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Locally Acquired mcr-1 in Escherichia coli, Australia, 2011 and 2013
Abstract:
We identified discrete importation events of the mcr-1 gene on incompatibility group IncI2 plasmids in Escherichia coli isolated from patients in New South Wales, Australia, in 2011 and 2013. mcr-1 is present in a small minority of colistin-resistant Enterobacteriaceae and appears not to be established locally.
Insights
The colistin resistance gene mcr-1 was detected in Escherichia coli in Australia in 2011 and 2013. This gene, found on IncI2 plasmids, does not appear to be widespread in the local bacterial population.
Area of Science:
- Microbiology
- Genetics
- Epidemiology
Background:
- Colistin is a critical antibiotic for treating multidrug-resistant Gram-negative infections.
- The emergence of colistin resistance, particularly the mcr-1 gene, is a global health concern.
- Escherichia coli is a common pathogen that can acquire antimicrobial resistance genes.
Observation:
- Discrete instances of the mcr-1 gene were identified in Escherichia coli isolates.
- These isolates were obtained from patients in New South Wales, Australia, during 2011 and 2013.
- The mcr-1 gene was located on incompatibility group IncI2 plasmids.
Findings:
- The mcr-1 gene was present in a small fraction of colistin-resistant Enterobacteriaceae.
- Evidence suggests that mcr-1 has not become endemic in the Australian bacterial population.
- The identified events represent distinct introductions of the mcr-1 gene.
Implications:
- The findings highlight the importance of surveillance for emerging antimicrobial resistance genes.
- Understanding importation events is crucial for preventing the establishment of resistance.
- Continued monitoring is necessary to track the spread of colistin resistance globally.
