Evaluation of antimicrobial activity of glycerol monolaurate nanocapsules against American foulbrood disease agent and toxicity on bees

Brevibacillus laterosporus is often present in beehives, including presence in hives infected with the causative agent of American Foulbrood (AFB), Paenibacillus larvae. In this work, 12 B. laterosporus bacteriophages induced bactericidal products in their host. Results demonstrate that P. larvae is susceptible to antimicrobials induced from field isolates of the bystander, B. laterosporus. Bystander antimicrobial activity was specific against the pathogen and not other bacterial species, indicating that the production was likely due to natural competition between the two bacteria. Three B. laterosporus phages were combined in a cocktail to treat AFB. Healthy hives treated with B. laterosporus phages experienced no difference in brood generation compared to control hives over 8 weeks. Phage presence in bee larvae after treatment rose to 60.8 ± 3.6% and dropped to 0 ± 0.8% after 72 h. In infected hives the recovery rate was 75% when treated, however AFB spores were not susceptible to the antimicrobials as evidenced by recurrence of AFB. We posit that the effectiveness of this treatment is due to the production of the bactericidal products of B. laterosporus when infected with phages resulting in bystander-killing of P. larvae. Bystander phage therapy may provide a new avenue for antibacterial production and treatment of disease.

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Using palynological evidence from royal jelly to mediate the spread of Paenibacillus larvae in Brazil

Hoehnea ◽

10.1590/2236-8906-45/2018 ◽

2018 ◽

Vol 45 (3) ◽

pp. 512-539 ◽

Cited By ~ 3

Author(s):

Cynthia Fernandes Pinto da Luz ◽

Lubiane Guimarães-Cestaro ◽

José Eduardo Serrão ◽

Dejair Message ◽

Marta Fonseca Martins ◽

...

Keyword(s):

Royal Jelly ◽

Pollen Grains ◽

Paenibacillus Larvae ◽

Inspection System ◽

American Foulbrood ◽

Pollen Spectrum ◽

Paulo State ◽

Total Percentage ◽

Brazilian Legislation ◽

American Foulbrood Disease

ABSTRACT Royal jelly may contain pollen grains and their presence can be used to determine the phytogeographical origin of the product. This study analyzed the phytogeographical origin of commercial royal jelly samples from São Paulo State, tested as part of the Brazilian Federal Inspection System (SIF), found to be contaminated with spores of the bacterium Paenibacillus larvae, that causes the American Foulbrood Disease. The pollen grains of Castanea had the highest total percentage, with lower percentages of Cirsium/Carduus, Cistus, Parthenocissus, Prunus, Quercus, Robinia, Scrophulariaceae, Taraxacum, Tilia, among others. This pollen spectrum is incompatible with royal jelly samples produced in Brazil. The pollen spectrum resembled that of an imported product, compatible with the Northern Hemisphere origin. Brazilian legislation does not require the phytogeographic origin of imported bee products to be analyzed by palynological procedures, but it is mandatory to have a certificate issued by the country of origin attesting the absence of pathogens, monitored with the objective of preventing the exotic diseases from entering Brazil. Palynology, therefore, proved to be fundamental in detecting imports of this contaminated batches.

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