…………………………….. is a pathogenic bacterium which causes typhoid fever in human beings.

Explanation

**Step-by-Step Text Solution:**

1. **Identify the Pathogenic Bacterium**: The question asks for a pathogenic bacterium that causes typhoid fever in humans.

2. **Understand the Definition of Pathogen**: A pathogen is defined as any organism that can cause disease. In this context, we are looking specifically for a bacterium.

3. **Recognize the Disease**: Typhoid fever is a bacterial infection that is known to be caused by a specific bacterium.

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