A patient who is diabetic and has been in the hospital twice in the last year presents with a boil on his neck. You drain it, but because of his hospitalizations you realize that there is a good chance that it could be a drug-resistant strain and order direct Gram stain cultures, as well as susceptibility testing and anaerobic culture. The preliminary report comes back with Gram-negative cocci in clusters. This puzzles you, so you call the lab supervisor who realizes the stain was done by a new lab person. It turns out to be Staphylococcus aureus. What mistake in the Gram stain did the new person most likely make to produce pink cocci with no hint of purple?

Question

Quizplus · Accepted Answer

It is most likely that she forgot to put the iodine on so the dye does not form the large complex; in this situation, the uncomplexed crystal violet will decolorize even Grampositive organisms. It was also a sharp physician who realized that there are no Gram-negative cocci arranged in clusters and that abscesses are either Staph. or rod-shaped anaerobes or mixed infections.

A Patient Who Is Diabetic and Has Been in the Hospital