ANTIBIOGRAM PROFILING OF VIBRO AND AEROMONAS SPECIES FROM SELECTED FISH FARMS IN BENIN CITY NIGERIA

ABSTRACT

Fish is known to be a good source of dietary protein and is consumed in many parts of the world. It is estimated that more than 30% of fish for human consumption comes from aquaculture However, a major setback in aquaculture is the sudden outbreak of diseases, and especially those caused by Vibrio species and Aeromonas species, which are considered significant economic and public health problems. Some of these diseases have been specifically associated with pathogens, which are resistant to antibiotics. Therefore, this study aimed to determine the antibiotics profile of Aeromonas and Vibrio species isolated from ponds in Benin City, Nigeria. Twenty (20) pond water samples were collected and analysed using culturebased methods. The samples were plated on Glutamate Starch Phenol (GSP) agar and Thiosulphate Citrate Bile Salt (TCBS) agar respectively. Presumptive colonies of Aeromonas and Vibrio were further characterized using biochemical tests. Isolates were tested against five (5) major classes of antibiotics using the disc diffusion method on Mueller-Hinton agar. Multiple Antibiotic Resistance (MAR) index of isolates was determined. Virulence potential of the isolates was determined based on haemolytic activity and results were shown as α (partial haemolysis), β (completre haemolysis) and γ (no haemolysis) respectively. Antibiotics test revealed high levels of resistance expressed by Vibro species to Cephalosporin, Penicillin, Tetracycline, Carbapenem and high level of sensitivity expressed by Vibro species to Kanamycin, Cephalosporin, tetracycline, and Carbapenems. Isolates of Aeromonas species showed high level of resistance to Cephalosporin, Penicillin, Monobactam and Carbapenem. However, they were observed to be sensitive to Aminoglycosides and Penicillin. The MAR index of the isolates was tested and was observed among isolate Aeromonas and Vibrio spp. The pathogenicity potential of Vibrio spp. based on haemolytic activity revealed β – Haemolysis [10/12(83.3%)], α –Haemolysis [2/12(16.7%)] and γ –Haemolysis [0/12(0%)] while that of Aeromonas spp revealed β –Haemolysis [0/6(0%)], α –Haemolysis [3/6(50%)] and γ –Haemolysis [3/6(50%)]. The antibiotics resistance level shown by isolates of Aeromonas and Vibrio species from this study as well as their ability to cause disease calls for serious attention to be given to the aquaculture industry as fish can act as vector for human pathogenic bacteria.