We have developed a novel blood lysis-centrifugation approach for highly sensitive Mycobacterium tuberculosis detection in large volumes of blood with the Xpert MTB/RIF assay. One through 20 ml of blood was spiked with 0.25 to 10 CFU/ml of the M. tuberculosis surrogate M. bovis BCG. Multiple replicates of each sample were processed by a new lysis-centrifugation method and tested with the Xpert MTB/RIF assay. The assay was very sensitive with increased blood volumes. In the 20-ml samples, BCG was detected in blood spiked with 10, 5, 1, and 0.25 CFU/ml 100, 100, 83, and 57% of the time, respectively, compared to 100, 66, 18, and 18%, of the time, respectively, in 1-ml blood samples. Assay sensitivity was influenced by the type of anticoagulant used, with acid-citrate-dextrose solution B (ACD-B) providing the best results. A limit of detection of 10 CFU/ml was established with BCG spiked into ACD-B-treated blood, and 92, 36, and 33% of the samples with 5, 1, and 0.5 CFU/ml, respectively, were assay positive. The lysis buffer was stable both at room temperature and at 4°C for 2 months. The assay was tested with blood stored for 8 days without a change in sensitivity as measured by cycle threshold. This new assay format extends the capability of the Xpert MTB/RIF test, enabling up to 20 ml of blood to be tested rapidly for the presence of M. tuberculosis. This approach may be a useful method to detect extrapulmonary tuberculosis and the risk of death in immunocompromised patients.
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http://dx.doi.org/10.1128/JCM.00332-13 | DOI Listing |
Anal Chem
December 2024
NHC Key Laboratory of Systems Biology of Pathogens, National Institute of Pathogen Biology, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 102629, P. R. China.
The great variety of antimicrobial resistance (AMR) profiles among tuberculosis (TB) patients necessitates a comprehensive detection method. This study developed culture-independent, long amplicon-based targeted next-generation sequencing (tNGS) methods for predicting AMR across 16 drugs within the complex (MTBC). Multiplex PCR amplification was employed to enrich 20 gene regions, with sequencing performed on either the Oxford Nanopore Technologies (ONT) or Illumina platforms.
View Article and Find Full Text PDFInt J Infect Dis
December 2024
Institut Pasteur, Paris, France.
Context: Tuberculosis (TB) diagnosis in children remains challenging due to the paucibacillary nature of specimens and the difficulty in obtaining suitable samples. The use of alternative samples like nasopharyngeal aspirate (NPA) and stools, alongside Xpert MTB/RIF testing, offers promising improvements.
Objective: This study aimed to assess the diagnostic performance of the Xpert MTB/RIF test on NPA and stool samples for detecting intrathoracic TB in children from Madagascar, Cameroon, and Ivory Coast.
PLoS One
December 2024
Mycobacteriology Unit, Institute of Tropical Medicine, Antwerp, Belgium.
Background: Non-tuberculous mycobacteria (NTM) are environmental agents that can cause opportunistic pulmonary disease in humans and animals, often misdiagnosed as tuberculosis (TB). In this study, we describe the cases of NTM identified during the first national anti-TB drug resistance survey conducted in Mali and explore associated risk factors.
Methods: Sputum was collected from people presenting for pulmonary TB diagnosis from April to December 2019, regardless of age.
Medicine (Baltimore)
December 2024
Infection Department, Suining Central Hospital, Suining, Sichuan, China.
This study aimed to evaluate the diagnostic value of rapid simultaneous RNA amplification and testing for tuberculosis (SAT-TB) in smear-negative pulmonary tuberculosis (PTB). We performed a multicenter prospective analysis of 206 patients with smear-negative suspected PTB between December 2018 and March 2022. We collected sputum or bronchoalveolar lavage fluid (BALF) for simultaneous SAT-TB and Xpert Mycobacterium tuberculosis/rifampin (MTB/RIF) assays.
View Article and Find Full Text PDFTher Adv Infect Dis
December 2024
Unidad de Investigación para la Generación y Síntesis de Evidencias en Salud, Universidad San Ignacio de Loyola, Lima, Campus 2, avenida La Fontana 750, La Molina, Lima, Peru.
Background: Molecular tests have contributed to reducing the mortality rate through early and accurate diagnosis of tuberculosis (TB). This is due to their low processing complexity and diagnostic accuracy superior to conventional methods.
Objective: To evaluate the diagnostic performance of Cobas MTB and Logix Smart MTB compared to Xpert MTB/RIF Ultra for pulmonary tuberculosis (PTB) and extrapulmonary tuberculosis (EPTB).
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