Effects of Tropilaelaps mercedesae on midgut bacterial diversity of Apis mellifera

Tropilaelaps mercedesae is an ectoparasite of Apis mellifera in Asia and is considered a major threat to honey bee health. Herein, we used the Illumina MiSeq platform 16S rDNA Amplicon Sequencing targeting the V3–V4 regions and analysed the effects on the midgut bacterial communities of honey bees infested with T. mercedesae. The overall bacterial community in honey bees infested with T. mercedesae were observed at different developmental stages. The community diversity variation in bacterial community was not significant, though specific bacterial richness were significantly varied at different stages. Newly emerged bees infested with T. mercedesae had significantly higher Enterococcus levels as well as a shift in Lactobacillus strain dominance. The midgut bacteria communities from larvae to adult make a series successions; however, we did not observe a significant change in the quantitative variation in the overall bacterial communities within different developmental stages or between infested and non-infested bees. We observed a significant reduction in the abundance of specific bacterial phylotypes between different developmental stages. The abundance of the overall bacterial community significantly increased in infested adults, variation may increase immune capabilitlies in individual bees. We observed no significant effect on the main bacterial community of honey bees infested with T. mercedesae, but significant effects were observed in Enterococcus, Brachybacterium, Snodgrassella and Lactobacillus abundance.