Rapid and sensitive detection of SARS-CoV-2 virus in human saliva samples using glycan based nanozyme: a clinical study.

A highly sensitive colorimetric method (glycan-based nano(e)zyme) was developed for sensitive and rapid detection of the SARS-CoV-2 virus based on N-acetyl neuraminic acid (sialic acid)-functionalized gold nanoparticles (SA-Au NZs). A number of techniques were used to characterize the prepared nanomaterials including XRD, FT-IR, UV-vis, DLS, and TEM. DLS analysis indicates an average hydrodynamic size of 34 nm, whereas TEM analysis indicates an average particle size of 15.78 nm. This observation confirms that water interacts with nanoparticle surfaces, resulting in a large hydrodynamic diameter. The peroxidase-like activity of SA-Au NZs was examined with SARS-CoV-2 and influenza viruses (influenza A (H1N1), influenza A (H3N2), and influenza B). UV-visible spectroscopy was used to monitor and record the results, as well as naked eye detection (photographs). SA-Au NZs exhibit a change in color from light red to purple when SARS-CoV-2 is present, and they exhibit a redshift in their spectrum. N-acetyl neuraminic acid interacts with SARS-CoV-2 spike glycoprotein, confirming its ability to bind glycans. As a result, SA-Au NZs can detect COVID-19 with sensitivity and specificity of over 95% and 98%, respectively. This method was approved by testing saliva samples from 533 suspected individuals at Ghaem Hospital of Mashhad, Mashhad, Iran. Sensitivity and specificity were calculated by comparing the results with the definitive results. The positive results were accompanied by a color change from bright red to purple within five minutes. Statistical analysis was performed based on variables such as age, gender, smoking, diabetes, hypertension, and lung involvement. In clinical trials, it was demonstrated that this method can be used to diagnose SARS-CoV-2 in a variety of places, such as medical centers, hospitals, airports, universities, and schools.

Evaluation of cord blood immunoglobulin E and its association with maternal factors in a group of Iranian newborns.

Allergic disorders are among the most common diseases around the world especially in children. Many factors contribute to the pathogenesis of atopic disorders, but early events during the pregnancy are very important. The aim of this study was to evaluate the level of cord blood immunoglobulin E (CB-IgE) and its association with maternal in a group of Iranian newborns. In a cross-sectional study, 163 pregnant women randomly selected and information about pregnancy and atopy were taken by questionnaire. Blood samples of mothers and matched cord blood were collected and total serum IgE levels were measured by enzyme-linked immunosorbent assay (ELISA) method. To rolling out the possibility of contamination with maternal blood, total IgA was checked for all the cord blood samples. Sixteen percent of mothers had the history of atopic diseases and the mean IgE level was significantly higher in an atopic than nonatopic mothers (241 vs 102, P < 0.001). About 73.9% of cord blood samples, had high IgE level (>0.9 IU/mL). The level of cord blood IgE (CB-IgE) was not significantly different in male and female newborns (2.14 vs 2.15 IU/mL). There was no significant correlation between maternal factors such as age, pregnancy variables, allergens exposure, smoking, and maternal IgE with cord blood IgE. The results of this study showed that CB-IgE is high in a remarkable number of samples; independent of maternal or fetal factors. Further studies need to evaluate the reasons for the high level of IgE in cord blood in our area.

Molecular Identification and Phylogenetic Analysis of Leishmania major Isolated from Zoonotic Cutaneous Leishmaniasis Foci in Northeast Iran.

Background: Epidemiological studies, classification and genetic studies of Leishmania species are effective in treatment, control and prevention in endemic areas. We aimed to investigate the genetic diversity and phylogeny of Leishmania in Zoonotic foci located in northeastern Iran using nagt gene for the first time. Methods: DNA of 100 confirmed positive slides collected from the health centers of Sarkhes, Darghez, Fariman, Esfarayen, and Sabzevar were extracted during 2020-2021. The partial sequence of kDNA was amplified to identify the species. Twenty-five DNA samples were randomly subjected to amplify by nagt gene primes and were sequenced. The sequences were aligned with reference sequences in National Center for Biotechnology Information (NCBI). Then, the genetic similarities of the sequences were checked using Clustalx2.1 software and the phylogenetic tree was drawn by Mega 7 software. Results: All the positive samples were diagnosed as L. major. Approximately, half of the sequences of species were similar to two reference genes JX103550.1:404-712 L. major Esfahan and KX759012.1:568-807 L. Major Ilam (more than 90% similarity). According to the results of the phylogeny tree, the closest genotype to our study samples was JX103550.1:404-712 L. major Esfahan. Conclusion: The most causative agent CL in these areas was L. major. The genetic diversity of L. major was high such as other zoonotic foci in Iran. Due to the high similarity of the strains in the study areas with the strains of Isfahan and Ilam, similar control and prevention methods is suggested in these areas.