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A state-wide prospective longitudinal investigation of the genomic surveillance of the omicron B.1.1.529 SARS-CoV-2 variant and its sublineages in Tamil Nadu, India, was conducted between December 2021 and March 2023. The study aimed to elucidate their mutational patterns and their genetic interrelationship in the Indian population. The study identified several unique mutations at different time-points, which likely could attribute to the changing disease characteristics, transmission, and pathogenicity attributes of omicron variants. The study found that the omicron variant is highly competent in its mutating potentials, and that it continues to evolve in the general population, likely escaping from natural as well as vaccine-induced immune responses. Our findings suggest that continuous surveillance of viral variants at the global scenario is warranted to undertake intervention measures against potentially precarious SARS-CoV-2 variants and their evolution.
Subject(s)
COVID-19 , SARS-CoV-2 , Humans , SARS-CoV-2/genetics , India/epidemiology , Longitudinal Studies , Prospective Studies , COVID-19/epidemiology , GenomicsABSTRACT
OBJECTIVE: The study focuses on time-dependent comparative evaluation of various biomarkers of acute cyanide poisoning in rats. METHODS: Blood gas (analyzer), lactate, pyruvate, cyanide, thiocyanate (spectrophotometer) and 2-amino-2-thiazoline-4-carboxylic acid (ATCA; gas chromatography-mass spectrometry) in plasma or urine, and various physiological parameters (polygraph) were measured. RESULTS: Cyanide poisoning was characterized by elevated lactate, cyanide, thiocyanate and ATCA concentrations in plasma up to 15 min, 4, 16 and 24 h, respectively, while high urinary thiocyanate and ATCA levels were measured between 4 and 24 h. CONCLUSION: ATCA concentration in plasma and urine was found to be more reliable indicator of cyanide poisoning.
Subject(s)
Biomarkers/metabolism , Cyanides/poisoning , Poisoning/diagnosis , Animals , Male , Poisoning/metabolism , Rats , Rats, WistarABSTRACT
CONTEXT: Due to several limitations of existing cyanide antidotes, α-ketoglutarate (α-KG) has been proposed as a promising treatment for cyanide. OBJECTIVE: This study reports the accelerated stability and bioassay of a new oral α-KG formulation. MATERIALS AND METHODS: Amber-colored PVDF bottles containing 100 ml of 10% α-KG in 70% sorbitol, preservative (sodium methyl paraben and sodium propyl paraben), sweetener (sodium saccharine), flavor (American ice-cream soda and peppermint) and color (tartrazine), at pH 7.0-8.0 were stored in stability chamber (40 ± 2 °C and 75 ± 5% humidity) for 6 months in a GMP compliant facility. Various physical (pH, color, evaporation, extractable volume and clarity), chemical (identification and quantification of active ingredient) and microbiological (total aerobic count) analyses, together with protection studies were carried periodically in mice. Acute toxicity of the formulation and bioavailability of α-KG were assessed in rats at the beginning of the experiment. RESULTS: No physical changes and microbiological growth were observed in the formulation. After 6 months, α-KG content in the formulation diminished by â¼24% but its protective efficacy against cyanide remained at 5.9-fold. Protection was further characterized spectrophotometrically by disappearance of α-KG spectrum in the presence of cyanide, confirming cyanohydrin formation. Oral LD50 of α-KG formulation in rats was >7.0 g/kg body weight, and did not produce any acute toxicity of clinical significance. Also, an appreciable amount of α-KG was measured in blood. CONCLUSION: As per the guidelines of International Conference on Harmonization, the new α-KG formulation exhibited satisfactory stability, bioefficacy and safety as cyanide antidote.
Subject(s)
Antidotes/administration & dosage , Ketoglutaric Acids/administration & dosage , Potassium Cyanide/poisoning , Administration, Oral , Animals , Antidotes/chemistry , Antidotes/toxicity , Biological Assay , Biological Availability , Chemistry, Pharmaceutical , Drug Compounding , Drug Stability , Drug Storage , Female , Ketoglutaric Acids/chemistry , Ketoglutaric Acids/toxicity , Lethal Dose 50 , Male , Mice , Rats , Rats, Wistar , Time Factors , Toxicity Tests, AcuteABSTRACT
BACKGROUND: In low-income countries, women with disabilities have limited access to essential sexual and reproductive health services and are disadvantaged socioeconomically. Even though some studies have been conducted previously, there are scanty findings on contraceptive use and associated factors among women with disabilities. Thus, this systematic review aimed to assess contraceptive use and associated factors among women with disabilities of reproductive age in Ethiopia. METHODS: The Preferred Reporting Item for Systematic Review and Meta-Analyses [PRISMA] guidance is used to conduct this systematic review. Data were searched from electronic databases: PubMed/Medline, Scopus, Google Scholar, and other relevant sources. Studies screening was done using Rayyan software. The findings were narratively synthesized using a socio-ecological framework for health promotion. RESULT: Ten cross-sectional studies and 4436 women with disabilities of reproductive age were included in this review. According to this review, women with disabilities are less likely to use contraceptives, with a prevalence of 21.7% in Gondor City and 44.4% in Addis Ababa. The associated factors were identified and themed at individual, interpersonal, community, and institutional levels. CONCLUSION: Overall, the review findings revealed that women with disabilities continue to encounter challenges ranging from individual level to disability-unfriendly health facility infrastructure or institutional level. Therefore, health professionals and other relevant stakeholders should draw attention to creating awareness towards contraceptive use at individual and interpersonal levels, ensuring accessible contraceptive services and disability-friendly health facilities.
Subject(s)
Contraceptive Agents , Disabled Persons , Health Services Accessibility , Female , Humans , Contraception Behavior , Contraceptive Agents/administration & dosage , Cross-Sectional Studies , Ethiopia , Family Planning ServicesABSTRACT
INTRODUCTION: Africa exhibits a considerably high prevalence of the hepatitis B virus among pregnant women. Furthermore, there is a discernible lack of a well-established surveillance system to adequately monitor and comprehend the epidemiology of the hepatitis B virus, particularly among pregnant women. The eradication efforts of the virus in Africa have been impeded by the significant disease burden in the region, and there is a lack of evidence regarding the pooled prevalence of the hepatitis B virus in Africa. Consequently, this systematic review and meta-analysis aims to determine the prevalence of hepatitis B virus infection among pregnant women in Africa. METHODS: We conducted a systematic literature search using reputable databases such as PubMed, Advanced Google Scholar, Scopus, and the Cochrane Library. The search spanned from July 2013 to July 2023 and included all relevant articles published within this period. To identify potentially eligible articles, we conducted a comprehensive manual review of the reference lists of the identified studies. Our review encompassed articles from the African Journal Online. The analysis focused on observational studies published in peer-reviewed journals that reported the prevalence of hepatitis B surface antigen-positive testing among pregnant women. We utilized the Newcastle-Ottawa critical appraisal checklist to assess the methodological quality of each paper. Finally, a meta-analysis was conducted using a random-effects model. RESULTS: Out of the 774 studies identified, 31 studies involving 33,967 pregnant women were selected for the meta-analysis. According to the random-effects model, the combined prevalence of hepatitis B virus among pregnant women was 6.77% [95% CI: 5.72, 7.83]. The I2 statistic was calculated to be 95.57% (p = 0.00), indicating significant heterogeneity among the studies. The high I2 value of 95.57% suggests a substantial degree of heterogeneity. A subgroup meta-analysis revealed that factors such as time-dependent bias, sample size dependence, or individual variation among study participants contributed to this heterogeneity (p-difference < 0.05). CONCLUSION: According to the findings of this study, the pooled prevalence of hepatitis B infection among pregnant women in Africa was found to be intermediate-high. It is recommended that policymakers implement hepatitis B virus immunization programs targeting pregnant women and their new-born babies at higher risk of exposure.
Subject(s)
Hepatitis B virus , Hepatitis B , Pregnancy Complications, Infectious , Humans , Pregnancy , Female , Hepatitis B/epidemiology , Prevalence , Africa/epidemiology , Pregnancy Complications, Infectious/epidemiology , Pregnancy Complications, Infectious/virologyABSTRACT
INTRODUCTION: The current systematic review aimed to collect and analyze the comprehensive evidence regarding Polymerase Spiral Reaction (PSR) and to estimate its diagnostic performance and usefulness as a point-of-care (PoC) assay. METHODS: Literature was retrieved systematically from 2015 to 2023 from PubMed and Scopus. Studies were screened and selected against pre-determined inclusion and exclusion criteria. Quality assessment and risk of bias were critiqued using QUADAS-2. A systematic, qualitative narrative synthesis was employed to synthesize the data. RESULTS: 11 studies were selected for the systematic review, testing diseases in humans utilizing PSR. Only 2 studies clinically validated the test with a sample size > 150. 5 studies were of poor quality; 3 studies were of moderate quality and 3 studies were deemed to be of high quality. 3 studies quantified the diagnostic throughput and reported clinical sensitivity and specificity of PSR approaching to be > 92% and ~ 100%, respectively. CONCLUSION: Polymerase spiral reaction promises to be an optimistic isothermal assay; however, a huge research gap can be attributed to the lack of statistical and clinical evidence to validate the assay. Adequate research, focused on optimization, coupled with statistical and clinical validation, can help in estimating its true diagnostic potential and applicability. REGISTRATION AND PROTOCOL: A detailed protocol of this review is registered and available in Prospero (registration number CRD42023406265).
Subject(s)
Molecular Diagnostic Techniques , Point-of-Care Systems , Point-of-Care Testing , Humans , Molecular Diagnostic Techniques/methods , Molecular Diagnostic Techniques/standards , Sensitivity and Specificity , Nucleic Acid Amplification Techniques/methodsABSTRACT
The spatio-temporal distribution of COVID-19 across India's states and union territories is not uniform, and the reasons for the heterogeneous spread are unclear. Identifying the space-time trends and underlying indicators influencing COVID-19 epidemiology at micro-administrative units (districts) will help guide public health strategies. The district-wise daily COVID-19 data of cases and deaths from February 2020 to August 2021 (COVID-19 waves-I and II) for the entire country were downloaded and curated from public databases. The COVID-19 data normalized with the projected population (2020) and used for space-time trend analysis shows the states/districts in southern India are the worst hit. Coastal districts and districts adjoining large urban regions of Mumbai, Chennai, Bengaluru, Goa, and New Delhi experienced > 50,001 cases per million population. Negative binomial regression analysis with 21 independent variables (identified through multicollinearity analysis, with VIF < 10) covering demography, socio-economic status, environment, and health was carried out for wave-I, wave-II, and total (wave-I and wave-II) cases and deaths. It shows wealth index, derived from household amenities datasets, has a high positive risk ratio (RR) with COVID-19 cases (RR: 3.577; 95% CI: 2.062-6.205) and deaths (RR: 2.477; 95% CI: 1.361-4.506) across the districts. Furthermore, socio-economic factors such as literacy rate, health services, other workers' rate, alcohol use in men, tobacco use in women, overweight/obese women, and rainfall have a positive RR and are significantly associated with COVID-19 cases/deaths at the district level. These positively associated variables are highly interconnected in COVID-19 hotspot districts. Among these, the wealth index, literacy rate, and health services, the key indices of socio-economic development within a state, are some of the significant indicators associated with COVID-19 epidemiology in India. The identification of district-level space-time trends and indicators associated with COVID-19 would help policymakers devise strategies and guidelines during public health emergencies.
Subject(s)
COVID-19 , Male , Humans , Female , COVID-19/epidemiology , India/epidemiology , Family CharacteristicsABSTRACT
In December 2023, we observed a notable shift in the COVID-19 landscape, when JN.1 omicron emerged as the predominant SARS-CoV-2 variant with a 95% incidence. We characterized the clinical profile, and genetic changes in JN.1, an emerging SARS-CoV-2 variant of interest. Whole genome sequencing was performed on SARS-CoV-2 positive clinical specimens, followed by sequence analysis. Mutations within the spike protein sequences were analysed and compared with the previously reported lineages and sub-lineages, to identify the potential impact of the unique mutations on protein structure and possible alterations in the functionality. Several unique and dynamic mutations were identified herein. Molecular docking analysis showed changes in the binding affinity, and key interacting residues of wild-type and mutated structures with key host cell receptors of SARS-CoV-2 entry viz., ACE2, CD147, CD209L and AXL. Our data provides key insights on the emergence of newer variants and highlights the necessity for robust and sustained global genomic surveillance of SARS-CoV-2.
Subject(s)
COVID-19 , Mutation , SARS-CoV-2 , Spike Glycoprotein, Coronavirus , Humans , SARS-CoV-2/genetics , SARS-CoV-2/isolation & purification , India/epidemiology , COVID-19/virology , COVID-19/epidemiology , COVID-19/genetics , Spike Glycoprotein, Coronavirus/genetics , Spike Glycoprotein, Coronavirus/chemistry , Male , Female , Adult , Middle Aged , Whole Genome Sequencing , Molecular Docking Simulation , Genome, Viral , Angiotensin-Converting Enzyme 2/genetics , Angiotensin-Converting Enzyme 2/metabolism , Aged , PhylogenyABSTRACT
In December 2023, we observed a notable shift in the COVID-19 landscape, when the JN.1 emerged as a predominant SARS-CoV-2 variant with a 95% incidence. We characterized the clinical profile, and genetic changes in JN.1, an emerging SARS-CoV-2 variant of interest. Whole genome sequencing was performed on SARS-CoV-2 positive samples, followed by sequence analysis. Mutations within the spike protein sequences were analyzed and compared with the previous lineages and sublineages of SARS-CoV-2, to identify the potential impact of these unique mutations on protein structure and possible functionality. Several unique and dynamic mutations were identified herein. Our data provides key insights into the emergence of newer variants of SARS-CoV-2 in our region and highlights the need for robust and sustained genomic surveillance of SARS-CoV-2.
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Background: Dengue is a vector-borne viral disease impacting millions across the globe. Nevertheless, akin to many other diseases, reports indicated a decline in dengue incidence and seroprevalence during the COVID-19 pandemic (2020-22). This presumably could be attributed to reduced treatment-seeking rates, under-reporting, misdiagnosis, disrupted health services and reduced exposure to vectors due to lockdowns. Scientific evidence on dengue virus (DENV) disease during the COVID-19 pandemic is limited globally. Methods: A cross-sectional, randomized cluster sampling community-based survey was carried out to assess anti-dengue IgM and IgG and SARS-CoV-2 IgG seroprevalence across all 38 districts of Tamil Nadu, India. The prevalence of DENV in the Aedes mosquito pools during 2021 was analyzed and compared with previous and following years of vector surveillance for DENV by real-time PCR. Findings: Results implicate that both DENV-IgM and IgG seroprevalence and mosquito viral positivity were reduced across all the districts. A total of 13464 mosquito pools and 5577 human serum samples from 186 clusters were collected. Of these, 3·76% of mosquito pools were positive for DENV. In the human sera, 4·12% were positive for DENV IgM and 6·4% were positive for DENV IgG. The anti-SARS-CoV-2 antibody titres correlated with dengue seropositivity with a significant association whereas vaccination status significantly correlated with dengue IgM levels. Interpretation: Continuous monitoring of DENV seroprevalence, especially with the evolving variants of the SARS-CoV-2 virus and surge in COVID-19 cases will shed light on the transmission and therapeutic attributes of dengue infection.
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Chikungunya (CHIK) fever is one of the most important arboviral infections of medical significance. The objective of the present study is to identify and characterize the etiology of a focal febrile arthritis outbreak from Gwalior, northern India, during October-November 2010. A detailed virological (isolation) and molecular (end-point RT-PCR, quantitative RT-PCR, and nucleotide sequencing) investigation of this outbreak was carried out by collecting and studying 52 clinical samples and 15 mosquito pools from the affected region. The investigation revealed the presence of CHIK viral RNA in 29% of clinical samples and 13% mosquito pool by RT-PCR. The quantification of CHIK viral RNA in samples varied from 10(2.50) to 10(6.67) copies/mL, as demonstrated through quantitative RT-PCR. In addition, six CHIK viruses were isolated from RT-PCR positive samples. The nucleotide sequences of partial E1 gene of five representative CHIK viruses were deciphered, which revealed that all the viral strains from this outbreak belong to the recently emerging ECS African genotype. Identification of Chikungunya virus ECSA African genotype as the etiology of the present outbreak confirms the continued circulation of the novel genotype, since 2006, in India. The identification of CHIK virus in Aedes aegypti also confirmed it as the major vector in northern India.
Subject(s)
Alphavirus Infections/epidemiology , Alphavirus Infections/virology , Alphavirus/genetics , Alphavirus/isolation & purification , Disease Outbreaks/statistics & numerical data , RNA, Viral/genetics , Adult , Aged , Alphavirus/classification , Alphavirus Infections/diagnosis , Base Sequence , Chikungunya Fever , Female , Humans , India/epidemiology , Male , Middle Aged , Molecular Sequence Data , Prevalence , Risk Factors , Species Specificity , Young AdultABSTRACT
Rickettsioses, a category of zoonosis primarily caused by Rickettsia and Orientia, is a huge cause of public health concern worldwide. Diseases like murine typhus, scrub typhus, Mediterranean spotted fever and rocky mountain spotted fever are major contributors of Rickettsioses globally, with peculiar distributions in south-east Asia, Africa, Arabia and the Americas. With the innovations in molecular diagnostics, Isothermal Amplification Technology is gaining popularity for its fidelity, rapidity and cost-effectiveness. Compared to commercial assays, they are easily adaptable for point-of-care (PoC) settings. Due to nonspecific presentation as an acute undifferentiated febrile illness, diagnosis of Rickettsioses poses a great challenge. Certain isothermal amplification assays have proven to be highly efficient in diagnosing vector borne diseases like dengue, malaria, and chikungunya. The purpose of this review is to provide readers the current advancements, scope, challenges, and future prospects of isothermal amplification technologies in the detection of zoonotic pathogens like Rickettsia and Orientia.
Subject(s)
Orientia tsutsugamushi , Rickettsia Infections , Rickettsia , Scrub Typhus , Typhus, Endemic Flea-Borne , Mice , Humans , Rickettsia Infections/diagnosis , Rickettsia Infections/microbiology , Rickettsia/genetics , Scrub Typhus/diagnosis , Typhus, Endemic Flea-Borne/diagnosis , AnimalsABSTRACT
Early detection of latent tuberculosis infection (LTBI) is critical to TB elimination in the current WHO vision of End Tuberculosis Strategy. The study investigates whether detecting plasma cytokines could aid in diagnosing LTBI across household contacts (HHCs) positive for IGRA, HHCs negative for IGRA, and healthy controls. The plasma cytokines were measured using a commercial Bio-Plex Pro Human Cytokine 17-plex assay. Increased plasma CXCL8 and decreased MCP-1, TNF-α, and IFN-γ were associated with LTBI. Regression analysis showed that a combination of CXCL8 and MCP-1 increased the risk of LTBI among HHCs to 14-fold. Our study suggests that CXCL-8 and MCP-1 could serve as the surrogate biomarkers of LTBI, particularly in resource-limited settings. Further laboratory investigations are warranted before extrapolating CXCL8 and MCP-1 for their usefulness as surrogate biomarkers of LTBI in resource-limited settings.
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Background: Despite the continued vaccination efforts, there had been a surge in breakthrough infections, and the emergence of the B.1.1.529 omicron variant of SARS-CoV-2 in India. There is a paucity of information globally on the role of newer XBB variants in community transmission. Here, we investigated the mutational patterns among hospitalised patients infected with the XBB omicron sub-variant, and checked if there was any association between the rise in the number of COVID-19 cases and the observed novel mutations in Tamil Nadu, India. Methods: Nasopharyngeal and oropharyngeal swabs, collected from symptomatic and asymptomatic COVID-19 patients were subjected to real-time PCR followed by Next Generation Sequencing (NGS) to rule out the ambiguity of mutations in viruses isolated from the patients (n = 98). Using the phylogenetic association, the mutational patterns were used to corroborate clinico-demographic characteristics and disease severity among the patients. Findings: Overall, we identified 43 mutations in the S gene across 98 sequences, of which two were novel mutations (A27S and T747I) that have not been reported previously with XBB sub-variants in the available literature. Additionally, the XBB sequences from our cohort had more mutations than omicron B.1.1.529. The phylogenetic analysis comprising six major branches clearly showed convergent evolution of XBB. Our data suggests that age, and underlying conditions (e.g., diabetes, hypertension, and cardiovascular disease) or secondary complications confers increased susceptibility to infection rather than vaccination status or prior exposure. Many vaccinated individuals showed evidence of a breakthrough infection, with XBB.3 being the predominant variant identified in the study population. Interpretation: Our study indicates that the XBB variant is highly evasive from available vaccines and may be more transmissible, and potentially could emerge as the 'next' predominant variant, which likely could overwhelm the existing variants of SARS-CoV-2 omicron variants. Funding: National Health Mission (India), SIDASARC, VINNMER (Sweden), ORIP/NIH (USA).
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Background: Early detection of latent tuberculosis infection (LTBI) is critical to TB elimination in the current WHO vision of End Tuberculosis Strategy. Methods: We investigated whether detecting plasma cytokines could aid in diagnosing LTBI across household contacts (HHCs) positive for IGRA, HHCs negative for IGRA, and healthy controls. We also measured the plasma cytokines using a commercial Bio-Plex Pro Human Cytokine 17-plex assay. Results: Increased plasma CXCL8 and decreased MCP-1, TNF-α, and IFN-γ were associated with LTBI. Regression analysis showed that a combination of CXCL8 and MCP-1 increased the risk of LTBI among HHCs to 14-fold. Conclusions: We postulated that CXCL8 and MCP-1 could be the surrogate biomarkers of LTBI, especially in resource-limited settings.
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INTRODUCTION: Human papillomavirus infections are the most prevalent sexually transmitted disease among women worldwide. Cervical cancer is the second-most frequent disease worldwide in terms of incidence and mortality, and it is primarily responsible for fatalities in low- to middle-income nations, including Ethiopia. OBJECTIVE: To assess awareness, acceptance, and associated factors of the human papillomavirus vaccine among parents of daughters in the Hadiya zone, southern Ethiopia. METHODS: From November to December 2021, a community-based cross-sectional study was conducted in the Hadiya zone among parents with daughters in the zone. The study respondents were chosen using a two-stage sampling technique from parents with a 9-14-year-old daughter. An interviewer-administered questionnaire was used to collect data. For analysis, the data were entered into Epidata version 3.1 and exported to SPSS version 25. Variables with a p-value less than 0.25 in the bivariate analysis were transferred to multivariable analysis. A logistic regression model was applied to forecast the association between the predictor and outcome variables. Statistical significance was considered at a 0.05 p-value. RESULTS: The study showed that the overall acceptance of parents to vaccinate their daughters with HPV vaccination was 450 (84.9%). Parents of daughters of male sex (AOR: 0.407; 95%CI: 0.221, 0.748), who had only one daughter (AOR: 2.122; 95%CI: 1.221, 3.685), whose daughter(s) attended a government school (AOR: 0.476; 95%CI: 0.263, 0.861), who had poor knowledge (AOR: 0.532; 95%CI: 0.293, 0.969) and who had a negative attitude (AOR: 0.540; 95%CI: 0.299, 0.977) were discovered to have a strong correlation. CONCLUSION: This study found that there was a high level of parental acceptance; attitudes and knowledge about the HPV vaccine are significant in determining their intentions to vaccinate their daughter. Authorities in high-risk areas for cervical cancer incidence should plan and implement strategies by providing health information regarding human papillomavirus vaccination with an emphasis on raising community awareness.
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The contamination of food and potable water with microorganisms may cause food-borne and water-borne diseases. The common contaminants include Escherichia coli (E. coli), Salmonella sp. etc. The conventional methods for monitoring the water quality for the presence of bacterial contaminants are time-consuming, expensive, and not suitable for rapid on-spot detection in field conditions. In the current study, super paramagnetic iron oxide nanoparticles (SPIONs) were synthesized and conjugated with E. coli specific Aptamer I to detect E. coli cells qualitatively as well as quantitatively. The sludge consisting of E. coli- SPION complex was separated via magnetic separation. The presence of E. coli cells was confirmed with the help of standard techniques and confocal laser scanning microscopy (CLSM) employing Aptamer II conjugated CdTe-MPA quantum dots (QDs). Finally, an ATmega 328P prototype biosensor based on Aptamer II conjugated CdTe MPA QDs exhibited quantitative and qualitative abilities to detect E.coli. This prototype biosensor can even detect low bacterial counts (up to 1 × 102 cfu) with the help of a photodiode and plano-convex lens. Further, the prototype biosensor made up of ultraviolet light-emitting diode (UV LED), liquid crystal display (LCD) and ATmega328Pmicrocontroller offers on-spot detection of E.coli in water samples with high resolution and sensitivity. Similarly, this in-house developed prototype biosensor can also be utilized to detect bacterial contamination in food samples.
Subject(s)
Biosensing Techniques , Cadmium Compounds , Escherichia coli Infections , Magnetite Nanoparticles , Quantum Dots , Biosensing Techniques/methods , Escherichia coli , Humans , Quantum Dots/chemistry , TelluriumABSTRACT
We report herein the amperometric immunosensor for antibodies to Plasmodium falciparum histidine rich protein-2 (PfHRP-2). Screen-printed electrodes (SPEs) were modified with alumina sol-gel (Al(2)O(3) sol-gel) derived film and gold nanoparticles i.e. AuNPs/Al(2)O(3)sol-gel/SPE. A thin film was formed by dripping Al(2)O(3) sol on SPE followed by electrochemical deposition of gold nanoparticles (AuNPs). The modified SPEs were characterized by scanning electron microscopy/energy dispersive X-ray analysis (SEM-EDAX), Raman spectra and voltammetric experiments. Antibodies in rabbit serum sample were allowed to react with the PfHRP-2 protein that was immobilized on the modified SPE to form antigen-antibody immune complex (PfHRP-2/anti-PfHRP-2). The bound antibodies were quantified by alkaline phosphatase (AP) enzyme labeled secondary antibodies (anti-rabbit immunoglobulins-AP conjugate). Enzymatic substrate, 1-naphthyl phosphate was converted to 1-naphthol by AP and an electroactive product was quantified using amperometry. The performances of the developed immunosensor and Dot-ELISA were tested against different dilutions of hyper immune serum (rabbit anti-PfHRP-2). Dot ELISA and the developed immunosensor (AuNPs/Al(2)O(3)sol-gel/SPE) results for the hyper immune serum containing anti-PfHRP-2 were distinctly positive when diluted upto 8 times (1 : 12800 dilution) and 11 times (1 : 102400 dilution), respectively. The developed immunosensor was applied for antibodies to PfHRP-2 in human clinical samples.
Subject(s)
Aluminum Oxide/chemistry , Antibodies, Protozoan/blood , Biosensing Techniques/methods , Gold/chemistry , Metal Nanoparticles/chemistry , Plasmodium falciparum/immunology , Proteins/immunology , Protozoan Proteins/immunology , Electrochemical Techniques , Electrodes , Enzyme-Linked Immunosorbent Assay , Gels , Humans , Microscopy, Electron, ScanningABSTRACT
Plasmodium lactate dehydrogenase (pLDH), owing to unique structural and kinetic properties, is a well known target for antimalarial compounds. To explore a new approach for high level soluble expression of Plasmodium falciparum lactate dehydrogenase (PfLDH) in E. coli, PfLDH encoding sequence was cloned into pQE-30 Xa vector. When transformed E. coli SG13009 cells were induced at 37 degrees C with 0.5mM isopropyl beta-d-thiogalactoside (IPTG) concentration, the protein was found to be exclusively associated with inclusion bodies. By reducing cell growth temperature to 15 degrees C and IPTG concentration to 0.25 mM, it was possible to get approximately 82% of expressed protein in soluble form. Recombinant PfLDH (rPfLDH) was purified to homogeneity yielding 18 mg of protein/litre culture. rPfLDH was found to be biologically active with specific activity of 453.8 micromol/min/mg. The enzyme exhibited characteristic reduced substrate inhibition and enhanced k(cat) [(3.2+/-0.02)x10(4)] with 3-acetylpyridine adenine dinucleotide (APAD+). The procedure described in this study may provide a reliable and simple method for production of large quantities of soluble and biologically active PfLDH.
Subject(s)
L-Lactate Dehydrogenase/biosynthesis , Plasmodium falciparum/enzymology , Animals , Blotting, Western , Chromatography, Gel , Cloning, Molecular , DNA, Protozoan/genetics , DNA, Protozoan/isolation & purification , Electrophoresis, Polyacrylamide Gel , Escherichia coli/genetics , Gene Expression Regulation, Enzymologic , Humans , Kinetics , L-Lactate Dehydrogenase/chemistry , L-Lactate Dehydrogenase/genetics , L-Lactate Dehydrogenase/isolation & purification , Plasmodium falciparum/genetics , Rabbits , TemperatureABSTRACT
Herbal medicines are known to mitigate radical induced cell damage. Hence identification and scientific validation of herbal medicines contribute to better use in Ayurvedic/Unani research. In the present study, we investigated antioxidant and anti-apoptotic properties of Convolvulus pluricaulis (C. pluricaulis). C. pluricaulis exhibited antioxidant potential evident by free radical scavenging activities. C. pluricaulis pretreatment inhibited H2O2 induced macromolecule damage such as plasmid DNA damage and AAPH induced oxidation of bovine serum albumin and lipid peroxidation of rat hepatic tissues. Further to identify the neuroprotective properties of C. pluricaulis, SHSY5Y cells were treated with H2O2 with or without pretreatment of C. pluricaulis. The C. pluricaulis pretreatment at 50 µg/ml dose exhibited 50% cell survival against 100 µM H2O2 challenge for 24 h and it also decreased the lactate dehydrogenase leakage. Further C. pluricaulis pretreatment restored and regulated the antioxidant and apoptosis markers such as SOD, CAT, p53, and caspase-3 and inhibited, reactive oxygen species generation and depolarization of the mitochondrial membrane. C. pluricaulis possess a high content of flavonoids and polyphenols and GC-MS and FTIR analysis showed a wide variety of compounds which may contribute to the observed effects.