IIBBA   05544
INSTITUTO DE INVESTIGACIONES BIOQUIMICAS DE BUENOS AIRES
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
The map locus of Brucella suis is involved in cell envelope biogenesis and virulence
Autor/es:
RUIZ-RANWEZ V.; ALTABE S.G.; BIALER M.G.; ESTEIN S.M.; RUSSO D.M.; SYCZ G.; ZORREGUIETA A.
Lugar:
Córdoba
Reunión:
Congreso; LII Reunión Anual de la Sociedad Argentina de Investigación Bioquímica y Biología Molecular (SAIB); 2016
Institución organizadora:
Sociedad Argentina de Investigación Bioquímica y Biología Molecular (SAIB)
Resumen:
Brucella species exhibit unique surface properties, which make them furtive pathogens and more resistant to several host defence compounds. We have identified a locus of Brucella suis encoding the MapA and MapB proteins, which are predicted to represent the TAM machinery, recently proposed to participate in the translocation/insertion of autotransporters (ATs) in the outer membrane (OM). In Brucella, ATs are involved in bacterial attachment to host components. However, the role of TAM in B. suis would not be restricted to AT translocation since the ∆mapB phenotypes were not only related to adhesion functions. Indeed, ∆mapB showed enhanced sensitivity to lysozyme, Triton X-100 and polymyxin B, indicating that the cell envelope integrity is compromised. This effect was not due to major differences in the LPS structure or to altered total fatty acid composition. Analysis by LC-MS/MS and Western Blot of membrane fractions suggested that the extent of some OM proteins is slightly altered in the mapB mutant. Interestingly, the number of bacteria recovered from macrophages during the initial stages of infection was reduced in the mutant and it showed an attenuated phenotype in mice. These results suggest that MapA/MapB assists in the correct insertion of an unknown subset of protein substrates or other OM components, which are important for OM stability and virulence.