Survival of certain Vibrio species at low temperature storage

Abstract

Vibrios are indigenous to marine creatures and the marine environment. The survival pattern of two important pathogenic vibrio species, namely V. parahaemolyticus and V. vulnificus isolated from seafood were studied at -18+/- degree C and at 6=/-2 degree C in three different substrates. viz. fish muscle homogenate tryptic soy broth and 3%sodium chloride solution. The rate of survival of vibrio parahaemolyticus was noted in fish muscle substrate at both test temperatures and they were found to be viable till the end of study period of 90 days. For V. vulnificus also the maximum survival was in fish muscle substrate at the two test temperatures, but the viability decreased gradually withstorage time, reaching undetectable levels by the end of 60 days at -18+/-2 degree C. However, at 6+/-2 degree C, they continued to survive till the end of storage period. The study indicates that even though multiplication of pathogenic vibrios are arrested at low temperatures, they can remain viable in fish muscle for long duration and that V. vulnificus is more sensitive tp low temperature than V. parahaemolyticus.