Viability of a capsule- and lipopolysaccharide-deficient mutant of Neisseria meningitidis

Neisseria meningitidis is the only lipopolysaccharide (LPS)-producing gram-negative bacterial species shown to be viable also without LPS. It was thought that the presence of capsular polysaccharide is necessary for this unusual feature. However, we show now that no part of the capsule gene cluster is required for maintaining LPS deficiency in N. meningitidis.