Gram ⊝, flagellated, oxidase ⊕, grows in alkaline media.- Endemic to developing countries.- Transmitted via ingestion of contaminated water or uncooked food (eg, raw shellfish).

- Fecal-oral spread; sensitive to stomach acid (acid labile), requires large inoculum (high ID₅₀) unless host has ↓ gastric acidity.- Produces profuse rice-water diarrhea (white flecks of mucus) via enterotoxin that permanently activates G_s, ↑ cAMP → efflux of Cl^- and H₂O. (Similar to E coli heat-labile toxin)- Fever is rare because V cholerae is noninvasive.

Diagnosis: Culture stool on TCBS

Treatment: Prompt oral rehydration is necessary