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Zelmer A, Carroll P, Andreu N, Hagens K, Mahlo J, Redinger N, Robertson BD, Wiles S, Ward TH, Parish T, Ripoll J, Bancroft GJ, Schaible UE. A new in vivo model to test anti-tuberculosis drugs using fluorescence imaging. J Antimicrob Chemother 2012; 67:1948-60. [PMID: 22635525 PMCID: PMC3394442 DOI: 10.1093/jac/dks161] [Citation(s) in RCA: 60] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2012] [Revised: 04/03/2012] [Accepted: 04/05/2012] [Indexed: 12/02/2022] Open
Abstract
OBJECTIVES The current method for testing new drugs against tuberculosis in vivo is the enumeration of bacteria in organs by cfu assay. Owing to the slow growth rate of Mycobacterium tuberculosis (Mtb), these assays can take months to complete. Our aim was to develop a more efficient, fluorescence-based imaging assay to test new antibiotics in a mouse model using Mtb reporter strains. METHODS A commercial IVIS Kinetic® system and a custom-built laser scanning system with fluorescence molecular tomography (FMT) capability were used to detect fluorescent Mtb in living mice and lungs ex vivo. The resulting images were analysed and the fluorescence was correlated with data from cfu assays. RESULTS We have shown that fluorescent Mtb can be visualized in the lungs of living mice at a detection limit of ∼8 × 10⁷ cfu/lung, whilst in lungs ex vivo a detection limit of ∼2 × 10⁵ cfu/lung was found. These numbers were comparable between the two imaging systems. Ex vivo lung fluorescence correlated to numbers of bacteria in tissue, and the effect of treatment of mice with the antibiotic moxifloxacin could be visualized and quantified after only 9 days through fluorescence measurements, and was confirmed by cfu assays. CONCLUSIONS We have developed a new and efficient method for anti-tuberculosis drug testing in vivo, based on fluorescent Mtb reporter strains. Using this method instead of, or together with, cfu assays will reduce the time required to assess the preclinical efficacy of new drugs in animal models and enhance the progress of these candidates into clinical trials against human tuberculosis.
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Affiliation(s)
- Andrea Zelmer
- Immunology and Infection Department, Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, Keppel St., London WC1E 7HT, UK
| | - Paul Carroll
- Centre for Immunology and Infectious Disease, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, 4 Newark Street, London E1 2AT, UK
| | - Nuria Andreu
- Microbiology, Department of Medicine, Imperial College London, South Kensington Campus, London SW7 2AZ, UK
| | - Kristine Hagens
- Cellular Microbiology, Department of Molecular Infection Research, Research Centre Borstel, Parkallee 22, 23845 Borstel, Germany
| | - Jacqueline Mahlo
- Cellular Microbiology, Department of Molecular Infection Research, Research Centre Borstel, Parkallee 22, 23845 Borstel, Germany
| | - Natalja Redinger
- Cellular Microbiology, Department of Molecular Infection Research, Research Centre Borstel, Parkallee 22, 23845 Borstel, Germany
| | - Brian D. Robertson
- Microbiology, Department of Medicine, Imperial College London, South Kensington Campus, London SW7 2AZ, UK
| | - Siouxsie Wiles
- Infectious Diseases & Immunity, Department of Medicine, Imperial College London, Hammersmith Campus, London W12 0NN, UK
- Department of Molecular Medicine and Pathology, University of Auckland, 85 Park Rd, Auckland, 1142, New Zealand
| | - Theresa H. Ward
- Immunology and Infection Department, Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, Keppel St., London WC1E 7HT, UK
| | - Tanya Parish
- Centre for Immunology and Infectious Disease, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, 4 Newark Street, London E1 2AT, UK
- Infectious Disease Research Institute, 1124 Columbia St., Seattle, WA 98104, USA
| | - Jorge Ripoll
- Institute for Electronic Structure and Laser, Foundation for Research and Technology—Hellas, PO Box 1527, 71110 Heraklion, Greece
| | - Gregory J. Bancroft
- Immunology and Infection Department, Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, Keppel St., London WC1E 7HT, UK
| | - Ulrich E. Schaible
- Immunology and Infection Department, Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, Keppel St., London WC1E 7HT, UK
- Cellular Microbiology, Department of Molecular Infection Research, Research Centre Borstel, Parkallee 22, 23845 Borstel, Germany
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