scholarly journals Development and Validation of aPneumocystis jiroveciiReal-time Polymerase Chain Reaction Assay for Diagnosis ofPneumocystisPneumonia

2015 ◽  
Vol 26 (5) ◽  
pp. 263-267 ◽  
Author(s):  
Deirdre L Church ◽  
Anshula Ambasta ◽  
Amanda Wilmer ◽  
Holly Williscroft ◽  
Gordon Ritchie ◽  
...  
Keyword(s):  
Real Time ◽  
Real Time Pcr ◽  
Gold Standard ◽  
Pathogenic Fungus ◽  
Immunofluorescence Assay ◽  
Immunocompromised Patients ◽  
Chain Reaction ◽  
Pcr Assay ◽  
Predictive Values ◽  
Sensitivity Specificity

BACKGROUND:Pneumocystis jirovecii(PJ), a pathogenic fungus, causes severe interstitialPneumocystispneumonia (PCP) among immunocompromised patients. A laboratory-developed real-time polyermase chain reaction (PCR) assay was validated for PJ detection to improve diagnosis of PCP.METHODS: Forty stored bronchoalveolar lavage (BAL) samples (20 known PJ positive [PJ+] and 20 known PJ negative [PJ−]) were initially tested using the molecular assay. Ninety-two sequentially collected BAL samples were then analyzed using an immunofluorescence assay (IFA) and secondarily tested using the PJ real-time PCR assay. Discrepant results were resolved by retesting BAL samples using another real-time PCR assay with a different target. PJ real-time PCR assay performance was compared with the existing gold standard (ie, IFA) and a modified gold standard, in which a true positive was defined as a sample that tested positive in two of three methods in a patient suspected to have PCP.RESULTS: Ninety of 132 (68%) BAL fluid samples were collected from immunocompromised patients. Thirteen of 92 (14%) BALs collected were PJ+ when tested using IFA. A total of 40 BAL samples were PJ+ in the present study including: all IFA positive samples (n=13); all referred PJ+ BAL samples (n=20); and seven additional BAL samples that were IFA negative, but positive using the modified gold standard. Compared with IFA, the PJ real-time PCR had sensitivity, specificity, and positive and negative predictive values of 100%, 91%, 65% and 100%, respectively. Compared with the modified gold standard, PJ real-time PCR had a sensitivity, specificity, and positive and negative predictive values of 100%.CONCLUSION: PJ real-time PCR improved detection of PJ in immunocompromised patients.

Development of a LUX real-time PCR for the detection and quantification of human herpesvirus 7

2009 ◽  
Vol 55 (3) ◽  
pp. 319-325 ◽  
Author(s):  
Massimiliano Bergallo ◽  
Cristina Costa ◽  
Maria Elena Terlizzi ◽  
Francesca Sidoti ◽  
Samuela Margio ◽  
...  
Keyword(s):  
Real Time ◽  
Real Time Pcr ◽  
Primary Infection ◽  
Latent Infection ◽  
Dynamic Range ◽  
Human Herpesvirus ◽  
Clinical Samples ◽  
House Light ◽  
Pcr Assay ◽  
Sensitivity Specificity

Human herpesvirus 7 is a highly seroprevalent β-herpesvirus that, following primary infection, remains latent in CD4+ T cells and determines a persistent rather than a latent infection in various tissues and organs, including the lung and skin. This paper describes the development of an in-house light upon extension real-time PCR assay for quantification of human herpesvirus 7 DNA in clinical samples. The efficiency, sensitivity, specificity, inter- and intra-assay variability, and dynamic range have been determined. Subsequently, the assay has been validated by evaluating the human herpesvirus 7 load in bronchoalveolar lavages and skin specimens, chosen as 2 persistency sites, from healthy and pathological individuals. The real-time PCR assay developed in this study could be a useful tool to detect and quantify human herpesvirus 7 DNA in different clinical specimens to elucidate its epidemiological and pathogenic roles.

Real-Time Polymerase Chain Reaction Detection of Bovine DNA in Meat and Bone Meal Samples

2002 ◽  
Vol 65 (7) ◽  
pp. 1158-1165 ◽  
Author(s):  
S. LAHIFF ◽  
M. GLENNON ◽  
J. LYNG ◽  
T. SMITH ◽  
N. SHILTON ◽  
...  
Keyword(s):  
Real Time ◽  
Real Time Pcr ◽  
Meat And Bone Meal ◽  
Bone Meal ◽  
Chain Reaction ◽  
Pcr Assay ◽  
The Real ◽  
Pcr Product ◽  
Pcr Products ◽  
Polymerase Chain

We describe a real-time polymerase chain reaction (PCR) assay for the detection of bovine DNA extracted from meat and bone meal (MBM) samples. PCR primers were used to amplify a 271-bp region of the mitochondrial ATPase 8–ATPase 6 gene, and a fluorogenic probe (BOV1) labeled with a 5′ FAM reporter and a 3′ TAMRA quencher was designed to specifically detect bovine PCR product. The specificity of the BOV1 probe for the detection of the bovine PCR product was confirmed by Southern blot hybridization analysis of the probe with PCR products generated from ovine, porcine, and bovine genomic DNA extracted from blood and with PCR products generated from genomic DNA extracted from single-species laboratory scale rendered MBM samples. The specificity of the BOV1 probe was also evaluated in real-time PCR reactions including these genomic targets. Both methods demonstrated that the BOV1 probe was specific for the detection of bovine PCR product. The BOV1 probe had a detection limit of 0.0001% bovine material by Southern blot DNA probe hybridization analysis and a detection limit of 0.001% bovine material in the real-time PCR assay. Application of the real-time PCR assay to six industrial samples that had previously tested positive for the presence of bovine material with a conventional PCR assay yielded positive results with the real-time PCR assay for four samples.

scholarly journals Performance comparison of two malaria rapid diagnostic test with real time polymerase chain reaction and gold standard of microscopy detection method

2020 ◽  
Author(s):  
Puspa Wardhani ◽  
Trieva Verawaty Butarbutar ◽  
Christophorus Oetama Adiatmaja ◽  
Amarensi Milka Betaubun ◽  
Nur Hamidah ◽  
...  
Keyword(s):  
Polymerase Chain Reaction ◽  
Real Time ◽  
Diagnostic Test ◽  
Real Time Pcr ◽  
Predictive Value ◽  
Gold Standard ◽  
Detection Method ◽  
Rt Pcr ◽  
Chain Reaction ◽  
Polymerase Chain

Background: The diagnostic test for malaria is mostly based on Rapid Diagnostic Test (RDT) and detection by microscopy. Polymerase Chain Reaction (PCR) is also a sensitive detection method that can be considered as a diagnostic tool. The outcome of malaria microscopy detection depends on the examiner's ability and experience. Some RDT has been distributed in Indonesia, which needs to be evaluated for their results. Objective: This study aimed to compare the performance of RightSign RDT and ScreenPlus RDT for detection of Plasmodium in human blood. We used specific real-time polymerase chain reaction abTESTMMalaria qPCRII) and gold standard of microscopy detection method to measure diagnostic efficiency. Methods: Blood specimens were evaluated using RightSign RDT, ScreenPlus RDT, Microscopy detection, and RT-PCR as the protocol described. The differences on specificity (Sp), sensitivity (Sn), positive predictive value (PPV), and negative predictive value (NPV) were analyzed using McNemar and Kruskal Wallis analysis. Results: A total of 105 subjects were recruited. Based on microscopy test, RightSign RDT had sensitivity, Specificity, PPV, NPV, 100%, 98%, 98.2%, 100%, respectively. ScreenPlus showed 100% sensitivity, 98% specificity, 98.2% PPV, 100% NPV. The sensitivity of both RDTs became lower (75%) and the specificity higher (100 %) when using real-time PCR. Both RDTs showed a 100% agreement. RT-PCR detected higher mix infection when compared to microscopy and RDTs. Conclusion: RightSign and ScreenPlus RDT have excellent performance when using microscopy detection as a gold standard. Real-time PCR method can be considered as a confirmation tool for malaria diagnosis.

scholarly journals Laboratory diagnosis of 37 cases of Bartonella endocarditis based on enzyme immunoassay and real-time PCR

2021 ◽  
Author(s):  
Lev Shapira ◽  
Michal Rasis ◽  
Inbal Binsky Ehrenreich ◽  
Yasmin Maor ◽  
Eugene A. Katchman ◽  
...  
Keyword(s):  
Enzyme Immunoassay ◽  
Real Time ◽  
Real Time Pcr ◽  
Heart Valves ◽  
Q Fever ◽  
Laboratory Diagnosis ◽  
Cross Reactivity ◽  
Immunofluorescence Assay ◽  
Complete Agreement ◽  
Pcr Assay

Bartonella spp., mostly B. quintana and B. henselae, are a common cause of culture-negative endocarditis. Serology, using immunofluorescence assay (IFA) and PCR performed on cardiac tissues are the mainstays of diagnosis. We developed an enzyme immunoassay (EIA) and a novel multiplex real-time PCR assay, utilizing Bartonella genus-specific, B. henselae-specific and B. quintana-specific SimpleProbe probes, for diagnosis of Bartonella endocarditis. We aimed to evaluate the performance of these assays. Thirty-seven patients with definite endocarditis, 18 with B. henselae, 18 with B. quintana and one with B. koehlerae were studied. Diagnosis was confirmed by conventional PCR and DNA sequencing of surgical cardiac specimens. Similarly to IFA, anti-Bartonella IgG titers ≥1:800 were found in 94% of patients by EIA; cross-reactivity between B. henselae and B. quintana precluded species-specific serodiagnosis, and frequent (41%) but low-titer cross-reactivity between Coxiella burnetii antibodies and B. henselae antigen was found in patients with Q fever endocarditis. Low-titer (1:100) cross-reactivity was uncommonly found also in patients with brucellosis and culture-positive endocarditis, particularly Enterococcus faecalis endocarditis. Real-time PCR performed on explanted heart valves/vegetations was in complete agreement with results of sequence-based diagnosis with characteristic melting curves. The genus-specific probe identified five additional endocarditis-associated Bartonella spp. at the genus level. In conclusion, EIA coupled with a novel real-time PCR assay can play an important role in Bartonella endocarditis diagnosis and expand the diagnostic arsenal at the disposal of the clinical microbiologist. Since serology remains a major diagnostic tool, recognizing its pitfalls is essential to avoid incorrect diagnosis.

scholarly journals Improvement of Legionnaires’ disease diagnosis using real-time PCR assay: a retrospective analysis, Italy, 2010 to 2015

2018 ◽  
Vol 23 (50) ◽  
Author(s):  
Maria Luisa Ricci ◽  
Antonella Grottola ◽  
Giulia Fregni Serpini ◽  
Antonino Bella ◽  
Maria Cristina Rota ◽  
...  
Keyword(s):  
Real Time ◽  
Legionella Pneumophila ◽  
Real Time Pcr ◽  
Reference Method ◽  
Disease Diagnosis ◽  
Pcr Assay ◽  
Predictive Values ◽  
The Real ◽  
Legionnaires Disease ◽  
Antigen Tests

Aim To evaluate real-time PCR as a diagnostic method for Legionnaires’ disease (LD). Detection of Legionella DNA is among the laboratory criteria of a probable LD case, according to the European Centre for Disease Prevention and Control, although the utility and advantages, as compared to culture, are widely recognised. Methods Two independent laboratories, one using an in-house and the other a commercial real-time PCR assay, analysed 354 respiratory samples from 311 patients hospitalised with pneumonia between 2010–15. The real-time PCR reliability was compared with that of culture and urinary antigen tests (UAT). Concordance, specificity, sensitivity and positive and negative predictive values (PPV and NPV, respectively) were calculated. Results Overall PCR detected eight additional LD cases, six of which were due to Legionella pneumophila (Lp) non-serogroup 1. The two real-time PCR assays were concordant in 99.4% of the samples. Considering in-house real-time PCR as the reference method, specificity of culture and UAT was 100% and 97.9% (95% CI: 96.2–99.6), while the sensitivity was 63.6% (95%CI: 58.6–68.6) and 77.8% (95% CI: 72.9–82.7). PPV and NPV for culture were 100% and 93.7% (95% CI: 91.2-96.3). PPV and NPV for UAT were 87.5% (95% CI: 83.6-91.4) and 95.8% (95% CI: 93.5-98.2). Conclusion Regardless of the real-time PCR assay used, it was possible to diagnose LD cases with higher sensitivity than using culture or UAT. These data encourage the adoption of PCR as routine laboratory testing to diagnose LD and such methods should be eligible to define a confirmed LD case.

scholarly journals Evaluation of the ELITe InGenius PCR Platform for Detection of Mycoplasma pneumoniae

2019 ◽  
Vol 57 (6) ◽  
Author(s):  
Arthur H. Totten ◽  
Sixto M. Leal ◽  
Amy E. Ratliff ◽  
Li Xiao ◽  
Donna M. Crabb ◽  
...  
Keyword(s):  
Real Time ◽  
Mycoplasma Pneumoniae ◽  
Real Time Pcr ◽  
Growth Media ◽  
Test Accuracy ◽  
Analytical Sensitivity ◽  
Pcr Assay ◽  
Predictive Values ◽  
Content Type ◽  
Significant Difference

ABSTRACT Mycoplasma pneumoniae is the leading cause of bacterial community-acquired pneumonia in persons of all ages. Due to the fastidious nature of this bacterium and the necessary specialized growth media, nucleic acid amplification testing is currently the most reliable means for patient diagnostics. Analytical sensitivity, specificity, reproducibility, and clinical performance of the ELITe InGenius automated PCR platform with its MGB Alert M. pneumoniae real-time PCR research use only reagents (ELITechGroup, Inc., Bothell, WA) were compared with those of a laboratory-developed real-time PCR assay targeting repMp1 for detection of M. pneumoniae. The ELITe InGenius PCR assay successfully detected 31 distinct M. pneumoniae clinical isolates and reference strains, and there was no cross-reactivity with other mollicutes, Gram-positive bacteria, or Gram-negative bacteria. In testing 223 clinical samples, the ELITe InGenius PCR showed 95.79% and 99.22% positive and negative agreement with the repMp1 assay, respectively. Additionally, the ELITech platform showed 98.91% positive and 96.95% negative predictive values, and there was no significant difference detected between the two assays (McNemar’s test, P = 0.375). The ELITe InGenius PCR assay limit of detection was 0.16 CFU/PCR test or 4.16 genome copies (GCs)/test. Accuracy, instrument ease-of-use, and decreased hands-on time make the ELITe InGenius platform suitable for detection of M. pneumoniae directly from clinical specimens.

scholarly journals Performance of real-time PCR and immunofluorescence assay for diagnosis of Pneumocystis pneumonia in real-world clinical practice

PLoS ONE ◽  
2020 ◽  
Vol 15 (12) ◽  
pp. e0244023
Author(s):  
Darunee Chotiprasitsakul ◽  
Pataraporn Pewloungsawat ◽  
Chavachol Setthaudom ◽  
Pitak Santanirand ◽  
Prapaporn Pornsuriyasak
Keyword(s):  
Real Time ◽  
Sensitivity And Specificity ◽  
Real World ◽  
Real Time Pcr ◽  
Pneumocystis Pneumonia ◽  
Immunofluorescence Assay ◽  
Cohen’S Kappa ◽  
Cohen's Kappa ◽  
Highly Sensitive ◽  
Sensitivity Specificity

Background PCR is more sensitive than immunofluorescence assay (IFA) for detection of Pneumocystis jirovecii. However, PCR cannot always distinguish infection from colonization. This study aimed to compare the performance of real-time PCR and IFA for diagnosis of P. jirovecii pneumonia (PJP) in a real-world clinical setting. Methods A retrospective cohort study was conducted at a 1,300-bed hospital between April 2017 and December 2018. Patients whose respiratory sample (bronchoalveolar lavage or sputum) were tested by both Pneumocystis PCR and IFA were included. Diagnosis of PJP was classified based on multicomponent criteria. Sensitivity, specificity, 95% confidence intervals (CI), and Cohen's kappa coefficient were calculated. Results There were 222 eligible patients. The sensitivity and specificity of PCR was 91.9% (95% CI, 84.0%–96.7%) and 89.7% (95% CI, 83.3%–94.3%), respectively. The sensitivity and specificity of IFA was 7.0% (95% CI, 2.6%–14.6%) and 99.2% (95% CI, 95.6%–100.0%), respectively. The percent agreement between PCR and IFA was 56.7% (Cohen's kappa -0.02). Among discordant PCR-positive and IFA-negative samples, 78% were collected after PJP treatment. Clinical management would have changed in 14% of patients using diagnostic information, mainly based on PCR results. Conclusions PCR is highly sensitive compared with IFA for detection of PJP. Combining clinical, and radiological features with PCR is useful for diagnosis of PJP, particularly when respiratory specimens cannot be promptly collected before initiation of PJP treatment.

Diagnosis of Invasive Fungal Infections by a Real-Time Panfungal PCR Assay in Pediatric Patients Undergoing Intensive Chemotherapy or Allogeneic Stem Cell Transplantion.

Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 343-343
Author(s):  
Christine Landlinger ◽  
Lenka Baskova ◽  
Sandra Preuner ◽  
Martine Van Grotel ◽  
Nico G. Hartwig ◽  
...  
Keyword(s):  
Real Time ◽  
Real Time Pcr ◽  
Predictive Value ◽  
Pediatric Patients ◽  
Fungal Infections ◽  
Invasive Fungal Infections ◽  
Immunocompromised Patients ◽  
Pcr Assay ◽  
Highly Sensitive ◽  
Panfungal Pcr

Abstract Abstract 343 Invasive fungal infections are life threatening events in severely immunocompromised patients, and there is urgent need for reliable screening methods facilitating rapid and broad detection of pathogenic fungi. We have established a two-reaction real-time PCR assay permitting highly sensitive detection and quantitative monitoring of more than 80 fungal pathogens, covering a large spectrum of moulds, yeasts and Zygomycetes (European patent No. 06817468.9). To assess the clinical potential of the panfungal real-time PCR assay, more than 600 consecutive specimens from 126 pediatric patients carrying a high risk of invasive fungal infections were analyzed. The results revealed an excellent correlation between PCR positivity and the presence of proven, probable or possible fungal infection according to the criteria of the European Organization for Research and Treatment of Cancer (EORTC), indicating a sensitivity of the assay of 96% (95%CI: 81-99.3%). Hence, the negative predictive value of the panfungal PCR assay presented is very high, and our current data indicate that molecular screening of patients during febrile neutropenic episodes by the assay can help prevent unnecessary toxicity resulting from empirical antifungal treatment in individuals who may not be at risk of imminent fungal disease. The specificity of the assay in the test cohort of patients was in the range of 76% (95%CI:62-87%), and the observations indicate that rapid species identification may be required to assess the positive predictive value for impending fungus-related disease. The availabel data provide a basis for appropriately designed clinical studies addressing the full diagnostic potential of fungal screening by highly sensitive, broad- spectrum molecular assays in severely immunocompromised patients. Disclosures: No relevant conflicts of interest to declare.

Early and simultaneous detection ofNosema bombycis(Microsporidia: Nosematidae), nucleopolyhedrovirus (Baculoviridae), and densovirus (Parvoviridae) by multiplex real-time polymerase chain reaction inBombyx mori(Lepidoptera: Bombycidae)

2017 ◽  
Vol 149 (2) ◽  
pp. 265-275
Author(s):  
Shan Wu ◽  
Yong-Qiang He ◽  
Xing-Meng Lu ◽  
Xiao-Feng Zhang ◽  
Jiang-Bing Shuai ◽  
...  
Keyword(s):  
Polymerase Chain Reaction ◽  
Early Detection ◽  
Bombyx Mori ◽  
Real Time ◽  
Real Time Pcr ◽  
Simultaneous Detection ◽  
Post Inoculation ◽  
Chain Reaction ◽  
Pcr Assay ◽  
Polymerase Chain

AbstractAn effective multiplex real-time polymerase chain reaction (PCR) assay for the simultaneous detection of three major pathogens,Nosema bombycisNägeli (Microsporidia: Nosematidae),Bombyx morinucleopolyhedrovirus (Baculoviridae: genusAlphabaculovirus) (NPV), andBombyx moridensovirus (Parvoviridae: genusIteravirus) (DNV), in silkworms (Bombyx mori(Linnaeus); Lepidoptera: Bombycidae) was developed in this study. Polymerase chain reaction and real-time PCR tests and basic local alignment search tool searches revealed that the primers and probes used in this study had high specificities for their target species. The ability of each primer/probe set to detect pure pathogen DNA was determined using a plasmid dilution panel, in which under optimal conditions the multiplex real-time PCR assay showed high efficiency in the detection of three mixed target plasmids with a detection limit of 8.5×103copies forN. bombycisandBombyx moriNPV (BmNPV) and 8.5×104copies forBombyx moriDNV (BmDNV). When the ability to detect these three pathogens was examined in artificially inoculated silkworms, our method presented a number of advantages over traditional microscopy, including specificity, sensitivity, and high-throughput capabilities. Under the optimal volume ratio for the three primer/probe sets (3:2:2=N. bombycis:BmNPV:BmDNV), the multiplex real-time PCR assay showed early detection of BmNPV and BmDNV by day 1 post inoculation using DNA templates of the three pathogens in various combinations from individually infected silkworms; the early detection ofN. bombyciswas possible by day 3 post inoculation using the DNA isolated from the midgut ofN. bombycis-infected silkworms.

scholarly journals 744. Clinical Performance of Real-time PCR in the Diagnosis of Pneumocystis jirovecii Pneumonia compared with Immunofluorescence Assay

2020 ◽  
Vol 7 (Supplement_1) ◽  
pp. S420-S420
Author(s):  
Cristina Veintimilla ◽  
Ana Alvarez-Uria ◽  
Pablo Martin-Rabadan ◽  
Luis Alcala ◽  
Patricia Muñoz ◽  
...  
Keyword(s):  
Real Time ◽  
Real Time Pcr ◽  
Large Subunit ◽  
Immunofluorescence Assay ◽  
Pneumocystis Jirovecii ◽  
Pneumocystis Jirovecii Pneumonia ◽  
Rrna Gene ◽  
Sample Type ◽  
Sensitivity Specificity ◽  
Pcr Targeting

Abstract Background The laboratory diagnosis of Pneumocystis jirovecii pneumonia (PJP) has been traditionally based on microscopy techniques, which have suboptimal sensitivity and depends on the experience and skills of the microbiologist. Molecular detection assays based in PCR (Polymerase chain reaction) could improve sensitivity. Our aim was to evaluate the utility of real-time PCR in the diagnosis of PJP compared with IFA (Immunofluorescence assay) performed in different respiratory samples of patients with PJP suspicion for routine use in a clinical laboratory setting. Methods From September 2015 to April 2018, we studied by a real-time PCR targeting the large subunit of rRNA gene of P. jirovecii (PJ-PCR RealCycler PJIR kit Progenie Molecular) and Immunofluorescence assay (MONOFLUO P. carinii IFA BioRad) in all respiratory samples received for microbiological diagnosis of PJP. The definite clinical diagnosis of PJP was established by infectious disease physicians considering symptoms, radiological and laboratory findings. Results Overall, 302 samples were included (182 bronchoalveolar lavage, 67 sputum, 53 tracheal aspirates). PJ-PCR was positive in 51 (16.9%) and IFA in 11 (3.6%) of the patients with PJP. There were not IFA positive/PCR negative samples. Sensitivity, specificity, PPV and NPV for IFA were 26% (95%CI 15.9-39.6%), 100% (95%CI 98.5-100%), 100% (95% CI 77.2-100%) and 87.2% (95% CI 82.6-90.6%). Whereas, sensitivity, specificity, PPV and NPV for PCR was 92% (95%CI 81.2-96.8%), 98% (95% CI 95.4-99.2%), 90.2% (95% CI 79.0-95.7%) and 98.4% (95% CI 96.0-99.4%). PJ-PCR had sensitivity > 80% and specificity > 90% in all type of samples included. A definitive diagnosis of PJP was considered in 50 (16.6%) patients, including 4 (1.3%) cases with negative PJ-PCR. Five cases (9.8%) with positive PJ-PCR were considered as colonization. Conclusion P. jirovecii PCR improves the sensitivity and NPV of PJP diagnosis respecting to IFA, regardless of respiratory sample type. Our results suggest that Microbiology laboratories should use PCR techniques to diagnose PJP better than IFA. Disclosures All Authors: No reported disclosures

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