Question

Jeff is a healthy 15-year-old young man. Due to severe allergy, he is unable to have vaccinations. Unfortunately, he has developed a fever, chills, and sore throat. When he is examined by the doctor, she notices a leathery, grey adherent membrane at the back of his throat that covers his tonsils. In this case, a Gram-stain is most likely to show:

• A. This is viral infection, therefore the Gram-stain won’t show anything.
• B. Pleomorphic Gram positive rods in clumps
• C. Gram negative cocci in groups
• D. Gram negative coccobaccili
• E. Gram positive cocci in chains

Answer 1

The correct option is B. (Pleomorphic Gram positive rods in clumps).

Physical examination of doctor revealed that Jeff had "leathery, gray-colored adherent membrane at the back of his throat covering the tonsils". He also had symptoms like fever, chills and sore throat.

These are characteristics of Diptheria infection caused by a gram positive bacteria Corynebacterium diphtheriae. Initial symptoms of Diptheria is similar to typical viral infection however, later on a gray membranous lining / patches are formed in the throat covering the tonsils, which confirm the presence of causal organism as Corynebacterium diphtheriae, which is a pleomorphic, rod shaped bacteria.

Hence, If Jeff has no vaccination done and showing symptoms as mentioned above, he is suffering from Diptheria caused by a pleomorphic, gram positive rods Corynebacterium diphtheriae.

Option A is incorrect: The symptoms especially gray membranous patches in the throat is not a symptom of viral infection but of Diptheria. Hence this option is incorrect.

Option C and D are incorrect: As Corynebacterium diphtheriae is a gram positive, rod-shaped bacteria, these options can not be true

Option E is incorrect: Though Corynebacterium diphtheriae (causal organism of Diptheria) is a gram-positive however they are rod-shaped and are not cocci, hence, this option is incorrect.