This document summarizes a study that screened 40 plant extracts for antimicrobial activity against Mycobacterium tuberculosis. The study aimed to screen extracts from plants traditionally used to treat tuberculosis and other infections in Sudan. The screening identified 5 extracts that showed distinct antimicrobial properties against M. tuberculosis through high-throughput screening using luciferase to determine bacterial growth and confirmation of inhibition through CFU plating and analysis of bacterial growth. The extracts warrant further study to evaluate their potential as sources of new anti-tuberculosis drugs.

1. Screening of 40 Plant extracts for antimicrobial activity against Mycobacterium tuberculosisRichin John KoshySupervisor: Maria Lerm

2. OverviewBackgroundHypothesis/AimMaterials and methods Results Conclusion

3. Epidemiology of MDR (TB)http://wwwnc.cdc.gov/travel/yellowbook/2010/http://wwwnc.cdc.gov/travel/yellowbook/2010/chapter-5/tuberculosis.htm

4. MorphologyMycobacteria are small rod shaped aerobic bacilliMycobacteria are present in the environment, soil and waterMycobacteria have high concentration of lipids and wax in the cell wall making them resistant to standard staining techniquesMtb grow quite slowly and colonies do not appear on solid media up to 2.5 -5 weekMedia which are used in growth of mycobacteria are selective media, semisynthetic media and broth mediawww.lookfordiagnosis.com

5. Pulmonary TB

6. commons.wikimedia.org

7. Treatment of TBniaid.nih.gov

8. Drug DevelopmentScreening of Chinese herbal medicine led to introduction of artemisinin from the leaves of Artemisia annua which is used worldwide for treatment against malaria At present, there are eight to ten drugs with therapies lasting to 18-24 months of which there are only four drugs which are actually developed to treat TBShifting the screening strategy from a single enzyme targets to a whole bacterial cell level have been showing successful results as it has a holistic approach and only gives hits that can enter the bacterium through the cell wall

9. Hypothesis Whole cell screening method is a more effective way than molecular/chemical approaches to identify new, anti-mycobacterial drug candidates/lead compoundsTraditionally used plants are a valuable source for the discovery of modern drugs

10. AimTo screen 40plant extracts prepared from plants used traditionally to treat tuberculosis and other infections in Sudan for possible antimicrobial activity against Mtb

11. Materials and Methods

12. ResultsEffect of DMSO on plant extracts DMSO at concentration of 10 %used along with plant extracts as treatments for reduction of antimycobacterial growth showing higher pattern of inhibition and a reduction of inhibition seen with DMSO concentration of 1 % and 0.1 %

13. Anti-mycobacterial screening of plant extracts against avirulent strain of Mtb H37Ra (1)

14. Anti-mycobacterial screening of plant extracts against avirulent strain of Mtb H37Ra (2)Screening of 40 plant extracts by analysis of mycobacterial growth by luminometry and measuring cell viability showing a pattern of inhibition in plant extracts A10, A12, A20, A22, A28, A29, A30, A34

15. Confirming screening of plant extracts showing inhibitionStudent paired t test was done assuming Gaussian distribution which show statistically insignificant hits

16. Detecting changes in mycobacterial growth by CFU plating

17. Determination of pH

18. ConclusionsHigh-throughput screening using luciferase determines mycobacterial growth giving conclusive results

19. 40 extracts of selected medicinal plants were analysed for antimycobacterial activities which yielded 5 extracts to have distinct antimycobacterial properties

20. Further studies were carried out in order to measure colonies in the presence of selected medicinal extracts showing inhibition of bacterial growth, thereby ruling out inhibition due to luciferase