Spectrum of Clinically Relevant Acremonium Species in the United States

Abstract

Some species in the polyphyletic fungal genus Acremonium are important opportunist pathogens. Determining the actual spectrum of species and their incidence in the clinical setting, however, has long been hampered because of the difficulties encountered in phenotypic species-level identification. The goal of this study was to re-identify a large number of clinical isolates morphologically and to confirm the identifications by comparing sequences of the internal transcribed spacer region of the rRNA gene of these isolates to those of type or reference strains of well-known Acremonium species. Of the 119 isolates referred to a United States reference laboratory under the name Acremonium, only 75 were identified morphologically as belonging to that genus. The remainder (44 isolates) were identified as belonging to other morphologically similar genera. The Acremonium clinical isolates were related to species of Hypocreales, Sordariales, and of an incertae sedis family of ascomycetes, Plectosphaerellaceae. A total of 50 of the 75 Acremonium isolates (67%) could be identified by molecular means, the prevalent species being Acremonium kiliense (15 isolates), A. sclerotigenum-A. egyptiacum (11 isolates), A. implicatum (7 isolates), A. persicinum (7 isolates), and A. atrogriseum (4 isolates). One of the most interesting findings of our study was that we identified several species among this large collection of clinical isolates that had not previously been reported from human infections, and we failed to confirm other Acremonium species, such as A. potronii, A. recifei, and A. strictum, that had been considered significant. The most common anatomic sites for Acremonium isolates were the respiratory tract (41.3%), nails (10.7%), and the eye (9.3%). Antifungal susceptibility testing demonstrated high MICs for all agents tested, except for terbinafine. Since numerous isolates could not be identified, we concluded that the list of opportunistic Acremonium species is far from be complete and that a considerable number of additional species will be discovered.

Domestic laundering: Environmental audit in Glasgow with emphasis on passive indoor drying and air quality

“…In this vein, research in West Virginia [55] cautions "allergen content in fungal extracts is highly variable" [56], with variability in particular species such as Alternaria alternata, Aspergillus fumigatus and Cladosporium herbarum [57]. It also found 6% sensitivity to Acremonium strictum, where all patients in a clinic "had symptoms consistent with allergic rhinitis or asthma"; while another USA study failed to confirm Acremonium strictum as significant [58].…”

A case report of pregnant female with right eye acremonium keratitis

“…Limitations makes this method difficult. 5 Therefore, this report also has the limitation that acremonium species was not confirmed via the DNA-based method. Acremonium can be easily isolated on modified Sabouraud's dextrose agar at a temperature of 25°C-37°C (optimum 30°C).…”

“…Acremonium is a large polyphyletic fungal genus that comprises approximately 150 species, most of them being sap-robes in soil and pathogens of plants. 5 In most cases, acremonium is diagnosed with microscopic morphology. To confirm acremonium species, deoxyribonucleic acid (DNA)-based method is essential but technical problems like no defined reference sequence and cost and time.…”

Acremonium Potronii Associated Pneumonia in an Allogeneic Stem Cell Transplantation Recipient

“…Acremonium species present low susceptibility to most antifungals including imidazoles, fluorocytosine and amphotericin B. Voriconazole treatment was shown to be succesful in some cases. However, the appropriate treatment for Acremonium spp infections is currently undetermined (7,10). As Acremonium spp grow slowly, cultures should be kept for at least 2 weeks to ensure detection of a positive sample (8).…”

“…However, patients may remain susceptible to opportunistic infections for an extended period in the post-transplant course due to the slow recovery of T cell immunity (3)(4)(5). Disseminated Acremonium infections are rare with the reported cases limited to immunocompromised patients with a large clinical spectrum including pneumonia, arthritis, osteomyelitis, endocarditis, peritonitis, meningitis and sepsis (6)(7)(8)(9)(10).…”