Enterobacteriaceae sensitivity of the broiler intestinal microbiota submitted to nifrofurans diet

Abstract

In this study, we aimed to detect the sensitivity of the Enterobacteriacea to different antimicrobials in broilers submitted to a nitrofurans diet. To evaluate this sensitivity, colonies of the broiler intestinal microbiota have been isolated and identified. The most frequent genera found have been Escherichia and Klebsiella, followed byEnterobacter, Pseudomonas, Hafnia, Proteus, Morganella and further Citrobacter. All isolates have presented resistance to two or more antimicrobials with different resistance level profiles. Resistance to nitrofurans, especially nitrofurantoin (100%), nitrofurazone (98.5%), and furaltadone (97.8%) has been observed. Concerning other antimicrobials classes, the higher resistance has been to tetracycline (92.5%) and the lower sensitivity, to amoxicillin/clavulanic acid (48.1%). It has not been possible to assert that the high resistance to the nitrofurans detected in the fecal isolates is due to the usage of these antimicrobials in the feed. The resistance to tetracycline and nitrofurans reaffirms the importance of not using of these drugs in poultry breeding