What is the appropriate action for a nurse when performing a throat culture?

When performing a throat culture, the appropriate action is to swab the back of the client's pharyngeal wall. This area is crucial because it is where pathogens such as bacteria or viruses typically reside and are likely to be present in cases of infection. Swabbing the pharyngeal wall effectively collects a sample that can be tested for streptococcus or other organisms that may be responsible for the patient's symptoms.

Focusing on the pharyngeal wall allows the nurse to obtain an accurate representation of the pathogens present, which is essential for an accurate diagnosis and subsequent treatment plan. In contrast, swabbing only the oral cavity or the tonsils may not gather as comprehensive a sample, potentially missing the primary site of infection. Using a tongue depressor before swabbing can aid in better visualization and access to the throat, but it is not the primary action taken; thus, it is not the correct answer in this scenario.