Isolation and biological characterization of bacteriophages which infect Aeromonas hydrophila

This study aims to isolate and biological characterize bacteriophages which infect Aeromonas hydrophila, a causative of aquatic animal diseases. Two A. hydrophila bacteriophages, øAH-S1 and øAH-T5 were isolated from a total 100 water samples collected from ponds in Bangkok, Thailand. Electron micrograph indicated that these bacteriophages belonged to the Myoviridae family. Host-range determination revealed that øAH-S1 and øAH-T5 have different host range patterns and capable to lyse 62.0% (18/29) and 55.1 % (16/29) of tested A. hydrophila, respectively. The study on host-range among different species also showed different host range patterns and unable to lyse other tested bacteria including Escherichia coli, Pseudomonas aeruginosa, Proteus mirabilis, Vibrio cholerae and Plesiomonas spp. The efficiency to eradicate A. hydrophila ATCC 35654 in vitro showed that after 3 h of infection at multiplicity of infection 10, the reduction of average OD 600 nm from both øAH-S1and øAH-T5 infected culture was decreased to 0.095 and 0.08 respectively compared with 1.679 of non-infected control. Therefore, this study demonstrated bacteriophages which infected A. hydrophila and these bacteriophages may be useful for future development as biocontrol agents for control of A. hydrophila infection in aqua animals.