Starvation effects on pathogenic Vibrio alginolyticus in natural seawater

To get a better understanding of the starvation survival strategy of pathogenic Vibrio alginolyticus, log-phase cells were inoculated into sterile natural seawater for starvation studies. The results showed that all of total bacteria number, viable bacteria number and CFU number of V. alginolyticus increased remarkably at the initial starvation stage; after reaching their peaks at 5 d, both total bacteria number and viable bacteria number of V. alginolyticus fell slowly, while the CFU number fell more quickly after reaching its peak at 10 d; V. alginolyticus elongated their cells at the prophase of starvation, and then shrunk their volume and turned their shapes into ovals from rods at the anaphase of starvation; starved cells showed more sensitivity to heating and UV; starved cells showed no significant difference from unstarved ones at the lowest detection limit determined by indirect enzyme-linked immunosorbent assay (ELISA); starved cells' ability to adhere to the skin mucus of large yellow croaker (Pseudosciaena crocea) showed a sharp decline as the starvation time increases; the cellular protein of V. alginolyticus increased remarkably at the anaphase of starvation. The results indicated that pathogenic V. alginolyticus could survive in starvation for relatively long periods of time (≥ 2 months) in 28℃ natural seawater due to the morphological and physiological changes; however, starved V. alginolyticus cells showed less virulence and higher sensitivity under environmental stresses.