RESUMEN
The effect of pyocyanine pigment, which was isolated and purified from Pseudomonas aeruginosa, on specific lymphocytes viability inside the body of white male Balb/c mice against the experimental secondary hydatidosis and the infectivity of protoscolices was studied in comparison with negative control mice groups, phosphate buffered saline [PBS] and positive control group [immunoferon]. Four groups of male Balb/c mice were intraperitoneally [IP] inoculated with four purified concentrations of pyocyanine [25, 50, 75, 100 micro m/ml]. Seven days later, they were given the same concentrations as a booster dose of the pigment, then 7 days later they were intraperitoneally infected with 2000 protoscoleces/ mL [PBS] as a challenge dose. The fifth group was intraperitoneally inoculated with 1ml of sterile PBS and used as a negative control group, while the sixth group was intraperitoneally inoculated with 100 micro mg/ml immunoferon and received the challenge dose of 2000 protoscoleces/ ml PBS and served as the positive control group. The concentrations of 50, 75 and 100 micro m/ml of this pigment had suppressive effect on these specific immune response cells. This effect was statistically significant [p<0.01] after six weeks from the challenge dose with intraperitoneal protoscolices infection. This effect revealed that the protoscolices infectivity increased due to suppression viability of T lymphocytes, while the immunoferon showed a significant stimulation of these specific cellular cells, which decrease the protoscolices infectivity in comparison with higher pigment concentrations. Pyocyanine is a toxic pigment causing suppression of T-cells activity, especially at higher concentrations which allow protoscolices development and growth