| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
Korean Agricultural Culture Collection, NIAB, Suwon, 441-707, Korea
Hyeon-Dong Shin
Division of Environmental Science and Ecological Engineering, College of Life and Environmental Science, Korea University, Seoul 136-701, Korea
Jens C. Frisvad
Center for Microbial Biotechnology, Biocentrum-DTU, Technical University of Denmark, Building 221, DK-2800, Kgs. Lyngby, Denmark
Robert A. Samson 1
Centraalbureau voor Schimmelcultures, Utrecht, The Netherlands
 |
ABSTRACT |
|---|
 TOP ABSTRACT INTRODUCTIONMATERIALS AND METHODSRESULTSDISCUSSIONTAXONOMYLITERATURE CITED |
|---|
The variability within Aspergillus fumigatus Fresenius and related species was examined using macro-, micro-morphology, growth temperature regimes and extrolite patterns. In addition, DNA analyses including partial ß-tubulin, calmodulin and actin gene sequences were used. Detailed examination of strains, considered as A. fumigatus earlier, showed that they could be divided into four groups including A. fumigatus sensu stricto, A. lentulus and two new species. The intraspecific genetic variability within A. fumigatus sensu stricto was low, the sequence differences among 23 strains of the species was at most two bases in each partial ß-tubulin and calmodulin gene. However, intraspecific morphological diversity within the species was high and delineation of the species was equivocal. Therefore, ß-tubulin and calmodulin gene sequences could be critical determinants for the delineation of the A. fumigatus sensu stricto species. A. lentulus including isolates from clinical origin, Korean soil and from a dolphin clustered into an isolated group based on ß-tubulin, calmodulin and actin gene sequences, differing from A. fumigatus by morphological characters, growth temperature and extrolite profile. A. lentulus produces the extrolites auranthine, cyclopiazonic acid, a dimeric indole of unknown structure, neosartorin, some pyripyropens, terrein and some tryptoquivalins and tryptoquivalons. Two pair of isolates (CBS 117194, 117186 and 117520, 117519) clustered into separate groups from A. fumigatus and the other Aspergillus section Fumigati species, including the teleomorph Neosartorya, are proposed as two new species. A. fumigatiaffinis spec. nov. produces the extrolites auranthine, cycloechinulin, helvolic acid, neosartorin, palitantin, pyripyropens, tryptoquivalins and tryptoquivalons, and A. novofumigatus spec. nov. produces the extrolites cycloechinuline, helvolic acid, neosartorin, palitantin and terrein.
Key words: A. fumigatiaffinis, A. fumigatus, A. lentulus, A. novofumigatus, polyphasic taxonomy
|
INTRODUCTION |
|---|
|
TOPABSTRACTINTRODUCTIONMATERIALS AND METHODSRESULTSDISCUSSIONTAXONOMYLITERATURE CITED |
|---|
). A. fumigatus generally is regarded as an extremely variable species in cultural characteristics and micromorphology (Raper and Fennell 1965, Varshney and Sarbhoy 1981, Samson 1979) and 12 varieties were described. However, Frisvad and Samson (1990) found that A. fumigatus is a homogeneous species with respect to profiles of extrolites (for definition see Frisvad and Samson 2004). In addition no great variation was observed when A. fumigatus strains were analyzed by restriction fragment length polymorphism (RFLP) (Burnie et al 1992, Spreadbury et al 1993), amplified fragment polymorphism (Loudon et al 1993, Rinyu et al 1995) and mitochondrial cytochrome b gene sequence analysis (Wang et al 2000).
Recently, Aspergillus lentulus was reported from clinical isolates which were resistant to multiple antifungals (Balajee et al 2005). The species could be separated from A. fumigatus by phylogenetic analyses based on multilocus sequence typing. During a survey of soil-borne Aspergillus and Penicillium in Korea, A. lentulus and many other strains belonging to section Fumigati were isolated.
In this study, we performed a polyphasic analysis of A. fumigatus and related species in order to examine the variability within the species and determine taxonomical position of the strains. Each strain was studied by their macro- and micro- morphology, growth characters, extrolite profiles, ß-tubulin, calmodulin and actin gene sequences, and Random Amplified Polymorphic DNA (RAPD), which proved useful for Aspergillus taxonomy (Brandt et al 1998, Feibelman et al 1998, Geiser et al 1998, Ito et al 2001, Varga et al 2000a, b).
|
MATERIALS AND METHODS |
|---|
|
TOPABSTRACTINTRODUCTIONMATERIALS AND METHODSRESULTSDISCUSSIONTAXONOMYLITERATURE CITED |
|---|
). The strains were maintained on malt-extract agar slants at 15 C.
|
). The isolates were inoculated at three points and incubated at 25 C in the dark for 7 d and at 37 C on CYA. For micromorphology observations, microscopic mounts were made in lactic acid from MEA colonies. Growth rate was determined on MEA and CZA. Conidia from a 7–14 d incubation were mixed into semisolid medium (0.2% agar and 0.05%, Tween 80) and inoculated in 9 cm petri dishes. The plates were incubated in the dark at 10 to 55 C with intervals of 5 C and colony diam were measured after 5 and 7 d.
Conidial strains were mated on OA and MEA at 25 C for 28 d and also tested with the heterothallic strains of N. fennelliae, CBS 598.74T (MT A) and CBS 599.74T (MT a), N. udagawae CBS 114217T and CBS 114218T, and N. spathulata CBS 408.89T (MT A) and CBS 409.89T (MT a).
Extrolites were analysed by HPLC using alkylphenone retention indices and diode array UV-VIS detection as described by Frisvad and Thrane (1987), with minor modifications by Smedsgaard (1997). Standards of auranthine, fumagillin, fumigaclavine A and B, fumigatin, fumitremorgin A, B and C, verrucologen, TR-2, gliotoxin, helvolic acid, palitantin, pseurotin A, terrein, territrem B, trypacidin, nortryptoquivalin and tryptoquivalone were available, while the evidence for presence of aszonalenin, cycloechinuline, fiscalins, fumiquinazolins and neosartorin was based on highly characteristic UV spectra. The confirmation by mass spectrometry and/or structure elucidation is being currently investigated (Larsen, T.O. in prep).
DNA analyses.— –
Genomic DNA was extracted according to the procedure described by Lee and Taylor (1990). For the sequencing of partial ß-tubulin gene, the fragment of the 5' portion of ß-tubulin was amplified using the primer bt2a and bt2b (Glass and Donaldson 1995). For the sequencing of partial calmodulin gene, a segment of the calmodulin was amplified using the primers cmd5 (5'-CCG-AGT-ACA-AGG-AGG-CCT-TC-3') and cmd6 (5'-CCG-ATA-GAG-GTC-ATA-ACG-TGG-3') which were made in this study based on the complete A. oryzae sequence, GenBank D44468
[GenBank]
. For the sequencing of partial actin gene, a segment of the actin was amplified using the primers act-512F (5'-ATG-TGC-AAG-GCC-GGT-TTC-GC-3') and ACT-783R (5'-TAC-GAG-TCC-TTC-TGG-CCC-AT-3') (Carbone and Kohn 1999).
The amplified DNA fragments were purified by QIAquick PCR purification kit (Qiagene, Hilden, Germany). DNA sequences were determined using BigDye Terminator 3.1 Cycle Sequencing kit (ABI 0401041, Foster City, California) and the ABI 3100 DNA sequencer. Both strands of each fragment were sequenced.
DNA Sequences were edited with the DNASTAR computer package, and an alignment of the sequences was performed using the CLUSTAL W (Thompson et al 1994). Both the neighbor-joining (NJ) and maximum parsimony (MP) methods were used for the phylogenetic analysis. For NJ analysis, the data were first analyzed using the Tamura-Nei parameter distance calculation model, which was then used to construct the NJ tree with MEGA 3.0 (Kumar et al 2004). To determine the support for each clade, bootstrap analysis was performed with 1000 replications. Maximum parsimony analysis (Fitch 1971) was performed with heuristic search with random addition sequences, branch swapping by tree bisection-reconnection (TBR) and MAXTREES set at 20 000, using PAUP* 4b10 (Swofford 2002). Relative robustness of the individual branches was estimated by bootstrapping, using 1000 replicates, with heuristic searches, branch swapping by tree bisection-reconnection (TBR) and MAXTREES set at 100.
For the RAPD-PCR, six random primers were screened and PELF (5'-ATA-TCA-TCG-AAG-CCG-C-6') and URP1F (5'-ATC-CAA-GGT-CCG-AGA-CAA-CC-3') (Kang et al 2002) were selected because they produced many polymorphic bands. PCR was performed in 50 µL reactions, using 1.2 µL of template DNA, 3 µL of 2.5 mM dNTPs, 0.4 µL of taq polymerase (5 u/µL, Bioneer Korea) and 0.4 µL of primer (100 pmol/µL). PCR was performed using the following parameters: 4 min at 95 C, followed by 35 steps of 1 min at 95 C, 1 min at 55 C and 2 min at 72 C, and then a final 8 min at 72 C. The PCR products were electrophoresed on a 1.2% agarose gel.
|
RESULTS |
|---|
|
TOPABSTRACTINTRODUCTIONMATERIALS AND METHODSRESULTSDISCUSSIONTAXONOMYLITERATURE CITED |
|---|
The phylogenetic relationships of the ß-tubulin sequence for the 55 isolates were inferred from the neighbor-joining (NJ) analysis, and the tree produced is presented (FIG. 1). In maximum parsimony (MP) analysis, out of 465 total characters, 110 were parsimony-informative, and parsimony analysis resulted in 54 most parsimonious trees of 248 steps with a CI of 0.8145 and an RI of 0.9501. No difference was found between the tree topologies from the NJ and MP analyses.
|
The phylogenetic relationships of the calmodulin gene for the 51 isolates were inferred from both NJ and the MP analyses. Out of 527 total characters, 140 were parsimony-informative, and parsimony analysis resulted in two most parsimonious trees of 252 steps with a CI of 0.8254 and an RI of 0.9622. Because the topologies of the NJ and MP trees obtained by the distance and heuristic methods were almost identical except for minor differences in bootstrap values, only the NJ tree is presented (FIG. 2). The topology of the calmodulin tree was similar to that of the ß-tubulin tree.
|
). The topology of the actin tree was similar to that of the ß-tubulin.
|
). Twenty-five isolates of A. fumigatus sensu stricto showed similar band patterns to each other, although some isolates showed differences in minor bands. Five isolates from Korean soil and CBS 175.97 from a dolphin showed almost the same band patterns as the four clinical strains of A. lentulus. The band patterns of A. fumigatiaffinis and A. novofumigatus were quite different from that of A. lentulus.
|
All strains of A. fumigatus sensu stricto grew at 50 C but did not grow at 10 C on MEA and CZA. Strains of A. lentulus, A. fumigatiaffinis and A. novofumigatus grew or germinated at 10 C on MEA and CZA but did not grow at 50 C. The growth ratio of 25 C/45 C on MEA for A. fumigatus sensu stricto strains fell in the range of 0.5–1.1, whereas for the strains of A. lentulus, A. fumigatiaffinis and A. novofumigatus they were (0.6) 1.3–4.0, 1.2–1.9 and 1.1–1.6, respectively.
From the mating experiments, any matches within conidial strains and heterothallic strains of Neosartorya fennelliae, N. spathulata and N. udagawae did not produce any sexual structures.
Extrolite analyses.— –
In TABLE II, the extrolite profiles of A. fumigatus sensu stricto, A. lentulus and related species are listed. Strains of A. fumigatus sensu stricto produced fumagillin, fumitremorgins, fumiquinazolins, gliotoxin, pseurotins, trypacidin and verrucologen, which are absent in A. lentulus, A. fumigatiaffinis and A. novofumigatus. Strains of A. lentulus produced cyclopiazonic acid and dimeric indoles showing its uniqueness in Aspergillus section Fumigati, while auranthine was shared with A. fumigatiaffinis and fiscalins with A. novofumigatus. Neosartorin was produced by A. lentulus, A. fumigatiaffinis and A. novofumigatus, but not by A. fumigatus. Pyripyropens, tryptoquivalins and tryptoquivalons are produced by A. fumigatus, A. lentulus and A. novofumigatus. A. fumigatiaffinis and A. novofumigatus shared an unknown compound with a characteristic UV spectrum and cycloechinuline.
|
|
DISCUSSION |
|---|
|
TOPABSTRACTINTRODUCTIONMATERIALS AND METHODSRESULTSDISCUSSIONTAXONOMYLITERATURE CITED |
|---|
A. fumigatus sensu stricto.— –
Our molecular analyses show that A. fumigatus sensu stricto is a homogeneous taxon. The varieties of A. fumigatus vars ellipticus, acolumnaris, phialiseptus, and anomalus and an albino mutant have almost identical DNA sequences (at most two bases difference) in each partial ß-tubulin and calmodulin gene (FIGS. 1
, 2) and the same band patterns in RAPD (FIG. 4) confirming that these varieties are synonymous. This result confirms earlier findings based on extrolites profiles (Frisvad and Samson 1991), RFLP (Burnie et al 1992, Spreadbury et al 1990), amplified fragment polymorphism (Loudon et al 1993, Rinyu et al 1995) and mitochondrial cytochrome b gene sequence analysis (Wang et al 2000). The extype of A. fumigatus var. sclerotium CBS 458.75 could not be accommodated in the A. fumigatus clade but clustered with the A. viridinutans complex.
However, the examined strains of A. fumigatus exhibited variable macro- and micro-morphologies. Stipe widths of most strains of A. fumigatus sensu stricto were in the range of 6–8 µm but in some strains were up to 10 µm, while CBS 542.75 (T of A. phialiseptus) had narrower stipes, 4–5 µm. Vesicle diam of the strains ranged between 10 and 26 µm, with the exception of CBS 542.75 which were only 10–12 µm. The smaller dimensions in these particular strains may probably be caused by the more or less degenerated nature of the strain with a clinical origin. Although A. fumigatus is typically characterized by subclavate vesicles Raper and Fennell (1965), Varshney and Sarbhoy (1981) and Klich (2002) also included globose shaped vesicles in their descriptions. We have observed that (sub)globose vesicles in A. fumigatus sensu stricto are rare but common in A. lentulus and the two new species. Therefore, if a strain has predominantly globose shaped vesicles, it will probably not be A. fumigatus sensu stricto.
All strains of A. fumigatus sensu stricto did not grow at 10 C but grew at 50 C. Most A. fumigatus strains produced fumagillin, fumigaclavines, fumitremorgin A, B, C and TR-2, fumiquinazolins, gliotoxin, helvolic acid, pseurotins, pyripyropens, trypacidin, tryptoquivalins, tryptoquivalons and verrucologen consistent with literature data (Cole and Cox 1981).
Some morphological characteristics of A. fumigatus sensu stricto, are therefore diverse and equivocal, but molecular characteristics including ß-tubulin and calmodulin gene sequences, extrolite profile and growth temperature regimes were unique and clear, and their characters could be critical determinants for the delineation of A. fumigatus sensu stricto.
A. lentulus.— –
From the partial ß-tubulin, calmodulin and actin sequence analyses, A. lentulus is separated clearly from A. fumigatus sensu stricto with high bootstrap value (FIGS. 1–3). In RAPD pattern by PELF and URP1F, 10 strains of A. lentulus had almost the same bands differing from A. fumigatus sensu stricto and related species (FIG. 4).
In the phenotypic analyses, strains of A. lentulus differ from A. fumigatus sensu stricto by thinner stipes, smaller and predominantly globose vesicles. All strains of A. lentulus grew between 10–45 C on MEA and CZA, while A. fumigatus sensu stricto strains, in the range of 15–50 C. Furthermore, they clearly differed from A. fumigatus sensu stricto in extrolite profiles (TABLE II). A. lentulus strongly resembles A. fumigatiaffinis and A. novofumigatus based on phenotypic analyses, except for their extrolite profiles.
Balajee et al (2005) proposed A. lentulus for some clinical strains considered to be variants of A. fumigatus. The species has smaller conidial heads and was not able to grow at 48 C. From this study, five strains from crop-cultivated soil and one CBS strain (from a dolphin nostril, Netherlands) also belong to this species. In Korean soil, this species was frequently isolated from six out of 13 crop cultivated soils. A. lentulus also was isolated from Australia (strain MK245) (Balajee et al 2005), and therefore this species seems to have a wide geographical distribution and can be isolated from common sources such as soil and air.
A. lentulus originally was called a sibling species of A. fumigatus (Balajee et al 2005), but actually it is phenotypically very different from the latter species. Even though A. fumigatus share the tryptoquivalins, tryptoquivalons and pyripyropens with A. lentulus both species have an unusually large number of different families of extrolites: A. lentulus produces six extrolite families never detected in A. fumigatus (auranthine, cyclopiazonic acid, dimeric indoles, fiscalins, neosartorin, terrein), while A. fumigatus can produce more than nine extrolite families not yet discovered in A. lentulus (fumagillins, fumigaclavines, fumigatins, fumitremorgins, fumiquinazolins, gliotoxin, helvolic acid, pseurotins, and trypacidins). If all extrolite families are compared within the five species, the pair Neosartorya fischeri, A. fumigatus and the pair A. fumigatiaffinis and A. novofumigatus had most extrolite families in common (five), while A. lentulus and A. fumigatus have the least extrolite families in common (two), apart from A. novofumigatus and A. fumigatus having only one family in common. All other species/species comparison gave three to four extrolites families in common. We confirm the conclusions of Geiser et al (1998) that phylogenetic relationships based on DNA sequence data are not in agreement with phylogenies suggested by phenotypic features and especially not with phylogenies suggested by extrolites.
New species based on phylogenetic species recognition and distinct phenotypic features.— –
In our ß-tubulin, calmodulin and actin analysis two groups each with two strains were separated from A. fumigatus sensu stricto, A. lentulus and N. fischeri. Also in their extrolite profiles these taxa differ from A. fumigatus sensu stricto and A. lentulus (TABLE II). A. fumigatiaffinis (CBS 117194 and IBT 12703) has comparatively small (sub)globose vesicles (16–24 µm). A. novofumigatus (IBT16806 and IBT 16755) has nearly flask-shaped and comparatively large vesicles (15–30 µm); it was similar to A. fumigatus sensu stricto. On the temperature growth regimes, the two species grew on 10 C and did not grow on 50 C.
Although the two species strongly resemble A. lentulus, the three sequence data sets indicate genetic separation of other taxa in section Fumigati providing evidence of a distinct species under the phylogenetic species recognition concept (Taylor et al 2000). However, the species are also highly distinct concerning extrolite profiles, so other species concepts would also have supported the hypotheses that A. fumigatiaffinis and A. novofumigatus are new species. We propose to describe them here on the basis of different profiles of extrolites and sequence differences.
|
TAXONOMY |
|---|
|
TOPABSTRACTINTRODUCTIONMATERIALS AND METHODSRESULTSDISCUSSIONTAXONOMYLITERATURE CITED |
|---|
Coloniae, conidiophora et conidiophora A. fumigato similes sed coloniae floccosae, parce sporulantes. Conidiophora ex hyphis aeriis oriunda. Vesiculae praecipue globosae, 18–24 µm diam. Coloniae in agaro CYA dicto expansae, 48–65 mm diametro post 7 dies 25 C vel plus quam 70 mm post 7 dies 37 C. Exudantur auranthinum, cycloechinulinum, fumigaclavina, acidum helvolicum, neosartorinum, palitantinum, pyripyropena, tryptoquivalina, tryptoquivalona.
Typus. – CBS 117186 (lyophilized culture) (= KACC 41148 = IBT 12703), isolated from soil, Socorro County, Sevilleta National Wildlife Refuge, New Mexico, USA. Additional culture CBS 117194 = KACC 41176 = IBT 13131, isolated from Dipodomys spectabilis cheek pouch, Socorro County, Sevilleta National Wildlife Refuge, New Mexico, USA.
Colony growth, conidiophore structures and conidia resembling A. fumigatus but floccose with poor sporulation. Conidiophore structures arising from aerial mycelium. Vesicles predominantly globose 18–24 µm diam. Colonies on CYA spreading broadly, 48–65 mm diam in 7 d at 25 C or more than 70 mm in 7 d at 37 C.
Colonies on MEA growing rapidly, 55–65 mm in 7 d at 25 C. Colony texture is floccose and colonies are usually white with poor sporulation, but center, dull green with abundant conidia and raised. Reverse yellowish orange (4B6) to grayish orange (5B6). Colonies on CYA spreading broadly, 48–65 mm in 7 d at 25 C or more than 70 mm in 7 d at 37 C. Colony appearance of CYA is similar with that of MEA. Reverse yellowish white to pale yellow (3A2-3).
Conidial heads short columnar (conidial chains less than 10 sequences). Conidiophores arising from aerial hyphae, 6–8 µm wide at the middle. Vesicles globose to subglobose, 18–24 µm in diam. Aspergilla uniseriate, phialides 6–8 µm, covering the upper half of vesicle. Conidia, globose to subglobose, smooth, 2–3 µm. Extrolites: Auranthine, cycloechinuline, fumigaclavines, helvolic acid, neosartorin, palitantin, pyripyropens,, tryptoquivalins, tryptoquivalons.
Aspergillus novofumigatus S.B Hong, Frisvad & Samson, sp. nov. MB 500297
Coloniae, conidiophora et conidia A. fumigato similes. Coloniae in agaris CYA dicto et maltoso rapide crescentes, 48–65 mm diam post 7 dies 25 C, 70–80 mm 37 C. Conidiophororum stipites angustiores, 2–6 µm lati, vesiculis subglobosis vel subclavatis, (13–)15–30 µm diam. Exudantur indolalkaloidea apolaria et polyketidea, aszonaleninum, cycloechinulinum, fiscalina, acidum helvolicum, neosartorinum, palitantinum, terreinum.
Typus. – CBS 117520 (lyophilized culture) (= KACC 41934 = IBT 16806), isolated from soil, Ecuador. Additional culture CBS 117519 also isolated from soil in Ecuador.
Colony growth, conidiophore structures and conidia resembling A. fumigatus. Colonies on CYA and MEA growing rapidly 48–65 mm in diam at 25 C, and 70–80 mm in 7 d at 37 C. Conidiophore structures having smaller stipes of 2–6 µm diam with vesicles subglobose to subclavate (13) 15–30 µm diam. Extrolites: apolar indolalkaloids and polyketides, aszonalenin, cycloechinuline, fiscalins, helvolic acid, neosartorin, palitantin, terrein, territrem B. CBS 117519 showed a weaker extrolites profile but in addition produced territrem B, which was not found in CBS 117520.
Colonies on MEA growing rapidly, 48–52 mm in 7 d at 25 C. Deep green to gray green (25DE7-8) with abundant conidial heads in central area and white in margin. Reverse, grayish orange (5B6) to yellowish orange (4B6).
Colonies on CYA spreading broadly, attaining diam of 48–65 mm in 7 d at 25 C or more than 70 mm in 7 d at 37 C. Deep green to gray green (25DE7-8) with abundant conidial heads in central area and white in marginal area, radially sulcate. Reverse yellow to orange yellow (3-4A7-8).
Conidial heads short columnar to compactly columnar. Conidiophores arising from aerial hyphae, 4–7 µm wide at the middle. Vesicles subglobose to flask shape (13)15–30 µm in diam. Aspergillus uniseriate, phialides 6–9 µm, covering the upper half of vesicle. Conidia broadly ellipsoidal to ellipsoidal, smooth 2.5–3 µm. Extrolites: apolar indolalkaloids, apolar unknown polyketide, aszonalenin, cycloechinuline, fiscalins, helvolic acid, neosartorin, palitantin, terrein and territrem B in CBS 117519.
|
|
|
FOOTNOTES |
|---|
1 Corresponding author. E-mail: samson{at}cbs.knaw.nl
|
LITERATURE CITED |
|---|
|
TOPABSTRACTINTRODUCTIONMATERIALS AND METHODSRESULTSDISCUSSIONTAXONOMYLITERATURE CITED |
|---|
Brandt ME, Padhye AA, Mayer LW, Holloway BP. 1998. Utility of Random amplified polymorphic DNA PCR and TaqMan automated detection in molecular identification of Aspergillus fumigatus. J Clin Microbiol 36:2057–2062.
Burnie JP, Coke A, Matthews RC. 1992. Restriction endonuclease analysis of Aspergillus fumigatus DNA. J Clin Pathol 45:324–327.
Carbone I, Kohn LM. 1999. A method for designing primer sets for speciation studies in filamentous ascomycetes. Mycologia 91:553–556.[CrossRef]
Cole RJ, Cox RH. 1981. Handbook of toxic fungal metabolites. Academic Press, New York.
Feibelman TP, Cotty PJ, Doster MA, Michailides TJ. 1998. A morphologically distinct strain of Aspergillus nomius. Mycologia 90:618–623.[CrossRef]
Fitch WM. 1971. Towards defining the course of evolution: minimum change for a specific tree topology. Syst Zool 20:406–416.[CrossRef]
Frisvad JC, Samson RA. 1990. Chemotaxonomy and morphology of Aspergillus fumigatus and related taxa. In: Samson RA, Pitt JI. eds. Modern concepts in Penicillium and Aspergillus classification. Plenum Press, New York. p 201–208.
———, ———. 2004. Polyphasic taxonomy of Penicillium subgenus Penicillium. A guide to identification of food and air-borne terverticillate Penicillia and their mycotoxins. Studies in Mycology 49:1–173.
———, Thrane U. 1987. Standardized high-performance liquid chromatography of 182 mycotoxins and other fungal metabolites based on alkylphenone indices and UV-VIS spectra (diode-array detection). J Chromatogr A 404:195–214.[CrossRef]
Geiser DM, Frisvad JC, Taylor JW. 1998. Evolutionary relationships in Aspergillus section Fumigati inferred from partial ß-tubulin and hydrophobin DNA sequences. Mycologia 90:831–845.[CrossRef]
Glass NL, Donaldson GC. 1995. Development of primer sets designed for use with the PCR to amplify conserved genes from filamentous ascomycetes. Appl Environ Microbiol 61:1323–1330.[Abstract]
Ito Y, Peterson SW, Wicklow DT, Goto T. 2001. Aspergillus pseudotamarii, a new aflatoxin producing species in Aspergillus section Flavi. Mycol Res 105: 233–239.[CrossRef]
Kang H-W, Park D-S, Go S-J, Eun M-Y. 2002. Fingerprinting of diverse genomes using PCR with universal rice primers generated from repetitive sequence of Korean weedy rice. Mol Cells 13:281–287.[Medline]
Klich MA. 2002. Aspergillus fumigatus. In: Identification of common Aspergillus species. Centraalbureau voor Schimmelcultures, Utrecht, The Netherlands. p 50–51.
Kornerup A, Wanscher JH. 1978. Methuen handbook of colour, 3rd ed. London: Eyre Methuen.
Kumar S, Tamura K, Nei M. 2004. MEGA3: Integrated software for Molecular Evolutionary Genetics Analysis and sequence alignment. Briefings in Bioinformatics 5:150–163.
Lee SB, Taylor JW. 1990. Isolation of DNA from fungal mycelia and single spores. In: Innis MA, Gelfand DH, Sninsky JJ, White TJ. eds. PCR protocols, a guide to methods and applications. San Diego: Academic Press. p 282–287.
Loudon KW, Burnie JP, Coke AP, Matthew RC. 1993. Application of polymerase chain reaction to fingerprinting Aspergillus fumigatus by random amplification of polymorphic DNA. J Clin Microbiol 31:1117–1121.
Raper KB, Fennell DI. 1965. Aspergillus fumigatus group. In: The genus Aspergillus. Baltimore, Maryland: Williams and Wilkins. p 238–268.
Rinyu E, Varga J, Ferenczy L. 1995. Phenotypic and genotypic analysis of variability in Aspergills fumigatus. J Clin Microbiol 33:2567–2575.[Abstract]
Samson RA. 1979. A compilation of the Aspergilli described since 1965. Studies in Mycology 18:1–38.
Smedsgaard J. 1997. Micro-scale extraction procedure for standardized screening of fungal metabolite production in cultures. J Chromatogr A 760:264–270.[CrossRef][Medline]
Spreadbury C, Holden D, Aufauvre-Brown A, Bainbridge B, Coben J. 1993. Detection of Aspergillus fumigatus by polymerase chain reaction. J Clin Microbiol 31: 615–621.
Swofford DL. 2002. PAUP*: phylogenetic analysis using parsimony (*and other methods). Version 4b10. Sunderland, Massachusetts: Sinauer Associates.
Taylor JW, Jacobson DJ, Kroken S, Kasuga T, Geiser DM, Hibbett DS, Fisher MC. 2000. Phylogenetic species recognition and species concepts in fungi. Fungal Genet Biol 31:21–32.[CrossRef][Medline]
Thompson JD, Higgins DG, Gibson TJ. 1994. CLUSTAL W: improving the sensitivity of progressive multiple sequence alignment through sequence weighting, position specific gap penalties and weight matrix choice. Nucl Acids Res 22:4673–4680.
Varga J, Toth B, Rigo K, Debets F, Kozakiewicz Z. 2000a. Genetic variability within the Aspergillus viridinutans species. Folia Microbiol 45:423–428.[CrossRef]
———, Vida Z, Toth B, Debets F, Horie Y. 2000b. Phylogenetic analysis of newly described Neosartorya species. Antonie van Leeuwenhoek 77:235–239.[CrossRef][Medline]
Varshney JL, Sarbhoy AK. 1981. A new species of Aspergillus fumigatus group and comments upon its synonymy. Mycopathologia 73:89–92.[CrossRef][Medline]
Wang L, Uokoyama K, Miyaji M, Nishimura K. 2000. Mitochondrial cytochrome b gene analysis of Aspergillus fumigatus and related species. J Clin Microbiol 38:1352–1358.
This article has been cited by other articles:
 |
|
 |
|
  J.-I. Han and K.-J. Na Dermatitis Caused by Neosartorya hiratsukae Infection in a Hedgehog J. Clin. Microbiol., September 1, 2008; 46(9): 3119 - 3123. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 J. Varga, J. Houbraken, H. A. L. Van Der Lee, P. E. Verweij, and R. A. Samson Aspergillus calidoustus sp. nov., Causative Agent of Human Infections Previously Assigned to Aspergillus ustus Eukaryot. Cell, April 1, 2008; 7(4): 630 - 638. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 J. Houbraken, J. Varga, E. Rico-Munoz, S. Johnson, and R. A. Samson Sexual Reproduction as the Cause of Heat Resistance in the Food Spoilage Fungus Byssochlamys spectabilis (Anamorph Paecilomyces variotii) Appl. Envir. Microbiol., March 1, 2008; 74(5): 1613 - 1619. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 S. W. Peterson Phylogenetic analysis of Aspergillus species using DNA sequences from four loci Mycologia, March 1, 2008; 100(2): 205 - 226. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
S. A. Balajee, S. T. Tay, B. A. Lasker, S. F. Hurst, and A. P. Rooney Characterization of a Novel Gene for Strain Typing Reveals Substructuring of Aspergillus fumigatus across North America Eukaryot. Cell, August 1, 2007; 6(8): 1392 - 1399. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 D.M. Geiser, M.A. Klich, J.C. Frisvad, S.W. Peterson, J. Varga, and R.A. Samson The current status of species recognition and identification in Aspergillus Stud Mycol, January 1, 2007; 59(1): 1 - 10. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
S.A. Balajee, J. Houbraken, P.E. Verweij, S-B. Hong, T. Yaghuchi, J. Varga, and R.A. Samson Aspergillus species identification in the clinical setting Stud Mycol, January 1, 2007; 59(1): 39 - 46. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J. Varga, M. Due, J.C. Frisvad, and R.A. Samson Taxonomic revision of Aspergillus section Clavati based on molecular, morphological and physiological data Stud Mycol, January 1, 2007; 59(1): 89 - 106. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J. Houbraken, M. Due, J. Varga, M. Meijer, J.C. Frisvad, and R.A. Samson Polyphasic taxonomy of Aspergillus section Usti Stud Mycol, January 1, 2007; 59(1): 107 - 128. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
R.A. Samson, S. Hong, S.W. Peterson, J.C. Frisvad, and J. Varga Polyphasic taxonomy of Aspergillus section Fumigati and its teleomorph Neosartorya Stud Mycol, January 1, 2007; 59(1): 147 - 203. [Abstract] [Full Text] [PDF]
|
|
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
