MRSA carrying mecC in captive mara.

Area of Science:

• Veterinary Microbiology
• Zoonotic Diseases
• Genomics

Background:

• Staphylococcus aureus sequence type 130 (ST130) is a globally emerging lineage.
• Methicillin resistance in S. aureus is often mediated by the staphylococcal cassette chromosome mec (SCCmec).
• The mecC gene confers methicillin resistance and has been detected in various animal species.

Purpose of the Study:

• To characterize the SCCmec, virulence factors, and antimicrobial susceptibility of S. aureus ST130 isolated from mara (Dolichotis patagonum).
• To investigate the genomic features of S. aureus ST130 from a captive rodent population.

Main Methods:

• PCR was used to confirm the presence of mecC in 15 S. aureus ST130 isolates from mara.
• Whole-genome sequencing (WGS) was performed on two isolates to analyze SCCmec, virulence, and resistance genes.
• Antimicrobial susceptibility testing was conducted using broth microdilution.

Main Results:

• All 15 mara isolates were identified as spa type t528 ST130 and carried mecC.
• WGS revealed that the mecC gene was identical to the prototype sequence, with SCCmec type XI differing by 23 SNPs from the prototype.
• The sequenced strains possessed known virulence factors typical of ST130 and only the norA gene as a putative antimicrobial resistance gene besides mecC.

Conclusions:

• A conserved mecC-carrying MRSA ST130 clone is prevalent in diverse hosts in Denmark.
• The presence of ST130 in mara, with limited contact with other species, raises questions about their role as natural hosts or acquisition sources.
• The broad host range of MRSA ST130 indicates its adaptability as a generalist lineage.