An outbreak of school influenza complicated with Mycoplasma pneumoniae infection

Objective: To describe the clinical features, causal agent and transmission mode of a fever outbreak in a school in Shanghai. Methods: Field epidemiological approaches including case definition development, searching for contacts, distribution of diseases description, environmental sampling and laboratory testing. Results: A total of 16 influenza-like cases were included, all concentrated in the one class of grade two, including 15 students and 1 teacher. Among student cases, the incidence rate was 36.59%(15/41), the average age was 7.4 years, the incidence rate was 36.84%(7/19) for boys, 36.36%(8/22) for girls. The clinical course was 5-15 days, with the median of 9 days, and 18.75%(3/16) of the cases stayed studying while sick. The nasopharyngeal swab specimens in 16 cases all tested positive for influenza B, of which 11 tested positive for mycoplasma pneumoniae and 1 case also tested positive for coronavirus OC43. Body temperature, number of mononuclear cells, and treatment time of patients infected with Influenza B and mycoplasma pneumoniae were higher than those of patients infected with influenza B alone(P < 0.05). The outbreak lasted for 12 days, all sick students were treated and discharged from hospital, with no severe cases or death, and the outbreak was effectively controlled. Conclusion: This campus cluster outbreak caused by influenza B and mycoplasma pneumoniae. Patients with influenza B with mycoplasma pneumoniae have severe symptoms and a long course of illness, suggesting the importance of early management of the epidemic.

Historical perspective: other human coronavirus infectious diseases, SARS and MERS

Alphacoronaviruses (HCoV-229E and HCoV-NL63) and betacoronaviruses (HCoV-OC43 and HCoV-HKU1) are common causes of upper respiratory tract infection in humans. SARS-CoV-1 and MERS-CoV emerged in 2002 and 2012, respectively, with the potential of causing severe and lethal disease in humans, termed SARS and MERS, respectively. Bats appear to be the common natural source of SARS-like coronaviruses including SARS-CoV-1, but their role in MERS-CoV is less clear. Civet cats and dromedary camels are the intermediary animal sources for SARS-CoV-1 and MERS-CoV, respectively. Nosocomial outbreaks are hallmarks of SARS and MERS. MERS patients with comorbidities or immunosuppression tend to progress more rapidly to respiratory failure and have a higher case fatality rate than SARS patients. SARS has disappeared since 2004, while there are still sporadic cases of MERS in the Middle East. Continued global surveillance is essential for SARS-like coronaviruses and MERS-CoV to monitor changing epidemiology due to viral variants.Copyright © ERS 2021.

Human coronaviruses in the 'One Health' context

Seven human coronaviruses have been identified so far: four seasonal coronaviruses (HCoV-229E, HCoV-OC43, HCoV-NL63, HCoV-HKU1) and three novel coronaviruses (SARS-CoV, MERS-CoV, SARS-CoV-2). While seasonal coronaviruses cause only mild symptoms, novel coronaviruses cause severe and potentially fatal infections. All known coronaviruses originated in animals. Bats are considered as an origin for the majority of coronaviruses capable of infecting humans;however, rodents are proposed as natural hosts for HCoV-OC43 and HCoV-HKU1. Different animal species could serve as intermediate hosts including alpacas (HCoV-229E), livestock (HCoV-OC43), civet cats (SARS-CoV), camels (MERS-CoV), and pangolins (SARS-CoV-2). In Croatia, SARS-CoV-2 was detected in humans, pet animals, wildlife, and the environment. The COVID-19 pandemic has highlighted the role of the 'One Health' approach in the surveillance of zoonotic diseases.Copyright © 2022, University Hospital of Infectious Diseases. All rights reserved.

Proteome2virus: Shotgun mass spectrometry data analysis pipeline for virus identification

Objectives: Shotgun proteomics is a generic method enabling detection of multiple viral species in one assay. The reliable and accurate identification of these viral species by analyzing peptides from MS-spectra is a challenging task. The aim of this study was to develop an easy accessible proteome analysis approach for the identification of viruses that cause respiratory and gastrointestinal infections. Method(s): For this purpose, a shotgun proteomics based method and a web application, 'proteome2virus', were developed. Identified peptides were searched in a database comprising proteomic data of 46 viruses known to be infectious to humans. Result(s): The method was successfully tested for cultured viruses and eight fecal samples consisting of ten different viral species from seven different virus families, including SARS-CoV-2. The samples were prepared with two different sample preparation methods and were measured with two different mass spectrometers. Conclusion(s): The results demonstrate that the developed web application is applicable to different MS data sets, generated from two different instruments, and that with this approach a high variety of clinically relevant viral species can be identified. This emphasizes the potential and feasibility for the diagnosis of a wide range of viruses in clinical samples with a single shotgun proteomics analysis.Copyright © 2023

Humoral response against SARS-CoV-2 and other endemic corona viruses

In a study of two Hospitals in Saxony (Chemnitz and Leipzig), we analyzed the antibody development towards SARS-CoV-2 and against a variety of endemic coronaviruses. Here we analyzed 760 sera from a Saxonian cohort for antibody reactivity against: Common cold coronaviruses, HCoV-229E, HCoV-HKU 1, HCoV-NL63 and HCoV-OC43, MERS-CoV and SARS-CoV. For the SARS CoV-2 immune response we tested the following antigens: Spike, S1, S2, RBD and nucleocapsid. These 11 antigen determinants were tested in a commercial multiplex Luminex based assay. We tested sera from 544 individuals (347 females and 197 males;498 SARS-CoV-2 PCR positive and 262 SARS-CoV-2 PCR negative) between May 2020 and March 2022. We observed up to 10% reactivity against the MERS virus in both the PCR positive and negative group. Against the common cold corona viruses 80%-90 % of the individuals in both groups show detectable antibodies. Regarding the antibody response against SARS-CoV a significant difference was observe. Only 19% of COVID-19 infected individuals show antibodies against the virus, while 81% of the PCR-positive individuals produced antibodies. The presence of antibodies against the SARS-CoV-2 is positively correlated with those against SARS-CoV (p = 0.001). No changes in endemic antibody responses were see in the two groups. The antibody status after first immunization event (infection/ vaccination) shows differences in nucleocapsiddirected antibody production, found in the natural infection group (about 60%). In the vaccination group, more individuals (up to 95%) show an immune response against Spike, S1 and RBD compare with natural infection. In summary, the examined cohort shows a general immunization up to 90% against most endemic corona viruses. Correlation analyses show cross-reactivity between SARS-CoV-2 and SARS-CoV. Longitudinal antibody analyses are under way, as also correlations of humoral response with immunogenetic factors.

Development of a Novel in-Vitro Hcov-Oc43 Screening Method

Aim: To develop a simple, inexpensive antiviral screening assay, applicable to SARS-CoV-2, using a plate-based bioassay approach to assess the in-vitro activity of compounds against HCoV-OC43. Background(s): Despite the successful deployment of vaccines against SARS-CoV-2 there remains a need for effective antivirals for acute infection treatment. A distinct problem facing the search for new anti-coronavirus compounds is the cost of antiviral screening, compounded by the biosecurity concerns of live SARSCoV- 2 culture. In concert with low pathogenic surrogate virus use, the resazurin reduction assay, which is often employed for compound cytotoxicity assessments can be employed for safe, rapid and inexpensive antiviral screening. Method(s): In-vitro cell based resazurin reduction assays were optimised using remdesivir as a control compound for the assessment of anti-HCoV-OC43 activity. Following optimisation, 246 purified natural compounds from the University of Western Australia's compound collection,were screened using the resazurin bioassay as a primary screen, under pre-treatment and cotreatment conditions. Five compounds, which demonstrated anti- HCoV-OC43 activity, were chosen for secondary screening with dose responses determined using qRT-PCR. Result(s): Primary screens of the 246 compounds using the resazurin bioassay identified five compounds with a relative viral inhibition >60% and a relative cell viability >70% (Table 1). The Z factor of the pre-treatment and co-treatment assays was >0.5 (average +/- SD;0.85 +/- 0.07, 0.91 +/- 0.03 respectively). Further dose response analysis of the top five compounds identified one compound with an IC50 value <10 muM. Conclusion(s): The method developed is an appropriate primary screening tool for the identification of novel compounds with anti-HCoV-OC43 activity.Copyright © 2023 Southern Society for Clinical Investigation.

RSV circulation during SARS-CoV-2 pandemic era: what happened in Italy

Background: In the northern hemisphere, Respiratory Syncytial Virus (RSV) is more frequently detected from December to February. In Italy, Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) presented a peak in incidence from the end of December 2021 to February 2022. Aim(s): To evaluate how SARS-CoV-2 pandemic has influenced RSV circulation. Method(s): We evaluated 389 children, aged 0-18 years, admitted for respiratory tract infections from September 2021 to January 2022 throughout Italy, from the north to the south. Children underwent nasal washing from 1 to 3 days after hospitalization. A (RT)-PCR was developed for detecting 15 respiratory viruses, including RSV, influenza virus A and B, human coronavirus OC43, 229E, NL-63 and HUK1, adenovirus, rhinovirus, parainfluenza virus 1-3, human bocavirus and human metapneumovirus. Result(s): We detected a virus in 338 children (86.9%): RSV was found in 267 (68.7%), other viruses in 71 (18.3%). 51 children (13.1%) resulted negative. Dividing our observational period in two-week timeframes, we found that RSV showed an early peak from October to the first half of December 2021 compared to its usual seasonality. In a previous study, we have demonstrated that RSV circulation was incredibly low from September 2020 to January 2021, in contrast with what we found in the same period in 2021-2022. Comparing RSV and SARS-CoV-2 incidences, we found that these two viruses spread in opposite ways: when SARS-CoV-2 present an incidence peak, RSV circulation reduced and viceversa. Conclusion(s): The relationship between RSV and SARS-CoV-2 showed that viral interference plays a crucial role in their epidemiology.

Multiple detection of 13 kinds of viruses in 500 children with acute respiratory tract infection in Hami of Xinjiang province

OBJECTIVE: To investigate and analyze multiple detection of 13 kinds of viruses in 500 children with acute respiratory tract infection in Hami of Xinjiang. METHODS: A total of 500 children with acute respiratory tract infection treated in the hospital between Jan 2018 and Jan 2021 were enrolled. Thirteen kinds of respiratory infection viruses including human respiratory syncytial virus(RSV), human rhinovirus(hRV), respiratory adenovirus(AdV), influenza A and B viruses(Inf A, Inf B), parainfluenza virus(PIV 1/2/3), human enterovirus(hEV), human metapneumovirus(hMPV), human coronavirus(hCoV 229E/OC43) and human Boca virus(hBoV) were detected by multiple reverse transcription polymerase chain reaction(RT-PCR) amplification and capillary electrophoresis. And the results were compared with those by direct sequencing method. RESULTS: Of the 500 samples, 379 samples were positive(75.80%), and the top three detection rates were RSV(19.40%), hRV(16.00%) and Inf B(12.60%). The differences in positive rates of the respiratory virus among <1 year group, 1-3 years group and >3 years group were significant(84.97%, 77.47%, 65.45%)(P<0.05). The detection rate of RSV was the highest in <1 year group, and the detection rates of Inf A and Inf B were the highest in >3 years group. The differences in positive rates of respiratory viruses among the spring group, summer group, autumn group and winter group were significant(74.05%, 63.73%, 77.24%, 84.03%)(P<0.05). The detection rates of RSV, PIV 3, and hMPV were the highest in the winter group, and detection rate of AdV was the highest in spring group. CONCLUSION: RSV is the main infection virus in children with acute respiratory infection in Hami of Xinjiang. The distribution of respiratory viruses is related to age and onset season in children.

The Circulation of Common Respiratory Viruses and Their Co-infection with Severe Acute Respiratory Syndrome Coronavirus 2 Before and After Coronavirus Disease of 2019 Vaccination

Background: Respiratory viruses play important roles in respiratory tract infections;they are the major cause of diseases such as the common cold, bronchiolitis, pneumonia, etc., in humans that circulate more often in the cold seasons. During the COVID-19 pandemic, many strict public health measures, such as hand hygiene, the use of face masks, social distancing, and quarantines, were implemented worldwide to control the pandemic. Besides controlling the COVID-19 pandemic, these introduced measures might change the spread of other common respiratory viruses. Moreover, with COVID-19 vaccination and reducing public health protocols, the circulation of other respiratory viruses probably increases in the community. Objective(s): This study aims to explore changes in the circulation pattern of common respiratory viruses during the COVID-19 pan-demic. Method(s): In the present study, we evaluated the circulation of seven common respiratory viruses (influenza viruses A and B, rhi-novirus, and seasonal human Coronaviruses (229E, NL63, OC43, and HKU1) and their co-infection with SARS-CoV-2 in suspected cases of COVID-19 in two time periods before and after COVID-19 vaccination. Clinical nasopharyngeal swabs of 400 suspected cases of COVID-19 were tested for SARS-CoV-2 and seven common respiratory viruses by reverse transcription real-time polymerase chain reaction. Result(s): Our results showed common respiratory viruses were detected only in 10% and 8% of SARS-CoV-2-positive samples before and after vaccination, respectively, in which there were not any significant differences between them (P-value = 0.14). Moreover, common viral respiratory infections were found only in 12% and 32% of SARS-CoV-2-negative specimens before and after vaccination, respectively, in which there was a significant difference between them (P-value = 0.041). Conclusion(s): Our data showed a low rate of co-infection of other respiratory viruses with SARS-CoV-2 at both durations, before and after COVID-19 vaccination. Moreover, the circulation of common respiratory viruses before the COVID-19 vaccination was lower, probably due to non-pharmaceutical interventions (NPI), while virus activity (especially influenza virus A) was significantly in-creased after COVID-19 vaccination with reducing strict public health measures.Copyright © 2023, Author(s).

Aseptic meningitis caused by Coronavirus OC43 in a child: A case report

Human coronavirus OC43 (HCoV-OC43) is one of the coronaviruses that cause the mild cold. On the other hand, extra-respiratory manifestations such as central nervous system infections with HCoV-OC43 are very rarely reported. We present a case of a previously healthy immunocompetent child with acute aseptic meningitis, as a result of HCoV-OC43 who admitted to the emergency department with a complaint of unconsciousness.. Respiratory tract and cerebrospinal fluid culture showed HCoV-OC43 in viral screening. During the follow-up period, the patient was completely asymptomatic, with normalized consciousness. The clinicians should keep in mind that HCoV-OC43 can be the etiological agent in the differential diagnosis of aseptic meningitis in immunocompetent individuals with reversible neurological symptoms.Copyright © 2022, Derman Medical Publishing. All rights reserved.

SARS-CoV-2 in Terms of Medical Microbiology Laboratory.

Coronaviruses (CoV), which are in the Coronaviridae family, cause different severity of gastrointestinal, respiratory and systemic diseases in wild and domestic animals, and can lead to different clinical manifestations, ranging from colds to pneumonia, depending on immunity. To date, seven types of coronavirus have been identified as infectious agents in humans;of these, HCoV 229E, HCoV NL63, HCoV HKU1 and HCoV OC43 typically cause cold symptoms in immunocompetent individuals, while SARS-CoV (Severe Acute Respiratory Syndrome Coronavirus) and MERS-CoV (Middle East Respiratory Syndrome Coronavirus) is zoonotic and cause severe respiratory diseases and deaths. SARS-CoV-2, the causative agent of COVID-19, is the seventh coronavirus identified as an infection agent in humans, which started in December 2019 in Wuhan, Hubei Province of China and was identified as a pandemic in a short time. Since the World Health Organization (WHO) defines SARS-CoV-2-sourced COVID-19 as a pandemic, and because of the increasing number of cases and deaths worldwide, structure of the novel virus and viral diagnosis methods gained importance respectively for vaccine studies and for controlling the outbreak caused by the virus.Copyright © 2020 Ankara Pediatric Hematology Oncology Training and Research Hospital. All rights reserved.

The Genomes of SARS-CoV-2 and Related Coronaviruses: Are Accessory Proteins Key for Pathogenesis?

Objective: In January 2020, scientists deciphered the first genome of SARS-CoV-2 that has created a ravage in the world by infecting over 30 million people worldwide with above 0.95 million deaths as of mid-September 2020. With no potent therapeutics against COVID-19, research-ers around the world are relentlessly working for the development of a vaccine that can ease the pain the world is suffering today, both in terms of economic and psychological instability. Understanding the genome of SARS-CoV-2 is essential to decipher the keys that would help scientists to develop drugs or vaccines to prevent the disease. Method(s): Coronaviruses are not unknown to the human as other than SARS-CoV-2, at least six ad-ditional coronaviruses (SARS-CoV, MERS-CoV, HCoV-229E, HCoV-NL63, HCoV-OC43, and HCoV-HKU1) are known that causes mild to severe diseases in human. We have compared the se-quences of these seven coronaviruses to identify the key regions which are responsible for pathoge-nesis. Result(s): The genomes of the seven coronaviruses that are known to infect humans differ signifi-cantly, especially in the regions of accessory genes. Conclusion(s): The analysis of these virus genomes is the key to find out targets for the development of a potent drug or vaccine against COVID-19.Copyright © 2021 Bentham Science Publishers.

Functional SARS-CoV-2 cross-reactive CD4+ T cells established in early childhood decline with age.

Pre-existing SARS-CoV-2-reactive T cells have been identified in SARS-CoV-2-unexposed individuals, potentially modulating COVID-19 and vaccination outcomes. Here, we provide evidence that functional cross-reactive memory CD4+ T cell immunity against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is established in early childhood, mirroring early seroconversion with seasonal human coronavirus OC43. Humoral and cellular immune responses against OC43 and SARS-CoV-2 were assessed in SARS-CoV-2-unexposed children (paired samples at age two and six) and adults (age 26 to 83). Pre-existing SARS-CoV-2-reactive CD4+ T cell responses targeting spike, nucleocapsid, and membrane were closely linked to the frequency of OC43-specific memory CD4+ T cells in childhood. The functional quality of the cross-reactive memory CD4+ T cell responses targeting SARS-CoV-2 spike, but not nucleocapsid, paralleled OC43-specific T cell responses. OC43-specific antibodies were prevalent already at age two. However, they did not increase further with age, contrasting with the antibody magnitudes against HKU1 (ß-coronavirus), 229E and NL63 (α-coronaviruses), rhinovirus, Epstein-Barr virus (EBV), and influenza virus, which increased after age two. The quality of the memory CD4+ T cell responses peaked at age six and subsequently declined with age, with diminished expression of interferon (IFN)-γ, interleukin (IL)-2, tumor necrosis factor (TNF), and CD38 in late adulthood. Age-dependent qualitative differences in the pre-existing SARS-CoV-2-reactive T cell responses may reflect the ability of the host to control coronavirus infections and respond to vaccination.

ZFP36 ring finger protein like 1 significantly suppresses human coronavirus OC43 replication.

CCCH-type zinc figure proteins (ZFP) are small cellular proteins that are structurally maintained by zinc ions. Zinc ions coordinate the protein structure in a tetrahedral geometry by binding to cystine-cystine or cysteines-histidine amino acids. ZFP's unique structure enables it to interact with a wide variety of molecules including RNA; thus, ZFP modulates several cellular processes including the host immune response and virus replication. CCCH-type ZFPs have shown their antiviral efficacy against several DNA and RNA viruses. However, their role in the human coronavirus is little explored. We hypothesized that ZFP36L1 also suppresses the human coronavirus. To test our hypothesis, we used OC43 human coronavirus (HCoV) strain in our study. We overexpressed and knockdown ZFP36L1 in HCT-8 cells using lentivirus transduction. Wild type, ZFP36L1 overexpressed, and ZFP36L1 knockdown cells were each infected with HCoV-OC43, and the virus titer in each cell line was measured over 96 hours post-infection (p.i.). Our results show that HCoV-OC43 replication was significantly reduced with ZFP36L1 overexpression while ZFP36L1 knockdown significantly enhanced virus replication. ZFP36L1 knockdown HCT-8 cells started producing infectious virus at 48 hours p.i. which was an earlier timepoint as compared to wild -type and ZFP36L1 overexpressed cells. Wild-type and ZFP36L1 overexpressed HCT-8 cells started producing infectious virus at 72 hours p.i. Overall, the current study showed that overexpression of ZFP36L1 suppressed human coronavirus (OC43) production.

SARS-CoV-2 in Terms of Medical Microbiology Laboratory

Coronaviruses (CoV), which are in the Coronaviridae family, cause different severity of gastrointestinal, respiratory and systemic diseases in wild and domestic animals, and can lead to different clinical manifestations, ranging from colds to pneumonia, depending on immunity. To date, seven types of coronavirus have been identified as infectious agents in humans;of these, HCoV 229E, HCoV NL63, HCoV HKU1 and HCoV OC43 typically cause cold symptoms in immunocompetent individuals, while SARS-CoV (Severe Acute Respiratory Syndrome Coronavirus) and MERS-CoV (Middle East Respiratory Syndrome Coronavirus) is zoonotic and cause severe respiratory diseases and deaths. SARS-CoV-2, the causative agent of COVID-19, is the seventh coronavirus identified as an infection agent in humans, which started in December 2019 in Wuhan, Hubei Province of China and was identified as a pandemic in a short time. Since the World Health Organization (WHO) defines SARS-CoV-2-sourced COVID-19 as a pandemic, and because of the increasing number of cases and deaths worldwide, structure of the novel virus and viral diagnosis methods gained importance respectively for vaccine studies and for controlling the outbreak caused by the virus.

Immune regulation of AP-N, DDP4 and ACE2 receptors and the susceptibility to infections with coronavirus 229E, MERS-CoV and SARS-CoV2

The Coronaviridae family includes the seven known human coronavi-ruses (HCoV) that cause mild to moderate respiratory infections (HCo-V-229E, HCoV-NL63, HCoV-OC43, HCoV-HKU1) as well as severe illness and death (MERS-CoV, SARS-CoV, SARS-CoV-2). Severe infections in-duce inflammatory responses that are often intensified by host ada-ptive immune pathways. Proinflammatory responses are triggered by CoV entry mediated by host cell surface receptors. Interestingly, four of the seven strains use cell surface metallopeptidases as receptors. The entry receptors for specific coronaviruses are: aminopeptidase N (AP-N), dipeptidyl peptidase 4 (DPP4) and angiotensin-converting enzyme 2 (ACE2) for HCoV-229E, MERS-CoV, SARS-CoV and SARS-CoV2, respectively. In addition, these receptors perform many physiological functions, including the regulation of the circulatory and immune sys-tems. Coronavirus receptors are also highly expressed in human tissues and organs (intestines, kidneys, heart, lungs). Additionally, some cy-tokines, chemokines, and other proteins and immune cells influence the modulation of the expression of coronavirus receptors. This review presents the biological role of receptor proteins in the regulation of human physiological systems, the impact of the immune response on susceptibility to coronavirus infections, and the potential effects of glucocorticosteroids (GCS) and specific allergen immunotherapy (AIT) used in the treatment of asthma and allergy on the suscpetibility to coronaviral infections.

Variants of SARS coronavirus-2 and their potential impact on the future of the COVID-19 pandemic

The emergence of SARS-CoV-2 variants of concern (VOCs), especially the sweeping spread of the delta variant, and differing public health management strategies, have rendered global eradication of SARS-CoV-2 unlikely. The currently available COVID-19 vaccines, including the inactivated whole virus vaccines, mRNA vaccines, and adenovirus-vectored vaccines, are effective in protecting people from severe disease and death from COVID-19, but they may not confer good mucosal immunity to prevent the establishment of infection and subsequent viral shedding and transmission. Mucosal vaccines delivered via intranasal route may provide a promising direction, which, if given as a third dose after a two-dose series of intramuscular vaccination, likely promotes mucosal immunity in addition to boosting the systemic cell-mediated immunity and antibody response. However, immunity induced by vaccination, and natural infection as well, is likely to wane followed by re-infection as in the case of human coronaviruses OC43, 229E, NL63, and HKU1. It is a challenge to prevent and control COVID-19 worldwide with the increasing number of VOCs associated with increased transmissibility and changing antigenicity. Nevertheless, we may seek to end the current pandemic situation through mass vaccination and gradual relaxation of non-pharmaceutical measures, which would limit the incidence of severe COVID-19. Repeated doses of booster vaccine will likely be required, similar to influenza virus, especially for the elderly and the immunocompromised patients who are most vulnerable to infection.

Antiviral effect of Fufang yinhua jiedu (FFYH) granules against coronavirus and its potential mechanism

To investigate the effect of Fufang yinhua jiedu (FFYH) granules against coronavirus and its potential mechanism, we used Huh7, Huh7.5, H460, and C3A cell lines as in vitro models to evaluate the cytotoxicity and antiviral activity of FFYH by observation of cell pathogenic effect (CPE);and then the inhibitory effect of FFYH on the transcription expression of coronavirus RNA and inflammatory factor mRNA were evaluated by quantitive reverse transcription PCR (qRT-PCR);finally, the inhibitory effect of FFYH on the expression of coronavirus protein and its underlying mechanism against coronavirus were investigated by Western blot and immunofluorescence. Our results indicated that 50% toxic concentration (TC50) FFYH on Huh7, Huh7.5, H460, and C3A cells were 2 035.21, 5 245.69, 2 935.28 and 520 µg·mL-1, respectively;50% inhibitory concentration (IC50) of FFYH on HCoV-229E in Huh7 and Huh7.5 cells were 438.16 and 238.54 µg·mL-1 with safety index (SI) of 4.64 and 21.99, respectively;IC50 of FFYH on HCoV-OC43 in H460 cells was 165.13 µg·mL-1 with SI of 17.78. Moreover, FFYH not only could inhibit the replication of coronaviruses (HCoV-OC43 and HCoV-229E) through inhibiting the transcription of viral RNA and the expression of viral protein, but also effectively suppress the expression of inflammatory factors interleukin-6 (IL-6), tumor necrosis factor α (TNF-α) and interleukin-8 (IL-8) at mRNA level caused by coronaviruses, which might be associated with the inhibitory effect of FFYH on mitogen-activated protein kinase (MAPK) pathway and the nuclear translocation of nuclear transcription factor-κB (NF-κB). In summary, our results demonstrated that FFYH exhibited a good in vitro anti-coronavirus effect, which provides a theoretical basis for its clinical use in the treatment of anti-coronavirus pneumonia.

Effectiveness of neutral electrolyzed water in inactivating HCoV-OC43 and SARS-CoV-2 on the surfaces of plastic and the medicinal plant Centella asiatica (L.) urban.

Concerns have been raised about viral contamination, including in crops due to the recent coronavirus disease 2019 pandemic. Limited evidence is available to support the use of sanitizing agents for human coronavirus-contaminated medicinal plants. Thus, we aimed to investigate the persistence of infectious human coronavirus OC43 (HCoV-OC43) as a SARS-CoV-2 surrogate in storage conditions and the capability of neutral electrolyzed water (NEW) to inactivate coronavirus, including in fresh plants such as C. asiatica. The levels of infectious HCoV-OC43 and the triterpenoid content of C. asiatica were quantified using a plaque assay and high-performance liquid chromatography, respectively. The results showed that the persistence of HCoV-OC43 on C. asiatica leaves is identical to that on inert polystyrene. When covered and kept at room temperature with high humidity (>90% RH), HCoV-OC43 can be stable on C. asiatica leaves for at least 24 h. NEW with 197 ppm of available chlorine concentration (ACC) was effective in inactivating both infectious HCoV-OC43 and SARS-CoV-2 in suspension (≥3.68 and ≥4.34 log reduction, respectively), and inactivated dried HCoV-OC43 on the surfaces of C. asiatica leaves (≥2.31 log reduction). Soaking C. asiatica leaves for 5 min in NEW with 205 ppm of ACC or water resulted in significantly higher asiaticoside levels (37.82 ± 0.29 and 35.32 ± 0.74 mg/g dry weight, respectively), compared to the unsoaked group (29.96 ± 0.78 mg/g dry weight). These findings suggest that although coronavirus-contaminated C. asiatica leaves can pose a risk of transmission, NEW could be an option for inactivation.

The genetic characteristics of human coronavirus OC43 in cases of severe acute respiratory infection

Human coronavirus (HCoV) is one of the important pathogens of human respiratory tract infection. in order to clarify the genetic characteristics of HCoV-0C43 in severe acute respiratory infection (SARI) cases at the molecular level, a total of 374 samples obtained from SARI cases in Henan Province, China, in 2019 were screened for the nucleic acids of HCoV -0C43 by real - time polymerase chain reaction (PCR). Reverse transcription-PCR amplification and sequencing of spike (5) RNA-dependent RNA polymerase (12dRp) and nucleocapsid (N) was carried out in samples with positive detection of the nucleic acids of FICoV-0C43. Upon. combination Of 42 representative sequences obtained from the GenBank database, phylogenetic trees were constructed based on three full-length sequences of S, RdRp and N genes. The FICoV -0C43 strains obtained from SARI cases were genotyped and the genetic characteristics of three target genes were analyzed. Variations in the amino acids of S protein (an important antigen of HCoV-0C43) were also analyzed. Results showed that 15 (4.01%) out of 374 samples from SARI cases were positive for FICoV-0C43, and the full-length sequences of S, RdRp and N genes were obtained from 4 out of 15 samples. Based on the phylogenetic trees of these three target genes, three strains belonged to the U genotype and one strain belonged to the H genotype. Analysis of the amino - acid variations of S protein indicated that there were three special sites of amino - acid variation (L272P, P5165 and 5902A) among the G genotype strains in 2019, including the three strains in our study and USA /MN306041/SC0810/2019. Another special variation in amino acids (N484D) was found among the II genotype strains in 2019, including one strain in our study and USA/MN306043/SC0841/2019. Based on the genotype identification and genetic characteristics of HCoV-0C43 strains from SARI cases in Henan Province in 2019, baseline data for the study of molecular epidemiology of HCoV 0C43 in China have been provided.