Distribution of Potentially Pathogenic Vibrio parahaemolyticus in Seafood and the Aquatic Environment of Mumbai, India

Abstract

The occurrence of total and pathogenic Vibrio
parahaemolyticus in fresh seafood and the coastal
environment of Mumbai, India was examined in this
study. Samples comprising of fish, shellfish, coastal
sediment and coastal waters were analyzed for
V. parahaemolyticus by selective enrichment and
isolation. Biochemically identified isolates were
tested for the presence of tlh (thermolabile hemolysin),
tdh (thermostable direct hemolysin) and trh
(tdh-related hemolysin) by polymerase chain reaction
(PCR). While Chromogenic Vibrio (CV) agar
yielded V. parhaemolyticus from all samples (100%),
TCBS agar yielded V. parahaemolyticus from 57.1% of
the samples. The incidence of trh+ V. parahaemolyticus
was high, being isolated from 16.4% of the samples
analyzed, while the tdh+ V. parahaemolyticus were
isolated from 1.4% of samples. Two tdh-, trh+ isolates
from the coastal water were positive by a in
pandemic group-specific (GS) PCR. The study
suggests that seafood and coastal environment may
harbor pathogenic V. parahaemolyticus with characteristics
of pandemic clones, although their incidence
is very low. Further, sodium taurocholate
(ST) broth and chromogenic Vibrio (CV) agar
combination is highly suitable for the isolation of
total and pathogenic V. parahaemolyticus from seafood
and environmental samples.