Dr. Paul D. StapletonAREEJ MOHAMMED ABDULHADI ALAJMI2022-05-292022-05-29https://drepo.sdl.edu.sa/handle/20.500.14154/46229Ants are a diverse group of insects with over 27,000 species. In spite of this diversity ant venom is still understudied. Insect venoms are abundant in peptides and proteins with diverse activities. For drug discovery, natural sources remain invaluable, ant venom is one such resource. The objective of this study was to determine the antibacterial activity of Pachycondyla sennaarensis (Samsum) ant venom, and to isolate the active fraction. Venom glands were extracted manually by ant dissection and samples tested for antibacterial activity. Crude separation was achieved by size exclusion filtration into high and low molecular weight fractions. High performance liquid chromatography (HPLC) was used to further fractionate the samples, followed antimicrobial testing and one-dimensional sodium dodecyl sulphate gel electrophoresis. The venom of P. sennaarensis has activities against both Gram-negative and Gram-positive bacteria, moreover it is active against multidrug resistant bacterial strains. Within the filtrate fraction (low molecular weight proteins and peptides), an active sub-faction was separated by high performance liquid chromatography, which was active against Gram-negative bacteria. The venom has shown to contain a wide range of protein and/or peptides that are active. This study provides the first initial separation of this complex mixture, and facilitates further analysis as an active fraction for antimicrobial drug discovery.en