This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Microbiology
Endotoxin of which gram negative bacteria does not cause pathogenesis of natural disease? 
Select and explain. 
A. E. coli, B. M. tuberculosis, C. V. Cholera, D. Pseudomonas aerogenosa
C: V. Cholera
Answer: C: V. Cholera 
Explanation: Culture
V cholerae produces convex, smooth, round colonies that are opaque and granular in transmitted light. V cholera and most other vibrios grow well at 37°C on many kinds of media, including defined media containing mineral salts and asparagines mineral salts and asparagines as sources of carbon and nitrogen. V cholerae grows well on thiosulfate-citrate-bile-sucrose (TCBS) agar, on which it produces yellow colonies that are readily visible against the dark-green background of the agar.