Abstract

Bolaji A. S., Adelowo O. O, Oyegoke O. O, *Opasola O. A and Sawyerr H. O

ABSTRACT

To control infectious diseases, strategies such as vaccination and use of antimicrobial agents are employed in aquaculture as in other areas of animal production. Use of antimicrobial agents in aquaculture has resulted in the emergence of reservoirs of antimicrobial resistant bacteria in fish and other aquatic animals as well as in the aquatic environment. This study was carried out with the aim of isolating and characterizing multiple antibiotic resistant bacteria from water and sediment of two fish ponds in Offatedo, Osogbo Nigeria. Sediment and water samples were collected with sterile sample bottle which was placed against the movement of the water current. One milliliter of pond water and 1g of pond sediment was suspended into 9ml of sterile distilled water and serially diluted up to 10-6. Muller Hinton Agar (MHA) was prepared in two 250ml conical flasks and each were supplemented separately with 20mg /ml of Oxytetracycline and Doxycycline respectively, Aliquot of 0.5ml each of serially diluted pond water and sediment was plated out in four replicates and incubated at 350c for 24hours. The isolated bacteria were characterized according to the procedure described in Bergey Manual of bacteriology. Following Identification, minimum inhibitory concentration (MICs) were determined for all Isolates using agar dilution method as described by the European Committee for Antimicrobial Susceptibility Testing. The isolates obtained from the experimental pond and control pond reveal that there is high population of tetracycline resistant bacteria (TRB) in water and sediment of both ponds. This may be as a result of the use of antibiotics in the pond which creates a selective pressure on the bacteria flora of the pond. The high level of resistance to the antibiotics used in this study may be as a result of adaptation of the bacteria species to stress imposed by antimicrobial agents. In the light of this study, to control and prevent effectively the development and spread of antimicrobial resistance from fish farms in Nigeria and environmental hazards associated with residues of antibiotics used in fish production. There should be reduction in the use of the antimicrobial agent in aquaculture production. Also there should be a regulatory framework at the national level to ensure registration, approval, monitoring and control the use of an antimicrobial agent in aquaculture for public health safety.