Screening of potential antibacterial activity of the medicinal insects from Burkina Faso against Gram-positive bacteria

Insects and their products are used to treat various pathologies, particularly in traditional medicine. This treatment is performed empirically. Currently, antibiotic resistance in pathogenic microorganisms is increasing exponentially. To address this situation, it is essential to find other sources of bioactive molecules. The objective of this study was to evaluate the antibacterial activity of aqueous extracts of medicinal insects against Gram-positive pathogenic bacteria. A total of thirteen aqueous extracts of medicinal insects at different stages of development were tested on seven Gram-positive bacteria. The antibacterial activity of the insect extracts was tested according to the diffusion method on agar medium. Imipenem was used as the reference antibiotic. Extraction yields varied from one insect to another. All aqueous insect extracts exhibited inhibitory activity against the different pathogenic strains tested. The inhibition diameter, revealed by the appearance of clear rings around the discs, varied from one bacterial strain to another and from one extract to another. The largest inhibition diameter reported was 22.5 ± 0.5 mm with the Acheta domesticus extract against Enterococcus faecalis ATCC 29212. The lowest diameter of 8.5 ± 0.5 mm against Clostridium sporogenes MAR03 19404 was reported with the Cirina butyrospermi extract. All of these bacteria are susceptible to imipenem. The highest bacterial multiresistance index was 0.69, reported with Staphylococcus saprophyticus 652615, and the lowest was 0.23, reported with Clostridium perfringens ATCC 13124. This study revealed the antibacterial activity of insect extracts used by traditional health practitioners to treat their patients. Entomotherapeutics could be an alternative for treating bacterial pathologies, particularly those related to multiresistant Gram-positive bacteria.