Fruit, vegetable and seed saccharides that block pseudomonas aeruginosa lectins might (like milks, egg whites and hive products) act as decoys, competitively hampering pathogen binding to sensitive target cells

The adherence of the devastating pathogen Pseudomonas aeruginosa to target cells for infection establishment involves non-specific and specific adhesins. The latter include its PA-IL (LecA) and PA-IIL (LecB) lectins, which are proteins that specifically bind to the target-cell surface-receptor saccharides. PA-IL shows selective affinity to D-galactose and its derivatives and PA-IIL preferentially binds to L-fucose and D-mannose derivatives. The strong binding of these lectins to cell receptors is inhibitable by competing saccharides (acting as decoys) in the cell vicinity. Animal fetuses and neonates, whose immune-system immaturity sensitizes them to infections, depend on the maternal or social (beehive) supply of such saccharides that would trap pathogens via their lectins, hampering their cell adhesion. In our previous studies, we showed that P. aeruginosa lectins bind to low and high MW (>10kDa) saccharides of diverse milks, avian egg whites, beehive products (honey and royal jelly) and several seeds, and are blocked by them. In the current manuscript, we describe similar PA-IL and PA-IIL-inhibiting activities in extracts of edible fruits, vegetables, and seeds. The examined fruits were apple, banana, carob, chikoo, cranberry, citron, coconut, date, fig, grape, guava, kiwi, mango, persimmon, pineapple, plum, pomegranate, and quince. Most of them (excluding cranberries) nicely inhibited both lectins. The vegetables used were onion, pumpkin, and tomato. Seeds of apricot, cashew, cocoa, coffee, papaya, soybean, and tomato were used. These lectin-blocking activities of ordinary fruits, vegetables, and seed-saccharides that are assumed to function in protecting their own embryos from infections (acting like those of the egg whites, milks, royal jelly, and honey) might also be useful for preventing P. aeruginosa infections in animals. The advantage of using the herein-described edible vegetable substances for hampering antibiotic-resistant intestinal and external lectin-dependent pathogen adhesion is their being harmless, widely available, and inexpensive.