Which one of the following groups includes sexually transmitted infections caused by bacteria only ?

Options

A. Syphilis, gonorrhoea, chancroid
B. Syphilis, chlamydiasis,chancroid
C. Syphilis, gonorrhoea, scabies
D. Syphilis, scabies,pediculosis

Explanation

To solve the question of which group includes sexually transmitted infections caused by bacteria only, we will analyze the options provided and identify the causative agents of each infection mentioned.

### Step-by-Step Solution:

1. **Identify the Infections**: We need to look at the sexually transmitted infections (STIs) mentioned in the options. Common STIs include syphilis, gonorrhea, chlamydia, scabies, and pediculosis.

2. **Determine Causative Agents**:
- **Syphilis**: Caused by the bacterium *Treponema pallidum*.
- **Gonorrhea**: Caused by the bacterium *Neisseria gonorrhoeae*.
- **Chlamydia**: Caused by the bacterium *Chlamydia trachomatis*.
- **Scabies**: Caused by the mite *Sarcoptes scabiei* (not a bacterium).
- **Pediculosis**: Caused by lice, specifically *Pediculus humanus capitis* (not a bacterium).

3. **Analyze the Options**: Now, we will check which option includes only those infections caused by bacteria:
- If an option includes syphilis, gonorrhea, and chlamydia, it would be correct as all are caused by bacteria.
- If an option includes scabies or pediculosis, it would be incorrect as these are caused by mites.

4. **Select the Correct Group**: Based on the analysis, the group that includes only sexually transmitted infections caused by bacteria would be:
- **Syphilis, Gonorrhea, and Chlamydia**.

5. **Final Answer**: The correct group that includes sexually transmitted infections caused by bacteria only is **Syphilis, Gonorrhea, and Chlamydia**.