Molecular Detection and Antibiotic Sensitivity Pattern of Aeromonas hydrophila Isolated from Diseased Oreochromis niloticus In Egypt

Abstract

The genus Aeromonas has been recognised as an important pathogenic species in aquaculture that causes motile Aeromonas septicaemia (MAS). This study was conducted on 224 samples were collected from tilapia (n = 56), water (n = 56), the sediment of the fish farm soil (n= 56), and stool of patients suffering from gastroenteritis (n = 56). A total of 87 positive Aeromonas spp. isolates were recovered from 224 samples with an overall prevalence of 38.8%, distribution of them based on their sources was 55.3% (31/56) from diseased tilapia fish, 21.4% (12/56) from water, 30.3% (17/56) from soil, and 48.2% (27/56) from stool swab of diarrheic patients. The Aeromonas species showed different level of antibiotics susceptibility based on the inhibition zone observed around the antibiotics disc. Aeromonas spp. were all resistant to ampicillin, amoxacillin and pencillin g with an average zone of inhibition of 10mm, 8mm and 9mm respectively but highly susceptible to moxfloxacin, norfloxacin and ciprofloxacin with an average zone of inhibition of 21 mm, 17 mm and 24 mm respectively while they were randomly susceptible to cefotaxime, gentamycin and streptomycin. Therefore, moxfloxacin, norfloxacin and ciprofloxacin are effective drugs that can be use in the treatment of Aeromonas associated infections. PCR using 16S rRNA was used to confirm A. hydrophila positive isolates. Due to Aeromonas is a hard stretched and elastic organism there is a need for antibiotic sensetivity test before the treatment since some strains of the Aeromonas species were randomly susceptible to the some of the antibiotics. PCR using 16S rRNA was used to confirm A. hydrophila positive isolates.