A. terreus Accessory Conidia Figure 4. b1-3-glucan expression on phialidic conidia and accessory conidia. Staining for b1-3-glucan surface exposure on A. fumigatus conidia (A), A. terreus phialidic conidia (B) and A. terreus accessory conidia (C) was performed and evaluated by fluorescence microscopy. Arrows denote the b1-3-glucan staining on accessory conidia. doi:10.1371/journal.pone.0007673.g004 during infection. Accessory conidia exhibit candidate virulence factors – adherence, excellent viability, rapid germination potential. Additionally, ACs have lower ergosterol content rendering them less susceptible to damage due to the antifungal drug AMB, furthering their pathogenic potential. Since most of these experiments were performed with one or few representative isolates, studies with more isolates and other detailed examinations are needed to understand the cell wall composition of these specialized structures and their interaction with immune cells. References 1. Magill SS, Chiller TM, Warnock DW (2008) Evolving strategies in the management of aspergillosis. Expert Opin Pharmacother 9: 193–209. 2. Malani AN, Kauffman CA (2007) Changing epidemiology of rare mould infections: implications for therapy. Drugs 67: 1803–1812. 3. Steinbach WJ, Benjamin DK, Jr., Kontoyiannis DP, Perfect JR, Lutsar I, et al. (2004) Infections due to Aspergillus terreus: a multicenter retrospective analysis of 83 cases. Clin Infect Dis 39: 192–198. 4. Walsh TJ, Petraitis V, Petraitiene R, Field-Ridley A, Sutton D, et al. (2003) Experimental pulmonary aspergillosis due to Aspergillus terreus: pathogenesis and treatment of an emerging fungal pathogen resistant to amphotericin B. J Infect Dis 188: 305–319. 5. Raper BK, Fennell DI (1965) The Genus Aspergillus. Baltimore, Md: The Williams and Wilkins Company. 657 p. 6. Ainsworth GC, PKCA (1955) A survey of animal mycoses in Britain:General aspects. Vet Record 67: 88–97. Disclaimer The findings and conclusions in this article are those of the author(s) and do not necessarily represent the views of the CDC. Author Contributions Conceived and designed the experiments: ED SAB. Performed the experiments: ED SDW EW JC. Analyzed the data: ED. Contributed reagents/materials/analysis tools: EW JC. Wrote the paper: ED SAB. 7. Walsh TJ, Groll A, Hiemenz J, Fleming R, Roilides E, et al. (2004) Infections due to emerging and uncommon medically important fungal pathogens. Clin Microbiol Infect 10 Suppl 1: 48–66. 8. Lass-Florl C, Rief A, Leitner S, Speth C, Wurzner R, et al. (2005) In vitro activities of amphotericin B and voriconazole against aleurioconidia from Aspergillus terreus. Antimicrob Agents Chemother 49: 2539–2540. 9. Girardin H, Paris S, Rault J, Bellon-Fontaine MN, Latge JP (1999) The role of the rodlet structure on the physicochemical properties of Aspergillus conidia. Lett Appl Microbiol 29: 364–369. 10. Sande WV, Tavakol M, Vianen WV, Bakker-Woudenberg IA (2009) The effects of antifungal agents to conidial and hyphal forms of Aspergillus fumigatus. Med Mycol. pp 1–8. 11. Arthington-Skaggs BA, Jradi H, Desai T, Morrison CJ (1999) Quantitation of ergosterol content: novel method for determination of fluconazole susceptibility of Candida albicans. J Clin Microbiol 37: 3332–3337. PLoS ONE | www.plosone.org 6 October 2009 | Volume 4 | Issue 10 | e7673