Newest perspectives of glycopeptide antibiotics: biosynthetic cascades, novel derivatives, and new appealing antimicrobial applications.

Glycopeptide antibiotics (GPAs) are a family of non-ribosomal peptide natural products with polypeptide skeleton characteristics, which are considered the last resort for treating severe infections caused by multidrug-resistant Gram-positive pathogens. Over the past few years, an increasing prevalence of Gram-positive resistant strain "superbugs" has emerged. Therefore, more efforts are needed to study and modify the GPAs to overcome the challenge of superbugs. In this mini-review, we provide an overview of the complex biosynthetic gene clusters (BGCs), the ingenious crosslinking and tailoring modifications, the new GPA derivatives, the discoveries of new natural GPAs, and the new applications of GPAs in antivirus and anti-Gram-negative bacteria. With the development and interdisciplinary integration of synthetic biology, next-generation sequencing (NGS), and artificial intelligence (AI), more GPAs with new chemical structures and action mechanisms will constantly be emerging.

Progress of study on biology, epidemiology and prevention strategies for SARS-CoV-2 lambda variant

The emergence of SARS-COV-2 caused the global pandemic crisis.As the pandemic evolves, the mutation of novel coronavirus genome continues, resulting in several novel coronavirus variants. For example, Alpha (B.1.1.7), Beta (B.1.351), Gamma (p.1), Delta (B.1.617.2) and Lambda (C.37) variants may cause changes in biological characteristics of the virus, such as pathogenicity and infectivity, which may lead immune escape from vaccine protection and antibodies, even bring greater harm to epidemic prevention and control and also disease treatment. In this paper, the pandemic characteristics and relevant prevention and control measures of lambda variant are reviewed.

Elevated Serum Levels of Progranulin and Soluble Vascular Cell Adhesion Molecule-1 in Patients with COVID-19.

BACKGROUND: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection is associated with the angiocentric inflammation and angiogenesis, yet the molecules involved in this process remain to be determined. METHODS: We did a cross-sectional study of a cohort of patients with COVID-19 in Zunyi, China between February 1 and March 30, 2020. Serum concentrations of PGRN were determined by enzyme-linked immunosorbent assay in patients with COVID-19 at hospital admission and at discharge. In parallel, the serum levels of soluble adhesion molecules, vascular cell adhesion molecule-1 (sVCAM-1), intercellular adhesion molecule-1 (sICAM-1), P-selectin (sP-selectin), and E-selectin (sE-selectin) were assayed by a human adhesion molecule multiplex kit. The association between serum PGRN levels and other laboratory test results was analyzed by Spearman correlation analysis. RESULTS: At baseline, the median serum PGRN levels in patients with COVID-19 were 94.8 ng/mL [interquartile range (IQR): 66.6-119.6 ng/mL], which was significantly elevated compared with those in healthy controls (46.3 ng/mL, IQR: 41.8-55.6 ng/mL). Moreover, the median serum sVCAM-1 levels were significantly higher in COVID-19 patients (1396.0 ng/mL, IQR: 1019.1-1774.8 ng/mL) than those in healthy controls (612.4 ng/mL, IQR: 466.4-689.3 ng/mL). However, the levels of sICAM-1, sP-selectin, and sE-selectin were not significantly elevated in patients with COVID-19 when compared to healthy controls. Further analysis showed that serum PGRN levels were significantly positively associated with sVCAM-1 (r= 0.675, P= 0.008) and inversely with sICAM-1 (r= -0.609, P= 0.021) and aspartate aminotransferase levels (r= -0.560, P= 0.037) in patients with COVID-19 at hospital admission. In COVID-19 patients, serum PGRN and sVCAM-1 levels fell significantly after successful treatment. CONCLUSION: The present study demonstrates elevated serum PGRN and sVCAM-1 levels in patients with COVID-19, which may provide clues as to the mechanisms underlying the pathogenesis of COVID-19. Further studies are warranted to evaluate the potential of PGRN and sVCAM-1 as biomarkers and investigate their role in the pathogenesis of COVID-19.

The use of medicinal plants to prevent COVID-19 in Nepal.

BACKGROUND: Medicinal plants are the fundamental unit of traditional medicine system in Nepal. Nepalese people are rich in traditional medicine especially in folk medicine (ethnomedicine), and this system is gaining much attention after 1995. The use of medicinal plants has increased during the COVID-19 pandemic as a private behavior (not under the control of government). A lot of misinterpretations of the use of medicinal plants to treat or prevent COVID-19 have been spreading throughout Nepal which need to be managed proactively. In this context, a research was needed to document medicinal plants used, their priority of use in society, their cultivation status, and the source of information people follow to use them. This study aimed to document the present status of medicinal plant use and make important suggestion to the concerned authorities. METHODS: This study used a web-based survey to collect primary data related to medicinal plants used during COVID-19. A total of 774 respondents took part in the survey. The study calculated the relative frequencies of citation (RFC) for the recorded medicinal plants. The relationship between plants recorded and different covariates (age, gender education, occupation, living place, and treatment methods) was assessed using Kruskal-Wallis test and Wilcoxon test. The relationship between the information sources people follow and the respondent characteristics was assessed using chi-square test. RESULTS: The study found that the use of medicinal plants has increased during COVID-19 and most of the respondents recommended medicinal plants to prevent COVID-19. This study recorded a total of 60 plants belonging to 36 families. The leaves of the plants were the most frequently used. The Zingiber officinale was the most cited species with the frequency of citation 0.398. Most of the people (45.61%) were getting medicinal plants from their home garden. The medicinal plants recorded were significantly associated with the education level, location of home, primary treatment mode, gender, and age class. The information source of plants was significantly associated with the education, gender, method of treatment, occupation, living with family, and location of home during the lockdown caused by COVID-19. CONCLUSIONS: People were using more medicinal plants during COVID-19 claiming that they can prevent or cure COVID-19. This should be taken seriously by concerned authorities. The authorities should test the validity of these medicinal plants and control the flow of false information spread through research and awareness programs.

Diagnosis and treatment process of a case of "Fuyang" after recovery of light COVID-19 and its influencing factors

OBJECTIVE: To analyze the key points and difficulties of diagnosis and management of the patients by reporting the case of positive nucleic re-examination in patient after treatment of a light novel coronavirus pneumonia. METHODS: A case of light novel coronavirus pneumonia diagnosed and treated in January 2020, the possible factors of rejuvenation and the process of isolation management during the period were retrospectively analyzed. RESULTS: The patient had only dry cough symptoms and no history of clear contact. After two times of pharynx swabs tested negative for nucleic acid, the patient was tested positive again, who was less likely re-infected and may have long detoxification time with the risk of spreading the virus. It maybe related to the limitations of nucleic acid reagent testing and sampling method. CONCLUSION: It is of great significance to accurately identify and control light and "Fuyang" patients and take strictly quarantine measures to reduce risk of transmission.

Comparative analysis of the main haematological indexes and RNA detection for the diagnosis of SARS-CoV-2 infection.

BACKGROUND: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection has become a public health emergency of international concern. SARS-CoV-2 RNA detection is the diagnostic criterion for coronavirus disease 2019 (COVID-19). Nevertheless, RNA detection has many limitations, such as being time-consuming and cost-prohibitive, and it must be performed in specialized laboratories. Virus antibody detection is a routine method for screening for multiple viruses, but data about SARS-CoV-2 antibody detection are limited. METHOD: Throat swabs and blood were collected from 67 suspected SARS-CoV-2 infection patients at the Affiliated Hospital of Zunyi Medical University and Zunyi Fourth People's Hospital isolated observation departments. Throat swab samples were subjected to SARS-CoV-2 RNA detection by real-time PCR. Blood was used subjected to SARS-CoV-2 IgG/IgM detection by an enzyme-linked immunosorbent assay (ELISA) and gold immunochromatography assay (GICA). Blood underwent C-reactive protein detection by immunoturbidimetry, and white blood cells, neutrophil percentages and lymphocyte percentages were counted and calculated, respectively. Clinical symptoms, age and lifestyle habits (smoking and drinking) in all patients were recorded. Data were analysed using SPSS version 19. The results were confirmed by T and χ2 tests; correlations with detection results were analysed by kappa coefficients. Odds ratio (OR) and corrected OR values were analysed by logistic regression. P < 0.05 was considered statistically significant. RESULTS: Of the 67 patients included in this study, 26 were SARS-CoV-2 RNA-positive. GICA IgM sensitivity was 50.9% (13/26), and specificity was 90.2% (37/41). ELISA IgM sensitivity was 76.9% (20/26), and specificity was 90.2% (37/41). ELISA IgG sensitivity was 76.9% (20/26), and specificity was 95.1% (39/41). The kappa coefficients between RNA detection and ELISA IgG, ELISA IgM, and GICA IgM results were 0.741 (P < 0.01), 0.681 (P < 0.01) and 0.430 (P < 0.01), respectively. CONCLUSION: Among the candidate blood indicators, serum IgG and IgM detected by ELISA had the best consistency and validity when compared with standard RNA detection; these indicators can be used as potential preliminary screening tools to identify those who should undergo nucleic acid detection in laboratories without RNA detection abilities or as a supplement to RNA detection.

The Use of Medicinal Plants to Prevent COVID-19 in Nepal (preprint)

Background: Medicinal plants are the fundamental unit of traditional medicine system in Nepal. Nepalese people are rich in traditional medicine especially in folk medicine (ethnomedicine) and this system is gaining much attention after 1995. The use of medicinal plants have increased during COVID-19 pandemic as a private behavior (not under the control of government). Lot of misinterpretations of the use of medicinal plants to treat or prevent COVID-19 have been spreading throughout Nepal which need to be managed proactively. In this context, a research was needed to document medicinal plants used, their priority of use in society, cultivation status and source of information people follow to use them. This study aimed to document the present status of medicinal plant use and make important suggestion to the concern authorities.Methods: This study used a web-based survey to collect primary data related to medicinal plants used during COVID-19. A total of 774 respondents took part in the survey. The study calculated the relative frequencies of citation (RFC) for the recorded medicinal plants. The relationship between plants recorded and different covariates (age, gender education, occupation, living place, and treatment methods were assessed using Kruskal Wallis test and Wilcox test. The relationship between the information sources people follow and respondent characteristics, were assessed using chi-square test.Results: The study found that the use of medicinal plants has increased during COVID-19 and most of the respondents recommended medicinal plants to prevent COVID-19. This study recorded a total of 60 plants belonging to 36 families. The leaves of the plants were the most frequently used. The Zingiber officinale was the most cited species with the frequency of citation 0.398. Most of the people (45.61%), were getting medicinal plants from their home garden. The medicinal plants recorded were significantly associated with the education level, location of home, primary treatment mode, gender, and age class. The information source of plants was significantly associated with the education, gender, method of treatment, occupation, living with family, and location of home during lockdown caused by COVID-19.Conclusions: People were using more medicinal plants during COVID-19 claiming that they can prevent or cure COVID-19. This should be taken seriously by concerned authorities. The authorities should test the validity of these medicinal plants and control the flow of false information spread through research and awareness programs.