METHODS: An operational utility test to elucidate the efficiency and effectiveness of the dengue RT-RPA assay was conducted among a group of researchers new to the assay. Nineteen volunteer researchers with different research experience were recruited. The participants performed the RT-RPA assay and interpreted the test results according to the protocol provided. Deviation from the protocol was identified and tabulated by trained facilitators. Post-test questionnaires were conducted to determine the user satisfaction and acceptability of the dengue RT-RPA assay.
RESULTS: All the participants completed the test and successfully interpreted the results according to the provided instructions, regardless of their research experience. Of the 19 participants, three (15.8%) performed the assay with no deviations and 16 (84.2%) performed the assay with only 1 to 5 deviations. The number of deviations from protocol, however, was not correlated with the user laboratory experience. The accuracy of the results was also not affected by user laboratory experience. The concordance of the assay results against that of the expected was at 89.3%. The user satisfaction towards the RT-RPA protocol and interpretation of results was 90% and 100%, respectively.
CONCLUSIONS: The dengue RT-RPA assay can be successfully performed by simply following the provided written instructions. Deviations from the written protocols did not adversely affect the outcome of the assay. These suggest that the RT-RPA assay is indeed a simple, robust and efficient laboratory method for detection of dengue virus. Furthermore, high new user acceptance of the RT-RPA assay suggests that this assay could be successfully deployed into new laboratories where RT-RPA was not previously performed.
METHODS: In the current project, we have described two extraction-free reverse transcription loop-mediated isothermal amplification (RT-LAMP) assays for the detection of SARS-CoV-2 by using E gene and RdRp gene as the targets.
RESULTS: Here, results showed that reverse transcription loop-mediated isothermal amplification assays with 88.4% sensitive (95% CI: 74.9-96.1%) and 67.4% sensitive (95% CI: 51.5-80.9%) for E gene and RdRp gene, respectively.
CONCLUSION: Without the need of RNA purification, our developed RT-LAMP assays for direct detection of SARS-CoV-2 from nasopharyngeal swab samples could be turned into alternatives to qRT-PCR for rapid screening.
MATERIALS AND METHODS: About 20 quails were divided into three groups (n=8 for Groups A and B; n=4 for the control group). The quails in the Groups A and B were infected via intraocular route with 0.03 ml of 103.5 ELD50 and 107.0 ELD50 of NDV strain IBS 002, respectively, while the control group received 1× phosphate-buffered saline. Cloacal swabs and necropsy were taken on day 7 post-infection for all quails were subjected to one-step reverse transcription real-time quantitative polymerase chain reaction (RT-qPCR) for detection of virus and examination for gross pathological lesion, respectively. Blood serums of infected quails were taken on day 10, 14, and 21 post-day infections and were subjected for hemagglutination inhibition (HI) assay.
RESULTS: Depression and ruffled feathers, trachea rales, leg paralysis, and torticollis were shown in some of the quails in both infected groups. Based on statistical analysis, there was no significant difference (p>0.05) in clinical signs between the infected groups. The results for RT-qPCR were found to be negative for all groups, and no gross pathological lesions of organs observed for quails in both infected groups. Trachea, proventriculus, and cecal tonsil were taken for the detection of NDV by RT-qPCR, and some of the organ samples showed positive detection of virus in both infected groups. HI assay showed an increase in mean titers of antibody across time and between infected groups.
CONCLUSION: In summary, Japanese quails are susceptible to genotype VII NDV based on parameters assessed.