Phenotypic virulence characterization of avian pathogenic Escherichia coli (APEC) isolates from broiler breeders with colibacillosis in Mississippi.

AIMS: In this study, we evaluated the phenotypic virulence characteristics of avian pathogenic Escherichia coli (APEC) isolates from broiler breeders with colibacillosis in Mississippi. Also, the relationship between phenotypic and genotypic virulence patterns was determined. METHODS AND RESULTS: Twenty-eight APEC isolated from lesions of broiler breeders diagnosed with colibacillosis were used for embryo lethality assay and chick challenge study. The percentage of embryo mortality following embryo lethality assay and pathogenicity score following the chick challenge study were used to categorize the isolates based on virulence. Pearson correlation analysis was performed to determine the relationship between embryo mortality, chick pathogenicity, and the presence of virulence-associated genes in the isolates. Overall, 39.3% of the isolates were highly virulent and 3.5% were avirulent, following both assays. There existed a positive correlation between embryo mortality and chick pathogenicity (r = 0.73, P < .01), as well as percentage embryo mortality and pathogenicity score with the presence of some virulence genes. CONCLUSIONS: Even though all the APEC were isolated from lesions of diseased breeders, the virulence potential varied from being avirulent to highly virulent. Further, we identified a positive relationship between phenotypic virulence and the frequency of virulence-associated genes.

Evaluating the effects of virulence genotype, swarming motility, and multi-locus sequence types of Escherichia coli on layer chicken embryo.

AIMS: To determine the effects of swarming motility (SM), and Multi-locus sequence types (MLST) on the main effect of virulence genotype (VG) of E. coli through an embryos lethality assay between the 12th -18th days of incubation. METHODS AND RESULTS: We collected 58 E. coli isolates from asymptomatic commercial hens (n = 42) and lesions of colibacillosis cases (n = 16), then classified their VG as avirulent, moderately-virulent, virulent-healthy, and virulent-colibacillosis categories by the presence of 5 virulence-associated genes (iroN, ompT, hlyF, iutA, and iss). These isolates were further classified as non-motile, motile, or hyper-motile by SM assay. From the 58 isolates we selected 29 for embryo lethality assay (ELA) and determined their MLST. Each isolate was inoculated into 15 embryonated eggs through the allantoic cavity. We found the avirulent isolates reduced the relative embryo weight compared to virulent-colibacillosis and moderately-virulent isolates (37.49 vs. 41.51 and 40.34%, P = 0.03). Among the moderately-virulent and virulent-colibacillosis categories, embryo lethality was lower when isolates were non-motile. Yolk retention was unaffected by virulence categories, motility, or MLST. CONCLUSION: Interaction between VG and SM substantially influenced the ELA of E. coli isolates.

Associations Between Surrogate Markers and Clinical Outcomes for Nononcologic Chronic Disease Treatments.

Importance: Surrogate markers are increasingly used as primary end points in clinical trials supporting drug approvals. Objective: To systematically summarize the evidence from meta-analyses, systematic reviews and meta-analyses, and pooled analyses (hereafter, meta-analyses) of clinical trials examining the strength of association between treatment effects measured using surrogate markers and clinical outcomes in nononcologic chronic diseases. Data sources: The Food and Drug Administration (FDA) Adult Surrogate Endpoint Table and MEDLINE from inception to March 19, 2023. Study Selection: Three reviewers selected meta-analyses of clinical trials; meta-analyses of observational studies were excluded. Data Extraction and Synthesis: Two reviewers extracted correlation coefficients, coefficients of determination, slopes, effect estimates, or results from meta-regression analyses between surrogate markers and clinical outcomes. Main Outcomes and Measures: Correlation coefficient or coefficient of determination, when reported, was classified as high strength (r ≥ 0.85 or R2 ≥ 0.72); primary findings were otherwise summarized. Results: Thirty-seven surrogate markers listed in FDA's table and used as primary end points in clinical trials across 32 unique nononcologic chronic diseases were included. For 22 (59%) surrogate markers (21 chronic diseases), no eligible meta-analysis was identified. For 15 (41%) surrogate markers (14 chronic diseases), at least 1 meta-analysis was identified, 54 in total (median per surrogate marker, 2.5; IQR, 1.3-6.0); among these, median number of trials and patients meta-analyzed was 18.5 (IQR, 12.0-43.0) and 90 056 (IQR, 20 109-170 014), respectively. The 54 meta-analyses reported 109 unique surrogate marker-clinical outcome pairs: 59 (54%) reported at least 1 r or R2, 10 (17%) of which reported at least 1 classified as high strength, whereas 50 (46%) reported slopes, effect estimates, or results of meta-regression analyses only, 26 (52%) of which reported at least 1 statistically significant result. Conclusions and Relevance: Most surrogate markers used as primary end points in clinical trials to support FDA approval of drugs treating nononcologic chronic diseases lacked high-strength evidence of associations with clinical outcomes from published meta-analyses.

Contributions of a LysR Transcriptional Regulator to Listeria monocytogenes Virulence and Identification of Its Regulons.

The capacity of Listeria monocytogenes to adapt to environmental changes is facilitated by a large number of regulatory proteins encoded by its genome. Among these proteins are the uncharacterized LysR-type transcriptional regulators (LTTRs). LTTRs can work as positive and/or negative transcription regulators at both local and global genetic levels. Previously, our group determined by comparative genome analysis that one member of the LTTRs (NCBI accession no. WP_003734782) was present in pathogenic strains but absent from nonpathogenic strains. The goal of the present study was to assess the importance of this transcription factor in the virulence of L. monocytogenes strain F2365 and to identify its regulons. An L. monocytogenes strain lacking lysR (the F2365ΔlysR strain) displayed significant reductions in cell invasion of and adhesion to Caco-2 cells. In plaque assays, the deletion of lysR resulted in a 42.86% decrease in plaque number and a 13.48% decrease in average plaque size. Furthermore, the deletion of lysR also attenuated the virulence of L. monocytogenes in mice following oral and intraperitoneal inoculation. The analysis of transcriptomics revealed that the transcript levels of 139 genes were upregulated, while 113 genes were downregulated in the F2365ΔlysR strain compared to levels in the wild-type bacteria. lysR-repressed genes included ABC transporters, important for starch and sucrose metabolism as well as glycerolipid metabolism, flagellar assembly, quorum sensing, and glycolysis/gluconeogenesis. Conversely, lysR activated the expression of genes related to fructose and mannose metabolism, cationic antimicrobial peptide (CAMP) resistance, and beta-lactam resistance. These data suggested that lysR contributed to L. monocytogenes virulence by broad impact on multiple pathways of gene expression.IMPORTANCEListeria monocytogenes is the causative agent of listeriosis, an infectious and fatal disease of animals and humans. In this study, we have shown that lysR contributes to Listeria pathogenesis and replication in cell lines. We also highlight the importance of lysR in regulating the transcription of genes involved in different pathways that might be essential for the growth and persistence of L. monocytogenes in the host or under nutrient limitation. Better understanding L. monocytogenes pathogenesis and the role of various virulence factors is necessary for further development of prevention and control strategies.

On the relationships between plant species richness and the environment: a case study in Eastern Ghats, India.

Many places of the earth support high plant species richness, but emphasis is given to biodiversity hotspots with rich endemic species under threats of destruction by anthropogenic interventions. This definitely underplays species conservation at several places significant for optimisation of preserving natural ecosystems. Here we explore influences of climate, physiography and disturbance on plant species richness of the Eastern Ghats. We focus on the implications of water-energy dynamics and climatic heterogeneity on community distribution. Initially, 26-environmental variables were considered for the study, but eight least correlated variables viz., aspect, human appropriation of net primary productivity, global human footprint, mean annual temperature, mean annual precipitation, precipitation of driest quarter, terrain ruggedness index and temperature seasonality were utilised for further analysis. A total of 1670 species from 2274 sampling locations of 22564 records were examined using canonical correspondence analysis (CCA) and decision trees. Water-energy dynamics broadly regulates plant richness, with significant influence of mean annual precipitation and temperature. Precipitation of the driest quarter is the most significant factor in describing plant richness, indicating the availability of water during the dry period is crucial. The rise in temperature is likely to deteriorate further, where temperature seasonality is significant. Temperature seasonality determines thermal variability and assesses the intensity of climate change impacts on plant richness. The study offers ecological insights for successful conservation and management planning for the sustenance of the Eastern Ghats' rich biodiversity.

Land use and climate change impacts on distribution of plant species of conservation value in Eastern Ghats, India: a simulation study.

Effective monitoring of the current status of species distributions and predicting future distributions are very important for conservation practices at the ecosystem and species levels. The human population, land use, and climate are important factors that influence the distributions of species. Even though future simulations have many uncertainties, such studies can provide a means of obtaining species distributions, range shifts, and food production and help mitigation and adaptation planning. Here, we simulate the population, land use/land cover and species distributions in the Eastern Ghats, India. A MaxEnt species distribution model was used to simulate the potential habitats of a group of endemic (28 species found in this region) and rare, endangered, and threatened (RET) (22 species found in this region) plant species on the basis of IPCC AR5 scenarios developed for 2050 and 2070. Simulations of populations in 2050 indicate that they will increase at a rate of 1.12% relative to the base year, 2011. These increases in population create a demand for more land for settlement and food productions. Land use land cover (LULC) simulations show an increase in built-up land from 3665.00 km2 in 2015 to 3989.56 km2 by 2050. There is a minor increase of 0.04% in the area under agriculture in 2050 compared with 2015. On the other hand, the habitat simulations show that the combined effects of climate and land use change have a greater influence on the decline of potential distributions of species. Climate change and the prevailing rate of LULC change will reduce the extents of the habitats of endemic and RET species (~ 60% and ~ 40%, respectively). The Eastern Ghats have become extensively fragmented due to human activities and have become a hotspot of endemic and RET species loss. Climate and LULC change will enhance the species loss and ecosystem services.

Implications for Public Health Regulation if Chevron Deference Is Overturned.

This Viewpoint describes implications for medicine and public health if the US Supreme Court decides to overturn or narrow Chevron deference.

Financial Conflicts of Interest in Public Comments on Medicare National Coverage Determinations of Medical Devices.

This study reviewed public comments for all Medicare National Coverage Determinations between June 2019 and 2022 on select pulmonary and cardiac devices to determine whether financial conflicts of interest were disclosed.

Pivotal Trial Demographic Representation and Clinical Development Times for Oncology Therapeutics.

This study evaluates whether FDA-approved novel cancer therapeutics supported by pivotal trials with adequate representation of minoritized groups were associated with slower clinical development times than those with inadequate representation.

Dynamics and determinants of land change in India: integrating satellite data with village socioeconomics.

We examine the dynamics and spatial determinants of land change in India by integrating decadal land cover maps (1985-1995-2005) from a wall-to-wall analysis of Landsat images with spatiotemporal socioeconomic database for ~630,000 villages in India. We reinforce our results through collective evidence from synthesis of 102 case studies that incorporate field knowledge of the causes of land change in India. We focus on cropland-fallow land conversions, and forest area changes (excludes non-forest tree categories including commercial plantations). We show that cropland to fallow conversions are prominently associated with lack of irrigation and capital, male agricultural labor shortage, and fragmentation of land holdings. We find gross forest loss is substantial and increased from ~23,810 km2 (1985-1995) to ~25,770 km2 (1995-2005). The gross forest gain also increased from ~6000 km2 (1985-1995) to ~7440 km2 (1995-2005). Overall, India experienced a net decline in forest by ~18,000 km2 (gross loss-gross gain) consistently during both decades. We show that the major source of forest loss was cropland expansion in areas of low cropland productivity (due to soil degradation and lack of irrigation), followed by industrial development and mining/quarrying activities, and excessive economic dependence of villages on forest resources.

The updated AMSA scorecard of conflict-of-interest policies: a survey of U.S. medical schools.

BACKGROUND: Best practices for conflict-of-interest (COI) policies in medical schools have evolved rapidly over the past decade, in part motivated by the American Medical Student Association (AMSA) scorecard that has publicly graded schools since 2007. This report describes the methodological update and impact of revisions to the scorecard in 2014. METHODS: The original AMSA scorecard (used annually from 2008 to 2013) was revised by a work group to improve its methodology and to increase the stringency of its criteria for scoring COI policies. All U.S. medical schools (both allopathic and osteopathic; n = 160) were invited to submit their COI policies to AMSA for scoring with the new scorecard; web site searches were used to acquire policy information for schools that did not submit. The authors developed a codebook and analyzed 14 distinct categories of COI policies, pertaining to activities such as industry-funded gifts, meals, educational events, site access for sales reps, and conflict-of-interest disclosure requirements. The analysis yielded four possible grades for each school: A, B, C, or I (incomplete). The authors compared 2014 grades with 2013 grades, and compared the distribution of grades of schools by type (allopathic vs. osteopathic) and geographical region. RESULTS: A total of 27 (16.9 %) medical schools scored A grades, indicating that their COI policies were strong, 81 (50.6 %) scored B, 25 (15.6 %) scored C and 26 (16.3 %) policies scored I. As compared to 2013, in 2014 fewer schools qualified for A grades (17.0 % vs. 26.0 %; p = 0.05). The grade distributions of allopathic and osteopathic schools were significantly different (p < 0.0001), with osteopathic schools more likely than allopathic schools to have incomplete policies. There were no significant grade differences by geographical region. CONCLUSIONS: The revised 2014 AMSA scorecard, with its more stringent criteria for evaluating COI policies, assigned fewer As and more Bs and Cs than in years past. This was the first study to identify schools with COI policies stronger than those recommended in 2008 by the Association of American Medical Colleges. Developing more stringent COI policies should be helpful in reducing the influence of pharmaceutical and device industry marketing on both trainees and faculty in American medical schools.

Estimating The Effects Of COVID-19 On Globalized Markets For Active Pharmaceutical Ingredients.

Global supply chains for active pharmaceutical ingredients (APIs) are highly centralized in certain countries and are susceptible to supply-chain shocks. However, there is no systematic monitoring or global coordination to manage risk and ensure equitable supply continuity during public health emergencies. In this study, we applied quasi-experimental methods on shipment-level customs data to determine how prices and export volume for APIs exported from India were affected by the COVID-19 pandemic. We found that API prices for key essential medicines not used for COVID-19 did not change significantly in the year after the World Health Organization pandemic declaration, but volume decreased by 80 percent. Prices for medicines speculatively repurposed for COVID-19, such as hydroxychloroquine and ivermectin, increased by as much as 250 percent compared with prices for nonrepurposed medicines, but only ivermectin saw a decrease in volume. Systematic monitoring of API markets, investments to promote supply diversification, and legal and political reforms to disincentivize price speculation could support supply-chain resilience and safeguard access to medicines.

Medicare Part B and Part D drug eligibility for center for Medicare and Medicaid Services price negotiation under the Inflation Reduction Act: estimates using 2016-2019 data.

Background: To reduce Medicare prescription drug expenditures, the 2022 Inflation Reduction Act (IRA) allows the Centers for Medicare & Medicaid Services (CMS) to directly negotiate with drug manufacturers on Medicare prices of high-expenditure drugs (≥$200m annual spending) which meet certain eligibility criteria. However, it is unclear what proportion of high-expenditure drugs covered by Medicare, and attributable annual drug spending, would typically be eligible for CMS negotiations in a given year. Methods: We used historical Medicare drug spending data to determine how many high-expenditure drugs, and attributable drug spending, would have been eligible for CMS negotiations had the IRA been in effect from 2016-2019, while also determining which of the IRA's eligibility criteria is most restrictive. Results: From 2016-2019, approximately one third (33.3% for Part B, 32.4% for Part D) of high-expenditure Medicare drugs would have been eligible for negotiation, with ineligible drugs accounting for 75.2% and 63.8% of spending on high-expenditure drugs in Medicare Part B and D, respectively. Most ineligible high-expenditure drugs were ineligible because they launched too recently. From 2016-2019, between 59 and 74 high-expenditure drugs were eligible per year, indicating that in some years there may not be enough eligible drugs for CMS to negotiate on the maximum number of drugs allowable by law. Conclusions: The IRA's current eligibility criteria may restrict CMS from being able to negotiate drug prices on approximately two-thirds of the high-expenditure drugs covered by Medicare and may not allow CMS to negotiate on the maximum number of drugs allowable by law. Congress could consider relaxing eligibility requirements for price negotiation, such as those pertaining to launch date recency, to ensure there are a sufficient number of high-expenditure drugs eligible for negotiation or make certain ineligible drugs contributing to significant annual Medicare spending eligible for negotiation on a case-by-case basis.

A Public Option for Clinical Trials? Lessons from Convalescent Plasma.

The case of clinical trials for convalescent plasma during COVID-19 illustrates important lessons for realizing public sector approaches to biomedical research and development. These lessons, centering on mission, transparency, and spillover effects, can be translated to wider efforts to develop a "public option" for clinical trials.

Trans-Cinnamaldehyde Primes More Robust Channel Catfish Immune Responses to Edwardsiella ictaluri Infection.

Infection with Edwardsiella ictaluri, a causative agent of enteric septicemia of catfish, threatens profitable catfish production through inventory losses. We previously demonstrated that trans-cinnamaldehyde (TC) enhances the survival of catfish following E. ictaluri infection. The present study was conducted to investigate catfish immune responses to TC feeding and E. ictaluri infection. The expression of 13 proinflammatory, innate, and adaptive immune-related genes was evaluated over time in two sets of experiments using real-time polymerase chain reaction (PCR). In the first experiment, catfish were fed a basal diet with or without TC supplementation, while in the second they were fed a TC-supplemented or normal diet followed by infection with E. ictaluri. The catfish group infected with E. ictaluri and fed a TC-diet showed significant changes in the expression of innate and adaptive immune-related genes compared to control group. At 21 and 28 days post-infection, recovered fish showed significant increases in the expression of IgM in the anterior kidney and spleen. These results suggest that the supplemental dietary intake of TC can improve the immune status of catfish via engaging innate and adaptive immune responses and the production of memory cells in immunocompetent tissues. Together, this study provides an important foundation for the potential application of TC as an antimicrobial alternative in aquaculture.