Performance of four transport and storage supports for molecular detection of multidrug resistant tuberculosis

RABODOARIVELO MS; B IMPERIALE; BRANDAO A; KUMAR P; SINGH S,; FERRAZOLI LUCILAINE; MORCILLO N; RASALOFO V; PALOMINO JC; VANDAMME P; MARTIN A

Riga

Congreso; 36th Annual Congress of the European Society of Mycobacteriology (ESM); 2015

European Society of Mycobacteriology (ESM)

PERFORMANCE OF FOuR TRANSPORT AND STORAGE SuPPORTS FOR MOLECuLAR DETECTION OF MuLTIDRuG RESISTANT TuBERCuLOSIS Marie Sylvianne Rabodoarivelo1, Belen Imperiale2, Angela Brandao3, Parveen kumar4, Sarman Singh4, Lucilaine Ferrazoli3, Nora Morcillo2, Voahangy Rasolofo5,juan Carlos Palomino6, Peter Vandamme6, Anandi Martin61. unité des Mycobactéries, institut Pasteur de Madagascar, Antananarivo, Madagascar2. Hospital Dr. cetrángolo, buenos Aires, Argentina3. instituto Adolfo lutz, Núcleo de tuberculose e Micobacteriosis, sao Paulo, brazil4. All india institute of Medical sciences, Delhi, india5. institut Pasteur de Madagascar6. laboratory of Microbiology, Department of biochemistry and Microbiology, Ghent university, Gent, belgiumBackground: Detection of drug resistant tuberculosis(TB), particularly in low-resource countries, is often hampered by the limitation of transport and storageof samples from remote locations to the reference laboratory. Consequently, the treatment of TB usually starts without the results of drug susceptibility testing (DST) being known or treatment gets delayed. Objective: The aim of this study was to evaluate the performance of four supports enabling the transportand storage of samples to be used for molecular detection of drug resistance using the commercial GenoType MTBDRplus. Material and methods: We performed a multicenter retrospective study with the following participating sites: Institute Pasteur of Madagascar (IPM); All India Institute of Medical Sciences (AIIMS), Delhi, India; Hospital Dr. Cetrángolo, Buenos Aires, Argentinaand Instituto Adolfo Lutz, Sao Paulo, Brazil. Fifty Mycobacterium tuberculosis strains were selected at each site (25 MDR and 25 susceptible) to evaluatethe DNA extraction and detection of resistance to rifampicin (RIF) and isoniazid (INH) using the GenoType MTBDRplus from samples stored on slides, on fi lter cards, such as the FTA card (Whatman International Ltd) and the GenoCard (Hain Lifescience, Nehren, Germany), and on samples stored in ethanol. The performance of each system was assessed separately by calculating sensitivity and specifi city, compared to the results obtained by DST performed by the proportion method on Löwenstein-Jensen (LJ)medium or the MGIT960 system. Results: From all sites, the sensitivity and specifi city for detection of resistance to RIF was 95% and100%, respectively, for DNA extracted from slides and Genocard; 96% and 100% for DNA extracted from FTA card and 96% and 98% for samples stored in ethanol. For the detection of resistance to INH, the sensitivity and specifi city were 95% and 98% for slides and Genocard, 96% and 98% for FTA card and 95% and 93.46% for samples stored in ethanol. Conclusion: The four transport and storage supports showed a good sensitivity and specifi city for the detection of resistance to RIF and INH in M. tuberculosis strains. Evaluation of the potential use ofthese four systems to detect RIF and INH resistance from direct sputum samples is under evaluation.