The activity of apo-transferrin on the growth of Staphylococcus pseudintermedius

Apo-transferrin is an iron-binding protein that has been reported to have an antimicrobial effect. It is considered a major component of the host defense mechanism as it limits microbial access to iron. This study was performed to investigate whether bovine apo-transferrin would have an inhibitory effect on the growth of S. pseudintermedius, which is one of the most isolated bacteria from dogs, and to compare the antimicrobial efficacy with bovine holo-transferrin. S. pseudintermedius were grown at 37 C in 96-well culture plates using Muller Hinton broth containing bovine apo-transferrin or bovine holo-transferrin at concentrations^o ranging from 0.5 or 2.5 to 5.0 mg/ ml. The optical densities of the wells were then measured at 570 nm. In this study, the apo-transferrin showed dose-dependent antimicrobial effect against S. pseudintermedius while holo-transferrin did not inhibit the growth of S. pseudintermedius effectively. The results suggest that iron deprivation is an important pathway for inhibiting bacterial growth and bovine apo-transferrin has great antimicrobial effects against S. pseudintermedius.