IalB FAMILY PROTEIN: SEEKING TO UNDERSTAND PATHOGEN-HOST INTERACTION

RÍOS, FLAVIO NICOLAÁS; COMERCI, DIEGO J.; MARCHESINI, MARÍA INÉS

Congreso; XVII Congreso Argentino de Microbiología General; 2022

SAMIGE

Brucella spp., are the causative agents of brucellosis, a worldwide distributed zoonosis. Brucellosis remains endemic in Argentina, affecting cattle productivity and human health. Brucella spp. are facultative intracellular pathogens whose success relies on diverse strategies that allow invasion, survival, and proliferation within mammalian cells. This study is focused on characterizing and understanding the role of the members of IalB family protein (PF06776) in B. abortus physiology and pathogenesis. IalB was originally described as a protein required for entry into erythrocytes in Bartonella spp., intracellular pathogens phylogenetically close to Brucella. After a bioinformatic characterization of B. abortus IalB proteins, intrinsically disordered regions containing short linear motifs predicted to interact with proteins involved in reorganization of the host cortical actin cytoskeleton were identified Single and multiple mutants were obtained by unmarked deletion. In these strains, vegetative growth and intracellular replication in non-professional phagocytic cells (HeLa) were assessed. Besides, bacterial morphology and replication were analyzed by immunofluorescence microscopy and time-lapse microscopy. Single mutants in some ialB genes showed statistically significant differences to the parental strain 2308 in generation time, intracellular replication, cell size, and in membrane integrity assays. These results suggest a role of IalB proteins in B. abortus cell shape, as well as in vegetative and intracellular multiplication.