Widespread Gyrovirus Co-Infections in Backyard Chickens in Türkiye: Molecular and Phylogenetic Insights

Gyroviruses are small DNA viruses that have been detected in poultry and several other animal species, but genetic insights on their diversity and coinfection patterns in backyard chickens is still limited. In this study, we investigated the presence and genetic diversity of gyroviruses in tissue samples collected from 100 clinically healthy backyard chickens from five provinces in the Middle East Anatolian region of Türkiye between 2020 and 2021. Species-specific PCR assays were implemented to detect six different gyroviruses: chicken anemia virus (CAV), avian gyrovirus 2 (AvGyV2), Gyrovirus 3 (GyV3), Gyrovirus 4 (GyV4), GyV6, and GyV7. At least one gyrovirus was detected in 90% of the samples, and multiple infections were common, especially the co-occurrence of CAV and AvGyV2. Partial VP1 gene sequences were obtained from representative samples and analysed using molecular and phylogenetic methods. The results showed that the gyrovirus strains detected in Türkiye were genetically similar to strains reported from other countries, although some genetic variation was observed, particularly among GyV4 sequences. Importantly, GyV6 and GyV7 were identified for the first time in chickens in Türkiye, expanding the known geographic distribution of these viruses. The frequent detection of multiple gyroviruses in the same samples suggests that these viruses can circulate together in backyard poultry. Overall, this study provides new information on the molecular characteristics and circulation of gyroviruses in backyard chickens in Türkiye and highlights the importance of continued monitoring to better understand their diversity and spread.