A Novel Two-Component Response Regulator Links rpfwith Biofilm Formation and Virulence of Xanthomonasaxonopodis pv. Citri

Citrus bacterial canker caused by Xanthomonas axonopodis pv. citri is a serious disease that impacts citrus productionworldwide, and X. axonopodis pv. citri is listed as a quarantine pest in certain countries. Biofilm formation is important forthe successful development of a pathogenic relationship between various bacteria and their host(s). To understand themechanisms of biofilm formation by X. axonopodis pv. citri strain XW19, the strain was subjected to transposonmutagenesis. One mutant with a mutation in a two-component response regulator gene that was deficient in biofilmformation on a polystyrene microplate was selected for further study. The protein was designated as BfdR for biofilmformation defective regulator. BfdR from strain XW19 shares 100% amino acid sequence identity with XAC1284 of X.axonopodis pv. citri strain 306 and 30–100% identity with two-component response regulators in various pathogens andenvironmental microorganisms. The bfdR mutant strain exhibited significantly decreased biofilm formation on the leafsurfaces of Mexican lime compared with the wild type strain. The bfdR mutant was also compromised in its ability to causecanker lesions. The wild-type phenotype was restored by providing pbfdR in trans in the bfdR mutant. Our data indicatedthat BfdR did not regulate the production of virulence-related extracellular enzymes including amylase, lipase, protease, andlecithinase or the expression of hrpG, rfbC, and katE; however, BfdR controlled the expression of rpfF in XVM2 medium,which mimics cytoplasmic fluids in planta. In conclusion, biofilm formation on leaf surfaces of citrus is important for cankerdevelopment in X. axonopodis pv. citri XW19. The process is controlled by the two-component response regulator BfdR viaregulation of rpfF, which is required for the biosynthesis of a diffusible signal factor

Quantum correlation generation capability of experimental processes

Einstein-Podolsky-Rosen (EPR) steering and Bell nonlocality illustrate two different kinds of correlations predicted by quantum mechanics. They not only motivate the exploration of the foundation of quantum mechanics, but also serve as important resources for quantum-information processing in the presence of untrusted measurement apparatuses. Herein, we introduce a method for characterizing the creation of EPR steering and Bell nonlocality for dynamical processes in experiments. We show that the capability of an experimental process to create quantum correlations can be quantified and identified simply by preparing separable states as test inputs of the process and then performing local measurements on single qubits of the corresponding outputs. This finding enables the construction of objective benchmarks for the two-qubit controlled operations used to perform universal quantum computation. We demonstrate this utility by examining the experimental capability of creating quantum correlations with the controlled-phase operations on the IBM Quantum Experience and Amazon Braket Rigetti superconducting quantum computers. The results show that our method provides a useful diagnostic tool for evaluating the primitive operations of nonclassical correlation creation in noisy intermediate scale quantum devices.Comment: 5 figures, 3 appendice

Simple and Specific Dual-Wavelength Excitable Dye Staining for Glycoprotein Detection in Polyacrylamide Gels and Its Application in Glycoproteomics

In this study, a commercially available fluorescent dye, Lissamine rhodamine B sulfonyl hydrazine (LRSH), was designed to specifically stain the glycoproteins in polyacrylamide gels. Through the periodate/Schiff base mechanism, the fluorescent dye readily attaches to glycoproteins and the fluorescence can be simultaneously observed under either 305 nm or 532 nm excitation therefore, the dye-stained glycoproteins can be detected under a regular UV transilluminator or a more elegant laser-based gel scanner. The specificity and detection limit were examined using a standard protein mixture in polyacrylamide gels in this study. The application of this glycoprotein stain dye was further demonstrated using pregnancy urine samples. The fluorescent spots were further digested in gel and their identities confirmed through LC-MS/MS analysis and database searching. In addition, the N-glycosylation sites of LRSH-labeled uromodulin were readily mapped via in-gel PNGaseF deglycosylation and LC-MS/MS analysis, which indicated that this fluorescent dye labeling does not interfere with enzymatic deglycosylation. Hence, the application of this simple and specific dual-wavelength excitable dye staining in current glycoproteome research is promising

Acute kidney injury in patients with COVID-19 compared to those with influenza: a systematic review and meta-analysis

BackgroundCOVID-19 and influenza can both lead to acute kidney injury (AKI) as a common complication. However, no meta-analysis has been conducted to directly compare the incidence of AKI between hospitalized patients with COVID-19 and influenza. The objective of our study aims to investigate the incidence and outcomes of AKI among hospitalized patients between these two groups.Materials and methodsA systematic search of PubMed, Embase, and Cochrane databases was conducted from December 2019 to August 2023 to identify studies examining AKI and clinical outcomes among hospitalized patients with COVID-19 and influenza. The primary outcome of interest was the incidence of AKI, while secondary outcomes included in-hospital mortality, recovery from AKI, hospital and ICU stay duration. The quality of evidence was evaluated using Cochrane and GRADE methods.ResultsTwelve retrospective cohort studies, involving 17,618 hospitalized patients with COVID-19 and influenza, were analyzed. COVID-19 patients showed higher AKI incidence (29.37% vs. 20.98%, OR: 1.67, 95% CI 1.56–1.80, p < 0.01, I2 = 92.42%), and in-hospital mortality (30.95% vs. 5.51%, OR: 8.16, 95% CI 6.17–10.80, p < 0.01, I2 = 84.92%) compared to influenza patients with AKI. Recovery from AKI was lower in COVID-19 patients (57.02% vs., 80.23%, OR: 0.33, 95% CI 0.27–0.40, p < 0.01, I2 = 85.17%). COVID-19 patients also had a longer hospital stay (SMD: 0.69, 95% CI 0.65–0.72, p < 0.01, I2 = 98.94%) and longer ICU stay (SMD: 0.61, 95% CI 0.50–0.73, p < 0.01, I2 = 94.80%) than influenza patients. In our study, evidence quality was high (NOS score 7–9), with low certainty for AKI incidence and moderate certainty for recovery form AKI by GRADE assessment.ConclusionCOVID-19 patients had higher risk of developing AKI, experiencing in-hospital mortality, and enduring prolonged hospital/ICU stays in comparison to influenza patients. Additionally, the likelihood of AKI recovery was lower among COVID-19 patients

Epifluorescence micrographs of <i>Xanthomonas axonopodis</i> pv.<i>citri</i> biofilms on grapefruit, Mexican lime and navel orange leaf discs.

<p><i>X. axonopodis</i> pv. <i>citri</i> TPH2, TPH3 and TPH5 were tagged with green fluorescent protein and expressed using the plasmid pGTKan. The culture suspensions (OD₆₂₀  = 0.05) were inoculated in a 24-well polystyrene plate containing grapefruit, Mexican lime and navel orange leaf discs and incubated at 27°C with shaking at 50 rpm for 2 days. Scale bars, 10 μm.</p

The two-component response regulator BfdR plays a role in the virulence of <b><i>Xanthomonas axonopodis</i></b> pv.<i>citri</i> in Mexican lime plants.

<p><b>A</b>, Symptoms on the upper (top panel) and lower (bottom panel) leaf surfaces of Mexican lime leaves at two months post-inoculation with strains TPH2, TPH3 and TPH5. Bacterial suspensions (OD₆₂₀  = 0.3) were inoculated on leaf surfaces using the spray method. <b>B</b>, Number of cankers per cm² on each leaf. All experiments were performed three times with similar results. The results are given as the means and standard deviations (error bars) of six replicates from one representative experiment. *, significantly different (p<0.05) from strain TPH2 based on one-way ANOVA and Tukey's HSD test. Scale bars, 1 cm.</p

<i>Xanthomonas axonopodis</i> pv.<i>citri</i> biofilm formation in a 24-well polystyrene microplate.

<p>Experiments were performed three times with six replicates for each strain. The data presented are the means and standard deviations (error bars) from one representative experiment. *, significantly different (p<0.05) from strain TPH2 based on one-way ANOVA and Tukey's HSD test.</p

Virulence-related gene expression in Xanthomonas <i>axonopodis</i> pv.<i>citri</i> measured by RT-PCR analysis.

<p>RNA was isolated from cultures of strains TPH2, TPH3 and TPH5 in TSB or XVM2 medium, the latter of which mimics cytoplasmic fluids <i>in planta</i>, at 27°C for 18 hr with shaking at 100 rpm. RT-PCR was performed with primers specific for <i>rfbC</i> (113 bp), <i>hrpG</i> (747 bp), <i>rpfF</i> (870 bp), <i>katE</i> (127 bp) and <i>rpoD</i> (263 bp). The mRNA level of <i>rpoD</i> was used as loading control. The experiments were performed three times with similar results, and representative results from one experiment are shown.</p

Confocal laser scanning micrographs of biofilms on Mexican lime leaf discs.

<p><i>X</i>. <i>axonopodis</i> pv. <i>citri</i> TPH2, TPH3 and TPH5 were tagged with green fluorescent protein and expressed using the plasmid pGTKan. The culture suspensions (OD₆₂₀  = 0.05) were inoculated in a 24-well polystyrene plate containing Mexican lime leaf discs and incubated at 27°C with shaking at 50 rpm for 2 days. <b>A</b>, Horizontal (xy-axis) biofilm section with lines indicating the positions of the xz-axis and yz-axis shown at the top and right margins of the images, respectively. <b>B</b>, A simulated projection shows a field of 141.56 μm ×141.56 μm ×9.55 μm (xyz) in TPH2/pGTKan, 141.56 μm ×141.56 μm ×9.18 μm (xyz) in TPH3/pGTKan and 141.56 μm ×141.56 μm ×10.65 μm (xyz) in TPH5/pGTKan. Scale bars, 10 μm.</p

Bacterial strains and plasmids used in this study.

<p>Bacterial strains and plasmids used in this study.</p