H9 s ubtype avian influenza virus（AIV） and infectious bronchitis virus（IBV） are major pathogens circulating in poultry and have resulted in great economic losses due to respiratory disease and reduced egg producti...H9 s ubtype avian influenza virus（AIV） and infectious bronchitis virus（IBV） are major pathogens circulating in poultry and have resulted in great economic losses due to respiratory disease and reduced egg production. As similar symptoms are elicited by the two pathogens, it is difficult for their differential diagnosis. So far, no reverse transcription-polymerase chain reaction（RT-PCR） assay has been found to differentiate between H9 AIV and IBV in one reaction. Therefore, developing a sensitive and specific method is of importance to simultaneously detect and differentiate H9 AIV and IBV. In this study, a duplex RT-PCR（d RT-PCR） was established. Two primer sets target the hemagglutinin（HA） gene of H9 AIV and the nucleocapsid（N） gene of IBV, respectively. Spec ific PCR products were obtained from all tested H9 AIVs and IBVs belonging to the major clades circulating in China, but not from AIVs of other subtypes or other infectious avian viruses. The sensitivity of the d RT-PCR assay corresponding to H9 AIV, IBV and mixture of H9 AIV and IBV were at a concentration of 1×10^1, 1.5×10^1 and 1.5×10^1 50% egg infective doses（EID_（50）） m L^–1, respectively. The concordance rates between the d RT-PCR and virus isolation were 99.1 and 98.2%, respectively, for detection of samples from H9N2 AIV or IBV infected chickens, while the concordance rate was 99.1% for detection of samples from H9N2 AIV and IBV co-infected chickens. Thus, the d RT-PCR assay reported herein is specific and sensitive, and suitable for the differential diagnosis of clinical infections and survei llance of H9 AIVs and IBVs.展开更多
While meeting the pandemic demand of SARS-CoV-2 testing, clinical laboratories worldwide tend to adopt new test systems offering cost-effective and faster test outcomes. However, the reliability of SARS-CoV-2 test res...While meeting the pandemic demand of SARS-CoV-2 testing, clinical laboratories worldwide tend to adopt new test systems offering cost-effective and faster test outcomes. However, the reliability of SARS-CoV-2 test results has paramount importance in the management of such a health crisis. Therefore, this study sought to determine the accuracy of the test results from a novel duplex Microchip RT-PCR test system using patient saliva samples and nasal swabs stabilized in Viral Transport Medium (VTM) with reference threshold Cycle Values (Ct). The VTM used to stabilize these samples during transport was found to be inhibitory to the RT-PCR. Therefore, all the samples were subjected to spin column purification of total RNA to remove the influence of VTM. A total of 70 patient samples, including 24 positive- and 31 negative-saliva in VTM samples and 15 positive nasal swab samples, were tested. Results obtained from both the sample types were compared to their reference values and no false positive or false negatives were observed. From this data, accuracy, specificity, and sensitivity were determined to be 100% applying the corresponding formulae. The limit of detection with 95% confidence probability was determined to be 2.5 copies/μl in the original sample.展开更多
Citrus viroids are the small but economically important RNA pathogens. For investigating their occurrence and distribution in China, 65 viroid samples collected from 8 major citrus cultivated regions were evaluated us...Citrus viroids are the small but economically important RNA pathogens. For investigating their occurrence and distribution in China, 65 viroid samples collected from 8 major citrus cultivated regions were evaluated using one-step or multiplex onestep RT-PCR and biological indexing for specifically detection of Citrus exocortis viroid （CEVd）, Citrus bent leaf viroid （CBLVd）, Hop stunt viroid （HSVd）, Citrus viroid-Ⅲ （CVd-Ⅲ） and Citrus viroid-Ⅳ （CVd-Ⅳ）. The results showed that there were at least 4 kinds of citrus viroids （CEVd, CBLVd, HSVd, and CVd-Ⅲ） on citrus trees in China. Most of the infected citrus plants harbored more than one viroid species, and two plants were infected with up to 4 citrus viroids. Sweet orange was more frequently infected by viroids than other citrus varieties. It is the preliminary report on the species and distribution of citrus viroids in China.展开更多
基金supported by the National High-Tech R&D Program of China(2012AA101303)
文摘H9 s ubtype avian influenza virus（AIV） and infectious bronchitis virus（IBV） are major pathogens circulating in poultry and have resulted in great economic losses due to respiratory disease and reduced egg production. As similar symptoms are elicited by the two pathogens, it is difficult for their differential diagnosis. So far, no reverse transcription-polymerase chain reaction（RT-PCR） assay has been found to differentiate between H9 AIV and IBV in one reaction. Therefore, developing a sensitive and specific method is of importance to simultaneously detect and differentiate H9 AIV and IBV. In this study, a duplex RT-PCR（d RT-PCR） was established. Two primer sets target the hemagglutinin（HA） gene of H9 AIV and the nucleocapsid（N） gene of IBV, respectively. Spec ific PCR products were obtained from all tested H9 AIVs and IBVs belonging to the major clades circulating in China, but not from AIVs of other subtypes or other infectious avian viruses. The sensitivity of the d RT-PCR assay corresponding to H9 AIV, IBV and mixture of H9 AIV and IBV were at a concentration of 1×10^1, 1.5×10^1 and 1.5×10^1 50% egg infective doses（EID_（50）） m L^–1, respectively. The concordance rates between the d RT-PCR and virus isolation were 99.1 and 98.2%, respectively, for detection of samples from H9N2 AIV or IBV infected chickens, while the concordance rate was 99.1% for detection of samples from H9N2 AIV and IBV co-infected chickens. Thus, the d RT-PCR assay reported herein is specific and sensitive, and suitable for the differential diagnosis of clinical infections and survei llance of H9 AIVs and IBVs.
文摘While meeting the pandemic demand of SARS-CoV-2 testing, clinical laboratories worldwide tend to adopt new test systems offering cost-effective and faster test outcomes. However, the reliability of SARS-CoV-2 test results has paramount importance in the management of such a health crisis. Therefore, this study sought to determine the accuracy of the test results from a novel duplex Microchip RT-PCR test system using patient saliva samples and nasal swabs stabilized in Viral Transport Medium (VTM) with reference threshold Cycle Values (Ct). The VTM used to stabilize these samples during transport was found to be inhibitory to the RT-PCR. Therefore, all the samples were subjected to spin column purification of total RNA to remove the influence of VTM. A total of 70 patient samples, including 24 positive- and 31 negative-saliva in VTM samples and 15 positive nasal swab samples, were tested. Results obtained from both the sample types were compared to their reference values and no false positive or false negatives were observed. From this data, accuracy, specificity, and sensitivity were determined to be 100% applying the corresponding formulae. The limit of detection with 95% confidence probability was determined to be 2.5 copies/μl in the original sample.
基金the National Key Technology R&D Program of China (2007BAD61B04)the National Natural Science Foundation of CQ CSTC, China (2006BB1351)
文摘Citrus viroids are the small but economically important RNA pathogens. For investigating their occurrence and distribution in China, 65 viroid samples collected from 8 major citrus cultivated regions were evaluated using one-step or multiplex onestep RT-PCR and biological indexing for specifically detection of Citrus exocortis viroid （CEVd）, Citrus bent leaf viroid （CBLVd）, Hop stunt viroid （HSVd）, Citrus viroid-Ⅲ （CVd-Ⅲ） and Citrus viroid-Ⅳ （CVd-Ⅳ）. The results showed that there were at least 4 kinds of citrus viroids （CEVd, CBLVd, HSVd, and CVd-Ⅲ） on citrus trees in China. Most of the infected citrus plants harbored more than one viroid species, and two plants were infected with up to 4 citrus viroids. Sweet orange was more frequently infected by viroids than other citrus varieties. It is the preliminary report on the species and distribution of citrus viroids in China.
