Royal College of Surgeons in Ireland
An automated culture system for use in preclinical testing of host-directed therapies ....pdf (994 kB)

An automated culture system for use in preclinical testing of host-directed therapies for tuberculosis

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journal contribution
posted on 2022-06-23, 08:58 authored by Seónadh O’leary, Ahmad BahloolAhmad Bahlool, Gemma O ConnorGemma O Connor, Sally-Ann CryanSally-Ann Cryan, Joseph M Keane, Mary P. O’Sullivan
Mycobacterium tuberculosis (Mtb), the causative agent of tuberculosis (TB), was the most significant infectious disease killer globally until the advent of COVID-19. Mtb has evolved to persist in its intracellular environment, evade host defenses, and has developed resistance to many anti-tubercular drugs. One approach to solving resistance is identifying existing approved drugs that will boost the host immune response to Mtb. These drugs could then be repurposed as adjunctive host-directed therapies (HDT) to shorten treatment time and help overcome antibiotic resistance. Quantification of intracellular Mtb growth in macrophages is a crucial aspect of assessing potential HDT. The gold standard for measuring Mtb growth is counting colony-forming units (CFU) on agar plates. This is a slow, labor-intensive assay that does not lend itself to rapid screening of drugs. In this protocol, an automated, broth-based culture system, which is more commonly used to detect Mtb in clinical specimens, has been adapted for preclinical screening of host-directed therapies. The capacity of the liquid culture assay system to investigate intracellular Mtb growth in macrophages treated with HDT was evaluated. The HDTs tested for their ability to inhibit Mtb growth were all-trans Retinoic acid (AtRA), both in solution and encapsulated in poly(lactic-co-glycolic acid) (PLGA) microparticles and the combination of interferon-gamma and linezolid. The advantages of this automated liquid culture-based technique over the CFU method include simplicity of setup, less labor-intensive preparation, and faster time to results (5-12 days compared to 21 days or more for agar plates).


Science Foundation Ireland (SFI 08/RFP/BMT1689)

Health Research 410 Board in Ireland [HRA-POR/2012/4 and HRA-POR-2015-1145]

Royal City of Dublin Hospital Trust



The original article is available at

Published Citation

O'Leary S. et al. An automated culture system for use in preclinical testing of host-directed therapies for tuberculosis. J Vis Exp. 2021 Aug 16;(174):e62838

Publication Date

16 August 2021

PubMed ID



  • Amber (Advanced Material & Bioengineering Research) Centre
  • CURAM Centre for Research in Medical Devices
  • School of Pharmacy and Biomolecular Sciences

Research Area

  • Respiratory Medicine
  • Chemistry and Pharmaceutical Sciences
  • Biomaterials and Regenerative Medicine


MyJove Corporation


  • Accepted Version (Postprint)