Prevalence of antimicrobial resistance in S. aureus and E. coli from lactating dairy cows in Maasai Mara, Kenya : a One Health perspective

Sammanfattning

Antimicrobial resistance (AMR) was found in an unexpectedly high prevalence in semi-domestic cats in Mararianta 2024. A suspected cause for this high prevalence of AMR in cats was milk from the Maasai dairy cows, because the milk is served to cats on a regular basis. The objective of this study was to investigate the prevalence of AMR against a number of antibiotic agents (Benzylpenicillin, Cefoxitin, Meropenem, Ciprofloxacin, Gentamicin and Tigecycline) using the disk diffusion test on S. aureus and E. coli isolated from milk. In this study a total of 124 cows were screened for subclinical mastitis (SCM) using the California Mastitis Test (CMT). In total 22 milk samples from udder quarters with SCM (CMT ≥ 3) and 10 swab samples from cat bowls and milk containers were collected for cultivation and bacterial typing. In the tested population, 12.1% of the cows had SCM and 1.6% of the population had S. aureus induced SCM. The scarce number of cultivated bacteria made it impossible to draw a conclusion on the prevalence of AMR in S. aureus and E. coli. Although, the unexpectedly low prevalence of SCM is an indication that the milk from the Maasai dairy cows is not likely the cause of high AMR prevalence in the semi domestic cats in Mararianta. Further research to establish the cause of high AMR prevalence in the cats is needed. Keywords: antimicrobial resistance, AMR, One Health, subclinical mastitis, E. coli, S. aureus, Maasai Mara, Kenya, milk, CMT, dairy cow