Comparison of the Staphylococcal Chromosome Cassette (SCC) <i>mec</i> in Methicillin-Resistant <i>Staphylococcus aureus</i> (MRSA) and Non-<i>aureus</i> Staphylococci (MRNAS) from Animals and Humans

• Main Authors: Cyrille Ngassam Tchamba, Jean-Noël Duprez, Pierrick Lucas, Yannick Blanchard, Filip Boyen, Freddy Haesebrouck, Maria A. Argudín, Jacques Mainil, Damien Thiry
• Format: Article
• Language: English
• Published: MDPI AG 2021-03-01
• Series: Antibiotics
• Subjects: <i>Staphylococcus aureus</i>; non-<i>aureus</i> staphylococci; methicillin resistance; <i>mecA</i> staphylococcal cassette chromosome; cattle; humans
• Online Access: https://www.mdpi.com/2079-6382/10/3/256

Methicillin-resistant <i>Staphylococcus aureus</i> (MRSA) and non-<i>aureus</i> staphylococci (MRNAS) cause different infections in animals, including mastitis, in livestock and humans. This study aimed to identify and compare the staphylococcal chromosome cassette <i>mec</i> (SCC<i>mec</i>) types of MRSA or MRNAS isolated from several animal species and humans in different countries. Of 1462 <i>S. aureus</i> and non-<i>aureus</i> staphylococci, 68 grew on Chrom MRSA ID^® agar, were phenotypically resistant to cefoxitin and tested positive with the PCR for the <i>mecA</i> gene. These 60 MRSA and 8 MRNAS were isolated in Belgium mainly from cows (livestock-associated (LA) MRS) and humans (community-acquired (CA) MRS) and in Japan from dogs and cats. The SCC<i>mec</i> cassettes were identified by multiplex PCR in 52 MRSA and 7 MRNAS and by whole genome sequencing (WGS) in 8 additional MRSA. The SCC<i>mec</i> types IV and V were the most frequent in Belgian LA-MRS and CA-MRS, while the SCC<i>mec</i> type II was identified in four of the five Japanese MRSA. The remaining isolate was a bovine <i>S. haemolyticus</i> in which no SCC<i>mec</i> was identified. These results confirm the high prevalence of the SCC<i>mec</i> types IV and V in LA-MRS and CA-MRS in Belgium, emphasizing the possible public health hazard of the former, and the absence of SCC<i>mec</i> in some MRNAS.