Ali Akbar Velayati1, Mohammad Reza Masjedi1, Parissa Farnia2, Payam Tabarsi1, Jalladein Ghanavi3, Abol Hassan ZiaZarifi1, Sven Eric Hoffner4. 1. Mycobacteriology Research Centre, the National Research Institute of Tuberculosis and Lung Disease (NRITLD), World Health Organization Collaborating Centre, Shahid Beheshti University (Medical Campus), Darabad, Tehran, Iran. 2. Mycobacteriology Research Centre, the National Research Institute of Tuberculosis and Lung Disease (NRITLD), World Health Organization Collaborating Centre, Shahid Beheshti University (Medical Campus), Darabad, Tehran, Iran. Electronic address: pfarnia@nritld.ac.ir. 3. Animal Research Laboratory, the National Research Institute of Tuberculosis and Lung Disease (NRITLD), World Health Organization Collaborating Centre, Shahid Beheshti University (Medical Campus), Darabad, Tehran, Iran. 4. Department of Bacteriology, Swedish Institute for Infectious Disease Control, Solna, Sweden.
Abstract
BACKGROUND: The study documented the emergence of new forms of resistant bacilli (totally drug-resistant [TDR] or super extensively drug-resistant [XDR] tuberculosis [TB] strains) among patients with multidrug-resistant TB (MDR-TB). METHODS: Susceptibility testing against first- and second-line drugs was performed on isolated Mycobacterium tuberculosis strains. Subsequently, the strains identified as XDR or TDR M tuberculosis were subjected to spoligotyping and variable numbers of tandem repeats (VNTR). RESULTS: Of 146 MDR-TB strains, 8 XDR isolates (5.4%) and 15 TDR isolates (10.3%) were identified. The remaining strains were either susceptible (67%) or had other resistant patterns (20%). Overall, the median of treatments and drugs previously received by MDR-TB patients was two courses of therapy of 15 months' duration with five drugs (isoniazid [INH], rifampicin [RF], streptomycin, ethambutol, and pyrazinamide). The median of in vitro drug resistance for all studied cases was INH and RF. The XDR or TDR strains were collected from both immigrants (Afghan, 30.4%; Azerbaijani, 8.6%; Iraqi, 4.3%) and Iranian (56.5%) MDR-TB cases. In such cases, the smear and cultures remained positive after 18 months of medium treatment with second-line drugs (ethionamide, para-aminosalicylic acid, cycloserine, ofloxacin, amikacin, and ciprofloxacin). Spoligotyping revealed Haarlem (39.1%), Beijing (21.7%), EAI (21.7%), and CAS (17.3%) superfamilies of M tuberculosis. These superfamilies had different VNTR profiles, which eliminated the recent transmission among MDR-TB cases. CONCLUSIONS: The isolation of TDR strains from MDR-TB patients from different regional countries is alarming and underlines the possible dissemination of such strains in Asian countries. Now the next question is how one should control and treat such cases.
BACKGROUND: The study documented the emergence of new forms of resistant bacilli (totally drug-resistant [TDR] or super extensively drug-resistant [XDR] tuberculosis [TB] strains) among patients with multidrug-resistant TB (MDR-TB). METHODS: Susceptibility testing against first- and second-line drugs was performed on isolated Mycobacterium tuberculosis strains. Subsequently, the strains identified as XDR or TDR M tuberculosis were subjected to spoligotyping and variable numbers of tandem repeats (VNTR). RESULTS: Of 146 MDR-TB strains, 8 XDR isolates (5.4%) and 15 TDR isolates (10.3%) were identified. The remaining strains were either susceptible (67%) or had other resistant patterns (20%). Overall, the median of treatments and drugs previously received by MDR-TB patients was two courses of therapy of 15 months' duration with five drugs (isoniazid [INH], rifampicin [RF], streptomycin, ethambutol, and pyrazinamide). The median of in vitro drug resistance for all studied cases was INH and RF. The XDR or TDR strains were collected from both immigrants (Afghan, 30.4%; Azerbaijani, 8.6%; Iraqi, 4.3%) and Iranian (56.5%) MDR-TB cases. In such cases, the smear and cultures remained positive after 18 months of medium treatment with second-line drugs (ethionamide, para-aminosalicylic acid, cycloserine, ofloxacin, amikacin, and ciprofloxacin). Spoligotyping revealed Haarlem (39.1%), Beijing (21.7%), EAI (21.7%), and CAS (17.3%) superfamilies of M tuberculosis. These superfamilies had different VNTR profiles, which eliminated the recent transmission among MDR-TB cases. CONCLUSIONS: The isolation of TDR strains from MDR-TB patients from different regional countries is alarming and underlines the possible dissemination of such strains in Asian countries. Now the next question is how one should control and treat such cases.
Authors: Parissa Farnia; Reza Masjedi Mohammad; Muayad Aghali Merza; Payam Tabarsi; Gennadii Konstantinovich Zhavnerko; Tengku Azmi Ibrahim; Ho Oi Kuan; Jalladein Ghanavei; Poopak Farnia; Reza Ranjbar; Nikolai Nikolaevich Poleschuyk; Leonid Petrovich Titov; Parviz Owlia; Mehadi Kazampour; Mohammad Setareh; Muaryam Sheikolslami; Giovanni Battista Migliori; Ali Akbar Velayati Journal: Int J Clin Exp Med Date: 2010-09-30
Authors: G B Migliori; G Sotgiu; N R Gandhi; D Falzon; K DeRiemer; R Centis; M G Hollm-Delgado; D Palmero; C Pérez-Guzmán; M H Vargas; L D'Ambrosio; A Spanevello; M Bauer; E D Chan; H S Schaaf; S Keshavjee; T H Holtz; D Menzies Journal: Eur Respir J Date: 2012-10-11 Impact factor: 16.671