Preexisting and newly emerging resistant pathogen subpopulations (heteroresistance) are potential risk factors for treatment failure of multi/extensively drug resistant (MDR/XDR) tuberculosis (TB). Intrapatient evolutionary dynamics of Mycobacterium tuberculosis complex (Mtbc) strains and their implications on treatment outcomes are still not completely understood. To elucidate how Mtbc strains escape therapy, we analyzed 13 serial isolates from a German patient by whole-genome sequencing. Sequencing data were compared with phenotypic drug susceptibility profiles and the patient's collective 27-year treatment history to further elucidate factors fostering intrapatient resistance evolution. The patient endured five distinct TB episodes, ending in resistance to 16 drugs and a nearly untreatable XDR-TB infection. The first isolate obtained, during the patient's 5th TB episode, presented fixed resistance mutations to 7 anti-TB drugs, including isoniazid, rifampin, streptomycin, pyrazinamide, prothionamide, para-aminosalicylic acid, and cycloserine-terizidone. Over the next 13 years, a dynamic evolution with coexisting, heterogeneous subpopulations was observed in 6 out of 13 sequential bacterial isolates. The emergence of drug-resistant subpopulations coincided with frequent changes in treatment regimens, which often included two or fewer active compounds. This evolutionary arms race between competing subpopulations ultimately resulted in the fixation of a single XDR variant. Our data demonstrate the complex intrapatient microevolution of Mtbc subpopulations during failing MDR/XDR-TB treatment. Designing effective treatment regimens based on rapid detection of (hetero) resistance is key to avoid resistance development and treatment failure.
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http://dx.doi.org/10.1128/AAC.02520-20 | DOI Listing |
The mycomembrane of mycobacteria has long been regarded as the primary barrier to the accumulation of molecules within these bacteria. Understanding accumulation beyond the mycomembrane of ( ) is crucial for developing effective antimycobacterial agents. This study investigates two design principles commonly found in natural products and mammalian cell-permeable peptides - backbone -methylation and macrocyclization - aimed at enhancing accumulation.
View Article and Find Full Text PDFBacterial serine-threonine protein kinases (STKs) regulate diverse cellular processes associated with cell growth, virulence, and pathogenicity. They are evolutionarily related to the druggable eukaryotic STKs. However, an incomplete knowledge of how bacterial STKs differ from their eukaryotic counterparts and how they have diverged to regulate diverse bacterial signaling functions presents a bottleneck in targeting them for drug discovery efforts.
View Article and Find Full Text PDFFront Immunol
January 2025
Rehabilitation Medicine Department, The Affiliated Changsha Hospital of Xiangya School of Medicine, Central South University (The First Hospital of Changsha, Changsha, China.
Tuberculous meningitis (TBM), a severe form of non-purulent meningitis caused by (Mtb), is the most critical extrapulmonary tuberculosis (TB) manifestation, with a 30-40% mortality rate despite available treatment. The absence of distinctive clinical symptoms and effective diagnostic tools complicates early detection. Recent advancements in nucleic acid detection, genomics, metabolomics, and proteomics have led to novel diagnostic approaches, improving sensitivity and specificity.
View Article and Find Full Text PDFBackground: Identification of young children with ( )-infection is critical to curb Tuberculosis (TB)-related pediatric morbidity and mortality. The optimal test to identify young children with evidence of -infection remains controversial.
Methods: Using a TB household contact (HHC) study design among 130 Ugandan children less than 5 years with established -exposure, we compared the usefulness of the tuberculin skin test (TST) and QuantiFERON Gold Plus (QFT-Plus) to identify children with evidence for -sensitization.
Although granulomatous interstitial nephritis (GIN) is a rare histological finding in kidney transplants, the joint occurrence of GIN and focal segmental glomerulosclerosis (FSGS) has not, to our knowledge, been reported in the literature. We report a case of GIN and de novo FSGS in kidney transplant recipients leading to allograft failure. A 69-year-old male with a history of end-stage renal disease (ESRD) of unknown etiology, as well as liver failure from hepatitis B and C co-infection, initially had a living unrelated kidney transplant (LURT) in 2007 and subsequently received both liver and kidney transplants (SLKTs) in 2017.
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