Objective: To establish in vivo and in vitro models of persistent Mycobacterium tuberculosis infection, and therefore to study the persisters in different conditions and periods of chemotherapy, and to explore the relationship between the persisters and chemotherapy.
Methods: The persisters in the two models were examined by culturing Mycobacterium tuberculosis in oxygen-starved condition and determining the mRNA expression of isocitrate lyase (ICL), alpha-crystallin chaperone (Acr) and 85B through quantitative PCR.
Results: The bacteria which could be cultured in oxygen-starved condition were discovered in both models. The mRNA expression of ICL and Acr increased gradually and dramatically after culture for 4 days in the in vitro model, their values being (5.3 +/- 0.9) and (6.4 +/- 1.6) log copy/ml respectively. While the mRNA expression of 85B showed no significant change in oxygen-starved condition, it increased significantly in the standard condition, the values being (6.1 +/- 0.9) log copy/ml at 10th day. In the mice infected with Mycobacterium tuberculosis, the mRNA expression of ICL was detected in 2 and 4 weeks post-infection, and decreased 4 weeks after treatment. The Acr mRNA showed no or very low expression 4 weeks post-infection or 4 weeks after treatment, but it increased significantly 8 and 10 weeks after treatment, with a value of (6.2 +/- 1.7) log copy/ml at 10 weeks, and its expression was still detected 12 weeks after treatment and 4 weeks after the cessation of treatment [(3.0 +/- 1.6) log copy/ml]. The expression of 85B mRNA was high before the treatment [(6.4 +/- 1.1) log copy/ml], and decreased gradually during the therapy.
Conclusion: The models of in vitro and in vivo persistence of Mycobacterium tuberculosis were established. ICL and Acr mRNAs were highly expressed, which may be the markers of persisters. Persisters can be detected by culture in oxygen-starved conditions and the measurement of mRNA expression.
Download full-text PDF |
Source |
|---|
Publication Analysis
Top Keywords
Similar Publications
Executive Summary: Clinical Practice Guidelines on the Management of Resistant Tuberculosis of the Spanish Society of Pulmonology and Thoracic Surgery (SEPAR) and the Spanish Society of Infectious Diseases and Clinical Microbiology (SEIMC).
Arch Bronconeumol
December 2024
Pulmonology Service, Cruces University Hospital (OSI EEC), Barakaldo, Spain; BioBizkaia Health Research Institute, Spain.
The Spanish Society of Pneumology and Thoracic Surgery (SEPAR) and the Spanish Society of Infectious Diseases and Clinical Microbiology (SEIMC) have developed together Clinical Practice Guidelines (GPC) on the management of people affected by tuberculosis (TB) resistant to drugs with activity against Mycobacterium tuberculosis. These clinical practice guidelines include the latest updates of the SEPAR regulations for the diagnosis and treatment of drug-resistant TB from 2017 and 2020 as the starting point. The methodology included asking relevant clinical questions based on PICO methodology, a literature search focusing on each question, and a systematic and comprehensive evaluation of the evidence, with a summary of this evidence for each question.
View Article and Find Full Text PDFGlobally, drug-resistant tuberculosis (DR-TB) is responsible for 13% of mortality attributable to antimicrobial resistance. In Ethiopia, extrapulmonary tuberculosis (EPTB) is a significant public health challenge, and drug resistance (DR) in EPTB is often overlooked. In a cross-sectional study conducted between August 2022 and October 2023, we aimed to explore the magnitude of phenotypic drug resistance and identify genetic mutations linked to resistance using 189 Mycobacterium tuberculosis (MTB) isolates cultured from extrapulmonary clinical specimens.
View Article and Find Full Text PDFUnlabelled: Crosstalk between autophagy, host cell death, and inflammatory host responses to bacterial pathogens enables effective innate immune responses that limit bacterial growth while minimizing coincidental host damage. ( ) thwarts innate immune defense mechanisms in alveolar macrophages (AMs) during the initial stages of infection and in recruited bone marrow-derived cells during later stages of infection. However, how protective inflammatory responses are achieved during infection and the variation of the response in different macrophage subtypes remain obscure.
View Article and Find Full Text PDFUnlabelled: Mycobacterial cell envelopes are rich in unusual lipids and glycans that play key roles during infection and vaccination. The most abundant envelope glycolipid is trehalose dimycolate (TDM). TDM compromises the host response to mycobacterial species via multiple mechanisms, including inhibition of phagosome maturation.
View Article and Find Full Text PDFPathogen sequencing is an important tool for disease surveillance and demonstrated its high value during the COVID-19 pandemic. Viral sequencing during the pandemic allowed us to track disease spread, quickly identify new variants, and guide the development of vaccines. Tiled amplicon sequencing, in which a panel of primers is used for multiplex amplification of fragments across an entire genome, was the cornerstone of SARS-CoV-2 sequencing.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!