Gram stains can be boring at times due to the volumes my department receives each day. For the most part, they are straight forward with nothing too out of the ordinary. Although, we do sometimes see some cool things captured like a freeze frame.
This slide is from a patient's sputum. It's kind of neat to see all the gram positive cocci stuck inside the neutrophils. At least, the ones you could tell there are vacuoles are definitely swallowed up by the white blood cells. It's not often I see this sort of arrangement in this consistent manner.
As for the potential pathogens, we won't know until we grow the culture. At a glance, I can only guess possible S. aureus mixed with oropharyngeal flora.
Now, this one is a bit more interesting. It's from a patient's stool sample. Under most circumstances, we'd never gram stain stool due to the sheer amount of fecal flora. In this case, we stained this one from the culture due to its suspicious nature.
On a stool culture, we do oxidase tests to narrow down our hunt for potential pathogens. When we do find oxidase positive colonies, we sub them to a new agar plate. Then, we attempt to identify them with the help of MALDI-TOF.
In this case, the instrument returned Bacillus species as it can't speciate this genus. Most of the times, they are environmental organisms. However, this was a nonhemolytic Bacillus. That raised some concerns. A quick catalase test revealed the colonies to be positive. The only thing we know about the patient is that they are from the rural farmlands of Utah.
By this time, we are suspecting Bacillus anthracis. That's right, Anthrax! Since we cannot rule out the possibility that it's B. anthracis, we had to ship the organism out to the state lab.
Granted, the gram stain doesn't quite match what you would expect from Anthrax. It was better to error on the side of caution. The good news is, this particular organism is sensitive to penicillin. The reason why it's a bioterror favorite is because of its hardy endospores. They can survive almost anything in that form.
Another night at the lab. Sometimes, it's interesting. Most of the times, it's repetitive.
