Entomotherapy: An alternative treatment for diseases due to Gram-negative bacteria in Burkina Faso

Abstract Insects are known for their harmful effects. However, they also have beneficial effects on humans, animals, plants, and ecosystems. Its beneficial uses include entomophagy and entomotherapy. The objective of this study was to evaluate the antibacterial activity of insect extracts against Gram-negative bacteria. Antibacterial activities of thirteen crude extracts of medicinal insects were tested against twelve Gram-negative bacteria by diffusion on agar. Imipenem was used as antibiotic for positive control. Extract yields varied among the insect species. All 13 extracts acted differently against certain Gram-negative bacteria. Largest inhibition diameter was 30.0 ± 0.0 mm for extracts of Cirina butyrospermi and Mylabris variabilis against Pseudomonas aeruginosa ATCC27853 and Salmonella enteritidis ATCC13076, respectively. Diameters of inhibition obtained using imipenem against these same bacterial strains were 13.0 ± 0.0mm and 22 ± 1.0 mm, respectively. The smallest inhibition diameter was 7.5 ± 0.0mm obtained using Anopheles gambiae extract against Salmonella Typhimurium ATCC14028. Imipenem used as a positive control was active on all strains tested. The highest multi-resistance index (0.85) was reported for Pseudomonas aeruginosa ATCC9027 and Serratia odorifera 652411. Results of this study confirmed the antibacterial activities of insects used by traditional health practitioners to treat different pathologies. Entomotherapy could be an alternative treatment for certain pathologies caused by gram-negative bacteria.