Bees on the run:spp. (Microsporidia) inand related products, Italy.

Abstract

INTRODUCTION: The decline of the European/western honeybee () population is on account of a plethora of microorganisms, such asand, two microsporidian fungi responsible of nosemosis that affects welfare and production of the bee industry. Accordingly, this study aimed to investigate the presence of both pathogens in bees, pollen and honey from apiaries in Southwestern Italy. METHODS: From March to July 2022 and 2023, apiaries ( = 10) were selected and classified as High Impact Areas (HIAs, = 5) and Low Impact Areas (LIAs, = 5) according to a 5-point environmental risk index based on factors affecting bee health sand related productions. Bee, pollen and honey samples, were collected and tested forspp. DNA by specific PCR protocols targeting the 16S rRNA gene. Signs/symptoms of nosemosis were monitored and collected by the cooperation of beekeepers. RESULTS: Out of 10 apiaries, 6 (i.e., 60%, 95% CI: 31.3-83.2) tested positive for at least one sample tospp. DNA, being 2 positives for, 2 forand 2 co-infected (i.e., 20%, 5.7-51.0). Based on the biological samples, honey was positive forin one apiary, pollen forin two apiaries, and bees forin 3 apiaries,in 1 apiary, and both species in 1 apiary. In all the apiaries positive toand, high mortality and low honey production were observed. A higher risk of infection was observed in apiaries from HIAs ( = 6.00). The sequences ofandhad 99.5-100% homology with those in the GenBank database. Whereas all sequences ofwere identical to each other, four sequences types ofcharacterized by single nucleotide polymorphisms (SNPs) were identified. The computation of polymorphisms revealed high haplotype diversity (i.e., = 1.000) and low nucleotide diversity (i.e., = 0.00913) ofsequence types. DISCUSSION: This study reveals a high circulation ofandin Southwestern Italy, indicating the need for improved monitoring of these microsporidia to protect bee welfare and bee industry.