da Silva, M. A. N. | bioRxiv Science

bioRxiv2023

Synanthropic Culicidae (Diptera) in three fragments of Atlantic Forest in northern Parana, Brazil.

Synanthropic Culicidae were sampled using natural and artificial traps in three forest fragments (Daher Wood, Botanical Garden, and Mata dos Godoy State Park) in Londrina, Parana, Brazil. To collect Culicidae, six traps were distributed in two separate transects of 70 m each, parallel, with a distance between them of 30 m. Three traps were natural (bamboo) and the other three were artificial (tires). In total, we collected 15,048 specimens distributed in eight species. The peri-urban fragments showed the highest richness. Tires were preferred as breeding sites. The seasons of highest and lowest sampling were summer and winter. The Daher Wood and Botanical Garden showed high similarity, and the Godoy Wood, an intact environment, showed the greatest dominance. The mosquitoes demonstrated varying degrees of synanthropy. Correlations were positive between temperature (0.53) and precipitation (0.40) with Culicid abundance. The Principal Component Analysis indicated that tires were most influenced by temperature, relative humidity, and bamboos by Total Dissolved Solids. Four of the collected species showed potential to be vectors of etiological agents. Abiotic factors directly influence the biology of mosquitoes, which is reflected in higher diversity in warmer and rainy periods. Urban and peri-urban areas showed more synanthropic mosquitoes due to their preference for modified sites. Vector species in these areas are of concern because they can modify disease cycles, and for this reason, it is essential to monitor these areas.

zoology↗

bioRxiv2021

Unlike Chloroquine, mefloquine inhibits SARS-CoV-2 infection in physiologically relevant cells and does not induce viral variants.

Repositioning of clinical approved drugs could represent the fastest way to identify therapeutic options during public health emergencies, the majority of drugs explored for repurposing as antivirals for 2019 coronavirus disease (COVID-19) have failed to demonstrate clinical benefit. Without specific antivirals, the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic continues to cause major global mortality. Antimalarial drugs, such as chloroquine (CQ)/hydroxychloroquine (HCQ) and mefloquine have emerged as potential anti-SARS-CoV-2 antivirals. CQ/HCQ entered the Solidarity and RECOVERY clinical trials against COVID-19 and showed lack of efficacy. Importantly, mefloquine is not a 4-aminoquinoline like CQ and HCQ and has been previously repurposed for other respiratory diseases. Unlike the 4-aminoquinolines that accumulate in the high pH of intracellular lysosomes of the lung, the high respiratory tract penetration of mefloquine is driven by its high lipophilicity. While CQ and HCQ exhibit activity in Vero E6 cells, their activity is obviated in TMPRSS2-expressing cells, such as Calu-3 cells, which more accurately recapitulate in vivo entry mechanisms for SARS-CoV-2. Accordingly, here we report the anti-SARS-CoV-2 activity of mefloquine in Calu-3 type II pneumocytes and primary human monocytes. Mefloquine inhibited SARS-CoV-2 replication in Calu-3 cells with low cytotoxicity and EC50 and EC90 values of 1.2 and 5.3 {micro}M, respectively. In addition, mefloquine reduced up to 68% the SARS-CoV-2 RNA levels in infected monocytes, reducing viral-induced inflammation. Mefloquine blocked early steps of the SARS-CoV-2 replicative cycle and was less prone than CQ to induce drug-associated viral mutations and synergized with RNA polymerase inhibitor. The pharmacological parameters of mefloquine are consistent with its plasma exposure in humans and its tissue-to-plasma predicted coefficient points that this drug may accumulate in the lungs. These data indicate that mefloquine could represent an orally available clinically approved drug option against COVID-19 and should not be neglected on the basis of the failure of CQ and HCQ.

microbiology↗