Biological characteristics of manganese transporter MntP in Klebsiella pneumoniae

is an important opportunistic pathogen that causes a variety of infections. It is critical for bacteria to maintain metal homeostasis during infection. By using an isogenic deletion mutant of strain NTUH-K2044, we found that MntP was a manganese efflux pump. Manganese increased the tolerance to oxidative stress, and oxidative stress could increase the intracellular manganese concentration. In oxidative stress, the deletion mutant exhibited significantly higher sensitivity to manganese. Furthermore, iron could increase the tolerance of the deletion mutant to manganese. Inductively coupled plasma mass spectrometry analysis revealed that the deletion mutant had higher intracellular manganese and iron concentrations than wild-type and complementary strains. These findings suggested that iron could increase manganese tolerance in . This work elucidated the role of MntP in manganese detoxification and Mn/Fe homeostasis in .IMPORTANCEMetal homeostasis plays an important role during the process of bacterial infection. Herein, we revealed that MntP was involved in intracellular manganese homeostasis. Manganese promoted resistance to oxidative stress in . Furthermore, we demonstrated that the deletion mutant exhibited significantly lower survival under manganese and H O conditions. Oxidative stress increased the intracellular manganese content of the deletion mutant. MntP played a critical role in maintaining intracellular manganese and iron concentrations. MntP contributed to manganese detoxification and Mn/Fe homeostasis in .