Chemical Composition, Antimicrobial Activity, and Mode of Action of Essential Oils against Paenibacillus larvae, Etiological Agent of American Foulbrood on Apis mellifera

Chem Biodivers. 2017 Apr;14(4). doi: 10.1002/cbdv.201600382. Epub 2017 Mar 20.

Abstract

This study aimed to characterize the chemical composition of Aloysia polystachia, Acantholippia seriphioides, Schinus molle, Solidago chilensis, Lippia turbinata, Minthostachys mollis, Buddleja globosa, and Baccharis latifolia essential oils (EOs), and to evaluate their antibacterial activities and their capacity to provoke membrane disruption in Paenibacillus larvae, the bacteria that causes the American Foulbrood (AFB) disease on honey bee larvae. The relationship between the composition of the EOs and these activities on P. larvae was also analyzed. Monoterpenes were the most abundant compounds in all EOs. All EOs showed antimicrobial activity against P. larvae and disrupted the cell wall and cytoplasmic membrane of P. larvae provoking the leakage of cytoplasmic constituents (with the exception of B. latifolia EO). While, the EOs' antimicrobial activity was correlated most strongly to the content of pulegone, carvone, (Z)-β-ocimene, δ-cadinene, camphene, terpinen-4-ol, elemol, β-pinene, β-elemene, γ-cadinene, α-terpineol, and bornyl acetate; the volatiles that better explained the membrane disruption were carvone, limonene, cis-carvone oxide, pentadecane, trans-carvyl acetate, trans-carvone oxide, trans-limonene oxide, artemisia ketone, trans-carveol, thymol, and γ-terpinene (positively correlated) and biciclogermacrene, δ-2-carene, verbenol, α-pinene, and α-thujene (negatively correlated). The studied EOs are proposed as natural alternative means of control for the AFB disease.

Keywords: Paenibacillus larvae; American foulbrood; Antimicrobials; Chemometrics; Essential oils; Membrane disruption.

MeSH terms

  • Animals
  • Anti-Bacterial Agents / isolation & purification*
  • Anti-Bacterial Agents / pharmacology
  • Bees / drug effects
  • Bees / microbiology*
  • Cell Membrane / drug effects
  • Cell Membrane Permeability / drug effects
  • Oils, Volatile / chemistry
  • Oils, Volatile / pharmacology*
  • Paenibacillus larvae / drug effects*
  • Plant Extracts / chemistry
  • Plant Extracts / pharmacology

Substances

  • Anti-Bacterial Agents
  • Oils, Volatile
  • Plant Extracts