Burkholderia insecticola sp. nov., a gut symbiotic bacterium of the bean bug Riptortus pedestris

A Gram-negative, aerobic, rod-shaped, non-spore-forming, motile bacterium, designated strain RPE64(T), was isolated from the gut symbiotic organ of the bean bug Riptortus pedestris, collected in Tsukuba, Japan, in 2007. 16S rRNA gene sequencing showed that this strain belongs to the Burkholderia glathei Glade, exhibiting the highest sequence similarity to Burkholderia peredens LMG 29314(T) (100%), Burkholderia turbans LMG 29316(T) (99.52%) and Burkholderia ptereochthonis LMG 29326(T) (99.04 %). Phylogenomic analyses based on 107 single-copy core genes and Genome BLAST Distance Phylogeny confirmed B. peredens LMG 29314(T), B. ptereochthonis LMG 29326(T) and several uncultivated, endophytic Burkholderia species as its nearest phylogenetic neighbours. Digital DNA-DNA hybridization experiments unambiguously demonstrated that strain RPE64(T) represents a novel species in this lineage. The G+C content of its genome was 63.2 mol%. The isoprenoid quinone was ubiquinone 8 and the predominant fatty acid components were C-16:0, C-18:1 omega 7c and C-17:0 cyclo. The absence of nitrate reduction and the capacity to grow at pH 8 clearly differentiated strain RPE64(T) from related Burkholderia species. Based on these genotypic and phenotypic characteristics, strain RPE64(T) is classified as representing a novel species of the genus Burkholderia, for which the name Burkholderia insecticola sp. nov. is proposed. The type strain is RPE64(T) (=NCIMB 15023(T)=JCM 31142(T))

Five isoforms of the phosphatidylinositol 3-kinase regulatory subunit exhibit different associations with receptor tyrosine kinases and their tyrosine phosphorylations

AbstractThere are five isoforms of the regulatory subunit for the heterodimeric type of phosphatidylinositol 3-kinase. These five regulatory subunit isoforms were overexpressed using an adenovirus transfection system, and their own tyrosine phosphorylations and associations with various tyrosine kinase receptors were investigated. When overexpressed in CHO-PDGFR cells, the associations of these regulatory subunit isoforms with the platelet-derived growth factor receptor were similar. However, when overexpressed in CHO-IR cells, p55γ exhibited a significantly lower ability to bind with IRS-1 upon insulin stimulation, as compared with other regulatory subunit isoforms. Furthermore, p55α and p55γ were found to be tyrosine-phosphorylated. Finally, interestingly, when overexpressed in CHO-EGFR cells or A431 cells and stimulated with epidermal growth factor (EGF), phosphorylated EGF receptor was detected in p85α, p85β and p50α immunoprecipitates, but not in p55α and p55γ immunoprecipitates. In addition, EGF-induced tyrosine phosphorylation was observed in p85α, p85β, p55α and p55γ, but not in p50α, immunoprecipitates. Thus, each regulatory subunit exhibits specific responses regarding both the association with tyrosine-phosphorylated substrates and its own tyrosine phosphorylation. These results suggest that each isoform possesses specific roles in signal transduction, based on its individual tyrosine kinase receptor

Arterial spin labeling image findings in the acute phase in paediatric patients with acute encephalopathy with biphasic seizures and late reduced diffusion

IntroductionDiagnosing acute encephalopathy with biphasic seizures and late reduced diffusion (AESD) after the first seizure (early seizure/seizures, ES/ESs) is challenging because a reduced apparent diffusion coefficient (ADC) in the cortical or subcortical white matter, often described as having a “bright-tree appearance (BTA),” is usually not observed until secondary seizures (late seizures, LSs) occur. Previous studies have reported hypoperfusion on arterial spin labeling (ASL) within 24 h after ES/ESs in patients with AESD and hyperperfusion within 24 h after LS onset. This study aimed to investigate cerebral blood flow in the hyperacute phase (between ES/ESs and LSs) using ASL in patients with AESD.MethodsEight ASL images were acquired in six patients with AESD admitted to our hospital from October 2021 to October 2022. ASL findings in the hyperacute phase were investigated and video-electroencephalogram findings obtained around ASL image acquisition in the hyperacute phase were evaluated.ResultsFour ASL images were obtained for three patients before LS onset, with three images showing hyperperfusion areas and one image showing hypoperfusion areas. These hyperperfuion regions coincided with BTA on subsequent images of these patients.In one patient, the first ASL image was obtained in the late hyperacute phase and revealed hyperperfusion areas with a slightly abnormal change on diffusion-weighted image (DWI), which were not accompanied by ADC abnormalities. The second ASL image obtained 51 h after the first ASL, and before LS onset revealed more prominent hyperperfusion areas than the first ASL image, which were accompanied by BTA. In another patient, the ASL image obtained 82 h after ES revealed hyperperfusion areas without abnormal change on DWI or ADC.ConclusionThis study revealed that two patients exhibited hyperperfusion regions and another patient exhibited hypoperfusion regions among three patients who underwent ASL imaging during the period from 24 h after ES/ESs to LSs in patients with LSs or cooling initiation in patients without LSs due to early anaesthesia induction (late hyperacute phase). Further prospective studies on cerebral blood flow are required to explore the relationship among the timing of image acquisition, the presence of electrographic seizures, and ASL findings in patients with AESD

Diversity of Wolbachia Endosymbionts in Heteropteran Bugs

An extensive survey of Wolbachia endosymbionts in Japanese terrestrial heteropteran bugs was performed by PCR detection with universal primers for wsp and ftsZ genes of Wolbachia, cloning of the PCR products, restriction fragment length polymorphism analysis of infecting Wolbachia types, and molecular phylogenetic characterization of all the detected Wolbachia strains. Of 134 heteropteran species from 19 families examined, Wolbachia infection was detected in 47 species from 13 families. From the 47 species, 59 Wolbachia strains were identified. Of the 59 strains, 16 and 43 were assigned to A group and B group in the Wolbachia phylogeny, respectively. The 47 species of Wolbachia-infected bugs were classified into 8 species with A infection, 28 species with B infection, 2 species with AA infection, 3 species with AB infection, 5 species with BB infection, and 1 species with ABB infection. Molecular phylogenetic analysis showed little congruence between Wolbachia phylogeny and host systematics, suggesting frequent horizontal transfers of Wolbachia in the evolutionary course of the Heteroptera. The phylogenetic analysis also revealed several novel lineages of Wolbachia. Based on statistical analyses of the multiple infections, we propose a hypothetical view that, in the heteropteran bugs, interactions between coinfecting Wolbachia strains are generally not intense and that Wolbachia coinfections have been established through a stochastic process probably depending on occasional horizontal transfers

Spatial and Temporal Population Dynamics of a Naturally Occurring Two-Species Microbial Community inside the Digestive Tract of the Medicinal Leech

The medicinal leech, Hirudo verbana, is one of the simplest naturally occurring models for digestive-tract symbioses, where only two bacterial species, Aeromonas veronii bv. sobria (γ-Proteobacteria) and a Rikenella-like bacterium (Bacteroidetes), colonize the crop, the largest compartment of the leech digestive tract. In this study, we investigated spatial and temporal changes of the localization and microcolony structure of the native symbionts in the crop, after ingestion of a sterile blood meal, by fluorescence in situ hybridization. The population dynamics differed between the two symbiotic bacteria. A. veronii was detected mainly as individual cells inside the intraluminal fluid (ILF) during 14 days after feeding (daf) unless it was found in association with Rikenella microcolonies. The Rikenella-like bacteria were observed not only inside the ILF but also in association with the luminal surface of the crop epithelium. The sizes of Rikenella microcolonies changed dynamically through the 14-day period. From 3 daf onward, mixed microcolonies containing both species were frequently observed, with cells of both species tightly associating with each other. The sizes of the mixed microcolonies were consistently larger than the size of either single-species microcolony, suggesting a synergistic interaction of the symbionts. Lectin staining with succinylated wheat germ agglutinin revealed that the planktonic microcolonies present in the ILF were embedded in a polysaccharide matrix containing N-acetylglucosamine. The simplicity, symbiont-symbiont interaction, and mixed microcolonies of this naturally occurring, digestive-tract symbiosis lay the foundation for understanding the more complex communities residing in most animals