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Toronto, Canada

Savory E.,University of Western Ontario | Sabarinathan J.,University of Western Ontario | Sauer A.,University of Western Ontario | Scott J.A.,University of Toronto | Scott J.A.,Sporometrics Inc.
Building and Environment | Year: 2012

The growth of mould in the indoor environment is an important contributor to the development and exacerbation of atopic disease, and potentially poses other health risks. Moreover, the detection and elimination of mould have resulted in massive remedial expenditures, often without clear engineering knowledge of the nature of the moisture events that led to the damage, especially for residential light wood-frame construction. Relatively little research has considered such failure of the building enclosure as a starting point for developing practical, evidence-based construction practices to improve building performance. One research limitation concerns the use of invasive or destructive testing as the sole means to monitor mould growth in concealed assemblies, such as wall cavities, making it difficult or impossible to conduct time-course experiments to assess the performance of different materials and designs. The present paper concerns the development and testing of a new optoelectronic sensor capable of non-invasive monitoring of mould growth in concealed spaces in real-time by measuring changes in light reflectance from the sensor's active element, a membrane impregnated with mould spores. It builds upon an earlier concept [1] in which mould-impregnated cellophane coupons were attached to building surfaces, then removed and examined periodically for growth by microscopy. The new device incorporates computer-controlled measurement of mould growth, in response to the environmental conditions and, thus, functions as a remote sensor. Although primarily intended for research use, the device has the potential to be used as a post-remediation monitoring device to provide early-warning of any re-occurrence of mould growth. © 2011 Elsevier Ltd. Source

Kantarcioglu A.S.,Istanbul University | Summerbell R.C.,Centraalbureau voor Schimmelcultures | Summerbell R.C.,Sporometrics Inc. | Sutton D.A.,University of Texas at San Antonio | And 3 more authors.
Medical Mycology | Year: 2010

Fusarium species are hyaline hyphomycetes widely distributed in nature and documented agents of both superficial and systemic infections in humans. In this paper, we report a darkly-pigmented and initially non-sporulating isolate in the Fusarium solani species complex (FSSC) causing a post-traumatic sporotrichoid infection in an otherwise healthy, male patient. Sequencing of multiple loci showed that the isolate represented an otherwise unknown lineage, possibly corresponding to a separate species, within the multi-species F. solani complex. In prolonged culture, the non-sporulating isolate produced revertant wild-type subcultures with typical Fusarium conidiation. This suggests that the original dense, dark, non-sporulating isolate was a host-adapted form selected in vivo for characters compatible with human pathogenicity. The production of such forms by Fusarium species is increasingly recognized now that sequencing has allowed the identification of highly atypical isolates. In vitro antifungal susceptibility of the isolate was investigated against seven conventional and two newly approved antifungal agents. The isolate showed in vitro resistance to amphotericin B, but appeared susceptible to itraconazole and terbinafine. A cure was ultimately achieved with combined terbinafine/itraconazole therapy with prolonged itraconazole follow-up therapy. © 2010 ISHAM. Source

Perdomo H.,Rovira i Virgili University | Sutton D.A.,University of Texas Health Science Center at San Antonio | Garcia D.,Rovira i Virgili University | Fothergill A.W.,University of Texas Health Science Center at San Antonio | And 6 more authors.
Journal of Clinical Microbiology | Year: 2011

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. Copyright © 2011, American Society for Microbiology. All Rights Reserved. Source

Sigler L.,University of Alberta | Sutton D.A.,University of Texas Health Science Center at San Antonio | Gibas C.F.C.,University of Alberta | Summerbell R.C.,Sporometrics Inc. | And 2 more authors.
Medical Mycology | Year: 2010

Anamorphic members of the ascomycete family Trichocomaceae including Aspergillus, Penicillium, Paecilomyces, Geosmithia and Sagenomella have been reported from infections in canines. Six clinical isolates (five associated with infections in canines and one from a human source) demonstrated simple phialides producing conidia in long chains and were investigated for their potential relationship to Sagenomella chlamydospora, a known agent of canine disseminated mycosis. Phylogenetic analyses of internal transcribed spacer (ITS) and small subunit (SSU) region sequences revealed that all of the canine-associated isolates were distinct from Sagenomella species. The new anamorphic genus and species Phialosimplex caninus is described to accommodate the clinical isolates. Sagenomella chlamydospora and Sagenomella sclerotialis are transferred to the new genus as Phialosimplex chlamydosporus comb. nov. and Phialosimplex sclerotialis comb. nov. © 2010 ISHAM. Source

Perdomo H.,Rovira i Virgili University | Sutton D.A.,University of Texas Health Science Center at San Antonio | Garcia D.,Rovira i Virgili University | Fothergill A.W.,University of Texas Health Science Center at San Antonio | And 6 more authors.
Journal of Clinical Microbiology | Year: 2011

Several members of the fungal genera Phialemonium and Lecythophora are occasional agents of severe human and animal infections. These species are difficult to identify, and relatively little is known about their frequency in the clinical setting. The objective of this study was to characterize morphologically and molecularly, on the basis of the analysis of large-subunit ribosomal DNA sequences, a set of 68 clinical isolates presumed to belong to these genera. A total of 59 isolates were determined to be Phialemonium species (n = 32) or a related Cephalotheca species (n = 6) or Lecythophora species (n = 20) or a related Coniochaeta species (n = 1). Nine isolates identified to be Acremonium spp. or Phaeoacremonium spp. were excluded from further study. The most common species were Phialemonium obovatum and Phialemonium curvatum, followed by Lecythophora hoffmannii, Cephalotheca foveolata, and Lecythophora mutabilis. Copyright © 2011, American Society for Microbiology. Source

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