Short-Term Effect of Pollen and Spore Exposure on Allergy Morbidity in the Brussels-Capital Region

Belgium is among the European countries that are the most affected by allergic rhinitis. Pollen grains and fungal spores represent important triggers of symptoms. However, few studies have investigated their real link with disease morbidity over several years. Based on aeroallergen counts and health insurance datasets, the relationship between daily changes in pollen, fungal spore concentrations and daily changes in reimbursable systemic antihistamine sales has been investigated between 2005 and 2011 in the Brussels-Capital Region. A Generalized Linear Model was used and adjusted for air pollution, meteorological conditions, flu, seasonal component and day of the week. We observed an augmentation in drug sales despite no significant increase in allergen levels in the long term. The relative risk of buying allergy medications associated with an interquartile augmentation in pollen distributions increased significantly for Poaceae, Betula, Carpinus, Fraxinus and Quercus. Poaceae affected the widest age group and led to the highest increase of risk which reached 1.13 (95% CI [1.11–1.14]) among the 19- to 39-year-old men. Betula showed the second most consistent relationship across age groups. Clear identification of the provoking agents may improve disease management by customizing prevention programmes. This work also opens several research perspectives related to impact of climate modification or subpopulation sensitivity.     

Toward a Novel Multilocus Phylogenetic Taxonomy for the Dermatophytes

Type and reference strains of members of the onygenalean family Arthrodermataceae have been sequenced for rDNA ITS and partial LSU, the ribosomal 60S protein, and fragments of β-tubulin and translation elongation factor 3. The resulting phylogenetic trees showed a large degree of correspondence, and topologies matched those of earlier published phylogenies demonstrating that the phylogenetic representation of dermatophytes and dermatophyte-like fungi has reached an acceptable level of stability. All trees showed Trichophyton to be polyphyletic. In the present paper, Trichophyton is restricted to mainly the derived clade, resulting in classification of nearly all anthropophilic dermatophytes in Trichophyton and Epidermophyton, along with some zoophilic species that regularly infect humans. Microsporum is restricted to some species around M. canis, while the geophilic species and zoophilic species that are more remote from the human sphere are divided over Arthroderma, Lophophyton and Nannizzia. A new genus Guarromyces is proposed for Keratinomyces ceretanicus. Thirteen new combinations are proposed; in an overview of all described species it is noted that the largest number of novelties was introduced during the decades 1920–1940, when morphological characters were used in addition to clinical features. Species are neo- or epi-typified where necessary, which was the case in Arthroderma curreyi, Epidermophyton floccosum, Lophophyton gallinae, Trichophyton equinum, T. mentagrophytes, T. quinckeanum, T. schoenleinii, T. soudanense, and T. verrucosum. In the newly proposed taxonomy, Trichophyton contains 16 species, Epidermophyton one species, Nannizzia 9 species, Microsporum 3 species, Lophophyton 1 species, Arthroderma 21 species and Ctenomyces 1 species, but more detailed studies remain needed to establish species borderlines. Each species now has a single valid name. Two new genera are introduced: Guarromyces and Paraphyton. The number of genera has increased, but species that are relevant to routine diagnostics now belong to smaller groups, which enhances their identification.     

Updating the Taxonomy of Dermatophytes of the BCCM/IHEM Collection According to the New Standard: A Phylogenetic Approach

Recent taxonomical revisions based on multilocus gene sequencing have provided some clarifications to dermatophyte (Arthrodermataceae) family tree. These changes promoted us to investigate the impact of the changed nomenclature of the dermatophyte strains in the BCCM/IHEM fungal collection, which contains strains of all dermatophyte genera except for Ctenomyces. For 688 strains from this collection, both internal transcribed spacer region (ITS) and partial β-tubulin (BT) sequences were aligned and a multilocus phylogenetic tree was constructed. The ITS?+?BT phylogentic tree was able to distinguish the genera Arthroderma, Lophophyton, Microsporum, Paraphyton, Nannizzia and Trichophyton with high certainty. Epidermophyton, which is widely considered as a well-defined genus with E. floccosum as the only representative, fell within the Nannizzia clade, whereas the phylogenetic analysis, based on the ITS region alone, differentiates Epidermophyton from Nannizzia as a separate genus. Re-identification and reclassification of many strains in the collection have had a profound impact on the composition of the BCCM/IHEM dermatophyte collection. The biggest change is the decline of prevalence of Arthroderma strains; starting with 103 strains, only 22 strains remain in the genus after reassessment. Most Arthroderma strains were reclassified into Trichophyton, with A. benhamiae and A. vanbreuseghemii leaving the genus. The amount of Microsporum strains also dropped significantly with most of these strains being reclassified into the genera Paraphyton and Nannizzia.

     

Lineages Within the Trichophyton rubrum Complex

The most important species of the Trichophyton rubrum group are T. rubrum, causing mainly skin and nail infections, and T. violaceum which is mostly scalp-associated. The status of a third species, T. soudanense, has been under debate. With a polyphasic approach, using molecular phylogenetic techniques, MALDI-TOF mass spectrometry and physiological and morphological analysis, we re-evaluated the T. rubrum complex. Our results support four genetic lineages within the complex each with a distinct morphology and identifiable via MALDI-TOF MS: T. rubrum, T. violaceum, T. soudanense and the T. yaoundei clade. However, ITS and Bt2 sequencing data could not confirm these taxa as four monophyletic species. Our results also suggest that strains formerly identified as T. kuryangei and T. megninii should be considered in future taxonomic studies.

     

KLHL12-mediated ubiquitination of the dopamine D4 receptor does not target the receptor for degradation

In previous studies, we identified KLHL12 as a novel interaction partner of the dopamine D4 receptor that functions as an adaptor in a Cullin3-based E3 ubiquitin ligase complex to target the receptor for ubiquitination. In this study, we show that KLHL12 promotes poly-ubiquitination of the receptor by performing ubiquitination assays in eukaryotic cells. Furthermore, we demonstrate that KLHL12 not only interacts with both immature, ER-associated and mature, plasma membrane-associated D4 receptors, but also promotes ubiquitination of both receptor subpools. Unexpectedly, however, KLHL12-mediated receptor ubiquitination does not promote proteasomal degradation of newly synthesized receptors through the ER-associated degradation pathway or lysosomal degradation of mature receptors. Moreover, our data reveal that D4 receptors do not undergo agonist-promoted ubiquitination or degradation, in contrast to many other G-protein-coupled receptors (GPCRs) indicating that ubiquitination of GPCRs does not defaultly lead to receptor degradation. Interestingly, KLHL12 does also interact with β-arrestin2 but this has no effect on the ubiquitination or localization of β-arrestin2 nor on the internalization of the D4 receptor.     

Thirty-four years of pollen monitoring: an evaluation of the temporal variation of pollen seasons in Belgium

For the first time in Belgium, fluctuations in airborne pollen quantities over a 34 years period have been analyzed. Seven pollen types have been selected comprising the most clinically relevant in Belgium nowadays (birch, alder, hazel and grasses) and others that are known to be allergenic in other European countries and frequently found in Belgium (plane, ash and mugwort). Pollen monitoring was performed with a seven-day recording volumetric spore trap placed in Brussels. We measured increasing airborne pollen for four trees, namely alder, hazel, ash and plane. Although the total pollen index for birch has not increased significantly, an increasing trend in the annual amount of days above the concentration threshold of 80 pollen grains/m³ was clearly observed. Concerning temporal variations, the pollen season has tended to end earlier for birch, ash and plane and the peak concentration of the pollen of plane has been appearing earlier in the year. In the investigated period, the pollen seasons of grasses and mugwort have tended to become less severe. Furthermore, we reported a temporal shift of the grass pollen season, beginning and ending earlier, together with an advance of the annual peak date.