scholarly journals Performance of the Microscopic Observation Drug Susceptibility Assay in Drug Susceptibility Testing for Mycobacterium tuberculosis

2002 ◽  
Vol 40 (12) ◽  
pp. 4750-4752 ◽  
Author(s):  
W. G. Park ◽  
W. R. Bishai ◽  
R. E. Chaisson ◽  
S. E. Dorman
2012 ◽  
Vol 4 (02) ◽  
pp. 101-111 ◽  
Author(s):  
Sarman Singh ◽  
Parveen Kumar ◽  
Shreya Sharma ◽  
Francis Mumbowa ◽  
Anandi Martin ◽  
...  

ABSTRACTMultidrug-resistant tuberculosis is an increasing public health concern in many parts of the world, especially in low-income countries, where most cases occur. Traditional mycobacteria culture and drug susceptibility testing (DST) is either time-consuming or expensive and for that reason uptake of these technologies has remained limited in many resource-constrained settings. However, several non-commercial culture and DST methods that do not require sophisticated infrastructure and techniques have been developed. One such method is the microscopic observation drug susceptibility assay (MODS). In this method microcolonies that form in the liquid culture medium after specimen inoculation to drug-free and drug-containing micro-wells are detected by visual observation with a simple inverted microscope. The identification and drug susceptibility results can be obtained in 7-15 days. This standard operating procedure document has been developed through the culture and DST subgroup of the STOP TB Partnership, New Diagnostic Working Group. It is intended for laboratories that would want to use or already using this rapid non-commercial method for culture identification and DST of Mycobacterium tuberculosis, notably in resource-constraint settings in Asia and Africa.


2015 ◽  
Vol 54 (1) ◽  
pp. 185-189 ◽  
Author(s):  
Daniela E. Kirwan ◽  
Cesar Ugarte-Gil ◽  
Robert H. Gilman ◽  
Luz Caviedes ◽  
Hasan Rizvi ◽  
...  

In this study, 132 patients with lymphadenopathy were investigated. Fifty-two (39.4%) were diagnosed with tuberculosis (TB). The microscopic observation drug susceptibility (MODS) assay provided rapid (13 days), accurate diagnosis (sensitivity, 65.4%) and reliable drug susceptibility testing (DST). Despite its lower sensitivity than that of other methods, its faster results and simultaneous DST are advantageous in resource-poor settings, supporting the incorporation of MODS into diagnostic algorithms for extrapulmonary TB.


2000 ◽  
Vol 38 (3) ◽  
pp. 1203-1208 ◽  
Author(s):  
Luz Caviedes ◽  
Tien-Shun Lee ◽  
Robert H. Gilman ◽  
Patricia Sheen ◽  
Emily Spellman ◽  
...  

Inexpensive, rapid, and reliable methods of detecting infection by and drug susceptibility of Mycobacterium tuberculosis (MTB) are crucial to the control of tuberculosis. The novel microscopic observation broth-drug susceptibility assay (MODS) detects early growth of MTB in liquid medium, allowing more timely diagnosis and drug susceptibility testing. Sputum samples from hospitalized patients in Peru were analyzed by using stains, culture, and PCR. Sensitivity of MODS (92%) compared favorably with the most sensitive of the other culture methods (93%). Sputum samples positive for tuberculosis were tested for susceptibility to isoniazid and rifampin with the microwell alamar blue assay (MABA) and MODS. In 89% of cases, there was concordance between MODS and MABA. Of the diagnostic and susceptibility testing methods used, MODS yielded results most rapidly (median, 9.0 and 9.5 days, respectively). MODS is a rapid, inexpensive, sensitive, and specific method for MTB detection and susceptibility testing; it is particularly appropriate for use in developing countries burdened by significant infection rates and increasing numbers of multiple-drug-resistant cases.


2010 ◽  
Vol 5 (1) ◽  
pp. 13-20
Author(s):  
S Acharya ◽  
P Ghimire ◽  
DK Khadka ◽  
S Nepali

Background: Tuberculosis (TB) is among the most serious infectious cause of global morbidity and mortality. Emergence of Multi-drug resistant tuberculosis (MDR-TB) is posing an increased threat to TB control programs. Drug susceptibility testing (DST) of Mycobacterium tuberculosis (M. tuberculosis) isolates is important for tackling such problems. Setting: National Tuberculosis Centre (NTC), Thimi, Bhaktapur, Nepal. Objectives: Comparative evaluation of two in vitro DST methods in determining susceptibility of M. tuberculosis isolates from patients attending NTC, to front-line anti-TB drugs: (Isoniazid-INH, Rifampicin-RFP, Streptomycin-SM, and Ethambutol-EMB). Methodology: This study was conducted from Sep 2006-Jun 2007. A total of 862 sputum samples (diagnosis or follow up cases) collected from patients (type of patients or their categories was not differentiated in this study) attending NTC bacteriology lab for sputum direct smear microscopy were analyzed using fluorescence microscopy. All smear positive samples, smear negative samples requested for culture were cultured. All culture positive samples confirmed as M. tuberculosis by biochemical tests were processed for DST by both proportion (PR) and resistance ratio (RR) methods. Results: Out of 862 sputum samples analyzed, 226 (26.2%) samples were positive for Acid Fast Bacilli (AFB) by fluorescence microscopy. Among 323 samples 226 smear positive samples and 97 smear negative samples requested for culture), 221 (68.4%) were culture positive, 92 (28.5%) were culture negative and 10 (3.1%) were contaminated. Out of 221 isolates of M. tuberculosis, 57.5% were resistant to one or more drugs by the PR method and 56.6% by the RR method. Similarly, MDR isolates were 29.9% and 29% by PR and RR methods respectively. On correlation analysis using Mc Nemar Chi-square test, no significant difference between the two tests were observed (p>0.05). The results showed high agreement between both methods and agreement rates to INH, RFP, SM and EMB were 93.2%, 93.7%, 93.2% and 94.1% respectively. Similarly, the agreement rates between both methods using kappa analysis showed kappa (k) value of 0.86, 0.85, 0.86 and 0.84 for INH, RFP, SM and EMB respectively, which is believed to be good agreement between both methods (k=0.80 to 1.00: Very good agreement). Conclusion: In conclusion, this study showed that both the Proportion and Resistance ratio methods are equally good for determining drug susceptibility of M. tuberculosis. Keywords: Mycobacterium tuberculosis; Drug Susceptibility Testing; Proportion Method; Resistance Ratio Method. DOI: 10.3126/saarctb.v5i1.3078 SAARC J. Tuber. Lung Dis. HIV/AIDS 2008 Vol.5(1) 13-20


2008 ◽  
Vol 53 (2) ◽  
pp. 808-810 ◽  
Author(s):  
Agustina I. de la Iglesia ◽  
Emma J. Stella ◽  
Héctor R. Morbidoni

ABSTRACT Resistance to rifampin (rifampicin), isoniazid, and streptomycin of 69 Mycobacterium tuberculosis isolates was analyzed by an in-house method based on mycobacteriophage D29 and a colorimetric micromethod. Both methods showed sensitivity and specificity values ranging from 93% to 100%. These simple methods offer an option for drug resistance assessment of M. tuberculosis.


Elkawnie ◽  
2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Mashuri Masri ◽  
Cut Muthiadin ◽  
Masita Masita ◽  
Tri Cahyanto ◽  
Lianah Lianah ◽  
...  

Abstract: Tuberculosis (TB) is a contagious infectious disease caused by Mycobacterium tuberculosis. 10 million people suffer from TB Every year. Although TB is a preventable and treatable disease, 1.5 million people die every year due to TB. Alternative treatments continue to be pursued, and treatment with the latest TB drugs that are continuously being encouraged. Black cumin (Nigella sativa) seed contains essential oils with active compounds such as thymohydroquinone, Oleoresins, flavonoids, alkaloids, saponins, tannins, and terpenoids that act as antibacterial drugs. This study aims to determine the sensitivity of  N. sativa seed extract in inhibiting the growth of  M. tuberculosis strain H37RV and MDR-TB (Multidrug Resistance-TB). This research using Microscopic-Observation and Drug-Susceptibility Assay (MODS) method. Extraction of N. sativa was carried out by the maceration method using 70% methanol as a solvent. The results showed that the M. tuberculosis strain H37RV and MDR-TB were sensitive to N. sativa extract at concentrations of 5 and 10% but resistant to N. sativa extract at concentrations of 1 and 3%.Abstrak: Tuberkulosis (TB) adalah penyakit menular yang disebabkan oleh Bakteri Mycobacterium tuberculosis. Penyakit ini menimbulkan dampak kematian yang cukup mengkhawatirkan.  Penyakit tersebut dapat dicegah dan diobati. Salah satu sumber pengobatannya menggunakan biji jintan hitam (Nigella sativa) yang mengandung minyak atsiri dengan senyawa aktif seperti timohidrokuinon, oleoresin, flavonoid, alkaloid, saponin, tanin, dan terpenoid yang berfungsi sebagai obat antibakteri. Penelitian ini bertujuan untuk mengetahui sensitivitas ekstrak biji N. sativa dalam menghambat pertumbuhan M. tuberculosis strain H37RV and MDR-TB (Multidrug-Resistance-TB). Penelitian ini menggunakan metode Microscopic-Observation and Drug-Susceptibility Assay (MODS). Ekstraksi N. sativa dilakukan dengan metode maserasi menggunakan pelarut metanol 70%. Hasil yang diperoleh menunjukkan bahwa bakteri M. tuberculosis strain H37RV dan TB-MDR, kedua  strain tsb sensitif terhadap ekstrak N. sativa konsentrasi 5 dan 10%,  tetapi resisten terhadap  ekstrak N. sativa konsentrasi 1 dan 3%.


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