Nonpathogenic bacterium present in large intestine is

Options

A. Staphylococcus aureus
B. Escherichia coli
C. Helicobacter pylori
D. Leptospira interogans

Answer

To determine the nonpathogenic bacterium present in the large intestine, we will analyze each of the given options one by one.

### Step-by-Step Solution:

1. **Identify the Options:**
The options provided are:
- A) Staphylococcus aureus
- B) Escherichia coli
- C) Helicobacter pylori
- D) Leptospira interrogans
- E) Tarragons

2. **Analyze Staphylococcus aureus:**
- Staphylococcus aureus is known to be a pathogenic bacterium.
- It can cause various diseases, including pneumonia, endocarditis, and pericarditis.
- **Conclusion:** This is not a nonpathogenic bacterium.

3. **Analyze Escherichia coli:**
- Escherichia coli (E. coli) is a gram-negative bacterium that is commonly found in the human gut, specifically in the large intestine.
- It is known to have a symbiotic relationship with humans, contributing to gut health.
- While some strains of E. coli can be pathogenic, the strain that resides in the large intestine is generally considered nonpathogenic and beneficial.
- **Conclusion:** This is a nonpathogenic bacterium.

4. **Analyze Helicobacter pylori:**
- Helicobacter pylori is known to cause gastric ulcers and is classified as a pathogenic bacterium.
- It is not associated with the large intestine in a beneficial manner.
- **Conclusion:** This is not a nonpathogenic bacterium.

5. **Analyze Leptospira interrogans:**
- Leptospira interrogans is responsible for leptospirosis, a disease that affects humans and animals.
- It is also a pathogenic bacterium.
- **Conclusion:** This is not a nonpathogenic bacterium.

6. **Analyze Tarragons:**
- Tarragons are not bacteria; they are herbs and do not fit the context of the question regarding nonpathogenic bacteria.
- **Conclusion:** This is not a relevant option.

### Final Answer:
The nonpathogenic bacterium present in the large intestine is **Escherichia coli (E. coli)**.

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