A mgtC-like protein of Bordetella pertussis is involved in intracellular survival

CAFIERO, JUAN HILARIO; LAMBERTI, YANINA; RODRIGUEZ, MARIA EUGENIA

Buenos Aires

Simposio; 11th International Bordetella Symposium; 2016

International Bordetella Society

Introduction: Bordetella pertussis (Bp) genome contains an ORF (BP0414) that shares homology with mgtC, a horizontally-acquired virulence factor of several pathogens that is involved in growth under Mg+2 limiting conditions and intramacrophage survival.Objective: Analyse the role of mgtC in the intracellular survival of BpMaterials and methods: A null mutant strain of mgtC was constructed by allelic exchange (BpmgtC). The growth in SS liquid medium of the mutant was determined in parallel with the parental strain (wt). Both strains were used to infect PMA differentiated THP-1 cells. Immunofluorescence microscopy was used to determine the uptake of bacteria. The intracellular survival of these strains inside THP-1 cells was analyzed by polymyxin B protection assays by CFU counts and FISH staining of intracellular viable bacteria at 3, 24 and 48 hours post-infection.Results: We found no differences in the growth kinetics in SS medium between the wt and the ΔmgtC strain. There were no differences in the uptake of the wt and the BpΔmgtC strain into THP-1 cells. In a polymyxin B protection assay the intracellular survival of BpΔmgtC strain was lower (p