Xpert MTB/XDR: a 10-Color Reflex Assay Suitable for Point-of-Care Settings To Detect Isoniazid, Fluoroquinolone, and Second-Line-Injectable-Drug Resistance Directly from Mycobacterium tuberculosis-Positive Sputum.

We describe the design, development, analytical performance, and a limited clinical evaluation of the 10-color Xpert MTB/XDR assay (CE-IVD only, not for sale in the United States). This assay is intended as a reflex test to detect resistance to isoniazid (INH), fluoroquinolones (FLQ), ethionamide (ETH), and second-line injectable drugs (SLIDs) in unprocessed sputum samples and concentrated sputum sediments which are positive for The Xpert MTB/XDR assay simultaneously amplifies eight genes and promoter regions in and analyzes melting temperatures ( s) using sloppy molecular beacon (SMB) probes to identify mutations associated with INH, FLQ, ETH, and SLID resistance. Results can be obtained in under 90 min using 10-color GeneXpert modules.

Multicenter Evaluation of the Cepheid Xpert Xpress SARS-CoV-2 Test.

Nucleic acid amplification tests (NAATs) are the primary means of identifying acute infections caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Accurate and fast test results may permit more efficient use of protective and isolation resources and allow rapid therapeutic interventions. We evaluated the analytical and clinical performance characteristics of the Xpert Xpress SARS-CoV-2 (Xpert) test, a rapid, automated molecular test for SARS-CoV-2.

Deregulation of cell growth and apoptosis in UV-induced melanomagenesis.

We have previously characterized the role of p16/Rb in coordinating the early events in UVB-irradiated skin. As an extension to this work, normal melanocytes and mutant p16-inducible melanoma cell models were employed to elucidate further the coordinated molecular mechanisms occurring during early UVB exposure. Our results showed that melanocytes expressed p16 only at a high UVB dose, with undetectable p53.

CD44 mediates stem cell mobilization to damaged lung its novel transcriptional targets, Cortactin and Survivin.

Beyond their role in bone and lung homeostasis, mesenchymal stem cells (MSCs) are becoming popular in cell therapy. Various insults may disrupt the repair mechanisms involving MSCs. One such insult is smoking, which is a major risk factor for osteoporosis and respiratory diseases.

Diversity of resistance mechanisms in carbapenem-resistant Enterobacteriaceae at a health care system in Northern California, from 2013 to 2016.

The mechanism of resistance in carbapenem-resistant Enterobacteriaceae (CRE) has therapeutic implications. We comprehensively characterized emerging mechanisms of resistance in CRE between 2013 and 2016 at a health system in Northern California. A total of 38.

Rapid and specific labeling of single live with a dual-targeting fluorogenic probe.

Tuberculosis (TB) remains a public health crisis and a leading cause of infection-related death globally. Although in high demand, imaging technologies that enable rapid, specific, and nongenetic labeling of live (Mtb) remain underdeveloped. We report a dual-targeting strategy to develop a small molecular probe (CDG-DNB3) that can fluorescently label single bacilli within 1 hour.

Clostridium difficile PCR Cycle Threshold Predicts Free Toxin.

There is no stand-alone diagnostic that can sensitively and rapidly detect fecal free toxins. We investigated the performance of the PCR cycle threshold ( ) for predicting free toxin status. Consecutive stool samples ( = 312) positive for toxigenic by the GeneXpert /Epi PCR assay were tested with the rapid membrane C.

Evaluation of QuantiFERON-TB Gold-Plus in Health Care Workers in a Low-Incidence Setting.

Although launched in 2015, little is known about the accuracy of QuantiFERON-TB Gold-Plus (QFT-Plus) for diagnosis of latent infection (LTBI). Unlike its predecessor, QFT-Plus utilizes two antigen tubes to elicit an immune response from CD4 and CD8 T lymphocytes. We conducted a cross-sectional study in low-risk health care workers (HCWs) at a single U.

Clostridium difficile rates in asymptomatic and symptomatic hospitalized patients using nucleic acid testing.

Background: The Clostridium difficile rate in symptomatic patients represents both those with C. difficile infection (CDI) and those with colonization. To predict the extent of CDI overdiagnosis, we compared the asymptomatic colonization rate to the symptomatic positivity rate in hospitalized patients using nucleic acid testing.

Organism burden, toxin concentration, and lactoferrin concentration do not distinguish between clinically significant and nonsignificant diarrhea in patients with Clostridium difficile.

Clostridium difficile infection is often overdiagnosed in patients with mild diarrhea. We evaluated 4 biomarkers as surrogates for clinically significant diarrhea (≥ 3 episodes in 24 hours) in 59 PCR-positive patients with and 59 PCR-positive patients without clinically significant diarrhea. Organism burden (median tcdB cycle threshold value, 26.

Interferon Gamma Release Assays for Latent Tuberculosis: What Are the Sources of Variability?

Interferon gamma release assays (IGRAs) are blood-based tests intended for diagnosis of latent tuberculosis infection (LTBI). IGRAs offer logistical advantages and are supposed to offer improved specificity over the tuberculin skin test (TST). However, recent serial testing studies of low-risk individuals have revealed higher false conversion rates with IGRAs than with TST.

Correction: LprG-Mediated Surface Expression of Lipoarabinomannan Is Essential for Virulence of Mycobacterium tuberculosis.

[This corrects the article DOI: 10.1371/journal.ppat.

In vitro immunomodulation for enhancing T cell-based diagnosis of Mycobacterium tuberculosis infection.

Interferon-gamma release assays have limited sensitivity for detecting latent tuberculosis infection. In this study, we determine if the addition of immunomodulators to the QuantiFERON-TB Gold In-Tube (QFT-GIT) increased test sensitivity without compromising specificity. We prospectively compared QFT-GIT results with and without incubation with 2 immunomodulators (lipopolysaccharide [LPS] and polyinosine-polycytidylic acid [PolyIC]) in 2 cohorts-113 culture-confirmed tuberculosis (TB) subjects in Hanoi, Vietnam, and 226 documented QFT-GIT-negative, low TB risk health care workers undergoing annual TB screening at a US academic institution.

LprG-mediated surface expression of lipoarabinomannan is essential for virulence of Mycobacterium tuberculosis.

Mycobacterium tuberculosis employs various virulence strategies to subvert host immune responses in order to persist and cause disease. Interaction of M. tuberculosis with mannose receptor on macrophages via surface-exposed lipoarabinomannan (LAM) is believed to be critical for cell entry, inhibition of phagosome-lysosome fusion, and intracellular survival, but in vivo evidence is lacking.

Simultaneous inhibition of cell-cycle, proliferation, survival, metastatic pathways and induction of apoptosis in breast cancer cells by a phytochemical super-cocktail: genes that underpin its mode of action.

Traditional chemotherapy and radiotherapy for cancer treatment face serious challenges such as drug resistance and toxic side effects. Complementary / Alternative medicine is increasingly being practiced worldwide due to its safety beneficial therapeutic effects. We hypothesized that a super combination (SC) of known phytochemicals used at bioavailable levels could induce 100% killing of breast cancer (BC) cells without toxic effects on normal cells and that microarray analysis would identify potential genes for targeted therapy of BC.

Chemoprevention of rat mammary carcinogenesis by spirulina.

Spirulina (SP) (Arthrospira platensis; previously Spirulina platensis) is a filamentous blue-green microalga (cyanobacterium) with potent dietary phytoantioxidant and anticancerous properties. We investigated the chemopreventive effect of SP against 7,12-dimethylbenz[a]anthracene (DMBA)-induced rat breast carcinogenesis, and further studied its underlying mechanisms of action in vitro. Remarkably, SP cleared DMBA-induced rat mammary tumors, which was clearly confirmed by morphological and histological methods.

Impact of blood volume, tube shaking, and incubation time on reproducibility of QuantiFERON-TB gold in-tube assay.

Gamma interferon (IFN-γ) release assays (IGRAs) are functional assays used serially to measure the efficacy of novel tuberculosis (TB) vaccines and to screen health care workers for latent tuberculosis infection (LTBI). However, studies have shown nonreproducible IGRA results. In this study, we investigated the effects of blood volume (0.

In vitro immunomodulation of a whole blood IFN-γ release assay enhances T cell responses in subjects with latent tuberculosis infection.

Background: Activation of innate immunity via pathogen recognition receptors (PRR) modulates adaptive immune responses. PRR ligands are being exploited as vaccine adjuvants and as therapeutics, but their utility in diagnostics has not been explored. Interferon-gamma (IFN-γ) release assays (IGRAs) are functional T cell assays used to diagnose latent tuberculosis infection (LTBI); however, novel approaches are needed to improve their sensitivity.

Can a simple flotation method lower the limit of detection of Mycobacterium tuberculosis in extrapulmonary samples analyzed by the GeneXpert MTB/RIF assay?

The rapid and accurate diagnosis of tuberculosis (TB) in children and extrapulmonary TB in adults continues to be a challenge. In this study, we determined the lower limit of detection (LOD) of the GeneXpert MTB/RIF assay with nonrespiratory specimens and investigated the utility of flotation procedures for concentrating the bacilli. Clinical specimens (9 cerebrospinal fluid [CSF], 13 gastric aspirate, 8 tissue, and 17 stool) were spiked with single-celled Mycobacterium tuberculosis, and the LOD of the GeneXpert assay was determined.

Fluorescent DNA chemosensors: identification of bacterial species by their volatile metabolites.

Polyfluorophores built on a DNA scaffold (ODFs) were synthesized and tested for fluorescence responses to the volatiles from M. tuberculosis, E. coli and P.

Structural and ultrastructural evidence of neurotoxic effects of fried potato chips on rat postnatal development.

Objective: Acrylamide (ACR), a proved rodent carcinogen and neurotoxic agent, is present in significant quantities in commonly consumed foods such as fried potato chips (FPC) and French fries, raising a health concern worldwide. We investigated and compared the neurotoxic effects of ACR and FPC on postnatal development.

Methods: Female rats were treated with ACR (30 mg/kg of body weight), fed a diet containing approximately 30% of FPC during pregnancy, or fed a standard diet (control) and their offspring were examined.

Survivin is a novel target of CD44-promoted breast tumor invasion.

The hyaluronan (HA) receptor CD44 plays an essential role in cell-cell or cell-extracellular matrix communications and is a bioactive signal transmitter. Although a number of studies have described the function of CD44 in breast cancer (BC) metastasis, the underlying mechanisms have yet to be determined. By using a validated tetracycline-off-regulated CD44 expression system in the MCF-7 cell line combined with microarray analysis, we identified survivin (SVV) as a potential downstream transcriptional target of CD44.

Preanalytical delay reduces sensitivity of QuantiFERON-TB gold in-tube assay for detection of latent tuberculosis infection.

The effects of incubation delays on the accuracy of the QuantiFERON-TB gold in-tube assay (QFT-GIT) were measured. Compared to immediate incubation, 6- and 12-hour delays resulted in positive-to-negative reversion rates of 19% (5/26) and 22% (5/23), respectively. These findings underscore the need for standardizing QFT-GIT preanalytical practices.