Dynamic expression of Ralstonia solanacearum virulence factors and metabolism-controlling genes during plant infection.

BACKGROUND: Ralstonia solanacearum is the causal agent of bacterial wilt, a devastating plant disease responsible for serious economic losses especially on potato, tomato, and other solanaceous plant species in temperate countries. In R. solanacearum, gene expression analysis has been key to unravel many virulence determinants as well as their regulatory networks. However, most of these assays have been performed using either bacteria grown in minimal medium or in planta, after symptom onset, which occurs at late stages of colonization. Thus, little is known about the genetic program that coordinates virulence gene expression and metabolic adaptation along the different stages of plant infection by R. solanacearum. RESULTS: We performed an RNA-sequencing analysis of the transcriptome of bacteria recovered from potato apoplast and from the xylem of asymptomatic or wilted potato plants, which correspond to three different conditions (Apoplast, Early and Late xylem). Our results show dynamic expression of metabolism-controlling genes and virulence factors during parasitic growth inside the plant. Flagellar motility genes were especially up-regulated in the apoplast and twitching motility genes showed a more sustained expression in planta regardless of the condition. Xylem-induced genes included virulence genes, such as the type III secretion system (T3SS) and most of its related effectors and nitrogen utilisation genes. The upstream regulators of the T3SS were exclusively up-regulated in the apoplast, preceding the induction of their downstream targets. Finally, a large subset of genes involved in central metabolism was exclusively down-regulated in the xylem at late infection stages. CONCLUSIONS: This is the first report describing R. solanacearum dynamic transcriptional changes within the plant during infection. Our data define four main genetic programmes that define gene pathogen physiology during plant colonisation. The described expression of virulence genes, which might reflect bacterial states in different infection stages, provides key information on the R. solanacearum potato infection process.

Identifying Public Policy and Advocacy Practices Among Millennial Pediatric Dental Residents.

Purpose: This study's purpose was to identify public policy and advocacy practices among millennial pediatric dental residents in order to provide recommendations for engagement to the American Academy of Pediatric Dentistry (AAPD) leadership and pediatric dental residency program directors. Methods: A total of 138 residents from the 2016 Public Policy Advocacy Conference (PPAC) participated in a 13-item survey addressing demographics, advocacy education experience, student debt and financial contributions, resident training interests, the impact of the PPAC, and technology utilization. Sixty responses (45 percent response) were analyzed using SPSS software. Results: Residents believed that the PPAC was more beneficial than advocacy didactic education (P=0.008). The impact of the PPAC versus clinical experience was not significant (P=0.61). Pediatric dental residents were more likely to contribute financial donations to the AAPD's advocacy efforts following attendance of a program like the PPAC (P=0.051). Conclusion: Pediatric dental residents who participated in the PPAC or a local clinically oriented experience, perceived these two types of activities to provide greater value in their advocacy education than that of a didactic lecture in this subject area. Study results can be used to guide program directors in developing millennial-specific, resident-driven advocacy education experiences to fulfill Commission on Dental Accreditation advocacy curricula requirements.

Lynx eats cat: disease risk assessment during an Iberian lynx intraguild predation.

Lethal interactions between members of the carnivore guild are well represented in literature. In the Iberian lynx, interspecific killing (without prey consumption) of some mesocarnivores, such as the Egyptian mongoose, genet, and red fox, has been reported. Although vaguely documented, evidence suggests feral cats fall victim to interactions with this apex predator. Here, we describe the first documented case of interspecific killing and partial consumption of a feral cat by an adult male Iberian lynx reintroduced in Southwestern Spain. Ulterior analyses demonstrated that the victim was viremic to feline leukemia virus. To prevent the dissemination of the virus and a potential outbreak in the Iberian lynx population, control measures, including the clinical evaluation of the male Iberian lynx, and intensive monitoring were implemented in order to detect intraspecific interactions. After 3 weeks, the lynx was evaluated, presented good condition and resulted negative to both ELISA and RT-PCR. Thanks to the long-term monitoring, this case could be detected and measures to prevent an outbreak could be implemented.

Metacaspases versus caspases in development and cell fate regulation.

Initially found to be critically involved in inflammation and apoptosis, caspases have since then been implicated in the regulation of various signaling pathways in animals. How caspases and caspase-mediated processes evolved is a topic of great interest and hot debate. In fact, caspases are just the tip of the iceberg, representing a relatively small group of mostly animal-specific enzymes within a broad family of structurally related cysteine proteases (family C14 of CD clan) found in all kingdoms of life. Apart from caspases, this family encompasses para- and metacaspases, and all three groups of proteases exhibit significant variation in biochemistry and function in vivo. Notably, metacaspases are present in all eukaryotic lineages with a remarkable absence in animals. Thus, metacaspases and caspases must have adapted to operate under distinct cellular and physiological settings. Here we discuss biochemical properties and biological functions of metacaspases in comparison to caspases, with a major focus on the regulation of developmental aspects in plants versus animals.

The plant metacaspase AtMC1 in pathogen-triggered programmed cell death and aging: functional linkage with autophagy.

Autophagy is a major nutrient recycling mechanism in plants. However, its functional connection with programmed cell death (PCD) is a topic of active debate and remains not well understood. Our previous studies established the plant metacaspase AtMC1 as a positive regulator of pathogen-triggered PCD. Here, we explored the linkage between plant autophagy and AtMC1 function in the context of pathogen-triggered PCD and aging. We observed that autophagy acts as a positive regulator of pathogen-triggered PCD in a parallel pathway to AtMC1. In addition, we unveiled an additional, pro-survival homeostatic function of AtMC1 in aging plants that acts in parallel to a similar pro-survival function of autophagy. This novel pro-survival role of AtMC1 may be functionally related to its prodomain-mediated aggregate localization and potential clearance, in agreement with recent findings using the single budding yeast metacaspase YCA1. We propose a unifying model whereby autophagy and AtMC1 are part of parallel pathways, both positively regulating HR cell death in young plants, when these functions are not masked by the cumulative stresses of aging, and negatively regulating senescence in older plants.

Programmed cell death in the plant immune system.

Cell death has a central role in innate immune responses in both plants and animals. Besides sharing striking convergences and similarities in the overall evolutionary organization of their innate immune systems, both plants and animals can respond to infection and pathogen recognition with programmed cell death. The fact that plant and animal pathogens have evolved strategies to subvert specific cell death modalities emphasizes the essential role of cell death during immune responses. The hypersensitive response (HR) cell death in plants displays morphological features, molecular architectures and mechanisms reminiscent of different inflammatory cell death types in animals (pyroptosis and necroptosis). In this review, we describe the molecular pathways leading to cell death during innate immune responses. Additionally, we present recently discovered caspase and caspase-like networks regulating cell death that have revealed fascinating analogies between cell death control across both kingdoms.

[Ultrasound features of entesopathy in patients with psoriatic dactylitis]. / Signes échographiques d'enthésopathies au cours des dactylites psoriasiques.

PURPOSE: To describe the sonographic features of entesopathy in patients with psoriatic dactylitis. Materials and methods. Clinical, radiographic and sonographic evaluation of 120 hand joints with clinical abnormality including 20 fingers in 17 patients with rheumatoid arthritis (RA) and 20 fingers in 17 patients with psoriatic arthritis (PA). RESULTS: Forty cases of dactylitis. In patients with RA: 29 cases of synovitis, 15 cases of tenosynovitis, and 2 cases of tendinitis; in patients with PA: 21 cases of synovitis and 3 cases of tenosynovitis. Bone erosions were present in RA patients whereas erosions with bone production were present in PA patients. A total of 60% of RA and PA patients showed erosions on conventional radiographs. Features suggesting entesopathy were present in PA patients only: specific changes of P3, capsular hyperostosis and periarticular periostitis. CONCLUSION: Based on evaluation of PA patients, it seems that sonographic features suggesting entesopathy in patients with dactylitis may be present.

[Malaise with sweating induced by eye-drop. A case of iatrogenic pathology caused by diagnostic error]. / Malaises avec sueurs dus à un collyre. Un cas d'errance diagnostique due à une pathologie iatrogène.

INTRODUCTION: Eye-drops can provoke various systemic side effects and diagnosis of an iatrogenic pathology can made difficult. Observation For 4 months, and 80 year-old man had experienced severe recurrent episodes of sweating concomitant with shaking of the legs. Alpha stimulating eye-drops, prescribed for his glaucoma, were at the origin of these problems. On withdrawal of the latter, the symptoms regressed. DISCUSSION: Diagnosis of an iatrogenic pathology was made after 3 months of medical explorations. The delay in diagnosis was prolonged because the patient had not mentioned the use of an active ingredient, since it was in the form of eye-drops. CONCLUSION: The search for drug-induced causes must be systematic when faced with any unexplained symptom and must include all the active ingredients, whatever their form of administration.

Occurrence and levels of indicator bacteriophages in bathing waters throughout Europe.

Somatic coliphages, F-specific RNA bacteriophages, bacteriophages infecting Bacteroides fragilis, Escherichia coli and enterococci were counted in bathing waters in the late spring and summer. We tested fresh and marine bathing waters from North, South, East and West Europe expected to contain between 100 and 500 E. coli per 100 ml, although wider ranges were sometimes found. Bacteriophages were counted after concentration, since a preliminary study proved that this step was necessary to obtain positive counts. During monitoring, a first-line quality control with reference materials for bacteria and bacteriophages was performed by all the laboratories participating in the study. The same microbes were also counted in raw sewage samples from various areas in Europe, where the bacterial indicators and the three groups of bacteriophages were detected in roughly the same numbers. All groups of bacteriophages were detected in both fresh and marine bathing waters throughout Europe. Reliable and complete results from 147 samples showed that for log-transformed values, E. coli and bacteriophages were slightly correlated. However, the slope of the regression line changed according to E. coli concentration and the correlation diminished when this concentration was close to zero per 100 ml. The ratios between E. coli and phages in bathing waters differed significantly from those in sewage. The relative amounts of bacteriophages, mainly somatic coliphages and phages infecting Bact. fragilis RYC2056, increased in bathing waters with low E. coli concentration, especially in seawater samples containing < 100 E. coli per 100 ml. The relationship of bacteriophages with respect to enterococci paralleled that of bacteriophages with respect to E. coli. Somatic coliphages and bacteriophages infecting Bact. fragilis are useful to predict the presence of some pathogens with the same origin as present bacterial indicators but with higher survival rates.

Eruptive pseudoangiomatosis.

We describe two children with acute onset and spontaneous resolution of angioma-like papules during a viral illness. The biopsy specimens from both patients showed a unique histologic appearance consisting of dilated dermal blood vessels with plump, hobnail-shaped endothelial cells. On the basis of the natural history and the histopathologic features we suggest the diagnosis of eruptive pseudoangiomatosis.