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.
This study explored Mycobacterium tuberculosis (MTB) growth from tongue swabs, both experimentally infected after sampling from healthy controls, or sampled from patients with smear-microscopy confirmed pulmonary tuberculosis (PTB). For both, we evaluated the performance of NALC-NaOH/MGIT960 (MGIT), Kudoh-Ogawa (KO), and cetylpyridinium chloride-Löwenstein-Jensen (CPC/LJ) culture processing methods. Experimentally spiked swabs from 20 participants exhibited 94.
View Article and Find Full Text PDFBMJ Open
July 2024
Introduction: An effective rifampicin-resistant tuberculosis (RR-TB) treatment regimen should include prevention of resistance amplification. While bedaquiline (BDQ) has been recommended in all-oral RR-TB treatment regimen since 2019, resistance is rising at alarming rates. This may be due to BDQ's delayed bactericidal effect, which increases the risk of selecting for resistance to fluoroquinolones and/or BDQ in the first week of treatment when the bacterial load is highest.
View Article and Find Full Text PDFSpecies belonging to the complex (MKC) are frequently isolated from humans and the environment and can cause serious diseases. The most common MKC infections are caused by the species (), leading to tuberculosis-like disease. However, a broad spectrum of virulence, antimicrobial resistance and pathogenicity of these non-tuberculous mycobacteria (NTM) are observed across the MKC.
View Article and Find Full Text PDFUnlabelled: Proteins encoded by the ESX-1 genes of interest are essential for full virulence in all complex (Mtbc) lineages, the pathogens causing the highest mortality worldwide. Identifying critical regions in these ESX-1-related proteins could provide preventive or therapeutic targets for Mtb infection, the game changer needed for tuberculosis control. We analyzed a compendium of whole genome sequences of clinical Mtb isolates from all lineages from >32,000 patients and identified single nucleotide polymorphisms.
View Article and Find Full Text PDFBackground: Post-exposure prophylaxis (PEP) using single-dose rifampicin reduces progression from infection with Mycobacterium leprae to leprosy disease. We compared effectiveness of different administration modalities, using a higher (20 mg/kg) dose of rifampicin-single double-dose rifampicin (SDDR)-PEP.
Methods: We did a cluster randomised study in 16 villages in Madagascar and 48 villages in Comoros.
Background: Mycobacterium tuberculosis culturing remains the gold standard for laboratory diagnosis of tuberculosis. Tuberculosis remains a great public health problem in developing countries like The Gambia, as most of the methods currently used for bacterial isolation are either time-consuming or costly.
Objective: To evaluate the Kudoh swab method in a West African setting in Gambia, with a particular focus on the method's performance when culturing Mycobacterium africanum West Africa 2 (MAF2) isolates.
Analysis of genome sequencing data from >100,000 genomes of Mycobacterium tuberculosis complex using TB-Annotator software revealed a previously unknown lineage, proposed name L10, in central Africa. Phylogenetic reconstruction suggests L10 could represent a missing link in the evolutionary and geographic migration histories of M. africanum.
View Article and Find Full Text PDFUnlabelled: Previous work reported unprecedented differences in the intrinsic susceptibility of the complex (MTBC) to pretomanid (Pa) using the Mycobacteria Growth Indicator Tube (MGIT) system. We tested 125 phylogenetically diverse strains from all known MTBC lineages (1-9) without known Pa resistance mutations and four strains with known resistance mutations as controls. This confirmed that MTBC, unlike most bacteria-antimicrobial combinations, displayed substantial differences in the intrinsic susceptibility relative to the technical variation of Pa MIC testing.
View Article and Find Full Text PDFIntroduction: Leprosy, one of the oldest known human diseases, continues to pose a global challenge for disease control due to an incomplete understanding of its transmission pathways. Ticks have been proposed as a potential contributor in leprosy transmission due to their importance as vectors for other infectious diseases.
Methods: In 2010, a sampling of ticks residing on cattle was conducted on the islands Grande Comore, Anjouan, and Mohéli which constitute the Union of the Comoros where leprosy remains endemic.
Directly observed treatment (DOT) for tuberculosis (TB) is recommended by the World Health Organization. However, DOT does not always meet patients' preferences, burdens health facilities, and is hard to implement in settings where access to healthcare services is regularly interrupted. A model addressing these limitations of DOT is community-supported self-administered treatment (CS-SAT), in which patients who self-administer TB treatment receive regular visits from community members.
View Article and Find Full Text PDFThe spread of multidrug-resistant tuberculosis (MDR-TB) is a growing problem in many countries worldwide. Resistance to one of the primary first-line drugs, rifampicin, is caused by mutations in the gene. So-called borderline mutations confer low-level resistance, in contrast to more common mutations which confer high-level resistance.
View Article and Find Full Text PDFBackground: Fluoroquinolones (FQs) have substantial activity against the Mycobacterium tuberculosis complex (MTBc) by preventing bacterial DNA synthesis through DNA gyrase inhibition. The reference standard for FQ-resistance testing is phenotypic drug-susceptibility testing (pDST) based on growth inhibition of MTBc in drug-containing Mycobacteria Growth Indicator Tube system (MGIT) media at a critical concentration (CC) that differentiates phenotypically wild-type from nonwild-type MTBc and at a clinical breakpoint that identifies strains that will likely still respond to treatment at higher doses. Despite the recent introduction of powerful new TB drugs, highly sensitive detection of clinically defined FQ resistance remains key.
View Article and Find Full Text PDFBackground: The World Health Organization-endorsed phenotypic and genotypic drug-susceptibility testing (gDST/pDST) assays for the detection of rifampicin-resistant (RR) tuberculosis (TB), may miss some clinically relevant rpoB mutants, including borderline mutations and mutations outside the gDST-targeted hotspot region. Sequencing of the full rpoB gene is considered the reference standard for rifampicin DST but is rarely available in RR-TB endemic settings and when done indirectly on cultured isolates may not represent the full spectrum of mutations. Hence, in most such settings, the diversity and trends of rpoB mutations remain largely unknown.
View Article and Find Full Text PDFBackground: Pulmonary tuberculosis (PTB) diagnosis relies on sputum examination, a challenge in sputum-scarce patients. Alternative non-invasive sampling methods such as face mask sampling (FMS) have been proposed.
Objective: To evaluate the value of FMS for PTB diagnosis by assessing its agreement with sputum samples processed by GeneXpert MTB/RIF (Ultra)(Xpert) testing, and describe FMS sensitivity and specificity.
Objective: To investigate the performance of GeneXpert MTB/RIF Ultra to accurately detect rifampicin resistance for less common rpoB mutations that potentially confer phenotypic resistance, we tested 28 such Mycobacterium tuberculosis cultures with Xpert Ultra.
Results: They represented 22 different (combinations of) rpoB mutations. Of 28 isolates tested, one was reported by Xpert Ultra as "No rifampicin resistance detected", 8 yielded a "Rifampicin indeterminate" result, and 19 were identified as rifampicin resistant.
EBioMedicine
July 2023
Background: Expansion of antimicrobial resistance monitoring and epidemiological surveillance are key components of the WHO strategy towards zero leprosy. The inability to grow Mycobacterium leprae in vitro precludes routine phenotypic drug susceptibility testing, and only limited molecular tests are available. We evaluated a culture-free targeted deep sequencing assay, for mycobacterial identification, genotyping based on 18 canonical SNPs and 11 core variable-number tandem-repeat (VNTR) markers, and detection of rifampicin, dapsone and fluoroquinolone resistance-associated mutations in rpoB/ctpC/ctpI, folP1, gyrA/gyrB, respectively, and hypermutation-associated mutations in nth.
View Article and Find Full Text PDFBMC Infect Dis
May 2023
Background: Leprosy is an ancient infectious disease with an annual global incidence of around 200,000 over the past decade. Since 2018, the World Health Organization (WHO) recommends single-dose rifampicin as post-exposure prophylaxis (SDR-PEP) for contacts of leprosy patients. The Post ExpOsure Prophylaxis for Leprosy (PEOPLE) trial evaluated PEP with a double dose of rifampicin in Comoros and Madagascar.
View Article and Find Full Text PDFObjectives: High-dose rifampicin (R) and isoniazid (H) are known to be safe but were not yet combined in a single regimen. The primary objective of the TRIple-DOse RE-treatment (TRIDORE) study is to determine whether a 6-month firstline regimen with triple dose of both R and H (intervention arm; 6RHZE) is non-inferior in terms of safety compared to a normal-dose regimen (6RHZE) in previously treated patients with R-susceptible (Rs) recurrent tuberculosis (TB).
Design/methods: TRIDORE is an ongoing pragmatic open-label multi-stage randomized clinical trial.
In settings with high tuberculosis (TB) endemicity, distinct genotypes of the Mycobacterium tuberculosis complex (MTBC) often differ in prevalence. However, the factors leading to these differences remain poorly understood. Here we studied the MTBC population in Dar es Salaam, Tanzania over a six-year period, using 1,082 unique patient-derived MTBC whole-genome sequences (WGS) and associated clinical data.
View Article and Find Full Text PDFBackground: Phenotypic drug-susceptibility testing (pDST), which relies on growth inhibition in the drug-containing media, remains a challenge for fastidious Mycobacterium tuberculosis complex (MTBc) isolates due to insufficient growth on the growth controls (GC). Middlebrook 7H11 (M7H11) medium contains casein hydrolysate, which may favor the growth of such strains.
Method: In this study, we tested whether M7H11 reduces invalid results due to insufficient growth on the GCs and the turnaround time (TAT) of pDST for MTBc compared to Middlebrook 7H10 (M7H10) without affecting the accuracy of the pDST results and how it differs between rifampicin- and isoniazid-susceptible non multi-drug resistant (non-MDR), MDR and MDR with additional resistance to fluoroquinolones (Pre-XDR) MTBc isolates.