[Endocarditis due to meticillin-resistant Staphylococcus aureus originating from pigs]

Area of Science:

• Infectious Diseases
• Microbiology
• Transplantation Immunology

Background:

• Meticillin-resistant Staphylococcus aureus (MRSA) poses a significant global health threat, particularly in hospital settings.
• Emergence of novel MRSA strains, such as livestock-associated MRSA (LA-MRSA), presents new challenges in infection control.
• Kidney transplant recipients are immunocompromised, increasing their susceptibility to severe infections.

Observation:

• A 63-year-old kidney transplant patient developed endocarditis caused by MRSA.
• The infecting MRSA strain was identified as sequence type 398 (ST398), a strain predominantly found in pigs.
• The patient recovered with adjusted antibiotic therapy, avoiding surgery.

Findings:

• This case represents the first reported instance of a life-threatening infection caused by pig-associated MRSA (ST398) in a non-livestock-associated individual.
• Genetic analysis revealed that this pig MRSA strain is distinct from globally disseminated hospital-acquired MRSA and US community-acquired MRSA strains.
• The patient's infection occurred despite her not belonging to the typical high-risk population (e.g., pig farmers, veterinarians).

Implications:

• The findings underscore the potential for zoonotic transmission of LA-MRSA to vulnerable patient populations.
• Updated infection prevention and control guidelines are crucial to mitigate the spread of emerging MRSA strains like ST398.
• This case highlights the need for vigilance and consideration of LA-MRSA in patients with severe infections, irrespective of their occupational or epidemiological risk factors.