Hand sanitizers – do they really work?
Published: September 8th, 2009
Revised: September 11th, 2009
Everywhere you turn of late, it seems you’re confronted with a bottle of hand sanitizer. Most sanitizers are alcohol-based, and destroy microorganisms by disrupting their cell membranes or protein coats. Although these materials have been available for some years, only recently have they enjoyed such widespread use and stirred so much discussion. U of T Experience Research asked Professor James Scott whether and how these products work.
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Reusable grocery bags
Published: September 1st, 2009
Revised: October 4th, 2009
The use of reusable food containers and carry devices for groceries is an important, to date overlooked piece in the study of the safety of the food supply in Canada. There has been little to no testing to investigate the public health implications of reusable bags, yet increasingly reusables are being advanced as a viable substitute for first-use or single use packaging/ containers. The food service sector has been particularly concerned about the use of reusables. In conjunction with the Plastics Council of Canada, we evaluated an independently collected pilot data set of microbiological tests on reusable bags. Our findings demonstrated a clear need for more study of microbiological risks and the need for clear usage guidelines as programs supporting reusable carrier bags become increasingly advocated in waste reduction strategies. Our findings garnered wide attention, resulting ultimately in the issuance of a HEALTH CANADA ADVISORY and substantial news coverage including an in-depth article by the FRASER INSTITUTE.
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MICROBE magazine features Baudoinia
Published: August 4th, 2009
Revised: September 11th, 2009
The March 2009 issue of MICROBE magazine, the news publication of the prestigious American Society for Microbiology, included a feature article by noted international science writer and former editor of Nature Biotechnology, Dr. Bernard Dixon, summarizing our recent work on the newly described, ethanol-loving fungal genus Baudoinia.
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Trehalose accumulation in Baudoinia compniacensis
Published: May 19th, 2009
Revised: August 4th, 2009
Abstract
Baudoinia compniacensis is a microfungus recently described as the principal agent of fouling known as “warehouse staining”, affecting building exteriors, fixtures and vegetation surfaces in areas proximate to distillery aging warehouses, commercial bakeries and other areas subject to low-level ethanol vapour exposure. The surfaces most affected tend to be highly exposed and undergo extreme diurnal temperature fluctuations. In previous work, we have demonstrated the existence of heat-inducible putative chaperone proteins that may also be induced by low-level exposures to ethanol vapour (e.g., <10 ppm). The present study investigated the cellular accumulation of trehalose, a disaccharide identified in some microorganisms to be important in the protection of cell components during adverse stress conditions, such as thermal stress. Following heat shock at 45 °C, we observed a 2.5-fold accumulation of trehalose relative to unheated controls maintained at 26 °C. Peak trehalose concentrations of 10 mg/g dry wt were seen at 90 min after heat treatment, followed by a gradual return to post-treatment by 150 min. Exposure of B. compniacensis cells to ethanol resulted in a similar increased accumulation of trehalose compared to unexposed controls. These findings imply that trehalose may be important in the tolerance of this fungus to abiotic stresses, such as heat and solvent exposure, and suggest future research directions for the control and prevention of warehouse staining.
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Indoor environment survey of Penicillium brevicompactum and P. bialowiezense
Published: June 23rd, 2008
Revised: August 4th, 2009
Abstract
We investigated the diversity of the Penicillium brevicompactum Dierckx group in dust from 54 houses in Wallaceburg, Ontario, Canada. Two taxa were predominant, P. brevicompactum and Pencillium bialowiezense Zaleski, accounting for 88.6% and 5.4% of the sample set, respectively. We further characterized multilocus haplotypes of iso- lates by characterizing three polymorphic genetic loci, β-tubulin (benA), histone 4 (his4A), and the internal transcribed spacer regions of ribosomal DNA (nucITS) amplified by PCR amplification and screened using heteroduplex mobility assay (HMA). Eight unique haplotypes were observed in P. brevicompactum s. str., and two in P. bialowiezense, both with a distribution characteristic of a predominantly clonal reproduction mode. Phylogenetic analysis of the β-tubulin and nucITS loci were carried out for members of the P. brevicompactum group, including ex-type material, that revealed three well-supported lineages corresponding to P. brevicompactum, P. bialowiezense (=Penicillium biourgeianum Zaleski), and Penicillium neocrassum R. Serra & S.W. Peterson. The mycophilic nature of many isolates of P. bialowiezense, and some isolates of P. brevicompactum, suggests that observation of members of the P. brevicompactum group in indoor environments may predict extensive and longterm fungal colonization. We also address some nomenclatural problems in the group and epitypify P. bialowiezense.
