RT- PCR technique with degenerative primers of three viral groups was used to select cerebrospinal (CSF) samples for isolating of mosquito borne viruses causing acute encephalitis (AES). The study results showed that 16 of 53 samples were confirmed with positive by RT-PCR as following: 8/53 (15.09%) were positive with primers of mosquito borne viruses; 7/53 (12.96%) positive with primers of latent viruses, and 1/53 (1.88%) positive with viral group of hand-food-mouth diseases. RT-PCR technique cannot replace virus isolation, but it orients the relevant selection of CSF samples for virus isolation. The Aedes albopictus clone C6/36 cells were used to isolate. There were 7 isolated virus strains, 5 of them were Japanese encephalitis virus, one of them belonged to a new type Arbovirus group in Vietnam and 1 strain was unknown
Reverse Transcriptase Polymerase Chain Reaction ; genome ; viruses ; Encephalitis

Astroviruses are widely detected in pigs but their detection in wild boars is rather sporadic. In this study, astroviruses were detected in organ homogenates of wild boars by applying nested reverse transcriptase polymerase chain reaction, and the typing was carried out by phylogenetic analysis. Overall, 30/200 (15.0%) homogenates were positive for astroviruses. Genetic typing revealed that of 13 amplicons analyzed, 8 were typed as porcine astrovirus lineage 2 (PAstV-2), 2 as lineage 4 (PAstV-4), 2 identical sequences were grouped with chicken astrovirus, and 1 sequence belonged to a bat astrovirus lineage. This first identification of chicken and bat astroviruses in wild boars indicates interspecies transmission.
Avastrovirus ; Chickens ; Reverse Transcriptase Polymerase Chain Reaction ; Sus scrofa ; Swine

Freshly collected seeds of Amomum tsaoko demonstrate obvious dormancy. Therefore, the selection of stable reference genes during seed dormancy release is very important for the subsequent functional research of related genes. In this study, ten commonly used reference genes(GAPDH, 40S, actin, tubulin, EIF4A-9, EIF2α, UBC, UBCE2, 60S, and UBQ) were selected as candidates for quantitative Real-time polymerase chain reaction(qRT-PCR) of the embryo samples of A. tsaoko at different dormancy release stages. Three kinds of software(BestKeeper, geNorm, and Normfinder) and the Delta CT method were used to evaluate the expression stability of the candidate reference genes, and the RefFinder online tool was employed to integrate the results and generate a comprehensive ranking. The results showed that the expression levels of the ten candidate reference genes differed greatly in different embryo samples. GAPDH and UBC had high expression levels, as manifested by the small Ct values. GeNorm identified 40S and UBCE2 as the most stable genes. NormFinder ranked EIF2α as the most stable gene and UBC as the least stable gene. UBCE2 was found to be the most stable gene and actin the least stable one by BestKeeper. Delta CT analysis suggested that the expression of 40S was most stable. UBCE2 was recommended as the most stably expressed gene by RefFinder. Thus, UBCE2 is the ideal reference gene for qRT-PCR analysis of A. tsaoko seeds at different dormancy release stages. The results may lay a foundation for analyzing the expression of related genes during seed dormancy release of A. tsaoko.
Amomum ; Gene Expression Profiling ; Real-Time Polymerase Chain Reaction ; Reverse Transcriptase Polymerase Chain Reaction ; Seeds/genetics*

Objective. To determine the diagnostic accuracy of self-collected snorted and spit saliva in detecting COVID-19 using RT-PCR (ssRT-PCR) and lateral flow antigen test (ssLFA) versus nasopharyngeal swab RT-PCR (npRT-PCR). Methods. One hundred ninety-seven symptomatic subjects for COVID-19 testing in a tertiary hospital underwent snort-spit saliva self-collection for RT-PCR and antigen testing and nasopharyngeal swab for RT-PCR as reference. Positivity rates, agreement, sensitivity, specificity, and likelihood ratios were estimated. Results. Estimated prevalence of COVID-19 using npRT-PCR was 9% (exact 95% CI of 5.5% - 14.1%). A higher positivity rate of 13% in the ssRT-PCR assay suggested possible higher viral RNA in the snort-spit samples. There was 92.9% agreement between ssRT-PCR and npRT-PCR (exact 95% CI of 88.4% to 96.1%; Cohen’s Kappa of 0.6435). If npRT-PCR will be assumed as reference standard, the estimated Sensitivity was 83.3% (exact 95% CI of 60.8% to 94.2%), Specificity 93.9% (exact 95% CI of 89.3% to 96.5%), Positive predictive value of 57.7% (exact 95% CI of 38.9% to 74.5%), Negative predictive value of 98.2% (exact 95% CI of 95% to 99.4%), positive likelihood ratio of 3.65 (95% CI of 7.37 to 24.9), negative likelihood ratio of 0.178 (95% CI of 0.063 to 0.499). There was 84.84% agreement (95% exact CI of 79.1% to 89.5%; Cohen’s Kappa of 0.2356) between ssLFAvs npRT-PCR, sensitivity of 38.9% (exact 95% CI of 20.3% to 61.4%), specificity of 89.4% (exact 95% CI of 84.1% to 93.1%), PPV of 26.9% (95% CI of 13.7% to 46.1%), NPV of 93.6% (exact 95% CI of 88.8% to 96.4%), LR+ of 3.67 (95% CI of 1.79 - 7.51), LR – of 0.68 (95% CI of 0.47 - 0.99). Conclusion. Our data showed that snort-spit saliva RT-PCR testing had acceptable diagnostic performance characteristics and can potentially be used as an alternative to the standard nasopharyngeal/oropharyngeal swab RT-PCR test for COVID-19 in certain situations. However, our data also showed that snort-spit saliva antigen testing using lateral flow assay did not offer acceptable performance.
Saliva ; SARS-CoV-2 ; Reverse Transcription ; Reverse Transcriptase Polymerase Chain Reaction

BACKGROUND: Real-time reverse transcriptase PCR (rRT-PCR) is widely used to detect novel influenza A/H1N1. We had observed several cases with positive result for influenza A and negative result for novel influenza A/H1N1 during a novel influenza A/H1N1 outbreak. The causes of those results were investigated in this study. METHODS: A total of 913 cases tested with rRT-PCR for novel influenza A/H1N1 (Real-time Ready Influenza A/H1N1 Detection Set, Roche Diagnostics, Germany) during 25 August 2009 to 8 September 2009 was enrolled in this study. Cases showing positive result for influenza A (M gene) and negative result for novel influenza A/H1N1 (H1 gene) were tested with multiplex RT-PCR for seasonal influenza and novel influenza A/H1N1 (Seeplex FluA ACE Subtyping kit, Seegene, Korea), and the amplicons were directly sequenced. RESULTS: One hundred and eleven cases (12.2%) were positive for novel influenza A/H1N1. Twenty-seven cases (3.0%) were positive for influenza A, but negative for novel influenza A/H1N1. Subtypes of influenza A were determined in 25 cases by multiplex RT-PCR and nucleotides sequencing. One novel influenza A/H1N1, six seasonal influenza A/H1N1, three seasonal influenza A/H3N2, and 15 influenza A/H9N2 were detected. CONCLUSIONS: Subtypes of influenza A were determined in most cases with positive result for influenza A and negative result for novel influenza A/H1N1. Several cases with seasonal influenza A were detected. Even if a nonepidemic period of seasonal influenza, tests for seasonal influenza A can help in the differential diagnosis of influenza.
Diagnosis, Differential ; Influenza, Human ; Nucleotides ; Reverse Transcriptase Polymerase Chain Reaction ; RNA-Directed DNA Polymerase ; Seasons

BACKGROUND: Mycobacterium leprae, the etiological agent of leprosy, is noncultivable on axenic media, so, the viability of M. leprae for clinical or experimental applications is often unknown. Quantitative reverse transcriptase PCR (RT-PCR) assays were recently introduced as the new tools for M. leprae viability determination. OBJECTIVE: For evaluating of correlation of results of quantitative real-time PCR(16S rRNA/RLEP) & AFB stain of slit skin smear & histopathology & estimating the viability of M. leprae, the author studied the comparison of results of them METHODS: Of 46 samples from 27 patients(MB 24 cases, PB 3 cases), M. leprae 16S rRNA was used as RNA targets, and M. leprae repetitive element (RLEP) DNA was used to determine relative bacterial numbers and the viability by the quantitative real-time PCR. The ratio of 16S rRNA and RLEP as the indicator of viability was calculated. Student t test and linear Pearson correlation were done by SPSS. RESULTS: There was a correlation between between 16S rRNA/RLEP ratio and BI (r=0.369, p=0.012), and was statistically significant between 16S rRNA/RLEP ratio and histopathological positivity of AFB (p=0.011). However there was no correlation between 16S rRNA/RLEP ratio and MI. CONCLUSIONS: Although the correlation between between 16S rRNA/RLEP ratio and BI and the statistically significant between 16S rRNA/RLEP ratio and histopathological positivity of AFB, there was no correlation between 16S rRNA/RLEP ratio and MI. It needs the further evaluation the correlation about that.
DNA ; Humans ; Leprosy* ; Mycobacterium leprae ; Real-Time Polymerase Chain Reaction* ; Reverse Transcriptase Polymerase Chain Reaction ; RNA ; Skin*

OBJECTIVETo establish a specific TaqMan-based Real-time PCR assay for the detection of hepatitis A virus in serum samples.

METHODSAccording to the references, primers-probe sets which were located in 5'-NCR, the most conservative part of HAV genome were designed and therefore we established a TaqMan real-time RT-PCR assay with great performance of specificity, sensitivity and reproducibility. And then it was used in the detection of HAV RNA in serum from HAV patients.

RESULTSThe HAV Real-time RT-PCR assay established in this study were able to detect HAV RNA and its detection limit ranged from 0.1CCID50/reaction to 0.01CCID50/reaction. When the detection of a same sample was repeated for three times, coefficients of varistion (CV) of intra- and inter-assay were calculated and they were all less than 2.0% and 2.6% respectively. Our data suggested that there were 5.18 x 10(2) - 4.93 x 10(7) RNA copies in 1 ml of the serum from acute HAV patients.

CONCLUSIONThe TaqMan-based Real-time PCR assay established in this study was specific and precise for the rapid detection of HAV RNA. It was applied successfully in the pathogen detection of clinical samples.

OBJECTIVETo establish the single genome amplification (SGA) method and analyze the quasispecies in HIV-infected patients.

METHODSAll 6 sample RNA acquired in 2010 in Shenzhen and genetic sequenced as overlap peaks were extracted and diluted to a single copy, nest-PCR after one step RT-PCR was employed to amplify HIV-1 genome, and then PCR products was purified and sequenced. Mega 4.02 software was used to analyze the genetic distance among HIV-1 quasispecies, and phylogenetic tree was constructed.

RESULTSOur data showed that viral sequences derived from different patients were grouped into different clusters. Subcluster was also observed in several clusters, indicating these existed competition and preferential replication of certain viral strains. The genetic distance within one cluster of 6 samples were between 0.008 and 0.06, it was likely to associate with the duration since infection and viral load.

CONCLUSIONSGA is a useful approach to gain information on quasispecies, the genetic distance within one cluster may help to determine the infection time and immune escaping. The analysis of related affecting factors need more samples.

Screening suitable reference genes is the premise of quantitative Real-time PCR(qRT-PCR)for gene expression analysis. To provide stable reference genes for expression analysis of genes in Aconitum vilmorinianum, this study selected 19 candidate re-ference genes(ACT1, ACT2, ACT3, aTUB1, aTUB2, bTUB, 18S rRNA, UBQ, eIF2, eIF3, eIF4, eIF5, CYP, GAPDH1, GAPDH2, PP2A1, PP2A2, ACP, and EF1α) based on the transcriptome data of A. vilmorinianum. qRT-PCR was conducted to profile the expression of these genes in the root, stem, leaf, and flower of A. vilmorinianum. The Ct values showed that 18S rRNA with high expression level and GAPDH2 with large expression difference among organs were not suitable as the reference genes. NormFinder and geNorm showed similar results of the expression stability of the other candidate reference genes and demonstrated PP2A1, EF1α, and CYP as the highly stable ones. However, BestKeeper suggested EF1α, ACT3, and PP2A1 as the top stable genes. In view of the different results from different softwares, the geometric mean method was employed to analyze the expression stability of the candidate re-ference genes, the results of which indicated that PP2A1, EF1α, and ACT3 were the most stable. Based on the comprehensive analysis results of geNorm, NormFinder, BestKeeper, and geometric mean method, PP2A1 and EF1α presented the most stable expression in different organs of A. vilmorinianum. PP2A1 and EF1α were the superior reference genes for gene expression profiling in different organs of A. vilmorinianum.
Aconitum ; Gene Expression Profiling ; Genes, Plant/genetics* ; Real-Time Polymerase Chain Reaction ; Reference Standards ; Reverse Transcriptase Polymerase Chain Reaction

BACKGROUND: One of main mechanisms responsible for acquired azole resistance of Candida glabrata is the increased drug efflux mediated ABS transporters, which are encoded by CgCDR1 and CgCDR2 genes. OBJECTIVES: We compared real-time reverse transcriptase PCR (RT-PCR) with northern hybridization for quantitative analysis of CgCDR1 and CgCDR2 expression in bloodstream isolates of C. glabrata. METHODS: Nineteen blood isolates of C. glabrata were selected, including nine fluconazole susceptible (MIC < or =8 microgram/ml), nine susceptible dose-dependent (S-DD, MIC 16~32 microgram/ml), and one resistant (MIC 128 microgram/ml), isolates. The expression of CgCDR1 and CgCDR2 was quantified using real-time RT-PCR with ROTOR Gene 3000 (Corbettet research, Austria). The results were compared with northern hybridization with sequence-specific probes. RESULTS: Correlation of quantification results between real-time RT-PCR and northern hybridization yielded correlation coefficients of 0.92 for CgCDR1 and 0.82 for CgCDR2 gene. By both methods, no significant differences were observed in the levels of expression of CgCDR1 and CgCDR2 between fluconazole-susceptible isolates and S-DD isolates. In contrast, a strain with high fluconazole resistance (MIC 128 microgram/ml) revealed a greater abundance of CgCDR1 by both methods, compared to the other isolates. Conclusion: This study show that real-time PCR method for C. glabrata RNA quantification correlates well with traditional northern hybridization and can be a valuable alternative to northern hybridization for rapid quantification of CgCDR1 and CgCDR2 genes in clinical isolates of C. glabrata.
Candida ; Candida glabrata ; Chimera ; Danazol ; Fluconazole ; Gene Expression ; Polymerase Chain Reaction ; Real-Time Polymerase Chain Reaction ; Reverse Transcriptase Polymerase Chain Reaction ; RNA ; Sprains and Strains