scholarly journals Resistance to Second-Line Antituberculosis Drugs and Delay in Drug Susceptibility Testing among Multidrug-Resistant Tuberculosis Patients in Shanghai

2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
Yong Chen ◽  
Zhengan Yuan ◽  
Xin Shen ◽  
Jie Wu ◽  
Zheyuan Wu ◽  
...  

Introduction. Second-line antituberculosis drugs (SLDs) are used for treating multidrug-resistant tuberculosis (MDR-TB). Prolonged delays before confirming MDR-TB with drug susceptibility testing (DST) could result in transmission of drug-resistant strains and inappropriate use of SLDs, thereby increasing the risk of resistance to SLDs. This study investigated the diagnostic delay in DST and prevalence of baseline SLD resistance in Shanghai and described the distribution of SLD resistance with varied delays to DST.Methods. All registered patients from 2011 to 2013 in Shanghai were enrolled. Susceptibility to ofloxacin, amikacin, kanamycin, and capreomycin was tested. Total delay in DST completion was measured from the onset of symptoms to reporting DST results.Results. Resistance to SLDs was tested in 217 of the 276 MDR-TB strains, with 118 (54.4%) being resistant to at least one of the four SLDs. The median total delay in DST was 136 days. Patients with delay longer than median days were roughly twice more likely to have resistance to at least one SLD (OR 2.22, 95% CI 1.19–4.11).Conclusions. During prolonged delay in DST, primary and acquired resistance to SLDs might occur more frequently. Rapid diagnosis of MDR-TB, improved nosocomial infection controls, and regulated treatment are imperative to prevent SLD resistance.

2017 ◽  
Vol 2017 ◽  
pp. 1-5 ◽  
Author(s):  
Elina Maharjan ◽  
Narayan Dutt Pant ◽  
Sanjeev Neupane ◽  
Jyoti Amatya ◽  
Bhawana Shrestha

The main aims of this study were to study the patterns of mutations in rpoB, katG, and inhA genes in Mycobacterium tuberculosis strains isolated from patients from Nepal and to evaluate the performance of genotype MTBDRplus assay, taking conventional drug susceptibility testing as gold standard for diagnosis of MDR-TB. A total of 69 Mycobacterium tuberculosis strains isolated from 73 smear positive sputum samples from patients suspected of suffering from multidrug-resistant tuberculosis were used in our study. The drug susceptibility pattern of Mycobacterium tuberculosis isolated from these sputum specimens was determined by using genotype MTBDRplus assay taking conventional drug susceptibility testing as reference. The sensitivity and specificity of the genotype MTBDRplus assay for the detection of MDR-TB were found to be 88.7% and 100%, respectively. 88.7% of the rifampicin resistant isolates had mutations in rpoB gene. Similarly, 79.7% and 9.4% of isoniazid resistant isolates had mutations in katG and inhA genes, respectively. Genotype MTBDRplus assay was found to be very rapid and highly sensitive and specific method for diagnosis of MDR-TB and will be very helpful for early diagnosis of MDR-TB in high tuberculosis burden countries.


2021 ◽  
Vol 30 (3) ◽  
pp. 143-151
Author(s):  
Noha S. Soliman ◽  
Sahar M. Khairat ◽  
Mohamed Abdullah ◽  
Yasmin Adel El-Mahdy

Background: Multidrug-resistant tuberculosis (MDR-TB) and infections by nontuberculous mycobacteria (NTM) are diseases of major public health concern. Objective: The aim of the present work is to study the prevalence and patterns of MDRTB as well as the characterization of isolated NTM species. Methodology: All samples (1069) were subjected to smear microscopy, culture on Lowenstein-Jensen (LJ) media, and phenotypic drug susceptibility testing (DST) of MTB to isoniazid (INH), rifampin (RF), streptomycin (S), and ethambutol (E). GeneXpert was used for direct detection of MTB and RF resistance. Matrix-assisted laser desorption ionization time of flight (MALDI-TOF) mass spectrometry (MS) was utilized for characterizing isolated NTM species. Results: M.tuberculosis (MTB) was isolated at a rate of 95.3% (1019/1069). MDR-TB was detected at rate of 7.16% with significant patterns for INH + RF + S + E (46.5%) and INR + RF (24.6%) (P-value <0.001). RF resistance was detected at a rate of 27.2% by GeneXpert. Seven NTM species (0.6%) were isolated in culture of which M.porcinum and M.fortuitum had confident identification by MALDI-TOF (score ≥1.8). Conclusion: MDR-TB rate was found to be 7.16% with significant dominance for INH + RF + S + E and INR + RF resistance patterns, while NTM rate was 0.6%.


2020 ◽  
Vol 51 (6) ◽  
pp. 606-613
Author(s):  
Ye-Cheng Zhou ◽  
Shu-Mei He ◽  
Zi-Lu Wen ◽  
Jun-Wei Zhao ◽  
Yan-Zheng Song ◽  
...  

Abstract Rapid and accurate diagnosis of multidrug-resistant tuberculosis (MDR-TB) is important for timely and appropriate therapy. In this study, a rapid and easy-to-perform molecular test that integrated polymerase chain reaction (PCR) amplification and a specific 96-well microplate hybridization assay, called PCR-ELISA (enzyme-linked immunosorbent assay), were developed for detection of mutations in rpoB, katG, and inhA genes responsible for rifampin (RIF) and isoniazid (INH) resistance and prediction of drug susceptibility in Mycobacterium tuberculosis clinical isolates. We evaluated the utility of this method by using 32 multidrug-resistent (MDR) isolates and 22 susceptible isolates; subsequently, we compared the results with data obtained by conventional drug susceptibility testing and DNA sequencing. The sensitivity and specificity of the PCR-ELISA test were 93.7% and 100% for detecting RIF resistance, and 87.5% and 100% for detecting INH resistance, respectively. These results were comparable to those yielded by commercially available molecular tests such as the GenoType MTBDRplus assay. Based on the aforementioned results, we conclude that the PCR-ELISA microplate hybridization assay is a rapid, inexpensive, convenient, and reliable test that will be useful for rapid diagnosis of MDR-TB, for improved clinical care.


2019 ◽  
Vol 45 (2) ◽  
Author(s):  
Angela Pires Brandao ◽  
Juliana Maira Watanabe Pinhata ◽  
Rosangela Siqueira Oliveira ◽  
Vera Maria Neder Galesi ◽  
Helio Hehl Caiaffa-Filho ◽  
...  

ABSTRACT Objective: To evaluate the rapid diagnosis of multidrug-resistant tuberculosis, by using a commercial line probe assay for rifampicin and isoniazid detection (LPA-plus), in the routine workflow of a tuberculosis reference laboratory. Methods: The LPA-plus was prospectively evaluated on 341 isolates concurrently submitted to the automated liquid drug susceptibility testing system. Results: Among 303 phenotypically valid results, none was genotypically rifampicin false-susceptible (13/13; 100% sensitivity). Two rifampicin-susceptible isolates harboured rpoB mutations (288/290; 99.3% specificity) which, however, were non-resistance-conferring mutations. LPA-plus missed three isoniazid-resistant isolates (23/26; 88.5% sensitivity) and detected all isoniazid-susceptible isolates (277/277; 100% specificity). Among the 38 (11%) invalid phenotypic results, LPA-plus identified 31 rifampicin- and isoniazid-susceptible isolates, one isoniazid-resistant and six as non-Mycobacterium tuberculosis complex. Conclusions: LPA-plus showed excellent agreement (≥91%) and accuracy (≥99%). Implementing LPA-plus in our setting can speed up the diagnosis of multidrug-resistant tuberculosis, yield a significantly higher number of valid results than phenotypic drug susceptibility testing and provide further information on the drug-resistance level.


2010 ◽  
Vol 139 (11) ◽  
pp. 1784-1793 ◽  
Author(s):  
H. LIN ◽  
S. SHIN ◽  
J. A. BLAYA ◽  
Z. ZHANG ◽  
P. CEGIELSKI ◽  
...  

SUMMARYWe examined the spatiotemporal distribution of laboratory-confirmed multidrug-resistant tuberculosis (MDR TB) cases and that of other TB cases in Lima, Peru with the aim of identifying mechanisms responsible for the rise of MDR TB in an urban setting. All incident cases of TB in two districts of Lima, Peru during 2005–2007 were included. The spatiotemporal distributions of MDR cases and other TB cases were compared with Ripley's K statistic. Of 11 711 notified cases, 1187 received drug susceptibility testing and 376 were found to be MDR. Spatial aggregation of patients with confirmed MDR disease appeared similar to that of other patients in 2005 and 2006; however, in 2007, cases with confirmed MDR disease were found to be more tightly grouped. Subgroup analysis suggests the appearance of resistance may be driven by increased transmission. Interventions should aim to reduce the infectious duration for those with drug-resistant disease and improve infection control.


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