Which of the following sutures should be used to close an infected wound?

When closing an infected wound, the use of a monofilament suture is particularly beneficial due to its properties. Monofilament sutures are made from a single strand of material, which helps minimize tissue drag and reduces bacterial colonization compared to multifilament sutures. This is particularly important in the context of an infection, as it limits the potential for bacteria to harbor in the suture material itself.

Furthermore, monofilament sutures are often made from materials that are less likely to elicit a significant inflammatory response, promoting better healing of the infected area. Their smooth surface also allows for easier passage through the tissue, causing less trauma.

In contrast, other suture types, such as catgut, silk, and polypropylene, have their advantages, but they may not be the most suitable for infected wounds. Catgut, being absorbable, can also provoke inflammatory reactions which could exacerbate infections. Silk is a multifilament suture that can trap bacteria due to its porous nature, potentially worsening the infection. Polypropylene is a monofilament suture, similar to the correct answer, but in this context, the properties of the specific monofilament chosen (often a material designed for infected or contaminated wounds) make it preferable.