Engineered gut symbiont inhibits microsporidian parasite and improves honey bee survival

Abstract

Honey bees ( Apis mellifera ) are critical agricultural pollinators as well as model organisms for research on development, behavior, memory, and learning. The parasite Nosema ceranae , a common cause of honey bee colony collapse, has developed resistance to small-molecule therapeutics. An alternative long-term strategy to combat Nosema infection is therefore urgently needed, with synthetic biology offering a potential solution. Honey bees harbor specialized bacterial gut symbionts that are transmitted within hives. Previously, these have been engineered to inhibit ectoparasitic mites by expressing double-stranded RNA (dsRNA) targeting essential mite genes, via activation of the mite RNA interference (RNAi) pathway. In this study, we engineered a honey bee gut symbiont to express dsRNA targeting essential genes of N. ceranae via the parasite’s own RNAi machinery. The engineered symbiont sharply reduced Nosema proliferation and improved bee survival following the parasite challenge. This protection was observed in both newly emerged and older forager bees. Furthermore, engineered symbionts were transmitted among cohoused bees, suggesting that introducing engineered symbionts to hives could result in colony-level protection.

TheCaenorhabditis elegansbacterial microbiome influences microsporidia infection through nutrient limitation and inhibiting parasite invasion

“…The most commonly used anti-microsporidia drugs suffer from either host toxicity or limited activity against some species (Han and Weiss 2018). C. elegans has been used to identify novel microsporidia inhibitors from small molecule libraries and we now show that this model organism can also be used to identify bacteria that produce anti-microsporidia compounds (Murareanu et al 2022; Qingyuan Huang et al 2023). There is an interest in using bacteria to combat infections, and probiotics have been used in honey bees to reduce microsporidia infections, though with mostly modest results (Alberoni et al 2016).…”

“…Bacteria can also produce molecules that inhibit microsporidia and bacteria engineered to produce double stranded RNA protect against microsporidia infection (Q. Huang et al 2023; Lang et al 2023; Porrini et al 2010; Tersigni et al 2024).…”