Which of the following would NOT be a likely member of the normal microbiota of the skin surface?

• A. Escherichia coli
• B. Propionibacterium acnes
• C. Staphylococcus epidermidis
• D. Micrococcus luteus

Answer: (A)

Verified step by step guidance

1. Understand the concept of normal microbiota: These are microorganisms that typically reside on or within a healthy human body without causing disease, often providing beneficial effects or simply coexisting harmlessly.
2. Recall the typical environment of the skin surface: The skin is generally dry, acidic, and exposed to oxygen, favoring certain bacteria adapted to these conditions.
3. Identify common skin microbiota: Bacteria such as Propionibacterium acnes (now Cutibacterium acnes), Staphylococcus epidermidis, and Micrococcus luteus are well-known residents of the skin because they thrive in this environment.
4. Consider the characteristics of Escherichia coli: E. coli is primarily found in the intestinal tract, which is a moist, nutrient-rich, anaerobic environment, making it unlikely to be a normal resident of the dry, aerobic skin surface.
5. Conclude that Escherichia coli would NOT be a likely member of the normal skin microbiota based on its typical habitat and environmental preferences.