RESUMO
The spatial network structure of Dergall is based on substances nontoxic to humans and the environment which, when applied on solid surfaces, creates a coating that reduces bacterial cell adhesion. The bacteriostatic properties of siloxanes are based on a purely physical action mechanism which excludes development of drug-resistant microorganisms. The aims of the present study were to 1) evaluate a Dergall layer formed on the eggshell surface regarding the potential harmful effects on the chick embryo; 2) evaluate antimicrobial activity and estimate the prolongation time of Dergall's potential antimicrobial activity. Dergall at a concentration of 0.6% formed a layer on the eggshell surface. In vitro testing of the potential harmful effects of Dergall by means of a hen embryo test of the chorioallantoic membrane showed no irritation reaction at a concentration of 3% and lower. The hatchability of the groups sprayed with a Dergall water solution with a concentration of 0 to 5% was 89.1 to 93.8% for fertilized eggs (P > 0.05) but decreased to 63.7% (P < 0.05) in the group sprayed with a 6% concentration of the solution. This phenomenon was caused by embryo mortality in the first week of incubation. At the concentration of 0.6%, Dergall exhibited strong antibacterial properties against bacteria such as Staphylococcus aureus, Escherichia coli, Shigella dysenteriae, Shigella flexneri, and Salmonella typhimurium. For Streptococcus pyogenes, the highest antibacterial activity of Dergall was reported in the concentrations of 100 and 50%. For Pseudomonas aeruginosa, no antibacterial activity of Dergall was generally observed, but in vivo testing showed a strong decrease of all gram-negative bacteria growth. Moreover, a prolonged antimicrobial effect lasting until 3 D after disinfection was observed, which makes Dergall a safe and efficient disinfectant.