Antibiotic profiling of multidrug resistant pathogens in one-day-old chicks imported from Belgium to Benin

Background
Little data exist on the presence of resistant pathogens in day-old chicks imported into Benin. The occurrence of pathogenic bacteria was assessed in 180 one-day-old chicks imported from Belgium and received at the Cardinal Bernardin Gantin International Airport in Cotonou (Benin). The samples included swabbing the blisters of 180 chicks, followed by 18 pools of 10 swabs for bacterial isolation. Classic bacteriological methods based on Gram staining, culture on specific media and biochemical characterization were used. Antibacterial susceptibility screening to antibiotics was conducted using the Kirby–Bauer disc diffusion method, and the results were interpreted according to guidelines from the European Committee on Antimicrobial Susceptibility Testing (EUCAST). DNA extraction was performed by the heat treatment method. Resistance genes were screened by real-time PCR.

Results
We isolated 32 bacteria, including Escherichia coli (50%), Enterococcus spp. (28%), and coagulase-negative staphylococci (10%). The isolates were investigated for antibiotic resistance against antibiotics using the disk diffusion method and showed that in the Escherichia coli strains isolated, the highest rate of resistance was obtained against ciprofloxacin (81%), followed by trimethoprim + sulfamethoxazole (62%). Enterobacter cloacae was sensitive to all the antibiotics tested. Pseudomonas spp. resistant to amoxicillin and trimethoprim + sulfamethoxazole was noted. The Sulll gene was found in all cloacal samples, while the Sull and blatem genes were present at 44.44% and 16.67%, respectively.

Conclusion
This study confirms that imported day-old chicks can be a potential source of dissemination of resistant bacteria in poultry production. A system for immediate detection of resistant bacteria in chicks upon arrival in the country is thus needed.