Despite this similarity, many Klebsiella species, including Klebsiella pneumoniae, possess a thick, extracellular polysaccharide capsule that distinguishes this genus from other enterobacteria.
The production of an extracellular polysaccharide capsule, primarily consisting of glucuronoxylomannans, and melanin are key virulence determinants, enabling macrophage colonisation (Chang and Kwonchung 1994; Salas et al. 1996) (Fig. 4B).
With more research, we foresee multiple applications such as light-activated self-healing capsules, extracellular scaffolds (nanofibers, hydrogels) providing on-demand delivery of cues for cell proliferation, differentiation, or migration, activatable fluorescent particles based on thermochromic dyes, and light-triggered drug delivery systems.
Virulence factors associated with resistance, including biofilm formation, and surface and extracellular polysaccharides associated with capsule formation have also been demonstrated [ 3].
Therefore, it is not surprising that strain GOBB3-209 lackseveralal features found in GOBB3-C103-3, e.g. the capsule and extracellular polysaccharide pathway, the denitrification pathway, etc. (data not shown).
They include, among others, CRISPR (Clustered Regularly Interspaced Short Palindromic Repeats) sequences, (type II) Restriction/Modification (R/M) systems and genes involved in the production of particular extracellular structures, such as capsule exopolysaccharides (EPS) and sortase-dependent pili [ 8].
The renal tissue of crescentic GN patients showed expression of LL37 and IFN-α at the Bowman's capsule and extracellular sites, suggesting the active release of LL37 and IFN-α.
Only encapsulated yeast cells formed extracellular fibrils as a capsule-deficient C. gattii mutant completely lacked fibrils.
In addition, lineage tracing has shown that activated PECs can participate in sclerotic lesions in which cells invade the capsule and deposit extracellular matrix leading to progressive glomerular scarring [98], which destroys the glomerulus and causes proteinuria that ultimately damages the nephron.
