Dextran-Conjugated Lysozymes Inhibit the Growth of Shigella sonnei and Viral Hemorrhagic Septicemia Virus

Abstract

Lysozyme is well known as a natural antimicrobial agent, but its function is limited in that it only combats Gram-positive bacteria. We investigated the inhibitory effects of dextran-conjugated lysozymes (DLs) against some strains of Gram-negative bacteria and viral hemorrhagic septicemia virus (VHSV). The Maillard reactions of the DL were performed at various pHs (3.0, 7.0, and 8.5) in the presence of saturated KBr solution for 1, 3, 5, 7, and 9 days. The growth inhibition effects against Gram-negative bacterial strains, such as Escherichia coli, Vibrio parahaemolyticus, Pseudomonas aeruginosa, Shigella sonnei, and Shigella flexneri were found only in some DLs. DLs incubated at pH 7.0 for 9 days strongly inhibited growth of S. sonnei (92.9%). Fathead minnow (FHM) cells were infected with VHSV. DLs treated at all pHs for 1 day resulted in more than 80% viability of VHSV-infected FHM cells. The results of this study suggest that our DLs can be useful in food preservatives, pharmaceuticals, or aquatic feed due to their inhibitory effects against pathogenic bacteria and viral infections.

Antibacterial activity of lysozyme-chitosan oligosaccharide conjugates (LYZOX) against Pseudomonas aeruginosa, Acinetobacter baumannii and Methicillin-resistant Staphylococcus aureus

“…The effect of heat on the antibacterial activity of lysozyme and LYZOX was evaluated by measuring the lytic activity against Micrococcus luteus in a turbidimetric analysis [34, 35]. Lysozyme hydrolyses peptidoglycan which is one of the bacterial wall components [8].…”

Can food processing produce hypoallergenic egg?

“…Results showed that both systems were effective in reducing IgE production in animal models sensitized. Besides galactomannan, conjugation with other polysaccharides, such as dextran and carboxymethilcellulose, was reported to increase either antimicrobial ability or foaming stability of lysozyme (Lee, Kim, Yeo, Kim, & Kim, 2018;Santos, Hernandez, Costa, Júnior, & dos Reis Coimbra, 2018), but whether its allergenicity changes was not investigated. Rupa, Nakamura, Katayama, and Mine (2014) found that after immunization with native egg white proteins, mice treated with its mannosylated product showed a preventive effect against egg allergy, while mannosylation of peanut or whey proteins did not show differences.…”

“…Results showed that both systems were effective in reducing IgE production in animal models sensitized. Besides galactomannan, conjugation with other polysaccharides, such as dextran and carboxymethilcellulose, was reported to increase either antimicrobial ability or foaming stability of lysozyme (Lee, Kim, Yeo, Kim, & Kim, 2018; Santos, Hernandez, Costa, Júnior, & dos Reis Coimbra, 2018), but whether its allergenicity changes was not investigated.…”

Cecropin A Improves the Antibacterial Activity of Hen Egg White Lysozyme against Challenging Salmonella enterica Serovars

“…Different approaches have been pursued to permeabilize the outer membrane of the Gram-negative bacteria, including the application of high hydrostatic pressure [ 15 , 45 ], using outer membrane permeabilizer, conjugation with dextran [ 17 ], and enzyme denaturation [ 46 ]. EDTA-induced permeabilization of the outer membrane was commonly reported, especially with peptidoglycan hydrolases from phage origin [ 35 , 45 , 47 , 48 , 49 , 50 ].…”

“…Nonetheless, their activity is largely diminished in the case of Gram-negative bacteria due to the protective outer membrane barrier [ 13 ]. Many efforts have been employed to expand the antibacterial activity of the lysozyme to cover Gram-negative bacteria, including the addition of outer membrane permeabilizers [ 14 ] (e.g., EDTA), application of high hydrostatic pressure [ 15 ], enzyme denaturation [ 16 ], and dextran conjugation [ 17 ]. However, most of these approaches may limit lysozyme application due to systemic toxicity (e.g., EDTA) or higher costs (high hydrostatic pressure and dextran conjugation).…”