures (25 degrees C and 35 degrees C) decreased cell numbers by approximately one order of magnitude. Ultrastructural changes in cell morphology were observed in starved cells. Our data confirm that A. hydrophila can persist in the aquatic environment for extended periods, but survival is strongly influenced by temperature.