Methicillin-resistant staphylococcus aureus with the novel mecC gene variant isolated from a cat suffering from chronic conjunctivitis

摘要

Methicillin-resistant Staphylococcus aureus (MRSA) is of growing concern in public and animal health and it is important to ensure efficient and reliable methods for MRSA identification. Standard confirmatory tests include PCR for detection of the mecA gene and protein agglutination for identification of the penicillin-binding protein 2a (PBP2a). In 2011, a novel mecA homologue designated mecC (or mecA_(LGA251)) was described in S. aureus. This MRSA variant will not be detected with the usual mecA PCR approaches or with the PBP2a agglutination tests, representing a challenge to MRSA confirmation in diagnostic laboratories. Searching for mecC has recently been performed in several countries. Investigated isolates have either been part of historical collections or originated from current diagnostic submissions. The chosen candidates for mecC screening have typically been isolates with a phenotype corresponding to MRSA but lacking mecA, and/or isolates belonging to clonal lineages already associated with mecC carriage.