Emergence of new multi-resistant Brachyspira hyodysenteriae strains in Belgian pigs, revealed by high-quality whole-genome sequencing

Abstract

Swine dysentery (SD) caused by Brachyspira hyodysenteriae results in economic losses in swine producing countries worldwide. Increased number of SD outbreaks raised fear in Belgium as treatment would be hampered due to increased (multi-)resistance against commonly used antibiotics. Therefore, 90 Belgian B. hyodysenteriae strains (2018–2020) were analysed with agar dilution testing and high-quality whole-genome sequencing. While multi-resistance was observed in 39.5% of strains, the presence of genetic hallmarks (e.g. tva(A)) raised the question on re-evaluation of phenotypic antimicrobial testing cut-offs in respect to the use of these hallmarks in rapid genomic antimicrobial resistance testing in the near future.