Title : Application of carp glycophorin from red blood cell membranes as an antibiotic reagent
Abstract:
Glycophorins (GPs) are transmembrane glycoproteins that contain sialic acid. These proteins are found in the red blood cell (RBC) membranes of mammals, birds and teleosts. We demonstrated that the teleost glycophorin, isolated from carp (Cyprinus carpio), inhibits bacterial activity by attachment to the flagellum of Vibrio anguillarum or the cell surface of Micrococcus luteus. Moreover, the carp glycophorin appears to be responsive to a broad range of bacteria. Carp glycophorin is also responsive to a carp pathogen. The adsorbent properties of the glycophorin was owed to the oligosaccharide moiety of glycophorin fraction.?The efficacy of carp glycophorin as an antibacterial reagent was evaluated for the control of disease in rainbow trout (Oncorhynchus mykiss). The results suggest that intravenous administration of glycophorin significantly delays the time of death following challenge with Vibrio anguillarum. The MIC value for carp glycophorin against E. coli (2.5 μg/ml) was higher than that of oxolinic acid (OA) (0.2 μg/ml) and miloxacin (MLX) (0.39 μg/ml), whereas, the value against M. luteus (2.5 μg/ml) was lower than that of sulfamonomethoxine (SMM) (25 μg/ml). Thus, the glycophorin fraction was more effective against Gram-positive than Gram-negative bacteria when compared with these antibiotics. The efficacy of carp glycophorin as an adsorbing reagent was evaluated. We demonstrated the ability of carp glycophorin to exclude bacteria from suspension using glycophorin-binding column, which reacted to bacterium within the column bed. Test organisms was V. anguillarum as Gram-negative bacterium or M. luteus as Gram-positive bacterium. The culture medium of each bacterium was diluted with PBS following by application to the glycophorin-binding column. The number of colony forming units (CFU) in bacterial suspension or elution was quantified by plating a 10-fold serial dilution on agar medium and counting the number of colonies after incubation at 25ºC (V. anguillarum) or 37ºC (M. luteus). In addition, we evaluated the ability of carp glycophorin-binding column in the case of a 500 l polycarbonate tubs attached to a large-scale column. The large-scale experiment was carried out using Escherichia coli suspension as test organism.
