HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via CrossRef Citing Articles via Google Scholar Google Scholar Articles by Scully, L. R. Articles by Bidochka, M. J. Search for Related Content PubMed PubMed Citation Articles by Scully, L. R. Articles by Bidochka, M. J. Agricola Articles by Scully, L. R. Articles by Bidochka, M. J.

A cysteine/methionine auxotroph of the opportunistic fungus Aspergillus flavus is associated with host-range restriction: a model for emerging diseases

Department of Biological Sciences, 500 Glenridge Avenue, Brock University, St Catharines, Ontario, Canada L2S 3A1

Correspondence
Michael J. Bidochka
bidochka{at}brocku.ca

The evolution of host specialization in pathogens is a topic of considerable interest, particularly since it can represent a decisive step in the emergence of infectious diseases. Aspergillus flavus is an opportunistic fungus capable of infecting a wide variety of hosts, including plants, insects and mammals, although with low virulence. Here the derivation of an A. flavus strain that exhibits severe host restriction is reported. This strain exhibited a severe diminution or a complete lack of conidial production on a variety of standard agar media and on various plant species. However, it retained its ability to infect insects from various orders and to re-emerge from and adequately conidiate on the insect cadavers as a culmination of the pathogenic life cycle. This strain, demonstrating insect-dependent conidiation, was discovered to be a cysteine/methionine auxotroph due to an inability to reduce sulfate to sulfite. However, other A. flavus auxotrophs tested for plant and insect host range failed to show insect-dependent conidiation. An association between this specific auxotroph and a decreased host range is shown, emphasizing the role of nutrition in the host–pathogen relationship with respect to host restriction and evolution towards obligate pathogenesis.

The GenBank/EMBL/DDBJ accession number for the ITS region sequence reported in this paper is AY521473.

This article has been cited by other articles:

				F. Rodrigues, M. Sarkar-Tyson, S. V. Harding, S. H. Sim, H. H. Chua, C. H. Lin, X. Han, R. K. M. Karuturi, K. Sung, K. Yu, et al. Global Map of Growth-Regulated Gene Expression in Burkholderia pseudomallei, the Causative Agent of Melioidosis J. Bacteriol., December 1, 2006; 188(23): 8178 - 8188. [Abstract] [Full Text] [PDF]

				A. C. Sexton and B. J. Howlett Parallels in Fungal Pathogenesis on Plant and Animal Hosts Eukaryot. Cell, December 1, 2006; 5(12): 1941 - 1949. [Full Text] [PDF]