- - - Department of Pathobiology, Faculty of Veterinary Medicine, Tabriz University, Tabriz, Iran.

is strong evidence that the use of antimicrobials can lead to the appearance and rise of bacterial resistance both in human and animals. Escherichia coli (E. coli) isolates from human and chicken samples were examined for their biofilm formation ability and antibiotic resistance patterns in this study. A total of 100 E. coli samples, isolated from humans and chickens were examined to determine the biofilm forming properties by tube test, cover slip test and microtitre plate method. After which the prevalence of antimicrobial resistance among the organisms was determined. Among avian isolates, tissue culture plate method, cover slip test and tube assay detected 68%, 54% and 60% antimicrobial resistance, respectively. In human isolates 72%, 56% and 66% antimicrobial resistance were evidence by tissue culture plate method, cover slip test and tube assay, respectively. The resistance pattern of these isolates showed that E. coli from chicken samples was resistant to Nalidixic acid (100%), Ciprofloxacin (80%), Doxycycline (80%), Tetracycline (76%), Cefotaxime (30%), Ceftriaxone (30%), Amikacin (28%), Nitrofurantoin (24%), Ceftazidime (22%), Furazolidone (20%), Cefixime (10%), and Gentamicin (0%). E. coli from human clinical samples was resistant to Tetracycline (62%), Doxycyclie (58%), Ciprofloxacin (58%), Nalidixic acid (50%), Ceftazidime (40%), Cefotaxime (36%), Ceftriaxon (24%), Cefixime (20%), Amikacin (16%) and gentamicin (8%), Furazolidone (4%) and Nitrofurantoin (0%). Furthermore multi resistant E. coli isolates were common in human and chicken samples. However, the percentages of multi resistant E. coli were higher in chicken than in human isolates. The results of this study suggested that chickens can act as reservoirs for transfer of antimicrobial resistant bacteria to humans. Furthermore, all of the E. coli biofilm producers from human and avian origins had multidrug resistance patterns and biofilm formation ability can increase the antibiotic resistance profile of E. coli isolates.

E. coli, biofilm, Antimicrobial resistance