scholarly journals Genotyping of Mycobacterium tuberculosis Isolates from Hormozgan Province of Iran Based on 15-Locus MIRU-VNTR and Spoligotyping

2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
Samin Zamani ◽  
Mehri Haeili ◽  
Mohammad Javad Nasiri ◽  
Abbas Ali Imani Fooladi ◽  
Sedigheh Javadpour ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Latin American ◽  
A Priori ◽  
Drug Susceptibility ◽  
Geographic Region ◽  
Drug Susceptibility Testing ◽  
High Genetic Diversity ◽  
Recent Transmission ◽  
Proportion Method ◽  
The Persian Gulf

Background. Considering that Hormozgan province in Iran (southern part of Iran on the Persian Gulf) is among the areas with high prevalence of MDR-MTB and attracts so many sailors and tourists, genetic diversity of MTB isolates circulating in this part of Iran was evaluated. Pattern of TB transmission was also examined. Methods and Material. A total of 38 isolates of MTB were cultured from TB patients from Hormozgan province of Iran and standard MIRU-VNTR typing and spoligotyping were applied to genotype these isolates. Drug susceptibility testing was performed using proportion method. Results. There were 28 VNTR profiles comprising 5 clusters and 23 unique isolates compared to 21 spoligotyping profiles, which contained 9 clusters and 12 unique isolates. Latin American-Mediterranean (n=9, 23.6%) was found to be the most predominant lineage. MIRU-VNTR analysis, with an HGDI of 0.975, was more discriminating than spoligotyping, which had an HGDI of 0.955. The estimated proportion of TB cases due to recent transmission was 26.3% and 44.7% by MIRU-VNTR and spoligotyping, respectively. The rates of monodrug resistance and MDR were 15.8% and 7.9%, respectively. Two of 3 MDR strains were found to be related to MIRU-VNTR and belonged to the same spoligotyping cluster characterized with T1/SIT53 genotype. Conclusions. The high genetic diversity among MTB isolates suggests that transmission occurred from different sources to this area. Reactivation of a priori, latent MTB infection was found to contribute mainly to TB cases in this geographic region.

scholarly journals First Insight into a Nationwide Genotypic Diversity ofMycobacterium tuberculosisamong Previously Treated Pulmonary Tuberculosis Cases in Benin, West Africa

2017 ◽  
Vol 2017 ◽  
pp. 1-6 ◽  
Author(s):  
Dissou Affolabi ◽  
N’Dira Sanoussi ◽  
Sergio Codo ◽  
Fréderic Sogbo ◽  
Prudence Wachinou ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Genotypic Diversity ◽  
Molecular Study ◽  
Drug Susceptibility ◽  
Drug Susceptibility Testing ◽  
Resistance Rate ◽  
High Genetic Diversity ◽  
Pulmonary Tb ◽  
Previously Treated ◽  
Insight Into

Background. Molecular studies on tuberculosis (TB) are rare in low-resource countries like Benin, where data on molecular study on previously treated TB cases is unavailable.Materials and Methods. From January to December 2014, all smear- and culture-positive previously treated pulmonary TB patients from all TB clinics were systematically recruited. Drug susceptibility testing and spoligotyping were performed on all isolates.Results. Of the 100 patients recruited, 71 (71.0%) were relapse cases and 24 (24.0%) were failure cases, while 5 (5.0%) were default cases. Resistance rate to any first-line drug was 40.0%, while 12.0% of strains were multidrug-resistant (MDR) and no strain was extensively drug-resistant (XDR). A total of 40 distinct spoligotypes were found to be corresponding to a genotypic diversity of 40.0%. ST61 was the most predominant spoligotype with prevalence of 33.0%. In all, 31 single spoligotypes and nine clusters were observed with 2 to 33 strains per cluster giving a clustering rate of 69.0%. Euro-American (Lineage 4) was the most prevalent lineage (74.0%) and Lineage 2 was associated with resistance to streptomycin.Conclusion. This first insight into genetic diversity of previously treated pulmonary TB patients in Benin showed a relatively high genetic diversity ofMycobacterium tuberculosis.

scholarly journals Improving tuberculosis control through the partnership between university and the health system

2012 ◽  
Vol 45 (4) ◽  
pp. 491-495 ◽  
Author(s):  
Mariana Soares Valença ◽  
Jeane Zanini da Rocha ◽  
Ivy Bastos Ramis ◽  
Lillian Lucas Carrion ◽  
Catiúcia Madruga ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Acquired Resistance ◽  
Variable Number Tandem Repeat ◽  
Drug Susceptibility ◽  
Drug Susceptibility Testing ◽  
Resistance Rate ◽  
Case Detection ◽  
Tuberculosis Control ◽  
High Genetic Diversity ◽  
Tb Control

INTRODUCTION: Tuberculosis (TB) control is linked to the availability of qualified methods for microbiological diagnostics; however, microscopy with limited sensitivity is the only method available in many locations. The objective of this study was to evaluate the introduction of culture, drug susceptibility testing (DST), and genotyping in the routine of a Municipal Program of Tuberculosis Control. METHODS: Direct microscopy of sputum and culture in Ogawa-Kudoh were performed on 1,636 samples from 787 patients. DST of positive cultures was performed by resazurin microtiter assay and genotyping by mycobacterial interspersed repetitive units-variable number tandem repeat. RESULTS: A total 91 patients with TB were identified. The culture increased case detection by 32% compared with the microscopy; acquired resistance was 3.3% and the genotyping showed high genetic diversity. CONCLUSIONS: Ogawa-Kudoh contributed significantly to the increase in case detection and is suitable for implementation in poor-resource locations. The acquired resistance rate was lower than that reported in a recent Brazilian survey. The high genetic diversity is possibly related to the high TB prevalence in the population, as well as to early detection and suitable treatment of patients. The interaction between research and health care is important for reorienting the practice, transferring technology, and improving TB control.

scholarly journals Genetic diversity and drug susceptibility patterns of the Mycobacterium tuberculosis complex in Yunnan, China

2019 ◽  
Vol 39 (5) ◽  
Author(s):  
Ruolan Bai ◽  
Shuijing Chi ◽  
Xiaofei Li ◽  
Xiting Dai ◽  
Zhenhua Ji ◽  
...  
Keyword(s):  
Public Health ◽  
Genetic Diversity ◽  
Mycobacterium Tuberculosis ◽  
Public Health Problem ◽  
Drug Susceptibility ◽  
Drug Resistant ◽  
Global Public Health ◽  
High Genetic Diversity ◽  
Dominant Feature ◽  
Mdr Tb

AbstractTuberculosis (TB) is an infectious disease caused by Mycobacterium tuberculosis (Mtb) which has been threatening global public health for many years. High genetic diversity is dominant feature of Mtb. Increasing cases of multidrug-resistant (MDR) tuberculosis (MDR-TB) is a serious public health problem to TB control in China. Spontaneous mutations in the Mtb genome can alter proteins which are the target of drugs, making the bacteria drug resistant. The purpose of the present study was to analyze the genotype of Mtb isolates from some areas in Yunnan, China and explore the association between genotypes and MDR-TB. Using spoligotyping, we identified Beijing genotypes, six non-Beijing genotypes and a number of orphan genotypes from 270 Mtb isolates from patients in Yunnan Province during 2014–2016. Of 270 Mtb isolates, 102 clinical Mtb strains were identified as drug-resistant (DR) by drug susceptibility testing (DST), among them, 52 MDR strains. Beijing genotypes occupied the highest MDR proportion (78.85%) followed by the orphan genotypes (15.38%). The characteristics of MDR strains showed high genetic diversity. The results will help to efficiently improve diagnosis and treatment and provide valuable information for Mtb molecular epidemiology.

scholarly journals Low Occurrence of Tuberculosis Drug Resistance among Pulmonary Tuberculosis Patients from an Urban Setting, with a Long-Running DOTS Program in Zambia

2010 ◽  
Vol 2010 ◽  
pp. 1-6 ◽  
Author(s):  
Chanda Mulenga ◽  
Allan Chonde ◽  
Innocent C. Bwalya ◽  
Nathan Kapata ◽  
Mathilda Kakungu-Simpungwe ◽  
...  
Keyword(s):  
Drug Resistance ◽  
Drug Susceptibility ◽  
Drug Susceptibility Testing ◽  
Urban Setting ◽  
Second Line ◽  
Community Based ◽  
Proportion Method ◽  
Previously Treated Patients ◽  
Previously Treated ◽  
Low Levels

We set out to determine the levels ofMycobacterium tuberculosisresistance to first- and second-line TB drugs in an urban population in Zambia. Sputum samples were collected consecutively from all smear-positive, new and previously treated patients, from four diagnostic centres in Ndola between January and July 2006. Drug susceptibility testing was performed using the proportion method against four first- and two second-line TB drugs.Results. Among 156 new cases, any resistance was observed to be 7.7%, monoresistance to isoniazid and rifampicin was 4.5% and 1.3%, respectively. Of 31 retreatment cases, any resistance was observed to be 16.1%, monoresistance to isoniazid and rifampicin was 3.3% for each drug, and one case of resistance to both isoniazid and rifampicin (multidrug resistance) was detected. No resistance to kanamycin or ofloxacin was detected.Conclusion. Although not representative of the country, these results show low levels of drug resistance in a community with a long-standing DOTS experience. Resource constrained countries may reduce TB drug resistance by implementing community-based strategies that enhance treatment completion.

scholarly journals How Well Do Routine Molecular Diagnostics Detect Rifampin Heteroresistance in Mycobacterium tuberculosis?

2019 ◽  
Vol 57 (11) ◽  
Author(s):  
Kamela C. S. Ng ◽  
Philip Supply ◽  
Frank G. J. Cobelens ◽  
Cyril Gaudin ◽  
Julian Gonzalez-Martin ◽  
...  
Keyword(s):  
Limit Of Detection ◽  
Drug Susceptibility ◽  
Multidrug Resistant ◽  
Drug Susceptibility Testing ◽  
Tb Treatment ◽  
Proportion Method ◽  
Targeted Deep Sequencing ◽  
Resistant Strains ◽  
Rifampin Resistance ◽  
To Receive

ABSTRACT Rifampin heteroresistance—where rifampin-resistant and -susceptible tuberculosis (TB) bacilli coexist—may result in failed standard TB treatment and potential spread of rifampin-resistant strains. The detection of rifampin heteroresistance in routine rapid diagnostic tests (RDTs) allows for patients to receive prompt and effective multidrug-resistant-TB treatment and may improve rifampin-resistant TB control. The limit of detection (LOD) of rifampin heteroresistance for phenotypic drug susceptibility testing by the proportion method is 1% and, yet, is insufficiently documented for RDTs. We, therefore, aimed to determine, for the four RDTs (XpertMTB/RIF, XpertMTB/RIF Ultra, GenoTypeMTBDRplusv2.0, and GenoscholarNTM+MDRTBII), the LOD per probe and mutation, validated by CFU counting and targeted deep sequencing (Deeplex-MycTB). We selected one rifampin-susceptible and four rifampin-resistant strains, with mutations D435V, H445D, H445Y, and S450L, respectively, mixed them in various proportions in triplicate, tested them with each RDT, and determined the LODs per mutation type. Deeplex-MycTB revealed concordant proportions of the minority resistant variants in the mixtures. The Deeplex-MycTB-validated LODs ranged from 20% to 80% for XpertMTB/RIF, 20% to 70% for Xpert Ultra, 5% to 10% for GenoTypeMTBDRplusv2.0, and 1% to 10% for GenoscholarNTM+MDRTBII for the different mutations. Deeplex-MycTB, GenoTypeMTBDRplusv2.0, and GenoscholarNTM+MDRTBII provide explicit information on rifampin heteroresistance for the most frequently detected mutations. Classic Xpert and Ultra report rifampin heteroresistance as rifampin resistance, while Ultra may denote rifampin heteroresistance through “mixed patterns” of wild-type and mutant melt probe, melt peak temperatures. Overall, our findings inform end users that the threshold for reporting resistance in the case of rifampin heteroresistance is the highest for Classic Xpert and Ultra to resolve phenotypic and genotypic discordant rifampin-resistant TB results.

Comparison of MB/BacT system and agar proportion method in drug susceptibility testing of Mycobacterium tuberculosis

2001 ◽  
Vol 39 (4) ◽  
pp. 229-232 ◽  
Author(s):  
Wing Wai Yew ◽  
Steena Ching Wa Tong ◽  
Kin Sang Lui ◽  
Simon Kwok Fai Leung ◽  
Chi Hung Chau ◽  
...  
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Susceptibility Testing ◽  
Drug Susceptibility ◽  
Drug Susceptibility Testing ◽  
Proportion Method

scholarly journals Transmission patterns of rifampicin resistant Mycobacterium tuberculosis complex strains in Cameroon: a genomic epidemiological study

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Matthias Merker ◽  
Nkongho F. Egbe ◽  
Yannick R. Ngangue ◽  
Comfort Vuchas ◽  
Thomas A. Kohl ◽  
...  
Keyword(s):  
Drug Resistance ◽  
Mycobacterium Tuberculosis ◽  
Prolonged Exposure ◽  
Drug Susceptibility ◽  
Multidrug Resistant ◽  
Drug Susceptibility Testing ◽  
High Dose ◽  
Factors Affecting ◽  
Recent Transmission ◽  
Mdr Tb

Abstract Background Determining factors affecting the transmission of rifampicin (RR) and multidrug-resistant (MDR) Mycobacterium tuberculosis complex strains under standardized tuberculosis (TB) treatment is key to control TB and prevent the evolution of drug resistance. Methods We combined bacterial whole genome sequencing (WGS) and epidemiological investigations for 37% (n = 195) of all RR/MDR-TB patients in Cameroon (2012–2015) to identify factors associated with recent transmission. Results Patients infected with a strain resistant to high-dose isoniazid, and ethambutol had 7.4 (95% CI 2.6–21.4), and 2.4 (95% CI 1.2–4.8) times increased odds of being in a WGS-cluster, a surrogate for recent transmission. Furthermore, age between 30 and 50 was positively correlated with recent transmission (adjusted OR 3.8, 95% CI 1.3–11.4). We found high drug-resistance proportions against three drugs used in the short standardized MDR-TB regimen in Cameroon, i.e. high-dose isoniazid (77.4%), ethambutol (56.9%), and pyrazinamide (43.1%). Virtually all strains were susceptible to fluoroquinolones, kanamycin, and clofazimine, and treatment outcomes were mostly favourable (87.5%). Conclusion Pre-existing resistance to high-dose isoniazid, and ethambutol is associated with recent transmission of RR/MDR strains in our study. A possible contributing factor for this observation is the absence of universal drug susceptibility testing in Cameroon, likely resulting in prolonged exposure of new RR/MDR-TB patients to sub-optimal or failing first-line drug regimens.

scholarly journals Effect of Piper nigrum (Linn.) seeds extract and second line anti-tuberculosis drugs on a few Mycobacterium tuberculosis strains

2021 ◽  
Vol 13 (1) ◽  
pp. 402-406
Author(s):  
G. V. Zodape ◽  
S. N. Dharmashale ◽  
V. S. Gaikwad
Keyword(s):  
Mycobacterium Tuberculosis ◽  
In Vitro Study ◽  
Ethanolic Extract ◽  
Drug Susceptibility ◽  
Drug Susceptibility Testing ◽  
Piper Nigrum ◽  
Amino Salicylic Acid ◽  
Lowenstein Jensen ◽  
Proportion Method

Piper nigrum (Linn.) belonging to the family Piperaceae have been reported for its multitudinous medicinal values. The present study was undertaken to examine the direct effect of Ethionamide (ETH), Para amino salicylic acid (PAS), ethanolic extracts of P. nigrum on Mycobacterium tuberculosis (MTB) strain H37Rv and Multi drug-resistant (MDR)-strains-12, 19 and 21. The proportion method was used to detect the anti-mycobacterial drug susceptibility testing for mycobacteria using Lowenstein Jensen (LJ) medium. It was found that P. nigrum does not interfere with single or in the combination of both ETH and PAS showing the bioenhancer activity. In vitro study of ethanolic extract of P. nigrum observed that the extract inhibited the growth of H37Rv strains and MDR strains-12, MDR strains 19, and MDR strains 21. The present results will pave new avenues to find a new medicine that possesses P. nigrum alone or in combination with drugs to combat MDR-strains controlling tuberculosis.

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