Accumulation of manganese in Neisseria gonorrhoeae correlates with resistance to oxidative killing by superoxide anion and is independent of superoxide dismutase activity

Tseng, Hsing-Ju, Srikhanta, Yogitha, McEwan, Alastair G. and Jennings, Michael P. (2001) Accumulation of manganese in Neisseria gonorrhoeae correlates with resistance to oxidative killing by superoxide anion and is independent of superoxide dismutase activity. Molecular Microbiology, 40 5: 1175-1186.


Author Tseng, Hsing-Ju
Srikhanta, Yogitha
McEwan, Alastair G.
Jennings, Michael P.
Title Accumulation of manganese in Neisseria gonorrhoeae correlates with resistance to oxidative killing by superoxide anion and is independent of superoxide dismutase activity
Journal name Molecular Microbiology
Publication date 2001-12-21
Sub-type Article
DOI 10.1046/j.1365-2958.2001.02460.x
Volume number 40
Issue number 5
ISSN 0950-382X; 1365-2958
Start page 1175
End page 1186
Total pages 12
Place of publication Oxford
Publisher Blackwell Science
Collection year 2001
Language eng
Subject C1
270300 Microbiology
780105 Biological sciences
Abstract As a facultative aerobe with a high iron requirement and a highly active aerobic respiratory chain, Neisseria gonorrhoeae requires defence systems to respond to toxic oxygen species such as superoxide. It has been shown that supplementation of media with 100 muM Mn(II) considerably enhanced the resistance of this bacterium to oxidative killing by superoxide. This protection was not associated with the superoxide dismutase enzymes of N. gonorrhoeae. In contrast to previous studies, which suggested that some strains of N. gonorrhoeae might not contain a superoxide dismutase, we identified a sodB gene by genome analysis and confirmed its presence in all strains examined by Southern blotting, but found no evidence for sodA or sodC. A sodB mutant showed very similar susceptibility to superoxide killing to that of wild-type cells, indicating that the Fe-dependent SOD B did not have a major role in resistance to oxidative killing under the conditions tested. The absence of a sodA gene indicated that the Mn-dependent protection against oxidative killing was independent of Mn-dependent SOD A. As a sodB mutant also showed Mn-dependent resistance to oxidative killing, then it is concluded that this resistance is independent of superoxide dismutase enzymes. Resistance to oxidative killing was correlated with accumulation of Mn(II) by the bacterium. We hypothesize that this bacterium uses Mn(II) as a chemical quenching agent in a similar way to the already established process in Lactobacillus plantarum. A search for putative Mn(II) uptake systems identified an ABC cassette-type system (MntABC) with a periplasmic-binding protein (MntC). An mntC mutant was shown to have lowered accumulation of Mn(II) and was also highly susceptible to oxidative killing, even in the presence of added Mn(II). Taken together, these data show that N. gonorrhoeae possesses a Mn(II) uptake system that is critical for resistance to oxidative stress.
Keyword Biochemistry & Molecular Biology
Microbiology
Escherichia-coli
Streptococcus-pneumoniae
Lactobacillus-plantarum
Oxygen-toxicity
Abc Transporter
Cloning
Locus
Virulence
Psaa
Lipopolysaccharide
Q-Index Code C1

Document type: Journal Article
Sub-type: Article
Collection: School of Chemistry and Molecular Biosciences
 
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