The effect of growth rate on pyrazinamide activity in Mycobacterium tuberculosis; insights for early bactericidal activity
ABSTRACT: Background: Pyrazinamide (PZA) plays an essential part in the shortened 6-month tuberculosis (TB) treatment course due to its activity against slow-growing, semi-dormant organisms. We tested the paradigm that PZA preferentially targets slow growing cells of Mycobacterium tuberculosis that remain after the initial kill by isoniazid, by observing the response of either slow growing or fast growing bacilli to differing concentrations of PZA. Methods: M. tuberculosis H37Rv was grown in continuous culture at either a constant fast growth rate (Mean Generation Time [MGT] of 23.1 h) or slow growth rate (69.3 h MGT) at a controlled dissolved oxygen tension of 10% and a controlled acidity at pH 6.3 ± 0.1. The cultures were exposed to step-wise increases in the concentration of PZA (25 µg ml-1 to 250 µg ml-1) every 2 MGTs, and bacterial survival was measured. PZA-induced global gene expression was explored for each increase in PZA-concentration, using microarray.
Pyrazinamide (PZA) plays an essential part in the shortened six-month tuberculosis (TB) treatment course due to its activity against slow-growing and non-replicating organisms. We tested whether PZA preferentially targets slow growing cells of Mycobacterium tuberculosis that could be representative of bacteria that remain after the initial kill with isoniazid (INH), by observing the response of either slow growing or fast growing bacilli to differing concentrations of PZA.M. tuberculosis H37Rv w ...[more]
Project description:This is a pilot study from the Knockout Mouse Phenotyping Program (KOMP2). The program provides broad, standardized phenotyping of a genome-wide collection of mouse knockouts generated by the International Knockout Mouse Consortium (IKMC), funded by the NIH, European Union, Wellcome Trust, Canada, and the Texas Enterprise Fund. In this experiment RNAseq was performed to profile expression of coding RNA in the liver, spleen, kidney, abdominal muscle and gonadal adipose tissue of knock out mice (1810027O10Rik knockout, Sik1 knockout, 3110043O21Rik knockout, 3110043O21Rik knockout) compared with wild type controls.
Project description:MaSC, Luminal progenitor enriched subpopulations were isolated from virgin and pregnant mice based on using both surface marker or internal reporter transgene (GFP) expression. (Tiede BJ et al., 2009, PLoS ONE 4(11): e8035. doi:10.1371/journal.pone.0008035), and the transcirptome profiles were determined and compared. Two MaSC differential methods: CD24/CD29 & GFP reporter; two physiolgical condition: virgin vs pregnant; the combination of ((P4, GFPhi) vs (P5, P6, GFPlo)) x (vg vs pg)
Project description:MaSC, luminal progenitor enriched subpopulations and total MECs as well, were isolated from both wild type and ∆Np63 KO heterozygous mouse and the transcriptome profiles were determined and compared. Three populations: P4, P5 and MECs; two genotypes: WT vs ∆Np63 heterozygous.
Project description:A RNA Seq analysis of 7 tissues from 16 week old male knockout mice. A total of 106 IMPC knockout lines were analysed by David West's group at Children's Hospital Oakland Research Institute.
Project description:Sirturo or Bedaquiline has been shown to inhibit the ATP synthase of Mycobacterium tuberculosis. We used microarrays to investigate compound-induced gene expression changes in general as well as effects on the transcription of the different ATP synthase genes and other metabolic pathways. Log phase Mycobacterium tuberculosis were cultivated in Middlebrook 7H9 broth and treated with 1 µM Bedaquiline. We have extracted RNA from five different time-points after treatment: 0 min (T0), 30 min (T30), 60 min (T60), 180 min (T180) and 360 min (T360).
Project description:Transcriptional profiling of H37Rv (WT), Mut1 and Comp1 bacteria under aerobic (Aer/0 day, i.e 0 D) and hypoxic conditions (Hyp/5 days standing culture, i.e 5 D). Mut1: H37Rv carrying devR gene disruption by in frame insertion of kanamycin resistance cassette and expressing DevRN-Kan fusion protein. Comp1: Mut1 complemented with low copy number plasmid carrying devR gene expressed from its native constitutive upstream promoter. (Reference: Majumdar et al., 2010, PLoS One 5:e9448). Goal is to compare transcriptional patterns of WT, Mut1 and Comp1 strains under aerobic (0 D) and hypoxic (5 D) conditions in vitro. Two color and One-color experiments,Organism: Mycobacterium tuberculosis, Genotypic Technology designed Custom Mycobacterium tuberculosis H37Rv Whole Genome 8x15k GE Microarray (AMADID-020181)
Project description:Tuberculosis (TB) is the deadliest infectious disease worldwide. One obstacle hindering the elimination of TB is our lack of understanding of host-pathogen interactions. Exosomes, naturally loaded with microbial molecules, are circulating markers of TB. Changes in the host protein composition of exosomes from Mycobacterium tuberculosis (Mtb)-infected cells have not been described, can contribute to our understanding of the disease process, and serve as a direct source of biomarkers or as capture targets to enrich for exosomes containing microbial molecules. Here, the protein composition of exosomes from Mtb-infected and uninfected THP-1-derived macrophages was evaluated by tandem-mass-spectrometry and differences in protein abundances were assessed. Our results show that infection with Mtb leads to significant changes in the protein composition of exosomes. Specifically, 41 proteins were significantly more abundant in exosomes from Mtb-infected cells; 63% of these were predicted to be membrane associated. Thus, we used a novel biotinylation strategy to verify protein localization, and confirmed the localization of some of these proteins in the exosomal membrane. Our findings reveal another important scenario where Mtb could be influencing changes in host cells that unveil new features of the host-pathogen interaction and may also be exploited as a source of biomarkers for TB.