Molecular and epidemiological characterisation of the novel mammalian orthoreovirus variantsMikuletič, Tina (Avtor) Steyer, Andrej (Mentor) mammalian orthoreovirusbatRT-PCRreal-time RT-PCRnext-generation sequencingphylogenetic analysisserum-neutralisation testvirus isolationcell cultureRecently, the mammalian orthoreovirus (MRV) isolate SI-MRV01 with high similarity to newly described bat MRVs was first observed in a child with severe diarrhoea. Furthermore, a closely related MRVs were described in a dog with haemorrhagic enteritis and pigs with diarrhoea. The aim of this doctoral dissertation was to determine the prevalence of MRVs in bats, dogs and hospitalised children with acute gastroenteritis to reveal the occurrence and genetic variability of these viruses. In addition, MRV seroprevalence in dogs and children was investigated. The particular focus was on the occurrence of SI-MRV01 variants in target populations. To determine MRV prevalence, archive bat guano samples, stool samples of hospitalised children with diarrhoea and prospective dog stool samples were analysed with a broad-spectrum RT-PCR and a specific real time RT-PCR, targeting a novel bat MRV. Subsequently, MRV isolates were propagated in cell line and whole-genomes were obtained with NGS sequencing. For MRV seroprevalence study, dog sera and sera samples from children were analysed with serum-neutralisation test on MRV serotype reference strains (Reo1TL, Reo2TJ, Reo3TD) and bat isolate SI-MRV01. A novel bat MRV variant with 99% whole genome identity to isolate SI-MRV01 is present in Slovenian bats. Overall, SI-MRV01 prevalence was at 9.1%. Five independent strains were successfully isolated in cell culture following whole genome sequence determination from the archived bat guano samples. In addition to SI-MRV01-like variant four further genetically distant bat MRV variants were identified. Acute MRV infection was detected in one hospitalised child with diarrhoea (0.2%) and in zero dogs (0%). Neutralising antibodies against SI-MRV01 were detected in 7.5% children‘s sera and in 81.3% dogs‘ sera. MRVs are frequently present in bats, indicating bats as possible reservoir of circulating MRVs. Serology analysis of dog sera indicates possible route of infection via pets.20212021-12-24 13:50:13Doktorsko delo/naloga134155VisID: 19936COBISS_ID: 128012291sl