Respiratory Burst Research Articles

Abscisic Acid Can Play a Dual Role in the Triticum aestivum–Stagonospora nodorum Pathosystem

Abscisic acid (ABA) is not only important for plant responses to abiotic stresses, but also plays a key and multifaceted role in plant immunity. In this work, we analyzed the role of ABA in the development of resistance/susceptibility in the wheat (Triticum aestivum L.)–Stagonospora nodorum Berk. pathosystem, which includes the recognition of the necrotic effectors (NEs) of a pathogen by the corresponding wheat susceptibility genes. We studied the interaction of the S. nodorum SnB isolate, which produces two NEs, SnToxA and SnTox3, with three wheat genotypes having different combinations of the corresponding host susceptibility genes (Tsn1 and Snn3-B1). The results of this work on the gene expression and redox status of resistant and sensitive wheat genotypes treated with ABA show that ABA signaling is directed at inducing the resistance of wheat plants to S. nodorum SnB isolate through the activation of the early post-invasive defense genes TaERD15 and TaABI5. The induction of the expression of these genes leads to reactive oxygen species (ROS) accumulation during the early stage of infection, with the subsequent limitation of the pathogen’s growth. In the presence of a compatible interaction of SnTox3–Snn3-B1, ABA signaling is suppressed. On the contrary, in the presence of a compatible interaction of SnToxA–Tsn1, ABA signaling is activated, but the activity of the early post-invasive defense genes TaERD15 and TaABI5 is inhibited, and the expression of the NAC (NAM, ATAF1/2, and CUC2) transcription factor (TF) family genes TaNAC29 and TaNAC21/22 is induced. The TF genes TaNAC29 and TaNAC21/22 in the presence of SnToxA induce the development of the susceptibility of wheat plants to S. nodorum SnB, associated with a decrease in the oxidative burst during the early stage of infection. Thus, our study provides new data on the role of the NEs SnTox3 and SnToxA in manipulating ABA signaling in the development of the susceptibility of wheat to S. nodorum. Deepening our knowledge in this area will be instrumental for developing new strategies for breeding programs and will contribute to the development of environmentally friendly sustainable agriculture.

How short-term change in temperature or salinity affect cellular immune parameters of three-spined stickleback, Gasterosteus aculeatus?

Reference values for the non-specific immune response of stickleback have been developed to better understand the natural variability of the immunomarkers and to increase their relevance for the detection of environmental perturbations. However, under field conditions, temperature and salinity can vary from station to station and their influence on the reference ranges of the immunomarkers should therefore be quantified. To this end, adult sticklebacks were exposed either to different temperatures (from 12 to 18°C) or to different salinities (from 0 to 30g/L) for 21 days after 10 days of acclimatization. The results were then projected onto reference ranges to better determine the effect of temperature and salinity on the innate immune response. With the exception of leucocyte necrosis at higher temperature and respiratory burst at lower temperature, previously established reference ranges for immunomarkers of sticklebacks were suitable when variations in temperature and salinity were tested. Finally, this study argues for the possibility of using stickleback and its immune reference range in the field regardless of temperature and salinity, due to its relatively temperature and salinity independent innate immune response. Reference ranges for immunomarkers in stickleback could be a real added value to water quality diagnosis in biomonitoring programs in variable seasonal and geographical environmental contexts. Furthermore, these results confirm the rapid adaptability of sticklebacks to different variations in temperature and salinity without affecting their immunological parameters.

Antioxidant and Anti-Inflammatory Effects of Vanillic Acid in Human Plasma, Human Neutrophils, and Non-Cellular Models In Vitro

Vanillic acid (VA) is a dietary benzoic acid derivative, flavoring agent, and food stabilizer. In this study, the antioxidant and anti-inflammatory potential of VA was explored in vitro and ex vivo in human immune cells and non-cellular models. In neutrophils, VA significantly downregulated the fMLP-induced oxidative burst and the generation of reactive oxygen species (ROS); it also suppressed the release of pro-inflammatory cytokines (TNF-α, IL-8) and the tissue-remodeling enzyme elastase-2 (ELA-2) in cells stimulated with LPS and fMLP+cytochalasin B. Additionally, VA showed good biocompatibility with human neutrophils and peripheral blood mononuclear cells (PBMCs) across the tested concentrations of 1–50 µg/mL. Furthermore, VA at 1–5 μg/mL enhanced the non-enzymatic antioxidant capacity of human plasma (NEAC) and prevented oxidative and nitrative damage to plasma proteins by protecting tyrosine moieties and thiols from peroxynitrite. VA also inhibited lipid peroxidation and the formation of thiobarbituric acid-reactive substances (at 50 μg/mL) and protein-bound carbonyls (at 5–50 μg/mL) in peroxynitrite-treated plasma. In non-cellular tests, VA acted as a hypochlorous acid and hydrogen peroxide scavenger and inhibited non-enzymatic protein glycation, outperforming the references Trolox and aminoguanidine. Along with existing data from animal models and studies on polyphenol intake, these results might support the synergic role of VA in dietary protection against chronic diseases related to oxidative stress and inflammation.

Calcitriol Treated Mesenchymal Stem Cells Modulated Immune Response in Collagen-Induced Rheumatoid Arthritis in BALB/c Mice.

Rheumatoid arthritis (RA) is a chronic inflammatory disease that primarily involves synovial joints. During the past decade, disease-modifying antirheumatic drugs and biologic agents have been introduced for the treatment of RA. However, they have limitations, including incomplete treatment response, adverse effects requiring drug withdrawal, fall off in efficacy over time, high cost of biologic agents, and refractory cases. Consequently, there is a need to establish safe and effective advanced therapeutic modalities for RA to overcome the shortcomings of current treatments. MSCs after isolation were exposed to 200 nM calcitriol. Rheumatoid arthritis was induced in BALB/c mice using collagen and Freund's complete adjuvant. One week after immunization, the mice were divided into 3 groups including without treatment, groups treated with untreated and treated MSCs. One week after the last injection, mice sacrificed and samples were taken and the desired evaluations were done. Our results revealed that the respiratory burst capacity, neutrophil phagocytosis, and nitric oxide production in the population of splenocytes were higher in the positive control group compared to the treatment groups. Also, the level of production of IL-4, IL-10 and TGF-β cytokines and INF-γ and IL-17 cytokines showed a significant increase and decrease, respectively, compared to the positive control group. Treatment of MSCs with calcitriol leads to an improvement in regulatory function and inhibitory effects on inflammatory mediators of innate immune cells, particularly splenocytes, in a rheumatoid arthritis model compared to untreated mesenchymal stem cells.

AI-Driven Medical Chatbot for Predicting and Managing Infectious Diseases

This paper explores the potential of chatbots to enhance the medical field by combating infectious diseases, including respiratory illnesses, zoonotic diseases, and viral outbreaks such as COVID-19. By increasing awareness among users, these chatbots can help individuals discover medical solutions to prevent and manage these conditions. We have developed a training model that facilitates better human interaction with databases through natural language processing, tailored to characterize users effectively. Our proposed AI chatbot model employs a recurrent neural network to ensure efficient interaction and prediction, addressing current deficiencies in guidelines for improving lifestyle programs. The model achieves a minimum loss of 0.112 and a maximum accuracy of 93. Additionally, this paper investigates the feasibility of implementing chatbots to offer 24/7 support, broaden healthcare services, and deliver personalized, real-time responses. Our conclusion emphasizes the capabilities, benefits, and challenges faced by healthcare chatbots during pandemics. This research aims to guide the development of chatbot technology, ensuring it remains innovative and effective in preventing infectious diseases, ranging from viral infections like influenza to emerging global health threats

Resurgence of common respiratory viruses and mycoplasma pneumoniae after ending the zero-COVID policy in Shanghai

China has adhered to policies of zero-COVID for almost three years since the outbreak of COVID-19, which has remarkably affected the circulation of respiratory pathogens. However, China has begun to end the zero-COVID policies in late 2022. Here, we reported a resurgence of common respiratory viruses and Mycoplasma pneumoniae with unique epidemiological characteristics among children after ending the zero-COVID policy in Shanghai, China, 2023. Children hospitalized with acute respiratory tract infections were enrolled from January 2022 to December 2023. Nine common respiratory viruses and 2 atypical bacteria were detected in respiratory specimens from the enrolled patients using a multiplex PCR-based assay. The data were analyzed and compared between the periods before (2022) and after (2023) ending the zero-COVID policies. A total of 8550 patients were enrolled, including 6170 patients in 2023 and 2380 patients in 2022. Rhinovirus (14.2%) was the dominant pathogen in 2022, however, Mycoplasma pneumoniae (38.8%) was the dominant pathogen in 2023. Compared with 2022, the detection rates of pathogens were significantly increased in 2023 (72.9% vs. 41.8%, p < 0.001). An out‐of-season epidemic of respiratory syncytial virus was observed during the spring and summer of 2023. The median age of children infected with respiratory viruses in 2023 was significantly greater than that in 2022. Besides, mixed infections were more frequent in 2023 (23.8% vs. 28.9%, p < 0.001). China is now facing multiple respiratory pathogen epidemics with changing seasonality, altered age distribution, and increasing mixed infection rates among children in 2023. Our finding highlights the need for public health interventions to prepare for the respiratory pathogen outbreaks in the post-COVID-19 era.

Incidence of neutrophil extracellular traps (NETs) in different membrane oxygenators: pilot in vitro experiments in commercially available coated membranes.

Neutrophil extracellular traps (NETs) were detected in blood samples and in cellular deposits of oxygenator membranes during extracorporeal membrane oxygenation (ECMO) therapy and may be responsible for thrombogenesis. The aim was to evaluate the effect of the base material of gas fiber (GF, polymethylpentene) and heat exchange (HE) membranes and different antithrombogenic coatings on isolated granulocytes from healthy volunteers under static culture conditions. Contact of granulocytes with membranes from different ECMO oxygenators (with different surface coatings) and uncoated-GFs allowed detection of adherent cells and NETotic nuclear structures (normal, swollen, ruptured) using nuclear staining. Flow cytometry was used to identify cell activation (CD11b/CD62L, oxidative burst) of non-adherent cells. Uncoated-GFs were used as a reference. Within 3h, granulocytes adhered to the same extent on all surfaces. In contrast, the ratio of normal to NETotic cells was significantly higher for uncoated-GFs (56-83%) compared to all coated GFs (34-72%) (p < 0.001) with no difference between the coatings. After material contact, non-adherent cells remained vital with unchanged oxidative burst function and the proportion of activated cells remained low. The expression of activation markers was independent of the origin of the GF material. In conclusion, the polymethylpentene surfaces of the GFs already induce NET formation. Antithrombogenic coatings can already reduce the proportion of NETotic nuclei. However, it cannot be ruled out that NET formation can induce thrombotic events. Therefore, new surfaces or coatings are required for future ECMO systems and long-term implantable artificial lungs.

Structural Analysis of Inhibitor Binding to Enterovirus-D68 3C Protease.

Enterovirus-D68 (EV68) continues to present as a global health issue causing respiratory illness and outbreaks associated with long-lasting neurological disease, with no antivirals or specific treatment options. The development of antiviral therapeutics, such as small-molecule inhibitors that target conserved proteins like the enteroviral 3C protease, remains to be achieved. While various 3C inhibitors have been investigated, their design does not consider the potential emergence of drug resistance mutations. For other antivirals where resistance has been a challenge, we have demonstrated that the likelihood of resistance can be minimized by designing inhibitors that leverage the evolutionary constraints of the target. Here, we characterize a series of 3C inhibitors against EV68-3C protease through enzyme inhibition, protein crystallography, and structural analysis. We have determined and analyzed three high-resolution inhibitor-bound crystal structures of EV68-3C protease, which revealed possible sites of resistance mutations, a key structural water molecule conserved during ligand binding, and the conformational flexibility of the catalytic histidine H40. This structural analysis combined with enzymatic assays provides insights for the rational design of inhibitors that are robust against resistance toward developing antiviral treatments for EV68 infections.

Nitrogen source type modulates heat stress response in coral symbiont (Cladocopium goreaui).

Ocean warming due to climate change endangers coral reefs, and regional nitrogen overloading exacerbates the vulnerability of reef-building corals as the dual stress disrupts coral-Symbiodiniaceae mutualism. Different forms of nitrogen may create different interactive effects with thermal stress, but the underlying mechanisms remain elusive. To address the gap, we measured and compared the physiological and transcriptional responses of the Symbiodiniaceae Cladocopium goreaui to heat stress (31°C) when supplied with different types of nitrogen (nitrate, ammonium, or urea). Under heat stress (HS), cell proliferation and photosynthesis of C. goreaui declined, while cell size, lipid storage, and total antioxidant capacity increased, both to varied extents depending on the nitrogen type. Nitrate-cultured cells exhibited the most robust acclimation to HS, as evidenced by the fewest differentially expressed genes (DEGs) and less ROS accumulation, possibly due to activated nitrate reduction and enhanced ascorbate biogenesis. Ammonium-grown cultures exhibited higher algal proliferation and ROS scavenging capacity due to enhanced carotenoid and ascorbate quenching, but potentially reduced host recognizability due to the downregulation of N-glycan biosynthesis genes. Urea utilization led to the greatest ROS accumulation as genes involved in photorespiration, plant respiratory burst oxidase (RBOH), and protein refolding were markedly upregulated, but the greatest cutdown in photosynthate potentially available to corals as evidenced by photoinhibition and selfish lipid storage, indicating detrimental effects of urea overloading. The differential warming nitrogen-type interactive effects documented here has significant implication in coral-Symbiodiniaceae mutualism, which requires further research.IMPORTANCERegional nitrogen pollution exacerbates coral vulnerability to globally rising sea-surface temperature, with different nitrogen types exerting different interactive effects. How this occurs is poorly understood and understudied. This study explored the underlying mechanism by comparing physiological and transcriptional responses of a coral symbiont to heat stress under different nitrogen supplies (nitrate, ammonium, and urea). The results showed some common, significant responses to heat stress as well as some unique, N-source dependent responses. These findings underscore that nitrogen eutrophication is not all the same, the form of nitrogen pollution should be considered in coral conservation, and special attention should be given to urea pollution.

Effects of different housing systems on the oxidative defence system, heterophil functions, cellular immune response and cytokines in laying hens

ABSTRACT 1. This study investigated the effects of different housing systems on oxidative defence mechanisms, heterophil functions, cellular immune response and cytokine production in laying hens. One hundred and twenty laying hens were allocated into one of four groups: conventional cages, furnished cages, deep litter, and free range. 2. Housing system did not affect malondialdehyde concentrations and enzymatic antioxidant status. Ascorbic acid values were higher in deep-litter hens than in those in conventional cages and free range. 3. Phagocytic and chemotactic activities tended to rise in the deep-litter system, and oxidative burst was higher than in furnished cages. Cytotoxic T cells were decreased in furnished cages, both cytotoxic and helper T cells decreased in deep litter compared to free range. 4. The IL-2 and IL-13 expression was higher in deep litter than in conventional cages, and IL-6 expression was higher in furnished cages than in free range. 5. Housing system had no significant effects on the oxidative defence system; however, they affected heterophil functions, cellular defence mechanisms and cytokine production. The results suggested that breeders need to consider the housing system’s potential effects on immune defence responses while applying a breeding strategy appropriate for animal welfare and consumer demand.

Phase partitioning of the neutrophil oxidative burst is coordinated by accessory pathways of glucose metabolism and mitochondrial activity.

Neutrophils are a part of the innate immune system and produce reactive oxygen species (ROS) to extinguish pathogens. The major source of ROS in neutrophils is NADPH oxidase, which is fueled by NADPH generated via the pentose phosphate pathway; however, it is unclear how other accessory glucose metabolism pathways and mitochondrial activity influence the respiratory burst. We examined the temporal dynamics of the respiratory burst and delineated how metabolism changes over time after neutrophil activation. Bone marrow-derived neutrophils were stimulated with phorbol 12-myristate 13-acetate, and the respiratory burst was measured via extracellular flux analysis. Metabolomics experiments utilizing 13C6-glucose highlighted the activation of glycolysis as well as ancillary pathways of glucose metabolism in activated neutrophils. Phorbol 12-myristate 13-acetate stimulation acutely increased 13C enrichment into glycerol 3-phosphate (G3P) and citrate, whereas increases in 13C enrichment in the glycogen intermediate, UDP-hexose, and end products of the hexosamine and serine biosynthetic pathways occurred only during the late phase of the oxidative burst. Targeted inhibition of the G3P shuttle, glycogenolysis, serine biosynthesis, and mitochondrial respiration demonstrated that the G3P shuttle contributes to the general magnitude of ROS production; that glycogen contributes solely to the early respiratory burst; and that the serine biosynthetic pathway activity and complex III-driven mitochondrial activity influence respiratory burst duration. Collectively, these results show that the neutrophil oxidative burst is highly dynamic, with coordinated changes in metabolism that control the initiation, magnitude, and duration of ROS production.

Immune response accelerated telomere shortening during early life stage of a passerine bird, the blue tit (Cyanistes caeruleus).

Dealing with infections is a daily challenge for wild animals. Empirical data show an increase in reactive oxygen species (ROS) production during immune response. This could have consequences on telomere length, the end parts of linear chromosomes, commonly used as proxy for good health and ageing. Telomere length dynamics may reflect the costs associated with physiological responses. In this study, immune system of blue tit (Cyanistes caeruleus) nestlings was experimentally challenged through a polyinosinic:polycytidylic acid (poly I:C) injection, a synthetic double-stranded RNA that mimics a virus, activating the pathway of immune response triggered via the toll-like receptors 3. This path is known to form ROS downstream. Immune response was quantified by white cell counts in blood, while brain lipoperoxidation has been evaluated as an indicator of oxidative damage. Finally, individuals' telomere length shortening between days 8 and 15 after hatching was measured in erythrocytes. Challenged nestlings showed increased leukocyte number when compared with control (treated with a saline solution), lower brain lipid peroxidation (likely as a result of a compensatory mechanism after oxidative stress burst) and accelerated telomere shortening. These findings support the 'ageing cost of infections pathway' hypothesis, which supposes a role for infections in quick biological ageing.

Respiratory human adenovirus outbreak captured in wastewater surveillance

Respiratory adenovirus wastewater surveillance was compared to clinical data from a 2022 outbreak, showing a correlation with cases. Respiratory adenoviruses were less prevalent, with types 40/41 dominating. The schematic illustrates findings.

Effects of Phytobiotic Curcuma longa, Allium sativum and Zingiber officinale‐Supplemented Diets on Growth, Utilisation of Feed and Nile Tilapia (Oreochromis niloticus) Resistance Against Streptococcus agalactiae

The study investigated how phytobiotic‐supplemented diets impact the growth performance, feed utilisation and resistance of Nile tilapia (Oreochromis niloticus) to Streptococcus agalactiae. Fish with a total mean initial mass (37.6 g) of 180 and a random stocking of 15 fingerlings per 150 L tank in triplicate were divided into four groups and fed isonitrogenous (299 g kg−1 crude protein) and isoenergetic (15.7 kJ g−1 gross energy) control diets supplemented with 1% turmeric (Curcuma longa; TUD), garlic (Allium sativum; GAD) and ginger (Zingiber officinale; GID) powder for 56 days. After the trial period, growth performance, feed utilisation and blood health were measured. Ten fish from each replicate were infected with S. agalactiae and mortality was observed for 14 days. The results showed a significantly higher weight gain (g), specific growth rate (SGR; %/day) and average daily growth (ADG; g) in GAD (80.3 ± 1.0, 2.04 ± 0.05 and 1.434 ± 0.02, respectively) and GID (77.03 ± 0.8, 2.0 ± 0.04 and 1.376 ± 0.01, respectively) compared to the control group (60.4 ± 2.5, 1.71 ± 0.02 and 1.079 ± 0.04, respectively). However, these metrics were not significantly higher in TUD (63.8 ± 2.2, 1.8 ± 0.05 and 1.139 ± 0.04, respectively) when compared to the control group. TUD, GAD and GID feed conversion ratio (FCR) and efficiency, as well as protein efficiency ratio (PER), were improved as compared to the control. The haemoglobin (HGB), haematocrit (HCT), platelets (PLTs), white blood cells (WBCs), serum biochemistry and respiratory burst activity (RBA) of TUD, GAD and GID were significantly better than the control. Lysozyme and bactericidal activities were also significantly improved in TUD, GAD and GID as compared to the control. Following the S. agalactiae infection, the fish survival rates of GAD (67.7%), GID (53.3%) and TUD (46.7%) were better than those of the control (26.3%). Dietary supplementation with the above‐mentioned phytobiotics in Nile tilapia culture can help to increase production in view of the current challenges posed by the increased incidence of disease in fish farms. They are recommended to enhance growth, immunity and resistance to disease.

Calcium Chloride Enhances Defense Response Against Diaporthe nobilis by Eliciting Reactive Oxygen Species in Kiwifruit

Kiwifruit (Actinidia spp.) rot, caused by pathogenic fungi, represents the most severe disease during postharvest storage. The utilization of induced resistance against fungal pathogens in harvested fruit has been demonstrated as a promising strategy for controlling postharvest losses. In this study, the effect of calcium chloride (CaCl2) on induction of resistance to Diaporthe nobilis, one of the most epidemic pathogens of soft rot in kiwifruit, and the underlying mechanisms were investigated. Our data showed that the application of 3% CaCl2 resulted in smaller rotten lesion diameters after inoculation with the pathogen, induced expression of the respiratory burst oxidase homolog (RBOH) gene family, and increased accumulation of reactive oxygen species (ROS). Moreover, we found that the activity of three pathogenesis‐related antioxidant enzymes—peroxidase (POD), catalase (CAT), and superoxide dismutase (SOD)—as well as the expression of important defense‐related genes, was enhanced by CaCl2 treatment. The results of our study suggest that the application of CaCl2 treatment holds promise as a green and viable method for effectively preventing and safeguarding kiwifruit against postharvest decay.

Inhibition of the invasive plant Ambrosia trifida by Sigesbeckia glabrescens extracts.

Ambrosia trifida is an invasive weed that destroys the local ecological environment, and causes a reduction in population diversity and grassland decline. The evolution of herbicide resistance has also increased the difficulty of managing A. trifida, so interspecific plant competition based on allelopathy has been used as an effective and sustainable ecological alternative. However, how to control A. trifida through interspecific competition and the underlying mechanisms are unclear. Here, we found that extracts from both the roots and leaves of the medicinal plant Sigesbeckia glabrescens suppressed the growth of A. trifida by reducing the plant height and biomass. The decrease in biomass may be explained by disruption of carbon and nitrogen metabolism. These disruptions are due to a significant decrease in the expression of genes related to nitrate absorption and transport in roots and a significant decrease in the expression of key genes related to photosynthesis and carbon fixation. Consequently, genes involved in sucrose synthesis are downregulated. In addition, increases in H2O2 content and respiratory burst oxidase homologue (RbohD) gene expression suggested that A. trifida underwent oxidative stress caused by reactive oxygen species (ROS) bursts, resulting in apoptosis due to the significant upregulation of key genes associated with apoptotic pathways. Furthermore, we identified three main allelochemicals, coumarin, ferulic acid, and 5-aminolevulinic acid (5-ALA), in S. glabrescens extracts and revealed that the combination of these three compounds could suppress the growth of A. trifida seedlings. The phenotypes and transcriptome profiles of the seedlings treated with these chemicals were the same as those of the seedlings treated with the S. glabrescens extracts. Taken together, the results of this study revealed the mechanism underlying the toxic effects of S. glabrescens on A. trifida, providing a theoretical basis for the use of interspecific plant competition for invasive weed control and further application of S. glabrescens allelochemicals in weed management.

Assessing Prevention Protocols by a Brief Questionnaire in the Infectious Respiratory Diseases Pandemics: An Application in Pedestrian Population in COVID-19 Pandemic

To perform effective prevention programs, we need to know how well people follow prevention protocols, like mask use and social distancing, measuring using standard tools. This study aims to develop and validate a brief questionnaire to assess the compliance with prevention protocols against infectious respiratory diseases pandemics including COVID-19 in pedestrians. This cross-sectional study was conducted using convenience sampling method in May and June 2021. Construct validity of the questionnaire was assessed using Exploratory Factor Analysis (EFA). Content validity was evaluated by quantitative method, thus, Content Validity Ratio (CVR) and Content Validity Index (CVI) were calculated. For reliability of the questionnaire, the internal consistency using Cronbach’s alpha, and test-retest reliability using Spearman-Brown correlation coefficient were assessed. A total of 324 persons from three provinces of Iran participated in this study. The mean age (SD) of participants was 41.5 (16.7). The CVR values resulted in the elimination of two questions. The Scale level CVI/Average (S-CVI/Ave) was equal to 0.992; and Scale level CVI/Universal Agreement (S-CVI/UA) was 0.889. One factor with five items emerged from principal component factor analysis accounting for 51.99% of the variance. Cronbach’s alpha coefficient equal to 0.76 indicated an acceptable internal consistency and the Spearman-Brown correlation coefficient of 0.939 depicted stability of the questionnaire. This questionnaire is a brief tool with acceptable validity and reliability to evaluate the compliance with preventive protocols during infectious respiratory diseases outbreaks in order for policy-makers to make effective interventions to slow down the spread of disease.

Identification of novel candidate genes for Ascochyta blight resistance in chickpea

Ascochyta blight, caused by the necrotrophic fungus Ascochyta rabiei, is a major threat to chickpea production worldwide. Resistance genes with broad-spectrum protection against virulent A. rabiei strains are required to secure chickpea yield in the US Northern Great Plains. Here, we performed a genome-wide association (GWA) study to discover novel sources of genetic variation for Ascochyta blight resistance using a worldwide germplasm collection of 219 chickpea lines. Ascochyta blight resistance was evaluated at 3, 9, 11, 13, and 14 days post-inoculation. Multiple GWA models revealed eight quantitative trait nucleotides (QTNs) across timepoints mapped to chromosomes 1, 3, 4, 6, and 7. Of these eight QTNs, only CM001767.1_28299946 on Chr 4 had previously been reported. QTN CM001766.1_36967269 on Chr 3 explained up to 33% of the variation in disease severity and was mapped to an exonic region of the pentatricopeptide repeat-containing protein At4g02750-like gene (LOC101506608). This QTN was confirmed across all models and timepoints. A total of 153 candidate genes, including genes with roles in pathogen recognition and signaling, cell wall biosynthesis, oxidative burst, and regulation of DNA transcription, were observed surrounding QTN-targeted regions. Further gene expression analysis on the QTNs identified in this study will provide insights into defense-related genes that can be further incorporated into breeding of new chickpea cultivars to minimize fungicide applications required for successful chickpea production in the US Northern Great Plains.

Remote disruption of intestinal homeostasis by Mycobacterium abscessus is detrimental to Drosophila survival

Mycobacterium abscessus (Mabs), an intracellular and opportunistic pathogen, is considered the most pathogenic fast-growing mycobacterium, and causes severe pulmonary infections in patients with cystic fibrosis. While bacterial factors contributing to its pathogenicity are well studied, the host factors and responses that worsen Mabs infection are not fully understood. Here, we report that Mabs systemic infection alters Drosophila melanogaster intestinal homeostasis. Mechanistically, Mabs remotely induces a self-damaging oxidative burst, leading to excessive differentiation of intestinal stem cells into enterocytes. We demonstrated that the subsequent increased intestinal renewal is mediated by both the Notch and JAK/STAT pathways and is deleterious to Drosophila survival. In conclusion, this work highlights that the ability of Mabs to induce an exacerbated and self-damaging response in the host contributes to its pathogenesis.

Trained Immunity Enhances Host Resistance to Infection in Aged Mice.

Aging significantly increases the incidence and severity of infections, with individuals aged 65 and above accounting for 65% of sepsis cases. Innate immune training, known as "trained immunity" or "innate immune memory", has emerged as a potential strategy to enhance infection resistance by modulating the aging immune system. We investigated the impact of β-glucan-induced trained immunity on aged mice (18-20 months old) compared to young adult mice (10-12 weeks old). Our findings showed that β-glucan equally augmented the host resistance to infection in both young and aged mice. This enhancement was characterized by augmented bacterial clearance, enhanced leukocyte recruitment and decreased cytokine production in response to Pseudomonas aeruginosa infection. Furthermore, young and aged trained macrophages displayed heightened metabolic capacity and improved antimicrobial functions, including enhanced phagocytosis and respiratory burst. RNA-seq analysis showed a distinctive gene expression pattern induced by trained immunity in macrophages characterized by activation of pathways regulating inflammation and the host response to infection and suppression of pathways regulating cell division, which was consistently observed in both young and aged groups. As compared to macrophages from young mice, aged macrophages showed increased activation of gene ontology pathways regulating angiogenesis, connective tissue deposition and wound healing. Our results indicate that immune training can be effectively induced in aging mice, providing valuable insights into potential strategies for enhancing infection resistance in the elderly.