Pyorrhoea is aggravated by

Options

A. Entamoeba hastmanni
B. Entamoeba coli
C. Entamoeba histolytica
D. Entamoeba gingivalis.

Answer

### Step-by-Step Solution:

1. **Understanding Pyorrhea**:
- Pyorrhea, also known as periodontitis, is a serious gum infection that damages the gums and can destroy the jaw bone. It is often caused by poor oral hygiene.

2. **Identifying the Role of Protozoa**:
- The question asks which organism aggravates pyorrhea. Aggravation means that the condition is already present, but its severity is increased by another factor.

3. **Analyzing the Options**:
- **Entamoeba hatmani**: This is not known to be associated with pyorrhea. It is a pathogenic protozoan but does not aggravate gum disease.
- **Entamoeba coli**: This organism is generally non-pathogenic and does not cause any diseases related to pyorrhea.
- **Entamoeba histolytica**: While this protozoan is pathogenic and causes amoebiasis, it does not have a role in aggravating pyorrhea.
- **Entamoeba gingivalis**: This organism is known to be associated with gum diseases and is responsible for aggravating pyorrhea.

4. **Conclusion**:
- The correct answer is **Entamoeba gingivalis**, as it is the organism that aggravates the condition of pyorrhea.

### Final Answer:
**Entamoeba gingivalis**

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