This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrowReprints and Permissions
Right arrow Copyright Information
Right arrow Books from ASM Press
Right arrow MicrobeWorld
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Gifford, A. H. T.
Right arrow Articles by Moore, M. M.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Gifford, A. H. T.
Right arrow Articles by Moore, M. M.

 Previous Article  |  Next Article 

Infection and Immunity, January 2002, p. 19-26, Vol. 70, No. 1
0019-9567/01/$04.00+0     DOI: 10.1128/IAI.70.1.19-26.2002
Copyright © 2002, American Society for Microbiology. All Rights Reserved.

Serum Stimulates Growth of and Proteinase Secretion by Aspergillus fumigatus

Anna H. T. Gifford, Jodine R. Klippenstein, and Margo M. Moore*

Department of Biological Sciences, Simon Fraser University, Burnaby, British Columbia, Canada

Received 7 May 2001/ Returned for modification 8 June 2001/ Accepted 25 September 2001

Serum contains iron-binding proteins, which inhibit the growth of most pathogenic microorganisms, including fungi. The purpose of this research was to investigate the effect of serum on growth of the opportunistic fungal pathogen Aspergillus fumigatus. Supplementing minimal essential medium (MEM) with up to 80% human serum or up to 80% fetal bovine serum (FBS) stimulated growth and increased the amount of A. fumigatus dry biomass approximately fourfold. In addition, a 100-fold increase in proteinase secretion, as measured by azocasein hydrolysis, was observed when 10% human serum or 10% FBS was added to MEM. The fungal proteinases secreted in serum-containing media were shown to degrade 3H-labeled basal lamina proteins. The factor in serum that stimulated proteinase secretion was larger than 10 kDa and was 85% inactivated when the serum was heated for 30 min at 66°C. The proportions of proteinases of each catalytic class secreted by A. fumigatus in the presence of serum were different from the proportions secreted in media containing single proteins. Proteinase secretion did not result from increased protein concentration in the medium per se because bovine serum albumin (BSA) at a concentration equivalent to the concentration of serum produced only 20% of the proteinase activity per milligram (dry weight) that was produced by FBS. Addition of BSA plus 100 µM FeCl3 to MEM resulted in the same level of growth as addition of serum, indicating that a combination of nutritional factors in serum may stimulate growth. However, the level of proteinase secretion was still only 30% of the level observed with FBS. These data indicate that serum does not inhibit the growth of A. fumigatus and that the nutrients in serum result in high levels of proteinase secretion, potentially increasing the invasiveness of this species.


* Corresponding author. Mailing address: Department of Biological Sciences, Simon Fraser University, 8888 University Drive, Burnaby, B.C., Canada V5A 1S6. Phone: (604) 291-3441. Fax: (604) 291-3496. Email: mmoore{at}sfu.ca.

Editor: T. R. Kozel


Infection and Immunity, January 2002, p. 19-26, Vol. 70, No. 1
0019-9567/01/$04.00+0     DOI: 10.1128/IAI.70.1.19-26.2002
Copyright © 2002, American Society for Microbiology. All Rights Reserved.




This article has been cited by other articles:

  • Hissen, A. H. T., Wan, A. N. C., Warwas, M. L., Pinto, L. J., Moore, M. M. (2005). The Aspergillus fumigatus Siderophore Biosynthetic Gene sidA, Encoding L-Ornithine N5-Oxygenase, Is Required for Virulence. Infect. Immun. 73: 5493-5503 [Abstract] [Full Text]  
  • Vicentefranqueira, R., Moreno, M. A., Leal, F., Calera, J. A. (2005). The zrfA and zrfB Genes of Aspergillus fumigatus Encode the Zinc Transporter Proteins of a Zinc Uptake System Induced in an Acid, Zinc-Depleted Environment. Eukaryot Cell 4: 837-848 [Abstract] [Full Text]  
  • Xiong, Q., Hassan, S. A., Wilson, W. K., Han, X. Y., May, G. S., Tarrand, J. J., Matsuda, S. P. T. (2005). Cholesterol Import by Aspergillus fumigatus and Its Influence on Antifungal Potency of Sterol Biosynthesis Inhibitors. Antimicrob. Agents Chemother. 49: 518-524 [Abstract] [Full Text]  
  • Hissen, A. H. T., Chow, J. M. T., Pinto, L. J., Moore, M. M. (2004). Survival of Aspergillus fumigatus in Serum Involves Removal of Iron from Transferrin: the Role of Siderophores. Infect. Immun. 72: 1402-1408 [Abstract] [Full Text]