%0 Journal Article
%T Evaluation of MGIT 960 System for the Second-Line Drugs Susceptibility Testing of Mycobacterium tuberculosis
%A Hyejin Kim
%A Minji Seo
%A Young Kil Park
%A Jae-Il Yoo
%A Yeong Seon Lee
%A Gyung Tae Chung
%A Sungweon Ryoo
%J Tuberculosis Research and Treatment
%D 2013
%I Hindawi Publishing Corporation
%R 10.1155/2013/108401
%X Many laboratories validate DST of the second-line drugs by BACTEC MGIT 960 system. The objective of this study is to evaluate the critical concentration and perform DST for the 2nd line drugs. We evaluated 193 clinical strains of M. tuberculosis isolated from patients in South Korea. Testing the critical concentration of six second-line drugs was performed by MGIT 960 and compared with L-J proportion method. The critical concentration was determined to establish the most one that gave the difference between drug resistance and susceptibility in MGIT960 system. Good agreement of the following concentrations was found: Concordance was 95% for 0.5ˋ米g/mL of moxifloxacin; 93.6%, 1.0ˋ米g/mL of levofloxacin; 97.5%, 2.5ˋ米g/mL of kanamycin; 90.6%, 2.5ˋ米g/mL of capreomycin; 86.2%, 5.0ˋ米g/mL of ethionamide; and 90.8%, 2.0ˋ米g/mL of -aminosalicylic acid. The critical concentrations of the four drugs, moxifloxacin, levofloxacin, kanamycin, and capreomycin, were concordant and reliable for testing 2nd line drug resistance. Further study of ethionamide and 老-aminosalicylic acid is required. 1. Introduction Tuberculosis represents a major public health concern especially due to the increasing number of multidrug-resistant tuberculosis TB (MDR TB). Particularly in developing countries, extensively drug-resistant tuberculosis TB (XDR TB) continues to pose serious problem [1每5]. The increase in MDR/XDR TB rates prompts effective diagnostic methods so that appropriate treatments can be given to infected patients [6每8]. Many studies reported that MGIT 960 (Becton Dickinson Diagnostic System, Sparks, MD) provided reliable and rapid results in the detection and recovery of mycobacterium from clinical specimens and also the drug susceptibility testing (DST) of the TB isolates for the first line drugs isoniazid, rifampicin, ethambutol, streptomycin, and pyrazinamide [9, 10]. Recently, laboratories are facing great hindrances to provide DST for second-line drugs to ensure effective treatment of MDR/XDR TB by using MGIT 960 system [11每16]. However, in most of these studies, the tested numbers of second-line anti-TB drug were limited and the critical concentrations ranges of the second-line drugs were also discordant [11每13]. Despite the recommendation by WHO in 2008 for the use of liquid media for the second-line DST using MGIT 960, it is still unreliable due to the difficulty in determining the critical concentration [16]. It is not easy to calibrate newly developed DST methods using altered conditions. In vitro results of DST to second-line drugs were affected by criteria for
%U http://www.hindawi.com/journals/trt/2013/108401/