title: A streptococcal NRAMP homologue is crucial for the survival of Streptococcus agalactiae under low pH conditions.
abstract: Streptococcus agalactiae or Group B Streptococcus (GBS) is a commensal bacterium of the human gastrointestinal and urogenital tracts as well as a leading cause of neonatal sepsis, pneumonia and meningitis. Maternal vaginal carriage is the main source for GBS transmission and thus the most important risk factor for neonatal disease. Several studies in eukaryotes identified a group of proteins natural resistance-associated macrophage protein (NRAMP) that function as divalent cation transporters for Fe(2+) and Mn(2+) and confer on macrophages the ability to control replication of bacterial pathogens. Genome sequencing predicted potential NRAMP homologues in several prokaryotes. Here we describe for the first time, a pH-regulated NRAMP Mn(2+) /Fe(2+) transporter in GBS, designated MntH, which confers resistance to reactive oxygen species (ROS) and is crucial for bacterial growth and survival under low pH conditions. Our investigation implicates MntH as an important colonization determinant for GBS in the maternal vagina as it helps bacteria to adapt to the harsh acidic environment, facilitates bacterial adherence, contributes to the coexistence with the vaginal microbiota and plays a role in GBS intracellular survival inside macrophages.
authors.affiliation: Institute of Medical Microbiology and Hygiene, University of Ulm, Ulm, Germany.|Microbiology and Immunology Department, Faculty of Pharmacy, Suez Canal University, Ismailia, Egypt.
authors.forename: Sarah
authors.initials: S
authors.lastname: Shabayek
authors.affiliation: Institute of Medical Microbiology and Hygiene, University of Ulm, Ulm, Germany.
authors.forename: Richard
authors.initials: R
authors.lastname: Bauer
authors.affiliation: Institute of Medical Microbiology and Hygiene, University of Ulm, Ulm, Germany.
authors.forename: Stefanie
authors.initials: S
authors.lastname: Mauerer
authors.affiliation: Institute of Analytical and Bioanalytical Chemistry, University of Ulm, Ulm, Germany.
authors.forename: Boris
authors.initials: B
authors.lastname: Mizaikoff
authors.affiliation: Institute of Medical Microbiology and Hygiene, University of Ulm, Ulm, Germany.
authors.forename: Barbara
authors.initials: B
authors.lastname: Spellerberg
mesh_terms: D001422:Bacterial Adhesion / Q000235:genetics / Q000502:physiology; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D027682:Cation Transport Proteins / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D005260:Female; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007477:Ions / Q000378:metabolism; D007501:Iron / Q000378:metabolism; D008264:Macrophages / Q000382:microbiology; D008345:Manganese / Q000378:metabolism; D009154:Mutation; D018384:Oxidative Stress / Q000235:genetics; D017386:Sequence Homology, Amino Acid; D013292:Streptococcus agalactiae / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D014621:Vagina / Q000382:microbiology; D000099173:Natural Resistance-associated Macrophage Protein 1
chemical_list: D001426:Bacterial Proteins; D027682:Cation Transport Proteins; D007477:Ions; D007501:Iron; D008345:Manganese; D000099173:Natural Resistance-associated Macrophage Protein 1