Porcine deltacoronavirus (PDCoV) cause diarrhea and dehydration in newborn piglets and has the potential for cross-species transmission. Rapid and early diagnosis is important for preventing and controlling infectious disease. In this study, two monoclonal antibodies (mAbs) were generated, which could specifically recognize recombinant PDCoV nucleocapsid (rPDCoV-N) protein. A colloidal gold immunochromatographic assay (GICA) strip using these mAbs was developed to detect PDCoV antigens within 15 min. Results showed that the detection limit of the GICA strip developed in this study was 103 TCID50/ml for the suspension of virus-infected cell culture and 0.125 μg/ml for rPDCoV-N protein, respectively. Besides, the GICA strip showed high specificity with no cross-reactivity with other porcine pathogenic viruses. Three hundred and twenty-five fecal samples were detected for PDCoV using the GICA strip and reverse transcription-quantitative real-time PCR (RT-qPCR). The coincidence rate of the GICA strip and RT-qPCR was 96.9%. The GICA strip had a diagnostic sensitivity of 88.9% and diagnostic specificity of 98.5%. The specific and efficient detection by the strip provides a convenient, rapid, easy to use and valuable diagnostic tool for PDCoV under laboratory and field conditions.
Deafness is a seriously disabling disease affecting the quality of human life and genetic factors account for a large proportion in the pathogenesis of newborn deafness.With the development of genomics technology, molecular genetics of hearing loss has become a cutting-edge field under investigation in otology.Molecular diagnostic technique plays an important role in exploring the pathogenesis, assisting clinical diagnosis and the prenatal diagnosis.In this review, we introduce the common pathogenic gene mutations and the diagnosis of non-syndromic inherited hearing impairment.
Key words:
Nonsyndromic hearing loss; Genetic diagnosis; Pathogenic gene
The porcine deltacoronavirus (PDCoV) is a newly discovered pig enteric coronavirus that can infect cells from various species. In Haiti, PDCoV infections in children with acute undifferentiated febrile fever were recently reported. Considering the great potential of inter-species transmission of PDCoV, we performed a comprehensive analysis of codon usage patterns and host adaptation profiles of 54 representative PDCoV strains with the spike (S) gene. Phylogenetic analysis of the PDCoV S gene indicates that the PDCoV strains can be divided into five genogroups. We found a certain codon usage bias existed in the S gene, in which the synonymous codons are often ended with U or A. Heat map analysis revealed that all the PDCoV strains shared a similar codon usage trend. The PDCoV S gene with a dN/dS ratio lower than 1 reveals a negative selection on the PDCoV S gene. Neutrality analysis showed that natural selection is the dominant force in shaping the codon usage bias of the PDCoV S gene. Unexpectedly, host adaptation analysis reveals a higher adaptation level of PDCoV to Homo sapiens and Gallus gallus than to Sus scrofa. Compared to the USA lineage, the PDCoV strains in the Early China lineage and Thailand lineage were less adapted to their hosts, which indicates that the evolutionary process plays an important role in the adaptation ability of PDCoV. These findings of this study add to our understanding of PDCoV's evolution, adaptability, and inter-species transmission.
In continuation of our search for new antibacterial and antioxidant metabolites from sponge-derived fungi, one new tyrosol derivative, hypocrol A (1), together with four known congeners, trichodenol B (2), 4-hydroxyphenethyl acetate (3), 4-hydroxyphenethyl tetradecanoate (4) and 1-oleyltyrosol (5), was isolated from the strain Hypocrea koningii PF04. Their planar structures were unequivocally elucidated by spectroscopic methods and comparison with the literature data. All the compounds displayed weak antibacterial activities against Staphylococcus aureus, methicillin-resistant S. aureus and Escherichia coli, whereas compounds 1 and 2 exhibited a moderate antioxidant efficacy in the DPPH (2,2-diphenyl-1-picrylhydrazyl) radical scavenging assay with IC50 values of 48.5 and 97.4 μg/mL, respectively.
Emerging and re-emerging swine coronaviruses (CoVs), including porcine epidemic diarrhea virus (PEDV), porcine deltacoronavirus (PDCoV), and swine acute diarrhea syndrome-CoV (SADS-CoV), cause severe diarrhea in neonatal piglets, and CoV infection is associated with significant economic losses for the swine industry worldwide. Reverse genetics systems realize the manipulation of RNA virus genome and facilitate the development of new vaccines. Thus far, five reverse genetics approaches have been successfully applied to engineer the swine CoV genome: targeted RNA recombination, in vitro ligation, bacterial artificial chromosome-based ligation, vaccinia virus -based recombination, and yeast-based method. This review summarizes the advantages and limitations of these approaches; it also discusses the latest research progress in terms of their use for virus-related pathogenesis elucidation, vaccine candidate development, antiviral drug screening, and virus replication mechanism determination.
The possible mechanism of preeclampsia is investigated in this study to facilitate the exploration of the future remediation of this disease by analysing the changes of IL-17 and IL-35 in peripheral blood and placental tissue of pregnant women with preeclampsia (PE).The study was conducted using 45 healthy pregnant women as the control group and 90 pregnant women in the preeclampsia group, including 45 cases with severe preeclampsia and 45 cases with mild preeclampsia. All of 135 pregnant women underwent caesarean delivery. IL-17 and IL-35 concentrations in the serum were measured by ELISA, and IL-17 and IL-35 expression in placental specimens was detected by immunohistochemistry.There were no statistically significant differences in age among the three study groups. Serum IL-17 levels were significantly higher in PE patients than in healthy pregnant women (P < 0.01). The ratio of positive staining for IL-17 was markedly higher in mild PE tissues (84.44%; 38/45) and severe PE tissues (86.67%; 39/45) than in healthy pregnant tissues (35.56%; 16/45) (P < 0.01). The strong positive rates for IL-17 were markedly higher in mild PE tissues (48.89%; 22/45) and severe PE tissues (68.89%; 31/45) than in healthy pregnant tissues (13.33%; 6/45) (P < 0.01). No differences between mild PE tissues and severe PE tissues were noted in both positive case rates and strong positive rates. Consistent with this finding, the ratio of strong positive staining for IL-35 was higher in healthy pregnant tissues (66.67%; 30/45) than in mild PE tissues (33.11%; 14/45) and severe PE tissues (26.67%; 12/45) (P < 0.01).The abnormal increase in serum and placental of IL-17 has an association with the formation and development of PE. IL-35 expression is significantly lower in severe PE placenta tissue and serum compared with normal pregnant women. These results suggested that IL-17/IL-35 imbalance may play a role in the pathophysiology of PE.
The whole-complete genome sequence of a strain of duck tembusu virus (DTMUV), DTMUV/CH/2014, affecting layer ducks in China, was determined and characterized. Compared with DTMUV sequences available in GenBank, DTMUV/CH/2014 has 3 amino acid mutations located in the capsid, prM, and NS3 genes of DTMUV/CH/2014.
Zoonotic coronaviruses represent an ongoing threat to public health. The classical porcine epidemic diarrhea virus (PEDV) first appeared in the early 1970s. Since 2010, outbreaks of highly virulent PEDV variants have caused great economic losses to the swine industry worldwide. However, the strategies by which PEDV variants escape host immune responses are not fully understood. Complement component 3 (C3) is considered a central component of the three complement activation pathways and plays a crucial role in preventing viral infection. In this study, we found that C3 significantly inhibited PEDV replication in vitro, and both variant and classical PEDV strains induced high levels of interleukin-1β (IL-1β) in Huh7 cells. However, the PEDV variant strain reduces C3 transcript and protein levels induced by IL-1β compared with the PEDV classical strain. Examination of key molecules of the C3 transcriptional signaling pathway revealed that variant PEDV reduced C3 by inhibiting CCAAT/enhancer-binding protein β (C/EBP-β) phosphorylation. Mechanistically, PEDV nonstructural protein 1 (NSP1) inhibited C/EBP-β phosphorylation via amino acid residue 50. Finally, we constructed recombinant PEDVs to verify the critical role of amino acid 50 of NSP1 in the regulation of C3 expression. In summary, we identified a novel antiviral role of C3 in inhibiting PEDV replication and the viral immune evasion strategies of PEDV variants. Our study reveals new information on PEDV-host interactions and furthers our understanding of the pathogenic mechanism of this virus. IMPORTANCE The complement system acts as a vital link between the innate and the adaptive immunity and has the ability to recognize and neutralize various pathogens. Activation of the complement system acts as a double-edged sword, as appropriate levels of activation protect against pathogenic infections, but excessive responses can provoke a dramatic inflammatory response and cause tissue damage, leading to pathological processes, which often appear in COVID-19 patients. However, how PEDV, as the most severe coronavirus causing diarrhea in piglets, regulates the complement system has not been previously reported. In this study, for the first time, we identified a novel mechanism of a PEDV variant in the suppression of C3 expression, showing that different coronaviruses and even different subtype strains differ in regulation of C3 expression. In addition, this study provides a deeper understanding of the mechanism of the PEDV variant in immune escape and enhanced virulence.
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