Methicillin-resistant Staphylococcus aureus among animals: current overview

Area of Science:

• Microbiology
• Epidemiology
• Veterinary Medicine

Background:

• Methicillin-resistant Staphylococcus aureus (MRSA) poses a universal health threat, extending beyond healthcare settings into communities and animal populations.
• Emergence of MRSA in animals and food products signifies new reservoirs and potential transmission routes to humans.
• Globalization and intensive livestock farming facilitate increased exchange of bacteria between humans and animals.

Purpose of the Study:

• To describe major MRSA clonal lineages circulating in hospitals, communities, and animals.
• To differentiate MRSA clones colonizing companion animals versus food-chain animals.
• To highlight the threat posed by livestock-associated MRSA (LA-MRSA) and the newly identified mecC MRSA.

Main Methods:

• Review and description of circulating MRSA clonal lineages.
• Analysis of MRSA colonization in companion and food-chain animals.
• Case reports of MRSA transmission between animals and humans.

Main Results:

• Identification of distinct MRSA clonal lineages in human and animal settings.
• Livestock-associated MRSA clonal complex (CC) 398 is widespread and pathogenic.
• The mecC MRSA variant is geographically distributed across Europe in diverse animal hosts and environments.
• Evidence of MRSA transmission between animals and humans, and adaptation of human MRSA strains to animals.

Conclusions:

• MRSA represents a significant and evolving threat with interconnected human and animal reservoirs.
• Understanding MRSA clonal dynamics and transmission pathways is crucial for public health.
• The emergence of new MRSA strains and reservoirs necessitates ongoing surveillance and control strategies.