Bugs and Drugs

It's the part of med school that everyone dreads. We're sludging through the parade of bacteria, fungi, viruses, and parasites. It's a lot of memorization. No particular fact or bug is too hard to learn, but there are so many that it feels quite overwhelming. How does it Gram stain? Does it ferment lactose or live in bile? Does it have catalase? Exotoxins? Pili? What kind of conditions do you need to culture it? What does it look like? What diseases does it cause?

A lot of times, things don't make sense. For example, Haemophilus influenzae is a gram negative rod that causes meningitis, bacteremia, sinusitis, pneumonia, even otitis media - pretty much everything except the flu (which is of course caused by a virus). It was originally thought to be the causative agent of the flu, but no one bothered to change the name after the confusion got cleared up. On the other hand, Alexandre Yersin named the causative agent of the plague Pasteurella pestis after his mentor, but after he died, they managed to change the bug to Yersinia pestis.

To go along with all these bacteria, we have many different antimicrobials to learn along with the mechanism of action, the clinical use, the metabolism and pharmacokinetics, the toxicities. In any case, we've gotten through the bacteria; we're just starting fungi and viruses now. We had an exam on Monday and another one is coming up in a little over a week.

Image is from adoptamicrobe.blogspot.com - Clostridium perfringens is the causative agent of gas gangrene.