Structure and properties of the outer membranes of Brucella abortus and Brucella melitensis

Authors

  • Ignacio Moriyón Departamento de Microbiología, Universidad de Navarra, Pamplona, Spain
  • Ignacio López-Goñi Departamento de Microbiología, Universidad de Navarra, Pamplona, Spain

Keywords:

Brucella abortus, Brucella melitensis, outer membrane (OM), lipopolysaccharide (LPS), bacterial pathogenicity

Abstract

The brucellae are Gram-negative bacteria characteristically able to multiply facultatively within phagocytic cells and which cause a zoonosis of world-wide importance. This article reviews the structure and topology of the main components (lipopolysaccharide, native hapten polysaccharide, free lipids and proteins) of the outer membranes of Brucella abortus and B. melitensis, as well as some distinctive properties (permeability and interactions with cationic peptides) of these membranes. On these data, an outer membrane model is proposed in which, as compared to other Gram-negatives, there is a stronger hydrophobic anchorage for the lipopolysaccharide, free lipids, porin proteins and lipoproteins, and a reduced surface density of anionic groups, which could be partially or totally neutralized by ornithine lipids. This model accounts for the permeability of Brucella to hydrophobic permeants and for its resistance to the bactericidal oxygen-independent systems of phagocytes.

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Published

2010-03-18

Issue

Section

Research Articles