Question

Ringworm fungal disease of skin affecting mammals and animals is caused by
(A) Trichophyton mentagrophytes
(B) Achorion species
(C) Microsporum species
(D) Gallus domesticus
Choose the correct answer from the options given below:

• A. (A), (B) and (D) only
• B. (A), (B) and (C) only
• C. (A), (B), (C) and (D)
• D. (B), (C) and (D) only

Hint:

Always check the scientific names in option lists carefully.
Identifying Gallus domesticus as the taxonomic name of the common chicken allows you to quickly eliminate any option containing (D), as a bird cannot be a fungal pathogen.

Answer 1

The Correct Option is B

Step 1: Understanding the Concept:
Ringworm, scientifically known as dermatophytosis, is a highly contagious, superficial fungal infection of the skin, hair, and nails in humans and other animals.
It is caused by a specialized group of keratinophilic fungi called dermatophytes.

Step 2: Detailed Explanation:
Dermatophytes digest and survive on keratin, a structural protein found in the outer layers of skin, hair, and nails.
These fungi are taxonomically classified into several key genera:
- Trichophyton: Species like Trichophyton mentagrophytes are major zoonotic pathogens that cause inflammatory ringworm lesions in rodents, rabbits, dogs, horses, and humans.
- Microsporum: Species like Microsporum canis are major causes of dermatophytosis in companion animals (cats and dogs).
- Achorion: This is an older, historical genus name used for certain dermatophytes associated with favus (a severe form of ringworm), such as Achorion schoenleinii (now classified under Trichophyton). It is still recognized in classical veterinary literature as a causative agent of animal ringworm.
Thus, (A), (B), and (C) are all fungal groups that cause ringworm.
In contrast, Gallus domesticus is the scientific name for the domestic chicken.
While chickens can get ringworm (often called "favus," caused by Microsporum gallinae), the chicken itself is an animal host, not a causative fungal pathogen.
Therefore, option (D) is incorrect.
Combining these facts, the correct causative groups are (A), (B), and (C) only.

Step 3: Final Answer:
The fungal organisms causing ringworm are Trichophyton mentagrophytes, Achorion species, and Microsporum species, making (A), (B), and (C) only the correct option.