In January 2024, the studies "Diversity of Staphylococcus aureus associated with mastitis from dairy cows in Rwanda" and "Diversity of Staphylococcus aureus isolated from nares of ruminants" were published as part of a transnational scientific collaboration.
AGES was involved in this project through Adriana Cabal Rosel and Werner Ruppitsch (Public Health Division, Institute of Medical Microbiology and Hygiene).
Together with scientists from veterinary universities in Vienna, Rwanda and Germany as well as other institutes, they analysed the diversity of Staphylococcus aureus in ruminants in Rwanda.
In the study "Diversity of Staphylococcus aureus associated with mastitis from dairy cows in Rwanda", Staphylococcus aureus was investigated in connection with inflammation of the mammary glands in dairy cows.
In the publication "Diversity of Staphylococcus aureus isolated from nares of ruminants", nasal swabs from cattle, goats and sheep were analysed for S. aureus.
Staphylococcus aureus
Staphylococcus aureus(S. aureus ) is a Gram-positive, spherical bacterium that is often arranged in clusters. Usually harmless, S. aureus can cause a variety of infections, including skin and soft tissue infections, pneumonia and endocarditis. In dairy cows, sheep and goats, S. aureus can cause udder inflammation (mastitis) and thus cause considerable economic losses in milk production.
Aim of the studies
Both studies focussed on investigating the diversity of Staphylococcus aureus in ruminants in Rwanda.
The study "Diversity of Staphylococcus aureus associated with mastitis from dairy cows in Rwanda" analysed the diversity ofStaphylococcus aureus in 1,080 milk samples from 279 cows with mastitis (inflammation of the udder) from 80 different farms in all five provinces of Rwanda.
In the study "Diversity of Staphylococcus aureus isolated from nares of ruminants", 454 nasal swabs from 203 cows, 170 goats and 81 sheep were analysed for the presence of Staphylococcus aureus and 30 S. aureus isolates were subsequently phenotypically and genotypically described.
Results
Resistance to penicillin and/or tetracycline was observed in both studies.
Ten sequence types belonging to seven clonal complexes were identified in the cows with mastitis. Eight different "specific staphylococcal protein A" (spa) types belonging to six clonal complexes were detected in the isolates from the nasal swabs.
Panton-Valentine leukocidin (PVL) genes, bovine leukocidin genes and tst-1 variants of the human and bovine toxic shock syndrome toxin gene were detected in both the milk samples and the nasal swabs.
Outlook
The results of the studies highlight the importance of hygiene measures in the handling of livestock and underline the need for a rigorous One Health surveillance programme at the interface between animals and humans to ensure the health of both parties.
The studies are available at: