Bordetella pertussis MgtC plays a role in intracelluar survival by facilitating the adaptation to mangesium limiting conditions and acidic pH

HUGO VALDEZ; JUAN HILARIO CAFIERO; MARIA EUGENIA RODRIGUEZ; YANINA ANDREA LAMBERTI

Congreso; LXIV Reunión Anual de la Sociedad Argentina de Inmunología; 2016

Bordetella pertussis (Bp), the causative agent of whooping cough, survives inside host cells, a process that requires the adaptation of the pathogen to this harsh environment. Bp genome contains a homolog of mgtC, a virulence factor of several pathogens that is involved in growth under mildly acidic pH and Mg+2 limiting conditions and that is crucial for intracellular survival. The aim of this study was to analyse the role of mgtC in Bp intracellular survival. A Bp∆mgtC mutant strain and a complemented strain were constructed and used in parallel with the wild type strain (wtBp) in an infection assay of PMA-differentiated THP-1 cells. Immunofluorescence microscopy showed that there were no differences between the strains in the uptake of bacteria by THP-1 cells. The intracellular survival of these strains inside THP-1 cells was analyzed in a polymyxin B protection assay by CFU counts at 3, 24 and 48 hours post-infection (pi). BpΔmgtC showed a decrease in intracellular survival at 24 and 48 hours pi (p