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Review
. 2024 Oct 22;13(11):921.
doi: 10.3390/pathogens13110921.

Aeromonas and mcr-3: A Critical Juncture for Transferable Polymyxin Resistance in Gram-Negative Bacteria

Nathan L McDonald  1 , David W Wareham  2 , David C Bean  1
Affiliations
Review

Aeromonas and mcr-3: A Critical Juncture for Transferable Polymyxin Resistance in Gram-Negative Bacteria

Nathan L McDonald et al. Pathogens. .

Abstract

Polymyxin antibiotics B and colistin are considered drugs of last resort for the treatment of multi-drug and carbapenem-resistant Gram-negative bacteria. With the emergence and dissemination of multi-drug resistance, monitoring the use and resistance to polymyxins imparted by mobilised colistin resistance genes (mcr) is becoming increasingly important. The Aeromonas genus is widely disseminated throughout the environment and serves as a reservoir of mcr-3, posing a significant risk for the spread of resistance to polymyxins. Recent phylogenetic studies and the identification of insertion elements associated with mcr-3 support the notion that Aeromonas spp. may be the evolutionary origin of the resistance gene. Furthermore, mcr-3-related genes have been shown to impart resistance in naïve E. coli and can increase the polymyxin MIC by up to 64-fold (with an MIC of 64 mg/L) in members of Aeromonas spp. This review will describe the genetic background of the mcr gene, the epidemiology of mcr-positive isolates, and the relationship between intrinsic and transferable mcr resistance genes, focusing on mcr-3 and mcr-3-related genes.

Keywords: Aeromonas; colistin; mcr–3; mcr–3-related genes; polymyxins.

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Conflict of interest statement

The authors declare no conflicts of interest.

Figures

Figure 1
Figure 1
Model of the mobilisation of polymyxin resistance from PET–A to mcr–3 and 7.
See this image and copyright information in PMC

References

    1. Magiorakos A.-P., Srinivasan A., Carey R.B., Carmeli Y., Falagas M.E., Giske C.G., Harbarth S., Hindler J.F., Kahlmeter G., Olsson-Liljequist B., et al. Multidrug-resistant, extensively drug-resistant and pandrug-resistant bacteria: An international expert proposal for interim standard definitions for acquired resistance. Clin. Microbiol. Infect. 2012;18:268–281. doi: 10.1111/j.1469-0691.2011.03570.x. - DOI - PubMed
    1. Gandra S., Alvarez-Uria G., Turner P., Joshi J., Limmathurotsakul D., van Doorn H.R. Antimicrobial Resistance Surveillance in Low- and Middle-Income Countries: Progress and Challenges in Eight South Asian and Southeast Asian Countries. Clin. Microbiol. Rev. 2020;33:e00048-19. doi: 10.1128/CMR.00048-19. - DOI - PMC - PubMed
    1. Naylor N.R., Atun R., Zhu N., Kulasabanathan K., Silva S., Chatterjee A., Knight M.G., Robotham J.V. Estimating the burden of antimicrobial resistance: A systematic literature review. Antimicrob. Resist. Infect. Control. 2018;7:58. doi: 10.1186/s13756-018-0336-y. - DOI - PMC - PubMed
    1. van der Zwaluw K., de Haan A., Pluister G.N., Bootsma H.J., de Neeling A.J., Schouls L.M. The carbapenem inactivation method (CIM), a simple and low-cost alternative for the Carba NP test to assess phenotypic carbapenemase activity in gram-negative rods. PLoS ONE. 2015;10:e0123690. doi: 10.1371/journal.pone.0123690. - DOI - PMC - PubMed
    1. Gaballa A., Wiedmann M., Carroll L.M. More than mcr: Canonical plasmid- and transposon-encoded mobilized colistin resistance genes represent a subset of phosphoethanolamine transferases. Front. Cell. Infect. Microbiol. 2023;13:1060519. doi: 10.3389/fcimb.2023.1060519. - DOI - PMC - PubMed

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