Parasitological and molecular study of nosemosis in migratory apiaries in Hormozgan Province, southern Iran

Nosemosis is a microsporidian disease caused by Nosema ceranae and N. apis and transmitted via oral-fecal and oral-oral routes. It is globally distributed among adult bees in honeybee colonies. Considering the health importance of nosemosis in honeybees, the study aims to determine the frequency of Nosema spp. infection in migratory apiaries in Hormozgan province by microscopic and molecular methods. In the present study, 20 bees from ten randomly selected hives in 84 migratory apiaries were collected. In the laboratory, the abdomen of the bees was separated from the rest of the body with entomological tweezers and scissors and then ground up in a mortar containing saline serum. The prepared suspension was filtered by passing through a sieve, then the prepared suspension was transferred to test tubes and centrifuged. The pellets were repeatedly washed by saline solution and centrifuged. Finally, the pellets were examined for spores of Nosema spp. by light microscopy and conventional PCR. In microscopy, 38.2 % of apiaries were positive for Nosema spp. spores. By PCR however, DNA of N. ceranae was detected in 39.2. % of apiaries with no samples positive for N. apis. Due to the considerable frequency of infection in migratory apiaries in Hormozgan province, it is necessary to carry out appropriate health measures such as screening of apiaries with appropriate diagnostic methods and training of beekeepers to disinfect hives in order to control Nosema infection in Iranian apiaries by the veterinary health officials.