Identification of Aerotaxis Receptor Proteins Involved in Host Plant Infection by Pseudomonas syringae pv. tabaci 6605

Pseudomonas syringae pv. tabaci 6605 (Pta6605) is a foliar plant pathogen that causes wildfire disease on tobacco plants. It requires chemotaxis to enter plants and establish infection. While chemotactic signals appear to be the main mechanism by which Pta6605 performs directional movement, the involvement of aerotaxis or energy taxis by this foliar pathogen is currently unknown. Based on domain structures and similarity with more than 50 previously identified putative methyl-accepting chemotaxis proteins (MCPs), the genome of Pta6605 encodes three potential aerotaxis transducers. We identified AerA as the main aerotaxis transducer and found that it possesses a taxis-to-serine-and-repellent (Tsr)-like domain structure that supports a periplasmic 4HB-type ligand-binding domain (LBD). The secondary aerotaxis transducer, AerB, possesses a cytosolic PAS-type LBD, similar to the Aer of Escherichia coli and Pseudomonas aeruginosa. Aerotaxis ability by single and double mutant strains of aerA and aerB was weaker than that by wild-type Pta6605. On the other hand, another cytosolic PAS-type LBD containing MCP did not make a major contribution to Pta6605 aerotaxis in our assay system. Furthermore, mutations in aerotaxis transducer genes did not affect surface motility or chemotactic attraction to yeast extract. Single and double mutant strains of aerA and aerB showed less colonization in the early stage of host plant infection and lower biofilm production than wild-type Pta6605. These results demonstrate the presence of aerotaxis transducers and their contribution to host plant infection by Pta6605

Positive chemotaxis to plant apoplastic fluids of Pseudomonas syringae pv. tabaci 6605 and metabolome analysis

Pseudomonas syringae pv. tabaci 6605 (Pta6605) is a causal agent of wildfire disease in host tobacco plants. Although chemotaxis has been shown to be necessary for Pta6605 in tobacco infection, the chemoattractants at the site of infection are unclear. Pta6605 was attracted to the apoplastic fluid from not only host tobacco leaves but also non-host plant leaves, indicating that Pta6605 is attracted to common plant metabolites. Metabolome analysis of apoplastic fluid from tobacco leaves revealed that amino acids including γ-aminobutyric acid and organic acids are abundant, suggesting that these compounds are potential chemoattractants

Muscular blood flow responses as an early predictor of the severity of diabetic neuropathy at a later stage in streptozotocin-induced type I diabetic rats: a diffuse correlation spectroscopy study

We propose a novel application of diffuse correlation spectroscopy to evaluate microvascular malfunctions of muscle tissue affected by hyperglycemia and determine their correlation with the severity of diabetic neuropathy at a later stage. Microvascular responses of the thigh muscle and the mechanical pain threshold of the hind paw of streptozotocin-induced type I diabetic rats were continuously monitored once per week for 70 days. Significantly decreased baseline blood flow and reactive hyperemia responses were observed as early as 1 week after hyperglycemia induction. The reactive hyperemia response at 2 weeks of hyperglycemia was highly correlated with the mechanical pain threshold at 8 weeks, at which time a decreased pain threshold was statistically confirmed in hyperglycemic rats relative to controls. © 2018 Optical Society of America.1

Specific growth inhibitors of Ralstonia solanacearum, Xanthomonas oryzae pv. oryzae, X. campestris pv. campestris, and Clavibacter michiganensis subsp. michiganensis

Plant pathogenic bacteria cause huge yield losses in crops globally. Therefore, finding effective bactericides to these pathogens is an immediate challenge. In this study, we sought compounds that specifically inhibit the growth of Ralstonia solanacearum. As a result, we identified one promising compound, 1-(4-bromophenyl)-6-methoxy-2,3,4,9-tetrahydro-1H-β-carboline, which inhibited the growth of R. solanacearum (Rs1002) from a pilot library of 376 chemicals provided from RIKEN. We further obtained its structural analogues and assessed their ability to inhibit Rs1002 growth. Then we identified five compounds, named ralhibitins A to E, that specifically inhibit growth of Rs1002 at >5 μg/ml final concentration. The most effective compounds, ralhibitins A, C, and E completely inhibited the growth of Rs1002 at 1.25 μg/ml. In addition, ralhibitins A to E inhibited growth of Xanthomonas oryzae pv. oryzae but not the other bacteria tested at a final concentration of 10 μg/ml. Whereas, ralhibitin E, besides inhibiting R. solanacearum and X. oryzae pv. oryzae, completely inhibited the growth of X. campestris pv. campestris and the Gram-positive bacterium Clavibacter michiganensis subsp. michiganensis at 10 μg/ml. Growth inhibition by these compounds was stable at pH 6–9 and after autoclaving. Because Rs1002 grew in the culture medium in which ralhibitins were incubated with the ralhibitin-insensitive bacteria, the unaffected bacteria may be able to inactivate the inhibitory effect of ralhibitins. These results suggest that ralhibitins might be potential lead compounds for the specific control of phytopathogenic bacteria

Development of eosinophilic granulomatosis with polyangiitis during the clinical course of microscopic polyangiitis: A case report

Rationale: Eosinophilic granulomatosis with polyangiitis (EGPA) is belongs to the antineutrophil cytoplasmic autoantibody (ANCA)-associated vasculitis (AAV) subgroups. EGPA, unlike other subgroups of AAV, including microscopic polyangiitis (MPA) and granulomatosis with polyangiitis, has the unique feature that both ANCA and eosinophilic inflammation are involved in its pathogenesis. Although AAV often relapses, there are currently no reports of EGPA developing during other subgroups of AAV. Herein, we document a case of EGPA that developed during the clinical course of MPA.Patient concerns: A 61-year-old Japanese woman was diagnosed with MPA based on interstitial lung disease and myeloperoxidase-ANCA positivity. After starting immunosuppression therapy, including prednisolone and tacrolimus, she was expected to achieve clinical remission. Nonetheless, she occasionally experienced MPA relapse, which required an increased prednisolone dose, rituximab, intravenous cyclophosphamide, and plasma exchange. Three years after MPA onset, she developed renal amyloidosis; thus, subcutaneous tocilizumab was added to her regimen. Following clinical remission, the administration interval of her subcutaneous tocilizumab therapy was extended and immunosuppressants were discontinued. She then developed bronchial asthma and mild eosinophilia (eosinophilic count: ~1000/μL). Further, a year later, she underwent total hip replacement using a titanium implant. Subsequently, she developed abnormal sensation in both hands, numbness, and muscle weakness, as well as palpable purpura and massive eosinophilia (eosinophilic count: ~8500/μL).Diagnosis: We diagnosed the patient with EGPA based on 5 items (asthma, multiple mononeuropathies, sinus abnormality, and extravascular eosinophils) of the 1990 American College of Rheumatology classification criteria.Interventions: We administered 400 mg/kg intravenous immunoglobulin for 5 consecutive days, 300 mg mepolizumab subcutaneously every 4 weeks, and 40 mg/day prednisolone following pulsed methylprednisolone therapy (1000 mg/day for 3 consecutive days).Outcomes: After these treatments, the patient’s symptoms improved, and eosinophilic count and inflammatory markers declined.Lessons: The present case suggests that EGPA can be induced by the development of eosinophilic inflammation in other subgroups of AAV.Abbreviations: AAV = ANCA-associated vasculitis, ANCA = antineutrophil cytoplasmic autoantibody, CCL = chemokine (C–C motif) ligands, CRP = C-reactive protein, EGPA = eosinophilic granulomatosis with polyangiitis, IL = interleukin, ILC2 = group 2 innate lymphoid cells, ILD = interstitial lung disease, MPA = microscopic polyangiitis, MPO = myeloperoxidase, mPSL = methylprednisolone, PSL = prednisolone, TAC = tacrolimus, TCZ = tocilizumab, Th2 = T helper 2

Spinocerebellar ataxia type 31 associated with REM sleep behavior disorder: a case report

Abstract Background Spinocerebellar ataxia type 31 (SCA 31) is a slowly progressive neurodegenerative disorder characterized by pure cerebellar ataxia. Unlike other CAG repeat diseases, sleep-related problems have not been reported in patients with SCA 31 so far. Case presentation A 67-year-old woman was admitted to our hospital with dysarthria and gait disturbance after onset age of 62 years. Neurological examination revealed pure cerebellar ataxia. Genetic analysis detected expansion of a TGGAA repeat in the coding region of the BEAN/TK2 gene on chromosome 16p22.1, confirming the diagnosis of SCA 31. One year later, her husband noticed the patient talking loudly during sleep once or twice a week. Overnight polysomnography showed rapid eye movement sleep without atonia. Cardiac scintigraphy with iodine-123-labeled meta-iodobenzylguanidine revealed a low heart/mediastinum ratio, indicating reduced uptake, and a high washout rate. Conclusion To our knowledge, this is the first report of a patient with SCA 31 associated with rapid eye movement sleep behavior disorder (RBD). In the future, evaluation of autonomic function, assessment of the frequency of RBD, and performance of cardiac iodine-123-labeled meta-iodobenzylguanidine scintigraphy in a larger number of SCA 31 patients could be useful to resolve important issues regarding the mechanism of RBD

Non-convulsive status epilepticus associated with neuronal intranuclear inclusion disease: A case report and literature review

We report a case of neuronal intranuclear inclusion disease (NIID) confirmed by detection of intranuclear inclusions in a skin biopsy specimen. Brain magnetic resonance imaging showed mild cerebral atrophy and linear hyperintensities at the corticomedullary junction on diffusion-weighted images. This patient developed nonconvulsive status epilepticus with generalized periodic discharges on electroencephalography after recurrent symptoms of paroxysmal nausea and slowly progressive cognitive decline. There have been no previous reports of NIID with nonconvulsive status epilepticus to our knowledge. Since adult patients with NIID display a wide variety of clinical manifestations, skin biopsy should be considered in patients who have leukoencephalopathy of unknown origin. Keywords: Neuronal intranuclear inclusion disease, Non-convulsive status epilepticus, Generalized periodic discharges, Autonomic neuropathy, Skin biops