A middle-aged man with poorly controlled diabetes develops a foot ulcer, which becomes infected with bacteria that are part of his normal skin flora. Which type of infection is this?

1. A

   An exogenous infection from hospital staff

2. B

   A zoonotic infection from animal contact

3. C

   An endogenous infection from resident bacteria

4. D

   An exotic infection by drug-resistant bacteria

Appeared in: RRB Nsg. Superintendent-2026 (Shift -3rd)

Explanation

• An endogenous infection is defined as an infection caused by an overgrowth of microorganisms that are part of the person's own normal flora.
• The question explicitly states the infection originated from the patient's 'normal skin flora,' which fits the definition of an endogenous infection.
• Predisposing factors like a foot ulcer (a breach in the skin's defense) and poorly controlled diabetes (a compromised immune state) allow these normally harmless resident bacteria to become pathogenic.

Why Other Options Were Wrong

• Option A: This is incorrect because an exogenous infection originates from a source outside the individual, such as contaminated equipment or another person. The question specifies the source was the patient's own skin flora.
• Option B: This is incorrect because a zoonotic infection is transmitted from an animal to a human. The source of infection in the scenario is the patient's own body.
• Option D: This is incorrect because an exotic infection is caused by a pathogen not commonly found in a particular geographic area, often acquired during travel. The bacteria described are 'normal skin flora,' which are common and not exotic.

Related Visual

• Visual 1: Diagram: Illustrating the difference between an endogenous infection (originating from within the body, e.g., gut or skin flora) and an exogenous infection (originating from an external source, e.g., another person or a contaminated surface).

Clinical Relevance

• Nursing practice connection: Use the key finding related to Classification of infections based on their source to guide bedside assessment, documentation, and the next nursing action.
• Recognizing the source of an infection (endogenous vs. exogenous) is critical for guiding appropriate antimicrobial therapy and implementing effective infection prevention strategies.
• Patients with compromised immunity, such as those with uncontrolled diabetes, are at a significantly higher risk for endogenous infections because their own flora can become opportunistic pathogens.
• Nurses play a key role in preventing endogenous infections by maintaining skin integrity, promoting glycemic control, and teaching patients with diabetes about meticulous foot care.

How to Approach the Question

• First, identify the most critical piece of information in the clinical scenario. Here, it is the source of the infection: 'bacteria that are part of his normal skin flora'.
• Next, analyze the options provided, which are different classifications of infections based on their origin.
• Define each term. 'Endogenous' means originating from within. 'Exogenous' means originating from outside. 'Zoonotic' means from an animal. 'Exotic' means from a foreign region.
• Match the critical information from the stem ('normal skin flora' = from within the body) to the correct definition.
• The source is internal to the patient, which directly corresponds to the definition of an endogenous infection.

Concept Tested & Keywords

• Concept Tested: Classification of infections based on their source
• Stem keywords: poorly controlled diabetes, foot ulcer, infected, normal skin flora
• Lead-in keywords: Which type of infection
• Clinical cues: The phrase 'normal skin flora' is the key clinical cue, indicating the origin of the bacteria is the patient's own body.
• Negative lead-in flag: false

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QMlGnEY-eo3SRFSSrwMkYd

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