Fast and accurate identification of dermatophytes by matrix-assisted laser desorption ionization-time of flight mass spectrometry: validation in the clinical laboratory.

The performance of a matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) workflow using an extensive reference database for dermatophyte identification was evaluated on 176 clinical strains. Using a direct-deposit procedure after 3 incubation days yielded 40% correct identification. Both increasing incubation time and using an extraction procedure resulted in 100% correct identification.

The role of indoor pollution in the development and maintenance of chronic airway inflammation in children.

Air pollution is one of the great problems of this century and it plays an important role in the increasing prevalence of chronic inflammatory problems in the upper airway in children. Since their lungs and immune system are not fully developed when exposure begins, newborns and children appear to be more sensitive to the effects of both outdoor and indoor air pollution. Furthermore, children spend most of their time indoors and are exposed more often to pollutants in indoor air. The link between health problems, chemical products and allergens (the latter mainly from cats and mites) has been extensively studied. Other important indoor contaminants are fungi, which are often present in damp buildings and can cause severe respiratory disease by producing spores, allergens, volatile irritant compounds and toxins. A proper identification of mould contamination of this kind is vital for correct diagnosis, treatment and the prevention of health problems, and improvements have been observed after the removal or cleaning of the contaminated materials and improvements to the ventilation of buildings. While a possible association between respiratory symptoms, such as rhinitis, and the presence of fungi in the indoor environment has been documented by several authors, other studies have observed no significant relationship. The development of standardised sampling, detection and diagnostic tests will be essential to understand the proper role of fungi in the indoor atmosphere and their impact on public health.

Genetic re-identification and antifungal susceptibility testing of Aspergillus section Nigri strains of the BCCM/IHEM collection.

Black Aspergilli are widely distributed in the environment and are frequently reported as causative agents of different types of mycoses. Many taxonomical revisions have been made, and presently 19 different species are accepted. In this study we (re-) identified 123 strains of the Aspergillus niger group of the BCCM/IHEM collection to check for the presence of species other than A. niger in both environmental and clinical samples. The susceptibility for antifungal drugs was compared between A. niger and Aspergillus tubingensis. Strains were identified based on morphological and molecular data and neighbour joining analysis. We revealed the presence of eight different species of this group in our collection. Our results suggest that Aspergillus foetidus, previously shown to be a species closely related to A. niger should not be considered as a separate species, but rather as a variety of A. niger. Furthermore, we found A. tubingensis at the same prevalence than A. niger in clinical samples. Interestingly, A. niger was shown to have a twofold higher sensitivity to treatment with voriconazole and itraconazole than A. tubingensis. These findings underline once more the importance of correct identification up to the species level in clinical isolates.

Bloodstream yeast infections: a 15-month survey.

A 15-month survey of 412 bloodstream yeast isolates from 54 Belgian hospitals was undertaken. Candida albicans was the most common species (47.3%) followed by C. glabrata (25.7%), C. parapsilosis (8.0%), C. tropicalis (6.8%) and Saccharomyces cerevisiae (5.1%). Common predisposing factors were antibacterial therapy (45%), hospitalization in intensive care units (34%), presence of in-dwelling catheters (32%), underlying cancer (23%) and major surgery (11%). Most patients had more than one predisposing factor. Fluconazole alone or in combination with another antifungal agent was the treatment of choice for 86.6% of the cases. Susceptibility testing revealed that 93.5% were susceptible to amphotericin B, 39.6% to itraconazole, 42.8% to fluconazole and 87% to voriconazole. Resistance to azoles was more common among C. glabrata isolates.

Trichophyton mentagrophytes of rabbit origin causing family incidence of kerion: an environmental study.

Our laboratory was contacted by a family living directly above a rabbit farm. Both their children had developed a kerion, in consequence of a misdiagnosed superficial mycosis. This study was designed to demonstrate a link between the two kerion cases and the environmental contamination. The degree of contamination was estimated and factors favourising the spread of infection were determined. Dermatophytes were isolated from various environmental sites using Rodac plates. For direct sampling of scalp and fur the brushing technique was used. The farm and home environment initially showed a severe contamination by Trichophyton mentagrophytes. At the farm, cages and surfaces covered with rabbit hair were strongly contaminated. As for the home environment, the dog's basket and clothes from the mother carried a large number of spores. Trichophyton mentagrophytes was identified as responsible agent for the children's kerions and the lesions of the rabbits. Mother, eldest child and dog seemed to be excellent carriers. Cleaning and disinfection measures resulted in a reduction of the overall contamination. The home environment was no longer a source of contamination. Nevertheless, on the farm a fair number of dermatophytes could still be isolated from the wire meshes and roof beams covered with fluff.

Responses in the start of Betula (birch) pollen seasons to recent changes in spring temperatures across Europe.

A shift in the timing of birch pollen seasons is important because it is well known to be a significant aeroallergen, especially in NW Europe where it is a notable cause of hay fever and pollen-related asthma. The research reported in this paper aims to investigate temporal patterns in the start dates of Betula (birch) pollen seasons at selected sites across Europe. In particular it investigates relationships between the changes in start dates and changes in spring temperatures over approximately the last 20 years. Daily birch pollen counts were used from Kevo, Turku, London, Brussels, Zurich and Vienna, for the core period from 1982 to 1999 and, in some cases, from 1970 to 2000. The sites represent a range of biogeographical situations from just within the Arctic Circle through to North West Maritime and Continental Europe. Pollen samples were taken with Hirst-type volumetric spore traps. Weather data were obtained from the sites nearest to the pollen traps. The timing of birch pollen seasons is known to depend mostly on a non-linear balance between the winter chilling required to break dormancy, and spring temperatures. Pollen start dates and monthly mean temperatures for January through to May were compiled to 5-year running means to examine trends. The start dates for the next 10 years were calculated from regression equations for each site, on the speculative basis that the current trends would continue. The analyses show regional contrasts. Kevo shows a marked trend towards cooler springs and later starts. If this continues the mean start date will become about 6 days later over the next 10 years. Turku exhibits cyclic patterns in start dates. A current trend towards earlier starts is expected to continue until 2007, followed by another fluctuation. London, Brussels, Zurich and Vienna show very similar patterns in the trends towards earlier start dates. If the trend continues the mean start dates at these sites will advance by about 6 days over the next 10 years. Following this work, amendments will be needed to pollen calendars and local predictive models. It will also be important to assess the implications of earlier seasons for allergy sufferers.

Fungal contamination of the floors of swimming pools, particularly subtropical swimming paradises.

We compared the level of dermatophyte contamination of the floors of traditional swimming pools and of subtropical swimming paradises, a new type of indoor swimming pool introduced in Belgium in 1981. From the results of routine hygiene inspections over several years and of a comparative study, we can conclude that the floors of subtropical swimming pools are much more highly contaminated by dermatophytes than the floors of traditional swimming pools. This higher degree of contamination is due to the huge number of visitors, the complexity of construction, the choice of materials and the long opening hours. In both types of swimming pools, the predominant species was Trichophyton mentagrophytes var. interdigitale, followed by T. rubrum. Other dermatophytes, such as Microsporum canis and M. gypseum, were isolated sporadically.