Introduction: Mollusc shells (bivalves and gastropods), known for their ability to bioaccumulate contaminants, may contain antimicrobial substances beneficial to human health. This study explores their potential in combating bacterial infections, particularly ulcerative keratitis.

Materials and Methods: An in vitro experiment was conducted at the University Clinics Laboratory of Lubumbashi. Shells of bivalve and gastropod molluscs were ground, extracted in a saline solution, and then tested by disk diffusion against Escherichia coli and Staphylococcus aureus on Mueller-Hinton agar. The impregnated disks were incubated at 37°C for 24 hours.

Results: Zones of bacterial growth inhibition were observed around the impregnated discs, with an average diameter of 7 mm. These results indicate modest but present antimicrobial activity against both tested strains.

Conclusion: Mollusc shells contain substances active against Gram-positive and Gram-negative bacteria. Although the activity is low, these results justify further research to identify the compounds responsible and evaluate their therapeutic potential, while monitoring the risks associated with antibiotic resistance.