RESUMO
The present research was carried out at the Institute of Biotechnology and Genetic Engineering, The University of Agriculture Peshawar, KPK Pakistan. In this study crude methanolic extracts from Thuja occidentalis were tested for their antimicrobial activity against five different bacterial strains (Bacillus subtilis, Escherichia coli, Klebsiella pneumonia, Xanthomonas sp. and Staphylococcus aureus) at two different concentrations (10 and 20 mg/ml) using disc diffusion assay. The results showed that Klebsiella pneumoniae was most sensitive to crude extracted sample from leaves at both low and high concentrations measuring 37 and 57% zone of inhibition respectively and Xanthomonas and Staphylococcus aureus was found to be more resistant to the crude extracted samples from leaves at both concentrations. Similarly, Klebsiella pneumoniae was most sensitive to crude extracted samples from seeds at high concentration followed by E. coli at both concentrations. Staphylococcus aureus on the other hand was found to be more resistant to the crude extracted samples at low and high concentrations. These results suggested that extracts prepared from the leaves and seeds of Thuja occidentalis can be used as natural remedy for the treatment of various bacterial infections.