High resistance of Escherichia coli have been demonstrated to 3rd generation cephalosporin in livestock, especially in broiler chickens; however, data on emission sources of these bacteria into Algeria are still rare. From January to March 2014, a preliminary epidemiological study of E. coli contamination in healthy broiler chicken flocks was carried out in the regions of Tlemcen, Algeria. 21 E. coli resistant isolates were examined to 3rd generation cephalosporin antibiotics (ceftriaxone, ceftazidime and cefotaxime). The antimicrobial susceptibility was determined by disk diffusion, and the MICs were determined by agar dilution method with Antibiogram Committee of the French Society for Microbiology (CA-SFM) 2013 guidelines. All strains were resistant to ceftriaxone and cefotaxime referring to CA-SFM, Antibiogram Committee of the French Society for Microbiology (EUCAST), and Clinical and Laboratory Standards Institute (CLSI). However, the resistance rate of ceftazidime is different according to the breakpoints criteria used; the susceptibility result of CA-SFM and EUCAST is similar for each farm. Farm B 50% of E. coli was resistant and 50% was susceptible, and 21% was susceptible and 79% was resistant for the farm C. However, comparing these two with CLSI, all strains were susceptible to ceftazidime.
Key words: Escherichia coli, antimicrobial resistance, 3rd generation cephalosporin, feces, broilers chicken.