Publications by authors named "A K Sharma"

17,666 Publications

Oral dysbiosis and its linkage with SARS-CoV-2 infection.

Microbiol Res 2022 May 4;261:127055. Epub 2022 May 4.

DBT-National Centre for Cell Science, Pune 411007, India. Electronic address:

The human oral cavity harbours complex microbial communities with various commensal microorganisms that play pivotal roles in maintaining host health and immunity but can elicit local and systemic diseases. The role of commensal microorganisms in SARS-CoV-2 infection and disease susceptibility and enrichment of opportunistic pathobionts in the oral cavity is poorly understood. The present study aims to understand the altered landscape of the oral microbiome and mycobiome in SARS-CoV-2 infected patients (n = 30) and its correlation with risk factors compared to non-infected individuals (n = 24) using targeted amplicon sequencing. Diminution of species richness, an elevated abundance of opportunistic pathogens (Veillonella, Acinetobacter, Klebsiella, Prevotella, Gemella, and Streptococcus) and impaired metabolic pathways were observed in the COVID-19 patients. Similarly, altered oral mycobiome with enrichment of known respiratory disease causing pathogenic fungi were observed in the infected individuals. The data further suggested that reduction in immunomodulatory microorganisms lowers the protection of individuals from SARS-CoV-2. Linear discriminant analysis identified several differentially abundant taxa associated with risk factors (ageing and co-morbidities). We also observed distinct bacterial and fungal community structures of elderly infected patients compared to the younger age group members making them highly vulnerable to SARS-CoV-2 infection and disease severity. Furthermore, we also assessed the dynamics of the oral microbiome and mycobiome in symptomatic and asymptomatic patients, host types, co-morbidities, and viral load in the augmentation of specific pathobionts. Overall, the present study demonstrates the microbiome and mycobiome profiling of the COVID-19 infected individuals, the data further suggests that the SARS-CoV-2 infection triggers the prevalence of specific pathobiont.
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http://dx.doi.org/10.1016/j.micres.2022.127055DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC9065653PMC
May 2022

Emerging impact of triazoles as anti-tubercular agent.

Eur J Med Chem 2022 May 13;238:114454. Epub 2022 May 13.

Department of Chemistry, Institute of Science, Banaras Hindu University, Varanasi, 221005, India. Electronic address:

Tuberculosis, a disease of poverty is a communicable infection with a reasonably high mortality rate worldwide. 10 Million new cases of TB were reported with approx 1.4 million deaths in the year 2019. Due to the growing number of drug-sensitive and drug-resistant tuberculosis cases, there is a vital need to develop new and effective candidates useful to combat this deadly disease. Despite tremendous efforts to identify a mechanism-based novel antitubercular agent, only a few have entered into clinical trials in the last six decades. In recent years, triazoles have been well explored as the most valuable scaffolds in drug discovery and development. Triazole framework possesses favorable properties like hydrogen bonding, moderate dipole moment, enhanced water solubility, and also the ability to bind effectively with biomolecular targets of M. tuberculosis and therefore this scaffold displayed excellent potency against TB. This review is an endeavor to summarize an up-to-date innovation of triazole-appended hybrids during the last 10 years having potential in vitro and in vivo antitubercular activity with structure activity relationship analysis. This review may help medicinal chemists to explore the triazole scaffolds for the rational design of potent drug candidates having better efficacy, improved selectivity and minimal toxicity so that these hybrid NCEs can effectively be explored as potential lead to fight against M. tuberculosis.
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http://dx.doi.org/10.1016/j.ejmech.2022.114454DOI Listing
May 2022

Resuscitation of preterm infants in Nigeria - A national survey on practice.

Niger J Clin Pract 2022 May;25(5):612-620

Department of Paediatrics, University of Nigeria, Nsukka, Enugu State, Nigeria.

Introduction And Aims: Preterm births constitute a major clinical problem associated with significant morbidity and mortality in the perinatal, neonatal, and childhood periods. Decisions around initiating and/or continuing resuscitation and treatment of preterm infants (PI) both at birth and afterwards need careful consideration. While the developed countries have published guidelines for the resuscitation and care of the PI, this is not the case in developing countries where availability of resources and the absence of a published guidelines impacts on practice. Our study was therefore carried out to access the practice and decision-making that surrounds the resuscitation of PIs by neonatologists and neonatal nurses working in neonatal intensive care units (NICU) across Nigeria.

Subjects And Methods: We conducted an online national survey on neonatal care providers working in level 2 and level 3 neonatal units (NICU) across Nigeria. Around 190 participants were selected from the six geopolitical zones of the country and they were asked about current practices relating to resuscitation and stopping life-sustaining treatment as well as estimated survival rates at different gestational ages (GA).

Results: In total, 138 clinicians responded to our survey. Of this, 73% completed the survey. Majority (83%) of the respondents worked in government-funded public hospitals while the remaining 17% worked in the private hospitals. 74% of the respondents' report having a guideline on the PI. Resuscitation practice varied amongst different neonatologists and neonatal nurses with 48% of the clinicians providing resuscitation at 23-26 weeks and the remainder providing resuscitation at a GA >26 weeks with a median GA threshold for initiating resuscitation at 27 weeks. From an institutional perspective, 75% of PIs <26 weeks were resuscitated in public hospitals while the remaining 25% were resuscitated in private hospital, however this is not statistically significant (P = 0.385). In situations when the GA is unknown, we found a median fetal weight of 700 g as the threshold for providing active treatment. We noticed wide variations in responses on the estimated survival rates of the PIs, however a common finding is the increased chances of survival with increasing GA. Also, PIs across all GAs had higher chances of survival in public hospitals than in private hospitals, however, this is not statistically significant (P = 0.385-0.956). The major factor influencing a clinicians' decision to limit resuscitation was the "risk of poor quality of life" (50%) and the prevalent way of palliating the newborn amongst respondents is by stopping life-sustaining treatment (34%).

Conclusion: Our survey revealed considerable variation in resuscitation practices amongst different neonatal care providers. Having a framework that will formulate and publish a national guideline based on factors like local survival rates, societal norms, and resources and ensuring that it is adopted by all NICUs will generate greater consistency of care.
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http://dx.doi.org/10.4103/njcp.njcp_1560_21DOI Listing
May 2022

Successful treatment of traction alopecia of beard with hair transplantation (follicular unit extraction).

Indian J Dermatol Venereol Leprol 2022 Apr 19:1-3. Epub 2022 Apr 19.

Department of Dermatology, Wockhardt Hospitals, Mumbai, Maharashtra, India.

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http://dx.doi.org/10.25259/IJDVL_576_2020DOI Listing
April 2022

Molecular and immunological characterization of cysteine protease from Phaseolus vulgaris and evolutionary cross-reactivity.

J Food Biochem 2022 May 20:e14232. Epub 2022 May 20.

Allergy and Immunology Section, CSIR-Institute of Genomics and Integrative Biology, New Delhi, India.

A commonly consumed legume in India, the kidney bean (Phaseolus vulgaris) is associated with allergy. We report molecular and immunological characterization of cysteine protease allergen and its cross-reactivity. In silico allergenicity assessment and phylogenetic analysis of kidney bean cysteine protease showed significant sequence homology (upto 67%) with allergens from kiwi, papaya, soybean, ragweed pollen and mites. Physicochemical properties and motif-analysis depicted cysteine protease as probable allergen. Multiple sequence alignment and phylogenetic analysis indicated structural conservation between kidney bean and homologous cysteine protease sequences. The gene was cloned, expressed and affinity purified. Cysteine protease was resolved at 42 kDa and exhibited high IgE binding (up to 89%) with hypersensitive sera. Cysteine protease showed functional property on cross-linking IgE receptors and upregulated expression of CD203c on activated basophils. In inhibition studies, 8.4 ng of cysteine protease was required for 50% self-inhibition, whereas significant inhibition was also observed with kidney bean (52 ng), black gram (155 ng), chick pea (437 ng), mesquite pollen (36 ng), house dust mite (64.85 ng), Alternaria alternata (78.8 ng) and Curvularia lunata (73.6 ng) extracts. ConSurf analysis indicated conserved active site and catalytic residues in mature domain among proteases from legumes, fruits, pollens, mites and fungus. In summary, P. vulgaris cysteine protease was molecularly characterized having functional activity. This study demonstrated, cross-reactivity between food and aeroallergens based on evolutionary conservancy that showed its clinical importance as cross-reactive allergen. PRACTICAL APPLICATIONS: Adaptation of sustainable lifestyle has led to a surge in consumption of plant-based foods especially legumes. Their high nutritional content lowers the risk of developing cardiovascular diseases, diabetes, obesity, and stroke. Kidney beans, a commonly consumed legume in Indian subcontinent, have a potential to be used as nutraceutical and functional food. Despite its alimentary nature, it elicits allergic reactions. Being a major sensitizer, trivial information regarding its allergic components has led to an urgent need for exploring its allergen repertoire. Our study reported biochemical and immunological characterization of its major cysteine protease allergen. Cysteine proteases are major cross-reactive allergens from insects, fruits and fungal sources. Identification and molecular characterization of such immunodominant allergens by RDT offers the prospect of using recombinant proteins for accurate diagnosis and therapeutic purposes. This study suggests that a potential major cross-reactive allergen may aid in developing allergy management interventions for a wide range of allergenic sources.
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http://dx.doi.org/10.1111/jfbc.14232DOI Listing
May 2022
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