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Research article2006Peer reviewedOpen access

Reclassification of Paenibacillus larvae subsp pulvifaciens and Paenibacillus larvae subsp larvae as Paenibacillus larvae without subspecies differentiation

Genersch E, Forsgren E, Pentikainen J, Ashiralieva A, Rauch S, Kilwinski J, Fries I

Abstract

A polyphasic taxonomic study of the two subspecies of Paenibacillus larvae, Paenibacillus larvae subsp. larvae and Paenibacillus larvae subsp. pulvifaciens, supported the reclassification of the subspecies into one species, Paenibacillus larvae, without subspecies separation. Our conclusions are based on the analysis of six reference strains of P. larvae subsp. pulvifaciens and three reference strains and 44 field isolates of P. larvae. subsp. larvae. The latter originated from brood or honey of clinically diseased honey bee colonies or from honey of both clinically diseased and asymptomatic colonies from Sweden, Finland and Germany. Colony and spore morphology, as well as the metabolism of mannitol and salicin, did not allow a clear identification of the two subspecies and SDS-PAGE of whole-cell proteins did not support the subspecies differentiation. For genomic fingerprinting, repetitive element-PCR fingerprinting using ERIC primers and PFGE of bacterial DNA were performed. The latter method is a high-resolution DNA fingerprinting method proven to be superior to most other methods for biochemical and molecular typing and has not previously been used to characterize P. larvae. ERIC-PCR identified four different genotypes, while PFGE revealed two main clusters. One cluster included most of the P. larvae subsp. larvae field isolates, as well as all P. larvae subsp. pulvifaciens reference strains. The other cluster comprised the pigmented variants of P. larvae subsp. larvae. 16S rRNA gene sequences were determined for some strains. Finally, exposure bioassays demonstrated that reference strains of P. larvae subsp. pulvifaciens were pathogenic for honey bee larvae, producing symptoms similar to reference strains of P. larvae subsp. larvae. In comparison with the type strain for P. larvae subsp. larvae, ATCC 9545(T), the P. larvae subsp. pulvifaciens strains tested were even more virulent, since they showed a shorter LTA(100). An emended description of the species is given

Published in

International Journal of Systematic and Evolutionary Microbiology
2006, Volume: 56, pages: 501-511
Publisher: SOC GENERAL MICROBIOLOGY

      SLU Authors

    • Forsgren, Eva

      • Department of Entomology, Swedish University of Agricultural Sciences

      • Fries, Ingemar

        • Department of Entomology, Swedish University of Agricultural Sciences

      UKÄ Subject classification

      Animal and Dairy Science
      Veterinary Science
      Environmental Sciences related to Agriculture and Land-use

      Publication identifier

      DOI: https://doi.org/10.1099/ijs.0.63928-0

      Permanent link to this page (URI)

      https://res.slu.se/id/publ/8720