Antimicrobial resistance pattern of avian pathogenic with detection of extended-spectrum β-lactamase-producing isolates in broilers in east Algeria.

Background And Aim: Avian pathogenic (APEC) is the causative agent of colibacillosis, one of the most prevalent bacterial diseases responsible for significant economic losses in the poultry industry worldwide. This study aimed to assess the antimicrobial resistance (AMR) patterns of APEC isolates recovered from poultry in east Algeria and estimate the prevalence of extended-spectrum β-lactamase (ESBL)-producing isolates.

Materials And Methods: In the slaughterhouse of Batna City (Algeria), livers indicating colibacillosis were sampled from 204 suspected carcasses with growth retardation and generalized congestion. isolation and identification were performed on MacConkey agar using conventional methods and the API 20E system. Antimicrobial resistance susceptibility was tested by the disk diffusion method according to the Clinical Laboratory Standards Institute Guidelines. Extended-spectrum β-lactamase detection was carried out using the double-disk confirmation test.

Results: One hundred sixty isolates were recovered (one isolate per sample). Avian pathogenic isolates showed high levels of resistance to ampicillin and tetracycline (100%), nalidixic acid (95%), ofloxacin (93.75%), doxycycline (91.87), ciprofloxacin (87.50%), trimethoprim/sulfamethoxazole (62.50%), gentamycin (32.50%), chloramphenicol (27.50%), amoxicillin/clavulanic acid (16.25%), colistin (14.37%), and nitrofurantoin (10.62%). All strains were multidrug-resistant to at least three antibiotics, and more than half (52.52%) of the isolates were resistant to at least seven antibiotics. All isolates were susceptible to ceftriaxone, ceftazidime, and aztreonam. Two isolates were ESBL producers (1.25%).

Conclusion: Avian pathogenic resistance to most antimicrobial agents used in poultry may lead to antimicrobial therapy failure.