Harmanmeet Kaur - Academia.edu (original) (raw)

Papers by Harmanmeet Kaur

Research paper thumbnail of Nano-Drug Delivery for Quinapyramine Sulphate

Research paper thumbnail of In Vitro Cytotoxicity of Multiwalled and Single-walled Carbon Nanotubes on Human Cell Lines

Fullerenes, Nanotubes and Carbon Nanostructures, 2014

Carbon nanotubes are the building blocks for future electronics, materials, health care devices e... more Carbon nanotubes are the building blocks for future electronics, materials, health care devices etc. In order to explore the health care applications of nanotubes in diagnosis and drug delivery, it is important to understand their toxicity. In the present study the in vitro responses were seen when carbon nanotubes were exposed to human cell lines. It typically involves dispersion of multiwall and single walled carbon nanotubes, as well as carbon black and quartz as reference material within the cell culture medium followed by their subsequent addition to human cell lines. MTT 3-(4, 5 dimethylthiazol-2 yl) 2, 5-diphenyl tetrazolium bromide, a tetrazole assay was performed; cell viability was measured by observing their absorbance using ELISA (enzyme-linked immunosorbent assay) reader. Cell viabilities at different concentrations i.e. 50, 10, 5, 3, 1 μg mL−1 were studied. In MTT assay, it was observed that cell viability increases with decrease in concentration of single walled and multiwall carbon nanotubes. We found that both behave almost in the same manner in terms of viability in case of MTT assay. Cellular uptake of FITC (fluorescein isothiocyanate) labeled carbon nanotubes were imaged using confocal microscopy and transmission electron microscope.

Research paper thumbnail of Inter-laboratory testing as a strategy for external quality assessment for qualitative detection of SARS-CoV-2 by real-time RT-PCR testing in India

Indian Journal of Medical Research

To implement the strategy of test, track and treat to tackle the ongoing COVID-19 pandemic, the n... more To implement the strategy of test, track and treat to tackle the ongoing COVID-19 pandemic, the number of real-time RT-PCR-based testing laboratories was increased for diagnosis of SARS-CoV-2 in the country. To ensure reliability of the laboratory results, the Indian Council of Medical Research initiated external quality assessment (EQA) by deploying inter-laboratory quality control (ILQC) activity for these laboratories by nominating 34 quality control (QC) laboratories. This report presents the results of this activity for a period of September 2020 till November 2020. A total of 597 laboratories participated in this activity and 86 per cent of these scored ≥90 per cent concordance with QC laboratories. This ILQC activity showcased India's preparedness in quality diagnosis of SARS-CoV-2.

Research paper thumbnail of Laboratory preparedness for SARS-CoV-2 testing in India: Harnessing a network of Virus Research & Diagnostic Laboratories

Indian Journal of Medical Research

Background & objectives: An outbreak of respiratory illness of unknown aetiology was reported fro... more Background & objectives: An outbreak of respiratory illness of unknown aetiology was reported from Hubei province of Wuhan, People's Republic of China, in December 2019. The outbreak was attributed to a novel coronavirus (CoV), named as severe acute respiratory syndrome (SARS)-CoV-2 and the disease as COVID-19. Within one month, cases were reported from 25 countries. In view of the novel viral strain with reported high morbidity, establishing early countrywide diagnosis to detect imported cases became critical. Here we describe the role of a countrywide network of VRDLs in early diagnosis of COVID-19. Methods: The Indian Council of Medical Research (ICMR)-National Institute of Virology (NIV), Pune, established screening as well as confirmatory assays for SARS-CoV-2. A total of 13 VRDLs were provided with the E gene screening real-time reverse transcription-polymerase chain reaction (rRT-PCR) assay. VRDLs were selected on the basis of their presence near an international airport/seaport

Research paper thumbnail of Expansion of the measles and rubella laboratory network, India

Bulletin of the World Health Organization

Objective To expand the measles and rubella laboratory network of India by integrating new labora... more Objective To expand the measles and rubella laboratory network of India by integrating new laboratories. Methods In collaboration with the World Health Organization (WHO), the Indian government developed a 10-step scheme to systematically expand the number of laboratories performing serological and molecular testing for measles and rubella. The Indian Council of Medical Research and WHO identified suitable laboratories based on their geographical location, willingness, preparedness, past performance and adherence to national quality control and quality assurance mechanisms. The 10-step scheme was initiated with training on measles and rubella diagnostic assays followed by testing of both measles and rubella serology and molecular unknown panels, cross-verification with reference laboratories and ended with WHO on-site accreditation. Findings After extensive training, technical support, funding and monitoring, all six selected laboratories attained passing scores of 90.0% or more in serological and molecular proficiency testing of measles and rubella. Since 2018, the laboratories are a part of the measles and rubella network of India. Within 12 months of initiation of independent reporting, the six laboratories have tested 2287 serum samples and 701 throat or nasopharyngeal swabs or urine samples. Conclusion The process led to strengthening and expansion of the network. This proficient laboratory network has helped India in scaling up serological and molecular testing of measles and rubella while ensuring high quality testing. The collaborative model developed by the Indian government with WHO can be implemented by other countries for expanding laboratory networks for surveillance of measles and rubella as well as other infectious diseases.

Research paper thumbnail of Detection and isolation of SARS‐CoV‐2 Eta variant from the international travelers and local residents of India

Journal of Medical Virology, 2022

International travel has been the major source for rapid spread of new SARS-CoV-2 variants across... more International travel has been the major source for rapid spread of new SARS-CoV-2 variants across the globe. During SARS-CoV-2 genomic surveillance, a total of 212 SARS-CoV-2 positive clinical specimens were sequenced using next generation sequencing. A complete SARS-CoV-2 genome could be retrieved from 90 clinical specimens. Of them, 14 sequences belong to Eta variant from clinical specimens of international travelers (n=12) and local residents (n=2) of India and 76 belonged to other SARS-CoV-2 variants. Of all the Eta positive specimens, the virus isolates were obtained from the clinical specimens of six international travelers. Many of Variants of Interest have been found to cause substantial community transmission or cluster infections. The detection of this variant with lethal E484K mutation across the globe and India necessitates persistent genomic surveillance of the SARS-CoV-2 variants which would aid in taking preventive action. This article is protected by copyright. All rights reserved.

Research paper thumbnail of External quality assessment of COVID-19 real time reverse transcription PCR laboratories in India

PLOS ONE, 2022

Sudden emergence and rapid spread of COVID-19 created an inevitable need for expansion of the COV... more Sudden emergence and rapid spread of COVID-19 created an inevitable need for expansion of the COVID-19 laboratory testing network across the world. The strategy to test-track-treat was advocated for quick detection and containment of the disease. Being the second most populous country in the world, India was challenged to make COVID-19 testing available and accessible in all parts of the country. The molecular laboratory testing network was augmented expeditiously, and number of laboratories was increased from one in January 2020 to 2951 till mid-September, 2021. This rapid expansion warranted the need to have inbuilt systems of quality control/ quality assurance. In addition to the ongoing inter-laboratory quality control (ILQC), India implemented an External Quality Assurance Program (EQAP) with assistance from World Health Organization (WHO) and Royal College of Pathologists, Australasia. Out of the 953 open system rRTPCR laboratories in both public and private sector who partici...

Research paper thumbnail of Isolation and characterization of SARS-CoV-2 Beta variant from UAE travelers

Journal of Infection and Public Health, 2021

Background The emergence of SARS-CoV-2 variants in places where the virus is uncontained poses a ... more Background The emergence of SARS-CoV-2 variants in places where the virus is uncontained poses a global threat from the perspective of public health and vaccine efficacy. Travel has been important factor for the easy spread of SARS-CoV-2 variants worldwide. India has also observed the importation of SARS-CoV-2 variants through international travelers. Methods In this study, we have collected the oropharyngeal and nasopharyngeal swab specimens from 58 individuals with travel history from United Arab Emirates (UAE), East, West and South Africa, Qatar, Ukraine and Saudi Arabia arrived in India during February-March 2021. The clinical specimens were initially screened for SARS-CoV-2 using Real time RT-PCR. All the specimens were inoculated on to Vero CCL-81 cells for virus isolation. The viral isolates were further sequenced using Next-Generation Sequencing. Results All 58 cases were tested positive for SARS-CoV-2 using Real time RT-PCR. Four specimens showed progressive infectivity with fusion of the infected cells with neighboring cells leading to large mass of cells. Replication competent virus was confirmed from culture supernatant of the passage 2 using Real time RT-PCR. Two plaque purified SARS-CoV-2 isolates demonstrated high viral RNA load of 3.8-7.5 × 1011 and 1.1-1.6 × 1011 at passage 4 and 5 respectively. Nucleotide variations along with amino acid changes were also observed among these two isolates at passage 2 to 5. All four cases were male with no symptoms and co-morbidity. The sequence analysis has shown two different clusters, first cluster with nucleotide deletions in the ORF1ab and the spike, while second cluster with deletions in spike region. The viral isolates demonstrated 99.88-99.96% nucleotide identity with the representative sequences of Beta variant (B.1.351). Conclusion These findings suggest easier transmission of SARS-CoV-2 variants with human mobility through international travel. The isolated Beta variant would be useful to determine the protective efficacy of the currently available and upcoming COVID-19 vaccines in India.

Research paper thumbnail of Performance assessment of seven SARS‐CoV‐2 IgG enzyme‐linked immunosorbent assays

Journal of Medical Virology, 2021

The pandemic of COVID-19 has caused enormous fatalities worldwide. Serological assays are importa... more The pandemic of COVID-19 has caused enormous fatalities worldwide. Serological assays are important for detection of asymptomatic or mild cases of COVID-19, and sero-prevalence and vaccine efficacy studies. Here, we evaluated and compared the performance of seven commercially available enzymelinked immunosorbent assay (ELISA)s for detection of anti-severe acute respiratory syndrome corona virus 2 (SARS-CoV-2) immunoglobulin G (IgG). The ELISAs were evaluated with a characterized panel of 100 serum samples from qRT-PCR confirmed COVID-19 patients, collected 14 days post onset disease, 100 SARS-CoV-2 negative samples and compared the results with that of neutralization assay. Results were analysed by creating the receiver operating characteristic curve of all the assays in reference to the neutralization assay. All kits, were found to be suitable for detection of IgG against SARS-CoV-2 with high accuracy. The DiaPro COVID-19 IgG ELISA showed the highest sensitivity (98%) among the kits. The assays demonstrated high sensitivity and specificity in detecting the IgG antibodies against SARS-CoV-2. However, the presence of IgG antibodies does not always correspond to neutralizing antibodies. Due to their good accuracy indices, these assays can also aid in tracing mild infections, in cohort studies and in pre-vaccine evaluations.

Research paper thumbnail of Imported SARS-CoV-2 V501Y.V2 variant (B.1.351) detected in travelers from South Africa and Tanzania to India

Travel Medicine and Infectious Disease, 2021

Research paper thumbnail of Pooled testing for COVID-19 diagnosis by real-time RT-PCR: A multi-site comparative evaluation of 5- & 10-sample pooling

Indian Journal of Medical Research, 2020

Background & objectives: Public health and diagnostic laboratories are facing huge sample loa... more Background & objectives: Public health and diagnostic laboratories are facing huge sample loads for COVID-19 diagnosis by real-time reverse transcription-polymerase chain reaction (RT-PCR). High sensitivity of optimized real-time RT-PCR assays makes pooled testing a potentially efficient strategy for resource utilization when positivity rates for particular regions or groups of individuals are low. We report here a comparative analysis of pooled testing for 5- and 10-sample pools by real-time RT-PCR across 10 COVID-19 testing laboratories in India. Methods: Ten virus research and diagnostic laboratories (VRDLs) testing for COVID-19 by real-time RT-PCR participated in this evaluation. At each laboratory, 100 nasopharyngeal swab samples including 10 positive samples were used to create 5- and 10-sample pools with one positive sample in each pool. RNA extraction and real-time RT-PCR for SARS-CoV-2-specific E gene target were performed for individual positive samples as well as pooled samples. Concordance between individual sample testing and testing in the 5- or 10-sample pools was calculated, and the variation across sites and by sample cycle threshold (Ct) values was analyzed. Results: A total of 110 each of 5- and 10-sample pools were evaluated. Concordance between the 5-sample pool and individual sample testing was 100 per cent in the Ct value ≤30 cycles and 95.5 per cent for Ctvalues ≤33 cycles. Overall concordance between the 5-sample pooled and individual sample testing was 88 per cent while that between 10-sample pool and individual sample testing was 66 per cent. Although the concordance rates for both the 5- and 10-sample pooled testing varied across laboratories, yet for samples with Ct values ≤33 cycles, the concordance was ≥90 per cent across all laboratories for the 5-sample pools. Interpretation & conclusions: Results from this multi-site assessment suggest that pooling five samples for SARS-CoV-2 detection by real-time RT-PCR may be an acceptable strategy without much loss of sensitivity even for low viral loads, while with 10-sample pools, there may be considerably higher numbers of false negatives. However, testing laboratories should perform validations with the specific RNA extraction and RT-PCR kits in use at their centres before initiating pooled testing.

Research paper thumbnail of An Epidemiological Analysis of SARS-CoV-2 Genomic Sequences from Different Regions of India

Viruses, 2021

The number of Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) cases is increasing in... more The number of Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) cases is increasing in India. This study looks upon the geographic distribution of the virus clades and variants circulating in different parts of India between January and August 2020. The NPS/OPS from representative positive cases from different states and union territories in India were collected every month through the VRDLs in the country and analyzed using next-generation sequencing. Epidemiological analysis of the 689 SARS-CoV-2 clinical samples revealed GH and GR to be the predominant clades circulating in different states in India. The northern part of India largely reported the ‘GH’ clade, whereas the southern part reported the ‘GR’, with a few exceptions. These sequences also revealed the presence of single independent mutations—E484Q and N440K—from Maharashtra (first observed in March 2020) and Southern Indian States (first observed in May 2020), respectively. Furthermore, this study indicates tha...

Research paper thumbnail of Clinical characterization and Genomic analysis of COVID-19 breakthrough infections during second wave in different states of India

During March to June 2021 India has experienced a deadly second wave of COVID-19 with an increase... more During March to June 2021 India has experienced a deadly second wave of COVID-19 with an increased number of post-vaccination breakthrough infections reported across the country. To understand the possible reason of these breakthroughs we collected 677 clinical samples (throat swab/ nasal swabs) of individuals who had received two doses (n=592) and one dose (n=85) of vaccines (Covishield and Covaxin,) and tested positive for COVID-19, from 17 states/Union Territories of country. These cases were telephonically interviewed and clinical data was analyzed. A total of 511 SARS-CoV-2 genomes were recovered with genome coverage of higher than 98% from both the cases. Analysis of both the cases determined that 86.69% (n=443) of them belonged to the Delta variant along with Alpha, Kappa, Delta AY.1 and Delta AY.2. The Delta variant clustered into 4 distinct sub-lineages. Sub-lineage–I had mutations: ORF1ab-A1306S, P2046L, P2287S, V2930L, T3255I, T3446A, G5063S, P5401L, A6319V and N-G215C; S...

Research paper thumbnail of Geographical distribution of primary & secondary dengue cases in India – 2017: A cross-sectional multicentric study

Indian Journal of Medical Research, 2019

Background & objectives: Dengue virus infection is endemic in India with all the four serotypes o... more Background & objectives: Dengue virus infection is endemic in India with all the four serotypes of dengue virus in circulation. This study was aimed to determine the geographic distribution of the primary and secondary dengue cases in India. Methods: A multicentre cross-sectional study was conducted at Department of Health Research / Indian Council of Medical Research (DHR)/(ICMR) viral research and diagnostic laboratories (VRDLs) and selected ICMR institutes located in India. Only laboratory-confirmed dengue cases with date of onset # Equal contribution

Research paper thumbnail of Chitosan quinapyramine sulfate nanoparticles exhibit increased trypanocidal activity in mice

Nano-Structures & Nano-Objects, 2018

An aminoquinaldine derivative, quinapyramine sulfate (QS) is the commonly used and effective drug... more An aminoquinaldine derivative, quinapyramine sulfate (QS) is the commonly used and effective drug for treatment of Trypanosoma evansi infection. It produces the trypanocidal effect, but often poorly tolerated causes serious local reactions. The encapsulation of QS in Chitosan/mannitol nanoparticles to provide sustained release and would improve both the therapeutic effect of QS was encapsulated into nanoformulation (ChQS-NPs) prepared from a Chitosan, tripolyphosphate and mannitol nanomatrix. ChQS-NPs showed an initial burst followed by slow release exhibiting quasi-fickian Higuchi diffusion mechanism. Our experiments revealed a dose-dependent safety/cytotoxicity (metabolic activity), in ChQS NPs treated mammalian cells. ChQS NPs were safe at effective trypanocidal doses and even at doses several times higher than the effective dose. ChQS-NPs produced a trypanocidal effect in mice and cleared the parasite at a highly reduced dose (QS 0.85 mg/kg bw) along with the sustained release. The extent of this protection was similar to that observed with the conventional drug with higher dosages (5mg QS/Kg bw). ChQS-NPs are safe, less toxic and effective as compared to the conventional QS and offer a promising alternative for drug-delivery against trypanosomosis in higher animal models.

Research paper thumbnail of Nanoscale Device for Veterinay Technology: Trends And Future Prospective

Advanced Materials Letters, 2013

Nanotechnology is an interdisciplinary science comprising of various disciplines such as physics,... more Nanotechnology is an interdisciplinary science comprising of various disciplines such as physics, chemistry, electronics, material science, health science, biology and veterinary science. The ability to manufacture and manipulate material at nanoscale has offered opportunities to interface biological systems with outer world in new ways and with unprecedented precision. Veterinary science deals with all non human animals including wildlife and domesticated animals, livestock, working animals and companion animals. Nanotechnology has contributed in revolutionizing health and veterinary sciences by providing new tools and new materials for molecular and cellular biology that are beneficial for living organisms. The variety of nanomaterials that are used for diagnosis and treatment include metallic nanoparticle, quantum dots, carbon nanotubes, magnetic nanoparticles, fullerenes, liposomes, dendrimers and engineered hybrid nanoparticles. However, at present, little data is available on the ecotoxicological and toxicological effects associated with these nanomaterials and hence there is a need to address these issues as physiological properties of nanomaterials are expected to influence their biological response. It is believed that in the upcoming years, nanotechnology will reform the science and technology of the animal health and will help to boost up the livestock production. Nanotechnology based techniques like bioanalytical nanosensors, nanofluidics, targeted drug delivery etc has the potential to solve problems related to diagnosis and treatment of diseases. In this review, we emphasize on how nanotechnology is swiftly changing the diagnosis and treatment patterns at faster and low cost in less time duration. There can be numerous applications of nanotechnology in disease diagnosis, treatment, drug delivery, animal nutrition, animal breeding, tissue engineering and animal identity verification. The role of nanotechnology in veterinary sciences is chiefly discussed as how nanomaterials can modernize the present life.

Research paper thumbnail of Preparation and Evaluation of Enrofloxacin-Loaded Solid Lipid Nanoparticles

Journal of Nanoengineering and Nanomanufacturing, 2013

ABSTRACT Solid lipid nanoparticles (SLNs) have been proposed as an alternative drug carrier syste... more ABSTRACT Solid lipid nanoparticles (SLNs) have been proposed as an alternative drug carrier system due to their improved physical stability, low cost, ease of scale up and manufacturing compared to other novel delivery approaches. Enrofloxacin, as a model drug was encapsulated into solid lipid nanoparticles prepared by solvent diffusion method employing oleic acid as a lipid carrier. Synthesized SLNs were evaluated for its particle size and encapsulation efficiency. A central composite design was employed to study the effect of independent variables (concentration of oleic acid and Tween 20) on the dependent variables (particle size and encapsulation efficiency). The optimized SLNs formulation (0.12% w/v of oleic acid and 0.30% w/v of Tween 20) was characterized for chemical interaction, morphology and particle size by FTIR, FE-SEM, and Particle Size Analyzer (PSA) respectively. The enrofloxacin-loaded SLNs showed enhanced antibacterial activity against Gram-negative and Gram-positive bacteria than aqueous solutions of enrofloxacin. Cytotoxicity analysis of enrofloxacin-loaded SLNs revealed lower toxicity (5.32%) compared to enrofloxacin (11.7%) against Vero cell lines using resazurin assay. The Zeta potential of SLNs subjected to stability studies at 4 °C, 25 °C and 40 °C indicated maximum stability at 40 °C with -21.5 mV zeta potential. These results suggest that SLNs might be a promising delivery system to enhance pharmacological activity of enrofloxacin.

Research paper thumbnail of Molecular characterization of influenza A(H1N1)pdm09 virus circulating during the 2009 outbreak in Thua Thien Hue, Vietnam

The Journal of Infection in Developing Countries, 2013

Introduction: The influenza A(H1N1)pdm09 virus arrived in Vietnam in May 2009 via the United Stat... more Introduction: The influenza A(H1N1)pdm09 virus arrived in Vietnam in May 2009 via the United States and rapidly spread throughout the country. This study provides data on the viral diagnosis and molecular epidemiology of influenza A(H1N1)pdm09 virus isolated in Thua Thien Hue Province, central Vietnam. Methodology: Nasopharyngeal swabs and throat swabs from 53 clinically infected patients in the peak of the outbreak were processed for viral diagnosis by culture and RT-PCR. Sequencing of entire HA and NA genes of representative isolates and molecular epidemiological analysis were performed. Results: A total of 32 patients were positive for influenza A virus by virus culture and/or RT-PCR; of these 22 were positive both by viral isolation and RT-PCR, 2 only by virus culture and 8 only by RT-PCR. The novel subtype of influenza A(H1N1)pdm09 was present in 93.4% of the isolates. Phylogenetic analysis of the HA and NA gene sequences showed identities higher than 99.50% in both genes. They...

Research paper thumbnail of Quinapyramine sulfate-loaded sodium alginate nanoparticles show enhanced trypanocidal activity

Nanomedicine, 2014

Aim: To reduce the dose, toxic effects and to ensure sustained release of quinapyramine sulfate (... more Aim: To reduce the dose, toxic effects and to ensure sustained release of quinapyramine sulfate (QS), a highly effective drug against Trypanosoma evansi. Materials & methods: QS-loaded sodium alginate nanoparticles (QS-NPs) were formed by emulsion-crosslinking technology using dioctyl-sodium-sulfosuccinate and sodium alginate. The formulation was characterized for size, stability, morphology and functional groups by a zetasizer, scanning electron microscopy, atomic force microscopy, transmission electron microscopy and Fourier transform infrared spectroscopy. In vitro safety and toxicity studies were performed by metabolic assay in Vero cell lines, and in vivo efficacy was evaluated in mice. Results: QS-NPs were <60 nm with 96.48% entrapment efficiency and 3.70% drug loading. The formulation showed an initial burst effect followed by slow drug release in accordance with quasi-Fickian Higuchi diffusion mechanism. QS-NPs were much less toxic and able to clear the parasite at a much...

Research paper thumbnail of Carboxymethyl tamarind kernel polysaccharide nanoparticles for ophthalmic drug delivery

International Journal of Biological Macromolecules, 2012

Tropicamide-loaded carboxymethyl tamarind kernel polysaccharide (CMTKP) nanoparticles were prepar... more Tropicamide-loaded carboxymethyl tamarind kernel polysaccharide (CMTKP) nanoparticles were prepared and evaluated for ocular delivery. Preparation of ionotropically gelled CMTKP nanoparticles was optimized employing three-levels, two-factor central composite design. Concentration of polymer and crosslinker had significant synergistic effect on particle size and % encapsulation efficiency. The optimal calculated parameters were concentrations of CMTKP 0.10% (w/v) and calcium chloride 0.11% (w/v). The optimized tropicamide-loaded CMTKP formulation showed ex vivo corneal permeation of tropicamide across isolated goat cornea comparable to its aqueous solution. Further, the mucoadhesive and non-irritant nature of CMTKP nanoparticles indicate their suitability as ocular delivery system.

Research paper thumbnail of Nano-Drug Delivery for Quinapyramine Sulphate

Research paper thumbnail of In Vitro Cytotoxicity of Multiwalled and Single-walled Carbon Nanotubes on Human Cell Lines

Fullerenes, Nanotubes and Carbon Nanostructures, 2014

Carbon nanotubes are the building blocks for future electronics, materials, health care devices e... more Carbon nanotubes are the building blocks for future electronics, materials, health care devices etc. In order to explore the health care applications of nanotubes in diagnosis and drug delivery, it is important to understand their toxicity. In the present study the in vitro responses were seen when carbon nanotubes were exposed to human cell lines. It typically involves dispersion of multiwall and single walled carbon nanotubes, as well as carbon black and quartz as reference material within the cell culture medium followed by their subsequent addition to human cell lines. MTT 3-(4, 5 dimethylthiazol-2 yl) 2, 5-diphenyl tetrazolium bromide, a tetrazole assay was performed; cell viability was measured by observing their absorbance using ELISA (enzyme-linked immunosorbent assay) reader. Cell viabilities at different concentrations i.e. 50, 10, 5, 3, 1 μg mL−1 were studied. In MTT assay, it was observed that cell viability increases with decrease in concentration of single walled and multiwall carbon nanotubes. We found that both behave almost in the same manner in terms of viability in case of MTT assay. Cellular uptake of FITC (fluorescein isothiocyanate) labeled carbon nanotubes were imaged using confocal microscopy and transmission electron microscope.

Research paper thumbnail of Inter-laboratory testing as a strategy for external quality assessment for qualitative detection of SARS-CoV-2 by real-time RT-PCR testing in India

Indian Journal of Medical Research

To implement the strategy of test, track and treat to tackle the ongoing COVID-19 pandemic, the n... more To implement the strategy of test, track and treat to tackle the ongoing COVID-19 pandemic, the number of real-time RT-PCR-based testing laboratories was increased for diagnosis of SARS-CoV-2 in the country. To ensure reliability of the laboratory results, the Indian Council of Medical Research initiated external quality assessment (EQA) by deploying inter-laboratory quality control (ILQC) activity for these laboratories by nominating 34 quality control (QC) laboratories. This report presents the results of this activity for a period of September 2020 till November 2020. A total of 597 laboratories participated in this activity and 86 per cent of these scored ≥90 per cent concordance with QC laboratories. This ILQC activity showcased India's preparedness in quality diagnosis of SARS-CoV-2.

Research paper thumbnail of Laboratory preparedness for SARS-CoV-2 testing in India: Harnessing a network of Virus Research & Diagnostic Laboratories

Indian Journal of Medical Research

Background & objectives: An outbreak of respiratory illness of unknown aetiology was reported fro... more Background & objectives: An outbreak of respiratory illness of unknown aetiology was reported from Hubei province of Wuhan, People's Republic of China, in December 2019. The outbreak was attributed to a novel coronavirus (CoV), named as severe acute respiratory syndrome (SARS)-CoV-2 and the disease as COVID-19. Within one month, cases were reported from 25 countries. In view of the novel viral strain with reported high morbidity, establishing early countrywide diagnosis to detect imported cases became critical. Here we describe the role of a countrywide network of VRDLs in early diagnosis of COVID-19. Methods: The Indian Council of Medical Research (ICMR)-National Institute of Virology (NIV), Pune, established screening as well as confirmatory assays for SARS-CoV-2. A total of 13 VRDLs were provided with the E gene screening real-time reverse transcription-polymerase chain reaction (rRT-PCR) assay. VRDLs were selected on the basis of their presence near an international airport/seaport

Research paper thumbnail of Expansion of the measles and rubella laboratory network, India

Bulletin of the World Health Organization

Objective To expand the measles and rubella laboratory network of India by integrating new labora... more Objective To expand the measles and rubella laboratory network of India by integrating new laboratories. Methods In collaboration with the World Health Organization (WHO), the Indian government developed a 10-step scheme to systematically expand the number of laboratories performing serological and molecular testing for measles and rubella. The Indian Council of Medical Research and WHO identified suitable laboratories based on their geographical location, willingness, preparedness, past performance and adherence to national quality control and quality assurance mechanisms. The 10-step scheme was initiated with training on measles and rubella diagnostic assays followed by testing of both measles and rubella serology and molecular unknown panels, cross-verification with reference laboratories and ended with WHO on-site accreditation. Findings After extensive training, technical support, funding and monitoring, all six selected laboratories attained passing scores of 90.0% or more in serological and molecular proficiency testing of measles and rubella. Since 2018, the laboratories are a part of the measles and rubella network of India. Within 12 months of initiation of independent reporting, the six laboratories have tested 2287 serum samples and 701 throat or nasopharyngeal swabs or urine samples. Conclusion The process led to strengthening and expansion of the network. This proficient laboratory network has helped India in scaling up serological and molecular testing of measles and rubella while ensuring high quality testing. The collaborative model developed by the Indian government with WHO can be implemented by other countries for expanding laboratory networks for surveillance of measles and rubella as well as other infectious diseases.

Research paper thumbnail of Detection and isolation of SARS‐CoV‐2 Eta variant from the international travelers and local residents of India

Journal of Medical Virology, 2022

International travel has been the major source for rapid spread of new SARS-CoV-2 variants across... more International travel has been the major source for rapid spread of new SARS-CoV-2 variants across the globe. During SARS-CoV-2 genomic surveillance, a total of 212 SARS-CoV-2 positive clinical specimens were sequenced using next generation sequencing. A complete SARS-CoV-2 genome could be retrieved from 90 clinical specimens. Of them, 14 sequences belong to Eta variant from clinical specimens of international travelers (n=12) and local residents (n=2) of India and 76 belonged to other SARS-CoV-2 variants. Of all the Eta positive specimens, the virus isolates were obtained from the clinical specimens of six international travelers. Many of Variants of Interest have been found to cause substantial community transmission or cluster infections. The detection of this variant with lethal E484K mutation across the globe and India necessitates persistent genomic surveillance of the SARS-CoV-2 variants which would aid in taking preventive action. This article is protected by copyright. All rights reserved.

Research paper thumbnail of External quality assessment of COVID-19 real time reverse transcription PCR laboratories in India

PLOS ONE, 2022

Sudden emergence and rapid spread of COVID-19 created an inevitable need for expansion of the COV... more Sudden emergence and rapid spread of COVID-19 created an inevitable need for expansion of the COVID-19 laboratory testing network across the world. The strategy to test-track-treat was advocated for quick detection and containment of the disease. Being the second most populous country in the world, India was challenged to make COVID-19 testing available and accessible in all parts of the country. The molecular laboratory testing network was augmented expeditiously, and number of laboratories was increased from one in January 2020 to 2951 till mid-September, 2021. This rapid expansion warranted the need to have inbuilt systems of quality control/ quality assurance. In addition to the ongoing inter-laboratory quality control (ILQC), India implemented an External Quality Assurance Program (EQAP) with assistance from World Health Organization (WHO) and Royal College of Pathologists, Australasia. Out of the 953 open system rRTPCR laboratories in both public and private sector who partici...

Research paper thumbnail of Isolation and characterization of SARS-CoV-2 Beta variant from UAE travelers

Journal of Infection and Public Health, 2021

Background The emergence of SARS-CoV-2 variants in places where the virus is uncontained poses a ... more Background The emergence of SARS-CoV-2 variants in places where the virus is uncontained poses a global threat from the perspective of public health and vaccine efficacy. Travel has been important factor for the easy spread of SARS-CoV-2 variants worldwide. India has also observed the importation of SARS-CoV-2 variants through international travelers. Methods In this study, we have collected the oropharyngeal and nasopharyngeal swab specimens from 58 individuals with travel history from United Arab Emirates (UAE), East, West and South Africa, Qatar, Ukraine and Saudi Arabia arrived in India during February-March 2021. The clinical specimens were initially screened for SARS-CoV-2 using Real time RT-PCR. All the specimens were inoculated on to Vero CCL-81 cells for virus isolation. The viral isolates were further sequenced using Next-Generation Sequencing. Results All 58 cases were tested positive for SARS-CoV-2 using Real time RT-PCR. Four specimens showed progressive infectivity with fusion of the infected cells with neighboring cells leading to large mass of cells. Replication competent virus was confirmed from culture supernatant of the passage 2 using Real time RT-PCR. Two plaque purified SARS-CoV-2 isolates demonstrated high viral RNA load of 3.8-7.5 × 1011 and 1.1-1.6 × 1011 at passage 4 and 5 respectively. Nucleotide variations along with amino acid changes were also observed among these two isolates at passage 2 to 5. All four cases were male with no symptoms and co-morbidity. The sequence analysis has shown two different clusters, first cluster with nucleotide deletions in the ORF1ab and the spike, while second cluster with deletions in spike region. The viral isolates demonstrated 99.88-99.96% nucleotide identity with the representative sequences of Beta variant (B.1.351). Conclusion These findings suggest easier transmission of SARS-CoV-2 variants with human mobility through international travel. The isolated Beta variant would be useful to determine the protective efficacy of the currently available and upcoming COVID-19 vaccines in India.

Research paper thumbnail of Performance assessment of seven SARS‐CoV‐2 IgG enzyme‐linked immunosorbent assays

Journal of Medical Virology, 2021

The pandemic of COVID-19 has caused enormous fatalities worldwide. Serological assays are importa... more The pandemic of COVID-19 has caused enormous fatalities worldwide. Serological assays are important for detection of asymptomatic or mild cases of COVID-19, and sero-prevalence and vaccine efficacy studies. Here, we evaluated and compared the performance of seven commercially available enzymelinked immunosorbent assay (ELISA)s for detection of anti-severe acute respiratory syndrome corona virus 2 (SARS-CoV-2) immunoglobulin G (IgG). The ELISAs were evaluated with a characterized panel of 100 serum samples from qRT-PCR confirmed COVID-19 patients, collected 14 days post onset disease, 100 SARS-CoV-2 negative samples and compared the results with that of neutralization assay. Results were analysed by creating the receiver operating characteristic curve of all the assays in reference to the neutralization assay. All kits, were found to be suitable for detection of IgG against SARS-CoV-2 with high accuracy. The DiaPro COVID-19 IgG ELISA showed the highest sensitivity (98%) among the kits. The assays demonstrated high sensitivity and specificity in detecting the IgG antibodies against SARS-CoV-2. However, the presence of IgG antibodies does not always correspond to neutralizing antibodies. Due to their good accuracy indices, these assays can also aid in tracing mild infections, in cohort studies and in pre-vaccine evaluations.

Research paper thumbnail of Imported SARS-CoV-2 V501Y.V2 variant (B.1.351) detected in travelers from South Africa and Tanzania to India

Travel Medicine and Infectious Disease, 2021

Research paper thumbnail of Pooled testing for COVID-19 diagnosis by real-time RT-PCR: A multi-site comparative evaluation of 5- & 10-sample pooling

Indian Journal of Medical Research, 2020

Background & objectives: Public health and diagnostic laboratories are facing huge sample loa... more Background & objectives: Public health and diagnostic laboratories are facing huge sample loads for COVID-19 diagnosis by real-time reverse transcription-polymerase chain reaction (RT-PCR). High sensitivity of optimized real-time RT-PCR assays makes pooled testing a potentially efficient strategy for resource utilization when positivity rates for particular regions or groups of individuals are low. We report here a comparative analysis of pooled testing for 5- and 10-sample pools by real-time RT-PCR across 10 COVID-19 testing laboratories in India. Methods: Ten virus research and diagnostic laboratories (VRDLs) testing for COVID-19 by real-time RT-PCR participated in this evaluation. At each laboratory, 100 nasopharyngeal swab samples including 10 positive samples were used to create 5- and 10-sample pools with one positive sample in each pool. RNA extraction and real-time RT-PCR for SARS-CoV-2-specific E gene target were performed for individual positive samples as well as pooled samples. Concordance between individual sample testing and testing in the 5- or 10-sample pools was calculated, and the variation across sites and by sample cycle threshold (Ct) values was analyzed. Results: A total of 110 each of 5- and 10-sample pools were evaluated. Concordance between the 5-sample pool and individual sample testing was 100 per cent in the Ct value ≤30 cycles and 95.5 per cent for Ctvalues ≤33 cycles. Overall concordance between the 5-sample pooled and individual sample testing was 88 per cent while that between 10-sample pool and individual sample testing was 66 per cent. Although the concordance rates for both the 5- and 10-sample pooled testing varied across laboratories, yet for samples with Ct values ≤33 cycles, the concordance was ≥90 per cent across all laboratories for the 5-sample pools. Interpretation & conclusions: Results from this multi-site assessment suggest that pooling five samples for SARS-CoV-2 detection by real-time RT-PCR may be an acceptable strategy without much loss of sensitivity even for low viral loads, while with 10-sample pools, there may be considerably higher numbers of false negatives. However, testing laboratories should perform validations with the specific RNA extraction and RT-PCR kits in use at their centres before initiating pooled testing.

Research paper thumbnail of An Epidemiological Analysis of SARS-CoV-2 Genomic Sequences from Different Regions of India

Viruses, 2021

The number of Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) cases is increasing in... more The number of Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) cases is increasing in India. This study looks upon the geographic distribution of the virus clades and variants circulating in different parts of India between January and August 2020. The NPS/OPS from representative positive cases from different states and union territories in India were collected every month through the VRDLs in the country and analyzed using next-generation sequencing. Epidemiological analysis of the 689 SARS-CoV-2 clinical samples revealed GH and GR to be the predominant clades circulating in different states in India. The northern part of India largely reported the ‘GH’ clade, whereas the southern part reported the ‘GR’, with a few exceptions. These sequences also revealed the presence of single independent mutations—E484Q and N440K—from Maharashtra (first observed in March 2020) and Southern Indian States (first observed in May 2020), respectively. Furthermore, this study indicates tha...

Research paper thumbnail of Clinical characterization and Genomic analysis of COVID-19 breakthrough infections during second wave in different states of India

During March to June 2021 India has experienced a deadly second wave of COVID-19 with an increase... more During March to June 2021 India has experienced a deadly second wave of COVID-19 with an increased number of post-vaccination breakthrough infections reported across the country. To understand the possible reason of these breakthroughs we collected 677 clinical samples (throat swab/ nasal swabs) of individuals who had received two doses (n=592) and one dose (n=85) of vaccines (Covishield and Covaxin,) and tested positive for COVID-19, from 17 states/Union Territories of country. These cases were telephonically interviewed and clinical data was analyzed. A total of 511 SARS-CoV-2 genomes were recovered with genome coverage of higher than 98% from both the cases. Analysis of both the cases determined that 86.69% (n=443) of them belonged to the Delta variant along with Alpha, Kappa, Delta AY.1 and Delta AY.2. The Delta variant clustered into 4 distinct sub-lineages. Sub-lineage–I had mutations: ORF1ab-A1306S, P2046L, P2287S, V2930L, T3255I, T3446A, G5063S, P5401L, A6319V and N-G215C; S...

Research paper thumbnail of Geographical distribution of primary & secondary dengue cases in India – 2017: A cross-sectional multicentric study

Indian Journal of Medical Research, 2019

Background & objectives: Dengue virus infection is endemic in India with all the four serotypes o... more Background & objectives: Dengue virus infection is endemic in India with all the four serotypes of dengue virus in circulation. This study was aimed to determine the geographic distribution of the primary and secondary dengue cases in India. Methods: A multicentre cross-sectional study was conducted at Department of Health Research / Indian Council of Medical Research (DHR)/(ICMR) viral research and diagnostic laboratories (VRDLs) and selected ICMR institutes located in India. Only laboratory-confirmed dengue cases with date of onset # Equal contribution

Research paper thumbnail of Chitosan quinapyramine sulfate nanoparticles exhibit increased trypanocidal activity in mice

Nano-Structures & Nano-Objects, 2018

An aminoquinaldine derivative, quinapyramine sulfate (QS) is the commonly used and effective drug... more An aminoquinaldine derivative, quinapyramine sulfate (QS) is the commonly used and effective drug for treatment of Trypanosoma evansi infection. It produces the trypanocidal effect, but often poorly tolerated causes serious local reactions. The encapsulation of QS in Chitosan/mannitol nanoparticles to provide sustained release and would improve both the therapeutic effect of QS was encapsulated into nanoformulation (ChQS-NPs) prepared from a Chitosan, tripolyphosphate and mannitol nanomatrix. ChQS-NPs showed an initial burst followed by slow release exhibiting quasi-fickian Higuchi diffusion mechanism. Our experiments revealed a dose-dependent safety/cytotoxicity (metabolic activity), in ChQS NPs treated mammalian cells. ChQS NPs were safe at effective trypanocidal doses and even at doses several times higher than the effective dose. ChQS-NPs produced a trypanocidal effect in mice and cleared the parasite at a highly reduced dose (QS 0.85 mg/kg bw) along with the sustained release. The extent of this protection was similar to that observed with the conventional drug with higher dosages (5mg QS/Kg bw). ChQS-NPs are safe, less toxic and effective as compared to the conventional QS and offer a promising alternative for drug-delivery against trypanosomosis in higher animal models.

Research paper thumbnail of Nanoscale Device for Veterinay Technology: Trends And Future Prospective

Advanced Materials Letters, 2013

Nanotechnology is an interdisciplinary science comprising of various disciplines such as physics,... more Nanotechnology is an interdisciplinary science comprising of various disciplines such as physics, chemistry, electronics, material science, health science, biology and veterinary science. The ability to manufacture and manipulate material at nanoscale has offered opportunities to interface biological systems with outer world in new ways and with unprecedented precision. Veterinary science deals with all non human animals including wildlife and domesticated animals, livestock, working animals and companion animals. Nanotechnology has contributed in revolutionizing health and veterinary sciences by providing new tools and new materials for molecular and cellular biology that are beneficial for living organisms. The variety of nanomaterials that are used for diagnosis and treatment include metallic nanoparticle, quantum dots, carbon nanotubes, magnetic nanoparticles, fullerenes, liposomes, dendrimers and engineered hybrid nanoparticles. However, at present, little data is available on the ecotoxicological and toxicological effects associated with these nanomaterials and hence there is a need to address these issues as physiological properties of nanomaterials are expected to influence their biological response. It is believed that in the upcoming years, nanotechnology will reform the science and technology of the animal health and will help to boost up the livestock production. Nanotechnology based techniques like bioanalytical nanosensors, nanofluidics, targeted drug delivery etc has the potential to solve problems related to diagnosis and treatment of diseases. In this review, we emphasize on how nanotechnology is swiftly changing the diagnosis and treatment patterns at faster and low cost in less time duration. There can be numerous applications of nanotechnology in disease diagnosis, treatment, drug delivery, animal nutrition, animal breeding, tissue engineering and animal identity verification. The role of nanotechnology in veterinary sciences is chiefly discussed as how nanomaterials can modernize the present life.

Research paper thumbnail of Preparation and Evaluation of Enrofloxacin-Loaded Solid Lipid Nanoparticles

Journal of Nanoengineering and Nanomanufacturing, 2013

ABSTRACT Solid lipid nanoparticles (SLNs) have been proposed as an alternative drug carrier syste... more ABSTRACT Solid lipid nanoparticles (SLNs) have been proposed as an alternative drug carrier system due to their improved physical stability, low cost, ease of scale up and manufacturing compared to other novel delivery approaches. Enrofloxacin, as a model drug was encapsulated into solid lipid nanoparticles prepared by solvent diffusion method employing oleic acid as a lipid carrier. Synthesized SLNs were evaluated for its particle size and encapsulation efficiency. A central composite design was employed to study the effect of independent variables (concentration of oleic acid and Tween 20) on the dependent variables (particle size and encapsulation efficiency). The optimized SLNs formulation (0.12% w/v of oleic acid and 0.30% w/v of Tween 20) was characterized for chemical interaction, morphology and particle size by FTIR, FE-SEM, and Particle Size Analyzer (PSA) respectively. The enrofloxacin-loaded SLNs showed enhanced antibacterial activity against Gram-negative and Gram-positive bacteria than aqueous solutions of enrofloxacin. Cytotoxicity analysis of enrofloxacin-loaded SLNs revealed lower toxicity (5.32%) compared to enrofloxacin (11.7%) against Vero cell lines using resazurin assay. The Zeta potential of SLNs subjected to stability studies at 4 °C, 25 °C and 40 °C indicated maximum stability at 40 °C with -21.5 mV zeta potential. These results suggest that SLNs might be a promising delivery system to enhance pharmacological activity of enrofloxacin.

Research paper thumbnail of Molecular characterization of influenza A(H1N1)pdm09 virus circulating during the 2009 outbreak in Thua Thien Hue, Vietnam

The Journal of Infection in Developing Countries, 2013

Introduction: The influenza A(H1N1)pdm09 virus arrived in Vietnam in May 2009 via the United Stat... more Introduction: The influenza A(H1N1)pdm09 virus arrived in Vietnam in May 2009 via the United States and rapidly spread throughout the country. This study provides data on the viral diagnosis and molecular epidemiology of influenza A(H1N1)pdm09 virus isolated in Thua Thien Hue Province, central Vietnam. Methodology: Nasopharyngeal swabs and throat swabs from 53 clinically infected patients in the peak of the outbreak were processed for viral diagnosis by culture and RT-PCR. Sequencing of entire HA and NA genes of representative isolates and molecular epidemiological analysis were performed. Results: A total of 32 patients were positive for influenza A virus by virus culture and/or RT-PCR; of these 22 were positive both by viral isolation and RT-PCR, 2 only by virus culture and 8 only by RT-PCR. The novel subtype of influenza A(H1N1)pdm09 was present in 93.4% of the isolates. Phylogenetic analysis of the HA and NA gene sequences showed identities higher than 99.50% in both genes. They...

Research paper thumbnail of Quinapyramine sulfate-loaded sodium alginate nanoparticles show enhanced trypanocidal activity

Nanomedicine, 2014

Aim: To reduce the dose, toxic effects and to ensure sustained release of quinapyramine sulfate (... more Aim: To reduce the dose, toxic effects and to ensure sustained release of quinapyramine sulfate (QS), a highly effective drug against Trypanosoma evansi. Materials & methods: QS-loaded sodium alginate nanoparticles (QS-NPs) were formed by emulsion-crosslinking technology using dioctyl-sodium-sulfosuccinate and sodium alginate. The formulation was characterized for size, stability, morphology and functional groups by a zetasizer, scanning electron microscopy, atomic force microscopy, transmission electron microscopy and Fourier transform infrared spectroscopy. In vitro safety and toxicity studies were performed by metabolic assay in Vero cell lines, and in vivo efficacy was evaluated in mice. Results: QS-NPs were <60 nm with 96.48% entrapment efficiency and 3.70% drug loading. The formulation showed an initial burst effect followed by slow drug release in accordance with quasi-Fickian Higuchi diffusion mechanism. QS-NPs were much less toxic and able to clear the parasite at a much...

Research paper thumbnail of Carboxymethyl tamarind kernel polysaccharide nanoparticles for ophthalmic drug delivery

International Journal of Biological Macromolecules, 2012

Tropicamide-loaded carboxymethyl tamarind kernel polysaccharide (CMTKP) nanoparticles were prepar... more Tropicamide-loaded carboxymethyl tamarind kernel polysaccharide (CMTKP) nanoparticles were prepared and evaluated for ocular delivery. Preparation of ionotropically gelled CMTKP nanoparticles was optimized employing three-levels, two-factor central composite design. Concentration of polymer and crosslinker had significant synergistic effect on particle size and % encapsulation efficiency. The optimal calculated parameters were concentrations of CMTKP 0.10% (w/v) and calcium chloride 0.11% (w/v). The optimized tropicamide-loaded CMTKP formulation showed ex vivo corneal permeation of tropicamide across isolated goat cornea comparable to its aqueous solution. Further, the mucoadhesive and non-irritant nature of CMTKP nanoparticles indicate their suitability as ocular delivery system.