Development and Validation of Reverse Transcriptase Loop-Mediated Isothermal Amplification (RT-LAMP) as a Simple and Rapid Diagnostic Tool for SARS-CoV-2 Detection.

Since the COVID-19 pandemic outbreak in the world, many countries have searched for quick diagnostic tools to detect the virus. There are many ways to design diagnostic assays; however, each may have its limitations. A quick, sensitive, specific, and simple approach is essential for highly rapidly transmitted infections, such as SARS-CoV-2. This study aimed to develop a rapid and cost-effective diagnostic tool using a one-step Reverse Transcriptase Loop-Mediated Isothermal Amplification (RT-LAMP) approach. The results were observed using the naked eye within 30-60 min using turbidity or colorimetric analysis. The sensitivity, specificity, and lowest limit of detection (LoD) for SARS-CoV-2 RNA against the RT-LAMP assay were assessed. This assay was also verified and validated against commercial quantitative RT-PCR used by health authorities in Saudi Arabia. Furthermore, a quick and direct sampling from the saliva, or buccal cavity, was applied after simple modification, using proteinase K and heating at 98 °C for 5 min to avoid routine RNA extraction. This rapid single-tube diagnostic tool detected COVID-19 with an accuracy rate of 95% for both genes (ORF1a and N) and an LoD for the ORF1a and N genes as 39 and 25 copies/reaction, respectively. It can be potentially used as a high-throughput national screening for different respiratory-based infections within the Middle East region, such as the MERS virus or major zoonotic pathogens such as Mycobacterium paratuberculosis and Brucella spp., particularly in remote and rural areas where lab equipment is limited.

Reply to Zandi, M.; Soltani, S. Comment on "Alfassam et al. Development of a Colorimetric Tool for SARS-CoV-2 and Other Respiratory Viruses Detection Using Sialic Acid Fabricated Gold Nanoparticles. Pharmaceutics 2021, 13, 502".

When COVID-19 was first announced back in 2019, there were vast number of attempts to halt the progression of the SARS-CoV-2 virus once and for all [...].

Formulation and Evaluation of Alcohol-Free Hand Sanitizer Gels to Prevent the Spread of Infections during Pandemics.

Hand hygiene is an essential factor to prevent or minimize the spread of infections. The ability to prepare an alcohol-free hand sanitizer (AFHS) with antimicrobial properties is crucial, especially during pandemics, when there are high demands and a low supply chain for ethanol and isopropanol. The objective of this study was to prepare AFHS gels based on natural materials that contain essential oils (EOs) that would be effective against a broad spectrum of pathogens. The results showed that the organoleptic characteristics of all prepared hand sanitizer gels were considered acceptable. The pH of the formulations was slightly acidic (circa 3.9) owing to the presence of aloe vera in large proportions (90% v/v), which is known for its acidity. The spreadability for all tested formulations was in the acceptable range. The antimicrobial effectiveness test demonstrated that the prepared hand sanitizer gels had antimicrobial activities against different gram-positive and gram-negative bacteria and Candida albicans yeast. The highest antibacterial effect was observed with tea tree oil hand sanitizers, which lack activity against the yeast, while clove oil hand sanitizers showed effectiveness against all microorganisms, including Candida albicans. The lavender hand sanitizer exhibited the least antimicrobial efficiency. The acceptability study on 20 human volunteers showed that the hand sanitizer gel containing 1.25% (v/v) clove oil did not produce any signs of skin irritation. This study suggested that the prepared natural hand sanitizer gel with 1.25% (v/v) clove oil can be a potential alternative to commonly used alcohol-based hand sanitizers (ABHS).

Preparation and evaluation of benzalkonium chloride hand sanitizer as a potential alternative for alcohol-based hand gels.

Hand hygiene is one of the effective measures for reducing the transmission of infections. Alcohol-based hand sanitizers containing ethanol or isopropanol are considered efficient alternatives to handwashing with water and soap. Despite being effective against a broad-spectrum of microbes, fining an effective alternative to the alcohol-based hand sanitizers became a necessity owning to the limitations associated with their use, such as skin dryness, irritant contact dermatitis, and intoxication upon their accidental ingestion. Furthermore, in certain circumstances when the demand for alcohol exceeds the supply, like in the current COVID19 pandemic, formulating an effective non-alcoholic hand sanitizer would be a potential solution. Therefore, in this study, a non-alcoholic hand sanitizer containing benzalkonium chloride (BKC) as an active ingredient was prepared and evaluated as a less irritant and more persistent hand sanitizer gel. The hand gel was characterized by pH, viscosity, and spreadability. Results showed that this product has low viscosity, high spreadability and pH of 6.3, which is less likely to cause skin irritation. The antibacterial assessment (zone of inhibition) of the BKC-based hand sanitizer demonstrated antibacterial activities against nine out of eleven gram-positive and gram-negative bacterial strains, while the acceptability study on ten participants showed no signs of skin irritation nor redness upon its application. Consequently, this non-alcoholic based hand sanitizer is suggested as a potential alternative to alcohol-based hand gels.