SIDEROCALIN: IRON SEQUESTRATION AND THE PRODUCTION OF SIDEROPHORES BY Pseudomonas aeroginosa

Introduction: Siderocalin, a member of the lipocalin family of binding proteins, is found in Neutrophils granules, Uterine secretions and markedly elevated levels in serum and synovium during bacterial infections; It’s also secreted from epithelial cells in response to inflammation or tumorigenesis, suggested a possible function for siderocalin: An antibacterial agent, completing the general antimicrobial innate immune system Iron-depletion strategy, sequestering Iron as a ferric siderophores complexes. Supporting this hypothesis, Siderocalin is a potent bacteriostatic agent In vitro.

Materiels and Methods: We have been working to elucidate the abnormalities associated with iron deficiency and the production of siderophores; we have also been trying to develop a practical application of our findings. We have focused on siderocalin. We also currently conducting further our experiments to evaluate the concentrations of siderophores produced by 10 specimens of Pseudomonas aeroginosa isolated from children with IDA and suffering from many infections. We added a human serum that we supposed it contains this composent in the bacterial medium and we compared the concentration of siderophores before and after the addition of this human serum.

Results: We found that the concentrations of siderophores produced by the 10 specimens before the addition of the human serum were between 0.97 μmol/ml to 3.27 μmol/ml .After the addition of the human serum, the concentration of the siderophores was between 0.14 μmol/ml to 0.27 μmol/ml. We can say that the concentration of the siderophores was significantly suppressed by the addition of a Human serum in the medium of culture. These results demonstrated that the sequestration of iron-loaded siderophores represents a direct attack on an important iron acquisition mechanism.

Conclusion: The findings of our study show that Siderocalin is a potent bacteriostatic agent In vitro Iron–limiting culture condition.