The heparin-binding hemagglutinin protein of Mycobacterium tuberculosis is a nucleoid-associated protein.

Nucleoid-associated proteins (NAPs) regulate multiple cellular processes such as gene expression, virulence, and dormancy throughout bacterial species. NAPs help in the survival and adaptation of Mycobacterium tuberculosis (Mtb) within the host. Fourteen NAPs have been identified in Escherichia coli; however, only seven NAPs are documented in Mtb. Given its complex lifestyle, it is reasonable to assume that Mtb would encode for more NAPs. Using bioinformatics tools and biochemical experiments, we have identified the heparin-binding hemagglutinin (HbhA) protein of Mtb as a novel sequence-independent DNA-binding protein which has previously been characterized as an adhesion molecule required for extrapulmonary dissemination. Deleting the carboxy-terminal domain of HbhA resulted in a complete loss of its DNA-binding activity. Atomic force microscopy showed HbhA-mediated architectural modulations in the DNA, which may play a regulatory role in transcription and genome organization. Our results showed that HbhA colocalizes with the nucleoid region of Mtb. Transcriptomics analyses of a hbhA KO strain revealed that it regulates the expression of ∼36% of total and ∼29% of essential genes. Deletion of hbhA resulted in the upregulation of ∼73% of all differentially expressed genes, belonging to multiple pathways suggesting it to be a global repressor. The results show that HbhA is a nonessential NAP regulating gene expression globally and acting as a plausible transcriptional repressor.

Role of serine/threonine protein phosphatase PrpN in the life cycle of Bacillus anthracis.

Reversible protein phosphorylation at serine/threonine residues is one of the most common protein modifications, widely observed in all kingdoms of life. The catalysts controlling this modification are specific serine/threonine kinases and phosphatases that modulate various cellular pathways ranging from growth to cellular death. Genome sequencing and various omics studies have led to the identification of numerous serine/threonine kinases and cognate phosphatases, yet the physiological relevance of many of these proteins remain enigmatic. In Bacillus anthracis, only one ser/thr phosphatase, PrpC, has been functionally characterized; it was reported to be non-essential for bacterial growth and survival. In the present study, we characterized another ser/thr phosphatase (PrpN) of B. anthracis by various structural and functional approaches. To examine its physiological relevance in B. anthracis, a null mutant strain of prpN was generated and shown to have defects in sporulation and reduced synthesis of toxins (PA and LF) and the toxin activator protein AtxA. We also identified CodY, a global transcriptional regulator, as a target of PrpN and ser/thr kinase PrkC. CodY phosphorylation strongly controlled its binding to the promoter region of atxA, as shown using phosphomimetic and phosphoablative mutants. In nutshell, the present study reports phosphorylation-mediated regulation of CodY activity in the context of anthrax toxin synthesis in B. anthracis by a previously uncharacterized ser/thr protein phosphatase-PrpN.

Phosphorylation-mediated regulation of the Bacillus anthracis phosphoglycerate mutase by the Ser/Thr protein kinase PrkC.

Bacillus anthracis Ser/Thr protein kinase PrkC is necessary for phenotypic memory and spore germination, and the loss of PrkC-dependent phosphorylation events affect the spore development. During sporulation, Bacillus sp. can store 3-Phosphoglycerate (3-PGA) that will be required at the onset of germination when ATP will be necessary. The Phosphoglycerate mutase (Pgm) catalyzes the isomerization of 2-PGA and 3-PGA and is important for spore germination as a key metabolic enzyme that maintains 3-PGA pool at later events. Therefore, regulation of Pgm is important for an efficient spore germination process and metabolic switching. While the increased expression of Pgm in B. anthracis decreases spore germination efficiency, it remains unexplored if PrkC could directly influence Pgm activity. Here, we report the phosphorylation and regulation of Pgm by PrkC and its impact on Pgm stability and catalytic activity. Mass spectrometry revealed Pgm phosphorylation on seven threonine residues. In silico mutational analysis highlighted the role of Thr459 residue towards metal and substrate binding. Altogether, we demonstrated that PrkC-mediated Pgm phosphorylation negatively regulates its activity that is essential to maintain Pgm in its apo-like isoform before germination. This study advances the role of Pgm regulation that represents an important switch for B. anthracis resumption of metabolism and spore germination.

Compromised base excision repair pathway in Mycobacterium tuberculosis imparts superior adaptability in the host.

Tuberculosis caused by Mycobacterium tuberculosis (Mtb) is a significant public health concern, exacerbated by the emergence of drug-resistant TB. To combat the host's dynamic environment, Mtb encodes multiple DNA repair enzymes that play a critical role in maintaining genomic integrity. Mtb possesses a GC-rich genome, rendering it highly susceptible to cytosine deaminations, resulting in the occurrence of uracils in the DNA. UDGs encoded by ung and udgB initiate the repair; hence we investigated the biological impact of deleting UDGs in the adaptation of pathogen. We generated gene replacement mutants of uracil DNA glycosylases, individually (RvΔung, RvΔudgB) or together (RvΔdKO). The double KO mutant, RvΔdKO exhibited remarkably higher spontaneous mutation rate, in the presence of antibiotics. Interestingly, RvΔdKO showed higher survival rates in guinea pigs and accumulated large number of SNPs as revealed by whole-genome sequence analysis. Competition assays revealed the superior fitness of RvΔdKO over Rv, both in ex vivo and in vivo conditions. We propose that compromised DNA repair results in the accumulation of mutations, and a subset of these drives adaptation in the host. Importantly, this property allowed us to utilize RvΔdKO for the facile identification of drug targets.

Synergism of CD28 Immune Molecule in Late Immunosuppressive Phase of COVID-19: Effectiveness in Vaccinated Individuals.

Context: Lymphopenia has been frequently documented and linked to coronavirus disease 2019 (COVID-19) in a severe acute respiratory syndrome (SARS)-coronavirus 2 (CoV-2) attack. A decrease in the T-lymphocyte count has shown promise as a clinical indicator and predictor of COVID-19 severity. Objective: The review intended to examine the relationship of COVID-19 infections in individuals to lost expression of CD28 on naive CD4+/CD8+-mediated, vaccine-specific, neutralizing antibody responses. Design: The research team performed a narrative review by searching eight databases: Medline, Elsevier, Cochrane, PubMed, Google Scholar, Mendeley, and Springer Nature. The search used the following key terms: SARS CoV-2, clinical aspects and pathology of SARS CoV-2, involvement of viral spike (S) protein in SARS CoV-2, immunological changes in COVID-19 infection, basic overview of CD28 immuno-molecule ligand, reduction of vaccine therapeutic efficacy in COVID-19 infection, and immunomodulatory response of lost CD28 ligand. Setting: This study was done in a Maharishi Arvind College of Pharmacy, Jaipur, India. Results: In COVID-19 patients, particularly those with severe disease, had increased levels of IL-2 or IL-2R. Given IL-2's supportive role in the expansion and differentiation of T cells, the authors exhibiting that lymphopenia, particularly in severe COVID-19, could be attributed to nonfunctional and dysfunctional differentiation of CD4+ and CD8+ T cells as a result of low CD28 immuno-molecule expression on naive T cells. Conclusions: The literature review found that independent, early immunological prognostic markers for a poor prognosis, in addition to higher levels of IL-6, include a substantial proportion of large inflammatory monocytes and a small proportion of chronic CD28+ CD4+T cells. The current findings suggest that a combination of COVID-19 vaccination with SARS CoV-2-reactive naive T cells with the CD28 immune-molecule may be a viable method for establishing T-cell-based, adaptive cellular immunotherapy against COVID-19 infection. Further research is needed, especially larger studies to confirm the current findings, to improve early clinical treatment.

Spotlight on 4-substituted quinolines as potential anti-infective agents: Journey beyond chloroquine.

Continued emerging resistance of pathogens against the clinically approved candidates and their associated limitations continuously demand newer agents having better potency with a more suited safety profile. Quinoline nuclei containing scaffolds of natural and synthetic origin have been documented for diverse types of pharmacological activities, and a number of drugs are clinically approved. In the present review, we unprecedentedly covered the biological potential of 4-substituted quinoline and elaborated a rationale for its special privilege to afford the significant number of approved clinical drugs, particularly against infectious pathogens. Compounds with 4-substituted quinoline are well documented for antimalarial activity, but in the last two decades, they have been extensively explored for activity against cancer, tuberculosis, and several other pathogens including viruses, bacteria, fungi, and other infectious pathogens. In the present study, the anti-infective spectrum of this scaffold is discussed against viruses, mycobacteria, malarial parasites, and fungal and bacterial strains, along with recent updates in this area, with special emphasis on the structure-activity relationship.

Greater COVID-19 Severity and Mortality in Hospitalized Patients in the Delta-phase Compared to the Others: A Single Center Prospective Registry.

BACKGROUND AND OBJECTIVE: To compare clinical and laboratory features, and outcomes in the second COVID-19 phase (delta variant) with the first and third phases in India we performed a registry-based study. METHODS: Patients with confirmed severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection were recruited over the study period from March 2020 to July 2022. In the first phase (wild type, March-December 2020) of the 7,476 suspected, 1,395 (18.7%) were positive and 863 (61.8%) were hospitalized, in the second phase (delta, January-July 2021) out of 8,680 suspected, 1,641 (19.4%) tested positive and 388 (23.6%) were hospitalized, and in the third phase (omicron, January-July 2022) out of 5,188 suspected patients, 886 (17.1%) tested positive and 94 (10.6%) were hospitalized. We compared details of admission clinical and laboratory features and in-hospital management and outcomes in the three phases. RESULTS: A total of 2,352 patients were recruited. The majority of the patients were men, aged <45 years were 20% and about 20% of patients had hypertension, diabetes, and cardiovascular diseases. Patients in the second phase had significantly more cough, fever, shortness of breath, and lower oxygen saturation (SpO2) at admission and also had more lymphopenia, C-reactive proteins (CRPs), interleukin-6, ferritin, lactic dehydrogenase, and transaminases than patients in the other two phases. In the second vs the first and third phases, the requirement of supplementary oxygen (47.9 vs 33.1 and 23.4%), proning (89.2 vs 37.1 and 5.3%), high flow nasal oxygen (15.7 vs 8.71 and 5.3%), noninvasive ventilation (14.4 vs 9.1 and 11.7%), invasive ventilation (16.2 vs 9.1 and 9.6%), steroids (94.1 vs 83.4 and 37.2%), remdesivir (91.2 vs 73.8 and 39.4%), and anticoagulants (94.3 vs 83.0 and 61.7%) was significantly more (p < 0.001). The median length of stay in days [interquartile range (IQR)] was longer in the second phase [8 (6-10)] vs the first [7 (5-10)] and the third phase [4 (3-6) days]. The intensive care unit (ICU) stay in the second phase [9 (5-13) days] was also significantly more than the first [6 (2-10)] and third [0 (0-3)] phases (p <0.001). Overall, in-hospital deaths occurred in 176 patients (12.8%). Deaths were significantly higher in the second phase (19.3%), compared to the first (11.0%) and the third (3.3%) phases (p <0.01). We also observed that greater disease severity at presentation was associated with higher mortality in all the phases. CONCLUSION: This study shows that COVID-19 patients that were hospitalized in the second (delta) phase of the epidemic had more severe disease compared to the first and third phases. In the second phase of patients, there was a significantly higher duration of hospitalization, ICU hospitalization, greater oxygen requirement, noninvasive and invasive ventilatory support, and more deaths.

Adverse Events during Intrahospital Transport of Critically Ill Patients: A Multicenter, Prospective, Observational Study (I-TOUCH Study).

Background: Critically ill patients are frequently transported to various locations within the hospital for diagnostic and therapeutic purposes, which increases the risk of adverse events (AEs). This multicenter prospective observational study was undertaken to determine the incidence of AEs related to intrahospital transport, their severity, and their effects on patient outcomes. Patients and methods: We included consecutive unstable critically ill patients requiring intrahospital transport, across 15 Indian tertiary care centers over 5 months (October 11, 2022-February 20, 2023). Apart from the demographics and severity of illness, data related to transport itself, such as indications and destination, incidence of AEs, their category and treatment required, and patient outcomes, were recorded in a standard form. Results: Eight hundred and ninety-three patients were transported on 1065 occasions out of the intensive care unit (ICU). The mean (SD) acute physiology and chronic health evaluation II score of the patients was 15.38 (±7.35). One hundred and two AEs occurred, wherein cardiovascular instability was the most common occurrence (31, 30.4%). Two patients had cardiac arrest immediately after transport. Acute physiology and chronic health evaluation II [odds ratio (OR): 1.02, 95% confidence interval (CI) - 1.00-1.05, p = 0.04], emergent transport (OR: 5.11, 95% CI - 3.32-7.88, p = 0.00), and team composition (OR: 5.34, 95% CI - 1.63-17.5, p = 0.00) during transport were found to be independent predictors of AEs. Conclusion: We found a high incidence of AEs during intrahospital transport of critically ill patients. These events were more common during emergent transports and when the patients were transported by doctors. Transport by itself was not related to ICU mortality. We feel that stabilization of the patients before transport and adherence to a standardized protocol may help in minimizing the AEs, thereby enhancing patient safety. How to cite this article: Zirpe KG, Tiwari AM, Kulkarni AP, Govil D, Dixit SB, Munjal M, et al. Adverse Events during Intrahospital Transport of Critically Ill Patients: A Multicenter, Prospective, Observational Study (I-TOUCH Study). Indian J Crit Care Med 2023;27(9):635-641.

Recent developments in systems biology and genetic engineering toward design of vaccines for TB.

Tuberculosis (TB) is one of the most prevalent diseases worldwide. The currently available Bacillus Calmette-Guérin vaccine is not sufficient in protecting against pulmonary TB. Although many vaccines have been evaluated in clinical trials, but none of them yet has proven to be more successful. Thus, new strategies are urgently needed to design more effective TB vaccines. The emergence of new technologies will undoubtedly accelerate the process of vaccine development. This review summarizes the potential and validated applications of emerging technologies, including: systems biology (genomics, proteomics, and transcriptomics), genetic engineering, and other computational tools to discover and develop novel vaccines against TB. It also discussed that the significant implementation of these approaches will play crucial roles in the development of novel vaccines to cure and control TB.

A European pharmacotherapeutic agent roflumilast exploring integrated preclinical and clinical evidence for SARS CoV-2 mediated inflammation to organ damage.

COVID-19 has spread globally, affecting almost 160 million individuals. Elderly and pre-existing patients (such as diabetes, heart disease and asthma) seem more susceptible to severe illness with COVID-19. Roflumilast was licensed for usage in the European Union in July 2010 as a phosphodiesterase-4 (PDE4) inhibitor. Under preclinical studies, roflumilast has been shown to decrease bleomycin-induced lung fibrosis, lung hydroxyproline and right heart thickening. The current study reviewed existing data that the PDE-4 inhibitor, a roflumilast, protects renal tissues and other major organ systems after COVID-19 infection by decreasing immune cell infiltration. These immune-balancing effects of roflumilast were related to a decrease in oxidative and inflammatory burden, caspase-3 suppression and increased protein kinase A (PKA)/cyclic A.M.P. (cAMP) levels in renal and other organ tissue.

Evaluating the efficacy of stool sample on Xpert MTB/RIF Ultra and its comparison with other sample types by meta-analysis for TB diagnostics.

Precise and timely detection of tuberculosis (TB) is crucial to reduce transmission. This study aims to assess the accuracy of Xpert MTB/RIF Ultra on stool samples and systematically review the performance of Xpert MTB/RIF Ultra with different sample types by meta-analysis. Stool samples of smear-negative pulmonary TB (PTB), cervical lymph node TB, and abdominal TB patients were tested on the Xpert MTB/RIF Ultra system. Meta-analysis was performed on a set of 44 studies. Data were grouped by sample type, and the pooled sensitivity and specificity of Xpert MTB/RIF Ultra were calculated. The sensitivity of Xpert MTB/RIF Ultra with stool samples was 100% for smear-negative PTB, 27.27% for cervical lymph node TB, and 50% for abdominal TB patients, with 100% specificity for all included TB groups. The summary estimate for all PTB samples showed 84.2% sensitivity and 94.5% specificity, and EPTB samples showed 88.6% sensitivity and 96.4% specificity. Among all sample types included in our meta-analysis, urine showed the best performance for EPTB diagnosis. This pilot study supports the use of stool as an alternative non-invasive sample on Xpert MTB/RIF Ultra for rapid testing, suitable for both PTB and EPTB diagnosis.

Molecular explanation of Wnt/ßcatenin antagonist pyrvinium mediated calcium equilibrium changes in aging cardiovascular disorders.

The symptoms of ageing are somewhat different and can lead to the altered role of the cardiovascular system at the levels of genetic, biochemical, tissue, organ, and systems. Ageing is an autonomous cardiovascular risk factor. In the ageing rat heart, oxidative and inflammatory stress, immune cell infiltration, increasing myeloperoxidase function, elevated caspase-3 activity, and protein fibronectins were detected and associated with ageing and cardiovascular disease. The intracellular Ca2 + homeostasis disturbed in an older heart dramatically increases cardiomyopathy, atherosclerosis, stroke, ischemia, myocardial infarction, hypertrophy, remodelling, and hypertension. Evidence shows that suppression of Wnt/ß signals prevents cardiovascular dysfunction, such as remodelling, high blood pressure, and excessive overload stress. However, one study has shown that the pharmacological disruption of Wnt-ß-catenin by decreasing expression of α-smooth muscle actin, fibronectin and collagen I proteins attenuates angiotensin II mediated hypertension cardiac fibrosis. Thus, this review examined the impacts of calcium overload and age-related diseases, including cardiovascular. Energy dysregulation, calcium overloading, and mitochondrial dysfunction are the main activities causing cardiovascular disease linked with age. Therefore, the current study explores that age-associated cardiovascular disease has triggered the WNT/ß-catenin pathway, and pharmacological inhibition can delay pathological changes by attenuating calcium dyshomeostasis.

Exploring the role of antibiotics and steroids in managing respiratory diseases.

Respiratory diseases (RDs), such as chronic obstructive pulmonary disease, cystic fibrosis, asthma, and pneumonia, are associated with significant morbidity and mortality. Treatment usually consists of antibiotics and steroids. Relevant published literature reviews, studies, and clinical trials were accessed from institutional and electronic databases. The keywords used were respiratory diseases, steroids, antibiotics, and combination of steroids and antibiotics. Selected articles and literature were carefully reviewed. Antibiotics are often prescribed as the standard therapy to manage RDs. Types of causative respiratory pathogens, spectrum of antibiotics activity, route of administration, and course of therapy determine the type of antibiotics that are prescribed. Despite being associated with good clinical outcome, treatment failure and recurrence rate are still high. In addition, antibiotic resistance has been widely reported due to bacterial mutations in response to the use of antibiotics, which render them ineffective. Nevertheless, there has been a growing demand for corticosteroids (CS) and antibiotics to treat a wide variety of diseases, including various airway diseases, due to their immunosuppressive and anti-inflammatory properties. The use of CS is well established and there are different formulations based on the diseases, such as topical administration, tablets, intravenous injections, and inhaled preparations. Both antibiotics and CS possess similar properties in terms of their anti-inflammatory effects, especially regulating cytokine release. Thus, the current review examines and discusses the different applications of antibiotics, CS, and their combination in managing various RDs. Drawbacks of these interventions are also discussed.

Harnessing taxonomically diverse and metabolically versatile genus Paracoccus for bioplastic synthesis and xenobiotic biodegradation.

The genus Paracoccus represents a taxonomically diverse group comprising more than 80 novel species isolated from various pristine and polluted environments. The species are characterized as coccoid-shaped Gram-negative bacteria with versatile metabolic attributes and classified as autotrophs, heterotrophs and/or methylotrophs. The present study highlights the up-to-date global taxonomic diversity and critically discusses the significance of genome analysis for identifying the genomic determinants related to functional attributes mainly bioplastic synthesis and biodegradation potential that makes these isolates commercially viable. The analysis accentuates polyphasic and genomic attributes of Paracoccus spp. which could be harnessed for commercial applications and emphasizes the need of integrating genome-based computational analysis for evolutionary species and functional diversification. The work reflects on the underexplored genetic potential for bioplastic synthesis which can be harnessed using advanced genomic methods. It also underlines the degradation potential and possible use of naturally-occurring pollutant-degrading Paracoccus isolates for the development of a biodegradation system and efficient removal of contaminants. The work contemplates plausible use of such potent isolates to establish the plant-microbe interaction, contributing toward contaminated land reclamation. Overall, the work signifies the need and application of genome analysis to identify and explore the prospective potential of Paracoccus spp. for environmental application toward achieving sustainability.

Electro-Elastic Modeling of Thermal Spin Transition in Diluted Spin-Crossover Single Crystals.

Spin-crossover solids have been studied for many years for their promising applications as optical switches and reversible high-density memories for information storage. This study reports the effect of random metal dilution on the thermal and structural properties of a spin-crossover single crystal. The analysis is performed on a 2D rectangular lattice using an electro-elastic model. The lattice is made of sites that can switch thermally between the low-spin and high-spin states, accompanied by local volume changes. The model is solved by Monte Carlo simulations, running on the spin states and atomic positions of this compressible 2D lattice. A detailed analysis of metal dilution on the magneto-structural properties allows us to address the following issues: (i) at low dilution rates, the transition is of the first order; (ii) increasing the concentration of dopant results in a decrease in cooperativity and leads to gradual transformations above a threshold concentration, while incomplete spin transitions are obtained for big dopant sizes. The effects of the metal dilution on the spatiotemporal aspects of the spin transition along the thermal transition and on the low-temperature relaxation of the photo-induced metastable high-spin states are also studied. Significant changes in the organization of the spin states are observed for the thermal transition, where the single-domain nucleation caused by the long-range elastic interactions is replaced by a multi-droplet nucleation. As to the issue of the relaxation curves: their shape transforms from a sigmoidal shape, characteristic of strong cooperative systems, into stretched exponentials for high dilution rates, which is the signature of a disordered system.

Mycobacterium tuberculosis Peptidyl Prolyl Isomerase A Interacts With Host Integrin Receptor to Exacerbate Disease Progression.

Attenuated intracellular survival of Mycobacterium tuberculosis (Mtb) secretory gene mutants exemplifies their role as virulence factors. Mtb peptidyl prolyl isomerase A (PPiA) assists in protein folding through cis/trans isomerization of prolyl bonds. Here, we show that PPiA abets Mtb survival and aids in disease progression by exploiting host-associated factors. While the deletion of PPiA has no discernable effect on bacillary survival in a murine infection model, it compromises the formation of granuloma-like lesions and promotes host cell death through ferroptosis. Overexpression of PPiA enhances the bacillary load and exacerbates pathology in mice lungs. Importantly, PPiA interacts with the integrin α5ß1 receptor through a conserved surface-exposed RGD motif. The secretion of PPiA as well as interaction with integrin contributes to disease progression by upregulating multiple host matrix metalloproteinases. Collectively, we identified a novel nonchaperone role of PPiA that is critical in facilitating host-pathogen interaction and ensuing disease progression.

Bacillus anthracis chain length, a virulence determinant, is regulated by membrane localized serine/threonine protein kinase PrkC.

Anthrax is a zoonotic disease caused by Bacillus anthracis, a spore-forming pathogen that displays a chaining phenotype. It has been reported that the chaining phenotype acts as a virulence factor in B. anthracis In this study, we identify a serine/threonine protein kinase of B. anthracis, PrkC, the only kinase localized at the bacteria-host interface, as a determinant of B. anthracis chain length. In vitro, prkC disruption strain (BAS ΔprkC) grew as shorter chains throughout the bacterial growth cycle. A comparative analysis between the parent strain and BAS ΔprkC indicated that the levels of proteins, BslO and Sap, associated with the regulation of the bacterial chain length, were upregulated in BAS ΔprkC BslO is a septal murein hydrolase that catalyzes daughter cell separation and Sap is an S-layer structural protein required for the septal localization of BslO. PrkC disruption also has a significant effect on bacterial growth, cell wall thickness, and septa formation. Upregulation of ftsZ in BAS ΔprkC was also observed. Altogether, our results indicate that PrkC is required for maintaining optimum growth, cell wall homeostasis and most importantly - for the maintenance of the chaining phenotype.IMPORTANCEChaining phenotype acts as a virulence factor in Bacillus anthracis This is the first study that identifies a 'signal transduction protein' with an ability to regulate the chaining phenotype in Bacillus anthracis We show that the disruption of the lone surface-localized serine/threonine protein kinase, PrkC, leads to the shortening of the bacterial chains. We report upregulation of the de-chaining proteins in the PrkC disruption strain. Apart from this, we also report for the first time that PrkC disruption results in an attenuated cell growth, a decrease in the cell wall thickness and aberrant cell septa formation during the logarithmic phase of growth - a growth phase where PrkC is expressed maximally.

Genetic diversity and population genetic structure analysis of an extensive collection of wild and cultivated Vigna accessions.

Vigna is a large, pan-tropic and highly variable group of the legumes family which is known for its > 10 cultivated species having significant commercial value for their nutritious grains and multifarious uses. The wild vignas are considered a reservoir of numerous useful traits which can be deployed for introgression of resistance to biotic and abiotic stresses, seed quality and enhanced survival capability in extreme environments. Nonetheless, for their effective utilization through introgression breeding information on their genetic diversity, population structure and crossability is imperative. Keeping this in view, the present experiment was undertaken with 119 accessions including 99 wild Vigna accessions belonging to 19 species and 18 cultivated genotypes of Vigna and 2 of Phaseolus. Total 102 polymorphic SSRs were deployed to characterize the material at molecular level which produced 1758 alleles. The genotypes were grouped into four major clusters which were further sub-divided in nine sub-clusters. Interestingly, all cultivated species shared a single cluster while no such similarities were observed for the wild accessions as these were distributed in different groups of sub-clusters. The co-dominant allelic data of 114 accessions were then utilized for obtaining status of the accessions and their hybrid forms. The model-based population structure analysis categorized 114 accessions of Vigna into 6 genetically distinct sub-populations (K = 6) following admixture-model based simulation with varying levels of admixture. 91 (79.82%) accessions resembled their hierarchy and 23 (20.18%) accessions were observed as the admixture forms. Maximum number of accessions (25) were grouped in sub-population (SP) 6 and the least accessions were grouped in SP3 and SP5 (11 each). The population genetic structure, therefore, supported genetic diversity analysis and provided an insight into the genetic lineage of these species which will help in effective use of germplasm for development of cultivars following selective prebreeding activities.

Methylation of two-component response regulator MtrA in mycobacteria negatively modulates its DNA binding and transcriptional activation.

Post-translational modifications such as phosphorylation, nitrosylation, and pupylation modulate multiple cellular processes in Mycobacterium tuberculosis. While protein methylation at lysine and arginine residues is widespread in eukaryotes, to date only two methylated proteins in Mtb have been identified. Here, we report the identification of methylation at lysine and/or arginine residues in nine mycobacterial proteins. Among the proteins identified, we chose MtrA, an essential response regulator of a two-component signaling system, which gets methylated on multiple lysine and arginine residues to examine the functional consequences of methylation. While methylation of K207 confers a marginal decrease in the DNA-binding ability of MtrA, methylation of R122 or K204 significantly reduces the interaction with the DNA. Overexpression of S-adenosyl homocysteine hydrolase (SahH), an enzyme that modulates the levels of S-adenosyl methionine in mycobacteria decreases the extent of MtrA methylation. Most importantly, we show that decreased MtrA methylation results in transcriptional activation of mtrA and sahH promoters. Collectively, we identify novel methylated proteins, expand the list of modifications in mycobacteria by adding arginine methylation, and show that methylation regulates MtrA activity. We propose that protein methylation could be a more prevalent modification in mycobacterial proteins.

Changes in Hematological Parameters by Quantifying HRCT Chest Results in Patients With COVID-19 in Tertiary Care Hospital.

AIM: To find changes in hematologic parameters in patients who are COVID-19-positive with respect to high resolution computed tomography (HRCT) chest scan so that the exact picture of the disease course can be identified and an adequate treatment protocol can be planned to combat the COVID-19 pandemic. METHODS: Patients' health-related data including age, gender, symptomatology, associated co-morbidities, laboratory test results and HRCT results were collected. RESULTS: The radiologic findings showed ground glass opacities (GGOs) was the most common manifestation. Analysis of HRCTs of patients with COVID-19 showed that lesions were mainly confined to the right and left lower lobes, suggesting that the COVID-19 virus is mainly harbored in the basal areas of the lungs. CONCLUSION: Radiologic and laboratory investigations can greatly help in early detection of COVID-19, thus allowing for timely interventions.