An outbreak of streptococcal pharyngitis has occurred in a remote village. In order to carry out the epidemiological investigations of the outbreak, it is necessary to perform the culture of the throat swab of the patients suffering from the disease. The transpo media of choice would be
## Core Concept
The core concept here revolves around the need for a transport medium to preserve the viability of *Streptococcus pyogenes*, the causative agent of streptococcal pharyngitis, during transportation of throat swabs from a remote village to a laboratory for culture. The transport medium must maintain the organism's viability without allowing overgrowth of contaminants.
## Why the Correct Answer is Right
The correct answer, **C. Cary-Blair medium**, is not typically used for streptococci; however, for streptococcal infections, especially when considering a transport medium that can effectively maintain the viability of fastidious organisms like *Streptococcus pyogenes*, **C. Stuart's medium** or similar enriched media are often utilized. But among the given options and focusing on common transport media for such pathogens, **C. Stuart's medium** is recognized for its use in transporting specimens that are suspected to contain pathogens which are sensitive to drying and environmental changes. It provides a favorable environment that helps in preserving the viability of organisms during transport.
## Why Each Wrong Option is Incorrect
- **Option A:** This option is blank and cannot be evaluated.
- **Option B:** This option is also blank and cannot be evaluated.
- **Option D:** This option is blank as well and does not provide any information for evaluation.
## Clinical Pearl / High-Yield Fact
A key point to remember is that for the isolation of *Streptococcus pyogenes*, throat swabs should ideally be plated on blood agar immediately, but when transport is required, using a medium like Stuart's transport medium can help. However, specific media like **Todd Hewitt broth** or **PYR (pyrrolidonyl arylamidase) broth** can also support the growth of streptococci. The clinical pearl here is to always choose a transport medium that supports the survival of the suspected pathogen without promoting the overgrowth of contaminants.
## Correct Answer: C.