Infect. Immun., Jul 1997, 2700-2706, Vol 65, No. 7
Copyright © 1997, American Society for Microbiology

Role of bacterial Mn-cofactored superoxide dismutase in oxidative stress responses, nasopharyngeal colonization, and sustained bacteremia caused by Haemophilus influenzae type b

RA D'Mello, PR Langford and JS Kroll
Department of Paediatrics, Imperial College School of Medicine at St. Mary's Hospital, London, United Kingdom.

Haemophilus influenzae type b, a causative agent of bacterial sepsis and meningitis in young children, contains a single superoxide dismutase (SOD), a cytoplasmic MnSOD. To study the role of this enzyme, a chromosomal sodA::lacZ mutant (M-2) was constructed. M-2 had an increased sensitivity towards oxygen and the redox-active agent paraquat. A 3.4-fold increase in sodA-lacZ expression was found in M-2 grown with oxygen supply rates between 3 and 36 mmol of O2/liter/h. In similar experiments with the wild type, assaying SodA activity, a 3.1- fold increase was found. Both the wild type and M-2 grew best at the lowest oxygen supply rate tested, consistent with the notion that H. influenzae prefers a more anaerobic environment. In the infant rat model of infection, the ability of M-2 to colonize the nasopharynx was found to be impaired, but its ability to cause invasive disease was unaffected. This suggests that after invasion, the growth disadvantage imposed by a SodA- phenotype is not limiting.

This article has been cited by other articles:

• Rosadini, C. V., Wong, S. M. S., Akerley, B. J. (2008). The Periplasmic Disulfide Oxidoreductase DsbA Contributes to Haemophilus influenzae Pathogenesis. Infect. Immun. 76: 1498-1508 [Abstract] [Full Text]  
• Wang, W., Reitzer, L., Rasko, D. A., Pearson, M. M., Blick, R. J., Laurence, C., Hansen, E. J. (2007). Metabolic Analysis of Moraxella catarrhalis and the Effect of Selected In Vitro Growth Conditions on Global Gene Expression. Infect. Immun. 75: 4959-4971 [Abstract] [Full Text]  
• Vergauwen, B., Pauwels, F., Vaneechoutte, M., Van Beeumen, J. J. (2003). Exogenous Glutathione Completes the Defense against Oxidative Stress in Haemophilus influenzae. J. Bacteriol. 185: 1572-1581 [Abstract] [Full Text]  
• De Souza-Hart, J. A., Blackstock, W., Di Modugno, V., Holland, I. B., Kok, M. (2003). Two-Component Systems in Haemophilus influenzae: a Regulatory Role for ArcA in Serum Resistance. Infect. Immun. 71: 163-172 [Abstract] [Full Text]  
• Valderas, M. W., Gatson, J. W., Wreyford, N., Hart, M. E. (2002). The Superoxide Dismutase Gene sodM Is Unique to Staphylococcus aureus: Absence of sodM in Coagulase-Negative Staphylococci. J. Bacteriol. 184: 2465-2472 [Abstract] [Full Text]  
• Luke, N. R., Karalus, R. J., Campagnari, A. A. (2002). Inactivation of the Moraxella catarrhalis Superoxide Dismutase SodA Induces Constitutive Expression of Iron-Repressible Outer Membrane Proteins. Infect. Immun. 70: 1889-1895 [Abstract] [Full Text]  
• Shea, R. J., Mulks, M. H. (2002). ohr, Encoding an Organic Hydroperoxide Reductase, Is an In Vivo-Induced Gene in Actinobacillus pleuropneumoniae. Infect. Immun. 70: 794-802 [Abstract] [Full Text]  
• Yesilkaya, H., Kadioglu, A., Gingles, N., Alexander, J. E., Mitchell, T. J., Andrew, P. W. (2000). Role of Manganese-Containing Superoxide Dismutase in Oxidative Stress and Virulence of Streptococcus pneumoniae. Infect. Immun. 68: 2819-2826 [Abstract] [Full Text]  
• Clements, M. O., Watson, S. P., Foster, S. J. (1999). Characterization of the Major Superoxide Dismutase of Staphylococcus aureus and Its Role in Starvation Survival, Stress Resistance, and Pathogenicity. J. Bacteriol. 181: 3898-3903 [Abstract] [Full Text]  
• Wilks, K. E., Dunn, K. L. R., Farrant, J. L., Reddin, K. M., Gorringe, A. R., Langford, P. R., Kroll, J. S. (1998). Periplasmic Superoxide Dismutase in Meningococcal Pathogenicity. Infect. Immun. 66: 213-217 [Abstract] [Full Text]