Intralaboratory comparison of drug susceptibility testing of Mycobacterium tuberculosis by BACTEC and conventional methodology

1985 ◽  
Vol 31 (10) ◽  
pp. 957-960 ◽  
Author(s):  
A. Laszlo
Keyword(s):  
Drug Resistance ◽  
Mycobacterium Tuberculosis ◽  
Statistical Analysis ◽  
Large Scale ◽  
Susceptibility Testing ◽  
Drug Susceptibility ◽  
Drug Susceptibility Testing ◽  
Resistant Strains ◽  
Derived Data ◽  
Level Of Agreement

The BACTEC radiometric method of drug susceptibility testing of Mycobacterium tuberculosis is a reliable and rapid diagnostic tool in clinical mycobacteriology. However, large scale comparative studies have also shown that the level of agreement with standard methodology was less satisfactory with strains resistant to ethambutol and streptomycin than with strains resistant to rifampin and to isoniazid. Since disagreement with drug resistance strains is far more frequent than with drug susceptible strains, it was felt that only the comparison of a large number of resistant strains would be needed to further refine this new technique. The analysis of BACTEC-derived data for isoniazid and rifampin shows that the level of agreement with conventional methodology falls well within accepted limits. Statistical analysis of the radiometric versus conventional comparisons shows no significant differences between the two methods in the case of isoniazid, rifampin, and ethambutol (3 mg/L). Streptomycin and two other ethambutol concentrations tested showed lower levels of agreement and significant statistical differences with conventional methodology.

scholarly journals Comparison of the Performances of Two In-House Rapid Methods for Antitubercular Drug Susceptibility Testing

2008 ◽  
Vol 53 (2) ◽  
pp. 808-810 ◽  
Author(s):  
Agustina I. de la Iglesia ◽  
Emma J. Stella ◽  
Héctor R. Morbidoni
Keyword(s):  
Drug Resistance ◽  
Mycobacterium Tuberculosis ◽  
Sensitivity And Specificity ◽  
Susceptibility Testing ◽  
Drug Susceptibility ◽  
Drug Susceptibility Testing ◽  
Antitubercular Drug ◽  
Rapid Methods ◽  
Resistance Assessment

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.

scholarly journals Molecular Detection of Mutations Associated with First- and Second-Line Drug Resistance Compared with Conventional Drug Susceptibility Testing of Mycobacterium tuberculosis

2011 ◽  
Vol 55 (5) ◽  
pp. 2032-2041 ◽  
Author(s):  
Patricia J. Campbell ◽  
Glenn P. Morlock ◽  
R. David Sikes ◽  
Tracy L. Dalton ◽  
Beverly Metchock ◽  
...  
Keyword(s):  
Drug Resistance ◽  
Mycobacterium Tuberculosis ◽  
Dna Sequencing ◽  
Susceptibility Testing ◽  
Drug Susceptibility ◽  
Drug Susceptibility Testing ◽  
Second Line ◽  
First Line ◽  
Content Type ◽  
Line Drug

ABSTRACTThe emergence of multi- and extensively drug-resistant tuberculosis is a significant impediment to the control of this disease because treatment becomes more complex and costly. Reliable and timely drug susceptibility testing is critical to ensure that patients receive effective treatment and become noninfectious. Molecular methods can provide accurate and rapid drug susceptibility results. We used DNA sequencing to detect resistance to the first-line antituberculosis drugs isoniazid (INH), rifampin (RIF), pyrazinamide (PZA), and ethambutol (EMB) and the second-line drugs amikacin (AMK), capreomycin (CAP), kanamycin (KAN), ciprofloxacin (CIP), and ofloxacin (OFX). Nine loci were sequenced:rpoB(for resistance to RIF),katGandinhA(INH),pncA(PZA),embB(EMB),gyrA(CIP and OFX), andrrs,eis, andtlyA(KAN, AMK, and CAP). A total of 314 clinicalMycobacterium tuberculosiscomplex isolates representing a variety of antibiotic resistance patterns, genotypes, and geographical origins were analyzed. The molecular data were compared to the phenotypic data and the accuracy values were calculated. Sensitivity and specificity values for the first-line drug loci were 97.1% and 93.6% forrpoB, 85.4% and 100% forkatG, 16.5% and 100% forinhA, 90.6% and 100% forkatGandinhAtogether, 84.6% and 85.8% forpncA, and 78.6% and 93.1% forembB. The values for the second-line drugs were also calculated. The size and scope of this study, in numbers of loci and isolates examined, and the phenotypic diversity of those isolates support the use of DNA sequencing to detect drug resistance in theM. tuberculosiscomplex. Further, the results can be used to design diagnostic tests utilizing other mutation detection technologies.

scholarly journals Lack of Correlation between embB Mutation and Ethambutol MIC in Mycobacterium tuberculosis Clinical Isolates from China

2007 ◽  
Vol 51 (12) ◽  
pp. 4515-4517 ◽  
Author(s):  
Ruiru Shi ◽  
Jianyuan Zhang ◽  
Koji Otomo ◽  
Guolong Zhang ◽  
Isamu Sugawara
Keyword(s):  
Drug Resistance ◽  
Mycobacterium Tuberculosis ◽  
Susceptibility Testing ◽  
Multiple Drug Resistance ◽  
Drug Susceptibility ◽  
Drug Susceptibility Testing ◽  
Clinical Isolates ◽  
Multiple Drug

ABSTRACT Seventy-four Mycobacterium tuberculosis clinical isolates from China were subjected to drug susceptibility testing using ethambutol, isoniazid, rifampin, and ofloxacin. The results revealed that the presence of embB mutations did not correlate with ethambutol resistance but was associated with multiple-drug resistance, especially resistance to both ethambutol and rifampin.

scholarly journals Prevalence of Multi-Drug Resistant Mycobacterium Tuberculosis in Khyber Pakhtunkhwa – A High Tuberculosis Endemic Area of Pakistan

2020 ◽  
Vol 69 (2) ◽  
pp. 133-137 ◽  
Author(s):  
SAJID ALI ◽  
MUHAMMAD TAHIR KHAN ◽  
ANWAR SHEED KHAN ◽  
NOOR MOHAMMAD ◽  
MUHAMMAD MUMTAZ KHAN ◽  
...  
Keyword(s):  
Drug Resistance ◽  
Mycobacterium Tuberculosis ◽  
Large Scale ◽  
Simple Random Sampling ◽  
Drug Susceptibility ◽  
Multidrug Resistant ◽  
Drug Susceptibility Testing ◽  
Drug Resistant ◽  
Khyber Pakhtunkhwa ◽  
Mdr Tb

Anti-tuberculosis therapy involves the combination of drugs to hamper the growth of Mycobacterium tuberculosis (MTB). The emergence of multidrug-resistant tuberculosis (MDR-TB) is a global concern. Pakistan has been ranked 5th position in terms of a high burden of MDR-TB in the world. The aim of the current study was to investigate the prevalence of drug resistance in MTB in Khyber Pakhtunkhwa. Random samples were collected from 25 districts using the simple random sampling formula. All samples were processed in a biosafety level 3 laboratory for culture and drug susceptibility testing. Among 5759 presumptive tuberculosis (TB) cases, 1969 (34%) were positive. The proportion of TB was higher in females (39%) than males (29%), thus it represents a significant association between gender and tuberculosis (p < 0.05). People ages between 25 to 34 years were more likely to be infected with MTB (40%). Drug-resistant profile showed 97 (4.9%) patients were infected with MDR-TB. Streptomycin resistance was the highest and was observed in 173 (9%) isolates followed by isoniazid in 119 (6%) isolates. The lowest resistance was observed to pyrazinamide (3%). The prevalence of MDR-TB (10.4%) among patients that previously received anti-tuberculosis treatment is seemingly high. A large-scale drug resistance survey is required to evaluate the drug resistance for better management of tuberculosis.

scholarly journals Drug susceptibility testing and mortality in patients treated for tuberculosis in high-burden countries

2018 ◽  
Author(s):  
Kathrin Zürcher ◽  
Marie Ballif ◽  
Lukas Fenner ◽  
Sonia Borrell ◽  
Peter M. Keller ◽  
...  
Keyword(s):  
Drug Resistance ◽  
Susceptibility Testing ◽  
Drug Susceptibility ◽  
Drug Susceptibility Testing ◽  
Reference Laboratory ◽  
Drug Resistant ◽  
Hiv Status ◽  
Resistant Tuberculosis ◽  
Resistant Strains ◽  
Drug Resistant Strains

ABSTRACTBackgroundDrug resistance and HIV co-infection are challenges for the global control of tuberculosis.MethodsWe collected Mycobacterium tuberculosis isolates from adult patients in Côte d’Ivoire, Democratic Republic of the Congo, Kenya, Nigeria, South Africa, Peru, and Thailand, stratified by HIV status and tuberculosis drug resistance. Molecular or phenotypic drug susceptibility testing (DST) was done locally and at the Swiss tuberculosis reference laboratory. We examined mortality during treatment according to DST results and treatment adequacy in logistic regression models adjusting for sex, age, sputum microscopy and HIV status.Findings634 tuberculosis patients were included; median age was 33.2 years, 239 (37.7%) were female, 272 (42.9%) HIV-positive and 69 (10.9%) patients died. Based on the reference laboratory DST, 394 (62.2%) strains were pan-susceptible, 45 (7.1%) mono-resistant, 163 (25.7%) multidrug-resistant (MDR-TB), and 30 (4.7%) had pre-extensive or extensive drug resistance (pre-XDR/XDR-TB). Results of reference and local laboratories were discordant in 121 (19.1%) cases, corresponding to a sensitivity of 84.3% and a specificity of 90.8%. In patients with drug-resistant tuberculosis, discordant results were associated with increased mortality (risk ratio 1.81; 95% CI 1.07-3.07). In logistic regression, compared to adequately treated patients with pan-susceptible strains, the adjusted odds ratio for death was 4.23 (95% CI 2.16-8.29) for adequately treated patients with drug-resistant strains and 21.54 (95% CI 3.36-138.1) for inadequately treated patients with drug-resistant strains. HIV status was not associated with mortality.InterpretationUsing a reference laboratory standard, inaccurate DST leading to inappropriate treatment of drug-resistant tuberculosis, but not HIV infection, contributed to mortality.

scholarly journals Rapid Drug Susceptibility Testing of Drug-Resistant Mycobacterium tuberculosis Isolates Directly from Clinical Samples by Use of Amplicon Sequencing: a Proof-of-Concept Study

2016 ◽  
Vol 54 (8) ◽  
pp. 2058-2067 ◽  
Author(s):  
Rebecca E. Colman ◽  
Julia Anderson ◽  
Darrin Lemmer ◽  
Erik Lehmkuhl ◽  
Sophia B. Georghiou ◽  
...  
Keyword(s):  
Drug Resistance ◽  
Mycobacterium Tuberculosis ◽  
Susceptibility Testing ◽  
Amplicon Sequencing ◽  
Drug Susceptibility ◽  
Drug Susceptibility Testing ◽  
Health Concern ◽  
Clinical Samples ◽  
Drug Resistant ◽  
Content Type

Increasingly complex drug-resistant tuberculosis (DR-TB) is a major global health concern and one of the primary reasons why TB is now the leading infectious cause of death worldwide. Rapid characterization of a DR-TB patient's complete drug resistance profile would facilitate individualized treatment in place of empirical treatment, improve treatment outcomes, prevent amplification of resistance, and reduce the transmission of DR-TB. The use of targeted next-generation sequencing (NGS) to obtain drug resistance profiles directly from patient sputum samples has the potential to enable comprehensive evidence-based treatment plans to be implemented quickly, rather than in weeks to months, which is currently needed for phenotypic drug susceptibility testing (DST) results. In this pilot study, we evaluated the performance of amplicon sequencing ofMycobacterium tuberculosisDNA from patient sputum samples using a tabletop NGS technology and automated data analysis to provide a rapid DST solution (the Next Gen-RDST assay). One hundred sixty-six out of 176 (94.3%) sputum samples from the Republic of Moldova yielded complete Next Gen-RDST assay profiles for 7 drugs of interest. We found a high level of concordance of our Next Gen-RDST assay results with phenotypic DST (97.0%) and pyrosequencing (97.8%) results from the same clinical samples. Our Next Gen-RDST assay was also able to estimate the proportion of resistant-to-wild-type alleles down to mixtures of ≤1%, which demonstrates the ability to detect very low levels of resistant variants not detected by pyrosequencing and possibly below the threshold for phenotypic growth methods. The assay as described here could be used as a clinical or surveillance tool.

scholarly journals Molecular Investigation of Resistance to Second-Line Injectable Drugs in Multidrug-Resistant Clinical Isolates of Mycobacterium tuberculosis in France

2016 ◽  
Vol 61 (2) ◽  
Author(s):  
Florence Brossier ◽  
Anne Pham ◽  
Christine Bernard ◽  
Alexandra Aubry ◽  
Vincent Jarlier ◽  
...  
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Primary Culture ◽  
Susceptibility Testing ◽  
Drug Susceptibility ◽  
Multidrug Resistant ◽  
Drug Susceptibility Testing ◽  
Clinical Isolates ◽  
Second Line ◽  
Injectable Drugs ◽  
Resistant Strains

ABSTRACT The second-line injectable drugs (SLID, i.e., amikacin, kanamycin, capreomycin) are key drugs for the treatment of multidrug-resistant tuberculosis. Mutations in rrs region 1400, tlyA, and eis promoter are associated with resistance to SLID, to capreomycin, and to kanamycin, respectively. In this study, the sequencing data of SLID resistance-associated genes were compared to the results of phenotypic drug susceptibility testing by the proportion method for the SLID in 206 multidrug-resistant clinical isolates of Mycobacterium tuberculosis collected in France. Among the 153 isolates susceptible to the 3 SLID, 145 showed no mutation, 1 harbored T1404C and G1473A mutations in rrs, and 7 had an eis promoter mutation. Among the 53 strains resistant to at least 1 of the SLID, mutations in rrs accounted for resistance to amikacin, capreomycin, and kanamycin for 81%, 75%, and 44% of the isolates, respectively, while mutations in eis promoter were detected in 44% of the isolates resistant to kanamycin. In contrast, no mutations in tlyA were observed in the isolates resistant to capreomycin. The discrepancies observed between the genotypic (on the primary culture) and phenotypic drug susceptibility testing were explained by (i) resistance to SLID with MICs close to the critical concentration used for routine DST and not detected by phenotypic testing (n = 8, 15% of SLID-resistant strains), (ii) low-frequency heteroresistance not detected by sequencing of drug resistance-associated genes on the primary culture (n = 8, 15% of SLID-resistant strains), and (iii) other resistance mechanisms not yet characterized (n = 7, 13% of SLID-resistant strains).

scholarly journals Comparison of Proportion and Resistance Ratio Methods for Drug Susceptibility Testing of Mycobacterium tuberculosis Isolated from Patients Attending National Tuberculosis Centre, Nepal

2010 ◽  
Vol 5 (1) ◽  
pp. 13-20
Author(s):  
S Acharya ◽  
P Ghimire ◽  
DK Khadka ◽  
S Nepali
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Fluorescence Microscopy ◽  
Susceptibility Testing ◽  
Drug Susceptibility ◽  
Drug Susceptibility Testing ◽  
Resistance Ratio ◽  
National Tuberculosis ◽  
Smear Negative ◽  
Culture Positive ◽  
Good Agreement

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

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