TITLE:
Antibiotics Resistance Pattern and Plasmid Profiling of Edwardsiella tarda Isolated from Heterobranchus longifilis
AUTHORS:
F. C. Ogbonne, E. R. Ukazu, F. C. Egbe
KEYWORDS:
Edwardsiella tarda, Plasmid Profiling, Antibiotic Resistance, Heterobranchus longifilis
JOURNAL NAME:
Journal of Biosciences and Medicines,
Vol.6 No.4,
April
27,
2018
ABSTRACT: A study
was carried out to investigate antibiotic resistance patterns and plasmid
profiling of Edwardsiella tarda isolated from farmed-cultured Heterobranchus
longifilis in Lagos State, Southwest of Nigeria. A
total of 44 Edwardsiella isolates were recovered from 80 fish samples
collected from the 10 fish farms using selective random
stratification. It was observed that Edwardsiella
tarda isolates were 100% resistant to Amoxicillin, Chloranphenicol,
Levofloxacin, Streptomycin and 90% resistant to Nalidixic Acid respectively.
All the isolates were 100% susceptible to Spectinomycin and Ciprofloxacin,
while Ofloxacin, Gentamycin, and Pefloxacin vary in their level of
susceptibility with 90%, 80% and 70% sensitivity respectively. Conversely, 8 out of 10
fish farm locations studied were observed to have antibiotic-resistant strains, and 5
out of 8 drug-resistant strains were found to carry plasmid and the sizes of
the plasmid ranges between 20.027 kb to 23.130 kb. The plasmid after
treatment with mitomycin C and ethidium bromide were lost during the process of
plasmid curing confirming that the multiple drug resistant exhibited by the
isolates was plasmid mediated. There are fewer studies on antibiotic resistance in Edwardsiella tarda from aquaculture
enterprises and this study provides further support to the view that there is a
potential risk of transfer of resistant bacteria and their genes to human
pathogen through the food chain. Although, in Nigeria there is no antibiotic
product registered for aquaculture usage, yet fish farmers use them off-label
for bacterial diseases prevention.