1- 2000 words excluding the bibliography
2- The bibliography should be in ASM style
How to tackle the essay:
1- You could select one microorganism and argue for or against.
Or multiple pathogens

Feel free to have sections and subsections
Useful to number there as ( Section 1, Section 2.1 )
Diagrams can be very useful

Critically, is the evidence there?
1- It is not simply about having the gene/protein/factor
2- Prevalence vs Importance
3- Animal
4- Human