The total number of pathogenic V. parahaemolyticus bacteria in
the respective samples was the sum of tdh+ and trh+ specimens
(Npat = Ntdh+ + Ntrh+), where the virulent factors in the
respective strains are independent of each other (only carry
the tdh gene or trh gene). This was based on recent literatures,
in which pathogenic V. parahaemolyticus isolates from Malaysia
only carry either the tdh or trh gene, respectively, but not both
(Letchumanan et al., 2015; Paydar et al., 2013).