scholarly journals RT-PCR and Dot Blot hybridization methods for a universal detection of tospoviruses

2001 ◽  
Vol 26 (2) ◽  
pp. 170-175 ◽  
Author(s):  
MARCELO EIRAS ◽  
RENATO O. RESENDE ◽  
ALEXANDRE A. MISSIAGGIA ◽  
ANTÔNIO C. DE ÁVILA

Transcriptase reverse - polymerase chain reaction (RT-PCR) and dot blot hybridization with digoxigenin-labeled probes were applied for the universal detection of Tospovirus species. The virus species tested were Tomato spotted wilt virus, Tomato chlorotic spot virus, Groundnut ringspot virus, Chrysanthemum stem necrosis virus, Impatiens necrotic spot virus, Zucchini lethal chlorosis virus, Iris yellow spot virus. Primers for PCR amplification were designed to match conserved regions of the tospovirus genome. RT-PCR using distinct primer combinations was unable to simultaneously amplify all tospovirus species and consistently failed to detect ZLCV and IYSV in total RNA extracts. However, all tospovirus species were detected by RT-PCR when viral RNA was used as template. RNA-specific PCR products were used as probes for dot hybridization. This assay with a M probe (directed to the G1/G2 gene) detected at low stringency conditions all Tospovirus species, except IYSV. At low stringency conditions, the L non-radioactive probe detected the seven Tospovirus species in a single assay. This method for broad spectrum detection can be potentially employed in quarantine services for indexing in vitro germplasm.

HortScience ◽  
2006 ◽  
Vol 41 (3) ◽  
pp. 729-732 ◽  
Author(s):  
Liping Wang ◽  
Guoping Wang ◽  
Ni Hong ◽  
Rongrong Tang ◽  
Xiaoyun Deng ◽  
...  

Apple stem grooving virus (ASGV) and apple chlorotic leaf spot virus (ACLSV) are two major viruses of pear. In this study, in vitro thermotherapy was carried out at 37°C for 25, 30 and 35 days followed by subculturing of meristem tips of different sizes to eliminate ASGV and ACLSV from pear plants. Virus titers in heat-treated shoot tips were evaluated by ELISA testing of regenerated plants. Results showed that thermotherapy for 35 days significantly decreased the titer of ASGV and ACLSV in cultures regenerated from tips of main and axillary shoots, especially in those from explants 1 mm in length from the tip of meristems. Dot-blot hybridization of biotinylated cDNA probes derived from ACLSV and ASGV was used to detect these viruses in crude tissue extracts of in vitro-grown pear plants. Intense signals were consistently detected in untreated plant samples equivalent to less than 0.5 mg tissue. Comparison of signals from dot-blot hybridization and ELISA absorbance values (A405) confirmed that dot-blot hybridization had a higher sensitivity than PAS-ELISA. Dot-blot hybridization could detect viruses with a titer below the threshold level of ELISA. These results indicate that dot-blot hybridization is a useful tool for large-scale surveys of viruses, which facilitates the production of virus-free propagation materials in certification and sanitation programs. Results of PAS-ELISA and dot-blot hybridization showed that high virus elimination efficiency was achieved by a combination of thermotherapy for 35 days and in vitro culture of 1 mm meristem tips.


2019 ◽  
Vol 19 (4) ◽  
pp. 220-227
Author(s):  
Najmiatul Masykura ◽  
Ummu Habibah ◽  
Siti Fatimah Selasih ◽  
Soegiarto Gani ◽  
Cosphiadi Irawan ◽  
...  

1986 ◽  
Vol 13 (4) ◽  
pp. 291-299 ◽  
Author(s):  
Volker Schuster ◽  
Bertfried Matz ◽  
Helga Wiegand ◽  
Brigitte Traub ◽  
Dieter Neumann-Haefelin

2009 ◽  
Vol 77 (6) ◽  
pp. 2399-2407 ◽  
Author(s):  
Rebecca C. Flanagan ◽  
Jason M. Neal-McKinney ◽  
A. Singh Dhillon ◽  
William G. Miller ◽  
Michael E. Konkel

ABSTRACT Campylobacter jejuni colonization of chickens is presumably dependent upon multiple surface-exposed proteins termed adhesins. Putative C. jejuni adhesins include CadF, CapA, JlpA, major outer membrane protein, PEB1, Cj1279c, and Cj1349c. We examined the genetic relatedness of 97 C. jejuni isolates recovered from human, poultry, bovine, porcine, ovine, and canine sources by multilocus sequence typing (MLST) and examined their profile of putative adhesin-encoding genes by dot blot hybridization. To assess the individual contribution of each protein in bacterium-host cell adherence, the C. jejuni genes encoding the putative adhesins were disrupted by insertional mutagenesis. The phenotype of each mutant was judged by performing in vitro cell adherence assays with chicken LMH hepatocellular carcinoma epithelial cells and in vivo colonization assays with broiler chicks. MLST analysis indicated that the C. jejuni isolates utilized in this study were genetically diverse. Dot blot hybridization revealed that the C. jejuni genes encoding the putative adhesins, with the exception of capA, were conserved among the isolates. The C. jejuni CadF, CapA, Cj1279c, and Cj1349c proteins were found to play a significant role in the bacterium's in vitro adherence to chicken epithelial cells, while CadF, PEB1, and Cj1279c were determined to play a significant role in the bacterium's in vivo colonization of broiler chicks. Collectively, the data indicate that Cj1279c is a novel adhesin. Because Cj1279c harbors fibronectin type III domains, we designated the protein FlpA, for fibronectin-like protein A.


Plant Disease ◽  
1998 ◽  
Vol 82 (1) ◽  
pp. 84-88 ◽  
Author(s):  
R. H. Li ◽  
G. C. Wisler ◽  
H.-Y. Liu ◽  
J. E. Duffus

A polyclonal antiserum prepared against purified virions of tomato infectious chlorosis virus (TICV) was used to evaluate serological tests for its detection, to determine its distribution in infected plants, to study relationships among isolates of this virus, and to detect it in field samples. A cRNA probe representing TICV RNA 1 and RNA 2 was used in dot blot hybridization tests. A reverse transcriptase-polymerase chain reaction (RT-PCR) assay was also developed for detection of TICV isolates. The comparative study of these four techniques indicated that RT-PCR was 100-fold more sensitive than enzyme-linked immunosorbent assay (ELISA), Western blot, and dot blot hybridization assays for TICV detection. TICV was detected in leaf, stem, flower, and root tissues of the infected tomato plants. However, the virus was not uniformly distributed throughout the infected tomato plants, and the highest viral concentration was observed in fully developed young tomato leaves at the onset of yellowing symptoms. The virus was detected by indirect ELISA, Western blot, dot blot hybridization, and RT-PCR assays in laboratory-infected tomato, tomatillo, potato, and Nicotiana clevelandii and in naturally infected tomato, petunia, and Ranunculus sp. plants obtained from commercial sources. These tests indicate that there are apparently no detectable serological or nucleic acid differences among four TICV isolates obtained from Orange and Yolo Counties of California or from North Carolina or Italy.


2021 ◽  
Author(s):  
Chih-Hsu Lin ◽  
Ting-Hsuan Hung ◽  
I Hu ◽  
Ta-Hsin Ku ◽  
Chun-Yi Lin ◽  
...  

Abstract BackgroundCitrus exocortis viroid (CEVd) is a circular single-stranded RNA pathogen consists of around 370 nucleotides and leads to a severe disease showing bark scaling symptom on citrus crops, which leads to yield decrease and economic loss. Since the absence of viroid-encoded proteins, methods for CEVd detection mainly counts on bioassays or nucleic acid-base approaches. In order to validate the CEVd disease, here we developed an integrated diagnostic protocol. MethodsCEVd transcripts were inoculated onto two susceptible cultivars of Solanum lycopersicum L., cv. Rutgers and cv. Double-Fortune, seedings. After inoculation, total RNAs of the two tomato cultivars were extracted to detect CEVd infection by dot blot hybridization, one-step reverse transcription PCR (one-step RT-PCR) and real-time reverse transcription PCR (real-time RT-PCR). In addition, the symptom development of both cultivars was recorded weekly. ResultsThe tomato cultivar Rutgers rather than Double-Fortune or others was selected as a suitable CEVd-indicator plant and the bio-index score was established based on epinasty, vein necrosis, leaf size reduction and stunting symptoms. In addition, the isolate of CEVd that collected from citrus field could rapidly and consistently cause the index symptoms on Rutgers. As expected, CEVd could be specifically and sensitively detected in both tomato and citrus plants by dot-blot hybridization and RT-PCR technologies, including one-step RT-PCR and real-time RT-PCR. Furthermore, we found that the levels of CEVd genomic RNA or CEVd derived small RNAs are correlated to symptom severity. ConclusionsIn this study, we developed an integrated detection method for CEVd and revealed potential underlying viroid-host interactions.


PLoS ONE ◽  
2021 ◽  
Vol 16 (4) ◽  
pp. e0248581
Author(s):  
Clyde S. Manuel ◽  
Cassandra Suther ◽  
Matthew D. Moore ◽  
Lee-Ann Jaykus

Human norovirus (NoV) is the leading cause of acute viral gastroenteritis and a major source of foodborne illness. Detection of NoV in food and environmental samples is typically performed using molecular techniques, including real-time reverse transcription polymerase chain reaction (RT-PCR) and less frequently, nested real-time PCR. In this study, we conducted a controlled comparison of two published NoV detection assays: a broadly reactive one-step real-time RT-PCR and a two-step nested real-time PCR assay. A 20% human fecal suspension containing a genogroup II human NoV was serially diluted, genome extracted, and subjected to amplification using the two assays compared via PCR Units. Additional amplicon confirmation was performed by dot blot hybridization using digoxigenin (DIG)-labeled oligonucleotide probes. Both assays displayed similar amplification standard curves/amplification efficiencies; however, the nested assay consistently detected one log10 lower virus. Dot blot hybridization improved the detection limit of the nested real-time PCR by one log10 NoV genome copies but impaired the detection limit of the one-step real-time RT-PCR by one log10 NoV genome copies. These results illustrate the complexities in designing and interpreting molecular techniques having a sufficient detection limit to detect low levels of viruses that might be anticipated in contaminated food and environmental samples.


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