Galactomannans exopolysaccharide (EPS) are cell wall polysaccharides consisting of a mannose backbone with galactose side groups. Other sugars include glucose, rhamnose, arabi nose and xylose. They are highly branched with 1-2, 1-5 and 1-6 linkages and are released from the cell wall during growth (Notermans and Soentoro, 1986; Noterrnans et al, 1987, 1988).
EPS are antigenic with 1-5 linked beta-D-galactofuranosides being immunodorninant from Aspergilius/Penicillium species (Notermans et al, 1988; Kamphuis et al, 1992).
Antibodies against EPS have been detected in the sera of animals and humans (Notermans et al, 1987, 1988). EPS are present in the sera of immuno-compromised organ transplant patients with invasive aspergillosis (Pfeiffer et al, 2006).
In addition, antigenic EPS are produced by species of Phizopus, Mucor, Rhizoniticor, Absidia connybifera and Syncephalasirum racemosum (De Ruiter et al, 1992).
EPS are readily detected in house dust of homes with reported dampness and are associated with respiratory symptoms in children (Douwes et al, 1999, 2003, 2006). They and 1-3-beta-D-glucans are good markers for the overall level of fungal concentrations in dust and as a surrogate for estimating airborne fungal exposure (Chew et al, 2001).
Thus, EPS are additional biocontaminants in damp indoor spaces and appear to be associated with respiratory symptoms in children.