Gloria Gutiérrez

TL;DR: The main determinant for beta-lactamase expression in Bacteroides strains is the cfxA gene, in which IS614B integration upstream of the coding sequence represents a molecular marker for higher levels of enzyme activity.

TL;DR: Among the DNA polymorphisms detected in the cfiA locus, only the integration of IS942 at its promoter was a determinant for expression of carbapenemase activity.

TL;DR: The use of colistin as a last resort antimicrobial is compromised by the emergence of resistant enterobacteria with acquired determinants like mcr genes, mutations that activate the PmrAB system and by still unknown mechanisms as discussed by the authors.

TL;DR: Low susceptibility to colistin is also becoming spread, mainly by plasmid mobilization of one of the enzymes that modify covalently the external layer of bacterial envelope, interfering antibiotic effectiveness.