LuxS promotes biofilm maturation and persistence of nontypeable haemophilus influenzae in vivo via modulation of lipooligosaccharides on the bacterial surface.

Nontypeable Haemophilus influenzae (NTHI) is an extremely common airway commensal which can cause opportunistic infections that are usually localized to airway mucosal surfaces. During many of these infections, NTHI forms biofilm communities that promote persistence in vivo. For many bacterial species, density-dependent quorum-signaling networks can affect biofilm formation and/or maturation.

Streptococcus pneumoniae forms surface-attached communities in the middle ear of experimentally infected chinchillas.

Background: Streptococcus pneumoniae (pneumococcus) causes respiratory and systemic infections that are a major public health problem worldwide. It has been postulated that pneumococci persist in vivo in biofilm communities.

Methods: In this study, we analyzed whether pneumococci form biofilms in vivo, and if so, whether biofilms correlated with bacterial persistence.