CIVETAN   23983
CENTRO DE INVESTIGACION VETERINARIA DE TANDIL
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
MapA, a protein involved in the envelope biogenesis of Brucella suis
Autor/es:
RUIZ-RANWEZ, V.; POSADAS, D.M.; ESTEIN, S.M.; BIALER, M.G.; RUSSO, D.M.; ABDIAN, P.L.; ZORREGUIETA, A.
Lugar:
Rosario
Reunión:
Congreso; Reunion Anual de la Sociedad Argentina de Investigacion Bioquimica y Biologia Molecular-SAIB; 2014
Resumen:
Brucellae have a cell surface with distinctive properties, which make them more resistant to polycationic peptides and more permeable to hydrophobic compounds. It has been proposed that this would reflect an adaptation to intracellular parasitism. We have identified a gene of B. suis encoding a protein (MapA) predicted to localize in the cell envelope. The mapA mutant did not show differences compared to the parental strain regarding: i) outer membrane protein profiles, ii) growth curves in rich medium or under saline stress and iii) tolerance to acidic pH and complement present in porcine serum. Instead, the mutant showed an enhanced sensitivity to Triton X-100, Polymyxin B (a cationic lipopeptide) and Lysozyme. Observation of the phenotype of mapA with acriflavine and LPS analysis by SDS-PAGE and silver staining suggest that the O-antigen portion of the LPS is not altered in the mutant. Interestingly, the mutant colonies in the presence of crystal violet showed a differential staining compared with the wild type. In addition, the mapA mutant was impaired in the binding to HeLa cells probably due to an altered cell surface. These results suggest that MapA plays a role in the integrity of the Brucella cell envelope. Since it is clear that a defective envelope could be linked to a reduced virulence, we are currently evaluating the virulence of the mutant using the murine model.