Nietcapsuleuze

Nietcapsuleuze is a Dutch term used in microbiology to describe organisms that lack a capsule. The term combines niet ('not') with capsuleuze ('capsule-like'), indicating absence of an extracellular polysaccharide capsule around the cell.

In bacteria, the capsule is a gelatinous layer composed primarily of polysaccharides (and sometimes polypeptides) that envelops the cell wall. It contributes to protection, adhesion, and immune evasion, and is a key virulence factor for many pathogens.

Nietcapsuleuze organisms either do not synthesize a capsule or express it only at undetectable levels under particular conditions. The absence of a capsule often correlates with reduced virulence, but non-encapsulated strains can still cause disease and may be important in studies of immunity, colonization, and vaccine design. Vaccines targeting capsule polysaccharides typically do not affect non-encapsulated variants.

Detection and study of nietcapsuleuze traits rely on capsule staining and microscopy, along with molecular methods to assess capsule gene loci and expression. Capsule presence can be phase-variable, and environmental factors or regulatory networks may switch capsule production on or off. The term is commonly used in Dutch-language microbiology literature; in English, 'non-encapsulated' is more frequently employed.