Transferable resistance to colistin: a new but old threat

Area of Science:

• Microbiology
• Antimicrobial Resistance
• Public Health

Background:

• The emergence and global dissemination of antimicrobial resistance genes pose a significant threat to public health.
• Colistin is a critical antibiotic for treating multidrug-resistant Gram-negative infections.
• The mcr-1 gene confers transferable resistance to colistin, raising concerns about its spread.

Purpose of the Study:

• To summarize current knowledge on the occurrence and spread of the mcr-1 gene.
• To explore the potential origins and transmission routes of mcr-1.
• To highlight the need for a global One Health approach to combat colistin resistance.

Main Methods:

• Review of existing literature and screening studies on mcr-1 prevalence.
• Analysis of isolate data from human and animal sources across different continents.
• Retrospective analysis of historical isolate data.

Main Results:

• The mcr-1 gene has been detected on five continents in various enteric bacteria.
• mcr-1 has been identified in Escherichia coli dating back to the 1980s in China and 2005 in Europe.
• Isolates carrying mcr-1 are more frequently found in animals than in humans, suggesting a potential animal origin.

Conclusions:

• The conjugative plasmid location of mcr-1 facilitates its rapid spread.
• The animal sector may be a significant reservoir for mcr-1 emergence and dissemination.
• Integrated global One Health strategies, including antibiotic stewardship and enhanced surveillance, are crucial to mitigate the spread of colistin resistance.