Polymyxin resistance in Enterobacterales: overview and epidemiology in the Americas

The worldwide spread of carbapenem-and polymyxin-resistant Enterobacterales represents an urgent public-health threat. However, for most countries in the Americas, the available data are limited, although Latin America has been suggested as a silent spreading reservoir for isolates carrying plasmid-mediated polymyxin resistance mechanisms. This work provides an overall update on polymyxin and polymyxin resistance and focuses on uses, availability and susceptibility testing. Moreover, a comprehensive review of the current polymyxin resistance epidemiology in the Americas is provided. We found that reports in the English and Spanish literature show widespread carbapenemase-producing and colistin-resistant Klebsiella pneumoniae in the Americas determined by the clonal expansion of the pandemic clone ST258 and mgrB-mediated colistin resistance. In addition, widespread IncI2 and IncX4 plasmids carrying mcr-1 in Escherichia coli come mainly from human sources; however, plasmid-mediated colistin resistance in the Americas is underreported in the veterinary sector. These findings demonstrate the urgent need for the implementation of polymyxin resistance surveillance in Enterobacterales as well as appropriate regulatory measures for antimicrobial use in veterinary medicine. (c) 2021 Elsevier Ltd and International Society of Antimicrobial Chemotherapy. All rights reserved.

Automated summary

This study provides an overview of the global spread of carbapenem-and polymyxin-resistant Enterobacterales, with a focus on the situation in the Americas. The findings highlight the urgent need for surveillance of polymyxin resistance in Enterobacterales and regulatory measures for antimicrobial use in veterinary medicine.