https://imcjms.com Ibrahim Medical College Journal of Medical Science https://imcjms.com/registration/journal_full_text/58 Tue, 02 Aug 2016 11:32:04 +0000 This study was designed to determine the extent of drug resistance of M. tuberculosis (MTB) isolated from category II treatment failure pulmonary tuberculosis (PTB) patients. A total of 100 Ziehl-Neelsen (Z-N) smear positive category II failure PTB patients were included in this study. Sputum culture was done in Lowenstein-Jensen (L-J) media. Conventional proportion method on Lowenstein-Jensen (L-J) media was used to determine the drug susceptibility of M. tuberculosis to isoniazid (INH), rifampicin (RMP), ofloxacin (OFX) and kanamycin (KA). Out of 100 sputum samples, a total of 87 samples were positive by culture. Drug susceptibility test (DST) revealed that 82 (94.25%) isolates were resistant to one or more anti -TB drugs. Resistance to isoniazide (INH), rifampicin (RMP), ofloxacin (OFX) and kanamycin (KA) was 94.25%, 82.75%, 29.90% and 3.45% respectively. Among these isolates, 79.31% and 3.45% isolates were multi-drug resistant (MDR) and extended drug resistant (XDR) M. tuberculosis respectively.  High rate of anti-tubercular drug resistance was observed among the category II treatment failure TB patients. Introduction Both MDR-TB and XDR-TB are the emerging threats to the success of tuberculosis control programs. Although treatable, MDR-TB cases are difficult and costly. On the other hand, XDR-TB cases are virtually untreatable since none of the standard or reserve drugs is effective. To prevent the transmission of these strains, early identification of this type of resistant strain is important. Such early detection could optimize treatment, improve the outcome and prevent the transmission of MDR-TB.   A total of 100 Z-N smear positive category II treatment failure pulmonary tuberculosis patients of different age and sex were enrolled in this study. Sample collection and laboratory works were done in the National Tuberculosis Referral Laboratory (NTRL) and National Institute of Disease of Chest and Hospital (NIDCH), during the period of January to December 2010. Drug susceptibility was done only on culture positive isolates.   During the study period a total of 100 smear positive category II treatment failure pulmonary tuberculosis patients were enrolled. Out of the 100 patients, sputum samples from 87 (87%) were positive by culture. All were identified as M. tuberculosis complex. Out of 87 isolates, 82 (94.25%) were resistant to one or more drugs. Highest resistant was found against isoniazid (94.25%) followed by rifampicin (82.75%), ofloxacin (29.90%) and Kanamycin (3.45%) either alone or in combination with other drugs (Table-1). Sixty nine (79.31%) isolates were detected as MDR while three (3.45%) were XDR (Table-2). Ten (11.49%) isolates were detected as resistant to only INH while no RMP mono resistant isolate was detected in the present study. Out of 87 isolates, five were sensitive to all four drugs tested. Table 1: Resistance pattern of M. tuberculosis isolated from category II treatment failure cases     Discussion Among these culture positive isolates, 79.31% were diagnosed as MDR-TB. Previously in 2009, similar high rate of multi drug resistant M. tuberculosis (83% and 87%) was also reported in two different studies among category II failure Bangladeshi patients.9,10 No national study has been conducted in Bangladesh to evaluate the current status of MDR/XDR-TB among the category II treatment failure cases. Recent national Drug Resistance Surveillance (DRS) data recorded the rate of MDR-TB as 1.4% among new cases and 29% among previously treated TB cases.5 Therefore, routine bacteriological monitoring of category II failure cases is needed to detect and isolate MDR-TB cases to prevent transmission and mortality. Out of total 87 isolates, about 10% isolates showed resistance to ofloxacin. Fluroqunolone is frequently used in respiratory tract as well as other types of community acquired infections. So, irrational and frequent short course use of fluoroquinolones for various other type infections may be restricted to prevent the development of fluoroquinolones resistance among M. tuberculosis.  Three isolates (3.45%) were diagnosed as XDR-TB. This high rate of XDR M. tuberculosis could be due to the fact that our enrolled patients were category II treatment failure cases from a tertiary care centre where difficult cases were referred from all over the country. However, the overall prevalence of XDR-TB among all MDR-B isolates was 6.6% worldwide, 6.5% in industrialized countries, 13.6% in Russia, 1.5% in Asia and 0.6% in Africa.7   1.    Gursimrat KS. Tuberculosis current situation, challenges and overview of its control program in India. J Glob Infect Dis 2011; 3: 143-150. 3.    Global tuberculosis control: surveillance, planning, financing; WHO report, WHO/HTM/TB/2009.411 5.    World Health Organization. Tuberculosis profile 2011. Available at : http//: www.who.int/countries/bgd/en/ 7.    Amita J and Pratima D. Multidrug resistance to extensively drug resistance tuberculosis: What is next? J Biosci 2008; 33: 605-16. 9.    Kamal SM, Shamim MD, Van Deun et al. An Anti-Tuberculosis Drug resistance Patterns among Category 2 failure patients in Bangladesh. Chest & Heart Journal 2009; 33: 118-21. 11.  Vernon A, Burman W, Benator D, et al. Acquired rifamycin monoresistance in patients with HIV-related tuberculosis treated with once-weekly rifapentine and isoniazid. Tuberculosis Trials Consortium. Lancet; 353: 1843–47. 2026 Ibrahim Medical College. All rights reserved.