Skip to main content

Free Content Beijing family Mycobacterium tuberculosis strains differ in their intracellular growth in THP-1 macrophages

Download Article:
(PDF 147.1 kb)


SETTING: Previous studies have shown that isolates from cases in IS6110 restriction fragment length polymorphism (RFLP) clusters that have persisted over several years and are widely distributed grow significantly faster in macrophages than isolates from cases with unique RFLP patterns. As members of the Beijing family of Mycobacterium tuberculosis are widely distributed and have been responsible for several large outbreaks, it has been suggested that this genotype may have a selective advantage over other strains.

OBJECTIVE: To determine whether rapid growth in macrophages is a common characteristic of Beijing family strains.

DESIGN: T-helper precursor-1 human macrophages were infected with various Beijing family strains, and intracellular growth and tumor necrosis factor alpha (TNF-α) secretion were assessed. Strains differed in their genotype, with IS6110 copy number ranging from 9 to 22.

RESULTS: Strains demonstrated a range of growth phenotypes over the 7-day infection period. Three grew significantly more slowly than the other strains, whereas the fastest growth was observed consistently with isolates of strain 210.

CONCLUSION: Rapid growth in macrophages is not a common characteristic of all Beijing strains. Few Beijing strains are as virulent as strain 210. The growth advantage is consistent with strain 210 having persisted many years in different locations and having caused many outbreaks.

Keywords: Beijing; epidemiology; genotype; macrophages; tuberculosis

Document Type: Regular Paper

Affiliations: 1: Department of Pathology, University of Arkansas for Medical Sciences and Central Arkansas Veterans Healthcare System, Little Rock, Arkansas, USA 2: Department of Medicine, Case Western Reserve University School of Medicine, Cleveland, Ohio, USA; Louis Stokes Cleveland VA Medical Center, Cleveland, Ohio, USA; and University of Cleveland Case Medical Center, Cleveland, Ohio, USA 3: Department of Neurobiology and Developmental Sciences, University of Arkansas for Medical Sciences and Central Arkansas Veterans Healthcare System, Little Rock, Arkansas, USA

Publication date: October 1, 2007

More about this publication?
  • The International Journal of Tuberculosis and Lung Disease publishes articles on all aspects of lung health, including public health-related issues such as training programmes, cost-benefit analysis, legislation, epidemiology, intervention studies and health systems research. The IJTLD is dedicated to the continuing education of physicians and health personnel and the dissemination of information on tuberculosis and lung health world-wide.

    Certain IJTLD articles are selected for translation into French, Spanish, Chinese or Russian. They are available on the Union website

  • Editorial Board
  • Information for Authors
  • Subscribe to this Title
  • International Journal of Tuberculosis and Lung Disease
  • Public Health Action
  • Ingenta Connect is not responsible for the content or availability of external websites

Access Key

Free Content
Free content
New Content
New content
Open Access Content
Open access content
Partial Open Access Content
Partial Open access content
Subscribed Content
Subscribed content
Free Trial Content
Free trial content
Cookie Policy
Cookie Policy
Ingenta Connect website makes use of cookies so as to keep track of data that you have filled in. I am Happy with this Find out more