Antimicrobial Activity of 11 Insects Extracts Against Multi Drug Resistant (MDR) Strains of Bacteria and Fungus

Abstract

Objective: 11 kinds of insects, which are traditional Chinese medicine (TCM), were detected by antimicrobial experiments to find new natural antibacterial extractives. Method: The body or shell of insects were extracted by two stage extraction solvent. Firstly, the body were impregnated two times with dichloromethane solvent, and then, soaked with 70% methanol and extracted two times. Disk diffusion test and Broth Dilution Assay were used to test MIC (MIC-minimum inhibitory concentration) value of these extractions. Multi Drug Resistant (MDR) Strains of Bacteria and Fungus were used as detected strains in the test. Result: Of all eleven species of insects, extractives of the shell of Cryptotympanapustulata Fabricius and the body of Mole cricket have significant antibacterial activity on Staphylococcus aureus and Mycobacterium tuberculosis; the different organic solvents components of C. Fabricius and M.cricket also have inhibit effects on S.aureus and M.tuberculosis; The MIC of the ethyl acetate fraction of M.cricket on M.tuberculosis was even reached to 0.01 g/mL. Moreover, the effect of water extractives from C. Fabricius on M.tuberculosis was 0.01 g/mL eighter. Discussion: The discovery of new antimicrobial medicine is always an urgent and successive need in the field of Medicine. Insects is a new field for the discovery of antibiotics.