METHODS: Medical records of hospitalized children from January 2020 to June 2021 with acute respiratory illness who received a FilmArray RP for respiratory pathogens were reviewed and compared with data from diagnosis-matched patients without receiving the test.
RESULTS: In total, 283 patients and 150 diagnosis-matched controls were included. Single pathogen was detected in 84.3% (193/229) of the patients. The most common pathogen was human rhinovirus/enterovirus (31.6%, 84/266), followed by respiratory syncytial virus (18.8%, 50/266) and adenovirus (15%, 40/266). Although antimicrobial days of therapy (DOT) was significantly longer in FilmArray group than the control [7.1 ± 4.9 days vs 5.7 ± 2.7 days, P = 0.002], the former showed a higher intensive care unit (ICU) admission rate (3.9% vs 0%; P = 0.010). All ICU admissions were in FilmArray RP-positive group. There was no difference in antimicrobial DOT between FilmArray RP-positive and the negative groups, in all admissions, even after excluding ICU admissions. Antimicrobial DOT was shorter in the positive than negative group in patients with lower respiratory tract infections without admission to ICU [median (IQR): 6 (4-9) days vs 9 (4-12) days, P = 0.047].
CONCLUSIONS: Shorter antimicrobial DOTs were identified in children with lower respiratory tract infection admitted to general pediatric ward and with an identifiable respiratory pathogen, indicating a role of the multiplex PCR in reducing antimicrobial use for children with respiratory tract infection.
RESULTS: A specific assay was developed, since no amplification was observed in viral strains from the same family of Paramyxoviridae, such as canine distemper virus (CDV), Newcastle disease virus (NDV), and measles virus (MeV), and other feline viruses, such as feline coronavirus (FCoV) and feline leukemia virus (FeLV). The lower detection limit of the assay was 1.74 × 104 copies/μL with Cq value of 34.32 ± 0.5 based on the cRNA copy number. The coefficient of variations (CV) values calculated for both intra- and inter-assay were low, ranging from 0.34-0.53% and 1.38-2.03%, respectively. In addition, the clinical sample evaluation using this assay showed a higher detection rate, with 25 (35.2%) clinical samples being FeMV-positive compared to 11 (15.5%) using conventional RT-PCR, proving a more sensitive assay compared to the conventional RT-PCR.
CONCLUSIONS: The TaqMan-based real-time RT-PCR assay targeting the N gene described in this study is more sensitive, specific, rapid, and reproducible compared to the conventional RT-PCR assay targeting the N gene, which could be used to detect early infection in cats.
METHODS: A total of 25 CLL patients and 25 normal individuals were recruited in this study. The methylation status of ADAM12 was determined using Methylation-Specific PCR (MSP); whereas, DNA sequencing method was applied for validation of the MSP results.
RESULTS: Among CLL patients, 12 (48%) were partially methylated and 13 (52%) were unmethylated. Meanwhile, 5 (20%) and 20 (80.6%) of healthy individuals were partially methylated and unmethylated, respectively. There was a statistically significant association between the status of methylation at ADAM12 and the presence of CLL (p=0.037).
CONCLUSION: The aberrant methylation of ADAM12 found in this study using MSP assay may provide new exposure to CLL that may improve the gaps involved in genetic epigenetic study in CLL.
METHODS: In the present study, a single-tube reverse transcription loop-mediated isothermal amplification (RT-LAMP) assay was developed for the detection of both the Asian and African-lineage ZIKV. The detection limit, strain coverage and cross-reactivity of the ZIKV RT-LAMP assay was evaluated. The sensitivity and specificity of the RT-LAMP were also evaluated using a total of 24 simulated clinical samples. The ZIKV quantitative reverse transcription-polymerase chain reaction (qRT-PCR) assay was used as the reference assay.
RESULTS: The detection limit of the RT-LAMP assay was 3.73 ZIKV RNA copies (probit analysis, P ≤ 0.05). The RT-LAMP assay detected the ZIKV genomes of both the Asian and African lineages without cross-reacting with other arthropod-borne viruses. The sensitivity and specificity of the RT-LAMP assay were 90% (95% CI = 59.6-98.2) and 100% (95% CI = 78.5-100.0), respectively. The RT-LAMP assay detected ZIKV genome in 9 of 24 (37.5%) of the simulated clinical samples compared to 10 of 24 (41.7%) by qRT-PCR assay with a high level of concordance (κ = 0.913, P
METHODS: The concordance rate, sensitivity and specificity of the duplex ddPCR assay were determined and compared to nested PCR and duplex qPCR.
RESULTS: The duplex ddPCR assay had higher analytical sensitivity (P. vivax = 10 copies/µL and P. knowlesi = 0.01 copies/µL) compared to qPCR (P. vivax = 100 copies/µL and P. knowlesi = 10 copies/µL). Moreover, the ddPCR assay had acceptable clinical sensitivity (P. vivax = 80% and P. knowlesi = 90%) and clinical specificity (P. vivax = 87.84% and P. knowlesi = 81.08%) when compared to nested PCR. Both ddPCR and qPCR detected more double infections in the samples.
CONCLUSIONS: Overall, the ddPCR assay demonstrated acceptable efficiency in detection of P. knowlesi and P. vivax, and was more sensitive than nested PCR in detecting mixed infections. However, the duplex ddPCR assay still needs optimization to improve the assay's clinical sensitivity and specificity.
OBJECTIVE: To design and evaluate a molecular diagnostic tool for detection and identification of all currently recognized and potentially future emergent CoVs from the Orthocoronavirinae subfamily.
STUDY DESIGN AND RESULTS: We designed a semi-nested, reverse transcription RT-PCR assay based upon 38 published genome sequences of human and animal CoVs. We evaluated this assay with 14 human and animal CoVs and 11 other non-CoV respiratory viruses. Through sequencing the assay's target amplicon, the assay correctly identified each of the CoVs; no cross-reactivity with 11 common respiratory viruses was observed. The limits of detection ranged from 4 to 4 × 102 copies/reaction, depending on the CoV species tested. To assess the assay's clinical performance, we tested a large panel of previously studied specimens: 192 human respiratory specimens from pneumonia patients, 5 clinical specimens from COVID-19 patients, 81 poultry oral secretion specimens, 109 pig slurry specimens, and 31 aerosol samples from a live bird market. The amplicons of all RT-PCR-positive samples were confirmed by Sanger sequencing. Our assay performed well with all tested specimens across all sample types.
CONCLUSIONS: This assay can be used for detection and identification of all previously recognized CoVs, including SARS-CoV-2, and potentially any emergent CoVs in the Orthocoronavirinae subfamily.