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Inhibition of pathogenic Vibrio spp. in shellfish harvested in Venezuela
Abstract
Venezuelan soft clams (Tivela mactroides), coastal seawater and fresh water were analyzed to determine the presence of Vibrio parahaemolyticus, Vibrio vulnificus, and Vibrio cholerae. Levels of Clostridium perfringens and fecal coliforms in these samples were evaluated to determine a relationship between incidence of these species and Vibrio species. A statistically significant relationship was found between Vibrio counts and C. perfringens counts in soft clams and seawater. No relationship was found between fecal coliform counts and Vibrio counts in the same samples or between C. perfringens and Vibrio spp. in river water. The growth and survival of V. cholerae, V. vulnificus and V. parahaemolyticus were determined in marine broth with different acids, pH levels, incubation times and temperatures. Greatest antimicrobial activity was observed at 25 C with lactic and acetic acids. All strains were capable of growth in media acidified with HCl at pH values lower than previously reported (pH 4.8). Inhibition of each Vibrio spp. by lactic acid bacteria (LAB) was tested at four concentrations of sucrose added to growth medium. All of the Vibrio spp. were inhibited by the presence of mesophilic lactic acid bacteria. The inhibitory capacity of Lactobacillus plantarum and Lactobacillus acidophilus against V. cholerae, V. vulnificus and V. parahaemolyticus, inoculated in soft clams, was also evaluated. All Vibrio spp. except V. vulnificus were inhibited by the LAB in media with 1% saccharose at 25 C. A higher inhibitory effect was obtained with L. acidophilus than with L. plantarum. At 5 C, all three pathogenic Vibrio spp. were inhibited. Thus, lactic acid bacteria could be used to inhibit Vibrio spp. in soft clams, or as a food safety system to guarantee rejection of Vibrio-contaminated seafood that has been subjected to temperature abuse.
Subject Area
Food science
Recommended Citation
Margolis de Arocha, Marlene Adela, "Inhibition of pathogenic Vibrio spp. in shellfish harvested in Venezuela" (1993). ETD collection for University of Nebraska-Lincoln. AAI9415983.
https://digitalcommons.unl.edu/dissertations/AAI9415983