Pseudomonas aeruginosa antibiotic resistance prompted the search for glycodecoys that would block its
lectin-dependent adhesion to human cells. We have used the
lectins of this pathogen, PA-IL (galactophilic LecA) and
PA-IIL (fucophilic LecB), and two additional pathogenic bacterial
lectins, CV-IIL (fucophilic, of Chromobacterium violaceum) and RS-IIL (mannophilic, of Ralstonia solanacearum), for assaying the pathogenic
lectin-blocking abilities of some plant and microbial polysaccharidic
food additives, adding the mannophilic
plant lectin Con A as a reference. Locust-bean and guar galactomannans and
acacia gum very strongly inhibited PA-IL. The other
lectins, excluding CV-IIL, were very strongly inhibited by yeast
mannan.
Xanthan and
inulin were weak inhibitors. The differential blocking of these
lectins by galactosylated branches of plant
polysaccharides and by
mannan matched their inhibition by avian egg whites, human milk, and
royal jelly (protecting animal embryos and neonates from
infections). The nondigestability and nontoxicity of the
food additives are advantageous for curing gastrointestinal and external
infections.