title: Loss of porins following carbapenem-resistance selection and adherence modification in enterobacteria.
abstract: The acquired resistance to the carbapenems is frequently joined to modified expression of porins or other outer membrane (OM) structures, thus bacterial adherence, that also depends on the presence of peculiar surface structures, might theoretically be influenced. In this study the ability to adhere to Hep-2 and I-407 eukaryotic cell monolayers was assayed for two susceptible strains of Serratia marcescens, one strain of Enterobacter cloacae and one of Providencia rettgeri in comparison with that of isogenic resistant mutants selected either by carbapenems or by cephalosporins. The mutants appeared slightly less adherent than the wild type strains, however, due to the high variability of this kind of assay, the differences observed in most cases could not be considered statistically significant. The data suggest that adherence, among the factors affecting the pathogenicity of the strains, remains probably unmodified in the resistant bacterial population possibly selected by a carbapenem treatment.
authors.affiliation: Institute of Medical Microbiology, University of Milano, Italy.
authors.forename: A
authors.initials: A
authors.lastname: Raimondi
authors.forename: A
authors.initials: A
authors.lastname: Pessina
authors.forename: M G
authors.initials: MG
authors.lastname: Neri
mesh_terms: D001422:Bacterial Adhesion / Q000187:drug effects / Q000502:physiology*; D015780:Carbapenems / Q000494:pharmacology*; D016972:Enterobacter cloacae / Q000187:drug effects / Q000235:genetics / Q000378:metabolism; D004755:Enterobacteriaceae / Q000187:drug effects / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D018272:Porins / Q000096:biosynthesis*; D011532:Providencia / Q000187:drug effects / Q000235:genetics / Q000378:metabolism; D012641:Selection, Genetic; D012706:Serratia marcescens / Q000187:drug effects / Q000235:genetics / Q000378:metabolism; D014407:Tumor Cells, Cultured; D018440:beta-Lactam Resistance / Q000235:genetics
chemical_list: D015780:Carbapenems; D018272:Porins