Molecular Technique as A Vigorous Instrument for Identification and Classification of Dickeya on The Ornamental Plants

Information on the genetic diversity of pathogenic bacteria causing plant disease is rare to find. This study aims to identify and classify disease-causing pathogens in several ornamental plants molecularly. Sixteen bacterial strains were isolated from carnation, chrysanthemum, and kalanchoe. All strains were grouped in D. dianthicola although the carnation strains and kalanchoe strains gave different results from the identified carnation strains. The differences were found in rep-PCR and 16S rDNA. Band patterns produced by rep-ERIC PCR revealed that the carnation strains, chrysanthemum strains, and kalanchoe strains formed slightly different from the identified carnation strains. Meanwhile, sequence analysis of 16S rDNA revealed that the carnation strains and kalanchoe strains were grouped separately from the identified carnation strains. Even though they were positioned independently from the identified carnation strains and other D. dianthicola strains, but they have closely related each other thus they are identified as a specific group of D. dianthicola. However, based on multilocus sequence analysis (MLSA) of dnaX, recA, gyrB and rpoD, all strains were grouped into D. dianthicola.  Furthermore, the result of pathogenicity test showed that all strains were pathogenic to carnation, potato, and chrysanthemum, but they were not pathogenic to kalanchoe

Next-generation sequencing analysis of the human T-cell and B-cell receptor repertoire diversity before and after hepatitis B vaccination

The hepatitis B (HB) vaccine effectively prevents the incidence of hepatitis B virus (HBV) infection. However, vaccine failure occurs in 5–10% of the recipients. The precise mechanisms leading to responsiveness to the HB vaccine are poorly understood. High-throughput sequencing (HTS) may help clarify the immune response to the HB vaccine, so we applied this method to investigate whether the HB vaccine induced a specific change in the T-cell receptor (TCR) and B-cell receptor (BCR) repertoires. We conducted HTS of the TCR β chain and BCR IgG heavy (H) chain complementary determining region 3 (CDR3) repertoires in five volunteers before and after the second and third immunizations with the HB vaccine. The HB surface antibody (HBsAb) levels were >10 mIU/ml after the third vaccination in all five participants. The TCR β chain CDR3 repertoire diversity significantly increased, while the BCR IgG H chain CDR3 repertoire diversity significantly decreased after the second vaccination. Although there was no marked inter-individual variation in terms of the numbers of unique reads, it is possible that the TCR β chain and BCR IgG H chain CDR3 repertoires may have changed within the same numbers of unique reads. Our data failed to identify the specific dominant clones that responded to the HB vaccine. In summary, the TCR β chain CDR3 repertoire diversity significantly increased, while the BCR IgG H chain CDR3 repertoire diversity significantly decreased, after the second HB vaccination. These diversity changes might be associated with a better response to the HB vaccine

Pseudomonas amygdali (syn. Pseudomonas savastanoi) pv. adzukicola pv. nov., causal agent of bacterial stem rot of adzuki bean

Bacterial stem rot of adzuki bean (BSRA) was first recorded in Japan in 1979. The pathogen was identified as a new species, designated as Pseudomonas adzukicola. However, due to the lack of a type strain, P. adzukicola has been recognized as invalid since 1980. In the 2000s, we obtained BSRA isolates and compared them with related Pseudomonas species. Inoculations with the BSRA isolates caused symptoms on adzuki bean, cowpea, hyacinth bean, and kidney bean. Pseudomonas savastanoi pv. glycinea (Psag) did not affect adzuki bean, whereas P. savastanoi pv. phaseolicola caused distinct symptoms on adzuki bean and had a different host range from the BSRA isolates. The BSRA isolates were similar to Psag in their bacteriological characteristics except that they utilized dl-alpha-alanine and l-histidine. Phylogenetic analyses based on four housekeeping genes suggested that the BSRA isolates were closely related genetically to Psag, belonging to P. syringae genomospecies 2 and hrp group IA. However, the rep-PCR results distinguished the BSRA isolates from Psag and the other Pseudomonas species. These results suggest that the BSRA agent is an independent taxon among genomospecies 2 bacteria and that the BSRA agent represents a new pathovar. Because P. amygdali is the oldest legitimate name of the genomospecies 2 bacteria, P. savastanoi should be treated as a synonym of P. amygdali. Therefore, we propose the name P. amygdali (syn. P. savastanoi) pv. adzukicola pv. nov. for the BSRA pathogen, as pathotype strain AZK-11 (SUPP2776, MAFF212478, ICMP24382)