The Hair Baiting Test is used to differentiate which two species of Trichophyton that produce red colonies on Sabouraud agar plates?

The Hair Baiting Test is a specific laboratory technique used to distinguish between certain species of the dermatophyte genus Trichophyton based on their ability to invade and grow on hair. In this context, the test is particularly effective in differentiating T. mentagrophytes from T. rubrum.

T. mentagrophytes typically exhibits a rapid growth pattern and produces microconidia, while T. rubrum tends to be slower growing and is characterized by its unique morphology, producing distinctive red colonies on Sabouraud agar. The Hair Baiting Test exploits these differences, as T. mentagrophytes can metabolize keratin in hair, leading to a visible growth response, whereas T. rubrum does not utilize hair in the same way, allowing for clear differentiation between the two species.

Understanding this technique and the responses of these fungi to hair helps in accurately diagnosing dermatophyte infections, making the Hair Baiting Test a valuable tool in microbiology.