• Title/Summary/Keyword: real-time reverse transcriptase-PCR

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Real Time Reverse Transcriptase-PCR to Detect Viable Enterobacteriaceae in Milk

  • Choi, Suk-Ho;Lee, Seung-Bae
    • Food Science of Animal Resources
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    • v.31 no.6
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    • pp.851-857
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    • 2011
  • This study was conducted to develop a real time reverse transcriptase-PCR (RT-PCR) method for the detection of viable Enterobacteriaceae in milk using primers based on the genes of ribosomal proteins S11 and S13 and to determine effects of heating and subsequent treatments on the threshold cycle (Ct) of the real time RT-PCR. Total RNA was isolated from 17 strains of bacteria including 11 strains of Enterobacteriaceae suspended in milk using a modified Tri reagent method. SYBR Green Master Mix was added to the RNA and the mixture was subjected to the real time RT-PCR. The Cts of eleven type strains of the Enterobacteriaceae in milk ($10^7$ cells) in the real time RT-PCR ranged from 21.5 to 24.6. However, the Cts of Pseudomonas fluorescens, Acinetobacter calcoaceticus, and three gram-positive bacteria were more than 40. The real time RT-PCR detected as low as $10^3$ cells in agarose gel electrophoresis. The Cts increased from 22.0 to 34.2 when milk samples contaminated with Escherichia coli ($10^7$ cells/mL) were heated at $65^{\circ}C$ for 30 min. In addition, subsequent incubation at $37^{\circ}C$ for 6 and 24 h increased the Cts further up to 36.2 and 37.2, respectively. Addition of RNase A to the bacterial suspension obtained from the heated milk and subsequent incubation at $37^{\circ}C$ for 1 h increased the Cts to more than 40. The results of this study suggests that pretreatment of bacterial cells heated in milk with RNase A before RNA extraction might enhance the ability to differentiate between viable and dead bacteria using real time RT-PCR.

Molecular cloning and expression analysis of annexin A2 gene in sika deer antler tip

  • Xia, Yanling;Qu, Haomiao;Lu, Binshan;Zhang, Qiang;Li, Heping
    • Asian-Australasian Journal of Animal Sciences
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    • v.31 no.4
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    • pp.467-472
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    • 2018
  • Objective: Molecular cloning and bioinformatics analysis of annexin A2 (ANXA2) gene in sika deer antler tip were conducted. The role of ANXA2 gene in the growth and development of the antler were analyzed initially. Methods: The reverse transcriptase polymerase chain reaction (RT-PCR) was used to clone the cDNA sequence of the ANXA2 gene from antler tip of sika deer (Cervus Nippon hortulorum) and the bioinformatics methods were applied to analyze the amino acid sequence of Anxa2 protein. The mRNA expression levels of the ANXA2 gene in different growth stages were examined by real time reverse transcriptase polymerase chain reaction (real time RT-PCR). Results: The nucleotide sequence analysis revealed an open reading frame of 1,020 bp encoding 339 amino acids long protein of calculated molecular weight 38.6 kDa and isoelectric point 6.09. Homologous sequence alignment and phylogenetic analysis indicated that the Anxa2 mature protein of sika deer had the closest genetic distance with Cervus elaphus and Bos mutus. Real time RT-PCR results showed that the gene had differential expression levels in different growth stages, and the expression level of the ANXA2 gene was the highest at metaphase (rapid growing period). Conclusion: ANXA2 gene may promote the cell proliferation, and the finding suggested Anxa2 as an important candidate for regulating the growth and development of deer antler.

False-Negative Results of Real-Time Reverse-Transcriptase Polymerase Chain Reaction for Severe Acute Respiratory Syndrome Coronavirus 2: Role of Deep-Learning-Based CT Diagnosis and Insights from Two Cases

  • Dasheng Li;Dawei Wang;Jianping Dong;Nana Wang;He Huang;Haiwang Xu;Chen Xia
    • Korean Journal of Radiology
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    • v.21 no.4
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    • pp.505-508
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    • 2020
  • The epidemic of 2019 novel coronavirus, later named as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), is still gradually spreading worldwide. The nucleic acid test or genetic sequencing serves as the gold standard method for confirmation of infection, yet several recent studies have reported false-negative results of real-time reverse-transcriptase polymerase chain reaction (rRT-PCR). Here, we report two representative false-negative cases and discuss the supplementary role of clinical data with rRT-PCR, including laboratory examination results and computed tomography features. Coinfection with SARS-COV-2 and other viruses has been discussed as well.

Expression of Enterotoxin Genes in Staphylococcus aureus Isolates Based on mRNA Analysis

  • Lee, Young-Duck;Moon, Bo-Youn;Park, Jong-Hyun;Chang, Hyo-Ihl;Kim, Wang-June
    • Journal of Microbiology and Biotechnology
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    • v.17 no.3
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    • pp.461-467
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    • 2007
  • Staphylococcus aureus strains are important foodborne pathogens that produce various toxins. To evaluate the risk of the enterotoxins, four S. aureus strains from kimbap and two clinical samples were isolated and identified, and their expression of the enterotoxin genes were analyzed using a reverse transcription real-time PCR. Various enterotoxin genes were detected, including sea, seg, seh, sei, sen, seo, and sem, where each isolate contained one or two. When the mRNA detection of the enterotoxin genes was analyzed using a reverse transcriptase PCR, various levels of expression were found depending on the species and enterotoxin gene. Therefore, it is reasonable to suggest that the poisoning risk of S. aureus can be effectively evaluated based on the gene expression at the mRNA level.

Prognostic Relevance of Human Telomerase Reverse Transcriptase (hTERT) Expression in Patients with Gall Bladder Disease and Carcinoma

  • Deblakshmi, Raj Kumari;Deka, Manab;Saikia, Anjan Kumar;Sharma, Bir Kumar;Singh, Nidhi;Das, NN;Bose, Sujoy
    • Asian Pacific Journal of Cancer Prevention
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    • v.16 no.7
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    • pp.2923-2928
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    • 2015
  • Background: Gallbladder carcinoma (GBC) has been stated as an Indian disease, with the highest number of cases being reported from certain districts of northeast India, which has an ethnically distinct population. Unfortunately there are no scientific reports on the underlying molecular mechanisms associated with the pathogenesis of the disease from this region. Aim: The present study evaluated the role of differential expression of human telomerase reverse transcriptase (hTERT) in the development of gall bladder anomalies. Materials and Methods: Blood and tissue samples were collected from patients undergoing routine surgical resection for clinically proven cases of gallbladder disease {cholelithiasis (CL, n=50), cholecystitis (CS, n=40) and GBC (n=30) along with adjacent histopathologically proved non-neoplastic controls (n=15)} with informed consent. Whole blood was also collected from age and sex matched healthy controls (n=25) for comparative analysis. Differential hTERT mRNA expression was evaluated by semi-quantitative rt-PCR and real-time PCR based analysis using ${\beta}$-actin as an internal control. Evaluation of differential hTERT protein expression was studied by Western blot analysis and immunoflourescence. Statistical analysis for differential expression and co-relation was performed by SPSSv13.0 software. Results: Gallbladder anomalies were mostly prevalent in females. The hTERT mRNA and protein expression increased gradiently from normal

Development and Evaluation of a SYBR Green Real-time PCR Assay for Canine Cytokine Gene Expression (SYBR Green 실시간 역전사 중합효소연쇄반응을 이용한 개 싸이토카인 유전자 발현의 정량)

  • Yu, Do-Hyeon;Ihn, Dong-Chul;Park, Chul;Park, Jin-Ho
    • Journal of Veterinary Clinics
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    • v.27 no.5
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    • pp.508-513
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    • 2010
  • Cytokines are important mediators of the immune response, and quantitating cytokine mRNA is a highly sensitive and attractive method for measuring cytokine production. The objective of the current study was to develop and validate a SYBR green quantitative real-time reverse transcriptase PCR (qRT-PCR) assay for measuring canine cytokine mRNA. The optimal annealing temperatures ($T_a$) of the designed primers were $62^{\circ}C$ for interleukin (IL)-$1{\beta}$, IL-6 and IL-10; $60^{\circ}C$ for glyceraldehyde 3-phosphate dehydrogenase (GAPDH) and tumor necrosis factor (TNF)-${\alpha}$; and $58^{\circ}C$ for high mobility group box 1 (HMGB1). Primer efficiencies of all primers calculated for standard curve samples were between 97.1% and 102.6%. No evidence of secondary structure or primer-dimer formation was seen via melt-curve analysis or gel electrophoresis. The developed qRT-PCR assays are highly specific and sensitive and can be used to quantify gene expression levels of canine cytokines.

Mining of Biomarker Genes from Expressed Sequence Tags and Differential Display Reverse Transcriptase-Polymerase Chain Reaction in the Self-fertilizing Fish, Kryptolebias marmoratus and Their Expression Patterns in Response to Exposure to an Endocrine-disrupting Alkylphenol, Bisphenol A

  • Lee, Young-Mi;Rhee, Jae-Sung;Hwang, Dae-Sik;Kim, Il-Chan;Raisuddin, Sheikh;Lee, Jae-Seong
    • Molecules and Cells
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    • v.23 no.3
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    • pp.287-303
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    • 2007
  • Expressed sequence tags (ESTs) and differentially expressed cDNAs from the self-fertilizing fish, Kryptolebias marmoratus were mined to develop alternative biomarkers for endocrine-disrupting chemicals (EDCs). 1,577 K. marmoratus cDNA clones were randomly sequenced from the 5'-end. These clones corresponded to 1,518 and 1,519 genes in medaka dbEST and zebrafish dbEST, respectively. Of the matched genes, 197 and 115 genes obtained Unigene IDs in medaka dbEST and zebrafish dbEST, respectively. Many of the annotated genes are potential biomarkers for environmental stresses. In a differential display reverse transcriptase-polymerase chain reaction (DD RT-PCR) study, 56 differential expressed genes were obtained from fish liver exposed to bisphenol A. Of these, 16 genes were identified after BLAST search to GenBank, and the annotated genes were mainly involved in catalytic activity and binding. The expression patterns of these 16 genes were validated by real-time RT-PCR of liver tissue from fish exposed to bisphenol A. Our findings suggest that expression of these 16 genes is modulated by endocrine disrupting chemicals, and therefore that they are potential biomarkers for environmental stress including EDCs exposure.

Loop-mediated isothermal amplification assay for the rapid detection of swine influenza virus (등온증폭법을 이용한 돼지인플루엔자바이러스 신속 진단법 개발)

  • Kim, Eun-Mi;Jeon, Hyo-Sung;Kim, Ji Jung;Kim, Hee-Jung;Shin, Yeun-Kyung;Song, Jae-Young;Yeo, Sang-Geon;Park, Choi-Kyu
    • Korean Journal of Veterinary Service
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    • v.38 no.2
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    • pp.107-116
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    • 2015
  • In this study, we developed a rapid, sensitive and specific reverse-transcriptase loop-mediated isothermal amplification (RT-LAMP) assay for detection of swine influenza viruse (SIV) including major subtypes of swine influenza viruses H1N1, H1N2 and H3N2, and a novel subtype of influenza A virus that accidentally infected in pig population. The RT-LAMP was completed in 40 min at $58^{\circ}C$ and the sensitivity of the RT-LAMP ($1copy/{\mu}L$) was 10-fold higher than conventional reverse transcription-polymerase chain reaction (RT-PCR) ($10copy/{\mu}L$) and the same to real time RT-PCR ($1copy/{\mu}L$). Also, the result of the RT-LAMP can be confirmed without any detection system. Therefore, the RT-LAMP could be a alternative diagnostic method for SIV detection in national SIV monitoring system and clinical diagnostic laboratory in the future.

Rapid and Sensitive Detection of Hepatitis C Virus in Clinical Blood Samples Using Reverse Transcriptase Polymerase Spiral Reaction

  • Sun, Wenying;Du, Ying;Li, Xingku;Du, Bo
    • Journal of Microbiology and Biotechnology
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    • v.30 no.3
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    • pp.459-468
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    • 2020
  • This study established a new polymerase spiral reaction (PSR) that combines with reverse transcription reactions for HCV detection targeting 5'UTR gene. To avoid cross-contamination of aerosols, an isothermal amplification tube (IAT), as a separate containment control, was used to judge the result. After optimizing the RT-PSR reaction system, its effectiveness and specificity were tested against 15 different virus strains which included 8 that were HCV positive and 7 as non-HCV controls. The results showed that the RT-PSR assay effectively detected all 8 HCV strains, and no false positives were found among the 7 non-HCV strains. The detection limit of our RT-PSR assay is comparable to the real-time RT-PCR, but is more sensitive than the RT-LAMP. The established RT-PSR assay was further evaluated for detection of HCV in clinical blood samples, and the resulting 80.25% detection rate demonstrated better or similar effectiveness compared to the RT-LAMP (79.63%) and real-time RT-PCR (80.25%). Overall, the results showed that the RT-PSR assay offers high specificity and sensitivity for HCV detection with great potential for screening HCV in clinical blood samples.

Prevalence of honeybee (Apis mellifera) diseases in Gwangju (광주광역시 꿀벌질병 동향조사)

  • Lee, In-Haeng;Kim, Ji-Yeon;Choi, Jong-Uk;Koh, Ba-Ra-Da;Jung, Bo-Ram;Park, Jae-Sung;Na, Ho-Myoug;Kim, Yong-Hwan
    • Korean Journal of Veterinary Service
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    • v.41 no.2
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    • pp.111-118
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    • 2018
  • This study was carried out to investigate the prevalence of honeybee (Apis mellifera) diseases in Gwangju area. From November 2016 to August 2017, 89 samples were collected from 33 apiculture farms and reverse transcriptase-polymerase chain reaction (RT-PCR), polymerase chain reaction (PCR), and real time PCR were conducted. 14 infectious pathogens, including seven viruses, two bacteria, three fungi, and two parasites, were investigated from random apiculture farms in Gwangju. The percentage of infectious pathogens were as follows: Stonebrood (76.4%), Deformed wing virus (51.7%), Nosema (27.0%) in PCR and RT-PCR. This result indicated that Stonebrood was most prevalent disease in Gwangju area. And we could get similar results from real time PCR. 84.8% of farms have more than two of infectious pathogens. Stonebrood and Deformed wing virus were major diseases in almost all seasons and Black queen cell virus disease was especially prevalent in May.