Use of suppression subtractive hybridization to identify genetic differences between differentially virulent genotypes of Paenibacillus larvae, the etiological agent of American Foulbrood of honeybees

Abstract

Paenibacillus larvae is the causative agent of American Foulbrood of honeybees, a fatal brood disease not only killing infected larvae but also lethal to infected colonies. Recently four different genotypes of P. larvae (enterobacterial repetitive intergenic consensus I-IV) have been described and it was shown that these genotypes also differ in phenotype, especially in virulence. To unravel the genetic differences between these four genotypes, suppression subtractive hybridization was used. From 106 analysed clones, 92 represented genotype-specific sequences, whereas 14 sequences turned out to be specific only for the particular strain used as tester in the subtraction. Nearly half of the sequences (46%) could only be annotated based on poorly characterized sequences. The remaining sequences corresponded to categories related to metabolism, especially secondary metabolite biosynthesis, transport and catabolism, to information storage and processing, and to cellular processes. In particular, we could show that the P. larvae genome contains genes and/or giant gene clusters coding for antibiotics, and we identified the first P. larvae toxin, a member of the family of adenosine diphosphate-ribosyltransferases.

Molecular pathogenesis of American Foulbrood: how Paenibacillus larvae kills honey bee larvae

“…This became evident with the recent publication of two complete, manually curated and annotated P. larvae sequences representing the genomes of P. larvae ERIC I (strain DSM25719, 4 579 589 bp, 4868 predicted protein-coding genes) and ERIC II (DSM25430, 4 056 006 bp, 3928 predicted protein-coding genes) [17 ]. These data provided significant progress in elucidating the genomic potential of P. larvae and allowed an in silico comparative genome analysis [17 ] which confirmed considerable differences between the genomes of P. larvae ERIC I and II as previously suggested by suppression subtractive hybridization [18]. In both genomes, a large number of mobile genetic elements and prophage regions were found as well as genomic regions containing repeats and repetitive sequences.…”

American Foulbrood in honeybees and its causative agent, Paenibacillus larvae

“…However, one characteristic of P. larvae is that it is consistently isolated as pure culture from AFB dead larvae (White, 1906) indicating that P. larvae itself obviously produces potent antibiotics as confirmed recently (Fünfhaus et al, 2009). Therefore, the efficacy of antagonistic bacteria against P. larvae infection in vivo remains to be shown.…”

In vitro Growth Inhibition by Hypericum Extracts and Isolated Pure Compounds of Paenibacillus larvae, a Lethal Disease Affecting Honeybees Worldwide

“…In an examination of P. larvae genotypes ERIC I -IV, a strain-specific genomic sequence (Fl 763330) with 46% similarity to an ABC transporter ATP-binding protein from Lactococcus lactis ssp. cremoris MG1363 was identified [35]. An interesting future direction of research, therefore, would be to determine whether hyperforin or structural derivatives thereof potentially upregulate the expression of this gene in this particular strain of P. larvae.…”