Effect of bodily fluids from honey bee (Apis mellifera) larvae on growth and genome-wide transcriptional response of the causal agent of American Foulbrood disease (Paenibacillus larvae)

PLoS One. 2014 Feb 20;9(2):e89175. doi: 10.1371/journal.pone.0089175. eCollection 2014.


Paenibacillus larvae, the causal agent of American Foulbrood disease (AFB), affects honey bee health worldwide. The present study investigates the effect of bodily fluids from honey bee larvae on growth velocity and transcription for this Gram-positive, endospore-forming bacterium. It was observed that larval fluids accelerate the growth and lead to higher bacterial densities during stationary phase. The genome-wide transcriptional response of in vitro cultures of P. larvae to larval fluids was studied by microarray technology. Early responses of P. larvae to larval fluids are characterized by a general down-regulation of oligopeptide and sugar transporter genes, as well as by amino acid and carbohydrate metabolic genes, among others. Late responses are dominated by general down-regulation of sporulation genes and up-regulation of phage-related genes. A theoretical mechanism of carbon catabolite repression is discussed.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Bees / metabolism*
  • Bees / microbiology
  • Body Fluids / metabolism*
  • Gene Ontology
  • Genome, Bacterial / genetics*
  • Larva / metabolism
  • Paenibacillus / genetics*
  • Paenibacillus / growth & development*
  • Phenotype
  • Transcription, Genetic*
  • Virulence Factors / genetics


  • Virulence Factors

Grant support

The authors gratefully acknowledge the Research Foundation of Flanders (FWO-Vlaanderen G.0163.11). DDK was funded by the Institute for the Promotion of Innovation through Science and Technology in Flanders (IWT-Vlaanderen). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.