Microbiology Rotation Part 2

Hi Tiffany...you are right about patient care being your mentors' highest and most important priority.  Feel free to ask me any questions about all this overwhelming stuff! :)

By the way, that nasty enterohemorrhagic E. coli is named O157:H7. The 157 "O" antigen is found on the organism's body, and the 7 "H" antigen can be located on its flagella.  Although the mainstream media shortens this organism's name to mere "E. coli" for simplicity's sake when discussing its associated illness with the general public, other strains of E. coli live harmlessly as normal flora within our digestive tracts.  

O157:H7 and one other strain, E. coli O121:H19, have genetically mutated and "gone bad," gaining the ability to produce "shiga" toxins usually produced by Shigella.  These two dangerous E. coli strains kill people by also causing hemolytic uremic syndrome, which is characterized by acute kidney failure, a low platelet count (thrombocytopenia), and hemolytic anemia (lysis of red blood cells).  It can be extremely terrible for the patient, but neatly interrelates all the different diagnostic testing areas in the lab to explain the "big picture."

I worked in microbiology at Duke in 2006, probably before rapid O157:H7 tests became widely accepted and available.  We would always add a MacConkey agar plate with sorbitol to our regular stool culture dishes on those bloody diarrhea specimens.  Unlike many benign strains of E. coli, which metabolize the sugar alcohol sorbitol as an energy source, E. coli O157:H7 does not and exhibits a "negative" reaction for sorbitol, sticking itself out like a sore thumb.

Have fun with the rest of your time in Microbiology!