Title : Non-typhoidal salmonella in bushmeat from Cameroon: Antimicrobial resistance profiles from a food safety perspective

Background: Foodborne diseases caused an estimated 866 million illnesses and 1.52 million deaths worldwide in 2021. Bushmeat could be a source of non-typhoidal Salmonella in the food chain. The study described the serovars and antimicrobial resistance profiles of non-typhoidal Salmonella isolated from bushmeat sold for human consumption in Central Cameroon.

Methods: We randomly collected 142 carcasses of nine wildlife species from markets in five cities in the Central Region, chosen because of their trade activity and accessibility. Salmonella were isolated by culture, phenotypic, and molecular techniques. Susceptibility to 11 antibiotics was tested by disk diffusion, and PCR targeted 12 AMR genes. We used chi-square and Fisher’s exact tests to examine associations between resistance phenotypes, genes, serovars, host species, and markets.

Results: The overall prevalence was 69%, with S. Enteritidis (65.5%) and S. Typhimurium (3.5%). Overall, 66% of the isolates were multidrug-resistant. S. Enteritidis possessed all AMR and virulence genes investigated; S. Typhimurium was negative for qnrA, qnrB, parE, and spvC. S. Enteritidis was associated with invA (χ² = 20.83; p < 0.0001), and prevalence of invA differed by host species (p = 0.021), with the highest prevalence in pangolins (57%) and civets (50%). S. Typhimurium did not show such an association (Fisher’s exact test, p = 0.326). Ciprofloxacin resistance was not associated with PMQR genes (qnrS: OR = 1.15; p = 1.00). MDR status was not associated with virulence at the global score level (Mann–Whitney, p = 0.629) and for each of the six virulence genes, indicating independent acquisition of both traits.

Conclusion: Virulent MDR Salmonella in bushmeat from animals that have not been exposed to dietary antibiotics shows that these strains are circulating in wildlife and can enter the food chain. Surveillance of Salmonella and AMR is required in a One Health approach.

Keywords: non-typhoidal Salmonella; Bushmeat; Antimicrobial resistance; Virulence genes; One Health

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