Whole genome characteristics of hedgehog coronaviruses from Poland and analysis of the evolution of the Spike protein for its interspecies transmission potential

Abstract

Background The hedgehogs have been recently identified as possible reservoir of Middle East respiratory syndromecoronavirus like (MERS-CoV-like). These viruses were classified as a distinct Betacoronavirus erinacei (BCoV-Eri) specieswithin the MerBCoV-Eriirus subgenus. As coronaviruses are known for their ability to jump between different hosts,including humans, this can pose a particular threat to people in direct contact with hedgehogs, such as thoseworking at animal asylums. Our previous studies have shown the presence of BCoV-Eri strains in animals collectedin the wildlife rehabilitation centre. This study aimed to investigate the presence of CoV in subsequent hedgehogscollected from the urban area of Poland and their molecular characteristics.Results Monitoring for the presence of coronavirus infection in hedgehogs revealed five positive individuals. Thepresence of BCoV-Eri was found in a total of 20% of animals tested. Our analyses revealed no correlation betweenCoVs positivity and animal health conditions but a higher probability of such infection in juveniles and females.The whole genome of two Polish Hedgehog coronavirus 1 strains were sequenced and compared with availablecounterparts from European and Asian countries. Phylogenetic analysis showed that both CoV strains formedcommon cluster with other similar MerBCoV-Eriirus, but they were also found to be genetically variable and mostchanges in the S protein were identified. Our analysis revealed that some S protein sites of the Hedgehog coronavirus 1strains evolved under positive selection pressure and of five such sites, three are in the S1 region while the other twoin the S2 region of the Spike.Conclusions BCoV-Eri is to some extent prevalent in wildlife asylums in Poland. Given that the S protein of BCoVs-Eri is highly variable and that some sites of this protein evolve under positive selection pressure, these strains couldpotentially acquire a favourable feature for cross-species transmission. Consequently, the threat to humans workingin such asylums is particularly high. Adequate biosecurity safeguards, but also human awareness of such risks, aretherefore essential.