Highly resistant Mycobacterium abscessus subsp. abscessus infection in a Swiss cat

A 2-year-old European shorthair cat was presented with a nonhealing skin lesion on the right abdominal wall. Repeated surgical excision and antimicrobial treatment with cefovecin, clindamycin, and trimethoprim-sulfamethoxazole did not lead to clinical improvement. Histopathology of the skin lesion showed pyogranulomatous dermatitis and panniculitis. Definitive diagnosis was made by mycobacterial culture and rpoB sequencing, revealing Mycobacterium abscessus subsp. abscessus. To the authors’ knowledge, this is the first report of Mycobacterium abscessus subsp. abscessus infection in a cat in Switzerland and the second case in Europe. The isolated strain carried a functional erm(41) gene that confers inducible macrolide resistance. Further phenotypic resistances to doxycycline, minocycline, and imipenem were detected, resulting in little chance of successful antimicrobial treatment. Mycobacterium abscessus subsp. abscessus is an emerging pathogen in human medicine and poses a non-negligible zoonotic risk for the owners of the cat.