scholarly journals Detection of drug-resistant mycobacterium tuberculosis strains isolated in Serbia by the GenoType MTBDRsl assay

2012 ◽  
Vol 64 (4) ◽  
pp. 1311-1318 ◽  
Author(s):  
Irena Zivanovic ◽  
Dragana Vukovic ◽  
Ivana Dakic ◽  
Gordana Stefanovic ◽  
Branislava Savic

The new GenoType MTBDRsl assay (Hain Lifescience) detects mutations most frequently associated with resistance to fluoroquinolones (FLQ), aminoglycosides/cyclic peptides (AG/CP), and ethambutol (EMB) and thus, enables rapid identification of extensively drug-resistant (XDR) Mycobacterium tuberculosis strains. A set of 19 multidrug-resistant (MDR) strains isolated in Serbia in 2011 was tested by the MTBDRsl assay and by conventional drug susceptibility testing (DST). The sensitivity and specificity of the MTBDRsl assay were as follows: 100% for both for FLQ; 100% for both for AG/ CP; and 58.3% and 85.7%, respectively, for EMB. The sensitivity for detection of XDR strains was 100%. Mutations in the gyrA, rrs, and embB genes established in local M. tuberculosis strains resistant to the respective drugs have been reported as the most prevalent in other studies as well. We recommend the MTBDRsl assay as a screening test for the preliminary detection of XDR-TB cases in Serbia, but not as a replacement of the conventional second-line DST.

2021 ◽  
Vol 49 (3) ◽  
pp. 030006052199759
Author(s):  
Mei-Chun Zeng ◽  
Qing-Jun Jia ◽  
Lei-Ming Tang

Objective The aim was to analyze genetic mutations in the rpoB gene of rifampin-resistant Mycobacterium tuberculosis isolates (RIFR-MTB) from Zhejiang, China. Methods We prospectively analyzed RIFR-associated mutations in 13 rural areas of Zhejiang. Isolates were subjected to species identification, phenotype drug susceptibility testing (DST), DNA extraction, and rpoB gene sequencing. Results A total of 103 RIFR isolates were identified by DST (22 RIFR only, 14 poly-drug resistant, 49 multidrug resistant, 13 pre-extensively drug resistant [pre-XDR], and 5 extensively drug resistant [XDR]) from 2152 culture-positive sputum specimens. Gene sequencing of rpoB showed that the most frequent mutation was S450L (37.86%, 39/103); mutations P280L, E521K, and D595Y were outside the rifampicin resistance-determining region (RRDR) but may be associated with RIFR. Mutations associated with poly-drug resistant, pre-XDR, and XDR TB were mainly located at codon 445 or 450 in the RRDR. Conclusions The frequency of rpoB RRDR mutation in Zhejiang is high. Further studies are needed to clarify the relationships between RIFR and the TTC insertion at codon 433 in the RRDR and the P280L and D595Y mutations outside the RRDR.


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.


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.


2020 ◽  
Vol 69 (2) ◽  
pp. 133-137 ◽  
Author(s):  
SAJID ALI ◽  
MUHAMMAD TAHIR KHAN ◽  
ANWAR SHEED KHAN ◽  
NOOR MOHAMMAD ◽  
MUHAMMAD MUMTAZ KHAN ◽  
...  

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.


2019 ◽  
Vol 4 (Suppl 3) ◽  
pp. A33.1-A33
Author(s):  
Tuelo Mogashoa ◽  
Lucy Mupfumi ◽  
Thato Iketleng ◽  
Pinkie Melamu ◽  
Nametso Kelentse ◽  
...  

BackgroundThe emergence and transmission of multidrug-resistant (MDR) and extensively drug-resistant (XDR) Mycobacterium tuberculosis (Mtb) strains is a serious threat to tuberculosis control in Botswana. Early detection of drug-resistant isolates is critical to ensure optimal treatment and thereby improve treatment outcomes. The objective of this study was to determine the extent of second-line drug resistance among drug-resistant Mtb-isolates from Botswana.MethodsA total of 60 drug-resistant Mtb isolates received at Botswana National Tuberculosis Reference Laboratory between 2012 and 2013 were analysed. DNA was extracted from BD Mycobacterial Growth Indicator Tubes (MGIT) using GenoLyse DNA isolation kit (Hain Lifescience). Spoligotyping was done using a commercially available spoligotyping kit (Isogen Life Science). The spoligotype patterns were compared with existing patterns in the SITVIT2 Web database. GenoType MTBDRs assay (Hain Lifescience) was used for second-line drug susceptibility testing. Fisher’s exact test was used to test for association between drug resistance patterns and HIV status, lineage and geographical location.ResultsSeventeen distinct spoligotype patterns were detected amongst the 60 drug-resistant isolates. The most predominant lineages were Euro-American (58.3%), East Asian (25%) and Indo-Oceanic (15%). Fifty (83.3%) were MDR, 7 (11.7%) were resistant to fluoroquinolones (Pre-XDR) whereas 3 (5%) were resistant to both fluoroquinolones and second-line injectable drugs (XDR). Drug resistance profiles were significantly associated with Mtb lineage (p<0.001). There was no association between drug resistance profile and HIV status (p=0.057) and geographical location (p=0.372).ConclusionThis study highlights the importance of including second-line drug susceptibility testing in a testing algorithm in Botswana. The detection of XDR isolates among MDR-TB isolates highlights the ongoing evolution of resistance and the need for strengthened treatment regimens to improve treatment outcomes and to prevent the spread of these highly resistant strains. Second-line testing will be essential if the 9 month MDR regimen is used in Botswana.


2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Daria N. Podlekareva ◽  
Dorte Bek Folkvardsen ◽  
Alena Skrahina ◽  
Anna Vassilenko ◽  
Aliaksandr Skrahin ◽  
...  

Background. To cure drug-resistant (DR) tuberculosis (TB), the antituberculous treatment should be guided by Mycobacterium tuberculosis drug-susceptibility testing (DST). In this study, we compared conventional DST performed in Minsk, Belarus, a TB DR high-burden country, with extensive geno- and phenotypic analyses performed at the WHO TB Supranational Reference Laboratory in Copenhagen, Denmark, for TB/HIV coinfected patients. Subsequently, DST results were related to treatment regimen and outcome. Methods. Thirty TB/HIV coinfected patients from Minsk were included and descriptive statistics applied. Results. Based on results from Minsk, 10 (33%) TB/HIV patients had drug-sensitive TB. Two (7%) had isoniazid monoresistant TB, 8 (27%) had multidrug-resistant (MDR) TB, 5 (17%) preextensive drug-resistant (preXDR) TB, and 5 (17%) had extensive drug-resistant (XDR) TB. For the first-line drugs rifampicin and isoniazid, there was DST agreement between Minsk and Copenhagen for 90% patients. For the second-line anti-TB drugs, discrepancies were more pronounced. For 14 (47%) patients, there were disagreements for at least one drug, and 4 (13%) patients were classified as having MDR-TB in Minsk but were classified as having preXDR-TB based on DST results in Copenhagen. Initially, all patients received standard anti-TB treatment with rifampicin, isoniazid, pyrazinamide, and ethambutol. However, this was only suitable for 40% of the patients based on DST. On average, DR-TB patients were changed to 4 (IQR 3-5) active drugs after 1.5 months (IQR 1-2). After treatment adjustment, the treatment duration was 8 months (IQR 2-11). Four (22%) patients with DR-TB received treatment for >18 months. In total, sixteen (53%) patients died during 24 months of follow-up. Conclusions. We found high concordance for rifampicin and isoniazid DST between the Minsk and Copenhagen laboratories, whereas discrepancies for second-line drugs were more pronounced. For patients with DR-TB, treatment was often insufficient and relevant adjustments delayed. This example from Minsk, Belarus, underlines two crucial points in the management of DR-TB: the urgent need for implementation of rapid molecular DSTs and availability of second-line drugs in all DR-TB high-burden settings. Carefully designed individualized treatment regimens in accordance with DST patterns will likely improve patients’ outcome and reduce transmission with drug-resistant Mycobacterium tuberculosis strains.


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