Establishment and application of triple PCR method for CPV, CCoV and CRV

Canine parvovirus (CPV), canine coronavirus (CCoV) and canine rotavirus (CRV) are the three main causative viruses of diarrhea in dogs with similar clinical symptoms;thereby it is necessary to establish a high effective molecular detection method for differentiating the above pathogens. By optimizing the primer concentration and annealing temperature, a triple PCR method was established for simultaneous detection of CPV, CCoV and CRV, and then the specificity, sensitivity and repeatability of the method were tested. The results showed that the target fragments of CPV VP2 gene (253 bp), CCoV ORF-1b gene (379 bp) and CRV VP6 gene (852 bp) could be accurately amplified by the triple PCR method with high specificity, the detection limits of CPV, CCOV and CRV were 6.44x10-1 pg/L, 8.72x10-1 pg/L and 8.35x10-1 pg/L respectively with high sensitivity, and the method had good stability. Using this triple PCR method, 135 canine diarrhea fecal samples collected in Chengdu region from 2019 to 2020 were detected, and compared with those of single PCR method. The detection rates of CPV, CCoV and CRV were 16.30%, 20.74% and 4.44%, respectively, and the total infection rate was 51.11% (65/135) with 20.00% (13/65) co-infection rate. The detection results were consistent with three single PCR methods. In conclusion, CPV/CCoV/CRV triple PCR method successfully established in this paper can be applied as an effective molecular method to detection of related pathogens and to the epidemiological investigation.

Establishment of a duplex fluorescent quantitative PCR assay for detection of Porcine circovirus type 2 and type 3

To establish a method for simultaneous detection of porcine circovirus type 2 (PCV2) and porcine circovirus type 3 (PCV3), specific primers and TaqMan probes were designed after sequence alignment according to the specific sequences of PCV2 Cap gene and PCV3 Cap gene on GenBank. By optimizing the reaction conditions, a duplex fluorescence quantitative PCR detection method for simultaneous detection of porcine circovirus type 2 and 3 was established, and the specificity, sensitivity, and reproducibility were tested. Specificity test results showed that in addition to the positive test results for PCV2 and PCV3, tests for PRRSV, CSFV, PPV, PRV, PEDV, and TGEV were all negative with no cross-reaction, indicating its good specificity. Sensitivity test results showed that the minimum detection limit for detection of PCV2 and PCV3 can both reach 10 copies.L-1, indicating its high sensitivity. The coefficient of variation within and between groups of this method was less than 2%, indicating its good stability. A total of 181 pork and whole blood samples collected from Zhejiang Province were tested using the detection method established in this article and the standard common fluorescent PCR detection method. The results showed that the positive rate of PCV2 was 50.83% (92/181), the positive rate of PCV3 was 37.57% (68/181), and the co-infection rate of PCV2 and PCV3 was 12.15% (22/181). The above detection results of ordinary fluorescent PCR were 50.28% (91/181), 36.46% (66/181), and the co-infection rate was 11.60% (21/181). The coincidence rates of the two methods for PCV2 and PCV3 can reach 98.91% and 97.06%, and the coincidence rate for PCV2 and PCV3 mixed infection were 95.45%. In summary, the duplex fluorescence quantitative PCR detection method established in this experiment can distinguish PCV2 and PCV3 rapidly, which can be used for pathogen detection and epidemiological investigation.

Effect of Drebrin protein on the proliferation of PEDV in Vero cells

Previous studies have revealed that developmental regulated brain protein (Drebrin) is involved in cell- to-cell communication, nerve transmission, tumor metastasis, spermatogenesis and other life activities, but there are few studies on viruses. The aim of the current research was therefore, to study the function of Drebrin and its effect on the proliferation of porcine epidemic diarrhea virus (PEDV). The Drebrin gene was cloned according to the Drebrin gene sequence (XM_008015438.2) of Chlorocebus sabaeus registered by GenBank, and the phylogenetic tree was constructed to analyze its homology. The results showed that the CDS region of Vero cells Drebrin gene was 2088 bp long, encoding 695 amino acids, and was relatively conserved and had high homology with all species. To investigate the effect of Drebrin on the proliferation of PEDV in Vero cells, the eukaryotic expression vector pcDNA3.1-Drebrin-Flag was constructed. After transfection of Vero cells with different concentrations of pcDNA3.1-Drebrin-Flag, cells were infected with PEDV. Our results showed that overexpression of Drebrin in Vero cells could significantly inhibit the intracellular PEDV mRNA level and N protein expression, reduce the extracellular virus titer and inhibit the proliferation of PEDV. Further study on the interaction between Drebrin and PEDV S proteins by laser confocal technique was also performed. The results showed that Drebrin and S protein were co-located in the cytoplasm, suggesting that the two proteins may interact with each other. This study demonstrated for the first time that Drebrin can inhibit PEDV proliferation in Vero cells, laying a foundation for further research in to Drebrin function and provides a valuable information for anti-PEDV research.

Development and application of a multiplex fluorescent quantitative RT-PCR for detection of Porcine epidemic diarrhea virus, porcine coronavirus and porcine acute diarrhea syndrome coronavirus

To develop a multiplex fluorescent quantitative RT-PCR for the detection of porcine epidemic diarrhea virus (PEDV), porcine deltacoronavirus (PDCoV) and swine acute diarrhea syndrome coronavirus (SADS-CoV), in this study, specific primers/probes were designed based on the conserved regions of M, M and N gene sequences of PEDV, PDCoV and SADS-CoV, respectively. After optimization of the reaction conditions, a multiplex fluorescent quantitative RT-PCR for PEDV, PDCoV and SADS-CoV was established. The results of specificity assay showed that the method was positive for detection of PEDV, PDCoV and SADS-CoV, and negative for detection of porcine transmissible gastroenteritis virus, porcine rotavirus, porcine reproductive and respiratory syndrome virus, porcine pseudorabies virus, porcine circovirus type 2, porcine parvovirus, classical swine fever virus and foot-and-mouth disease virus. The results of sensitivity assay showed that the detection limit of this method for PEDV, PDCoV, and SADS-CoV plasmids standard was 1.0x101 copies/L, and had a good linear relationship with their Ct values in the range of 101 copies/L to 106 copies/L. The results of repeatability assay showed that the coefficients of variation (CVs) of intra- and inter-assay reproducibility ranged from 0.33% to 2.53%, indicating good repeatability and stability. To evaluate the effects of the developed method, 100 clinical samples collected from different parts of Henan province were used for detection of these three viruses and compared with those of single RT-PCR and standard methods. The results of multiplex fluorescent quantitative RT-PCR showed that the positive rates of PEDV, PDCoV and SADS-CoV were 38% (38/100), 14% (14/100) and 5% (5/100), respectively. There was no mixed infection. The coincidence rate with the standard detection methods of PEDV and PDCoV was 100%, and the sensitivity was higher than that of single RT-PCR. In this study, a specific, sensitive and rapid multiplex fluorescent quantitative RTPCR method was established for the first time, which could be used for the differential detection of PEDV, PDCoV and SADS-CoV, and laid a foundation for the differential diagnosis and control of porcine diarrheal diseases.

Photodynamic therapy: a new treatment against COVID-19

In 2019, a new coronavirus (COVID-19) was discovered in Wuhan, China, which soon spread all over the world. The main hallmark of the disease includes fever, diarrhea, vomiting, and dry cough with dyspnea in half of the patients and acute respiratory distress syndrome (ARDS). Currently, no definitive treatment or prevention therapy exists for COVID-19 but scientists and researchers all over the world are relentlessly working to understand COVID-19 to discover novel therapeutic tools and vaccines. Today, photodynamic therapy (PDT) has been investigated as a noninvasive therapy for the treatment of this pandemic and was able to increase the healing process with the help of appropriate photosensitizers by targeting the pathogen inside the patient's body.

Molecular investigation of Campylobacter spp. and Salmonella infection in children with community acquired diarrhea

Introduction : Acute gastroenteritis is a typical disorder that accounts for 8-12% of pediatric outpatient visits. Campylobacter and Salmonella infections account for about 8.4% and 11% of global diarrhea cases. Due to the importance of these bacteria in pediatric diseases, the aim of this study was to determine the infectious rate of Salmonella and Campylobacter species and also the frequency of the gene encoding Cytholethal distending toxin in children with community-acquired diarrhea. Materials and Methods: Stool samples of children under 5 years of age with diarrhea were collected. The samples were related to children referred to hospitals in Hamadan, Ardabil, Bandar Abbas and two hospitals in Tehran. DNA was extracted from the samples using a DNA extraction kit from stool. The presence of Campylobacter in the studied samples was detected by polymerase chain reaction using specific primers. A control stool sample was spiked with 10-fold dilution of C. jejuni suspension for LOD (detection limit determination) measurement. Results: In this study, PCR results showed a LOD of 100 CFU per gram in the spiked feces sample. Accordingly, out of 144 fecal samples of children with acute diarrhea, one case was positive for Campylobacter jejuni;this sample was also positive for the presence of cdtB gene. Presence of Salmonella was confirmed in two samples of the patients (1.4%). Conclusion: Low prevalence of Campylobacter and Salmonella was detected in symptomatic children under 5 years of age during the Covid-19 pandemic. Examination of these samples for viruses and other microbial agents can clarify the etiology of diarrhea in children referred to the hospitals.

Porcine epidemic diarrhoea virus (PEDV) infection activates AMPK and JNK through TAK1 to induce autophagy and enhance virus replication.

Autophagy plays an important role in defending against invading microbes. However, numerous viruses can subvert autophagy to benefit their replication. Porcine epidemic diarrhoea virus (PEDV) is an aetiological agent that causes severe porcine epidemic diarrhoea. How PEDV infection regulates autophagy and its role in PEDV replication are inadequately understood. Herein, we report that PEDV induced complete autophagy in Vero and IPEC-DQ cells, as evidenced by increased LC3 lipidation, p62 degradation, and the formation of autolysosomes. The lysosomal protease inhibitors chloroquine (CQ) or bafilomycin A and Beclin-1 or ATG5 knockdown blocked autophagic flux and inhibited PEDV replication. PEDV infection activated AMP-activated protein kinase (AMPK) and c-Jun terminal kinase (JNK) by activating TGF-beta-activated kinase 1 (TAK1). Compound C (CC), an AMPK inhibitor, and SP600125, a JNK inhibitor, inhibited PEDV-induced autophagy and virus replication. AMPK activation led to increased ULK1^S777 phosphorylation and activation. Inhibition of ULK1 activity by SBI-0206965 (SBI) and TAK1 activity by 5Z-7-Oxozeaenol (5Z) or by TAK1 siRNA led to the suppression of autophagy and virus replication. Our study provides mechanistic insights into PEDV-induced autophagy and how PEDV infection leads to JNK and AMPK activation.

A Cholera Case Imported from Bangladesh to Italy: Clinico-Epidemiological Management and Molecular Characterization in a Non-Endemic Country.

Despite the number of cholera outbreaks reported worldwide, only a few cases are recorded among returning European travellers. We describe the case of a 41-year-old male, returning to Italy after a stay in Bangladesh, his origin country, who presented with watery diarrhoea. Vibrio cholerae and norovirus were detected in the patient's stools via multiplex PCR methods. Direct microscopy, Gram staining, culture and antibiotic susceptibility tests were performed. The isolates were tested using end-point PCR for the detection of potentially enteropathogenic V. cholera. Serotype and cholera toxins identification were carried out. Whole genome sequencing and bioinformatics analysis were performed, and antimicrobial resistance genes identified. A phylogenetic tree with the most similar genomes of databases previously described was built. Sample of the food brought back by the patient were also collected and analysed. The patient was diagnosed with V. cholerae O1, serotype Inaba, norovirus and SARS-CoV-2 concomitant infection. The isolated V. cholerae strain was found to belong to ST69, encoding for cholera toxin, ctxB7 type and was phylogenetically related to the 2018 outbreak in Dhaka, Bangladesh. Adopting a multidisciplinary approach in a cholera non-endemic country ensured rapid and accurate diagnosis, timely clinical management, and epidemiological investigation at national and international level.

Swine acute diarrhoea syndrome coronavirus (SADS-CoV) Nsp5 antagonizes type I interferon signaling by cleaving DCP1A.

Swine acute diarrhoea syndrome coronavirus (SADS-CoV), which is a recently discovered enteric coronavirus, is the major aetiological agent that causes severe clinical diarrhoea and intestinal pathological damage in pigs, and it has caused significant economic losses to the swine industry. Nonstructural protein 5, also called 3C-like protease, cleaves viral polypeptides and host immune-related molecules to facilitate viral replication and immune evasion. Here, we demonstrated that SADS-CoV nsp5 significantly inhibits the Sendai virus (SEV)-induced production of IFN-ß and inflammatory cytokines. SADS-CoV nsp5 targets and cleaves mRNA-decapping enzyme 1a (DCP1A) via its protease activity to inhibit the IRF3 and NF-κB signaling pathways in order to decrease IFN-ß and inflammatory cytokine production. We found that the histidine 41 and cystine 144 residues of SADS-CoV nsp5 are critical for its cleavage activity. Additionally, a form of DCP1A with a mutation in the glutamine 343 residue is resistant to nsp5-mediated cleavage and has a stronger ability to inhibit SADS-CoV infection than wild-type DCP1A. In conclusion, our findings reveal that SADS-CoV nsp5 is an important interferon antagonist and enhance the understanding of immune evasion by alpha coronaviruses.

Insights and progress on epidemic characteristics, genotyping, and preventive measures of PEDV in China: A review.

Porcine Epidemic Diarrhoea (PED) is an acute, extremely infectious intestinal disease of pigs caused by the Porcine Epidemic Diarrhoea Virus (PEDV). The virus can affect pigs of all breeds and age groups and shows varying degrees of symptoms, with piglets, in particular, being infected with mortality rates of up to 100%. PEDV was first identified in China in the 1980s and in October 2010 a large-scale PED outbreak caused by a variant of PEDV occurred in China, resulting in huge economic losses. Initially, vaccination can effectively prevent the classical strain, but since December 2010, the PEDV variant has caused "persistent diarrhoea" with severe vomiting, watery diarrhoea, and high morbidity and mortality in newborn piglets as the dominant clinical features, with a significant increase in morbidity and mortality. This indicates that PEDV strains have mutated during evolution and that traditional vaccines no longer provide effective cross-immune protection, so it is necessary to optimize immunization programs and find effective treatments through epidemiological surveys of PEDV to reduce the economic losses caused by infections with mutated strains. This article reviews the progress of research on the aetiology, epidemiological characteristics, genotyping, pathogenesis, transmission routes, and comprehensive control of PEDV infection in China.

Glycyrrhizin inhibits swine acute diarrhea syndrome coronavirus infection via the HMGB1/TLR4/JNK signal pathway

Swine acute diarrhea syndrome coronavirus (SADS-CoV), a newly discovered enteric coronavirus, is the etiological agent that causes severe clinical diarrhea and intestinal pathological damage in piglets. In this study, Vero E6 and IPI-2I cells were pretreated with different concentrations of glycyrrhizin (GLY) for 2 hours, and then infected with different concentrations of SADSCoV, aiming to investigate the inhibitory effect of GLY on SADS-CoV. Western blot and TCID50 results revealed a significantly decreased N protein expression and viral titer, indicating that GLY can inhibit the infection of SADS-CoV. Vero E6 and IPI-2I cells were pretreated with different concentrations of GLY for 2 hours and infected with SADS-CoV. Western blot results showed that when the concentration of GLY was 0.8 mmol/L, the expression of N protein decreased significantly, indicating that GLY inhibited the invasion of the virus. At first, cells were treated with 0.4 mmol/L GLY, and cell samples were collected at 2 hours, 6 hours and 12 hours after being infected with SADS-CoV for analysis, and the expression of N protein were found to be significantly reduced at all points, indicating that GLY had a significant inhibitory effect on the replication of the virus. GLY is a competitive inhibitor of high mobility group box 1 (HMGB1), and the receptors of HMGB1 mainly include TLR4 and RAGE. Based on this fact, the mutant plasmid at the key sites of HMGB1 (C45S, C106S, C45/106S) and the siRNA of the RAGE receptor were transfected to Vero E6 cells and infected with SADS-CoV, and the cell supernatant and samples were harvested. The western blot and TCID50 results showed that the expression of N protein and the virus titer were decreased, suggesting that GLY exerts its function by affecting the binding of HMGB1/TLR4/RAGE during SADS-CoV infection. To further explore the signaling pathway through which GLY functions, Vero E6 and IPI-2I cells were inoculated with SADS-CoV, and cell samples were harvested, western blot was used to detect the changes of MAPK proteins. The results showed that the protein expression levels of p-p38, p-JNK and p-ERK were up-regulated in the early and late stages, indicating that the MAPK pathway was activated by SADS-CoV infection. Vero E6 and IPI-2I were pretreated with different concentrations of GLY and TLR4 inhibitor TAK for 2 hours and infected with SADS-CoV. Protein samples were harvested and analysed by western blot which showed a decreased p-JNK and N proteins, while other proteins showed no significant changes. These results indicated that GLY and TAK regulated the phosphorylation of JNK but did not regulate the phosphorylation of p38 and ERK. Also, Vero E6 cells were treated with HMGB1 antibody, the siRNA of HMGB1 and HMGB1 mutants plasmid, and infected with SADS-CoV. Protein samples were harvested, western blot results showed that phosphorylation of JNK decreased, indicating that HMGB1 affected JNK phosphorylation. Finally, Vero E6 and IPI-2I cells were pretreated with different concentrations of JNK inhibitor SP600125 to infect SADS-CoV, western blot, TCID50 and IFA results showed that the expression of N protein and virus titer, as well as virus replication were reduced, indicating that SP600125 inhibited virus replication. In conclusion, our results revealed that GLY can inhibit in vitro replication of SADS- CoV, mainly through the HMGB1/TLR4/JNK signaling pathway. The discovery of this pathway provides theoretical support for the research of novel anti-SADS-CoV drugs.

Establishment and applications of a duplex quantitative real-time RT-PCR assay for simultaneous detection of bovine rhinitis A virus and bovine rhinitis B virus

Bovine rhinitis virus (BRV) is an important pathogen responsible for the bovine respiratory disease complex (BRDC) and can be divided into two genotypes (BRAV and BRBV). To establish a duplex quantitative real-time RT-PCR assay for simultaneous detection of BRAV and BRBV, specific primers and TaqMan probes targeting the 5'NTR of BRAV and 3'NTR of BRBV were designed. A duplex quantitative real- time RT- PCR assay for simultaneous detecting BRAV and BRBV was preliminarily established by optimizing reaction conditions for each step. The assay specifically detects BRAV and BRBV, and no crossreaction with other common bovine respiratory pathogens, including IDV, BCoV, BVDV-1, BRSV, BPIV-3, BAdV-3, mycoplasma bovis, Pasteurella multocida, Mannheimia haemolytica, Escherichia coli, and Salmonella, was observed. In addition, the sensitivity test showed that the detection limits of this assay were 3.2x101 copies/L for both BRAV and BRBV plasmid standards. Besides, the repeatability test showed that the variation coefficients of this assay were less than 0.05 from both lot-to-lot and intra-lot. These results showed that the assay has high specificity, extreme sensitivity, and good repeatability. Moreover, a total of 43 nasal swabs of BRDC cattle were tested by our assay and four other quantitative real-time RT-PCR assays, including 3 BRAV assays and 4 BRBV assays. The results showed that the detection rates of our assay were 32.56%(14/43) for BRAV and 30.23%(13/43) for BRBV, and the detection rates of other quantitative real-time RT-PCR assays were 0(0/43), 2.33%(1/43), 23.26%(10/43) for BRAV and 27.91% (12/43), 27.91%(12/43), 27.91%(12/43), 27.91%(12/43) for BRBV, indicating that our assay has a more substantial detection capability than other assays. This study firstly established a duplex quantitative real-time RT-PCR assay for simultaneous detection of BRAV and BRBV, and the assay exhibited high specificity, sensitivity, and stability. Moreover, the study firstly confirmed the existence of BRAV in China, contributing to the prevention and control of BRDC.

Surveillance of SARS CoV-2 and other respiratory viruses in 2020-2021 winter season

Aim: The global COVID-19 pandemic and new variants continue to seriously threaten society. In this study;It was aimed to investigate surveillance of SARS CoV-2 and other respiratory viruses in respiratory tract samples in the winter season of 2020-2021 in Sakarya province. Material and Method: The study was carried out at Sakarya Training and Research Hospital between 2020-2021. e study was carried out with respiratory tract samples (Nasopharyngeal swab) stored in the laboratory. Clinical samples included in study were stored in a Bio-SpeedyRvNATRtransfer tube (Bioeksen,Turkey) and no extraction was performed in accordance with manufacturer's instructions. All analyzes were recorded on BIO-RAD CFX-96C1000 Touch Real-time system device using Diagnovital influenza A/B, SARS CoV-2, RSV multiplex Real Time PCR amplification kit. Results: Of the 200 patients diagnosed with URTI/LRTI, 54.5% were male and 45.5% female. e most common clinical symptoms;sore throat 74%, cough 73.5%, fatigue 71%, fever 57%, runny nose 56%, headache 48.5%, sneezing 41.5%, loss of smell / taste 39.5%, diarrhea 36%, dyspnea was 31.5% and myalgia was 23.5%. PCR positivity rates of samples were analyzed as 28.5% for SARS COV-2 and 1.5% for RSV, respectively. PCR positivity for influenza A/B was not defined in the study. Considering the statistical significance between PCR results and COVID-19 symptoms in patients;symptoms of dyspnea (n=63), fever(n= 62) and sneezing(n=56), respectively, were statistically significant(p<0.05). Conclusion: Due to the circumstances, only three main viral agents could be investigated in the study. RSV was frequently identified as an important factor in pediatric patients, whereas influenza-which may be related to social and individual measures (mask,distance,hygiene)- was not detected in any sample. More comprehensive scientific studies are needed to support the data.

Interaction between target peptide and complementary peptide by bimolecular fluorescence complementary technology

[Objective] Using the bimolecular fluorescence complementation (BiFC) technology, the present experiment aimed to study the interaction relationship and localization of the target peptide and the complementary peptide based on the porcine epidemic diarrhea virus (PEDV) S protein receptor binding site peptide in living cells, so as to provide the foundation and theoretical support for the further use of the peptide in the detection of porcine epidemic diarrhea virus. [Method] The target peptide was designed according to the physical and chemical characteristics of the target protein, such as the amino acid composition, the type of charge, the ability to form intennolecular hydrogen bonds, the strength of polarity, and hydrophobicity;According to the amino acid composition of the target protein, a complementary peptide that interacted with it in theory was designed, and the target peptide and complementary peptide were predicted and analyzed by using bioinfonnatics tools;The target peptide and complementary peptide were inserted into the pBiFC-VC155 and pBiFC-VN173 vector, which was double digested by the EcoRI/XhoI and NotI/SalI, respectively, verified by enzyme digestion and sequencing, and then transfected into Vero cells to study the interaction between the target peptide and the complementary peptide, and the precise localization of BiFC complex in cells. [Result] Bioinfonnatics analysis showed that the target peptide and complementary peptide had hydrophilic and hydrophobic domains, respectively, and the hydrophilic domains were both positively and negatively charged, which could generate electrostatic attraction. The results of enzyme digestion and sequencing showed that the pBiFC-VC155-target peptide and pBiFC-VNI73-complementary peptide plasmids were successfully constructed;Cell transfection experiments showed that the target peptide and complementary peptide could form BiFC complexes in Vcro cells after co-transfection of recombinant plasmids, indicating that they could interact with each other;Indirect immuttolluorescence assay confirmed that the BiFC complex was mainly distributed in the nucleus. [Conclusion] It was confirmed that the peptide designed based on the PEW/ S protein receptor binding site can interact with each other in living cells, demonstrating the feasibility of the peptide for detection.

Improved virus inhibition by microencapsulated monoclonal antibody against porcine epidemic diarrhea virus

Porcine epidemic diarrhea virus (PEDV) has been affecting the swine industry, especially in suckling pigs in with a high mortality rate. Among all the strategies to overcome PEDV, boosting mucosal immunity in pig intestine via oral administration appears to be more efficient than other routes. However, there are biological obstacles such as acidic environment that could damage biologics, a product from organisms often used for PEDV treatment. The plant-derived 2C10 monoclonal antibody (mAb) from Nicotiana benthamiana produced by transient expression was revealed as one of the potential candidates against PEDV through oral delivery. Herein, we demonstrated the calcium-alginate microencapsulation system to protect the 2C10 mAb from the harsh condition in the stomach and to be released the 2C10 mAb when arriving in the intestine. The pH-responsive encapsulated 2C10 mAb microbeads were constructed from the calcium-alginate system. The microbeads were well-tolerated under the acidic environment of simulated gastric fluid (SGF) and were digested under the alkaline condition of simulated intestinal fluid (SIF). The encapsulated 2C10 mAb in the SPF-treated microbeads exhibited high virus neutralization efficiency in Vero cells when compared to the unencapsulated 2C10 mAb treated by SPF that cannot neutralize the virus. For these reasons, calcium-alginate microencapsulation system is an attractive platform to be considered as a candidate for the next generation of oral vaccine development.

The general characteristics of hospitalized patients with the diagnosis of COVID-19, and the relationship between presenting symptoms and clinical course: a single center experience

Objective: In this study, it was aimed to reveal the relationship between the clinical features, presenting symptoms, and prognosis of COVID-19 patients who were hospitalized in our center. Materials and Methods: 499 patients with the diagno-sis of COVID-19 followed in the service and intensive care units of Sakarya University Training and Research Hospital between March 2020 and January 2021 were included in the study. The clinical and demographical data of the patients were obtained from the patient files and hospital automation system. The obtained data were ana-lyzed statistically. Results: Of 499 patients, 171 were followed up in the ward and 328 in the intensive care unit. Follow-up of 230 patients resulted in death, while 269 patients were dis-charged. Comorbid diseases were found to be more fre-quently seen in the mortal group (p< 0.05). Mean leuko-cyte, neutrophil, c-reactive protein (CRP), procalcitonin (PCT), lactate dehydrogenase (LDH), ferritin, d-dimer, and troponin values were higher in the mortal group;whereas mean lymphocyte value was found to be lower (p< 0.05). While fever, cough, and other less common symptoms (diarrhea, nausea, muscle weakness, etc.) were more frequently seen in the non-mortal group (p=0.022, p=0.038, and p=0.000 respectively), shortness of breath was significantly more common in the mortal group (p=0.000). The frequency of symptoms such as sputum, fatigue, sore throat, and the headache were found to be similar in both groups (p >0.05). Conclusion: It was concluded that the clinical course of patients with dyspnea at admission may be more severe and these patients should be followed more closely.

Duplex Taq man qPCR for detecting porcine epidemic diarrhea and transmissible gastroenteritis viruses and epidemic study in Fujian

Objective: A Taq Man probe-based duplex real-time PCR for rapid detection of porcine epidemic diarrhea virus(PEDV) and transmissible gastroenteritis virus(TGEV) was developed. A study was conducted using the methodology to analyze the related 2019-2021 epidemic occurred in Fujian. Method: Specific primers and probes labeled with FAM and VIC were designed to amplify the N gene of PEDV and the S gene of TGEV, respectively. A reaction system for the assay was established, optimized, and tested for sensitivity, specificity, and repeatability. The assay was used for the viral detection on297 suspected clinic specimens collected from 2019 to 2021 for an epidemiology study. Result: The newly developed duplex qPCR methodology showed a sensitivity of 10 copies.L-1 on PEDV and TGEV, which was 100 times higher than that of regular PCR. There were no cross reactions with other common viruses. The inter-and intra-assays had variations on Ct values below 1%. On the 297 specimens, the infection rate of PEDV was 88.89%, that of TGEV 1.01%, and that of both PEDV and TGEV 3.37%. Conclusion: The established duplex qPCR had high sensitivity, specificity, repeatability, and reproducibility for detecting PEDV and TGEV. The 2019-2021 epidemic involving the viruses appeared to be mostly PEDV with low incidents of mixed TGEV and PEDV/TGEV infection.

Epidemiological and etiological analysis of a case cluster caused by norovirus in a nursing home in Lanzhou

Objective: To understand the epidemiology and etiology of a cluster of cases with gastroenteritis in a nursing home in Anning district of Lanzhou, and to provide a scientific evidence for the prevention and control of norovirus diarrhea in community nursing centers. Methods: From January 28 to February 4 2021, an epidemiological investigation was conducted on all diarrhea cases, nursing staff and chefs in a nursing home in Anning district, Lanzhou city. Samples of patients' anal swabs, feces, vomitus were collected for norovirus detection by real-time fluorescent PCR. ORF1/ORF2 junction region of norovirus in some selected positive samples(Ct value 25) was sequenced. MEGA-X software was used to construct a phylogenetic tree for genetic evolution analysis using the neighboring method. Results: The first case was confirmed on January20,2021, and the number of cases peaked during January 25and 29.A total of 58 clinically diagnosed cases were reported,57were older people, with an incidence of(57/360,15.83%). Diarrhea(50/58,86.21%),vomiting(35/58,60.34%),nausea(13/58,22.41%)and abdominal pain(6/58,10.34%)were common symptoms, all cases were mild. Fifty-three asymptomatic cases were detected among chefs, housekeepers and nurses.A total of 163specimens were tested, the positive rate of norovirus GII was 49.08%(80/163). The positive rate of fecal samples collected from nurses, chefs and housekeepers was 48.62%(53/109), and was11.11%(2/18)in environmental surface swabs. The possibility of other pathogenic infections such as SARS-CoV-2was ruled out by further tests. Thirteen positive samples were selected for sequencing, and 9were successfully sequenced, they were all recombinant GII.4Sydney_2012 [P16]genotypes, forming an independent cluster, while in a large evolutionary branch with the 2020GII.10 [P16]and 2019GII.2 [P16]virus strains in Lanzhou city, showing a relative close genetic connection. Conclusions: GII .4Sydney_2012[P16]genotype of norovirus is found to be causative pathogen of this outbreak, and close contact is the main reason of the outbreak and persistence of the infection,so asymptomatic infections of norovirus play an important role in the disease spreading. Therefore, public health management in nursing homes and other centralized nursing facilities should be strengthened especially for asymptomatic workers in order to prevent virus transmission.

Stopping Feline Coronavirus Shedding Prevented Feline Infectious Peritonitis.

After an incubation period of weeks to months, up to 14% of cats infected with feline coronavirus (FCoV) develop feline infectious peritonitis (FIP): a potentially lethal pyogranulomatous perivasculitis. The aim of this study was to find out if stopping FCoV faecal shedding with antivirals prevents FIP. Guardians of cats from which FCoV had been eliminated at least 6 months earlier were contacted to find out the outcome of their cats; 27 households were identified containing 147 cats. Thirteen cats were treated for FIP, 109 cats shed FCoV and 25 did not; a 4-7-day course of oral GS-441524 antiviral stopped faecal FCoV shedding. Follow-up was from 6 months to 3.5 years; 11 of 147 cats died, but none developed FIP. A previous field study of 820 FCoV-exposed cats was used as a retrospective control group; 37 of 820 cats developed FIP. The difference was statistically highly significant (p = 0.0062). Cats from eight households recovered from chronic FCoV enteropathy. Conclusions: the early treatment of FCoV-infected cats with oral antivirals prevented FIP. Nevertheless, should FCoV be re-introduced into a household, then FIP can result. Further work is required to establish the role of FCoV in the aetiology of feline inflammatory bowel disease.