Changes in antimicrobial resistance of Escherichia coli isolated from community associated urinary tract infection before and during the COVID-19 pandemic in India

PURPOSE

Impact of COVID-19 pandemic on antimicrobial resistance (AMR) is largely studied in healthcare settings, there is a need to understand the fluctuations in AMR during pandemic at the community level. Urinary tract infection (UTI) being one of the most common infections in the community, AMR profile of Community-acquired UTI (CA-UTI) is considered representative AMR at the community level.

PATIENTS AND METHODS

The study was taken in cohort of patients with clinical diagnosis of CA-UTI. The four study sites represented different community health centres in India. Escherichia coli (E.coli) isolates were analysed phenotypically and genotypically for AMR during Pre-COVID (Oct 2019- Feb 2020), 1st wave (Mar 2020 - Feb 2021) and 2nd wave of COVID-19 (Mar 2021- Dec 2021).

RESULTS

E. coli was the predominant uropathogen (229, 82%) . Increased susceptibility to nitrofurantoin was observed during pandemic. Reduced susceptibility to first line oral antibiotics and carbapenems was seen during 2nd wave. Increased MIC50 to beta-lactams and fluoroquinolones was seen during pandemic. Genomic analysis of E. coli isolates showed some AMR genes {aacC1, aacC4, SHV, QepA} only during 2nd wave.

CONCLUSION

The good impact of pandemic was evidenced by increased susceptibility to nitrofurantoin. The significant decrease in susceptibility to oral antibiotics during 2nd wave and increased MIC50 of few antibiotics are the bad impact. Decreased susceptibility to last-resort carbapenems and occurrence of various AMR genes only during 2nd wave of pandemic are of great concern and are the ugly impact of pandemic on AMR.

Antimicrobial resistance heterogeneity among multidrug-resistant Gram-negative pathogens: Phenotypic, genotypic, and proteomic analysis

Microbes evolve rapidly by modifying their genomes through mutations or through the horizontal acquisition of mobile genetic elements (MGEs) linked with fitness traits such as antimicrobial resistance (AMR), virulence, and metabolic functions. We conducted a multicentric study in India and collected different clinical samples for decoding the genome sequences of bacterial pathogens associated with sepsis, urinary tract infections, and respiratory infections to understand the functional potency associated with AMR and its dynamics. Genomic analysis identified several acquired AMR genes (ARGs) that have a pathogen-specific signature. We observed that blaCTX-M-15, blaCMY-42, blaNDM-5, and aadA(2) were prevalent in Escherichia coli, and blaTEM-1B, blaOXA-232, blaNDM-1, rmtB, and rmtC were dominant in Klebsiella pneumoniae. In contrast, Pseudomonas aeruginosa and Acinetobacter baumannii harbored blaVEB, blaVIM-2, aph(3'), strA/B, blaOXA-23, aph(3') variants, and amrA, respectively. Regardless of the type of ARG, the MGEs linked with ARGs were also pathogen-specific. The sequence type of these pathogens was identified as high-risk international clones, with only a few lineages being predominant and region-specific. Whole-cell proteome analysis of extensively drug-resistant K. pneumoniae, A. baumannii, E. coli, and P. aeruginosa strains revealed differential abundances of resistance-associated proteins in the presence and absence of different classes of antibiotics. The pathogen-specific resistance signatures and differential abundance of AMR-associated proteins identified in this study should add value to AMR diagnostics and the choice of appropriate drug combinations for successful antimicrobial therapy.

Genome profiling of uropathogenic E. coli from strictly defined community-acquired UTI in paediatric patients: a multicentric study

BACKGROUND

Urinary tract infection (UTI) in children is a common bacterial infection. The emergence of extended-spectrum beta-lactamases (ESBLs) poses a major challenge against the treatment of uropathogens. We aimed to characterize the E. coli isolates recovered from children with UTI for their resistance profile and circulating sequence types (ST).

METHODS

Children (> 1.5-18 years of age) from different community health centres of India with symptoms of UTI were enrolled. Isolates causing significant bacteriuria were identified by Matrix-Assisted Laser Desorption Ionization Time of Flight Mass Spectrometry (MALDI-TOF MS) and tested for antimicrobial susceptibility by the automated system, VITEK-2 (Biomeriux, Durhum, US). Nineteen E. coli isolates (15 ESBL positive and 4 ESBL negative) were sequenced in Oxford Nanopore platform followed by core-genome phylogeny, accessory genome cluster analysis, identification of sequence types, mobile genetic elements, genetic antimicrobial resistance markers. The correlation between detection of antimicrobial resistance genes with phenotypic resistance profiles was also investigated.

RESULTS

Eleven percent of children had significant bacteriuria [male:female-1:1, > 50% were 11-18 years of age group]. E. coli was predominant (86%) followed by K. pneumoniae (11%). Susceptibility of E. coli was highest against fosfomycin (100%) followed by carbapenems (90.7%) and nitrofurantoin (88.8%). ST131 (15.8%) and ST167 (10.5%) found as high-risk clones with the presence of plasmid [IncFIB (63.1%), IncFIA (52.6%)], and composite transposon [Tn2680 (46.6%)] in many isolates. Few isolates coharboured multiple beta-lactamases including blaNDM-5 (33.3%), blaOXA-1 (53.3%), blaCTX-M-15 (60%) and blaTEM-4 (60%).

CONCLUSIONS

This study highlights horizontal transmission of resistance genes and plasmids in paediatric patients at community centers across the nation harbouring multidrug-resistant genes such as blaNDM-5 and blaCTX-M-15 associated with high-risk clones ST131 and ST167. The data is alarming and emphasizes the need for rapid identification of resistance markers to reduce the spread in community. To our knowledge, this is the first multicentric study targeting paediatric UTI patients from the community setting of India.

Colistin potentiation in multidrug-resistant Acinetobacter baumannii by a non-cytotoxic guanidine derivative of silver

A novel nano-formulation (NF) that sensitizes Acinetobacter baumannii (AB) to otherwise ineffective colistin is described in the present study. Infections due to multidrug resistant (MDR) AB represent a major therapeutic challenge, especially in situations of pre-existing colistin resistance (colR). Subsequently, boosting the effectiveness of colistin would be a better alternative tactic to treat AB infections rather than discovering a new class of antibiotics. We have previously demonstrated an NF comprising self-assembled guanidinium and ionic silver nanoparticles [AD-L@Ag(0)] to have anti-biofilm and bactericidal activity. We report NF AD-L@Ag(0) for the very first time for the potentiation of colistin in Gram-negative colistin-resistant bacteria. Our results implied that a combination of clinically relevant concentrations of colistin and AD-L@Ag(0) significantly decreased colistin-resistant AB bacterial growth and viability, which otherwise was elevated in the presence of only colistin. In this study, we have described various combinations of minimum inhibitory concentration (MIC) of colistin (MICcol, ^1/2 MICcol, and ^1/4 MICcol) and that of AD-L@Ag(0) [MICAD-L@Ag(0), ^1/2 MICAD-L@Ag(0), and ^1/4 MICAD-L@Ag(0)] and tested them against MDR AB culture. The results (in broth as well as in solid media) signified that AD-L@Ag(0) was able to potentiate the anti-microbial activity of colistin at sub-MIC concentrations. Furthermore, the viability and metabolic activity of bacterial cells were also measured by CTC fluorescence assay and ATP bioluminescence assay. The results of these assays were in perfect concordance with the scores of cultures (colony forming unit and culture turbidity). In addition, quantitative real-time PCR (qRT-PCR) was performed to unveil the expression of selected genes, DNAgyrA, DNAgyrB, and dac. These genes introduce negative supercoiling in the DNA, and hence are important for basic cellular processes. These genes, due to mutation, modified the Lipid A of bacteria, further resisting the uptake of colistin. Therefore, the expression of these genes was upregulated when AB was treated with only colistin, substantiating that AB is resistant to colistin, whereas the combinations of MICcol + MICAD-L@Ag(0) downregulated the expression of these genes, implying that the developed formulation can potentiate the efficiency of colistin. In conclusion, AD-L@Ag(0) can potentiate the proficiency of colistin, further enhancing colistin-mediated death of AB by putatively disrupting the outer membrane (OM) and facilitating bacterial death.

Antibiotic resistance of uropathogens among the community-dwelling pregnant and nonpregnant female: a step towards antibiotic stewardship

BACKGROUND

Indiscriminate and widespread use of antibiotics has resulted in emergence of many antibiotic-resistant organisms. Antibiotic administration during pregnancy is mostly avoided, unless there is compelling medical condition. We hypothesized that the uropathogens isolated from pregnant women would be more susceptible to antibiotics compared to those isolated from nonpregnant women, thus will be helpful in formulating separate empiric guideline for pregnant women based on the resistance pattern.

METHODS

This was a prospective cross-sectional study conducted over a period of 2 years in which females with the clinical diagnosis of either cystitis or asymptomatic bacteriuria during pregnancy were included from the community settings. Uropathogen species and their antimicrobial resistance pattern were compared between the pregnant and nonpregnant groups. After accounting for centre-to-centre variation and adjusting for age and socio-economic status, the adjusted odds ratio for antibiotic resistance was calculated and compared between pregnant and nonpregnant women using logistic regression analysis.

RESULTS

A total of 1758 women (pregnant: 43.3%; nonpregnant: 56.6%) were screened in the study over a period of 2 years, out of which 9.3% (163/1758) were having significant bacteriuria. Escherichia coli and Klebsiella pneumoniae were the two commonest uropathogen in both the groups; their prevalence being 83.6% in pregnant women and 85.2% in nonpregnant women, respectively. Resistance against ampicillin, cefixime, cefoxitin, ceftazidime, ceftriaxone and amoxicillin-clavulanic acid were found significantly lower in the pregnant women compared to nonpregnant. After adjusting the age and socio-economic status accounting for centre-to-centre variation, the odds of resistance for cefixime, amoxicillin-clavulanic acid and co-trimoxazole were found lower and statistically significant among the pregnant women group.

CONCLUSIONS

The antimicrobial resistance was significantly higher among the community-dwelling nonpregnant women compared to pregnant women in case of few antibiotics. The study highlighted the need of building local antibiogram that could help to initiate the empirical treatment and thus prevent emergence of antimicrobial resistance.

Formic acid, an organic acid food preservative, induces viable-but-non-culturable state, and triggers new Antimicrobial Resistance traits in Acinetobacter baumannii and Klebsiella pneumoniae

Numerous human pathogens, especially Gram-negative bacteria, are able to enter the viable-but-non-culturable (VBNC) state when they are exposed to environmental stressors and pose the risk of being resuscitated and causing infection after the removal of the trigger. Widely used food preservatives like weak organic acids are potential VBNC inducers in food processing and packaging facilities but have only been reported for food-borne pathogens. In the present study, it is demonstrated for the first time that one such agent, formic acid (FA), can induce a VBNC state at food processing, storage, and distribution temperatures (4, 25, and 37°C) with a varied time of treatment (days 4-10) in pathogenic Gram-negative bacteria Acinetobacter baumannii and Klebsiella pneumoniae. The use of hospital-associated pathogens is critical based on the earlier reports that demonstrated the presence of these bacteria in hospital kitchens and commonly consumed foods. VBNC induction was validated by multiple parameters, e.g., non-culturability, metabolic activity as energy production, respiratory markers, and membrane integrity. Furthermore, it was demonstrated that the removal of FA was able to resuscitate VBNC with an increased expression of multiple virulence and Antimicrobial Resistance (AMR) genes in both pathogens. Since food additives/preservatives are significantly used in most food manufacturing facilities supplying to hospitals, contamination of these packaged foods with pathogenic bacteria and the consequence of exposure to food additives emerge as pertinent issues for infection control, and control of antimicrobial resistance in the hospital setting.

Can a shock-induced phonon up-pumping model relate to impact sensitivity of molecular crystals, polymorphs and cocrystals?

Impact sensitivity engineering of high-energy molecular crystals requires accurate predictive models. For this purpose, the promising multi-phonon based approach is selected, assessing a bit more its strengths and weaknesses. Presently used with high-quality phonon calculations of 22 molecular crystals, using a physics-based criterion to determine the phonon bath extent, the resulting intrinsic shock sensitivity index (SSI) is compared to the most common marker of impact sensitivity, h 50, as determined from drop-weight impact tests. Selecting a data subset from experiments performed under very similar conditions (2.5 kg hammer with grit and 30-40 mg samples), the model can predict h 50 values for mono-molecular crystals with very good accuracy, including the ability to discriminate the polymorphs of HMX and CL20. This very good agreement validates an initial indirect up-pumping mechanism occurring under these conditions, where the doorway modes also interact with the phonon bath. However, the phonon bath criterion for mono-molecular crystals does not transfer well to cocrystals. Owing to the vibrational coupling of the co-molecules, it seems a broader phonon bath should be considered. Additionally recalling experimental uncertainty and various experimental factors affecting h 50 values for a given compounds, we recommend that the density of the sample, granularity and morphology be systematically considered and reported along with measurements, which will in turn allow for more systematic data and predictive capabilities for sensitivity models.

A combination therapy strategy for treating antibiotic resistant biofilm infection using a guanidinium derivative and nanoparticulate Ag(0) derived hybrid gel conjugate

Bacteria organized in biofilms show significant tolerance to conventional antibiotics compared to their planktonic counterparts and form the basis for chronic infections. Biofilms are composites of different types of extracellular polymeric substances that help in resisting several host-defense measures, including phagocytosis. These are increasingly being recognized as a passive virulence factor that enables many infectious diseases to proliferate and an essential contributing facet to anti-microbial resistance. Thus, inhibition and dispersion of biofilms are linked to addressing the issues associated with therapeutic challenges imposed by biofilms. This report is to address this complex issue using a self-assembled guanidinium-Ag(0) nanoparticle (AD-L@Ag(0)) hybrid gel composite for executing a combination therapy strategy for six difficult to treat biofilm-forming and multidrug-resistant bacteria. Improved efficacy was achieved primarily through effective biofilm inhibition and dispersion by the cationic guanidinium ion derivative, while Ag(0) contributes to the subsequent bactericidal activity on planktonic bacteria. Minimum Inhibitory Concentration (MIC) of the AD-L@Ag(0) formulation was tested against Acinetobacter baumannii (25 μg mL-1), Pseudomonas aeruginosa (0.78 μg mL-1), Staphylococcus aureus (0.19 μg mL-1), Klebsiella pneumoniae (0.78 μg mL-1), Escherichia coli (clinical isolate (6.25 μg mL-1)), Klebsiella pneumoniae (clinical isolate (50 μg mL-1)), Shigella flexneri (clinical isolate (0.39 μg mL-1)) and Streptococcus pneumoniae (6.25 μg mL-1). Minimum bactericidal concentration, and MBIC50 and MBIC90 (Minimum Biofilm Inhibitory Concentration at 50% and 90% reduction, respectively) were evaluated for these pathogens. All these results confirmed the efficacy of the formulation AD-L@Ag(0). Minimum Biofilm Eradication Concentration (MBEC) for the respective pathogens was examined by following the exopolysaccharide quantification method to establish its potency in inhibition of biofilm formation, as well as eradication of mature biofilms. These effects were attributed to the bactericidal effect of AD-L@Ag(0) on biofilm mass-associated bacteria. The observed efficacy of this non-cytotoxic therapeutic combination (AD-L@Ag(0)) was found to be better than that reported in the existing literature for treating extremely drug-resistant bacterial strains, as well as for reducing the bacterial infection load at a surgical site in a small animal BALB/c model. Thus, AD-L@Ag(0) could be a promising candidate for anti-microbial coatings on surgical instruments, wound dressing, tissue engineering, and medical implants.

Virulence gene mutations as a differentiator of clinical phenotypes: insights from community-acquired uropathogenic Escherichia coli

Uropathogenic Escherichia coli (UPEC) remains an important cause of urinary tract infection during pregnancy. Multiple molecular virulence determinants and antibiotic resistant genes facilitate its pathogenesis and virulence phenotype. Hence it is hypothesized that there will be considerable variation in genes among the isolates from symptomatic as well as asymptomatic bacteriuria (ABU) during pregnancy. The aim of this study was to decipher the genetic variation among the two phenotypes. Six different UPEC isolates collected from urine specimens of consecutive pregnant females (five, symptomatic bacteriuria and one, ABU) were tested for their growth kinetics, and biofilm formation. A total of 87 virulence determinants and 56 antibiotic resistance genes were investigated using whole-genome sequencing, to identify putative drives of virulence phenotype. In this analysis, we identified eight different types of fully functional toxin antitoxin (TA) systems [HipAB, YefM-YoeB, YeeU-YeeV (CbtA), YhaV-PrlF, ChpBS, HigAB, YgiUT and HicAB] in the isolates from symptomatic bacteriuria; whereas partially functional TA system with mutations were observed in the asymptomatic one. Isolates of both the groups showed equivalent growth characteristics and biofilm-formation ability. Genes for an iron transport system (Efe UOB system, Fhu system except FhuA) were observed functional among all symptomatic and asymptomatic isolates, however functional mutations were observed in the latter group. Gene YidE was observed predominantly associated with the biofilm formation along with few other genes (BssR, BssS, YjgK, etc.). This study outlines putative critical relevance of specific variations in the genes for the TA system, biofilm formation, cell adhesion and colonization among UPEC isolates from symptomatic and asymptomatic bacteriuria among pregnant women. Further functional genomic study in the same cohort is warranted to establish the pathogenic role of these genes.

Unpacking Land Degradation Neutrality (LDN), An Emerging Paradigm to Conserve Land Systems’ Sustainability in the 21st Century? Meta-analysis of Challenges and Opportunities

The UN Sustainable Development Goals specifically note the growing importance of land degradation management and mitigation strategies, advocating for global collaboration and innovative research and policy outlook. In this reflective summary, we synthesize the current worldview (post-2000) on land degradation neutrality (LDN), an emerging concept in the field of environmental sustainability that advocates a dynamic balance between degradation and restoration, to ensure no net loss in productive land resources. We first introduce the LDN Causal Framework (theoretical framework of LDN), followed by the Logic Model – guideline for on-ground LDN method implementation (comprising preparatory activities, followed by Integrated Land Use Planning (ILUP), and LDN Response Hierarchy (Avoid-Reduce-Reverse)). We draw attention to growing concerns about LDN technical problems: restore vs. rehabilitate; selecting indicator variables, and establishing a baseline. In the final section, we reflect on the social-ecological aspect of LDN – harnessing participatory action (multi-stakeholder engagement) and gender mainstreaming. Overall, LDN presents an umbrella vision for environmental regeneration and land capital management, that requires seamless integration of natural with social sciences, the policy with law, and requires strategic community mobilization.

Randomized, Double Blind, Placebo Controlled, Clinical Trial to Study Ashwagandha Administration in Participants Vaccinated Against COVID-19 on Safety, Immunogenicity, and Protection With COVID-19 Vaccine–A Study Protocol

Introduction

Vaccines have emerged as the most effective tool in the fight against COVID-19. Governments all over the world have rolled out the COVID-19 vaccine program for their populations. Oxford-AstraZeneca COVID-19 vaccine (COVISHIELD™) is widely used in India. A large number of Indian people have been consuming various traditional medicines in the hope of better protection against COVID-19 infection. Several studies have reported immunological benefits of Withania somnifera (Ashwagandha) and its potential as a vaccine adjuvant. We propose to study the safety, immunogenicity and clinical protection offered by a 6-month regimen of Ashwagandha in participants who volunteer to be vaccinated against COVID-19 (COVISHIELD^TM) in the ongoing national program of vaccination.

Methods and Analysis

We designed a prospective, randomized, double-blind, parallel-group, placebo-controlled, two-arm, exploratory study on healthy volunteers receiving the COVISHIELD^TM vaccine. The administration of Ashwagandha will begin within 7 days of the first or second dose of COVISHIELDTM. Primary outcome measure is immunogenicity as measured by SARS-CoV-2 spike (S1) and RBD-specific IgG antibody titres. Secondary outcome measures are safety, protective immune response and quality of life measures. All adverse events will be monitored at each time throughout the study. Participants will be tracked on a daily basis with a user-friendly mobile phone application. Following power calculation 600 participants will be recruited per arm to demonstrate superiority by a margin of 7% with 80% power. Study duration is 28 weeks with interim analysis at the end of 12 weeks.

Ethics and Dissemination

Ethics approval was obtained through the Central and Institutional Ethics Committees. Participant recruitment commenced in December 2021. Results will be presented in conferences and published in preprints followed by peer-reviewed medical journals.

Clinical Trial Registration

[www.ClinicalTrials.gov], identifier [CTRI/2021/06/034496].

Prevalence and resistance pattern of uropathogens from community settings of different regions: an experience from India

Introduction

Urinary tract infection (UTI) is one of the most common infections in clinical practice worldwide in both healthcare and community settings causing significant morbidity and mortality. It is one of the major conditions at the community level treated empirically and regarded as a potential cause of emergence of antimicrobial resistance (AMR). Limited information is available regarding community-acquired UTI (CA-UTI) from India.

Methodology

This is a first of its kind, multicentric-cross-sectional study at the community level targeting patients attending the out-patient department (OPD) of the community health centre (CHC) from four geographical regions (North, South, West and East) of India. The study had been designed to determine the epidemiology, antibiogram profile and identification of extended-spectrum beta-lactamase (ESBL) producer and carbapenem resistant (CR) uropathogens. Samples were collected prospectively from UTI suspected patients coming at CHC and processed at the tertiary healthcare centres using a common standard operating procedure. Clinical history of all the patients exhibiting significant bacteriuria was collected and data was analysed.

Result

Overall, 250 out of a total of 2459 (10.1 %) urine samples were positive for bacteria with significant bacteriuria (adult: paediatrics, 6.7 : 1). Females were predominantly affected (male: female, 1 : 2.9). History of recent episode of UTI was observed as the commonest risk factor followed by diabetes mellitus. Altogether, 86 % of total cases were caused by Escherichia coli (68 %) and Klebsiella pneumoniae (17.6 %) together. Among the commonly used oral antibiotics for the Gram-negative bacilli (GNB), the highest resistance was observed against beta-lactams, first- and second-generation cephalosporins, fluoroquinolones and co-trimoxazole. Overall, the prevalence of ESBL producer and CR isolates were 44.8, and 4.3 %, respectively. However, the ESBL production, CR and nitrofurantoin resistance among the uropathogenic E. coli (UPEC) isolates was 52.8, 5.1 and 14 %, respectively. No resistance was found against fosfomycin among the UPEC isolates.

Conclusion

The current study highlights the increasing incidence of AMR among uropathogens at the community-settings of India. A significant percentage of ESBL producers among the isolated UPEC and K. pneumoniae were observed. The currently available evidence supports the clinical recommendation of fosfomycin and nitrofurantoin for empiric therapy in CA-UTI in India.

Longitudinal Serology of SARS-CoV-2-Infected Individuals in India: A Prospective Cohort Study

Clinical and epidemiological characteristics of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are now widely available, but there are few data regarding longitudinal serology in large cohorts, particularly those from low-income and middle-income countries. We established an ongoing prospective cohort of 3,840 SARS-CoV-2-positive individuals according to RT-PCR in the Delhi-National Capital Region of India to document clinical and immunological characteristics during illness and convalescence. The immunoglobulin G (IgG) responses to the receptor binding domain (RBD) and nucleocapsid were assessed at 0 to 7 days, 10 to 28 days, and 6 to 10 weeks after infection. The clinical predictors of seroconversion were identified by multivariable regression analysis. The seroconversion rates during the postinfection windows of 0 to 7 days, 10 to 28 days, and 6 to 10 weeks were 46%, 84.7%, and 85.3%, respectively (N = 743). The proportion with a serological response increased with the severity of coronavirus disease 2019 (COVID-19). All participants with severe disease, 89.6% with mild to moderate infection, and 77.3% of asymptomatic participants had IgG antibodies to the RBD antigen. The threshold values for the nasopharyngeal viral RNA RT-PCR of a subset of asymptomatic and symptomatic seroconverters were comparable (P = 0.48) to those of nonseroconverters (P = 0.16) (N = 169). This is the first report of longitudinal humoral immune responses to SARS-CoV-2 over a period of 10 weeks in South Asia. The low seropositivity of asymptomatic participants and differences between assays highlight the importance of contextualizing the understanding of population serosurveys.

Improved predictions of thermomechanical properties of molecular crystals from energy and dispersion corrected DFT

Thermal stability and pressure-dependent changes are key to molecular crystals and their properties. The determination of their thermal properties from ab initio methods is, however, a challenging task. While the low-frequency phonon spectrum related to intermolecular vibrations remains difficult to describe, the Quasi-Harmonic Approximation (QHA) also induces for molecular crystals a significant volume deviation, which makes their thermal behavior ill-determined. To overcome these difficulties, we consider a pragmatic energy correction (EC) that has long been used for atomic crystals, and we presently report the first ever use for molecular crystals. Applying the QHA in dispersion-corrected density functional theory (DFT-D) calculations with an ab initio parameterized EC, the resulting model can simultaneously and accurately derive thermal and mechanical properties of high-explosive molecular crystals. When compared to experiments, the mean absolute percent error of previous DFT-based thermomechanical models is 12% for mechanical and 31% for thermal properties. Our model performs significantly better and reduces these uncertainties to 4.1% and 9.8%, respectively. In particular, the agreement between our model and experiments for the thermal properties is three times better. This significant improvement greatly benefits the determination of thermomechanical properties such as the Grüneisen parameter and the shock properties. The method has been successfully applied to molecular crystals showing a large diversity of weak intermolecular interactions (β-1,3,5,7-tetranitro-1,3,5,7-tetrazoctane (HMX), α-1,1-diamino-2,2-dinitroethylene (FOX-7), Triaminotrinitrobenzene (TATB), ε-Hexanitrohexaazaisowurtzitane (CL20), and Pentaerythritol tetranitrate (PETN)-I). Due to its accuracy and transferability, our model is expected to work for a large class of computationally designed molecular crystals and co-crystals, providing a basis for a predictive framework.

The potential impact of the COVID-19 pandemic on global antimicrobial and biocide resistance: an AMR Insights global perspective

The COVID-19 pandemic presents a serious public health challenge in all countries. However, repercussions of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections on future global health are still being investigated, including the pandemic’s potential effect on the emergence and spread of global antimicrobial resistance (AMR). Critically ill COVID-19 patients may develop severe complications, which may predispose patients to infection with nosocomial bacterial and/or fungal pathogens, requiring the extensive use of antibiotics. However, antibiotics may also be inappropriately used in milder cases of COVID-19 infection. Further, concerns such as increased biocide use, antimicrobial stewardship/infection control, AMR awareness, the need for diagnostics (including rapid and point-of-care diagnostics) and the usefulness of vaccination could all be components shaping the influence of the COVID-19 pandemic. In this publication, the authors present a brief overview of the COVID-19 pandemic and associated issues that could influence the pandemic’s effect on global AMR.

Wuhan to World: The COVID-19 Pandemic

COVID-19 is a Severe Acute Respiratory Syndrome (SARS), caused by SARS-CoV-2, a novel virus which belongs to the family Coronaviridae. It was first reported in December 2019 in the Wuhan city of China and soon after, the virus and hence the disease got spread to the entire world. As of February 26, 2021, SARS-CoV-2 has infected ~112.20 million people and caused ~2.49 million deaths across the globe. Although the case fatality rate among SARS-CoV-2 patient is lower (~2.15%) than its earlier relatives, SARS-CoV (~9.5%) and MERS-CoV (~34.4%), the SARS-CoV-2 has been observed to be more infectious and caused higher morbidity and mortality worldwide. As of now, only the knowledge regarding potential transmission routes and the rapidly developed diagnostics has been guiding the world for managing the disease indicating an immediate need for a detailed understanding of the pathogen and the disease-biology. Over a very short period of time, researchers have generated a lot of information in unprecedented ways in the key areas, including viral entry into the host, dominant mutation, potential transmission routes, diagnostic targets and their detection assays, potential therapeutic targets and drug molecules for inhibiting viral entry and/or its replication in the host including cross-neutralizing antibodies and vaccine candidates that could help us to combat the ongoing COVID-19 pandemic. In the current review, we have summarized the available knowledge about the pathogen and the disease, COVID-19. We believe that this readily available knowledge base would serve as a valuable resource to the scientific and clinical community and may help in faster development of the solution to combat the disease.

Half metallicity in Cr substituted Fe2TiSn

Band structure tailoring has been a great avenue to achieve the half-metallic electronic ground state in materials. Applying this approach to the full Heusler alloy Fe₂TiSn, Cr is introduced systematically at Ti site that conforms to the chemical formula \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${\text{Fe}}_{2} {\text{Ti}}_{{1 - x}} {\text{Cr}}_{x}$$\end{document}Fe2Ti1-xCrxSn. Compositions so obtained have been investigated for its electronic, magnetic, and electrical transport properties with an aim to observe the half-metallic ferromagnetic ground state, anticipated theoretically for Fe₂CrSn. Our experimental study using synchrotron X-ray diffraction reveals that only compositions with \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$x \le$$\end{document}x≤ 0.25 yield phase pure L2\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$_1$$\end{document}1 cubic structures. The non-magnetic ground state of Fe₂TiSn gets dramatically affected upon inclusion of Cr giving rise to a localized magnetic moment in the background of Ruderman–Kittel–Kasuya–Yosida (RKKY) correlations. The ferromagnetic interactions begin to dominate for x = 0.25 composition. Results of its resistivity and magnetoresistance (MR) measurement point towards a half-metallic ground state. The calculation of exchange coupling parameter, \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\hbox {J}_{{ij}}$$\end{document}Jij, and orbital projected density of states that indicate a change in hybridization between 3d and 5p orbital, support the observations made from the study of local crystal structure made using the extended X-ray absorption fine structure spectroscopy. Our findings here highlight an interesting prospect of finding half-metallicity via band structure tailoring for wide application in spintronics devices.

Relationship of socio-economic inequality and overweight with non-communicable diseases risk factors: A study on underprivileged population

BACKGROUND

Out of every five deaths in India three are due to Non-Communicable Diseases (NCDs). Two major modifiable risk factors for NCDs are overweight and socioeconomic inequality. This study assesses the burden of various NCDs risk factors and their relationship with socioeconomic inequality and overweight among the underprivileged population.

AIM

To compare the different Non-Communicable Diseases risk factors with socioeconomic inequality and overweight. To evaluate the relationship between socioeconomic inequality and body weight with NCDs.

MATERIALS AND METHODS

A cross-sectional study incorporating 241 random sample of participants was assessed using WHO Stepwise approach to NCD risk factor surveillance. Anthropometric measurements and biochemical analysis of 12 h of fasting venous blood samples were done. Data were analyzed using Stata version 16 and Graph Pad Prism 8, using two-sided significance tests at the 5% significance level.

RESULTS

The study finds a 10-fold higher risk of tobacco use ( AOR = 10.18, C.I = 2.79 - 37.10) and 5 times higher risk of alcohol use AOR = 5.57, C.I = 1.25 - 24.65) among people with poor SES compared to higher SES. A significant correlation was observed between BMI, LDL cholesterol ( r = -16.0; P = 0.009) and HDL cholesterol (r = 18.0;P = 0.006) with socioeconomic status. The study finds that for individuals who were overweight the odds of systolic blood pressure (AOR = 2.11, C.I = 1.03-4.31), fasting blood sugar (AOR = 3.84, C.I = 1.30 -11.32), triglyceride level, (AOR = 2.20, C.I = 1.18 - 4.09) high-density lipoprotein ( AOR = 2.63, C.I = 1.26 - 5.46) were significantly higher compared to normal BMI individuals.

CONCLUSION

The study showed that the socioeconomic patterning of the population is significantly associated with NCD risk factors. Obesity was closely linked with several major NCD risk factors.

Menstrual hygiene practices among women aged 15-49 years attending a medical college hospital in Kolkata: A cross-sectional study

Background and Aims:

Menstruation is a normal physiological process and a key sign of reproductive health in women in the reproductive age group. Poor menstrual hygiene affects the educational activities as well as the day to day activities of women. The objective of this study is to assess the practices of menstrual hygiene among women aged 15-49 years attending a tertiary care hospital in Kolkata and to assess their knowledge regarding menstrual hygiene.

Materials and Methods:

This was a hospital-based cross-sectional study conducted among the women belonging to the age group of 15-49 years attending the outpatient department of Gynaecology. Predesigned, pretested, semi-structured questionnaire was used as a study tool. Interview method was used for data collection after obtaining informed consent from the participants. Data were analysed by SPSS 20v software. Association between variables was checked by Chi-square test & P < 0.05 was considered as significant.

Results:

Mean age of respondents was 28.03 ± 7.01 years. The cause of menstruation as a normal body function constituted maximum response (43.5%) whereas the reason was unknown to many (37%). Regarding restrictions during menstruation, it was mentioned that avoiding worshipping was the commonest restriction (90.2%), followed by restriction in diet (32.6%). Use of readymade absorbents was found in most of the subjects (91%) followed by homemade reusable (6.5%) and homemade disposable (2.2%). Around 77.2% of them packed the napkins and disposed in garbage. Those who were aware about menstrual hygiene were found to be practicing satisfactory perineal cleaning (p < 0.05).

Conclusion:

Health education and awareness programme focusing on menstrual hygiene must be intensified. School curriculum can play a vital role in implementing health education.

T11TS immunotherapy potentiates the repressed calcineurin-NFAT signalling pathway of T cells in Cryptococcus neoformans infected rats: a cue towards T-cell activation for antifungal immunity

AIMS

To examine the modulation of the interacting partners of the calcineurin (CaN)-NFAT pathway in T cells during Cryptococcus neoformans fungal infection and post-T11TS immunotherapy.

METHODS AND RESULTS

Wistar rats were infected with C. neoformans and followed by immunotherapy with immune-potentiator T11TS. T cells were analysed by flow cytometry, immunoblotting and nuclear translocation study. The signalling proteins LCK, FYN, LAT, PLCγ1 and CaN in T cells were regulated by C. neoformans infection resulting in reduced nuclear translocation of NFAT and IL-2 expression. Following T11TS immunotherapy, the expressions of the above-mentioned proteins were boosted and thus resulting in the clearance of C. neoformans from lung and spleen.

CONCLUSIONS

The precise mechanism of suppression of the T-cell function by C. neoformans is still unknown. Previously, we have shown that T11TS positively regulates the function of T cells to abrogate glioma and other immunosuppressive conditions. T11TS immunotherapy increased the expression of the above signalling partners of the CaN-NFAT pathway in T cells and improved nuclear retention of NFAT. As a result, an increased IL-2 expression leads to activation and proliferation of T cells.

SIGNIFICANCE AND IMPACT OF THE STUDY

Our results demonstrate the role of T11TS in restoring the CaN-NFAT signalling pathway in T cells. It identifies T11TS as an immunotherapeutic agent with potential clinical outcomes to counteract C. neoformans infection.

Internet addiction among medical undergraduates in a medical college of West Bengal- a cross-sectional study

Background: The era of 21st century is burdened with internet usage worldwide specially in the developing countries such as India. Internet addiction has been related to physical, social, psychological impairment. Aim& Objectives: To find out the prevalence of internet addiction among the medical students and the effect of internet addiction on health status among them. Settings and Design: This was an observational descriptive study of cross-sectional design conducted in a tertiary medical college of West Bengal. Material & Methods: All the undergraduate medical students were approached and interview was done using interview schedule consisting of sociodemographic characteristics, Young’s criteria of internet addiction test and Duke’s health profile screening test. Statistical analysis used: Data was analysed using SPSS version 20&presented in percentages, mean with standard deviation, ANOVA with Tukey’s Post-hoc test. Results: Total of 201 participants responded giving a response rate of about 50%. The distribution of respondents as per Young’s criteria of internet addiction which showed that majority of the respondents were mild addicted (58.7%) & moderate addicted (15%).Comparison of Duke health profile score across various internet addicts where physical health score differs significantly among the non-addicted (81.42+20.02) vs mildly addicted (67+20.36)& moderately addicted (63.31+ 20.15) participants (p=0.00). Mental health score also differs considerably among the non-addicts (78.16+18.36) vs mildly addicts (67+18.28) & moderately addicts (61.87+18.33) (p= 0.00). Conclusions: A good number of medical students were addicted to internet that requires timely remedial action. Educational institutions had to formulate strategies so that proper action could be taken.

Demonstration of Athena X-IFU Compatible 40-Row Time-Division-Multiplexed Readout

Time-division multiplexing (TDM) is the backup readout technology for the X-ray Integral Field Unit (X-IFU), a 3,168-pixel X-ray transition-edge sensor (TES) array that will provide imaging spectroscopy for ESA's Athena satellite mission. X-0IFU design studies are considering readout with a multiplexing factor of up to 40. We present data showing 40-row TDM readout (32 TES rows + 8 repeats of the last row) of TESs that are of the same type as those being planned for X-IFU, using measurement and analysis parameters within the ranges specified for X-IFU. Singlecolumn TDM measurements have best-fit energy resolution of (1.91 ± 0.01) eV for the Al Kα complex (1.5 keV), (2.10 ± 0.02) eV for Ti Kα (4.5 keV), (2.23 ± 0.02) eV for Mn Kα (5.9 keV), (2.40 ± 0.02) eV for Co Kα (6.9 keV), and (3.44 ± 0.04) eV for Br Kα (11.9 keV). Three-column measurements have best-fit resolution of (2.03 ± 0.01) eV for Ti Kα and (2.40 ± 0.01) eV for Co Kα. The degradation due to the multiplexed readout ranges from 0.1 eV at the lower end of the energy range to 0.5 eV at the higher end. The demonstrated performance meets X-IFU's energy-resolution and energy-range requirements. True 40-row TDM readout, without repeated rows, of kilopixel scale arrays of X-IFU-like TESs is now under development.

Optimization of Time- and Code-Division-Multiplexed Readout for Athena X-IFU

Readout of a large, spacecraft-based array of superconducting transition-edge sensors (TESs) requires careful management of the layout area and power dissipation of the cryogenic-circuit components. We present three optimizations of our time- (TDM) and code-division-multiplexing (CDM) systems for the X-ray Integral Field Unit (X-IFU), a several-thousand-pixel-TES array for the planned Athena-satellite mission. The first optimization is a new readout scheme that is a hybrid of CDM and TDM. This C/TDM architecture balances CDM's noise advantage with TDM's layout compactness. The second is a redesign of a component: the shunt resistor that provides a dc-voltage bias to the TESs. A new layout and a thicker Pd-Au resistive layer combine to reduce this resistor's area by more than a factor of 5. Third, we have studied the power dissipated by the first-stage SQUIDs (superconducting quantum-interference devices) and the readout noise versus the critical current of the first-stage SqUIDs. As a result, the X-IFU TDM and C/TDM SQUIDs will have a specified junction critical current of 5 μA. Based on these design optimizations and TDM experiments described by Durkin, et al. (these proceedings), TDM meets all requirements to be X-IFU's backup-readout option. Hybrid C/TDM is another viable option that could save spacecraft resources.

Unraveling the physical properties and superparamagnetism in anti-site disorder controlled Fe2TiSn

With an aim to control the anti-site disorder between Fe and Ti atoms in the full Heusler alloy, Fe[Formula: see text]TiSn, we substitute a small percentage of Ti at Fe site to form the Fe[Formula: see text]Ti[Formula: see text]Sn ([Formula: see text]) series. Using the incident x-rays tuned to the Fe K-edge absorption energy, we record the high resolution synchrotron x-ray diffraction profiles and unambiguously show the reduction in anti-site disorder. In particular, the Fe-Ti anti-site disorder decreases up to an excess Ti content of 0.07; further increase of Ti content leads to disorder between Ti-Sn sites. Detailed characterization vis-á-vis the excess Ti content has been carried out in terms of its thermal and electrical transport, and magnetic properties. Signatures of strong spin fluctuation are seen in all the physical properties reported here. The much disputed high value of the Sommerfeld constant has been shown to be a resultant of such strong spin fluctuations, thus ruling out the long standing controversy of heavy fermionic nature of Fe[Formula: see text]TiSn. Magnetization and the Seebeck coefficient show clear dependence on the disorder. Both dc and ac magnetic measurements reveal the low temperature superparamagnetic nature of this system, comprising of large magnetic clusters [Formula: see text]3 nm in size.

A flexible-molecule force field to model and study hexanitrohexaazaisowurtzitane (CL-20) – polymorphism under extreme conditions

The quantum-chemistry based force field (FF) developed for HMX by Smith and Bharadwaj (SB) [G. D. Smith and R. K. Bharadwaj, J. Phys. Chem. B, 1999, 103(18), 3570–3575] is transferred to another nitramine of different stoichiometry: hexanitrohexaazaisowurtzitane (CL-20 or HNIW). The modification of a single parameter alongside a very small number of add-ons related to carbon–carbon bonds, angles and dihedrals lead to two SB FF variants denoted SB-CL20 and SB-CL20 + CCNN. These flexible-molecule FFs should inherit the predictive capabilities of SB FF. For this purpose, we perform Molecular Dynamics simulations at ambient temperature and selected pressures. The modeled structures of the various CL-20 polymorphs are consistent with experimental data. Focusing on the ε-polymorph, we determine an equation of state which consolidates the general trend underpinned by most published results, and we confirm the increasing stiffness of the crystal under pressures up to 90 GPa. Moreover, we link some subtle pressure-induced changes of the elastic and structural properties to the flexibility and mobility of well-identified nitro groups. Finally, the simulations of the γ ↔ ζ phase transition suggest different multiple-step direct and reverse thermodynamic paths.

The quantum-chemistry based force field developed by Smith and Bharadwaj is transferred to hexanitrohexaazaisowurtzitane (CL20), revealing pressure-induced alterations of ε-CL20.

Nonsmoked Tobacco Addiction Playing a Major Role in Oral Mucosal Changes in Northern Indian Population Over Smoked and Alcohol Use

Background: Oral cavity is prone for myriad of changes with advancing age as well result of environmental and life style related factors like consumption of tobacco (smoke or smokeless) and alcohol. Aim: The aim of this study was to quantify and compare the association of oral mucosal changes (OMC) with nonsmoked tobacco over smoked tobacco and alcohol. Methods: Data of 11,145 subjects from 106 health screening camps, organized in Uttar Pradesh and Rajasthan between April 2015 to June 2017 was analyzed to unveil and determine the mode of addiction and prevalence of OMC. Bivariate and multivariable models were tested for comparison and identification of factors associated with an increasing risk of developing OMC. Results: The primary symptoms were mouth ulcer in 5.6% and trismus (1.0%). The overall proportions of tobacco chewing, smoking and alcohol addiction were 12.5%, 10.7% and 2.5% respectively. The highest prevalence of smoking noted in the age-group 55-64 years (14.4%), for tobacco chewing and alcohol consumption in the age-group 25-34 years was 15.6% and 4.2% respectively ( P < 0.001). The prevalence of mouth ulcers were 20.7% among smokers and 27.8% among tobacco chewers ( P < 0.001) while the percentage of trismus 26.1% among smokers and 53.0% among tobacco chewers ( P < 0.001). Conclusion: Results of this study can be used for creating awareness among the population regarding the hazards of tobacco use. More number of studies needs to be conducted all over India to understand the prevalence and the biologic behavior of these oral premalignant lesions and its progression to invasive diseases.

Disparity Between Metro-Centric Cancer Care and Rural Outreach in India: Situational Analysis and Future Trends in Context of Developing Countries

Background: Radiation therapy is used in two-third of all patients diagnosed with cancer in any form and it has become an integral part of modern treatment strategies for many types of cancers in recent decade. Semi-urban and rural places in India lack healthcare facilities and so as the cancer care facilities. Aim: To identify the propensity of a metro-centric oncologic care in developing countries undermining the need of availability of facilities in smaller towns and cities. Methods: Data for state-wise population for 2016 and 2026 was projected using cohort component method. For the projection of cancer incidence and prevalence in 2016 and 2026, we assumed that the state-level prevalence and incidence of cancer in the year 2015 will not change over time in 2016. Data collected through telephonic interviews from the radiotherapy centers listed by Atomic Energy Regulatory Board (AERB), India. Further, we assumed few scenarios of cancer incidence and prevalence increase and projected state wise cancer burden in 2026. Results: With almost 70% population of India residing in districts and cities lacking quality health care, the situation of cancer care is much grave. India is currently equipped with only 394 RTU (Radiation Therapy Unit) against requirement of almost 1300 RTU, amounting to 0.38 RTU per million populations as per World Health Organization. The public sponsored healthcare infrastructure for cancer treatment, and research is centralized with all the resources centered in metro/major cities. Eight metro cities of India with a combined population of 140.6 million hold control of 188 RTU under their boundaries. Thus, while habitants of these eight metro cities, constituting only 10.9% of the national population, avail treatment benefit from 38% of total RTU capacity of India, rest of Indian population at 1143.8 million strengths is left prey to the wrath of cancer with just 306 machines at disposal. In comparison, the developed nations as the United States of America, Australia, and the United Kingdom fare far better in RTU availability for treatment of diagnosed cancer patients, with RTU per million population density of 12.45, 10.12 and 5.04 respectively. Similar scenario has been seen in other LMICs in world like Congo, Mongolia, Sudan, Nigeria, Nepal etc. Conclusion: We observed that wide disparity exists in India concerning RTU and cancer facility availability and density per million populations in between metro cities and rest of India and a dire need of improvement to fight against cancer which is very similar to the situation in developing countries.

Reaction Characteristics of Antiprothrombin Antibody on the Activation of Prothrombin (Sheep)

1. Prothrombin was purified by a series of steps and subsequently on DEAE-Cellu- lose chromatography and specific antibody to pure prothrombin was prepared.

2. The effect of Anti-prothrombin antibody was tested on the activation of prothrombin. The generated thrombin was assayed for its clotting function as well as for esterase activity on TAMe (Tosyl-Arginine-Methyl ester) as substrate.

3. Anti-prothrombin antibody inhibits the clotting function of generated thrombin completely but its esterase function is only partially affected.

Possible half-metallicity and variable range hopping transport in Sb-substituted Fe2TiSn Heusler alloys

The investigation of the magnetotransport properties on [Formula: see text] [Formula: see text]Sb _x with 0 [Formula: see text] 0.6 are presented in this paper. The substitution of Sb in place of Sn decreases the anti-site disorder as evident from x-ray diffraction patterns as well as from transport properties measurement. The much-disputed upturn in low temperature electrical resistivity of [Formula: see text]TiSn has been demonstrated to be a result of weak localization induced by anti-site disorder. With increased Sb substitution (⩾25%) the metallic transport behavior of [Formula: see text]TiSn changes to semiconductor-like. At low temperature, carrier transport in such compositions occurs via the variable range hopping mechanism. Moreover, a systematic increase in the anomalous Hall voltage is observed with increasing Sb-content, attributable to a side jump or Berry phase curvature effect. Electrical resistivity in the entire temperature regime hints towards half metallicity of the system. Our ab initio electronic structure calculations using generalised gradient approximation formalism further supports the results of our magnetotransport study.

A tunable coupler for superconducting microwave resonators using a nonlinear kinetic inductance transmission line

We present a tunable coupler scheme that allows us to tune the coupling strength between a feedline and a superconducting resonator in situ over a wide range. In this scheme, we shunt the feedline with a 50-Ω lumped-element nonlinear transmission line made from a 20 nm NbTiN film. By injecting a DC current, the nonlinear kinetic inductance changes and the effective impedance shunting the resonator periodically varies from a short to an open, which tunes the coupling strength and coupling quality factor Qc . We have demonstrated Qc tuning over a factor of 40, between Qc ~ 5.5 × 104 and Qc ~ 2.3 × 106, for a 4.5 GHz resonator by applying a DC current less than 3.3 mA. Our tunable coupler scheme is easy to implement and may find broad applications in superconducting detector and quantum computing/information experiments.

A repertoire of high-affinity monoclonal antibodies specific to S. typhi: as potential candidate for improved typhoid diagnostic

Typhoid fever is a significant global health problem with highest burden on the developing world. The severity of typhoid is often underestimated, and currently available serological diagnostic assays are inadequate due to lack in requisite sensitivity and specificity. This underlines an absolute need to develop a reliable and accurate diagnostics that would benefit long-term disease control and treatment and to understand the real disease burden. Here, we have utilized flagellin protein of S. typhi that is surface accessible, abundantly expressed, and highly immunogenic, for developing immunodiagnostic tests. Flagellin monomers are composed of conserved amino-terminal and carboxy-terminal, and serovar-specific middle region. We have generated a panel of murine monoclonal antibodies (mAbs) against the middle region of flagellin, purified from large culture of S. typhi to ensure its native conformation. These mAbs showed unique specificity and very high affinity toward S. typhi flagellin without showing any cross-reactivity with other serovars. Genetic analysis of mAbs also revealed high frequency of somatic mutation due to antigenic selection process across variable region to achieve high binding affinity. These antibodies also displayed stable binding in stringent reaction conditions for antigen-antibody interactions, like DMSO, urea, KSCN, guanidinium HCl, and extremes of pH. One of the mAbs potentially reversed the TLR5-mediated immune response, in vitro by inhibiting TLR5-flagellin interaction. In our study, binding of these mAbs to flagellin, with high affinity, present on bacterial surface, as well as in soluble form, validates their potential use in developing improved diagnostics with significantly higher sensitivity and specificity.

Autism Spectrum Disorder: the Present Perspective

The last decade has witnessed a surge of awareness about autism among the public and professionals. Much revealing research is being done on this issue and the knowledge base has improved substantially and a set of professionals are specializing on the subject, focusing on its causative factors and management. Autism being a disorder stemming from early childhood and the prevalence rate rising alarmingly over the years, Pediatricians are expected to play a vital role in early detection and early intervention in management of the problem. But, unfortunately, autism is not yet considered to be under the purview of pediatricians. As pediatricians, we are often perplexed when faced with such a different child in our office and either overlook the problem or hurry to hand him over to a psychiatrist, not trying to really identify and understand the problem as a medical entity ourselves. Hence better awareness among pediatricians is the need of the day. As specialists have worked with autism over the decades, it has become clear that: autism is a disorder that involves early development, presently there is no medical answer to autism, and the only management strategy hinges largely on effective training. The earlier the training begins the better it is for the child. It is of paramount importance to start training and bring about changes by the time the child is 18 months old. This throws up interesting new challenges to the profession of pediatrics. To identify the early warning signs of autism, it is important that Pediatricians are able to recognize the signs and symptoms of autistic spectrum disorders (ASD), have a strategy for assessing them systematically, be familiar with available tools for screening as well as developmental and educational resources.DOI: http://dx.doi.org/10.3126/jcmsn.v10i3.12775 Journal of College of Medical Sciences-Nepal, 2014, Vol-10, No-3, 37-47

Ecoepidemics overcoming the species barrier and being subject to harvesting

An ecoepidemiological model in which the disease can be transmitted from one population to another one is considered. Linear harvesting on all the populations is considered. By means of numerical simulations, the role of the epidemiological parameters as well as that of harvesting are investigated. Some relevant consequences of harvesting on the system dynamics are discovered.

Dynamics of a robust photo-induced insulator-metal transition driven by coherent and broad-band light in epitaxial films of La(0.625-y)Pr(y)Ca(0.375)MnO(3)

A dramatic drop of ≈5 orders of magnitude in the resistance (R) of La(0.175)Pr(0.45)Ca(0.375)MnO(3) epitaxial films upon exposure to optical photons derived from both continuous and pulsed lasers, as well as broad-band sources at temperatures (T) < 30 K is reported. The strength of change is a sensitive function of both the incident photon flux and temperature. Under isothermal conditions the photo-generated low resistance state persists eternally after removal of light. This non-equilibrium state is metallic, as revealed by the positive dR/dT for T ≤ T(p) (≈120 K). This electrically conducting state is presumably ferromagnetic as T(p) coincides with the temperature where a weak ferromagnetism sets in on cooling the insulating film from room temperature. To rule out the possibility of photon-induced local heating of the sample as a mechanism of the observed effects, photo-illumination experiments were performed under identical conditions on thin films of two non-charge-ordered manganites deposited on substrates of similar thermal conductivity. Our model for the observed transition encompasses a global charge-ordered state in which ferromagnetic metallic clusters of fraction p much less than the critical fraction p(c) for percolation exists at low temperatures. Photo-induced melting of the charge-ordered state increases this fraction beyond p(c) in a cumulative manner as successive pulses of light fall on the sample.

Microalbuminuria: An inexpensive, non invasive bedside tool to predict outcome in critically ill patients

This study was conducted to evaluate whether microalbuminuria on admission and after 24 hrs of admission to intensive care unit (ICU) predicts outcome as well as the Acute Physiology and Chronic Health Evaluation (APACHE) II severity illness score, the current accepted method of doing so. The study was carried out in a 20 bed mixed medical-surgical ICU of a tertiary care hospital. Of 525 consecutive adult patients with ICU stay of more than 24 hrs, 238 were included for the study. Patients with pregnancy, menstruation, anuria, macroscopic hematuria, urinary tract infection, marked proteinuria due to renal and post-renal structural diseases, were excluded. Spot urine samples were collected on admission to ICU and 24 hrs thereafter. Urine albumincreatinine ratio (ACR) was measured on ICU admission (ACR1) and after 24 hrs (ACR2) and expressed in mg/g. Patient demographics were noted on admission. For disease severity scoring, APACHE II scores were calculated. Each patient was followed up throughout their ICU stay for a maximum of 28 days and the following outcome data were obtained: ICU length of stay and ICU mortality. Of the 238 patients, 196 survived while 42 patients died in the ICU. Non-survivors had a significantly higher median ACR2 [162.7 mg/g (IQR 69.5-344.3)] in comparison to the survivors who had a median ACR2 = 54.4 mg/g (IQR 19.0-129.1) (P< 0.0001). The median ACR1 [161.0 mg/g (IQR 29.0-369.3)] of non-survivors was higher than the median ACR1 [80.4 mg/g (IQR 35.1-167.6)] of survivors but failed to reach statistical significance (P= 0.0948). In a receiver operating characteristic curve (ROC) analysis, ACR2 emerged as the best indicator of mortality [(area under curve (AUC) of ACR2 = 0.71 > AUC (ACR1) =0.58 > AUC (ΔACR) =0.55] similar to the currently used APACHE II scores (AUC = 0.78) (P=0.3). At a cutoff of 101 mg/g, ACR2 had a sensitivity of 69%, specificity of 67%, positive predictive value of 31% and a negative predictive value of 91% for predicting mortality in the critically ill patients. Absence of significant microalbuminuria at 24 hrs of ICU admission may help to predict survival in the ICU.

A study of coupling interactions in finite arbitrarily-shaped grooves in electromagnetic scattering problem

A study of coupling between finite number of general-shaped grooves in electromagnetic plane-wave scattering problem is presented. The formulation for a single groove [1] is extended to two grooves. The importance of inclusion of coupling interaction between two grooves in scattering analysis is presented and its dependence on the grooves separation distance and the angle of incident of the electromagnetic field is demonstrated quantitatively. For larger angle of incident and smaller separation distance between grooves indicate larger discrepancy between between simulation results with and without inclusion of the coupling effects. Although the results presented here considers two grooves, the formulation can be extended to arbitrary number of grooves.