Identification of multiresistance gene cfr in methicillin-resistant Staphylococcus aureus from pigs: plasmid location...

Area of Science:

• Veterinary Microbiology
• Antimicrobial Resistance
• Molecular Epidemiology

Background:

• Methicillin-resistant Staphylococcus aureus (MRSA) is a significant pathogen in both human and animal health.
• The cfr gene confers resistance to multiple classes of antibiotics, including oxazolidinones, lincosamides, and macrolides.
• Porcine MRSA isolates are a potential reservoir for antimicrobial resistance genes.

Purpose of the Study:

• To investigate the presence and genetic context of the multiresistance gene cfr in porcine MRSA isolates.
• To characterize the molecular epidemiology of these isolates using various typing methods.
• To determine the location and genetic elements associated with the cfr gene in these strains.

Main Methods:

• Multilocus sequence typing (MLST)
• spa typing
• dru typing
• Staphylococcal cassette chromosome mec (SCCmec) typing
• Plasmid analysis
• Identification of insertion sequences and gene fragments

Main Results:

• The cfr gene was detected in 8 out of 231 porcine MRSA isolates.
• Isolates were characterized into distinct sequence types (STs) and spa types, including ST627, ST6, ST9, and ST63.
• In seven isolates, cfr was located on plasmids of approximately 35 kb.
• For the first time, an ISEnfa4-cfr-IS256 fragment was identified integrated into a chromosomal SCCmec IVb element in one isolate.

Conclusions:

• The cfr gene is present in porcine MRSA, highlighting the importance of monitoring antimicrobial resistance in livestock.
• The cfr gene in porcine MRSA can be located on both plasmids and integrated chromosomal elements.
• The novel finding of cfr integrated within an SCCmec element in a porcine MRSA isolate warrants further investigation into its dissemination and impact.