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1.
Aging Cell ; 23(4): e14099, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38317404

RESUMEN

Although the two-dose mRNA vaccination regime provides protection against SARS-CoV-2, older adults have been shown to exhibit poorer vaccination responses. In addition, the role of vaccine-induced T-cell responses is not well characterised. We aim to assess the impact of age on immune responses after two doses of the BNT162b2 mRNA vaccine, focussing on antigen-specific T-cells. A prospective 3-month study was conducted on 15 young (median age 31 years, interquartile range (IQR) 25-35 years) and 14 older adults (median age 72 years, IQR 70-73 years). We assessed functional, neutralising antibody responses against SARS-CoV-2 variants using ACE-2 inhibition assays, and changes in B and T-cell subsets by high-dimensional flow cytometry. Antigen-specific T-cell responses were also quantified by intracellular cytokine staining and flow cytometry. Older adults had attenuated T-helper (Th) response to vaccination, which was associated with weaker antibody responses and decreased SARS-CoV-2 neutralisation. Antigen-specific interferon-γ (IFNγ)-secreting CD4+ T-cells to wild-type and Omicron antigens increased in young adults, which was strongly positively correlated with their neutralising antibody responses. Conversely, this relationship was negative in older adults. Hence, older adults' relative IFNγ-secreting CD4+ T cell deficiency might explain their poorer COVID-19 vaccination responses. Further exploration into the aetiology is needed and would be integral in developing novel vaccination strategies and improving infection outcomes in older adults.


Asunto(s)
COVID-19 , Interferón gamma , Adulto Joven , Humanos , Anciano , Adulto , Linfocitos T CD4-Positivos , Vacunas contra la COVID-19 , Vacuna BNT162 , Estudios Prospectivos , COVID-19/prevención & control , SARS-CoV-2 , Vacunación , Anticuerpos Neutralizantes , Anticuerpos Antivirales
2.
NPJ Vaccines ; 9(1): 43, 2024 Feb 23.
Artículo en Inglés | MEDLINE | ID: mdl-38396073

RESUMEN

The advent of SARS-CoV-2 variants with defined mutations that augment pathogenicity and/or increase immune evasiveness continues to stimulate global efforts to improve vaccine formulation and efficacy. The extraordinary advantages of lipid nanoparticles (LNPs), including versatile design, scalability, and reproducibility, make them ideal candidates for developing next-generation mRNA vaccines against circulating SARS-CoV-2 variants. Here, we assess the efficacy of LNP-encapsulated mRNA booster vaccines encoding the spike protein of SARS-CoV-2 for variants of concern (Delta, Omicron) and using a predecessor (YN2016C isolated from bats) strain spike protein to elicit durable cross-protective neutralizing antibody responses. The mRNA-LNP vaccines have desirable physicochemical characteristics, such as small size (~78 nm), low polydispersity index (<0.13), and high encapsulation efficiency (>90%). We employ in vivo bioluminescence imaging to illustrate the capacity of our LNPs to induce robust mRNA expression in secondary lymphoid organs. In a BALB/c mouse model, a three-dose subcutaneous immunization of mRNA-LNPs vaccines achieved remarkably high levels of cross-neutralization against the Omicron B1.1.529 and BA.2 variants for extended periods of time (28 weeks) with good safety profiles for all constructs when used in a booster regime, including the YN2016C bat virus sequences. These findings have important implications for the design of mRNA-LNP vaccines that aim to trigger durable cross-protective immunity against the current and newly emerging variants.

3.
Sci Rep ; 13(1): 21810, 2023 12 09.
Artículo en Inglés | MEDLINE | ID: mdl-38071323

RESUMEN

The scale and duration of neutralizing antibody responses targeting SARS-CoV-2 viral variants represents a critically important serological parameter that predicts protective immunity for COVID-19. In this study, we describe the development and employment of a new functional assay that measures neutralizing antibodies for SARS-CoV-2 and present longitudinal data illustrating the impact of age, sex and comorbidities on the kinetics and strength of vaccine-induced antibody responses for key variants in an Asian volunteer cohort. We also present an accurate quantitation of serological responses for SARS-CoV-2 that exploits a unique set of in-house, recombinant human monoclonal antibodies targeting the viral Spike and nucleocapsid proteins and demonstrate a reduction in neutralizing antibody titres across all groups 6 months post-vaccination. We also observe a marked reduction in the serological binding activity and neutralizing responses targeting recently newly emerged Omicron variants including XBB 1.5 and highlight a significant increase in cross-protective neutralizing antibody responses following a third dose (boost) of vaccine. These data illustrate how key virological factors such as immune escape mutations combined with host demographic factors such as age and sex of the vaccinated individual influence the strength and duration of cross-protective serological immunity for COVID-19.


Asunto(s)
COVID-19 , Vacunas , Humanos , SARS-CoV-2 , Anticuerpos ampliamente neutralizantes , COVID-19/prevención & control , Anticuerpos Neutralizantes , Empleo , Vacunación , Anticuerpos Antivirales
4.
Bioeng Transl Med ; 8(6): e10490, 2023 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-38023718

RESUMEN

Despite being a convenient clinical substrate for biomonitoring, saliva's widespread utilization has not yet been realized. The non-Newtonian, heterogenous, and highly viscous nature of saliva complicate the development of automated fluid handling processes that are vital for accurate diagnoses. Furthermore, conventional saliva processing methods are resource and/or time intensive precluding certain testing capabilities, with these challenges aggravated during a pandemic. The conventional approaches may also alter analyte structure, reducing application opportunities in point-of-care diagnostics. To overcome these challenges, we introduce the SHEAR saliva collection device that mechanically processes saliva, in a rapid and resource-efficient way. We demonstrate the device's impact on reducing saliva's viscosity, improving sample's uniformity, and increasing diagnostic performance of a COVID-19 rapid antigen test. Additionally, a formal user experience study revealed generally positive comments. SHEAR saliva collection device may support realization of the saliva's potential, particularly in large-scale and/or resource-limited settings for global and community diagnostics.

5.
Immunohorizons ; 7(10): 708-717, 2023 10 01.
Artículo en Inglés | MEDLINE | ID: mdl-37889158

RESUMEN

COVID-19 vaccination has significantly impacted the global pandemic by reducing the severity of infection, lowering rates of hospitalization, and reducing morbidity/mortality in healthy individuals. However, the degree of vaccine-induced protection afforded to renal transplant recipients who receive forms of maintenance immunosuppression remains poorly defined. This is particularly important when we factor in the emergence of SARS-CoV-2 variants of concern (VOCs) that have defined mutations that reduce the effectiveness of Ab responses targeting the Spike Ags from the ancestral Wuhan-Hu-1 variants employed in the most widely used vaccine formats. In this study, we describe a qualitative, longitudinal analysis of neutralizing Ab responses against multiple SARS-CoV-2 VOCs in 129 renal transplant recipients who have received three doses of the Pfizer-BioNTech COVID-19 vaccine (BNT162b2). Our results reveal a qualitative and quantitative reduction in the vaccine-induced serological response in transplant recipients versus healthy controls where only 51.9% (67 of 129) made a measurable vaccine-induced IgG response and 41.1% (53 of 129) exhibited a significant neutralizing Ab titer (based on a pseudovirus neutralization test value >50%). Analysis on the VOCs revealed strongest binding toward the wild-type Wuhan-Hu-1 and Delta variants but none with both of the Omicron variants tested (BA1 and BA2). Moreover, older transplant recipients and those who are on mycophenolic acid as part of their maintenance therapy exhibited a profound reduction in all of the analyzed vaccine-induced immune correlates. These data have important implications for how we monitor and manage transplant patients in the future as COVID-19 becomes endemic in our populations.


Asunto(s)
Vacunas contra la COVID-19 , COVID-19 , Humanos , Vacuna BNT162 , Receptores de Trasplantes , COVID-19/prevención & control , SARS-CoV-2
6.
Pediatr Pulmonol ; 58(10): 2889-2898, 2023 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-37530492

RESUMEN

BACKGROUND: To evaluate the diagnostic accuracy of sonographic assessment of diaphragmatic dimensions and excursions in predicting Continuous Positive Airway Pressure (CPAP) failure in preterm neonates with respiratory distress. METHODS: Prospective cohort study among preterm neonates less than 34 weeks of gestation who were hemodynamically stable and either admitted with respiratory distress or who developed respiratory distress shortly after admission to the NICU and having Silverman-Anderson Score (SAS) ≥ 3/10 were included. We performed sonographic assessment of diaphragmatic dimensions and excursions before and one hour ±30 minutes after application of CPAP. 'CPAP failure' was defined as combined outcome of the need of surfactant and/or upgradation of respiratory support within first 72 hours after a trial of CPAP. Clinical parameters and diaphragmatic measurements were compared between CPAP failure and success groups. RESULTS: Of 62 participants, 20 (32%) failed CPAP. On binomial logistic regression (after adjustment for gestational age and birth weight), initial SAS, higher diaphragmatic excursion (both left and right, before and after CPAP application), lower left hemidiaphragm diaphragmatic thickness fraction (DTF) (before CPAP application) and lower right DTF (after CPAP application) were independent predictors of CPAP failure. However, the receiver-operating characteristics curves showed that excursions of right and left hemi-diaphragm both before and after CPAP application, had highest accuracies in predicting CPAP failure (AUC 0.84, 0.80 and 0.86, 0.78, respectively; p < .001). CONCLUSION: Diaphragmatic excursion can be a useful parameter to predict the failure of CPAP in preterm neonates with respiratory distress.

7.
Indian J Nephrol ; 33(2): 108-113, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37234434

RESUMEN

Background: Atypical hemolytic uremic syndrome (aHUS) is hemolytic uremic syndrome (HUS) without a coexisting disease or specific infection. Eculizumab is the standard of care for children with aHUS. However, since it is not yet available in India, plasma therapy remains the treatment of choice in these patients. We studied the clinical profile of children with aHUS and the determinants associated with low estimated glomerular filtration rate (eGFR) on follow-up. Materials and Methods: A retrospective chart review of children (1-18 years) with aHUS managed at a tertiary care center was done. Demographic details, clinical features, and investigations at presentation and on subsequent visits were noted. Details of treatment and duration of hospital stay were recorded. Results: Of 26 children, boys outnumbered girls (2:1). The mean age at presentation was 80 ± 37.6 months. All children were hypertensive during the early phase of illness. Anti-factor H antibodies were elevated in 84% (22/26). Plasma therapy was initiated for 25 patients, and in 17 children, additionally immunosuppression was given. The median duration to achieve hematological remission was 17 days. As compared to children with normal eGFR, those with CKD stage 2 or more had significant delay in initiation of plasma therapy (4 vs. 14 days) and also took a longer time to achieve hematological remission (15 vs. 28 days). The prevalence of hypertension and proteinuria at the last follow-up was 63% and 27%, respectively. Conclusion: Delayed initiation of plasma therapy and longer time to achieve hematological remission are associated with lower eGFR on follow-up. Long-term monitoring of hypertension and proteinuria is needed in these children.

8.
Environ Sci Pollut Res Int ; 30(10): 24899-24906, 2023 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-35113375

RESUMEN

Microbubbles are small gas-filled bubbles which have wide application in various industries. The stability of microbubble is of primary concern for the application of microbubble. In this research, the stability of microbubble dispersion generated using CTAB surfactant is analyzed by drainage mechanism. The stability of microbubble dispersion is studied on the basis of the half-life of microbubble dispersion. Microbubble dispersion gas fraction and apparent rise velocity of interface of microbubble dispersion are also calculated. The size of microbubble is estimated from the apparent rise velocity of interface of microbubble dispersion. Further, silica nano-particles are added to the surfactants to study their effect on the stability of microbubble dispersion. The observed results clearly indicate that the stability of microbubble dispersion is significantly affected by the surfactant concentration and the weight of silica nano-particle in the liquid. Similar results were observed for the apparent rise velocity of interface and bubble size of dispersion. The present work may be beneficial for the application of microbubble in various chemical and biochemical industries and scientific community.


Asunto(s)
Microburbujas , Dióxido de Silicio , Tensoactivos
9.
Prog Mol Biol Transl Sci ; 192(1): 205-229, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36280320

RESUMEN

Malnutrition is a global health issue and the leading cause of childhood morbidity and mortality under 5 years old. Malnutrition comprises undernutrition (stunting, wasting, underweight), overweight, and obesity. Infancy and child malnutrition are substantially influenced by a number of variables, such as insufficient nutrients, early birth, intestinal inflammation, and gastrointestinal tract microbiota. A variety of environmental factors have been identified that modulate the structure and diversity of newborns' gut microbiomes and their long-term health. Significant data demonstrate that the functional potency and compositional diversity of the microbiome differ in different types of malnutrition. The divergence in the gut microbiome composition between malnourished and healthy children can be observed at an age as young as 12 months. This focuses on variations in the gut microbiome that may influence adult obesity/health status, beginning in the early years of life. The therapeutic potential of supporting a healthy microbiome in malnourished children is being studied as a technique to aid in the fight against malnutrition. The goal of this chapter was to determine the makeup of gut microbiota in obese and undernourished children under the age of 5 years.


Asunto(s)
Microbioma Gastrointestinal , Desnutrición , Recién Nacido , Niño , Adulto , Humanos , Lactante , Preescolar , Disbiosis/complicaciones , Tracto Gastrointestinal , Obesidad
10.
Front Pediatr ; 10: 949756, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36186648

RESUMEN

COVID-19 can be severe in pregnant women, and have adverse consequences for the subsequent infant. We profiled the post-infectious immune responses in maternal and child blood as well as breast milk in terms of antibody and cytokine expression and performed histopathological studies on placentae obtained from mothers convalescent from antenatal COVID-19. Seventeen mother-child dyads (8 cases of antenatal COVID-19 and 9 healthy unrelated controls; 34 individuals in total) were recruited to the Gestational Immunity For Transfer (GIFT) study. Maternal and infant blood, and breast milk samples were collected over the first year of life. All samples were analyzed for IgG and IgA against whole SARS-CoV-2 spike protein, the spike receptor-binding domain (RBD), and previously reported immunodominant epitopes, as well as cytokine levels. The placentae were examined microscopically. The study is registered at clinicaltrials.gov under the identifier NCT04802278. We found high levels of virus-specific IgG in convalescent mothers and similarly elevated titers in newborn children. Thus, antenatal SARS-CoV-2 infection led to high plasma titers of virus-specific antibodies in infants postnatally. However, this waned within 3-6 months of life. Virus neutralization by plasma was not uniformly achieved, and the presence of antibodies targeting known immunodominant epitopes did not assure neutralization. Virus-specific IgA levels were variable among convalescent individuals' sera and breast milk. Antibody transfer ratios and the decay of transplacentally transferred virus-specific antibodies in neonatal circulation resembled that for other pathogens. Convalescent mothers showed signs of chronic inflammation marked by persistently elevated IL17RA levels in their blood. Four placentae presented signs of acute inflammation, particularly in the subchorionic region, marked by neutrophil infiltration even though > 50 days had elapsed between virus clearance and delivery. Administration of a single dose of BNT162b2 mRNA vaccine to mothers convalescent from antenatal COVID-19 increased virus-specific IgG and IgA titers in breast milk, highlighting the importance of receiving the vaccine even after natural infection with the added benefit of enhanced passive immunity.

11.
Artículo en Inglés | MEDLINE | ID: mdl-35935741

RESUMEN

In the current era, the increased demand of healthy food rich in antioxidants, vitamins and minerals and those having therapeutic value has led to over-exploitation of major agricultural and medicinal plants. This overburden can be reduced by an efficient utilization of underutilized plants with nutritional and medicinal importance. These underutilized plants are neglected or undervalued 'minor' crops having low production and sale. These less documented and less studied group of underutilized plants are considered as a rich source of various phytochemicals and secondary metabolites having bioactive compounds. These underutilized wild herbs that have not gained much attention from commercial as well as scientific community were selected for the present study. The present review elucidates the significance of these plants and recent biotechnological methods to conserve them. The present study on such food and medically important herbs would contribute in a wide recognition of their benefits for our society.

12.
Front Microbiol ; 13: 887251, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35847117

RESUMEN

Antimicrobial resistance in clinically important microbes has emerged as an unmet challenge in global health. Extensively drug-resistant bacterial pathogens have cropped up lately defying the action of even the last resort of antibiotics. This has led to a huge burden in the health sectors and increased morbidity and mortality rate across the world. The dwindling antibiotic discovery pipeline and rampant usage of antibiotics has set the alarming bells necessitating immediate actions to combat this looming threat. Various alternatives to discovery of new antibiotics are gaining attention such as reversing the antibiotic resistance and hence reviving the arsenal of antibiotics in hand. Antibiotic resistance reversal is mainly targeted against the antibiotic resistance mechanisms, which potentiates the effective action of the antibiotic. Such compounds are referred to as resistance breakers or antibiotic adjuvants/potentiators that work in conjunction with antibiotics. Many studies have been conducted for the identification of compounds, which decrease the permeability barrier, expression of efflux pumps and the resistance encoding enzymes. Compounds targeting the stability, inheritance and dissemination of the mobile genetic elements linked with the resistance genes are also potential candidates to curb antibiotic resistance. In pursuit of such compounds various natural sources and synthetic compounds have been harnessed. The activities of a considerable number of compounds seem promising and are currently at various phases of clinical trials. This review recapitulates all the studies pertaining to the use of antibiotic potentiators for the reversal of antibiotic resistance and what the future beholds for their usage in clinical settings.

13.
Front Immunol ; 13: 886442, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35844549

RESUMEN

Systemic Autoimmune Rheumatic Diseases (SARDs) are characterized by the production of anti-nuclear antibodies (ANAs). ANAs are also seen in healthy individuals and can be detected years before disease onset in SARD. Both the immunological changes that promote development of clinical symptoms in SARD and those that prevent autoimmunity in asymptomatic ANA+ individuals (ANA+ NS) remain largely unexplored. To address this question, we used flow cytometry to examine peripheral blood immune populations in ANA+ individuals, with and without SARD, including 20 individuals who subsequently demonstrated symptom progression. Several immune populations were expanded in ANA+ individuals with and without SARD, as compared with ANA- healthy controls, particularly follicular and peripheral T helper, and antibody-producing B cell subsets. In ANA+ NS individuals, there were significant increases in T regulatory subsets and TGF-ß1 that normalized in SARD patients, whereas in SARD patients there were increases in Th2 and Th17 helper cell levels as compared with ANA+ NS individuals, resulting in a shift in the balance between inflammatory and regulatory T cell subsets. Patients with SARD also had increases in the proportion of pro-inflammatory innate immune cell populations, such as CD14+ myeloid dendritic cells, and intermediate and non-classical monocytes, as compared to ANA+ NS individuals. When comparing ANA+ individuals without SARD who progressed clinically over the subsequent 2 years with those who did not, we found that progressors had significantly increased T and B cell activation, as well as increased levels of LAG3+ T regulatory cells and TGF-ß1. Collectively, our findings suggest that active immunoregulation prevents clinical autoimmunity in ANA+ NS and that this becomes impaired in patients who progress to SARD, resulting in an imbalance favoring inflammation.


Asunto(s)
Enfermedades Autoinmunes , Enfermedades Reumáticas , Anticuerpos Antinucleares , Autoinmunidad , Humanos , Linfocitos T Reguladores
14.
J Heart Lung Transplant ; 41(7): 937-951, 2022 07.
Artículo en Inglés | MEDLINE | ID: mdl-35570129

RESUMEN

BACKGROUND: Prognostic factors in lung transplantation are those variables that are associated with transplant outcomes. Knowledge of donor and recipient prognostic variables can aid in the optimal allocation of donor lungs to transplant recipients and can also inform post-operative discussions with patients about prognosis. Current research findings related to prognostic factors in lung transplantation are inconsistent and the relative importance of various factors is unclear. This review aims to provide the best possible estimates of the association between putative prognostic variables and 1-year all-cause mortality in adult lung transplant recipients. METHODS: We searched 5 bibliographic databases for studies assessing the associations between putative predictors (related to lung donors, recipients, or the transplant procedure) and 1-year recipient mortality. We pooled data across studies when justified and utilized GRADE methodology to assess the certainty in the evidence. RESULTS: From 72 eligible studies (2002-2020), there were 34 recipient variables, 4 donor variables, 10 procedural variables, and 7 post-transplant complication variables that were amenable to a meta-analysis. With a high degree of certainty in the evidence only post-transplant need for extra-corporeal membrane oxygenation (ECMO) (HR 1.91, 95% CI 1.79-2.04) predicted 1-year mortality. No donor variables appeared to predict transplant outcome with high or even moderate certainty. CONCLUSION: Across the range of contemporary donors and recipients that clinicians accept for lung transplantation, this review, with high certainty, found 1 prognostic factor that predicted 1-year mortality, and 37 additional factors with a moderate degree of certainty. The lack of prognostic significance for some widely accepted factors (e.g., donor smoking, age) likely relates to existing limits in the range of these variables at the time of donor and recipient selection.


Asunto(s)
Trasplante de Pulmón , Adulto , Humanos , Complicaciones Posoperatorias , Pronóstico , Estudios Retrospectivos , Donantes de Tejidos , Receptores de Trasplantes
16.
NPJ Vaccines ; 6(1): 105, 2021 Aug 19.
Artículo en Inglés | MEDLINE | ID: mdl-34413319

RESUMEN

Lactating women can produce protective antibodies in their milk after vaccination, which has informed antenatal vaccination programs for diseases such as influenza and pertussis. However, whether SARS-CoV-2-specific antibodies are produced in human milk as a result of COVID-19 vaccination is still unclear. In this study, we show that lactating mothers who received the BNT162b2 vaccine secreted SARS-CoV-2-specific IgA and IgG antibodies into milk, with the most significant increase at 3-7 days post-dose 2. Virus-specific IgG titers were stable out to 4-6 weeks after dose 2. In contrast, SARS-CoV-2-specific IgA levels showed substantial decay. Vaccine mRNA was detected in few milk samples (maximum of 2 ng/ml), indicative of minimal transfer. Additionally, infants who consumed post-vaccination human milk had no reported adverse effects up to 28 days post-ingestion. Our results define the safety and efficacy profiles of the vaccine in this demographic and provide initial evidence for protective immunity conferred by milk-borne SARS-CoV-2-specific antibodies. Taken together, our study supports recommendations for uninterrupted breastfeeding subsequent to mRNA vaccination against COVID-19.

17.
Commun Med (Lond) ; 1: 46, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-35602218

RESUMEN

Background: Neutralizing antibodies (NAbs) prevent pathogens from infecting host cells. Detection of SARS-CoV-2 NAbs is critical to evaluate herd immunity and monitor vaccine efficacy against SARS-CoV-2, the virus that causes COVID-19. All currently available NAb tests are lab-based and time-intensive. Method: We develop a 10 min cellulose pull-down test to detect NAbs against SARS-CoV-2 from human plasma. The test evaluates the ability of antibodies to disrupt ACE2 receptor-RBD complex formation. The simple, portable, and rapid testing process relies on two key technologies: (i) the vertical-flow paper-based assay format and (ii) the rapid interaction of cellulose binding domain to cellulose paper. Results: Here we show the construction of a cellulose-based vertical-flow test. The developed test gives above 80% sensitivity and specificity and up to 93% accuracy as compared to two current lab-based methods using COVID-19 convalescent plasma. Conclusions: A rapid 10 min cellulose based test has been developed for detection of NAb against SARS-CoV-2. The test demonstrates comparable performance to the lab-based tests and can be used at Point-of-Care. Importantly, the approach used for this test can be easily extended to test RBD variants or to evaluate NAbs against other pathogens.

18.
Genomics ; 112(3): 2130-2145, 2020 05.
Artículo en Inglés | MEDLINE | ID: mdl-31837401

RESUMEN

Powdery mildew (PM) is a serious fungal disease of legumes. To gain novel insights into PM pathogenesis and host resistance/susceptibility, we used dual RNA-Seq to simultaneously capture host and pathogen transcriptomes at 1 d post-inoculation of resistant and susceptible Medicago truncatula genotypes with the PM Erysiphe pisi (Ep). Differential expression analysis indicates that R-gene mediated resistance against Ep involves extensive transcriptional reprogramming. Functional enrichment of differentially expressed host genes and in silico analysis of co-regulated promoters suggests that amplification of PTI, activation of the JA/ET signaling network, and regulation of growth-defense balance correlate with resistance. In contrast, processes that favor biotrophy, including suppression of defense signaling and programmed cell death, and weaker cell wall defenses are important susceptibility factors. Lastly, Ep effector candidates and genes with known/putative virulence functions were identified, representing a valuable resource that can be leveraged to improve our understanding of legume-PM interactions.


Asunto(s)
Resistencia a la Enfermedad/genética , Erysiphe/genética , Erysiphe/patogenicidad , Medicago truncatula/genética , Medicago truncatula/microbiología , Enfermedades de las Plantas/microbiología , Erysiphe/crecimiento & desarrollo , Erysiphe/metabolismo , Interacciones Huésped-Patógeno/genética , Medicago truncatula/metabolismo , Enfermedades de las Plantas/genética , Regiones Promotoras Genéticas , RNA-Seq , Factores de Transcripción/metabolismo , Factores de Virulencia/genética
19.
PLoS One ; 10(7): e0132770, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-26231030

RESUMEN

Inoculation of leguminous seeds with bioinoculants has been practiced in agriculture for decades to ameliorate grain yield by enhanced growth parameters and soil fertility. However, effective enhancement of plant growth parameters results not only from the direct effects these bioinoculants impose on them but also from their non-target effects. The ability of bioinoculants to reduce the application of chemicals for obtaining optimum yield of legume appears to be of great ecological and economic importance. In the present study, we compared the influence of seed inoculation of Cajanus cajan with a microbial consortium, comprising Bacillus megaterium, Pseudomonas fluorescens and Trichoderma harzianum, with that of application of chemical fertilizers on plant's growth parameters and its rhizospheric microbial communities. Real-time PCR assay was carried out to target the structure (16S rRNA) and function (nitrogen cycle) of rhizospheric microbiota, using both DNA and RNA as markers. The results showed that the microbial consortium was the most efficient in increasing grain yield (2.5-fold), even better than the recommended dose of chemical fertilizers (by 1.2-fold) and showed enhancement in nifH and amoA transcripts by 2.7- and 2.0-fold, respectively. No adverse effects of bioinoculants' application were observed over the rhizospheric microbial community, rendering the consortium to be safe for release in agricultural fields.


Asunto(s)
Cajanus/crecimiento & desarrollo , Cajanus/microbiología , Agricultura/métodos , Bacillus megaterium/genética , Bacillus megaterium/metabolismo , Cajanus/efectos de los fármacos , Fertilizantes , Genes Bacterianos , Genes Fúngicos , Consorcios Microbianos , Ciclo del Nitrógeno/genética , Pseudomonas fluorescens/genética , Pseudomonas fluorescens/metabolismo , ARN Bacteriano/genética , ARN Bacteriano/metabolismo , ARN de Hongos/genética , ARN de Hongos/metabolismo , ARN Ribosómico 16S/genética , ARN Ribosómico 16S/metabolismo , Rizosfera , Trichoderma/genética , Trichoderma/metabolismo
20.
Environ Sci Pollut Res Int ; 22(15): 11290-300, 2015 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-25801369

RESUMEN

Intensive agriculture has resulted in an indiscriminate use of pesticides, which demands in-depth analysis of their impact on indigenous rhizospheric microbial community structure and function. Hence, the objective of the present work was to study the impact of two chemical pesticides (chlorpyrifos and cypermethrin) and one biological pesticide (azadirachtin) at two dosages on the microbial community structure using cultivation-dependent approach and on rhizospheric bacterial communities involved in nitrogen cycle in Vigna radiata rhizosphere through cultivation-independent technique of real-time PCR. Cultivation-dependent study highlighted the adverse effects of both chemical pesticide and biopesticide on rhizospheric bacterial and fungal communities at different plant growth stages. Also, an adverse effect on number of genes and transcripts of nifH (nitrogen fixation); amoA (nitrification); and narG, nirK, and nirS (denitrification) was observed. The results from the present study highlighted two points, firstly that nontarget effects of pesticides are significantly detrimental to soil microflora, and despite being of biological origin, azadirachtin exerted negative impact on rhizospheric microbial community of V. radiata behaving similar to chemical pesticides. Hence, such nontarget effects of chemical pesticide and biopesticide in plants' rhizosphere, which bring out the larger picture in terms of their ecotoxicological effect, demand a proper risk assessment before application of pesticides as agricultural amendments.


Asunto(s)
Fabaceae/microbiología , Plaguicidas/efectos adversos , Rizosfera , Microbiología del Suelo , Cloropirifos/efectos adversos , Desnitrificación/efectos de los fármacos , Desnitrificación/genética , Fabaceae/crecimiento & desarrollo , Regulación Bacteriana de la Expresión Génica/efectos de los fármacos , Genes Bacterianos/genética , Limoninas/efectos adversos , Nitrificación/efectos de los fármacos , Nitrificación/genética , Fijación del Nitrógeno/efectos de los fármacos , Fijación del Nitrógeno/genética , Piretrinas/efectos adversos
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