**Question:** In a completely and adequately immunized child against Diphtheria, the throat swab was collected. It showed the presence of Corynebacterium diphtheriae like organisms on Albert staining. These organisms can have one of the following properties on further laboratory processing -

A. Production of toxin
B. Production of toxin and production of diphtheria toxin receptor
C. Production of toxin and production of diphtheria toxin receptor and toxin
D. Production of toxin and production of diphtheria toxin receptor

**Correct Answer:** D. Production of toxin and production of diphtheria toxin receptor

**Core Concept:**
Corynebacterium diphtheriae is a bacterium that causes diphtheria, a potentially life-threatening disease. In a fully immunized child, the presence of Corynebacterium diphtheriae-like organisms in the throat swab suggests a non-typical or atypical presentation of diphtheria, which may involve the production of toxin and/or toxin receptors.

**Why the Correct Answer is Right:**
In this scenario, the correct answer (option D) refers to the production of toxin and toxin receptor by the Corynebacterium diphtheriae-like organisms. This is because fully immunized children should not have Corynebacterium diphtheriae in their throat swabs, as their immune systems would have developed immunity against the bacterium and its toxins.

**Why Each Wrong Option is Incorrect:**
Option A refers to the production of toxin only, which is not specific enough to explain the scenario presented. Option B and C include the production of toxin receptor, which is irrelevant in a fully immunized child. Option E does not address the presence of Corynebacterium diphtheriae-like organisms in the throat swab.

**Clinical Pearl:**
Diphtheria is a serious bacterial infection caused by C. diphtheriae. In fully immunized children, the presence of C. diphtheriae-like organisms suggests an atypical presentation, which may involve the production of toxin and toxin receptors. It is essential to differentiate between typical and atypical presentations of diphtheria to initiate appropriate treatment and prevent further spread of the disease.