Tuberculosis (TB), caused by (Mtb), remains a public health issue, particularly due to multi-drug-resistant Mtb. The bacillus is wrapped in a waxy envelope containing lipids acting as essential virulence factors, accounting for the natural antibiotic resistance of mycobacteria. Telacebec (previously known as Q203) is a promising new anti-TB agent inhibiting the cytochrome complex of a mycobacterial electron transport chain (ETC).
View Article and Find Full Text PDFA bedaquiline-resistant Mycobacterium abscessus isolate was sequenced, and a candidate mutation in the gene was identified as responsible for the antibiotic resistance phenotype. To establish a direct genotype-phenotype relationship of this mutation which results in a Asp-to-Ala change at position 29 (D29A), we developed a recombineering-based method consisting of the specific replacement of the desired mutation in the bacterial chromosome. As surrogate bacteria, we used two M.
View Article and Find Full Text PDFObjectives: Since January 2019, the Belgian National Reference Center for Mycobacteria (NRC) has switched from conventional typing to prospective whole-genome sequencing (WGS) of all submitted complex (MTB) isolates. The ISO17025 validated procedure starts with semi-automated extraction and purification of gDNA directly from the submitted MGIT tubes, without preceding subculturing. All samples are then sequenced on an Illumina MiSeq sequencer and analyzed using an in-house developed and validated bioinformatics workflow to determine the species and antimicrobial resistance.
View Article and Find Full Text PDFTesting is an essential part of containment of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic. This review summarizes studies for SARS-CoV-2 infection and testing. Nasopharyngeal samples are best at sensitivity detection, especially in early stages of disease and in asymptomatic individuals.
View Article and Find Full Text PDFBackground: Growing international migration has increased the complexity of tuberculosis transmission patterns. Italy's decision to close its borders in 2018 made of Spain the new European porte entrée for migration from the Horn of Africa (HA). In one of the first rescues of migrants from this region at the end of 2018, tuberculosis was diagnosed in eight subjects, mainly unaccompanied minors.
View Article and Find Full Text PDFThe use of whole-genome sequencing (WGS) for routine typing of bacterial isolates has increased substantially in recent years. For (MTB), in particular, WGS has the benefit of drastically reducing the time required to generate results compared to most conventional phenotypic methods. Consequently, a multitude of solutions for analyzing WGS MTB data have been developed, but their successful integration in clinical and national reference laboratories is hindered by the requirement for their validation, for which a consensus framework is still largely absent.
View Article and Find Full Text PDFInt J Tuberc Lung Dis
March 2021
Conventional molecular tests for detecting complex (MTBC) drug resistance on clinical samples cover a limited set of mutations. Whole-genome sequencing (WGS) typically requires culture.Here, we evaluated the Deeplex Myc-TB targeted deep-sequencing assay for prediction of resistance to 13 anti-tuberculous drugs/drug classes, directly applicable on sputum.
View Article and Find Full Text PDFTwo billion people are infected with , leading to 10 million new cases of active tuberculosis and 1.5 million deaths annually. Universal access to drug susceptibility testing (DST) has become a World Health Organization priority.
View Article and Find Full Text PDFBedaquiline (BDQ) is a recently approved antibiotic for the treatment of multidrug-resistant tuberculosis, but its potential against slow-growing mycobacteria (SGM) is still unknown. The objective of this study was to determine the in vitro activity of BDQ on SGM by assessing their MIC and minimal bactericidal concentration (MBC). The MIC of BDQ against 17 clinical isolates including Mycobacterium avium, Mycobacterium intracellulare, Mycobacterium chimaera, Mycobacterium kansasii and Mycobacterium simiae species was determined by the resazurin microtitre assay and the MBC by the c.
View Article and Find Full Text PDFIntroductionIn 2007, a new federal legislation in Belgium prohibited non-biosafety level 3 laboratories to process culture tubes suspected of containing mycobacteria.AimTo present mycobacterial surveillance/diagnosis data from the Belgian National Reference Centre for mycobacteria (NRC) from 2007 to 2016.MethodsThis retrospective observational study investigated the numbers of analyses at the NRC and false positive cultures (interpreted as containing mycobacteria at referring clinical laboratories, but with no mycobacterial DNA detected by PCR in the NRC).
View Article and Find Full Text PDFAntimicrob Agents Chemother
March 2019
Accumulating evidence suggests that the bactericidal activity of some antibiotics may not be directly initiated by target inhibition. The activity of isoniazid (INH), a key first-line bactericidal antituberculosis drug currently known to inhibit mycolic acid synthesis, becomes extremely poor under stress conditions, such as hypoxia and starvation. This suggests that the target inhibition may not fully explain the bactericidal activity of the drug.
View Article and Find Full Text PDFN Engl J Med
October 2018
Background: The World Health Organization recommends drug-susceptibility testing of Mycobacterium tuberculosis complex for all patients with tuberculosis to guide treatment decisions and improve outcomes. Whether DNA sequencing can be used to accurately predict profiles of susceptibility to first-line antituberculosis drugs has not been clear.
Methods: We obtained whole-genome sequences and associated phenotypes of resistance or susceptibility to the first-line antituberculosis drugs isoniazid, rifampin, ethambutol, and pyrazinamide for isolates from 16 countries across six continents.
Purpose: Pulmonary infections due to non-tuberculous mycobacteria (NTM) are an emerging issue in the cystic fibrosis (CF) population. Due to bacterial and fungal overgrowth, isolation of mycobacteria from the sputum samples of these patients remains challenging. RGM medium, a novel agar-based culture medium was evaluated for the isolation of NTM from sputum samples of CF patients.
View Article and Find Full Text PDFTreatment of tuberculosis still represent a major public health issue. The emergence of multi-and extensively-drug resistant (MDR and XDR) clinical strains further pinpoint the urgent need for new anti-tuberculous drugs. We previously showed that vancomycin can target mycobacteria lacking cell wall integrity, especially those lacking related phthiocerol and phthiodolone dimycocerosates, PDIM A and PDIM B, respectively.
View Article and Find Full Text PDFBackground: Use of the Xpert MTB/RIF assay has increased the number of people diagnosed with rifampicin-resistant tuberculosis (RR-TB), especially in South Africa where Xpert is now the initial diagnostic for individuals with TB symptoms. We hypothesized that a proportion of RR-TB patients determined by Xpert can be treated with a rifabutin-containing regimen.
Methods: Rifabutin susceptibility by rpoB mutation was assessed in 349 individuals from South Africa and 172 from Belgium.
Setting: Implementation of novel diagnostic assays in tuberculosis (TB) laboratory diagnosis requires effective management of time and resources.
Objective: To further develop and assess at multiple centres a time-and-motion (T&M) tool as an objective means for recording the actual time spent on running laboratory assays.
Design: Multicentre prospective study conducted in six European Union (EU) reference TB laboratories.
Background: The risk of tuberculosis outbreaks among people fleeing hardship for refuge in Europe is heightened. We describe the cross-border European response to an outbreak of multidrug-resistant tuberculosis among patients from the Horn of Africa and Sudan.
Methods: On April 29 and May 30, 2016, the Swiss and German National Mycobacterial Reference Laboratories independently triggered an outbreak investigation after four patients were diagnosed with multidrug-resistant tuberculosis.
Int J Tuberc Lung Dis
January 2018
Background: Extensively drug-resistant tuberculosis (XDR-TB), defined as TB caused by a Mycobacterium strain resistant to at least rifampicin, isoniazid, any fluoroquinolone and one of the injectable anti-tuberculosis drugs, remains a worldwide public health threat. Among repurposed drugs empirically used for XDR-TB cases, carbapenems have been studied in vitro and in animal models, with encouraging results. However, only short-term follow-up data from clinical studies are currently available.
View Article and Find Full Text PDFAntibiotic resistance is one of the biggest threats to human health globally. Alarmingly, multidrug-resistant and extensively drug-resistant have now spread worldwide. Some key antituberculosis antibiotics are prodrugs, for which resistance mechanisms are mainly driven by mutations in the bacterial enzymatic pathway required for their bioactivation.
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