Wound, Ostomy and Continence Nurses Society (WOCN) Practice Exam

Which saline swab is recommended for quantitative culture collection?

1. Moistened alginate swab

2. Dry cotton swab

3. Unsaturated gauze swab

4. Any available swab

The correct answer is: Moistened alginate swab

Using a moistened alginate swab for quantitative culture collection is recommended because alginate has properties that enhance the preservation of the bacteria during transport and processing. Alginate swabs contain calcium alginate, which is a biocompatible substance that does not inhibit the growth of bacteria, allowing for a more accurate quantitative assessment. The moisture level in the swab also ensures that the bacteria remain viable until analysis, increasing the reliability of the culture results. In contrast, a dry cotton swab may not adequately preserve the sample, leading to a potential decrease in the number of viable organisms that can be cultured. Unsaturated gauze swabs may not provide enough material for effective quantitative analysis and can dry out too quickly or harbor substances that could interfere with the culture results. While any available swab might seem convenient, it doesn't ensure the optimal conditions necessary for accurate quantitative culture collection, which is why a moistened alginate swab is preferred in this context.