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Objective: To analyze and compare the effects of different clinical characteristics on the negative conversion time of nucleic acid detection after severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) Omicron variant infection, and to provide a scientific basis for the isolation and treatment of coronavirus disease 2019 (COVID-19). Methods: The epidemiological and clinical data of 228 mild SARS-CoV-2 Omicron variant infected patients diagnosed in Shanghai were retrospectively collected from April 27, 2022 to June 8, 2022 in Wujiaochang designated Hospital, Yangpu District, Shanghai. The negative conversion time of nucleic acid detection was used as the outcome variable, and the patients were divided into A (18 days) and B (>18 days). Univariate and multivariate logistic regression analysis were used to analyze the influencing factors of the negative conversion time of nucleic acid detection. Results: The mean nucleic acid conversion time of 228 patients was (18.7+or-12.1) d, with the median time of 18 (2-46) d. Among them, 120 patients in group A had an average nucleic acid conversion time of (13.2+or-2.0) d, and 108 cases in group B had an average nucleic acid conversion time of (20.8+or-1.3) d. Univariate analysis showed that there were no statistically significant differences in the effects of hypertension, coronary heart disease, diabetes, hypokalemia, malignant tumors, neuropsychiatric diseases, chronic digestive diseases on the negative nucleic acid conversion time (P > 0.05);however, there were significant differences in the effects of combined cerebrovascular disease, leukopenia, chronic respiratory system diseases and vaccination on the negative nucleic acid conversion time (P < 0.05). Further multivariate logistic regression analysis revealed that the combination of chronic respiratory diseases and non-vaccination were significant risk factors for prolongation of negative nucleic acid conversion time (P < 0.05). Conclusions: The results of this study show that gender, age and whether hypertension, coronary heart disease, diabetes mellitus, hypokalemia, malignant tumor, neuropsychiatric disease and chronic digestive disease have no significant effect on the nucleic acid conversion time, whereas chronic respiratory disease and no vaccination are significantly correlated with the prolongation of nucleic acid conversion time in SARS-CoV-2 Omicron-infected patients.
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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.
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Variant Omicron was discovered as a newest severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The first emergence of the omicron variant was detected in November 2021. In this study, we investigated the clinical manifestation, laboratory and radiological findings and responding to treatment of 70 pediatric patients with positive RT- PCR COVID-19 in Omicron peak. We described 20 criteria associated with efficacy, such as demographic data, clinical manifestation, laboratory and radiological findings. All of the patients received Remdesivir that 5.7% of patients responded to the treatment. No patients were given Intravenous Immunoglobulin (IVIG). This is the first study aimed at assessing symptoms clinical manifestation among hospitalization pediatrics patients in pediatric Hospital of Amir kola, Babol. The findings of this study can be effective in preventing and controlling disease transmission among children.
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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.
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Teledermatology is one of the most important developments of digitalisation in dermatology. It has helped to ensure continuity of care during the COVID-19 pandemic. The combination of teledermatology with artificial intelligence can significantly improve medical decision-making. Among imaging modalities, dermoscopy is the most widely used, and its effectiveness can be significantly enhanced when combined with artificial intelligence. Novel techniques that have emerged in recent years include high-frequency ultrasound, optical coherence tomography or multispectral imaging. These are currently used in dermatological research but are expected to gradually become part of daily patient care. The knowledge of digital technologies and new imaging techniques is essential for the modern dermatologist. In the future, it is expected to be an essential part of modern and optimised patient care.
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Objective: We aimed to find the parameters that can change during herpes zoster infection and observe the relationship of these parameters throughout the disease. Material and Methods: We compared 40 herpes zoster patients and 2 separate control groups, who were healthy and had comorbidities similar in age and gender. Patient files were retrospectively analyzed, and laboratory parameters were compared between groups. The laboratory values of the patient group with herpes zoster were evaluated among themselves according to the duration of the symptoms. Results: Fasting glucose, creatinine, aspartate aminotransferase values, the percentage and the absolute number of monocytes, red blood cell distribution width-coefficient of variation, and C-reactive protein levels of the patients with herpes zoster were significantly higher, and the absolute number of lymphocytes, mean corpuscular volume and platelet distribution width levels were lower than the control groups. The percentage of monocytes in the first 5 days was significantly higher than in the following days, and hematocrit values were lower in the last days. Conclusion: Examining routine laboratory values during diseases may help diagnose the disease, especially in patients with faint clinical signs and zoster sine zoster. In addition, it may be useful to question patients with herpes zoster for renal dysfunction, rheumatological diseases, and malignancy.
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Health-care providers or health-care workers (HCWs) are at higher risk of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection when compared to the general population. An early routine screening of both symptomatic and asymptomatic HCWs is essential to prevent transmission of infection and thus the nosocomial spread. The cumulative prevalence of SARS-CoV-2 infection among Indian HCWs is unknown. This systematic review was aimed to analyse the prevalence of SARS-Co-V2 disease (COVID-19) among Indian HCWs. Data were collected from a comprehensive computerised search in PubMed, Google Scholar, ScienceDirect, ResearchGate, Scopus and Web of Science using the terms 'Prevalence of COVID-19 among HCWs in India' and 'prevalence of SARS-CoV-2 among HCWs in India'. Results of original research papers and meta-analysis published were collected and data analysed. Results of seven studies on 31656 HCWs in India were pooled. Overall, average prevalence of COVID-19 among the HCWs was 12.3%. Majorities were frontline workers irrespective of the gender. Most of the cases were symptomatic, with cough and fever as major clinical presentations. Findings suggest that adequate organisation of clinical wards and personnel, appropriate personal protective equipment supply and training of all workers directly and repeatedly exposed to COVID-19 patients should be prioritised to decrease the risk of infection. Furthermore, the duty time of HCWs who works in COVID treating area should be minimised.
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These proceedings comprise 85 articles spanning diverse fields such as bacteriology, molecular biology, biotechnology, dermatology, infectious and parasitic diseases, epidemiology, physiotherapy, immunology, mycology, parasitology, pathology, collective health, and virology. The articles delve into a wide range of research topics, from repurposing drugs for Mycobacterium abscessus complex infections to utilising artificial intelligence for SARS-CoV-2 diagnosis. In bacteriology, investigations explore the correlation between smoking and Helicobacter pylori infection in gastric adenocarcinoma patients, as well as the resistance profiles of Staphylococcus aureus and Pseudomonas aeruginosa in tracheostomised children. Molecular biology studies focus on gene polymorphisms related to diseases like paracoccidioidomycosis. Biotechnology research emphasises bioactive molecules in species like Croton urucurana and the development of computational models for cytotoxicity prediction. Dermatology articles address stability characterisation in vegetable oil-based nanoemulsions. The section on infectious and parasitic diseases encompasses studies on COVID-19 vaccine response in pregnant women and the impact of infection prevention measures in rehabilitation hospitals. Epidemiology investigations analyse trends in premature mortality, tuberculosis in diabetic patients, and public adherence to non-pharmacological COVID-19 measures. Physiotherapy research covers topics such as telerehabilitation through a developed game and the prevalence of congenital anomalies. Immunology studies explore immune responses in HIV and Leishmaniasis, whilst mycology investigates the biotechnological potential of fungi from the cerrado biome. Parasitology research evaluates treatment efficacy against vectors parasites such as Aedes aegypti and Toxoplasma gondii. Pathology articles discuss intentional intoxication in cattle and the influence of curcumin on acute kidney injury therapy. Collective health studies focus on intervention plan development in healthcare settings and pesticide use in horticulture. Lastly, virology research investigates parvovirus occurrence in hospitalised children during the COVID-19 pandemic, hidden hepatitis B virus infection in inmates, and the prevalence of HPV and HTLV-1/2 infections in specific populations.
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A 64-year-old never-smoker man, with professional exposure, presented to Marius Nasta Pneumophtisiology Institute for fatigability to effort, in the context of severe SARS-COV2 infection one month previously. His medical history includes pulmonary tuberculosis (55 years ago) and newly diagnosed type II diabetes (261 mg/dL glycemia). The thoracic tomography computer in the immediate post-COVID period (Fig. 1A) revealed the presence of glass ground lesions and a 3 cm nodule with cystic degeneration in the upper left lobe. A gross examination of the specimen identified a condensation area of 2.5 cm diameter, brown-grey colored, with necrosis and central ulceration. Microscopic examination showed the presence of bronchiectasis with squamous metaplasia of the epithelium, which appears ulcerated;numerous calcium oxalate crystals with adjacent foreign body granulomatous reaction;endobronchial are present fibrinous and inflammatory debris, brown-black pigment, and septate, dichotomous branching hyphae, suggestive of Aspergillus spp. A periodic acid-Schiff stain was performed, identifying the fungal hyphae. The histopathological diagnosis was bronchiectasis supra-infected and colonized with fungal filaments (Aspergillus niger).
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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.
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Since Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) first appeared in China in December 2019, the globe has been dealing with an ever-increasing incidence of COVID-19 (Corona Virus Disease 2019). In addition to respiratory disorders, 40% of patients present with gastrointestinal (GI) involvement. Abdominal pain is the most common indication for computed tomography (CT) and ultrasonography. After GI tract involvement, solid visceral organ infarction is the most prevalent abdominal abnormality in COVID-19. This review aims to gather the available data in the literature about imaging features of solid abdominal organs in patients with COVID-19. Gallbladder wall thickening and distension, cholelithiasis, hyperdense biliary sludge, acalculous cholecystitis, periportal edema, heterogeneous liver enhancement, and liver hypodensity and infarction are among hepatobiliary imaging findings in CT, particularly in patients admitted to ICU. Pancreatic involvement can develop as a result of direct SARS-CoV2 invasion with signs of acute pancreatitis in abdominal CT, such as edema and inflammation of the pancreas. Infarction was the most prevalent renal and splenic involvement in patients with COVID-19 who underwent abdominal CT presenting with areas of parenchymal hypodensity. In conclusion, although solid abdominal organs are rarely affected by COVID-19, clinicians must be familiar with the manifestations since they are associated with the disease severity and poor outcome.
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AIMS: To compare specific T-cell responses between laboratory employees in South Africa with and without previously diagnosed SARS-CoV-2 infection. METHODS: Employees at a private pathology laboratory in South Africa were invited to participate in a nationwide cross-sectional study. T-cell proliferation to SARS-CoV-2 nucleocapsid (N)-proteins and spike (S)-proteins was measured by flow cytometry and compared between participants. RESULTS: Based on classification according to SARS-CoV-2 reverse transcription (RT)-PCR results, a total of 81% (42/52) of positive participants demonstrated T-cell proliferation to SARS-CoV-2 N-proteins or S-proteins (95% CI 67.5% to 90.4%), while 62% (68/110) of negative participants also had detectable T-cell responses to SARS-CoV-2 proteins (95% CI 52.1% to 70.9%). When classified according to SARS-CoV-2 serology results, 92.6% (50/54) of positive participants demonstrated T-cell proliferation to SARS-CoV-2 proteins (95% CI 82.1 to 97,9 %), while 56% (60/108) of negative participants demonstrated T-cell proliferation (95% CI 45.7% to 65.1%). The magnitude of the T-cell responses as determined by a stimulation index, was significantly higher in the group previously infected by SARS-CoV-2 than in the negative group. A statistically significant difference in T-cell proliferation was noted between high risk and low risk groups for exposure to SARS-CoV-2 within the negative group, but no significant difference in magnitude of the response. CONCLUSIONS: A significant proportion of South African laboratory employees who were not previously diagnosed with COVID-19 demonstrated T-cell reactivity to SARS-CoV-2 N-proteins and S-proteins. The pre-existing T-cell proliferation responses may be attributable to cross-reactive immune responses to other human coronaviruses, or possibly asymptomatic infection.
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Objective: In this study, it was aimed to evaluate the effectiveness of chest radiography in the diagnosis of COVID-19 pneumonia in pediatric patients. Materials and Methods: Between 2020 and 2021, the radiological findings of pediatric patients diagnosed with COVID-19 by polymerase chain reaction test were evaluated retrospectively. 140 patients who had both chest X-ray and thorax tomography were included in the study. The effectiveness of chest radiography in the diagnosis of COVID-19 pneumonia was determined. Thoracic computed tomography scans were compared in cases without pneumonia findings on chest X-ray. Results: COVID-19 pneumonia was detected in 100 of 140 thorax computed tomography scans. An increase in opacity was observed in the chest X-ray of 48 of these 100 patients (48%). Radiographs of the other 52 patients were normal. The reasons for this were low-density opacities (n=26 patients, 50%), small-sized opacities (n=16 patients, 30.7%), opacities adjacent to the diaphragm and liver (n=10 patients, 19.2%). Computed tomography showed consolidation in 36 patients (36%), and pure ground glass appearance in 64 patients (64%). An increase in opacity was observed in the chest X-ray (72.2%) of 26 of 36 patients with consolidation. In 22 (34.3%) of 64 patients with ground glass appearance, increased opacity was observed on chest X-ray. Consolidation detection rate of chest radiography was significantly higher than that of ground glass (p < 0.01). Conclusion: Low-density and small-sized opacities reduce the effectiveness of chest radiography. Although chest X-ray imaging is useful in detecting consolidations in pediatric patients, it was not sufficient to detect ground glass appearances.
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Coinfection caused by bacteria, parasites, or viruses complicates almost all feline panleukopenia virus (FPV) infections. Pathogens that colonize the gastrointestinal tract, Clostridium perfingens, Clostridium piliforme, Cryptosporidium spp, Giardia spp, Tritrichomonas fetus, canine parvovirus type 2,Salmonella sp., feline coronavirus, feline bocavirus, and feline astrovirus were isolated in the presence of FPV infection. Complex mechanisms between viruses, bacteria, protozoa, and hosts contribute to the pathogenesis and severity of coinfection. Prompt and accurate diagnosis, vaccination precautions, and appropriate treatment play important roles in reducing morbidity and mortality. This article outlines the etiology, pathogenesis, diagnosis, prevention, and treatment that can help veterinarians and pet owners improve their knowledge of managing the diseases.
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BACKGROUND: A common secondary effect after SARS-CoV-2 immunization is an increased in size of the axillary lymph nodes ipsilateral to the vaccinated site. Eventually, an increased in size of the axillary lymph nodes may lead to a misinterpretation of the breast screening mammogram, performed in asymptomatic women between the age 50 to 69 years old for early breast cancer diagnosis. The aim of our research was to evaluate the impact of the vaccination for SARS-CoV-2 in the breast screening programmes in terms of recall rates and number of false positive results. As a secondary purpose we would analysed the protocols adopted by different breast screening units around the world after SARS-CoV-2 vaccination. METHODS: Observational and retrospective study analysing breast screening mammograms from a single Breast Cancer Screening Unit in Madrid. The mammograms of previously vaccinated women were analysed, reviewing the axillary lymph nodes and the re-call rate secondary to axillary lymphadenopathies. RESULTS: Four hundred and twenty three screening mammograms were performed in May 2021 in the University Hospital Ramon y Cajal in Madrid, which is part of the Breast Screening Programme in Madrid, Spain. None of the women previously vaccinated for SARS-CoV-2 were recalled for complementary studies due to an increased in the axillary lymph nodes. CONCLUSIONS: The protocol stablished by the Spanish Society of Breast Image that stands up for a routine breast screening mammogram after SARS-CoV-2 immunization, has no increase in the recall rate or increase in number of false positives.
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BACKGROUND: One of the problems associated to SARS-CoV-2 was its persistence in nasopharyngeal tract. The existence of markers that help to predict this situation could be useful to management of the patients. The objective of this paper was to determine the relationship between the CT value from the initial PCR of patients with COVID-19 and the persistence of the infection. METHODS: It was performed an observational retrospective study of patients with positive PCR to SARS-CoV-2 attended in emergency department of a general hospital. Data about compatible symptoms, radiological findings and the CT value obtained with each PCR kit were collected. The control group (G0) included patients with a positive PCR followed by two negative PCR results (P-N-N), while problem group (G1) included patients with at least three consecutive positive PCR results (P-P-P). Chronic infections were discarded selecting only patients with negative serology, and only were included those whose PCR were separated by a minimum of five and maximum of twenty days. The comparison between the study groups was carried out using the t-student test for quantitative variables and the X2 test for qualitative variables. RESULTS: The mean CT value were 30.8 and 21.5 (p<0.001) on G0 and G1, respectively. G0 reported higher CT values than G1, regardless of symptoms, radiological pattern and the PCR kit utilized. CONCLUSIONS: The CT value from the SARS-CoV-2 initial PCR is related to the persistence of its positivity, regardless of the patient's symptoms or radiological pattern. Thus, low CT values could be related to persistent infections.
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[Objective] To prepare broad-spectrum monoclonal antibody against N protein of avian infectious bronchitis virus (IBV), so as to lay a foundation for identifying conservative domain epitope of N protein and establish a universal IBV detection method. [Method] N protein of GX-YL5, a representative strain of IBV dominant serotype in Guangxi, was expressed in prokaryote. BALB/c mice were immunized with the purified protein. After the serum titer of the immunized mice reached 104 or more, the splenocytes were fused with SP2/0 myeloma cells. After screening by indirect ELISA, monoclonal antibody was prepared by ascites-induced method. Western blotting, IFA and indirect ELISA were used to identify the titer, subtype, reaction specificity and cross-reaction spectrum. And the prepared monoclonal antibody was used for immunohistochemical detection. And the prepared monoclonal antibody was used to detect the IBV in the trachea and kidney tissues of SPF chickens artificially infected with 4 representative IBV variants (GX-N130048, GX-N160421, GX-QZ171023 and GX-QZ170728). [Result] The prepared monoclonal antibody N2D5 had a titer greater than 217 and its subtype was IgG2b. The Western blotting and IFA results showed that the monoclonal antibody N2D5 only reacted with IBV, and were negative with Newcastle disease virus (NDV), infectious laryngotracheitis virus (ILTV), avian metapneumovirus (aMPV), infectious bursal disease virus (IBDV), avian leukosis virus (ALV) and Marek's disease virus (MDV). Monoclonal antibody N2D5 reacted with many genotypes in China and all 7 serotypes of IBV currently prevalent in Guangxi, including commonly used standard strains, vaccine strains and field strains. Immunohistochemistry showed that the virus signals could be detected in the trachea and kidney tissues of SPF chickens at different time after artificial infection of 3 representative IBV strains from chicken and 1 isolated strain from duck, which further proved its broad spectrum. [Conclusion] The monoclonal antibody N2D5 of IBV prepared based on hybridoma technology belongs to the IgG2b subtype. It has the characteristics of high specificity, wide response spectrum and strong binding ability with IBV. It can be used as a specific diagnostic antibody for clinical diagnosis of IBV and the study of virus distribution.
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Objective: Provide a digital microfluidic RT-qPCR chip for rapid detection of several upper respiratory diseases. Methods: Several specific primer-probe sets were designed according to the conserved sequences of 2019 novel corona virus(2019-n COV), influenza A virus(Flu A), influenza B virus(Flu B), severe acute respiratory syndrome corona virus(SARS-Co V), Middle East respiratory syndrome corona virus(MERS-Co V), and then packaged into a digital microfluidic chip which allowed simultaneous detection of five upper respiratory tract pathogens with the help of reverse transcription quantitative PCR(RT-q PCR)technology. In the meanwhile, the detection limit, specificity and sensitivity of this digital microfluidic chip were evaluated base on the clinical specimens, plasmids and unrelated pathogens. Results: The established digital microfluidic RT-q PCR chip for 2019-n COV, Flu A, Flu B,SARS-Co V,MERS-Co V had a detection limit of 12 copies/reaction, while the detection limit of the RT-q PCR method without digital microfluidics was 15 copy/reaction;the detection limit of the two methods was basically the same. For nucleic acid samples extracted from clinical samples, the detection results of digital microfluidic RT-q PCR chips were all negative without non-specific amplification. At the same time, the RT-qPCR method and the digital microfluidic RT-qPCR chip method were used to carry out clinical comparative tests of 5 items in 20 clinical samples, total 100 tests. The results showed that the sensitivity of the digital microfluidic RT-q PCR chip reached 94%, the specificity was 100%. SPSS was used to analyze the consistency of the two methods, and the results showed that the two methods had a high degree of consistency(Kappa=0.962, P<0.05). Conclusion: Based on digital microfluidic RT-q PCR chip technology,a multi-target rapid detection method of upper respiratory tract susceptible virus was established, which could provide a new detection method for early clinical identification of respiratory pathogens.
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Objectives: Various reagents and equipment for testing SARS-CoV-2 infections have been developed, particularly rapid molecular tests based on polymerase chain reaction (PCR). Methods: We evaluated the analytical performance of four rapid molecular tests for SARS-CoV-2. We used 56 nasopharyngeal swabs from patients with confirmed SARS-CoV-2 infection;36 diagnosed as positive by the AmpdirectTM 2019-nCoV Detection Kit (Shimadzu assay) were considered as true-positive samples. Results: The sensitivity of CobasR Liat SARS-CoV-2 and Flu A/B (Cobas) was the highest among the four molecular test kits. The limit of detection was 1.49 x 10-2 copies/ micro L (95% confidence interval [CI]: 1.46x10-2-1.51 x 10-2 copies/ micro L) for Cobas;1.43 x 10-1 copies/ micro L (95% CI: 8.01x10-3-2.78 x 10-1 copies/ micro L) for XpertR Xpress SARS-CoV-2 test (Xpert);2.00 x 10-1 copies/ micro L (95% CI: 1.95x10-1-2.05 x 10-1 copies/ micro L) for FilmArray Respiratory Panel v2.1 (FilmArray);and 3.33 x 10 copies/ micro L (95% CI: 1.93 x 10-4.72x10 copies/ micro L) for Smart GeneR SARS-CoV-2 (Smart gene). Cobas also had a high sensitivity (100%) compared with Shimadzu assay. The sensitivities of Xpert, FilmArray, and Smart Gene were 97.2%, 97.2%, and 75.0%, respectively. The specificity of all tests was 100%. Conclusions: In conclusion, the four rapid SARS-CoV-2 molecular test kits have high specificity and sensitivity for detecting SARS-CoV-2. As they are easy to use, they could be a useful method for detecting SARS-CoV-2.
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Coronavirus disease 2019 (COVID-19) is an acute respiratory infection. Its virus called SARS-COV-2 which is an RNA virus with high homology to the bat coronavirus. In this review study, first the molecular and cellular characteristics and the proliferation and replication of SARS-COV-2 are investigated. Then, by reviewing bioinformatics studies regarding protected domain analysis, homology modeling, and molecular docking, the biological role of some specific SARS-COV-2 proteins are examined. The results showed that the open reading frame 8 (ORF8) and surface glycoprotein could bind to porphyrin. At the same time, ORF1ab, ORF10, and ORF3a can attack the heme part of hemoglobin to dissociate iron and form porphyrin. This attack reduces hemoglobin ability to carry oxygen and carbon dioxide. As a result, lung cells become severely inflamed due to their inability to exchange carbon dioxide and oxygen, which leads to large ground-glass opacities on CT scan images. Based on the bioinformatics results, chloroquine can prevent ORF1ab, ORF3a, and ORF10 from attacking hemoglobin to form porphyrin and avoid the binding of ORF8 and surface glycoprotein to porphyrin, which effectively relieves the symptoms of acute respiratory syndrome. In the current pandemic, bioinformatics studies are of great importance for preventing the spread of COVID-19, developing drugs and vaccines, and clinical practice.