|
Document Type |
: |
Thesis |
|
Document Title |
: |
Antimicrobial Potential and Chromatographic Evaluation of Azadirachta indicia A. Juss., Meliaceae Leaves Extracts and Genomic Studies of Potent Pathogenic Bacteria الإمكانية المضادة للميكروبات والتقييم الكروماتوجرافي لمستخلصات أوراق Azadirachta indicia A. Juss., Meliaceae والدراسات الجينومية للبكتريا المسببة للأمراض |
|
Subject |
: |
Faculty of Science |
|
Document Language |
: |
Arabic |
|
Abstract |
: |
Antimicrobial resistance has become a serious threat to human health nowadays. This research aimed to explore the potential of plants to be used as antimicrobial agent against pathogenic bacteria. Three different extracts of Azadirachta indicia (Neem) leaves (methanolic, ethanolic and aqueous extracts) were tested against 5 Gram-positive bacteria and 4 Gram-negative bacteria. For Gram-positive bacteria, ethanolic extract showed the best antimicrobial potential. Bacillus cereus were found more sensitive to ethanolic extract at 500 mg/ml conc. with 21.1 mm zone of inhibition (ZOI). For methanolic extract, at 500 mg/ml conc. Bacillus cereus and Methicillin-resistant Staphylococcus aureus were found more sensitive with 15.4 mm and 15.1 mm ZOI, respectively. Streptococcus pneumoniae were resistant to methanolic Neem extract. Three Gram-negative bacteria: Klebsiella pneumoniae, Escherichia coli, and Salmonella typhimurium were resistant to all Neem leaves extracts. The best antimicrobial results of ethanolic and methanolic extracts against Pseudomonas aeruginosa were at 200 mg/ml conc. of each extract with 18.3 and 21.2 mm ZOI, respectively. Negative results were found for aqueous extract with all tested pathogenic bacteria. HPLC analysis of Neem leaves extracts depicted that benzoic acid was detected in ethanolic extract, while ferulic acid and 4-hydroxy benzoic acid were detected in all three Neem leaves extracts. 16S rRNA gene sequencing were used for identification of five bacteria obtained from soil. These bacteria were identified as: Bacillus velezensis (strain FZB42), Bacillus cereus ATCC 14579, Bacillus endophyticus 2DT, Lysinibacillus pakistanensis NCCP-54, and Bacillus paramycoides strain MCCC 1A04098. The optimal growth of these bacterial strains was observed at pH 7-8 and at 37°C. The optimal growth of Bacillus velezensis and Lysinibacillus pakistanensis was with 4%NaCl, while it was with 2%NaCl for Bacillus cereus and Bacillus endophyticus, and 0%NaCl for Bacillus paramycoides. Bacillus cereus ATCC 14579 was sensitive to ethanolic and methanolic Neem extracts at 100mg/ml concentration with 16.7 mm ZOI. This study confirmed the antibacterial activity of Neem leaves against these bacterial strains and the possibility of employing this knowledge in new antibacterial drugs development. |
|
Supervisor |
: |
Dr. Munazza Gull |
|
Thesis Type |
: |
Master Thesis |
|
Publishing Year |
: |
1444 AH
2023 AD |
|
Co-Supervisor |
: |
Dr. Ebtihaj Jambi |
|
Added Date |
: |
Monday, April 17, 2023 |
|
Researchers
| أسماء وصل المغامسي | Almaghamsi, Asmaa Wasl | Researcher | Master | |
|