Detection of Virulence Genes in Aeromonas Hydrophil Isolated from Rabbits by Polymerase Chain Reaction

The present study was performed on 260 rabbits (48 diseased and 212 freshly dead ones) from rabbit farms at Kaliobia Governorate for inspection of Aeromonas hydrophila. Samples were taken from these rabbits (liver; heart blood; lung; intestine; kidney and spleen from each one) after clinical and postmortem examinationfor bacteriological examination. The results revealed that, 195 A. hydrophila strains (12.5%) were isolated, 13(0.8%) from48 diseased rabbits and 182(11.7%) from 212 freshly dead ones. Moreover, higher rates of isolation of A. hydrophila from intestine (42.0%); liver (24.1%); heart blood (14.9%); lung (9.2%); kidney (6.7%) and spleen (3.1%).Ciprofloxacin, Enrofloxacin, Gentamicin, and Sulpha trimethoprim were the most proper antibiotics with the highest in vitro efficiency against isolated A. hydrophila. PCR results showed that, aerolysin (aerA) toxin virulence gene was detected in 10 out of 14 studied strains (71.4%). While haemolysin (hly) toxin virulence gene was detected in 4 out of 10 studied strains (40.0%).Moreover, the sequences obtained for aerolysin (aerA) gene had accession number KM 592977atGenBankand were 94% to 98% identical to the corresponding GenBank sequences. To the best of our knowledge, it may be the first record of studying the virulence genes of A. hydrophila strains isolated from rabbits in Egypt.