General Medicine


Publications (461)

Phylogenetic analyses of Candidatus Branchiomonas cysticola refine the taxonomic classification of Betaproteobacteria associated with epitheliocystis in fish

Citation
Bysveen Mjølnerød et al. (2023). Archives of Microbiology 205 (6)
Names
“Branchiomonaceae” Ca. Branchiomonas Ca. Branchiomonas cystocola
Subjects
Biochemistry General Medicine Genetics Microbiology Molecular Biology
Abstract
AbstractCandidatus Branchiomonas cysticola is recognized as the most prevalent bacterial agent causing epitheliocystis in Atlantic salmon (Salmo salar). Based on its partial 16S rRNA sequence, the bacterium has previously been found to be a member of Burkholderiales in the class Betaproteobacteria. Multilocus Sequence Analysis (MLSA) of the bacterium and 60 type strains of Betaproteobacteria using newly identified housekeeping genes (dnaK, rpoC, and fusA) and ribosomal subunit sequences (16S and 23S), instead supported the bacterium’s affiliation to Nitrosomodales. Taxonomic rank normalization by Relative Evolutionary Divergence (RED) showed the phylogenetic distinction between Cand. B. cysticola and its closest related type strain to be at the family level. A novel bacterial family named Branchiomonaceae has thus been proposed to include a monophyletic clade of Betaproteobacteria exclusively associated with epitheliocystis in fish.

Update and Validation of the 16S rDNA qPCR Assay for the Detection of Three ‘<i>Candidatus</i> Liberibacter Species’ Following Current MIQE Guidelines and Workflow

Citation
Osman et al. (2023). PhytoFrontiers™
Names
Ca. Liberibacter asiaticus Liberibacter
Subjects
General Medicine
Abstract
An updated real-time multiplex quantitative polymerase chain reaction (qPCR) assay was designed and validated for the simultaneous detection of three ‘ Candidatus Liberibacter species’ (CLsp), ‘ Ca. Liberibacter asiaticus’ (CLas), ‘africanus’ (CLaf), and ‘americanus’ (CLam), associated with the huanglongbing disease of citrus. The multiplex assay was designed based on the qPCR assay published in 2006 by Li et al., considering all available CLsp 16S rRNA gene sequences in GenBank and the MIQE guidelines and workflow for qPCR optimization, which became available after 2006. When using the updated multiplex CLsp qPCR assay compared with singleplex qPCR, no significant increase in quantitative cycle (Cq) values was detected. The specificity and sensitivity of the updated qPCR assay was optimal, and measuring the intra- and interassay variations confirmed the reproducibility and repeatability of the assay. The assay was also successfully used with a large number of diverse samples at independent laboratories in four countries, thus demonstrating its transferability, applicability, practicability, and robustness as different qPCR reaction conditions or instruments had a minor effect on Cq values. This updated multiplex CLsp qPCR assay can be used in a variety of citrus surveys, germplasm, or nursery stock programs that require different pathogen detection tools for their successful operation. [Formula: see text] Copyright © 2023 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license .

Spatial Distribution and Temporal Dynamics of Candidatus Liberibacter Asiaticus in Different Stages of Embryos, Nymphs and Adults of Diaphorina citri

Citation
Nian et al. (2023). International Journal of Molecular Sciences 24 (10)
Names
Ca. Liberibacter asiaticus Liberibacter
Subjects
Catalysis Computer Science Applications General Medicine Inorganic Chemistry Molecular Biology Organic Chemistry Physical and Theoretical Chemistry Spectroscopy
Abstract
Huanglongbing, a globally devastating citrus disease, is associated with Candidatus Liberibacter asiaticus (CLas) and is mainly transmitted by Diaphorina citri. Verification of the distribution and dynamics of CLas in D. citri is critical to understanding CLas transmitted by vectors in nature. Here, the distribution and titers of CLas in different sexes and tissues of D. citri adults were investigated by fluorescence in-situ hybridization (FISH) and quantitative real-time PCR (qRT-PCR). Results showed that CLas had widespread distribution in the brain, salivary glands, digestive system, and reproductive system of both females and males, indicating a systemic infection of CLas in D. citri. Moreover, CLas fluorescence intensity and titers were significantly increased in both the digestive system and the female reproductive system with development and there was a marked decreased in both the salivary glands and the male brain, but there was no significant change in the female brain or the male reproductive system. Furthermore, the distribution and dynamics of CLas in embryos and nymphs were investigated. CLas was observed in all laid eggs and subsequent first–second-instar nymphs, indicating that a high percentage of embryos and nymphs resulting from infected D. citri mothers were infected with CLas.

Inoculation of Tomato With Plant Growth Promoting Rhizobacteria Affects the Tomato—Potato Psyllid—<i>Candidatus</i> Liberibacter Solanacearum Interactions

Citation
de Leon et al. (2023). Journal of Economic Entomology 116 (2)
Names
“Liberibacter solanacearum” Liberibacter
Subjects
Ecology General Medicine Insect Science
Abstract
Abstract The Rio Grande Valley (RGV) in southern Texas is well-suited for vegetable production due to its relatively mild/warm weather conditions in the fall and winter. Consequently, insects inflict year-round, persistent damage to crops in the RGV and regions with similar climate. Bactericera cockerelli (Šulc) (Hemiptera: Triozidae), commonly known as the potato psyllid, is a known vector of Candidatus Liberibacter solanacearum (CLso) (Hyphomicrobiales: Rhizobiaceae), a fastidious phloem-limited bacterium associated to vein-greening in tomatoes and Zebra Chip in potatoes. Vector control is the primary approach of integrated pest management (IPM) strategies that aim to prevent plant diseases in commercial agricultural systems. However, resistance-selective pressures that decrease the effectiveness of chemical control (insecticide) applications over time are of increasing concern. Therefore, we explore an ecological approach to devising alternative IPM methodologies to manage the psyllid-transmitted CLso pathogen to supplement existing chemical products and application schedules without increasing resistance. In this study, our objective was to examine the effects of plant-growth promoting rhizobacteria (PGPR) on host-vector-pathogen interactions. Soil-drench applications of PGPRs to Solanum lycopersicum (Solanales: Solanaceae) seedlings revealed structural and possible physiological changes to the plant host and indirect changes on psyllid behavior: host plants had increased length and biomass of roots and exhibited delayed colonization by CLso, while psyllids displayed changes in parental (F0) psyllid behavior (orientation and oviposition) in response to treated hosts and in the sex ratio of their progeny (F1). Based on our results, we suggest that PGPR may have practical use in commercial tomato production.

Expresión de la proteína B8Y674 Candidatus Liberibacter asiaticus mediante electroforesis en geles de poliacrilamida (page) y dot blot

Citation
Ojeda et al. (2023). Brazilian Journal of Animal and Environmental Research 6 (1)
Names
Ca. Liberibacter asiaticus Liberibacter
Subjects
General Medicine
Abstract
El Huanglongbing (HLB), es una de las enfermedades más devastadoras de los cítricos a nivel mundial y representa una seria amenaza para la citricultura mexicana. El agente causal es una bacteria incultivable que pertenece al género Candidatus Liberibacter spp. y afecta a todas las especies de cítricos, especialmente los cítricos agrios. Para su detección, se emplean técnicas moleculares como es la reacción en cadena de la polimerasa (QT-PCR), técnicas serológicas y espectrofotométricas. El objetivo de este trabajo fue expresar la proteína recombinante BY8743 de Candidatus Liberibacter mediante electroforesis en geles de poliacrilamida al 12 % (PAGE) y Dot Blot. Para obtener la secuencia se acudió a la base de datos del National Center Biotechnology Information (NCBI). Una vez obtenida la secuencia, se revisó y modificó el marco de lectura abierto, por sus siglas en ingles Open Reading Frame (ORF) mediante el programa CLC Main Workbench 7 y se procedió a sintetizar el vector pET22b+, también se verificó el codón de inicio y de termino acoplado al vector. Para la transformación se usaron células comerciales One Shot® TOP10 Chemically Competent (InvitrogenTM), posteriormente fueron subclonadas en células de E. coli BL21. Se realizaron minipreparaciones usando un método de lisis alcalina y además se realizó una cinética de crecimiento, observando que en tres horas se alcanza la fase estacionaria. Se aplicaron concentraciones de 0.5, 0.8 y 1 mM del inductor metabólico isopropil-β-D-1-tiogalactopiranósido (IPTG) y la mejor concentración fue 1 mM, ya que a las cuatro horas después de su aplicación se pudo visualizar una proteína sobreexpresada de 38 kDa. Cuando se realizó el Dot Blot se obtuvieron resultados sobresalientes de inmunoexpresión en las tres concentraciones del inductor utilizado a diferencia del control y de las células sin transfectar.