Project description:Tuberculosis (TB) is one of the deadliest infectious disorders in the world. To effectively TB manage, an essential step is to gain insight into the lineage of Mycobacterium tuberculosis (MTB) strains and the distribution of drug resistance. Although the Campania region is declared a cluster area for the infection, to contribute to the effort to understand TB evolution and transmission, still poorly known, we have generated a dataset of 159 genomes of MTB strains, from Campania region collected during 2018-2021, obtained from the analysis of whole genome sequence data. The results show that the most frequent MTB lineage is the 4 according for 129 strains (81.11%). Regarding drug resistance, 139 strains (87.4%) were classified as multi susceptible, while the remaining 20 (12.58%) showed drug resistance. Among the drug-resistance strains, 8 were isoniazid-resistant MTB (HR-MTB), 7 were resistant only to one antibiotic (3 were resistant only to ethambutol and 3 isolate to streptomycin while one isolate showed resistance to fluoroquinolones), 4 multidrug-resistant MTB, while only one was classified as pre-extensively drug-resistant MTB (pre-XDR). This dataset expands the existing available knowledge on drug resistance and evolution of MTB, contributing to further TB-related genomics studies to improve the management of TB infection.
Project description:The lengthy and complicated multidrug therapy currently available to treat active tuberculosis (TB) infection has contributed to medical non-adherence and the emerging problems of multidrug-resistant (MDR)- and extensively drug-resistant (XDR)-TB, which are particularly deadly in the setting of HIV co-infection. The prolonged therapy required to eradicate TB infection is believed to reflect the ability of Mycobacterium tuberculosis (Mtb) to persist within host necrotic granulomas in a non-replicating state characterized by antibiotic tolerance to bactericidal drugs, which predominantly target actively dividing tubercle bacilli. The stringent response enzyme, RelMtb, is essential for Mtb survival under physiologically relevant stress conditions in vitro and in the lungs of mice and guinea pigs. A library of over 2 million compounds was screened in RelMtb-inhibition assays and whole-cell screens under conditions in which RelMtb is essential. A total of 178 RelMtb inhibitor candidates, representing 18 unique scaffolds, were identified and 39 compounds were tested against nutrient-starved wild-type Mtb. The antibiotic susceptibility of a relMtb deletion mutant (Δrel) was studied during nutrient starvation and chronic infection in mice, and isoniazid and RelMtb inhibitor candidates were tested for synergy against nutrient-starved wild-type Mtb and Δrel using checkerboard assays. The minimum bactericidal concentration of isoniazid was 500-fold lower against Δrel relative to wild type during nutrient starvation, and the potent bactericidal activity of isoniazid was maintained against Δrel during chronic infection in the lungs of mice. Inhibition of RelMtb appears to be a promising new approach to target Mtb persisters, with the potential to shorten the duration of treatment for drug-susceptible and drug-resistant TB. We used microarray to characterize the transcriptomic profiles of the wild type and Δrel during nutrient starvation. The RelMtb inhibitor, (E)-4-(3-methyl-4-(2-(4-methylthiazol-5-yl)ethoxy)styryl)benzoic acid, killed wild-type Mtb and prevented isoniazid tolerance during nutrient starvation. Treatment of nutrient-starved wild-type with the RelMtb inhibitor led to downregulation of the RelMtb regulon. Transcriptomic analysis revealed an altered gene expression in Δrel and wild-type treated with RelMtb inhibitor during nutrient starvation.
Project description:Tuberculosis (TB) is still a major life-threatening infectious disease, within which especially the rise of multidrug resistant TB (MDR-TB) is currently worrying. This study focuses on mechanisms of development of rifampicin resistance, since rifampicin seems to play an important role in the development of MDR-TB. To provide further insight in rifampicin resistance, we performed a genome-wide transcriptional profile analysis for Mycobacterium tuberculosis (M. tuberculosis) using microarray technology and qRT-PCR analysis. We exposed a rifampicin-susceptible H37Rv wild type (H37Rv-WT) and a rifampicin-resistant progeny H37Rv strain with a H526Y mutation in the rpoB gene (H37Rv-H526Y) to several concentrations of rifampicin, to define the effect of rifampicin on the transcription profile. Our study showed that there are resistance-dependant differences in response between both M. tuberculosis strains. Gene clusters associated with efflux, transport and virulence were altered in the rifampicin-resistant H37Rv mutant compared to the rifampicin-susceptible H37Rv-WT strain after exposure to rifampicin. We conclude that the small gene cluster Rv0559c-Rv0560c in the H37Rv-H526Y strain was remarkably up-regulated in the microarray analysis and qRT-PCR results and appeared to be dependent on rifampicin concentration and time of exposure. Therefore this study suggests that Rv0559c and Rv0560c play a pivotal role in rifampicin resistance of M. tuberculosis. Further investigation of Rv0559c and Rv0560c is needed to reveal function and mechanism of both genes that were triggered upon rifampicin exposure. [Data is also available from http://bugs.sgul.ac.uk/E-BUGS-139]
Project description:Tuberculosis (TB) remains one of the world’s major infectious diseases affecting nations with limited public health resources. Multidrug resistance development has seriously compromised therapeutic treatment choices. The pathology of latent TB shows evidence of a reservoir of Mycobacterium tuberculosis (Mtb) in the lungs of affected individuals. If the pathogen is contained by the immune system, no overt disease symptoms occur. The environmental and internal triggers leading to disease reactivation are not well understood. Proteomic investigations of blood plasma and sputum derived from subjects with active TB versus latent TB versus healthy individuals may yield new biomarkers and, when surveying larger longitudinally monitored cohorts, may discriminate infection outcomes in an endemic setting.
Project description:Mycobacterium tuberculosis (Mtb), the causative agent of tuberculosis (TB), latently infects one quarter of the world’s population. The rise of multidrug resistant (MDR) Mtb infections worldwide presents a significant obstacle to curb TB globally. While human studies report dysregulated immune responses in MDR TB patients, there is a lack of clear understanding of the host-pathogen interactions following MDR Mtb infection. We recently showed that Mtb carrying a rifampicin drug resistance (RDR)-conferring single nucleotide polymorphism in the RNA polymerase-B gene (Mtb rpoB-H445Y) can modulate host macrophage metabolic reprogramming by production of Type I IFNs. Here, using a mouse model, we have characterized the host immune response in vivo following RDR Mtb infection. We show that despite establishment of Mtb infection in the lung and dissemination to the peripheral organs, lung myeloid and lymphoid immune responses to RDR Mtb is suppressed through a Type I IFN-dependent mechanism. These results coincide with a muted responses in the bone marrow hematopoietic stem and progenitor cells (HSPCs) and progenitors following RDR Mtb infection. These results suggest that host directed therapeutics and vaccines for drug resistant TB may need to be target specific host immune pathways for protection.
Project description:Efforts to eradicate TB are largely threatened by drug-resistant tuberculosis, particularly, multidrug-resistant tuberculosis (MDR-TB). It is imperative to find one or more specific biomarkers for diagnosing MDR-TB earlier and declining the incidence. Growing evidences have showed lncRNAs are widely expressed and take part in the genesis and development of many diseases, including tuberculosis. Therefore, to screen the differential lncRNAs among MDR-TB, drug-sensitive tuberculosis(DS-TB) and healthy controls(HCs) is a good strategy to acquire potential biomarkers for MDR-TB diagnosis and partly describe the mechanism of MDR-TB. Here, the present study aimed to investigate the differential expression profile of lncRNAs in serum among patients with MDR-TB ,DS-TB and HCs using lncRNA microarray
Project description:Tuberculosis (TB), which is caused by Mycobacterium tuberculosis (Mtb), continues to be a public health threat. With the development and widespread of drug-resistant TB, the pressure of prevention and treatment is increasing. To determine and quantify the modified proteins, high resolution mass spectrometry were used to label and quantify the peptides and proteins modified.
Project description:The emergence of drug resistance among tuberculosis (TB) patients is often associated with their non-compliance to the length of the chemotherapy, which can reach up to 2 years for the treatment of multi-drug-resistant (MDR) TB. Drugs that would kill TB faster and would not lead to the development of drug resistance could shorten chemotherapy significantly. In Escherichia coli, the common mechanism of cell death by bactericidal antibiotics is the generation of highly reactive hydroxyl radicals via the Fenton reaction. Since ascorbic acid (vitamin C) is known to drive the Fenton reaction, we tested whether the Fenton reaction could lead to a bactericidal event in Mycobacterium tuberculosis by treating M. tuberculosis cultures with vitamin C. Here, we report that the addition of vitamin C to drug-susceptible, MDR and extensively drug-resistant (XDR) M. tuberculosis strains results in sterilization of the cultures in vitro. We show that the sterilizing effect of vitamin C on M. tuberculosis was dependent on the production of high ferrous ion levels and reactive oxygen species. Although, this potent sterilizing activity of vitamin C against M. tuberculosis in vitro was not observed in mice, we believe this activity needs further investigation.