Two novel roles of buffalo milk lactoperoxidase, antibiofilm agent and immunomodulator against multidrug resistant Salmonella enterica serovar Typhi and Listeria monocytogenes.

The increasing occurrence of multidrug resistant bacteria causing bacteremia infection, constitutes a major health problem, difficult-to-treat bacteremia due to its ability to form biofilm. Buffalo milk lactoperoxidase (BMLpo) is effective and safe to use as bacteriostatic agent. The MIC of BMLpo and amikacin were used to evaluate the antibiofilm activity against resistant L. monocytogenes and S. typhi. Prophylactic effects of BMLpo against L. monocytogenes and S. typhi bacteremia in vivo have been tested and ELISA test used to evaluate serum cytokines. Significant antibiofilm activity of BMLpo observed against the highest biofilm producer isolates. Our results showed that the prophylactic effect of BMLpo in BALB/c mice bacteremic model. A significant clearance of L. monocytogenes and S. typhi, investigated in blood and different organs tissues in BMLpo-treated infected groups when compared to the non-treated groups. Further, analysis of serum cytokines levels revealed that BMLpo prophylaxis modulates their release in different way when it compared to the control. This study showed, BMLpo effects as an alternative antibiofilm agent to compact gram negative pathogens, and protects the host against bacteremia infection. Moreover, the BMLpo role as an immunomodulatory. These investigations indicated the BMLpo crucial role in the practical clinical applications.