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.

Scoring System for the Diagnosis of COVID-19

2020 ◽  
Vol 13 (1) ◽  
pp. 413-414 ◽  
Author(s):  
Mohamed Farouk Allam
Keyword(s):  
Scoring System ◽  
Clinical Symptoms ◽  
False Negative ◽  
Nasopharyngeal Swab ◽  
Rt Pcr ◽  
Pcr Assay ◽  
Negative Results ◽  
False Negative Results ◽  
Symptoms And Signs

Due to the international spread of COVID-19, the difficulty of collecting nasopharyngeal swab specimen from all suspected patients, the costs of RT-PCR and CT, and the false negative results of RT-PCR assay in 41% of COVID-19 patients, a scoring system is needed to classify the suspected patients in order to determine the need for follow-up, home isolation, quarantine or the conduction of further investigations. A scoring system is proposed as a diagnostic tool for suspected patients. It includes Epidemiological Evidence of Exposure, Clinical Symptoms and Signs, and Investigations (if available). This scoring system is simple, could be calculated in a few minutes, and incorporates the main possible data/findings of any patient.

scholarly journals Evaluation of the Carba NP Test for Rapid Detection of Carbapenemase-Producing Enterobacteriaceae and Pseudomonas aeruginosa

2013 ◽  
Vol 57 (9) ◽  
pp. 4578-4580 ◽  
Author(s):  
Nathalie Tijet ◽  
David Boyd ◽  
Samir N. Patel ◽  
Michael R. Mulvey ◽  
Roberto G. Melano
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Positive Predictive Value ◽  
Negative Predictive Value ◽  
Predictive Value ◽  
Rapid Detection ◽  
False Negative ◽  
Bacterial Extract ◽  
Content Type ◽  
Negative Results ◽  
False Negative Results

ABSTRACTThe Carba NP test was evaluated against a panel of 244 carbapenemase- and non-carbapenemase-producingEnterobacteriaceaeandPseudomonas aeruginosaisolates. We confirmed the 100% specificity and positive predictive value of the test, but the sensitivity and negative predictive value were 72.5% and 69.2%, respectively, and increased to 80% and 77.3%, respectively, using a more concentrated bacterial extract. False-negative results were associated with mucoid strains or linked to enzymes with low carbapenemase activity, particularly OXA-48-like, which has emerged globally in enterobacteria.

scholarly journals Most but not all laboratories can detect the recently emerged Neisseria gonorrhoeae porA mutants – results from the QCMD 2013 N. gonorrhoeae external quality assessment programme

2014 ◽  
Vol 19 (8) ◽  
Author(s):  
D Luijt ◽  
C Di Lorenzo ◽  
A M van Loon ◽  
M Unemo
Keyword(s):  
Neisseria Gonorrhoeae ◽  
Quality Assessment ◽  
External Quality Assessment ◽  
False Negative ◽  
Molecular Diagnostic ◽  
External Quality ◽  
Diagnostic Assays ◽  
Assessment Programme ◽  
Negative Results ◽  
False Negative Results

We describe the results of the Quality Control for Molecular Diagnostics 2013 Neisseria gonorrhoeae external quality assessment programme that included an N. gonorrhoeae strain harbouring an N. meningitidis porA gene which causes false-negative results in molecular diagnostic assays targeting the gonococcal porA pseudogene. Enhanced awareness of the international transmission of such gonococcal strains is needed to avoid false-negative results in both in-house and commercial molecular diagnostic assays used in laboratories worldwide, but particularly in Europe.

scholarly journals Detection of LytA Genes in Streptococcus pneumoniae Isolated from sputum pneumonia patients

Biomedika ◽  
2020 ◽  
Vol 13 (1) ◽  
pp. 23-30
Author(s):  
Mustika Sari Hutabarat ◽  
Firdaus Hamid ◽  
Irawaty Djaharuddin ◽  
Alfian Zainuddin ◽  
Rossana Agus ◽  
...  
Keyword(s):  
Streptococcus Pneumoniae ◽  
False Negative ◽  
Pneumococcal Infection ◽  
Diagnostic Methods ◽  
Molecular Diagnostic ◽  
Clinical Samples ◽  
Biochemical Tests ◽  
Negative Results ◽  
False Negative Results ◽  
Polymerase Chain

Streptococcus pneumoniae (pneumococcus) is a Gram-positive facultative anaerobic bacterium that is a major cause of morbidity and mortality worldwide. But the lack of reporting of disease by this bacterium in Indonesia, one of the causes is because the diagnosis of pneumococcal infection is often clinically not typical and conventional methods which are still the standard gold method often give false-negative results. So the purpose of this study was to evaluate the performance of culture and molecular diagnostic methods using the Polymerase Chain Reaction (PCR) technique in detecting Streptococcus pneumoniae in sputum clinical samples using the Autolysin (LytA) gene which is a virulence factor of this bacterium. 57 isolates from 60 samples were confirmed as Streptococcus sp through microscopic identification, culture, and biochemical tests. Then the sensitivity test with an optochin test of 9 (9%) compared the results descriptively with the PCR technique using the Autolysin A (LytA) gene which was obtained more sensitive by 15 (25%).

scholarly journals Clinical Neisseria gonorrhoeae isolate with a N. meningitidis porA gene and no prolyliminopeptidase activity, Sweden, 2011 – danger of false-negative genetic and culture diagnostic results

2012 ◽  
Vol 17 (9) ◽  
Author(s):  
D Golparian ◽  
E Johansson ◽  
M Unemo
Keyword(s):  
Neisseria Gonorrhoeae ◽  
False Negative ◽  
Gonorrhoeae Strain ◽  
Negative Results ◽  
False Negative Results ◽  
Gonorrhoeae Isolate

We describe a Neisseria gonorrhoeae strain, found in Sweden in 2011, that harbours a N. meningitidis porA gene causing false-negative results in PCRs targeting the gonococcal porA pseudogene. Furthermore, the strain had no prolyliminopeptidase (PIP) activity that many commercial biochemical kits for species verification in culture rely on. Enhanced awareness of the spread of such strains and screening for them can be crucial.

scholarly journals Culture-Independent Detection of Nontuberculous Mycobacteria in Clinical Respiratory Samples

2016 ◽  
Vol 54 (9) ◽  
pp. 2395-2398 ◽  
Author(s):  
Gianny P. Scoleri ◽  
Jocelyn M. Choo ◽  
Lex E. X. Leong ◽  
Thomas R. Goddard ◽  
Lisa Shephard ◽  
...  
Keyword(s):  
Quantitative Pcr ◽  
Nontuberculous Mycobacteria ◽  
Direct Detection ◽  
Clinical Samples ◽  
Pcr Assay ◽  
Content Type ◽  
Culture Independent ◽  
Quantitative Pcr Assay ◽  
Single Reaction

Culture-based detection of nontuberculousMycobacteria(NTM) in respiratory samples is time consuming and can be subject to overgrowth by nonmycobacterial bacteria. We describe a single-reaction TaqMan quantitative PCR assay for the direct detection of NTM species in clinical samples that is specific, sensitive, and robust.

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.

Prevalence of porA pseudogene deletion among Neisseria gonorrhoeae isolates referred to the UK’s Gonococcal Resistance to Antimicrobials Surveillance Program

Sexual Health ◽  
2017 ◽  
Vol 14 (4) ◽  
pp. 392 ◽  
Author(s):  
Martina Toby ◽  
Pamela Saunders ◽  
Michelle Cole ◽  
Vlad Grigorjev ◽  
Sarah Alexander ◽  
...  
Keyword(s):  
Neisseria Gonorrhoeae ◽  
False Negative ◽  
Public Health Problem ◽  
Surveillance Program ◽  
Major Public Health Problem ◽  
Negative Results ◽  
False Negative Results ◽  
Confirmatory Tests ◽  
Polymerase Chain ◽  
Low Prevalence

porA pseudogene-negative Neisseria gonorrhoeae isolates produce false-negative results when examined by polymerase chain reaction (PCR) with porA pseudogene targets. In the present study, 533 representative gonococcal isolates received in 2011 via the Gonococcal Resistance to Antimicrobials Surveillance Program were examined to determine the prevalence of porA-negative isolates. Less than 0.4% (2/533) of isolates were found to be reproducibly negative with the porA real-time PCR but were confirmed as N. gonorrhoeae with molecular, biochemical and immunological confirmatory tests. Sequencing revealed both isolates contained the Neisseria meningitidis porA gene. Low prevalence indicates that although these isolates do not present a major public health problem, microbiologists should remain vigilant.

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