Abstract:
Ornamental fish export trade being a thriving industry, its substantial contribution to the Sri
Lankan economy underscores the necessity to address the associated issues. Presence of
pathogenic Vibrio spp. in export fish and packing water is a critical concern as they can pose public
health hazards while failing to comply with quarantine regulations during export, leading to
economic losses. The objective of this study was to isolate and characterize Vibrio spp. associated
with fish and packing water in the ornamental fish export trade, to assess its microbial safety.
Fish (n = 20) and packing water (n = 41) samples received by the Veterinary Investigation Center,
Welisara for routine quarantine certification during the period from August to October 2023,
were used in this study. Fish were dissected and bacterial cultures were attempted from internal
tissues while water samples were pre-enriched in alkaline peptone water, before culturing. All
cultures were attempted on Thiosulphate Citrate Bile-salts Sucrose agar at 37℃ for a period of
24 hours. Bacterial colonies isolated were characterized by employing a series of biochemical
tests. The occurrence of Vibrio spp. in samples obtained from different districts in Sri Lanka and
different sources, were analyzed and compared by using Chi-square test. Vibrio spp. was isolated
from both fish (10%; 2/20) and packing water (24.4%; 10/41). All Vibrio isolates from fish
samples were identified as V. cholerae. The occurrence of V. cholerae in packing water samples
tested was 60% (6/10) while it was 40% (4/10) for V. parahaemolyticus. There was no difference
in the occurrence of Vibrio between samples received from different districts and between
freshwater and marine fish tested (p > 0.05). In conclusion, Vibrio cholerae and Vibrio
parahaemolyticus were isolated from ornamental fish and packing water samples. Remedial
measures were suggested to the relevant ornamental fish farms to rectify the situation.
