scholarly journals A unique strain of Mycobacterium tuberculosis and a cautionary tale for users of molecular techniques

2004 ◽  
Vol 25 (4) ◽  
pp. 32
Author(s):  
C Frank Haverkort ◽  
Christopher Gilpin
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Binding Sites ◽  
Direct Detection ◽  
False Negative ◽  
Molecular Techniques ◽  
Cautionary Tale ◽  
Testing Methods ◽  
Negative Results ◽  
False Negative Results ◽  
Unique Strain

Molecular techniques are now widely applied in Australia and elsewhere for the direct detection of Mycobacterium tuberculosis DNA in clinical specimens and culturally enhanced material. All nucleic acid testing methods have the potential to give false negative results due to mutations that may arise at primer or probe binding sites. We describe one such strain of M. tuberculosis that was encountered in 1995 and that has not been encountered in Australia since.

scholarly journals Emerging approaches for detection of methylation sites in RNA

Open Biology ◽  
2018 ◽  
Vol 8 (9) ◽  
pp. 180121 ◽  
Author(s):  
Anna Ovcharenko ◽  
Andrea Rentmeister
Keyword(s):  
High Throughput Sequencing ◽  
De Novo ◽  
Direct Detection ◽  
False Negative ◽  
Detection Methods ◽  
Rna Modifications ◽  
Negative Results ◽  
Third Generation Sequencing ◽  
False Negative Results ◽  
Generation Sequencing

RNA methylations play a significant regulatory role in diverse biological processes. Although the transcriptome-wide discovery of unknown RNA methylation sites is essential to elucidate their function, the development of a bigger variety of detection approaches is desirable for multiple reasons. Many established detection methods for RNA modifications heavily rely on the specificity of the respective antibodies. Thus, the development of antibody-independent transcriptome-wide methods is beneficial. Even the antibody-independent high-throughput sequencing-based methods are liable to produce false-positive or false-negative results. The development of an independent method for each modification could help validate the detected modification sites. Apart from the transcriptome-wide methods for methylation detection de novo , methods for monitoring the presence of a single methylation at a determined site are also needed. In contrast to the transcriptome-wide detection methods, the techniques used for monitoring purposes need to be cheap, fast and easy to perform. This review considers modern approaches for site-specific detection of methylated nucleotides in RNA. We also discuss the potential of third-generation sequencing methods for direct detection of RNA methylations.

scholarly journals Comparison of conventional and molecular techniques for Trypanosoma vivax diagnosis in experimentally infected cattle

2019 ◽  
Vol 28 (2) ◽  
pp. 203-209 ◽  
Author(s):  
Otavio Luiz Fidelis Junior ◽  
Paulo Henrique Sampaio ◽  
Luiz Ricardo Gonçalves ◽  
Marcos Rogério André ◽  
Rosangela Zacarias Machado ◽  
...  
Keyword(s):  
False Negative ◽  
Infectious Agent ◽  
Diagnostic Techniques ◽  
Molecular Techniques ◽  
South American ◽  
Trypanosoma Vivax ◽  
Negative Results ◽  
False Negative Results ◽  
Highly Sensitive ◽  
Centrifugation Technique

Abstract Livestock infections by Trypanosoma vivax have been occurring with increasing frequency, mainly due to the presence of animals with subclinical infections and without apparent parasitaemia, making diagnosis challenging. The aim of the present study was to evaluate several techniques used for T. vivax diagnosis in order to assess the best way of using them during the course of the disease. Molecular methods demonstrated higher rates of detection than parasitological methods, detecting 33 of the 54 (61.1%) known positive samples, while the hematocrit centrifugation technique (best parasitological test) detected only 44.4%. The serological methods, IFAT and ELISA, detected seropositivity in 51 of the 54 (94.4%) and 49 of the 54 (90.7%) known positive samples, respectively. Despite being highly sensitive, the latter only demonstrates exposure to the infectious agent and does not indicate whether the infection is active. The present study was the first to use the qPCR for a South American isolate, improving disease detection and quantification. Furthermore, the analyses revealed that the patent phase of the disease may extend up to 42 days, longer than previously reported. The combination of several diagnostic techniques can lower the frequency of false negative results and contributes toward better disease control.

scholarly journals Distribution of a Specific 500-Base-Pair Fragment in Mycobacterium bovis Isolates from Sardinian Cattle

2000 ◽  
Vol 38 (10) ◽  
pp. 3837-3839 ◽  
Author(s):  
Leonardo A. Sechi ◽  
Ilaria Duprè ◽  
Guido Leori ◽  
Giovanni Fadda ◽  
Stefania Zanetti
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Mycobacterium Bovis ◽  
Base Pair ◽  
False Negative ◽  
Negative Results ◽  
False Negative Results ◽  
Base Pair Fragment ◽  
Pair Fragment

Amplification of a specific, 500-bp fragment fromMycobacterium bovis isolates and use of the fragment to differentiate between Mycobacterium tuberculosis andM. bovis was previously reported (J. G. Rodriguez, G. A. Meja, P. Del Portillo, M. E. Patarroyo, and L. A. Murillo, Microbiology 141:2131–2138, 1995). In the present study, 30M. bovis isolates from Sardinian cattle were examined for the presence of this 500-bp fragment; 4 of the 30 isolates lacked the fragment. This result indicates that identification of M. bovis strains by amplification of the 500-bp sequence may lead to false-negative results.

scholarly journals Identification of Novel Mutations in the N Gene of SARS-CoV-2 That Adversely Affect the Detection of the Virus by Reverse Transcription-Quantitative PCR

2021 ◽  
Author(s):  
Rashedul Hasan ◽  
Mohammad Enayet Hossain ◽  
Mojnu Miah ◽  
Md Mahmudul Hasan ◽  
Mustafizur Rahman ◽  
...  
Keyword(s):  
Quantitative Pcr ◽  
Reverse Transcription ◽  
Binding Sites ◽  
False Negative ◽  
N Gene ◽  
Novel Mutations ◽  
Viral Spread ◽  
Negative Results ◽  
False Negative Results ◽  
Reverse Transcription Quantitative Pcr

Accurate and timely diagnosis of SARS-CoV-2 is a critical step toward controlling the viral spread, since it facilitates the identification and isolation of infected individuals. Mutations in the primer-/probe-binding sites may lead to false-negative results.

scholarly journals Multitarget PCR Assay for Direct Detection of Penicillinase-Producing Neisseria gonorrhoeae for Enhanced Surveillance of Gonococcal Antimicrobial Resistance

2015 ◽  
Vol 53 (8) ◽  
pp. 2706-2708 ◽  
Author(s):  
Cameron Buckley ◽  
Ella Trembizki ◽  
Robert W. Baird ◽  
Marcus Chen ◽  
Basil Donovan ◽  
...  
Keyword(s):  
Antimicrobial Resistance ◽  
Neisseria Gonorrhoeae ◽  
Direct Detection ◽  
False Negative ◽  
Clinical Samples ◽  
Pcr Assay ◽  
Content Type ◽  
Negative Results ◽  
False Negative Results ◽  
Sequence Variations

A multitarget PCR was developed for the direct detection of penicillinase-producing Neisseria gonorrhoeae (PPNG). The assay was validated by testing 342 PPNG isolates and 415 clinical samples. The method is suitable for routine detection of PPNG strains. Its multitarget approach reduces the potential for false-negative results caused by sequence variations.

scholarly journals Internal control in PCR for Mycobacterium tuberculosis: usefulness and improvement of the diagnosis

2008 ◽  
Vol 51 (4) ◽  
pp. 485-491 ◽  
Author(s):  
Elizabeth Cortez-Herrera ◽  
Rosa Dea Sperhacke ◽  
Daniela Becker ◽  
Afrânio Kritski ◽  
Arnaldo Zaha ◽  
...  
Keyword(s):  
Public Health ◽  
Mycobacterium Tuberculosis ◽  
Internal Control ◽  
False Negative ◽  
Clinical Results ◽  
Public Health Laboratory ◽  
Negative Results ◽  
False Negative Results ◽  
Diagnostic Fragment ◽  
Pcr Test

The aim of this work was to construct and test a plasmidial Internal Control (IC) to detect the inhibition in the PCR test for M. tuberculosis and also its contribution for a Public Health Laboratory routine. The IC was a 600-bp of DNA linked to a plasmid with the same primer sites, allowing the amplification with the 245-bp diagnostic fragment. The amplification of the positive samples rendered the IC and the diagnostic fragment; instead negative samples only showed the IC. A total of 149 tuberculosis samples were studied and introduced the IC to monitor. Results showed 3.3% of the samples without amplification of the IC, suggesting the inhibition. These samples showed results in accordance with the clinical results. The objective of the IC was to identify the false negative results.

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