Clinical applications of spectroscopic techniques in conjunction with multivariate analysis in virus diagnosis

In view of the global pandemic that started in 2020, caused by COVID-19, the importance of the existence of fast, reliable, cheap diagnostic techniques capable of detecting the virus even in the first days of infection became evident. This review discusses studies involving the use of spectroscopic techniques in the detection of viruses in clinical samples. Techniques based on mid-infrared, near-infrared, Raman, and molecular fluorescence are explained and it was demonstrated how they can be used in conjunction with computational tools of multivariate analysis to build models capable of detecting viruses. Studies that used real clinical samples from 2011 to 2021 were analyzed. The results demonstrate the potential of the techniques in detecting viruses. Spectroscopic techniques, as well as chemometric techniques, were also explained. Viral diagnosis based on spectroscopy has interesting advantages compared to standard techniques such as: fast results, no need for reagents, non-destructiveness for the sample, no need for sample preparation, relatively low cost, among others. Several studies have corroborated the real possibility that, in the near future, we may have spectroscopic tools being successfully applied in viral diagnosis.

Epidemic Preparedness—Leishmania tarentolae as an Easy-to-Handle Tool to Produce Antigens for Viral Diagnosis: Application to COVID-19

To detect and prevent emerging epidemics, discovery platforms are urgently needed, for the rapid development of diagnostic assays. Molecular diagnostic tests for COVID-19 were developed shortly after the isolation of SARS-CoV-2. However, serological tests based on antiviral antibody detection, revealing previous exposure to the virus, required longer testing phases, due to the need to obtain correctly folded and glycosylated antigens. The delay between the identification of a new virus and the development of reliable serodiagnostic tools limits our readiness to tackle future epidemics. We suggest that the protozoan Leishmania tarentolae can be used as an easy-to-handle microfactory for the rapid production of viral antigens to face emerging epidemics. We engineered L. tarentolae to express the SARS-CoV-2 receptor-binding domain (RBD) and we recorded the ability of the purified RBD antigen to detect SARS-CoV-2 infection in human sera, with a sensitivity and reproducibility comparable to that of a reference antigen produced in human cells. This is the first application of an antigen produced in L. tarentolae for the serodiagnosis of a Coronaviridae infection. On the basis of our results, we propose L. tarentolae as an effective system for viral antigen production, even in countries that lack high-technology cell factories.

Aptamers in Virology—A Consolidated Review of the Most Recent Advancements in Diagnosis and Therapy

The use of short oligonucleotide or peptide molecules as target-specific aptamers has recently garnered substantial attention in the field of the detection and treatment of viral infections. Based on their high affinity and high specificity to desired targets, their use is on the rise to replace antibodies for the detection of viruses and viral antigens. Furthermore, aptamers inhibit intracellular viral transcription and translation, in addition to restricting viral entry into host cells. This has opened up a plethora of new targets for the research and development of novel vaccines against viruses. Here, we discuss the advances made in aptamer technology for viral diagnosis and therapy in the past decade.

Epidemic preparedness - Leishmania tarentolae as an easy-to-handle tool to produce antigens for viral diagnosis: application to COVID-19

To control future epidemics, discovery platforms are urgently needed, for the rapid development of diagnostic assays. Molecular diagnostic tests for COVID-19 emerged shortly after the isolation of SARS-CoV-2, however, serological tests based on antiviral antibody detection, revealing previous exposure to the virus, required longer developmental phases, due to the need for correctly folded and glycosylated antigens. The delay between the identification of a new virus and the development of reliable serodiagnostic tools limits our readiness for the control of a future epidemic. In this context, we propose the protozoan Leishmania tarentolae as an easy-to-handle micro-factory for the rapid production of viral antigens, to be used at the forefront of emerging epidemics. As a study model, we engineered L. tarentolae to express the SARS-CoV-2 Receptor Binding Domain (RBD) and report the ability of the purified RBD antigen to detect SARS-CoV-2 infection, with a sensitivity and reproducibility comparable to that of a reference antigen produced in human cells. This is the first application of an antigen produced in L. tarentolae for the serodiagnosis of a Coronaviridae infection. Based on our results, we propose L. tarentolae as an effective system for viral antigen production, even in countries that lack high-tech cell factories.

Healthcare-Associated Viral Respiratory Infections in a Pediatric Intensive Care Unit and Cardiovascular Intensive Care Unit

Background: Healthcare-associated infections (HAIs) affect patient health and are tracked closely by infection prevention. Patients in a pediatric intensive care unit (PICU) acquired viral respiratory infections had longer use of respiratory support. We sought to determine the types of viral respiratory HAIs (VR-HAIs) acquired in the PICU and the characteristics of those affected. Methods: CHOC Children’s Hospital is a 334-bed tertiary-care center. Charts were reviewed on patients with VR-HAIs from fiscal years (FY) 2005–2020. High-risk VR-HAI (HR-VR-HAI) were influenza A and B, respiratory syncytial virus (RSV), adenovirus, parainfluenza, and human metapneumovirus (hMPV, added in FY 2014). Patients in the PICU, cardiovascular ICU (CVICU), and oncology ICU (OICU) with HR-VR-HAIs were reviewed. Patients were categorized according to underlying pathology, immunosuppression, and isolation prior to HR-VR-HAI. Increased respiratory support was defined as any increase from a patient’s baseline support ±24 hours of viral diagnosis: increase in oxygen flow or transition from nasal cannula to high-flow nasal cannula or ventilator support. Antibiotic escalation, defined as initiation of antibiotic therapy for ≥2 days ±24 hours of viral diagnosis or broadening the spectrum of antimicrobials for ≥2 days ±24 hours of viral diagnosis. Results: During FY 2005–2020, there were 204 VR-HAIs: 143 HR-VR-HAIs (70%), of which 39 (27.2%) occurred in ICUs (Figure 1). Most of the HR-VR-HAIs were RSV, parainfluenza, and hMPV (Figure 2). Of 39 patients, 10 (25.6%) had underlying oncologic conditions, 9 of whom were immunosuppressed. Of 39 patients, 16 (41%) had structural cardiac disease, 4 (10.3%) had pulmonary disease, 5 (12.8%) had neurologic disease, and the remaining 4 (10.3%) had other comorbidities. Of 39 patients, 12 (31%) required an increase in respiratory support and 13 (33%) had escalation of antibiotics. Of 39 HR-VR-HAI patients, 2 died within 2 weeks of acquisition. Conclusions: HR-VR-HAIs are uncommon in ICUs. RSV, parainfluenza, and hMPV are the most common, and 1 of 3 of patients required escalation in respiratory support and/or escalation in antibiotics. All patients had underlying comorbidities. In our series, there were 2 deaths within 2 weeks of infection.Funding: NoDisclosures: None

Aptamers for Anti-Viral Therapeutics and Diagnostics

Viral infections cause a host of fatal diseases and seriously affect every form of life from bacteria to humans. Although most viral infections can receive appropriate treatment thereby limiting damage to life and livelihood with modern medicine and early diagnosis, new types of viral infections are continuously emerging that need to be properly and timely treated. As time is the most important factor in the progress of many deadly viral diseases, early detection becomes of paramount importance for effective treatment. Aptamers are small oligonucleotide molecules made by the systematic evolution of ligands by exponential enrichment (SELEX). Aptamers are characterized by being able to specifically bind to a target, much like antibodies. However, unlike antibodies, aptamers are easily synthesized, modified, and are able to target a wider range of substances, including proteins and carbohydrates. With these advantages in mind, many studies on aptamer-based viral diagnosis and treatments are currently in progress. The use of aptamers for viral diagnosis requires a system that recognizes the binding of viral molecules to aptamers in samples of blood, serum, plasma, or in virus-infected cells. From a therapeutic perspective, aptamers target viral particles or host cell receptors to prevent the interaction between the virus and host cells or target intracellular viral proteins to interrupt the life cycle of the virus within infected cells. In this paper, we review recent attempts to use aptamers for the diagnosis and treatment of various viral infections.

Introduction pages

Notulae Botanicae Horti Agrobotanici Cluj-Napoca (NBHA): The papers published in Issue 1, Volume 49, 2021 represent new exciting researches in different topics of life science, respectively in plant science, horticulture, agronomy and crop science. Among the interesting articles we invite you to find news about: Comparative transcriptome analysis reveals gene network regulation of TGase-induced thermotolerance in tomato; Characterization the coding and non-coding RNA components in the transcriptome of invasion weed Alternanthera philoxeroides; Morphometric analysis and sequence related amplified polymorphism determine genetic diversity in Salvia species; Viral diagnosis in cultivars of Ipomoea batatas (L.) Lam.; Influence of fertilizer and salicylic acid treatments on growth, physiological, and antioxidant characteristics in green and red Perilla frutescens varieties; In-vitro evaluation of antioxidant and antiradical potential of successive extracts, semi-purified fractions and biosynthesized silver nanoparticles of Rumex vesicarius; Zoophagous entomofauna and entomopathogenic agents reported on Cydalima perspectalis (Walker, 1859) in north-western of Romania; Vegetative propagation and ex-situ conservation of Acantholimon androsaceum and Limonium chersonesum, two promising local endemics of Crete (Greece) available for floricultural and pharmaceutical sustainable exploitation; Quality attributes during maturation of ‘Golden Delicious’ and ‘Red Delicious’ apples grown in two geographical regions with different environmental conditions, etc. The Impact Factor communicated by ISI Clarivate, June 29, 2020, is IF 2019 = 1.168 (position 149 of 234 journals, Q3 in Plant Sciences). The metrics in Scopus – Elsevier (June 22, 2020): CiteScore 1.40 (#43/84 in Horticulture); SJR 0.35 - Q2, #41/90 in Horticulture (SJR Scimago Journal). ---------------------------------------------------------------------------------- Announcement From Volume 49, Issue 1, 2021, Notulae Botanicae Horti Agrobotanici Cluj-Napoca journal will use article numbers in place of the traditional method of continuous pagination through the volume. This step helps us to maintain a rapid, efficient production process by being able to define pagination as soon as a paper is accepted. For papers that use article numbers, the page number of full-text articles will start from 1 to the last page and the citation needs only to list the article number. The journal will continue to appear quarterly, as before, with four annual numbers (see Publication Frequency).

Hepatitis C virus (HCV) diagnosis via microfluidics

Several microfluidic techniques for HCV viral diagnosis.

Rapid detection of SARS-CoV-2 with CRISPR-Cas12a

The recent outbreak of betacoronavirus Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2), which is responsible for the Coronavirus Disease 2019 (COVID-19) global pandemic, has created great challenges in viral diagnosis. The existing methods for nucleic acid detection are of high sensitivity and specificity, but the need for complex sample manipulation and expensive machinery slow down the disease detection. Thus, there is an urgent demand to develop a rapid, inexpensive, and sensitive diagnostic test to aid point-of-care viral detection for disease monitoring. In this study, we developed a clustered regularly interspaced short palindromic repeats (CRISPR)-CRISPR associated proteins (Cas) 12a-based diagnostic method that allows the results to be visualized by the naked eye. We also introduced a rapid sample processing method, and when combined with recombinase polymerase amplification (RPA), the sample to result can be achieved in 50 minutes with high sensitivity (1–10 copies per reaction). This accurate and portable detection method holds a great potential for COVID-19 control, especially in areas where specialized equipment is not available.