In HIV infected patients, smear from oral lesions will show which organism –
**Core Concept**
The question is testing the ability to identify the causative organism of oral lesions in HIV-infected patients. This is a classic example of an opportunistic infection, where a pathogen takes advantage of a compromised immune system to cause disease.
**Why the Correct Answer is Right**
The correct answer is **Candida albicans**. This organism is a type of fungus that is normally found in the mouth, but in HIV-infected patients, it can overgrow and cause oral lesions. This is due to the impaired immune response, which allows the fungus to proliferate unchecked. **Candida albicans** produces hyphae and pseudohyphae, which can be seen on a smear from the oral lesion.
**Why Each Wrong Option is Incorrect**
* **Option A:** This option is incorrect because **Streptococcus** species are not typically associated with oral lesions in HIV-infected patients.
* **Option B:** This option is incorrect because **Staphylococcus** species, while common in skin infections, are not typically associated with oral lesions in HIV-infected patients.
* **Option D:** This option is incorrect because **Herpes simplex virus** can cause oral lesions in HIV-infected patients, but it is not the most common cause, and the question is asking for a specific organism that can be identified on a smear.
**Clinical Pearl / High-Yield Fact**
Candida albicans can be identified on a smear from the oral lesion by looking for the presence of hyphae and pseudohyphae. This is a key clinical finding that can help diagnose oral candidiasis in HIV-infected patients.
**Correct Answer:** C. **Candida albicans**