INT J TUBERC LUNG DIS 16(1):24–31 © 2012 The Union http://dx.doi.org/10.5588/ijtld.11.0223 The TDR Tuberculosis Strain Bank: a resource for basic science, tool development and diagnostic services V. Vincent,* † L. Rigouts, ‡ E. Nduwamahoro, ‡ B. Holmes, § J. Cunningham,* M. Guillerm,* C-M. Nathanson,* F. Moussy,* B. De Jong, ‡ F. Portaels, ‡ A. Ramsay* * United Nations Children’s Fund/United Nations Development Programme/World Bank/World Health Organization Special Programme for Research and Training in Tropical Diseases (TDR), Geneva, Switzerland; † Institut Pasteur, Paris, France; ‡ Institute of Tropical Medicine, Antwerp, Belgium; § National Collection of Type Cultures, London, UK Correspondence to: Leen Rigouts, Mycobacteriology Unit, Institute of Tropical Medicine, Nationalestraat 155, 2000 Antwerpen, Belgium. Tel: (+32) 3 247 65 51. Fax: (+32) 3 247 63 33. e-mail: lrigouts@itg.be Article submitted 4 April 2011. Final version accepted 15 July 2011. BACKGROUND: The Special Programme for Research and Training in Tropical Diseases recently launched a Mycobacterium tuberculosis strain bank (TDR-TB Strain Bank). OBJECTIVE: To describe the TDR-TB Strain Bank, the characterisation of strains, bank management and the procedure for releasing materials. RESULTS: The TDR-TB Strain Bank consists of 229 clinical M. tuberculosis isolates (single-colony derived cultures) plus five mycobacterial reference strains for purposes of identification. These are available as freeze- dried, viable strains or as heat-inactivated bacterial sus- pensions, quality controlled for purity, viability and au- thenticity. Isolates originated from diverse geographical settings and were selected for their resistance profiles against first- and second-line drugs. Low and high levels of resistance were determined by the minimum inhibi- tory concentrations of isoniazid, rifampicin, ethambutol, streptomycin, ofloxacin, kanamycin, capreomycin, ethi- onamide and para-aminosalicylic acid. Sequencing for drug resistance mutations was performed on the rele- vant sections of the rpoB, katG, inhA, embB, rpsL, rrs, gyrA and gyrB genes. Typing using lineage-defining loci of mycobacterial interspersed repetitive unit–variable number tandem repeats indicated that the most impor- tant genetic lineages were represented. CONCLUSIONS: The TDR-TB Strain Bank is a high quality bioresource for basic science, supporting the de- velopment of new diagnostics and drug-resistant detec- tion tools and providing reference materials for labora- tory quality management programmes. KEY WORDS: strain bank; Mycobacterium tuberculo- sis; diagnostics development; drug susceptibility testing TUBERCULOSIS (TB) remains a global public health emergency. Despite decades of effort, the pandemic is not under control and targets for reducing global in- cidence and mortality have not been met in all World Health Organization (WHO) regions. 1 Three major obstacles to TB control are recognised: the weak health systems that prevail in many of the disease- endemic countries, the high prevalence of human immunodefciency virus (HIV) associated TB, and the increasing prevalence of multidrug-resistant TB. 1,2 Furthermore, extensively drug-resistant TB (XDR- TB) is being increasingly identifed and poses a signif- icant therapeutic challenge, with a high mortality rate. Since the frst reported cases of XDR-TB in 2006 in South Africa, 3 XDR-TB has been recognised as a worldwide problem, with rates of as many as 10% of MDR-TB cases being recorded. 2,4 SUMMARY New diagnostic tools are urgently needed to reli- ably identify TB cases—including HIV-associated TB cases, who tend to have lower bacillary loads—and detect critical forms of drug resistance at points of care in endemic countries. Robust laboratory quality management systems are, and will continue to be, needed to ensure continued optimal performance of diagnostic services. Beyond diagnostics, new classes of drugs are urgently needed to broaden our failing armamentarium of anti-tuberculosis drugs, and ulti- mately an effective vaccine is needed with improved effcacy relative to bacille Calmette-Guérin (BCG) vaccination. Resistance mechanisms for most drugs are still poorly understood, except for rifampicin (RMP). Re- sistance to RMP is linked to a small 81 base pair se- quence within a single gene; 96% of phenotypically resistant isolates contain mutations within this se- quence. 5 The situation differs drastically for the other anti-tuberculosis drugs, where, in most cases, several VV and LR are joint frst authors. FP and AR are joint senior authors.