World Aquaculture Singapore 2022

November 29 - December 2, 2022



Md Yasin Ina-Salwanya,b*, Wan Omar Haifa-Haryania, Mohd Zamri-Saada,

Mohammad Noor Amal Azmaia,b and I. Natraha,b

aAquatic Animal Health and Therapeutics Laboratory, Institute of Bioscience,

Universiti Putra Malaysia, Serdang 43400, Selangor, Malaysia

bDepartment of Aquaculture, Faculty of Agriculture, Universiti Putra Malaysia, Serdang 43400, Selangor, Malaysia


Antibiotics are widely used in shrimp farming to prevent or treat disease outbreaks. Unfortunately, overuse of antibiotics leads to antimicrobial resistance (AMR) in the aquatic environment. Moreover, it is important to understand the current state of AMR strains, particularly in Malaysia. Thus, the study aims to provide a comprehensive database on the occurrence of Vibrio spp. as well as the distribution of virulence genes, antibiotic resistance, and the plasmid profiles of Vibrio spp. isolated from cultured shrimp in Peninsular Malaysia.

Briefly, a total of 210 cultured shrimp were collected from the seven farms in Peninsular Malaysia. The findings revealed that 225 presumptive Vibrio isolates were successfully isolated from the cultured shrimp which were then subjected to biochemical tests and molecular detection using the pyrH gene analysis. Eventually, 13 different Vibrio spp. were successfully isolated and characterized (Figure 1). The isolates were then analyzed with virulence genes; eight of the eleven virulence genes were detected, including pirA, pirB, tlh, flaC, toxR, chiA, luxR, and hlyA. Other virulence genes, such as tdh, trh, and ctxA, were not detected in any isolates. The findings revealed that, chiA (89%) was the most common virulence gene found, while the least common was hlyA (1%). Three Vibrio strains were chosen for the pathogenicity test based on virulence gene analysis. The results revealed that V. parahaemolyticus strain S12-3 was found to be more virulent compared to V. campbellii strain S10-4 and V. rotiferanius strain S24- 4.

Meanwhile, antibiotic susceptibility profiles revealed that all isolates were resistant to penicillin G (100%), but susceptible to norfloxacin (96%). 84% of Vibrio spp. exhibited a multiple antibiotic resistance (MAR) index of more than 0.2 while 16% of the isolates with MAR of less than 0.2. A total of 125 isolates harbored plasmids with molecular weights between 1.0 and above 10 kb, were detected among the resistant isolates. In conclusion, the current findings will be useful for policy-making and planning in aquaculture development as well as in the management of shrimp farming.