Abstract

One hundred and two Escherichia coli strains isolated from healthy broiler chickens collected from April 2012 to November 2014 in seven geographic areas of western Algeria were studied. Susceptibility pattern to 11 antimicrobial agents was determined by disk diffusion method as recommended by the Clinical Laboratory Standard Institute (CLSI). Antibiograms revealed high levels of resistance to quinolones and fluoroquinolones including nalidixic acid (100%), flumequin (86, 27%) and enrofloxacin (84, 31%), and to other antibiotics, notably: tetracycline (92, 15%), trimethoprim-sulfamethoxazol (80, 39%) and amoxicillin (68, 62%). However, a moderate percentage of strains were resistant to neomycin (31, 37%), chloramphenicol (27, 45%) and nitrofurantoin (21, 56%). Only 7, 84% of the isolates were resistant to gentamicin and all the isolates were susceptible to colistin. All isolated E. coli were resistant to at least three antibiotics. 96, 08% and 91, 12% of the isolates were resistant to at least four and five antimicrobials, respectively. Twenty eight antibiotic resistance patterns of E. coli strains were detected, of which 11 were present significantly. The results of this survey indicate very high levels of resistance to quinolones and to other antibiotics in E. coli from healthy broiler chickens in Algeria, and suggested that this reservoir of resistance may affect the therapeutic potential of fluoroquinolones in human and veterinary medicine.

Key words: Escherichia coli, antibiotic resistance, poultry, Algeria.