Phenological analysis of grasses (Poaceae) as a support for the dissection of their pollen season in Perugia (Central Italy)

New biomolecular tools for aerobiological monitoring: Identification of major allergenic Poaceae species through fast real‐time PCR

“…On the other hand, all the four species were present consistently in samples collected between May 30 and June 12, coinciding with the period of maximum pollen emission, just after the peak, registered on May 28. Late season samples (July 18–24, August 8–14, August 22–28) showed a legit absence of the species, as in the considered area, this period is commonly dominated by non‐Pooideae grasses, such as Cynodon , Digitaria , Setaria, and Echinocloa species (Ghitarrini, Tedeschini, et al., ). Overall results suggest that, until the DNA extraction protocol for aerobiological daily mixed samples is not optimized, the extraction on weekly basis ensures a higher amount and better representativeness of the templates for qualitative identification at species level.…”

“…Presence/absence of the species was evaluated (Table —only qualitatively), but the pattern of appearance along the grass pollen season was not always clear. For example, it is not likely to find flowering P. pratense at the beginning of May, or F. arundinacea and D. glomerata at the end beginning of July, in Central Italy (Frenguelli et al., ; Ghitarrini, Tedeschini, et al., ), even if phenomena of transport from other latitudes and/or resuspension after deposition could be involved. Sometimes species were detected in a half of the sample and not in the other (e.g., May 8, June 30), and this can indicate low efficiency of extraction and/or of detection.…”

“…Species to be investigated were selected based on the information on their richness in allergens (Hrabina et al., ) and on their distribution in the area of Perugia (Frenguelli et al., ; Ghitarrini, Tedeschini, et al., ). They were as follows: Dactylis glomerata L. (orchard grass, Figure ), Lolium perenne L. (perennial ryegrass), Poa pratensis L. (Kentucky bluegrass), Festuca arundinacea L. (tall fescue), and Phleum pratense L. (Timothy grass).…”

“…The aim of this study was to assess a simple biomolecular procedure, applicable on routine basis, to identify grass species in aerobiological samples with higher resolution respect to microscope pollen counts. We identified a subset of Poaceae species among the most widespread in the area of Perugia (Central Italy) (Ghitarrini, Tedeschini, et al., ), all belonging to the Pooideae subfamily and highly allergenic, and exploited their DNA sequence to design fast real‐time PCR protocols to verify their presence in different types of aerobiological real samples. The application of such techniques could integrate classic aerobiological monitoring data and help the “decomposition” of the cumulative grass pollination curve that usually represents a sum of the pollens released contemporarily by different species, which cannot be discriminated.…”

“…Several scientists have investigated the importance of grass pollen as outdoor aeroallergen, focusing on the mechanisms of patient sensitization and therapies (Durham et al, 1999;Moreira et al, 2015;Tripodi et al, 2012), relationship between grains/allergens concentration and symptoms (Annesi-Maesano et al, 2012;Erbas et al, 2012;Feo Brito et al, 2010), patterns of emission (Emberlin et al, 2000;Fernández Rodríguez et al, 2014;Galán, Emberlin, Domínguez, Bryant, & Villamandos, 1995;Ghitarrini, Galán, Frenguelli, & Tedeschini, 2017;Sánchez-Mesa et al, 2003), and influence of meteorological factors on the pollen season timing and intensity (García-Mozo, Mestre, & Galán, 2010;Ghitarrini, Tedeschini, Timorato, & Frenguelli, 2017;Smith et al, 2009;Zhang et al, 2015). The grasses that mostly contribute to the airborne pollen load vary spatially, but those responsible for grass pollinosis are essentially included into a group of about 20 species, principally belonging to the subfamily Pooideae.…”