Metabolic Engineering of Corynebacterium glutamicum for the Production of Flavonoids and Stilbenoids.

Flavonoids and stilbenoids, crucial secondary metabolites abundant in plants and fungi, display diverse biological and pharmaceutical activities, including potent antioxidant, anti-inflammatory, and antimicrobial effects. However, conventional production methods, such as chemical synthesis and plant extraction, face challenges in sustainability and yield. Hence, there is a notable shift towards biological production using microorganisms like Escherichia coli and yeast. Yet, the drawbacks of using E. coli and yeast as hosts for these compounds persist. For instance, yeast's complex glycosylation profile can lead to intricate protein production scenarios, including hyperglycosylation issues. Consequently, Corynebacterium glutamicum emerges as a promising alternative, given its adaptability and recent advances in metabolic engineering. Although extensively used in biotechnological applications, the potential production of flavonoid and stilbenoid in engineered C. glutamicum remains largely untapped compared to E. coli. This review explores the potential of metabolic engineering in C. glutamicum for biosynthesis, highlighting its versatility as a cell factory and assessing optimization strategies for these pathways. Additionally, various metabolic engineering methods, including genomic editing and biosensors, and cofactor regeneration are evaluated, with a focus on C. glutamicum. Through comprehensive discussion, the review offers insights into future perspectives in production, aiding researchers and industry professionals in the field.

Harvesting water from unsaturated atmospheres: deliquescence of salt secreted onto leaf surfaces drives reverse sap flow in a dominant arid climate mangrove, Avicennia marina.

The mangrove Avicennia marina adjusts internal salt concentrations by foliar salt secretion. Deliquescence of accumulated salt causes leaf wetting that may provide a water source for salt-secreting plants in arid coastal wetlands where high nocturnal humidity can usually support deliquescence whereas rainfall events are rare. We tested the hypotheses that salt deliquescence on leaf surfaces can drive top-down rehydration, and that such absorption of moisture from unsaturated atmospheres makes a functional contribution to dry season shoot water balances. Sap flow and water relations were monitored to assess the uptake of atmospheric water by branches during shoot wetting events under natural and manipulated microclimatic conditions. Reverse sap flow rates increased with increasing relative humidity from 70% to 89%, consistent with function of salt deliquescence in harvesting moisture from unsaturated atmospheres. Top-down rehydration elevated branch water potentials above those possible from root water uptake, subsidising transpiration rates and reducing branch vulnerability to hydraulic failure in the subsequent photoperiod. Absorption of atmospheric moisture harvested through deliquescence of salt on leaf surfaces enhances water balances of Avicennia marina growing in hypersaline wetlands under arid climatic conditions. Top-down rehydration from these frequent, low intensity wetting events contributes to prevention of carbon starvation and hydraulic failure during drought.

Foliar water uptake via cork warts in mangroves of the Sonneratia genus.

Foliar water uptake (FWU) occurs in plants of diverse ecosystems; however, the diversity of pathways and their associated FWU kinetics remain poorly resolved. We characterized a novel FWU pathway in two mangrove species of the Sonneratia genus, S. alba and S. caseolaris. Further, we assessed the influence of leaf wetting duration, wet-dry seasonality and leaf dehydration on leaf conductance to surface water (Ksurf ). The symplastic tracer dye, disodium fluorescein, revealed living cells subtending and encircling leaf epidermal structures known as cork warts as a pathway of FWU entry into the leaf. Rehydration kinetics experiments revealed a novel mode of FWU, with slow and steady rates of water uptake persistent over a duration of 12 hr. Ksurf increased with longer durations of leaf wetting and was greater in leaves with more negative water potentials at the initiation of leaf wetting. Ksurf declined by 68% between wet and dry seasons. Our results suggest that FWU via cork warts in Sonneratia sp. may be rate limited and under active regulation. We conclude that FWU pathways in halophytes may require ion exclusion to avoid uptake of salt when inundated, paralleling the capacity of halophyte roots for ion selectivity during water acquisition.

Decreased Cephalosporin Susceptibility of Oropharyngeal Neisseria Species in Antibiotic-using Men Who Have Sex With Men in Hanoi, Vietnam.

BACKGROUND: Neisseria gonorrhoeae (NG) infections are a global health burden. NG resistance to cephalosporins, which is increasingly reported, is an imminent threat to public health. Many hypothesize that commensal Neisseria species are an important reservoir for genetic material conferring antimicrobial resistance in NG; however, clinical data are lacking. METHODS: Men who have sex with men (MSM) in Hanoi, Vietnam, completed a questionnaire regarding antibiotic use. We collected pharyngeal specimens, cultured Neisseria species, and measured minimum inhibitory concentrations (MICs) to ciprofloxacin, cefixime, ceftriaxone, and cefpodoxime. Using MIC criteria for antimicrobial susceptibility in NG, we categorized the Neisseria species and compared mean MIC levels between different antibiotic user groups. RESULTS: Of 207 participants, 38% used at least 1 antibiotic in the past 6 months; 52% without a prescription. A median of 1 Neisseria species was cultured from each participant (range, 1-4) with 10 different Neisseria species identified overall. The proportion of Neisseria with reduced susceptibility to ciprofloxacin was 93%, cefpodoxime 84%, cefixime 31%, and ceftriaxone 28%. Antibiotic use within the past month was strongly associated with Neisseria species having increased MICs to cefixime, ceftriaxone, and cefpodoxime (mean MIC ratios of 6.27, 4.11, and 7.70, respectively), compared with those who used antibiotics between 1 and 6 months prior (P < .05, all comparisons). CONCLUSIONS: MSM in our study often used antibiotics without a prescription. At least 1 commensal Neisseria species colonized all men. Recent use of any antibiotics may select for oropharyngeal Neisseria species with antimicrobial resistance. The normal flora of the oropharynx may be an important source of antimicrobial resistance in Neisseria gonorrhoeae.

Earlier and Concurrent Food Insecurity Are Associated with Suboptimal Parenting in Early Childhood.

BACKGROUND: Food insecurity (FI) is associated with poor health, suboptimal nutrition, and disadvantaged linguistic, social, and academic development for children. Given the prominent role that parents play in children's development, FI may be associated with parenting practices. OBJECTIVES: We aimed to understand how FI and its change over time relate to parenting in early childhood. METHODS: Data were from the Early Childhood Longitudinal Study-Birth Cohort: parental interviews and child assessments at 9 mo and 2, 4, and 5 y old. Dependent variables were parenting practices in years 2, 4, and 5 in parent-child interaction, discipline, rules, and routines in general and food-related settings. Stratified by gender, parenting outcomes were regressed on earlier FI and child, parent, and contextual covariates, then additionally regressed on concurrent FI, using models with full-information-maximum-likelihood and cluster control. RESULTS: Earlier FI was associated with harsh discipline (girls, year 5: ß1 = 0.0811, P < 0.05) and frequent evening meals at a regular time (girls and boys, years 2 and 4), before adding concurrent FI. Accounting for earlier FI and covariates, concurrent FI was associated with harsh discipline (girls, years 2 and 4: ß2 = 0.0489 and 0.0705, P < 0.05; boys, year 2: ß2 = 0.0584, P < 0.05), rules about foods (girls, year 4), frequent evening meals as a family (girls, years 2 and 4), and frequent evening meals at a regular time (girls, years 2 and 4; boys, year 2); earlier FI remained associated with harsh discipline (girls, year 5) and frequent evening meals at a regular time (girls, years 2 and 4; boys, year 4). CONCLUSIONS: FI was linked with suboptimal parenting practices in structuring a general and food-related living environment, particularly for girls and by the age of 5 y.

Monitoring occurrence, extinction, and colonization probabilities for gibbon populations.

All gibbon species (Family: Hylobatidae) are considered threatened with extinction and recognized on the International Union for Conservation of Nature Red List of Threatened Species. Because gibbons are one of the most threatened families of primates, monitoring their status is now critically important. Long-term monitoring programs applying occupancy approaches, in addition to assessing occurrence probability, improves understanding of other population parameters such as site extinction or colonization probabilities, which elucidate temporal and spatial changes and are therefore important for guiding conservation efforts. In this study, we used multiple season occupancy models to monitor occurrence, extinction, and colonization probabilities for northern yellow-cheeked crested gibbon Nomascus annamensis in three adjacent protected areas in the Central Annamites mountain range, Vietnam. We collected data at 30 listening posts in 2012, 2014, and 2016 using the auditory point count method. Occurrence probabilities were highest in 2012 (0.74, confidence interval [CI]: 0.56-0.87) but slightly lower in 2014 (0.66, CI: 0.51-0.79) and 2016 (0.67, CI: 0.49-0.81). Extinction probabilities during the 2012-2014 and 2014-2016 intervals were 0.26 (0.14-0.44) and 0.25 (0.12-0.44), respectively. Colonization probabilities during 2012-2014 were 0.44 (0.19-0.73) and between 2014 and 2016 was 0.51 (0.26-0.75). Although local site extinctions have occurred, high recolonization probability helped to replenish the unoccupied sites and kept the occurrence probability stable. Long-term monitoring programs which use occurrence probability alone might not fully reveal the true dynamics of gibbon populations. We strongly recommend including multiple season occupancy models to monitor occurrence, extinction, and colonization probabilities in long-term gibbon monitoring programs.

Food Insecurity Is More Strongly Associated with Poor Subjective Well-Being in More-Developed Countries than in Less-Developed Countries.

BACKGROUND: Food insecurity is strongly associated with subjective well-being. People compare their well-being to a subjective reference that adjusts over time, which is called hedonic adaptation. OBJECTIVE: We aimed to deepen understanding of the relation between food insecurity and subjective well-being among countries from the perspective of possible hedonic adaptation between food insecurity and subjective well-being. METHODS: Global data from the Gallup World Poll 2014 were collected from 152,206 individuals in 147 countries. Telephone and face-to-face surveys were conducted in 37 and 111 countries, respectively, collecting data on law and order; food and shelter; institutions and infrastructure; job climate; and financial, social, physical, and evaluative well-being, including the Food Insecurity Experience Scale. Data were aggregated to country level and merged with economic and social measures from World Bank and United Nations sources: infant mortality, gross domestic product, economic inequality, agricultural value added, fertility, maternal mortality, female schooling, and female participation in the labor force. Multilevel linear regression was used to examine associations between well-being and food insecurity. RESULTS: Experiencing moderate or severe food insecurity was prevalent among countries, with a mean probability of 0.273 ± 0.220. Countries that were less developed economically and socially had a higher probability of experiencing food insecurity, lower subjective well-being as measured by the daily experience index, and less negative slopes for the relation between daily experience index and food insecurity. Food insecurity was the strongest predictor of daily experience from among the measures of economic and social development. CONCLUSIONS: The prevalence of food insecurity was strongly and negatively associated with subjective well-being across 147 countries. The association between food insecurity and poor subjective well-being within countries was stronger for more-developed countries, providing evidence of hedonic adaptation between food insecurity and subjective well-being. Food insecurity explained substantial variation in subjective well-being both among and within countries.

Methylfolate Trap Promotes Bacterial Thymineless Death by Sulfa Drugs.

The methylfolate trap, a metabolic blockage associated with anemia, neural tube defects, Alzheimer's dementia, cardiovascular diseases, and cancer, was discovered in the 1960s, linking the metabolism of folate, vitamin B12, methionine and homocysteine. However, the existence or physiological significance of this phenomenon has been unknown in bacteria, which synthesize folate de novo. Here we identify the methylfolate trap as a novel determinant of the bacterial intrinsic death by sulfonamides, antibiotics that block de novo folate synthesis. Genetic mutagenesis, chemical complementation, and metabolomic profiling revealed trap-mediated metabolic imbalances, which induced thymineless death, a phenomenon in which rapidly growing cells succumb to thymine starvation. Restriction of B12 bioavailability, required for preventing trap formation, using an "antivitamin B12" molecule, sensitized intracellular bacteria to sulfonamides. Since boosting the bactericidal activity of sulfonamides through methylfolate trap induction can be achieved in Gram-negative bacteria and mycobacteria, it represents a novel strategy to render these pathogens more susceptible to existing sulfonamides.

A redox regulatory system critical for mycobacterial survival in macrophages and biofilm development.

Survival of M. tuberculosis in host macrophages requires the eukaryotic-type protein kinase G, PknG, but the underlying mechanism has remained unknown. Here, we show that PknG is an integral component of a novel redox homeostatic system, RHOCS, which includes the ribosomal protein L13 and RenU, a Nudix hydrolase encoded by a gene adjacent to pknG. Studies in M. smegmatis showed that PknG expression is uniquely induced by NADH, which plays a key role in metabolism and redox homeostasis. In vitro, RenU hydrolyses FAD, ADP-ribose and NADH, but not NAD+. Absence of RHOCS activities in vivo causes NADH and FAD accumulation, and increased susceptibility to oxidative stress. We show that PknG phosphorylates L13 and promotes its cytoplasmic association with RenU, and the phosphorylated L13 accelerates the RenU-catalyzed NADH hydrolysis. Importantly, interruption of RHOCS leads to impaired mycobacterial biofilms and reduced survival of M. tuberculosis in macrophages. Thus, RHOCS represents a checkpoint in the developmental program required for mycobacterial growth in these environments.

Plumbing the depths: extracellular water storage in specialized leaf structures and its functional expression in a three-domain pressure -volume relationship.

A three-domain pressure-volume relationship (PV curve) was studied in relation to leaf anatomical structure during dehydration in the grey mangrove, Avicennia marina. In domain 1, relative water content (RWC) declined 13% with 0.85 MPa decrease in leaf water potential, reflecting a decrease in extracellular water stored primarily in trichomes and petiolar cisternae. In domain 2, RWC decreased by another 12% with a further reduction in leaf water potential to -5.1 MPa, the turgor loss point. Given the osmotic potential at full turgor (-4.2 MPa) and the effective modulus of elasticity (~40 MPa), domain 2 emphasized the role of cell wall elasticity in conserving cellular hydration during leaf water loss. Domain 3 was dominated by osmotic effects and characterized by plasmolysis in most tissues and cell types without cell wall collapse. Extracellular and cellular water storage could support an evaporation rate of 1 mmol m-2 s-1 for up to 54 and 50 min, respectively, before turgor loss was reached. This study emphasized the importance of leaf anatomy for the interpretation of PV curves, and identified extracellular water storage sites that enable transient water use without substantive turgor loss when other factors, such as high soil salinity, constrain rates of water transport.

Leaf water storage increases with salinity and aridity in the mangrove Avicennia marina: integration of leaf structure, osmotic adjustment and access to multiple water sources.

Leaf structure and water relations were studied in a temperate population of Avicennia marina subsp. australasica along a natural salinity gradient [28 to 49 parts per thousand (ppt)] and compared with two subspecies grown naturally in similar soil salinities to those of subsp. australasica but under different climates: subsp. eucalyptifolia (salinity 30 ppt, wet tropics) and subsp. marina (salinity 46 ppt, arid tropics). Leaf thickness, leaf dry mass per area and water content increased with salinity and aridity. Turgor loss point declined with increase in soil salinity, driven mainly by differences in osmotic potential at full turgor. Nevertheless, a high modulus of elasticity (ε) contributed to maintenance of high cell hydration at turgor loss point. Despite similarity among leaves in leaf water storage capacitance, total leaf water storage increased with increasing salinity and aridity. The time that stored water alone could sustain an evaporation rate of 1 mmol m-2  s-1 ranged from 77 to 126 min from subspecies eucalyptifolia to ssp. marina, respectively. Achieving full leaf hydration or turgor would require water from sources other than the roots, emphasizing the importance of multiple water sources to growth and survival of Avicennia marina across gradients in salinity and aridity.

Food Insecurity Is Associated with Subjective Well-Being among Individuals from 138 Countries in the 2014 Gallup World Poll.

Background: Food insecurity is an aspect of living conditions that is particularly important for quality of life, health, and subjective well-being. The implementation of the 8-item Food Insecurity Experience Scale in 147 countries in the 2014 Gallup World Poll provided an unprecedented opportunity to understand the association of food insecurity with subjective well-being.Objective: We examined how food insecurity relates with measures of living conditions and how food insecurity and other living conditions relate with physical health and, in turn, subjective well-being.Methods: Data were collected from individuals aged ≥15 y by telephone in 38 countries and via face-to-face interviews in 111 others. The available sample was 132,618 (138 countries) and 122,137 (137 countries) for the daily experience and life evaluation indexes of subjective well-being, respectively. Daily experience was a continuous measure and life evaluation was categorized into thriving, struggling, and suffering. We estimated 6 linear or logistic regression models for each index controlling for country as a fixed effect.Results: Food insecurity was associated with the other 3 measures of living conditions: household income, shelter and housing, and employment. Food insecurity explained poor physical health and lower subjective well-being beyond other measures of living conditions. Instrumental and emotional support was associated with higher subjective well-being. The associations of food insecurity with subjective well-being were larger than with other explanatory variables. Food insecurity was associated with subjective well-being within each of the 4 World Bank income classes of countries, with a larger magnitude of differences for the higher-income classes.Conclusions: Food insecurity was strongly and negatively associated with subjective well-being in a large global sample of individuals aged ≥15 y. These results demonstrate the consistency of goal 2 of the Sustainable Development Goals, which has targeted 2030 to ensure food security for all people, year-round, with other goals to reduce food insecurity.

Growth responses of the mangrove Avicennia marina to salinity: development and function of shoot hydraulic systems require saline conditions.

BACKGROUND AND AIMS: Halophytic eudicots are characterized by enhanced growth under saline conditions. This study combines physiological and anatomical analyses to identify processes underlying growth responses of the mangrove Avicennia marina to salinities ranging from fresh- to seawater conditions. METHODS: Following pre-exhaustion of cotyledonary reserves under optimal conditions (i.e. 50% seawater), seedlings of A. marina were grown hydroponically in dilutions of seawater amended with nutrients. Whole-plant growth characteristics were analysed in relation to dry mass accumulation and its allocation to different plant parts. Gas exchange characteristics and stable carbon isotopic composition of leaves were measured to evaluate water use in relation to carbon gain. Stem and leaf hydraulic anatomy were measured in relation to plant water use and growth. KEY RESULTS: Avicennia marina seedlings failed to grow in 0-5% seawater, whereas maximal growth occurred in 50-75% seawater. Relative growth rates were affected by changes in leaf area ratio (LAR) and net assimilation rate (NAR) along the salinity gradient, with NAR generally being more important. Gas exchange characteristics followed the same trends as plant growth, with assimilation rates and stomatal conductance being greatest in leaves grown in 50-75% seawater. However, water use efficiency was maintained nearly constant across all salinities, consistent with carbon isotopic signatures. Anatomical studies revealed variation in rates of development and composition of hydraulic tissues that were consistent with salinity-dependent patterns in water use and growth, including a structural explanation for low stomatal conductance and growth under low salinity. CONCLUSIONS: The results identified stem and leaf transport systems as central to understanding the integrated growth responses to variation in salinity from fresh- to seawater conditions. Avicennia marina was revealed as an obligate halophyte, requiring saline conditions for development of the transport systems needed to sustain water use and carbon gain.

The prescription of beta-blockers in older patients with heart failure with reduced ejection fraction: an observational study in Vietnam.

This study in older hospitalized patients with heart failure with reduced ejection fraction (HFrEF) aimed to examine the prevalence of beta-blocker prescription and its associated factors. A total of 190 participants were recruited from July 2019 to July 2020. The inclusion criteria included: (1) aged ≥ 60 years, (2) having a diagnosis of chronic HFrEF in the medical records, (3) hospitalized for at least 48 h. The participants had a mean age of 75.5 ± 9.1, and 46.8% were female. Of these, 55.3% were prescribed beta-blockers during admission. To explore the factors associated with beta-blocker prescription, multivariable logistic regression analysis was applied and the results were presented as odds ratios (OR) and 95% confidence intervals (CI). On multivariate logistic regression models, higher NYHA classes (OR 0.49, 95%CI 0.26-0.94), chronic obstructive pulmonary disease (OR 0.17, 95% CI 0.04-0.85), chronic kidney disease (OR 0.40, 95% CI 0.19-0.83), and heart rate under 65 (OR 0.34, 95% CI 0.12-0.98) were associated with a reduced likelihood of prescription. In this study, we found a low rate of beta-blocker prescriptions, with only around half of the participants being prescribed beta-blockers. Further studies are needed to examine the reasons for the under-prescription of beta-blockers, and to evaluate the long-term benefits of beta-blockers in elderly patients with HFrEF in this population.

The influence of socioenvironmental risk factors on risk-taking behaviors among Bahamian adolescents: a structural equation modeling analysis.

Background: Adolescents' risk-taking behaviors can have profound impacts on their future health. Few studies have established a relationship between multiple social environmental factors and adolescent risk behaviors. We used structural equation modeling to examine the role of parental monitoring and environmental risks on adolescents' behavioral intentions and risk behaviors. Methods: Data were collected through the baseline survey of a national implementation project among 2205 Grade 6 students in 24 government schools in The Bahamas in 2019. Structural equation modeling examined relations among parental monitoring, environmental risk factors, behavioral intentions, and risk behaviors. Results: Students had engaged in various delinquent, substance use, and sexual risks. In the structural equation model, parental monitoring demonstrated direct negative (protective) effects on behavioral intentions and risk behaviors, whereas environmental risk factors had a direct positive effect on adolescent behavioral intentions and risk behaviors. The model had an R2 value of 0.57 for adolescent risk behaviors. Conclusion: Parental monitoring and environmental risk factors had strong influences on risk-taking behaviors of early adolescents. Future adolescent health behavior interventions should consider offering additional prevention resources to early adolescents who are exposed to multiple environmental risk factors.

Development of a shape-based algorithm for identification of asymptomatic vertebral compression fractures: A proof-of-principle study.

Objectives: Vertebral fracture is both common and serious among adults, yet it often goes undiagnosed. This study aimed to develop a shape-based algorithm (SBA) for the automatic identification of vertebral fractures. Methods: The study included 144 participants (50 individuals with a fracture and 94 without a fracture) whose plain thoracolumbar spine X-rays were taken. Clinical diagnosis of vertebral fracture (grade 0 to 3) was made by rheumatologists using Genant's semiquantitative method. The SBA algorithm was developed to determine the ratio of vertebral body height loss. Based on the ratio, SBA classifies a vertebra into 4 classes: 0 = normal, 1 = mild fracture, 2 = moderate fracture, 3 = severe fracture). The concordance between clinical diagnosis and SBA-based classification was assessed at both person and vertebra levels. Results: At the person level, the SBA achieved a sensitivity of 100% and specificity of 62% (95% CI, 51%-72%). At the vertebra level, the SBA achieved a sensitivity of 84% (95% CI, 72%-93%), and a specificity of 88% (95% CI, 85%-90%). On average, the SBA took 0.3 s to assess each X-ray. Conclusions: The SBA developed here is a fast and efficient tool that can be used to systematically screen for asymptomatic vertebral fractures and reduce the workload of healthcare professionals.

Prevalence, incidence of and risk factors for vertebral fracture in the community: the Vietnam Osteoporosis Study.

The epidemiology of vertebral fractures (VF) in underrepresented populations is not well-documented. This cohort study was part of a longitudinal osteoporosis research project with the aim of determining the prevalence, incidence, and risk factors for VF. 401 individuals (155 men) aged 50 years and older without a clinical diagnosis of VF were took radiographs at baseline and 2 years later. VF were ascertained using the Genant's semi-quantitative method. Bone mineral density (BMD) of femoral neck and lumbar spine were measured by dual-energy X-ray absorptiometry (Hologic Inc). The association between VF and risk factors was analyzed by the multiple logistic regression. The 95% confidence interval for prevalence and incidence was estimated by exact Poisson test. At baseline, the prevalence of VF was 12.2% (n = 49, 95% CI 9.0-16.2%) and increased with advancing age with one-fifth of those aged 70 and older having a VF. During the follow-up period, we observed 6 new VF, making the incidence of 6.6/1000 person-years (n = 6, 95% CI 2.4-14.3). The risk of prevalent VF was associated with male gender (OR: 2.67; 95% CI 1.28-5.87) and T-score at the femoral neck (OR per one SD decrease: 1.1; 1.03-1.17). These data indicate that VF is common among adults, and that lower femoral neck BMD was a risk factor for VF.

Comparative Analysis of Swine Antibody Responses following Vaccination with Live-Attenuated and Killed African Swine Fever Virus Vaccines.

African swine fever virus (ASFV) is circulating in many swine-producing countries, causing significant economic losses. It is observed that pigs experimentally vaccinated with a live-attenuated virus (LAV) but not a killed virus (KV) vaccine develop solid homologous protective immunity. The objective of this study was to comparatively analyze antibody profiles between pigs vaccinated with an LAV vaccine and those vaccinated with a KV vaccine to identify potential markers of vaccine-induced protection. Thirty ASFV seronegative pigs were divided into three groups: Group 1 received a single dose of an experimental LAV, Group 2 received two doses of an experimental KV vaccine, and Group 3 was kept as a non-vaccinated (NV) control. At 42 days post-vaccination, all pigs were challenged with the parental virulent ASFV strain and monitored for 21 days. All pigs vaccinated with the LAV vaccine survived the challenge. In contrast, eight pigs from the KV group and seven pigs from the NV group died within 14 days post-challenge. Serum samples collected on 41 days post-vaccination were analyzed for their reactivity against a panel of 29 viral structural proteins. The sera of pigs from the LAV group exhibited a strong antibody reactivity against various viral structural proteins, while the sera of pigs in the KV group only displayed weak antibody reactivity against the inner envelope (p32, p54, p12). There was a negative correlation between the intensity of antibody reactivity against five ASFV antigens, namely p12, p14, p15, p32, and pD205R, and the viral DNA titers in the blood of animals after the challenge infection. Thus, antibody reactivities against these five antigens warrant further evaluation as potential indicators of vaccine-induced protection.

Bacterial conversion of folinic acid is required for antifolate resistance.

Antifolates, which are among the first antimicrobial agents invented, inhibit cell growth by creating an intracellular state of folate deficiency. Clinical resistance to antifolates has been mainly attributed to mutations that alter structure or expression of enzymes involved in de novo folate synthesis. We identified a Mycobacterium smegmatis mutant, named FUEL (which stands for folate utilization enzyme for leucovorin), that is hypersusceptible to antifolates. Chemical complementation indicated that FUEL is unable to metabolize folinic acid (also known as leucovorin or 5-formyltetrahydrofolate), whose metabolic function remains unknown. Targeted mutagenesis, genetic complementation, and biochemical studies showed that FUEL lacks 5,10-methenyltetrahydrofolate synthase (MTHFS; also called 5-formyltetrahydrofolate cyclo-ligase; EC 6.3.3.2) activity responsible for the only ATP-dependent, irreversible conversion of folinic acid to 5,10-methenyltetrahydrofolate. In trans expression of active MTHFS proteins from bacteria or human restored both antifolate resistance and folinic acid utilization to FUEL. Absence of MTHFS resulted in marked cellular accumulation of polyglutamylated species of folinic acid. Importantly, MTHFS also affected M. smegmatis utilization of monoglutamylated 5-methyltetrahydrofolate exogenously added to the medium. Likewise, Escherichia coli mutants lacking MTHFS became susceptible to antifolates. These results indicate that folinic acid conversion by MTHFS is required for bacterial intrinsic antifolate resistance and folate homeostatic control. This novel mechanism of antimicrobial antifolate resistance might be targeted to sensitize bacterial pathogens to classical antifolates.

Food Insecurity among Adolescent Students from 95 Countries Is Associated with Diet, Behavior, and Health, and Associations Differ by Student Age and Sex.

Background: Adolescents' developmental tasks and challenges vary based on age, sex, and social context. Food insecurity affects adolescents, but existing research has been limited to a few country contexts and has treated adolescence as a singular developmental moment with limited consideration of potential differences in how food insecurity relates to developmental experiences based on adolescent age and sex. Objectives: We aimed to describe relations between student-reported food insecurity and students' profiles of nutritional, physical activity, school absenteeism, health/mental health, and victimization experiences, and how these differ by student age and sex. Methods: Using cross-sectional data from the Global School-based Student Health Survey, we examined adolescent reports of their food security among 337,738 students 11-18 y old from 95 countries. We identified their profiles of focal experiences, and used mixed-effects linear and logistic regression models to examine differences in these profiles by student food insecurity and how these differ by student age and sex. Results: Of students, 25.5% aged 11-14 y compared with 30% aged 15-18 y reported food insecurity in the past 30 d. Food insecurity was associated with less frequent fruit and vegetable intake; more frequent soft drink intake; worse mental health; less physical activity; more missed school; higher odds of smoking, drinking, and using drugs; and more bullying victimization and sexual partners. Food insecurity was associated with reduced age- and sex-specific protection: greater substance use among younger adolescents, more sexual partners among older females, and greater worry among younger males. Food insecurity was also associated with increased age-specific risk: greater soft drink consumption among younger adolescents. Conclusions: Across countries, adolescent food insecurity was associated with poorer nutritional, mental health, behavioral, and relationship profiles; these associations differed with student age and sex. Food insecurity interventions should attend to adolescent developmental stage and the gendered contexts through which adolescents navigate daily life.