Antibacterial Activity of Albizia coriaria Ethanolic Extract Against Archived Methicillin-Resistant Staphylococcus aureus and Carbapenem-Resistant Pseudomonas aeruginosa Isolates from Pakwach District, Uganda

Samson Piraciel Okhello; Stephen Alafi; Opio Gabdesio; Saphan Muzoora; Jacqueline Kyosimiire

doi:10.51168/b53efs42

Autori

Samson Piraciel Okhello Faculty of Health Sciences, University of Kisubi, Entebbe, Uganda
Stephen Alafi Department of Veterinary Microbiology and Parasitology,Makerere University,Kampala,Uganda
Opio Gabdesio Department of Veterinary Microbiology and Parasitology,Makerere University,Kampala,Uganda
Saphan Muzoora Faculty of Health Sciences, University of Kisubi, Entebbe, Uganda
Jacqueline Kyosimiire Faculty of Health Sciences, University of Kisubi, Entebbe, Uganda

DOI:

https://doi.org/10.51168/b53efs42

Cuvinte cheie:

Albizia coriaria, methicillin-resistant Staphylococcus aureus, carbapenem-resistant Pseudomonas aeruginosa, antibacterial activity, phytochemicals, minimum inhibitory concentration

Rezumat

Background:

Antimicrobial resistance is a major public health concern, particularly with methicillin-resistant Staphylococcus aureus (MRSA) and carbapenem-resistant Pseudomonas aeruginosa (CRPA), which are associated with limited treatment options and poor clinical outcomes. This study assessed the antibacterial activity of its ethanolic extract against archived MRSA and CRPA isolates.

Methods:

This was a laboratory-based experimental study. Stem bark of A. coriaria was collected from two sites in Pakwach District, Uganda, air-dried, powdered, and extracted using ethanol via cold maceration. Qualitative phytochemical screening was performed following standard protocols. Antibacterial activity against archived MRSA and CRPA isolates was determined using the agar well diffusion method, and the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were determined using broth microdilution with resazurin dye reduction.

Results:

The extract screened positive for alkaloids, flavonoids, tannins, saponins, and phenols. It produced a significantly larger mean zone of inhibition against MRSA (23.25 ± 0.48 mm) than against CRPA (11.50 ± 0.50 mm). Conversely, the extract required a lower concentration to inhibit and kill CRPA (MIC = 62.5 mg/mL; MBC = 125 mg/mL) than to inhibit and kill MRSA (MIC = 125 mg/mL; MBC = 250 mg/mL). Both organisms produced an MBC/MIC ratio of 2, confirming bactericidal rather than bacteriostatic activity.

Conclusion:

Albizia coriaria ethanolic extract possesses a rich phytochemical profile that confers bactericidal activity against both MRSA and CRPA through what appears to be a multi-target mechanism largely independent of conventional beta-lactam and carbapenem resistance pathways.

Recommendation:

Further studies are recommended to isolate and characterize the specific bioactive compounds responsible for the observed antibacterial activity, and to evaluate the extract's safety, toxicity, and efficacy through in vivo and clinical studies before it can be considered for pharmaceutical development or enrollment in the market.

Biografii autori

Samson Piraciel Okhello, Faculty of Health Sciences, University of Kisubi, Entebbe, Uganda

is a bachelor’s degree researcher in Biomedical Laboratory Technology at the Faculty of Health Sciences, University of Kisubi.
Saphan Muzoora, Faculty of Health Sciences, University of Kisubi, Entebbe, Uganda

BVM, MSc, Biochem, PHD. is a research supervisor and Associate Dean, Faculty of Health Sciences at the University of Kisubi.
Jacqueline Kyosimiire, Faculty of Health Sciences, University of Kisubi, Entebbe, Uganda

BBLT, MBA, PhD, is a research supervisor and Dean, Faculty of Health Sciences, University of Kisubi.

Referințe

1. Alibi, S., Crespo, D., & Navas, J. (2021). Plant-derived small molecules with antibacterial activity. Antibiotics, 10(3), 231. https://doi.org/10.3390/antibiotics10030231

2. Arowolo, M. T., Orababa, O. Q., Olaitan, M. O., Osibeluwo, B. V., Essiet, U. U., Batholomew, O. H., Ogunrinde, O. G., Lagoke, O. A., Soriwei, J. D., Ishola, O. D., Ezeani, O. M., Onishile, A. O., Olumodeji, E., Duse, A. G., & Oreiby, A. (2023). Prevalence of carbapenem resistance in Acinetobacter baumannii and Pseudomonas aeruginosa in sub-Saharan Africa: A systematic review and meta-analysis. PLOS ONE, 18(11), e0287762. https://doi.org/10.1371/journal.pone.0287762

3. Azzam, A., Khaled, H., Fayed, H. M., Mansour, Y., Eldalil, M., Elshennawy, E., Salem, H., & Elkatan, H. A. (2025). Prevalence, antibiogram, and risk factors of methicillin-resistant Staphylococcus aureus (MRSA) asymptomatic carriage in Africa: A systematic review and meta-analysis. BMC Infectious Diseases, 25, Article 505. https://doi.org/10.1186/s12879-025-10819-4

4. Azzam, A., Khaled, H., Salem, A., Sayed, M., Mohieldein, A., Elsayed, M. S., Lotfy, E. M., Abdullah, H. H. A. M., Hassan, F. E., Marei, H., Hassan, N., Abdulnaby, E., Kamel, G. A. M., Osman, I., Reda, M. A., Ismail, D., Nazih, M., Salem, H., Basil, A., & Rady, D. (2026). Proportion and antibiogram of methicillin-resistant Staphylococcus aureus (MRSA) in Africa: A systematic review and meta-analysis. Antimicrobial Resistance & Infection Control, 15, Article 13. https://doi.org/10.1186/s13756-025-01687-3

5. Chen, X., Wu, Z., Zhou, Y., Zhu, J., Li, K., Shao, H., & Wei, L. (2017). Molecular and virulence characteristics of methicillin-resistant Staphylococcus aureus in burn patients. Frontiers in Laboratory Medicine, 1(1), 43-47. https://doi.org/10.1016/j.flm.2017.02.010

6. Clinical and Laboratory Standards Institute. (2021). Performance standards for antimicrobial susceptibility testing (31st ed.). CLSI.

7. Cushnie, T. P. T., & Lamb, A. J. (2011). Recent advances in understanding the antibacterial properties of flavonoids. International Journal of Antimicrobial Agents, 38(2), 99-107. https://doi.org/10.1016/j.ijantimicag.2011.02.014

8. Esemu, S. N., Nya'Nying, S. F., Ndip, L. M., Bessong, P. O., Tanih, N. F., Smith, S. I., & Ndip, R. N. (2024). Isolation and characterization of methicillin-resistant Staphylococcus aureus from bovine mastitis in North West Cameroon: Public health implications. BMC Research Notes, 17(1), Article 389. https://doi.org/10.1186/s13104-024-07073-3

9. Fais, A., & Era, B. (2024). Phytochemical composition and biological activity. Plants, 13(3), 331. https://doi.org/10.3390/plants13030331

10. GBD 2021 Antimicrobial Resistance Collaborators. (2024). Global burden of bacterial antimicrobial resistance 1990-2021: A systematic analysis with forecasts to 2050. The Lancet, 404(10459), 1199-1226.

11. Guedes, B. N., Krambeck, K., Durazzo, A., Lucarini, M., Santini, A., Oliveira, M. B. P., Fathi, F., & Souto, E. B. (2024). Natural antibiotics against antimicrobial resistance: Sources and bioinspired delivery systems. Brazilian Journal of Microbiology, 55(3), 2753-2766. https://doi.org/10.1007/s42770-024-01410-1

12. Kateete, D. P., et al. (2016). Carbapenem-resistant Pseudomonas aeruginosa and Acinetobacter baumannii at Mulago Hospital in Kampala, Uganda (2007-2009). SpringerPlus, 5, Article 1308. https://doi.org/10.1186/s40064-016-2986-7

13. Klánčnik, A., Piskernik, S., Jeršek, B., & Možina, S. S. (2010). Evaluation of diffusion and dilution methods to determine the antibacterial activity of plant extracts. Journal of Microbiological Methods, 81(2), 121-126. https://doi.org/10.1016/j.mimet.2010.02.004

14. Lee, A. S., de Lencastre, H., Garau, J., Kluytmans, J., Malhotra-Kumar, S., Peschel, A., & Harbarth, S. (2018). Methicillin-resistant Staphylococcus aureus. Nature Reviews Disease Primers, 4, Article 18033. https://doi.org/10.1038/nrdp.2018.33

15. Obakiro, S. B., et al. (2022). Phytochemical, cytotoxicity, and antimycobacterial activity evaluation of extracts and compounds from the stem bark of Albizia coriaria Welw ex. Oliver. Evidence-Based Complementary and Alternative Medicine, 2022, Article 7148511. https://doi.org/10.1155/2022/7148511

16. Omara, T., Kiprop, A. K., & Kosgei, V. J. (2023). Albizia coriaria Welw ex Oliver: A review of its ethnobotany, phytochemistry and ethnopharmacology. Advances in Traditional Medicine, 23(3), 631-646. https://doi.org/10.1007/s13596-021-00600-8

17. Otto, M. (2012). MRSA virulence and spread. Cellular Microbiology, 14(10), 1513-1521. https://doi.org/10.1111/j.1462-5822.2012.01832.x

18. Palanisamy, J., Palanichamy, V. S., Vellaichamy, G., Perumal, P., Vinayagam, J., Gunalan, S., Prabhakaran, S. G., Thiraviam, P. P., Musthafa, F., & Balaraman, A. K. (2025). A comprehensive review on the green synthesis of silver nanoparticles from marine sources. Naunyn-Schmiedeberg's Archives of Pharmacology, 398(4), 3409-3432. https://doi.org/10.1007/s00210-024-03547-0

19. Parekh, J., Jadeja, D., & Chanda, S. (2005). Efficacy of aqueous and methanol extracts of some medicinal plants for potential antibacterial activity. Turkish Journal of Biology, 29(4), 203-210.

20. Ramatla, T., Nkhebenyane, J., Lekota, K. E., Thekisoe, O., Monyama, M., Achilonu, C. C., & Khasapane, G. (2025). Global prevalence and antibiotic resistance profiles of carbapenem-resistant Pseudomonas aeruginosa reported from 2014 to 2024: A systematic review and meta-analysis. Frontiers in Microbiology, 16, Article 1599070. https://doi.org/10.3389/fmicb.2025.1599070

21. Ssekatawa, K., Byarugaba, D. K., Wampande, E., & Ejobi, F. (2018). A systematic review: The current status of carbapenem resistance in East Africa. BMC Research Notes, 11(1), Article 629. https://doi.org/10.1186/s13104-018-3738-2

22. Wangai, F. K., Masika, M. M., Maritim, M. C., & Seaton, R. A. (2019). Methicillin-resistant Staphylococcus aureus (MRSA) in East Africa: Red alert or red herring? BMC Infectious Diseases, 19(1), Article 596. https://doi.org/10.1186/s12879-019-4245-3

23. Yin, L., Bao, Z., He, L., Lu, L., Lu, G., Zhai, X., & Wang, C. (2025). Virulence factors, molecular characteristics, and resistance mechanisms of carbapenem-resistant Pseudomonas aeruginosa isolated from pediatric patients in Shanghai, China. BMC Microbiology, 25(1), Article 130. https://doi.org/10.1186/s12866-025-03856-1