Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 23
Filtrar
Más filtros












Intervalo de año de publicación
1.
Plant Cell Rep ; 43(10): 230, 2024 Sep 09.
Artículo en Inglés | MEDLINE | ID: mdl-39251423

RESUMEN

KEY MESSAGE: OsLec-RLK overexpression enhances cell signalling and salt stress tolerance in pigeon pea, enhancing seed yield and harvest index and thus, enabling marginal lands to increase food and nutritional security. Lectin Receptor-like kinases (Lec-RLKs) are highly effective cell signaling molecules that counteract various stresses, including salt stress. We engineered pigeon pea by overexpressing OsLec-RLK gene for enhancing salt tolerance. The OsLec-RLK overexpression lines demonstrated superior performance under salt stress, from vegetative to reproductive phase, compared to wild types (WT). The overexpression lines had significantly higher K+/Na+ ratio than WT exposed to 100 mM NaCl. Under salt stress, transgenic lines showed higher levels of chlorophyll, proline, total soluble sugars, relative water content, and peroxidase and catalase activity than WT plants. Membrane injury index and lipid peroxidation were significantly reduced in transgenic lines. Analysis of phenological and yield attributes confirmed that the OsLec-RLK pigeon pea lines maintain plant vigor, with 10.34-fold increase in seed yield (per plant) and 4-5-fold increase in harvest index of overexpression lines, compared to wild type. Meanwhile, the overexpression of OsLec-RLK up-regulated the expression levels of histone deacetylase1, acyl CoA, ascorbate peroxidase, peroxidase, glutathione reductase and catalase, which were involved in the K+/Na+ homeostasis pathway. This study showed the potential of OsLec-RLK gene for increasing crop productivity and yields under salt stress and enabling the crops to be grown on marginal lands for increasing food and nutritional security.


Asunto(s)
Cajanus , Clorofila , Regulación de la Expresión Génica de las Plantas , Proteínas de Plantas , Plantas Modificadas Genéticamente , Tolerancia a la Sal , Semillas , Semillas/genética , Semillas/crecimiento & desarrollo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Cajanus/genética , Cajanus/fisiología , Cajanus/crecimiento & desarrollo , Tolerancia a la Sal/genética , Clorofila/metabolismo , Oryza/genética , Oryza/fisiología , Oryza/crecimiento & desarrollo , Oryza/enzimología , Estrés Salino/genética , Potasio/metabolismo
2.
BMC Genomics ; 25(1): 439, 2024 May 02.
Artículo en Inglés | MEDLINE | ID: mdl-38698307

RESUMEN

BACKGROUND: Chickpea is prone to many abiotic stresses such as heat, drought, salinity, etc. which cause severe loss in yield. Tolerance towards these stresses is quantitative in nature and many studies have been done to map the loci influencing these traits in different populations using different markers. This study is an attempt to meta-analyse those reported loci projected over a high-density consensus map to provide a more accurate information on the regions influencing heat, drought, cold and salinity tolerance in chickpea. RESULTS: A meta-analysis of QTL reported to be responsible for tolerance to drought, heat, cold and salinity stress tolerance in chickpeas was done. A total of 1512 QTL responsible for the concerned abiotic stress tolerance were collected from literature, of which 1189 were projected on a chickpea consensus genetic map. The QTL meta-analysis predicted 59 MQTL spread over all 8 chromosomes, responsible for these 4 kinds of abiotic stress tolerance in chickpea. The physical locations of 23 MQTL were validated by various marker-trait associations and genome-wide association studies. Out of these reported MQTL, CaMQAST1.1, CaMQAST4.1, CaMQAST4.4, CaMQAST7.8, and CaMQAST8.2 were suggested to be useful for different breeding approaches as they were responsible for high per cent variance explained (PVE), had small intervals and encompassed a large number of originally reported QTL. Many putative candidate genes that might be responsible for directly or indirectly conferring abiotic stress tolerance were identified in the region covered by 4 major MQTL- CaMQAST1.1, CaMQAST4.4, CaMQAST7.7, and CaMQAST6.4, such as heat shock proteins, auxin and gibberellin response factors, etc. CONCLUSION: The results of this study should be useful for the breeders and researchers to develop new chickpea varieties which are tolerant to drought, heat, cold, and salinity stresses.


Asunto(s)
Cicer , Sitios de Carácter Cuantitativo , Estrés Fisiológico , Cicer/genética , Estrés Fisiológico/genética , Mapeo Cromosómico , Sequías , Estudio de Asociación del Genoma Completo
3.
Plant Genome ; 17(1): e20307, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-36751876

RESUMEN

The grain-filling stage in Triticum aestivum (wheat) is highly vulnerable to increasing temperature as terminal heat stress diminishes grain quality and yield. To examine the mechanism of terminal heat tolerance, we performed the biochemical and gene expression analyses using two heat-tolerant (WH730 and WH1218) and two heat-sensitive (WH711 and WH157) wheat genotypes. We observed a significant increase in total soluble sugar (25%-47%), proline (7%-15%), and glycine betaine (GB) (22%-34%) contents in flag leaf, whereas a decrease in grain-filling duration, 1000-kernel weight (8%-25%), and grain yield per plant (11%-23%) was observed under the late-sown compared to the timely sown. The maximum content of osmolytes, including total soluble sugar, proline, and GB, was observed in heat-tolerant genotypes compared to heat-sensitive genotypes. The expression of 10 heat-responsive genes associated with heat shock proteins (sHsp-1, Hsp17, and HsfA4), flavonoid biosynthesis (F3'-1 and PAL), ß-glucan synthesis (CslF6 and CslH), and xyloglucan metabolism (XTH1, XTH2, and XTH5) was studied in flag leaf exposed to different heat treatments (34, 36, 38, and 40°C) at 15 days after anthesis by quantitative real-time polymerase chain reaction. A significant increase in the relative fold expression of these genes with increasing temperature indicated their involvement in providing heat-stress tolerance. The high differential expression of most of the genes in heat-tolerant genotype "WH730" followed by "WH1218" indicates the high adaptability of these genotypes to heat stress compared to heat-sensitive wheat genotypes. Based on the previous results, "WH730" performed better in terms of maximum osmolyte accumulation, grain yield, and gene expression under heat stress.


Asunto(s)
Pan , Triticum , Triticum/genética , Respuesta al Choque Térmico/genética , Grano Comestible/genética , Prolina/genética , Expresión Génica , Azúcares
4.
Front Plant Sci ; 14: 1287950, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-38093989

RESUMEN

The 26S proteasome is a molecular machine that catalyzes and degrades protein intracellularly with the help of its core complex called 20S proteasome. The 20S proteasomes degrade and cleave denatured, cytotoxic, damaged, and unwanted proteins via proteolysis and impart biotic and abiotic stress tolerance in model plants. This study identified 20 genes, namely, 10 SbPA and 10 SbPB that encode for α- and ß-subunits of the 20S proteasome in Sorghum bicolor (L.) Moench (2n= 20). These genes have been found distributed on the 1st, 2nd, 3rd, 4th, 5th, 7th, and 10th chromosomes. These sorghum genes were orthologous to corresponding rice. Phylogenetic analysis clustered these genes into seven clades, each with one of the seven α-subunits (1 to 7) and one of the seven ß-subunits (1 to 7). In silico gene expression analysis suggested that nine genes were involved in abiotic stress response (cold, drought, and abscisic acid hormone). The expression of these proteasomal genes was studied in shoots and roots exposed to different abiotic stresses (cold, drought, and abscisic acid) by quantitative real-time polymerase chain reaction. A significant increase in the relative fold expression of SbPBA1, SbPAA1, SbPBG1, SbPBE1, and SbPAG1 genes under ABA and drought stress provides an insight into its involvement in abiotic stress. No expression was observed for cold stress of these genes indicating their non-involvement. It is believed that additional investigation into the SbPA/SbPB genes would aid in the creation of S. bicolor cultivars that are resistant to climate change.

5.
Plant Physiol Biochem ; 203: 108004, 2023 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-37714027

RESUMEN

Plant tissue culture is the primary, fundamental, and applied aspect of plant biology. It is an indispensable and valuable technique for investigating morphogenesis, embryogenesis, clonal propagation, crop improvements, generation of pathogen-free plants, gene transfer and expression, and the production of secondary metabolites. The extensive use of various nanoparticles (NPs) in fields such as cosmetics, energy, medicine, pharmaceuticals, electronics, agriculture, and biotechnology have demonstrated positive impacts in microbial decontamination, callus differentiation, organogenesis, somatic variations, biotransformation, cryopreservation, and enhanced synthesis of bioactive compounds. This review summarizes the current state of knowledge with regard to the use of nanoparticles in plant tissue culture, with a particular focus on the beneficial outcomes. The positive (beneficial) and negative (toxic) effects of engineered NPs in tissue culture medium, delivery of transgenes, NPs toxicity concerns, safety issues, and potential hazards arising from utilization of nanomaterials in agriculture through plant tissue culture are discussed in detail, along with the future prospects for these applications. In addition, the potential use of novel nanomaterials such as graphene, graphite, dendrimers, quantum dots, and carbon nanotubes as well as unique metal or metalloid NPs are proposed. Further, the potential mechanisms underlying NPs elicitation of tissue culture response in different applications are critically evaluated. The potential of these approaches in plant nanobiotechnology is only now becoming understood and it is clear that the role of these strategies in sustainably increasing crop production to combat global food security and safety in a changing climate will be significant.

6.
Mol Biol Rep ; 50(6): 5091-5103, 2023 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-37101006

RESUMEN

BACKGROUND: Nitrogen (N) and phosphorous (P) play a very important role in the growth and development of wheat as well as major constituents of biological membranes. To meet the plant's nutritional demand these nutrients are applied in the form of fertilizers. But the plant can utilize only half of the applied fertilizer whereas the rest is lost through surface runoff, leaching and volatilization. Thus, to overcome the N/P loss we need to elucidate the molecular mechanism behind the N/P uptake. METHODS: In our study, we used DBW16 (low NUE), and WH147 (high NUE) wheat genotypes under different doses of N, whereas HD2967 (low PUE) and WH1100 (high PUE) genotypes were studied under different doses of P. To check the effect of different doses of N/P, the physiological parameters like total chlorophyll content, net photosynthetic rate, N/P content, and N/PUE of these genotypes were calculated. In addition, gene expression of various genes involved in N uptake, utilization, and acquisition such as Nitrite reductase (NiR), Nitrate transporter 1/Peptide transporter family (NPF2.4/2.5), Nitrate transporter (NRT1) and NIN Like Protein (NLP) and induced phosphate starvation (IPS), Phosphate Transporter (PHT1.7) and Phosphate 2 (PHO2) acquisition was studied by quantitative real-time PCR. RESULTS: Statistical analysis revealed a lower percent reduction in TCC, NPR, and N/P content in N/P efficient wheat genotypes (WH147 & WH1100). A significant increase in relative fold expression of genes under low N/P concentration was observed in N/P efficient genotypes as compared to N/P deficient genotypes. CONCLUSION: Significant differences in physiological data and gene expression among N/ P efficient and deficient wheat genotypes could be useful for future improvement of N/P use efficiency.


Asunto(s)
Nitrógeno , Triticum , Nitrógeno/metabolismo , Triticum/metabolismo , Transportadores de Nitrato , Fenotipo , Fósforo/metabolismo , Fosfatos
7.
Front Plant Sci ; 13: 1067063, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36483946

RESUMEN

In wheat, lodging is affected by anatomical and chemical characteristics of the stem cell wall. Plant characteristics determining the stem strength were measured in lodging tolerant mutant (PMW-2016-1) developed through mutation breeding utilizing hexaploid wheat cultivar, DPW-621-50. Various anatomical features, chemical composition, and mechanical strength of the culms of newly developed lodging-tolerant mutant (PMW-2016-1) and parent (DPW-621-50), were examined by light microscopy, the Klason method, prostate tester coupled with a Universal Tensile Machine, and Fourier Transform Infrared Spectroscopy. Significant changes in the anatomical features, including the outer radius of the stem, stem wall thickness, and the proportions of various tissues, and vascular bundles were noticed. Chemical analysis revealed that the lignin level in the PMW-2016-1 mutant was higher and exhibited superiority in stem strength compared to the DPW-621-50 parent line. The force (N) required to break the internodes of mutant PMW-2016-1 was higher than that of DPW-621-50. The results suggested that the outer stem radius, stem wall thickness, the proportion of sclerenchyma tissues, the number of large vascular bundles, and lignin content are important factors that affect the mechanical strength of wheat stems, which can be the key parameters for the selection of varieties having higher lodging tolerance. Preliminary studies on the newly identified mutant PMW-2016-1 suggested that this mutant may possess higher lodging tolerance because it has a higher stem strength than DPW-621-50 and can be used as a donor parent for the development of lodging-tolerant wheat varieties.

8.
Front Plant Sci ; 13: 1037206, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36388569

RESUMEN

The core particle represents the catalytic portions of the 26S proteasomal complex. The genes encoding α- and ß-subunits play a crucial role in protecting plants against various environmental stresses by controlling the quality of newly produced proteins. The 20S proteasome gene family has already been reported in model plants such as Arabidopsis and rice; however, they have not been studied in oilseed crops such as rapeseed (Brassica napus L.). In the present study, we identified 20S proteasome genes for α- (PA) and ß-subunits (PB) in B. napus through systematically performed gene structure analysis, chromosomal location, conserved motif, phylogenetic relationship, and expression patterns. A total of 82 genes, comprising 35 BnPA and 47 BnPB of the 20S proteasome, were revealed in the B. napus genome. These genes were distributed on all 20 chromosomes of B. napus and most of these genes were duplicated on homoeologous chromosomes. The BnPA (α1-7) and BnPB (ß1-7) genes were phylogenetically placed into seven clades. The pattern of expression of all the BnPA and BnPB genes was also studied using RNA-seq datasets under biotic and abiotic stress conditions. Out of 82 BnPA/PB genes, three exhibited high expression under abiotic stresses, whereas two genes were overexpressed in response to biotic stresses at both the seedling and flowering stages. Moreover, an additional eighteen genes were expressed under normal conditions. Overall, the current findings developed our understanding of the organization of the 20S proteasome genes in B. napus, and provided specific BnPA/PB genes for further functional research in response to abiotic and biotic stresses.

9.
Front Genet ; 13: 933560, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36092892

RESUMEN

Grain yield is one of the most important aims for combating the needs of the growing world population. The role of development and nutrient transfer in flag leaf for higher yields at the grain level is well known. It is a great challenge to properly exploit this knowledge because all the processes, starting from the emergence of the flag leaf to the grain filling stages of wheat (Triticum aestivum L.), are very complex biochemical and physiological processes to address. This study was conducted with the primary goal of functionally and structurally annotating the candidate genes associated with different developmental stages of flag leaf in a comprehensive manner using a plethora of in silico tools. Flag leaf-associated genes were analyzed for their structural and functional impacts using a set of bioinformatics tools and algorithms. The results revealed the association of 17 candidate genes with different stages of flag leaf development in wheat crop. Of these 17 candidate genes, the expression analysis results revealed the upregulation of genes such as TaSRT1-5D, TaPNH1-7B, and TaNfl1-2B and the downregulation of genes such as TaNAP1-7B, TaNOL-4D, and TaOsl2-2B can be utilized for the generation of high-yielding wheat varieties. Through MD simulation and other in silico analyses, all these proteins were found to be stable. Based on the outcome of bioinformatics and molecular analysis, the identified candidate genes were found to play principal roles in the flag leaf development process and can be utilized for higher-yield wheat production.

10.
Qual Quant ; : 1-25, 2022 Sep 09.
Artículo en Inglés | MEDLINE | ID: mdl-36105624

RESUMEN

The current research tries to contribute to the prospect theory by examining how personality factors affect behaviour biases. Moreover, the study tries to inspect how risk-tolerance behaviour moderates the relationship between personality traits and behavior biases. The research considered a cross-sectional research design to collect responses from 847 individual investors through a questionnaire. The study considered a convenience sampling technique. Further to examine the hypotheses, the study used SEM and PROCESS macro v3.0 for SPSS. The findings of the study suggest that conscientiousness and extroversion traits significantly influence behaviour biases. The findings also explain that neuroticism was associated with herding, disposition, and anchoring bias. The findings confirmed the moderating effect of risk-tolerance on the association between personality traits and behaviour biases. The findings contribute to the existing literature of behaviour finance by focusing on the prospect theory as well as some practical implications for investors and financial advisors. The study suggests to the individual investors with different traits how they can overcome these biases while investing. The study suggests that financial advisors should educate their clients and also establish a lock-gain point and stop-loss point to reduce the effect of such biases. The study also suggests that investment advisors should provide information more efficiently so that investors' portfolios could be amassed into a well-diversified investment and tries to set up efficient approaches associated with investment quality and give swapping options as per their risk-tolerance behavior. The research contributes to behaviour finance literature by signifying the moderation effect of risk tolerance on the association amid personality factors and behavioural biases and how it reduces the influence of biases while taking investment decisions among Indian investors. To the best of our knowledge, this is the first comprehensive study that examines the moderation effect of risk-tolerance among the relationship between personality traits and behaviour biases. Furthermore, it demonstrates that an individual's risk-tolerance enhances their involvement in the decision-making process, allowing them to make the best financial option possible.

11.
NanoImpact ; 26: 100407, 2022 04.
Artículo en Inglés | MEDLINE | ID: mdl-35594741

RESUMEN

Nutrient deficiency in food crops severely compromises human health, particularly in under privileged communities. Globally, billions of people, particularly in developing nations, have limited access to nutritional supplements and fortified foods, subsequently suffering from micronutrient deficiency leading to a range of health issues. The green revolution enhanced crop production and provided food to billions of people but often falls short with respect to the nutritional quality of that food. Plants may assimilate nutrients from synthetic chemical fertilizers, but this approach generally has low nutrient delivery and use efficiency. Further, the overexposure of chemical fertilizers may increase the risk of neoplastic diseases, render food crops unfit for consumption and cause environmental degradation. Therefore, to address these challenges, more research is needed for sustainable crop yield and quality enhancement with minimum use of chemical fertilizers. Complex nutritional disorders and 'hidden hunger' can be addressed through biofortification of food crops. Nanotechnology may help to improve food quality via biofortification as plants may readily acquire nanoparticle-based nutrients. Nanofertilizers are target specific, possess controlled release, and can be retained for relatively long time periods, thus prevent leaching or run-off from soil. This review evaluates the recent literature on the development and use of nanofertilizers, their effects on the environment, and benefits to food quality. Further, the review highlights the potential of nanomaterials on plant genetics in biofortification, as well as issues of affordability, sustainability, and toxicity.


Asunto(s)
Biofortificación , Micronutrientes , Agricultura/métodos , Biofortificación/métodos , Productos Agrícolas , Fertilizantes , Humanos , Micronutrientes/análisis , Nanotecnología
12.
Heredity (Edinb) ; 128(6): 391-401, 2022 06.
Artículo en Inglés | MEDLINE | ID: mdl-35132208

RESUMEN

Among all the nutrients, nitrogen (N) and phosphorous (P) are the most limiting factors reducing wheat production and productivity world-wide. These macronutrients are directly applied to soil in the form of fertilizers. However, only 30-40% of these applied fertilizers are utilized by crop plants, while the rest is lost through volatilization, leaching, and surface run off. Therefore, to overcome the deficiency of N and P, it becomes necessary to improve their use efficiency. Marker-assisted selection (MAS) combined with traditional plant breeding approaches is considered best to improve the N and P use efficiency (N/PUE) of wheat varieties. In this study, we developed and evaluated a total of 98 simple sequence repeat (SSR) markers including 66 microRNAs and 32 gene-specific SSRs on a panel of 10 (N and P efficient/deficient) wheat genotypes. Out of these, 35 SSRs were found polymorphic and have been used for the study of genetic diversity and population differentiation. A set of two SSRs, namely miR171a and miR167a were found candidate markers able to discriminate contrasting genotypes for N/PUE, respectively. Therefore, these two markers could be used as functional markers for characterization of wheat germplasm for N and P use efficiency. Target genes of these miRNAs were found to be highly associated with biological processes (24 GO terms) as compared to molecular function and cellular component and shows differential expression under various P starving conditions and abiotic stresses.


Asunto(s)
MicroARNs , Triticum , Fertilizantes , Marcadores Genéticos , MicroARNs/genética , Repeticiones de Microsatélite , Nitrógeno , Fósforo , Fitomejoramiento , Triticum/genética
13.
J Cosmet Dermatol ; 19(1): 234-240, 2020 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-31087753

RESUMEN

BACKGROUND: Alopecia areata (AA) is an autoimmune disease due to aberrant T-cell response against hair follicle self-antigens. Previous studies support the role of Th1 cytokines in pathogenesis of AA, but the role of Th2, Th17, and Treg cytokines remains to be fully elucidated. OBJECTIVES: To assess the serum levels of cytokines secreted by Th1 (IL-2, IFN-γ), Th2 (IL-4), Th17 (IL-23, IL-17A), and Treg (IL-10) pathways in patients of active AA and to correlate their levels with the severity of the disease. MATERIAL AND METHODS: Forty patients with untreated active AA of the scalp and forty age- and sex-matched healthy controls were included. Serum levels of cytokines IL-2, IFN-γ, IL-17A, IL-23, IL-4, and IL-10 were measured using enzyme-linked immunosorbent assay. RESULTS: Serum levels of cytokines IL-2, IFN-γ, IL-17A, and IL-10 were significantly raised while serum levels of IL-23 were nonsignificantly raised in AA patients as compared to controls. The levels of IL-4 were significantly lower in AA patients as compared to controls. (P < 0.05). Also, significant positive correlation was found between increase in SALT Score and serum levels of IL-2, IL-17A, and IL-23. (P < 0.05). CONCLUSION: Th1 and Th17 pathways play a central role in the initiation and progression of AA, while Th2 pathway is suppressed in active AA. Treg pathway may be opposing Th1 and Th17 pathway and causes disease localization. The instant study lays the groundwork for understanding the pathogenesis of AA and suggests the role of implicated cytokines as potential therapeutic targets and as biomarkers of disease activity.


Asunto(s)
Alopecia Areata/inmunología , Citocinas/sangre , Adolescente , Adulto , Alopecia Areata/sangre , Biomarcadores/sangre , Estudios de Casos y Controles , Estudios Transversales , Citocinas/metabolismo , Progresión de la Enfermedad , Femenino , Voluntarios Sanos , Humanos , Masculino , Estudios Prospectivos , Cuero Cabelludo , Linfocitos T Reguladores/inmunología , Linfocitos T Reguladores/metabolismo , Células TH1/inmunología , Células TH1/metabolismo , Células Th17/inmunología , Células Th17/metabolismo , Células Th2/inmunología , Células Th2/metabolismo , Adulto Joven
14.
Sci Rep ; 9(1): 1192, 2019 02 04.
Artículo en Inglés | MEDLINE | ID: mdl-30718779

RESUMEN

Data on the genetic diversity of Pneumocystis jirovecii causing Pneumocystis pneumonia (PCP) among children are still limited, and there are no available data from the Indian subcontinent, particularly associations between genotypes and clinical characteristics. A total of 37 children (62 days-12 years [median 5.5 years]) were included in this study. Pneumocystis was diagnosed by microscopy using Grocott-Gomori methenamine silver stain in 12 cases and by nested PCR using mtLSUrRNA in 25 cases. Genotyping was performed using three different genes, mitochondrial large subunit ribosomal RNA (mtLSUrRNA), dihydropteroate synthase (DHPS) and dihydrofolate reductase (DHFR). mtLSUrRNA genotype 3 and novel mutations at the gene target DHFR (401 T > C) and DHPS 96/98 were frequently observed and clinically associated with severe PCP and treatment failure. Phylogenetic analyses revealed 13 unique sequence types (STs). Two STs (i) 3-DHFR 401 T > C-DHPS 96/98 - PJ1 and (ii) 3-DHFR 401 T > C-DHPS 96- PJ3 were significantly associated with treatment failure and high mortality among PCP-positive patients. In conclusion, the present study strongly suggests the emergence of virulent P. jirovecii strains or genetic polymorphisms, leading to treatment failure and high mortality. Our study is the first of its kind from the Indian subcontinent and has highlighted the genetic diversity of Pneumocystis jirovecii among children and their clinical outcomes. These findings emphasize the need to focus more on genotypes to better understand the epidemiology of Pneumocystis pneumonia.


Asunto(s)
Pneumocystis carinii/genética , Neumonía por Pneumocystis/genética , Neumonía por Pneumocystis/mortalidad , Niño , Preescolar , Dihidropteroato Sintasa/genética , Femenino , Variación Genética/genética , Genotipo , Humanos , Lactante , Masculino , Mutación/genética , Filogenia , Reacción en Cadena de la Polimerasa , Polimorfismo Genético/genética , ARN Ribosómico/genética , Subunidades Ribosómicas Grandes/genética , Análisis de Secuencia de ADN , Tetrahidrofolato Deshidrogenasa/genética , Insuficiencia del Tratamiento
15.
J Glob Antimicrob Resist ; 17: 236-239, 2019 06.
Artículo en Inglés | MEDLINE | ID: mdl-30658203

RESUMEN

OBJECTIVES: Pneumocystis pneumonia (PCP) remains a debilitating cause of death among HIV-infected patients. The combination trimethoprim/sulfamethoxazole (SXT) is the most effective anti-Pneumocystis treatment and prophylaxis. However, long-term use of this combination has raised alarms about the emergence of resistant organisms. This study was performed to investigate mutations in the dihydropteroate synthase (DHPS) gene and their clinical consequences in HIV-infected patients with PCP. METHODS: A total of 76 clinically suspected cases of PCP among HIV-seropositive adult patients from March 2014 to March 2017 were included. Clinical samples (bronchoalveolar lavage fluid and sputum) were investigated for the detection of Pneumocystis jirovecii using both microscopy and nested PCR. DHPS genotyping and mutational analyses were performed and the data were correlated with clinical characteristics. RESULTS: Among the 76 enrolled HIV-positive patients, only 17 (22.4%) were positive for P. jirovecii. DHPS gene sequencing showed a novel nucleotide substitution at position 288 (Val96Ile) in three patients (3/12; 25.0%). Patients infected with the mutant P. jirovecii genotype had severe episodes of PCP, did not respond to SXT and had a fatal outcome (P=0.005). All three patients had a CD4+ T-cell count <100 cells/µL, and two also had co-infections. CONCLUSION: This study suggests that the emergence of a mutant P. jirovecii genotype is probably associated with drug resistance and mortality. The data also suggest that DHPS mutational analyses should be performed in HIV-seropositive patients to avoid treatment failure and death due to PCP. However, the role of underlying disease severity and co-morbidities should not be underestimated.


Asunto(s)
Dihidropteroato Sintasa/genética , Farmacorresistencia Bacteriana Múltiple/genética , Infecciones por VIH/complicaciones , Mutación , Pneumocystis carinii/genética , Adulto , Anciano , Líquido del Lavado Bronquioalveolar/microbiología , Coinfección/microbiología , Análisis Mutacional de ADN , Farmacorresistencia Fúngica/genética , Femenino , Genotipo , Infecciones por VIH/tratamiento farmacológico , Humanos , India , Masculino , Persona de Mediana Edad , Infecciones por Pneumocystis/tratamiento farmacológico , Infecciones por Pneumocystis/microbiología , Pneumocystis carinii/aislamiento & purificación , Reacción en Cadena de la Polimerasa , Esputo/microbiología , Combinación Trimetoprim y Sulfametoxazol/farmacología , Adulto Joven
19.
Gastroenterol Hepatol Bed Bench ; 10(4): 311-318, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-29379597

RESUMEN

AIM: Present hospital based study was carried out at our tertiary care centre with an aim to study the distribution of Cryptosporidium species subtypes in patients with complaints of diarrhea. BACKGROUND: Cryptosporidium species are one of the important causative agents of parasitic diarrhea, amongst which Cryptosporidium hominis (C.hominis) and Cryptosporidium parvum (C.parvum) are the two major species that are associated with human cryptosporidiosis. METHODS: Four hundred and fifty (n=450) diarrheic patients complaining of different types of diarrhea were enrolled in the present study. Both microscopic and molecular diagnostic methods were used for the detection as well as for identification of Cryptosporidium species and its speciation and subtyping. RESULTS: Forty one (n=41) and forty three (n=43) patients were positive for Cryptosporidium species by microscopy and Polymerase chain reaction (PCR) assay respectively. Of these 43 cases, 70% (30/43) were identified as C. hominis and 21% (9/43) was as C. parvum, 7% (3/43) was as Cryptosporidium felis (C.felis) and 2% (1/43) as Cryptopsoridium viatorum (C. viatorum) respectively . Upon subtyping of C. hominis and C. parvum, 16 subtypes belonging to 8 different subtype families could be identified. The frequency of different families were Ia (13%, 5/39), Ib (15%, 6/39), Id (18%, 7/39), Ie (30%, 12/39) and IIa (5%, 2/39), IIc (8%, 3/39), IId (8%, 3/39) and IIe (3%, 1/39). CONCLUSION: Our study results strongly suggest and reinforces the fact that most of the human cryptosporidiosis is anthroponotic and we expect that present molecular epidemiological data will provide more insight to unravel the changing clinical paradigm of human cryptosporidiosis at large.

SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...