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

Exploring interdisciplinary aspects for conservation management: The case of land hermit crab wildlife trade in Taiwan

Most conservation policies and management primarily focus on vertebrate animals. However, considering the high demand for invertebrate species in the exotic pet markets, it is crucial to give them great consideration. This research explores Coenobita purpureus, a land hermit crab newly recorded in Taiwan in 2017. We noticed that it has gained popularity in the online pet market recently, despite limited studies confirming its population. To mitigate the potential risks associated with this species, our study investigated online wildlife trade markets, conducted field surveys for its distribution and scrutinised relevant regulations in Taiwan. The price of the species increased significantly following its scientific record, suggesting a growing demand in the exotic pet market, potentially driven by an advertisement effect. Additionally, both the sales platform and the individuals' coloration were found to influence market prices. Furthermore, we discovered that C. purpureus is more widely distributed in Taiwan than initially described in the literature, confirming its native status, though the population may be small. We also identified limitations in current Taiwanese regulations and policies regarding the risk of unsustainable trade in potentially threatened invertebrate species. Moreover, we found evidence of individuals being smuggled from China through e‐commerce channels. Regulatory measures addressing the smuggling of small amounts of wildlife are also insufficient, potentially posing invasion risks from alien species. Finally, we drew upon the conclusions from these aspects to provide integrated and practical management implications for policymakers. Additionally, we aim to offer this valuable case study to spotlight the state of the global invertebrate trade. Read the free Plain Language Summary for this article on the Journal blog

Sibling recurrence risk ratio analysis of the metabolic syndrome and its components over time

BACKGROUND: The purpose of this study was to estimate both cross-sectional sibling recurrence risk ratio (λ(s)) and lifetime λ(s )for the metabolic syndrome and its individual components over time among sibships in the prospectively followed-up cohorts provided by the Genetic Analysis Workshop 13. Five measures included in the operational criteria of the metabolic syndrome by the Adult Treatment Panel III were examined. A method for estimating sibling recurrence risk with correction for complete ascertainment was used to estimate the numerator, and the prevalence in the whole cohort was used as the denominator of λ(s). RESULTS: Considerable variability in the λ(s )was found in terms of different time-points for the cross-sectional definition, the times of fulfilling the criterion for lifetime definition, and different components. Obesity and hyperglycemia had the highest cross-sectional λ(s )of the five components. Both components also had the largest slopes in the linear trend of the lifetime λ(s). However, the magnitudes of the lifetime λ(s )were similar to that of the mean cross-sectional λ(s), which were <2. The results of nonparametric linkage analysis showed only suggestive evidence of linkage between one marker and lifetime diagnosis of low high-density lipoprotein cholesterol and metabolic syndrome, respectively. CONCLUSION: The λ(s )of the metabolic syndrome and its components varies substantially across time, and the λ(s )of lifetime diagnosis was not necessarily larger than that of a cross-sectional diagnosis. The magnitude of λ(s )does not predict well the maximum LOD score of linkage analysis

Improving Voice Outcomes After Thyroid Surgery – Review of Safety Parameters for Using Energy-Based Devices Near the Recurrent Laryngeal Nerve

Technological advances in thyroid surgery have rapidly increased in recent decades. Specifically, recently developed energy-based devices (EBDs) enable simultaneous dissection and sealing tissue. EBDs have many advantages in thyroid surgery, such as reduced blood loss, lower rate of post-operative hypocalcemia, and shorter operation time. However, the rate of recurrent laryngeal nerve (RLN) injury during EBD use has shown statistically inconsistent. EBDs generate high temperature that can cause iatrogenic thermal injury to the RLN by direct or indirect thermal spread. This article reviews relevant medical literatures of conventional electrocauteries and different mechanisms of current EBDs, and compares two safety parameters: safe distance and cooling time. In general, conventional electrocautery generates higher temperature and wider thermal spread range, but when applying EBDs near the RLN adequate activation distance and cooling time are still required to avoid inadvertent thermal injury. To improve voice outcomes in the quality-of-life era, surgeons should observe safety parameters and follow the standard procedures when using EBDs near the RLN in thyroid surgery

Mixed Infections of Helicobacter pylori

Background. Persistent Helicobacter pylori infection may induce several upper gastrointestinal diseases. Two major virulence factors of H. pylori, vacuolating cytotoxin A (VacA) and cytotoxin-associated gene A (CagA), are thought to be associated with the severity of disease progression. The distribution of vacA and cag-pathogenicity island (cag-PAI) alleles varies in H. pylori isolated from patients in different geographic regions. Aim. To assess the association between mixed infection of H. pylori clinical isolates from Taiwanese patients and the severity of gastrointestinal diseases. Methods. A total of 70 patients were enrolled in this study. Six distinct and well-separated colonies were isolated from each patient and 420 colonies were analyzed to determine the genotypes of virulence genes. Results. The prevalence of mixed infections of all H. pylori-infected patients was 28.6% (20/70). The rate of mixed infections in patients with duodenal ulcer (47.6%) was much higher than that with other gastrointestinal diseases (P<0.05). Conclusions. H. pylori mixed infections show high genetic diversity that may enhance bacterial adaptation to the hostile environment of the stomach and contribute to disease development

Late initiation of renal replacement therapy is associated with worse outcomes in acute kidney injury after major abdominal surgery

Introduction Abdominal surgery is probably associated with more likelihood to cause acute kidney injury (AKI). The aim of this study was to evaluate whether early or late start of renal replacement therapy (RRT) defined by simplified RIFLE (sRIFLE) classification in AKI patients after major abdominal surgery will affect outcome. Methods A multicenter prospective observational study based on the NSARF ( National Taiwan University Surgical ICU Associated Renal Failure) Study Group database. 98 patients (41 female, mean age 66.4 +/- 13.9 years) who underwent acute RRT according to local indications for post-major abdominal surgery AKI between 1 January, 2002 and 31 December, 2005 were enrolled The demographic data, comorbid diseases, types of surgery and RRT, as well as the indications for RRT were documented. The patients were divided into early dialysis (sRIFLE-0 or Risk) and late dialysis (LD, sRIFLE -Injury or Failure) groups. Then we measured and recorded patients' outcome including in-hospital mortality and RRT wean-off until 30 June, 2006. Results The in-hospital mortality was compared as endpoint. Fifty-seven patients (58.2%) died during hospitalization. LD (hazard ratio (HR) 1.846; P = 0.027), old age (HR 2.090; P = 0.010), cardiac failure (HR 4.620; P < 0.001), pre-RRT SOFA score (HR 1.152; P < 0.001) were independent indicators for in-hospital mortality. Conclusions The findings of this study support earlier initiation of acute RRT, and also underscore the importance of predicting prognoses of major abdominal surgical patients with AKI by using RIFLE classification

Biological Control of Collar Rot on Passion Fruits Via Induction of Apoptosis in the Collar Rot Pathogen by Bacillus subtilis

The seedlings and fresh fruits of passion fruits are of high value in local and global trade. Fusarium solani is a main disease-causing agent affecting passion fruits. The objectives of this study were to develop Bacillus-based biocontrol agents for the management of Fusarium diseases on passion fruits and to investigate their putative control mechanisms. Our studies indicated that B. subtilis YBC and 151B1 show antagonistic activity to F. solani PF7 from passion fruits and inhibited the conidial germination of strain PF7. The application of broth cultures from B. subtilis 151B1 and YBC in SYB medium reduced disease severity of Fusarium wilt on the leaves of passion fruits and enhanced the survival rates of passion fruit seedlings challenged with F. solani PF7. With regard to the putative mechanisms of disease control, the results indicated that treatments consisting of the respective culture filtrates from B. subtilis 151B1 and YBC broths caused aberrant conidial morphology and loss of cell membrane integrity. Additionally, the treatments caused reductions in mitochondrial membrane potential and interfered with the energy metabolism of F. solani PF7. The treatments also enhanced reactive oxygen species accumulation and resulted in the externalization of phosphatidylserine, chromatin condensation, and DNA fragmentation, suggesting their function in triggering apoptotic-like cell death. In conclusion, B. subtilis 151B1 and YBC are potential biocontrol agents for passion fruit disease caused by F. solani. Their control efficacy may result from the surfactins produced to trigger apoptotic-like cell death, reducing mitochondrial membrane potential and interfering with the energy metabolism of the pathogen

Biological Control of Collar Rot on Passion Fruits Via Induction of Apoptosis in the Collar Rot Pathogen by <i>Bacillus subtilis</i>

The seedlings and fresh fruits of passion fruits are of high value in local and global trade. Fusarium solani is a main disease-causing agent affecting passion fruits. The objectives of this study were to develop Bacillus-based biocontrol agents for the management of Fusarium diseases on passion fruits and to investigate their putative control mechanisms. Our studies indicated that B. subtilis YBC and 151B1 show antagonistic activity to F. solani PF7 from passion fruits and inhibited the conidial germination of strain PF7. The application of broth cultures from B. subtilis 151B1 and YBC in SYB medium reduced disease severity of Fusarium wilt on the leaves of passion fruits and enhanced the survival rates of passion fruit seedlings challenged with F. solani PF7. With regard to the putative mechanisms of disease control, the results indicated that treatments consisting of the respective culture filtrates from B. subtilis 151B1 and YBC broths caused aberrant conidial morphology and loss of cell membrane integrity. Additionally, the treatments caused reductions in mitochondrial membrane potential and interfered with the energy metabolism of F. solani PF7. The treatments also enhanced reactive oxygen species accumulation and resulted in the externalization of phosphatidylserine, chromatin condensation, and DNA fragmentation, suggesting their function in triggering apoptotic-like cell death. In conclusion, B. subtilis 151B1 and YBC are potential biocontrol agents for passion fruit disease caused by F. solani. Their control efficacy may result from the surfactins produced to trigger apoptotic-like cell death, reducing mitochondrial membrane potential and interfering with the energy metabolism of the pathogen. [Formula: see text] Copyright © 2021 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license . </jats:p