Expression of a new disialyllacto structure in the lipopolysaccharide of non-typeable Haemophilus influenzae

► We determined the LPS structures of two non-typeable H. influenzae strains. ► The proximal and the distal inner core heptoses were found to be elongated. ► NTHi strain 1008 contains globoside elongations from two sites of the inner core. ► Globotetraose and globoside were found in the NTHi strain 1247. ► The NTHi 1247lpsA mutant indicated disialyllactose to extend from GlcI.