Multidrug resistance in pathogenic and commensal Escherichia coli from poultry.

A total of 355 E. coli (299 APEC and 56 AFEC) isolated from broilers (110), turkeys (188) and layer hens (57) were tested for their susceptibility to 21 antimicrobials belonging to 8 different classes: aminoglycosides, cephalosporins, quinolones, phenicols, penicillins, tetracyclines, sulphonamides, polymyxins. The disk diffusion method was performed according to the CLSI standard (2008). Multidrug resistance (MDR) was detected against 3 to 8 antimicrobial classes, with 7 strains resistant to all. Indeed, 90.1% of APEC and AFEC strains was MDR (APEC: 84.5% in chickens, 87.1% in layers, 94.4% in turkeys; AFEC: 76.9% in layers, 100% in turkeys). Out of 50 MDR patterns, AmPhPenCepFluSulTe was the most frequently detected (20.6%). Results suggest that MDR is widespread among pathogenic and commensal E. coli from poultry