The use of gut bacteria isolated from Thai honey bees (Apis spp.) to control Nosema ceranae infection in the giant honey bee, Apis dorsata

Abstract

Honey bee (Apis spp.) health is threatened by various pests and pathogens, including the microsporidia, Nosema ceranae. We investigated using two groups of beneficial gut bacteria isolated from Thai honey bees, Apilactobacillus kunkeei and Bifidobacterium sp., as a potential strategy to mitigate N. ceranae infections in the giant honey bee, Apis dorsata. For 24 h, newly emerged workers were individually fed 2 µL of a 50 % sucrose solution containing 2 × 10⁵ colony-forming units (CFU) of gut bacteria isolated from A. cerana, A. dorsata, A. florea, and A. mellifera workers. The bees were maintained in an incubator at 34 ± 2 °C and 55 ± 5 % RH. Subsequently, they were group-fed, 50 bees/group, with 500 μL of 50 % sucrose solution containing 10⁷N. ceranae spores. Bees fed A. kunkeei and Bifidobacterium sp. had significantly reduced mortality, N. ceranae infectivity, infection rate, and infection ratio compared to bees not fed the beneficial gut bacteria. Consumption of gut bacteria isolated from all four Thai honey bee species significantly increased the protein content of the hypopharyngeal glands of A. dorsata workers over that of bees not fed the bacteria. Collectively, these findings suggest that beneficial gut bacteria may serve as a promising strategy for protecting honey bee colonies from Nosema disease.