Phase Variation in HMW1A Controls a Phenotypic Switch in Haemophilus influenzae Associated with Pathoadaptation during Persistent Infection

phase variation lowers adhesin expression, which controls an NTHi lifestyle switch from high epithelial invasiveness to lower invasion and higher biofilm formation. This reversible loss of function aligns with the previously stated notion that epithelial infection is essential for NTHi infection establishment, but once established, persistence favors gene inactivation, in this case facilitating biofilm growth.