Identification of meningococcal factors required for adhesion to epithelial and endothelial cells by high throughput screening. meningococcus_tnseq

Neisseria meningitidis is a leading cause of bacterial meningitis and septicaemia affecting infants and adults worldwide. N. meningitidis is also a common inhabitant of the human nasopharynx and, as such, is highly adapted to its niche. During bacteremia, N. meningitidis gains access to the blood compartment where it adheres to endothelial cells of blood vessels causing dramatic vascular damage. To investigate genes of importance in meningococcal host colonization we generated 3 saturated transposon insertion mutant libraries of N. meningitidis and used Tn-seq analysis. The transposon mutant libraries were selected using an in vitro colonization model in order to identify mutants displaying decreased capacity to colonize human epithelial and endothelial cells in parallel. Comparison of input/output pools of bacteria by high-throughput insertion tracking by deep sequencing (HITS) has allowed the comprehensive identification of essential genes during exponential phase of growth and in vitro colonization of either epithelial or endothelial cells. This innovative high throughput screening provides new insights into the meningococcal functions necessary for the bacterium to adapt to its changing environments and grow in contact with human cells.