摘要:The effect of ethanolic extracts of Punica granatum ( P. granatum ) and Quercus infectoria ( Q. infectoria ) on cell surface hydrophobicity of 10 clinically isolated Helicobacter pylori strains were investigated using salt aggregation test. Both P. granatum and Q. infectoria significantly increased the hydrophobicity of all isolates, irrespective of their antibiotic resistance patterns. These two plant species were demonstrated to produce both bacteriostatic and bactericidal activities. The minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) values were from 0.78 to 6.25 and 3.12 to 6.25 mg/ml for P. granatum , and from 3.12 to 6.25 and 3.12 to 12.5 mg/ml for Q. infectoria , respectively. Ethyl acetate and n -butanol fractions of both plants had values at least 10-fold lower than the MIC and MBC values of the ethanolic extracts. The results indicate no relationship of the increased cell-surface hydrophobicity with the MIC or MBC values.