In a patient with UTI, CLED (Cystine, Lactose Electrolyte Deficient) Media is preferred over Mac Conkeys media because –
**Core Concept**
CLED media is used for the isolation and identification of urinary pathogens, particularly in situations where the urine sample may contain multiple types of microorganisms. This media is selective for gram-negative bacteria, which are commonly responsible for urinary tract infections (UTIs).
**Why the Correct Answer is Right**
CLED media is preferred over MacConkey's agar because it allows for the growth of both lactose-fermenting and non-lactose fermenting organisms, including gram-positive bacteria. The addition of cystine helps to support the growth of staphylococci and other gram-positive bacteria, which may not grow well on MacConkey's agar. This is particularly useful in patients with complicated UTIs, where multiple types of bacteria may be present.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because MacConkey's agar is selective for gram-negative bacteria, but it does not support the growth of gram-positive bacteria as well as CLED media.
**Option B:** This option is incorrect because the primary advantage of CLED media is its ability to support the growth of a broader range of bacteria, including gram-positive species.
**Option C:** This option is incorrect because while MacConkey's agar is selective for gram-negative bacteria, it is not the primary reason for preferring CLED media in patients with UTIs.
**Clinical Pearl / High-Yield Fact**
When selecting a media for urine culture, it is essential to consider the type of bacteria that may be present and the specific needs of the patient. CLED media is a good choice for patients with complicated UTIs or those who are at risk for gram-positive bacteremia.
**Correct Answer:** C.