Use of dot immunoassay for rapid detection of pathogenic bacteria <i>Vibrio alginolyticus</i> and <i>Aeromonas hydrophila</i> from shrimps and fishes

Abstract

Dot immunoasay (DIA) method was used to detect <i>Vibrio alginolyticus</i> and <i>Aeromonas hydrophila</i> in samples collected from infected shrimps <i>Penaeus monodon</i> and fishes <i>Mugil cephalus</i>. Bacterial cultures (OD₆₅₀ = 0.5) were diluted to 1:40 and 5 µl were spotted onto nitrocellulose paper (NCP). The NCPs were allowed to react separately with antiserum raised against <i>V. alginolyticus</i> and <i>A. hydrophila</i>. Out of 52 isolates from shrimp and 20 from fish, 19 and 6 isolates showed positive color reaction, respectively from shrimp and fishes. Cross reaction of <i>V. alginolyticus</i> antiserum was noted with <i>V. parahaemolyticus, V. harveyi</i> and <i>V. anguillarum</i> but not with <i>A. hydrophila</i> or <i>Pseudomonas</i> sp. Antiserum raised against <i>A. hydrophila</i> did not react with any <i>Vibrio</i> sp. or <i>Pseudomonas</i> sp. The test was found suitable for rapid detection of pathogenic bacteria in shrimps and fishes.