Abstract: The invention provides a synthetic peptide which reproduces at least 5 of the 11 amino acids common to the .gamma. chain of sub-unit A of cholera toxin and the .gamma. chain of LT toxin of Escherichia coli. It is preferably constituted by a pentadecapeptide which corresponds to the following formula (I): ##STR1## The process of synthesis is by the step by step construction of the peptide chain starting from the C terminal end of said chain, by the successive fixing of the amino acids which constitute the latter. A novel medicament for the treatment of cholera and infectious gastro-enterites comprises said synthetic peptide as active constituent. A diagnosis agent for cholera and/or infectious gastro-enterites comprises a sequence of nucleotides corresponding to the 5 minimum amino acids of the synthetic peptide.

Abstract: The invention provides a synthetic peptide comprising at least 5 of the 11 amino acids common to the .gamma.chain of sub-unit A of the cholera toxin and the .gamma.chain of the LT toxin of Escherichia coli. The peptide is preferably constituted by a pentadecapeptide which corresponds to the following formula (I): ##STR1## The process of synthesis is by the step by step construction of the peptide chain starting form the C terminal end of said chain, by the successive fixing of the amino acids which constitute the peptide. A novel medicament for the treatment of cholera and infectious gastro-enterites is also disclosed which comprises said synthetic peptide as an active constituent. A diagnosis agent for cholera and/or infectious gastroenterites comprises a sequence of at least the 5 amino acids of the synthetic peptide.