Comparison of solid and liquid culture media with the polymerase chain reaction for detection ofMycobacterium tuberculosis in clinical samples

1996 ◽  
Vol 15 (6) ◽  
pp. 478-483 ◽  
Author(s):  
J. J. Palacios ◽  
J. Ferro ◽  
M. Telenti ◽  
S. G. Roces ◽  
P. Prendes ◽  
...  
Keyword(s):  
Polymerase Chain Reaction ◽  
Liquid Culture ◽  
Culture Media ◽  
Clinical Samples ◽  
Chain Reaction ◽  
Ofmycobacterium Tuberculosis ◽  
Polymerase Chain ◽  
Detection Ofmycobacterium Tuberculosis

scholarly journals DNA Sequencing to Evaluate Nail Pathogens: An Investigation into Bacteria and Fungi

2021 ◽  
Vol 111 (2) ◽  
Author(s):  
Ebony Love ◽  
Jonathan D. Furmanek ◽  
Courtney M. Foote ◽  
James McGuire ◽  
Ziad Labbad
Keyword(s):  
Polymerase Chain Reaction ◽  
Dna Sequencing ◽  
Culture Media ◽  
Nail Plate ◽  
Polymerase Chain Reaction Analysis ◽  
Clinical Samples ◽  
Fungal Culture ◽  
Chain Reaction ◽  
Polymerase Chain ◽  
Bacteria And Fungi

Background It is well established and accepted that fungi are a major contributing factor in nail dystrophy. It has also been recognized that bacteria play a crucial role in onycholysis. However, the bacteria and fungi that can be grown on culture media in the laboratory are only a small fraction of the total diversity that exists in nature. Contemporary studies have revealed that fungi and bacteria often form physically and metabolically interdependent consortia that harbor properties and pathogenicity distinct from those of their individual components. Metagenomic DNA “shotgun” sequencing has proved useful in determining microbial etiology in clinical samples, effective for not only bacteria but also fungi, archaea, and viruses. Methods Thirty-nine consecutive nail and subungual debris samples with suspected onychomycosis were sent for laboratory analysis using three examination techniques: DNA sequencing, polymerase chain reaction analysis, and standard fungal culture. The nail plate and surrounding areas were disinfected with an ethyl alcohol swab before nail sampling. Samples from 16 patients were analyzed for suspected onychomycosis with DNA sequencing, searching a database of 25,000 known pathogens. These results were compared with 15 real-time polymerase chain reaction screening assays and eight fungal cultures sampled with the same methods. Results The DNA sequencing detected 32 species of bacteria and 28 species of fungi: 50% were solely bacterial, 6.3% were solely fungal, and 43.7% were mixed communities of bacteria and fungi. Conclusions Toenails tested with DNA sequencing demonstrated the presence of both bacteria and fungi in many samples. Further work is required to fully investigate its relevance to nail pathology and treatment.

Using a Polymerase Chain Reaction as a Complementary Test to Improve the Detection of Dermatophyte Fungus in Nails

2014 ◽  
Vol 104 (3) ◽  
pp. 233-237 ◽  
Author(s):  
María José Iglesias Sánchez ◽  
Ana María Pérez Pico ◽  
Félix Marcos Tejedor ◽  
María Jesús Iglesias Sánchez ◽  
Raquel Mayordomo Acevedo
Keyword(s):  
Polymerase Chain Reaction ◽  
Dna Sequences ◽  
Classical Method ◽  
Clinical Manifestations ◽  
Culture Method ◽  
Clinical Samples ◽  
Chain Reaction ◽  
Nested Polymerase Chain Reaction ◽  
Traditional Procedure ◽  
Polymerase Chain

Background Dermatomycoses are a group of pathologic abnormalities frequently seen in clinical practice, and their prevalence has increased in recent decades. Diagnostic confirmation of mycotic infection in nails is essential because there are several pathologic conditions with similar clinical manifestations. The classical method for confirming the presence of fungus in nail is microbiological culture and the identification of morphological structures by microscopy. Methods We devised a nested polymerase chain reaction (PCR) that amplifies specific DNA sequences of dermatophyte fungus that is notably faster than the 3 to 4 weeks that the traditional procedure takes. We compared this new technique and the conventional plate culture method in 225 nail samples. The results were subjected to statistical analysis. Results We found concordance in 78.2% of the samples analyzed by the two methods and increased sensitivity when simultaneously using the two methods to analyze clinical samples. Now we can confirm the presence of dermatophyte fungus in most of the positive samples in just 24 hours, and we have to wait for the result of culture only in negative PCR cases. Conclusions Although this PCR cannot, at present, substitute for the traditional culture method in the detection of dermatophyte infection of the nails, it can be used as a complementary technique because its main advantage lies in the significant reduction of time used for diagnosis, in addition to higher sensitivity.

scholarly journals Analysis and validation of a highly sensitive one-step nested quantitative real-time polymerase chain reaction assay for specific detection of severe acute respiratory syndrome coronavirus 2

2020 ◽  
Vol 17 (1) ◽  
Author(s):  
Yang Zhang ◽  
Chunyang Dai ◽  
Huiyan Wang ◽  
Yong Gao ◽  
Tuantuan Li ◽  
...  
Keyword(s):  
Polymerase Chain Reaction ◽  
Real Time ◽  
Quantitative Polymerase Chain Reaction ◽  
Clinical Samples ◽  
Chain Reaction ◽  
Pcr Assay ◽  
Qrt Pcr ◽  
Highly Sensitive ◽  
One Step ◽  
Polymerase Chain

Abstract Background Coronavirus disease 2019 (COVID-19), caused by SARS-CoV-2, is posing a serious threat to global public health. Reverse transcriptase real-time quantitative polymerase chain reaction (qRT-PCR) is widely used as the gold standard for clinical detection of SARS-CoV-2. Due to technical limitations, the reported positive rates of qRT-PCR assay of throat swab samples vary from 30 to 60%. Therefore, the evaluation of alternative strategies to overcome the limitations of qRT-PCR is required. A previous study reported that one-step nested (OSN)-qRT-PCR revealed better suitability for detecting SARS-CoV-2. However, information on the analytical performance of OSN-qRT-PCR is insufficient. Method In this study, we aimed to analyze OSN-qRT-PCR by comparing it with droplet digital PCR (ddPCR) and qRT-PCR by using a dilution series of SARS-CoV-2 pseudoviral RNA and a quality assessment panel. The clinical performance of OSN-qRT-PCR was also validated and compared with ddPCR and qRT-PCR using specimens from COVID-19 patients. Result The limit of detection (copies/ml) of qRT-PCR, ddPCR, and OSN-qRT-PCR were 520.1 (95% CI: 363.23–1145.69) for ORF1ab and 528.1 (95% CI: 347.7–1248.7) for N, 401.8 (95% CI: 284.8–938.3) for ORF1ab and 336.8 (95% CI: 244.6–792.5) for N, and 194.74 (95% CI: 139.7–430.9) for ORF1ab and 189.1 (95% CI: 130.9–433.9) for N, respectively. Of the 34 clinical samples from COVID-19 patients, the positive rates of OSN-qRT-PCR, ddPCR, and qRT-PCR were 82.35% (28/34), 67.65% (23/34), and 58.82% (20/34), respectively. Conclusion In conclusion, the highly sensitive and specific OSN-qRT-PCR assay is superior to ddPCR and qRT-PCR assays, showing great potential as a technique for detection of SARS-CoV-2 in patients with low viral loads.

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