First report of a linezolid-resistant MRSA (methicillin resistant Staphylococcus aureus) isolated from a dog with a severe bilateral otitis in Portugal

Abstract

The widespread use of antimicrobials has lead to the emergence of resistant bacteria to one or more antibiotic, including new drugs like linezolid. This antimicrobial is the first of the oxazolidinone group and soon after its approval in 2000, linezolid-resistant MRSA and linezolid vancomycin-resistant enterococci have emerged. Several outbreaks of linezolid-resistant MRSA have been reported worldwide but, to our knowledge, this is the first report of a linezolid-resistant MRSA isolated from a dog in Portugal. The animal arrived at the Teaching Hospital of the Faculty of Veterinary Medicine, Technical University of Lisboa with a severe bilateral otitis that was refractory to antibiotic therapy. Bacteriology showed that the infection was caused by a multiresistant Staphylococcus aureus strain that also phenotipically expressed other virulence factors. Besides the challenge to practitioners, the isolation of this strain is of pub­lic health concern due to its antimicrobial resistant profile.