The manganese transporter MntH is a critical virulence determinant for Brucella abortus 2308 in experimentally infected mice.
The gene designated BAB1_1460 in the Brucella abortus 2308 genome sequence is predicted to encode the manganese transporter MntH. Phenotypic analysis of an isogenic mntH mutant indicates that MntH is the sole high-affinity manganese transporter in this bacterium but that MntH does not play a detectable role in the transport of Fe(2+), Zn(2+), Co(2+), or Ni(2+). Consistent with the apparent selectivity of the corresponding gene product, the expression of the mntH gene in B. abortus 2308 is repressed by Mn(2+), but not Fe(2+), and this Mn-responsive expression is mediated by a Mur-like repressor. The B. abortus mntH mutant MWV15 exhibits increased susceptibility to oxidative killing in vitro compared to strain 2308, and a comparative analysis of the superoxide dismutase activities present in these two strains indicates that the parental strain requires MntH in order to make wild-type levels of its manganese superoxide dismutase SodA. The B. abortus mntH mutant also exhibits extreme attenuation in both cultured murine macrophages and experimentally infected C57BL/6 mice. These experimental findings indicate that Mn(2+) transport mediated by MntH plays an important role in the physiology of B. abortus 2308, particularly during its intracellular survival and replication in the host.
Anderson
Eric S
ES
Department of Microbiology and Immunology, East Carolina University School of Medicine, Greenville, NC 27834, USA.
Paulley
James T
JT
Gaines
Jennifer M
JM
Valderas
Michelle W
MW
Martin
Daniel W
DW
Menscher
Evan
E
Brown
Timothy D
TD
Burns
Colin S
CS
Roop
R Martin
RM
D000818:Animals; D001426:Bacterial Proteins / Q000502:physiology*; D002003:Brucella abortus / Q000472:pathogenicity*; D002006:Brucellosis / Q000382:microbiology*; D027682:Cation Transport Proteins / Q000172:deficiency / Q000502:physiology*; D002478:Cells, Cultured; D015169:Colony Count, Microbial; D003593:Cytoplasm / Q000382:microbiology; D005260:Female; D017353:Gene Deletion; D020869:Gene Expression Profiling; D015964:Gene Expression Regulation, Bacterial; D005816:Genetic Complementation Test; D017737:Macrophages, Peritoneal / Q000276:immunology / Q000382:microbiology; D008345:Manganese / Q000378:metabolism; D051379:Mice; D008810:Mice, Inbred C57BL; D013154:Spleen / Q000382:microbiology; D014774:Virulence; D037521:Virulence Factors / Q000172:deficiency / Q000502:physiology*
D001426:Bacterial Proteins; D027682:Cation Transport Proteins; C433793:MntH protein, bacteria; D037521:Virulence Factors; D008345:Manganese