Wound cultures are heavily influenced by source and collection method. The Gram stain, though somewhat subjective should also be used in conjunction with the patient’s clinical history.

How a specimen is collected directly affects the amount of normal flora present in the culture. Grossly contaminated cultures can mask clinically significant organisms or make interpretation at the bench impossible. In these cases, recollection of a more appropriate specimen may be warranted.

Generally, when teaching new techs, I ask them to look at all of the plates at once, then put them down to make a decision. Make a decision and look again more closely. Your interpretation may change on the second look. The goal is to avoid staring at the plates without direction.

Once you’ve made a decision on how to proceed it’s best to subculture anything that may get lost if the culture is messy. If it’s pure, go for it: susceptibility, identification, biochemicals.

At this point it’s a good time to check the Gram stain results to see if they match the plates. The Gram stain is often read blind by a tech, meaning the tech has limited patient history or previous culture information available. It is subjective and can be heavily influenced by the fields examined. The original Gram stain is a tool, not a verdict. Let the culture tell you what grew.

Primary Pathogens:

Potential Pathogens:

Normal Flora: