Plasmid-mediated colistin resistance in Escherichia coli recovered from healthy poultry

Spread of Clonally Related Escherichia coli Strains Harboring an IncA/C 1 Plasmid Encoding IMP-8 and Its Recruitment into an Unrelated MCR-1-Containing Isolate

“…Plasmid-mediated colistin resistance, commonly found in carbapenem-susceptible strains, has also been reported in Enterobacteriaceae producing different carbapenemases such as VIM-1, VIM-2, NDM-5, NDM-9, IMP-4, KPC-2, and OXA-48 (29)(30)(31)(32)(33)(34)(35). In our country, mcr-1 was previously described both in clinical isolates and in poultry farms (8,36). Here, we have described the presence of mcr-1 in a bla IMP-8 -producing E. coli isolate, which adds an extra level of plasticity in the evolving epidemiology of carbapenem and colistin resistance.…”

“…The rising frequency of carbapenem-resistant Enterobacteriaceae infections prompted the use of colistin as a last therapeutic option. However, the scenario became more complex as a consequence of the silent spread of plasmid-carried mcr-1 in the past decade (7,8).…”

Simultaneous Carriage of mcr-1 and Other Antimicrobial Resistance Determinants in Escherichia coli From Poultry

“…As part of a technical support program to national poultry producers, our team conducted studies to understand the antimicrobial resistance evolution in food-borne bacteria under commercial production systems in Argentina. Our studies included the selection of Escherichia coli as an indicator microorganism and concluded that almost 50% of the strains were found to be resistant to colistin used as AGP (Dominguez et al, 2017 ) which was much higher than reported in studies published previously. Therefore, the aim of this work was to evaluate the susceptibility pattern to different classes of antimicrobials of colistin-resistant E. coli isolated from poultry production systems that use AGP, and to characterize the resistance determinants associated to transmissible elements.…”

Molecular characteristics of mcr-1-carrying plasmids and new mcr-1 variant recovered from polyclonal clinical Escherichia coli from Argentina and Canada

“…However, a recent report describes a broad dissemination of mcr-1 gene in E . coli recovered from healthy poultry in Argentina, suggesting an important source of this colistin resistant microorganism since at least 2013 [33]. In contrast, in countries like Canada where colistin is not commonly used in clinical therapy schemes, low detection of this mechanism in clinical isolates [34] was the result of ‘imported’ pathogens by patients hospitalized in countries where the mcr gene is more common to be found (e.g.…”

“…The worldwide emergence of colistin resistant bacteria without any prior clinical colistin exposure could be considered a consequence of polymyxins use in veterinary medicine [37–39] and as promoter factors in the agriculture and food production sectors [1,33,37–40]. Abundant bibliography supports this presumption: mcr -carrying Enterobacteriaceae are frequently isolated from different animal species such as cattle, chicken, and pigs [4,41].…”