The Genetic Characterization of the First Detected Bat Coronaviruses in Poland Revealed SARS-Related Types and Alphacoronaviruses

Prevalence of coronaviruses in European bison (Bison bonasus) in Poland

Coronaviruses have been confirmed to infect a variety of species, but only one case of associated winter dysentery of European bison has been described. The study aimed to analyze the prevalence, and define the impact on the species conservation, the source of coronavirus infection, and the role of the European bison in the transmission of the pathogen in Poland. Molecular and serological screening was performed on 409 European bison from 6 free-ranging and 14 captive herds over the period of 6 years (2017-2023). Presence of coronavirus was confirmed in one nasal swab by pancoronavirus RT-PCR and in 3 nasal swab samples by bovine coronavirus (BCoV) specific real time RT-PCR. The detected virus showed high (> 98%) homology in both RdRp and Spike genes to BCoV strains characterised recently in Polish cattle and strains isolated from wild cervids in Italy. Antibodies specific to BCoV were found in 6.4% of tested samples, all originating from free-ranging animals. Seroprevalence was higher in adult animals over 5 years of age (p = 0.0015) and in females (p = 0.09). Our results suggest that European bison play only a limited role as reservoirs of bovine-like coronaviruses. Although the most probable source of infections in the European bison population in Poland is cattle, other wild ruminants could also be involved. In addition, the zoonotic potential of bovine coronaviruses is quite low.

Lack of detection of SARS-CoV-2 in British wildlife 2020-21 and first description of a stoat (Mustela erminea) Minacovirus

Repeat spillover of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) into new hosts has highlighted the critical role of cross-species transmission of coronaviruses and establishment of new reservoirs of virus in pandemic and epizootic spread of coronaviruses. Species particularly susceptible to SARS-CoV-2 spillover include Mustelidae (mink, ferrets and related animals), cricetid rodents (hamsters and related animals), felids (domestic cats and related animals) and white-tailed deer. These predispositions led us to screen British wildlife with sarbecovirus-specific quantitative PCR and pan coronavirus PCR assays for SARS-CoV-2 using samples collected during the human pandemic to establish if widespread spillover was occurring. Fourteen wildlife species (n=402) were tested, including: two red foxes (Vulpes vulpes), 101 badgers (Meles meles), two wild American mink (Neogale vison), 41 pine marten (Martes martes), two weasels (Mustela nivalis), seven stoats (Mustela erminea), 108 water voles (Arvicola amphibius), 39 bank voles (Myodes glareolous), 10 field voles (Microtus agrestis), 15 wood mice (Apodemus sylvaticus), one common shrew (Sorex aranaeus), two pygmy shrews (Sorex minutus), two hedgehogs (Erinaceus europaeus) and 75 Eurasian otters (Lutra lutra). No cases of SARS-CoV-2 were detected in any animals, but a novel minacovirus related to mink and ferret alphacoronaviruses was detected in stoats recently introduced to the Orkney Islands. This group of viruses is of interest due to pathogenicity in ferrets. The impact of this virus on the health of stoat populations remains to be established.

A comprehensive dataset of animal-associated sarbecoviruses

Zoonotic spillover of sarbecoviruses (SarbeCoVs) from non-human animals to humans under natural conditions has led to two large-scale pandemics, the severe acute respiratory syndrome (SARS) pandemic in 2003 and the ongoing COVID-19 pandemic. Knowledge of the genetic diversity, geographical distribution, and host specificity of SarbeCoVs is therefore of interest for pandemic surveillance and origin tracing of SARS-CoV and SARS-CoV-2. This study presents a comprehensive repository of publicly available animal-associated SarbeCoVs, covering 1,535 viruses identified from 63 animal species distributed in 43 countries worldwide (as of February 14,2023). Relevant meta-information, such as host species, sampling time and location, was manually curated and included in the dataset to facilitate further research on the potential patterns of viral diversity and ecological characteristics. In addition, the dataset also provides well-annotated sequence sets of receptor-binding domains (RBDs) and receptor-binding motifs (RBMs) for the scientific community to highlight the potential determinants of successful cross-species transmission that could be aid in risk estimation and strategic design for future emerging infectious disease control and prevention.

Sarbecoviruses of British horseshoe bats; sequence variation and epidemiology

Horseshoe bats are the natural hosts of the Sarbecovirus subgenus that includes SARS-CoV and SARS-CoV- 2. Despite the devastating impact of the COVID-19 pandemic, there is still little known about the underlying epidemiology and virology of sarbecoviruses in their natural hosts, leaving large gaps in our pandemic preparedness. Here we describe the results of PCR testing for sarbecoviruses in the two horseshoe bat species (Rhinolophus hipposideros and R. ferrumequinum) present in Great Britain, collected in 2021-22 during the peak of COVID-19 pandemic. One hundred and ninety seven R. hipposideros samples from 33 roost sites and 277 R. ferrumequinum samples from 20 roost sites were tested. No coronaviruses were detected in any samples from R. ferrumequinum whereas 44 and 56 % of individual and pooled (respectively) faecal samples from R. hipposideros across multiple roost sites tested positive in a sarbecovirus-specific qPCR. Full genome sequences were generated from three of the positive samples (and partial genomes from two more) using Illumina RNAseq on unenriched samples. Phylogenetic analyses showed that the obtained sequences belong to the same monophyletic clade, with >95 % similarity to previously-reported European isolates from R. hipposideros. The sequences differed in the presence or absence of accessory genes ORF 7b, 9b and 10. All lacked the furin cleavage site of SARS-CoV-2 spike gene and are therefore unlikely to be infective for humans. These results demonstrate a lack, or at least low incidence, of SARS-CoV-2 spill over from humans to susceptible GB bats, and confirm that sarbecovirus infection is widespread in R. hipposideros. Despite frequently sharing roost sites with R. ferrumequinum, no evidence of cross-species transmission was found.

Circulation of SARS-CoV-Related Coronaviruses and Alphacoronaviruses in Bats from Croatia

Bats are natural hosts of various coronaviruses (CoVs), including human CoVs, via an assumed direct zoonotic spillover or intermediate animal host. The present study aimed to investigate the circulation of CoVs in a bat colony in the Mediterranean region of Croatia. Guano and individual droppings from four bat species were sampled and tested with the E-gene sarbecovirus RT-qPCR, the pan-CoV semi-nested RT-PCR targeting the RdRp gene and NGS. Furthermore, bat blood samples were investigated for the presence of sarbecovirus-specific antibodies with the surrogate virus neutralization test (sVNT). The initial testing showed E-gene Sarebeco RT-qPCR reactivity in 26% of guano samples while the bat droppings tested negative. The application of RdRp semi-nested RT-PCR and NGS revealed the circulation of bat alpha- and betaCoVs. Phylogenetic analysis confirmed the clustering of betaCoV sequence with SARS-CoV-related bat sarbecoviruses and alpha-CoV sequences with representatives of the Minunacovirus subgenus. The results of sVNT show that 29% of bat sera originated from all four species that tested positive. Our results are the first evidence of the circulation of SARS-CoV-related coronaviruses in bats from Croatia.