Outbreak of large skin wounds and necrotising soft tissue infection in Iberian pigs affected by Streptococcus dysgalactiae subspecies equisimilis

Abstract

AbstractStreptococcus dysgalactiae subspecies equisimilis is an emerging pathogen in animals and humans. Herein, we describe an outbreak of S. dysgalactiae subspecies equisimilis infection in Iberian pigs with large skin ulcerations and necrotising soft tissue. Postmortem examination was performed on two animals that had larger chronic lesions and secondary myiasis. Swabs from the edges of wounds from animals with more acute injuries were collected. The β‐haemolytic colonies obtained from the skin wounds and lymph nodes were identified as S. dysgalactiae subspecies equisimilis. The isolate had low minimum inhibitory concentrations for β‐lactams. Stress due to the change of groups and the consequent increase in fights for the establishment of a new hierarchical order could be the reason why pigs that carry the bacteria in their gingival mucosa transmit them to other individuals through bites. This stressful situation could cause a certain immunosuppression, potentially favouring the exacerbation of S. dysgalactiae subspecies equisimilis and the development of the lesions observed.