Resistance of Avian Salmonella spp. Strains to Critical Antibiotics: The Case of Quails at the SAP in La Mé, Côte d’Ivoire

Abstract

Background and Aims: Contamination of poultry products with bacteria of the genus Salmonella is a major public health problem worldwide. The aim of this study was to assess the prevalence of Salmonella spp. in faecal samples from Japanese quails (Coturnix japonica) reared on a commercial farm in the La Mé region of Côte d’Ivoire, to determine the antibiotic susceptibility profile of the isolates, and to characterise their genetic profiles by detecting the aminoglycoside resistance gene aac(6′)-Ib. Methodology: A total of 18 faecal samples were collected from different batches of quails, grouped according to age. Strain isolation was carried out in accordance with ISO 6579-1:2017. The isolates were identified using conventional bacteriological methods and then subjected to antibiotic susceptibility testing using the Mueller-Hinton agar diffusion method, in accordance with EUCAST-CASFM recommendations. The gentamicin-resistant strains were then analysed by PCR to detect the aac(6′)-Ib gene. Result: A prevalence of 61.11 % of Salmonella spp. was observed. This prevalence varied across age groups, but no statistically significant difference was observed (p = 0.49). All isolated strains were resistant to colistin (100 %); 54.54 % were resistant to Augmentin, 36.36 % to gentamicin, 27.27 % to cefotaxime and cefixime, 18.2 % to norfloxacin, and 9.09 % to ceftriaxone. Three strains exhibited a multidrug-resistance profile involving three families of antibiotics. However, none of the strains analysed by PCR harboured the aac(6′)-Ib gene. Conclusion: This study highlights the circulation of multidrug-resistant Salmonella strains in Japanese quail farms in Côte d’Ivoire, suggesting that quails may act as potential reservoirs for the transmission of antibiotic-resistant pathogens to humans via the food chain. The absence of the aac(6′)-Ib gene suggests that other genetic mechanisms may explain the observed resistance to aminoglycosides. The findings indicate a need to establish continuous surveillance of antibiotic resistance and to ensure the prudent use of antibiotics in poultry production.