Effects of mucus of the snail Archachatina marginata on the bacteria Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus and S. epidermidis: The relative difference amongst the raw, diluted and filtered mucus

The study aimed to assess the antibacterial activity of the raw, diluted and filtered mucus of the snail Archachatina marginata against the bacteria E. coli, P. aeruginosa, S. aureus and S. epidermidis. The collected snails were manually stimulated and the secreted mucus obtained. Antimicrobial tests were then carried out using various fractions of this mucus. The method of antimicrobial-impregnated discs on the agar culture medium was used. Results showed that in the presence of raw mucus, the mean inhibition zone diameters ranged from 11.70 to 17.50mm. The largest was observed with S. aureus and the smallest with P. aeruginosa. When using diluted mucus, the mean values of the inhibition diameters of bacterial cells varied between 9.00 and 17.44 mm in the presence of the different doses of mucus. The largest diameter was recorded with S. aureus at the 80% mucus dose and the smallest with E. coli at the 20% mucus dose. With the filtered mucus, inhibition of S. aureus and S. epidermidis growth started with 20 µL of the mucus. Inhibition if E. coli growth was observed from a minimum volume of 20 µL of the mucus. However, no inhibition of P. aeruginosa growth was observed from 20 µL to 175 µL of filtrate and it particularly distinguished itself from the others. The MICs MBCs of the filtered mucus were greater than those of the raw mucus. It seems necessary to continue exploring the secretions of other molluscs against infectious bacteria, to search for therapeutic alternatives to classical antibiotics.