BIO2071: Research Skills and Bioethics
Jennifer George
Tutor: Dawe
Essay Plan
Question:
Discuss how manipulation of parasitic fungi could lead to new ways of tackling
malaria
Introduction
-What is Malaria and how is it caused?
-Mosquitoes as main vector
-Current/old control methods
-Mention of DDT
-What is an entomopathogenic fungus?
- Giving examples such as -Spinochordodes tellinii in grasshoppers
-Toxoplasma gondi in cats
-Which two fungi are going to be discussed and why?
-Beauveria bassiana
-Metarhizium acridium
-How are they going to be discussed?
-Manipulation of application
-Manipulation of culture
-Manipulation of genetics
Paragraph One
-What is Beauvaria bassiana?
-What is it currently used for?
-Pest control in many countries- caterpillars, aphids, beetles- commercial
biopesticide for crops
-How is the fungi applied to environment to provide opportunity for infection?
-Adulticide- targeting adults
-chemical drops, treating water
-Research into the affects on Anopheles stephensi
-T.Baker et.al.- research published August 2011 (Sock stimuli)
- Olfactory receptor neurones- electrophysical sensitivity impaired
- Minimal detection of 1-octen-3-01
-What has been the effect of selectively culturing the fungi?
-Less reaction to ‘human’ stimuli- will target other animals
- T. Baker research- high toxicity-kills Anopheles fairly easily- ethical issues
- Anopheles resistance- malaria still being spread
Paragraph Two
- What is Metarhizium acridium?
-Current locust pathogen
-What is the result of selective culturing?
- “Moderate Virulence” strain
-Enough to interfere with ORN’s but not enough to kill the Anopheles
-How is virulence affected by drought and temperature?
-Extreme conditions (often Anopheles habitat)
-Application in wet Anopheles breeding habitats
-How does Trehalose carbohydrate (stress metabolite) overcome conditions in order to
increase virulence?
-Presence helps to survive desiccation- ability to retain water
- Genetic manipulation
- Increasing expression
-Chinese research, Y. Leng, Y.Cao et.al
-Thermotolerance- surviving desiccation without affecting
virulence
Conclusion
-Metarhizium acridium more viable than Beauvaria bassiana
-working with entomopatogenic fungi to avoid resistance issues.
-Generating a strain:
-Selectively culturing fungi
-Enhanced trehalose gene expression
-Applying to environment appropriately
Increase of virulence
without causing
resistance
-Less ethical issues
- Issue: Anopheles- attracted to more than just 1-octen-3-01
-Adrenaline and other common host factors such as heat
-Combination of factors- potential lead to a significant reduction in malaria
-Probably no complete eradication with this method