Search results for "diagnostic techniques"
showing 10 items of 122 documents
A nanomaterial-based breath test for distinguishing gastric cancer from benign gastric conditions
2013
Background: Upper digestive endoscopy with biopsy and histopathological evaluation of the biopsy material is the standard method for diagnosing gastric cancer (GC). However, this procedure may not be widely available for screening in the developing world, whereas in developed countries endoscopy is frequently used without major clinical gain. There is a high demand for a simple and non-invasive test for selecting the individuals at increased risk that should undergo the endoscopic examination. Here, we studied the feasibility of a nanomaterial-based breath test for identifying GC among patients with gastric complaints. Methods: Alveolar exhaled breath samples from 130 patients with gastric …
The Dual/Global Value of SARS-CoV-2 Genome Surveillance on Migrants Arriving to Europe via the Mediterranean Routes.
2021
Despite the pandemic, 34,154 migrants, refugees or asylum-seekers landed in Sicily (Italy) in 2020, representing the main point of entry by sea into Europe. The SARS-CoV-2 surveillance program among migrants arriving to Sicily via the Mediterranean Sea, made by the combination of clinical examination and molecular testing, has been integrated by full-genome sequencing strains using the NGS technology from the last week of February. To date, more than one hundred full-genome strains have been sequenced and 8 different lineages have been identified mostly belonging to the lineages B.1.1.7 and B.1.525. As global access to COVID-19 vaccines should be ensured, the need to provide more detailed i…
Cytomegalovirus Infection Management in Allogeneic Stem Cell Transplant Recipients: a National Survey in Spain.
2015
ABSTRACT This study gathered information about current practices of cytomegalovirus (CMV) infection management in allogeneic stem cell transplant recipients at Spanish centers. A wide variety of preemptive antiviral therapy strategies for CMV infection guided by real-time PCR assays was found, yet the incidence of CMV disease was low (<3%).
Epidemiological cutoff values for fluconazole, itraconazole, posaconazole, and voriconazole for six Candida species as determined by the colorimetric…
2013
ABSTRACT In the absence of clinical breakpoints (CBP), epidemiological cutoff values (ECVs) are useful to separate wild-type (WT) isolates (without mechanisms of resistance) from non-WT isolates (those that can harbor some resistance mechanisms), which is the goal of susceptibility tests. Sensititre YeastOne (SYO) is a widely used method to determine susceptibility of Candida spp. to antifungal agents. The CLSI CBP have been established, but not for the SYO method. The ECVs for four azoles, obtained using MIC distributions determined by the SYO method, were calculated via five methods (three statistical methods and based on the MIC 50 and modal MIC). Respectively, the median ECVs (in mg/lit…
Characterization and multicentric validation of a common standard for Toxoplasma gondii detection using nucleic acid amplification assays.
2014
ABSTRACT The molecular diagnosis of toxoplasmosis essentially relies upon laboratory-developed methods and suffers from lack of standardization, hence the large diversity of performances between laboratories. Moreover, quantifications of parasitic loads differ among centers, a fact which prevents the possible prediction of the severity of this disease as a function of parasitic loads. The objectives of this multicentric study performed in eight proficient laboratories of the Molecular Biology Pole of the French National Reference Center for Toxoplasmosis (NRC-T) were (i) to assess the suitability of a lyophilized preparation of Toxoplasma gondii as a common standard for use in this PCR-base…
Molecular Diagnosis of Toxoplasmosis in Immunocompromised Patients: a 3-Year Multicenter Retrospective Study
2015
ABSTRACT Toxoplasmosis is a life-threatening infection in immunocompromised patients (ICPs). The definitive diagnosis relies on parasite DNA detection, but little is known about the incidence and burden of disease in HIV-negative patients. A 3-year retrospective study was conducted in 15 reference laboratories from the network of the French National Reference Center for Toxoplasmosis, in order to record the frequency of Toxoplasma gondii DNA detection in ICPs and to review the molecular methods used for diagnosis and the prevention measures implemented in transplant patients. During the study period, of 31,640 PCRs performed on samples from ICPs, 610 were positive (323 patients). Blood ( n …
Freezing and storage at -20 °C provides adequate preservation of Toxoplasma gondii DNA for retrospective molecular analysis.
2014
Equipe EA MERS; International audience; Nucleic acid-based testing has become crucial for toxoplasmosis diagnosis. For retrospective (forensic or scientific) studies, optimal methods must be employed for DNA long-term storage. We compared Toxoplasma gondii detection before and after DNA storage using real-time PCR. No significant differences were found depending on duration or storage conditions at -20 °C or -80 °C.
Evaluation of the Amplex eazyplex Loop-Mediated Isothermal Amplification Assay for Rapid Diagnosis of Pneumocystis jirovecii Pneumonia
2020
ABSTRACT Quantitative PCR (qPCR) assays are the gold standard for diagnosis of Pneumocystis jirovecii pneumonia (PCP). However, they are laborious and require skilled personnel. Therefore, execution outside regular working hours of the molecular biology laboratory is limited. The eazyplex P. jirovecii assay (PJA) uses loop-mediated isothermal amplification for detection of P. jirovecii. It is performed directly with respiratory specimens, without the need for special skills, and delivers a result within 3 to 25 min. The goal of our study was to compare the performance of the eazyplex PJA with that of established P. jirovecii qPCR assays. All archived bronchoalveolar lavage fluid (BALF) samp…
Application of fnbA gene as new target for the species-specific and quantitative detection of Staphylococcus aureus directly from lower respiratory t…
2013
Staphylococcus aureus is a significant cause of hospital-acquired pneumonia (HAP), particularly in mechanically ventilated patients. We used the fibronectin-binding protein A gene (fnbA) for the species-specific and quantitative detection of S. aureus directly from lower respiratory tract (LRT) specimens by a Taq Man real time PCR. For this reason, a total of 269 lower respiratory tract (LRT) specimens collected from patients with hospital-acquired pneumonia were assayed. Amplification of fnbA in serial dilutions ranged from 10(9) CFU/ ml to 10(2) CFU/ml. Standard curve of triplicate every dilution had slope 3.34±0.1 and R2>0.99 with SD 0.1. Based on these data, the sensitivity and specif…
Reverse transcriptase loop-mediated isothermal amplification (RT-LAMP) as a user-friendly system to detect SARS-CoV-2 infection: a multicentric study
2021
Although reverse transcriptase quantitative PCR remains the gold standard to perform viral detection, reverse transcriptase loop-mediated isothermal amplification (RT-LAMP) is already used to perform diagnosis of various infections. This work reports the results of a multicentric study performed in Sicily to evaluate the diagnostic power of an RT-LAMP kit for the diagnosis of SARS-CoV-2 infection on a total of 551 samples collected in January and February 2021, revealing sensitivity, specificity, accuracy, positive and negative predictive values ≥95%. Our results suggest the potential employment of this kit as a screening test to be used where fast and reliable results are demanded without …