<prompt> Cholera is caused by-V.cholerae O1V.cholerae O1 and O139V. cholerae O139NAG vibrios  <response>: Vibrio cholerae is sero-grouped on the basis of O antigen into several O serogroups. Of these, O1 and O139 produce the cholera toxin. Hence cholera is caused by only these 2 serogroups as only that enteritis is called cholera which is due to cholera toxin 