Mycology/Parasitology Exam 4 corrections:
12/10: Dr. Archibald's slide on cutaneous larva migrans incorrectly says that you can diagnose this disease by eggs in the stool. Since the larvae migrate throught he skin tissues and never make it to the intestines to mature into adults, there can be no eggs in the stool.
12/10: Dr. Gulig's handout and PowerPoint are incorrect. Under damage they say that S. mansoni and S. haematobium cause intestinal and liver damage and S. haematobium causing urinary damage, while it should be S. mansoni and S. japonicum causing intestinal/liver and S. haematobium causing urinary symtpoms. Note that there is some crossover, as shown on the CDC page, but these general characteristics are what you should be familiar with.
12/6: I noted (and I hope that you did, too) during Dr. Archibald’s lecture today he twice referred to the rhabditiform larvae of Strongyloides as being the tissue invasive form. This is not correct. For both exogenous infection from the soil and auto/hyper infection in the gut, it is filariform larvae that do the invading. In the gut, it is the rare transformation that occurs from rhab-filari that causes a low grade autoinfection that keeps the patient infected for longer than the life span of an adult in the absence of reinfection from contaminated soil. With hyperinfection, the rhabs in the gut convert to filiaris en masse causing a severe invasion through the intestines with hitch hiking bacteria (sepsis and peritonitis) and the worms going all through the body, as he graphically described in lecture. Check out the CDC’s excellent web page on this for clarification: http://www.dpd.cdc.gov/DPDx/HTML/Strongyloidiasis.htm.
12/5: Here is the first official course correction for this last part of MMID. It is very clear from authoritative sources that Candida albicans DOES make true hyphae (in addition to pseudohyphae) even during infection. I must also state for the record that, although I will not ask this specific question on your exam, the terms hyphae or pseudohyphae WILL show up on exam questions (both ours and standardized) because understanding that hyphae are the invasive form of Candida expressed during infection at 37C is a very important part of diagnosis and understanding pathogenesis. It is also important to note that this yeast-mycelial transition is different for Candida versus the other systemic fungi (Histo, Blasto, Coccidio).
Bacteriology Exam 3 Corrections:
Dr. Forsmark gave a great lecture today that complemented very nicely what I had already taught in my previous three lectures. However, I noted that he had EHEC under "invasive" organisms, whereas I told you that it is not invasive. In fact, it is not invasive - see Schaecter page 207. Because it causes bloody diarrhea (kind of like dysentery but not exactly), it is easy to assign it to this group (along with Shigella which belongs there). Dr. Forsmark's predecessor did the same thing. But that doesn't make EHEC invasive. I will ask Dr. Forsmark to change his PowerPoint for next year to avoid further confusion. So please note this FOR THE RECORD. If there is ever a question about EHEC being invasive, you will not be allowed to quote Dr. Forsmark's lecture to say that it is invasive.