Evaluation of Antimicrobial Effect of Ghalghaf Gall Extract on Gram positive and Gram Negative Bacteria

In the recent century, the improper use of antibiotics has led to the emergence of resistant isolates that pose a serious threat to the health of human populations. In order to deal with this phenomenon, various approaches have been used, including the use of natural herbal extracts to treat infectious diseases. Ghalghaf Gall is caused by abnormal growth of plant tissues under the influence of living factors such as bees on various organs of the oak tree. Laboratory findings obtained from the evaluation of this plant indicate its high potential for antimicrobial properties. In the present study, the antimicrobial effect of Ghalghaf Gall extract on Escherichia coli and Staphylococcus aureus was investigated.

This study was performed on standard strains of Escherichia coli ATCC 25922 and Staphylococcus aureus ATCC 25923. Aqueous extract of Ghalghaf Gall was obtained by Soxhlet method. To evaluate the antibacterial activity, the minimum inhibitory concentration (MIC) and the minimum bactericidal concentration (MBC) were determined by broth-macrodilution method.

The MIC value of the extracts of Ghalghaf Gall obtained for Escherichia coli and Staphylococcus aureus were 3125 µg/ml and 98 µg/ml respectively. Also The MBC value of the Escherichia coli and Staphylococcus aureus obtained 50000 µg/ml and 1562 µg/ml respectively.

The results of this study showed that the herbal extract of Ghalghaf Gall has a very good antimicrobial effect on the gram-positive bacterium Staphylococcus aureus compared to the gram-negative bacterium Escherichia coli. Also, although relatively strong bacteriostatic function of the above extract was observed on Staphylococcus aureus, but there was a significant difference between bactericidal and bacteriostatic concentrations.