Viral pathogens and plant parasitic nematode

This special focus is dedicated to three parts：i）One of the most ubiquitous viral pathogens of stone fruit tree,Plum pox virus（PPV）;ii）a re-emerging pathogen,Wheat streak mosaic virus（WSMV）of cereal crops in Central Europe;and iii）a less studied plant parasitic,cyst-forming nematode in cereal crops Heterodera avenae.

Pitfalls of restriction enzyme analysis in identifying, characterizing,typing, and naming viral pathogens in the era of whole genome data, as illustrated by HAdV type 55

Restriction endonuclease analysis(REA),or restriction fragment length polymorphism(RFLP),was useful for identifying and determining the relatedness and putative identities of microbial strains(Tang et al.,1997)and for characterizing and discriminating large numbers of samples inexpensively in the past。

How does Cellular Heparan Sulfate Function in Viral Pathogenicity?

Heparan sulfate （HS） is ubiquitously expressed on the surfaces and in the extracellular matrix of virtually all cell types, making it an ideal receptor for viral infection. Compared with wild‐type viruses, cell culture‐adapted laboratory strains exhibit more efficient binding to cellular HS receptors. HS‐binding viruses are typically cleared faster from the circulation and cause lower viremia than their non‐HS‐binding counterparts, suggesting that the HS‐binding phenotype is a tissue culture adaptation that lowers virus fitness in vivo. However, when inoculated intracranially, efficient cell attachment through HS binding can contribute to viral neurovirulence. The primary aim of this review is to discuss the roles of HS binding in viral pathogenicity, including peripheral virulence and neurovirulence. Understanding how heparan sulfate functions during virus infection in vivo may prove critical for elucidating the molecular mechanism of viral pathogenesis, and may contribute to the development of therapeutics targeting HS.

Myocarditis–A silent killer in athletes:Comparative analysis on the evidence before and after COVID-19 pandemic

Myocarditis is a rare cardiomyocyte inflammatory process,typically caused by viruses,with potentially devastating cardiac sequalae in both competitive athletes and in the general population.Investigation into myocarditis prevalence in the Coronavirus disease 2019(COVID-19)era suggests that infection with Severe acute respiratory syndrome coronavirus(SARS-CoV-2)is an independent risk factor for myocarditis,which is confirmed mainly through cardiovascular magnetic resonance imaging.Recent studies indicated that athletes have a decreased risk of myocarditis after recent COVID-19 infection compared to the general population.However,given the unique nature of competitive athletics with their frequent participation in high-intensity exercise,athletes possess distinct factors of susceptibility for the development of myocarditis and its subsequent severe cardiac complications(e.g.,sudden cardiac death,fulminant heart failure,etc.).Under this context,this review focuses on comparing myocarditis in athletes versus non-athletes,owing special attention to the distinct clinical presentations and outcomes of myocarditis caused by different viral pathogens such as cytomegalovirus,Epstein-Barr virus,human herpesvirus-6,human immunodeficiency virus,and Parvovirus B19,both before and after the COVID-19 pandemic,as compared with SARS-CoV-2.By illustrating distinct clinical presentations and outcomes of myocarditis in athletes versus non-athletes,we also highlight the critical importance of early detection,vigilant monitoring,and effective management of viral and non-viral myocarditis in athletes and the necessity for further optimization of the return-to-play guidelines for athletes in the COVID-19 era,in order to minimize the risks for the rare but devastating cardiac fatality.

Long-Term Existence of SARS-CoV-2 in COVID-19 Patients:Host Immunity,Viral Virulence,and Transmissibility

COVID-19 patients can recover with a median SARS-CoV-2 clearance of 20 days post initial symptoms(PIS).However,we observed some COVID-19 patients with existing SARS-CoV-2 for more than 50 days PIS.This study aimed to investigate the cause of viral clearance delay and the infectivity in these patients.Demographic data and clinical characteristics of 22 long-term COVID-19 patients were collected.The median age of the studied cohort was59.83±12.94 years.All patients were clinically cured after long-term SARS-CoV-2 infection ranging from 53 to112 days PIS.Peripheral lymphocytes counts were normal.The ratios of interferon gamma(IFN-c)-secreting cells to total CD4^(+)and CD8^(+)cells were normal as 24.68%±9.60%and 66.41%±14.87%respectively.However,the number of IFNc-secreting NK cells diminished(58.03%±11.78%).All patients presented detectable IgG,which positively correlated with mild neutralizing activity(Mean value neutralisation antibodies titers=157.2,P=0.05).No SARS-CoV-2 virus was isolated in Vero E6 cells inoculated with nasopharyngeal swab samples from all patients 50 days PIS,and the cytopathic effect was lacking.But one sample was positive for SARS-CoV-2 nucleic acid test in cell supernatants after two passages.Genome sequencing revealed that only three synonymous variants were identified in spike protein coding regions.In conclusion,decreased IFN-c production by NK cells and low neutralizing antibodies might favor SARS-CoV-2 long-term existence.Further,low viral load and weak viral pathogenicity were observed in COVID-19 patients with long-term SARSCoV-2 infection.