Inhibitory Effect of Grapefruit Extracts on the Growth and Adhesion Ability of Staphylococcus aureus

Abstract

Ten isolates belong to the Staphylococcus bacteria from different clinical swabs were taken from patients in Ibn al-Nafis Hospital and Central Public Health laboratory, according to many morphological and biochemical tests that used to identify bacterial species S. aureus, the results showed that 8 isolates when investigated their ability to produce a slime layer using Congo red agar method the results showed that SA5 isolate was the best compared to other isolates through change the color of colonies to the pink and Congo red agar -colored Black.
When examining the inhibitory effect of grapefruit extracts in the growth of isolated bacteria SA5 S.aureus, results showed that the aqueous extract of the seeds at different concentrations did not show any inhibitory effect on the bacterial growth while the juice extract of this plant had an effective antibacterial activity against SA5of S.aureus in different concentrations(50%,75%,100%) were the zones of inhibition reached (8 mm ,10mm,12mm) respectively, while plant seeds extract had more effective antibacterial activity against SA5 S.aureus in different concentrations(25%,50%,75%,100%) were the zones of inhibition reached (7 mm ,9mm,12mm,15mm) respectively; Also this study tested the adhesion ability of SA5 bacterial isolate on the stainless steel material where the results showed that a large number of bacterial cells up to 58 × 105cells / ml adhered to the surface of stainless steel piece as the control, while the number of bacterial cells that adherent to the surface of this material decreased to24 × 104cells/ ml when treated with GSE.