Effect of Leech (Hirudo medicinalis) Saliva on Staphylococcus aureus and Escherichia coli, in vitro

In order to increase in microbial resistance, finding biological antimicrobial materials is valuable. Therefore, in this research, antimicrobial effect of leech saliva on the growth of two bacteria, Staphylococcus aureus (Gram positive) and Escherichia coli (Gram negative) was studied.

The leech saliva was extracted in vitro and cultured in different dilutions with BHI broth and 1×10 8 S.aureus and E.coli bacteria in sterile microplate. The results were observed and interpreted after 24 and 48 hour incubation at 490 nm wave length. All experiment procedures were repeated 2 weeks later.

After 24 hour, in S.aureus culture significant difference was observed among all wells with positive control, in E.coli was just among 1-7 wells (P<0.05). After 48 hour, again significant difference was observed among all wells of S.aureus with positive control but in E.coli was just in well number 1 (The highest concentration of leech saliva).

According to the results, leech saliva has antimicrobial effect and more studies on animal models are necessary.