Antimicrobial activity of cuticle and outer eggshell protein extracts from three species of domestic birds.

1. The eggshell cuticle is the proteinaceous outermost layer of the eggshell which regulates water exchange and protects against entry of micro-organisms. In this study, we investigated the hypothesis that the cuticle may also reduce microbial contamination by providing a chemical defence. 2. Outer eggshell and cuticle protein was extracted from domestic chicken (Gallus gallus), duck (Anas platyrhynchos) and goose (Anser anser) eggs by HCl and urea treatment, respectively. Antimicrobial activity of the extracts against Gram-positive and Gram-negative bacteria was evaluated. 3. C-type lysozyme, ovotransferrin and ovocalyxin-32 were identified in all extracts by Western blotting. All extracts from all species demonstrated lysozyme enzymatic activity. Immobilised c-type lysozyme retained some enzymatic activity. Protein extracts demonstrated activity against Pseudomonas aeruginosa, Staphylococcus aureus and Bacillus subtilis suggesting the action of antimicrobial proteins in addition to lysozyme. 4. The results suggest that the antimicrobial outer eggshell and cuticle proteins present in a number of avian species may be a mechanism which enhances avian reproductive success.

Comparative antibacterial activity of avian egg white protein extracts.

1. Egg white proteins from the eggs of domestic chicken (Gallus gallus), turkey (Meleagris gallopavo), duck (Anas platyrhynchos) and goose (Anser anser) were analysed in order to compare the antimicrobial activity of these products. 2. Albumen from each species was sampled and analysed by SDS-PAGE and Western blotting. Antimicrobial activity and lysozyme activity were measured. 3. Ovotransferrin and ovalbumin were identified in all species while c-type lysozyme was present in chicken, turkey and duck egg white samples, but not in goose. 4. Galliformes appear to possess albumens with greater antimicrobial activity than those of the Anseriformes. This can be attributed to higher concentrations of ovotransferrin and the broad acting c-type lysozyme.

Treatment of dermatitis caused by the sesquiterpene lactone helenin.

Many sesquiterpene lactones, terpenoid compounds present in members of the Compositae (Asteraceae) family of plants, are known to cause allergic contact dermatitis. There is no treatment of this skin disease. We report on the use of an amino acid, L-cysteine, to control dermatitis in guinea pigs sensitized to the sesquiterpene lactone, helenin. The cysteine treatment of allergic reactions induced by helenin reduced the recovery time of the animals by about 50%. The effect of cysteine treatment might be explained by: cysteine reaction with free helenin, and substitution of skin proteins from the protein-helenin complex by cysteine through competitive reactions. Cysteine treatment present a new promising way for control of this type of allergy in humans.

Treatment of dermatitis from parthenin.

Composites and some other plants containing sesquiterpene lactones, frequently cause allergic contact dermatitis in man. No treatment is available to control this disease successfully. We have used an amino acid, cysteine, to treat allergic contact dermatitis in guinea pigs sensitized to parthenin, a major sesquiterpene lactone of an allergenic weed, Parthenium hysterophorus L. Cysteine treatment of the allergic reaction induced by parthenin resulted in (a) reduced time of recovery and (b) reduced intensity of the skin reaction.