True about cholera vibrios is -a) Can tolerate wide range of alkaline pHb) Non motile bacillic) Can’t be grown in mediad) NaCl stimulates growth

**Core Concept**
Cholera vibrios, specifically Vibrio cholerae, are a type of Gram-negative bacterium that cause the diarrheal disease cholera. These bacteria thrive in aquatic environments and possess unique characteristics that enable them to infect humans.

**Why the Correct Answer is Right**
Vibrio cholerae can tolerate a wide range of alkaline pH due to the presence of an S-layer on its surface. This S-layer provides protection against environmental stressors, including extreme pH levels. Additionally, Vibrio cholerae is a motile bacterium, possessing a single polar flagellum that enables it to move through water. The bacterium can be grown in media, such as TCBS agar, which selectively allows Vibrio species to grow. Sodium chloride (NaCl) stimulates the growth of Vibrio cholerae, as it provides an optimal environment for the bacterium to thrive.

**Why Each Wrong Option is Incorrect**
**Option B:** This option is incorrect because Vibrio cholerae is actually a motile bacterium, not non-motile.
**Option C:** This option is incorrect because Vibrio cholerae can be grown in media, such as TCBS agar, which selectively allows Vibrio species to grow.
**Option D:** This option is incorrect because while sodium chloride does stimulate the growth of Vibrio cholerae, it is not the correct statement regarding the unique characteristic of these bacteria.

**Clinical Pearl / High-Yield Fact**
Cholera is typically spread through contaminated water or food, and Vibrio cholerae can survive for extended periods in aquatic environments. The bacterium produces cholera toxin, which causes a profuse, watery diarrhea leading to severe dehydration.

**Correct Answer:** d) NaCl stimulates growth