Occurrence of antibiotic resistant Staphylococcus aureus in pigs in smallholder farms in Lira, Uganda

Sammanfattning: According to the United Nations (World Health Organization in particular) and the European Union, antibiotic resistance has become an enormous public health issue. Both veterinary and human medicine, and thus animal and human welfare, are at stake. Methicillin-resistant Staphylococcus aureus (MRSA) is a well-known variant of the common bacterium S. aureus that has acquired resistance to methicillin. The transferrable mutation in the bacterium makes it antibiotic resistant, which yearly leads to great impact in healthcare, and available treatments are limited. In Europe, several studies on the occurrence of MRSA in pigs are performed, but in Africa the studies are very few and in Uganda almost non-existent. In this study the occurrence of MRSA, alongside other Staphylococcus spp., in smallholder pig farms were studied. The samples were collected within the district of Lira, located in the northern region of Uganda. The study included 51 samples from pigs: swabs taken from the snout, the skin behind the ears and the perineum from weaned pigs in nineteen different farms. The samples were analyzed by two pre-enrichment broths and on selective agar for MRSA, in parallel to culturing with one pre-enrichment broth followed by cultivation on bovine blood agar. In total, four isolates of S. aureus were obtained, of which one via the selective medium. The latter S. aureus was identified as MRSA through PCR, with demonstration of the genes for nuc, PVL and mecA. Another fifteen Staphylococcus spp. were found, of which four were resistant to at least three different classes of antibiotics, and thus can be regarded as multi-drug resistant.