Heteromultivalent Ligand Display on Reversible Self-Assembled Monolayers (rSAMs): A Fluidic Platform for Tunable Influenza Virus Recognition

We report on the design of heteromultivalent influenza A virus (IAV) receptors based on reversible self-assembled monolayers (SAMs) featuring two distinct mobile ligands. The principal layer building blocks consist of α-(4-amidinophenoxy)alkanes decorated at the ω-position with sialic acid (SA) and the neuraminidase inhibitor Zanamivir (Zan), acting as two mobile ligands binding to the complementary receptors hemagglutinin (HA) and neuraminidase (NA) on the virus surface. From ternary amphiphile mixtures comprising these ligands, the amidines spontaneously self-assemble on top of carboxylic acid-terminated SAMs to form reversible mixed monolayers (rSAMs) that are easily tunable with respect to the ligand ratio. We show that this results in the ability to construct surfaces featuring a very strong affinity for the surface proteins and specific virus subtypes. Hence, an rSAM prepared from solutions containing 15% SA and 10% Zan showed an exceptionally high affinity and selectivity for the avian IAV H7N9 (Kd = 11 fM) that strongly exceeded the affinity for other subtypes (H3N2, H5N1, H1N1). Changing the SA/Zan ratio resulted in changes in the relative preference between the four tested subtypes, suggesting this to be a key parameter for rapid adjustments of both virus affinity and selectivity.

Detection of SARS-CoV-2 in the sewerage system in Tunisia: a promising tool to confront COVID-19 pandemic

Aim: The current study undertaken in Tunisia examines the use of wastewaters to monitor SARS-CoV-2 circulation. Materials & methods: Viral genetic materials collected in wastewaters during two different periods (September-October 2020 and February-April 2021) were concentrated using the adsorption-elution method. SARS-CoV-2 genes were researched by real-time PCR. Results: During the first period of the study, viral RNA was detected in 61.11% of the analyzed samples collected from Monastir city with a rate of 88.88% for raw wastewaters and 33.33% for treated wastewaters. Then, during the second period of the study, the quantitative analysis of wastewaters collected from seven governorates showed the presence of viral RNA among around 25% of them with variable RNA loads. The increased amounts of viral RNA detected in wastewaters were accompanied by an increase in the number of COVID-19 patients in Tunisia. Conclusion: Our results emphasize the importance of sewage survey in SARS-CoV-2 tracking.

Diversity of West Nile and Usutu virus strains in mosquitoes at an international airport in Austria

Increased globalization and international transportation have resulted in the inadvertent introduction of exotic mosquitoes and new mosquito‐borne diseases. International airports are among the possible points of entry for mosquitoes and their pathogens. We established a mosquito and mosquito‐borne diseases monitoring programme at the largest international airport in Austria and report the results for the first two years, 2018 and 2019. This included weekly monitoring and sampling of adult mosquitoes, and screening them for the presence of viral nucleic acids by standard molecular diagnostic techniques. Additionally, we surveyed the avian community at the airport, as birds are potentially amplifying hosts. In 2018, West Nile virus (WNV) was detected in 14 pools and Usutu virus (USUV) was detected in another 14 pools of mosquitoes (minimum infection rate [MIR] of 6.8 for each virus). Of these 28 pools, 26 consisted of female Culex pipiens/torrentium, and two contained male Culex sp. mosquitoes. Cx. pipiens/torrentium mosquitoes were the most frequently captured mosquito species at the airport. The detected WNV strains belonged to five sub‐clusters within the sub‐lineage 2d‐1, and all detected USUV strains were grouped to at least seven sub‐clusters among the cluster Europe 2; all strains were previously shown to be endemic in Austria. In 2019, all mosquito pools were negative for any viral nucleic acids tested. Our study suggests that airports may serve as foci of arbovirus activity, particularly during epidemic years, and should be considered when designing mosquito control and arbovirus monitoring programmes.

Honey Bee Queens and Virus Infections

The honey bee queen is the central hub of a colony to produce eggs and release pheromones to maintain social cohesion. Among many environmental stresses, viruses are a major concern to compromise the queen's health and reproductive vigor. Viruses have evolved numerous strategies to infect queens either via vertical transmission from the queens' parents or horizontally through the worker and drones with which she is in contact during development, while mating, and in the reproductive period in the colony. Over 30 viruses have been discovered from honey bees but only few studies exist on the pathogenicity and direct impact of viruses on the queen's phenotype. An apparent lack of virus symptoms and practical problems are partly to blame for the lack of studies, and we hope to stimulate new research and methodological approaches. To illustrate the problems, we describe a study on sublethal effects of Israeli Acute Paralysis Virus (IAPV) that led to inconclusive results. We conclude by discussing the most crucial methodological considerations and novel approaches for studying the interactions between honey bee viruses and their interactions with queen health.