First Molecular Detection and Characterization of Nosema ceranae in Honey Bees (Apis mellifera) from the Northern Highlands of Ecuador

The development of beekeeping in Ecuador has generated the need to strengthen the bee health program. Research on the main pathogens responsible for diseases like nosemosis, which can severely impact bee health, is of special interest. This study aims to identify the <i>Nosema apis</i> and/or <i>Nosema ceranae</i> species infecting honey bee colonies located in the northern Andean region of Ecuador using multiplex PCR targeting the RNA polymerase II gene (RPB1), and the phylogenetic analysis of <i>N. ceranae</i> based on the 16 S rRNA gene sequences. Among the 164 honey bee samples collected from colonies in the provinces of Carchi, Imbabura, and Pichincha, the prevalence of <i>Nosema apis</i> and <i>Nosema ceranae</i> was 14.63% and 21.34%, respectively. Phylogenetic analysis showed that <i>N. ceranae</i> from Ecuador is closely related to the sequences from Argentina and Brazil. These findings provide the first molecular confirmation of <i>N. ceranae</i> in Ecuador and support the need for molecular monitoring of honey bee pathogens in the region.