Abstract
Aspergillus fumigatus is an important pathogen of the immunocompromised host, causing pneumonia and invasive disseminated disease with high mortality. In order to determine the importance of lysine biosynthesis for growth and pathogenicity, the A. fumigatus lysF gene, encoding a homologue of the A. nidulans homoaconitase LysF, was cloned and characterized. Cosmid cosGTM encoding lysF complemented a lysF mutant of Aspergillus nidulans. A. fumigatus lysF was deleted, resulting in a lysine-auxotroph. This phenotype was complemented to the wild-type by supplementation of the medium with both L-lysine and α-aminoadipic acid, or transformation using cosmid cosGTM. To study the virulence of the lysF deletion mutant of A. fumigatus, a low-dose intranasal mouse infection model of invasive aspergillosis was optimized for immunosuppressed BALB/c mice, allowing the application of an infection dose as low as 5×103 conidia per mouse. In this murine model, the ΔlysF mutant was avirulent, suggesting that lysine biosynthesis, or at least a functional homoaconitase, is important for survival of A. fumigatus in vivo and a potential target for antifungal drugs.
This is a preview of subscription content, log in via an institution to check access.
References
Bhattacharjee JK (1992) Evolution of α-aminoadipate pathway for the synthesis of lysine in fungi. In: Mortlock RP (ed) Evolution of metabolic function, CRC, Boca Raton, pp 47–80
Brakhage AA, Langfelder K (2002) Menacing mold: the molecular biology of Aspergillus fumigatus. Annu Rev Microbiol 56:433–455
Brown JS, Aufauvre-Brown A, Brown J, Jennings JM, Arst H Jr, Holden DW (2000) Signature-tagged and directed mutagenesis identify PABA synthetase as essential for Aspergillus fumigatus pathogenicity. Mol Microbiol 36:1371–1380
Denning DW (1998) Invasive aspergillosis. Clin Infect Dis 26:781–803
D’Enfert C, Diaquin M, Delit A, Wuscher N, Debeaupuis JP, Huerre M, Latgé JP (1996) Attenuated virulence of uridine–uracil auxotrophs of Aspergillus fumigatus. Infect Immun 64:4401–4405
Garrad RC, Bhattacharjee JK (1992) Lysine biosynthesis in selected pathogenic fungi: characterization of lysine auxotrophs and the cloned LYS1 gene of Candida albicans. J Bacteriol 174:7379–7384
Langfelder K, Jahn B, Gehringer H, Schmidt A, Wanner G, Brakhage AA (1998) Identification of a polyketide synthase gene (pksP) of Aspergillus fumigatus involved in conidial pigment biosynthesis and virulence. Med Microbiol Immunol 187:79–89
Langfelder K, Philippe B, Jahn B, Latgé JP, Brakhage AA (2001) Differential expression of the Aspergillus fumigatus pksP gene detected in vitro and in vivo with green fluorescent protein. Infect Immun 69:6411–6418
Latgé JP (1999) Aspergillus fumigatus and aspergillosis. Clin Microbiol Rev 12:310–350
Manning M, Snoddy CB, Fromtling RA (1984) Comparative pathogenicity of auxotrophic mutants of Candida albicans. Can J Microbiol 30:31–35
Sandhu DK, Sandhu RS, Khan ZU, Damodaran VN (1976) Conditional virulence of a p-aminobenzoic acid requiring mutant of Aspergillus fumigatus. Infect Immun 13:527–532
Shepherd MG (1985) Pathogenicity of morphological and auxotrophic mutants of Candida albicans in experimental infections. Infect Immun 50:541–544
Smith JM, Tang CM, Van Noorden S, Holden DW (1994) Virulence of Aspergillus fumigatus double mutants lacking restrictocin and an alkaline protease in a low-dose model of invasive pulmonary aspergillosis. Infect Immun 62:5247–5254
Tang CM, Smith JM, Arst HN Jr, Holden DW (1994) Virulence studies of Aspergillus nidulans mutants requiring lysine or p-aminobenzoic acid in invasive pulmonary aspergillosis. Infect Immun 62:5255–5260
Weidner G, Steffan B, Brakhage AA (1997) The Aspergillus nidulans lysF gene encodes homoaconitase, an enzyme involved in the fungus-specific lysine biosynthesis pathway. Mol Gen Genet 255:237–247
Weidner G, D’Enfert C, Koch A, Mol PC, Brakhage AA (1998) Development of a homologous transformation system for the human pathogenic fungus Aspergillus fumigatus based on the pyrG gene encoding orotidine 5′-monophosphate decarboxylase. Curr Genet 33:378–385
Acknowledgements
We thank Sybille Traupe for excellent technical assistance. This work was supported by the Deutsche Forschungsgemeinschaft (Sonderforschungsbereich 587, TpA8 and B4).
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Liebmann, B., Mühleisen, T.W., Müller, M. et al. Deletion of the Aspergillus fumigatus lysine biosynthesis gene lysF encoding homoaconitase leads to attenuated virulence in a low-dose mouse infection model of invasive aspergillosis. Arch Microbiol 181, 378–383 (2004). https://doi.org/10.1007/s00203-004-0667-3
Received:
Revised:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s00203-004-0667-3