This study presents evaluation of effects of
aluminium ions on the development of experimental
infection induced by the injection of Listeria monocytogenes bacteria into growing mice. We show that single exposure of mice to 0.05 LD50 or 0.5 LD50 of
aluminium ions does not affect the accumulation of bacteria in liver and spleen of experimental animals. Long-term exposure of mice to
aluminium ions (injection of 0.05 LD50 Al3+ every 3 days for totally 6 weeks) did not slow down the increase in weight of animals while in the infected animals
aluminium significantly reduced their growth. Animals subjected to chronic
aluminium exposure have shown lower accumulation of bacteria in liver 24 h after the initiation of experimental
infection as compared to the mice after single injection of 0.05 LD50 Al3+. Also, long-term exposure to
aluminium causes more complicated development of experimental
infection, which was evidenced by the decreased survival of
aluminium-treated animals (77% compared to 83% in control group) as well as by the increase in the fraction of animals carrying
infection after 6 weeks (36% versus 5% in control group). In addition,
aluminium-exposed animals had significantly lower blood serum agglutination titer to the listeria, and decrease in the delayed type of
hypersensitivity to the listeria
antigens. Results, presented here, indicate that the long-term exposure to low
aluminium doses activates the antibacterial defence in experimental animals while the specific immunity becomes suppressed.