Antibiotics resistance of Vibrio spp. isolated from diseased seabass and tilapia in cage culture

Vibriosis has become one of the most important bacterial diseases in marine cultured
organisms in recent years. This study was focusing on isolation and identification of Vibrio spp.
isolated from diseased seabass (Lates calcarifer), tilapia (Oreochromis niloticus) and seawater
from Sri Tujuh lagoon in East Coast of Malaysia; also determination of antibiotic resistance
patterns among Vibrio spp. Vibrio species isolated from diseased seabass in Pantai Sri Tujuh,
Tumpat, Kelantan were screened for their antibiotic sensitivity patterns by Kirby-Bauer method. A
total of 47 isolates belonging to three different species were identified which are V.
parahaemolyticus, V. vulnificus, and V. alginolyticus. In this study, high incidence of
erythromycin, chloramphenicol and sulfamethoxazole resistance was observed among the Vibrio
isolates, whereas all isolates were susceptible to oxytetracycline. Vibrio isolates were 96% resistant
to one or more different classes of antibiotic, and 17 different resistance patterns were identified.
The MAR index of 0.4 indicating the Vibrio spp. in these farmed fish might have been
indiscriminately and continuously exposed to those antibiotics during culturing stages of the fish.
This study showed that multidrug-resistant Vibrio spp. were common in diseased seabass and
tilapia cultured at Sri Tujuh lagoon. These essential findings suggested involvement of seafood in
transmission of these pathogen to human. In addition, oxytetracycline can be used as a treatment to
combat vibriosis in diseased seabass and tilapia.