Silk of the spider Pholcus phalangioides (Fuesslin, 1775) (Araneae: Pholcidae) as antibacterial agent

Spider silk has gained much attention in recent years because of its valuable properties. The present study is focused on the evaluation of the antibacterial properties of silk recovered from the cellar spider Pholcus phalangioides (Fuesslin, 1775) of the family Pholcidae. For the assessment of its inhibitory activities we used four pathogenic bacterial strains, i.e. two Gram negative (Acinetobacter baumannii and Pasteurella multocida) and two Gram positive (Staphylococcus aureus and Streptococcus pneumoniae). Antibacterial activity was evaluated following the Kirby-Bauer Disk diffusion method. The spider silk induced the highest inhibition zones against A. baumannii followed by S. aureus and S. pneumonia. The silk showed least effectiveness against P multocida. Moreover, the inhibitory potential of silk varied with the concentration of the silk solution. On the basis of our results, we recommend further studies on the antibacterial action of spider silk, so that we may use silk of our local spider species for designing novel therapeutic agents in the near future.