Biologically Active Extracts from Different Medicinal Plants Tested as Potential Additives against Bee Pathogens.

Claudia Pașca,Ancuța Rotaru,Ioana Adriana Matei,Daniel Severus Dezmirean,Zorița Diaconeasa,Silvio Erler

doi:10.3390/antibiotics10080960

Abstract

Honey bees (Apis mellifera) perform pollination service for many agricultural crops and contribute to the global economy in agriculture and bee products. However, honey bee health is an ongoing concern, as illustrated by persistent local population decline, caused by some severe bee diseases (e.g., nosemosis, AFB, EFB, chalkbrood). Three natural recipes are in development based on the bioactive compounds of different plants extract (Agastache foeniculum, Artemisia absinthium, Evernia prunastri, Humulus lupulus, Laurus nobilis, Origanum vulgare and Vaccinium myrtillus), characterised by HPLC-PDA. The antimicrobial activity of these recipes was tested in vitro against Paenibacillus larvae, Paenibacillus alvei, Brevibacillus laterosporus, Enterococcus faecalis, Ascosphaera apis and in vivo against Nosema ceranae. A mix of 20% blueberry, 40% absinthium, 10% oakmoss, 10% oregano, 10% Brewers Gold hops, 5% bay laurel and 5% anise hyssop extract showed the strongest antibacterial and antifungal activity. Combing several highly active plant extracts might be an alternative treatment against bee-disease-associated parasites and pathogens, in particular to replace synthetic antibiotics.

Highlights

Introduction published maps and institutional affilHoney bee diseases are still a serious problem causing local decline in honey bee populations worldwide
A sensitive, accurate and specific method coupling HPLC with photodiode array detection (PDA) and spectrometry was developed for the analysis of phenolic and flavonoid compounds in extracts of Agastache foeniculum, Artemisia absinthium, Evernia prunastri, of 17
The present study attempts to be part of the replacement of synthetic antibiotics, which are used in treating bee diseases, with proposing medicinal additive recipes composed of plants extracts or with biologically active compounds of different plant extracts

Summary

Introduction

Honey bee diseases are still a serious problem causing local decline in honey bee populations worldwide. Numerous pathogens and parasites are threatening the health and optimal maintenance of honey bee populations, including bacteria (Paenibacillus larvae and Melissococcus plutonius), fungi (Ascosphaera apis), microsporidia (Nosema apis and Nosema ceranae), trypanosomes (Crithidia mellificae and Lotmaria passim) and mites (Varroa spp. and Tropilaelaps sp.) [1,2,3,4,5,6,7,8]. Paenibacillus larvae is a gram-positive endospore-forming bacterium, the causative agent of American foulbrood (AFB) disease, which infects the brood stages of honey bees iations. The microbial balance of honey bees, in particular their gut bacterial symbionts—the possible pathogen counterpart, is influenced by a variety of agricultural, colony developmental and environmental factors [9]; such as contaminated water, food or flowers, cleaning activities and trophallaxis, as well as bee faeces deposited in/on the hive or material with infective spores from infected worker honey bees.

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