Which of the following is true of cholera-(

Ans. is 'b' i.e., Causes secretory diarrhoea . Recent epidemic was due to non-01 V.cholerae (NAG vibrio) in 1992. This strain was designated serovar 0-139 (0-139 Bengal). . Enterotoxin (Cholera toxin) causes watery diarrhea by acting directly on secretory mechanism through cAMP. . Cholera is due to exotoxin (cholera toxin). Cholera vibrios also possess lipopolysaccharide (endotoxin), but it has no role in pathogenesis. . "Vibriocidal antibodies in serum have been associated with protection against colonization and disease"