Characterization of IalB family protein in Brucella abortus

RÍOS, FLAVIO NICOLAÁS; COMERCI, DIEGO JOSÉ; MARCHESINI, MARÍA INÉS

Congreso; Congreso Conjunto SAIB-SAMIGE 2021; 2021

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 has originally been described as a protein required for entry into erythrocytes in Bartonella spp., intracellular pathogens phylogenetically close to Brucella.After a bioinformatic characterization of IalB proteins in B. abortus, 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 the use of fluorescent D-amino acid derivatives as probes in peptidoglycan synthesis were analyzed by immunofluorescence microscopy. Single mutants in some ialB genes showed statistically significant differences to the parental strain 2308 in generation time, intracellular replication and in cell size. These results suggest a role of IalB proteins in B. abortus cell shape, as well as in vegetative and intracellular multiplication.