Shreya Singh - Academia.edu (original) (raw)

Papers by Shreya Singh

Indian Journal of Ophthalmology

Indian Journal of Medical Microbiology, 2022

PURPOSE Chronic pulmonary aspergillosis (CPA) is an infection of the lung usually caused by Asper... more PURPOSE Chronic pulmonary aspergillosis (CPA) is an infection of the lung usually caused by Aspergillus fumigatus in patients with pre-existing pulmonary diseases. Its diagnosis hinges on demonstrating IgG antibodies against A. fumigatus. Herein, we evaluated the performance of a newly introduced point of care test (POCT) kit, the LDBio Aspergillus IgG/IgM lateral flow assay (LFA) in India with the standard ImmunoCAP kit for diagnosing CPA. METHODS A total of 60 serum samples (30 CPA cases and 30 controls) were evaluated by the Aspergillus immunochromatographic test (ICT) IgG/IgM LFA. Fluorescent-enzyme immunoassay was used to determine specific A. fumigatus-IgG concentrations (positive >27 mgA/L). Further, a systematic review and meta-analysis of studies (up to August 26, 2021) reporting the performance of LDBio ICT for the diagnosis of CPA was performed. RESULT A sensitivity of 86.7%, specificity of 90%, negative predictive value of 87.1%, positive predictive value of 89.7%, negative likelihood ratio of 0.15, positive likelihood ratio of 8.67, and was observed for the LDBio IC. There was good agreement between LDBio ICT and ImmunoCAP (88.3%) with a Cohen's Kappa score of 0.77. Our systematic review identified four studies and the pooled sensitivity of 90%, specificity of 91%, area under the curve of 0.94 and diagnostic odds ratio of 57.2, for CPA diagnosis by LDBio ICT. CONCLUSION Aspergillus LDBio ICT assay exhibits good sensitivity and can be used to screen CPA cases.

Environmental Science and Pollution Research, 2022

Fast growing arsenic menace is causing serious health hazards in Bihar, India, with an estimated ... more Fast growing arsenic menace is causing serious health hazards in Bihar, India, with an estimated 10 million people at risk. The exposed population is often unaware of the problem, which only amplifies the burden of arsenic health effects. In the present study, we have assessed the current situation of arsenic exposure in Chapar village of Samastipur district, Bihar. The health of the inhabitants was assessed and correlated with (1) arsenic concentrations in the groundwater of individual wells and (2) arsenic concentration found in their hair and urine. Altogether, 113 inhabitants were assessed, and 113 hair, urine and groundwater samples were collected. The health study reveals that the exposure to arsenic has caused serious health hazard amongst the exposed population with pronounced skin manifestations, loss of appetite, anaemia, constipation, diarrhoea, general body weakness, raised blood pressure, breathlessness, diabetes, mental disabilities, diabetes, lumps in the body and few cancer incidences. It was found that 52% of the total collected groundwater samples had arsenic levels higher than the WHO limit of 10 µg/l (with a maximum arsenic concentration of 1212 µg/l) and the reduced arsenite was the predominant form in samples tested for speciation (N = 19). In the case of hair samples, 29% of the samples had arsenic concentrations higher than the permissible limit of 0.2 mg/kg, with a maximum arsenic concentration of 46 µg/l, while in 20% exposed population, there was significant arsenic contamination in urine samples > 50 µg/l. In Chapar village, the probability of carcinogenic-related risk in the exposed population consuming arsenic contaminated water is 100% for children, 99.1% for females and 97.3% for male subjects. The assessment report shared to the government enabled the village population to receive two arsenic filter units. These units are currently operational and catering 250 households providing arsenic-free water through piped water scheme. This study therefore identified a significant solution for this arsenic-exposed population.

Clinical Infection in Practice, 2021

Abstract Objectives The clinical profile, molecular characteristics and antifungal susceptibility... more Abstract Objectives The clinical profile, molecular characteristics and antifungal susceptibility patterns of the Mucoraceous mould, Syncephalastrum spp are poorly characterized. The present study provides a comprehensive overview of these aspects of this rare fungus. Methods We characterized 8 clinical isolates of Syncephalestrum spp by matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF), 28SrDNA sequencing, Amplified Fragment Length Polymorphism (AFLP, n=7) and in-vitro antifungal susceptibility testing. Clinical details of these eight cases were reviewed with all cases of Syncephalestrum infections reported in the literature till August 2020. Results S. racemosum (n= 4) and S. monosporum (n=4) were identified by MALDI-TOF, sequencing and AFLP also clearly differentiated the two. All isolates were uniformly susceptible to amphotericin B and terbinafine. Analysis of clinical details in our eight patients with 43 more cases reported in the literature revealed that most of the reports were (78.4%) from India and cutaneous mucormycosis was the most common (37.3%) presentation followed by rhino-orbito-cerebral (23.5%) and pulmonary(17.6%) infection. Association of trauma with skin infection (p:0.042); immunosuppression/steroid use (p:0.005) and neutropenia (p:0.000) with pulmonary infection was seen. Conclusion S. racemosum, S. monosporum give rise to human infections. The improved database of MALDI-TOF could distinguish the two species. Such rare and emerging infections merit careful consideration and clinical attention.

Indian Journal of Medical Microbiology, 2021

The ubiquitous presence and rampant spread of antibiotic resistant strains of Shigella spp is a m... more The ubiquitous presence and rampant spread of antibiotic resistant strains of Shigella spp is a major public health concern. Therefore, monitoring the trends of antimicrobial resistance in them is essential. A total of 15440 stool samples were inoculated on MacConkey agar, lysine deoxycholate agar and Selenite F enrichment broth from 2001 to 2015.Out of 491 shigellae isolated, 250 isolates were recovered from our culture collection. Antimicrobial susceptibility was performed by Kirby Bauer disc diffusion method, E-test and phenotypic resistance screening for ESBL and AmpC production was performed. For the detection of beta-lactamase genes, PCR for blaTEM, blaSHV, blaOXA, blaCTX-M-15, CMY-2 and mphA PCR in isolates with decreased susceptibility to azithromycin(DSA) was performed. S. flexneri (n = 173) was most common, followed by S.dysenteriae (n = 24), S.sonnei (n = 23), S.boydii (n = 10) and Non agglutinating Shigella (NAG, n = 20). A see-saw pattern in the prevalence of S. flexneri and S. dysenteriae and rising prevalence of S. sonnei and NAG was seen. Majority (77%) of the isolates had MICs >4 mg/L for ciprofloxacin and >50% had high MIC90 (12 mg/L) for ceftriaxone and cefepime (8 mg/L). Nearly 20% of S.flexneri were resistant to third generation cephalosporin by disc diffusion and 33.7% had MIC ≥1 μg/mL. Among the ceftriaxone resistant isolates (n = 29) the blaTEM beta-lactamase resistance gene was seen in all, blaCTX-M-15 in 37%, blaCMY-2 in 45.6% and blaOXA in 52%. The first report of DSA at our institute was in 2001 (n = 1, 2.5%) which increased to 35.1% (n = 40) in 2011-15. The isolates with DSA included S. flexneri (n = 40), S. boydii (n = 4) and S. sonnei (n = 1) and plasmid mediated resistance to azithromycin by mphA gene was detected in 19 out of 40 isolates of S. flexneri. Global emergence of resistance Shigella is a matter of concern and calls for systematic monitoring and periodic updates of countrywide and local antibiogram.

2021 2nd International Conference for Emerging Technology (INCET), 2021

An EHV substation, Transfers power usually from the generator end to transmission level. Voltage ... more An EHV substation, Transfers power usually from the generator end to transmission level. Voltage level is stepped up to the EHV transmission level, which is more economical and efficient considering the losses and length of line. One of the most important components of the substation is a Grounding grid, which provides a ground path for all the devices and equipment. the key concern for a grounding grid is the safety of the personnel as well as of the equipment. As nowadays HV and EHV substations are much widely used due to the bulk power transmission requirements to longer distances, Safety as well as optimum operation of substation gears is to be taken into account on priority. Hence, an optimally designed grounding grid is highly necessary to meet these requirements. This work is to simulate and optimize the structure of Grounding grid for a 400kV AIS substation, respective voltage level chosen as it is most suitable today in power evacuation substations. The software used for the complete design and analysis is ETAP – Electrical transients analyzer program. The key factors effecting the Step and Touch potentials and also the grounding resistance are taken into consideration and analyzed.

Journal of Clinical and Experimental Hepatology, 2021

Background Gastrointestinal candidiasis is often neglected and potentially serious infection in c... more Background Gastrointestinal candidiasis is often neglected and potentially serious infection in cirrhosis patients. Therefore, we evaluated the prevalence, risk factors, and outcomes of esophageal candidiasis (EC) in cirrhotics and did a systematic review to summarize EC's available evidence in cirrhosis. Methods Consecutive patients with cirrhosis posted for esophagogastroduodenoscopy (EGD) at a tertiary care institute were screened for EC (cases) between January 2019 and March 2020. EC was diagnosed on EGD findings and/or brush cytology. Controls (without EC) were recruited randomly, and EC's risk factors and outcomes were compared between cases and controls.Four electronic databases were searched for studies describing EC in cirrhosis. Prevalence estimates of EC were pooled on random-effects meta-analysis, and heterogeneity was assessed by I2. A checklist for prevalence studies was used to evaluate the risk of bias in studies. Results EC was diagnosed in 100 of 2762 patients with cirrhosis (3.6%). Patients with EC had a higher model for end-stage liver disease (MELD) (12.4 vs. 11.2; P = 0.007), acute-on-chronic liver failure (ACLF) (26% vs. 10%; P = 0.003) and concomitant bacterial infections (24% vs. 7%; P = 0.001), as compared with controls. A multivariable model, including recent alcohol binge, hepatocellular carcinoma (HCC), upper gastrointestinal (UGI) bleed, ACLF, diabetes, and MELD, predicted EC's development in cirrhosis with excellent discrimination (C-index: 0.918). Six percent of cases developed the invasive disease and worsened with multiorgan failures, and four patients with EC died on follow-up.Of 236 articles identified, EC's pooled prevalence from 8 studies (all with low-risk of bias) was 2.1% (95% CI: 0.8-5.8). Risk factors and outcomes of EC in cirrhosis were not reported in the literature. Conclusions EC is not a rare infection in cirrhosis patients, and it may predispose to invasive candidiasis and untimely deaths. Alcohol binge, HCC, UGI bleed, ACLF, diabetes, and higher MELD are the independent predictors of EC in cirrhosis. At-risk patients with cirrhosis or those with deglutition symptoms should be rapidly screened and treated for EC.

Advancing Frontiers in Mycology & Mycotechnology, 2019

The term invasive fungal disease (IFD) incorporates severe systemic or deep-seated infections due... more The term invasive fungal disease (IFD) incorporates severe systemic or deep-seated infections due to fungi. A rise in the prevalence of IFD has been observed in recent years, primarily due to the rising numbers of susceptible host population, increasing invasive therapeutic interventions and immunosuppressive treatments. In addition, the expanding spectrum of fungal pathogenicity, rise in infection due to previously obscure fungi, and development of fungal thermal adaptation are also main concerns. Challenge also lies in diagnostics due to the absence of validated, prompt, and accurate diagnostic test for IFD and also differentiating infection from mere colonization. Factors related to antifungal treatment, such as point of initiation, duration of treatment, lack of ideal drug with good pharmacokinetics and pharmacodynamics, drug toxicity, and difficulty in accessing antifungal drugs affect the patient outcome. The rise in antifungal resistance, which stems from incoherent antifungal use in clinical practice and the agriculture industry, is also a matter of concern. Although IFD continues to threaten humans worldwide, our understanding of the factors affecting its changing epidemiology is still not clear. Educating clinicians and laboratory personnel about the complex issues regarding IFD diagnosis and management is essential.

The Genus Aspergillus - Pathogenicity, Mycotoxin Production and Industrial Applications, 2021

Aspergillus species are ubiquitous saprophytes and opportunistic pathogens causing wide spectrum ... more Aspergillus species are ubiquitous saprophytes and opportunistic pathogens causing wide spectrum of diseases in humans depending on the host immune status. Following pathogen entry, various soluble bronchopulmonary factors enhance conidial clearance. However, due to virulence factors and poor host immune response Aspergillus conidia bind and damage the airway epithelium. The host immune cells like neutrophils and macrophages recognise Aspergillus spp. through various pathogen recognition receptors and form reactive oxygen species which mediate conidial killing. Neutrophils also attack extracellular hyphae by oxidative attack, non-oxidative granule proteins and neutrophil extracellular traps. In case of adaptive immunity, Th1 cells are crucial sources of IFN-γ mediated protective immunity. The Th17 also display a highly pro-inflammatory which is counterbalanced by a Treg cell. B cells and antibodies also enhance fungal clearance although excessive IgE production may result in atopy. ...

Indian Journal of Sexually Transmitted Diseases and AIDS, 2020

et al. Partner age difference and sociodemographic correlates of herpes simplex virus type 2 sero... more et al. Partner age difference and sociodemographic correlates of herpes simplex virus type 2 seropositivity: A community-based study in South India. Indian J

PLOS ONE, 2021

Increasing reports of azole resistance inCandida tropicalis, highlight the development of rapid r... more Increasing reports of azole resistance inCandida tropicalis, highlight the development of rapid resistance detection techniques. Nonsynonymous mutations in the lanosterol C14 alpha-demethylase (ERG11) gene is one of the predominant mechanisms of azole resistance inC.tropicalis. We evaluated the tetra primer-amplification refractory mutation system-PCR (T-ARMS-PCR), restriction site mutation (RSM), and high-resolution melt (HRM) analysis methods for rapid resistance detection based onERG11polymorphism inC.tropicalis. Twelve azole-resistant and 19 susceptible isolates ofC.tropicaliswere included. DNA sequencing of the isolates was performed to check theERG11polymorphism status among resistant and susceptible isolates. Three approaches T-ARMS-PCR, RSM, and HRM were evaluated and validated for the rapid detection ofERG11mutation. The fluconazole MICs for the 12 resistant and 19 susceptible isolates were 32–256 mg/L and 0.5–1 mg/L, respectively. The resistant isolates showed A339T and C4...

International Surgery Journal, 2020

Background: Non-stress test (NST) is a graphical recording of changes in fetal heart activity and... more Background: Non-stress test (NST) is a graphical recording of changes in fetal heart activity and uterine contraction along with fetal movement when uterus is quiescent. NST is primarily a test of fetal condition and it differs from contraction stress test which is a test of uteroplacental function. The present study aimed at evaluating the efficacy and diagnostic value of NST for antenatal surveillance in high-risk pregnancy and comparing the mode of delivery with test results.Methods: A clinical study of NST was done between November 2014 to October 2015. NST was used for their surveillance from 32 weeks of gestation and NST was recorded weekly, biweekly, on alternate days or even on daily basis depending on high risk factors and were followed up.Results: A total of 100 cases were enrolled in the study. The mean age of patients was 25.09±3.78 years. In all 14 cases (23.3%) with reactive NST underwent lower caesarean section (LSCS) whereas 36 cases (90%) with non-reactive NST under...

Transactions of The Royal Society of Tropical Medicine and Hygiene, 2020

Background The Tuberculosis (TB) Control Program in India changed the TB diagnostic algorithm and... more Background The Tuberculosis (TB) Control Program in India changed the TB diagnostic algorithm and recommended sputum testing and chest x-ray (CXR) for presumptive TB up front. There is no experience of testing this algorithm in routine field settings. Methods In a public–private partnership (PPP), a private hospital provided mobile digital CXR services (mounted on a van) to complement the existing diagnostic services of sputum microscopy and GeneXpert testing. All presumptive TB patients (cough >2 weeks) underwent CXR and sputum microscopy, and GeneXpert testing if eligible (smear-negative CXR suggestive of TB). Results All 2973 presumptive TB patients underwent CXR and sputum microscopy; 471 (15.8%) had abnormal CXR findings suggestive of TB, 129 (4.3%) were smear positive and 17 were extrapulmonary TB. Of the remaining 325 with smear-negative and CXR suggestive of TB, 147 (45.2%) underwent GeneXpert testing, yielding 32 positives (21.8%). Of the remaining 178 with no GeneXpert ...

Indian Journal of Medical Microbiology, 2019

Introduction: Various stool concentration techniques have been used to increase the microscopic d... more Introduction: Various stool concentration techniques have been used to increase the microscopic detection of parasites. We assessed the enclosed, single-vial, Mini Parasep® technique in comparison to the currently used coprodiagnosis procedures. Materials and Methods: A total of 150 stool samples were collected. Samples concentrated by formol–ether method (FEM) and Mini Parasep® SF foecal concentrator and unconcentrated samples were subjected to wet mount, iodine mount microscopy and smear examination by modified acid-fast staining. Results: Direct wet mount detected 72 positive samples (48.6%), whereas 77 (51.3%) and 80 (53.3%) samples were detected by FEM and Mini Parasep® SF methods, respectively. The sensitivity of detection of parasites was 98.7%, 95% and 90.1% with Mini Parasep®, FEM and direct microscopy, respectively. A clearer background with less foecal debris and a better yield of Hymenolepis nana, Trichuris trichiura, Entamoeba coli and Giardia lamblia were noted with Mini Parasep®. Conclusion: Mini Parasep® SF technique is simple, rapid and less cumbersome than conventional diagnostics, making it suitable for routine use. In addition, it offers higher sensitivity and better background clearance than both direct stool examination and FEM.

Nano Letters, 2019

Atomically thin two-dimensional (2D) materials are promising candidates for sub-10 nm transistor ... more Atomically thin two-dimensional (2D) materials are promising candidates for sub-10 nm transistor channels due to their ultrathin body thickness, which results in strong electrostatic gate control. Properly scaling a transistor technology requires reducing both the channel length (distance from source to drain) and the contact length (distance that source and drain interface with semiconducting channel). Contact length scaling remains an unresolved epidemic for transistor scaling, affecting devices from all semiconductorssilicon to 2D materials. Here, we show that clean edge contacts to 2D MoS 2 provide immunity to the contact-scaling problem, with performance that is independent of contact

SSRN Electronic Journal, 2019

Speech is viewed as a combination of voiced and unvoiced regions. Voiced speech is produced due t... more Speech is viewed as a combination of voiced and unvoiced regions. Voiced speech is produced due to vibration of the vocal cords. The vibrating pattern of vocal cords is different in different emotions. During production of some consonant sound units, vocal cords do not vibrate. Therefore, consonants are less effective for emotion generation in speech signal. In this paper, we have considered only vowel regions for emotion synthesis using three prosody parameters duration, intensity and pitch patterns. Vowel like regions (VLR) is identified using vowel onset and offset points. Onset and offset points are starting and ending points of the vowel like regions. It is observed that during emotional synthesis from neutral speech mainly vowel regions of speech utterance are modified significantly. Our experimental result shows that the emotion synthesis using only prosody modification of VLR is significantly better than emotion synthesis of prosody modification at syllable level and it is also very effective in time consideration. The average mean opinion score is calculated using only vowel level prosody modification. The average mean opinion scores for angry, happy and fear emotional speeches are 3.85, 3.60 and 4.03, respectively. These mean opinion scores are better than syllable level prosody modification which are 3.56, 3.17 and 3.92 for angry, happy and fear emotions, respectively.

Journal of Antimicrobial Chemotherapy, 2019

Background: With the rise of fluconazole resistance in Candida tropicalis in Asian countries, the... more Background: With the rise of fluconazole resistance in Candida tropicalis in Asian countries, the rapid detection of resistance is required to optimize therapy. Objectives: We evaluated a stable isotope labelling by/with amino acids in cell culture (SILAC) approach for rapid detection of fluconazole resistance in C. tropicalis by MALDI-TOF MS. Methods: Twenty-six fluconazole-resistant and 19-susceptible C. tropicalis isolates were used. Isolates were grown in media containing normal lysine (NL), isotopically labelled ('heavy') lysine (HL) and fluconazole (FLC) with labelled lysine (HL ! FLC). MALDI-TOF MS was performed, acquired spectra were visually compared and composite correlation index (CCI) values were calculated. The results were analysed by CCI matrix, virtual gel and principal component analysis (PCA). Results: The MICs of fluconazole in 26 resistant and 19 susceptible isolates were 16-256 mg/L and 0.5-1 mg/L, respectively. The m/z values of 15 peaks specific for media containing NL and their corresponding peaks specific for media with HL were detected to differentiate resistant and susceptible isolates. The CCI cutoff values for susceptible and resistant isolates were significant (P , 0.05). The CCI matrix, virtual gel and PCA dendrogram confirmed the results. The sensitivity, specificity, positive predictive value, negative predictive value and accuracy of this method for detection of fluconazole resistance were 92.31%, 100%, 100%, 90.48% and 95.56%, respectively. Conclusions: SILAC, a promising approach for rapid resistance detection in C. tropicalis using MALDI-TOF MS, may be used in the routine laboratory in the near future.

Mycopathologia, Jan 30, 2018

Aspergillus terreus may colonize the airways of patients with cystic fibrosis (CF). Whether this ... more Aspergillus terreus may colonize the airways of patients with cystic fibrosis (CF). Whether this merits antifungal treatment is still unclear due to heterogeneous reports regarding its pathogenic potential. Although allergic manifestations are documented, invasive aspergillosis (IA) caused by A. terreus has not been described. We present here one case of probable IA caused by A. terreus, highlighting its role as an emerging agent of IA in CF patients. Voriconazole was effective, and the patient was healthy after 12 weeks of treatment. Serial determination of serum galactomannan level and periodic cultures from respiratory specimens may help in monitoring CF patients by identifying such pathogens. Further studies on the fungal species colonizing the CF airways are warranted, especially in India. This case report suggests A. terreus as a potential agent of IA which should not be ignored, particularly in this patient group.

Indian Journal of Dental Sciences, 2017

Aims: The present study was conducted with the aim to explore the authenticity and evidentiary va... more Aims: The present study was conducted with the aim to explore the authenticity and evidentiary value of imprints of the lips for any peculiar pattern regarding specific gender so that it could be used as a reliable tool in the identification of an individual at the crime scene. Materials and Methods: This study comprised 500 (248 females and 252 males) randomly selected dental students with age ranging from 18 to 30 years. Lip prints were recorded with the help of a cellophane tape strip and analyzed according to Suzuki and Tsuchihashi classification. Results: The most predominant pattern in the entire study population was found to be Type I in females and Type III in males with highly significant statistical values. It was also demonstrated that no two lip prints were found to match each other which proves that every individual has unique lip prints. This uniqueness can further help in personal identification. Conclusion: Cheiloscopy or lip print analysis can be used to identify an individual and place him/her at the crime scene. It is an important antemortem tool which may aid in justice to the victim.