In vitro study of the antimicrobial activity of European propolis against Paenibacillus larvae

Abstract

-Typical European propolis is an antibiotic substance derived from the resin of poplar, birch, and aspen buds. Here, we tested the ability of propolis originating from the resins of these plants to inhibit the in vitro growth of Paenibacillus larvae , the organism that causes American foulbrood, a fatal honeybee larval disease. The study involved GC-MS analysis of extracts from nine samples of propolis gathered from the temperate climate zone of Europe. The extracts showed noticeable differences in the content of flavonoids and other phenolic compounds. Despite the differences in chemical composition, all tested extracts inhibited the growth of P. larvae , with a minimum inhibitory concentration of 7.8 to 62.4 μg mL −1. It was found that not only did the content of flavonoids affect the strength of antimicrobial activity, but other phenolics, such as the phenylpropenoids hydroxycinnamyl sesquiterpenols, glycerides and benzoates also had an effect. This is the first report on the comparative activity of different types of European propolis against P. larvae.Paenibacillus larvae / American foulbrood / Apis mellifera / propolis / antibacterial action

Activity of selected plant extracts against honey bee pathogen Paenibacillus larvae

“…The isolates KB25, KB35, KB41, and KB55 used in this study were previously classified as P. larvae (Isidorov et al 2017) based on the colony shape (round, slightly whitish), lack of catalase, formation of spiral forms in the Plagemann test, and the 16S RNA sequences (Neuendorf et al 2004;Plagemann 1985). In this study, we determined that all of them belong to the ERIC I genotype.…”

“…Substantially, more active against the pathogen is propolis (Antúnez et al 2008;Bastos et al 2008;Bilikova et al 2013;Chen et al 2018;Isidorov et al 2016Isidorov et al , 2017Mihai et al 2012;Wilson et al 2015;Simone-Finstrom et al 2017). Extracts of this natural antimicrobial bee product demonstrated lower (as a rule, an order of magnitude) MIC values in tests with P. larvae than essential oils.…”

“…2.2. P. larvae strain isolation P. larvae were isolated from dead honey bee larvae and honey sample originating from apiaries in south-eastern Poland with AFB-diseased colonies (Isidorov et al 2017). Briefly, dead larvae were aseptically removed from brood combs and then were crushed and suspended in 5 mL of physiological saline (0.9% NaCl), and shook for 10 min.…”

Functional Properties and Antimicrobial Activity from Lactic Acid Bacteria as Resources to Improve the Health and Welfare of Honey Bees

“…Macelignan and corosolic acid, the latter extracted from the banaba ( Lagerstroemia speciosa ) leaf, showed strong in vitro antibacterial activity against both P. larvae and M. plutonius [ 289 ]. Several studies are showing the in vitro ability of propolis extracts, from different botanical origins, or their constituents, to inhibit the growth of P. larvae [ 245 , 284 , 291 , 292 , 293 ]. Borba and Spivak [ 294 ], using colonies with and without a propolis envelope, demonstrated that the presence of the envelope provides an antimicrobial layer around the colony that protects the brood from P. larvae infection, resulting in a lower colony-level infection load.…”

Chemodiversity of propolis samples collected in various areas of Benin and Congo: Chromatographic profiling and chemical characterization guided by 13C NMR dereplication

“…29 The increasing use of this natural substance of diversified composition and therefore varying biological activities in the pharmaceutical, cosmetic, and food industries is generating particular interest in scientific research, especially when it comes to defining its chemical composition. Most studies have been carried out on samples from Europe 19,[30][31][32][33] and Latin America, more specifically Brazil, 20,23,[34][35][36] while few studies were conducted in Africa. [37][38][39][40][41] Information on Beninese and Congolese 42 propolis remains scarce.…”