Characterization of the low-salinity stress in Vibrio vulnificus.
Vibrio vulnificus is a marine pathogenic bacterium commonly found in seawater or seafood. This organism encounters low-salinity stress in its natural environment and during food processing. This study was designed to investigate the response of V. vulnificus YJ03 to lethal low salinity (0.04% NaCl) and its adaptation to sublethal salinity (0.12% NaCl with 20 amino acids added). A short period in the nonculturable state was induced by lethal low-salinity stress followed by cell death after 30 min of stress. Addition of 1 mM glycine betaine or 0.5 mM sucrose reduced the damage. Low-salinity adaptation was achieved in the exponential-phase cells but not in the stationary-phase cells. Significant protection against lethal low-salinity stress was attained when the cells were adapted for as little as 1.5 min. The adapted cells were significantly protected against lethal low salinity and 2.4% sodium sorbate but sensitized to the challenge of heat (52 degrees C) and acid (pH 3.2). Nonlethal low-salinity treatment of seafood should be avoided to prevent stress adaptation of V. vulnificus.
Wong
Hin-Chung
HC
Department of Microbiology, Soochow University, Taipei, Taiwan 111, Republic of China. wonghc@scu.edu.tw
Liu
Shu-Hui
SH
D000222:Adaptation, Physiological; D000818:Animals; D015169:Colony Count, Microbial; D003257:Consumer Product Safety; D004305:Dose-Response Relationship, Drug; D005511:Food Handling / Q000379:methods*; D005516:Food Microbiology; D006801:Humans; D006863:Hydrogen-Ion Concentration; D017747:Seafood / Q000382:microbiology; D012965:Sodium Chloride / Q000494:pharmacology*; D013997:Time Factors; D041261:Vibrio vulnificus / Q000187:drug effects* / Q000254:growth & development / Q000502:physiology*; D014882:Water-Electrolyte Balance
D012965:Sodium Chloride