RT Journal Article SR Electronic(1) A1 Wagner, Dirk A1 Maser, Jörg A1 Moric, Ivana A1 Boechat, Neio A1 Vogt, Stefan A1 Gicquel, Brigitte A1 Lai, Barry A1 Reyrat, Jean-Marc A1 Bermudez, LuizYR 2005 T1 Changes of the phagosomal elemental concentrations by Mycobacterium tuberculosis Mramp JF Microbiology, VO 151 IS 1 SP 323 OP 332 DO https://doi.org/10.1099/mic.0.27213-0 PB Microbiology Society, SN 1465-2080, AB Pathogenic mycobacteria survive within phagosomes which are thought to represent a nutrient-restricted environment. Divalent cation transporters of the Nramp family in phagosomes and mycobacteria (Mramp) may compete for metals that are crucial for bacterial survival. The elemental concentrations in phagosomes of macrophages infected with wild-type Mycobacterium tuberculosis (M. tuberculosis strain H37Rv) and a M. tuberculosis Mramp knockout mutant (Mramp-KO), derived from a clinical isolate isogenic to the strain MT103, were compared. Time points of 1 and 24 h after infection of mouse peritoneal macrophages (bcg S) were compared in both cases. Increased concentrations of P, Ni and Zn and reduced Cl concentration in Mramp-KO after 1 h of infection were observed, compared to M. tuberculosis vacuoles. After 24 h of infection, significant differences in the P, Cl and Zn concentrations were still present. The Mramp-KO phagosome showed a significant increase of P, Ca, Mn, Fe and Zn concentrations between 1 and 24 h after infection, while the concentrations of K and Ni decreased. In the M. tuberculosis vacuole, the Fe concentration showed a similar increase, while the Cl concentration decreased. The fact that the concentration of several divalent cations increased in the Mramp-KO strain suggests that Mramp may have no impact on the import of these divalent cations into the mycobacterium, but may function as a cation efflux pump. The concordant increase of Fe concentrations within M. tuberculosis, as well as within the Mramp-KO vacuoles, implies that Mramp, in contrast to siderophores, might not be important for the attraction of Fe and its retention in phagosomes of unstimulated macrophages., UL https://www.microbiologyresearch.org/content/journal/micro/10.1099/mic.0.27213-0