Determination of Tetracycline and Enrofloxacine Resistance in Salmonella Isolated From Poultry

In recent years, an increase in antibiotic resistance has been observed in Salmonella in different countries. The aim of this study was to determine the tetracycline and enrofloxacine resistance in salmonella isolated from poultry.
The pattern of antibiotic resistance to tetracycline and enrofloxacin in isolated Salmonella of fecal broiler chickens from Shiraz, southern Iran, was assessed using minimum inhibitory concentration (MIC) and PCR methods.
Of 100 fecal samples of broiler chickens, 5 samples (5%) were infected to Salmonella. The antimicrobial susceptibility showed that MIC90 of isolated Salmonella strains for enrofloxacin and tetracycline was less than 0.2 μg/mL and 180 μg/mL, respectively, indicating a high sensitivity to these antibiotics. In two samples the presence of tetracycline resistance plasmid was also found, while all the strains were susceptible to enrofloxacin.
According to the results, the isolated Salmonella spp. showed higher resistance in tetracycline than enrofloxacin, which seems due to the excessive usage of this antibiotic in poultry industry.