In Vitro Study of the Antimicrobial Activity of Brazilian Propolis Against Paenibacillus Larvae
J Invertebr Pathol, 2007 Oct 17
The honey bee disease American foulbrood (AFB) is a serious problem since its causative agent (Paenibacillus larvae) has become increasingly resistant to conventional antibiotics.
The objective of this study was to investigate the in vitro activity of propolis collected from various states of Brazil against P. larvae…
The propolis extracts from the various states of Brazil showed significant inhibition of P. larvae. Clear dose responses were found for individual propolis extracts, particularly between the concentrations of 1.7 and 0.12mg propolis/treatment disk, but the source of the propolis, rather than the concentration, may be more influential in determining overall activity.
Two of the three tested antibiotics (tylosin and terramycin) exhibited a greater level of inhibition compared to most of the Brazilian samples, which could be due to the low concentrations of active compounds present in the propolis extracts. Additionally, the majority of the Brazilian propolis samples were more effective than the few collected in MN, USA.
Due to the evolution of resistance of P. larvae to conventional antibiotic treatments, this research is an important first step in identifying possible new active compounds to treat AFB in honey bee colonies.