Characterizing obesity in a large health care delivery system.

OBJECTIVES: To characterize the prevalence of obesity and associated health care use within an integrated health care system in California. STUDY DESIGN: Cross-sectional study using electronic health records. METHODS: Primary care patients 18 years and older receiving care at Sutter Health between 2015 and 2020 were included in the study. Obesity was classified and health care utilization was ascertained at index and during the follow-up periods. Differences in prevalence by demographic and clinical characteristics among patients with and without obesity were assessed. Logistic regression was used to estimate the relationship between obesity class and health care utilization (outpatient encounters). RESULTS: Of the 1,094,790 primary care patients included in the analysis, 35% were classified as having obesity, defined as a body mass index of 30 kg/m2 or more or 25 kg/m2 or more for Asian individuals. Obesity prevalence was greater in Hispanic patients (46%) than in non-Hispanic White patients (30%). Patients without obesity had fewer outpatient visits (mean [SD], 3.7 [3.8]) than those with class 1 (4.1 [4.0]), class 2 (4.6 [4.4]), and class 3 (5.2 [4.8]) obesity. In the fully adjusted regression model, the odds of being a high utilizer among patients with obesity were 1.1 (class 1), 1.2 (class 2), and 1.3 (class 3) times that of patients without obesity (P < .001). CONCLUSION: Obesity prevalence is high among patients in the Sutter Health system, varying by race/ethnicity, and was associated with increased outpatient visit utilization. There is a need for greater awareness of the impact of obesity and the specific patient populations affected by the disease.

The Unmet Needs of Breast Cancer Navigation Services: Reconciling Clinical Care With the Emotional and Logistical Challenges Experienced by Younger Women with Breast Cancer in a Healthcare Delivery System.

This study explores the experience of the breast cancer journey for younger women receiving patient navigation services in a healthcare delivery system and any remaining challenges that navigation services may leave unaddressed. In this qualitative analysis, we used a purposeful sampling approach to conduct a semistructured in-person interview with 19 younger women (under 50 years at the time of diagnosis) at various stages of breast cancer treatment and receiving care that included some form of patient navigation services/within the Sutter Health system. Thematic analysis was performed using an inductive grounded theory approach. The patient experience revealed that women receiving navigation services throughout their cancer journey had little concern related to clinical decision-making and treatment. Rather, emotional, and logistical challenges dominate their experience and perceptions of the cancer journey. Managing day-to-day life and the emotional aspects of a cancer diagnosis cannot be disentangled from clinical care. Navigating the emotional and logistical aspects of the cancer journey is an ongoing unmet need for women under age 50, and navigation services can potentially be enhanced to help address these specific needs. Women with breast cancer may benefit from navigation programs focused not only on clinically related challenges but also on recognizing the daily needs of younger women and guiding them through family and job-related obstacles encountered while navigating cancer care. Health systems could enhance existing nurse navigation programs and redesign other aspects of care to focus on meeting these needs.

Core-Genome Multilocus Sequence Typing for Epidemiological and Evolutionary Analyses of Phytopathogenic Xanthomonas citri.

Xanthomonas citri subsp. citri is the cause of bacterial citrus canker, responsible for major economic losses to the citrus industry. X. citri subspecies and pathovars are responsible for diseases in soybean, common bean, mango, pomegranate, and cashew. X. citri disease has been tracked using several typing methods, but recent studies using genomic sequencing have been key to understanding the evolutionary relationships within the species, including fundamental differences among X. citri subsp. citri pathotypes. Here, we describe a core-genome multilocus sequence typing (cgMLST) scheme for X. citri based on 250 genomes comprising multiple examples of X. citri subsp. citri pathotypes A, A*, and Aw; X. citri subsp. malvacearum; X. citri pv. aurantifolii, pv. fuscans, pv. glycines, pv. mangiferaeindicae, pv. viticola, and pv. vignicola; and single isolates of X. citri pv. dieffenbachiae and pv. punicae. This data set included genomic sequencing of 100 novel X. citri subsp. citri isolates. cgMLST, based on 1,618 core genes across 250 genomes, is implemented at PubMLST (https://pubmlst.org/organisms/xanthomonas-citri/). GrapeTree minimum-spanning tree and Interactive Tree of Life (iTOL) neighbor-joining phylogenies generated from the cgMLST data resolved almost identical groupings of isolates to a core-genome single nucleotide polymorphism (SNP)-based neighbor-joining phylogeny. These resolved identical groupings of X. citri subsp. citri pathotypes and X. citri subspecies and pathovars. X. citri cgMLST should prove to be an increasingly valuable resource for the study of this key species of plant-pathogenic bacteria. Users can submit genomic data and associated metadata for comparison with previously characterized isolates at PubMLST to allow the rapid characterization of the local, national, and global epidemiology of these pathogens and examine evolutionary relationships. IMPORTANCE Xanthomonas citri is a plant pathogen that causes major economic losses to the citrus industry and sweet orange production in particular. Several subspecies and pathogens are recognized, with host ranges including soybean, common bean, mango, pomegranate, and cashew, among others. Recent genomic studies have shown that host-adapted X. citri subspecies and pathovars and X. citri subsp. citri pathotypes form distinct clades. In this study, we describe a core-genome multilocus sequence typing (cgMLST) scheme for this species that can rapidly and robustly discriminate among these ecologically distinct, host-adapted clades. We have established this scheme and associated databases containing genomic sequences and metadata at PubMLST, which users can interrogate with their own genome sequences to determine X. citri subspecies, pathovars, and pathotypes. X. citri cgMLST should prove to be an invaluable tool for the study of the epidemiology and evolution of this major plant pathogen.

Medication non-adherence and therapeutic inertia independently contribute to poor disease control for cardiometabolic diseases.

Poorly controlled cardiometabolic biometric health gap measures [e.g.,uncontrolled blood pressure (BP), HbA1c, and low-density lipoprotein cholesterol (LDL-C)] are mediated by medication adherence and clinician-level therapeutic inertia (TI). The study of comparing relative contribution of these two factors to disease control is lacking. We conducted a retrospective cohort study using 7 years of longitudinal electronic health records (EHR) from primary care cardiometabolic patients who were 35 years or older. Cox-regression modeling was applied to estimate how baseline proportion of days covered (PDC) and TI were associated with cardiometabolic related health gap closure. 92,766 patients were included in the analysis, among which 89.9%, 85.8%, and 73.3% closed a BP, HbA1c, or LDL-C gap, respectively, with median days to gap closure ranging from 223 to 408 days. Patients who did not retrieve a medication were the least likely to achieve biometric control, particularly for LDL-C (HR = 0.58, 95% CI: 0.55-0.60). TI or uncertainty of TI was associated with a high risk of health gap persistence, particularly for LDL-C (HR ranges 0.46-0.48). Both poor medication adherence and TI are independently associated with persistent health gaps, and TI has a much higher impact on disease control compared to medication adherence, implying disease management strategies should prioritize reducing TI.

Evaluating the Impact of a Point-of-Care Cardiometabolic Clinical Decision Support Tool on Clinical Efficiency Using Electronic Health Record Audit Log Data: Algorithm Development and Validation.

BACKGROUND: Electronic health record (EHR) systems are becoming increasingly complicated, leading to concerns about rising physician burnout, particularly for primary care physicians (PCPs). Managing the most common cardiometabolic chronic conditions by PCPs during a limited clinical time with a patient is challenging. OBJECTIVE: This study aimed to evaluate a Cardiometabolic Sutter Health Advanced Reengineered Encounter (CM-SHARE), a web-based application to visualize key EHR data, on the EHR use efficiency. METHODS: We developed algorithms to identify key clinic workflow measures (eg, total encounter time, total physician time in the examination room, and physician EHR time in the examination room) using audit data, and we validated and calibrated the measures with time-motion data. We used a pre-post parallel design to identify propensity score-matched CM-SHARE users (cases), nonusers (controls), and nested-matched patients. Cardiometabolic encounters from matched case and control patients were used for the workflow evaluation. Outcome measures were compared between the cases and controls. We applied this approach separately to both the CM-SHARE pilot and spread phases. RESULTS: Time-motion observation was conducted on 101 primary care encounters for 9 PCPs in 3 clinics. There was little difference (<0.8 minutes) between the audit data-derived workflow measures and the time-motion observation. Two key unobservable times from audit data, physician entry into and exiting the examination room, were imputed based on time-motion studies. CM-SHARE was launched with 6 pilot PCPs in April 2016. During the prestudy period (April 1, 2015, to April 1, 2016), 870 control patients with 2845 encounters were matched with 870 case patients and encounters, and 727 case patients with 852 encounters were matched with 727 control patients and 3754 encounters in the poststudy period (June 1, 2016, to June 30, 2017). Total encounter time was slightly shorter (mean -2.7, SD 1.4 minutes, 95% CI -4.7 to -0.9; mean -1.6, SD 1.1 minutes, 95% CI -3.2 to -0.1) for cases than controls for both periods. CM-SHARE saves physicians approximately 2 minutes EHR time in the examination room (mean -2.0, SD 1.3, 95% CI -3.4 to -0.9) compared with prestudy period and poststudy period controls (mean -1.9, SD 0.9, 95% CI -3.8 to -0.5). In the spread phase, 48 CM-SHARE spread PCPs were matched with 84 control PCPs and 1272 cases with 3412 control patients, having 1119 and 4240 encounters, respectively. A significant reduction in total encounter time for the CM-SHARE group was observed for short appointments (≤20 minutes; 5.3-minute reduction on average) only. Total physician EHR time was significantly reduced for both longer and shorter appointments (17%-33% reductions). CONCLUSIONS: Combining EHR audit log files and clinical information, our approach offers an innovative and scalable method and new measures that can be used to evaluate clinical EHR efficiency of digital tools used in clinical settings.

Patient Preferences for Preventive Healthcare During the COVID-19 Pandemic in a Large Integrated Health System.

The COVID-19 pandemic caused healthcare systems and patients to cancel or postpone healthcare services, particularly preventive care. Many patients still have not received these services raising concerns about the potential for preventable morbidity and mortality. At Sutter Health, a large integrated healthcare system in Northern California, we conducted a population-based email survey in August 2020 to evaluate perceptions and preferences about where, when, and how healthcare is delivered during the COVID-19 pandemic. In total, 3351 patients completed surveys, and 42.6% reported that they would "wait until they felt safe" before receiving a colonoscopy as compared to 22.4% for a mammogram. The doctor's office was the most common preferred location for receiving vaccines/shots (79.9%), though many also reported preferring an outdoor setting or in a car (63.7%). With over 40% of patients reporting that they would "wait until they feel safe" for a colonoscopy, healthcare systems could focus on promoting other evidence-based options such a fecal-occult blood test to ensure timely colon cancer screening.

Simulated Leaching of Foliar Applied Copper Bactericides on the Soil Microbiome Utilizing Various Beta Diversity Resemblance Measurements.

Copper bactericides are routinely used to control Xanthomonas perforans (XP), causal agent of bacterial spot of tomato. Given the widespread tolerance to copper in XP strains in FL, USA, nanotechnology-based elemental composites have gained interest for their potential applications in agriculture in part due to their enhanced antimicrobial properties and toxicity to copper-tolerant strains. However, little is known about the potential impact of conventional copper bactericides as well as nano-based elemental composites on soil microbial communities, as determined by high-throughput sequencing of the 16S rDNA. We compared the effects of 2 and 200 µg/mL of core-shell (CS), a metallic copper composite, and a conventional copper bactericide + mancozeb (Cu+Man) on the soil microbiome. These treatments were compared to three controls, the microbial profile of the soil prior to application of copper products, a water application, and spiking the soil with a soilborne phytobacterium, Ralstonia solanacearum (RS). The RS treatment was included to determine if downstream analysis could detect the artificial inoculation. Utilizing multiple ß diversity measurements, each emphasizing various tenets of ecology, provided a greater perspective of the effects the treatments had on the microbiome. Analysis of HTS data revealed that the two treatments containing field applied rates of metallic copper, CS 200 and Cu+Man, had the largest impact on the soil microbiome at seven-days posttreatment compared to water. However, we simulated field applied rates of CS 200 entering the soil by treating soil with CS 2 and determined this concentration had a negligible effect on the soil microbiome. IMPORTANCE Nanotechnology-based elemental composites have gained popularity for their potential applications in plant disease management due to their enhanced antimicrobial properties. However, little is known about their potential impact on the environment. Foliar applications of nano metallic composites upon leaching into the soil have the potential to impact soil microbial populations that in turn influence soil health. Utilizing multiple ß diversity measurements, high-throughput sequencing analysis revealed that field applied rates of metallic copper (200 µg/mL) from an advanced copper composite (core-shell [CS]) and a conventional copper bactericide in combination with mancozeb had the largest impact on the soil microbiome compared to water and nontreated control. To simulate leaching from the leaf surface, a lower concentration (2 µg/mL) of CS was also applied to the soil and had a negligible effect on the soil microbiome. Thus, field applied rates of CS may have a minimal effect on soil microbial communities.

IsoTag™AAV: an innovative, scalable & non-chromatographic method for streamlined AAV manufacturing.

Demand for gene therapies capable of treating previously inaccessible targets has risen precipitously in the past decade. Adeno-associated viruses (AAVs) are the preferred vector for gene delivery because of their favorable safety profile and tissue tropism, but they have significant manufacturing challenges, with end-to-end yields as low as 10-30%. To combat these low yields, we developed IsoTag™AAV, a novel purification technology for AAV that is a departure from the chromatographic paradigm in downstream processing. This proprietary technology uses a self-scaffolding recombinant protein reagent that can improve manufacturing yields. It enables purification by cost-effective and scalable filtration processes and improves product quality with minimal optimization. Herein, we describe the development of IsoTag™AAV, provide a head-to-head comparison to industry-leading affinity chromatography (evaluation carried out through a joint research project with Capsida Biotherapeutics), and demonstrate how it can reduce cost of goods for a clinical AAV program by 25%.

Three new species of Acanthocephala from Acanthogyrus (Acanthosentis) (Acanthocephala: Quadrigyridae) from tinfoil barb fish, Barbonymus schwanenfeldii in Lake Kenyir, Terengganu, Malaysia.

This study was carried out in order to identify acanthocephalan species complexes, based on morphological variability, infecting Barbonymus schwanenfeldii from Lake Kenyir, Terengganu, Malaysia. Acanthocephala were fixed in ethanol, stained with aceto-carmine and studied morphologically by using a light microscope. Variation in morphological traits such as proboscis, proboscis receptacle, egg, testes shape and location, number of hooks and cement gland has been traditionally used to diagnose the acanthocephalans species but the delimitations between closely related species are still confusing and are always questionable among taxonomists. Molecular analysis was used for support the identification. Morphological variability prospecting reveals the presence of three different new species complexes from the subgenus Acanthosentis by referring published taxonomic keys. These new species may be distinguished from the other 46 described species of Acanthosentis by having six unique structures: the presence of an anterior parareceptacle structure (PRS); vaginal sleeve structure; a paired lateral, cone-shaped, muscular jacket surrounding the vagina; alternating pattern and size of proboscis hooks, variation in proboscis size and shape; the presence of the circular collar ring around the neck between the proboscis and trunk and lastly the presence of a muscular-like structure attached to the collar ring on the proboscis. These acanthocephalans found in the intestine of B. schwanenfeldii in Kenyir Lake Malaysia represent new species, named Acanthogyrus ( Acanthosentis) kenyirensis n.sp., A. ( A.) terengganuensis n.sp. and A. ( A.) tembatensis n. sp.

Electronic Health Record Technology Designed for the Clinical Encounter: MS NeuroShare.

OBJECTIVE: Advances in medical discoveries have bolstered expectations of precise and complete care, but delivering on such a promise for complex, chronic neurologic care delivery requires solving last-mile challenges. We describe the iterative human-centered design and pilot process for multiple sclerosis (MS) NeuroShare, a digital health solution that brings practical information to the point of care so that clinicians and patients with MS can view, discuss, and make informed decisions together. METHODS: We initiated a comprehensive human-centered process to iteratively design, develop, and implement a digital health solution for managing MS in the routine outpatient setting of the nonprofit Sutter Health system in Northern California. The human-centered codesign process included 3 phases: discovery and design, development, and implementation and pilot. Stakeholders included Sutter Health's Research Development and Dissemination team, academic domain experts, neurologists, patients with MS, and an advisory group. RESULTS: MS NeuroShare went live in November 2018. It included a patient- and clinician-facing web application that launches from the electronic health record, visually displays a patient's data relevant to MS, and prompts the clinician to comprehensively evaluate and treat the patient. Both patients and clinicians valued the ability to jointly view patient-generated and other data. Preliminary results suggest that MS NeuroShare promotes patient-clinician communication and more active patient participation in decision-making. CONCLUSIONS: Lessons learned in the design and implementation of MS NeuroShare are broadly applicable to the design and implementation of digital tools aiming to improve the experience of delivering and receiving high-quality care for complex, neurologic conditions across large health systems.

An electronic, unsupervised patient-reported Expanded Disability Status Scale for multiple sclerosis.

BACKGROUND: In persons with multiple sclerosis (MS), the Expanded Disability Status Scale (EDSS) is the criterion standard for assessing disability, but its in-person nature constrains patient participation in research and clinical assessments. OBJECTIVE: The aim of this study was to develop and validate a scalable, electronic, unsupervised patient-reported EDSS (ePR-EDSS) that would capture MS-related disability across the spectrum of severity. METHODS: We enrolled 136 adult MS patients, split into a preliminary testing Cohort 1 (n = 50), and a validation Cohort 2 (n = 86), which was evenly distributed across EDSS groups. Each patient completed an ePR-EDSS either immediately before or after a MS clinician's Neurostatus EDSS evaluation. RESULTS: In Cohort 2, mean age was 50.6 years (range = 26-80) and median EDSS was 3.5 (interquartile range (IQR) = [1.5, 5.5]). The ePR-EDSS and EDSS agreed within 1-point for 86% of examinations; kappa for agreement within 1-point was 0.85 (p < 0.001). The correlation coefficient between the two measures was 0.91 (<0.001). DISCUSSION: The ePR-EDSS was highly correlated with EDSS, with good agreement even at lower EDSS levels. For clinical care, the ePR-EDSS could enable the longitudinal monitoring of a patient's disability. For research, it provides a valid and rapid measure across the entire spectrum of disability and permits broader participation with fewer in-person assessments.

Three new species of Acanthocephala from Acanthogyrus (Acanthosentis) (Acanthocephala: Quadrigyridae) from tinfoil barb fish, Barbonymus schwanenfeldii in Lake Kenyir, Terengganu, Malaysia

@#This study was carried out in order to identify acanthocephalan species complexes, based on morphological variability, infecting Barbonymus schwanenfeldii from Lake Kenyir, Terengganu, Malaysia. Acanthocephala were fixed in ethanol, stained with aceto-carmine and studied morphologically by using a light microscope. Variation in morphological traits such as proboscis, proboscis receptacle, egg, testes shape and location, number of hooks and cement gland has been traditionally used to diagnose the acanthocephalans species but the delimitations between closely related species are still confusing and are always questionable among taxonomists. Molecular analysis was used for support the identification. Morphological variability prospecting reveals the presence of three different new species complexes from the subgenus Acanthosentis by referring published taxonomic keys. These new species may be distinguished from the other 46 described species of Acanthosentis by having six unique structures: the presence of an anterior parareceptacle structure (PRS); vaginal sleeve structure; a paired lateral, cone-shaped, muscular jacket surrounding the vagina; alternating pattern and size of proboscis hooks, variation in proboscis size and shape; the presence of the circular collar ring around the neck between the proboscis and trunk and lastly the presence of a muscular-like structure attached to the collar ring on the proboscis. These acanthocephalans found in the intestine of B. schwanenfeldii in Kenyir Lake Malaysia represent new species, named Acanthogyrus (Acanthosentis) kenyirensis n.sp., A. (A.) terengganuensis n.sp. and A. (A.) tembatensis n. sp.

Improved deferred antagonism technique for detecting antibiosis.

The deferred antagonism technique has been utilized for several decades for detecting antibiosis activity. Most protocols require the elimination of antibiotic-producing cells by exposing them to chloroform vapour, UV radiation or filter sterilizing the filtrate steps that require additional time and expense to complete. We provide a modified approach to current soft agar overlay practices, which involves addition of antibiotics to the soft agar overlay to inhibit growth of the producer but not the indicator strain. This technique can be used to reproducibly and efficiently screen for antibiotic production with ease. We demonstrate the effectiveness of this technique with three bacterial systems: inhibition of the bacterial spot of tomato pathogen, Xanthomonas euvesicatoria, by its pathogenic competitor Xanthomonas perforans; and inhibition of the fire blight pathogen, Erwinia amylovora, by Pantoea vagans C9-1 or Pseudomonas fluorescens A506. SIGNIFICANCE AND IMPACT OF THE STUDY: Deferred antagonism assays are used commonly to observe antibiotic production by micro-organisms. Killing or removing the producer cells prior to introduction of the indicator strain is a standard practice but requires additional time and special handling procedures. We evaluated a modification of the assay, where the overlay medium is amended with an antibiotic to which the indicator strain is resistant and the producer strain is sensitive. This modification obviates extra steps to kill the producer strain prior to overlaying with the indicator strain and provides a rapid, consistent and cost-effective method to detect antibiosis.

Using the PARAFAC2 tensor factorization on EHR audit data to understand PCP desktop work.

BACKGROUND: Activity or audit log data are required for EHR privacy and security management but may also be useful for understanding desktop workflow. OBJECTIVE: We determined if the EHR audit log file, a rich source of complex time-stamped data on desktop activities, could be processed to derive primary care provider (PCP) level workflow measures. METHODS: We analyzed audit log data on 876 PCPs across 17,455 ambulatory care encounters that generated 578,394 time-stamped records. Each individual record represents a user interaction (e.g., point and click) that reflects all or part of a specific activity (e.g., order entry access). No dictionary exists to define how to combine clusters of sequential audit log records to represent identifiable PCP tasks. We determined if PARAFAC2 tensor factorization could: (1) learn to identify audit log record clusters that specifically represent defined PCP tasks; and (2) identify variation in how tasks are completed without the need for ground-truth labels. To interpret the result, we used the following PARAFAC2 factors: a matrix representing the task definitions and a matrix containing the frequency measure of each task for each encounter. RESULTS: PARAFAC2 automatically identified 4 clusters of audit log records that represent 4 common clinical encounter tasks: (1) medications' access, (2) notes' access, (3) order entry access, and (4) diagnosis modification. PARAFAC2 also identified the most common variants in how PCPs accomplish these tasks. It discovered variation in how the notes' access task was done, including identification of 9 distinct variants of notes access that explained 77% of the input data variation for notes. The discovered variants mapped to two known workflows for notes' access and to two distinct PCP user groups who accessed notes by either using the Visit Navigator or the Wrap-Up option. CONCLUSIONS: Our results demonstrate that EHR audit log data can be rapidly processed to create higher-level constructed features that represent time-stamped PCP tasks.

Impacts of epizootic ulcerative syndrome on subsistence fisheries and wildlife.

Epizootic ulcerative syndrome (EUS), caused by the water mould (Oomycota) Aphanomyces invadans, has spread throughout the world's major continents over the last 50 years, with the apparent exception of South and Central America. With over 160 susceptible fish species representing 54 families and 16 orders recorded to date, EUS is of international concern and infection with A. invadans is a World Organisation for Animal Health (OIE) listed disease. This paper examines what little has been reported on the impacts of EUS on subsistence fisheries and wildlife, or what can be deduced about those impacts, and concludes that there is a need for systematic data collection on the size and socio-economic importance of subsistence fisheries. Such fisheries are often relied upon by the poorest communities, thus food and nutrition security impacts can be significant. Similarly, impacts on wildlife are poorly documented, emphasising the lack of, and the need for, research on and modelling of the ecosystem-level impacts of EUS and other aquatic animal diseases. The history of EUS and several other aquatic animal diseases also brings into question the effectiveness of current measures for controlling the international spread of aquatic animal diseases and calls for a re-think on how best to meet this ongoing challenge.

En l'espace d'un demi-siècle, le syndrome ulcératif épizootique dû à l'oomycète Aphanomyces invadans s'est propagé dans toutes les régions du monde, à l'exception, semble-t-il, de l'Amérique du Sud et Centrale. Avec plus de 160 espèces de poissons répertoriées comme sensibles, réparties en 54 familles et 16 ordres, le syndrome ulcératif épizootique est une maladie préoccupante à l'échelle internationale et figure parmi les maladies listées par l'Organisation mondiale de la santé animale (OIE) sous le nom d'infection à A. invadans. Les auteurs font état des très rares signalements concernant l'impact du syndrome ulcératif épizootique sur la pêche de subsistance et sur la faune sauvage et tentent d'en tirer quelques conclusions, en insistant sur la nécessité de procéder à une collecte systématique de données afin de déterminer l'envergure et l'importance socioéconomique de la pêche de subsistance. Les communautés les plus pauvres étant souvent celles qui dépendent le plus de cette activité, la maladie a sans doute un impact majeur sur la sécurité alimentaire et nutritionnelle de ces populations. De même, l'impact sur la faune sauvage n'a pas vraiment été étudié jusqu'à présent, d'où la nécessité de conduire des travaux de recherche et de modélisation sur l'impact du syndrome ulcératif épizootique (et d'autres maladies des animaux aquatiques) à l'échelle des écosystèmes. L'histoire du syndrome ulcératif épizootique et d'autres maladies des animaux aquatiques pose également la question de l'efficacité des mesures appliquées actuellement pour maîtriser la propagation internationale de ces maladies et invite à repenser la réponse à apporter à ce défi toujours présent.

En los últimos 50 años, el síndrome ulcerante epizoótico, causado por el hongo acuático (oomiceto) Aphanomyces invadans, se ha diseminado por casi todos los continentes del planeta, con la aparente salvedad de Sudamérica y Centroamérica. Se trata de una enfermedad de importancia internacional que, hasta donde consta a día de hoy, afecta a más de 160 especies piscícolas de 54 familias y 16 órdenes. De ahí que la infección por A. invadans sea una patología inscrita en la lista de la Organización Mundial de Sanidad Animal (OIE). Los autores, tras exponer lo poco que hasta ahora se ha descrito de los efectos de la enfermedad sobre la pesca de subsistencia y la fauna silvestre o lo que es posible inferir acerca de esos efectos, llegan a la conclusión de que se requiere una labor sistemática de obtención de datos sobre la magnitud e importancia socioeconómica de la actividad pesquera de subsistencia, de la que dependen a menudo las comunidades más pobres, por lo que las consecuencias para la seguridad nutricional y alimentaria pueden ser de calado. Tampoco están bien descritas las repercusiones de la enfermedad en los animales silvestres, lo que pone de relieve la ausencia, y por ende la necesidad, de investigaciones y de modelos sobre los efectos ecosistémicos del síndrome ulcerante epizoótico y otras varias enfermedades de los animales acuáticos. La historia de estas patologías también arroja dudas sobre la eficacia de las medidas aplicadas actualmente para controlar la propagación internacional de las enfermedades de los animales acuáticos y exige replantearse cuál es la respuesta idónea a este problema que no cesa.

Particle-size dependent bactericidal activity of magnesium oxide against Xanthomonas perforans and bacterial spot of tomato.

Bacterial spot, caused by Xanthomonas spp., is a highly destructive disease of tomatoes worldwide. Copper (Cu) bactericides are often ineffective due to the presence of Cu-tolerant strains. Magnesium oxide (MgO) is an effective alternative to Cu bactericides against Xanthomonas spp. However, the effects of particle size on bactericidal activity and fruit elemental levels are unknown. In this study, nano (20 nm) and micron (0.3 and 0.6 µm) size MgO particles were compared for efficacy. Nano MgO had significantly greater in vitro bactericidal activity against Cu-tolerant X. perforans than micron MgO at 25-50 µg/ml. In field experiments nano and micron MgO applied at 200 and 1,000 µg/ml were evaluated for disease control. Nano MgO at 200 µg/ml was the only treatment that consistently reduced disease severity compared to the untreated control. Inductively Coupled Plasma Optical Emission Spectroscopy revealed that nano MgO applications did not significantly alter Mg, Cu, Ca, K, Mn, P and S accumulation compared to fruits from the untreated plots. We demonstrated that although both nano MgO and micron MgO had bactericidal activity against Cu-tolerant strains in vitro, only nano MgO was effective in bacterial spot disease management under field conditions.

Independent Evolution with the Gene Flux Originating from Multiple Xanthomonas Species Explains Genomic Heterogeneity in Xanthomonas perforans.

Xanthomonas perforans is the predominant pathogen responsible for bacterial leaf spot of tomato and X. euvesicatoria for that of pepper in the southeast United States. Previous studies have indicated significant changes in the X. perforans population collected from Florida tomato fields over the span of 2 decades, including a shift in race and diversification into three phylogenetic groups driven by genome-wide homologous-recombination events derived from X. euvesicatoria In our sampling of Xanthomonas strains associated with bacterial spot disease in Alabama, we were readily able to isolate X. perforans from symptomatic pepper plants grown in several Alabama counties, indicating a recent shift in the host range of the pathogen. To investigate the diversity of these pepper-pathogenic strains and their relation to populations associated with tomatoes grown in the southeast United States, we sequenced the genomes of eight X. perforans strains isolated from tomatoes and peppers grown in Alabama and compared them with previously published genome data available from GenBank. Surprisingly, reconstruction of the X. perforans core genome revealed the presence of two novel genetic groups in Alabama that each harbored a different transcription activation-like effector (TALE). While one TALE, AvrHah1, was associated with an emergent lineage pathogenic to both tomato and pepper, the other was identified as a new class within the AvrBs3 family, here designated PthXp1, and was associated with enhanced symptom development on tomato. Examination of patterns of homologous recombination across the larger X. euvesicatoria species complex revealed a dynamic pattern of gene flow, with multiple donors of Xanthomonas spp. associated with diverse hosts of isolation.IMPORTANCE Bacterial leaf spot of tomato and pepper is an endemic plant disease with a global distribution. In this study, we investigated the evolutionary processes leading to the emergence of novel X. perforans lineages identified in Alabama. While one lineage was isolated from symptomatic tomato and pepper plants, confirming the host range expansion of X. perforans, the other lineage was isolated from tomato and acquired a novel transcription activation-like effector, here designated PthXp1. Functional analysis of PthXp1 indicated that it does not induce Bs4-mediated resistance in tomato and contributes to virulence, providing an adaptive advantage to strains on tomato. Our findings also show that different phylogenetic groups of the pathogen have experienced independent recombination events originating from multiple Xanthomonas species. This suggests a continuous gene flux between related xanthomonads associated with diverse plant hosts that results in the emergence of novel pathogen lineages and associated phenotypes, including host range.

Pathogenicity of the bacterium New Zealand rickettsia-like organism (NZ-RLO2) in Chinook salmon Oncorhynchus tshawytscha smolt.

Farmed New Zealand Chinook salmon Oncorhynchus tshawytscha Walbaum have been found to be infected by rickettsia-like organisms (NZ-RLO). While these Gram-negative intra-cellular bacteria are closely related to Piscirickettsia salmonis, a significant pathogen for farmed salmon globally, the pathogenicity of NZ-RLO is unknown. The aim of the present study was to determine if one strain, NZ-RLO2, causes disease in Chinook salmon. Post-smolt salmon were inoculated with NZ-RLO2 by intraperitoneal injection at high, medium and low doses and observed for 30 d. All fish in the high and medium dosed groups died by the end of the study and 63% of the low dose group died within 30 d of inoculation. Necropsy revealed the fish inoculated with NZ-RLO2 had internal multifocal haemorrhages. The most consistent histological finding in fish inoculated with NZ-RLO2 was neutrophilic and necrotizing pancreatitis and steatitis with intra-cytoplasmic organisms often visible within areas of inflammation. Other histological lesions included multifocal hepatic necrosis, haematopoietic cell necrosis and splenic and renal lymphoid depletion. The presence of NZ-RLO2 within the inoculated fish was confirmed by replication in cell culture and qPCR. The results suggest NZ-RLO2 can cause disease in Chinook salmon and therefore could be a significant pathogen in farmed Chinook salmon.