scholarly journals Cost-effective optimization of real-time PCR-based detection of Campylobacter and Salmonella with inhibitor tolerant DNA polymerases

2015 ◽  
Vol 119 (5) ◽  
pp. 1391-1402 ◽  
Author(s):  
M.S.R. Fachmann ◽  
M.H. Josefsen ◽  
J. Hoorfar ◽  
M.T. Nielsen ◽  
C. Löfström
2008 ◽  
Vol 98 (4) ◽  
pp. 405-412 ◽  
Author(s):  
Xinshun Qu ◽  
Leslie A. Wanner ◽  
Barbara J. Christ

The phytotoxin thaxtomin, produced by plant pathogenic Streptomyces species, is the only known pathogenicity determinant for common scab diseases of potato and other root and tuber crops. Genes encoding thaxtomin synthetase (txtAB) are found on a pathogenicity island characteristic of genetically diverse plant pathogenic Streptomyces species. In this study, an SYBR Green quantitative real-time polymerase chain reaction (PCR) assay using primers designed to anneal to the txtAB operon of Streptomyces was developed to quantify pathogenic bacterial populations in potatoes and soil. The real-time PCR assay was specific for pathogenic Streptomyces strains. The detection limit of the assay was 10 fg of the target DNA, or one genome equivalent. Cycle threshold (Ct) values were linearly correlated with the concentration of the target DNA (correlation coefficient R2 = 0.99) and were not affected by the presence of plant DNA extracts, indicating the usefulness of the assay for quantitative analyses of the pathogenic bacteria in plant tissues. The amount of pathogenic Streptomyces DNA in total DNA extracts from 1 g asymptomatic and symptomatic tubers was quantified using the assay and ranged from 101 to 106 pg. A standard curve was established to quantify pathogenic Streptomyces in soil. Using the standard curve, numbers of pathogenic Streptomyces colony forming units were extrapolated to range from 103 to 106 per gram of soil from potato fields where common scab was found. This real-time PCR assay using primers designed from the txtAB operon allows rapid, accurate, and cost effective quantification of pathogenic Streptomyces strains in potato tubers and in soil.


2010 ◽  
Vol 48 (3) ◽  
pp. 466-469 ◽  
Author(s):  
Kelly W. Sheff ◽  
Emily R. York ◽  
Elizabeth M. Driebe ◽  
Bridget M. Barker ◽  
Steven D. Rounsley ◽  
...  

2013 ◽  
Vol 60 (4) ◽  
Author(s):  
Tomasz Gosiewski ◽  
Monika Brzychczy-Włoch ◽  
Agata Pietrzyk ◽  
Agnieszka Sroka ◽  
Małgorzata Bulanda

The study aim was evaluation of the usefulness of several thermostable DNA polymerases in real time PCR conducted in the presence of the heme. Our study had the advantage of testing several different polymerases, one of which proved to be the least sensitive to heme activity. We also found that there is no need of supplementing the reaction mixture with protective substances like BSA. Selection of the appropriate polymerase can increase the efficiency of the PCR reaction which is very important for diagnosis of sepsis and for other analyses performed on DNA template isolated from the blood.


2022 ◽  
Vol 47 (1) ◽  
Author(s):  
Ridim D Mote ◽  
Shinde Laxmikant V ◽  
Surya Bansi Singh ◽  
Mahak Tiwari ◽  
Hemant Singh ◽  
...  

Author(s):  
Liuyang Hu ◽  
Bing Han ◽  
Qin Tong ◽  
Hui xiao ◽  
Donglin Cao

Background and Objective. Acinetobacter baumannii, Escherichia coli, Klebsiella pneumoniae, Streptococcus pneumoniae, Haemophilus influenzae, Staphylococcus aureus, Pseudomonas aeruginosa, and Mycobacterium tuberculosis are primary respiratory bacterial pathogens contributing to morbidity and mortality in developing countries. This study evaluated the diagnostic performance of multiplex real-time PCR with fluorescence melting curve analysis (MCA) assay, which was used to detect eight respiratory bacterial pathogens simultaneously. Methods. A total of 157 sputum specimens were examined by multiplex real-time with fluorescence MCA, and the results were compared with the conventional culture method. Results. Multiplex real-time PCR with fluorescence MCA specifically detected and differentiated eight respiratory bacterial pathogens by different melting curve peaks for each amplification product within 2 hours and exhibited high repeatability. The limit of detection ranged from 64 to 102 CFU/mL in the multiplex PCR system. Multiplex real-time PCR with fluorescence MCA showed a sensitivity greater than 80% and a 100% specificity for each pathogen. The kappa correlation of eight bacteria ranged from 0.89 to 1.00, and the coefficient of variation ranged from 0.05% to 0.80%. Conclusions. Multiplex real-time PCR with fluorescence MCA assay is a sensitive, specific, high-throughput, and cost-effective method to detect multiple bacterial pathogens simultaneously.


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