The rapid spread of SARS-COV-2 Omicron variant in Italy reflected early through wastewater surveillance

The SARS-CoV-2 Omicron variant emerged in South Africa in November 2021, and has later been identified worldwide, raising serious concerns. A real-time RT-PCR assay was designed for the rapid screening of the Omicron variant, targeting characteristic mutations of the spike gene. The assay was used to test 737 sewage samples collected throughout Italy (19/21 Regions) between 11 November and 25 December 2021, with the aim of assessing the spread of the Omicron variant in the country. Positive samples were also tested with a real-time RT-PCR developed by the European Commission, Joint Research Centre (JRC), and through nested RT-PCR followed by Sanger sequencing. Overall, 115 samples tested positive for Omicron SARS-CoV-2 variant. The first occurrence was detected on 7 December, in Veneto, North Italy. Later on, the variant spread extremely fast in three weeks, with prevalence of positive wastewater samples rising from 1.0% (1/104 samples) in the week 5-11 December, to 17.5% (25/143 samples) in the week 12-18, to 65.9% (89/135 samples) in the week 19-25, in line with the increase in cases of infection with the Omicron variant observed during December in Italy. Similarly, the number of Regions/Autonomous Provinces in which the variant was detected increased from one in the first week, to 11 in the second, and to 17 in the last one. The presence of the Omicron variant was confirmed by the JRC real-time RT-PCR in 79.1% (91/115) of the positive samples, and by Sanger sequencing in 66% (64/97) of PCR amplicons. In conclusion, we designed an RT-qPCR assay capable to detect the Omicron variant, which can be successfully used for the purpose of wastewater-based epidemiology. We also described the history of the introduction and diffusion of the Omicron variant in the Italian population and territory, confirming the effectiveness of sewage monitoring as a powerful surveillance tool

Floral anatomy, micromorphology and visitor insects in three species of Aristolochia L. (Aristolochiaceae)

The genus Aristolochia L. has a specialised pollination system based on flowers that represent traps for insects. The floral anatomy and micromorphology of the perianth were studied to detect structural characters and secretory cells that are essential for the pollination and reproduction in A. esperanzae, A. fimbriata and A. triangularis. Additionally, we identified the insects collected inside the flowers in natural populations of the north of Argentina. Our observations indicate the presence of osmophores in the limbs of A. esperanzae and A. triangularis, and in the tube of A. fimbriata, because in this last species the fimbriae probably play the first optical attraction role. The papillose cells and epicuticular waxes in the limbs and tube entrances, particularly in A. esperanzae and A. fimbriata, ensure that insects slip into the tube, and the nonsecretory conical hairs of the tube, when turgid, guide the insects to the utricle. Idioblasts on the abaxial surfaces of the tubes andutricles were observed in A. esperanzae and A. fimbrita, and probably represent ethereal oil cells that protect flowers from predation. Secretion of sugar was confirmed on all internal surfaces of the utricle in the three species, and was more abundant at the entrance. The insects were diverse species of Diptera (Sarcophagidae, Muscidae, Ulidiidae, Drosophilidae and Anthomyiidae) and Coleoptera (Staphylinidae), although pollen loads on the body were only detected on specimens of Ulidiidae and Sarcophagidae.Fil: Aliscioni, Sandra Silvina. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Botánica Darwinion. Academia Nacional de Ciencias Exactas, Físicas y Naturales. Instituto de Botánica Darwinion; Argentina. Universidad de Buenos Aires. Facultad de Agronomía. Cátedra de Botánica General; ArgentinaFil: Achler, Andrea Paula. Universidad de Buenos Aires. Facultad de Agronomía. Cátedra de Botánica General; ArgentinaFil: Torretta, Juan Pablo. Universidad de Buenos Aires. Facultad de Agronomía. Cátedra de Botánica General; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin