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Emericella quadrilineata as cause of invasive aspergillosis.

Verweij PE, Varga J, Houbraken J, Rijs AJ, Verduynlunel FM, Blijlevens NM, Shea YR, Holland SM, Warris A, Melchers WJ, Samson RA - Emerging Infect. Dis. (2008)

Bottom Line: We noted a cluster of 4 cases of infection or colonization by Emericella spp., identified by sequence-based analysis as E. quadrilineata.For 12 isolates classified as E. quadrilineata, only 6 had been previously identified accordingly.These data indicate that sequence-based identification is more accurate than morphologic examination for identifying Emericella spp. and that correct species demarcation and in vitro susceptibility testing may affect patient management.

View Article: PubMed Central - PubMed

Affiliation: Radboud University Nijmegen Medical Center, Nijmegen, the Netherlands. p.verweij@mmb.umcn.nl

ABSTRACT
We noted a cluster of 4 cases of infection or colonization by Emericella spp., identified by sequence-based analysis as E. quadrilineata. Sequence-based analysis of an international collection of 33 Emericella isolates identified 12 as E. nidulans, all 12 of which had previously been identified by morphologic methods as E. nidulans. For 12 isolates classified as E. quadrilineata, only 6 had been previously identified accordingly. E. nidulans was less susceptible than E. quadrilineata to amphotericin B (median MICs 2.5 and 0.5 mg/L, respectively, p<0.05); E. quadrilineata was less susceptible than E. nidulans to caspofungin (median MICs, 1.83 and 0.32 mg/L, respectively, p<0.05). These data indicate that sequence-based identification is more accurate than morphologic examination for identifying Emericella spp. and that correct species demarcation and in vitro susceptibility testing may affect patient management.

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Neighbor-joining tree based on calmodulin sequence data of Emericella isolates examined. Clinical isolates are set in boldface. Numbers above branches are bootstrap values. Only values >70% are indicated. T indicates the type strain; * indicates the isolates that had been misidentified by morphologic identification as E. nidulans. Scale bar represents genetic distance calculated by the Kimura 2-parameter model (18).
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Figure 2: Neighbor-joining tree based on calmodulin sequence data of Emericella isolates examined. Clinical isolates are set in boldface. Numbers above branches are bootstrap values. Only values >70% are indicated. T indicates the type strain; * indicates the isolates that had been misidentified by morphologic identification as E. nidulans. Scale bar represents genetic distance calculated by the Kimura 2-parameter model (18).

Mentions: During analysis of part of partial β-tubulin gene sequences, we analyzed 367 bases of all 33 isolates. Among the polymorphic sites, 23 were phylogenetically informative. The neighbor-joining tree (Figure 1) based on partial β-tubulin gene sequences had the same topologic features as 1 of the 2 maximum-parsimony trees constructed by the PAUP program (length 94 steps, consistency index 0.9787, retention index 0.9762). The calmodulin dataset included 489 bases, with 50 parsimony informative sites. The topologic features of the neighbor-joining tree (Figure 2) and 1 of the 2 most parsimonious trees were the same (tree length 162, consistency index 0.9691, retention index 0.9854). Molecular data indicated that 12 of 33 isolates could be classified as E. nidulans, all of which had previously been identified as E. nidulans by microscopic examination of morphologic characteristics or other methods. For the 12 isolates classified as E. quadrilineata, only 6 had previously been identified accordingly. These 6 isolates included the 4 in our cluster, 1 from the CBS culture collection, and 1 previously reported as the cause of onychomycosis (12). The remaining 6 isolates had been previously identified as E. nidulans (online Appendix, available from www.cdc.gov/EID/content/14/4/566-appT.htm). Of these, 1 belonged to the CBS culture collection, 1 was reported as the cause of cerebral aspergillosis (11), and 2 were from patients with CGD and confirmed invasive aspergillosis.


Emericella quadrilineata as cause of invasive aspergillosis.

Verweij PE, Varga J, Houbraken J, Rijs AJ, Verduynlunel FM, Blijlevens NM, Shea YR, Holland SM, Warris A, Melchers WJ, Samson RA - Emerging Infect. Dis. (2008)

Neighbor-joining tree based on calmodulin sequence data of Emericella isolates examined. Clinical isolates are set in boldface. Numbers above branches are bootstrap values. Only values >70% are indicated. T indicates the type strain; * indicates the isolates that had been misidentified by morphologic identification as E. nidulans. Scale bar represents genetic distance calculated by the Kimura 2-parameter model (18).
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2570940&req=5

Figure 2: Neighbor-joining tree based on calmodulin sequence data of Emericella isolates examined. Clinical isolates are set in boldface. Numbers above branches are bootstrap values. Only values >70% are indicated. T indicates the type strain; * indicates the isolates that had been misidentified by morphologic identification as E. nidulans. Scale bar represents genetic distance calculated by the Kimura 2-parameter model (18).
Mentions: During analysis of part of partial β-tubulin gene sequences, we analyzed 367 bases of all 33 isolates. Among the polymorphic sites, 23 were phylogenetically informative. The neighbor-joining tree (Figure 1) based on partial β-tubulin gene sequences had the same topologic features as 1 of the 2 maximum-parsimony trees constructed by the PAUP program (length 94 steps, consistency index 0.9787, retention index 0.9762). The calmodulin dataset included 489 bases, with 50 parsimony informative sites. The topologic features of the neighbor-joining tree (Figure 2) and 1 of the 2 most parsimonious trees were the same (tree length 162, consistency index 0.9691, retention index 0.9854). Molecular data indicated that 12 of 33 isolates could be classified as E. nidulans, all of which had previously been identified as E. nidulans by microscopic examination of morphologic characteristics or other methods. For the 12 isolates classified as E. quadrilineata, only 6 had previously been identified accordingly. These 6 isolates included the 4 in our cluster, 1 from the CBS culture collection, and 1 previously reported as the cause of onychomycosis (12). The remaining 6 isolates had been previously identified as E. nidulans (online Appendix, available from www.cdc.gov/EID/content/14/4/566-appT.htm). Of these, 1 belonged to the CBS culture collection, 1 was reported as the cause of cerebral aspergillosis (11), and 2 were from patients with CGD and confirmed invasive aspergillosis.

Bottom Line: We noted a cluster of 4 cases of infection or colonization by Emericella spp., identified by sequence-based analysis as E. quadrilineata.For 12 isolates classified as E. quadrilineata, only 6 had been previously identified accordingly.These data indicate that sequence-based identification is more accurate than morphologic examination for identifying Emericella spp. and that correct species demarcation and in vitro susceptibility testing may affect patient management.

View Article: PubMed Central - PubMed

Affiliation: Radboud University Nijmegen Medical Center, Nijmegen, the Netherlands. p.verweij@mmb.umcn.nl

ABSTRACT
We noted a cluster of 4 cases of infection or colonization by Emericella spp., identified by sequence-based analysis as E. quadrilineata. Sequence-based analysis of an international collection of 33 Emericella isolates identified 12 as E. nidulans, all 12 of which had previously been identified by morphologic methods as E. nidulans. For 12 isolates classified as E. quadrilineata, only 6 had been previously identified accordingly. E. nidulans was less susceptible than E. quadrilineata to amphotericin B (median MICs 2.5 and 0.5 mg/L, respectively, p<0.05); E. quadrilineata was less susceptible than E. nidulans to caspofungin (median MICs, 1.83 and 0.32 mg/L, respectively, p<0.05). These data indicate that sequence-based identification is more accurate than morphologic examination for identifying Emericella spp. and that correct species demarcation and in vitro susceptibility testing may affect patient management.

Show MeSH
Related in: MedlinePlus