Identification and characterization of two novel toxins expressed by the lethal honey bee pathogen Paenibacillus larvae, the causative agent of American foulbrood.

摘要: Paenibacillus larvae is a Gram-positive bacterial pathogen causing the epizootic American foulbrood in honey bee larvae. Four so-called enterobacterial repetitive intergenic consensus (ERIC) genotypes of P. exist with ERIC I and II being responsible for disease outbreaks all over world. Very few molecular data on pathogen, pathogenesis or virulence factors exist. We now identified two genomic loci coding binary AB toxins, Plx1 Plx2. In silico analyses revealed that third member an enigmatic family toxins so far only comprising MTX1 Lysinibacillus sphaericus pierisin-like expressed by several butterflies. Plx2 also remarkable because A-domain highly similar to C3 exoenzymes, which normally are single domain proteins, while B-domain homologous B-domains C2-toxins. constructed mutants lacking expression Plx1, both demonstrated these important I.