Emericellaquadrilineataas Cause of Invasive Aspergillosis

Abstract

We noted a cluster of 4 cases of infection or colonization by Emericella spp., identifi ed by sequence-based analysis as E. quadrilineata. Sequence-based analysis of an international collection of 33 Emericella isolates identifi ed 12 as E. nidulans, all 12 of which had previously been identifi ed by morphologic methods as E. nidulans. For 12 isolates classifi ed as E. quadrilineata, only 6 had been previously identifi ed 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 identifi cation is more accurate than morphologic examination for identifying Emericella spp. and that correct species demarcation and in vitro susceptibility testing may affect patient management.T he genus Aspergillus includes >250 species; ≈20 have been reported to cause opportunistic infections in humans. The most important human pathogens in this genus are A. fumigatus, A. fl avus, A. niger, A. terreus, and Emericella nidulans (anamorph: A. nidulans) (1). A. fumigatus is the most common cause of invasive aspergillosis, a condition associated with substantial severity and mortality rates (2). Invasive infections caused by E. nidulans are uncommon in animals and humans (3-5); in humans they appear to occur predominantly in patients who have chronic granulomatous disease (CGD), a rare disorder of phagocytes in which the absence of both superoxide and hydrogen peroxide production in phagocytes predisposes patients to bacterial and fungal infections. Invasive E. nidulans infections in this patient group are associated with higher mortality rates than those caused by A. fumigatus (6,7). The most common site of infection is the lungs; other manifestations are subcutaneous abscesses or liver abscesses, suppurative adenitis, osteomyelitis, fungemia, cellulitis, and meningitis (7,8). Within the genus Emericella, other species have only rarely been identifi ed as agents of human or animal infections.The identifi cation of E. nidulans in clinical microbiology laboratories is commonly based on the characteristic microscopic morphology, the production of hülle cells, or the production of ascospores. A. fumigatus is identifi ed by its heat tolerance; other species fail to grow when incubated at high temperature, typically 48°C.We recently noted a cluster of infection or colonization by E. quadrilineata, a species closely related to E. nidulans. Within a 3-month period, 4 cases were identifi ed at the Radboud University Nijmegen Medical Center. No apparent epidemiologic link between the cases was found because each patient was cared for in a different ward, and 2 patients with invasive aspergillosis were admitted directly from home. One of the latter 2 patients was a 10-year-old boy with X-linked CGD and a probable diagnosis of invasive pulmonary aspergillosis (9); the other patient was a 60-year-old man...

Development of a Clinically Comprehensive Database and a Simple Procedure for Identification of Molds from Solid Media by Matrix-Assisted Laser Desorption Ionization–Time of Flight Mass Spectrometry

“…(3) 3 (100) NA Trichoderma viridae (1) 1 (100) NA Trichophyton rubrum (5) 5 (100) (24) and organisms that are genetically distinct from morphologically similar species. Several reports of mistaken identities have drawn attention (1)(2)(3)25) because these masquerading molds are often refractory to antifungal agents (6,24,25). Correct identification is therefore imperative for appropriate disease management.…”

“…In July 2012, Bruker launched a separate library for the identification of molds grown in liquid media (23) that must be purchased separately from the primary library. Retrospective analysis against this expanded library (obtained post- (2) 2 (100) 0 (0) 2 (100) Ascomycete 1 (100) NA Aspergillus aculeatus (4) 4 (100) NA Aspergillus flavipes (1) 1 (100) NA Aspergillus flavus (10) 10 (100) 0 (0) 0 (0) Aspergillus fumigatus (50) 50 (100) 3 (6) 16 (323) Aspergillus nidulans (5) 5 (100) NA Aspergillus niger (6) 6 (100) 0 (0) 1 (16.7) Aspergillus ochraceus (1) 1 (100) NA Aspergillus oryzae (2) 2 (100) 0 (0) 0 (0) Aspergillus sclerotiorum (2) 2 (100) NA Aspergillus sp. (1) 1 (100) NA Aspergillus sydowii (8) 8 (100) NA Aspergillus terreus (9) 9 (100) 0 (0) 0 (0) Aspergillus tubingensis (2) 2 (100) NA Aspergillus ustus (11) 11 (100) NA Aspergillus uvarum (1) 1 (100) NA Aspergillus versicolor (11) 9 (81.8) 2 (18.2) 0 (0) 1 (9) Aspergillus viridinutans (2) 2 (100) NA Aspergillus westerdijkiae (3) 3 (100) NA Basidiomycete (37) 11 (29.7) 1 (2.7) NA Chaetomium globosum (1) 1 (100) 0 (0) 0 (0) Cladophialophora sp.…”

“…This decade alone has seen the emergence of numerous new species and species complexes, many of which (i) are resistant to antifungals or display atypical susceptibility profiles or (ii) are phenotypically similar but genetically and possibly pathogenically different from their counterparts (1)(2)(3)(4)(5)(6). Such factors have complicated the accuracy of traditional phenotypic mold identification, compelling laboratories, where possible, to adopt methods such as DNA sequencing or matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) to enhance discriminatory power.…”

Aspergillus tanneri sp. nov., a New Pathogen That Causes Invasive Disease Refractory to Antifungal Therapy

“…The most common fungal infection encountered by CGD patients is invasive aspergillosis (IA), and the disease has been the most important cause of mortality in these patients (9,23,42). The genus Aspergillus contains over 200 species (15) (9,17,30,(37)(38)(39). Among these, A. fumigatus is by far the most common cause of IA, followed by A. nidulans, while the remaining seven species have been reported as a cause of IA only rarely (4,9,10,17,30,38,39).…”

“…For example, most strains of A. fumigatus are considered susceptible to amphotericin B, triazoles, and caspofungin (40), while a morphologically similar and phylogenetically related species, A. udagawae, has higher resistance to these antifungals and tends to cause refractory infection (39). Aspergillus nidulans is reported to be more resistant to amphotericin B but more susceptible to caspofungin than the similar-appearing and phylogenetically related species A. quadrilineatus (37). Correct identification of Aspergillus species, therefore, is essential for appropriate disease management.…”