Pathogen profiles and antimicrobial resistance in mastitis cases from Algerian dairy she-camels in semi-intensive...

This study aimed to assess the prevalence, aetiology and antimicrobial susceptibility profiles of mastitis in lactating she-camels on semi-intensive dromedary dairy farms. A total of 179 lactating camels from nine farms across five key regions were examined, with 716 udder quarters analysed. Mastitis was identified in 17.9% of animals and 9.4% of udder quarters (95% confidence intervals [CI]: 7.4-11.7), comprising clinical (7.3% of animals; 3.5% of quarters) and subclinical (10.6% of animals; 5.9% of quarters) forms. Bacteriological analysis revealed Staphylococcus aureus as the most frequently isolated pathogen (a combined prevalence 34.3%; 95% CI: 23.2-46.9), followed by Streptococcus spp. and Escherichia coli. Antimicrobial susceptibility testing of 43 isolates showed high susceptibility to trimethoprim-sulfamethoxazole in both S. aureus (100%; 95% CI: 80.5-100) and Streptococcus spp. (100%; 95% CI: 78.2-100). For erythromycin, susceptibility was 100% (95% CI: 78.2-100) in Streptococcus spp. and 76.5% (95% CI: 50.1-93.2) in S. aureus. Conversely, E. coli exhibited high rates of resistance to tetracycline (72.7%; 95% CI: 39.0-94.0) and ampicillin (54.5%; 95% CI: 23.4-83.3), highlighting concerns about the efficacy of empirical treatment and the emergence of antimicrobial resistance in this production context. These findings underscore the need for systematic udder health monitoring, evidence-based antimicrobial stewardship and improved biosecurity on semi-intensive camel dairy farms. This study contributes to the understanding of the microbial landscape and resistance profiles in camel dairy production, with implications for animal productivity, milk safety and public health within a One Health framework.