IgG response of dysenteric patients to antigens coded by the virulence plasmid of enteroinvasive pathogens.

IgG antibody response to antigens coded by the virulence plasmid of enteroinvasive pathogens was studied in dysenteric patients by ELISA. A plasmidless Escherichia coli K-12 strain and its transconjugant harbouring the 140 megadalton plasmid of a virulent E. coli 0124 strain were used as antigens. Sera of 12 dysenteric patients taken on the first, third an twelfth week after Shigella sonnei infection were examined. For comparison sera of 23 nondysenteric persons were also applied. Titres of the first week samples did not differ significantly from those of the controls. Patients' sera taken on the third week showed a fivefold rise in titres as compared to the first week ones. Antibody activity remained on a comparable high level till the twelfth week. The data prove that there is a considerable IgG response to plasmid coded antigens common in shigellae and enteroinvasive E. coli.