ABSTRACT
Background: Coronavirus disease (COVID-19) has now morphed into the most serious healthcare challenge that the world has faced in a century. The coronavirus disease (COVID-19) was declared as a public health emergency of international concern (PHEIC) on January 30, 2020, and a pandemic on March 11 by the World Health Organization (WHO). The number of cases and the death toll are rapidly increasing frequently because of its fast transmission from human to human through droplets, contaminated hands or body, and inanimate surfaces. Objective(s): SDS has been found to exhibit broad-spectrum and effective microbicidal and viral inactivation agents through the denaturation of both envelope and non-envelop proteins Methods: Viable SARS-COV-2 particles may also be found on contaminated sites such as steel surfaces, plastic surfaces, stainless steel, cardboard, and glass surfaces that can serve as a source of virus transmission. We reviewed the available literature about the SARS-CoV-2 persistence on inanimate surfaces as well as the decontamination strategies of corona and other viruses by using Sodium dodecyl sulfate (SDS) as well as other cleaning chemicals and disinfectants. Result(s): The efficacy of SDS has been amply demonstrated in several studies involving human immunodeficiency virus (HIV), human papillomavirus (HPV) and herpes simplex virus (HSV). SDS has also been found as deactivator of SARS-CoV-2. In toxic profile, up to 1% concentration of SDS is safe for humans and showed no toxic effect if ingested. Conclusion(s): Since no specific treatment is available as yet so containment and prevention continue to be important strategies against COVID-19. In this context, SDS can be an effective chemical disinfectant to slow and stop the further transmissions and spread of COVID-19.Copyright © 2021 Bentham Science Publishers.
ABSTRACT
The SARS-CoV-2 virus caused the COVID-19 pandemic is related to the SARS-CoV-1 and MERS coronaviruses, which were resulted in 2003 and 2012 epidemics. Antibodies in patients with COVID-19 emerge 7–14 days after the onset of symptoms and gradually increase. Because the COVID-19 pandemic is still in progress, it is hard to say how long the immunological memory to the SARS-CoV-2 virus may be retained. The aim of this study was to study a ratio between humoral and cellular immunity against the SARS-CoV-2 S protein in COVID-19 convalescents. There were enrolled 60 adults with mild to moderate COVID-19 2 to 12 months prior to the examination. The control group consisted of 15 adults without COVID-19 or unvaccinated. Specific antibodies to the SARS-CoV-2 virus were determined by ELISA with the SARS-CoV-2-IgG-ELISA-BEST kit. To determine the specific IgG and IgA subclasses, the anti-IgG conjugate from the kit was replaced with a conjugate against the IgG subclasses and IgA. Additional incubation with or without denaturing urea solution was used to determine the avidity of antibodies. Peripheral blood mononuclear cells were isolated by gradient centrifugation, incubated with or without coronavirus S antigen for 20 hours, stained by fluorescently labeled antibodies, and the percentage of CD8highCD107a cells was assessed on flow cytometer BD FACSCanto II. In the control group, neither humoral nor cellular immunity against the SARS-CoV-2 S protein was found. In the group of convalescents, the level of IgG antibodies against the SARS-CoV-2 S protein varies greatly not being strictly associated with the disease duration, with 57% and 43% of COVID-19 patients having high vs. low level of humoral response, respectively. A correlation between level of specific IgG and IgA was r = 0.43. The avidity of antibodies increased over time in convalescents comprising 49.9% at 6–12 months afterwards. No virus-specific IgG2 and IgG4 subclasses were detected, and the percentage of IgG1 increased over time comprising 100% 6–12 months after recovery. 50% of the subjects examined had high cellular immunity, no correlations with the level of humoral immunity were found. We identified 4 combinations of humoral and cellular immunity against the SARS-CoV-2 S protein: high humoral and cellular, low humoral and cellular, high humoral and low cellular, and vice versa, low humoral and high cellular immunity.
ABSTRACT
Hand hygiene is crucial as it gets contaminated easily from direct contact with airborne microorganism droplets and droplet nuclei from coughs and sneezes. In situations like a pandemic outbreak of COVID-19, it is imperative to interrupt the transmission chain of the pathogens by the practice of proper hand sanitization. It can be achieved with contact isolation and strict infection control tools like maintaining good hand hygiene in the house, in hospital settings, and in public. The success of hand sanitization solely depends on practical hand disinfecting agents formulated in various types and forms, such as antimicrobial soaps and water-based or alcohol-based hand sanitiser, with the latter being widely used in hospital settings and by common people. Most effective hand sanitiser products are alcohol-based formulations containing 62%–95% of alcohol as they can denature the proteins of microbes and the ability to inactivate pathogens. Considering the need, we prepared five herbal hand sanitizers in Arka form using drugs of krimighna gana dravyas that have an antimicrobial property and are volatile. Among all the five preparations, it was noticed from the statistical analysis, that there was a significant reduction in the bacterial count in the ‘immediate application’ of Batch I (Tulsi Arka), and Batch II (Tulsi, Nimba Arka) showed a significant decrease in the bacterial count in ‘after 30 minutes of application’. However, Batch III (Tulsi, Nimba, Haridra arka) gave an intermediate result in ‘immediate application’ and ‘after 30 minutes of application’. None of the preparations showed any sort of irritation, dryness or discomfort to the subjects even after 30 minutes while conducting the study.
ABSTRACT
Background-aim: World Health Organization (WHO) announced that diagnostic testing for Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-COV2) should be performed by real-time reverse transcriptase-polymerase chain reaction (RT-PCR). Most of these methods use different gene props and therefore the sensitivity and specificity of each method may different. In this study, we have compared two RT-PCR methods using two different genes for detection SARS-COV2. Methods: A total of random 40 nasopharyngeal swab samples were collected, transported and received in iced box shipment. All samples were performed on two separate semi-automated PCR systems (Qiagen and Abbott m2000). For Qiagen method, 200uL from each sample were added in 96-well QiAcube plate which loaded in QiAcube HT (SN:019658;Qiagen, Germany) to extract RNA. Following extraction, master mix prepared using SARS-COV2-RT-PCR kit 1.0 (REF: 821005;Altona, Germany) for 44 samples including 40 patient samples, two negative controls using nuclease-free water (with and without internal control), and two positive controls (with and without internal control). Extraction elute of each sample (20uL) added to master mix (10uL) to have a total volume of 30uL which uploaded into Rotor-Gene Q (SN:R0219307;Qiagen, Germany). The primer pair used to amplify S gene and E gene in SARS-COV2. Amplifications were done as follow: reverse transcriptase (20 minutes at 55oC);initial denaturation (2 minutes at 95oC);45 cycles of denaturation (15 seconds at 95oC), annealing for (45 seconds at 55oC), and extension (15 seconds at 72oC). Results reported as valid for internal control less than 35 cycle threshold (CT). The Abbott m2000 System uses SARS-CoV-2 assay was a dual target assay for the RdRp and N genes. All 40 samples were extracted using m2000sp (Abbott, United States) as recommend by manufacture using 100uL. An RNA sequence that was unrelated to the SARS-CoV-2 target sequence was introduced into each specimen at the beginning of sample preparation. This unrelated RNA sequence was simultaneously amplified by RT-PCR and serves as an internal control (IC) to demonstrate that the process has proceeded correctly for each sample. Following extraction, master mix (20uL) added to extraction elute of each sample (30uL) to have a total volume of 50uL which uploaded into m2000rp (Abbott, United States). Amplification were done as follow: reverse transcriptase (25 minutes at 55oC);initial denaturation (5 minutes at 94oC);40 cycles of denaturation (20 seconds at 94oC), annealing for (55 seconds at 55oC), and extension (15 seconds at 72oC). Result: All samples had valid extraction process with a CT value of internal control between 26.97 to 28.89. A total of 30 samples displayed positive results and 10 samples exhibited negative results with 100% agreement for both methods. This has resulted with a 100% accuracy between both methods. Conclusions: Both semi-automated methods from Qiagen and Abbott are comparable and accurate despite different technology and different primer genes.
ABSTRACT
Since SARS-COV-2 virus spread worldwide and COVID-19 turned rapidly into a pandemic illness, the necessity for vaccines and diagnostic tests became crucial. The viral surface is decorated with Spike, the major antigenic determinant and main target for vaccine development. Within Spike, the receptor binding domain (RBD), constitutes the main target of highly neutralizing antibodies found in COVID-19 convalescent plasma. Besides vaccination, another important aspect of Spike (and RBD) is their use as immunogen for the development of poli- and monoclonal antibodies (mAbs) for therapeutic and diagnostic purposes. Here we report the development and preliminary biochemical characterization of a set of monoclonal antibodies against the Spike RBD domain along with the recombinant expression of two mayor COVID-19 protein reagents: the viral Spike RBD domain and the extracellular domain of the human receptor ACE2. RBD and the extracellular domain of ACE2 (aa 1-740) were obtained through transient gene transfection (TGE) in two different mammalian cell culture systems: HEK293T adherent monolayers and Expi293F™ suspension cultures. Due to its low cost and ease scale-up, all transfections were carried with polyethyleneimine (PEI). Expressed proteins were purified from culture supernatants by immobilized metal affinity chromatography. Anti-RBD mAbs were developed from two different immunization schemes: one aimed to elicit antibodies with viral neutralizing potential, and the other with the ability to recognize denatured RBD for routine lab immunoassays. To achieve this, the first group of mice was immunized with RBD in aluminum salts (RBD/Al) and the other with RBD emulsified in Freunds adjuvant (RBD/FA). Polyclonal and monoclonal antibody reactivities against native or denatured RBD forms were then assessed by ELISA. Complete RBD denaturation was followed by intrinsic fluorescence spectral changes upon different physicochemical stress treatments. As expected, RBD/Al immunized mice developed an antibody response shifted to native RBD while those immunized with RBD/FA showed a high response against both forms of the protein. In accordance with the observed polyclonal response, RBD/FA derived mAbs recognize both, native and denatured RBD. On the contrary, hybridomas generated from the RBD/Al protocol mostly recognize RBD in its native state. Further ELISA binding assays revealed that all RBD/FA derived mAbs can form a trimeric complex with ACE2 and RBD, denoting they would not have viral neutralizing activity. ELISA competition assays with the RBD/ACE2 complex aimed to determine the neutralization potential of the RBD/Al derived mAbs are under way. Overall, the anti-Spike RBD mAbs and the recombinant RBD and ACE2 proteins presented here constitute valuable tools for diverse COVID-19 academic research projects and local immunity surveillance testing.
ABSTRACT
The disinfecting properties of sun (heat and UV radiation) are adequate in warm sunny regions to rid beach sand of coronavirus particles, if present. Here we detail the mechanism of natural disinfection offered by the sun on coronaviral particles that may find their way onto beach sand. We conclude that heat and UV radiation generated by the sun destroy the virus infection ability.