Apilactobacillus kunkeei Alleviated Toxicity of Acetamiprid in Honeybee

SIMPLE SUMMARY: The honeybee is an important pollinator and is key in maintaining ecological balance. Insecticides, especially neonicotinoids, are considered as critical factors in colony collapse disorder. However, the question of how to reduce the toxic effect of pesticides on bees has not been comprehensively answered. Probiotics are an important and valid way to combat stress and have the benefit of maintaining healthy honeybees. Our study found that Apilactobacillus kunkeei, which was isolated from beebread, can reduce the mortality effect of acetamiprid on honeybees. However, the mechanism is not clear, and we attempted to elaborate on it, based on the symbiotic honeybee microbiota. We found that some opportunistic and pathogenic bacteria invaded the intestinal regions of honeybees under acetamiprid exportation. Meanwhile, the community richness and diversity of symbiotic microbiota were decreased, and the community structure of intestinal bacteria was changed and differentiated. However, with the supplementation of A. kunkeei, the community richness and diversity of symbiotic microbiota showed an upward trend, and the community structure was stabilized. These data suggest that A. kunkeei may be beneficial to a stabilized community structure which reduces the toxic effects of acetamiprid on honeybees. Our results offer important insights into the application of probiotics and potential probiotics in beekeeping. ABSTRACT: Nowadays, colony collapse disorder extensively affects honeybees. Insecticides, including acetamiprid, are considered as critical factors. As prevalent probiotics, we speculated that supplementation with lactic acid bacteria (LAB) could alleviate acetamiprid-induced health injuries in honeybees. Apilactobacillus kunkeei was isolated from beebread; it significantly increased the survival of honeybees under acetamiprid exportation (from 84% to 92%). Based on 16S rRNA pyrosequencing, information on the intestinal bacteria of honeybees was acquired. The results showed that supplementation with A. kunkeei significantly increased survival and decreased pollen consumption by honeybees under acetamiprid exportation. Under acetamiprid exportation, some opportunistic and pathogenic bacteria invaded the intestinal regions. Subsequently, the community richness and diversity of symbiotic microbiota were decreased. The community structure of intestinal bacteria was changed and differentiated. However, with the supplementation of A. kunkeei, the community richness and community diversity of symbiotic microbiota showed an upward trend, and the community structure was stabilized. Our results showed that A. kunkeei alleviated acetamiprid-induced symbiotic microbiota dysregulation and mortality in honeybees. This demonstrates the importance of symbiotic microbiota in honeybees and supports the application of Apilactobacillus kunkeei as probiotics in beekeeping.