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

CAFIERO, HILARIO; LAMBERTI YANINA; RODRIGUEZ MARÍA EUGENIA

Simposio; 11th International Bordetella Symposium.; 2016

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 Bp. Materials 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 Bp∆mgtC strain. There were no differences in the uptake of the wt and the Bp∆mgtC strain into THP-1 cells. In a polymyxin B protection assay the intracellular survival of Bp∆mgtC strain was lower (p