bioRxiv Science⌕ Search

Biology subjects

DeLiberto, T.

Publications and source records attributed to DeLiberto, T..

2 recordsLinked to original sources

SARS-CoV-2 exposure in Norwegian rats (Rattus norvegicus) from New York City

Millions of Norway rats (Rattus norvegicus)inhabit New York City (NYC), presenting the potential for transmission of SARS-CoV-2 from humans to rats and other wildlife. We evaluated SARS-CoV-2 exposure among 79 rats captured from NYC during the fall of 2021. Results showed that 13 of 79 rats (16.5%) tested IgG or IgM positive, and partial genomes of SARS-CoV-2 were recovered from four rats that were qRT-PCR positive. Using a virus challenge study, we also showed that Alpha, Delta, and Omicron variants can cause robust infections in wild-type Sprague Dawley (SD) rats, including high level replications in the upper and lower respiratory tracts and induction of both innate and adaptive immune responses. Additionally, the Delta variant resulted in the highest infectivity. In summary, our results indicated that rats are susceptible to infection with Alpha, Delta, and Omicron variants, and rats in the NYC municipal sewer systems have been exposed to SARS-CoV-2. Our findings highlight the potential risk of secondary zoonotic transmission from urban rats and the need for further monitoring of SARS-CoV-2 in those populations. ImportanceSince its emergence causing the COVID-19 pandemic, the host tropism expansion of SARS-CoV-2 raises a potential risk for reverse-zoonotic transmission of emerging variants into rodent species, including wild rat species. In this study, we presented both genetic and serological evidence for SARS-CoV-2 exposure in wild rat population from New York City, and these viruses are potentially linked to the viruses during the early stages of the pandemic. We also demonstrated that rats are susceptible to additional variants (i.e., Alpha, Delta, and Omicron) predominant in humans and that the susceptibility to different variants vary. Our findings highlight the potential risk of secondary zoonotic transmission from urban rats and the need for further monitoring of SARS-CoV-2 in those populations.

microbiology↗

Tissue tropisms of avian influenza A viruses affect their spillovers from wild birds to pigs

Wild aquatic birds maintain a large genetically diverse pool of influenza A viruses (IAVs), which can be transmitted to lower mammals and ultimately humans. Through phenotypic analyses, only a small set of avian IAVs replicated well in the epithelial cells of swine upper respiratory tracts, and these viruses were shown to infect and cause virus shedding in pigs. Such a phenotypic trait appears to emerge randomly and are distributed among IAVs across multiple avian species, geographic and temporal orders, and is determined not by receptor binding preference but other markers across genomic segments, such as those in the ribonucleoprotein complex. This study demonstrates that phenotypic variants exist among avian IAVs, only a few of which may result in viral shedding in pigs upon infection, providing opportunities for these viruses to become pig adapted, thus posing a higher potential risk for creating novel variants or detrimental reassortants within pig populations. Author SummaryHaving both avian-like receptors and human-like 2,6-linked sialic acid receptors, swine serve as a "mixing vessel" for generating human influenza pandemic strains. All HA subtypes of IAVs can infect swine; however, only sporadic cases of avian IAVs are reported in domestic swine. The molecular mechanisms affecting avian IAVs ability to infect swine are still not fully understood. Through phenotypic analyses, this study suggested that tissue tropisms (i.e., in swine upper respiratory tracts) of avian IAVs affect their spillovers from wild birds to pigs, and this phenotype was determined not by receptor binding preference but by other markers across genomic segments, such as those in the ribonucleoprotein complex. In addition, our results showed that such a phenotypic trait was sporadically and randomly distributed among IAVs across multiple avian species, geographic and temporal orders. This study suggested an efficient way for risk assessment of avian IAVs, such as in evaluating their potentials to be transmitted from avian to pigs.

microbiology↗