Characterization of pig-associated methicillin-resistant Staphylococcus aureus

Area of Science:

• Veterinary Microbiology
• Antimicrobial Resistance
• Public Health

Background:

• Livestock-associated methicillin-resistant Staphylococcus aureus (LA-MRSA) is a global concern.
• China, a major pork producer, lacks large-scale studies on pig-associated LA-MRSA.

Purpose of the Study:

• To determine the prevalence of pig-associated MRSA in China.
• To characterize the antimicrobial resistance and genotypes of these isolates.

Main Methods:

• Analysis of 2420 pig samples from farms and slaughterhouses.
• Antimicrobial susceptibility testing, MLST, spa typing, PFGE, and resistance gene screening.

Main Results:

• MRSA identified in 11.2% of samples, all belonging to CC9 and spa type t899.
• High resistance rates observed for tetracycline, erythromycin, clindamycin, and other antibiotics.
• Detection of linezolid-non-susceptible isolates with cfr gene and rifampicin-non-susceptible isolates with rpoB mutations.

Conclusions:

• Pigs are a significant host for LA-MRSA in China.
• Monitoring pig-associated MRSA is crucial for understanding epidemiological changes and pathogen characteristics.