Antibacterial effects of Eucalyptus globulus leaf extract on pathogenic bacteria isolated from specimens of patients with respiratory tract disorders.

The antibacterial activity of Eucalyptus globulus leaf extract was determined for 56 isolates of Staphylococcus aureus, 25 isolates of Streptococcus pyogenes, 12 isolates of Streptococcus pneumoniae and seven isolates of Haemophilus influenzae obtained from 200 clinical specimens of patients with respiratory tract disorders. MIC50s for these species were 64, 32, 16 and 16 mg/L, respectively; MIC90s were 128, 64, 32 and 32 mg/L, respectively; and MBCs were 512, 128, 64 and 64 mg/L, respectively. These results suggest that further studies to clarify the possible therapeutic role of E. globulus leaf extract in the treatment of respiratory tract infection are warranted.