Which one of the following is part of the normal flora of the skin?

The normal flora of the skin refers to the diverse population of microorganisms that typically inhabit the skin without causing disease under normal circumstances. The correct answer, Acinetobacter calcoaceticus, is often found in the environment and on skin, particularly in certain areas of the body where skin is moist or occluded. It can be part of the transient flora, meaning that it may not consistently remain on the skin, but can be considered part of the normal ecosystem.

In contrast, Staphylococcus aureus, while a well-known skin colonizer, is not classified as part of the normal flora because it has the potential to cause infections, especially when its balance is disturbed or when it breaches the skin barrier. Escherichia coli is primarily found in the intestines and is typically not present on the skin, making it an inappropriate representative of skin flora. Candida albicans is a yeast that can be part of the normal flora in certain mucosal areas (like the mouth and vagina) but is not typically associated with normal microbial flora of the skin.

Thus, Acinetobacter calcoaceticus stands out as the most appropriate answer regarding the skin’s typical microbial population.