Identification and Antibiotic Sensitivity Test of the Bacteria Isolated from Tra Catfish (Pangasianodon hypophthalmus [Sauvage, 1878]) Cultured in Pond in Vietnam

Abstract

Tra catfish (Pangasianodon hypophthalmus [Sauvage, 1878]) cultured in Vietnam is one of the most important products for export to international market such as U.S.A., Japan and Europe. The bacterial isolation was conducted from pond-cultured Tra catfish in the provinces with intensive culture system. There were a total of 97 isolates from 65 diseased fish. Sixty-six isolates from 97 isolates were identified by biochemical tests. They were consisted of Edwardsiella ictaruli (58 isolates [87.9%]), Aeromonas hydrophila (2 isolates [3.03%]) and 6 unidentified isolates (9.07%). Antibiotic sensitivity test was also conducted to determine the drugs that could be used to control these two bacteria. Effective drugs that showed good sensitivity against E. ictaluri were ciprofloxacin, amoxycillin and ampicillin, florfenicol, doxycycline and oxytetracycline (in order of number of isolates that showed sensitive). Two isolates of Aeromonas hydrophila were sensitive to sulphamethoxazole, ciprofloxacin, oxytetracycline, enrofloxacin, erythromycin, sulphamethoxazole/trimethoprim, doxycycline and florfenicol.