Antibiotic Resistant Bacteria in the Gut of Hatchery-reared Tilapia and Coho Salmon

Hasinakarki, Ahmed Mustafa,Arlislamaster, Shree Dhawale

doi:10.13189/ujmr.2013.010303

Abstract

Experiments were conducted to investigate the presence of antibiotic resistant bacteria in hatchery-reared fish that are important in commercial aquaculture. Two fish species, tilapia (Oreochromisniloticus) and cohosalmon(Oncorhynchuskisu tch)were obtained from certified hatcheries to investigate ifantibiotic resistant bacteria are present in their guts. The antibiotic resistant bacteria were isolated on the basis of their resistance to ampicillin. Six out of 8 tilapia and 3 out of 8 salmon yielded antibiotic resistant isolates. These results indicated prevalence of antibiotic resistant bacteria in guts of both fish species. Five bacterial isolates were taken from each of these nine fish that yielded ampicillin resistant bacteria (45 bacterial isolates in total) to test antibiotic sensitivity using six additional antibiotics: penicillin, vancomycin, chloramphenicol, tetracycline, streptomycin, and gentamicin. In addition to ampicillin, all isolates showed resistance to penicillin and sensitivity to gentamicin.Overall, ten different resistance phenotypes were observed and many isolates displayed multidrug resistance.

Highlights

Aquaculture is the fastest growing industry in the world that produces millions of tons of proteins and employs thousands of people
Husevag et al.[2] examined fish pathogens and their antibiotic resistance in the previously used aquaculture sites which were abandoned at the time of research and found fish pathogensin the sediments with resistance to antibiotics previously used for their treatment
The objectives of this research, were to test whether antibiotic resistant bacteria are present in coho salmon and tilapia guts and 2) to determine whether these bacterial isolates are resistant to multiple antibiotics

Summary

Introduction

Aquaculture is the fastest growing industry in the world that produces millions of tons of proteins and employs thousands of people. Husevag et al.[2] examined fish pathogens and their antibiotic resistance in the previously used aquaculture sites which were abandoned at the time of research and found fish pathogensin the sediments with resistance to antibiotics previously used for their treatment. This raised further awareness of the use of antibiotics in fish culture. We wanted to see if current hatchery-raised fish in the USA have antibiotic resistant bacteria in their gut. The objectives of this research, were to test whether antibiotic resistant bacteria are present in coho salmon and tilapia guts and 2) to determine whether these bacterial isolates are resistant to multiple antibiotics

Fish Sampling

Collection of Bacterial Samples

Isolation of Ampicillin Resistant Bacteria from Gut Samples

Gram Staining and Antibiotic Sensitivity Test

Ampicillin Resistant Bacterial Isolates

Discussion