Investigation of gcat gene and antibiotic resistance pattern of Aeromonas hydrophila isolated from hemorrhagic septicemia’s cases in fish farms

The significance of Aeromonas hydrophila concerning hemorrhagic septicemia in aquaculture farms production in Duhok province, Iraq was investigated. Antibiotic-resistant profiles of isolates were also investigated with 8 antibiotics. Bacterial isolates were identified by using morphological and biochemical tests and confirmed molecularly by amplification of gcat gene. Out of 25 examined fish, only 19 fish were harbored A. hydrophila. Twenty-four A. hydrophila strains were isolates from 100 organ samples. Ninety-six percentages of the isolates were resistant to each of the imipenem and gentamicin, followed by doxycycline 92%, ciprofloxacin and trimethoprim-sulfamethoxazole 88%, norfloxacin 58% and ceftriaxone 33%. None were resistant to levofloxacin. Eighty-eight percentages were multiple antibiotics resistant. The high isolation rate of A. hydrophila in our study indicates that this species was the major cause of the outbreak in hemorrhagic septicemia’s cases in our area affecting carp farms and the high rate of resistance should be considered as these isolates can serve as a resistance source for human being during food series and make a great challenge for their therapeutic opportunity.