The first molecular characterization of Lake Sinai virus in honey bees (Apis mellifera) and Varroa destructor mites in Iran

The honey bee is a key pollinator in natural and agricultural ecosystems. Unfortunately, the population of this rather important insect is declining worldwide due to factors such as infection with RNA viruses. Apiaries in Iran are also faced with these challenges, therefore, this study was conducted to identify the Lake Sinai virus (LSV) in both honey bee colonies and associated Varroa destructor mites, as well as phylogenetic analysis of the virus in Iran. In the present study, a total of 30 apiaries with a distance of at least 10 km from each other were selected in Hamedan, Iran. Samples including 10 adults and 10 immature bees (capped larva) and 10 Varroa mites were collected from each colony. After RNA extraction, one-step RT-PCR was performed and the phylogenetic tree was constructed. The results showed that the majority of sampled apiaries were infested with Varroa mites. It was also found that out of 30 apiaries, Varroa mites and capped larvae were infected with LSV in 13 (43.3%), and 3 (10%) apiaries, respectively. The results of the phylogenetic analysis also showed two distinct clades in the samples of adult honey bees and Varroa mites (including LSV isolate Hamedan-1, isolate Hamedan-4 and isolate Hamedan-5 belonging to the same clade, and samples of larvae and adult honey bees (including isolate Hamedan-2 and isolate Hamedan-3) placed in the same clade. Based on the results, it can be concluded that LSV is present in Iran apiaries, and country-wide implementation of prevention and control measures is warranted.