title: The role of outer membrane in Serratia marcescens intrinsic resistance to antibiotics.
abstract: Three different porins from Serratia marcescens were described. They were named Omp1, Omp2 and Omp3 and their molecular weights were 42, 40 and 39 kDa respectively. Omp2 and Omp3 showed osmoregulation and thermoregulation in a similar way to OmpC and OmpF of Escherichia coli. Permeability coefficients of the outer membrane of this species were calculated following the Zimmermann and Rosselet method. P values were similar to those obtained in Escherichia coli, which suggests that the chromosomal beta-lactamase would play a major role in the resistance of Serratia marcescens to beta-lactam antibiotics. Both MIC values and permeabilities were modified by salycilates and acetylsalycilate. Synergism between the outer membrane and the beta-lactamase was also evaluated. When bacteria grew in the presence of a beta-lactam in the medium, the beta-lactamase accounted for most of the resistance.
authors.affiliation: Laboratori de Microbiologia, Institut de Salut Pública, Universitat de Barcelona, Spain.
authors.forename: L
authors.initials: L
authors.lastname: Sánchez
authors.forename: N
authors.initials: N
authors.lastname: Ruiz
authors.forename: S
authors.initials: S
authors.lastname: Leranoz
authors.forename: M
authors.initials: M
authors.lastname: Viñas
authors.forename: M
authors.initials: M
authors.lastname: Puig
mesh_terms: D001425:Bacterial Outer Membrane Proteins / Q000235:genetics / Q000502:physiology*; D002462:Cell Membrane / Q000502:physiology*; D002463:Cell Membrane Permeability / Q000187:drug effects; D002876:Chromosomes, Bacterial / Q000235:genetics; D004352:Drug Resistance, Microbial / Q000235:genetics / Q000502:physiology*; D018432:Drug Resistance, Multiple / Q000235:genetics / Q000502:physiology*; D008970:Molecular Weight; D018272:Porins / Q000235:genetics / Q000378:metabolism*; D011993:Recombinant Fusion Proteins / Q000502:physiology; D012459:Salicylates / Q000494:pharmacology; D012706:Serratia marcescens / Q000187:drug effects* / Q000235:genetics / Q000502:physiology; D001618:beta-Lactamases / Q000235:genetics / Q000502:physiology
chemical_list: D001425:Bacterial Outer Membrane Proteins; D018272:Porins; D011993:Recombinant Fusion Proteins; D012459:Salicylates; D001618:beta-Lactamases