The effects of medicinal plant extracts on the microbial, biofilm and autolytic activity of several pathogenic bacteria.

More people are aware of the problems with drugs and are reverting to herbal (plant) and over-the-counter medications. The conclusion made is the urgency to study new plants for antimicrobial activity. Various plant extracts were used in the study to determine the antimicrobial, mode of action and autolytic activity against various microbial species. Techniques used in this study include culturing via streaking method, sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE), zymography, high performance liquid chromatography (HPLC), autolytic activity assay, minimum inhibition concentration assay, dilution activity assay, Spot-on-lawn assay and Bicinchoninic acid (BCA) assay. The whole cell protein profile was used to show the proteins without any extraction method for comparison with the applied extraction method. With the extraction method implemented, less proteins where seen as the extraction method was specific to the peptidoglycan hydrolases. Sodium dodecyl sulfate (SDS) (4%) extraction method was more effective as an extraction method when compared to lithium chloride (LiCl). Plant extract 4.2 showedantimicrobial activity as seen by the inhibition zone on the agar plate (Figure 27 and Figure 28). Plant extract 4.2 and 5.2 showed decreased autolytic activity (Figure 20-22). The conclusion made was that the presence of the plant extracts decreases growth of the microbial species thus decreases protein production. Markers were identified using HPLC where 1 marker showed antimicrobial activity (Sebacic acid) and another marker showed anti-inflammatory activity (Loxoprofen Sodium) based on previous literature. S. aureus 12600 in the presences of extract 4.2 had antimicrobial activity but results were not significant. Extract 5.2 showed biofilm formation. Extract 4.2 showed positive results in most experiments conducted.Dissertation (MSc)--University of Pretoria, 2018.South African Biochemistry and Informatics for Natural Products (SABINA) National Research Foundation (NRF)BiochemistryMScUnrestricte