Investigating isoniazid minimum inhibitory concentrations, mutations and clustering in Mycobacterium tuberculosis clinical isolates without classic resistance-associated mutations in katG and inhA
Ontology highlight
ABSTRACT:
PROVIDER: PRJEB53484 | ENA |
REPOSITORIES: ENA
Similar Datasets
Project description:This project provides the first characterization of protein differences in clinical isolates of Mtb after acquisition of resistance to isoniazid (INH), one of the most important drug treatment options against TB. This study determines the global protein differences in a clinical isogenic pair of Mtb, comparing INH susceptibility versus INH resistance.
2016-03-14 | PXD002986 | Pride
Project description:This project describes the isoniazid (INH) resistance acquisition event in Mycobacterium tuberculosis (Mtb) from the proteomics perspective. In this way, an exploration of the protein differences, comparing clonal INH susceptible (INHs) and INHr pairs of Mtb were evaluated. One clonal clinical and one clonal laboratory-derived Mtb pair with different susceptibility profiles to INH were studied. The laboratory INHr strain had one katG mutation (V1A), while the clinical INHr strain had two (V1A and E3V). Large-scale bacterial cultures were grown in triplicate to obtain secreted proteins as well as proteins from cell fractions. The resulting peptide solutions from all fractions were analyzed using liquid-chromatography coupled with tandem mass spectrometry (LC-MS/MS). LC-MS/MS spectra were compared against an Mtb database to determine the protein abundance. Protein abundance differences were tested by Student’s t test. Looking at the same cellular fractions, there were 25 commonly altered Mtb proteins after acquiring INH resistance. These proteins were involved in ATP synthase machinery, lipid metabolism, regulatory events, virulence, detoxification and adaptation processes.
2018-06-25 | PXD009549 | Pride
Project description:Out of the 10 million of tuberculosis (TB) cases estimated in the world, around 14% are isoniazid (INH) resistant among new cases and 29% among previously treated cases in the last decade. INH is one of the oldest but also one of the more potent drugs to eliminate Mycobacterium tuberculosis (Mtb), the causing agent of TB. Because of the efficiency of isoniazid (INH) against Mycobacterium tuberculosis (Mtb), many studies are still focused in better understand its role in different bacterial metabolic pathways. We recently conducted a study that evaluated the changes in the protein abundance at different cellular fractions when clonal strains of Mtb developed INH resistance in the clinical and laboratory setting. Here, we want to establish which of the protein changes occurred or started because of the initial exposure to INH. Additionally, we wanted to evaluate if those changes happen differently in strains that are sensitive or resistant to INH, evaluating different cellular compartments from two different genetic lineages of Mtb. For this purpose, we analyzed the proteome of each cellular compartment (cytosol, cell wall, membrane and secreted proteins) through liquid chromatography (nano-HPLC) coupled to mass spectrometry using the Orbitrap Velos instrument and a t-test to perform the statistical analysis for each pair comparison.
2019-06-17 | PXD007588 | Pride
Project description:IntroductionTraditionally, single critical concentrations of drugs are utilized for Mycobacterium tuberculosis (Mtb) drug susceptibility testing (DST); however, the level of drug resistance can impact treatment choices and outcomes. Mutations at the katG gene are the major genetic mutations in multidrug resistant (MDR) Mtb and usually associated with high level resistance. We assessed the minimum inhibitory concentrations (MICs) of MDR or rifampin resistant (RR) and isoniazid (INH) resistant Mtb isolates to determine the quantification of drug resistance among key anti-tuberculosis drugs.MethodsThe study was conducted on stored Mtb isolates collected as part of a national drug resistance survey in Ethiopia. MIC values were determined using Sensititre™ MYCOTB plates. A line probe assay (MTBDRplus) was also performed to identify genetic determinants of resistance for all isolates.ResultsMIC testing was performed on 74 Mtb isolates including 46 MDR, 2 RR and 26 INH phenotypically resistant isolates as determined by the Löwenstein Jensen (LJ) method. Four (15%) INH resistant Mtb isolates were detected as borderline rifampin resistance (MIC = 1 μg/ml) using MYCOTB MIC plates and no rifampin resistance mutations were detected by LPA. Among the 48 MDR/RR TB cases, 9 (19%) were rifabutin susceptible (MIC was between ≤0.25 and 0.5μg/ml). Additionally, the MIC for isoniazid was between 2-4 μg/ml (moderate resistance) for 58% of MDR TB isolates and 95.6% (n = 25) of the isolates had mutations at the katG gene.ConclusionOur findings suggest a role for rifabutin treatment in a subset of RR TB patients, thus potentially preserving an important drug class. The high proportion of moderate level INH resistant among MDR Mtb isolates indicates the potential benefit of high dose isoniazid treatment in a high proportion of katG gene harboring MDR Mtb isolates.
| S-EPMC9469996 | biostudies-literature
Project description:Background: Understanding how growth state influences Mycobacterium tuberculosis responses to antibiotic exposure provides a window into drug action during patient chemotherapy. In this article, we describe the transcriptional programs mediated by isoniazid (INH) during the transition from log-phase to nonreplicating bacilli, from INH-sensitive to INH-tolerant bacilli respectively, using the Wayne model. Results: INH treatment did not elicit a transcriptional response from nonreplicating bacteria under microarophilic conditions (NRP2), unlike the induction of a robust and well-characterized INH signature in log-phase bacilli. Conclusion: The differential regulation (between drug-free NRP2 and log-phase bacilli) of genes directly implicated in INH resistance could not account for the abrogation of INH killing in nongrowing bacilli. Thus, factors affecting the requirement for mycolic acids and the redox status of bacilli are likely responsible for the reduction in INH efficacy. We speculate on additional mechanisms revealed by transcriptome analysis that might account for INH tolerance. Data is also available from <ahref=http://bugs.sgul.ac.uk/E-BUGS-104 target=_blank>BuG@Sbase</a>
2011-01-17 | E-BUGS-104 | biostudies-arrayexpress
Project description:The ability of Mycobacterium tuberculosis (Mtb) to adopt heterogeneous physiological states, underlies it’s success in evading the immune system and tolerating antibiotic killing. Drug tolerant phenotypes are a major reason why the tuberculosis (TB) mortality rate is so high, with over 1.8 million deaths annually. To develop new TB therapeutics that better treat the infection (faster and more completely), a systems-level approach is needed to reveal the complexity of network-based adaptations of Mtb. Here, we report the transcriptional response of Mtb to the drug isoniazid. We performed transcriptomic sequencing (RNA-seq) on Mtb bacilli at 4, 24, 72 h following exposure to the drug.
2021-12-15 | GSE165581 | GEO
Project description:A cell-based phenotypic screen for inhibitors of biofilm formation in Mycobacterium tuberculosis (Mtb) identified the small molecule TCA1, which has bactericidal activity against both drug susceptible and drug resistant Mtb, and synergizes with rifampicin (RIF) or isoniazid (INH) in sterilization of Mtb in vitro. In addition, TCA1 has bactericidal activity against non-replicating Mtb in vitro and is efficacious in acute and chronic Mtb infection mouse models, both alone and in combination with INH or RIF. Transcriptional analysis revealed that TCA1 down-regulates genes known to be involved in Mtb dormancy and drug tolerance. Mutagenesis and affinity-based methods identified DprE1 and MoeW, enzymes involved in cell wall and molybdenum cofactor biosynthesis, respectively, as the targets responsible for TCA1M-bM-^@M-^Ys activity. These in vitro and in vivo results indicate that TCA1functions by a novel mechanism and suggest that it may be the first product of a promising new approach for the development of anti-tuberculosis drugs. Transcriptional profile of TCA1-treated cells relative to DMSO-treated control. Three biological replicates, third is a dye flip.
2013-05-24 | E-GEOD-42151 | biostudies-arrayexpress
Project description:A cell-based phenotypic screen for inhibitors of biofilm formation in Mycobacterium tuberculosis (Mtb) identified the small molecule TCA1, which has bactericidal activity against both drug susceptible and drug resistant Mtb, and synergizes with rifampicin (RIF) or isoniazid (INH) in sterilization of Mtb in vitro. In addition, TCA1 has bactericidal activity against non-replicating Mtb in vitro and is efficacious in acute and chronic Mtb infection mouse models, both alone and in combination with INH or RIF. Transcriptional analysis revealed that TCA1 down-regulates genes known to be involved in Mtb dormancy and drug tolerance. Mutagenesis and affinity-based methods identified DprE1 and MoeW, enzymes involved in cell wall and molybdenum cofactor biosynthesis, respectively, as the targets responsible for TCA1’s activity. These in vitro and in vivo results indicate that TCA1functions by a novel mechanism and suggest that it may be the first product of a promising new approach for the development of anti-tuberculosis drugs.
2013-05-24 | GSE42151 | GEO
Project description:BackgroundMucormycosis is a destructive invasive mold infection afflicting patients with diabetes and hematologic malignancies. Patients with diabetes are often treated with statins, which have been shown to have antifungal properties. We sought to examine the effects of statins on Rhizopus oryzae, a common cause of mucormycosis.MethodsClinical strains of R. oryzae were exposed to lovastatin, atorvastatin, and simvastatin and the minimum inhibitory concentrations (MICs) were determined. R. oryzae germination, DNA fragmentation, susceptibility to oxidative stress, and ability to damage endothelial cells were assessed. We further investigated the impact of exposure to lovastatin on the virulence of R. oryzaeResultsAll statins had MICs of >64 µg/mL against R. oryzae Exposure of R. oryzae to statins decreased germling formation, induced DNA fragmentation, and attenuated damage to endothelial cells independently of the expression of GRP78 and CotH. Additionally, R. oryzae exposed to lovastatin showed macroscopic loss of melanin, yielded increased susceptibility to the oxidative agent peroxide, and had attenuated virulence in both fly and mouse models of mucormycosis.ConclusionsExposure of R. oryzae to statins at concentrations below their MICs decreased virulence both in vitro and in vivo. Further investigation is warranted into the use of statins as adjunctive therapy in mucormycosis.
| S-EPMC5007635 | biostudies-literature
Project description:Minimum inhibitory concentrations (MICs) against E. coli were measured for three nylon-3 polymers using Luria-Bertani broth (LB), brain-heart infusion broth (BHI), and a chemically defined complete medium (EZRDM). The polymers differ in the ratio of hydrophobic to cationic subunits. The cationic homopolymer is inert against E. coli in BHI and LB, but becomes highly potent in EZRDM. A mixed hydrophobic/cationic polymer with a hydrophobic t-butylbenzoyl group at its N-terminus is effective in BHI, but becomes more effective in EZRDM. Supplementation of EZRDM with the tryptic digest of casein (often found in LB) recapitulates the LB and BHI behavior. Additional evidence suggests that polyanionic peptides present in LB and BHI may form electrostatic complexes with cationic polymers, decreasing activity by diminishing binding to the anionic lipopolysaccharide layer of E. coli. In contrast, two natural antimicrobial peptides show no medium effects. Thus, the use of a chemically defined medium helps to reveal factors that influence antimicrobial potency of cationic polymers and functional differences between these polymers and evolved antimicrobial peptides.
| S-EPMC4143223 | biostudies-literature