Detection and Molecular Analysis of Bovine Enteric Norovirus and Nebovirus in Turkey

INTRODUCTION: Bovine Norovirus (BoNeV) which has been confirmed in Asia, America, and Europe, seems to be distributed worldwide, even though only reported from a number of countries. Bovine noroviruses are predominantly detected in diarrhoeic animals rather than neboviruses. The study reveals the importance of noro- and neboviruses in early age diarrhoea of calves. MATERIAL AND METHODS: A total of 127 stool samples were collected from three provinces located in the central region of Turkey. Samples were subjected to nucleic acid isolation and reverse transcription and polymerase chain reaction (PCR). Positive samples were sequenced and analysed. RESULTS: According to PCR, five samples (3.93%) were found to be positive for bovine norovirus while 32 (25.19%) samples were found to be positive for bovine nebovirus. Phylogenetic analysis indicated that the novel Turkish norovirus strains were found to be of genotype III.2 and all novel neboviruses were substituted under Nebraska-like strains. CONCLUSION: Although predominantly bovine noroviruses are detected worldwide, the study indicated that bovine neboviruses were more prevalent in the studied area. We suggest that bovine neboviruses are more frequently responsible for calf diarrhoea than supposed by virologists. This is also the first report of neboviruses other than Kirklareli virus which is distantly related to neboviruses detected in Turkey.