scholarly journals Sensititre MycoTB Plate Compared to Bactec MGIT 960 for First- and Second-Line Antituberculosis Drug Susceptibility Testing in Tanzania: a Call To Operationalize MICs

2015 ◽  
Vol 59 (11) ◽  
pp. 7104-7108 ◽  
Author(s):  
Scott K. Heysell ◽  
Suporn Pholwat ◽  
Stellah G. Mpagama ◽  
Saumu J. Pazia ◽  
Happy Kumburu ◽  
...  

ABSTRACTMIC testing forMycobacterium tuberculosisis now commercially available. Drug susceptibility testing by the MycoTB MIC plate has not been directly compared to that by the Bactec MGIT 960. We describe a case of extensively drug-resistant tuberculosis (XDR-TB) in Tanzania where initial MIC testing may have prevented acquired resistance. From testing on archived isolates, the accuracy with the MycoTB plate was >90% for important first- and second-line drugs compared to that with the MGIT 960, and clinically useful quantitative interpretation was also provided.

2013 ◽  
Vol 57 (6) ◽  
pp. 2522-2525 ◽  
Author(s):  
Imran Ahmed ◽  
Kauser Jabeen ◽  
Raunaq Inayat ◽  
Rumina Hasan

ABSTRACTPakistan is a high-burden country for tuberculosis (TB). The emergence and increasing incidence of extensively drug-resistant (XDR) TB has been reported in Pakistan. Similarly, the prevalence of multidrug-resistant TB infections with fluoroquinolone resistance (pre-XDR) is also increasing. To treat these infections, local drug susceptibility patterns of alternate antituberculosis agents, including levofloxacin (LVX), linezolid (LZD), and amoxicillin-clavulanate (AMC), is urgently needed. The aim of this study was to determine the susceptibility frequencies of drug-resistant (DR)Mycobacterium tuberculosisagainst LVX, LZD, and AMC. All susceptibilities were determined on Middlebrook 7H10 agar. A critical concentration was used for LVX (1 μg/ml), whereas MICs were determined for LZD and AMC.M. tuberculosisH37Rv was used as a control strain. A total of 102M. tuberculosisisolates (XDR,n= 59; pre-XDR,n= 43) were tested. Resistance to LVX was observed in 91.2% (93/102). Using an MIC value of 0.5 μg/ml as a cutoff, resistance to LZD (MIC ≥ 1 μg/ml) was noted in 5.9% (6/102). Although the sensitivity breakpoints are not established for AMC, the MIC values were high (>16 μg/ml) in 97.1% (99/102). Our results demonstrate that LZD may be effective for the treatment of XDR and pre-XDR cases from Pakistan. High resistance rates against LVX in our study suggest the use of this drug with caution for DR-TB cases from this area. Drug susceptibility testing against LVX and AMC may be helpful in complicated and difficult-to-manage cases.


Author(s):  
Sarah Rahmayani Siregar

Tuberkulosis adalah penyakit infeksi kronis menular yang masih merupakan masalah kesehatan masyarakat di dunia termasuk Indonesia. Tuberkulosis (TB) sebagian besar akan mengalami penyembuhan dengan pengobatan. Namun tidak semua penyakit TB sembuh dengan pengobatan. Hal ini disebabkan pengobatan dari TB yang belum terlaksana dengan baik sehingga dapat pula menyebabkan terjadinya resistensi terhadap Obat Anti Tuberkulosis (OAT), berupa Multidrug Resistant Tuberkulosis (MDR TB) dan Extensively Drug Resistant Tuberculosis (XDR TB). XDR TB adalah TB yang disebabkan oleh strain yang resistensi terhadap isoniazid dan rifampisin, disertai resisten terhadap salah satu fluorokuinolon dan salah satu dari tiga obat injeksi lini kedua (amikasin, kapreomisin atau kanamisin). XDR TB diperkenalkan tahun 2006 ketika terjadi epidemi yang sangat fatal di Afrika Selatan. XDR-TB dapat ditularkan melalui bakteri yang disebarkan oleh orang yang sudah terkena resistensi obat. Diagnosis XDR-TB ditegakkan dengan uji sensitiviti obat atau Drug Susceptibility Testing (DST), bukan sekedar berdasarkan gambaran foto toraks dan adanya faktor resiko yang ada pada seseorang. WHO telah merancang strategi Directly Observed Treatment Short Course (DOTS-Plus) untuk mengelola TB M/XDR di negara-negara miskin sumber daya. Revisi National Tuberculosis Programme (RNTCP) di bawah DOTS-Plus akan menggunakan rejimen pengobatan standar (STR) kategori IV, yang terdiri dari 6 obat (kanamisin, levofloxacin, etionamid, sikloserin, pirazinamid, dan etambutol) selama 6-9 bulan fase intensif dan 4 obat (levofloxacin, ethionamide, cycloserine, dan ethambutol) selama 18 bulan dari fase lanjutan. Penyembuhan tergantung pada tingkat resistensi obat, tingkat keparahan penyakit dan apakah sistem kekebalan pasien terganggu.


2014 ◽  
Vol 20 (3) ◽  
pp. 408-416 ◽  
Author(s):  
Eugene Lam ◽  
Sriprapa Nateniyom ◽  
Sara Whitehead ◽  
Amornrat Anuwatnonthakate ◽  
Patama Monkongdee ◽  
...  

2017 ◽  
Vol 62 (2) ◽  
Author(s):  
Jan Heyckendorf ◽  
Sönke Andres ◽  
Claudio U. Köser ◽  
Ioana D. Olaru ◽  
Thomas Schön ◽  
...  

ABSTRACTRapid and accurate drug susceptibility testing (DST) is essential for the treatment of multi- and extensively drug-resistant tuberculosis (M/XDR-TB). We compared the utility of genotypic DST assays with phenotypic DST (pDST) using Bactec 960 MGIT or Löwenstein-Jensen to construct M/XDR-TB treatment regimens for a cohort of 25 consecutive M/XDR-TB patients and 15 possible anti-TB drugs. Genotypic DST results from Cepheid GeneXpert MTB/RIF (Xpert) and line probe assays (LPAs; Hain GenoType MTBDRplus2.0 and MTBDRsl2.0) and whole-genome sequencing (WGS) were translated into individual algorithm-derived treatment regimens for each patient. We further analyzed if discrepancies between the various methods were due to flaws in the genotypic or phenotypic test using MIC results. Compared with pDST, the average agreement in the number of drugs prescribed in genotypic regimens ranged from just 49% (95% confidence interval [CI], 39 to 59%) for Xpert and 63% (95% CI, 56 to 70%) for LPAs to 93% (95% CI, 88 to 98%) for WGS. Only the WGS regimens did not contain any drugs to which pDST showed resistance. Importantly, MIC testing revealed that pDST likely underestimated the true rate of resistance for key drugs (rifampin, levofloxacin, moxifloxacin, and kanamycin) because critical concentrations (CCs) were too high. WGS can be used to rule in resistance even in M/XDR strains with complex resistance patterns, but pDST for some drugs is still needed to confirm susceptibility and construct the final regimens. Some CCs for pDST need to be reexamined to avoid systematic false-susceptible results in low-level resistant isolates.


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