Molecular detection of Nosema ceranae and determining the percentage of colony infection and workers in some provinces of Iraq

Abstract

Nosema ceranae is one of the most serious diseases affecting adult honey bees worldwide. It is referred to as a silent killer because there are no distinguishing symptoms. So, Polymerase chain reaction( multiplex PCR) was used to identify the rRNA marker for Nosema ceranae in 2700 Apis mellifera samples collected from three Governorates (AL-Najaf ، Wasit ، Diyala) in Iraq over six months in 2021-2022. DNA sequencing analysis of the N. ceranae samples revealed no intraspecific variation in the 219 bp of the 16s SSU of N. ceranae from Iraq, and the strain was recorded in NCBI with number OM985045.1 ، OM985047.1 and OM9790821.1 respectively. Before using PCR, the samples were examined using an optical microscope. It was discovered that the high percentage of infection in colonies in Autumn 2021 was 70.3 % in Diyala in October, the low percentage was 47.5% in Wasit in December, and The high percentage in workers was 92.7 % in October in Diyala. The low percentage is 52.0% in Wasit in December. The highest number of spores per bee was recorded in Diyala in November it was 86.9x105 spores ، the lowest number was 49.5x105 spores recorded in Wasit in October. In Spring 2022, the high percentage in colonies was 54.4% in April in Al-Najaf in May. The low percentage was 32.3% ، the high percentage in workers was 84.0% in March in Diyala, and the low percentage was 38.7% in May in AL-Najaf ، The high number of spores was recorded in November in Diyala was 86.9x105 spores. The lowest number was 48x104 spores in May in Al-Najaf. Keywords: Nosema ceranae, colonies infection, Honey bees