Just having studied micro today and done a LOT of practice questions on the subject. I would have to say that two things really stood out:
1. Lyme Disease
2. Diptheria
I don't know why these two in particular (qbank bias?), but I would definitely know everything there is to know about these two.
As for the other 8:
3. Gram positive bacteria
4. Gram negative bacteria
5. DNA viruses
6. RNA viruses
7. Protazoa
8. Nematodes (to a lesser degree)
9. Prions
10. Antimicrobials and their mechanisms of action and side effects
😀 Haha, obviously there is alot to know and many minutiae, but I have found just answering a whole lot of practice questions once I have gone through it has helped tremendously.