RT Journal Article SR Electronic(1) A1 Mallea, Monique A1 Chevalier, Jacqueline A1 Bornet, Charleric A1 Eyraud, Annie A1 Davin-Regli, Anne A1 Bollet, Claude A1 Pages, Jean-MarieYR 1998 T1 Porin alteration and active efflux: two in vivo drug resistance strategies used by Enterobacter aerogenes JF Microbiology, VO 144 IS 11 SP 3003 OP 3009 DO https://doi.org/10.1099/00221287-144-11-3003 PB Microbiology Society, SN 1465-2080, AB SUMMARY: Entembacter aemgenes is among the five most frequently isolated nosocomial pathogens in France, and this bacterium also shows increasing multidrug resistance. In this study, various E. aerogenes strains isolated from hospital units were characterized for their outer-membrane proteins, antibiotic susceptibilities (inhibition diameters and MICs) and resistance mechanisms associated with modification of envelope permeability (porin alteration and active efflux). Diminished outer-membrane permeability due to porin alterations was found in conjunction with the expression of an enzymic barrier in resistant isolates. Interestingly, changes in the functional expression of porins appeared to play a special role in susceptibility to cefepime. An active efflux to quinolones was also identified. Simultaneous changes in envelope permeability, i.e. a porin deficiency (in) and an efflux mechanism (out), were clearly evident in two clinical strains., UL https://www.microbiologyresearch.org/content/journal/micro/10.1099/00221287-144-11-3003