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Sample records for drug resistant mycobacterium

  1. Drug Resistance of Mycobacterium tuberculosis Complex among ...

    African Journals Online (AJOL)

    BACKGROUND: In Burkina Faso, there is no recent data about the level of drug resistance in Mycobacterium tuberculosis strains among newly diagnosed tuberculosis cases. OBJECTIVE: To provide an update of the primary drug resistance of mycobacterium tuberculosis among patients in Burkina faso. METHODS: ...

  2. Adaptation and evolution of drug-resistant Mycobacterium tuberculosis

    NARCIS (Netherlands)

    Bergval, I.L.

    2013-01-01

    Many studies have been conducted on drug resistance and the evolution of Mycobacterium tuberculosis. Notwithstanding, many molecular mechanisms facilitating the emergence, adaptation and spread of drug-resistant tuberculosis have yet to be discovered. This thesis reports studies of the adaptive

  3. Diversity and evolution of drug resistance mechanisms in Mycobacterium tuberculosis

    Directory of Open Access Journals (Sweden)

    Al-Saeedi M

    2017-10-01

    Full Text Available Mashael Al-Saeedi, Sahal Al-Hajoj Department of Infection and Immunity, Mycobacteriology Research Section, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia Abstract: Despite the efficacy of antibiotics to protect humankind against many deadly pathogens, such as Mycobacterium tuberculosis, nothing can prevent the emergence of drug-resistant strains. Several mechanisms facilitate drug resistance in M. tuberculosis including compensatory evolution, epistasis, clonal interference, cell wall integrity, efflux pumps, and target mimicry. In this study, we present recent findings relevant to these mechanisms, which can enable the discovery of new drug targets and subsequent development of novel drugs for treatment of drug-resistant M. tuberculosis. Keywords: Mycobacterium tuberculosis, antibiotic resistance, compensatory evolution, epistasis, efflux pumps, fitness cost

  4. Beijing/W genotype Mycobacterium tuberculosis and drug resistance.

    NARCIS (Netherlands)

    Glynn, Judith R; Kremer, Kristin; Borgdorff, Martien W; Rodriguez, Mar Pujades; Soolingen, Dick van

    2006-01-01

    Beijing/W genotype Mycobacterium tuberculosis is widespread, may be increasing, and may have a predilection for drug resistance. Individual-level data on >29,000 patients from 49 studies in 35 countries were combined to assess the Beijing genotype's prevalence worldwide, trends over time and with

  5. Characterization of extensively drug-resistant Mycobacterium tuberculosis in Nepal.

    Science.gov (United States)

    Poudel, Ajay; Maharjan, Bhagwan; Nakajima, Chie; Fukushima, Yukari; Pandey, Basu D; Beneke, Antje; Suzuki, Yasuhiko

    2013-01-01

    The emergence of extensively drug-resistant tuberculosis (XDR-TB) has raised public health concern for global control of TB. Although molecular characterization of drug resistance-associated mutations in multidrug-resistant isolates in Nepal has been made, mutations in XDR isolates and their genotypes have not been reported previously. In this study, we identified and characterized 13 XDR Mycobacterium tuberculosis isolates from clinical isolates in Nepal. The most prevalent mutations involved in rifampicin, isoniazid, ofloxacin, and kanamycin/capreomycin resistance were Ser531Leu in rpoB gene (92.3%), Ser315Thr in katG gene (92.3%), Asp94Gly in gyrA gene (53.9%) and A1400G in rrs gene (61.5%), respectively. Spoligotyping and multilocus sequence typing revealed that 69% belonged to Beijing family, especially modern types. Further typing with 26-loci variable number of tandem repeats suggested the current spread of XDR M. tuberculosis. Our result highlights the need to reinforce the TB policy in Nepal with regard to control and detection strategies. Copyright © 2012 Elsevier Ltd. All rights reserved.

  6. Study on drug resistance of mycobacterium tuberculosis in patients with pulmonary tuberculosis by drug resistance gene detecting

    International Nuclear Information System (INIS)

    Wang Wei; Li Hongmin; Wu Xueqiong; Wang Ansheng; Ye Yixiu; Wang Zhongyuan; Liu Jinwei; Chen Hongbing; Lin Minggui; Wang Jinhe; Li Sumei; Jiang Ping; Feng Bai; Chen Dongjing

    2004-01-01

    To investigate drug resistance of mycobacterium tuberculosis in different age group, compare detecting effect of two methods and evaluate their the clinical application value, all of the strains of mycobacterium tuberculosis were tested for resistance to RFP, INH SM PZA and EMB by the absolute concentration method on Lowenstein-Jensen medium and the mutation of the rpoB, katG, rpsL, pncA and embB resistance genes in M. tuberculosis was tested by PCR-SSCP. In youth, middle and old age group, the rate of acquired drug resistance was 89.2%, 85.3% and 67.6% respectively, the gene mutation rate was 76.2%, 81.3% and 63.2% respectively. The rate of acquired drug resistance and multiple drug resistance in youth group was much higher than those in other groups. The gene mutation was correlated with drug resistance level of mycobacterium tuberculosis. The gene mutation rate was higher in strains isolated from high concentration resistance than those in strains isolated from low concentration resistance. The more irregular treatment was longer, the rate of drug resistance was higher. Acquired drug resistance varies in different age group. It suggested that surveillance of drug resistence in different age group should be taken seriously, especially in youth group. PCR - SSCP is a sensitive and specific method for rapid detecting rpoB, katG, rpsL, pncA and embB genes mutations of MTB. (authors)

  7. Genetic Determinants of Drug Resistance in Mycobacterium tuberculosis and Their Diagnostic Value

    NARCIS (Netherlands)

    Farhat, M.R.; Sultana, R.; Iartchouk, O.; Bozeman, S.; Galagan, J.; Sisk, P.; Stolte, C.; Nebenzahl-Guimaraes, H.; Jacobson, K.; Sloutsky, A.; Kaur, D.; Posey, J.; Kreiswirth, B.N.; Kurepina, N.; Rigouts, L.; Streicher, E.M.; Victor, T.C.; Warren, R.M.; Soolingen, D. van; Murray, M.

    2016-01-01

    RATIONALE: The development of molecular diagnostics that detect both the presence of Mycobacterium tuberculosis in clinical samples and drug resistance-conferring mutations promises to revolutionize patient care and interrupt transmission by ensuring early diagnosis. However, these tools require the

  8. Genome-wide analysis of multi- and extensively drug-resistant Mycobacterium tuberculosis

    KAUST Repository

    Coll, Francesc; Phelan, Jody; Hill-Cawthorne, Grant A.; Nair, Mridul; Mallard, Kim; Ali, Shahjahan; Abdallah, Abdallah; Alghamdi, Saad; Alsomali, Mona; Ahmed, Abdallah O.; Portelli, Stephanie; Oppong, Yaa; Alves, Adriana; Bessa, Theolis Barbosa; Campino, Susana; Caws, Maxine; Chatterjee, Anirvan; Crampin, Amelia C.; Dheda, Keertan; Furnham, Nicholas; Glynn, Judith R.; Grandjean, Louis; Minh Ha, Dang; Hasan, Rumina; Hasan, Zahra; Hibberd, Martin L.; Joloba, Moses; Jones-Ló pez, Edward C.; Matsumoto, Tomoshige; Miranda, Anabela; Moore, David J.; Mocillo, Nora; Panaiotov, Stefan; Parkhill, Julian; Penha, Carlos; Perdigã o, Joã o; Portugal, Isabel; Rchiad, ‍ Zineb; Robledo, Jaime; Sheen, Patricia; Shesha, Nashwa Talaat; Sirgel, Frik A.; Sola, Christophe; Oliveira Sousa, Erivelton; Streicher, Elizabeth M.; Helden, Paul Van; Viveiros, Miguel; Warren, Robert M.; McNerney, Ruth; Pain, Arnab; Clark, Taane G.

    2018-01-01

    To characterize the genetic determinants of resistance to antituberculosis drugs, we performed a genome-wide association study (GWAS) of 6,465 Mycobacterium tuberculosis clinical isolates from more than 30 countries. A GWAS approach within a mixed

  9. Ribonucleotide reductase as a drug target against drug resistance Mycobacterium leprae: A molecular docking study.

    Science.gov (United States)

    Mohanty, Partha Sarathi; Bansal, Avi Kumar; Naaz, Farah; Gupta, Umesh Datta; Dwivedi, Vivek Dhar; Yadava, Umesh

    2018-06-01

    Leprosy is a chronic infection of skin and nerve caused by Mycobacterium leprae. The treatment is based on standard multi drug therapy consisting of dapsone, rifampicin and clofazamine. The use of rifampicin alone or with dapsone led to the emergence of rifampicin-resistant Mycobacterium leprae strains. The emergence of drug-resistant leprosy put a hurdle in the leprosy eradication programme. The present study aimed to predict the molecular model of ribonucleotide reductase (RNR), the enzyme responsible for biosynthesis of nucleotides, to screen new drugs for treatment of drug-resistant leprosy. The study was conducted by retrieving RNR of M. leprae from GenBank. A molecular 3D model of M. leprae was predicted using homology modelling and validated. A total of 325 characters were included in the analysis. The predicted 3D model of RNR showed that the ϕ and φ angles of 251 (96.9%) residues were positioned in the most favoured regions. It was also conferred that 18 α-helices, 6 β turns, 2 γ turns and 48 helix-helix interactions contributed to the predicted 3D structure. Virtual screening of Food and Drug Administration approved drug molecules recovered 1829 drugs of which three molecules, viz., lincomycin, novobiocin and telithromycin, were taken for the docking study. It was observed that the selected drug molecules had a strong affinity towards the modelled protein RNR. This was evident from the binding energy of the drug molecules towards the modelled protein RNR (-6.10, -6.25 and -7.10). Three FDA-approved drugs, viz., lincomycin, novobiocin and telithromycin, could be taken for further clinical studies to find their efficacy against drug resistant leprosy. Copyright © 2018 Elsevier B.V. All rights reserved.

  10. Drug Resistance and Population Structure of Mycobacterium tuberculosis Beijing Strains Isolated in Poland.

    Science.gov (United States)

    Kozińska, Monika; Augustynowicz-Kopeć, Ewa

    2015-01-01

    In total, 1095 Mycobacterium tuberculosis clinical isolates from 282 patients with drug-resistant and 813 with drug-sensitive tuberculosis (TB) in Poland during 2007-2011 were analysed. Seventy-one (6.5%) patients were found to have strains of Beijing genotype as defined by spoligotyping. The majority of patients were Polish-born; among foreign-born a large proportion came from Chechnya and Vietnam. Analysis showed strong associations between Beijing genotype infection and MDR, pre-XDR and XDR resistance, with a considerable relative risk among new patients, suggesting that this is due to increased spread of drug-resistant strains rather than acquisition of resistance during treatment.

  11. Decreasing prevalence of multi-drugs resistant Mycobacterium tuberculosis in Nashik City, India

    OpenAIRE

    More, Arun Punaji; Nagdawane, Ramkrishna Panchamrao; Gangurde, Aniket K

    2013-01-01

    Objective: In India, increasing prevalence of multi-drug resistant tuberculosis (MDR) has aggravated the control oftuberculosis problem. In many urban and semi-urban regions of India, no surveillance data of multidrug resistance inMycobacterium tuberculosisis available.Methods: A surveillance study on multidrug resistance was carried out in semi-urban and rural regions in and aroundNashik City of Maharashtra, India. The surveillance study was conducted in this region found that the prevalence...

  12. The Association between Mycobacterium Tuberculosis Genotype and Drug Resistance in Peru.

    Directory of Open Access Journals (Sweden)

    Louis Grandjean

    Full Text Available The comparison of Mycobacterium tuberculosis bacterial genotypes with phenotypic, demographic, geospatial and clinical data improves our understanding of how strain lineage influences the development of drug-resistance and the spread of tuberculosis.To investigate the association of Mycobacterium tuberculosis bacterial genotype with drug-resistance. Drug susceptibility testing together with genotyping using both 15-loci MIRU-typing and spoligotyping, was performed on 2,139 culture positive isolates, each from a different patient in Lima, Peru. Demographic, geospatial and socio-economic data were collected using questionnaires, global positioning equipment and the latest national census.The Latin American Mediterranean (LAM clade (OR 2.4, p<0.001 was significantly associated with drug-resistance and alone accounted for more than half of all drug resistance in the region. Previously treated patients, prisoners and genetically clustered cases were also significantly associated with drug-resistance (OR's 2.5, 2.4 and 1.8, p<0.001, p<0.05, p<0.001 respectively.Tuberculosis disease caused by the LAM clade was more likely to be drug resistant independent of important clinical, genetic and socio-economic confounding factors. Explanations for this include; the preferential co-evolution of LAM strains in a Latin American population, a LAM strain bacterial genetic background that favors drug-resistance or the "founder effect" from pre-existing LAM strains disproportionately exposed to drugs.

  13. Clinical implications of molecular drug resistance testing for Mycobacterium tuberculosis: a TBNET/RESIST-TB consensus statement

    NARCIS (Netherlands)

    Domínguez, J.; Boettger, E. C.; Cirillo, D.; Cobelens, F.; Eisenach, K. D.; Gagneux, S.; Hillemann, D.; Horsburgh, R.; Molina-Moya, B.; Niemann, S.; Tortoli, E.; Whitelaw, A.; Lange, C.

    2016-01-01

    The emergence of drug-resistant strains of Mycobacterium tuberculosis is a challenge to global tuberculosis (TB) control. Although culture-based methods have been regarded as the gold standard for drug susceptibility testing (DST), molecular methods provide rapid information on mutations in the M.

  14. Mycobacterium tuberculosis drug-resistance in previously treated ...

    African Journals Online (AJOL)

    Corresponding to: Professor Lassana Sangaré, Department of Bacteriology and Virology, University Hospital Centre. Yalgado Ouedraogo, 03 BP 7022 Ouagadougou 03, Burkina Faso. E-mail: sangarel@hotmail.com. Abstract. Background: Tuberculosis drug-resistance becomes common in sub-Saharan Africa; however, ...

  15. Disinfectant-susceptibility of multi-drug-resistant Mycobacterium tuberculosis isolated in Japan

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    Noriko Shinoda

    2016-02-01

    Full Text Available Abstract Background Multi-drug-resistant Mycobacterium tuberculosis has been an important problem in public health around the world. However, limited information about disinfectant-susceptibility of multi-drug-resistant strain of M. tuberculosis was available. Findings We studied susceptibility of several Japanese isolates of multi-drug-resistant M. tuberculosis against disinfectants, which are commonly used in clinical and research laboratories. We selected a laboratory reference strain (H37Rv and eight Japanese isolates, containing five drug-susceptible strains and three multi-drug-resistant strains, and determined profiles of susceptibility against eight disinfectants. The M. tuberculosis strains were distinguished into two groups by the susceptibility profile. There was no relationship between multi-drug-resistance and disinfectant-susceptibility in the M. tuberculosis strains. Cresol soap and oxydol were effective against all strains we tested, regardless of drug resistance. Conclusions Disinfectant-resistance is independent from multi-drug-resistance in M. tuberculosis. Cresol soap and oxydol were effective against all strains we tested, regardless of drug resistance.

  16. Molecular detection methods of resistance to antituberculosis drugs in Mycobacterium tuberculosis.

    Science.gov (United States)

    Brossier, F; Sougakoff, W

    2017-09-01

    Molecular methods predict drug resistance several weeks before phenotypic methods and enable rapid implementation of appropriate therapeutic treatment. We aimed to detail the most representative molecular tools used in routine practice for the rapid detection of resistance to antituberculosis drugs among Mycobacterium tuberculosis strains. The molecular diagnosis of resistance to antituberculosis drugs in clinical samples or from in vitro cultures is based on the detection of the most common mutations in the genes involved in the development of resistance in M. tuberculosis strains (encoding either protein targets of antibiotics, or antibiotic activating enzymes) by commercial molecular kits or by sequencing. Three hypotheses could explain the discrepancies between the genotypic results and the phenotypic drug susceptibility testing results: a low percentage of resistant mutants precluding the detection by genotypic methods on the primary culture; a low level of resistance not detected by phenotypic testing; and other resistance mechanisms not yet characterized. Molecular methods have varying sensitivity with regards to detecting antituberculosis drug resistance; that is why phenotypic susceptibility testing methods are mandatory for detecting antituberculosis drug-resistant isolates that have not been detected by molecular methods. The questionable ability of existing phenotypic and genotypic drug susceptibility testing to properly classify strains as susceptible or resistant, and at what level of resistance, was raised for several antituberculosis agents. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  17. Molecular Characterization of the Resistance of Mycobacterium ...

    African Journals Online (AJOL)

    Purpose: To characterize the resistance of Mycobacterium tuberculosis to second line drugs using a line probe assay. Methods: Multi-drug resistant strains of Mycobacterium tuberculosis isolated between December 2008 and December 2009 were tested for resistance to fluoroquinolones and second-line injectable drugs ...

  18. Association between Mycobacterium tuberculosis complex phylogenetic lineage and acquired drug resistance.

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    Courtney M Yuen

    Full Text Available BACKGROUND: Development of resistance to antituberculosis drugs during treatment (i.e., acquired resistance can lead to emergence of resistant strains and consequent poor clinical outcomes. However, it is unknown whether Mycobacterium tuberculosis complex species and lineage affects the likelihood of acquired resistance. METHODS: We analyzed data from the U.S. National Tuberculosis Surveillance System and National Tuberculosis Genotyping Service for tuberculosis cases during 2004-2011 with assigned species and lineage and both initial and final drug susceptibility test results. We determined univariate associations between species and lineage of Mycobacterium tuberculosis complex bacteria and acquired resistance to isoniazid, rifamycins, fluoroquinolones, and second-line injectables. We used Poisson regression with backward elimination to generate multivariable models for acquired resistance to isoniazid and rifamycins. RESULTS: M. bovis was independently associated with acquired resistance to isoniazid (adjusted prevalence ratio = 8.46, 95% CI 2.96-24.14 adjusting for HIV status, and with acquired resistance to rifamycins (adjusted prevalence ratio = 4.53, 95% CI 1.29-15.90 adjusting for homelessness, HIV status, initial resistance to isoniazid, site of disease, and administration of therapy. East Asian lineage was associated with acquired resistance to fluoroquinolones (prevalence ratio = 6.10, 95% CI 1.56-23.83. CONCLUSIONS: We found an association between mycobacterial species and lineage and acquired drug resistance using U.S. surveillance data. Prospective clinical studies are needed to determine the clinical significance of these findings, including whether rapid genotyping of isolates at the outset of treatment may benefit patient management.

  19. Drug resistance in Mycobacterium leprae from patients with leprosy in China.

    Science.gov (United States)

    Liu, D; Zhang, Q; Sun, Y; Wang, C; Zhang, Y; Fu, X; Chen, M; Zhou, G; Yu, X; Wang, J; Liu, H; Zhang, F

    2015-12-01

    Previous studies of drug resistance have shown that mutations in the drug resistance-determining region (DRDR) in the Folp1, RpoB and GyrA genes of Mycobacterium leprae are responsible for resistance to dapsone, rifampin and ofloxacin, respectively. To investigate the prevalence of mutations in genes associated with drug resistance in M. leprae isolates from patients with leprosy in Shandong Province. The DRDR in the FolP1, RpoB and GyrA genes was analysed by direct sequencing of the PCR product from 85 isolates of M. leprae sampled from patients with leprosy in Shandong, China. Sequencing results were obtained for FolP1, RpoB and GyrA in 67, 57 and 81 of the 85 samples, with mutation rates of 1.5% (1/67), 8.8% 5/57 and 25.9% (21/81). Three multidrug-resistant samples were found among the new cases: one had a mutation in both Folp1 and RpoB, while the other two had a mutation in both RpoB and GyrA. Primary resistance appears to be to either single drugs or combinations of two drugs. The resistance rate to dapsone seems to be low. To our knowledge, this is the first case of multidrug-resistant M. leprae from China. © 2015 British Association of Dermatologists.

  20. Interplay between Mutations and Efflux in Drug Resistant Clinical Isolates of Mycobacterium tuberculosis

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    Miguel Viveiros

    2017-04-01

    Full Text Available Numerous studies show efflux as a universal bacterial mechanism contributing to antibiotic resistance and also that the activity of the antibiotics subject to efflux can be enhanced by the combined use of efflux inhibitors. Nevertheless, the contribution of efflux to the overall drug resistance levels of clinical isolates of Mycobacterium tuberculosis is poorly understood and still is ignored by many. Here, we evaluated the contribution of drug efflux plus target-gene mutations to the drug resistance levels in clinical isolates of M. tuberculosis. A panel of 17 M. tuberculosis clinical strains were characterized for drug resistance associated mutations and antibiotic profiles in the presence and absence of efflux inhibitors. The correlation between the effect of the efflux inhibitors and the resistance levels was assessed by quantitative drug susceptibility testing. The bacterial growth/survival vs. growth inhibition was analyzed through the comparison between the time of growth in the presence and absence of an inhibitor. For the same mutation conferring antibiotic resistance, different MICs were observed and the different resistance levels found could be reduced by efflux inhibitors. Although susceptibility was not restored, the results demonstrate the existence of a broad-spectrum synergistic interaction between antibiotics and efflux inhibitors. The existence of efflux activity was confirmed by real-time fluorometry. Moreover, the efflux pump genes mmr, mmpL7, Rv1258c, p55, and efpA were shown to be overexpressed in the presence of antibiotics, demonstrating the contribution of these efflux pumps to the overall resistance phenotype of the M. tuberculosis clinical isolates studied, independently of the genotype of the strains. These results showed that the drug resistance levels of multi- and extensively-drug resistant M. tuberculosis clinical strains are a combination between drug efflux and the presence of target-gene mutations, a reality

  1. Decreasing prevalence of multi-drugs resistant Mycobacterium tuberculosis in Nashik City, India

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    Arun P. More

    2013-03-01

    Full Text Available Objective: In India, increasing prevalence of multi-drug resistant tuberculosis (MDR has aggravated the control oftuberculosis problem. In many urban and semi-urban regions of India, no surveillance data of multidrug resistance inMycobacterium tuberculosisis available.Methods: A surveillance study on multidrug resistance was carried out in semi-urban and rural regions in and aroundNashik City of Maharashtra, India. The surveillance study was conducted in this region found that the prevalence ofcombined resistance to first and second-line anti-tuberculosis drugs is remarkably high. The isolates of M. tuberculosiswas identified and subjected to drug susceptibility testing. The patterns of drug susceptibility of isolates of M. tuberculosisduring the periods 2000 and 2004 were compared with drug susceptibility patterns of the organisms during theperiod 2008 to 2011.Results: The 260 isolates identified as M. tuberculosis show mean drug resistance prevalence of 45.6% for more than anytwo drugs and the MDR rate as 37% in the years 2000 to 2004 whereas 305 isolates of the organism show mean drugresistance prevalence of 30.2% and the MDR rate as 25% in the years 2008 to 2011.Conclusion: The researcher found that, though the prevalence of multidrug resistance to the drugs tested is remarkablyhigh, it has come down noticeably during the past seven years due to efforts of State Government and strict implementationof treatment guidelines of WHO by the physicians. J Microbiol Infect Dis 2013; 3(1: 12-17Key words: MDR-TB, XDR-TB, DOTS, drug-resistance prevalence rate.

  2. Genome-wide analysis of multi- and extensively drug-resistant Mycobacterium tuberculosis

    KAUST Repository

    Coll, Francesc

    2018-01-16

    To characterize the genetic determinants of resistance to antituberculosis drugs, we performed a genome-wide association study (GWAS) of 6,465 Mycobacterium tuberculosis clinical isolates from more than 30 countries. A GWAS approach within a mixed-regression framework was followed by a phylogenetics-based test for independent mutations. In addition to mutations in established and recently described resistance-associated genes, novel mutations were discovered for resistance to cycloserine, ethionamide and para-aminosalicylic acid. The capacity to detect mutations associated with resistance to ethionamide, pyrazinamide, capreomycin, cycloserine and para-aminosalicylic acid was enhanced by inclusion of insertions and deletions. Odds ratios for mutations within candidate genes were found to reflect levels of resistance. New epistatic relationships between candidate drug-resistance-associated genes were identified. Findings also suggest the involvement of efflux pumps (drrA and Rv2688c) in the emergence of resistance. This study will inform the design of new diagnostic tests and expedite the investigation of resistance and compensatory epistatic mechanisms.

  3. Phenotypic and genotypic analysis of anti-tuberculosis drug resistance in Mycobacterium tuberculosis isolates in Myanmar.

    Science.gov (United States)

    Aung, Wah Wah; Ei, Phyu Win; Nyunt, Wint Wint; Swe, Thyn Lei; Lwin, Thandar; Htwe, Mi Mi; Kim, Kyung Jun; Lee, Jong Seok; Kim, Chang Ki; Cho, Sang Nae; Song, Sun Dae; Chang, Chulhun L

    2015-09-01

    Tuberculosis (TB) is one of the most serious health problems in Myanmar. Because TB drug resistance is associated with genetic mutation(s) relevant to responses to each drug, genotypic methods for detecting these mutations have been proposed to overcome the limitations of classic phenotypic drug susceptibility testing (DST). We explored the current estimates of drug-resistant TB and evaluated the usefulness of genotypic DST in Myanmar. We determined the drug susceptibility of Mycobacterium tuberculosis isolated from sputum smear-positive patients with newly diagnosed pulmonary TB at two main TB centers in Myanmar during 2013 by using conventional phenotypic DST and the GenoType MTBDRplus assay (Hain Lifescience, Germany). Discrepant results were confirmed by sequencing the genes relevant to each type of resistance (rpoB for rifampicin; katG and inhA for isoniazid). Of 191 isolates, phenotypic DST showed that 27.7% (n=53) were resistant to at least one first-line drug and 20.9% (n=40) were resistant to two or more, including 18.3% (n=35) multidrug-resistant TB (MDR-TB) strains. Monoresistant strains accounted for 6.8% (n=13) of the samples. Genotypic assay of 189 isolates showed 17.5% (n=33) MDR-TB and 5.3% (n=10) isoniazid-monoresistant strains. Genotypic susceptibility results were 99.5% (n=188) concordant and agreed almost perfectly with phenotypic DST (kappa=0.99; 95% confidence interval 0.96-1.01). The results highlight the burden of TB drug resistance and prove the usefulness of the genotypic DST in Myanmar.

  4. First insights into circulating Mycobacterium tuberculosis complex lineages and drug resistance in Guinea

    Science.gov (United States)

    Ejo, Mebrat; Gehre, Florian; Barry, Mamadou Dian; Sow, Oumou; Bah, Nene Mamata; Camara, Mory; Bah, Boubacar; Uwizeye, Cecile; Nduwamahoro, Elie; Fissette, Kristina; Rijk, Pim De; Merle, Corinne; Olliaro, Piero; Burgos, Marcos; Lienhardt, Christian; Rigouts, Leen; de Jong, Bouke C.

    2015-01-01

    In this study we assessed first-line anti-tuberculosis drug resistance and the genotypic distribution of Mycobacterium tuberculosis complex (MTBC) isolates that had been collected from consecutive new tuberculosis patients enrolled in two clinical trials conducted in Guinea between 2005 and 2010. Among the total 359 MTBC strains that were analyzed in this study, 22.8% were resistant to at least one of the first line anti-tuberculosis drugs, including 2.5% multidrug resistance and 17.5% isoniazid resistance, with or without other drugs. In addition, further characterization of isolates from a subset of the two trials (n = 184) revealed a total of 80 different spoligotype patterns, 29 “orphan” and 51 shared patterns. We identified the six major MTBC lineages of human relevance, with predominance of the Euro-American lineage. In total, 132 (71.7%) of the strains were genotypically clustered, and further analysis (using the DESTUS model) suggesting significantly faster spread of LAM10_CAM family (p = 0.00016). In conclusion, our findings provide a first insight into drug resistance and the population structure of the MTBC in Guinea, with relevance for public health scientists in tuberculosis control programs. PMID:26004194

  5. Genotypes of Mycobacterium tuberculosis in patients at risk of drug resistance in Bolivia.

    Science.gov (United States)

    Monteserin, Johana; Camacho, Mirtha; Barrera, Lucía; Palomino, Juan Carlos; Ritacco, Viviana; Martin, Anandi

    2013-07-01

    Bolivia ranks among the 10 Latin American countries with the highest rates of tuberculosis (TB) and multidrug resistant (MDR) TB. In view of this, and of the lacking information on the population structure of Mycobacterium tuberculosis in the country, we explored genotype associations with drug resistance and clustering by analyzing isolates collected in 2010 from 100 consecutive TB patients at risk of drug resistance in seven of the nine departments in which Bolivia is divided. Fourteen isolates were MDR, 29 had other drug resistance profiles, and 57 were pansusceptible. Spoligotype family distribution was: Haarlem 39.4%, LAM 26.3%, T 22.2%, S 2.0%, X 1.0%, orphan 9.1%, with very low intra-family diversity and absence of Beijing genotypes. We found 66 different MIRU-VNTR patterns; the most frequent corresponded to Multiple Locus Variable Analysis (MLVA) MtbC15 patterns 860, 372 and 873. Twelve clusters, each with identical MIRU-VNTR and spoligotypes, gathered 35 patients. We found no association of genotype with drug resistant or MDR-TB. Clustering associated with SIT 50 and the H3 subfamily to which it belongs (pBolivia. However, results should be taken cautiously because the sample is small and includes a particular subset of M. tuberculosis population. Copyright © 2013 Elsevier B.V. All rights reserved.

  6. Molecular Genetic Analysis of Multi-drug Resistance in Indian Isolates of Mycobacterium tuberculosis

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    Noman Siddiqi

    1998-09-01

    Full Text Available A total of 116 isolates from patients attending the out-patient department at the All India Institute of Medical Sciences, New Delhi and the New Delhi Tuberculosis Centre, New Delhi, India were collected. They were analyzed for resistance to drugs prescribed in the treatment for tuberculosis. The drug resistance was initially determined by microbiological techniques. The Bactec 460TB system was employed to determine the type and level of resistance in each isolate. The isolates were further characterized at molecular level. The multi-drug loci corresponding to rpo b, gyr A, kat G were studied for mutation(s by the polymerase chain reaction-single strand conformational polymorphism (PCR-SSCP technique. The SSCP positive samples were sequenced to characterize the mutations in rpo b, and gyr A loci. While previously reported mutations in the gyr A and rpo b loci were found to be present, several novel mutations were also scored in the rpo b locus. Interestingly, analysis of the gyr A locus showed the presence of point mutation(s that could not be detected by PCR-SSCP. Furthermore, rifampicin resistance was found to be an important marker for checking multi-drug resistance (MDR in clinical isolates of Mycobacterium tuberculosis. This is the first report on molecular genetic analysis of MDR tuberculosis one from India, highlights the increasing incidence of MDR in the Indian isolates of M. tuberculosis.

  7. Cutaneous squamous cell carcinoma in lupus vulgaris caused by drug resistant Mycobacterium tuberculosis

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    Muthu S Kumaran

    2017-01-01

    Full Text Available Tuberculosis (TB is still a major public health problem in the world, with many factors contributing to this burden, including poor living conditions, overcrowding, poverty, malnutrition, illiteracy, and rapid spread of human immunodeficiency virus infection. Cutaneous tuberculosis is a less common form of extrapulmonary tuberculosis, and in this paucibacillary form the diagnosis depends on histopathology, tuberculin positivity, and response to treatment. The diagnosis is even more difficult in cases with drug resistant Mycobacterium tuberculosis due to lack of awareness and lack of facilities to diagnose drug resistant tuberculosis. In this article, we describe an unusual case of multidrug resistant lupus vulgaris (LV, in a 34-year-old male who responded to anti-tubercular treatment (ATT initially, but developed recurrent disease which failed to respond to standard four-drug ATT; subsequently, tissue culture showed growth of multidrug resistant M. tuberculosis. Subsequently, he also developed cutaneous squamous cell carcinoma. This article aims to exemplify a grave complication that can occur in long-standing case of LV, the limitations faced by clinicians in developing countries where tuberculosis is endemic, and classical methods of proving drug resistance are generally unavailable or fail.

  8. Global transcriptional profiling of longitudinal clinical isolates of Mycobacterium tuberculosis exhibiting rapid accumulation of drug resistance.

    Directory of Open Access Journals (Sweden)

    Anirvan Chatterjee

    Full Text Available The identification of multidrug resistant (MDR, extensively and totally drug resistant Mycobacterium tuberculosis (Mtb, in vulnerable sites such as Mumbai, is a grave threat to the control of tuberculosis. The current study aimed at explaining the rapid expression of MDR in Directly Observed Treatment Short Course (DOTS compliant patients, represents the first study comparing global transcriptional profiles of 3 pairs of clinical Mtb isolates, collected longitudinally at initiation and completion of DOTS. While the isolates were drug susceptible (DS at onset and MDR at completion of DOTS, they exhibited identical DNA fingerprints at both points of collection. The whole genome transcriptional analysis was performed using total RNA from H37Rv and 3 locally predominant spoligotypes viz. MANU1, CAS and Beijing, hybridized on MTBv3 (BuG@S microarray, and yielded 36, 98 and 45 differentially expressed genes respectively. Genes encoding transcription factors (sig, rpoB, cell wall biosynthesis (emb genes, protein synthesis (rpl and additional central metabolic pathways (ppdK, pknH, pfkB were found to be down regulated in the MDR isolates as compared to the DS isolate of the same genotype. Up regulation of drug efflux pumps, ABC transporters, trans-membrane proteins and stress response transcriptional factors (whiB in the MDR isolates was observed. The data indicated that Mtb, without specific mutations in drug target genes may persist in the host due to additional mechanisms like drug efflux pumps and lowered rate of metabolism. Furthermore this population of Mtb, which also showed reduced DNA repair activity, would result in selection and stabilization of spontaneous mutations in drug target genes, causing selection of a MDR strain in the presence of drug pressures. Efflux pump such as drrA may play a significant role in increasing fitness of low level drug resistant cells and assist in survival of Mtb till acquisition of drug resistant mutations with

  9. Association between genotype and drug resistance profiles of Mycobacterium tuberculosis strains circulating in China in a national drug resistance survey

    NARCIS (Netherlands)

    Zhou, Yang; van den Hof, Susan; Wang, Shengfen; Pang, Yu; Zhao, Bing; Xia, Hui; Anthony, Richard; Ou, Xichao; Li, Qiang; Zheng, Yang; Song, Yuanyuan; Zhao, Yanlin; van Soolingen, Dick

    2017-01-01

    We describe the population structure of a representative collection of 3,133 Mycobacterium tuberculosis isolates, collected within the framework of a national resistance survey from 2007 in China. Genotyping data indicate that the epidemic strains in China can be divided into seven major complexes,

  10. Whole Genome Sequencing Based Characterization of Extensively Drug-Resistant Mycobacterium tuberculosis Isolates from Pakistan

    KAUST Repository

    Ali, Asho; Hasan, Zahra; McNerney, Ruth; Mallard, Kim; Hill-Cawthorne, Grant A.; Coll, Francesc; Nair, Mridul; Pain, Arnab; Clark, Taane G.; Hasan, Rumina

    2015-01-01

    Improved molecular diagnostic methods for detection drug resistance in Mycobacterium tuberculosis (MTB) strains are required. Resistance to first- and second- line anti-tuberculous drugs has been associated with single nucleotide polymorphisms (SNPs) in particular genes. However, these SNPs can vary between MTB lineages therefore local data is required to describe different strain populations. We used whole genome sequencing (WGS) to characterize 37 extensively drug-resistant (XDR) MTB isolates from Pakistan and investigated 40 genes associated with drug resistance. Rifampicin resistance was attributable to SNPs in the rpoB hot-spot region. Isoniazid resistance was most commonly associated with the katG codon 315 (92%) mutation followed by inhA S94A (8%) however, one strain did not have SNPs in katG, inhA or oxyR-ahpC. All strains were pyrazimamide resistant but only 43% had pncA SNPs. Ethambutol resistant strains predominantly had embB codon 306 (62%) mutations, but additional SNPs at embB codons 406, 378 and 328 were also present. Fluoroquinolone resistance was associated with gyrA 91-94 codons in 81% of strains; four strains had only gyr B mutations, while others did not have SNPs in either gyrA or gyrB. Streptomycin resistant strains had mutations in ribosomal RNA genes; rpsL codon 43 (42%); rrs 500 region (16%), and gidB (34%) while six strains did not have mutations in any of these genes. Amikacin/kanamycin/capreomycin resistance was associated with SNPs in rrs at nt1401 (78%) and nt1484 (3%), except in seven (19%) strains. We estimate that if only the common hot-spot region targets of current commercial assays were used, the concordance between phenotypic and genotypic testing for these XDR strains would vary between rifampicin (100%), isoniazid (92%), flouroquinolones (81%), aminoglycoside (78%) and ethambutol (62%); while pncA sequencing would provide genotypic resistance in less than half the isolates. This work highlights the importance of expanded

  11. Whole Genome Sequencing Based Characterization of Extensively Drug-Resistant Mycobacterium tuberculosis Isolates from Pakistan

    KAUST Repository

    Ali, Asho

    2015-02-26

    Improved molecular diagnostic methods for detection drug resistance in Mycobacterium tuberculosis (MTB) strains are required. Resistance to first- and second- line anti-tuberculous drugs has been associated with single nucleotide polymorphisms (SNPs) in particular genes. However, these SNPs can vary between MTB lineages therefore local data is required to describe different strain populations. We used whole genome sequencing (WGS) to characterize 37 extensively drug-resistant (XDR) MTB isolates from Pakistan and investigated 40 genes associated with drug resistance. Rifampicin resistance was attributable to SNPs in the rpoB hot-spot region. Isoniazid resistance was most commonly associated with the katG codon 315 (92%) mutation followed by inhA S94A (8%) however, one strain did not have SNPs in katG, inhA or oxyR-ahpC. All strains were pyrazimamide resistant but only 43% had pncA SNPs. Ethambutol resistant strains predominantly had embB codon 306 (62%) mutations, but additional SNPs at embB codons 406, 378 and 328 were also present. Fluoroquinolone resistance was associated with gyrA 91-94 codons in 81% of strains; four strains had only gyr B mutations, while others did not have SNPs in either gyrA or gyrB. Streptomycin resistant strains had mutations in ribosomal RNA genes; rpsL codon 43 (42%); rrs 500 region (16%), and gidB (34%) while six strains did not have mutations in any of these genes. Amikacin/kanamycin/capreomycin resistance was associated with SNPs in rrs at nt1401 (78%) and nt1484 (3%), except in seven (19%) strains. We estimate that if only the common hot-spot region targets of current commercial assays were used, the concordance between phenotypic and genotypic testing for these XDR strains would vary between rifampicin (100%), isoniazid (92%), flouroquinolones (81%), aminoglycoside (78%) and ethambutol (62%); while pncA sequencing would provide genotypic resistance in less than half the isolates. This work highlights the importance of expanded

  12. Genetic diversity of drug and multidrug-resistant Mycobacterium tuberculosis circulating in Veracruz, Mexico

    Science.gov (United States)

    Munro-Rojas, Daniela; Fernandez-Morales, Esdras; Zarrabal-Meza, José; Martínez-Cazares, Ma. Teresa; Parissi-Crivelli, Aurora; Fuentes-Domínguez, Javier; Séraphin, Marie Nancy; Lauzardo, Michael; González-y-Merchand, Jorge Alberto; Rivera-Gutierrez, Sandra

    2018-01-01

    Background Mexico is one of the most important contributors of drug and multidrug-resistant tuberculosis in Latin America; however, knowledge of the genetic diversity of drug-resistant tuberculosis isolates is limited. Methods In this study, the genetic structure of 112 Mycobacterium tuberculosis strains from the southeastern Mexico was determined by spoligotyping and 24-loci MIRU-VNTRs. Findings The results show eight major lineages, the most of which was T1 (24%), followed by LAM (16%) and H (15%). A total of 29 (25%) isolates were identified as orphan. The most abundant SITs were SIT53/T1 and SIT42/LAM9 with 10 isolates each and SIT50/H3 with eight isolates. Fifty-two spoligotype patterns, twenty-seven clusters and ten clonal complexes were observed, demonstrating an important genetic diversity of drug and multidrug-resistant tuberculosis isolates in circulation and transmission level of these aggravated forms of tuberculosis. Being defined as orphan or as part of an orphan cluster, was a risk factor for multidrug resistant-tuberculosis (OR 2.5, IC 1.05–5.86 and OR 3.3, IC 1–11.03, respectively). Multiple correspondence analyses showed association of some clusters and SITs with specific geographical locations. Conclusions Our study provides one of the most detailed description of the genetic structure of drug and multidrug-resistant tuberculosis strains in southeast Mexico, establishing for the first time a baseline of the genotypes observed in resistant isolates circulating, however further studies are required to better elucidate the genetic structure of tuberculosis in region and the factors that could be participating in their dispersion. PMID:29543819

  13. Mechanisms of first-line antimicrobial resistance in multi-drug and extensively drug resistant strains of Mycobacterium tuberculosis in KwaZulu-Natal, South Africa

    Directory of Open Access Journals (Sweden)

    Navisha Dookie

    2016-10-01

    Full Text Available Abstract Background In South Africa, drug resistant tuberculosis is a major public health crisis in the face of the colossal HIV pandemic. Methods In an attempt to understand the distribution of drug resistance in our setting, we analysed the rpoB, katG, inhA, pncA and embB genes associated with resistance to key drugs used in the treatment of tuberculosis in clinical isolates of Mycobacterium tuberculosis in the KwaZulu-Natal province. Results Classical mutations were detected in the katG, inhA and embB genes associated with resistance to isoniazid and ethambutol. Diverse mutations were recorded in the multidrug resistant (MDR and extensively drug resistant (XDR isolates for the rpoB and pncA gene associated with resistance to rifampicin and pyrazinamide. Conclusions M.tuberculosis strains circulating in our setting display a combination of previously observed mutations, each mediating resistance to a different drug. The MDR and XDR TB isolates analysed in this study displayed classical mutations linked to INH and EMB resistance, whilst diverse mutations were linked to RIF and PZA resistance. The similarity of the XDR strains confirms reports of the clonality of the XDR epidemic. The successful dissemination of the drug resistant strains in the province underscores the need for rapid diagnostics to effectively diagnose drug resistance and guide treatment.

  14. Meropenem-Clavulanate is Effective Against Extensive Drug-Resistant Mycobacterium Tuberculosis

    Energy Technology Data Exchange (ETDEWEB)

    Hugonnet, J.; Tremblay, L; Boshoff, H; Barry, C; Blanchard, J

    2009-01-01

    e-lactam antibiotics are ineffective against Mycobacterium tuberculosis, being rapidly hydrolyzed by the chromosomally encoded blaC gene product. The carbapenem class of e-lactams are very poor substrates for BlaC, allowing us to determine the three-dimensional structure of the covalent BlaC-meropenem covalent complex at 1.8 angstrom resolution. When meropenem was combined with the e-lactamase inhibitor clavulanate, potent activity against laboratory strains of M. tuberculosis was observed [minimum inhibitory concentration (MICmeropenem) less than 1 microgram per milliliter], and sterilization of aerobically grown cultures was observed within 14 days. In addition, this combination exhibited inhibitory activity against anaerobically grown cultures that mimic the 'persistent' state and inhibited the growth of 13 extensively drug-resistant strains of M. tuberculosis at the same levels seen for drug-susceptible strains. Meropenem and clavulanate are Food and Drug Administration-approved drugs and could potentially be used to treat patients with currently untreatable disease.

  15. Unraveling Mycobacterium tuberculosis genomic diversity and evolution in Lisbon, Portugal, a highly drug resistant setting

    KAUST Repository

    Perdigão, João

    2014-11-18

    Background Multidrug- (MDR) and extensively drug resistant (XDR) tuberculosis (TB) presents a challenge to disease control and elimination goals. In Lisbon, Portugal, specific and successful XDR-TB strains have been found in circulation for almost two decades. Results In the present study we have genotyped and sequenced the genomes of 56 Mycobacterium tuberculosis isolates recovered mostly from Lisbon. The genotyping data revealed three major clusters associated with MDR-TB, two of which are associated with XDR-TB. Whilst the genomic data contributed to elucidate the phylogenetic positioning of circulating MDR-TB strains, showing a high predominance of a single SNP cluster group 5. Furthermore, a genome-wide phylogeny analysis from these strains, together with 19 publicly available genomes of Mycobacterium tuberculosis clinical isolates, revealed two major clades responsible for M/XDR-TB in the region: Lisboa3 and Q1 (LAM). The data presented by this study yielded insights on microevolution and identification of novel compensatory mutations associated with rifampicin resistance in rpoB and rpoC. The screening for other structural variations revealed putative clade-defining variants. One deletion in PPE41, found among Lisboa3 isolates, is proposed to contribute to immune evasion and as a selective advantage. Insertion sequence (IS) mapping has also demonstrated the role of IS6110 as a major driver in mycobacterial evolution by affecting gene integrity and regulation. Conclusions Globally, this study contributes with novel genome-wide phylogenetic data and has led to the identification of new genomic variants that support the notion of a growing genomic diversity facing both setting and host adaptation.

  16. Drug resistance-related mutations in multidrug-resistant Mycobacterium tuberculosis isolates from diverse geographical regions

    Directory of Open Access Journals (Sweden)

    Senia Rosales-Klintz

    2012-01-01

    Conclusion: This study confirms that there are significant geographical differences in the distribution of resistance-related mutations and suggests that an increased understanding of such differences in the specific distribution of resistance conferring mutations is crucial for development of new, generally applicable, molecular tools for rapid diagnosis of drug-resistant TB. The fact that a narrower distribution of mutations in high MDR-TB prevalence settings was seen suggests that much of the problems in these settings can be a result of an ongoing transmission of certain MDR-TB strains.

  17. Genotypic characterization of multi-drug-resistant Mycobacterium tuberculosis isolates in Myanmar.

    Science.gov (United States)

    Aye, Khin Saw; Nakajima, Chie; Yamaguchi, Tomoyuki; Win, Min Min; Shwe, Mu Mu; Win, Aye Aye; Lwin, Thandar; Nyunt, Wint Wint; Ti, Ti; Suzuki, Yasuhiko

    2016-03-01

    The number of multi-drug-resistant tuberculosis (MDR-TB) cases is rising worldwide. As a countermeasure against this situation, the implementation of rapid molecular tests to identify MDR-TB would be effective. To develop such tests, information on the frequency and distribution of mutations associating with phenotypic drug resistance in Mycobacterium tuberculosis is required in each country. During 2010, the common mutations in the rpoB, katG and inhA of 178 phenotypically MDR M. tuberculosis isolates collected by the National Tuberculosis Control Program (NTP) in Myanmar were investigated by DNA sequencing. Mutations affecting the 81-bp rifampicin (RIF) resistance-determining region (RRDR) of the rpoB were identified in 127 of 178 isolates (71.3%). Two of the most frequently affected codons were 531 and 526, with percentages of 48.3% and 14.0% respectively. For isoniazid (INH) resistance, 114 of 178 MDR-TB isolates (64.0%) had mutations in the katG in which a mutation-conferring amino acid substitution at codon 315 from Ser to Thr was the most common. Mutations in the inhA regulatory region were also detected in 20 (11.2%) isolates, with the majority at position -15. Distinct mutation rate and pattern from surrounding countries might suggest that MDR-TB has developed and spread domestically in Myanmar. Copyright © 2015 Japanese Society of Chemotherapy and The Japanese Association for Infectious Diseases. Published by Elsevier Ltd. All rights reserved.

  18. Quadruple-first line drug resistance in Mycobacterium tuberculosis in Vietnam: What can we learn from genes?

    Science.gov (United States)

    Nguyen, Huy Quang; Nguyen, Nhung Viet; Contamin, Lucie; Tran, Thanh Hoa Thi; Vu, Thuong Thi; Nguyen, Hung Van; Nguyen, Ngoc Lan Thi; Nguyen, Son Thai; Dang, Anh Duc; Bañuls, Anne-Laure; Nguyen, Van Anh Thi

    2017-06-01

    In Vietnam, a country with high tuberculosis (137/100.000 population) and multidrug-resistant (MDR)-TB burdens (7.8/100.000 population), little is known about the molecular signatures of drug resistance in general and more particularly of second line drug (SLD) resistance. This study is specifically focused on Mycobacterium tuberculosis isolates resistant to four first-line drugs (FLDs) that make TB much more difficult to treat. The aim is to determine the proportion of SLD resistance in these quadruple drug resistant isolates and the genetic determinants linked to drug resistance to better understand the genetic processes leading to quadruple and extremely drug resistance (XDR). 91 quadruple (rifampicin, isoniazid, ethambutol and streptomycin) FLD resistant and 55 susceptible isolates were included. Spoligotyping and 24-locus MIRU-VNTR techniques were performed and 9 genes and promoters linked to FLD and SLD resistance were sequenced. SLD susceptibility testing was carried out on a subsample of isolates. High proportion of quadruple-FLD resistant isolates was resistant to fluoroquinolones (27%) and second-line injectable drugs (30.2%) by drug susceptibility testing. The sequencing revealed high mutation diversity with prevailing mutations at positions katG315, inhA-15, rpoB531, embB306, rrs1401, rpsL43 and gyrA94. The sensitivity and specificity were high for most drug resistances (>86%), but the sensitivity was lower for injectable drug resistances (resistance. Nevertheless, particular mutation patterns linked to high-level resistance and low fitness costs seem to be favored. Copyright © 2017 Elsevier B.V. All rights reserved.

  19. Genomic diversity among drug sensitive and multidrug resistant isolates of Mycobacterium tuberculosis with identical DNA fingerprints.

    Directory of Open Access Journals (Sweden)

    Stefan Niemann

    2009-10-01

    Full Text Available Mycobacterium tuberculosis complex (MTBC, the causative agent of tuberculosis (TB, is characterized by low sequence diversity making this bacterium one of the classical examples of a genetically monomorphic pathogen. Because of this limited DNA sequence variation, routine genotyping of clinical MTBC isolates for epidemiological purposes relies on highly discriminatory DNA fingerprinting methods based on mobile and repetitive genetic elements. According to the standard view, isolates exhibiting the same fingerprinting pattern are considered direct progeny of the same bacterial clone, and most likely reflect ongoing transmission or disease relapse within individual patients.Here we further investigated this assumption and used massively parallel whole-genome sequencing to compare one drug-susceptible (K-1 and one multidrug resistant (MDR isolate (K-2 of a rapidly spreading M. tuberculosis Beijing genotype clone from a high incidence region (Karakalpakstan, Uzbekistan. Both isolates shared the same IS6110 RFLP pattern and the same allele at 23 out of 24 MIRU-VNTR loci. We generated 23.9 million (K-1 and 33.0 million (K-2 paired 50 bp purity filtered reads corresponding to a mean coverage of 483.5 fold and 656.1 fold respectively. Compared with the laboratory strain H37Rv both Beijing isolates shared 1,209 SNPs. The two Beijing isolates differed by 130 SNPs and one large deletion. The susceptible isolate had 55 specific SNPs, while the MDR variant had 75 specific SNPs, including the five known resistance-conferring mutations.Our results suggest that M. tuberculosis isolates exhibiting identical DNA fingerprinting patterns can harbour substantial genomic diversity. Because this heterogeneity is not captured by traditional genotyping of MTBC, some aspects of the transmission dynamics of tuberculosis could be missed or misinterpreted. Furthermore, a valid differentiation between disease relapse and exogenous reinfection might be impossible using

  20. Genomic diversity among drug sensitive and multidrug resistant isolates of Mycobacterium tuberculosis with identical DNA fingerprints.

    Science.gov (United States)

    Niemann, Stefan; Köser, Claudio U; Gagneux, Sebastien; Plinke, Claudia; Homolka, Susanne; Bignell, Helen; Carter, Richard J; Cheetham, R Keira; Cox, Anthony; Gormley, Niall A; Kokko-Gonzales, Paula; Murray, Lisa J; Rigatti, Roberto; Smith, Vincent P; Arends, Felix P M; Cox, Helen S; Smith, Geoff; Archer, John A C

    2009-10-12

    Mycobacterium tuberculosis complex (MTBC), the causative agent of tuberculosis (TB), is characterized by low sequence diversity making this bacterium one of the classical examples of a genetically monomorphic pathogen. Because of this limited DNA sequence variation, routine genotyping of clinical MTBC isolates for epidemiological purposes relies on highly discriminatory DNA fingerprinting methods based on mobile and repetitive genetic elements. According to the standard view, isolates exhibiting the same fingerprinting pattern are considered direct progeny of the same bacterial clone, and most likely reflect ongoing transmission or disease relapse within individual patients. Here we further investigated this assumption and used massively parallel whole-genome sequencing to compare one drug-susceptible (K-1) and one multidrug resistant (MDR) isolate (K-2) of a rapidly spreading M. tuberculosis Beijing genotype clone from a high incidence region (Karakalpakstan, Uzbekistan). Both isolates shared the same IS6110 RFLP pattern and the same allele at 23 out of 24 MIRU-VNTR loci. We generated 23.9 million (K-1) and 33.0 million (K-2) paired 50 bp purity filtered reads corresponding to a mean coverage of 483.5 fold and 656.1 fold respectively. Compared with the laboratory strain H37Rv both Beijing isolates shared 1,209 SNPs. The two Beijing isolates differed by 130 SNPs and one large deletion. The susceptible isolate had 55 specific SNPs, while the MDR variant had 75 specific SNPs, including the five known resistance-conferring mutations. Our results suggest that M. tuberculosis isolates exhibiting identical DNA fingerprinting patterns can harbour substantial genomic diversity. Because this heterogeneity is not captured by traditional genotyping of MTBC, some aspects of the transmission dynamics of tuberculosis could be missed or misinterpreted. Furthermore, a valid differentiation between disease relapse and exogenous reinfection might be impossible using standard

  1. Genomic diversity of drug-resistant Mycobacterium tuberculosis isolates in Lisbon Portugal: Towards tuberculosis genomic epidemiology

    Directory of Open Access Journals (Sweden)

    João Perdigão

    2015-01-01

    Full Text Available Multidrug- (MDR and extensively drug-resistant (XDR tuberculosis (TB present a challenge to disease control and elimination goals. Lisbon, Portugal, has a high TB incidencerate and unusual and successful XDR-TB strains that have been found in circulation foralmost two decades. For the last 20 years, a continued circulation of two phylogenetic clades, Lisboa3 and Q1, which are highly associated with MDR and XDR, have been observed. In recent years, these strains have been well characterized regarding the molecular basis of drug resistance and have been inclusively subjected to whole genome sequencing (WGS. Researchers have been studying the genomic diversity of strains circulating in Lisbon and its genomic determinants through cutting-edge next generation sequencing. An enormous amount of whole genome sequence data are now available for the most prevalent and clinically relevant strains circulating in Lisbon. It is the persistence, prevalence and rapid evolution towards drug resistance that has prompted researchers to investigate the properties of these strains at the genomic level and in the future at a global transcriptomic level. Seventy Mycobacterium tuberculosis (MTB isolates, mostly recovered in Lisbon, were genotyped by 24-loci Mycobacterial Interspersed Repetitive Unit – Variable Number of Tandem Repeats (MIRU-VNTR and the genomes sequenced using a next generation sequencing platform – Illumina HiSeq 2000. The genotyping data revealed three major clusters associated with MDR-TB (Lisboa3-A, Lisboa3-B and Q1, two of which are associated with XDR-TB (Lisboa3-B and Q1, whilst the genomic data contributed to elucidating the phylogenetic positioning of circulating MDR-TB strains, showing a high predominance of a single SNP cluster group 5. Furthermore, a genome-wide phylogeny analysis from these strains, together with 19 publicly available genomes of MTB clinical isolates, revealed two major clades responsible for MDR/XDR-TB in the region

  2. Genomic diversity of drug-resistant Mycobacterium tuberculosis isolates in Lisbon Portugal: Towards tuberculosis genomic epidemiology

    KAUST Repository

    Perdigã o, Joã o; Silva, Hugo; Machado, Diana; Macedo, Rita; Maltez, Fernando; Silva, Carla; Jordao, Luisa; Couto, Isabel; Mallard, Kim; Coll, Francesc; Hill-Cawthorne, Grant A.; McNerney, Ruth; Pain, Arnab; Clark, Taane G.; Viveiros, Miguel; Portugal, Isabel

    2015-01-01

    Multidrug- (MDR) and extensively drug-resistant (XDR) tuberculosis (TB) present a challenge to disease control and elimination goals. Lisbon, Portugal, has a high TB incidence rate and unusual and successful XDR-TB strains that have been found in circulation for almost two decades. For the last 20. years, a continued circulation of two phylogenetic clades, Lisboa3 and Q1, which are highly associated with MDR and XDR, have been observed. In recent years, these strains have been well characterized regarding the molecular basis of drug resistance and have been inclusively subjected to whole genome sequencing (WGS). Researchers have been studying the genomic diversity of strains circulating in Lisbon and its genomic determinants through cutting-edge next generation sequencing. An enormous amount of whole genome sequence data are now available for the most prevalent and clinically relevant strains circulating in Lisbon.It is the persistence, prevalence and rapid evolution towards drug resistance that has prompted researchers to investigate the properties of these strains at the genomic level and in the future at a global transcriptomic level. Seventy Mycobacterium tuberculosis (MTB) isolates, mostly recovered in Lisbon, were genotyped by 24-. loci Mycobacterial Interspersed Repetitive Unit - Variable Number of Tandem Repeats (MIRU-VNTR) and the genomes sequenced using a next generation sequencing platform - Illumina HiSeq 2000.The genotyping data revealed three major clusters associated with MDR-TB (Lisboa3-A, Lisboa3-B and Q1), two of which are associated with XDR-TB (Lisboa3-B and Q1), whilst the genomic data contributed to elucidating the phylogenetic positioning of circulating MDR-TB strains, showing a high predominance of a single SNP cluster group 5. Furthermore, a genome-wide phylogeny analysis from these strains, together with 19 publicly available genomes of MTB clinical isolates, revealed two major clades responsible for MDR/XDR-TB in the region: Lisboa3 and Q

  3. Genomic diversity of drug-resistant Mycobacterium tuberculosis isolates in Lisbon Portugal: Towards tuberculosis genomic epidemiology

    KAUST Repository

    Perdigão, João

    2015-03-01

    Multidrug- (MDR) and extensively drug-resistant (XDR) tuberculosis (TB) present a challenge to disease control and elimination goals. Lisbon, Portugal, has a high TB incidence rate and unusual and successful XDR-TB strains that have been found in circulation for almost two decades. For the last 20. years, a continued circulation of two phylogenetic clades, Lisboa3 and Q1, which are highly associated with MDR and XDR, have been observed. In recent years, these strains have been well characterized regarding the molecular basis of drug resistance and have been inclusively subjected to whole genome sequencing (WGS). Researchers have been studying the genomic diversity of strains circulating in Lisbon and its genomic determinants through cutting-edge next generation sequencing. An enormous amount of whole genome sequence data are now available for the most prevalent and clinically relevant strains circulating in Lisbon.It is the persistence, prevalence and rapid evolution towards drug resistance that has prompted researchers to investigate the properties of these strains at the genomic level and in the future at a global transcriptomic level. Seventy Mycobacterium tuberculosis (MTB) isolates, mostly recovered in Lisbon, were genotyped by 24-. loci Mycobacterial Interspersed Repetitive Unit - Variable Number of Tandem Repeats (MIRU-VNTR) and the genomes sequenced using a next generation sequencing platform - Illumina HiSeq 2000.The genotyping data revealed three major clusters associated with MDR-TB (Lisboa3-A, Lisboa3-B and Q1), two of which are associated with XDR-TB (Lisboa3-B and Q1), whilst the genomic data contributed to elucidating the phylogenetic positioning of circulating MDR-TB strains, showing a high predominance of a single SNP cluster group 5. Furthermore, a genome-wide phylogeny analysis from these strains, together with 19 publicly available genomes of MTB clinical isolates, revealed two major clades responsible for MDR/XDR-TB in the region: Lisboa3 and Q

  4. Comparative molecular study of Mycobacterium tuberculosis strains, in times of antimicrobial drug resistance

    Directory of Open Access Journals (Sweden)

    G. Varela

    2005-03-01

    Full Text Available Strains of Mycobacterium tuberculosis were compared using two DNA fingerprinting techniques: Restriction Fragment Length Polymorphism (RFLP and Double-Repetitive-Element-PCR (DRE-PCR. Two of these strains: IH1 (susceptible to isoniazid and IH2 (resistant to isoniazid were recovered from cases of pulmonary tuberculosis which occurred in two brothers who lived together. The first one was recognized on July 1999, and the second was diagnosed one year later. IH1 and IH2 showed the same pattern of bands with both molecular tests. These results suggest that single drug chemoprophylaxis may occasionally select resistant strains for that drug, which can eventually cause disease and be recognized through these tests. Strains IH3, IH4 and IH5 were obtained from sputum samples of 3 different patients, and intra-laboratory cross-contamination was suspected when it was realized that the 3 positive materials had been consecutively processed the same day by the same worker in the same biological safety cabinet. Again, the 3 strains revealed identical band patterns with RFLP and DRE-PCR, confirming the posed suspicion. The results with DRE-PCR were obtained after only 8 hours of work, without the need for subcultures. This procedure allows quick correction of treatment conducts, avoiding unnecessary exposure of people and bacteria to antimicrobial drugs.Se compararon cepas de Mycobacterium tuberculosis utilizando 2 procedimientos de ADN fingerprinting: polimorfismo de los fragmentos de restricción (RFLP y Double-Repetitive-Element-PCR (DRE-PCR. Dos de las cepas: IH1 (susceptible a isoniazida e IH2 (resistente a isoniazida se recuperaron a partir de casos de tuberculosis pulmonar que ocurrieron en dos hermanos convivientes. La primera fue aislada en julio de 1999 y la segunda un año después. IH1 e IH2 mostraron el mismo patrón de bandas por ambos procedimientos. Estos resultados sugieren que la quimioprofilaxis con una sola droga puede ocasionalmente

  5. Drug-resistance patterns of Mycobacterium tuberculosis strains and associated risk factors among multi drug-resistant tuberculosis suspected patients from Ethiopia.

    Science.gov (United States)

    Mesfin, Eyob Abera; Beyene, Dereje; Tesfaye, Abreham; Admasu, Addisu; Addise, Desalegn; Amare, Miskir; Dagne, Biniyam; Yaregal, Zelalem; Tesfaye, Ephrem; Tessema, Belay

    2018-01-01

    Multidrug drug-resistant tuberculosis (MDR-TB) is a major health problem and seriously threatens TB control and prevention efforts globally. Ethiopia is among the 30th highest TB burden countries for MDR-TB with 14% prevalence among previously treated cases. The focus of this study was on determining drug resistance patterns of Mycobacterium tuberculosis among MDR-TB suspected cases and associated risk factors. A cross-sectional study was conducted in Addis Ababa from June 2015 to December 2016. Sputum samples and socio-demographic data were collected from 358 MDR-TB suspected cases. Samples were analyzed using Ziehl-Neelsen technique, GeneXpert MTB/RIF assay, and culture using Lowenstein-Jensen and Mycobacterial growth indicator tube. Data were analyzed using SPSS version 23. A total of 226 the study participants were culture positive for Mycobacterium tuberculosis, among them, 133 (58.8%) participants were males. Moreover, 162 (71.7%) had been previously treated for tuberculosis, while 128 (56.6%) were TB/HIV co-infected. A majority [122 (54%)] of the isolates were resistant to any first-line anti-TB drugs. Among the resistant isolates, 110 (48.7%) were determined to be resistant to isoniazid, 94 (41.6%) to streptomycin, 89 (39.4%) to rifampicin, 72 (31.9%) to ethambutol, and 70 (30.9%) to pyrazinamide. The prevalence of MDR-TB was 89 (39.4%), of which 52/89 (58.4%) isolates were resistance to all five first-line drugs. Risk factors such as TB/HIV co-infection (AOR = 5.59, p = 0.00), cigarette smoking (AOR = 3.52, p = 0.045), alcohol drinking (AOR = 5.14, p = 0.001) hospital admission (AOR = 3.49, p = 0.005) and visiting (AOR = 3.34, p = 0.044) were significantly associated with MDR-TB. The prevalence of MDR-TB in the study population was of a significantly high level among previously treated patients and age group of 25-34. TB/HIV coinfection, smoking of cigarette, alcohol drinking, hospital admission and health facility visiting were identified as risk factors

  6. A study on demographic characteristics of drug resistant Mycobacterium tuberculosis isolates in Belarus

    Directory of Open Access Journals (Sweden)

    L Surkova

    2012-01-01

    Conclusion: As Belarus is a high-burden MDR-TB country and treatment of drug-resistant TB is long and complicated, the findings of this study provided useful information to deliver effective community-based disease control measures and a proposed plane for the effective management of drug-resistant TB at the national level.

  7. Genotypic diversity of multidrug-, quinolone- and extensively drug-resistant Mycobacterium tuberculosis isolates in Thailand.

    Science.gov (United States)

    Disratthakit, Areeya; Meada, Shinji; Prammananan, Therdsak; Thaipisuttikul, Iyarit; Doi, Norio; Chaiprasert, Angkana

    2015-06-01

    Drug-resistant tuberculosis (TB), which includes multidrug-resistant (MDR-TB), quinolone-resistant (QR-TB) and extensively drug-resistant tuberculosis (XDR-TB), is a serious threat to TB control. We aimed to characterize the genotypic diversity of drug-resistant TB clinical isolates collected in Thailand to establish whether the emergence of drug-resistant TB is attributable to transmitted resistance or acquired resistance. We constructed the first molecular phylogeny of MDR-TB (n=95), QR-TB (n=69) and XDR-TB (n=28) in Thailand based on spoligotyping and proposed 24-locus multilocus variable-number of tandem repeat analysis (MLVA). Clustering analysis was performed using the unweighted pair group method with arithmetic mean. Spoligotyping identified the Beijing strain (SIT1) as the most predominant genotype (n=139; 72.4%). The discriminatory power of 0.9235 Hunter-Gaston Discriminatory Index (HGDI) with the 15-locus variable-number tandem repeats of mycobacterial interspersed repetitive units typing was improved to a 0.9574 HGDI with proposed 24-locus MLVA, thereby resulting in the subdivision of a large cluster of Beijing strains (SIT1) into 17 subclusters. We identified the spread of drug-resistant TB clones caused by three different MLVA types in the Beijing strain (SIT1) and a specific clone of XDR-TB caused by a rare genotype, the Manu-ancestor strain (SIT523). Overall, 49.5% of all isolates were clustered. These findings suggest that a remarkable transmission of drug-resistant TB occurred in Thailand. The remaining 50% of drug-resistant TB isolates were unique genotypes, which may have arisen from the individual acquisition of drug resistance. Our results suggest that transmitted and acquired resistance have played an equal role in the emergence of drug-resistant TB. Further characterization of whole genome sequences of clonal strains could help to elucidate the mycobacterial genetic factors relevant for drug resistance, transmissibility and virulence

  8. Sensitivity Pattern of Second Line Anti-Tuberculosis Drugs against Clinical Isolates of Multidrug Resistant Mycobacterium Tuberculosis

    International Nuclear Information System (INIS)

    Ghafoor, T.; Ikram, A.; Abbasi, S. A.; Zaman, G.; Ayyub, M.; Palomino, J. C.; Vandamme, P.; Martin, A.

    2015-01-01

    Objective:To determine the current sensitivity pattern of second line anti-tuberculosis drugs against clinical isolates of Multidrug Resistant Mycobacterium tuberculosis (MDR-TB). Study Design: A cross-sectional study. Place and Duration of Study: Department of Microbiology, Armed Forces Institute of Pathology (AFIP), Rawalpindi, from November 2011 to April 2013. Methodology: Samples received during the study period were processed on BACTEC MGIT 960 system for Mycobacterium tuberculosis (MTB) culture followed by first line drugs susceptibility testing of culture proven MTB isolates. On the basis of resistance to rifampicin and isoniazid, 100 clinical isolates of MDR-TB were further subjected to susceptibility testing against amikacin (AMK), capreomycin (CAP), ofloxacin (OFL) and ethionamide (ETH) as per standard BACTEC MGIT 960 instructions. Results: Out of 100 MDR-TB isolates, 62% were from male patients and 38% from female patients. 97% were sensitive to AMK, 53% to OFL, 87% to CAP; and 87% were sensitive to ETH. Conclusion: The majority of the MDR-TB isolates showed excellent sensitivity against AMK, CAP and ETH. However, sensitivity of MDR-TB isolates against fluoroquinolones like OFL was not encouraging. (author)

  9. Whole genome sequencing-based characterization of extensively drug resistant (XDR) strains of Mycobacterium tuberculosis from Pakistan

    KAUST Repository

    Hasan, Zahra; Ali, Asho; McNerney, Ruth; Mallard, Kim; Hill-Cawthorne, Grant A.; Coll, Francesc; Nair, Mridul; Pain, Arnab; Clark, Taane G.; Hasan, Rumina

    2015-01-01

    Objectives: The global increase in drug resistance in Mycobacterium tuberculosis (MTB) strains increases the focus on improved molecular diagnostics for MTB. Extensively drug-resistant (XDR) - TB is caused by MTB strains resistant to rifampicin, isoniazid, fluoroquinolone and aminoglycoside antibiotics. Resistance to anti-tuberculous drugs has been associated with single nucleotide polymorphisms (SNPs), in particular MTB genes. However, there is regional variation between MTB lineages and the SNPs associated with resistance. Therefore, there is a need to identify common resistance conferring SNPs so that effective molecular-based diagnostic tests for MTB can be developed. This study investigated used whole genome sequencing (WGS) to characterize 37 XDR MTB isolates from Pakistan and investigated SNPs related to drug resistance. Methods: XDR-TB strains were selected. DNA was extracted from MTB strains, and samples underwent WGS with 76-base-paired end fragment sizes using Illumina paired end HiSeq2000 technology. Raw sequence data were mapped uniquely to H37Rv reference genome. The mappings allowed SNPs and small indels to be called using SAMtools/BCFtools. Results: This study found that in all XDR strains, rifampicin resistance was attributable to SNPs in the rpoB RDR region. Isoniazid resistance-associated mutations were primarily related to katG codon 315 followed by inhA S94A. Fluoroquinolone resistance was attributable to gyrA 91-94 codons in most strains, while one did not have SNPs in either gyrA or gyrB. Aminoglycoside resistance was mostly associated with SNPs in rrs, except in 6 strains. Ethambutol resistant strains had embB codon 306 mutations, but many strains did not have this present. The SNPs were compared with those present in commercial assays such as LiPA Hain MDRTBsl, and the sensitivity of the assays for these strains was evaluated. Conclusions: If common drug resistance associated with SNPs evaluated the concordance between phenotypic and

  10. Whole genome sequencing-based characterization of extensively drug resistant (XDR) strains of Mycobacterium tuberculosis from Pakistan

    KAUST Repository

    Hasan, Zahra

    2015-03-01

    Objectives: The global increase in drug resistance in Mycobacterium tuberculosis (MTB) strains increases the focus on improved molecular diagnostics for MTB. Extensively drug-resistant (XDR) - TB is caused by MTB strains resistant to rifampicin, isoniazid, fluoroquinolone and aminoglycoside antibiotics. Resistance to anti-tuberculous drugs has been associated with single nucleotide polymorphisms (SNPs), in particular MTB genes. However, there is regional variation between MTB lineages and the SNPs associated with resistance. Therefore, there is a need to identify common resistance conferring SNPs so that effective molecular-based diagnostic tests for MTB can be developed. This study investigated used whole genome sequencing (WGS) to characterize 37 XDR MTB isolates from Pakistan and investigated SNPs related to drug resistance. Methods: XDR-TB strains were selected. DNA was extracted from MTB strains, and samples underwent WGS with 76-base-paired end fragment sizes using Illumina paired end HiSeq2000 technology. Raw sequence data were mapped uniquely to H37Rv reference genome. The mappings allowed SNPs and small indels to be called using SAMtools/BCFtools. Results: This study found that in all XDR strains, rifampicin resistance was attributable to SNPs in the rpoB RDR region. Isoniazid resistance-associated mutations were primarily related to katG codon 315 followed by inhA S94A. Fluoroquinolone resistance was attributable to gyrA 91-94 codons in most strains, while one did not have SNPs in either gyrA or gyrB. Aminoglycoside resistance was mostly associated with SNPs in rrs, except in 6 strains. Ethambutol resistant strains had embB codon 306 mutations, but many strains did not have this present. The SNPs were compared with those present in commercial assays such as LiPA Hain MDRTBsl, and the sensitivity of the assays for these strains was evaluated. Conclusions: If common drug resistance associated with SNPs evaluated the concordance between phenotypic and

  11. Supplementary Material for: Mycobacterium tuberculosis whole genome sequencing and protein structure modelling provides insights into anti-tuberculosis drug resistance

    KAUST Repository

    Phelan, Jody

    2016-01-01

    Abstract Background Combating the spread of drug resistant tuberculosis is a global health priority. Whole genome association studies are being applied to identify genetic determinants of resistance to anti-tuberculosis drugs. Protein structure and interaction modelling are used to understand the functional effects of putative mutations and provide insight into the molecular mechanisms leading to resistance. Methods To investigate the potential utility of these approaches, we analysed the genomes of 144 Mycobacterium tuberculosis clinical isolates from The Special Programme for Research and Training in Tropical Diseases (TDR) collection sourced from 20 countries in four continents. A genome-wide approach was applied to 127 isolates to identify polymorphisms associated with minimum inhibitory concentrations for first-line anti-tuberculosis drugs. In addition, the effect of identified candidate mutations on protein stability and interactions was assessed quantitatively with well-established computational methods. Results The analysis revealed that mutations in the genes rpoB (rifampicin), katG (isoniazid), inhA-promoter (isoniazid), rpsL (streptomycin) and embB (ethambutol) were responsible for the majority of resistance observed. A subset of the mutations identified in rpoB and katG were predicted to affect protein stability. Further, a strong direct correlation was observed between the minimum inhibitory concentration values and the distance of the mutated residues in the three-dimensional structures of rpoB and katG to their respective drugs binding sites. Conclusions Using the TDR resource, we demonstrate the usefulness of whole genome association and convergent evolution approaches to detect known and potentially novel mutations associated with drug resistance. Further, protein structural modelling could provide a means of predicting the impact of polymorphisms on drug efficacy in the absence of phenotypic data. These approaches could ultimately lead to novel

  12. Mycobacterium tuberculosis whole genome sequencing and protein structure modelling provides insights into anti-tuberculosis drug resistance

    KAUST Repository

    Phelan, Jody

    2016-03-23

    Background Combating the spread of drug resistant tuberculosis is a global health priority. Whole genome association studies are being applied to identify genetic determinants of resistance to anti-tuberculosis drugs. Protein structure and interaction modelling are used to understand the functional effects of putative mutations and provide insight into the molecular mechanisms leading to resistance. Methods To investigate the potential utility of these approaches, we analysed the genomes of 144 Mycobacterium tuberculosis clinical isolates from The Special Programme for Research and Training in Tropical Diseases (TDR) collection sourced from 20 countries in four continents. A genome-wide approach was applied to 127 isolates to identify polymorphisms associated with minimum inhibitory concentrations for first-line anti-tuberculosis drugs. In addition, the effect of identified candidate mutations on protein stability and interactions was assessed quantitatively with well-established computational methods. Results The analysis revealed that mutations in the genes rpoB (rifampicin), katG (isoniazid), inhA-promoter (isoniazid), rpsL (streptomycin) and embB (ethambutol) were responsible for the majority of resistance observed. A subset of the mutations identified in rpoB and katG were predicted to affect protein stability. Further, a strong direct correlation was observed between the minimum inhibitory concentration values and the distance of the mutated residues in the three-dimensional structures of rpoB and katG to their respective drugs binding sites. Conclusions Using the TDR resource, we demonstrate the usefulness of whole genome association and convergent evolution approaches to detect known and potentially novel mutations associated with drug resistance. Further, protein structural modelling could provide a means of predicting the impact of polymorphisms on drug efficacy in the absence of phenotypic data. These approaches could ultimately lead to novel resistance

  13. Reduced pyrazinamidase activity and the natural resistance of Mycobacterium kansasii to the antituberculosis drug pyrazinamide.

    Science.gov (United States)

    Sun, Z; Zhang, Y

    1999-03-01

    Pyrazinamide (PZA), an analog of nicotinamide, is a prodrug that requires conversion to the bactericidal compound pyrazinoic acid (POA) by the bacterial pyrazinamidase (PZase) activity of nicotinamidase to show activity against Mycobacterium tuberculosis. Mutations leading to a loss of PZase activity cause PZA resistance in M. tuberculosis. M. kansasii is naturally resistant to PZA and has reduced PZase activity along with an apparently detectable nicotinamidase activity. The role of the reduction in PZase activity in the natural PZA resistance of M. kansasii is unknown. The MICs of PZA and POA for M. kansasii were determined to be 500 and 125 micrograms/ml, respectively. Using [14C]PZA and [14C]nicotinamide, we found that M. kansasii had about 5-fold-less PZase activity and about 25-fold-less nicotinamidase activity than M. tuberculosis. The M. kansasii pncA gene was cloned on a 1.8-kb BamHI DNA fragment, using M. avium pncA probe. Sequence analysis showed that the M. kansasii pncA gene encoded a protein with homology to its counterparts from M. tuberculosis (69.9%), M. avium (65.6%), and Escherichia coli (28.5%). Transformation of naturally PZA-resistant M. bovis BCG with M. kansasii pncA conferred partial PZA susceptibility. Transformation of M. kansasii with M. avium pncA caused functional expression of PZase and high-level susceptibility to PZA, indicating that the natural PZA resistance in M. kansasii results from a reduced PZase activity. Like M. tuberculosis, M. kansasii accumulated POA in the cells at an acidic pH; however, due to its highly active POA efflux pump, the naturally PZA-resistant species M. smegmatis did not. These findings suggest the existence of a weak POA efflux mechanism in M. kansasii.

  14. Proteomic analysis of drug-resistant Mycobacterium tuberculosis by one-dimensional gel electrophoresis and charge chromatography.

    Science.gov (United States)

    Yari, Shamsi; Hadizadeh Tasbiti, Alireza; Ghanei, Mostafa; Shokrgozar, Mohammad Ali; Fateh, Abolfazl; Mahdian, Reza; Yari, Fatemeh; Bahrmand, Ahmadreza

    2017-01-01

    Multidrug-resistant tuberculosis (MDR-TB) is a form of TB caused by Mycobacterium tuberculosis (M. tuberculosis) that do not respond to, at least, isoniazid and rifampicin, the two most powerful, first-line (or standard) anti-TB drugs. Novel intervention strategies for eliminating this disease were based on finding proteins that can be used for designing new drugs or new and reliable kits for diagnosis. The aim of this study was to compare the protein profiles of MDR-TB with sensitive isolates. Proteomic analysis of M. tuberculosis MDR-TB and sensitive isolates was obtained with ion exchange chromatography coupled with MALDI-TOF-TOF (matrix-assisted laser desorption/ionization) in order to identify individual proteins that have different expression in MDR-TB to be used as a drug target or diagnostic marker for designing valuable TB vaccines or TB rapid tests. We identified eight proteins in MDR-TB isolates, and analyses showed that these proteins are absent in M. tuberculosis-sensitive isolates: (Rv2140c, Rv0009, Rv1932, Rv0251c, Rv2558, Rv1284, Rv3699 and MMP major membrane proteins). These data will provide valuable clues in further investigation for suitable TB rapid tests or drug targets against drug-resistant and sensitive M. tuberculosis isolates.

  15. Removing the bottleneck in whole genome sequencing of Mycobacterium tuberculosis for rapid drug resistance analysis: a call to action

    Directory of Open Access Journals (Sweden)

    Ruth McNerney

    2017-03-01

    Full Text Available Whole genome sequencing (WGS can provide a comprehensive analysis of Mycobacterium tuberculosis mutations that cause resistance to anti-tuberculosis drugs. With the deployment of bench-top sequencers and rapid analytical software, WGS is poised to become a useful tool to guide treatment. However, direct sequencing from clinical specimens to provide a full drug resistance profile remains a serious challenge. This article reviews current practices for extracting M. tuberculosis DNA and possible solutions for sampling sputum. Techniques under consideration include enzymatic digestion, physical disruption, chemical degradation, detergent solubilization, solvent extraction, ligand-coated magnetic beads, silica columns, and oligonucleotide pull-down baits. Selective amplification of genomic bacterial DNA in sputum prior to WGS may provide a solution, and differential lysis to reduce the levels of contaminating human DNA is also being explored. To remove this bottleneck and accelerate access to WGS for patients with suspected drug-resistant tuberculosis, it is suggested that a coordinated and collaborative approach be taken to more rapidly optimize, compare, and validate methodologies for sequencing from patient samples.

  16. Molecular Characterization of the Resistance of Mycobacterium ...

    African Journals Online (AJOL)

    Abstract. Purpose: To characterize the resistance of Mycobacterium tuberculosis to second line drugs using a line probe assay. Methods: ... Marne-la-Coquette,. France). Bacterial isolates contained in 500 µl of liquid culture were heat- inactivated at 95 °C for 30 min and then sonicated for 12 min. Finally, the suspension was ...

  17. GENETIC DIVERSITY OF DRUG RESISTANT STRAINS OF MYCOBACTERIUM TUBERCULOSIS IN OMSK REGION

    Directory of Open Access Journals (Sweden)

    O. A. Pаsechnik

    2017-01-01

    Full Text Available The article presents the investigation results of the specific epidemic situation on tuberculous infection in Omsk Region in 2006-2015 and molecular genetic features of M. tuberculosis strains with multiple drug resistance circulating in this region. Bacteriological, molecular genetic methods, VNTR-typing were used as well as descriptive techniques of the epidemiological process. Tuberculosis prevalence made 269.2 per 100,000 population. There is an increase in those with bacillary excretion among new cases of respiratory tuberculosis from 39.8% to 53.4%. Drug resistance was detected in 48.0% of new cases. Among drug resistance patterns, MDR made 57%, and extensive drug resistance (XDR increased from 2.5 to 7.0%. In 2015 prevalence of XDR tuberculosis made 8.9 per 100,000 population in Omsk Region. When performing VNTR-typing of 77 samples of M. tuberculosis DNA with MDR, 27 genetic types were identified. The population of MDR strain of M. tuberculosis is heterogeneous and presented by strains of various genetic families -Beijing, LAM, S,Haarlem,Uganda. The investigation showed that isolates ofBeijing family prevailed (76.6%.

  18. Dominant incidence of multidrug and extensively drug-resistant specific Mycobacterium tuberculosis clones in Osaka Prefecture, Japan.

    Directory of Open Access Journals (Sweden)

    Aki Tamaru

    Full Text Available Infection and transmission of multidrug-resistant Mycobacterium tuberculosis (MDR-Mtb and extensively drug-resistant M. tuberculosis (XDR-Mtb is a serious health problem. We analyzed a total of 1,110 Mtb isolates in Osaka Prefecture and neighboring areas from April 2000 to March 2009. A total of 89 MDR-Mtb were identified, 36 (48.5% of which were determined to be XDR-Mtb. Among the 89 MDR-Mtb isolates, 24 (27.0% phylogenetically distributed into six clusters based on mycobacterial interspersed repetitive units-various number of tandem repeats (MIRU-VNTR typing. Among these six clusters, the MIRU-VNTR patterns of four (OM-V02, OM-V03, OM-V04, and OM-V06 were only found for MDR-Mtb. Further analysis revealed that all isolates belonging to OM-V02 and OM-V03, and two isolates from OM-V04 were clonal. Importantly such genotypes were not observed for drug-sensitive isolates. These suggest that few but transmissible clones can transmit after acquiring multidrug resistance and colonize even in a country with a developed, well-organized healthcare system.

  19. Genotyping and drug resistance patterns of Mycobacterium tuberculosis strains observed in a tuberculosis high-burden municipality in Northeast, Brazil

    Directory of Open Access Journals (Sweden)

    Roberta dos Santos Silva Luiz

    2013-06-01

    Full Text Available OBJECTIVES: This study has used a combination of clinical information, spoligotyping, and georeferencing system to elucidate the genetic diversity of the Mycobacterium tuberculosis isolates circulating in a TB-prevalent municipality of Northeast Brazil. METHODS: A total of 115 M. tuberculosis strains were isolated from pulmonary tuberculosis patients from January 2007 to March 2008 in Fortaleza. Drug susceptibility and spoligotyping assays were performed and place of residence of the patients were georeferenced. RESULTS: Of the M. tuberculosis strains studied, 51 (44.3% isolates were resistant to at least one drug (R-TB and 64 (55.7% were sensitive to all the drugs tested (S-TB. A high frequency of resistance was found in previously treated cases (84% and among new cases (16%; p < 0.001. a total of 74 (64% isolates were grouped into 22 spoligotyped lineages, while 41 (36% isolates were identified as new. among the predominant genotypes, 33% were latim american mediterranean (lam, 12% haarlem (h, and 5% u. there was no association of geographic distribution of rt-tb patients as compared to the controls and also the geographic location to the spoligotype patterns. the geospatial analysis revealed that 24 (23% patients (hot spot zones either shared the same residence or lived in a close neighborhood of a case. among these concentration zones, the patients lived in the same residence and shared a common genotype pattern and resistance pattern. DISCUSSION: it was observed that the spoligopatterns family distribution was similar to that reported for south america, prevailing the lam and h lineages. a high rate-case among the resistant TB group occurs as a result of transmitted and acquired resistance. A more effective surveillance program is needed in order to succeed in reducing tuberculosis in Northeast Brazil.

  20. Genotyping and drug resistance patterns of Mycobacterium tuberculosis strains observed in a tuberculosis high-burden municipality in Northeast, Brazil

    Directory of Open Access Journals (Sweden)

    Roberta dos Santos Silva Luiz

    Full Text Available OBJECTIVES: This study has used a combination of clinical information, spoligotyping, and georeferencing system to elucidate the genetic diversity of the Mycobacterium tuberculosis isolates circulating in a TB-prevalent municipality of Northeast Brazil. METHODS: A total of 115 M. tuberculosis strains were isolated from pulmonary tuberculosis patients from January 2007 to March 2008 in Fortaleza. Drug susceptibility and spoligotyping assays were performed and place of residence of the patients were georeferenced. RESULTS: Of the M. tuberculosis strains studied, 51 (44.3% isolates were resistant to at least one drug (R-TB and 64 (55.7% were sensitive to all the drugs tested (S-TB. A high frequency of resistance was found in previously treated cases (84% and among new cases (16%; p < 0.001. a total of 74 (64% isolates were grouped into 22 spoligotyped lineages, while 41 (36% isolates were identified as new. among the predominant genotypes, 33% were latim american mediterranean (lam, 12% haarlem (h, and 5% u. there was no association of geographic distribution of rt-tb patients as compared to the controls and also the geographic location to the spoligotype patterns. the geospatial analysis revealed that 24 (23% patients (hot spot zones either shared the same residence or lived in a close neighborhood of a case. among these concentration zones, the patients lived in the same residence and shared a common genotype pattern and resistance pattern. DISCUSSION: it was observed that the spoligopatterns family distribution was similar to that reported for south america, prevailing the lam and h lineages. a high rate-case among the resistant TB group occurs as a result of transmitted and acquired resistance. A more effective surveillance program is needed in order to succeed in reducing tuberculosis in Northeast Brazil.

  1. Viability, biofilm formation, and MazEF expression in drug-sensitive and drug-resistant Mycobacterium tuberculosis strains circulating in Xinjiang, China.

    Science.gov (United States)

    Zhao, Ji-Li; Liu, Wei; Xie, Wan-Ying; Cao, Xu-Dong; Yuan, Li

    2018-01-01

    Tuberculosis (TB) caused by Mycobacterium tuberculosis (MTB) is one of the most common chronic infectious amphixenotic diseases worldwide. Prevention and control of TB are greatly difficult, due to the increase in drug-resistant TB, particularly multidrug-resistant TB. We speculated that there were some differences between drug-sensitive and drug-resistant MTB strains and that mazEF 3,6,9 toxin-antitoxin systems (TASs) were involved in MTB viability. This study aimed to investigate differences in viability, biofilm formation, and MazEF expression between drug-sensitive and drug-resistant MTB strains circulating in Xinjiang, China, and whether mazEF 3,6,9 TASs contribute to MTB viability under stress conditions. Growth profiles and biofilm-formation abilities of drug-sensitive, drug-resistant MTB strains and the control strain H37Rv were monitored. Using molecular biology experiments, the mRNA expression of the mazF 3, 6, and 9 toxin genes, the mazE 3, 6, and 9 antitoxin genes, and expression of the MazF9 protein were detected in the different MTB strains, H37RvΔ mazEF 3,6,9 mutants from the H37Rv parent strain were generated, and mutant viability was tested. Ex vivo culture analyses demonstrated that drug-resistant MTB strains exhibit higher survival rates than drug-sensitive strains and the control strain H37Rv. However, there was no statistical difference in biofilm-formation ability in the drug-sensitive, drug-resistant, and H37Rv strains. mazE 3,6 mRNA-expression levels were relatively reduced in the drug-sensitive and drug-resistant strains compared to H37Rv. Conversely, mazE 3,9 expression was increased in drug-sensitive strains compared to drug-resistant strains. Furthermore, compared with the H37Rv strain, mazF 3,6 expression was increased in drug-resistant strains, mazF 9 expression was increased in drug-sensitive strains, and mazF 9 exhibited reduced expression in drug-resistant strains compared with drug-sensitive strains. Protein expression of mazF9

  2. Recent transmission of drug-resistant Mycobacterium tuberculosis in a prison population in southern Brazil

    Directory of Open Access Journals (Sweden)

    Ana Julia Reis

    Full Text Available ABSTRACT We conducted a cross-sectional, retrospective study, characterized by classical and molecular epidemiology, involving M. tuberculosis isolates from a regional prison in southern Brazil. Between January of 2011 and August of 2014, 379 prisoners underwent sputum smear microscopy and culture; 53 (13.9% were diagnosed with active tuberculosis. Of those, 8 (22.9% presented with isoniazid-resistant tuberculosis. Strain genotyping was carried out by 15-locus mycobacterial interspersed repetitive unit-variable-number tandem-repeat analysis; 68.6% of the patients were distributed into five clusters, and 87.5% of the resistant cases were in the same cluster. The frequency of drug-resistant tuberculosis cases and the rate of recent transmission were high. Our data suggest the need to implement an effective tuberculosis control program within the prison system.

  3. Mycobacterium tuberculosis Complex Genotype Diversity and Drug Resistance Profiles in a Pediatric Population in Mexico

    Directory of Open Access Journals (Sweden)

    Mercedes Macías Parra

    2011-01-01

    Full Text Available The aim of this study was to determine the frequency of drug resistance and the clonality of genotype patterns in M. tuberculosis clinical isolates from pediatric patients in Mexico (n=90 patients from 19 states; time period—January 2002 to December 2003. Pulmonary disease was the most frequent clinical manifestation (71%. Children with systemic tuberculosis (TB were significantly younger compared to patients with localized TB infections (mean 7.7±6.2 years versus 15±3.4 years P=0.001. Resistance to any anti-TB drug was detected in 24/90 (26.7% of the isolates; 21/90 (23.3% and 10/90 (11.1% were resistant to Isoniazid and Rifampicin, respectively, and 10/90 (11.1% strains were multidrug-resistant (MDR. Spoligotyping produced a total of 55 different patterns; 12/55 corresponded to clustered isolates (n=47, clustering rate of 52.2%, and 43/55 to unclustered isolates (19 patterns were designated as orphan by the SITVIT2 database. Database comparison led to designation of 36 shared types (SITs; 32 SITs (n=65 isolates matched a preexisting shared type in SITVIT2, whereas 4 SITs (n=6 isolates were newly created. Lineage classification based on principal genetic groups (PGG revealed that 10% of the strains belonged to PGG1 (Bovis and Manu lineages. Among PGG2/3 group, the most predominant clade was the Latin-American and Mediterranean (LAM in 27.8% of isolates, followed by Haarlem and T lineages. The number of single drug-resistant (DR and multidrug-resistant (MDR-TB isolates in this study was similar to previously reported in studies from adult population with risk factors. No association between the spoligotype, age, region, or resistance pattern was observed. However, contrary to a study on M. tuberculosis spoligotyping in Acapulco city that characterized a single cluster of SIT19 corresponding to the EAI2-Manila lineage in 70 (26% of patients, not a single SIT19 isolate was found in our pediatric patient population. Neither did we find any

  4. Definition of drug resistance of Mycobacterium tuberculosis to antituberculosis drugs in patients with multidrugresistant tuberculosis and TB with extremely drug resistant depending on the case of the disease

    Directory of Open Access Journals (Sweden)

    Kryzhanovsky D.G.

    2014-11-01

    Full Text Available There was studied the profile of drug resistance to the main (I line and reserve (II line antituberculosis drugs in patients with MDR and XDR tuberculosis, depending of the case of the disease. According to the randomized retrospective research 200 patients with MDR and XDR tuberculosis, who received treatment in the clinic of hospital Municipal institution «Dnipropetrovsk rigional clinical association «Phthisiology» Dnipropetrovsk regional Council» during the period 2010 – 2012 were involved. Data about patients contained the data on a case of the disease and the results of the test of drug sensitivity to MBT. XDR – TB was revealed in 7.5% of patients with MDR tuberculosis. In patients with MDR tuberculosis as compared with patients with XDR tuberculosis «new cases» were diagnosed in 19.5% against 18.5% (p <0.05. In patients with MDR tuberculosis and with XDR tuberculosis resistance to the antituberculosis drug more commonly developed to S - 88.5%, E - 55% and Z - 24%. The presence of MDR-TB and XDR-TB prevails in patients, who underwent previous courses of treatment with anti-TB drugs in case history as compared with patients with «new cases» of treatment. The development of resistance to anti-TB drugs depends on the availability of these drugs in the previous treatment regimens.

  5. Direct detection of Mycobacterium tuberculosis and drug resistance in respiratory specimen using Abbott Realtime MTB detection and RIF/INH resistance assay.

    Science.gov (United States)

    Tam, Kingsley King-Gee; Leung, Kenneth Siu-Sing; To, Sabrina Wai-Chi; Siu, Gilman Kit-Hang; Lau, Terrence Chi-Kong; Shek, Victor Chi-Man; Tse, Cindy Wing-Sze; Wong, Samson Sai-Yin; Ho, Pak-Leung; Yam, Wing-Cheong

    2017-10-01

    Abbott RealTime MTB (Abbott-RT) in conjunction with Abbott RealTime MTB RIF/INH Resistance (Abbott-RIF/INH) is a new, high-throughput automated nucleic acid amplification platform (Abbott-MDR) for detection of Mycobacterium tuberculosis complex (MTBC) and the genotypic markers for rifampicin (RIF) and isoniazid (INH) resistance directly from respiratory specimens. This prospective study evaluated the diagnostic performance of this new platform for MTBC and multidrug-resistant tuberculosis (MDR-TB) using 610 sputum specimens in a tuberculosis high-burden setting. Using conventional culture results and clinical background as reference standards, Abbott-RT exhibited an overall sensitivity and specificity of 95.2% and 99.8%, respectively. Genotypic RIF/INH resistance of 178 "MTB detected" specimens was subsequently analyzed by Abbott-RIF/INH. Compared to phenotypic drug susceptibility test results, Abbott-RIF/INH detected resistance genotypic markers in 84.6% MDR-TB, 80% mono-RIF-resistant and 66.7% mono-INH-resistant specimens. Two of the RIF-resistant specimens carried a novel single, nonsense mutation at rpoB Q513 and in silico simulation demonstrated that the truncated RpoB protein failed to bind with other subunits for transcription. Overall, Abbott-MDR platform provided high throughput and reliable diagnosis of MDR-TB within a TB high-burden region. Copyright © 2017 Elsevier Inc. All rights reserved.

  6. Recent transmission of drug-resistant Mycobacterium tuberculosis in a prison population in southern Brazil.

    Science.gov (United States)

    Reis, Ana Julia; David, Simone Maria Martini de; Nunes, Luciana de Souza; Valim, Andreia Rosane de Moura; Possuelo, Lia Gonçalves

    2016-01-01

    We conducted a cross-sectional, retrospective study, characterized by classical and molecular epidemiology, involving M. tuberculosis isolates from a regional prison in southern Brazil. Between January of 2011 and August of 2014, 379 prisoners underwent sputum smear microscopy and culture; 53 (13.9%) were diagnosed with active tuberculosis. Of those, 8 (22.9%) presented with isoniazid-resistant tuberculosis. Strain genotyping was carried out by 15-locus mycobacterial interspersed repetitive unit-variable-number tandem-repeat analysis; 68.6% of the patients were distributed into five clusters, and 87.5% of the resistant cases were in the same cluster. The frequency of drug-resistant tuberculosis cases and the rate of recent transmission were high. Our data suggest the need to implement an effective tuberculosis control program within the prison system. RESUMO Estudo transversal, retrospectivo, com isolados de M. tuberculosis de pacientes de um presídio regional no sul do Brasil, caracterizado através de epidemiologia clássica e molecular. Entre janeiro de 2011 e agosto de 2014, 379 detentos foram submetidos a baciloscopia e cultura, sendo 53 (13,9%) diagnosticados com tuberculose ativa. Desses, 8 (22,9%) apresentavam tuberculose resistente a isoniazida. A genotipagem das cepas foi realizada por 15-locus mycobacterial interspersed repetitive units-variable number of tandem repeat analysis; 68,6% dos pacientes estavam distribuídos em cinco clusters, e 87,5% dos casos resistentes estavam em um mesmo cluster. Verificou-se uma frequência elevada de casos de resistência e alta taxa de transmissão recente. Estes dados sugerem a necessidade da implantação de um programa efetivo de controle da tuberculose no sistema prisional.

  7. SILVER NANOPARTICLES IN THE SOLUTION OF THE PROBLEM OF DRUG RESISTANCE IN MYCOBACTERIUM TUBERCULOSIS

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    A. V. Zaharov

    2017-01-01

    Full Text Available The goal — a scientific evaluation of the effectiveness and safety of NHS in the treatment of experimental drug-resistant tuberculosis. Materials and methods. Used silver nanoparticles obtained by an electrochemical method. With a size of 5-60 nm, 120-270 kontsentratsiey- 1 mcm² and the size of the stabilizer shell — 2-5 nm. 750 crops studied Inhibitory activity of the silver nanoparticles in an isolated form and as part of a nanocomposite with chemotherapy in concentrations of 5; 25 and 50 mcg/ml. Defines the minimum inhibitory concentration of bactericidal nanoparticles composed of a nanocomposite with isoniazid. To evaluate the morphometry M.tuberculosis used atomic force microscopy. Toxicology nanopreparations studied 83 non-linear white mice and 146 white rats. Chemotherapeutic Activity nanopreparations determined on an experimental model of tuberculosis in 65 white male mice imbrednoy line BALB/c. Infectivity dose amount 5х106 colony forming units injected into the sinus venosus animal eyes. Isoniazid, nanoparticles and nanocomposite began administered 14 days after infection by intramuscular injection daily. Treatment efficacy was determined by comparing the evaluation criteria in the experimental and control groups of animals. Evaluated the following indicators: survival index, body mass index and weight of target organ, lesions index, index smear and inoculation of affected organs. Conducted pathological examination. Results. When using isoniazid, which had resistant pathogens, with silver nanoparticles full and significant inhibition of the growth of the M.tuberculosis observed in 49,2% of cases. When the concentration of the nanoparticles 5 mcg/ml in the composite bactericidal activity reached 91,3%. The minimum inhibitory concentration of silver nanoperticles in combination with isoniazid was 2,5 mcg/ml, the minimum bactericidal — 5 mcg /ml. There have been changes in the M.tuberculosis morphometry under the influence of the

  8. Is drug-resistant Mycobacterium leprae a real cause for concern?: First approach to molecular monitoring of multibacillary Colombian patients with and without previous leprosy treatment.

    Science.gov (United States)

    Guerrero, Martha Inírida; Colorado, Claudia Lucía; Torres, José Fernando; León, Clara Inés

    2014-04-01

    There is no information in Colombia on Mycobacterium leprae primary and secondary drug resistance in regards to the WHO-multidrug therapy regime. On the other hand, public health authorities around the world have issued various recommendations, one of which prompts for the immediate organization of resistance surveillance through simple molecular methods. To determine the prevalence of Mycobacterium leprae drug resistance to rifampicin, ofloxacin and dapsone in untreated and previously treated patients at the Centro Dermatológico Federico Lleras Acosta during the 1985-2004 period. We conducted a retrospective study which included multibacillary patient biopsies through elective sampling: 381 of them from new patients and 560 from previously treated patients. Using a microtome, we obtained six slides from each skin biopsy preserved in paraffin, and we extracted M. leprae DNA. We amplified three molecular targets through PCR and obtained the patterns of drug resistance to dapsone, rifampicin and ofloxacin by reverse hybridization. Finally, we collected epidemiological, clinical and demographical data for analyses. From 941 samples under study, 4.14% of them were resistant to one or more drugs, and 5.77 and 3.04% had resistant genotypes in new and previously treated patients, respectively. Total resistance for each drug was 0.43% for dapsone, 3.19% for rifampicin and 1.17% for ofloxacin. We found statistically significant differences for rifampicin and for the total population when comparing the results from untreated versus previously treated patients. Two thirds of the resistant samples were resistant to rifampicin alone or combined. The standard multidrug therapy schemes continue being effective for leprosy cases; however, it is necessary to guarantee adherence and regularity. Surveillance to drug resistance in new and previously treated leprosy cases should be established.

  9. Clinical data and molecular analysis of Mycobacterium tuberculosi isolates from drug-resistant tuberculosis patients in Goiás, Brazil

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    Sueli Lemes de Ávila Alves

    2011-09-01

    Full Text Available Drug resistance is one of the major concerns regarding tuberculosis (TB infection worldwide because it hampers control of the disease. Understanding the underlying mechanisms responsible for drug resistance development is of the highest importance. To investigate clinical data from drug-resistant TB patients at the Tropical Diseases Hospital, Goiás (GO, Brazil and to evaluate the molecular basis of rifampin (R and isoniazid (H resistance in Mycobacterium tuberculosis. Drug susceptibility testing was performed on 124 isolates from 100 patients and 24 isolates displayed resistance to R and/or H. Molecular analysis of drug resistance was performed by partial sequencing of the rpoB and katGgenes and analysis of the inhA promoter region. Similarity analysis of isolates was performed by 15 loci mycobacterial interspersed repetitive unit-variable number tandem repeat (MIRU-VNTR typing. The molecular basis of drug resistance among the 24 isolates from 16 patients was confirmed in 18 isolates. Different susceptibility profiles among the isolates from the same individual were observed in five patients; using MIRU-VNTR, we have shown that those isolates were not genetically identical, with differences in one to three loci within the 15 analysed loci. Drug-resistant TB in GO is caused by M. tuberculosis strains with mutations in previously described sites of known genes and some patients harbour a mixed phenotype infection as a consequence of a single infective event; however, further and broader investigations are needed to support our findings.

  10. Supplementary Material for: Mycobacterium tuberculosis whole genome sequencing and protein structure modelling provides insights into anti-tuberculosis drug resistance

    KAUST Repository

    Phelan, Jody; Coll, Francesc; McNerney, Ruth; Ascher, David; Pires, Douglas; Furnham, Nick; Coeck, Nele; Hill-Cawthorne, Grant; Nair, Mridul; Mallard, Kim; Ramsay, Andrew; Campino, Susana; Hibberd, Martin; Pain, Arnab; Rigouts, Leen; Clark, Taane

    2016-01-01

    Abstract Background Combating the spread of drug resistant tuberculosis is a global health priority. Whole genome association studies are being applied to identify genetic determinants of resistance to anti-tuberculosis drugs. Protein structure

  11. Evolution of extensively drug-resistant tuberculosis over four decades revealed by whole genome sequencing of Mycobacterium tuberculosis from KwaZulu-Natal, South Africa

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    Keira A Cohen

    2015-01-01

    Full Text Available The largest global outbreak of extensively drug-resistant (XDR tuberculosis (TB was identified in Tugela Ferry, KwaZulu-Natal (KZN, South Africa in 2005. The antecedents and timing of the emergence of drug resistance in this fatal epidemic XDR outbreak are unknown, and it is unclear whether drug resistance in this region continues to be driven by clonal spread or by the development of de novo resistance. A whole genome sequencing and drug susceptibility testing (DST was performed on 337 clinical isolates of Mycobacterium tuberculosis (M.tb collected in KZN from 2008 to 2013, in addition to three historical isolates, one of which was isolated during the Tugela Ferry outbreak. Using a variety of whole genome comparative approaches, 11 drug-resistant clones of M.tb circulating from 2008 to 2013 were identified, including a 50-member clone of XDR M.tb that was highly related to the Tugela Ferry XDR outbreak strain. It was calculated that the evolutionary trajectory from first-line drug resistance to XDR in this clone spanned more than four decades and began at the start of the antibiotic era. It was also observed that frequent de novo evolution of MDR and XDR was present, with 56 and 9 independent evolutions, respectively. Thus, ongoing amplification of drug-resistance in KwaZulu-Natal is driven by both clonal spread and de novo acquisition of resistance. In drug-resistant TB, isoniazid resistance was overwhelmingly the initial resistance mutation to be acquired, which would not be detected by current rapid molecular diagnostics that assess only rifampicin resistance.

  12. Multi-clonal evolution of multi-drug-resistant/extensively drug-resistant Mycobacterium tuberculosis in a high-prevalence setting of Papua New Guinea for over three decades

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    Bainomugisa, Arnold; Lavu, Evelyn; Hiashiri, Stenard; Majumdar, Suman; Honjepari, Alice; Moke, Rendi; Dakulala, Paison; Hill-Cawthorne, Grant A.; Pandey, Sushil; Marais, Ben J.; Coulter, Chris; Coin, Lachlan

    2018-01-01

    An outbreak of multi-drug resistant (MDR) tuberculosis (TB) has been reported on Daru Island, Papua New Guinea. Mycobacterium tuberculosis strains driving this outbreak and the temporal accrual of drug resistance mutations have not been described. Whole genome sequencing of 100 of 165 clinical isolates referred from Daru General Hospital to the Supranational reference laboratory, Brisbane, during 2012–2015 revealed that 95 belonged to a single modern Beijing sub-lineage strain. Molecular dating suggested acquisition of streptomycin and isoniazid resistance in the 1960s, with potentially enhanced virulence mediated by an mycP1 mutation. The Beijing sub-lineage strain demonstrated a high degree of co-resistance between isoniazid and ethionamide (80/95; 84.2 %) attributed to an inhA promoter mutation combined with inhA and ndh coding mutations. Multi-drug resistance, observed in 78/95 samples, emerged with the acquisition of a typical rpoB mutation together with a compensatory rpoC mutation in the 1980s. There was independent acquisition of fluoroquinolone and aminoglycoside resistance, and evidence of local transmission of extensively drug resistant (XDR) strains from 2009. These findings underline the importance of whole genome sequencing in informing an effective public health response to MDR/XDR TB. PMID:29310751

  13. The risk of global epidemic replacement with drug-resistant Mycobacterium tuberculosis strains

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    Emma S. McBryde

    2017-03-01

    Results and conclusions: The ability of MDR-TB to dominate DS-TB was highly sensitive to the relative transmissibility of the resistant strain; however, MDR-TB could dominate even when its transmissibility was modestly reduced (to between 50% and 100% as transmissible as the DS-TB strain. This model suggests that it may take decades or more for strain replacement to occur. It was also found that while the amplification of resistance is the early cause of MDR-TB, this will rapidly give way to person-to-person transmission.

  14. Importance of the Genetic Diversity within the Mycobacterium tuberculosis Complex for the Development of Novel Antibiotics and Diagnostic Tests of Drug Resistance

    KAUST Repository

    Koser, C. U.; Feuerriegel, S.; Summers, D. K.; Archer, John A.C.; Niemann, S.

    2012-01-01

    Despite being genetically monomorphic, the limited genetic diversity within the Mycobacterium tuberculosis complex (MTBC) has practical consequences for molecular methods for drug susceptibility testing and for the use of current antibiotics and those in clinical trials. It renders some representatives of MTBC intrinsically resistant against one or multiple antibiotics and affects the spectrum and consequences of resistance mutations selected for during treatment. Moreover, neutral or silent changes within genes responsible for drug resistance can cause false-positive results with hybridization-based assays, which have been recently introduced to replace slower phenotypic methods. We discuss the consequences of these findings and propose concrete steps to rigorously assess the genetic diversity of MTBC to support ongoing clinical trials.

  15. Importance of the Genetic Diversity within the Mycobacterium tuberculosis Complex for the Development of Novel Antibiotics and Diagnostic Tests of Drug Resistance

    KAUST Repository

    Koser, C. U.

    2012-09-24

    Despite being genetically monomorphic, the limited genetic diversity within the Mycobacterium tuberculosis complex (MTBC) has practical consequences for molecular methods for drug susceptibility testing and for the use of current antibiotics and those in clinical trials. It renders some representatives of MTBC intrinsically resistant against one or multiple antibiotics and affects the spectrum and consequences of resistance mutations selected for during treatment. Moreover, neutral or silent changes within genes responsible for drug resistance can cause false-positive results with hybridization-based assays, which have been recently introduced to replace slower phenotypic methods. We discuss the consequences of these findings and propose concrete steps to rigorously assess the genetic diversity of MTBC to support ongoing clinical trials.

  16. Whole genome sequencing of clinical strains of Mycobacterium tuberculosis from Mumbai, India: A potential tool for determining drug-resistance and strain lineage.

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    Chatterjee, Anirvan; Nilgiriwala, Kayzad; Saranath, Dhananjaya; Rodrigues, Camilla; Mistry, Nerges

    2017-12-01

    Amplification of drug resistance in Mycobacterium tuberculosis (M.tb) and its transmission are significant barriers in controlling tuberculosis (TB) globally. Diagnostic inaccuracies and delays impede appropriate drug administration, which exacerbates primary and secondary drug resistance. Increasing affordability of whole genome sequencing (WGS) and exhaustive cataloguing of drug resistance mutations is poised to revolutionise TB diagnostics and facilitate personalized drug therapy. However, application of WGS for diagnostics in high endemic areas is yet to be demonstrated. We report WGS of 74 clinical TB isolates from Mumbai, India, characterising genotypic drug resistance to first- and second-line anti-TB drugs. A concordance analysis between phenotypic and genotypic drug susceptibility of a subset of 29 isolates and the sensitivity of resistance prediction to the 4 drugs was calculated, viz. isoniazid-100%, rifampicin-100%, ethambutol-100% and streptomycin-85%. The whole genome based phylogeny showed almost equal proportion of East Asian (27/74) and Central Asian (25/74) strains. Interestingly we also found a clonal group of 9 isolates, of which 7 patients were found to be from the same geographical location and accessed the same health post. This provides the first evidence of epidemiological linkage for tracking TB transmission in India, an approach which has the potential to significantly improve chances of End-TB goals. Finally, the use of Mykrobe Predictor, as a standalone drug resistance and strain typing tool, requiring just few minutes to analyse raw WGS data into tabulated results, implies the rapid clinical applicability of WGS based TB diagnosis. Copyright © 2017 Elsevier Ltd. All rights reserved.

  17. The Inhibition of Folylpolyglutamate Synthetase (folC in the Prevention of Drug Resistance in Mycobacterium tuberculosis by Traditional Chinese Medicine

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    Tzu-Chieh Hung

    2014-01-01

    Full Text Available Tuberculosis (TB is an infectious disease caused by many strains of mycobacteria, but commonly Mycobacterium tuberculosis. As a possible method of reducing the drug resistance of M. tuberculosis, this research investigates the inhibition of Folylpolyglutamate synthetase, a protein transcript from the resistance association gene folC. After molecular docking to screen the traditional Chinese medicine (TCM database, the candidate TCM compounds, with Folylpolyglutamate synthetase, were selected by molecular dynamics. The 10,000 ps simulation in association with RMSD analysis and total energy and structural variation defined the protein-ligand interaction. The selected TCM compounds Saussureamine C, methyl 3-O-feruloylquinate, and Labiatic acid have been found to inhibit the activity of bacteria and viruses and to regulate immunity. We also suggest the possible pathway in protein for each ligand. Compared with the control, similar interactions and structural variations indicate that these compounds might have an effect on Folylpolyglutamate synthetase. Finally, we suggest Saussureamine C is the best candidate compound as the complex has a high score, maintains its structural composition, and has a larger variation value than the control, thus inhibiting the drug resistance ability of Mycobacterium tuberculosis.

  18. Whole genome sequencing-based characterization of extensively drug resistant (XDR strains of Mycobacterium tuberculosis from Pakistan

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    Zahra Hasan

    2015-01-01

    Conclusions: If common drug resistance associated with SNPs evaluated the concordance between phenotypic and genotypic testing, the results would be rifampicin (100%, isoniazid (89%, fluoroquinolones (95%, aminoglycoside (81% and ethambutol (61%. This work highlights the importance of expanded targets for drug resistance detection in MTB isolates.

  19. The draft genome of Mycobacterium aurum , a potential model organism for investigating drugs against Mycobacterium tuberculosis and Mycobacterium leprae

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    Jody Phelan

    2015-01-01

    Full Text Available Mycobacterium aurum (M. aurum is an environmental mycobacteria that has previously been used in studies of anti-mycobacterial drugs due to its fast growth rate and low pathogenicity. The M. aurum genome has been sequenced and assembled into 46 contigs, with a total length of 6.02 Mb containing 5684 annotated protein-coding genes. A phylogenetic analysis using whole genome alignments positioned M. aurum close to Mycobacterium vaccae and Mycobacterium vanbaalenii, within a clade related to fast-growing mycobacteria. Large-scale genomic rearrangements were identified by comparing the M. aurum genome to those of Mycobacterium tuberculosis and Mycobacterium leprae. M. aurum orthologous genes implicated in resistance to anti-tuberculosis drugs in M. tuberculosis were observed. The sequence identity at the DNA level varied from 68.6% for pncA (pyrazinamide drug-related to 96.2% for rrs (streptomycin, capreomycin. We observed two homologous genes encoding the catalase-peroxidase enzyme (katG that is associated with resistance to isoniazid. Similarly, two emb B homologues were identified in the M. aurum genome. In addition to describing for the first time the genome of M. aurum , this work provides a resource to aid the use of M. aurum in studies to develop improved drugs for the pathogenic mycobacteria M. tuberculosis and M. leprae.

  20. The draft genome of Mycobacterium aurum, a potential model organism for investigating drugs against Mycobacterium tuberculosis and Mycobacterium leprae

    KAUST Repository

    Phelan, Jody

    2015-06-04

    Mycobacterium aurum (M. aurum) is an environmental mycobacteria that has previously been used in studies of anti-mycobacterial drugs due to its fast growth rate and low pathogenicity. The M. aurum genome has been sequenced and assembled into 46 contigs, with a total length of 6.02 Mb containing 5684 annotated protein-coding genes. A phylogenetic analysis using whole genome alignments positioned M. aurum close to Mycobacterium vaccae and Mycobacterium vanbaalenii, within a clade related to fast-growing mycobacteria. Large-scale genomic rearrangements were identified by comparing the M. aurum genome to those of Mycobacterium tuberculosis and Mycobacterium leprae. M. aurum orthologous genes implicated in resistance to anti-tuberculosis drugs in M. tuberculosis were observed. The sequence identity at the DNA level varied from 68.6% for pncA (pyrazinamide drug-related) to 96.2% for rrs (streptomycin, capreomycin). We observed two homologous genes encoding the catalase-peroxidase enzyme (katG) that is associated with resistance to isoniazid. Similarly, two embB homologues were identified in the M. aurum genome. In addition to describing for the first time the genome of M. aurum, this work provides a resource to aid the use of M. aurum in studies to develop improved drugs for the pathogenic mycobacteria M. tuberculosis and M. leprae.

  1. The draft genome of Mycobacterium aurum, a potential model organism for investigating drugs against Mycobacterium tuberculosis and Mycobacterium leprae

    KAUST Repository

    Phelan, Jody; Maitra, Arundhati; McNerney, Ruth; Nair, Mridul; Gupta, Antima; Coll, Francesc; Pain, Arnab; Bhakta, Sanjib; Clark, Taane G.

    2015-01-01

    Mycobacterium aurum (M. aurum) is an environmental mycobacteria that has previously been used in studies of anti-mycobacterial drugs due to its fast growth rate and low pathogenicity. The M. aurum genome has been sequenced and assembled into 46 contigs, with a total length of 6.02 Mb containing 5684 annotated protein-coding genes. A phylogenetic analysis using whole genome alignments positioned M. aurum close to Mycobacterium vaccae and Mycobacterium vanbaalenii, within a clade related to fast-growing mycobacteria. Large-scale genomic rearrangements were identified by comparing the M. aurum genome to those of Mycobacterium tuberculosis and Mycobacterium leprae. M. aurum orthologous genes implicated in resistance to anti-tuberculosis drugs in M. tuberculosis were observed. The sequence identity at the DNA level varied from 68.6% for pncA (pyrazinamide drug-related) to 96.2% for rrs (streptomycin, capreomycin). We observed two homologous genes encoding the catalase-peroxidase enzyme (katG) that is associated with resistance to isoniazid. Similarly, two embB homologues were identified in the M. aurum genome. In addition to describing for the first time the genome of M. aurum, this work provides a resource to aid the use of M. aurum in studies to develop improved drugs for the pathogenic mycobacteria M. tuberculosis and M. leprae.

  2. The draft genome of Mycobacterium aurum, a potential model organism for investigating drugs against Mycobacterium tuberculosis and Mycobacterium leprae.

    Science.gov (United States)

    Phelan, Jody; Maitra, Arundhati; McNerney, Ruth; Nair, Mridul; Gupta, Antima; Coll, Francesc; Pain, Arnab; Bhakta, Sanjib; Clark, Taane G

    2015-09-01

    Mycobacterium aurum (M. aurum) is an environmental mycobacteria that has previously been used in studies of anti-mycobacterial drugs due to its fast growth rate and low pathogenicity. The M. aurum genome has been sequenced and assembled into 46 contigs, with a total length of 6.02Mb containing 5684 annotated protein-coding genes. A phylogenetic analysis using whole genome alignments positioned M. aurum close to Mycobacterium vaccae and Mycobacterium vanbaalenii, within a clade related to fast-growing mycobacteria. Large-scale genomic rearrangements were identified by comparing the M. aurum genome to those of Mycobacterium tuberculosis and Mycobacterium leprae. M. aurum orthologous genes implicated in resistance to anti-tuberculosis drugs in M. tuberculosis were observed. The sequence identity at the DNA level varied from 68.6% for pncA (pyrazinamide drug-related) to 96.2% for rrs (streptomycin, capreomycin). We observed two homologous genes encoding the catalase-peroxidase enzyme (katG) that is associated with resistance to isoniazid. Similarly, two embB homologues were identified in the M. aurum genome. In addition to describing for the first time the genome of M. aurum, this work provides a resource to aid the use of M. aurum in studies to develop improved drugs for the pathogenic mycobacteria M. tuberculosis and M. leprae. Copyright © 2015 Asian-African Society for Mycobacteriology. Published by Elsevier Ltd. All rights reserved.

  3. Genome Analysis of the First Extensively Drug-Resistant (XDR Mycobacterium tuberculosis in Malaysia Provides Insights into the Genetic Basis of Its Biology and Drug Resistance.

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    Chee Sian Kuan

    Full Text Available The outbreak of extensively drug-resistant tuberculosis (XDR-TB has become an increasing problem in many TB-burdened countries. The underlying drug resistance mechanisms, including the genetic variation favored by selective pressure in the resistant population, are partially understood. Recently, the first case of XDR-TB was reported in Malaysia. However, the detailed genotype family and mechanisms of the formation of multiple drugs resistance are unknown. We sequenced the whole genome of the UM 1072388579 strain with a 2-kb insert-size library and combined with that from previously sequenced 500-bp-insert paired-end reads to produce an improved sequence with maximal sequencing coverage across the genome. In silico spoligotyping and phylogenetic analyses demonstrated that UM 1072388579 strain belongs to an ancestral-like, non-Beijing clade of East Asia lineage. This is supported by the presence of a number of lineage-specific markers, including fadD28, embA, nuoD and pks7. Polymorphism analysis showed that the drug-susceptibility profile is correlated with the pattern of resistance mutations. Mutations in drug-efflux pumps and the cell wall biogenesis pathway such as mmpL, pks and fadD genes may play an important role in survival and adaptation of this strain to its surrounding environment. In this work, fifty-seven putative promoter SNPs were identified. Among them, we identified a novel SNP located at -4 T allele of TetR/acrR promoter as an informative marker to recognize strains of East Asian lineage. Our work indicates that the UM 1072388579 harbors both classical and uncommon SNPs that allow it to escape from inhibition by many antibiotics. This study provides a strong foundation to dissect the biology and underlying resistance mechanisms of the first reported XDR M. tuberculosis in Malaysia.

  4. Detecting Mutations in the Mycobacterium tuberculosis Pyrazinamidase Gene pncA to Improve Infection Control and Decrease Drug Resistance Rates in Human Immunodeficiency Virus Coinfection

    Science.gov (United States)

    Dudley, Matthew Z.; Sheen, Patricia; Gilman, Robert H.; Ticona, Eduardo; Friedland, Jon S.; Kirwan, Daniela E.; Caviedes, Luz; Rodriguez, Richard; Cabrera, Lilia Z.; Coronel, Jorge; Grandjean, Louis; Moore, David A. J.; Evans, Carlton A.; Huaroto, Luz; Chávez-Pérez, Víctor; Zimic, Mirko

    2016-01-01

    Hospital infection control measures are crucial to tuberculosis (TB) control strategies within settings caring for human immunodeficiency virus (HIV)–positive patients, as these patients are at heightened risk of developing TB. Pyrazinamide (PZA) is a potent drug that effectively sterilizes persistent Mycobacterium tuberculosis bacilli. However, PZA resistance associated with mutations in the nicotinamidase/pyrazinamidase coding gene, pncA, is increasing. A total of 794 patient isolates obtained from four sites in Lima, Peru, underwent spoligotyping and drug resistance testing. In one of these sites, the HIV unit of Hospital Dos de Mayo (HDM), an isolation ward for HIV/TB coinfected patients opened during the study as an infection control intervention: circulating genotypes and drug resistance pre- and postintervention were compared. All other sites cared for HIV-negative outpatients: genotypes and drug resistance rates from these sites were compared with those from HDM. HDM patients showed high concordance between multidrug resistance, PZA resistance according to the Wayne method, the two most common genotypes (spoligotype international type [SIT] 42 of the Latino American-Mediterranean (LAM)-9 clade and SIT 53 of the T1 clade), and the two most common pncA mutations (G145A and A403C). These associations were absent among community isolates. The infection control intervention was associated with 58–92% reductions in TB caused by SIT 42 or SIT 53 genotypes (odds ratio [OR] = 0.420, P = 0.003); multidrug-resistant TB (OR = 0.349, P < 0.001); and PZA-resistant TB (OR = 0.076, P < 0.001). In conclusion, pncA mutation typing, with resistance testing and spoligotyping, was useful in identifying a nosocomial TB outbreak and demonstrating its resolution after implementation of infection control measures. PMID:27928075

  5. Phenotypic and genomic comparison of Mycobacterium aurum and surrogate model species to Mycobacterium tuberculosis: implications for drug discovery.

    Science.gov (United States)

    Namouchi, Amine; Cimino, Mena; Favre-Rochex, Sandrine; Charles, Patricia; Gicquel, Brigitte

    2017-07-13

    Tuberculosis (TB) is caused by Mycobacterium tuberculosis and represents one of the major challenges facing drug discovery initiatives worldwide. The considerable rise in bacterial drug resistance in recent years has led to the need of new drugs and drug regimens. Model systems are regularly used to speed-up the drug discovery process and circumvent biosafety issues associated with manipulating M. tuberculosis. These include the use of strains such as Mycobacterium smegmatis and Mycobacterium marinum that can be handled in biosafety level 2 facilities, making high-throughput screening feasible. However, each of these model species have their own limitations. We report and describe the first complete genome sequence of Mycobacterium aurum ATCC23366, an environmental mycobacterium that can also grow in the gut of humans and animals as part of the microbiota. This species shows a comparable resistance profile to that of M. tuberculosis for several anti-TB drugs. The aims of this study were to (i) determine the drug resistance profile of a recently proposed model species, Mycobacterium aurum, strain ATCC23366, for anti-TB drug discovery as well as Mycobacterium smegmatis and Mycobacterium marinum (ii) sequence and annotate the complete genome sequence of this species obtained using Pacific Bioscience technology (iii) perform comparative genomics analyses of the various surrogate strains with M. tuberculosis (iv) discuss how the choice of the surrogate model used for drug screening can affect the drug discovery process. We describe the complete genome sequence of M. aurum, a surrogate model for anti-tuberculosis drug discovery. Most of the genes already reported to be associated with drug resistance are shared between all the surrogate strains and M. tuberculosis. We consider that M. aurum might be used in high-throughput screening for tuberculosis drug discovery. We also highly recommend the use of different model species during the drug discovery screening process.

  6. Estimating Fitness by Competition Assays between Drug Susceptible and Resistant Mycobacterium tuberculosis of Predominant Lineages in Mumbai, India

    Science.gov (United States)

    Bhatter, Purva; Chatterjee, Anirvan; D'souza, Desiree; Tolani, Monica; Mistry, Nerges

    2012-01-01

    Background Multi Drug Resistant Tuberculosis (MDR TB) is a threat to global tuberculosis control. A significant fitness cost has been associated with DR strains from specific lineages. Evaluation of the influence of the competing drug susceptible strains on fitness of drug resistant strains may have an important bearing on understanding the spread of MDR TB. The aim of this study was to evaluate the fitness of MDR TB strains, from a TB endemic region of western India: Mumbai, belonging to 3 predominant lineages namely CAS, Beijing and MANU in the presence of drug susceptible strains from the same lineages. Methodology Drug susceptible strains from a single lineage were mixed with drug resistant strain, bearing particular non synonymous mutation (rpoB D516V; inhA, A16G; katG, S315T1/T2) from the same or different lineages. Fitness of M.tuberculosis (M.tb) strains was evaluated using the difference in growth rates obtained by using the CFU assay system. Conclusion/Significance While MANU were most fit amongst the drug susceptible strains of the 3 lineages, only Beijing MDR strains were found to grow in the presence of any of the competing drug susceptible strains. A disproportionate increase in Beijing MDR could be an alarm for an impending epidemic in this locale. In addition to particular non synonymous substitutions, the competing strains in an environment may impact the fitness of circulating drug resistant strains. PMID:22479407

  7. [Identification and drug susceptibility testing of Mycobacterium thermoresistibile and Mycobacterium elephantis isolated from a cow with mastitis].

    Science.gov (United States)

    Li, W B; Ji, L Y; Xu, D L; Liu, H C; Zhao, X Q; Wu, Y M; Wan, K L

    2018-05-10

    Objective: To understand the etiological characteristics and drug susceptibility of Mycobacterium thermoresistibile and Mycobacterium elephantis isolated from a cow with mastitis and provide evidence for the prevention and control of infectious mastitis in cows. Methods: The milk sample was collected from a cow with mastitis, which was pretreated with 4 % NaOH and inoculated with L-J medium for Mycobacterium isolation. The positive cultures were initially identified by acid-fast staining and multi-loci PCR, then Mycobacterium species was identified by the multiple loci sequence analysis (MLSA) with 16S rRNA , hsp65 , ITS and SodA genes. The drug sensitivity of the isolates to 27 antibiotics was tested by alamar blue assay. Results: Two anti-acid stain positive strains were isolated from the milk of a cow with mastitis, which were identified as non- tuberculosis mycobacterium by multi-loci PCR, and multi-loci nucleic acid sequence analysis indicated that one strain was Mycobacterium thermoresistibile and another one was Mycobacterium elephantis . The results of the drug susceptibility test showed that the two strains were resistant to most antibiotics, including rifampicin and isoniazid, but they were sensitive to amikacin, moxifloxacin, levofloxacin, ethambutol, streptomycin, tobramycin, ciprofloxacin and linezolid. Conclusions: Mycobacterium thermoresistibile and Mycobacterium elephantis were isolated in a cow with mastitis and the drug susceptibility spectrum of the pathogens were unique. The results of the study can be used as reference for the prevention and control the infection in cows.

  8. [Resistance to first-line drugs and major genotypic lineages of Mycobacterium tuberculosis in the 3 French Department of the Americas: Profiles, evolution, and trends (1995-2011)].

    Science.gov (United States)

    Millet, J; Berchel, M; Prudenté, F; Streit, E; Bomer, A-G; Schuster, F; Vanhomwegen, J; Paasch, D; Galbert, I; Valery, E; Aga, R; Rastogi, N

    2014-05-01

    This is the first overview on resistant and multidrug resistant isolates of Mycobacterium tuberculosis circulating in the French Department of the Americas (Guadeloupe, Martinique, and French Guiana) over 17 years (January 1995-December 2011). A total of 1,239 cases were studied: 1,199 new cases (primary and multidrug resistance of 11.8 and 1.6% respectively), and 40 persistent (defined as cases with a previous history of positive culture over 6 months interval and whose spoligotypes remain unchanged), in which significantly higher proportions of resistance to at least isoniazid (22.5%, P = 0.002), rifampicin (20.0%, P < 0.001), and multidrug resistance (17.5%, P < 0.001) were observed as compared to new cases. The 281 spoligotypes obtained showed the presence of five major lineages, T (29.9%), LAM (23.9%), Haarlem (22.1%), EAI (7.1%), and X (6.7%). Two of these lineages, X and LAM, predominate among resistant and multidrug resistant isolates respectively (X: 10.5% of resistant isolates, P = 0.04; LAM: 42.3% of multidrug resistant isolates, P = 0.02). Four of the 19 major spoligo-profiles, corresponding to SIT 20, 64, 45, and 46, were significantly associated with drug resistance. Among them, genotype SIT 20, associated with monoresistance to isoniazid and multidrug resistance, would be actively and persistently in circulation, since 1999, in French Guiana, department in which one may also observe the presence of strains of M. tuberculosis phylogeographically associated to Guiana and Suriname (SIT 131 and SIT 1340).

  9. Evaluation of cost-effective total nucleic acids extraction protocols for cultured Mycobacterium tuberculosis; a comparison by PCR amplification of genes associated with drug resistance

    Directory of Open Access Journals (Sweden)

    Gyamfi Oti K

    2010-02-01

    Full Text Available Abstract Background The emergence of drug resistant strains of Mycobacterium tuberculosis complex has made the management of tuberculosis difficult. Also, Mycobacterium species has a peculiar cell wall, made of an impermeable complex structure rich in mycolate, making the lyses of its cell difficult. In order to apply a radio-labelled-probe based detection of mutations in selected genes leading to drug resistance, we concede that the evaluation and modifications of nucleic acid extraction protocols that are less sophisticated and less prone to contamination would be useful in the management of tuberculosis in a resource-constrained setting. Findings The average amount of nucleic acids was determined for different extraction treatments. High temperature treatment only, yielded the lowest amount of nucleic acids, i.e. 15.7 ± 3.2 μg. The average amount of nucleic acids obtained with the addition of TE and triton-X100, was 133.7 ± 8.9 μg, while that obtained with the addition of TE only, and TE and SDS were 68.4 ± 22.7 μg and 70.4 ± 20.3 μg respectively. Other treatments yielded 28.8 ± 6.7 μg, 32.5 ± 2.4 μg and 36.9 ± 15.5 μg. The average amount of nucleic acids obtained with high temperature treatment in TE, and that obtained by freezing prior to high temperature treatment, successfully amplified for the genes of interest (rpoB, KatG, rrs. Conclusion We strongly recommend the use of 1× TE buffer, and freezing and heating for improved lysis of cultured M. tuberculosis, and therefore, as an effective method for the preparation of M. tuberculosis nucleic acid useful for PCR.

  10. Prevalence and occurrence rate of Mycobacterium tuberculosis Haarlem family multi-drug resistant in the worldwide population: A systematic review and meta-analysis

    Science.gov (United States)

    Ramazanzadeh, Rashid; Roshani, Daem; Shakib, Pegah; Rouhi, Samaneh

    2015-01-01

    Background: Transmission of Mycobacterium tuberculosis (M. tuberculosis) can occur in different ways. Furthermore, drug resistant in M. tuberculosis family is a major problem that creates obstacles in treatment and control of tuberculosis (TB) in the world. One of the most prevalent families of M. tuberculosis is Haarlem, and it is associated with drug resistant. Our objectives of this study were to determine the prevalence and occurrence rate of M. tuberculosis Haarlem family multi-drug resistant (MDR) in the worldwide using meta-analysis based on a systematic review that performed on published articles. Materials and Methods: Data sources of this study were 78 original articles (2002-2012) that were published in the literatures in several databases including PubMed, Science Direct, Google Scholar, Biological abstracts, ISI web of knowledge and IranMedex. The articles were systematically reviewed for prevalence and rate of MDR. Data were analyzed using meta-analysis and random effects models with the software package Meta R, Version 2.13 (P < 0.10). Results: Final analysis included 28601 persons in 78 articles. The highest and lowest occurrence rate of Haarlem family in M. tuberculosis was in Hungary in 2006 (66.20%) with negative MDR-TB and in China in 2010 (0.8%), respectively. From 2002 to 2012, the lowest rate of prevalence was in 2010, and the highest prevalence rate was in 2012. Also 1.076% were positive for MDR and 9.22% were negative (confidence interval: 95%).0020. Conclusion: Many articles and studies are performed in this field globally, and we only chose some of them. Further studies are needed to be done in this field. Our study showed that M. tuberculosis Haarlem family is prevalent in European countries. According to the presence of MDR that was seen in our results, effective control programs are needed to control the spread of drug-resistant strains, especially Haarlem family. PMID:25767526

  11. Prevalence and occurrence rate of Mycobacterium tuberculosis Haarlem family multi-drug resistant in the worldwide population: A systematic review and meta-analysis

    Directory of Open Access Journals (Sweden)

    Rashid Ramazanzadeh

    2015-01-01

    Full Text Available Background: Transmission of Mycobacterium tuberculosis (M. tuberculosis can occur in different ways. Furthermore, drug resistant in M. tuberculosis family is a major problem that creates obstacles in treatment and control of tuberculosis (TB in the world. One of the most prevalent families of M. tuberculosis is Haarlem, and it is associated with drug resistant. Our objectives of this study were to determine the prevalence and occurrence rate of M. tuberculosis Haarlem family multi-drug resistant (MDR in the worldwide using meta-analysis based on a systematic review that performed on published articles. Materials and Methods: Data sources of this study were 78 original articles (2002-2012 that were published in the literatures in several databases including PubMed, Science Direct, Google Scholar, Biological abstracts, ISI web of knowledge and IranMedex. The articles were systematically reviewed for prevalence and rate of MDR. Data were analyzed using meta-analysis and random effects models with the software package Meta R, Version 2.13 (P < 0.10. Results: Final analysis included 28601 persons in 78 articles. The highest and lowest occurrence rate of Haarlem family in M. tuberculosis was in Hungary in 2006 (66.20% with negative MDR-TB and in China in 2010 (0.8%, respectively. From 2002 to 2012, the lowest rate of prevalence was in 2010, and the highest prevalence rate was in 2012. Also 1.076% were positive for MDR and 9.22% were negative (confidence interval: 95%.0020. Conclusion: Many articles and studies are performed in this field globally, and we only chose some of them. Further studies are needed to be done in this field. Our study showed that M. tuberculosis Haarlem family is prevalent in European countries. According to the presence of MDR that was seen in our results, effective control programs are needed to control the spread of drug-resistant strains, especially Haarlem family.

  12. Mycobacterium tuberculosis whole genome sequencing and protein structure modelling provides insights into anti-tuberculosis drug resistance

    KAUST Repository

    Phelan, Jody; Coll, Francesc; McNerney, Ruth; Ascher, David B.; Pires, Douglas E. V.; Furnham, Nick; Coeck, Nele; Hill-Cawthorne, Grant A.; Nair, Mridul; Mallard, Kim; Ramsay, Andrew; Campino, Susana; Hibberd, Martin L.; Pain, Arnab; Rigouts, Leen; Clark, Taane G.

    2016-01-01

    of 144 Mycobacterium tuberculosis clinical isolates from The Special Programme for Research and Training in Tropical Diseases (TDR) collection sourced from 20 countries in four continents. A genome-wide approach was applied to 127 isolates to identify

  13. Drug Resistance

    Science.gov (United States)

    ... Drug-resistance testing is also recommended for all pregnant women with HIV before starting HIV medicines and also in some pregnant women already taking HIV medicines. Pregnant women will work with their health ...

  14. Resistance to first-line anti-TB drugs is associated with reduced nitric oxide susceptibility in Mycobacterium tuberculosis

    DEFF Research Database (Denmark)

    Idh, Jonna; Mekonnen, Mekidim; Abate, Ebba

    2012-01-01

    The relative contribution of nitric oxide (NO) to the killing of Mycobacterium tuberculosis in human tuberculosis (TB) is controversial, although this has been firmly established in rodents. Studies have demonstrated that clinical strains of M. tuberculosis differ in susceptibility to NO, but how...

  15. Genome sequence of Mycobacterium yongonense RT 955-2015 isolate from a patient misdiagnosed with multi-drug resistant tuberculosis: first clinical isolate in Tanzania.

    Science.gov (United States)

    Mnyambwa, Nicholaus Peter; Kim, Dong-Jin; Ngadaya, Esther; Chun, Jongsik; Ha, Sung-Min; Petrucka, Pammla; Addo, Kennedy Kwasi; Kazwala, Rudovick R; Mfinanga, Sayoki G

    2018-04-24

    Mycobacterium yongonense is a recently described novel species belonging to Mycobacterium avium complex which is the most prevalent etiology of non-tuberculous mycobacteria associated with pulmonary infections, and posing tuberculosis diagnostic challenges in high-burden, resource-constrained settings. We used whole genome shotgun sequencing and comparative microbial genomic analyses to characterize the isolate from a patient diagnosed with multi-drug resistant tuberculosis (MDR-TB) after relapse. We present a genome sequence of the first case of M. yongonense (M. yongonense RT 955-2015) in Tanzania. Sequence analysis revealed that the RT 955-2015 strain had a high similarity to M. yongonense 05-1390(T) (98.74%) and M. chimaera DSM 44623(T) (98%). Its 16S rRNA showed similarity to M. paraintracellulare KCTC 290849(T) (100%); M. intracellulare ATCC 13950(T) (100%); M. chimaera DSM 44623(T) (99.9%); and M. yongonense 05-1390(T) (98%). The strain had a substantially different rpoB sequence from that of M. yongonense 05-1390 (95.16%) but exhibited a sequence closely related to M. chimaera DSM 44623(T) (99.86%), M. intracellulare ATCC 13950(T) (99.53%), and M. paraintracellulare KCTC 290849(T) (99.53%). In light of the OrthoANI algorithm, and phylogenetic analysis, we conclude that the isolate was M. yongonense Type II genotype, which is an indication that the patient was misdiagnosed with TB/MDR-TB and received inappropriate treatment. Copyright © 2018. Published by Elsevier Ltd.

  16. Drug resistance

    NARCIS (Netherlands)

    Gorter, J.A.; Potschka, H.; Noebels, J.L.; Avoli, M.; Rogawski, M.A.; Olsen, R.W.; Delgado-Escueta, A.V.

    2012-01-01

    Drug resistance remains to be one of the major challenges in epilepsy therapy. Identification of factors that contribute to therapeutic failure is crucial for future development of novel therapeutic strategies for difficult-to-treat epilepsies. Several clinical studies have shown that high seizure

  17. Antituberculosis drug resistance patterns in adults with tuberculous meningitis

    DEFF Research Database (Denmark)

    Senbayrak, Seniha; Ozkutuk, Nuri; Erdem, Hakan

    2015-01-01

    BACKGROUND: Tuberculous meningitis (TBM) caused by Mycobacterium tuberculosis resistant to antituberculosis drugs is an increasingly common clinical problem. This study aimed to evaluate drug resistance profiles of TBM isolates in adult patients in nine European countries involving 32 centers...

  18. Role of Mutations in Dihydrofolate Reductase DfrA (Rv2763c) and Thymidylate Synthase ThyA (Rv2764c) in Mycobacterium tuberculosis Drug Resistance

    KAUST Repository

    Koser, C. U.

    2010-09-17

    We would like to comment on a number of recent reports in this journal (6, 8, 12, 18) concerning Mycobacterium tuberculosis dihydrofolate reductase (DHFR), encoded by dfrA (Rv2763c). Around 36% of phenotypically para-aminosalicylic acid (PAS)-resistant M. tuberculosis strains harbor mutations in thyA (Rv2764c), which encodes a thymidylate synthase (20). In their effort to elucidate the remaining unknown resistance mechanism(s), Mathys et al. extended their sequence analysis to a number of additional genes, including dfrA (12). It was unclear whether the three dfrA mutations they identified in the PAS-resistant strains P-693 and P-3158 could contribute to PAS resistance on their own. Nonetheless, these findings are notable for two reasons. First, isoniazid (INH) has been shown to inhibit M. tuberculosis DHFR in vitro (1). Whether the same holds true for ethionamide, which shares a number of common resistance mechanisms with INH, was not tested (J. Blanchard, personal communication). In any case, the clinical relevance of DHFR-mediated INH resistance remains enigmatic. To date, only Ho et al. have addressed this question, but they did not identify any dfrA mutations in a screen of 127 INH-resistant clinical isolates (8). Consequently, Mathys et al. remain the first to describe mutations in this target (12). However, given that isolates with mutated DHFR are members of a cluster with baseline INH resistance, the importance of these mutations with respect to INH resistance remains unclear. Irrespective of their relevance in INH resistance, these dfrA mutations are noteworthy for a second reason. Contrary to previous wisdom, Forgacs et al. recently showed that M. tuberculosis is sensitive to the drug combination trimethoprim-sulfamethoxazole (TMP-SMX) (6, 18). DHFR is competitively inhibited by TMP, and consequently, mutations therein lead to resistance in a variety of organisms (9, 16, 19). The crystal structures of the wild-type M. tuberculosis DHFR in complex with

  19. Rapid drug susceptibility test of mycobacterium tuberculosis by bioluminescence sensor

    Science.gov (United States)

    Lu, Bin; Xu, Shunqing; Chen, Zifei; Zhou, Yikai

    2001-09-01

    With the persisting increase of drug-resistant stains of M. Tuberculosis around the world, rapid and sensitive detection of antibiotic of M. Tuberculosis is becoming more and more important. In the present study, drug susceptibility of M. tuberculosis were detected by recombination mycobacteriophage combined with bioluminescence sensor. It is based on the use of recombination mycobacteriophage which can express firefly luciferase when it infects viable mycobacteria, and can effectively produce quantifiable photon. Meanwhile, in mycobacterium cells treated with active antibiotic, no light is observed. The emitted light is recorded by a bioluminscence sensor, so the result of drug-resistant test can be determined by the naked eye. 159 stains of M. tuberculosis were applied to this test on their resistant to rifampin, streptomycin and isoniazid. It is found that the agreement of this assay with Liewenstein- Jensen slat is: rifampin 95.60 percent, isoniazid 91.82 percent, streptomycin 88.68 percent, which showed that it is a fast and practical method to scene and detect drug resistant of mycobacterium stains.

  20. Wild-type catalase peroxidase vs G279D mutant type: Molecular basis of Isoniazid drug resistance in Mycobacterium tuberculosis.

    Science.gov (United States)

    Singh, Aishwarya; Singh, Aditi; Grover, Sonam; Pandey, Bharati; Kumari, Anchala; Grover, Abhinav

    2018-01-30

    Mycobacterium tuberculosis katG gene is responsible for production of an enzyme catalase peroxidase that peroxidises and activates the prodrug Isoniazid (INH), a first-line antitubercular agent. INH interacts with catalase peroxidase enzyme within its heme pocket and gets converted to an active form. Mutations occurring in katG gene are often linked to reduced conversion rates for INH. This study is focussed on one such mutation occurring at residue 279, where glycine often mutates to aspartic acid (G279D). In the present study, several structural analyses were performed to study the effect of this mutation on functionality of KatG protein. On comparison, mutant protein exhibited a lower docking score, smaller binding cavity and reduced affinity towards INH. Molecular dynamics analysis revealed the mutant to be more rigid and less compact than the native protein. Essential dynamics analysis determined correlated motions of residues within the protein structure. G279D mutant was found to have many residues that showed related motions and an undesirable effect on the functionality of protein. Copyright © 2017 Elsevier B.V. All rights reserved.

  1. Characterization of drug susceptibility of Mycobacterium tuberculosis isolated from new cases of tuberculosis concurrent with HIV infection

    Directory of Open Access Journals (Sweden)

    G. V. Panov

    2015-01-01

    Full Text Available The paper characterizes drug susceptibility in Mycobacterium tuberculosis isolated from new cases of tuberculosis concurrent with HIV infection. The investigators have studied the spectrum of drug resistance in Mycobacterium tuberculosis isolated from new cases of tuberculosis concurrent with and without HIV infection (172 and 309 clinical isolates, respectively. There are differences in the rate of primary drug resistance to antituberculosis drugs in patients with and without HIV infection (59 and 43.5% of the cases, respectively. The HIV-infected have also shown high rifampicin resistance rates in Mycobacterium tuberculosis (41.7%. The reasons for these differences are as yet unknown and call for further investigation.

  2. Drug Susceptibility of Mycobacterium tuberculosis Beijing Genotype and Association with MDR TB

    Science.gov (United States)

    ten Kate, Marian T.; de Knegt, Gerjo J.; Kremer, Kristin; Aarnoutse, Rob E.; Boeree, Martin J.; Verbrugh, Henri A.; van Soolingen, Dick; Bakker-Woudenberg, Irma A.J.M.

    2012-01-01

    To determine differences in the ability of Mycobacterium tuberculosis strains to withstand antituberculosis drug treatment, we compared the activity of antituberculosis drugs against susceptible Beijing and East-African/Indian genotype M. tuberculosis strains. Beijing genotype strains showed high rates of mutation within a wide range of drug concentrations, possibly explaining this genotype’s association with multidrug-resistant tuberculosis. PMID:22469099

  3. Draft Genome Sequences of Two Extensively Drug-Resistant Strains of Mycobacterium tuberculosis Belonging to the Euro-American S Lineage

    NARCIS (Netherlands)

    Malinga, L.A.; Abeel, T.; Desjardins, C.A.; Dlamini, T.C.; Cassell, G.; Chapman, S.B.; Birren, B.W.; Earl, A.M.; Van der Walt, M.

    2016-01-01

    We report the whole-genome sequencing of two extensively drug-resistant tuberculosis strains belonging to the Euro-American S lineage. The RSA 114 strain showed single-nucleotide polymorphisms predicted to have drug efflux activity.

  4. Structural Implications of Mutations Conferring Rifampin Resistance in Mycobacterium leprae.

    Science.gov (United States)

    Vedithi, Sundeep Chaitanya; Malhotra, Sony; Das, Madhusmita; Daniel, Sheela; Kishore, Nanda; George, Anuja; Arumugam, Shantha; Rajan, Lakshmi; Ebenezer, Mannam; Ascher, David B; Arnold, Eddy; Blundell, Tom L

    2018-03-22

    The rpoB gene encodes the β subunit of RNA polymerase holoenzyme in Mycobacterium leprae (M. leprae). Missense mutations in the rpoB gene were identified as etiological factors for rifampin resistance in leprosy. In the present study, we identified mutations corresponding to rifampin resistance in relapsed leprosy cases from three hospitals in southern India which treat leprosy patients. DNA was extracted from skin biopsies of 35 relapse/multidrug therapy non-respondent leprosy cases, and PCR was performed to amplify the 276 bp rifampin resistance-determining region of the rpoB gene. PCR products were sequenced, and mutations were identified in four out of the 35 cases at codon positions D441Y, D441V, S437L and H476R. The structural and functional effects of these mutations were assessed in the context of three-dimensional comparative models of wild-type and mutant M. leprae RNA polymerase holoenzyme (RNAP), based on the recently solved crystal structures of RNAP of Mycobacterium tuberculosis, containing a synthetic nucleic acid scaffold and rifampin. The resistance mutations were observed to alter the hydrogen-bonding and hydrophobic interactions of rifampin and the 5' ribonucleotide of the growing RNA transcript. This study demonstrates that rifampin-resistant strains of M. leprae among leprosy patients in southern India are likely to arise from mutations that affect the drug-binding site and stability of RNAP.

  5. Phylogenomics and antimicrobial resistance of the leprosy bacillus Mycobacterium leprae.

    Science.gov (United States)

    Benjak, Andrej; Avanzi, Charlotte; Singh, Pushpendra; Loiseau, Chloé; Girma, Selfu; Busso, Philippe; Fontes, Amanda N Brum; Miyamoto, Yuji; Namisato, Masako; Bobosha, Kidist; Salgado, Claudio G; da Silva, Moisés B; Bouth, Raquel C; Frade, Marco A C; Filho, Fred Bernardes; Barreto, Josafá G; Nery, José A C; Bührer-Sékula, Samira; Lupien, Andréanne; Al-Samie, Abdul R; Al-Qubati, Yasin; Alkubati, Abdul S; Bretzel, Gisela; Vera-Cabrera, Lucio; Sakho, Fatoumata; Johnson, Christian R; Kodio, Mamoudou; Fomba, Abdoulaye; Sow, Samba O; Gado, Moussa; Konaté, Ousmane; Stefani, Mariane M A; Penna, Gerson O; Suffys, Philip N; Sarno, Euzenir Nunes; Moraes, Milton O; Rosa, Patricia S; Baptista, Ida M F Dias; Spencer, John S; Aseffa, Abraham; Matsuoka, Masanori; Kai, Masanori; Cole, Stewart T

    2018-01-24

    Leprosy is a chronic human disease caused by the yet-uncultured pathogen Mycobacterium leprae. Although readily curable with multidrug therapy (MDT), over 200,000 new cases are still reported annually. Here, we obtain M. leprae genome sequences from DNA extracted directly from patients' skin biopsies using a customized protocol. Comparative and phylogenetic analysis of 154 genomes from 25 countries provides insight into evolution and antimicrobial resistance, uncovering lineages and phylogeographic trends, with the most ancestral strains linked to the Far East. In addition to known MDT-resistance mutations, we detect other mutations associated with antibiotic resistance, and retrace a potential stepwise emergence of extensive drug resistance in the pre-MDT era. Some of the previously undescribed mutations occur in genes that are apparently subject to positive selection, and two of these (ribD, fadD9) are restricted to drug-resistant strains. Finally, nonsense mutations in the nth excision repair gene are associated with greater sequence diversity and drug resistance.

  6. Drug-resistant spinal tuberculosis

    Directory of Open Access Journals (Sweden)

    Anil K Jain

    2018-01-01

    Full Text Available Drug-resistant spinal tuberculosis (TB is an emerging health problem in both developing and developed countries. In this review article, we aim to define management protocols for suspicion, diagnosis, and treatment of such patients. Spinal TB is a deep-seated paucibacillary lesion, and the demonstration of acid-fast bacilli on Ziehl-Neelsen staining is possible only in 10%–30% of cases. Drug resistance is suspected in patients showing the failure of clinicoradiological improvement or appearance of a fresh lesion of osteoarticular TB while on anti tubercular therapy (ATT for a minimum period of 5 months. The conventional culture of Mycobacterium tuberculosis remains the gold standard for both bacteriological diagnosis and drug sensitivity testing (DST; however, the high turn around time of 2–6 weeks for detection with added 3 weeks for DST is a major limitation. To overcome this problem, rapid culture methods and molecular methods have been introduced. From a public health perspective, reducing the period between diagnosis and treatment initiation has direct benefits for both the patient and the community. For all patients of drug-resistant spinal TB, a complete Drug-O-Gram should be prepared which includes details of all drugs, their doses, and duration. Patients with confirmed multidrug-resistant TB strains should receive a regimen with at least five effective drugs, including pyrazinamide and one injectable. Patients with resistance to additional antitubercular drugs should receive individualized ATT as per their DST results.

  7. Assessment of trends of ofloxacin resistance in Mycobacterium tuberculosis

    Directory of Open Access Journals (Sweden)

    J S Verma

    2011-01-01

    Full Text Available Purpose: Ofloxacin (OFX is one of the potent fluoroquinolone (FQ recommended to treat MDR-TB. Over a decade, the preexposure of this drug for the treatment of other bacterial infections has resulted in acquisition of FQ resistance among Mycobacterium tuberculosis strains. Considering this possibility, a study was undertaken in a tertiary care center in the capital city (India to assess the drug resistance trends of OFX among susceptible and multidrug resistant (MDR strains of M. tuberculosis. Materials and Methods: A total of 102 M. tuberculosis isolates (47 susceptible to first-line drugs and 55 MDR isolates were screened for susceptibility testing of OFX with a critical concentration of 2 μg/ml by Lowenstein Jensen (LJ proportion method. Results: The results showed 40 (85.1% isolates among 47 susceptible isolates and 34 (61.8% isolates among 55 MDR isolates, were found to be susceptible to OFX. Fisher′s exact test showed significant P-value (0.0136 demonstrating 1.377 fold (95% confidence interval increased risk to become resistant to OFX than susceptible isolates. These finding shows decreased OFX susceptibility is not only limited to MDR isolates but also increasingly seen in susceptible strains as a result of drug abuse. Conclusions: Our finding were not alarming, but highlights the general risk of acquiring resistance to OFX, jeopardizing the potential for these drugs to be used as second-line anti-TB agents in the management of drug-resistant TB and creating incurable TB strains .

  8. Microbial sensor for drug susceptibility testing of Mycobacterium tuberculosis.

    Science.gov (United States)

    Zhang, Z-T; Wang, D-B; Li, C-Y; Deng, J-Y; Zhang, J-B; Bi, L-J; Zhang, X-E

    2018-01-01

    Drug susceptibility testing (DST) of clinical isolates of Mycobacterium tuberculosis is critical in treating tuberculosis. We demonstrate the possibility of using a microbial sensor to perform DST of M. tuberculosis and shorten the time required for DST. The sensor is made of an oxygen electrode with M. tuberculosis cells attached to its surface. This sensor monitors the residual oxygen consumption of M. tuberculosis cells after treatment with anti-TB drugs with glycerine as a carbon source. In principle, after drug pretreatment for 4-5 days, the response differences between the sensors made of drug-sensitive isolates are distinguishable from the sensors made of drug-resistant isolates. The susceptibility of the M. tuberculosis H37Ra strain, its mutants and 35 clinical isolates to six common anti-TB drugs: rifampicin, isoniazid, streptomycin, ethambutol, levofloxacin and para-aminosalicylic acid were tested using the proposed method. The results agreed well with the gold standard method (LJ) and were determined in significantly less time. The whole procedure takes approximately 11 days and therefore has the potential to inform clinical decisions. To our knowledge, this is the first study that demonstrates the possible application of a dissolved oxygen electrode-based microbial sensor in M. tuberculosis drug resistance testing. This study used the microbial sensor to perform DST of M. tuberculosis and shorten the time required for DST. The overall detection result of the microbial sensor agreed well with that of the conventional LJ proportion method and takes less time than the existing phenotypic methods. In future studies, we will build an O 2 electrode array microbial sensor reactor to enable a high-throughput drug resistance analysis. © 2017 The Authors. Journal of Applied Microbiology published by John Wiley & Sons Ltd on behalf of The Society for Applied Microbiology.

  9. Polymorphisms in Isoniazid and Prothionamide Resistance Genes of the Mycobacterium tuberculosis Complex

    KAUST Repository

    Projahn, M.; Koser, C. U.; Homolka, S.; Summers, D. K.; Archer, John A.C.; Niemann, S.

    2011-01-01

    Sequence analyses of 74 strains that encompassed major phylogenetic lineages of the Mycobacterium tuberculosis complex revealed 10 polymorphisms in mshA (Rv0486) and four polymorphisms in inhA (Rv1484) that were not responsible for isoniazid or prothionamide resistance. Instead, some of these mutations were phylogenetically informative. This genetic diversity must be taken into consideration for drug development and for the design of molecular tests for drug resistance.

  10. Polymorphisms in Isoniazid and Prothionamide Resistance Genes of the Mycobacterium tuberculosis Complex

    KAUST Repository

    Projahn, M.

    2011-06-27

    Sequence analyses of 74 strains that encompassed major phylogenetic lineages of the Mycobacterium tuberculosis complex revealed 10 polymorphisms in mshA (Rv0486) and four polymorphisms in inhA (Rv1484) that were not responsible for isoniazid or prothionamide resistance. Instead, some of these mutations were phylogenetically informative. This genetic diversity must be taken into consideration for drug development and for the design of molecular tests for drug resistance.

  11. FIND Tuberculosis Strain Bank: a Resource for Researchers and Developers Working on Tests To Detect Mycobacterium tuberculosis and Related Drug Resistance.

    Science.gov (United States)

    Tessema, Belay; Nabeta, Pamela; Valli, Eloise; Albertini, Audrey; Collantes, Jimena; Lan, Nguyen Huu; Romancenco, Elena; Tukavdze, Nestani; Denkinger, Claudia M; Dolinger, David L

    2017-04-01

    The spread of multidrug-resistant (MDR) tuberculosis (TB) and extensively drug-resistant (XDR) TB hampers global efforts in the fight against tuberculosis. To enhance the development and evaluation of diagnostic tests quickly and efficiently, well-characterized strains and samples from drug-resistant tuberculosis patients are necessary. In this project, the Foundation for Innovative New Diagnostics (FIND) has focused on the collection, characterization, and storage of such well-characterized reference materials and making them available to researchers and developers. The collection is being conducted at multiple centers in Southeast Asia, South America, Eastern Europe, and soon the sub-Saharan Africa regions. Strains are characterized for their phenotypic resistances and MICs to first-line drugs (FLDs) and second-line drugs (SLDs) using the automated MGIT 960 system following validated procedures and WHO criteria. Analysis of resistance-associated mutations is done by whole-genome sequencing (WGS) using the Illumina NextSeq system. Mycobacterial interspersed repetitive-unit-variable-number tandem-repeat analysis and WGS are used to determine strain lineages. All strains are maintained frozen at -80°C ± 10°C as distinct mother and daughter lots. All strains are extensively quality assured. The data presented here represent an analysis of the initial part of the collection. Currently, the bank contains 118 unique strains with extracted genomic DNA and matched sputum, serum, and plasma samples and will be expanded to a minimum of 1,000 unique strains over the next 3 years. Analysis of the current strains by phenotypic resistance testing shows 102 (86.4%), 10 (8.5%), and 6 (5.1%) MDR, XDR, and mono/poly resistant strains, respectively. Two of the strains are resistant to all 11 drugs that were phenotypically tested. WGS mutation analysis revealed FLD resistance-associated mutations in the rpoB , katG , inhA , embB , embA , and pncA genes; SLD resistance in the gyr

  12. Bioenergetics of Mycobacterium: An Emerging Landscape for Drug Discovery

    Directory of Open Access Journals (Sweden)

    Iram Khan Iqbal

    2018-02-01

    Full Text Available Mycobacterium tuberculosis (Mtb exhibits remarkable metabolic flexibility that enables it to survive a plethora of host environments during its life cycle. With the advent of bedaquiline for treatment of multidrug-resistant tuberculosis, oxidative phosphorylation has been validated as an important target and a vulnerable component of mycobacterial metabolism. Exploiting the dependence of Mtb on oxidative phosphorylation for energy production, several components of this pathway have been targeted for the development of new antimycobacterial agents. This includes targeting NADH dehydrogenase by phenothiazine derivatives, menaquinone biosynthesis by DG70 and other compounds, terminal oxidase by imidazopyridine amides and ATP synthase by diarylquinolines. Importantly, oxidative phosphorylation also plays a critical role in the survival of persisters. Thus, inhibitors of oxidative phosphorylation can synergize with frontline TB drugs to shorten the course of treatment. In this review, we discuss the oxidative phosphorylation pathway and development of its inhibitors in detail.

  13. Bioenergetics of Mycobacterium: An Emerging Landscape for Drug Discovery

    Science.gov (United States)

    Iqbal, Iram Khan; Bajeli, Sapna; Akela, Ajit Kumar

    2018-01-01

    Mycobacterium tuberculosis (Mtb) exhibits remarkable metabolic flexibility that enables it to survive a plethora of host environments during its life cycle. With the advent of bedaquiline for treatment of multidrug-resistant tuberculosis, oxidative phosphorylation has been validated as an important target and a vulnerable component of mycobacterial metabolism. Exploiting the dependence of Mtb on oxidative phosphorylation for energy production, several components of this pathway have been targeted for the development of new antimycobacterial agents. This includes targeting NADH dehydrogenase by phenothiazine derivatives, menaquinone biosynthesis by DG70 and other compounds, terminal oxidase by imidazopyridine amides and ATP synthase by diarylquinolines. Importantly, oxidative phosphorylation also plays a critical role in the survival of persisters. Thus, inhibitors of oxidative phosphorylation can synergize with frontline TB drugs to shorten the course of treatment. In this review, we discuss the oxidative phosphorylation pathway and development of its inhibitors in detail. PMID:29473841

  14. Antimicrobial (Drug) Resistance

    Science.gov (United States)

    ... with facebook share with twitter share with linkedin Antimicrobial (Drug) Resistance Go to Information for Researchers ► Credit: ... and infectious diseases. Why Is the Study of Antimicrobial (Drug) Resistance a Priority for NIAID? Over time, ...

  15. Drug resistance and genotypes of strains of Mycobacterium tuberculosis isolated from human immunodeficiency virus-infected and non-infected tuberculosis patients in Bauru, São Paulo, Brazil

    Directory of Open Access Journals (Sweden)

    Baptista Ida Maria Foschiani Dias

    2002-01-01

    Full Text Available Little is known about transmission and drug resistance of tuberculosis (TB in Bauru, State of São Paulo. The objective of this study was to evaluate risk factors for transmission of Mycobacterium tuberculosis strains in this area. Strains were collected from patients attended at ambulatory services in the region and susceptibility towards the main first line antibiotics was determined and fingerprinting performed. A total of 57 strains were submitted to susceptibility testing: 23 (42.6% were resistant to at least one drug while 3 (13% were resistant against both rifampicin and isoniazide. Resistant strains had been isolated from patients that had not (n = 13 or had (n = 9 previously been submitted to anti-TB treatment, demonstrating a preoccupying high level of primary resistance in the context of the study. All strains were submitted to IS6110 restriction fragment length polymorphism (IS6110-RFLP and double repetitive element PCR (DRE-PCR. Using IS6110-RFLP, 26.3% of the strains were clustered and one cluster of 3 patients included 2 HIV-infected individuals that had been hospitalized together during 16 days; clustering of strains of patients from the hospital was however not higher than that of patients attended at health posts. According to DRE-PCR, 55.3% belonged to a cluster, confirming the larger discriminatory power of IS6110-RFLP when compared to DRE-PCR, that should therefore be used as a screening procedure only. No clinical, epidemiological or microbiological characteristics were associated with clustering so risk factors for transmission of TB could not be defined in the present study.

  16. A proportion of mutations fixed in the genomes of in vitro selected isogenic drug-resistant Mycobacterium tuberculosis mutants can be detected as minority variants in the parent culture

    KAUST Repository

    Bergval, Indra; Coll, Francesc; Schuitema, Anja; de Ronde, Hans; Mallard, Kim; Pain, Arnab; McNerney, Ruth; Clark, Taane G.; Anthony, Richard M.

    2015-01-01

    We studied genomic variation in a previously selected collection of isogenic Mycobacterium tuberculosis laboratory strains subjected to one or two rounds of antibiotic selection. Whole genome sequencing analysis identified eleven single, unique mutations (four synonymous, six non-synonymous, one intergenic), in addition to drug resistance-conferring mutations, that were fixed in the genomes of six monoresistant strains. Eight loci, present as minority variants (five non-synonymous, three synonymous) in the genome of the susceptible parent strain, became fixed in the genomes of multiple daughter strains. None of these mutations are known to be involved with drug resistance. Our results confirm previously observed genomic stability for M. tuberculosis, although the parent strain had accumulated allelic variants at multiple locations in an antibiotic-free in vitro environment. It is therefore likely to assume that these so-called hitchhiking mutations were co-selected and fixed in multiple daughter strains during antibiotic selection. The presence of multiple allelic variations, accumulated under non-selective conditions, which become fixed during subsequent selective steps, deserves attention. The wider availability of 'deep' sequencing methods could help to detect multiple bacterial (sub)populations within patients with high resolution and would therefore be useful in assisting in the detailed investigation of transmission chains.

  17. A proportion of mutations fixed in the genomes of in vitro selected isogenic drug-resistant Mycobacterium tuberculosis mutants can be detected as minority variants in the parent culture

    KAUST Repository

    Bergval, Indra

    2015-01-09

    We studied genomic variation in a previously selected collection of isogenic Mycobacterium tuberculosis laboratory strains subjected to one or two rounds of antibiotic selection. Whole genome sequencing analysis identified eleven single, unique mutations (four synonymous, six non-synonymous, one intergenic), in addition to drug resistance-conferring mutations, that were fixed in the genomes of six monoresistant strains. Eight loci, present as minority variants (five non-synonymous, three synonymous) in the genome of the susceptible parent strain, became fixed in the genomes of multiple daughter strains. None of these mutations are known to be involved with drug resistance. Our results confirm previously observed genomic stability for M. tuberculosis, although the parent strain had accumulated allelic variants at multiple locations in an antibiotic-free in vitro environment. It is therefore likely to assume that these so-called hitchhiking mutations were co-selected and fixed in multiple daughter strains during antibiotic selection. The presence of multiple allelic variations, accumulated under non-selective conditions, which become fixed during subsequent selective steps, deserves attention. The wider availability of \\'deep\\' sequencing methods could help to detect multiple bacterial (sub)populations within patients with high resolution and would therefore be useful in assisting in the detailed investigation of transmission chains.

  18. MicroRNA signatures from multidrug-resistant Mycobacterium tuberculosis

    Science.gov (United States)

    REN, NA; GAO, GUIJU; SUN, YUE; ZHANG, LING; WANG, HUIZHU; HUA, WENHAO; WAN, KANGLIN; LI, XINGWANG

    2015-01-01

    Tuberculosis (TB) infections, caused by multi-drug-resistant Mycobacterium tuberculosis (MDR MTB), remain a significant public health concern worldwide. The regulatory mechanisms underlying the emergence of MDR MTB strains remain to be fully elucidated, and further investigation is required in order to develop better strategies for TB control. The present study investigated the expression profile of microRNA (miRNA) in MTB strains, and examined the differences between sensitive MTB and MDR MTB using next generation sequencing (NGS) with Illumina Deep Sequencing technology to better understand the mechanisms of resistance in MDR MTB, A total of 5, 785 and 195, and 6, 290 and 595 qualified Illumina reads were obtained from two MDR MTB strains, and 6, 673 and 665, and 7, 210 and 217 qualified Illumina reads were obtained from two sensitive MTB strains. The overall de novo assembly of miRNA sequence data generated 62 and 62, and 95 and 112 miRNAs between the 18 and 30 bp long from sensitive MTB strains and MDR MTB strains, respectively. Comparative miRNA analysis revealed that 142 miRNAs were differentially expressed in the MDR MTB strain, compared with the sensitive MTB strain, of which 48 were upregulated and 94 were downregulated. There were six similarly expressed miRNAs between the MDR and sensitive MTB strains, and 108 miRNAs were expressed only in the MDR MTB strain. The present study acquired miRNA data from sensitive MTB and MDR MTB strains using NGS techniques, and this identification miRNAs may serve as an invaluable resource for revealing the molecular basis of the regulation of expression associated with the mechanism of drug-resistance in MTB. PMID:26324150

  19. Sulfonamide-Based Inhibitors of Aminoglycoside Acetyltransferase Eis Abolish Resistance to Kanamycin in Mycobacterium tuberculosis

    Energy Technology Data Exchange (ETDEWEB)

    Garzan, Atefeh; Willby, Melisa J.; Green, Keith D.; Gajadeera, Chathurada S.; Hou, Caixia; Tsodikov, Oleg V.; Posey, James E.; Garneau-Tsodikova, Sylvie

    2016-12-08

    A two-drug combination therapy where one drug targets an offending cell and the other targets a resistance mechanism to the first drug is a time-tested, yet underexploited approach to combat or prevent drug resistance. By high-throughput screening, we identified a sulfonamide scaffold that served as a pharmacophore to generate inhibitors of Mycobacterium tuberculosis acetyltransferase Eis, whose upregulation causes resistance to the aminoglycoside (AG) antibiotic kanamycin A (KAN) in Mycobacterium tuberculosis. Rational systematic derivatization of this scaffold to maximize Eis inhibition and abolish the Eis-mediated KAN resistance of M. tuberculosis yielded several highly potent agents. A crystal structure of Eis in complex with one of the most potent inhibitors revealed that the inhibitor bound Eis in the AG-binding pocket held by a conformationally malleable region of Eis (residues 28–37) bearing key hydrophobic residues. These Eis inhibitors are promising leads for preclinical development of innovative AG combination therapies against resistant TB.

  20. Genotyping of rifampin-resistant Mycobacterium tuberculosis isolates from Western Turkey

    International Nuclear Information System (INIS)

    Cavasoglu, Cengiz; Bilgic, Altinay; Durmaz, Riza; Gunal, Selami

    2004-01-01

    Although the rate of multiple drug resistance is high there is no published data on the transmission rate of drug-resistant strains of Mycobacterium tuberculosis in the Aegean region of Western Turkey that are based on molecular methods. IS6110 and pTBN12 restriction fragment lengthpolymorphism (RFLP) methods were used for typing Mycobacterium tuberculosis isolated from 26 sputum samples from 26 patients. 19 of rifampin-resistant isolates (73.1%) contained 6 to 11 copies of 156110. Eighteen different IS6110 DNA fingerprint patterns were observed in the 26 rifampin resistant isolates. 23 of the 26 rifampin-resistant isolates were also resistant to isoniazid. When evaluated together, both methods yielded 21 (80.9%) different banding patterns and the level of clustering was 34.6%. The average number per pattern was 1.23 (26/21). IS6110 fingerprinting suggests that the rifampin-resistant isolates obtained from the Aegean region had a relatively high clustering rate and were clonally related. These findings showed that the rifampin-resistant isolates are actively transmitted between patients. Urgent measures should be taken to prevent the spread of these resistant strains. (author)

  1. Characterization of a Mycobacterium avium subsp. avium Operon Associated with Virulence and Drug Detoxification

    Directory of Open Access Journals (Sweden)

    Mariana Noelia Viale

    2014-01-01

    Full Text Available The lprG-p55 operon of Mycobacterium tuberculosis and Mycobacterium bovis is involved in the transport of toxic compounds. P55 is an efflux pump that provides resistance to several drugs, while LprG is a lipoprotein that modulates the host's immune response against mycobacteria. The knockout mutation of this operon severely reduces the replication of both mycobacterial species during infection in mice and increases susceptibility to toxic compounds. In order to gain insight into the function of LprG in the Mycobacterium avium complex, in this study, we assayed the effect of the deletion of lprG gene in the D4ER strain of Mycobacterium avium subsp. avium. The replacement of lprG gene with a hygromycin cassette caused a polar effect on the expression of p55. Also, a twofold decrease in ethidium bromide susceptibility was observed and the resistance to the antibiotics rifampicin, amikacin, linezolid, and rifabutin was impaired in the mutant strain. In addition, the mutation decreased the virulence of the bacteria in macrophages in vitro and in a mice model in vivo. These findings clearly indicate that functional LprG and P55 are necessary for the correct transport of toxic compounds and for the survival of MAA in vitro and in vivo.

  2. Inhibition of Glutamine Synthetase: A Potential Drug Target in Mycobacterium tuberculosis

    Directory of Open Access Journals (Sweden)

    Sherry L. Mowbray

    2014-08-01

    Full Text Available Tuberculosis is an infectious disease caused by Mycobacterium tuberculosis. Globally, tuberculosis is second only to AIDS in mortality and the disease is responsible for over 1.3 million deaths each year. The impractically long treatment schedules (generally 6–9 months and unpleasant side effects of the current drugs often lead to poor patient compliance, which in turn has resulted in the emergence of multi-, extensively- and totally-drug resistant strains. The development of new classes of anti-tuberculosis drugs and new drug targets is of global importance, since attacking the bacterium using multiple strategies provides the best means to prevent resistance. This review presents an overview of the various strategies and compounds utilized to inhibit glutamine synthetase, a promising target for the development of drugs for TB therapy.

  3. Increasing incidence of fluoroquinolone-resistant Mycobacterium tuberculosis in Mumbai, India.

    Science.gov (United States)

    Agrawal, D; Udwadia, Z F; Rodriguez, C; Mehta, A

    2009-01-01

    Tertiary referral centre, private hospital, Mumbai, India. To analyse the incidence of fluoroquinolone (FQ) resistant Mycobacterium tuberculosis (TB) in our laboratory from 1995 to 2004. Retrospective review and analysis of the drug susceptibility test records of all M. tuberculosis culture-positive samples from our Microbiology Department from 1995 to 2004. FQ resistance has increased exponentially in our laboratory, from 3% in 1996 to 35% in 2004. The incidence of multidrug-resistant tuberculosis has also increased during the same period, from 33% in 1995 to 56% in 2004. The incidence of FQ-resistant M. tuberculosis is gradually increasing to alarming levels. This may be due to widespread use of this vital group of drugs in the treatment of community-acquired infections. We urge that these broad spectrum antibiotics be used judiciously, and ideally be reserved for treatment of resistant TB in TB-endemic areas.

  4. Antimicrobial (Drug) Resistance Prevention

    Science.gov (United States)

    ... June 6, 2018 HIV Vaccine Elicits Antibodies in Animals that Neutralize Dozens of HIV Strains , June 4, 2018 ... Antimicrobial (Drug) Resistance > Understanding share with facebook share with twitter share ...

  5. Genome-wide re-sequencing of multidrug-resistant Mycobacterium leprae Airaku-3.

    Science.gov (United States)

    Singh, P; Benjak, A; Carat, S; Kai, M; Busso, P; Avanzi, C; Paniz-Mondolfi, A; Peter, C; Harshman, K; Rougemont, J; Matsuoka, M; Cole, S T

    2014-10-01

    Genotyping and molecular characterization of drug resistance mechanisms in Mycobacterium leprae enables disease transmission and drug resistance trends to be monitored. In the present study, we performed genome-wide analysis of Airaku-3, a multidrug-resistant strain with an unknown mechanism of resistance to rifampicin. We identified 12 unique non-synonymous single-nucleotide polymorphisms (SNPs) including two in the transporter-encoding ctpC and ctpI genes. In addition, two SNPs were found that improve the resolution of SNP-based genotyping, particularly for Venezuelan and South East Asian strains of M. leprae. © 2014 The Authors Clinical Microbiology and Infection © 2014 European Society of Clinical Microbiology and Infectious Diseases.

  6. Role of Mutations in Dihydrofolate Reductase DfrA (Rv2763c) and Thymidylate Synthase ThyA (Rv2764c) in Mycobacterium tuberculosis Drug Resistance

    KAUST Repository

    Koser, C. U.; Veerapen-Pierce, R. N.; Summers, D. K.; Archer, John A.C.

    2010-01-01

    note that the mutational loss of ThyA leads to TMP resistance in other organisms. Under these circumstances, tetrahydrofolate, the product of DHFR, is no longer required to regenerate N5,N10-methylenetetrahydrofolate, which would otherwise be oxidized

  7. Combating highly resistant emerging pathogen Mycobacterium abscessus and Mycobacterium tuberculosis with novel salicylanilide esters and carbamates.

    Science.gov (United States)

    Baranyai, Zsuzsa; Krátký, Martin; Vinšová, Jarmila; Szabó, Nóra; Senoner, Zsuzsanna; Horváti, Kata; Stolaříková, Jiřina; Dávid, Sándor; Bősze, Szilvia

    2015-08-28

    In the Mycobacterium genus over one hundred species are already described and new ones are periodically reported. Species that form colonies in a week are classified as rapid growers, those requiring longer periods (up to three months) are the mostly pathogenic slow growers. More recently, new emerging species have been identified to lengthen the list, all rapid growers. Of these, Mycobacterium abscessus is also an intracellular pathogen and it is the most chemotherapy-resistant rapid-growing mycobacterium. In addition, the cases of multidrug-resistant Mycobacterium tuberculosis infection are also increasing. Therefore there is an urgent need to find new active molecules against these threatening strains. Based on previous results, a series of salicylanilides, salicylanilide 5-chloropyrazinoates and carbamates was designed, synthesized and characterised. The compounds were evaluated for their in vitro activity on M. abscessus, susceptible M. tuberculosis H37Rv, multidrug-resistant (MDR) M. tuberculosis MDR A8, M. tuberculosis MDR 9449/2006 and on the extremely-resistant Praha 131 (XDR) strains. All derivatives exhibited a significant activity with minimum inhibitory concentrations (MICs) in the low micromolar range. Eight salicylanilide carbamates and two salicylanilide esters exhibited an excellent in vitro activity on M. abscessus with MICs from 0.2 to 2.1 μM, thus being more effective than ciprofloxacin and gentamicin. This finding is potentially promising, particularly, as M. abscessus is a threateningly chemotherapy-resistant species. M. tuberculosis H37Rv was inhibited with MICs from 0.2 μM, and eleven compounds have lower MICs than isoniazid. Salicylanilide esters and carbamates were found that they were effective also on MDR and XDR M. tuberculosis strains with MICs ≥1.0 μM. The in vitro cytotoxicity (IC50) was also determined on human MonoMac-6 cells, and selectivity index (SI) of the compounds was established. In general, salicylanilide

  8. Rapid determination of anti-tuberculosis drug resistance from whole-genome sequences

    KAUST Repository

    Coll, Francesc; McNerney, Ruth; Preston, Mark D; Guerra-Assunç ã o, José Afonso; Warry, Andrew; Hill-Cawthorne, Grant A.; Mallard, Kim; Nair, Mridul; Miranda, Anabela; Alves, Adriana; Perdigã o, Joã o; Viveiros, Miguel; Portugal, Isabel; Hasan, Zahra; Hasan, Rumina; Glynn, Judith R; Martin, Nigel; Pain, Arnab; Clark, Taane G

    2015-01-01

    Mycobacterium tuberculosis drug resistance (DR) challenges effective tuberculosis disease control. Current molecular tests examine limited numbers of mutations, and although whole genome sequencing approaches could fully characterise DR, data

  9. Laboratory methods for diagnosis and detection of drug resistant ...

    African Journals Online (AJOL)

    Data source: Published series of peer reviewed journals and manuals written on laboratory methods that are currently used for diagnosis and detection of drug resistance of Mycobacterium tuberculosis complex were reviewed using the index medicus, pubmed and medline search. Conventional bacteriological microscopy ...

  10. Kinetically Controlled Drug Resistance

    DEFF Research Database (Denmark)

    Sun, Xin E.; Hansen, Bjarne Gram; Hedstrom, Lizbeth

    2011-01-01

    The filamentous fungus Penicillium brevicompactum produces the immunosuppressive drug mycophenolic acid (MPA), which is a potent inhibitor of eukaryotic IMP dehydrogenases (IMPDHs). IMPDH catalyzes the conversion of IMP to XMP via a covalent enzyme intermediate, E-XMP*; MPA inhibits by trapping E...... of resistance is not apparent. Here, we show that, unlike MPA-sensitive IMPDHs, formation of E-XMP* is rate-limiting for both PbIMPDH-A and PbIMPDH-B. Therefore, MPA resistance derives from the failure to accumulate the drug-sensitive intermediate....

  11. Rapid, radiolabeled-microculture method that uses macrophages for in vitro evaluation of Mycobacterium leprae viability and drug susceptibility.

    Science.gov (United States)

    Mittal, A; Sathish, M; Seshadri, P S; Nath, I

    1983-04-01

    This paper describes a microculture rapid assay using radiolabeling and mouse macrophages to determine the viability and the drug susceptibility or resistance of Mycobacterium leprae. Comparison of M. leprae resident macrophage cultures maintained in 96-well flat-bottomed plates showed results for viability and susceptibility or resistance to dapsone that were similar to results for concurrent cultures in Leighton tubes with greater numbers of bacilli and macrophages.

  12. Rapid, Radiolabeled-Microculture Method That Uses Macrophages for In Vitro Evaluation of Mycobacterium leprae Viability and Drug Susceptibility

    OpenAIRE

    Mittal, A.; Sathish, M.; Seshadri, P. S.; Nath, Indira

    1983-01-01

    This paper describes a microculture rapid assay using radiolabeling and mouse macrophages to determine the viability and the drug susceptibility or resistance of Mycobacterium leprae. Comparison of M. leprae resident macrophage cultures maintained in 96-well flat-bottomed plates showed results for viability and susceptibility or resistance to dapsone that were similar to results for concurrent cultures in Leighton tubes with greater numbers of bacilli and macrophages.

  13. Genomic analysis of globally diverse Mycobacterium tuberculosis strains provides insights into emergence and spread of multidrug resistance

    Science.gov (United States)

    Manson, Abigail L.; Cohen, Keira A.; Abeel, Thomas; Desjardins, Christopher A.; Armstrong, Derek T.; Barry, Clifton E.; Brand, Jeannette; Chapman, Sinéad B.; Cho, Sang-Nae; Gabrielian, Andrei; Gomez, James; Jodals, Andreea M.; Joloba, Moses; Jureen, Pontus; Lee, Jong Seok; Malinga, Lesibana; Maiga, Mamoudou; Nordenberg, Dale; Noroc, Ecaterina; Romancenco, Elena; Salazar, Alex; Ssengooba, Willy; Velayati, A. A.; Winglee, Kathryn; Zalutskaya, Aksana; Via, Laura E.; Cassell, Gail H.; Dorman, Susan E.; Ellner, Jerrold; Farnia, Parissa; Galagan, James E.; Rosenthal, Alex; Crudu, Valeriu; Homorodean, Daniela; Hsueh, Po-Ren; Narayanan, Sujatha; Pym, Alexander S.; Skrahina, Alena; Swaminathan, Soumya; Van der Walt, Martie; Alland, David; Bishai, William R.; Cohen, Ted; Hoffner, Sven; Birren, Bruce W.; Earl, Ashlee M.

    2017-01-01

    Multidrug-resistant tuberculosis (MDR-TB), caused by drug resistant strains of Mycobacterium tuberculosis, is an increasingly serious problem worldwide. In this study, we examined a dataset of 5,310 M. tuberculosis whole genome sequences from five continents. Despite great diversity with respect to geographic point of isolation, genetic background and drug resistance, patterns of drug resistance emergence were conserved globally. We have identified harbinger mutations that often precede MDR. In particular, the katG S315T mutation, conferring resistance to isoniazid, overwhelmingly arose before rifampicin resistance across all lineages, geographic regions, and time periods. Molecular diagnostics that include markers for rifampicin resistance alone will be insufficient to identify pre-MDR strains. Incorporating knowledge of pre-MDR polymorphisms, particularly katG S315, into molecular diagnostics will enable targeted treatment of patients with pre-MDR-TB to prevent further development of MDR-TB. PMID:28092681

  14. Repurposing and Revival of the Drugs: A New Approach to Combat the Drug Resistant Tuberculosis

    Directory of Open Access Journals (Sweden)

    Divakar Sharma

    2017-12-01

    Full Text Available Emergence of drug resistant tuberculosis like multi drug resistant tuberculosis (MDR-TB, extensively drug-resistant tuberculosis (XDR-TB and totally drug resistant tuberculosis (TDR-TB has created a new challenge to fight against these bad bugs of Mycobacterium tuberculosis. Repurposing and revival of the drugs are the new trends/options to combat these worsen situations of tuberculosis in the antibiotics resistance era or in the situation of global emergency. Bactericidal and synergistic effect of repurposed/revived drugs along with the latest drugs bedaquiline and delamanid used in the treatment of MDR-TB, XDR-TB, and TDR-TB might be the choice for future promising combinatorial chemotherapy against these bad bugs.

  15. Cytosolic proteome profiling of aminoglycosides resistant Mycobacterium tuberculosis clinical isolates using MALDI-TOF/MS

    Directory of Open Access Journals (Sweden)

    Divakar Sharma

    2016-11-01

    Full Text Available Emergence of extremely drug resistant tuberculosis (XDR-TB is the consequence of the failure of second line TB treatment. Aminoglycosides are the important second line anti-TB drugs used to treat the multi drug resistant tuberculosis (MDR-TB. Main known mechanism of action of aminoglycosides is to inhibit the protein synthesis by inhibiting the normal functioning of ribosome. Primary target of aminoglycosides are the ribosomal RNA and its associated proteins. Various mechanisms have been proposed for aminoglycosides resistance but still some are unsolved. As proteins are involved in most of the biological processes, these act as a potential diagnostic markers and drug targets. In the present study we analyzed the purely cytosolic proteome of amikacin (AK and kanamycin (KM resistant Mycobacterium tuberculosis isolates by proteomic and bioinformatic approaches. Twenty protein spots were found to have over expressed in resistant isolates and were identified. Among these Rv3208A, Rv2623, Rv1360, Rv2140c, Rv1636 and Rv2185c are six proteins with unknown functions or undefined role. Docking results showed that AK and KM binds to the conserved domain (DUF, USP-A, Luciferase, PEBP and Polyketidecyclase/dehydrase domain of these hypothetical proteins and over expression of these proteins might neutralize/modulate the effect of drug molecules. TBPred and GPS-PUP predicted cytoplasmic nature and potential pupylation sites within these identified proteins respectively. String analysis also suggested that over expressed proteins along with their interactive partners might be involved in aminoglycosides resistance. Cumulative effect of these over expressed proteins could be involved in AK and KM resistance by mitigating the toxicity, repression of drug target and neutralizing affect. These findings need further exploitation for the expansion of newer therapeutics or diagnostic markers against AK and KM resistance so that an extreme condition like XDR-TB can

  16. Cytosolic Proteome Profiling of Aminoglycosides Resistant Mycobacterium tuberculosis Clinical Isolates Using MALDI-TOF/MS.

    Science.gov (United States)

    Sharma, Divakar; Lata, Manju; Singh, Rananjay; Deo, Nirmala; Venkatesan, Krishnamurthy; Bisht, Deepa

    2016-01-01

    Emergence of extensively drug resistant tuberculosis (XDR-TB) is the consequence of the failure of second line TB treatment. Aminoglycosides are the important second line anti-TB drugs used to treat the multi drug resistant tuberculosis (MDR-TB). Main known mechanism of action of aminoglycosides is to inhibit the protein synthesis by inhibiting the normal functioning of ribosome. Primary target of aminoglycosides are the ribosomal RNA and its associated proteins. Various mechanisms have been proposed for aminoglycosides resistance but still some are unsolved. As proteins are involved in most of the biological processes, these act as a potential diagnostic markers and drug targets. In the present study we analyzed the purely cytosolic proteome of amikacin (AK) and kanamycin (KM) resistant Mycobacterium tuberculosis isolates by proteomic and bioinformatic approaches. Twenty protein spots were found to have over expressed in resistant isolates and were identified. Among these Rv3208A, Rv2623, Rv1360, Rv2140c, Rv1636, and Rv2185c are six proteins with unknown functions or undefined role. Docking results showed that AK and KM binds to the conserved domain (DUF, USP-A, Luciferase, PEBP and Polyketidecyclase/dehydrase domain) of these hypothetical proteins and over expression of these proteins might neutralize/modulate the effect of drug molecules. TBPred and GPS-PUP predicted cytoplasmic nature and potential pupylation sites within these identified proteins, respectively. String analysis also suggested that over expressed proteins along with their interactive partners might be involved in aminoglycosides resistance. Cumulative effect of these over expressed proteins could be involved in AK and KM resistance by mitigating the toxicity, repression of drug target and neutralizing affect. These findings need further exploitation for the expansion of newer therapeutics or diagnostic markers against AK and KM resistance so that an extreme condition like XDR-TB can be prevented.

  17. Conjugated and Entrapped HPMA-PLA Nano-Polymeric Micelles Based Dual Delivery of First Line Anti TB Drugs: Improved and Safe Drug Delivery against Sensitive and Resistant Mycobacterium Tuberculosis.

    Science.gov (United States)

    Upadhyay, Seema; Khan, Iliyas; Gothwal, Avinash; Pachouri, Praveen K; Bhaskar, N; Gupta, Umesh D; Chauhan, Devendra S; Gupta, Umesh

    2017-09-01

    First line antiTB drugs have several physical and toxic manifestations which limit their applications. RIF is a hydrophobic drug and has low water solubility and INH is hepatotoxic. The main objective of the study was to synthesize, characterize HPMA-PLA co-polymeric micelles for the effective dual delivery of INH and RIF. HPMA-PLA co-polymer and HPMA-PLA-INH (HPI) conjugates were synthesized and characterized by FT-IR and 1 H-NMR spectroscopy. Later on RIF loaded HPMA-PLA-INH co-polymeric micelles (PMRI) were formulated and characterized for size, zeta potential and surface morphology (SEM, TEM) as well as critical micellar concentration. The safety was assessed through RBC's interaction study. The prepared PMRI were evaluated through MABA assay against sensitive and resistant strains of M. Tuberculosis. Size, zeta and entrapment efficiency for RIF loaded HPMA-PLA-INH polymeric micelles (PMRI) was 87.64 ± 1.98 nm, -19 ± 1.93 mV and 97.2 ± 1.56%, respectively. In vitro release followed controlled and sustained delivery pattern. Sustained release was also supported by release kinetics. Haemolytic toxicity of HPI and PMRI was 8.57 and 7.05% (p PLA polymeric micelles (PMRI) were more effective against sensitive and resistant M tuberculosis. The developed approach can lead to improved patient compliance and reduced dosing in future, offering improved treatment of tuberculosis.

  18. Rapid detection of multidrug-resistant Mycobacterium tuberculosis using the malachite green decolourisation assay

    Science.gov (United States)

    Coban, Ahmet Yilmaz; Uzun, Meltem

    2013-01-01

    Early detection of drug resistance in Mycobacterium tuberculosis isolates allows for earlier and more effective treatment of patients. The aim of this study was to investigate the performance of the malachite green decolourisation assay (MGDA) in detecting isoniazid (INH) and rifampicin (RIF) resistance in M. tuberculosis clinical isolates. Fifty M. tuberculosis isolates, including 19 multidrug-resistant, eight INH-resistant and 23 INH and RIF-susceptible samples, were tested. The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and agreement of the assay for INH were 92.5%, 91.3%, 92.5%, 91.3% and 92%, respectively. Similarly, the sensitivity, specificity, PPV, NPV and agreement of the assay for RIF were 94.7%, 100%, 100%, 96.8% and 98%, respectively. There was a major discrepancy in the tests of two isolates, as they were sensitive to INH by the MGDA test, but resistant by the reference method. There was a minor discrepancy in the tests of two additional isolates, as they were sensitive to INH by the reference method, but resistant by the MGDA test. The drug susceptibility test results were obtained within eight-nine days. In conclusion, the MGDA test is a reliable and accurate method for the rapid detection of INH and RIF resistance compared with the reference method and the MGDA test additionally requires less time to obtain results. PMID:24402143

  19. Rapid detection of multidrug-resistant Mycobacterium tuberculosis using the malachite green decolourisation assay

    Directory of Open Access Journals (Sweden)

    Ahmet Yilmaz Coban

    2013-12-01

    Full Text Available Early detection of drug resistance in Mycobacterium tuberculosis isolates allows for earlier and more effective treatment of patients. The aim of this study was to investigate the performance of the malachite green decolourisation assay (MGDA in detecting isoniazid (INH and rifampicin (RIF resistance in M. tuberculosis clinical isolates. Fifty M. tuberculosis isolates, including 19 multidrug-resistant, eight INH-resistant and 23 INH and RIF-susceptible samples, were tested. The sensitivity, specificity, positive predictive value (PPV, negative predictive value (NPV and agreement of the assay for INH were 92.5%, 91.3%, 92.5%, 91.3% and 92%, respectively. Similarly, the sensitivity, specificity, PPV, NPV and agreement of the assay for RIF were 94.7%, 100%, 100%, 96.8% and 98%, respectively. There was a major discrepancy in the tests of two isolates, as they were sensitive to INH by the MGDA test, but resistant by the reference method. There was a minor discrepancy in the tests of two additional isolates, as they were sensitive to INH by the reference method, but resistant by the MGDA test. The drug susceptibility test results were obtained within eight-nine days. In conclusion, the MGDA test is a reliable and accurate method for the rapid detection of INH and RIF resistance compared with the reference method and the MGDA test additionally requires less time to obtain results.

  20. Use of Mycobacterium smegmatis deficient in ADP-ribosyltransferase as surrogate for Mycobacterium tuberculosis in drug testing and mutation analysis.

    Science.gov (United States)

    Agrawal, Priyanka; Miryala, Sandeep; Varshney, Umesh

    2015-01-01

    Rifampicin (Rif) is a first line drug used for tuberculosis treatment. However, the emergence of drug resistant strains has necessitated synthesis and testing of newer analogs of Rif. Mycobacterium smegmatis is often used as a surrogate for M. tuberculosis. However, the presence of an ADP ribosyltransferase (Arr) in M. smegmatis inactivates Rif, rendering it impractical for screening of Rif analogs or other compounds when used in conjunction with them (Rif/Rif analogs). Rifampicin is also used in studying the role of various DNA repair enzymes by analyzing mutations in RpoB (a subunit of RNA polymerase) causing Rif resistance. These analyses use high concentrations of Rif when M. smegmatis is used as model. Here, we have generated M. smegmatis strains by deleting arr (Δarr). The M. smegmatis Δarr strains show minimum inhibitory concentration (MIC) for Rif which is similar to that for M. tuberculosis. The MICs for isoniazid, pyrazinamide, ethambutol, ciprofloxacin and streptomycin were essentially unaltered for M. smegmatis Δarr. The growth profiles and mutation spectrum of Δarr and, Δarr combined with ΔudgB (udgB encodes a DNA repair enzyme that excises uracil) strains were similar to their counterparts wild-type for arr. However, the mutation spectrum of ΔfpgΔarr strain differed somewhat from that of the Δfpg strain (fpg encodes a DNA repair enzyme that excises 8-oxo-G). Our studies suggest M. smegmatis Δarr strain as an ideal model system in drug testing and mutation spectrum determination in DNA repair studies.

  1. Use of Mycobacterium smegmatis deficient in ADP-ribosyltransferase as surrogate for Mycobacterium tuberculosis in drug testing and mutation analysis.

    Directory of Open Access Journals (Sweden)

    Priyanka Agrawal

    Full Text Available Rifampicin (Rif is a first line drug used for tuberculosis treatment. However, the emergence of drug resistant strains has necessitated synthesis and testing of newer analogs of Rif. Mycobacterium smegmatis is often used as a surrogate for M. tuberculosis. However, the presence of an ADP ribosyltransferase (Arr in M. smegmatis inactivates Rif, rendering it impractical for screening of Rif analogs or other compounds when used in conjunction with them (Rif/Rif analogs. Rifampicin is also used in studying the role of various DNA repair enzymes by analyzing mutations in RpoB (a subunit of RNA polymerase causing Rif resistance. These analyses use high concentrations of Rif when M. smegmatis is used as model. Here, we have generated M. smegmatis strains by deleting arr (Δarr. The M. smegmatis Δarr strains show minimum inhibitory concentration (MIC for Rif which is similar to that for M. tuberculosis. The MICs for isoniazid, pyrazinamide, ethambutol, ciprofloxacin and streptomycin were essentially unaltered for M. smegmatis Δarr. The growth profiles and mutation spectrum of Δarr and, Δarr combined with ΔudgB (udgB encodes a DNA repair enzyme that excises uracil strains were similar to their counterparts wild-type for arr. However, the mutation spectrum of ΔfpgΔarr strain differed somewhat from that of the Δfpg strain (fpg encodes a DNA repair enzyme that excises 8-oxo-G. Our studies suggest M. smegmatis Δarr strain as an ideal model system in drug testing and mutation spectrum determination in DNA repair studies.

  2. Integration of published information into a resistance-associated mutation database for Mycobacterium tuberculosis.

    Science.gov (United States)

    Salamon, Hugh; Yamaguchi, Ken D; Cirillo, Daniela M; Miotto, Paolo; Schito, Marco; Posey, James; Starks, Angela M; Niemann, Stefan; Alland, David; Hanna, Debra; Aviles, Enrique; Perkins, Mark D; Dolinger, David L

    2015-04-01

    Tuberculosis remains a major global public health challenge. Although incidence is decreasing, the proportion of drug-resistant cases is increasing. Technical and operational complexities prevent Mycobacterium tuberculosis drug susceptibility phenotyping in the vast majority of new and retreatment cases. The advent of molecular technologies provides an opportunity to obtain results rapidly as compared to phenotypic culture. However, correlations between genetic mutations and resistance to multiple drugs have not been systematically evaluated. Molecular testing of M. tuberculosis sampled from a typical patient continues to provide a partial picture of drug resistance. A database of phenotypic and genotypic testing results, especially where prospectively collected, could document statistically significant associations and may reveal new, predictive molecular patterns. We examine the feasibility of integrating existing molecular and phenotypic drug susceptibility data to identify associations observed across multiple studies and demonstrate potential for well-integrated M. tuberculosis mutation data to reveal actionable findings. © The Author 2014. Published by Oxford University Press on behalf of the Infectious Diseases Society of America. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  3. Drug resistance patterns in pulmonary tuberculosis

    International Nuclear Information System (INIS)

    Khoharo, H.K.; Shaikh, I.A.

    2011-01-01

    Objective: To determine the resistance patterns of mycobacterium tuberculosis (MTB) isolates among category I and II patients of pulmonary tuberculosis. Methods: This cross sectional study was conducted at the Department of Medicine, Liaquat University of Medical and Health Sciences Jamshoro, from November 2008 to September 2009. Patients were divided into category I and II. The sputa were collected, stained with Ziehl-Nielsen (Z-N) staining and ultimately inoculated on Lowenstein-Jensen (L-J) media for six weeks. Out of 890 pulmonary tuberculosis (PTB) patients, the growth was obtained in 285 cases. The Drug sensitivity testing (DST) for Isoniazid (INH), Rifampicin (RIF), Ethambutol (EMB) Pyrazinamide (PZA) and Streptomycin (SM) were performed. The data was analyzed on SPSS 10.0. A p-value of <0.05 was taken as significant. Result: Out of 285 cases, 176 (61.75%) were male and 109 (38.24%) female. The mean age was 37 +- 19.90 years. The DST showed drug sensitive and drug resistant isolates in 80 (28.05%) and 205 (71.92%) cases respectively (p=0.001). The drug resistant tuberculosis (DR-TB) rates for individual drugs; INH, RIF, EMB, PZA and SM were 51,22%, 15.4%, 13.33%, 9%12, and 3.85% respectively (p=0.03). The MDR-TB isolates were detected in 120 (42.10%) cases, including 5 (5.88%) in category I and 115 (57.50%) in category II patients (p=0.0001). Conclusion: Drug resistant and multidrug resistant tuberculosis was observed mainly in category II patients. However, primary MDR was also observed in category I patients and reflects dissemination of MDR cases within the community. (author)

  4. A novel marRAB operon contributes to the rifampicin resistance in Mycobacterium smegmatis.

    Science.gov (United States)

    Zhang, Haiwei; Gao, Long; Zhang, Jiaoling; Li, Weihui; Yang, Min; Zhang, Hua; Gao, Chunhui; He, Zheng-Guo

    2014-01-01

    The multiple-antibiotic resistance regulator (MarR) plays an important role in modulating bacterial antibiotic resistance. However, the regulatory model of the marRAB operon in mycobacteria remains to be characterized. Here we report that a MarR, encoded by Ms6508, and its marRAB operon specifically contribute to rifampicin (RIF) resistance in Mycobacterium smegmatis. We show that the MarR recognizes a conserved 21-bp palindromic motif and negatively regulates the expression of two ABC transporters in the operon, encoded by Ms6509-6510. Unlike other known drug efflux pumps, overexpression of these two ABC transporters unexpectedly increased RIF sensitivity and deletion of these two genes increased mycobacterial resistance to the antibiotic. No change can be detected for the sensitivity of recombinant mycobacterial strains to three other anti-TB drugs. Furthermore, HPLC experiments suggested that Ms6509-Ms6510 could pump RIF into the mycobacterial cells. These findings indicated that the mycobacterial MarR functions as a repressor and constitutively inhibits the expression of the marRAB operon, which specifically contributes to RIF resistance in M. smegmatis. Therefore, our data suggest a new regulatory mechanism of RIF resistance and also provide the new insight into the regulatory model of a marRAB operon in mycobacteria.

  5. Pyrosequencing for Rapid Detection of Mycobacterium tuberculosis Resistance to Rifampin, Isoniazid, and Fluoroquinolones ▿

    Science.gov (United States)

    Bravo, Lulette Tricia C.; Tuohy, Marion J.; Ang, Concepcion; Destura, Raul V.; Mendoza, Myrna; Procop, Gary W.; Gordon, Steven M.; Hall, Geraldine S.; Shrestha, Nabin K.

    2009-01-01

    After isoniazid and rifampin (rifampicin), the next pivotal drug class in Mycobacterium tuberculosis treatment is the fluoroquinolone class. Mutations in resistance-determining regions (RDR) of the rpoB, katG, and gyrA genes occur with frequencies of 97%, 50%, and 85% among M. tuberculosis isolates resistant to rifampin, isoniazid, and fluoroquinolones, respectively. Sequences are highly conserved, and certain mutations correlate well with phenotypic resistance. We developed a pyrosequencing assay to determine M. tuberculosis genotypic resistance to rifampin, isoniazid, and fluoroquinolones. We characterized 102 M. tuberculosis clinical isolates from the Philippines for susceptibility to rifampin, isoniazid, and ofloxacin by using the conventional submerged-disk proportion method and validated our pyrosequencing assay using these isolates. DNA was extracted and amplified by using PCR primers directed toward the RDR of the rpoB, katG, and gyrA genes, and pyrosequencing was performed on the extracts. The M. tuberculosis H37Rv strain (ATCC 25618) was used as the reference strain. The sensitivities and specificities of pyrosequencing were 96.7% and 97.3%, 63.8% and 100%, and 70.0% and 100% for the detection of resistance to rifampin, isoniazid, and ofloxacin, respectively. Pyrosequencing is thus a rapid and accurate method for detecting M. tuberculosis resistance to these three drugs. PMID:19846642

  6. Surveillance of drug resistance for tuberculosis control: why and how?

    Science.gov (United States)

    Chaulet, P; Boulahbal, F; Grosset, J

    1995-12-01

    The resistance of Mycobacterium tuberculosis to antibiotics, which reflects the quality of the chemotherapy applied in the community, is one of the elements of epidemiological surveillance used in national tuberculosis programmes. Measurement of drug resistance poses problems for biologists in standardization of laboratory methods and quality control. The definition of rates of acquired and primary drug resistance also necessitates standardization in the methods used to collect information transmitted by clinicians. Finally, the significance of the rates calculated depends on the choice of the patients sample on which sensitivity tests have been performed. National surveys of drug resistance therefore require multidisciplinary participation in order to select the only useful indicators: rates of primary resistance and of acquired resistance. These indicators, gathered in representative groups of patients over a long period, are a measurement of the impact of modern chemotherapy regimens on bacterial ecology.

  7. Role of P27 -P55 operon from Mycobacterium tuberculosis in the resistance to toxic compounds

    Directory of Open Access Journals (Sweden)

    Cataldi Angel A

    2011-07-01

    Full Text Available Abstract Background The P27-P55 (lprG-Rv1410c operon is crucial for the survival of Mycobacterium tuberculosis, the causative agent of human tuberculosis, during infection in mice. P55 encodes an efflux pump that has been shown to provide Mycobacterium smegmatis and Mycobacterium bovis BCG with resistance to several drugs, while P27 encodes a mannosylated glycoprotein previously described as an antigen that modulates the immune response against mycobacteria. The objective of this study was to determine the individual contribution of the proteins encoded in the P27-P55 operon to the resistance to toxic compounds and to the cell wall integrity of M. tuberculosis. Method In order to test the susceptibility of a mutant of M. tuberculosis H37Rv in the P27-P55 operon to malachite green, sodium dodecyl sulfate, ethidium bromide, and first-line antituberculosis drugs, this strain together with the wild type strain and a set of complemented strains were cultivated in the presence and in the absence of these drugs. In addition, the malachite green decolorization rate of each strain was obtained from decolorization curves of malachite green in PBS containing bacterial suspensions. Results The mutant strain decolorized malachite green faster than the wild type strain and was hypersensitive to both malachite green and ethidium bromide, and more susceptible to the first-line antituberculosis drugs: isoniazid and ethambutol. The pump inhibitor reserpine reversed M. tuberculosis resistance to ethidium bromide. These results suggest that P27-P55 functions through an efflux-pump like mechanism. In addition, deletion of the P27-P55 operon made M. tuberculosis susceptible to sodium dodecyl sulfate, suggesting that the lack of both proteins causes alterations in the cell wall permeability of the bacterium. Importantly, both P27 and P55 are required to restore the wild type phenotypes in the mutant. Conclusions The results clearly indicate that P27 and P55 are

  8. Emergence and spread of a human-transmissible multidrug-resistant nontuberculous mycobacterium

    DEFF Research Database (Denmark)

    Bryant, Josephine M; Grogono, Dorothy M; Rodriguez-Rincon, Daniela

    2016-01-01

    Lung infections with Mycobacterium abscessus, a species of multidrug-resistant nontuberculous mycobacteria, are emerging as an important global threat to individuals with cystic fibrosis (CF), in whom M. abscessus accelerates inflammatory lung damage, leading to increased morbidity and mortality....

  9. Molecular detection of multidrug-resistant Mycobacterium leprae from Indian leprosy patients.

    Science.gov (United States)

    Lavania, Mallika; Singh, Itu; Turankar, Ravindra P; Ahuja, Madhvi; Pathak, Vinay; Sengupta, Utpal; Das, Loretta; Kumar, Archana; Darlong, Joydeepa; Nathan, Rajeev; Maseey, Asha

    2018-03-01

    The emergence of multidrug-resistant (MDR) organisms for any infectious disease is a public health concern. Global efforts to control leprosy by intensive chemotherapy have led to a significant decrease in the number of registered patients. Currently recommended control measures for treating leprosy with multidrug therapy (MDT) were designed to prevent the spread of dapsone-resistant Mycobacterium leprae strains. Here we report the identification of MDR M. leprae from relapse leprosy patients from endemic regions in India. Resistance profiles to rifampicin, dapsone and ofloxacin of the isolated strains were confirmed by identification of mutations in genes previously shown to be associated with resistance to each drug. Between 2009-2016, slit-skin smear samples were collected from 239 relapse and 11 new leprosy cases from hospitals of The Leprosy Mission across India. DNA was extracted from the samples and was analysed by PCR targeting the rpoB, folP and gyrA genes associated with resistance to rifampicin, dapsone and ofloxacin, respectively, in M. leprae. M. leprae Thai-53 (wild-type) and Zensho-4 (MDR) were used as reference strains. Fifteen strains showed representative mutations in at least two resistance genes. Two strains showed mutations in all three genes responsible for drug resistance. Seven, seven and one strain, respectively, showed mutations in genes responsible for rifampicin and dapsone resistance, for dapsone and ofloxacin resistance and for rifampicin and ofloxacin resistance. This study showed the emergence of MDR M. leprae in MDT-treated leprosy patients from endemic regions of India. Copyright © 2017 International Society for Chemotherapy of Infection and Cancer. Published by Elsevier Ltd. All rights reserved.

  10. Molecular characterization of multidrug-resistant Mycobacterium tuberculosis isolated in Nepal.

    Science.gov (United States)

    Poudel, Ajay; Nakajima, Chie; Fukushima, Yukari; Suzuki, Haruka; Pandey, Basu Dev; Maharjan, Bhagwan; Suzuki, Yasuhiko

    2012-06-01

    Despite the fact that Nepal is one of the first countries globally to introduce multidrug-resistant tuberculosis (MDR-TB) case management, the number of MDR-TB cases is continuing to rise in Nepal. Rapid molecular tests applicable in this setting to identify resistant organisms would be an effective tool in reversing this trend. To develop such tools, information about the frequency and distribution of mutations that are associated with phenotypic drug resistance in Mycobacterium tuberculosis is required. In the present study, we investigated the prevalence of mutations in rpoB and katG genes and the inhA promoter region in 158 M. tuberculosis isolates (109 phenotypically MDR and 49 non-MDR isolates collected in Nepal) by DNA sequencing. Mutations affecting the 81-bp rifampin (RIF) resistance-determining region (RRDR) of rpoB were identified in 106 of 109 (97.3%) RIF-resistant isolates. Codons 531, 526, and 516 were the most commonly affected, at percentages of 58.7, 15.6, and 15.6%, respectively. Of 113 isoniazid (INH)-resistant isolates, 99 (87.6%) had mutations in the katG gene, with Ser315Thr being the most prevalent (81.4%) substitution. Mutations in the inhA promoter region were detected in 14 (12.4%) INH-resistant isolates. The results from this study provide an overview of the current situation of RIF and INH resistance in M. tuberculosis in Nepal and can serve as a basis for developing or improving rapid molecular tests to monitor drug-resistant strains in this country.

  11. Significance of Coexisting Mutations on Determination of the Degree of Isoniazid Resistance in Mycobacterium tuberculosis Strains.

    Science.gov (United States)

    Karunaratne, Galbokka Hewage Roshanthi Eranga; Wijesundera, Sandhya Sulochana; Vidanagama, Dhammika; Adikaram, Chamila Priyangani; Perera, Jennifer

    2018-04-23

    The emergence and spread of drug-resistant tuberculosis (TB) pose a threat to TB control in Sri Lanka. Isoniazid (INH) is a key element of the first-line anti-TB treatment regimen. Resistance to INH is mainly associated with point mutations in katG, inhA, and ahpC genes. The objective of this study was to determine mutations of these three genes in INH-resistant Mycobacterium tuberculosis (MTb) strains in Sri Lanka. Complete nucleotide sequence of the three genes was amplified by polymerase chain reaction and subjected to DNA sequencing. Point mutations in the katG gene were identified in 93% isolates, of which the majority (78.6%) were at codon 315. Mutations at codons 212 and 293 of the katG gene have not been reported previously. Novel mutations were recognized in the promoter region of the inhA gene (C deletion at -34), fabG1 gene (codon 27), and ahpC gene (codon 39). Single S315T mutation in the katG gene led to a high level of resistance, while a low level of resistance with high frequency (41%) was observed when katG codon 315 coexisted with the mutation at codon 463. Since most of the observed mutations of all three genes coexisted with the katG315 mutation, screening of katG315 mutations will be a useful marker for molecular detection of INH resistance of MTb in Sri Lanka.

  12. MicroRNA signatures from multidrug‑resistant Mycobacterium tuberculosis.

    Science.gov (United States)

    Ren, Na; Gao, Guiju; Sun, Yue; Zhang, Ling; Wang, Huizhu; Hua, Wenhao; Wan, Kanglin; Li, Xingwang

    2015-11-01

    Tuberculosis (TB) infections, caused by multidrug‑resistant Mycobacterium tuberculosis (MDR MTB), remain a significant public health concern worldwide. The regulatory mechanisms underlying the emergence of MDR MTB strains remain to be fully elucidated, and further investigation is required in order to develop better strategies for TB control. The present study investigated the expression profile of microRNA (miRNA) in MTB strains, and examined the differences between sensitive MTB and MDR MTB using next generation sequencing (NGS) with Illumina Deep Sequencing technology to better understand the mechanisms of resistance in MDR MTB, A total of 5, 785 and 195, and 6, 290 and 595 qualified Illumina reads were obtained from two MDR MTB strains, and 6, 673 and 665, and 7, 210 and 217 qualified Illumina reads were obtained from two sensitive MTB strains. The overall de novo assembly of miRNA sequence data generated 62 and 62, and 95 and 112 miRNAs between the 18 and 30 bp long from sensitive MTB strains and MDR MTB strains, respectively. Comparative miRNA analysis revealed that 142 miRNAs were differentially expressed in the MDR MTB strain, compared with the sensitive MTB strain, of which 48 were upregulated and 94 were downregulated. There were six similarly expressed miRNAs between the MDR and sensitive MTB strains, and 108 miRNAs were expressed only in the MDR MTB strain. The present study acquired miRNA data from sensitive MTB and MDR MTB strains using NGS techniques, and this identification miRNAs may serve as an invaluable resource for revealing the molecular basis of the regulation of expression associated with the mechanism of drug‑resistance in MTB.

  13. Performance of PCR-reverse blot hybridization assay for detection of rifampicin-resistant Mycobacterium leprae.

    Science.gov (United States)

    Wang, Hye-young; Kim, Hyunjung; Kim, Yeun; Bang, Hyeeun; Kim, Jong-Pill; Hwang, Joo Hwan; Cho, Sang-Nae; Kim, Tae Ue; Lee, Hyeyoung

    2015-10-01

    Drug resistance in Mycobacterium leprae is a significant problem in countries where leprosy is endemic. A sensitive, specific, and high-throughput reverse blot hybridization assay (REBA) for the detection of genotypic resistance to rifampicin (RIF) was designed and evaluated. It has been shown that resistance to RIF in M. leprae involves mutations in the rpoB gene encoding the -subunit of the RNA polymerase. The PCR-REBA simultaneously detects both 6 wild-type regions and 5 different mutations (507 AGC, 513 GTG, 516 TAT, 531 ATG, and 531 TTC) including the most prevalent mutations at positions 507 and 531. Thirty-one clinical isolates provided by Korea Institute of Hansen-s Disease were analyzed by PCR-REBA with RIF resistance of rpoB gene. As a result, missense mutations at codons 507 AGC and 531 ATG with 2-nucleotide substitutions were found in one sample, and a missense mutation at codon 516 TAT and ΔWT6 (deletion of 530-534) was found in another sample. These cases were confirmed by DNA sequence analysis. This rapid, simple, and highly sensitive assay provides a practical alternative to sequencing for genotypic evaluation of RIF resistance in M. leprae.

  14. Subspecies distribution and macrolide and fluoroquinolone resistance genetics of Mycobacterium abscessus in Korea.

    Science.gov (United States)

    Kim, J; Sung, H; Park, J-S; Choi, S-H; Shim, T-S; Kim, M-N

    2016-01-01

    Treating Mycobacterium abscessus infections with antimicrobials remains difficult, possibly due to drug resistance. To investigate the subspecies distribution of M. abscessus and its correlation with antibiotic susceptibility and the genetics of antibiotic resistance, focusing on macrolides and fluoroquinolones, in the Republic of Korea. A total of 53 M. abscessus isolates were identified to the subspecies level by sequencing of hsp65 and erm(41). The minimal inhibitory concentrations (MICs) of clarithromycin (CLM) and ciprofloxacin (CFX) were determined using Sensititre™ RAPMYCO plates. The rrl, gyrA and gyrB genes were sequenced to elucidate the molecular mechanisms of macrolide and fluoroquinolone resistance. Isolates included 22 M. abscessus subsp. abscessus and 31 M. abscessus subsp. bolletii. erm(41) sequences showing subspecies-specific deletions and sequence variations in the 28th nucleotide were concordant with inducible CLM resistance; however, mutations in rrl were not detected. Low- and high-level CFX resistance was observed in respectively 19 (35.8%) and 10 (18.9%) of the 53 clinical isolates, regardless of subspecies. However, no non-synonymous mutations were detected in gyrA or gyrB. Sequencing of the erm gene and subspeciation of M. abscessus may be used to predict inducible macrolide susceptibility. Further studies of the relationship between specific mutations in gyrA or gyrB to MIC change are required.

  15. Lipoprotein Processing Is Essential for Resistance of Mycobacterium tuberculosis to Malachite Green▿

    Science.gov (United States)

    Banaei, Niaz; Kincaid, Eleanor Z.; Lin, S.-Y. Grace; Desmond, Edward; Jacobs, William R.; Ernst, Joel D.

    2009-01-01

    Malachite green, a synthetic antimicrobial dye, has been used for over 50 years in mycobacterial culture medium to inhibit the growth of contaminants. The molecular basis of mycobacterial resistance to malachite green is unknown, although the presence of malachite green-reducing enzymes in the cell envelope has been suggested. The objective of this study was to investigate the role of lipoproteins in resistance of Mycobacterium tuberculosis to malachite green. The replication of an M. tuberculosis lipoprotein signal peptidase II (lspA) mutant (ΔlspA::lspAmut) on Middlebrook agar with and without 1 mg/liter malachite green was investigated. The lspA mutant was also compared with wild-type M. tuberculosis in the decolorization rate of malachite green and sensitivity to sodium dodecyl sulfate (SDS) detergent and first-line antituberculosis drugs. The lspA mutant has a 104-fold reduction in CFU-forming efficiency on Middlebrook agar with malachite green. Malachite green is decolorized faster in the presence of the lspA mutant than wild-type bacteria. The lspA mutant is hypersensitive to SDS detergent and shows increased sensitivity to first-line antituberculosis drugs. In summary, lipoprotein processing by LspA is essential for resistance of M. tuberculosis to malachite green. A cell wall permeability defect is likely responsible for the hypersensitivity of lspA mutant to malachite green. PMID:19596883

  16. Lipoprotein processing is essential for resistance of Mycobacterium tuberculosis to malachite green.

    Science.gov (United States)

    Banaei, Niaz; Kincaid, Eleanor Z; Lin, S-Y Grace; Desmond, Edward; Jacobs, William R; Ernst, Joel D

    2009-09-01

    Malachite green, a synthetic antimicrobial dye, has been used for over 50 years in mycobacterial culture medium to inhibit the growth of contaminants. The molecular basis of mycobacterial resistance to malachite green is unknown, although the presence of malachite green-reducing enzymes in the cell envelope has been suggested. The objective of this study was to investigate the role of lipoproteins in resistance of Mycobacterium tuberculosis to malachite green. The replication of an M. tuberculosis lipoprotein signal peptidase II (lspA) mutant (DeltalspA::lspAmut) on Middlebrook agar with and without 1 mg/liter malachite green was investigated. The lspA mutant was also compared with wild-type M. tuberculosis in the decolorization rate of malachite green and sensitivity to sodium dodecyl sulfate (SDS) detergent and first-line antituberculosis drugs. The lspA mutant has a 10(4)-fold reduction in CFU-forming efficiency on Middlebrook agar with malachite green. Malachite green is decolorized faster in the presence of the lspA mutant than wild-type bacteria. The lspA mutant is hypersensitive to SDS detergent and shows increased sensitivity to first-line antituberculosis drugs. In summary, lipoprotein processing by LspA is essential for resistance of M. tuberculosis to malachite green. A cell wall permeability defect is likely responsible for the hypersensitivity of lspA mutant to malachite green.

  17. Clinical and Drug Resistance Characteristics of New Pediatric Tuberculosis Cases in Northern China.

    Science.gov (United States)

    Wang, Ting; Dong, Fang; Li, Qin-Jing; Yin, Qing-Qin; Song, Wen-Qi; Mokrousov, Igor; Jiao, Wei-Wei; Shen, A-Dong

    2018-05-09

    The aim of this study was to evaluate the clinical features and characteristics of drug resistance in newly diagnosed pediatric tuberculosis (TB) patients in northern China. Mycobacterium tuberculosis isolates were collected from September 2010 to October 2016 at the Beijing Children's Hospital. Patients were divided into two groups (resistant to at least one drug and pan-susceptible) according to drug susceptibility testing (DST) results. A total of 132 new cases, mainly from northern China (87.9%), were included in the study. The median age was 1.9 years (1 month-15 years). Resistance to at least one drug was detected in Mycobacterium tuberculosis isolates from 33 (25%) cases. Eight cases of multidrug-resistant TB (MDR-TB) (6.1%) were detected. The two groups did not differ in clinical presentations (disease site, fever >2 weeks, and cough >2 weeks) or in chest imaging (lesion location, lymphadenitis [mediastinal], and pleural effusion). The rate of Mycobacterium tuberculosis drug resistance in new pediatric TB cases was as high as in the new adult patients surveyed in the national drug resistance survey conducted in 2007. No significant difference was observed in clinical features between patients infected with drug-resistant and drug-susceptible strains. Routine DST is important for prescribing effective antituberculosis treatment regimens.

  18. Drug susceptibility testing of Mycobacterium tuberculosis to fluoroquinolones

    DEFF Research Database (Denmark)

    Johansen, I S; Larsen, A R; Sandven, P

    2003-01-01

    In the first attempt to establish a quality assurance programme for susceptibility testing of Mycobacterium tuberculosis to fluoroquinolones, 20 strains with different fluoroquinolone susceptibility patterns were distributed by the Supranational Reference Laboratory in Stockholm to the other...

  19. Proteins with complex architecture as potential targets for drug design: a case study of Mycobacterium tuberculosis.

    Directory of Open Access Journals (Sweden)

    Bálint Mészáros

    2011-07-01

    Full Text Available Lengthy co-evolution of Homo sapiens and Mycobacterium tuberculosis, the main causative agent of tuberculosis, resulted in a dramatically successful pathogen species that presents considerable challenge for modern medicine. The continuous and ever increasing appearance of multi-drug resistant mycobacteria necessitates the identification of novel drug targets and drugs with new mechanisms of action. However, further insights are needed to establish automated protocols for target selection based on the available complete genome sequences. In the present study, we perform complete proteome level comparisons between M. tuberculosis, mycobacteria, other prokaryotes and available eukaryotes based on protein domains, local sequence similarities and protein disorder. We show that the enrichment of certain domains in the genome can indicate an important function specific to M. tuberculosis. We identified two families, termed pkn and PE/PPE that stand out in this respect. The common property of these two protein families is a complex domain organization that combines species-specific regions, commonly occurring domains and disordered segments. Besides highlighting promising novel drug target candidates in M. tuberculosis, the presented analysis can also be viewed as a general protocol to identify proteins involved in species-specific functions in a given organism. We conclude that target selection protocols should be extended to include proteins with complex domain architectures instead of focusing on sequentially unique and essential proteins only.

  20. Au-nanoprobes for detection of SNPs associated with antibiotic resistance in Mycobacterium tuberculosis

    International Nuclear Information System (INIS)

    Veigas, Bruno; Baptista, Pedro V; Machado, Diana; Couto, Isabel; Viveiros, Miguel; Perdigao, Joao; Portugal, Isabel

    2010-01-01

    Tuberculosis (TB) is one of the leading causes of infection in humans, causing high morbility and mortality all over the world. The rate of new cases of multidrug resistant tuberculosis (MDRTB) continues to increase, and since these infections are very difficult to manage, they constitute a serious health problem. In most cases, drug resistance in Mycobacterium tuberculosis has been related to mutations in several loci within the pathogen's genome. The development of fast, cheap and simple screening methodologies would be of paramount relevance for the early detection of these mutations, essential for the timely and effective diagnosis and management of MDRTB patients. The use of gold nanoparticles derivatized with thiol-modified oligonucleotides (Au-nanoprobes) has led to new approaches in molecular diagnostics. Based on the differential non-cross-linking aggregation of Au-nanoprobes, we were able to develop a colorimetric method for the detection of specific sequences and to apply this approach to pathogen identification and single base mutations/single nucleotide polymorphisms (SNP) discrimination. Here we report on the development of Au-nanoprobes for the specific identification of SNPs within the beta subunit of the RNA polymerase (rpoB locus), responsible for resistance to rifampicin in over 95% of rifampicin resistant M. tuberculosis strains.

  1. Au-nanoprobes for detection of SNPs associated with antibiotic resistance in Mycobacterium tuberculosis

    Energy Technology Data Exchange (ETDEWEB)

    Veigas, Bruno; Baptista, Pedro V [CIGMH, Departamento de Ciencias da Vida, Faculdade de Ciencias e Tecnologia, Universidade Nova de Lisboa, Caparica (Portugal); Machado, Diana; Couto, Isabel; Viveiros, Miguel [Unidade de Micobacterias, Instituto de Higiene e Medicina Tropical, Universidade Nova de Lisboa (IHMT/UNL) (Portugal); Perdigao, Joao; Portugal, Isabel, E-mail: pmvb@fct.unl.pt [Centro de Patogenese Molecular/URIA, Faculdade de Farmacia, Universidade de Lisboa, Lisboa (Portugal)

    2010-10-15

    Tuberculosis (TB) is one of the leading causes of infection in humans, causing high morbility and mortality all over the world. The rate of new cases of multidrug resistant tuberculosis (MDRTB) continues to increase, and since these infections are very difficult to manage, they constitute a serious health problem. In most cases, drug resistance in Mycobacterium tuberculosis has been related to mutations in several loci within the pathogen's genome. The development of fast, cheap and simple screening methodologies would be of paramount relevance for the early detection of these mutations, essential for the timely and effective diagnosis and management of MDRTB patients. The use of gold nanoparticles derivatized with thiol-modified oligonucleotides (Au-nanoprobes) has led to new approaches in molecular diagnostics. Based on the differential non-cross-linking aggregation of Au-nanoprobes, we were able to develop a colorimetric method for the detection of specific sequences and to apply this approach to pathogen identification and single base mutations/single nucleotide polymorphisms (SNP) discrimination. Here we report on the development of Au-nanoprobes for the specific identification of SNPs within the beta subunit of the RNA polymerase (rpoB locus), responsible for resistance to rifampicin in over 95% of rifampicin resistant M. tuberculosis strains.

  2. Multi drug resistance tuberculosis: pattern seen in last 13 years

    International Nuclear Information System (INIS)

    Iqbal, R.; Shabbir, I.; Munir, K.; Tabassum, M.N.; Khan, S.U.; Khan, M.Z.U.

    2011-01-01

    Background: Drug resistance in tuberculosis is a serious problem throughout the world especially, after the emergence of multi drug resistant TB strains. Objectives: To estimate drug resistance in TB patients and compare it with previous studies to see the changing trends. Materials and Methods: The PMRC Research Centre receives sputum samples from all the leading hospitals of Lahore. This retrospective analysis was done from 1996 to 2008 on the multi drug resistant TB strains that were seen during these years. Five first lines anti tuberculosis drugs were tested on Lowenstein Jensen medium using standard proportion method. Results: A total of 2661 confirmed isolates of Mycobacterium tuberculosis were seen over the past 13 years. Of the total, 2182 were pulmonary and 479 were extra pulmonary specimens. The patients comprised of those with and without history of previous treatment. These specimens were subjected to drug susceptibility testing. Almost half of the patient had some resistance; multiple drug resistance was seen in 12.3% and 23.0% cases without and with history of previous treatment respectively. Overall resistance to rifampicin was 26.4%, isoniazid 24.1% streptomycin 21.6% ethambutol 13.4% and pyrazinamide 28.4% respectively. Statistically significant difference was seen between primary and acquired resistance. When compared with the reports from previous studies from the same area, there was a trend of gradual increase of drug resistance. Conclusions Resistance to anti tuberculosis drugs is high. Policy message. TB Control Program should start 'DOTS Plus' schemes for which drug susceptibility testing facilities should be available for correctly managing the patients. (author)

  3. Multi drug resistance tuberculosis: pattern seen in last 13 years

    Energy Technology Data Exchange (ETDEWEB)

    Iqbal, R; Shabbir, I; Munir, K [King Edward Medical University Hospital, Lahore (Pakistan). Dept. of Research Centre; Tabassum, M N; Khan, S U; Khan, M Z.U. [King Edward Medical University Hospital, Lahore (Pakistan). Dept. of Chest Medicine

    2011-01-15

    Background: Drug resistance in tuberculosis is a serious problem throughout the world especially, after the emergence of multi drug resistant TB strains. Objectives: To estimate drug resistance in TB patients and compare it with previous studies to see the changing trends. Materials and Methods: The PMRC Research Centre receives sputum samples from all the leading hospitals of Lahore. This retrospective analysis was done from 1996 to 2008 on the multi drug resistant TB strains that were seen during these years. Five first lines anti tuberculosis drugs were tested on Lowenstein Jensen medium using standard proportion method. Results: A total of 2661 confirmed isolates of Mycobacterium tuberculosis were seen over the past 13 years. Of the total, 2182 were pulmonary and 479 were extra pulmonary specimens. The patients comprised of those with and without history of previous treatment. These specimens were subjected to drug susceptibility testing. Almost half of the patient had some resistance; multiple drug resistance was seen in 12.3% and 23.0% cases without and with history of previous treatment respectively. Overall resistance to rifampicin was 26.4%, isoniazid 24.1% streptomycin 21.6% ethambutol 13.4% and pyrazinamide 28.4% respectively. Statistically significant difference was seen between primary and acquired resistance. When compared with the reports from previous studies from the same area, there was a trend of gradual increase of drug resistance. Conclusions Resistance to anti tuberculosis drugs is high. Policy message. TB Control Program should start 'DOTS Plus' schemes for which drug susceptibility testing facilities should be available for correctly managing the patients. (author)

  4. Multi drug resistant tuberculosis presenting as anterior mediastinal mass

    Directory of Open Access Journals (Sweden)

    Parmarth Chandane

    2016-01-01

    Full Text Available Enlargement of the mediastinal lymphatic glands is a common presentation of intrathoracic tuberculosis (TB in children. However, usually, the mediastinal TB nodes enlarge to 2.8 ± 1.0 cm. In this report, we describe a case of anterior mediastinal lymphnode TB seen as huge mass (7 cm on computed tomography (CT thorax without respiratory or food pipe compromise despite anterior mediastinum being an enclosed space. CT guided biopsy of the mass cultured Mycobacterium TB complex which was resistant to isoniazide, rifampicin, streptomycin ofloxacin, moxifloxacin, and pyrazinamide. Hence, we report primary multi drug resistant TB presenting as anterior mediastinal mass as a rare case report.

  5. Maximum flow approach to prioritize potential drug targets of Mycobacterium tuberculosis H37Rv from protein-protein interaction network.

    Science.gov (United States)

    Melak, Tilahun; Gakkhar, Sunita

    2015-12-01

    In spite of the implementations of several strategies, tuberculosis (TB) is overwhelmingly a serious global public health problem causing millions of infections and deaths every year. This is mainly due to the emergence of drug-resistance varieties of TB. The current treatment strategies for the drug-resistance TB are of longer duration, more expensive and have side effects. This highlights the importance of identification and prioritization of targets for new drugs. This study has been carried out to prioritize potential drug targets of Mycobacterium tuberculosis H37Rv based on their flow to resistance genes. The weighted proteome interaction network of the pathogen was constructed using a dataset from STRING database. Only a subset of the dataset with interactions that have a combined score value ≥770 was considered. Maximum flow approach has been used to prioritize potential drug targets. The potential drug targets were obtained through comparative genome and network centrality analysis. The curated set of resistance genes was retrieved from literatures. Detail literature review and additional assessment of the method were also carried out for validation. A list of 537 proteins which are essential to the pathogen and non-homologous with human was obtained from the comparative genome analysis. Through network centrality measures, 131 of them were found within the close neighborhood of the centre of gravity of the proteome network. These proteins were further prioritized based on their maximum flow value to resistance genes and they are proposed as reliable drug targets of the pathogen. Proteins which interact with the host were also identified in order to understand the infection mechanism. Potential drug targets of Mycobacterium tuberculosis H37Rv were successfully prioritized based on their flow to resistance genes of existing drugs which is believed to increase the druggability of the targets since inhibition of a protein that has a maximum flow to

  6. Drug susceptibility of Mycobacterium tuberculosis in a rural area of Bangladesh and its relevance to the national treatment regimens.

    Science.gov (United States)

    Van Deun, A; Aung, K J; Chowdhury, S; Saha, S; Pankaj, A; Ashraf, A; Rigouts, L; Fissette, K; Portaels, F

    1999-02-01

    Greater Mymensingh District, a rural area of Bangladesh, at the start of the National Tuberculosis Programme (NTP). To determine the prevalence of initial and acquired drug resistance of Mycobacterium tuberculosis, and to assess the appropriateness of the NTP's standard regimens. Sampling of pre-treatment sputum from all newly registered smear-positive cases in five centres covering the area. Culture and susceptibility testing in a supra-national reference laboratory. Initial resistance to isoniazid (H) was 5.4%, and to rifampicin (R) 0.5%. Acquired H and R resistance were 25.9% and 7.4%, respectively. Multidrug resistance (MDR) was observed in one new case only and in 5.6% of previously treated patients. Changing the present NTP indication for retreatment regimen to one month of previous H intake would increase coverage of H-resistant cases from 52% to 89%, adding 6% to drug costs. The prevalence of drug resistance is surprisingly low in Bangladesh, but could rise with improving economic conditions. The NTP regimens for smear-positive cases are appropriate, all the more so since the human immunodeficiency virus is virtually absent. Indications for the retreatment regimen should be extended to include all patients treated for at least one month with any drug. The NTP regimen for smear-negative cases runs the risk of leading to MDR under present field conditions.

  7. PCR-Restriction Fragment Length Polymorphism for Rapid, Low-Cost Identification of Isoniazid-Resistant Mycobacterium tuberculosis▿

    Science.gov (United States)

    Caws, Maxine; Tho, Dau Quang; Duy, Phan Minh; Lan, Nguyen Thi Ngoc; Hoa, Dai Viet; Torok, Mili Estee; Chau, Tran Thi Hong; Van Vinh Chau, Nguyen; Chinh, Nguyen Tran; Farrar, Jeremy

    2007-01-01

    PCR-restriction fragment length poymorphism (PCR-RFLP) is a simple, robust technique for the rapid identification of isoniazid-resistant Mycobacterium tuberculosis. One hundred consecutive isolates from a Vietnamese tuberculosis hospital were tested by MspA1I PCR-RFLP for the detection of isoniazid-resistant katG_315 mutants. The test had a sensitivity of 80% and a specificity of 100% against conventional phenotypic drug susceptibility testing. The positive and negative predictive values were 1 and 0.86, respectively. None of the discrepant isolates had mutant katG_315 codons by sequencing. The test is cheap (less than $1.50 per test), specific, and suitable for the rapid identification of isoniazid resistance in regions with a high prevalence of katG_315 mutants among isoniazid-resistant M. tuberculosis isolates. PMID:17428939

  8. Molecular Identification of Mycobacterium Tuberculosis and Analysis of Its Resistance to Rifampin in Sputa from Tuberculosis Suspected Patients

    International Nuclear Information System (INIS)

    Syaifudin, M.

    2010-01-01

    An accurate identification of different species of Mycobacterium provides to allow appropriate treatment for Mycobacterium tuberculosis infection. Beside that, drug resistance of M. tuberculosis strains to rifampin is not clearly understood in contributing to the spread of tuberculosis in Indonesia. To assess the molecular mechanism of rifampin resistance, a number of clinical specimens of M. tuberculosis were analyzed their molecular nature of a part of the rpoB gene using polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) methods. DNA's extracted from sputum samples were amplified and 32 P-labeled by PCR with the specific primers and the product was analyzed their mutation conferring resistance by MDE gel electrophoresis. Of the 70 specimens tested, 57 specimens were positive for M. tuberculosis organism only, three specimens contained a mixture of M. tuberculosis and non tuberculosis mycobacteria (NTM), and 10 specimens were negative approved by Duplex PCR. Of these sixty DNA positive samples (thus the sensitivity of PCR was 85.71%), 5 (8.3%) of them suspected to contain mutations in rpoB which were associated with rifampin resistance. Even though the frequency of mutation was low, the results from our study clearly indicate that the molecular mechanism of rifampin resistance in M. tuberculosis isolates from Indonesia involves alterations in the rpoB gene. Molecular diagnosis by PCR which is fast and easy to perform is useful for early and rapid detection of TB in sputum specimen. (author)

  9. Mutation at codon 442 in the rpoB gene of Mycobacterium leprae does not confer resistance to rifampicin.

    Science.gov (United States)

    Lavania, Mallika; Hena, Abu; Reja, Hasanoor; Nigam, Astha; Biswas, Nibir Kumar; Singh, Itu; Turankar, Ravindra P; Gupta, Ud; Kumar, Senthil; Rewaria, Latika; Patra, Pradip K R; Sengupta, Utpal; Bhattacharya, Basudeb

    2016-03-01

    Rifampicin is the major drug in the treatment of leprosy. The rifampicin resistance of Mycobacterium leprae results from a mutation in the rpoB gene, encoding the β subunit of RNA polymerase. As M. leprae is a non-cultivable organism observation of its growth using mouse food-pad (MFP) is the only Gold Standard assay used for confirmation of "in-vivo" drug resistance. Any mutation at molecular level has to be verified by MFP assay for final confirmation of drug resistance in leprosy. In the present study, M. leprae strains showing a mutation only at codon 442 Gln-His and along with mutation either at codon 424 Val-Gly or at 438 Gln-Val within the Rifampicin Resistance Determining Region (RRDR) confirmed by DNA sequencing and by high resolution melting (HRM) analysis were subjected for its growth in MFP. The M. leprae strain having the new mutation at codon 442 Gln-His was found to be sensitive to all the three drugs and strains having additional mutations at 424 Val-Gly and 438 Gln-Val were conferring resistance with Multi drug therapy (MDT) in MFP. These results indicate that MFP is the gold standard method for confirming the mutations detected by molecular techniques.

  10. Enriched whole genome sequencing identified compensatory mutations in the RNA polymerase gene of rifampicin-resistant Mycobacterium leprae strains.

    Science.gov (United States)

    Lavania, Mallika; Singh, Itu; Turankar, Ravindra P; Gupta, Anuj Kumar; Ahuja, Madhvi; Pathak, Vinay; Sengupta, Utpal

    2018-01-01

    Despite more than three decades of multidrug therapy (MDT), leprosy remains a major public health issue in several endemic countries, including India. The emergence of drug resistance in Mycobacterium leprae (M. leprae) is a cause of concern and poses a threat to the leprosy-control program, which might ultimately dampen the achievement of the elimination program of the country. Rifampicin resistance in clinical strains of M. leprae are supposed to arise from harboring bacterial strains with mutations in the 81-bp rifampicin resistance determining region (RRDR) of the rpoB gene. However, complete dynamics of rifampicin resistance are not explained only by this mutation in leprosy strains. To understand the role of other compensatory mutations and transmission dynamics of drug-resistant leprosy, a genome-wide sequencing of 11 M. leprae strains - comprising five rifampicin-resistant strains, five sensitive strains, and one reference strain - was done in this study. We observed the presence of compensatory mutations in two rifampicin-resistant strains in rpoC and mmpL7 genes, along with rpoB , that may additionally be responsible for conferring resistance in those strains. Our findings support the role for compensatory mutation(s) in RNA polymerase gene(s), resulting in rifampicin resistance in relapsed leprosy patients.

  11. Resistance patterns and trends of extensively drug-resistant tuberculosis: 5-year experience

    Directory of Open Access Journals (Sweden)

    Amresh Kumar Singh

    2013-12-01

    Full Text Available Objective:Extensively drug-resistant tuberculosis (XDR-TB strains were emerged when multidrug-resistant TB (MDR- TB was inadequately treated. Inadequate treatment of MDR-TB cases may result in additional resistance especially non-XDR-TB and then XDR-TB. The aim of this study was to know the prevalence, resistance patterns and trends of the XDR-TB strains among the MDR-TB at a tertiary care hospital in Lucknow, India Methods: A total of 430 Mycobacterium isolates were underwent NAP test and TB MPT64 Ag test for the identification of Mycobacterium tuberculosis complex (MTBC. Drug-susceptibility test (DST was performed over MTBC for the first line drugs by 1% proportion method (Bactec and for the second-line drugs by 1% proportion method (Lowenstein- Jensen media. The XDR-TB status was further confirmed by line probe assay (GenoType® MTBDRsl assay. Results: Among the 430 isolates of mycobacterium, 365 (84.9% were MTBC and 139 (38.1% were MDR-TB respectively. Further 97 MDR-TB from “highly suspected drug resistant-TB (DR-TB” cases among MDR-TB were tested with second line drugs in which 15 (15.5% XDR-TB and 82 (84.5% were non-XDR-TB. Regarding XDR-TB status, using the 1% proportion method a 100% agreement was seen with the GenoType® MTBDRsl assay. Resistance patterns of XDR-TB were as; 10/15 (66.7% as isoniazid + rifampicin + ciprofloxacin + amikacin resistance and 5/15 (33.3% as isoniazid + rifampicin + ciprofloxacin + amikacin + kanamycin resistance. Conclusion:The prevalence of XDR-TB was 15.5% among MDR-TB. Hence laboratory testing of “highly suspected drug resistant-TB” isolates should be done for both first and second line drugs simultaneously especially in developing countries.J Microbiol Infect Dis 2013;3(4: 169-175

  12. High prevalence of multidrug-resistant tuberculosis among patients with rifampicin resistance using GeneXpert Mycobacterium tuberculosis/rifampicin in Ghana.

    Science.gov (United States)

    Boakye-Appiah, Justice K; Steinmetz, Alexis R; Pupulampu, Peter; Ofori-Yirenkyi, Stephen; Tetteh, Ishmael; Frimpong, Michael; Oppong, Patrick; Opare-Sem, Ohene; Norman, Betty R; Stienstra, Ymkje; van der Werf, Tjip S; Wansbrough-Jones, Mark; Bonsu, Frank; Obeng-Baah, Joseph; Phillips, Richard O

    2016-06-01

    Drug-resistant strains of tuberculosis (TB) represent a major threat to global TB control. In low- and middle-income countries, resource constraints make it difficult to identify and monitor cases of resistance using drug susceptibility testing and culture. Molecular assays such as the GeneXpert Mycobacterium tuberculosis/rifampicin may prove to be a cost-effective solution to this problem in these settings. The objective of this study is to evaluate the use of GeneXpert in the diagnosis of pulmonary TB since it was introduced into two tertiary hospitals in Ghana in 2013. A 2-year retrospective audit of clinical cases involving patients who presented with clinically suspected TB or documented TB not improving on standard therapy and had samples sent for GeneXpert testing. GeneXpert identified 169 cases of TB, including 17 cases of rifampicin-resistant TB. Of the seven cases with final culture and drug susceptibility testing results, six demonstrated further drug resistance and five of these were multidrug-resistant TB. These findings call for a scale-up of TB control in Ghana and provide evidence that the expansion of GeneXpert may be an optimal means to improve case finding and guide treatment of drug-resistant TB in this setting. Copyright © 2016. Published by Elsevier Ltd.

  13. Computational Studies of Drug Resistance

    DEFF Research Database (Denmark)

    da Silva Martins, João Miguel

    Drug resistance has been an increasing problem in patient treatment and drug development. Starting in the last century and becoming a major worry in the medical and scienti c communities in the early part of the current millennium, major research must be performed to address the issues of viral...... is of the utmost importance in developing better and less resistance-inducing drugs. A drug's in uence can be characterized in many diff erent ways, however, and the approaches I take in this work re ect those same different in uences. This is what I try to achieve in this work, through seemingly unrelated...... approaches that come together in the study of drug's and their in uence on proteins and vice-versa. In part I, I aim to understand through combined theoretical ensemble analysis and free energy calculations the e ects mutations have over the binding anity and function of the M2 proton channel. This research...

  14. Drug-resistant tuberculosis

    African Journals Online (AJOL)

    statistics show that almost half a million new ... testing for second-line drugs, no international consensus has been reached about .... Given the high background rates of TB and MDR-TB in several countries, regimens are often constructed ...

  15. Genetic Mimetics of Mycobacterium tuberculosis and Methicillin-Resistant Staphylococcus aureus as Verification Standards for Molecular Diagnostics.

    Science.gov (United States)

    Machowski, Edith Erika; Kana, Bavesh Davandra

    2017-12-01

    Molecular diagnostics have revolutionized the management of health care through enhanced detection of disease or infection and effective enrollment into treatment. In recognition of this, the World Health Organization approved the rollout of nucleic acid amplification technologies for identification of Mycobacterium tuberculosis using platforms such as GeneXpert MTB/RIF, the GenoType MTBDR plus line probe assay, and, more recently, GeneXpert MTB/RIF Ultra. These assays can simultaneously detect tuberculosis infection and assess rifampin resistance. However, their widespread use in health systems requires verification and quality assurance programs. To enable development of these, we report the construction of genetically modified strains of Mycobacterium smegmatis that mimic the profile of Mycobacterium tuberculosis on both the GeneXpert MTB/RIF and the MTBDR plus line probe diagnostic tests. Using site-specific gene editing, we also created derivatives that faithfully mimic the diagnostic result of rifampin-resistant M. tuberculosis , with mutations at positions 513, 516, 526, 531, and 533 in the rifampin resistance-determining region of the rpoB gene. Next, we extended this approach to other diseases and demonstrated that a Staphylococcus aureus gene sequence can be introduced into M. smegmatis to generate a positive response for the SCC mec probe in the GeneXpert SA Nasal Complete molecular diagnostic cartridge, designed for identification of methicillin-resistant S. aureus These biomimetic strains are cost-effective, have low biohazard content, accurately mimic drug resistance, and can be produced with relative ease, thus illustrating their potential for widespread use as verification standards for diagnosis of a variety of diseases. Copyright © 2017 American Society for Microbiology.

  16. Identification and Genetic Diversity of Etambutol Resistant Strains of Mycobacterium Tuberculosis by Allelic-Specific PCR and Spologiotyping

    Directory of Open Access Journals (Sweden)

    Zahra Derakhshani Nezhad

    2012-09-01

    Full Text Available Background & Objectives: Ethambutol is one of the four main drugs in treatment of tuberculosis. The most common mutation associated with this drug resistance usually occurs in codon 306 of embB. The aim of this study was to detect ethambutol resistance using Allele-Specific PCR and Spoligotyping in various subtypes of Mycobacterium tuberculosis.   Methods : 140 sputum specimens were collected from suspected TB patients. They were digested and decontaminated using Pettrof method before culturing them on LJ medium. Drug susceptibility testing was performed on 106 culture positive specimens using proportional method. DNA was extracted from the isolated organisms and subsequently subjected to Allele-Specific PCR to detect any mutationin embB306. Spoligotyping was then used to determine the subtypes.   Results: Out of 106 cultures positive samples, 36 samples (33.9% showed resistance to ethambutol using proportional method. Allele-Specific PCR assay identified 93 as sensitive and 13 (27.6% as resistant strains. The results of PCR were in agreement with result of proportional method. The PCR method revealed that 61.5% of mutation occurred in the first and 38.5% in third nucleotides. Spoligotyping differentiated Mycobacterium tuberculosis strains into Beijing (10 9.4%, Bovis (2 1.8%, CAS (24 22.6%, EAI (1 0.9%, Haarlem (27 25.4%, LAM (5 4.7%, Manu (5 4.7%, T (27 25.4% and U( 2 1,8% families. The high frequency of mutation in embB gene was belonged to Haarlem, CAS and T subfamilies.   Conclusion: Based on results current study, mutations in the genes other than embB might have occurred in the resistant strains that gave negative result in Allele-Specific PCR assay. Therefore other mechanisms of resistance to this antibiotic should be investigated.

  17. Transmission of Drug-Resistant Leprosy in Guinea-Conakry Detected Using Molecular Epidemiological Approaches.

    Science.gov (United States)

    Avanzi, Charlotte; Busso, Philippe; Benjak, Andrej; Loiseau, Chloé; Fomba, Abdoulaye; Doumbia, Glodia; Camara, Idrissa; Lamou, André; Sock, Gouressy; Drame, Tiguidanké; Kodio, Mamadou; Sakho, Fatoumata; Sow, Samba O; Cole, Stewart T; Johnson, Roch Christian

    2016-12-01

    Molecular drug susceptibility testing was performed on skin biopsies from 24 leprosy patients from Guinea-Conakry for the first time. We identified primary drug resistance in 4 cases and a dapsone-resistant cluster caused by the same strain. Primary transmission of drug-resistant Mycobacterium leprae, including a rifampicin-resistant strain, is reported. © The Author 2016. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail journals.permissions@oup.com.

  18. High prevalence of drug-resistant tuberculosis, Republic of Lithuania, 2002

    DEFF Research Database (Denmark)

    Dewan, P; Sosnovskaja, A; Thomsen, V

    2005-01-01

    BACKGROUND: Nations of the former Soviet Union have the world's highest reported levels of resistance to anti-tuberculosis drugs. We conducted the first national survey of anti-tuberculosis drug resistance in the Republic of Lithuania. METHODS: We tested Mycobacterium tuberculosis isolates from all...... isolates, 475 (41%) were resistant to at least one first-line drug, and 263 (23%) were resistant to at least INH and RMP (MDR); this included 76/818 (9.3%) from new patients and 187/345 (54%) from previously treated patients. Of 52 MDR isolates randomly selected for extended testing at an international...

  19. Mutations in DNA repair genes are associated with the Haarlem lineage of Mycobacterium tuberculosis independently of their antibiotic resistance.

    Science.gov (United States)

    Olano, Juanita; López, Beatriz; Reyes, Alejandro; Lemos, María del Pilar; Correa, Nidia; Del Portillo, Patricia; Barrera, Lucia; Robledo, Jaime; Ritacco, Viviana; Zambrano, María Mercedes

    2007-11-01

    The analysis of the DNA repair genes ogt and ung was carried out in 117 Mycobacterium tuberculosis clinical isolates from Argentina and Colombia in order to explore correlation between mutations in these genes and multi-drug resistance. With the exception of two Beijing family isolates, the rest of the strains harbored either two wild-type or two mutant alleles with identical single nucleotide polymorphisms (SNPs) in each gene (ogt44 and ung501). These ogt44 and ung501 mutations were not associated with multi-drug resistance and occurred simultaneously in circulating Haarlem genotype M. tuberculosis strains. We therefore propose the use of these markers as tools in phylogenetic and epidemiologic studies.

  20. Extensively Drug-Resistant Tuberculosis: Principles of Resistance, Diagnosis, and Management.

    Science.gov (United States)

    Wilson, John W; Tsukayama, Dean T

    2016-04-01

    Extensively drug-resistant (XDR) tuberculosis (TB) is an unfortunate by-product of mankind's medical and pharmaceutical ingenuity during the past 60 years. Although new drug developments have enabled TB to be more readily curable, inappropriate TB management has led to the emergence of drug-resistant disease. Extensively drug-resistant TB describes Mycobacterium tuberculosis that is collectively resistant to isoniazid, rifampin, a fluoroquinolone, and an injectable agent. It proliferates when established case management and infection control procedures are not followed. Optimized treatment outcomes necessitate time-sensitive diagnoses, along with expanded combinations and prolonged durations of antimicrobial drug therapy. The challenges to public health institutions are immense and most noteworthy in underresourced communities and in patients coinfected with human immunodeficiency virus. A comprehensive and multidisciplinary case management approach is required to optimize outcomes. We review the principles of TB drug resistance and the risk factors, diagnosis, and managerial approaches for extensively drug-resistant TB. Treatment outcomes, cost, and unresolved medical issues are also discussed. Copyright © 2016 Mayo Foundation for Medical Education and Research. Published by Elsevier Inc. All rights reserved.

  1. Characterization of Ofloxacin Interaction with Mutated (A91V) Quinolone Resistance Determining Region of DNA Gyrase in Mycobacterium Leprae through Computational Simulation.

    Science.gov (United States)

    Nisha, J; Shanthi, V

    2018-06-01

    Mycobacterium leprae, the causal agent of leprosy is non-cultivable in vitro. Thus, the assessment of antibiotic activity against Mycobacterium leprae depends primarily upon the time-consuming mouse footpad system. The GyrA protein of Mycobacterium leprae is the target of the antimycobacterial drug, Ofloxacin. In recent times, the GyrA mutation (A91V) has been found to be resistant to Ofloxacin. This phenomenon has necessitated the development of new, long-acting antimycobacterial compounds. The underlying mechanism of drug resistance is not completely known. Currently, experimentally crystallized GyrA-DNA-OFLX models are not available for highlighting the binding and mechanism of Ofloxacin resistance. Hence, we employed computational approaches to characterize the Ofloxacin interaction with both the native and mutant forms of GyrA complexed with DNA. Binding energy measurements obtained from molecular docking studies highlights hydrogen bond-mediated efficient binding of Ofloxacin to Asp47 in the native GyrA-DNA complex in comparison with that of the mutant GyrA-DNA complex. Further, molecular dynamics studies highlighted the stable binding of Ofloxacin with native GyrA-DNA complex than with the mutant GyrA-DNA complex. This mechanism provided a plausible reason for the reported, reduced effect of Ofloxacin to control leprosy in individuals with the A91V mutation. Our report is the first of its kind wherein the basis for the Ofloxacin drug resistance mechanism has been explored with the help of ternary Mycobacterium leprae complex, GyrA-DNA-OFLX. These structural insights will provide useful information for designing new drugs to target the Ofloxacin-resistant DNA gyrase.

  2. Detection of mutation in isoniazid-resistant Mycobacterium tuberculosis isolates from tuberculosis patients in Belarus

    Directory of Open Access Journals (Sweden)

    Bostanabad S

    2008-01-01

    Full Text Available The aim of this study was to investigate the frequency, location and type of katG mutations in Mycobacterium tuberculosis strains isolated from patients in Belarus. Forty two isoniazid-resistant isolates were identified from sputum of 163 patients with active pulmonary tuberculosis. Drug susceptibility testing was determined by using CDC standard conventional proportional method and BACTEC system. Standard PCR method for detection of isoniazid resistance associated mutations was performed by katG gene amplification and DNA sequencing. Most mutations were found in katG gene codons 315, 316 and 309. Four types of mutations were identified in codon 315: AGC→ACC ( n = 36 85%, AGC→AGG ( n = 1 2.3%, AGC→AAC ( n = 2 4.7%, AGC→GGC ( n = 1 2.3%. One type of mutation was found in codon 316: GGC→AGC ( n = 1841.4%, four types of mutations were detected in codon 309: GGT→GGT ( n = 716.1%, GGT→GCT ( n = 49.2%, GGT→GTC ( n = 36.9%, GGT→GGG ( n = 12.7%. The highest frequency of mutations sharing between primary and secondary infections was found in codon 315.

  3. L-form transformation phenomenon in Mycobacterium tuberculosis associated with drug tolerance to ethambutol

    Directory of Open Access Journals (Sweden)

    Georgi Slavchev

    2016-01-01

    Full Text Available Objective/background: Cell wall-deficient bacterial forms (L-forms may occur along with resistance to factors that trigger their appearance. It is of interest to study the relationship between the L-form transformation of Mycobacterium tuberculosis and the exhibition of drug tolerance to ethambutol (EMB, an inhibitor of cell wall synthesis. Methods: L-form variant was produced from a sensitive EMB strain of M. Tuberculosis through a cryogenic stress treatment protocol and was subsequently cultivated in Middlebrook 7H9 semisolid medium, containing EMB in a minimal inhibitory concentration of 2 mg/L. Susceptibility to EMB of the parental strain and its L-form variant was evaluated phenotypically and using polymerase chain reaction-restriction fragment length polymorphism assay targeting a mutation in the embB306 gene fragment. Results: In contrast to the sensitivity to EMB of the parental strain, its L-form variant showed phenotypic resistance to high concentrations of EMB (16 mg/L, but the mutation in embB306 was not found. Electron microscopy observation of the L-form variant showed a heterogenic population of bacteria, with different degrees of cell wall deficiency, as well as cells of protoplastic type without cell walls. Of special interest were the observed capsule-like structures around the L-form cells and the biofilm-like matrix produced by the L-form population. Conclusion: We suggest that the expression of phenotypic resistance to EMB in M. Tuberculosis can be associated with alterations or loss of cell walls in L-form bacteria, respectively, which results in a lack of a specific target for EMB action. In addition, production of capsule-like structures and biofilm matrix by L-forms could contribute to their resistance and survival in the presence of antibacterial agents.

  4. Extensively Drug-Resistant TB

    Centers for Disease Control (CDC) Podcasts

    2016-12-16

    Dr. Charlotte Kvasnovsky, a surgery resident and Ph.D. candidate in biostatistics, discusses various types of drug resistance in TB patients in South Africa.  Created: 12/16/2016 by National Center for Emerging and Zoonotic Infectious Diseases (NCEZID).   Date Released: 12/16/2016.

  5. Initial drug resistance in India

    Indian Academy of Sciences (India)

    First page Back Continue Last page Overview Graphics. Initial drug resistance in India. There is gradual increase in primary MDR all over India : Pondi= Pondicherry 1985; Bangalore =1986; Jaipur = 1991; Jaipur =2000. Overall the MDR is less than 3% (TRC studies).

  6. Mutation of Rv2887, a marR-like gene, confers Mycobacterium tuberculosis resistance to an imidazopyridine-based agent.

    Science.gov (United States)

    Winglee, Kathryn; Lun, Shichun; Pieroni, Marco; Kozikowski, Alan; Bishai, William

    2015-11-01

    Drug resistance is a major problem in Mycobacterium tuberculosis control, and it is critical to identify novel drug targets and new antimycobacterial compounds. We have previously identified an imidazo[1,2-a]pyridine-4-carbonitrile-based agent, MP-III-71, with strong activity against M. tuberculosis. In this study, we evaluated mechanisms of resistance to MP-III-71. We derived three independent M. tuberculosis mutants resistant to MP-III-71 and conducted whole-genome sequencing of these mutants. Loss-of-function mutations in Rv2887 were common to all three MP-III-71-resistant mutants, and we confirmed the role of Rv2887 as a gene required for MP-III-71 susceptibility using complementation. The Rv2887 protein was previously unannotated, but domain and homology analyses suggested it to be a transcriptional regulator in the MarR (multiple antibiotic resistance repressor) family, a group of proteins first identified in Escherichia coli to negatively regulate efflux pumps and other mechanisms of multidrug resistance. We found that two efflux pump inhibitors, verapamil and chlorpromazine, potentiate the action of MP-III-71 and that mutation of Rv2887 abrogates their activity. We also used transcriptome sequencing (RNA-seq) to identify genes which are differentially expressed in the presence and absence of a functional Rv2887 protein. We found that genes involved in benzoquinone and menaquinone biosynthesis were repressed by functional Rv2887. Thus, inactivating mutations of Rv2887, encoding a putative MarR-like transcriptional regulator, confer resistance to MP-III-71, an effective antimycobacterial compound that shows no cross-resistance to existing antituberculosis drugs. The mechanism of resistance of M. tuberculosis Rv2887 mutants may involve efflux pump upregulation and also drug methylation. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  7. Genome sequencing and annotation of multidrug resistant Mycobacterium tuberculosis (MDR-TB PR10 strain

    Directory of Open Access Journals (Sweden)

    Mohd Zakihalani A. Halim

    2016-03-01

    Full Text Available Here, we report the draft genome sequence and annotation of a multidrug resistant Mycobacterium tuberculosis strain PR10 (MDR-TB PR10 isolated from a patient diagnosed with tuberculosis. The size of the draft genome MDR-TB PR10 is 4.34 Mbp with 65.6% of G + C content and consists of 4637 predicted genes. The determinants were categorized by RAST into 400 subsystems with 4286 coding sequences and 50 RNAs. The whole genome shotgun project has been deposited at DDBJ/EMBL/GenBank under the accession number CP010968. Keywords: Mycobacterium tuberculosis, Genome, MDR, Extrapulmonary

  8. Lipoprotein Processing Is Essential for Resistance of Mycobacterium tuberculosis to Malachite Green▿

    OpenAIRE

    Banaei, Niaz; Kincaid, Eleanor Z.; Lin, S.-Y. Grace; Desmond, Edward; Jacobs, William R.; Ernst, Joel D.

    2009-01-01

    Malachite green, a synthetic antimicrobial dye, has been used for over 50 years in mycobacterial culture medium to inhibit the growth of contaminants. The molecular basis of mycobacterial resistance to malachite green is unknown, although the presence of malachite green-reducing enzymes in the cell envelope has been suggested. The objective of this study was to investigate the role of lipoproteins in resistance of Mycobacterium tuberculosis to malachite green. The replication of an M. tubercu...

  9. Efflux pumps of Mycobacterium tuberculosis play a significant role in antituberculosis activity of potential drug candidates.

    Science.gov (United States)

    Balganesh, Meenakshi; Dinesh, Neela; Sharma, Sreevalli; Kuruppath, Sanjana; Nair, Anju V; Sharma, Umender

    2012-05-01

    Active efflux of drugs mediated by efflux pumps that confer drug resistance is one of the mechanisms developed by bacteria to counter the adverse effects of antibiotics and chemicals. To understand these efflux mechanisms in Mycobacterium tuberculosis, we generated knockout (KO) mutants of four efflux pumps of the pathogen belonging to different classes. We measured the MICs and kill values of two different compound classes on the wild type (WT) and the efflux pump (EP) KO mutants in the presence and absence of the efflux inhibitors verapamil and l-phenylalanyl-l-arginyl-β-naphthylamide (PAβN). Among the pumps studied, the efflux pumps belonging to the ABC (ATP-binding cassette) class, encoded by Rv1218c, and the SMR (small multidrug resistance) class, encoded by Rv3065, appear to play important roles in mediating the efflux of different chemical classes and antibiotics. Efflux pumps encoded by Rv0849 and Rv1258c also mediate the efflux of these compounds, but to a lesser extent. Increased killing is observed in WT M. tuberculosis cells by these compounds in the presence of either verapamil or PAβN. The efflux pump KO mutants were more susceptible to these compounds in the presence of efflux inhibitors. We have shown that these four efflux pumps of M. tuberculosis play a vital role in mediating efflux of different chemical scaffolds. Inhibitors of one or several of these efflux pumps could have a significant impact in the treatment of tuberculosis. The identification and characterization of Rv0849, a new efflux pump belonging to the MFS (major facilitator superfamily) class, are reported.

  10. SUSCEPTIBILITY OF RIFAMPICIN-ISONIAZID RESISTANT MYCOBACTERIUM TUBERCULOSIS ISOLATES AGAINST LEVOFLOXACIN

    Directory of Open Access Journals (Sweden)

    A. H. Kurniawan

    2016-01-01

    Full Text Available Background: Tuberculosis (TB is a high burden disease in Indonesia with multidrug-resistant (MDR TB incidence started to increase. Treatment success of MDR-TB globally was low in number than it was targeted which was especially caused by fluoroquinolone resistance. One of the fluoroquinolone is levofloxacin, an antibiotic that has been widely used irrationally as antimicrobial treatment. Therefore, this study investigated the sensitivity and MBC of MDR Mycobacterium tuberculosis isolates against Levofloxacin. Method: The susceptibility test for MDR-Mycobacterium tuberculosis on levofloxacin by standard method with levofloxacin were on concentrations 0,5 μg/ml, 1 μg/ml, and 2 μg/ml. Sample of 8 strains MDR-Mycobacterium tuberculosis were cultured with each concentrations on Middlebrook 7H9 for 1 week incubation. Next, each of the incubated concentration was subcultured on solid media Middlebrook 7H10 for 3 weeks incubation. Colonized agar plates after 3 weeks incubation were confirmed with acid-fast stain. Results: On MB 7H10 with levofloxacin concentration 2 μg/ml showed bactericidal effect 100% by no MDR Mycobacterium tuberculosis colony grew (0/8 while the MB 7H10 with levofloxacin concentration 1 μg/ml and 0,5 μg/ml showed the bactericidal effect 37,5% and 25% respectively. The colonized agar plate implied that the MDR Mycobacterium tuberculosis with levofloxacin concentration 1 μg/ml (5/8 and 0,5 μg/ml (6/8 grew well. Conclusion: Levofloxacin concentration 2 μg/ml was susceptible on MDR Mycobacterium tuberculosis. The concentration 2 μg/ml of levofloxacin could be considered as MBC.

  11. Shifts in Mycobacterial Populations and Emerging Drug-Resistance in West and Central Africa.

    Directory of Open Access Journals (Sweden)

    Florian Gehre

    Full Text Available In this study, we retrospectively analysed a total of 605 clinical isolates from six West or Central African countries (Benin, Cameroon, Central African Republic, Guinea-Conakry, Niger and Senegal. Besides spoligotyping to assign isolates to ancient and modern mycobacterial lineages, we conducted phenotypic drug-susceptibility-testing for each isolate for the four first-line drugs. We showed that phylogenetically modern Mycobacterium tuberculosis strains are more likely associated with drug resistance than ancient strains and predict that the currently ongoing replacement of the endemic ancient by a modern mycobacterial population in West/Central Africa might result in increased drug resistance in the sub-region.

  12. Efficacy of moxifloxacin & econazole against multidrug resistant (MDR Mycobacterium tuberculosis in murine model

    Directory of Open Access Journals (Sweden)

    U D Gupta

    2015-01-01

    Full Text Available Background & objectives: Studies have shown the bactericidal potential of econazole and clotrimazole against Mycobacterium tuberculosis under in vitro and ex vivo conditions along with their synergism with conventional antituberculosis drugs. These molecules were also found to be effective against different multidrug resistant (MDR M. tuberculosis isolates in vitro. Hence the present study was designed to evaluate the in vivo antimycobacterial potential of moxifloxacin and econazole alone and in combination against multidrug resistant tuberculosis (MDR-TB in a mice model. Methods: Mice were infected with 2.5×10 [7] bacilli of MDR strain of M. tuberculosis by aerosol route of infection. After four weeks of infection, chemotherapy was started orally by moxifloxacin 8.0 mg/kg body wt and econazole 3.3 mg/kg alone and in combination, as well as with four first line anti-tuberculosis drugs as a positive control. The animals were sacrificed and the lungs and spleen were excised under aspetic conditions. The tissues were homogenized with sterile normal saline, an aliquot of the homogenate was plated on Middlebrook 7H11 agar supplemented with oleate albumin dextrose catalase (OADC and incubated at 37°C for four weeks. The number of visible and individual colonies were counted. Results: The first line anti-tuberculosis drugs (RIF+INH+EMB+PZA after eight weeks of therapy had no impact as the bacillary load in lungs and spleens remained unchanged. However, econazole, moxifloxacin alone as well as in combination significantly reduced the bacillary load in lungs as well as in spleens of MDR-TB bacilli infected mice. Interpretation & conclusions: Co-administration of the two drugs (econazole and moxifloxacin to MDR-TB strain JAL-7782 infected mice exhibited additive effect, the efficacy of the drugs in combination being higher as compared with ECZ or MOX alone. These results were substantiated by histopathological studies. This study suggests the utility of

  13. Enriched whole genome sequencing identified compensatory mutations in the RNA polymerase gene of rifampicin-resistant Mycobacterium leprae strains

    Directory of Open Access Journals (Sweden)

    Lavania M

    2018-01-01

    Full Text Available Mallika Lavania,1 Itu Singh,1 Ravindra P Turankar,1 Anuj Kumar Gupta,2 Madhvi Ahuja,1 Vinay Pathak,1 Utpal Sengupta1 1Stanley Browne Laboratory, The Leprosy Mission Trust India, TLM Community Hospital Nand Nagari, 2Agilent Technologies India Pvt Ltd, Jasola District Centre, New Delhi, India Abstract: Despite more than three decades of multidrug therapy (MDT, leprosy remains a major public health issue in several endemic countries, including India. The emergence of drug resistance in Mycobacterium leprae (M. leprae is a cause of concern and poses a threat to the leprosy-control program, which might ultimately dampen the achievement of the elimination program of the country. Rifampicin resistance in clinical strains of M. leprae are supposed to arise from harboring bacterial strains with mutations in the 81-bp rifampicin resistance determining region (RRDR of the rpoB gene. However, complete dynamics of rifampicin resistance are not explained only by this mutation in leprosy strains. To understand the role of other compensatory mutations and transmission dynamics of drug-resistant leprosy, a genome-wide sequencing of 11 M. leprae strains – comprising five rifampicin-resistant strains, five sensitive strains, and one reference strain – was done in this study. We observed the presence of compensatory mutations in two rifampicin-resistant strains in rpoC and mmpL7 genes, along with rpoB, that may additionally be responsible for conferring resistance in those strains. Our findings support the role for compensatory mutation(s in RNA polymerase gene(s, resulting in rifampicin resistance in relapsed leprosy patients. Keywords: leprosy, rifampicin resistance, compensatory mutations, next generation sequencing, relapsed, MDT, India

  14. DRUG RESISTANCE IN HELICOBACTER PYLORI

    Directory of Open Access Journals (Sweden)

    Júlia Silveira VIANNA

    Full Text Available ABSTRACT Background Helicobacter pylori has a worldwide distribution and is associated with the pathogenesis of various diseases of the digestive system. Treatment to eradicate this microorganism involves the use of a combination of antimicrobials, such as amoxicillin, metronidazole, clarithromycin, and levofloxacin, combined with proton pump inhibitors. Although the current therapy is effective, a high rate of treatment failure has been observed, mainly because of the acquisition of point mutations, one of the major resistance mechanisms developed by H. pylori. This phenomenon is related to frequent and/or inappropriate use of antibiotics. Conclusion This review reported an overview of the resistance to the main drugs used in the treatment of H. pylori, confirming the hypothesis that antibacterial resistance is a highly local phenomenon and genetic characteristics of a given population can influence which therapy is the most appropriate.

  15. Drug-resistant tuberculosis: time for visionary political leadership.

    Science.gov (United States)

    Abubakar, Ibrahim; Zignol, Matteo; Falzon, Dennis; Raviglione, Mario; Ditiu, Lucica; Masham, Susan; Adetifa, Ifedayo; Ford, Nathan; Cox, Helen; Lawn, Stephen D; Marais, Ben J; McHugh, Timothy D; Mwaba, Peter; Bates, Matthew; Lipman, Marc; Zijenah, Lynn; Logan, Simon; McNerney, Ruth; Zumla, Adam; Sarda, Krishna; Nahid, Payam; Hoelscher, Michael; Pletschette, Michel; Memish, Ziad A; Kim, Peter; Hafner, Richard; Cole, Stewart; Migliori, Giovanni Battista; Maeurer, Markus; Schito, Marco; Zumla, Alimuddin

    2013-06-01

    Two decades ago, WHO declared tuberculosis a global emergency, and invested in the highly cost-effective directly observed treatment short-course programme to control the epidemic. At that time, most strains of Mycobacterium tuberculosis were susceptible to first-line tuberculosis drugs, and drug resistance was not a major issue. However, in 2013, tuberculosis remains a major public health concern worldwide, with prevalence of multidrug-resistant (MDR) tuberculosis rising. WHO estimates roughly 630 000 cases of MDR tuberculosis worldwide, with great variation in the frequency of MDR tuberculosis between countries. In the past 8 years, extensively drug-resistant (XDR) tuberculosis has emerged, and has been reported in 84 countries, heralding the possibility of virtually untreatable tuberculosis. Increased population movement, the continuing HIV pandemic, and the rise in MDR tuberculosis pose formidable challenges to the global control of tuberculosis. We provide an overview of the global burden of drug-resistant disease; discuss the social, health service, management, and control issues that fuel and sustain the epidemic; and suggest specific recommendations for important next steps. Visionary political leadership is needed to curb the rise of MDR and XDR tuberculosis worldwide, through sustained funding and the implementation of global and regional action plans. Copyright © 2013 World Health Organization. Published by Elsevier Ltd/Inc/BV. All rights reserved. Published by Elsevier Ltd. All rights reserved.

  16. Direct sequencing for rapid detection of multidrug resistant Mycobacterium tuberculosis strains in Morocco

    Directory of Open Access Journals (Sweden)

    Zakham F

    2013-11-01

    new case. The most recorded mutation in the rpoB gene was the substitution TCG > TTG at codon 531 (Ser531 Leu, accounting for 46.15%. Significantly, the only mutation found in the katG gene was at codon 315 (AGC to ACC with a Ser315Thr amino acid change. Only one sample harbored mutation in the inhA promoter region and was a point mutation at the -15p position (C > T.Conclusion: The polymerase chain reaction sequencing approach is an accurate and rapid method for detection of drug-resistant TB in clinical specimens, and could be of great interest in the management of TB in critical cases to adjust the treatment regimen and limit the emergence of MDR and XDR strains.Keywords: Morocco, Mycobacterium tuberculosis, multidrug resistance, rpoB, katG, inhA promoter

  17. Functional drug screening reveals anticonvulsants as enhancers of mTOR-independent autophagic killing of Mycobacterium tuberculosis through inositol depletion.

    Science.gov (United States)

    Schiebler, Mark; Brown, Karen; Hegyi, Krisztina; Newton, Sandra M; Renna, Maurizio; Hepburn, Lucy; Klapholz, Catherine; Coulter, Sarah; Obregón-Henao, Andres; Henao Tamayo, Marcela; Basaraba, Randall; Kampmann, Beate; Henry, Katherine M; Burgon, Joseph; Renshaw, Stephen A; Fleming, Angeleen; Kay, Robert R; Anderson, Karen E; Hawkins, Phillip T; Ordway, Diane J; Rubinsztein, David C; Floto, Rodrigo Andres

    2015-02-01

    Mycobacterium tuberculosis (MTB) remains a major challenge to global health made worse by the spread of multidrug resistance. We therefore examined whether stimulating intracellular killing of mycobacteria through pharmacological enhancement of macroautophagy might provide a novel therapeutic strategy. Despite the resistance of MTB to killing by basal autophagy, cell-based screening of FDA-approved drugs revealed two anticonvulsants, carbamazepine and valproic acid, that were able to stimulate autophagic killing of intracellular M. tuberculosis within primary human macrophages at concentrations achievable in humans. Using a zebrafish model, we show that carbamazepine can stimulate autophagy in vivo and enhance clearance of M. marinum, while in mice infected with a highly virulent multidrug-resistant MTB strain, carbamazepine treatment reduced bacterial burden, improved lung pathology and stimulated adaptive immunity. We show that carbamazepine induces antimicrobial autophagy through a novel, evolutionarily conserved, mTOR-independent pathway controlled by cellular depletion of myo-inositol. While strain-specific differences in susceptibility to in vivo carbamazepine treatment may exist, autophagy enhancement by repurposed drugs provides an easily implementable potential therapy for the treatment of multidrug-resistant mycobacterial infection. © 2014 The Authors. Published under the terms of the CC BY 4.0 license.

  18. Development of a three component complex to increase isoniazid efficacy against isoniazid resistant and nonresistant Mycobacterium tuberculosis.

    Science.gov (United States)

    Manning, Thomas; Plummer, Sydney; Baker, Tess; Wylie, Greg; Clingenpeel, Amy C; Phillips, Dennis

    2015-10-15

    The bacterium responsible for causing tuberculosis has evolved resistance to antibiotics used to treat the disease, resulting in new multidrug resistant Mycobacterium tuberculosis (MDR-TB) and extensively drug resistant M. tuberculosis (XDR-TB) strains. Analytical techniques (1)H and (13)C Nuclear Magnetic Resonance (NMR), Fourier Transform-Ion Cyclotron Resonance with Electrospray Ionization (FT-ICR/ESI), and Matrix Assisted Laser Desorption Ionization-Mass Spectrometry (MALDI-TOF-MS) were used to study different aspects of the Cu(II)-polyethylene glycol (PEG-3350)-sucrose-isoniazid and Cu(II)-polyethylene glycol (PEG3350)-glucose-isoniazid complexes. The Cu(II) cation, sucrose or glucose, and the aggregate formed by PEG primarily serve as a composite drug delivery agent for the frontline antibiotic, however the improvement in MIC values produced with the CU-PEG-SUC-INH complex suggest an additional effect. Several Cu-PEG-SUC-INH complex variations were tested against INH resistant and nonresistant strains of M. tuberculosis. Copyright © 2015 Elsevier Ltd. All rights reserved.

  19. Phenotypic low-level isoniazid resistance as a marker to predict ethionamide resistance in Mycobacterium tuberculosis

    Directory of Open Access Journals (Sweden)

    Salima Qamar

    2017-01-01

    Full Text Available Background: Tuberculosis is one of the most prevalent diseases in Pakistan. Pakistan has the highest burden of MDR-TB in the Eastern Mediterranean region. Ethionamide is an anti-tuberculous drug frequently used to treat MDR-TB. Its drug susceptibility testing is not easily available in resource limited settings. Since it acts on the same target protein as isoniazid (inhA protein encoded by inhA gene, we sought to find out if phenotypic isoniazid resistance can be a marker of ethionamide resistance. Materials and Methods: This was a retrospective observational study conducted at the Aga Khan University hospital section of microbiology. Data was retrieved between 2011 to 2014 for all culture positive MTB strains. All culture positive MTB isolates with susceptibilities to isoniazid and ethionamide recorded were included in the study. Isoniazid and ethionamide susceptibilities were performed using agar proportion method on Middlebrook 7H10 agar. Rate of Ethionamide resistance between low-level isoniazid resistant, high level isoniazid resistant and isoniazid sensitive MTB was compared. Results: A total of 11,274 isolates were included in the study. A statistically significant association (P < 0.001 was found between Ethionamide resistance and low-level isoniazid resistance (26.6% as compared to high-level isoniazid resistance (8.85% and isoniazid sensitivity (0.71% in MTB strains. However this association was not seen in XDR-TB strains. Conclusion: Low level isoniazid resistance may be used as marker for phenotypic ethionamide resistance and hence guide clinicians' choice of antituberculous agent for MDR-TB in Pakistan. Further studies involving detection of genotypic association of isoniazid and ethionamide susceptibilities are needed before a final conclusion can be derived.

  20. Esters of pyrazinoic acid are active against pyrazinamide-resistant strains of Mycobacterium tuberculosis and other naturally resistant mycobacteria in vitro and ex vivo within macrophages.

    KAUST Repository

    Pires, David

    2015-10-05

    Pyrazinamide (PZA) is active against major Mycobacterium tuberculosis species (M. tuberculosis, M. africanum, and M. microti), but not against M. bovis and M. avium. The latter two are mycobacteria species involved in human and cattle tuberculosis and in HIV co-infections, respectively. PZA is a first-line agent for the treatment of human tuberculosis and requires activation by a mycobacterial pyrazinamidase to form the active metabolite pyrazinoic acid (POA). As a result of this mechanism, resistance to PZA as often found in tuberculosis patients is caused by point mutations in pyrazinamidase. In previous work, we have shown that POA esters and amides synthesized in our laboratory were stable in plasma. Although the amides did not present significant activity, the esters were active against sensitive mycobacteria at concentrations 5-to-10 fold lower than those of PZA. Here, we report that these POA derivatives possess antibacterial efficacy in vitro and ex vivo against several species and strains of Mycobacterium with natural or acquired resistance to PZA, including M. bovis and M. avium. Our results indicate that the resistance was probably overcome by cleavage of the prodrugs into POA and a long-chain alcohol. Although it is not possible to rule out that the esters may have intrinsic activity per se, we bring evidence here that long-chain fatty alcohols possess a significant anti-mycobacterial effect against PZA-resistant species and strains and are not mere inactive promoieties. These findings may lead to candidate dual-drugs having enhanced activity against both PZA-susceptible and PZA-resistant isolates and being suitable for clinical development.

  1. Modelling the Transitional Dynamics of Mycobacterium Tuberculosis ...

    African Journals Online (AJOL)

    The World Health Organization's targets of eliminating Tuberculosis (TB) by 2050 is challenged by the emergence and spread of drug resistance TB. However, the traditional mechanism of resistance is that of acquired resistance, whereby the mycobacterium Tuberculosis (MTB) strain develops mutations under selective ...

  2. Multidrug resistant to extensively drug resistant tuberculosis: What is ...

    Indian Academy of Sciences (India)

    Prakash

    The modern, ... World Health Organization is based on a four-drug regimen ... Better management and control of tuberculosis specially drug resistant TB by experienced and qualified .... a comprehensive approach including the major DOTS.

  3. Molecular genetics of Mycobacterium tuberculosis resistant to aminoglycosides and cyclic peptide testing by MTBDRsl in Armenia

    Directory of Open Access Journals (Sweden)

    Hasmik Margaryan

    2016-01-01

    Conclusion: Isolates with rrs structural gene mutations were cross-resistant to streptomycin, KAN, CAP, and AMK. Detection of the A1401G mutation appeared to be 100% specific for the detection of resistance to KAN and AMK. Being the first assessment, these data establish the presence of phenotypic drug-resistant and extensively drug-resistant strains using molecular profiling and are helpful in understanding aminoglycoside resistance on a molecular level.

  4. Tumor Heterogeneity and Drug Resistance

    International Nuclear Information System (INIS)

    Kucerova, L.; Skolekova, S.; Kozovska, Z.

    2015-01-01

    New generation of sequencing methodologies revealed unexpected complexity and genomic alterations linked with the tumor subtypes. This diversity exists across the tumor types, histologic tumor subtypes and subsets of the tumor cells within the same tumor. This phenomenon is termed tumor heterogeneity. Regardless of its origin and mechanisms of development it has a major impact in the clinical setting. Genetic, phenotypic and expression pattern diversity of tumors plays critical role in the selection of suitable treatment and also in the prognosis prediction. Intratumoral heterogeneity plays a key role in the intrinsic and acquired chemoresistance to cytotoxic and targeted therapies. In this review we focus on the mechanisms of intratumoral and inter tumoral heterogeneity and their relationship to the drug resistance. Understanding of the mechanisms and spatiotemporal dynamics of tumor heterogeneity development before and during the therapy is important for the ability to design individual treatment protocols suitable in the given molecular context. (author)

  5. A robust SNP barcode for typing Mycobacterium tuberculosis complex strains

    KAUST Repository

    Coll, Francesc; McNerney, Ruth; Guerra-Assunç ã o, José Afonso; Glynn, Judith R.; Perdigã o, Joã o; Viveiros, Miguel; Portugal, Isabel; Pain, Arnab; Martin, Nigel; Clark, Taane G.

    2014-01-01

    Strain-specific genomic diversity in the Mycobacterium tuberculosis complex (MTBC) is an important factor in pathogenesis that may affect virulence, transmissibility, host response and emergence of drug resistance. Several systems have been proposed

  6. Detection of First-Line Drug Resistance Mutations and Drug-Protein Interaction Dynamics from Tuberculosis Patients in South India.

    Science.gov (United States)

    Nachappa, Somanna Ajjamada; Neelambike, Sumana M; Amruthavalli, Chokkanna; Ramachandra, Nallur B

    2018-05-01

    Diagnosis of drug-resistant tuberculosis predominantly relies on culture-based drug susceptibility testing, which take weeks to produce a result and a more time-efficient alternative method is multiplex allele-specific PCR (MAS-PCR). Also, understanding the role of mutations in causing resistance helps better drug designing. To evaluate the ability of MAS-PCR in the detection of drug resistance and to understand the mechanism of interaction of drugs with mutant proteins in Mycobacterium tuberculosis. Detection of drug-resistant mutations using MAS-PCR and validation through DNA sequencing. MAS-PCR targeted five loci on three genes, katG 315 and inhA -15 for the drug isoniazid (INH), and rpoB 516, 526, and 531 for rifampicin (RIF). Furthermore, the sequence data were analyzed to study the effect on interaction of the anti-TB drug molecule with the target protein using in silico docking. We identified drug-resistant mutations in 8 out of 114 isolates with 2 of them as multidrug-resistant TB using MAS-PCR. DNA sequencing confirmed only six of these, recording a sensitivity of 85.7% and specificity of 99.3% for MAS-PCR. Molecular docking showed estimated free energy of binding (ΔG) being higher for RIF binding with RpoB S531L mutant. Codon 315 in KatG does not directly interact with INH but blocks the drug access to active site. We propose DNA sequencing-based drug resistance detection for TB, which is more accurate than MAS-PCR. Understanding the action of resistant mutations in disrupting the normal drug-protein interaction aids in designing effective drug alternatives.

  7. Drug-resistant tuberculosis in Sindh

    International Nuclear Information System (INIS)

    Almani, S.A.; Memon, N.M.; Qureshi, A.F.

    2002-01-01

    Objective: To assess the prevalence of primary and secondary drug resistance amongst the clinical isolates of M.tuberculosis, to identify risk factors and how to overcome this problem. Design: A case series of 50 indoor patients with sputum smear-positive pulmonary tuberculosis. Place and duration of Study: Department of Medicine, Liaquat University of Medical and Health Sciences Jamshoro, Sindh, (Pakistan) from January 1999 to December 2000. Patients and methods: Four first line anti-tuberculous drugs rifampicine, ethambutol and streptomycin were tested for sensitivity pattern. Results: Twelve (26.66%) were sensitive to all four drugs, 12(26.66%) were resistant to one drug, 14 (31.11%) were resistant to two drugs, 2 (4.44%) were resistant to three drugs, and 5(11.11%) were resistant to all four drugs. Resistance to isoniazid was the most common in 27 cases (60%) with primary resistance in 6(13.33%) and secondary resistance in 21(46.66%), followed by resistance to streptomycin in 17 cases (37.77%) with primary resistance in 5(11.11%) and secondary resistance in 12 (26.66%). Resistance to ethambutol in 10 cases (22.22%) and rifampicine in 11 (24.44%) and all cases were secondary. Similarly multi-drugs resistance (MRD) TB was found in 11(24.44%) isolates. Conclusion: This study showed high prevalence of drug resistance among clinical isolates of M. tuberculosis. Their is a need to establish centers at number of places with adequate facilities for susceptibility testing so that the resistant pattern could be ascertained and treatment regimens tailored accordingly. (author)

  8. Mechanisms of drug resistance in cancer cells

    International Nuclear Information System (INIS)

    Iqbal, M.P.

    2003-01-01

    Development of drug resist chemotherapy. For the past several years, investigators have been striving hard to unravel mechanisms of drug resistance in cancer cells. Using different experimental models of cancer, some of the major mechanisms of drug resistance identified in mammalian cells include: (a) Altered transport of the drug (decreased influx of the drug; increased efflux of the drug (role of P-glycoprotein; role of polyglutamation; role of multiple drug resistance associated protein)), (b) Increase in total amount of target enzyme/protein (gene amplification), (c) alteration in the target enzyme/protein (low affinity enzyme), (d) Elevation of cellular glutathione, (e) Inhibition of drug-induced apoptosis (mutation in p53 tumor suppressor gene; increased expression of bcl-xl gene). (author)

  9. Clinical Management of HIV Drug Resistance

    Science.gov (United States)

    Cortez, Karoll J.; Maldarelli, Frank

    2011-01-01

    Combination antiretroviral therapy for HIV-1 infection has resulted in profound reductions in viremia and is associated with marked improvements in morbidity and mortality. Therapy is not curative, however, and prolonged therapy is complicated by drug toxicity and the emergence of drug resistance. Management of clinical drug resistance requires in depth evaluation, and includes extensive history, physical examination and laboratory studies. Appropriate use of resistance testing provides valuable information useful in constructing regimens for treatment-experienced individuals with viremia during therapy. This review outlines the emergence of drug resistance in vivo, and describes clinical evaluation and therapeutic options of the individual with rebound viremia during therapy. PMID:21994737

  10. Molecular detection of drug resistance in microbes by isotopic techniques: The IAEA experience

    International Nuclear Information System (INIS)

    Dar, L.; Boussaha, A.; Padhy, A.K.; Khan, B.

    2003-01-01

    The International Atomic Energy Agency (IAEA) supports various programmes on the uses of radionuclide techniques in the management of human communicable diseases. An important issue, being addressed through several technology transfer projects, is the detection of drug resistance in microbes by radioisotope based molecular-biology diagnostic procedures. The techniques employed include dot blot hybridisation with P-32 labelled oligonucleotide probes to detect point mutations, associated with drug resistance, in microbial genes amplified by the polymerase chain reaction (PCR). Molecular methods have been used for the detection of drug resistance in the malarial parasite, Plasmodium falciparum, and in Mycobacterium tuberculosis. Radioisotope based molecular-biology methods have been demonstrated to have comparative advantages in being sensitive, specific, cost-effective, and suitable for application to large-scale molecular surveillance for drug resistance. (author)

  11. Curcumin, an antibiotic resistance breaker against a multiresistant clinical isolate of Mycobacterium abscessus.

    Science.gov (United States)

    Marini, Emanuela; Di Giulio, Mara; Magi, Gloria; Di Lodovico, Silvia; Cimarelli, Maria Enrica; Brenciani, Andrea; Nostro, Antonia; Cellini, Luigina; Facinelli, Bruna

    2018-03-01

    Curcumin, a phenolic compound extracted from Curcuma longa, exerts multiple pharmacological effects, including an antimicrobial action. Mycobacterium abscessus, an environmental, nontuberculous, rapidly growing mycobacterium, is an emerging human pathogen causing serious lung infections and one of the most difficult to treat, due to its multidrug resistance and biofilm-forming ability. We wanted to evaluate the antimicrobial and antivirulence activity of curcumin and its ability to synergize with antibiotics against a clinical M. abscessus strain (29904), isolated from the bronchoaspirate of a 66-year-old woman admitted to hospital for suspected tuberculosis. Curcumin [minimum inhibitory concentrations (MIC) = 128 mg/L] was synergic (fractional inhibitory concentration index ≤0.5) with amikacin, clarithromycin, ciprofloxacin, and linezolid, to which strain 29904 showed resistance/intermediate susceptibility. Curcumin at 1/8 × MIC significantly reduced motility, whereas at 4 × MIC, it completely inhibited 4- and 8-day mature biofilms. Synergistic combinations of curcumin and amikacin induced a general reduction in microbial aggregates and substantial loss in cell viability. Disruption of 4- and 8-day biofilms was the main effect detected when curcumin was the predominant compound. The present findings support previous evidence that curcumin is a potential antibiotic resistance breaker. Curcumin, either alone or combined with antibiotics, could provide a novel strategy to combat antibiotic resistance and virulence of M. abscessus. Copyright © 2017 John Wiley & Sons, Ltd.

  12. Preventing drug resistance in severe influenza

    Science.gov (United States)

    Dobrovolny, Hana; Deecke, Lucas

    2015-03-01

    Severe, long-lasting influenza infections are often caused by new strains of influenza. The long duration of these infections leads to an increased opportunity for the emergence of drug resistant mutants. This is particularly problematic for new strains of influenza since there is often no vaccine, so drug treatment is the first line of defense. One strategy for trying to minimize drug resistance is to apply periodic treatment. During treatment the wild-type virus decreases, but resistant virus might increase; when there is no treatment, wild-type virus will hopefully out-compete the resistant virus, driving down the number of resistant virus. We combine a mathematical model of severe influenza with a model of drug resistance to study emergence of drug resistance during a long-lasting infection. We apply periodic treatment with two types of antivirals: neuraminidase inhibitors, which block release of virions; and adamantanes, which block replication of virions. We compare the efficacy of the two drugs in reducing emergence of drug resistant mutants and examine the effect of treatment frequency on the emergence of drug resistant mutants.

  13. Gene expression analysis of two extensively drug-resistant tuberculosis isolates show that two-component response systems enhance drug resistance.

    Science.gov (United States)

    Yu, Guohua; Cui, Zhenling; Sun, Xian; Peng, Jinfu; Jiang, Jun; Wu, Wei; Huang, Wenhua; Chu, Kaili; Zhang, Lu; Ge, Baoxue; Li, Yao

    2015-05-01

    Global analysis of expression profiles using DNA microarrays was performed between a reference strain H37Rv and two clinical extensively drug-resistant isolates in response to three anti-tuberculosis drug exposures (isoniazid, capreomycin, and rifampicin). A deep analysis was then conducted using a combination of genome sequences of the resistant isolates, resistance information, and related public microarray data. Certain known resistance-associated gene sets were significantly overrepresented in upregulated genes in the resistant isolates relative to that observed in H37Rv, which suggested a link between resistance and expression levels of particular genes. In addition, isoniazid and capreomycin response genes, but not rifampicin, either obtained from published works or our data, were highly consistent with the differentially expressed genes of resistant isolates compared to those of H37Rv, indicating a strong association between drug resistance of the isolates and genes differentially regulated by isoniazid and capreomycin exposures. Based on these results, 92 genes of the studied isolates were identified as candidate resistance genes, 10 of which are known resistance-related genes. Regulatory network analysis of candidate resistance genes using published networks and literature mining showed that three two-component regulatory systems and regulator CRP play significant roles in the resistance of the isolates by mediating the production of essential envelope components. Finally, drug sensitivity testing indicated strong correlations between expression levels of these regulatory genes and sensitivity to multiple anti-tuberculosis drugs in Mycobacterium tuberculosis. These findings may provide novel insights into the mechanism underlying the emergence and development of drug resistance in resistant tuberculosis isolates and useful clues for further studies on this issue. Copyright © 2015 Elsevier Ltd. All rights reserved.

  14. Combined antiretroviral and anti- tuberculosis drug resistance ...

    African Journals Online (AJOL)

    these epidemics, many challenges remain.[3] Antiretroviral and anti-TB drug resistance pose considerable threats to the control of these epidemics.[4,5]. The breakdown in HIV/TB control within prisons is another emerging threat.[6,7] We describe one of the first reports of combined antiretroviral and anti-TB drug resistance ...

  15. Emergence of Extensively Drug Resistant Tuberculosis

    Centers for Disease Control (CDC) Podcasts

    Extensively drug-resistant tuberculosis (XDR TB) outbreaks have been reported in South Africa, and strains have been identified on 6 continents. Dr. Peter Cegielski, team leader for drug-resistant TB with the Division of Tuberculosis Elimination at CDC, comments on a multinational team's report on this emerging global public health threat.

  16. [Change in drug resistance of Staphylococcus aureus].

    Science.gov (United States)

    Lin, Yan; Liu, Yan; Luo, Yan-Ping; Liu, Chang-Ting

    2013-11-01

    To analyze the change in drug resistance of Staphylococcus aureus (SAU) in the PLA general hospital from January 2008 to December 2012, and to provide solid evidence to support the rational use of antibiotics for clinical applications. The SAU strains isolated from clinical samples in the hospital were collected and subjected to the Kirby-Bauer disk diffusion test. The results were assessed based on the 2002 American National Committee for Clinical Laboratory Standards (NCCLS) guidelines. SAU strains were mainly isolated from sputum, urine, blood and wound excreta and distributed in penology, neurology wards, orthopedics and surgery ICU wards. Except for glycopeptide drugs, methicillin-resistant Staphylococcus aureus (MRSA) had a higher drug resistance rate than those of the other drugs and had significantly more resistance than methicillin-sensitive Staphylococcus aureus (MSSA) (P resistance, we discovered a gradual increase in drug resistance to fourteen test drugs during the last five years. Drug resistance rate of SAU stayed at a higher level over the last five years; moreover, the detection ratio of MRSA keeps rising year by year. It is crucial for physicians to use antibiotics rationally and monitor the change in drug resistance in a dynamic way.

  17. Ergothioneine Maintains Redox and Bioenergetic Homeostasis Essential for Drug Susceptibility and Virulence of Mycobacterium tuberculosis

    Directory of Open Access Journals (Sweden)

    Vikram Saini

    2016-01-01

    Full Text Available The mechanisms by which Mycobacterium tuberculosis (Mtb maintains metabolic equilibrium to survive during infection and upon exposure to antimycobacterial drugs are poorly characterized. Ergothioneine (EGT and mycothiol (MSH are the major redox buffers present in Mtb, but the contribution of EGT to Mtb redox homeostasis and virulence remains unknown. We report that Mtb WhiB3, a 4Fe-4S redox sensor protein, regulates EGT production and maintains bioenergetic homeostasis. We show that central carbon metabolism and lipid precursors regulate EGT production and that EGT modulates drug sensitivity. Notably, EGT and MSH are both essential for redox and bioenergetic homeostasis. Transcriptomic analyses of EGT and MSH mutants indicate overlapping but distinct functions of EGT and MSH. Last, we show that EGT is critical for Mtb survival in both macrophages and mice. This study has uncovered a dynamic balance between Mtb redox and bioenergetic homeostasis, which critically influences Mtb drug susceptibility and pathogenicity.

  18. Evaluation of rapid radiometric method for drug susceptibility testing of Mycobacterium tuberculosis

    International Nuclear Information System (INIS)

    Siddiqi, S.H.; Libonati, J.P.; Middlebrook, G.

    1981-01-01

    A total of 106 isolates of Mycobacterium tuberculosis were tested for drug susceptibility by the conventional 7H11 plate method and by a new rapid radiometric method using special 7H12 liquid medium with 14 C-labeled substrate. Results obtained by the two methods were compared for rapidity, sensitivity, and specificity of the new test method. There was 98% overall agreement between the results obtained by the two methods. Of a total of 424 drug tests, only 8 drug results did not agree, mostly in the case of streptomycin. This new procedure was found to be rapid, with 87% of the tests results reportable within 4 days and 98% reportable within 5 days as compared to the usual 3 weeks required with the conventional indirect susceptibility test method. The results of this preliminary study indicate that the rapid radiometric method seems to have the potential for routine laboratory use and merits further investigations

  19. Esters of pyrazinoic acid are active against pyrazinamide-resistant strains of Mycobacterium tuberculosis and other naturally resistant mycobacteria in vitro and ex vivo within macrophages.

    KAUST Repository

    Pires, David; Valente, Emí lia; Simoes, Marta; Carmo, Nuno; Testa, Bernard; Constantino, Luí s; Anes, Elsa

    2015-01-01

    In previous work, we have shown that POA esters and amides synthesized in our laboratory were stable in plasma. Although the amides did not present significant activity, the esters were active against sensitive mycobacteria at concentrations 5-to-10 fold lower than those of PZA. Here, we report that these POA derivatives possess antibacterial efficacy in vitro and ex vivo against several species and strains of Mycobacterium with natural or acquired resistance to PZA, including M. bovis and M. avium. Our results indicate that the resistance was probably overcome by cleavage of the prodrugs into POA and a long-chain alcohol. Although it is not possible to rule out that the esters may have intrinsic activity per se, we bring evidence here that long-chain fatty alcohols possess a significant anti-mycobacterial effect against PZA-resistant species and strains and are not mere inactive promoieties. These findings may lead to candidate dual-drugs having enhanced activity against both PZA-susceptible and PZA-resistant isolates and being suitable for clinical development.

  20. The Genotype MTBDRplus ver. 2.0 test as a quick indicator of resistance to rifampicin and isoniazid in Mycobacterium tuberculosis strains

    Directory of Open Access Journals (Sweden)

    Salvatore Nisticò

    2013-08-01

    Full Text Available Tuberculosis is still a global emergency and a major public health problem, in some cases related to the appearance of strains of multi drug resistance (MDR and extensive drug resistance (XDR Mycobacterium tuberculosis complex.The correct determination of antibiotic sensitivity profiles is therefore crucial to carry out appropriate treatment aimed to decrease the infectivity of each patient and to reduce mortality. The poor adherence to treatment by the patient or the use of therapies based on a single drug, as a result of incorrect requirements, promote the development of drug-resistance. Have some time on the market of molecular diagnostic tests that allow, quickly and directly from biological sample to search for resistance genes some key drugs of anti-TB therapy (Rifampicin and Isoniazid. One of the tests in question is the Genotype MTBDRplus ver 2.0 which can reveal the presence of genes for resistance to Isoniazid (INH and Rifampin (RMP.The loci analyzed are those corresponding to the rpoB gene for rifampicin, katG and inhA for isoniazid. Our study is based on the analysis of 83 strains of tubercular Mycobacteria identified and isolated from patients with tuberculosis disease and subjected to the tests sensitivity, searching for mutations and phenotypic susceptibility testing for Rifampicin and Isoniazid.The comparison of the results has shown that the results obtained using the Genotype MTBDRplus ver 2.0 test, were similar to the results obtained by the traditional susceptibility testing.

  1. Mechanistic and Structural Insights Into the Unique TetR-Dependent Regulation of a Drug Efflux Pump in Mycobacterium abscessus.

    Science.gov (United States)

    Richard, Matthias; Gutiérrez, Ana Victoria; Viljoen, Albertus J; Ghigo, Eric; Blaise, Mickael; Kremer, Laurent

    2018-01-01

    Mycobacterium abscessus is an emerging human pathogen causing severe pulmonary infections and is refractory to standard antibiotherapy, yet few drug resistance mechanisms have been reported in this organism. Recently, mutations in MAB_4384 leading to up-regulation of the MmpS5/MmpL5 efflux pump were linked to increased resistance to thiacetazone derivatives. Herein, the DNA-binding activity of MAB_4384 was investigated by electrophoretic mobility shift assays using the palindromic sequence IR S5/L5 located upstream of mmpS5/mmpL5 . Introduction of point mutations within IR S5/L5 identified the sequence requirements for optimal binding of the regulator. Moreover, formation of the protein/IR S5/L5 complex was severely impaired for MAB_4384 harboring D14N or F57L substitutions. IR S5/L5 /lacZ reporter fusions in M. abscessus demonstrated increased β-galactosidase activity either in strains lacking a functional MAB_4384 or in cultures treated with the TAC analogs. In addition, X-ray crystallography confirmed a typical TetR homodimeric structure of MAB_4384 and unraveled a putative ligand binding site in which the analogs could be docked. Overall, these results support drug recognition of the MAB_4384 TetR regulator, alleviating its binding to IR S5/L5 and steering up-regulation of MmpS5/MmpL5. This study provides new mechanistic and structural details of TetR-dependent regulatory mechanisms of efflux pumps and drug resistance in mycobacteria.

  2. Clusters of Multidrug-Resistant Mycobacterium tuberculosis Cases, Europe

    Science.gov (United States)

    Kremer, Kristin; Heersma, Herre; Van Soolingen, Dick

    2009-01-01

    Molecular surveillance of multidrug-resistant tuberculosis (MDR TB) was implemented in Europe as case reporting in 2005. For all new MDR TB cases detected from January 2003 through June 2007, countries reported case-based epidemiologic data and DNA fingerprint patterns of MDR TB strains when available. International clusters were detected and analyzed. From 2003 through mid-2007 in Europe, 2,494 cases of MDR TB were reported from 24 European countries. Epidemiologic and molecular data were linked for 593 (39%) cases, and 672 insertion sequence 6110 DNA fingerprint patterns were reported from 19 countries. Of these patterns, 288 (43%) belonged to 18 European clusters; 7 clusters (242/288 cases, 84%) were characterized by strains of the Beijing genotype family, including the largest cluster (175/288 cases, 61%). Both clustering and the Beijing genotype were associated with strains originating in eastern European countries. Molecular cluster detection contributes to identification of transmission profile, risk factors, and control measures. PMID:19624920

  3. Antimicrobial Drugs in Fighting against Antimicrobial Resistance

    OpenAIRE

    Cheng, Guyue; Dai, Menghong; Ahmed, Saeed; Hao, Haihong; Wang, Xu; Yuan, Zonghui

    2016-01-01

    The outbreak of antimicrobial resistance, together with the lack of newly developed antimicrobial drugs, represents an alarming signal for both human and animal healthcare worldwide. Selection of rational dosage regimens for traditional antimicrobial drugs based on pharmacokinetic/pharmacodynamic principles as well as development of novel antimicrobials targeting new bacterial targets or resistance mechanisms are key approaches in tackling AMR. In addition to the cellular level resistance (i....

  4. Molecular characterization and drug susceptibility profile of a Mycobacterium avium subspecies avium isolate from a dog with disseminated infection.

    Science.gov (United States)

    Armas, Federica; Furlanello, Tommaso; Camperio, Cristina; Trotta, Michele; Novari, Gianluca; Marianelli, Cinzia

    2016-01-12

    Mycobacterium avium complex (MAC) infections have been described in many mammalian species including humans and pets. We isolated and molecularly typed the causative agent of a rare case of disseminated mycobacteriosis in a dog. We identified the pathogen as a M. avium subspecies avium by sequencing the partial genes gyrB and rpsA. Considering the zoonotic potential of this infection, and in an attempt to ensure the most effective treatment for the animal, we also determined the drug susceptibility profile of the isolate to the most common drugs used to treat MAC disease in humans. The pathogen was tested in vitro against the macrolide clarithromycin, as well as against amikacin, ciprofloxacin, rifampicin, ethambutol and linezolid by the resazurin microdilution assay. It was found to be sensitive to all tested drugs save ethambutol. Despite the fact that the pathogen was sensitive to the therapies administered, the dog's overall clinical status worsened, and the animal died shortly after antimicrobial susceptibility results became available. Nucleotide sequencing of the embB gene, the target gene most commonly associated with ethambutol resistance, showed new missense mutations when compared to sequences available in public databases. In conclusion, we molecularly identified the MAC pathogen and determined its drug susceptibility profile in a relatively short period of time (seven days). We also characterized new genetic mutations likely to have been involved in the observed ethambutol resistance. Our results confirm the usefulness of both the gyrB and the rpsA genes as biomarkers for an accurate identification and differentiation of MAC pathogens.

  5. Computational Modelling of Dapsone Interaction With Dihydropteroate Synthase in Mycobacterium leprae; Insights Into Molecular Basis of Dapsone Resistance in Leprosy.

    Science.gov (United States)

    Chaitanya V, Sundeep; Das, Madhusmita; Bhat, Pritesh; Ebenezer, Mannam

    2015-10-01

    The molecular basis for determination of resistance to anti-leprosy drugs is the presence of point mutations within the genes of Mycobacterium leprae (M. leprae) that encode active drug targets. The downstream structural and functional implications of these point mutations on drug targets were scarcely studied. In this study, we utilized computational tools to develop native and mutant protein models for 5 point mutations at codon positions 53 and 55 in 6-hydroxymethyl-7, 8-dihydropteroate synthase (DHPS) of M. leprae, an active target for dapsone encoded by folp1 gene, that confer resistance to dapsone. Molecular docking was performed to identify variations in dapsone interaction with mutant DHPS in terms of hydrogen bonding, hydrophobic interactions, and energy changes. Schrodinger Suite 2014-3 was used to build homology models and in performing molecular docking. An increase in volume of the binding cavities of mutant structures was noted when compared to native form indicating a weakening in interaction (60.7 Å(3) in native vs. 233.6 Å(3) in Thr53Ala, 659.9 Å(3) in Thr53Ile, 400 Å(3) for Thr53Val, 385 Å(3) for Pro55Arg, and 210 Å(3) for Pro55Leu). This was also reflected by changes in hydrogen bonds and decrease in hydrophobic interactions in the mutant models. The total binding energy (ΔG) decreased significantly in mutant forms when compared to the native form (-51.92 Kcal/mol for native vs. -35.64, -35.24, -46.47, -47.69, and -41.36 Kcal/mol for mutations Thr53Ala, Thr53Ile, Thr53Val, Pro55Arg, and Pro55Leu, respectively. In brief, this analysis provided structural and mechanistic insights to the degree of dapsone resistance contributed by each of these DHPS mutants in leprosy. © 2015 Wiley Periodicals, Inc.

  6. Thr202Ala in thyA Is a Marker for the Latin American Mediterranean Lineage of the Mycobacterium tuberculosis Complex Rather than Para-Aminosalicylic Acid Resistance

    KAUST Repository

    Feuerriegel, S.; Koser, C.; Trube, L.; Archer, John A.C.; Rusch Gerdes, S.; Richter, E.; Niemann, S.

    2010-01-01

    Single nucleotide polymorphisms (SNPs) involved in the development of resistance represent powerful markers for the rapid detection of first- and second-line resistance in clinical Mycobacterium tuberculosis complex (MTBC) isolates. However

  7. Whole genome sequencing reveals complex evolution patterns of multidrug-resistant Mycobacterium tuberculosis Beijing strains in patients.

    Directory of Open Access Journals (Sweden)

    Matthias Merker

    Full Text Available Multidrug-resistant (MDR Mycobacterium tuberculosis complex (MTBC strains represent a major threat for tuberculosis (TB control. Treatment of MDR-TB patients is long and less effective, resulting in a significant number of treatment failures. The development of further resistances leads to extensively drug-resistant (XDR variants. However, data on the individual reasons for treatment failure, e.g. an induced mutational burst, and on the evolution of bacteria in the patient are only sparsely available. To address this question, we investigated the intra-patient evolution of serial MTBC isolates obtained from three MDR-TB patients undergoing longitudinal treatment, finally leading to XDR-TB. Sequential isolates displayed identical IS6110 fingerprint patterns, suggesting the absence of exogenous re-infection. We utilized whole genome sequencing (WGS to screen for variations in three isolates from Patient A and four isolates from Patient B and C, respectively. Acquired polymorphisms were subsequently validated in up to 15 serial isolates by Sanger sequencing. We determined eight (Patient A and nine (Patient B polymorphisms, which occurred in a stepwise manner during the course of the therapy and were linked to resistance or a potential compensatory mechanism. For both patients, our analysis revealed the long-term co-existence of clonal subpopulations that displayed different drug resistance allele combinations. Out of these, the most resistant clone was fixed in the population. In contrast, baseline and follow-up isolates of Patient C were distinguished each by eleven unique polymorphisms, indicating an exogenous re-infection with an XDR strain not detected by IS6110 RFLP typing. Our study demonstrates that intra-patient microevolution of MDR-MTBC strains under longitudinal treatment is more complex than previously anticipated. However, a mutator phenotype was not detected. The presence of different subpopulations might confound phenotypic and

  8. Plasmodium falciparum drug resistance in Angola.

    Science.gov (United States)

    Fançony, Cláudia; Brito, Miguel; Gil, Jose Pedro

    2016-02-09

    Facing chloroquine drug resistance, Angola promptly adopted artemisinin-based combination therapy as the first-line to treat malaria. Currently, the country aims to consolidate malaria control, while preparing for the elimination of the disease, along with others African countries in the region. However, the remarkable capacity of Plasmodium to develop drug resistance represents an alarming threat for those achievements. Herein, the available, but relatively scarce and dispersed, information on malaria drug resistance in Angola, is reviewed and discussed. The review aims to inform but also to encourage future research studies that monitor and update the information on anti-malarial drug efficacy and prevalence of molecular markers of drug resistance, key fields in the context and objectives of elimination.

  9. Evaluation of possible occurrence of mutation in MMR repair system genes in resistant and sensitiveclinical strains of Mycobacterium tuberculosisby using sequencing method

    Directory of Open Access Journals (Sweden)

    AmirPoyan Afzali

    2016-07-01

    Full Text Available Background:during recent years, the incidence and spread of drug resistance in Mycobacterium tuberculosis, the bacterium causing tuberculosis, has set this disease in World Health Organizationpriorities alignment of diseases like AIDS and hepatitis. Study of close examination of resistant and susceptible clinical strains genotypes is necessary to overcome drug resistance. Among the numerous repair systems, only there are limited number of encoding genes of DNA repair enzymes in Mycobacterium tuberculosis. Commonly these genes have been conserved and any changes among them likely increasethe mutation occurance due to the impossibility of correctionof spontaneous mutations insensitive strains of this bacteria.mut genes encodeDNA repairable enzymes.This study investigated the mutations in these genes and the effect of these mutations on tuberculosis drug resistance. Materials&Methods: In this study,of 29 available specimens,we were selected 8 susceptible strains and 21 resistantstrains andafter ordering appropriate primers and performing the proliferation reaction two types of amplicons produced which includingfragments of genes mut T2 and mut T4 and they were sent inorder to sequencing. Results:The results of chain reactionprimer represents an appropriate choice of primerswhich were investigated. Sequencing results showed that overall 73% of resistant strains that had been selected for study of mutT4gene, have no mutations in codons 48of mutT4 gene, and 70% of resistant strains have no GGA >>> CGA mutation at codon 58 of mutT2 gene. Conclusion: One of the strategies to overcome tuberculosis drug resistance is a close examination of genotypes of resistant and susceptible clinical strains. Results of this study was performedby examining changes in mut T2 and mut T4 gene sequence. The mutation in mut T2 always associated with mutation in mut T4, in this way, the first mutation may occurs in mut T4and after that, the second mutationmay occurs in mut T

  10. Crowd Sourcing a New Paradigm for Interactome Driven Drug Target Identification in Mycobacterium tuberculosis

    Science.gov (United States)

    Rohira, Harsha; Bhat, Ashwini G.; Passi, Anurag; Mukherjee, Keya; Choudhary, Kumari Sonal; Kumar, Vikas; Arora, Anshula; Munusamy, Prabhakaran; Subramanian, Ahalyaa; Venkatachalam, Aparna; S, Gayathri; Raj, Sweety; Chitra, Vijaya; Verma, Kaveri; Zaheer, Salman; J, Balaganesh; Gurusamy, Malarvizhi; Razeeth, Mohammed; Raja, Ilamathi; Thandapani, Madhumohan; Mevada, Vishal; Soni, Raviraj; Rana, Shruti; Ramanna, Girish Muthagadhalli; Raghavan, Swetha; Subramanya, Sunil N.; Kholia, Trupti; Patel, Rajesh; Bhavnani, Varsha; Chiranjeevi, Lakavath; Sengupta, Soumi; Singh, Pankaj Kumar; Atray, Naresh; Gandhi, Swati; Avasthi, Tiruvayipati Suma; Nisthar, Shefin; Anurag, Meenakshi; Sharma, Pratibha; Hasija, Yasha; Dash, Debasis; Sharma, Arun; Scaria, Vinod; Thomas, Zakir; Chandra, Nagasuma; Brahmachari, Samir K.; Bhardwaj, Anshu

    2012-01-01

    A decade since the availability of Mycobacterium tuberculosis (Mtb) genome sequence, no promising drug has seen the light of the day. This not only indicates the challenges in discovering new drugs but also suggests a gap in our current understanding of Mtb biology. We attempt to bridge this gap by carrying out extensive re-annotation and constructing a systems level protein interaction map of Mtb with an objective of finding novel drug target candidates. Towards this, we synergized crowd sourcing and social networking methods through an initiative ‘Connect to Decode’ (C2D) to generate the first and largest manually curated interactome of Mtb termed ‘interactome pathway’ (IPW), encompassing a total of 1434 proteins connected through 2575 functional relationships. Interactions leading to gene regulation, signal transduction, metabolism, structural complex formation have been catalogued. In the process, we have functionally annotated 87% of the Mtb genome in context of gene products. We further combine IPW with STRING based network to report central proteins, which may be assessed as potential drug targets for development of drugs with least possible side effects. The fact that five of the 17 predicted drug targets are already experimentally validated either genetically or biochemically lends credence to our unique approach. PMID:22808064

  11. Crowd sourcing a new paradigm for interactome driven drug target identification in Mycobacterium tuberculosis.

    Directory of Open Access Journals (Sweden)

    Rohit Vashisht

    Full Text Available A decade since the availability of Mycobacterium tuberculosis (Mtb genome sequence, no promising drug has seen the light of the day. This not only indicates the challenges in discovering new drugs but also suggests a gap in our current understanding of Mtb biology. We attempt to bridge this gap by carrying out extensive re-annotation and constructing a systems level protein interaction map of Mtb with an objective of finding novel drug target candidates. Towards this, we synergized crowd sourcing and social networking methods through an initiative 'Connect to Decode' (C2D to generate the first and largest manually curated interactome of Mtb termed 'interactome pathway' (IPW, encompassing a total of 1434 proteins connected through 2575 functional relationships. Interactions leading to gene regulation, signal transduction, metabolism, structural complex formation have been catalogued. In the process, we have functionally annotated 87% of the Mtb genome in context of gene products. We further combine IPW with STRING based network to report central proteins, which may be assessed as potential drug targets for development of drugs with least possible side effects. The fact that five of the 17 predicted drug targets are already experimentally validated either genetically or biochemically lends credence to our unique approach.

  12. Emergence of Extensively Drug Resistant Tuberculosis

    Centers for Disease Control (CDC) Podcasts

    2007-03-01

    Extensively drug-resistant tuberculosis (XDR TB) outbreaks have been reported in South Africa, and strains have been identified on 6 continents. Dr. Peter Cegielski, team leader for drug-resistant TB with the Division of Tuberculosis Elimination at CDC, comments on a multinational team's report on this emerging global public health threat.  Created: 3/1/2007 by Emerging Infectious Diseases.   Date Released: 3/26/2007.

  13. HIV resistance testing and detected drug resistance in Europe

    DEFF Research Database (Denmark)

    Schultze, Anna; Phillips, Andrew N; Paredes, Roger

    2015-01-01

    to Southern Europe. CONCLUSIONS: Despite a concurrent decline in virological failure and testing, drug resistance was commonly detected. This suggests a selective approach to resistance testing. The regional differences identified indicate that policy aiming to minimize the emergence of resistance......OBJECTIVES: To describe regional differences and trends in resistance testing among individuals experiencing virological failure and the prevalence of detected resistance among those individuals who had a genotypic resistance test done following virological failure. DESIGN: Multinational cohort...... study. METHODS: Individuals in EuroSIDA with virological failure (>1 RNA measurement >500 on ART after >6 months on ART) after 1997 were included. Adjusted odds ratios (aORs) for resistance testing following virological failure and aORs for the detection of resistance among those who had a test were...

  14. Medical devices; immunology and microbiology devices; classification of nucleic acid-based devices for the detection of Mycobacterium tuberculosis complex and the genetic mutations associated with antibiotic resistance. Final order.

    Science.gov (United States)

    2014-10-22

    The Food and Drug Administration (FDA) is classifying nucleic acid-based in vitro diagnostic devices for the detection of Mycobacterium tuberculosis complex (MTB-complex) and the genetic mutations associated with MTB-complex antibiotic resistance in respiratory specimens devices into class II (special controls). The Agency is classifying the device into class II (special controls) because special controls, in addition to general controls, will provide a reasonable assurance of safety and effectiveness of the device.

  15. Multi-drug-resistant tuberculosis in HIV positive patients in Eastern Europe

    DEFF Research Database (Denmark)

    Post, Frank A; Grint, Daniel; Efsen, Anne Marie Werlinrud

    2014-01-01

    Observational data from Eastern Europe on the management and outcome of multi-drug-resistant tuberculosis (MDR TB) in HIV positive populations remain sparse in the English-language literature.We compared clinical characteristics and outcomes of 55 patients who were diagnosed with HIV and MDR TB...... in Eastern Europe between 2004 and 2006 to 89 patients whose Mycobacterium tuberculosis isolates were susceptible to isoniazid and rifampicin.Patients with HIV and MDR TB were young and predominantly male with high rates of intravenous drug use, imprisonment and hepatitis C co-infection. Eighty-four per cent...... of patients with MDR TB had no history of previous TB drug exposure suggesting that the majority of MDR TB resulted from transmission of drug-resistant M. tuberculosis. The use of non-standardized tuberculosis treatment was common, and the use of antiretroviral therapy infrequent. Compared to those...

  16. Drug resistance in the mouse cancer clinic

    NARCIS (Netherlands)

    Rottenberg, Sven; Borst, Piet

    2012-01-01

    Drug resistance is one of the most pressing problems in treating cancer patients today. Local and regional disease can usually be adequately treated, but patients eventually die from distant metastases that have become resistant to all available chemotherapy. Although work on cultured tumor cell

  17. Malaria epidemic and drug resistance, Djibouti.

    Science.gov (United States)

    Rogier, Christophe; Pradines, Bruno; Bogreau, H; Koeck, Jean-Louis; Kamil, Mohamed-Ali; Mercereau-Puijalon, Odile

    2005-02-01

    Analysis of Plasmodium falciparum isolates collected before, during, and after a 1999 malaria epidemic in Djibouti shows that, despite a high prevalence of resistance to chloroquine, the epidemic cannot be attributed to a sudden increase in drug resistance of local parasite populations.

  18. Rapid, serial, non-invasive assessment of drug efficacy in mice with autoluminescent Mycobacterium ulcerans infection.

    Directory of Open Access Journals (Sweden)

    Tianyu Zhang

    Full Text Available Buruli ulcer (BU caused by Mycobacterium ulcerans is the world's third most common mycobacterial infection. There is no vaccine against BU and surgery is needed for patients with large ulcers. Although recent experience indicates combination chemotherapy with streptomycin and rifampin improves cure rates, the utility of this regimen is limited by the 2-month duration of therapy, potential toxicity and required parenteral administration of streptomycin, and drug-drug interactions caused by rifampin. Discovery and development of drugs for BU is greatly hampered by the slow growth rate of M. ulcerans, requiring up to 3 months of incubation on solid media to produce colonies. Surrogate markers for evaluating antimicrobial activity in real-time which can be measured serially and non-invasively in infected footpads of live mice would accelerate pre-clinical evaluation of new drugs to treat BU. Previously, we developed bioluminescent M. ulcerans strains, demonstrating proof of concept for measuring luminescence as a surrogate marker for viable M. ulcerans in vitro and in vivo. However, the requirement of exogenous substrate limited the utility of such strains, especially for in vivo experiments.For this study, we engineered M. ulcerans strains that express the entire luxCDABE operon and therefore are autoluminescent due to endogenous substrate production. The selected reporter strain displayed a growth rate and virulence similar to the wild-type parent strain and enabled rapid, real-time monitoring of in vitro and in vivo drug activity, including serial, non-invasive assessments in live mice, producing results which correlated closely with colony-forming unit (CFU counts for a panel of drugs with various mechanisms of action.Our results indicate that autoluminescent reporter strains of M. ulcerans are exceptional tools for pre-clinical evaluation of new drugs to treat BU due to their potential to drastically reduce the time, effort, animals, compound

  19. Changing prevalence and resistance patterns in children with drug-resistant tuberculosis in Mumbai.

    Science.gov (United States)

    Shah, Ira; Shah, Forum

    2017-05-01

    The prevalence of drug-resistant (DR) tuberculosis (TB) in children is increasing. Although, in India, multi-drug-resistant (MDR) TB rates have been relatively stable, the number of children with pre-extensively drug-resistant and extensively drug-resistant (XDR) TB is increasing. To determine whether the prevalence of DR TB in children in Mumbai is changing and to study the evolving patterns of resistance. A retrospective study was undertaken in 1311 paediatric patients referred between April 2007 and March 2013 to the Paediatric TB clinic at B. J. Wadia Hospital for Children, Mumbai. Children were defined as having DR TB on the basis of drug susceptibility testing (DST) of Mycobacterium tuberculosis grown on culture of body fluids (in the case of extra pulmonary TB) or from gastric lavage/bronchi-alveolar lavage/sputum in patients with pulmonary TB or from DST of the contacts. The prevalence of DR TB was calculated and the type of DR was evaluated yearly and in the pre-2010 and post-2010 eras. The overall prevalence of DR TB was 86 (6.6%) with an increase from 23 (5.6%) patients pre-2010 to 63 (7%) post-2010 (P = 0.40). Nine (10.4%) patients were diagnosed on the basis of contact with a parent with DR TB. Overall fluoroquinolone resistance increased from 9 (39.1%) pre-2010 to 59 (93.7%) post-2010 (P = 0.0001): moxifloxacin resistance increased from 2 (8.7%) to 29 (46%) (P = 0.0018) and ofloxacin resistance increased from 7 (30.4%) to 30 (47.6%) (P = 0.14). Ethionamide resistance also increased from 6 (26.1%) to 31 (49.2%) (P = 0.04), aminoglycoside resistance was one (4.3%) pre-2010 and 12 (19%) post-2010 (P = 0.17) and resistance remained virtually the same for both amikacin [0 pre-2010 and 6 (9.5%) after 2010] and kanamycin [one (4.3%) pre- and 6 (9.5%) post-2010]. Of the first-line drugs, resistance remained the same for isoniazid [23 (100%) to 61 (96.8%)], rifampicin [22 (95.7%) to 51 (80.9%),P = 0.17], pyrazinamide [15 (65.2%) to

  20. Killing of intracellular Mycobacterium tuberculosis by receptor-mediated drug delivery

    International Nuclear Information System (INIS)

    Majumdar, S.; Basu, S.K.

    1991-01-01

    p-Aminosalicylic acid (PAS) conjugated to maleylated bovine serum albumin (MBSA) was taken up efficiently through high-affinity MBSA-binding sites on macrophages. Binding of the radiolabeled conjugate to cultured mouse peritoneal macrophages at 4 degrees C was competed for by MBSA but not by PAS. At 37 degrees C, the radiolabeled conjugate was rapidly degraded by the macrophages, leading to release of acid-soluble degradation products in the medium. The drug conjugate was nearly 100 times as effective as free PAS in killing the intracellular mycobacteria in mouse peritoneal macrophages infected in culture with Mycobacterium tuberculosis. The killing of intracellular mycobacteria mediated by the drug conjugate was effectively prevented by simultaneous addition of excess MBSA (100 micrograms/ml) or chloroquine (3 microM) to the medium, whereas these agents did not affect the microbicidal action of free PAS. These results suggest that (i) uptake of the PAS-MBSA conjugate was mediated by cell surface receptors on macrophages which recognize MBSA and (ii) lysosomal hydrolysis of the internalized conjugate resulted in intracellular release of a pharmacologically active form of the drug, which led to selective killing of the M. tuberculosis harbored by mouse macrophages infected in culture. This receptor-mediated modality of delivering drugs to macrophages could contribute to greater therapeutic efficacy and minimization of toxic side effects in the management of tuberculosis and other intracellular mycobacterial infections

  1. Mycobacterium abscessus subsp. abscessus Lung Disease: Drug Susceptibility Testing in Sputum Culture Negative Conversion

    Directory of Open Access Journals (Sweden)

    Takehiko Kobayashi

    2018-01-01

    Full Text Available Background: Among Mycobacterium abscessus complex infections, patients with M. abscessus subsp. abscessus (MAA lung disease are difficult to treat and no standard therapy has been established. Few reports have investigated the drug susceptibility of these strains. We retrospectively investigated how in vitro drug susceptibility testing (DST of MAA affects the induction of sputum conversion using pharmacotherapy. Methods: Patients with MAA lung disease diagnosed and treated between 2010 and 2014 at our hospital were enrolled and divided into Group A (sputum conversion without relapse within 1 year and Group B (persistent positive cultured or negative conversion with relapse. MAA was identified in M. abscessus using sequence with genotyping, and DST of MAA was performed. Results: We assessed 23 patients (9 males and 14 females. There were 8 patients in Group A and 15 in Group B. Higher prevalence of susceptible isolates for clarithromycin (CAM susceptibility on day 14 was noted in Group A than in Group B (P = 0.03 and no significant difference observed in the two groups for other drugs. Conclusions: In vitro DST of MAA, especially CAM susceptibility on day 14, affected the results of negative conversion. No other drugs were found to affect sputum culture negative conversion.

  2. Acid-fast bacilli culture positivity and drug resistance in abdominal tuberculosis in Mumbai, India.

    Science.gov (United States)

    Samant, Hrishikesh; Desai, Devendra; Abraham, Philip; Joshi, Anand; Gupta, Tarun; Rodrigues, Camilla; George, Siji

    2014-09-01

    Culture positivity for Mycobacterium tuberculosis complex (MTB) in abdominal tuberculosis (TB) using Lowenstein Jensen medium and Bactec system varies from 25 % to 36 %. Data on the prevalence of drug resistance in primary abdominal TB is scant. Our aim was to study the acid-fast bacilli (AFB) culture positivity rate in primary abdominal TB using Bactec Mycobacterial Growth Indicator Tubes (MGIT) system and the prevalence of drug resistance in these patients. Records of patients with abdominal TB (diagnosed on clinical features, endoscopy, histology, microbiology) seen during the period 2008 to 2013 were retrieved from the Gastroenterology and Microbiology departments. Patients with extra-abdominal TB (five pulmonary, two nodal), adnexal (one), and HIV (one) were excluded from analysis. Of 61 patients, 31 (50.8 %) had a positive AFB culture. In the 30 culture-negative patients, histology showed non-caseating granulomas in 25 patients. Drug sensitivity pattern was analyzed in 18 patients; resistance was detected in eight (14.3 % of all patients and 44.4 % of patients in whom drug sensitivity was done) including three (5.4 % of all subjects and 16.6 % in whom drug sensitivity was available) who were multidrug-resistant. The rate of AFB culture positivity in primary abdominal TB was 50.8 % using Bactec MGIT. Likelihood of drug resistance was seen in 14.3 %, of whom 5.4 % were multidrug-resistant.

  3. Quinolone resistance-associated amino acid substitutions affect enzymatic activity of Mycobacterium leprae DNA gyrase.

    Science.gov (United States)

    Yamaguchi, Tomoyuki; Yokoyama, Kazumasa; Nakajima, Chie; Suzuki, Yasuhiko

    2017-07-01

    Quinolones are important antimicrobials for treatment of leprosy, a chronic infectious disease caused by Mycobacterium leprae. Although it is well known that mutations in DNA gyrase are responsible for quinolone resistance, the effect of those mutations on the enzymatic activity is yet to be studied in depth. Hence, we conducted in vitro assays to observe supercoiling reactions of wild type and mutated M. leprae DNA gyrases. DNA gyrase with amino acid substitution Ala91Val possessed the highest activity among the mutants. DNA gyrase with Gly89Cys showed the lowest level of activity despite being found in clinical strains, but it supercoiled DNA like the wild type does if applied at a sufficient concentration. In addition, patterns of time-dependent conversion from relaxed circular DNA into supercoiled DNA by DNA gyrases with clinically unreported Asp95Gly and Asp95Asn were observed to be distinct from those by the other DNA gyrases.

  4. Streptococcus pneumoniae Drugs Resistance in Acute Rhinosinusitis

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    Chong Jie Hao

    2016-03-01

    Full Text Available Background: Acute rhinosinusitis that usually caused by Streptococcus pneumoniae becomes the reason why patients seek for medical care. Drugs resistance in Streptococcus pneumoniae is increasing worldwide. This study was conducted to determine drugs resistance of Streptococcus pneumonia from acute rhinosinusitis in Dr. Hasan Sadikin General Hospital. Methods: A descriptive laboratory study was conducted in June–October 2014 at the Laboratory of Microbiology Faculty of Medicine Universitas Padjadjaran. The sample was taken using nasopharyngeal swabbing from 100 acute rhinosinusitis patients in Dr. Hasan Sadikin General Hospital and planted on tryptic soy agar containing 5% sheep blood and 5 μg/ml of gentamicin sulphate and then incubated in 5% CO2 incubator at 37°C for 24 hours. The identification of Streptococcus pneumonia was performed by optochin test. The susceptibility test against Streptococcus pneumoniae was done using disk diffusion method.The antibiotic disks were trimethoprim-sulfamethoxazole, oxacillin, levofloxacin, azithromycin, and doxycycline. Results: Out of 100 samples, 8 of them were tested positive for Streptococcus pneumoniae. Three of Streptococcus pneumoniae isolates died with unknown reason after it were stored at -80 .The drugs resistance test showed the resistance of Streptococcus pneumonia to oxacillin, azithromycin and trimethoprim were 6, whereas levofloxacin and doxycycline are 4. Conclusions: Streptococcus pneumonia drugs resistance in acute rhinosinusitis shows the resistance of Streptococcus pneumoniae to oxacillin, azithromycin and trimethoprim are 6, whereas the resistance to levofloxacin and doxycycline are 4.

  5. Activity of moxifloxacin and linezolid against Mycobacterium tuberculosis in combination with potentiator drugs verapamil, timcodar, colistin and SQ109.

    Science.gov (United States)

    de Knegt, Gerjo J; van der Meijden, Aart; de Vogel, Corné P; Aarnoutse, Rob E; de Steenwinkel, Jurriaan E M

    2017-03-01

    Current treatment for tuberculosis (TB) is complicated by the emergence of multidrug resistant TB (MDR-TB). As a result, there is an urgent need for new powerful anti-TB regimens and novel strategies. In this study, we aimed to potentiate a moxifloxacin + linezolid backbone as treatment for MDR-TB with the efflux pump inhibitors verapamil and timcodar as well as with drugs that act on mycobacterial cell wall stability such as colistin and SQ109. Using a time-kill kinetics assay, the activities of moxifloxacin, linezolid, verapamil, timcodar, colistin and SQ109 as single drugs against Mycobacterium tuberculosis were evaluated. In addition, the activity of the moxifloxacin + linezolid backbone in combination with one of the potentiator drugs was assessed. As little as 0.125 mg/L moxifloxacin achieved 99% killing of M. tuberculosis after 6 days of exposure. Linezolid showed moderate killing but 99% killing was not achieved. Verapamil, timcodar and colistin only resulted in killing with the highest concentrations tested but 99% killing was not achieved. SQ109 resulted in complete elimination after 1 day of exposure to 256 mg/L and in 99% elimination after 6 days of exposure to 1 mg/L. Furthermore, colistin added to the moxifloxacin + linezolid backbone resulted in increased elimination, whereas verapamil, timcodar and SQ109 showed no added value to the backbone. This finding that colistin potentiates the activity of the moxifloxacin + linezolid backbone against M. tuberculosis suggests its potential role in further studies on the applicability of a moxifloxacin + linezolid treatment of MDR-TB. Copyright © 2017 Elsevier B.V. and International Society of Chemotherapy. All rights reserved.

  6. In vitro drug susceptibility of Mycobacterium tuberculosis for amikacin, kanamycin and capreomycin.

    NARCIS (Netherlands)

    Dijkstra, J A; van der Laan, T; Akkerman, O W; Bolhuis, M S; de Lange, W C M; Kosterink, J G W; van der Werf, T S; Alffenaar, J W C; van Soolingen, D

    2018-01-01

    Amikacin, kanamycin and capreomycin are listed among the most important 2nd line drugs for multidrug resistant tuberculosis. Although amikacin and kanamycin are administered in the same dose and show the same pharmacokinetics, they have different WHO breakpoints suggesting that the two drugs have a

  7. Antimicrobial Drug Resistance and Gonorrhea

    Centers for Disease Control (CDC) Podcasts

    2017-12-26

    Dr. Robert Kirkcaldy, a medical officer at CDC, discusses his article on antimicrobial resistance and gonorrhea.  Created: 12/26/2017 by National Center for Emerging and Zoonotic Infectious Diseases (NCEZID).   Date Released: 12/26/2017.

  8. Nanoparticles as Antituberculosis Drugs Carriers: Effect on Activity Against Mycobacterium tuberculosis in Human Monocyte-Derived Macrophages

    International Nuclear Information System (INIS)

    Anisimova, Y.V.; Gelperina, S.I.; Peloquin, C.A.; Heifets, L.B.

    2000-01-01

    This is the first report evaluating the nanoparticle delivery system for three antituberculosis drugs: isoniazid, rifampin, and streptomycin. The typical particle size is 250 nm. We studied accumulation of these drugs in human monocytes as well as their antimicrobial activity against Mycobacterium tuberculosis residing in human monocyte-derived macrophages. Nanoparticle encapsulation increased the intracellular accumulation (cell-association) of all three tested drugs, but it enhanced the antimicrobial activity of isoniazid and streptomycin only. On the other hand, the activity of encapsulated rifampin against intracellular bacteria was not higher than that of the free drug

  9. Role of drug transporters and drug accumulation in the temporal acquisition of drug resistance

    International Nuclear Information System (INIS)

    Hembruff, Stacey L; Laberge, Monique L; Villeneuve, David J; Guo, Baoqing; Veitch, Zachary; Cecchetto, Melanie; Parissenti, Amadeo M

    2008-01-01

    Anthracyclines and taxanes are commonly used in the treatment of breast cancer. However, tumor resistance to these drugs often develops, possibly due to overexpression of drug transporters. It remains unclear whether drug resistance in vitro occurs at clinically relevant doses of chemotherapy drugs and whether both the onset and magnitude of drug resistance can be temporally and causally correlated with the enhanced expression and activity of specific drug transporters. To address these issues, MCF-7 cells were selected for survival in increasing concentrations of doxorubicin (MCF-7 DOX-2 ), epirubicin (MCF-7 EPI ), paclitaxel (MCF-7 TAX-2 ), or docetaxel (MCF-7 TXT ). During selection cells were assessed for drug sensitivity, drug uptake, and the expression of various drug transporters. In all cases, resistance was only achieved when selection reached a specific threshold dose, which was well within the clinical range. A reduction in drug uptake was temporally correlated with the acquisition of drug resistance for all cell lines, but further increases in drug resistance at doses above threshold were unrelated to changes in cellular drug uptake. Elevated expression of one or more drug transporters was seen at or above the threshold dose, but the identity, number, and temporal pattern of drug transporter induction varied with the drug used as selection agent. The pan drug transporter inhibitor cyclosporin A was able to partially or completely restore drug accumulation in the drug-resistant cell lines, but had only partial to no effect on drug sensitivity. The inability of cyclosporin A to restore drug sensitivity suggests the presence of additional mechanisms of drug resistance. This study indicates that drug resistance is achieved in breast tumour cells only upon exposure to concentrations of drug at or above a specific selection dose. While changes in drug accumulation and the expression of drug transporters does occur at the threshold dose, the magnitude of

  10. Enhancing hit identification in Mycobacterium tuberculosis drug discovery using validated dual-event Bayesian models.

    Directory of Open Access Journals (Sweden)

    Sean Ekins

    Full Text Available High-throughput screening (HTS in whole cells is widely pursued to find compounds active against Mycobacterium tuberculosis (Mtb for further development towards new tuberculosis (TB drugs. Hit rates from these screens, usually conducted at 10 to 25 µM concentrations, typically range from less than 1% to the low single digits. New approaches to increase the efficiency of hit identification are urgently needed to learn from past screening data. The pharmaceutical industry has for many years taken advantage of computational approaches to optimize compound libraries for in vitro testing, a practice not fully embraced by academic laboratories in the search for new TB drugs. Adapting these proven approaches, we have recently built and validated Bayesian machine learning models for predicting compounds with activity against Mtb based on publicly available large-scale HTS data from the Tuberculosis Antimicrobial Acquisition Coordinating Facility. We now demonstrate the largest prospective validation to date in which we computationally screened 82,403 molecules with these Bayesian models, assayed a total of 550 molecules in vitro, and identified 124 actives against Mtb. Individual hit rates for the different datasets varied from 15-28%. We have identified several FDA approved and late stage clinical candidate kinase inhibitors with activity against Mtb which may represent starting points for further optimization. The computational models developed herein and the commercially available molecules derived from them are now available to any group pursuing Mtb drug discovery.

  11. Radiosensitivity of drug-resistant human tumour xenografts

    International Nuclear Information System (INIS)

    Mattern, J.; Bak, M. Jr.; Volm, M.; Hoever, K.H.

    1989-01-01

    The radiosensitivity of three drug-resistant sublines of a human epidermoid lung carcinoma growing as xenografts in nude mice was investigated. Drug resistance to vincristine, actinomycin D and cisplatin was developed in vivo by repeated drug treatment. It was found that all three drug-resistant tumour lines were not cross-resistant to irradiation. (orig.) [de

  12. Clinical Concentrations of Thioridazine Kill Intracellular Multidrug-Resistant Mycobacterium tuberculosis

    Science.gov (United States)

    Ordway, Diane; Viveiros, Miguel; Leandro, Clara; Bettencourt, Rosário; Almeida, Josefina; Martins, Marta; Kristiansen, Jette E.; Molnar, Joseph; Amaral, Leonard

    2003-01-01

    The phenothiazines chlorpromazine (CPZ) and thioridazine (TZ) have equal in vitro activities against antibiotic-sensitive and -resistant Mycobacterium tuberculosis. These compounds have not been used as anti-M. tuberculosis agents because their in vitro activities take place at concentrations which are beyond those that are clinically achievable. In addition, chronic administration of CPZ produces frequent severe side effects. Because CPZ has been shown to enhance the killing of intracellular M. tuberculosis at concentrations in the medium that are clinically relevant, we have investigated whether TZ, a phenothiazine whose negative side effects are less frequent and serious than those associated with CPZ, kills M. tuberculosis organisms that have been phagocytosed by human macrophages, which have nominal killing activities against these bacteria. Both CPZ and TZ killed intracellular antibiotic-sensitive and -resistant M. tuberculosis organisms when they were used at concentrations in the medium well below those present in the plasma of patients treated with these agents. These concentrations in vitro were not toxic to the macrophage, nor did they affect in vitro cellular immune processes. TZ thus appears to be a serious candidate for the management of a freshly diagnosed infection of pulmonary tuberculosis or as an adjunct to conventional antituberculosis therapy if the patient originates from an area known to have a high prevalence of multidrug-resistant M. tuberculosis isolates. Nevertheless, we must await the outcomes of clinical trials to determine whether TZ itself may be safely and effectively used as an antituberculosis agent. PMID:12604522

  13. Identifying co-targets to fight drug resistance based on a random walk model

    Directory of Open Access Journals (Sweden)

    Chen Liang-Chun

    2012-01-01

    Full Text Available Abstract Background Drug resistance has now posed more severe and emergent threats to human health and infectious disease treatment. However, wet-lab approaches alone to counter drug resistance have so far still achieved limited success due to less knowledge about the underlying mechanisms of drug resistance. Our approach apply a heuristic search algorithm in order to extract active network under drug treatment and use a random walk model to identify potential co-targets for effective antibacterial drugs. Results We use interactome network of Mycobacterium tuberculosis and gene expression data which are treated with two kinds of antibiotic, Isoniazid and Ethionamide as our test data. Our analysis shows that the active drug-treated networks are associated with the trigger of fatty acid metabolism and synthesis and nicotinamide adenine dinucleotide (NADH-related processes and those results are consistent with the recent experimental findings. Efflux pumps processes appear to be the major mechanisms of resistance but SOS response is significantly up-regulation under Isoniazid treatment. We also successfully identify the potential co-targets with literature confirmed evidences which are related to the glycine-rich membrane, adenosine triphosphate energy and cell wall processes. Conclusions With gene expression and interactome data supported, our study points out possible pathways leading to the emergence of drug resistance under drug treatment. We develop a computational workflow for giving new insights to bacterial drug resistance which can be gained by a systematic and global analysis of the bacterial regulation network. Our study also discovers the potential co-targets with good properties in biological and graph theory aspects to overcome the problem of drug resistance.

  14. Is IQG-607 a Potential Metallodrug or Metallopro-Drug With a Defined Molecular Target in Mycobacterium tuberculosis?

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    Bruno L. Abbadi

    2018-05-01

    Full Text Available The emergence of strains of Mycobacterium tuberculosis resistant to isoniazid (INH has underscored the need for the development of new anti-tuberculosis agents. INH is activated by the mycobacterial katG-encoded catalase-peroxidase, forming an acylpyridine fragment that is covalently attached to the C4 of NADH. This isonicotinyl-NAD adduct inhibits the activity of 2-trans-enoyl-ACP(CoA reductase (InhA, which plays a role in mycolic acid biosynthesis. A metal-based INH analog, Na3[FeII(CN5(INH]·4H2O, IQG-607, was designed to have an electronic redistribution on INH moiety that would lead to an intramolecular electron transfer to bypass KatG activation. HPLC and EPR studies showed that the INH moiety can be oxidized by superoxide or peroxide yielding similar metabolites and isonicotinoyl radical only when associated to IQG-607, thereby supporting redox-mediated drug activation as a possible mechanism of action. However, IQG-607 was shown to inhibit the in vitro activity of both wild-type and INH-resistant mutant InhA enzymes in the absence of KatG activation. IQG-607 given by the oral route to M. tuberculosis-infected mice reduced lung lesions. Experiments using early and late controls of infection revealed a bactericidal activity for IQG-607. HPLC and voltammetric methods were developed to quantify IQG-607. Pharmacokinetic studies showed short half-life, high clearance, moderate volume of distribution, and low oral bioavailability, which was not altered by feeding. Safety and toxic effects of IQG-607 after acute and 90-day repeated oral administrations in both rats and minipigs showed occurrence of mild to moderate toxic events. Eight multidrug-resistant strains (MDR-TB were resistant to IQG-607, suggesting an association between katG mutation and increasing MIC values. Whole genome sequencing of three spontaneous IQG-607-resistant strains harbored katG gene mutations. MIC measurements and macrophage infection experiments with a laboratorial

  15. A Case of Acquired Rifampin Resistance in Mycobacterium bovis Bacillus Calmette-Guérin-Induced Cystitis: Necessity for Treatment Guidelines

    Directory of Open Access Journals (Sweden)

    Joyce N Wolfe

    2006-01-01

    Full Text Available A case of presumed bacillus Calmette-Guérin (BCG cystitis in an elderly female patient following direct intravesical BCG instillation treatment for papillary transitional cell carcinoma is reported. The organism cultured from urine samples was eventually identified as a rifampin-resistant Mycobacterium bovis BCG isolate. Because the patient had received rifampin monotherapy during the course of treatment for presumed BCG disease, the clinical picture favoured acquired rifampin resistance. Sequencing of the target gene for rifampin (rpoB confirmed a known mutation responsible for conferring high levels of resistance to both rifampin and rifabutin (Ser531Tyr. To the authors' knowledge, this is the first reported case of M bovis BCG disease in a non-HIV patient where the organism had acquired drug resistance to rifampin, and the second reported case of M bovis BCG that had acquired drug resistance. The present case demonstrates the necessity to re-evaluate appropriate guidelines for the effective treatment of BCG disease.

  16. Resistance mechanisms and drug susceptibility testing of nontuberculous mycobacteria.

    NARCIS (Netherlands)

    Ingen, J. van; Boeree, M.J.; Soolingen, D. van; Mouton, J.W.

    2012-01-01

    Nontuberculous mycobacteria (NTM) are increasingly recognized as causative agents of opportunistic infections in humans. For most NTM infections the therapy of choice is drug treatment, but treatment regimens differ by species, in particular between slow (e.g. Mycobacterium avium complex,

  17. Overview of drug-resistant tuberculosis worldwide

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    Ali A Velayati

    2016-01-01

    Full Text Available Even in the 21st century, we are losing the battle against eradication of tuberculosis (TB. In 2015, 9.6 million people were estimated to have fallen ill with TB, of which 1.5 million people died. This is the real situation despite the well-structured treatment programs and availability of effective treatment options since the 1950s. The high mortality rate has been associated with other risk factors, such as the HIV epidemic, underlying diseases, and decline of socioeconomic standards. Furthermore, the problem of drug resistance that was recognized in the early days of the chemotherapeutic era raises serious concerns. Although resistance to a single agent is the most common type, resistance to multiple agents is less frequent but of greater concern. The World Health Organization estimated approximately 5% of all new TB cases involved multidrug-resistant (MDR-TB. The estimation for MDR-TB is 3.3% for new cases, and 20.5% for previously treated cases. Failure to identify and appropriately treat MDR-TB patients has led to more dangerous forms of resistant TB. Based on World Health Organization reports, 5% of global TB cases are now considered to be extensively drug resistant (XDR, defined as MDR with additional resistance to both fluoroquinolones and at least one second-line injectable drug. XDR-TB had been reported by 105 countries by 2015. An estimated 9.7% of people with MDR-TB have XDR-TB. More recently, another dangerous form of TB bacillus was identified, which was named totally drug resistant (TDR-TB or extremely drug resistant TB. These strains were resistant to all first- and second-line anti-TB drugs. Collectively, it is accepted that 2% of MDR-TB strains turn to be TDR-TB. This number, however, may not reflect the real situation, as many laboratories in endemic TB countries do not have proper facilities and updated protocols to detect the XDR or TDR-TB strains. Nevertheless, existing data emphasize the need for additional control

  18. HIV Genetic Diversity and Drug Resistance

    Science.gov (United States)

    Santos, André F.; Soares, Marcelo A.

    2010-01-01

    Most of the current knowledge on antiretroviral (ARV) drug development and resistance is based on the study of subtype B of HIV-1, which only accounts for 10% of the worldwide HIV infections. Cumulative evidence has emerged that different HIV types, groups and subtypes harbor distinct biological properties, including the response and susceptibility to ARV. Recent laboratory and clinical data highlighting such disparities are summarized in this review. Variations in drug susceptibility, in the emergence and selection of specific drug resistance mutations, in viral replicative capacity and in the dynamics of resistance acquisition under ARV selective pressure are discussed. Clinical responses to ARV therapy and associated confounding factors are also analyzed in the context of infections by distinct HIV genetic variants. PMID:21994646

  19. Mesenchymal change and drug resistance in neuroblastoma.

    Science.gov (United States)

    Naiditch, Jessica A; Jie, Chunfa; Lautz, Timothy B; Yu, Songtao; Clark, Sandra; Voronov, Dimitry; Chu, Fei; Madonna, Mary Beth

    2015-01-01

    Metastatic initiation has many phenotypic similarities to epithelial-to-mesenchymal transition, including loss of cell-cell adhesion, increased invasiveness, and increased cell mobility. We have previously demonstrated that drug resistance is associated with a metastatic phenotype in neuroblastoma (NB). The purpose of this project was to determine if the development of doxorubicin resistance is associated with characteristics of mesenchymal change in human NB cells. Total RNA was isolated from wild type (WT) and doxorubicin-resistant (DoxR) human NB cell lines (SK-N-SH and SK-N-BE(2)C) and analyzed using the Illumina Human HT-12 version 4 Expression BeadChip. Differentially expressed genes (DEGs) were identified. Volcano plots and heat maps were generated. Genes of interest with a fold change in expression >1.5 and an adjusted P change via multiple pathways in the transition to a drug-resistant state. Copyright © 2015 Elsevier Inc. All rights reserved.

  20. Investigating the metabolic capabilities of Mycobacterium tuberculosis H37Rv using the in silico strain iNJ661 and proposing alternative drug targets

    Directory of Open Access Journals (Sweden)

    Palsson Bernhard Ø

    2007-06-01

    Full Text Available Abstract Background: Mycobacterium tuberculosis continues to be a major pathogen in the third world, killing almost 2 million people a year by the most recent estimates. Even in industrialized countries, the emergence of multi-drug resistant (MDR strains of tuberculosis hails the need to develop additional medications for treatment. Many of the drugs used for treatment of tuberculosis target metabolic enzymes. Genome-scale models can be used for analysis, discovery, and as hypothesis generating tools, which will hopefully assist the rational drug development process. These models need to be able to assimilate data from large datasets and analyze them. Results: We completed a bottom up reconstruction of the metabolic network of Mycobacterium tuberculosis H37Rv. This functional in silico bacterium, iNJ661, contains 661 genes and 939 reactions and can produce many of the complex compounds characteristic to tuberculosis, such as mycolic acids and mycocerosates. We grew this bacterium in silico on various media, analyzed the model in the context of multiple high-throughput data sets, and finally we analyzed the network in an 'unbiased' manner by calculating the Hard Coupled Reaction (HCR sets, groups of reactions that are forced to operate in unison due to mass conservation and connectivity constraints. Conclusion: Although we observed growth rates comparable to experimental observations (doubling times ranging from about 12 to 24 hours in different media, comparisons of gene essentiality with experimental data were less encouraging (generally about 55%. The reasons for the often conflicting results were multi-fold, including gene expression variability under different conditions and lack of complete biological knowledge. Some of the inconsistencies between in vitro and in silico or in vivo and in silico results highlight specific loci that are worth further experimental investigations. Finally, by considering the HCR sets in the context of known

  1. Extent and origin of resistance to antituberculosis drugs in the Netherlands, 1993 to 2011.

    Science.gov (United States)

    Ruesen, C; van Gageldonk-Lafeber, A B; de Vries, G; Erkens, C G; van Rest, J; Korthals Altes, H; de Neeling, H; Kamst, M; van Soolingen, D

    2014-03-20

    The elimination of tuberculosis (TB) is threatened by an apparent increase in the level of resistance in Mycobacterium tuberculosis. In the Netherlands, where the majority of TB patients are migrants, resistance may also be increasing. We conducted a retrospective study, using 18,294 M. tuberculosis isolates from TB cases notified between 1993 and 2011. We investigated the trends in antituberculosis drug resistance, focusing on the country of birth of the patients and whether resistance had developed during treatment or was the result of transmission of resistant M. tuberculosis strains. For both scenarios, we determined whether this had happened in or outside the Netherlands. Antituberculosis drug resistance was found in 13% of all cases analysed and showed an increasing trend among patients who had been born in the Netherlands (pNetherlands or before 1993 (when DNA fingerprinting was not systematically performed), in some cases (n=45), resistance was acquired in the Netherlands. We conclude that antituberculosis drug resistance is increasing in the Netherlands, mostly related to migration from high TB-incidence countries, but also to domestic acquisition.

  2. Drug-resistant tuberculosis: emerging treatment options

    Directory of Open Access Journals (Sweden)

    Adhvaryu MR

    2011-12-01

    Full Text Available Meghna Adhvaryu1, Bhasker Vakharia21Department of Biotechnology, SRK Institute of Computer Education and Applied Sciences, 2R&D, Bhuma Research in Ayurvedic and Herbal Medicine, Surat, Gujarat, IndiaAbstract: Multidrug-resistant tuberculosis has emerged worldwide, with an increasing incidence due to failure of implementation of apparently effective first-line antituberculous therapy as well as primary infection with drug-resistant strains. Failure of current therapy is attributed to a long duration of treatment leading to nonadherence and irregular therapy, lack of patient education about the disease, poverty, irregular supply by care providers, drug–drug interactions in patients coinfected with human immunodeficiency virus (HIV, inadequate regulations causing market overlap and irresponsible drug usage in the private sector, and lack of research, with no addition of new drugs in the last four decades. Present standards of care for the treatment of drug-susceptible tuberculosis, multidrug-resistant tuberculosis, tuberculosis-HIV coinfection, and latent tuberculosis infection are all unsatisfactory. Since 2000, the World Health Organization (WHO has focused on drug development for tuberculosis, as well as research in all relevant aspects to discover new regimens by 2015 and to eliminate tuberculosis as a public health concern by 2050. As a result, some 20 promising compounds from 14 groups of drugs have been discovered. Twelve candidates from eight classes are currently being evaluated in clinical trials. Ongoing research should prioritize identification of novel targets and newer application of existing drugs, discovery of multitargeted drugs from natural compounds, strengthening host factors by immunopotentiation with herbal immunomodulators, as well as protective vaccines before and after exposure, consideration of surgical measures when indicated, development of tools for rapid diagnosis, early identification of resistant strains, and

  3. Analytical and clinical performance characteristics of the Abbott RealTime MTB RIF/INH Resistance, an assay for the detection of rifampicin and isoniazid resistant Mycobacterium tuberculosis in pulmonary specimens.

    Science.gov (United States)

    Kostera, Joshua; Leckie, Gregor; Tang, Ning; Lampinen, John; Szostak, Magdalena; Abravaya, Klara; Wang, Hong

    2016-12-01

    Clinical management of drug-resistant tuberculosis patients continues to present significant challenges to global health. To tackle these challenges, the Abbott RealTime MTB RIF/INH Resistance assay was developed to accelerate the diagnosis of rifampicin and/or isoniazid resistant tuberculosis to within a day. This article summarizes the performance of the Abbott RealTime MTB RIF/INH Resistance assay; including reliability, analytical sensitivity, and clinical sensitivity/specificity as compared to Cepheid GeneXpert MTB/RIF version 1.0 and Hain MTBDRplus version 2.0. The limit of detection (LOD) of the Abbott RealTime MTB RIF/INH Resistance assay was determined to be 32 colony forming units/milliliter (cfu/mL) using the Mycobacterium tuberculosis (MTB) strain H37Rv cell line. For rifampicin resistance detection, the Abbott RealTime MTB RIF/INH Resistance assay demonstrated statistically equivalent clinical sensitivity and specificity as compared to Cepheid GeneXpert MTB/RIF. For isoniazid resistance detection, the assay demonstrated statistically equivalent clinical sensitivity and specificity as compared to Hain MTBDRplus. The performance data presented herein demonstrate that the Abbott RealTime MTB RIF/INH Resistance assay is a sensitive, robust, and reliable test for realtime simultaneous detection of first line anti-tuberculosis antibiotics rifampicin and isoniazid in patient specimens. Copyright © 2016 The Author. Published by Elsevier Ltd.. All rights reserved.

  4. Economic implications of resistance to antimalarial drugs.

    Science.gov (United States)

    Phillips, M; Phillips-Howard, P A

    1996-09-01

    The widespread evolution of drug resistance in malarial parasites has seriously hampered efforts to control this debilitating disease. Chloroquine, the mainstay of malaria treatment for many decades, is now proving largely ineffective in many parts of the world, particularly against the most severe form of malaria--falciparum. Alternative drugs have been developed, but they are frequently less safe and are all between 50 and 700% more expensive than chloroquine. Choice of drug clearly has important budgetary implications and national malaria control programmes need to weigh up the costs and benefits in deciding whether to change to more effective but more expensive drugs. The growth in drug resistance also has implications for the choice of diagnostic tool. Clinical diagnosis of malaria is relatively cheap, but less specific than some technological approaches. As more expensive drugs are employed, the cost of wasted treatment on suspected cases who do not in fact have malaria rises and the more worthwhile it becomes to invest in more specific diagnostic techniques. This paper presents an economic framework for analysing the various malaria drug and diagnostic tool options available. It discusses the nature of the key factors that need to be considered when making choices of malaria treatment (including treatment costs, drug resistance, the costs of treatment failure and compliance) and diagnosis (including diagnosis cost and accuracy, and the often overlooked costs associated with delayed treatment), and uses some simple equations to illustrate the impact of these on the relative cost effectiveness of the alternatives being considered. On the basis of some simplifying assumptions and illustrative calculations, it appears that in many countries more effective drugs and more specific and rapid diagnostic approaches will be worth adopting even although they imply additional expense.

  5. Evaluation of four colourimetric susceptibility tests for the rapid detection of multidrug-resistant Mycobacterium tuberculosisisolates

    Directory of Open Access Journals (Sweden)

    Ahmet Yilmaz Coban

    2015-08-01

    Full Text Available The purpose of this study is to evaluate four rapid colourimetric methods, including the resazurin microtitre assay (REMA, malachite green decolourisation assay (MGDA, microplate nitrate reductase assay (MNRA and crystal violet decolourisation assay (CVDA, for the rapid detection of multidrug-resistant (MDR tuberculosis. Fifty Mycobacterium tuberculosisisolates were used in this study. Eighteen isolates were MDR, two isolates were only resistant to isoniazid (INH and the remaining isolates were susceptible to both INH and rifampicin (RIF. INH and RIF were tested in 0.25 µg/mL and 0.5 µg/mL, respectively. The agar proportion method was used as a reference method. MNRA and REMA were performed with some modifications. MGDA and CVDA were performed as defined in the literature. The agreements of the MNRA for INH and RIF were 96% and 94%, respectively, while the agreement of the other assays for INH and RIF were 98%. In this study, while the specificities of the REMA, MGDA and CVDA were 100%, the specificity of the MNRA was lower than the others (93.3% for INH and 90.9% for RIF. In addition, while the sensitivity of the MNRA was 100%, the sensitivities of the others were lower than that of the MNRA (from 94.1-95%. The results were reported on the seventh-10th day of the incubation. All methods are reliable, easy to perform, inexpensive and easy to evaluate and do not require special equipment.

  6. Genitourinary and pulmonary multidrug resistant Mycobacterium tuberculosis infection in an Asian elephant (Elephas maximus).

    Science.gov (United States)

    Dumonceaux, Genevieve A; St Leger, Judy; Olsen, John H; Burton, Michael S; Ashkin, David; Maslow, Joel N

    2011-12-01

    A female Asian elephant (Elephas maximus) developed vaginal and trunk discharge. Cultures were positive for pan-susceptible Mycobacterium tuberculosis. Isoniazid and pyrazinamide were given rectally and monitored by serum levels. After being trained at 10 mo to accept oral dosing, treatment was changed and rifampin was added. Oral medications were administered for another 10 mo. A year after completion of therapy, the vaginal discharge increased and cultures yielded M. tuberculosis, resistant to isoniazid and rifampin. Treatment with oral ethambutol, pyrazinamide, and enrofloxacin and intramuscular amikacin was initiated. Although followup cultures became negative, adverse reactions to medications precluded treatment completion. Due to public health concerns related to multidrug resistant M. tuberculosis (MDR-TB), the elephant was euthanized. Postmortem smears from the lung, peribronchial, and abdominal lymph nodes yielded acid-fast bacteria, although cultures were negative. This case highlights important considerations in the treatment of M. tuberculosis in animals and the need for a consistent approach to diagnosis, treatment, and follow-up.

  7. Mechanisms of Candida biofilm drug resistance

    Science.gov (United States)

    Taff, Heather T; Mitchell, Kaitlin F; Edward, Jessica A; Andes, David R

    2013-01-01

    Candida commonly adheres to implanted medical devices, growing as a resilient biofilm capable of withstanding extraordinarily high antifungal concentrations. As currently available antifungals have minimal activity against biofilms, new drugs to treat these recalcitrant infections are urgently needed. Recent investigations have begun to shed light on the mechanisms behind the profound resistance associated with the biofilm mode of growth. This resistance appears to be multifactorial, involving both mechanisms similar to conventional, planktonic antifungal resistance, such as increased efflux pump activity, as well as mechanisms specific to the biofilm lifestyle. A unique biofilm property is the production of an extracellular matrix. Two components of this material, β-glucan and extracellular DNA, promote biofilm resistance to multiple antifungals. Biofilm formation also engages several stress response pathways that impair the activity of azole drugs. Resistance within a biofilm is often heterogeneous, with the development of a subpopulation of resistant persister cells. In this article we review the molecular mechanisms underlying Candida biofilm antifungal resistance and their relative contributions during various growth phases. PMID:24059922

  8. characterization of drug resistant pseudomonas aeruginosa and ...

    African Journals Online (AJOL)

    Abstract: Lizards as well as some other reptiles have been known to carry pathogenic bacteria organisms as well as drug resistant pathogens. Despite the fact that they remain asymptomatic in many cases, they nevertheless play significant roles in the epidemiology of these pathogens through their dissemination to the ...

  9. Repurposing salicylanilide anthelmintic drugs to combat drug resistant Staphylococcus aureus.

    Science.gov (United States)

    Rajamuthiah, Rajmohan; Fuchs, Beth Burgwyn; Conery, Annie L; Kim, Wooseong; Jayamani, Elamparithi; Kwon, Bumsup; Ausubel, Frederick M; Mylonakis, Eleftherios

    2015-01-01

    Staphylococcus aureus is a Gram-positive bacterium that has become the leading cause of hospital acquired infections in the US. Repurposing Food and Drug Administration (FDA) approved drugs for antimicrobial therapy involves lower risks and costs compared to de novo development of novel antimicrobial agents. In this study, we examined the antimicrobial properties of two commercially available anthelmintic drugs. The FDA approved drug niclosamide and the veterinary drug oxyclozanide displayed strong in vivo and in vitro activity against methicillin resistant S. aureus (minimum inhibitory concentration (MIC): 0.125 and 0.5 μg/ml respectively; minimum effective concentration: ≤ 0.78 μg/ml for both drugs). The two drugs were also effective against another Gram-positive bacteria Enterococcus faecium (MIC 0.25 and 2 μg/ml respectively), but not against the Gram-negative species Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa and Enterobacter aerogenes. The in vitro antimicrobial activity of niclosamide and oxyclozanide were determined against methicillin, vancomycin, linezolid or daptomycin resistant S. aureus clinical isolates, with MICs at 0.0625-0.5 and 0.125-2 μg/ml for niclosamide and oxyclozanide respectively. A time-kill study demonstrated that niclosamide is bacteriostatic, whereas oxyclozanide is bactericidal. Interestingly, oxyclozanide permeabilized the bacterial membrane but neither of the anthelmintic drugs exhibited demonstrable toxicity to sheep erythrocytes. Oxyclozanide was non-toxic to HepG2 human liver carcinoma cells within the range of its in vitro MICs but niclosamide displayed toxicity even at low concentrations. These data show that the salicylanilide anthelmintic drugs niclosamide and oxyclozanide are suitable candidates for mechanism of action studies and further clinical evaluation for treatment of staphylococcal infections.

  10. Population mobility, globalization, and antimicrobial drug resistance.

    Science.gov (United States)

    MacPherson, Douglas W; Gushulak, Brian D; Baine, William B; Bala, Shukal; Gubbins, Paul O; Holtom, Paul; Segarra-Newnham, Marisel

    2009-11-01

    Population mobility is a main factor in globalization of public health threats and risks, specifically distribution of antimicrobial drug-resistant organisms. Drug resistance is a major risk in healthcare settings and is emerging as a problem in community-acquired infections. Traditional health policy approaches have focused on diseases of global public health significance such as tuberculosis, yellow fever, and cholera; however, new diseases and resistant organisms challenge existing approaches. Clinical implications and health policy challenges associated with movement of persons across barriers permeable to products, pathogens, and toxins (e.g., geopolitical borders, patient care environments) are complex. Outcomes are complicated by high numbers of persons who move across disparate and diverse settings of disease threat and risk. Existing policies and processes lack design and capacity to prevent or mitigate adverse health outcomes. We propose an approach to global public health risk management that integrates population factors with effective and timely application of policies and processes.

  11. Rifampicin resistance in mycobacterium tuberculosis patients using GeneXpert at Livingstone Central Hospital for the year 2015: a cross sectional explorative study.

    Science.gov (United States)

    Masenga, Sepiso K; Mubila, Harrison; Hamooya, Benson M

    2017-09-22

    Since the recent introduction of GeneXepert for the detection of Tuberculosis (TB) drug resistance mutations in both primary resistance and acquired resistance in Zambia, little has been documented in literature on the issue of rifampicin resistance especially in the face of a high National TB burden. The study aimed to determine the prevalence of rifampicin resistance in tuberculosis patients at Livingstone Central Hospital for the year 2015. This was a cross sectional study conducted at Livingstone Central Hospital where we reviewed 152 records (from January 1, 2015 to 31st December, 2015) involving patients who presented with clinically suspected TB or documented TB, whose samples were sent to the laboratory for GeneXpert Mycobacterium tuberculosis/rifampicin testing. Statistical evaluations used a one-sample test of proportion and Fisher's exact test. The age of participants ranged from 8 months to 73 years old (median = 34). Of the participants with complete data on gender, 99 (66%) and 52 (34%) were males and females respectively. The TB co-infection with HIV prevalence was 98.3% (p < 0.001). Prevalence of rifampicin resistance was 5.9% and there was no statistical significant difference between being male or female (p = 0.721). We were able to show from our study, evidence of rifampicin resistance at Livingstone Central Hospital. Hence, there was need for further in-depth research and appropriate interventions (i.e close follow-up and patient care for drug resistance positive patients).

  12. PCR (Polymerase Chain Reaction) Assay On Antibiotics Resistant Clinical Isolates Of Mycobacterium tuberculosis

    International Nuclear Information System (INIS)

    R, Maria Lina; S, Dadang; Suhadi, F.

    2000-01-01

    To detect to DNA of 9 drug-resistant isolates of m. tuberculosis such as isoniazid, streptomycin, isoniazid + streptomycin and isoniazid + rifampisin- resistant isolates, the DNA amplification by using PCR assay was carried out after lysing the bacterial cells. Two primer pairs for amplification used were Pt8 and Pt9 and Pt3 and Pt6. The amplified DNA taeget of 8 drug-resistant isolates and 1 drug-resistant isolate by means Pt8 8 Pt9 primer, gave the positive and negative result, respectively. Presence of amplified DNA target fragmens/bands on agarose gel, showed the positive result and vice verse. PCR process by using Pt3 and Pt6 primer revealed the positive results on 2 drug-resistant islates, whereas there was no amplified DNA bands from the other 7 isolates. DNA amplification by using either Pt8 and Pt9 or Pt3 and Pt6 primers occurred on H sub.37Rv strain DNA. Size of the amplified DNA products with Pt8 and Pt9 and Pt3 and Pt6 primers were 541 bp and 188 bp, respectively

  13. Comparative genomics of archived pyrazinamide resistant Mycobacterium tuberculosis complex isolates from Uganda

    Science.gov (United States)

    Bovine tuberculosis is a ‘neglected zoonosis’ and its contribution to the proportion of Mycobacterium tuberculosis complex infections in humans is unknown. A retrospective study on archived Mycobacterium tuberculosis complex (MTC) isolates from a reference laboratory in Uganda was undertaken to iden...

  14. Drug resistance in Mexico: results from the National Survey on Drug-Resistant Tuberculosis.

    Science.gov (United States)

    Bojorquez-Chapela, I; Bäcker, C E; Orejel, I; López, A; Díaz-Quiñonez, A; Hernández-Serrato, M I; Balandrano, S; Romero, M; Téllez-Rojo Solís, M M; Castellanos, M; Alpuche, C; Hernández-Ávila, M; López-Gatell, H

    2013-04-01

    To present estimations obtained from a population-level survey conducted in Mexico of prevalence rates of mono-, poly- and multidrug-resistant strains among newly diagnosed cases of pulmonary tuberculosis (TB), as well as the main factors associated with multidrug resistance (combined resistance to isoniazid and rifampicin). Study data came from the National Survey on TB Drug Resistance (ENTB-2008), a nationally representative survey conducted during 2008-2009 in nine states with a stratified cluster sampling design. Samples were obtained for all newly diagnosed cases of pulmonary TB in selected sites. Drug susceptibility testing (DST) was performed for anti-tuberculosis drugs. DST results were obtained for 75% of the cases. Of these, 82.2% (95%CI 79.5-84.7) were susceptible to all drugs. The prevalence of multidrug-resistant TB (MDR-TB) was estimated at 2.8% (95%CI 1.9-4.0). MDR-TB was associated with previous treatment (OR 3.3, 95%CI 1.1-9.4). The prevalence of drug resistance is relatively low in Mexico. ENTB-2008 can be used as a baseline for future follow-up of drug resistance.

  15. Enhanced Anti-Mycobacterium tuberculosis Immunity over Time with Combined Drug and Immunotherapy Treatment

    Directory of Open Access Journals (Sweden)

    Sasha E. Larsen

    2018-05-01

    Full Text Available It is estimated that one third of the world’s population is infected with Mycobacterium tuberculosis (Mtb. This astounding statistic, in combination with costly and lengthy treatment regimens make the development of therapeutic vaccines paramount for controlling the global burden of tuberculosis. Unlike prophylactic vaccination, therapeutic immunization relies on the natural pulmonary infection with Mtb as the mucosal prime that directs boost responses back to the lung. The purpose of this work was to determine the protection and safety profile over time following therapeutic administration of our lead Mtb vaccine candidate, ID93 with a synthetic TLR4 agonist (glucopyranosyl lipid adjuvant in a stable emulsion (GLA-SE, in combination with rifampicin, isoniazid, and pyrazinamide (RHZ drug treatment. We assessed the host inflammatory immune responses and lung pathology 7–22 weeks post infection, and determined the therapeutic efficacy of combined treatment by enumeration of the bacterial load and survival in the SWR/J mouse model. We show that drug treatment alone, or with immunotherapy, tempered the inflammatory responses measured in brochoalveolar lavage fluid and plasma compared to untreated cohorts. RHZ combined with therapeutic immunizations significantly enhanced TH1-type cytokine responses in the lung over time, corresponding to decreased pulmonary pathology evidenced by a significant decrease in the percentage of lung lesions and destructive lung inflammation. These data suggest that bacterial burden assessment alone may miss important correlates of lung architecture that directly contribute to therapeutic vaccine efficacy in the preclinical mouse model. We also confirmed our previous finding that in combination with antibiotics therapeutic immunizations provide an additive survival advantage. Moreover, therapeutic immunizations with ID93/GLA-SE induced differential T cell immune responses over the course of infection that correlated

  16. Rapid, automated, nonradiometric susceptibility testing of Mycobacterium tuberculosis complex to four first-line antituberculous drugs used in standard short-course chemotherapy

    DEFF Research Database (Denmark)

    Johansen, Isik Somuncu; Thomsen, Vibeke Østergaard; Marjamäki, Merja

    2004-01-01

    The increasing prevalence of drug-resistant tuberculosis necessitates rapid and accurate susceptibility testing. The nonradiometric BACTEC Mycobacteria Growth Indicator Tube 960 (MGIT) system for susceptibility testing was evaluated on 222 clinical Mycobacterium tuberculosis complex isolates...... for isoniazid, rifampin, and ethambutol. Fifty-seven of the isolates were tested for pyrazinamide. Results were compared to those of radiometric BACTEC 460 system and discrepancies were resolved by the agar proportion method. We found an overall agreement of 99.0% for isoniazid, 99.5% for rifampin, 98.......2% for ethambutol, and 100% for pyrazinamide. After resolution of discrepancies, MGIT yielded no false susceptibility for rifampin and isoniazid. Although turnaround times were comparable, MGIT provides an advantage as inoculation can be done on any weekday as the growth is monitored automatically. The automated...

  17. Quantitative proteomic analysis of ofloxacin resistant and sensitive clinical isolates of Mycobacterium tuberculosis

    Directory of Open Access Journals (Sweden)

    Xiang-yu HUANG

    2014-10-01

    Full Text Available Objective To identify the proteins related to ofloxacin (OFX resistance of Mycobacterium tuberculosis (MTB. Methods Standard MTB H37Rv strain, clinical isolates of OFX resistant strain (OFXR and sensitive strain (OFXS were obtained from the Chinese Center for Disease Control and Prevention, and they were cultured in Sauton's medium, and then inactivated by 60Co. Whole cellular proteins were extracted from OFXR, OFXS and H37Rv strain of MTB, respectively. The peptides were labeled, separated and identified by isobaric tags of relative and absolute quantitation (iTRAQ combined with Nano LCMS/MS technology. Results One hundred and seventy-five and 134 differential expression proteins were identified in MTB OFXR compared with MTB OFXS and H37Rv, respectively. One hundred and four common differential expression proteins were identified in MTB OFXR compared with both MTB OFXS and H37Rv. The isoelectric point and theoretic relative molecular mass of differential expression proteins were widely distributed. The majority of the common differential expression proteins were involved in intermediary metabolism, respiration, and lipid metabolism. Twelve common differential expression proteins showed significant differences (the ratio>1.2 or <0.55 in MTB OFXR, including Rv0106, Rv0895, Rv2185c, Rv3248c and Rv3841 up-regulation and Rv2524c, Rv2986c, Rv3118 and Rv3597c down-regulation. Conclusion iTRAQ has been used to identify the common differential expression proteins in MTB OFXR compared with both MTB OFXS and H37Rv, which provides a basis for further study of the mechanism of OFX-resistance. DOI: 10.11855/j.issn.0577-7402.2014.09.06

  18. Radiometric studies on the oxidation of (I-14C) fatty acids by drug-susceptible and drug-resistant mycobacteria

    International Nuclear Information System (INIS)

    Camargo, E.E.; Kopajtic, T.M.; Hopkins, G.K.; Cannon, N.P.; Wagner Junior, H.N.

    1987-01-01

    A radiometric assay system has been used to study oxidation patterns of (l - 14 C) fatty acids by drug-susceptible and drug-resistant organisms of the genus Mycobacterium (M. tuberculosis - H 37 Rv and Erdman, M. bovis, M. avium, M. intracellulare, M.Kansasii and M. chelonei). The organisms were inoculated in sterile reaction vials containing liquid 7H9 medium, 10% ADC enrichment and 1.0 uli of one of the (l- 14 C) fatty acids (butyric, hexanoic, octanoic, decanoic, lauric, myristic, palmitic, stearic, oleic, linoleic, linolenic). Vials were incubated at 37 0 C and the 14 CO 2 envolved was measured daily for 3 days with a Bactec R-301 instrument. (M.A.C.) [pt

  19. Performance of the Abbott RealTime MTB RIF/INH resistance assay when used to test Mycobacterium tuberculosis specimens from Bangladesh

    Directory of Open Access Journals (Sweden)

    Kostera J

    2018-05-01

    Full Text Available Joshua Kostera, Gregor Leckie, Klara Abravaya, Hong Wang Abbott Molecular, Abbott Laboratories, Des Plaines, IL, USA Introduction: The Abbott RealTime MTB RIF/INH Resistance Assay (RT MTB RIF/INH is an assay for the detection of rifampicin (RIF- and/or isoniazid (INH-resistant Mycobacterium tuberculosis (MTB. The assay can be used to test sputum, bronchial alveolar lavage, and N-Acetyl-L-Cysteine (NALC/NaOH pellets prepared from these samples. The assay can be used in direct testing mode, or in reflex mode following a MTB positive result produced by its companion assay, Abbott RT MTB. Methods: In this study, the direct testing mode was used to test paired sputum and NALC/NaOH pellets prepared from sputum collected from Bangladesh TB patients. One hundred and thirty two paired samples were tested. Results: The RT MTB RIF/INH inhibition rate was 0%. One hundred and twenty-two paired samples had results above the assay limit of detection and were analyzed by comparing with results from phenotypic drug sensitivity testing, GeneXpert MTB/RIF (Xpert, and MTBDR plus (Hain. RT MTB RIF/INH results were in good agreement with those of GeneXpert and Hain. Conclusion: The ability of this assay to detect RIF and INH resistance may contribute to the global control of multidrug resistant tuberculosis. Keywords: tuberculosis, rifampicin, isoniazid, resistance

  20. Toward the virtual screening of potential drugs in the homology modeled NAD+ dependent DNA ligase from Mycobacterium tuberculosis.

    Science.gov (United States)

    Singh, Vijai; Somvanshi, Pallavi

    2010-02-01

    DNA ligase is an important enzyme and it plays vital role in the replication and repair; also catalyzes nick joining between adjacent bases of DNA. The NAD(+) dependent DNA ligase is selectively present in eubacteria and few viruses; but missing in humans. Homology modeling was used to generate 3-D structure of NAD(+) dependent DNA ligase (LigA) of Mycobacterium tuberculosis using the known template (PDB: 2OWO). Furthermore, the stereochemical quality and torsion angle of 3-D structure was validated. Numerous effective drugs were selected and the active amino acid residue in LigA was targeted and virtual screening through molecular docking was done. In this analysis, four drugs Chloroquine, Hydroxychloroquine, Putrienscine and Adriamycin were found more potent in inhibition of M. tuberculosis through the robust binding affinity between protein-drug interactions in comparison with the other studied drugs. A phylogenetic tree was constructed and it was observed that homology of LigA in M. tuberculosis resembled with other Mycobacterium species. The conserved active amino acids of LigA may be useful to target these drugs. These findings could be used as the starting point of a rational design of novel antibacterial drugs and its analogs.

  1. Structural and functional features of enzymes of Mycobacterium tuberculosis peptidoglycan biosynthesis as targets for drug development.

    Science.gov (United States)

    Moraes, Gleiciane Leal; Gomes, Guelber Cardoso; Monteiro de Sousa, Paulo Robson; Alves, Cláudio Nahum; Govender, Thavendran; Kruger, Hendrik G; Maguire, Glenn E M; Lamichhane, Gyanu; Lameira, Jerônimo

    2015-03-01

    Tuberculosis (TB) is the second leading cause of human mortality from infectious diseases worldwide. The WHO reported 1.3 million deaths and 8.6 million new cases of TB in 2012. Mycobacterium tuberculosis (M. tuberculosis), the infectious bacteria that causes TB, is encapsulated by a thick and robust cell wall. The innermost segment of the cell wall is comprised of peptidoglycan, a layer that is required for survival and growth of the pathogen. Enzymes that catalyse biosynthesis of the peptidoglycan are essential and are therefore attractive targets for discovery of novel antibiotics as humans lack similar enzymes making it possible to selectively target bacteria only. In this paper, we have reviewed the structures and functions of enzymes GlmS, GlmM, GlmU, MurA, MurB, MurC, MurD, MurE and MurF from M. tuberculosis that are involved in peptidoglycan biosynthesis. In addition, we report homology modelled 3D structures of those key enzymes from M. tuberculosis of which the structures are still unknown. We demonstrated that natural substrates can be successfully docked into the active sites of the GlmS and GlmU respectively. It is therefore expected that the models and the data provided herein will facilitate translational research to develop new drugs to treat TB. Copyright © 2015. Published by Elsevier Ltd.

  2. Examination of bedaquiline- and linezolid-resistant Mycobacterium tuberculosis isolates from the Moscow region.

    Science.gov (United States)

    Zimenkov, Danila V; Nosova, Elena Yu; Kulagina, Elena V; Antonova, Olga V; Arslanbaeva, Liaisan R; Isakova, Alexandra I; Krylova, Ludmila Yu; Peretokina, Irina V; Makarova, Marina V; Safonova, Svetlana G; Borisov, Sergey E; Gryadunov, Dmitry A

    2017-07-01

    To study the isolates with acquired resistance to bedaquiline and linezolid that were obtained from patients enrolled in a clinical study of a novel therapy regimen for drug-resistant TB in Moscow, Russia. Linezolid resistance was detected using MGIT 960 with a critical concentration of 1 mg/L. The MIC of bedaquiline was determined using the proportion method. To identify genetic determinants of resistance, sequencing of the mmpR ( Rv0678 ), atpE , atpC , pepQ , Rv1979c , rrl , rplC and rplD loci was performed. A total of 85 isolates from 27 patients with acquired resistance to linezolid and reduced susceptibility to bedaquiline (MIC ≥0.06 mg/L) were tested. Most mutations associated with a high MIC of bedaquiline were found in the mmpR gene. We identified for the first time two patients whose clinical isolates had substitutions D28N and A63V in AtpE, which had previously been found only in in vitro -selected strains. Several patients had isolates with elevated MICs of bedaquiline prior to treatment; four of them also bore mutations in mmpR , indicating the presence of some hidden factors in bedaquiline resistance acquisition. The C154R substitution in ribosomal protein L3 was the most frequent in the linezolid-resistant strains. Mutations in the 23S rRNA gene (g2294a and g2814t) associated with linezolid resistance were also found in two isolates. Heteroresistance was identified in ∼40% of samples, which reflects the complex nature of resistance acquisition. The introduction of novel drugs into treatment must be accompanied by continuous phenotypic susceptibility testing and the analysis of genetic determinants of resistance. © The Author 2017. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  3. Alarming levels of drug-resistant tuberculosis in HIV-infected patients in metropolitan Mumbai, India.

    Science.gov (United States)

    Isaakidis, Petros; Das, Mrinalini; Kumar, Ajay M V; Peskett, Christopher; Khetarpal, Minni; Bamne, Arun; Adsul, Balkrishna; Manglani, Mamta; Sachdeva, Kuldeep Singh; Parmar, Malik; Kanchar, Avinash; Rewari, B B; Deshpande, Alaka; Rodrigues, Camilla; Shetty, Anjali; Rebello, Lorraine; Saranchuk, Peter

    2014-01-01

    Drug-resistant tuberculosis (DR-TB) is a looming threat to tuberculosis control in India. However, no countrywide prevalence data are available. The burden of DR-TB in HIV-co-infected patients is likewise unknown. Undiagnosed and untreated DR-TB among HIV-infected patients is a major cause of mortality and morbidity. We aimed to assess the prevalence of DR-TB (defined as resistance to any anti-TB drug) in patients attending public antiretroviral treatment (ART) centers in greater metropolitan Mumbai, India. A cross-sectional survey was conducted among adults and children ART-center attendees. Smear microscopy, culture and drug-susceptibility-testing (DST) against all first and second-line TB-drugs using phenotypic liquid culture (MGIT) were conducted on all presumptive tuberculosis patients. Analyses were performed to determine DR-TB prevalence and resistance patterns separately for new and previously treated, culture-positive TB-cases. Between March 2013 and January 2014, ART-center attendees were screened during 14135 visits, of whom 1724 had presumptive TB. Of 1724 attendees, 72 (4%) were smear-positive and 202 (12%) had a positive culture for Mycobacterium tuberculosis. Overall DR-TB was diagnosed in 68 (34%, 95% CI: 27%-40%) TB-patients. The proportions of DR-TB were 25% (29/114) and 44% (39/88) among new and previously treated cases respectively. The patterns of DR-TB were: 21% mono-resistant, 12% poly-resistant, 38% multidrug-resistant (MDR-TB), 21% pre-extensively-drug-resistant (MDR-TB plus resistance to either a fluoroquinolone or second-line injectable), 6% extensively drug-resistant (XDR-TB) and 2% extremely drug-resistant TB (XDR-TB plus resistance to any group-IV/V drug). Only previous history of TB was significantly associated with the diagnosis of DR-TB in multivariate models. The burden of DR-TB among HIV-infected patients attending public ART-centers in Mumbai was alarmingly high, likely representing ongoing transmission in the community and

  4. Alarming levels of drug-resistant tuberculosis in HIV-infected patients in metropolitan Mumbai, India.

    Directory of Open Access Journals (Sweden)

    Petros Isaakidis

    Full Text Available BACKGROUND: Drug-resistant tuberculosis (DR-TB is a looming threat to tuberculosis control in India. However, no countrywide prevalence data are available. The burden of DR-TB in HIV-co-infected patients is likewise unknown. Undiagnosed and untreated DR-TB among HIV-infected patients is a major cause of mortality and morbidity. We aimed to assess the prevalence of DR-TB (defined as resistance to any anti-TB drug in patients attending public antiretroviral treatment (ART centers in greater metropolitan Mumbai, India. METHODS: A cross-sectional survey was conducted among adults and children ART-center attendees. Smear microscopy, culture and drug-susceptibility-testing (DST against all first and second-line TB-drugs using phenotypic liquid culture (MGIT were conducted on all presumptive tuberculosis patients. Analyses were performed to determine DR-TB prevalence and resistance patterns separately for new and previously treated, culture-positive TB-cases. RESULTS: Between March 2013 and January 2014, ART-center attendees were screened during 14135 visits, of whom 1724 had presumptive TB. Of 1724 attendees, 72 (4% were smear-positive and 202 (12% had a positive culture for Mycobacterium tuberculosis. Overall DR-TB was diagnosed in 68 (34%, 95% CI: 27%-40% TB-patients. The proportions of DR-TB were 25% (29/114 and 44% (39/88 among new and previously treated cases respectively. The patterns of DR-TB were: 21% mono-resistant, 12% poly-resistant, 38% multidrug-resistant (MDR-TB, 21% pre-extensively-drug-resistant (MDR-TB plus resistance to either a fluoroquinolone or second-line injectable, 6% extensively drug-resistant (XDR-TB and 2% extremely drug-resistant TB (XDR-TB plus resistance to any group-IV/V drug. Only previous history of TB was significantly associated with the diagnosis of DR-TB in multivariate models. CONCLUSION: The burden of DR-TB among HIV-infected patients attending public ART-centers in Mumbai was alarmingly high, likely representing

  5. Mycobacterium tuberculosis exploits asparagine to assimilate nitrogen and resist acid stress during infection.

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    Alexandre Gouzy

    2014-02-01

    Full Text Available Mycobacterium tuberculosis is an intracellular pathogen. Within macrophages, M. tuberculosis thrives in a specialized membrane-bound vacuole, the phagosome, whose pH is slightly acidic, and where access to nutrients is limited. Understanding how the bacillus extracts and incorporates nutrients from its host may help develop novel strategies to combat tuberculosis. Here we show that M. tuberculosis employs the asparagine transporter AnsP2 and the secreted asparaginase AnsA to assimilate nitrogen and resist acid stress through asparagine hydrolysis and ammonia release. While the role of AnsP2 is partially spared by yet to be identified transporter(s, that of AnsA is crucial in both phagosome acidification arrest and intracellular replication, as an M. tuberculosis mutant lacking this asparaginase is ultimately attenuated in macrophages and in mice. Our study provides yet another example of the intimate link between physiology and virulence in the tubercle bacillus, and identifies a novel pathway to be targeted for therapeutic purposes.

  6. Evaluation of MGIT 960 System for the Second-Line Drugs Susceptibility Testing of Mycobacterium tuberculosis

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    Hyejin Kim

    2013-01-01

    Full Text Available Many laboratories validate DST of the second-line drugs by BACTEC MGIT 960 system. The objective of this study is to evaluate the critical concentration and perform DST for the 2nd line drugs. We evaluated 193 clinical strains of M. tuberculosis isolated from patients in South Korea. Testing the critical concentration of six second-line drugs was performed by MGIT 960 and compared with L-J proportion method. The critical concentration was determined to establish the most one that gave the difference between drug resistance and susceptibility in MGIT960 system. Good agreement of the following concentrations was found: Concordance was 95% for 0.5 μg/mL of moxifloxacin; 93.6%, 1.0 μg/mL of levofloxacin; 97.5%, 2.5 μg/mL of kanamycin; 90.6%, 2.5 μg/mL of capreomycin; 86.2%, 5.0 μg/mL of ethionamide; and 90.8%, 2.0 μg/mL of ρ-aminosalicylic acid. The critical concentrations of the four drugs, moxifloxacin, levofloxacin, kanamycin, and capreomycin, were concordant and reliable for testing 2nd line drug resistance. Further study of ethionamide and ρ-aminosalicylic acid is required.

  7. Combining Metabolite-Based Pharmacophores with Bayesian Machine Learning Models for Mycobacterium tuberculosis Drug Discovery.

    Science.gov (United States)

    Ekins, Sean; Madrid, Peter B; Sarker, Malabika; Li, Shao-Gang; Mittal, Nisha; Kumar, Pradeep; Wang, Xin; Stratton, Thomas P; Zimmerman, Matthew; Talcott, Carolyn; Bourbon, Pauline; Travers, Mike; Yadav, Maneesh; Freundlich, Joel S

    2015-01-01

    Integrated computational approaches for Mycobacterium tuberculosis (Mtb) are useful to identify new molecules that could lead to future tuberculosis (TB) drugs. Our approach uses information derived from the TBCyc pathway and genome database, the Collaborative Drug Discovery TB database combined with 3D pharmacophores and dual event Bayesian models of whole-cell activity and lack of cytotoxicity. We have prioritized a large number of molecules that may act as mimics of substrates and metabolites in the TB metabolome. We computationally searched over 200,000 commercial molecules using 66 pharmacophores based on substrates and metabolites from Mtb and further filtering with Bayesian models. We ultimately tested 110 compounds in vitro that resulted in two compounds of interest, BAS 04912643 and BAS 00623753 (MIC of 2.5 and 5 μg/mL, respectively). These molecules were used as a starting point for hit-to-lead optimization. The most promising class proved to be the quinoxaline di-N-oxides, evidenced by transcriptional profiling to induce mRNA level perturbations most closely resembling known protonophores. One of these, SRI58 exhibited an MIC = 1.25 μg/mL versus Mtb and a CC50 in Vero cells of >40 μg/mL, while featuring fair Caco-2 A-B permeability (2.3 x 10-6 cm/s), kinetic solubility (125 μM at pH 7.4 in PBS) and mouse metabolic stability (63.6% remaining after 1 h incubation with mouse liver microsomes). Despite demonstration of how a combined bioinformatics/cheminformatics approach afforded a small molecule with promising in vitro profiles, we found that SRI58 did not exhibit quantifiable blood levels in mice.

  8. Rapid determination of anti-tuberculosis drug resistance from whole-genome sequences

    KAUST Repository

    Coll, Francesc

    2015-05-27

    Mycobacterium tuberculosis drug resistance (DR) challenges effective tuberculosis disease control. Current molecular tests examine limited numbers of mutations, and although whole genome sequencing approaches could fully characterise DR, data complexity has restricted their clinical application. A library (1,325 mutations) predictive of DR for 15 anti-tuberculosis drugs was compiled and validated for 11 of them using genomic-phenotypic data from 792 strains. A rapid online ‘TB-Profiler’ tool was developed to report DR and strain-type profiles directly from raw sequences. Using our DR mutation library, in silico diagnostic accuracy was superior to some commercial diagnostics and alternative databases. The library will facilitate sequence-based drug-susceptibility testing.

  9. Progression of chronic pulmonary tuberculosis in mice intravenously infected with ethambutol resistant Mycobacterium tuberculosis

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    Srivastava S

    2008-01-01

    Full Text Available Purpose: Ethambutol (EMB is an important first line drug, however little information on its molecular mechanism of resistance and pathogenicity of resistant isolates is available. Present work was designed to study virulence of the EMB resistant M. tuberculosis strains and the host responses in-vivo on infection of EMB resistant M. tuberculosis using Balb/c mouse model of infection. Methods: Three groups of Balb/c mice (female, age 4-6 wk; 21 mice in each group were infected intravenously with 106 CFU of M. tuberculosis H37Rv and two EMB resistant clinical isolates. Age and sex matched control animals were mock inoculated with Middlebrook 7H9 broth alone. At 10, 20, 30, 40, 50, 60, and 70 days post-infection three animals from each group were sacrificed by cervical dislocation and lung tissue was collected for further analysis. Results: Infection with EMB resistant M. tuberculosis led to progressive and chronic disease with significantly high bacillary load (p=0.02. Massive infiltration and exacerbated lung pathology with increased expression of IFN-γ and TNF-α was observed in lungs of mice infected with EMB resistant strains. The present study suggests that infection with EMB resistant M. tuberculosis leads to chronic infection with subsequent loss of lung function, bacterial persistence with elevated expression of TNF-α resulting in increased lung pathology. Conclusion: These findings highlight that EMB resistant M. tuberculosis regulates host immune response differentially and its pathogenicity is different from drug sensitive strains of M. tuberculosis.

  10. Supermolecular drug challenge to overcome drug resistance in cancer cells.

    Science.gov (United States)

    Onishi, Yasuhiko; Eshita, Yuki; Ji, Rui-Cheng; Kobayashi, Takashi; Onishi, Masayasu; Mizuno, Masaaki; Yoshida, Jun; Kubota, Naoji

    2018-06-04

    Overcoming multidrug resistance (MDR) of cancer cells can be accomplished using drug delivery systems in large-molecular-weight ATP-binding cassette transporters before entry into phagolysosomes and by particle-cell-surface interactions. However, these hypotheses do not address the intratumoral heterogeneity in cancer. Anti-MDR must be related to alterations of drug targets, expression of detoxification, as well as altered proliferation. In this study, it is shown that the excellent efficacy and sustainability of anti-MDR is due to a stable ES complex because of the allosteric facilities of artificial enzymes when they are used as supramolecular complexes. The allosteric effect of supermolecular drugs can be explained by the induced-fit model and can provide stable feedback control systems through the loop transfer function of the Hill equation. Copyright © 2018 Elsevier Ltd. All rights reserved.

  11. A Prospective Study of Tuberculosis Drug Susceptibility in Sabah, Malaysia, and an Algorithm for Management of Isoniazid Resistance

    Science.gov (United States)

    Rashid Ali, Muhammad Redzwan S.; Parameswaran, Uma; William, Timothy; Bird, Elspeth; Wilkes, Christopher S.; Lee, Wai Khew; Yeo, Tsin Wen; Anstey, Nicholas M.; Ralph, Anna P.

    2015-01-01

    Introduction. The burden of tuberculosis is high in eastern Malaysia, and rates of Mycobacterium tuberculosis drug resistance are poorly defined. Our objectives were to determine M. tuberculosis susceptibility and document management after receipt of susceptibility results. Methods. Prospective study of adult outpatients with smear-positive pulmonary tuberculosis (PTB) in Sabah, Malaysia. Additionally, hospital clinicians accessed the reference laboratory for clinical purposes during the study. Results. 176 outpatients were enrolled; 173 provided sputum samples. Mycobacterial culture yielded M. tuberculosis in 159 (91.9%) and nontuberculous Mycobacterium (NTM) in three (1.7%). Among outpatients there were no instances of multidrug resistant M. tuberculosis (MDR-TB). Seven people (4.5%) had isoniazid resistance (INH-R); all were switched to an appropriate second-line regimen for varying durations (4.5–9 months). Median delay to commencement of the second-line regimen was 13 weeks. Among 15 inpatients with suspected TB, 2 had multidrug resistant TB (one extensively drug resistant), 2 had INH-R, and 4 had NTM. Conclusions. Current community rates of MDR-TB in Sabah are low. However, INH-resistance poses challenges, and NTM is an important differential diagnosis in this setting, where smear microscopy is the usual diagnostic modality. To address INH-R management issues in our setting, we propose an algorithm for the treatment of isoniazid-resistant PTB. PMID:25838829

  12. Telomerase and drug resistance in cancer

    OpenAIRE

    Lipinska, Natalia; Romaniuk, Aleksandra; Paszel-Jaworska, Anna; Toton, Ewa; Kopczynski, Przemyslaw; Rubis, Blazej

    2017-01-01

    It is well known that a decreased expression or inhibited activity of telomerase in cancer cells is accompanied by an increased sensitivity to some drugs (e.g., doxorubicin, cisplatin, or 5-fluorouracil). However, the mechanism of the resistance resulting from telomerase alteration remains elusive. There are theories claiming that it might be associated with telomere shortening, genome instability, hTERT translocation, mitochondria functioning modulation, or even alterations in ABC family gen...

  13. Multi-drug resistant Ewingella Americana

    International Nuclear Information System (INIS)

    Bukhari, Syed Z.; Ashshi, Ahmad M.; Hussain, Waleed M.; Fatani, Mohammad I.

    2008-01-01

    We report a case of pneumonia due to multi-drug resistant Ewingella Americana in a young patient admitted in the Intensive Care Unit of Hera General Hospital, Makkah, Saudi Arabia with severe head injury in a road traffic accident. He was an Indonesian pilgrim who had traveled to the Kingdom of Saudi Arabia to perform Hajj in December 2007. Ewingella Americana was identified to be the pathogen of pneumonia with clinical signs and symptoms along with positive radiological findings. (author)

  14. [Morphological signs of inflammatory activity in different clinical forms of drug-resistant pulmonary tuberculosis].

    Science.gov (United States)

    Elipashev, A A; Nikolsky, V O; Shprykov, A S

    to determine whether the activity of tuberculous inflammation is associated with different clinical forms of drug-resistant pulmonary tuberculosis. The material taken from 310 patients operated on in 2010-2015 were retrospectively examined. The patients underwent economical lung resections of limited extent (typical and atypical ones of up to 3 segments) for circumscribed forms of tuberculosis with bacterial excretion. A study group consisted of 161 (51.9%) patients with drug-resistant variants of pulmonary tuberculosis. A control group included 149 (48.1%) patients with preserved susceptibility of Mycobacterium tuberculosis to anti-TB drugs. The activity of specific changes in tuberculosis was morphologically evaluated in accordance with the classification proposed by B.M. Ariel in 1998. The highest activity of fourth-to-fifth degree specific inflammation, including that outside the primary involvement focus, was obtained in the drug-resistant pulmonary tuberculosis group due to the predominance of patients with cavernous and fibrous-cavernous tuberculosis versus those in whom the susceptibility to chemotherapeutic agents was preserved. A macroscopic study showed that the primary lesion focus had a median size in one-half of the all the examinees; but large tuberculomas, caverns, and fibrous caverns over 4 cm in diameter were multiple and detected in the drug-resistant pulmonary tuberculosis group. Multidrug resistance was observed in more than 60% of the patients with fibrous-cavernous pulmonary tuberculosis, extensive drug resistance was seen in those with cavernous tuberculosis, which is an aggravating factor. The data obtained from the morphological study of the intraoperative material can specify the clinical form of tuberculosis and evaluate the efficiency of preoperative specific therapy. The highest activity of specific inflammation was observed in patients with multiple drug-resistant pulmonary tuberculosis, the prevalence of third-to-fourth degree

  15. Multidrug-Resistant Mycobacterium tuberculosis of the Latin American Mediterranean Lineage, Wrongly Identified as Mycobacterium pinnipedii (Spoligotype International Type 863 [SIT863]), Causing Active Tuberculosis in South Brazil

    KAUST Repository

    Dalla Costa, Elis R.; Vasconcelos, Sidra E. G.; Esteves, Leonardo S.; Gomes, Harrison M.; Gomes, Lia L.; Almeida da Silva, Pedro; Perdigã o, Joã o; Portugal, Isabel; Viveiros, Miguel; McNerney, Ruth; Pain, Arnab; Clark, Taane G.; Rastogi, Nalin; Unis, Gisela; Rossetti, Maria Lucia R.; Suffys, Philip Noel

    2015-01-01

    We recently detected the spoligotype patterns of strains of Mycobacterium pinnipedii, a species of the Mycobacterium tuberculosis complex, in sputum samples from nine cases with pulmonary tuberculosis residing in Porto Alegre, South Brazil. Because this species is rarely encountered in humans, we further characterized these nine isolates by additional genotyping techniques, including 24-locus mycobacterial interspersed repetitive-unit–variable-number tandem-repeat (MIRU-VNTR) typing, verification of the loci TbD1, RD9, pks15/1, RDRio, and fbpC, the insertion of IS6110 at a site specific to the M. tuberculosis Latin American Mediterranean (LAM) lineage, and whole-genome sequencing. The combined analysis of these markers revealed that the isolates are in fact M. tuberculosis and more specifically belong to the LAM genotype. Most of these isolates (n = 8) were shown to be multidrug resistant (MDR), which prompted us to perform partial sequencing of the rpoA, rpoB, rpoC, katG, and inhA genes. Seven isolates (77.8%) carried the S315T mutation in katG, and one of these (11%) also presented the C(−17)T single-nucleotide polymorphism (SNP) in inhA. Interestingly, six of the MDR isolates also presented an undescribed insertion of 12 nucleotides (CCA GAA CAA CCC) in codon 516 of rpoB. No putative compensatory mutation was found in either rpoA or rpoC. This is the first report of an M. tuberculosis LAM family strain with a convergent M. pinnipedii spoligotype. These spoligotypes are observed in genotype databases at a modest frequency, highlighting that care must be taken when identifying isolates in the M. tuberculosis complex on the basis of single genetic markers.

  16. Multidrug-Resistant Mycobacterium tuberculosis of the Latin American Mediterranean Lineage, Wrongly Identified as Mycobacterium pinnipedii (Spoligotype International Type 863 [SIT863]), Causing Active Tuberculosis in South Brazil

    KAUST Repository

    Dalla Costa, Elis R.

    2015-09-23

    We recently detected the spoligotype patterns of strains of Mycobacterium pinnipedii, a species of the Mycobacterium tuberculosis complex, in sputum samples from nine cases with pulmonary tuberculosis residing in Porto Alegre, South Brazil. Because this species is rarely encountered in humans, we further characterized these nine isolates by additional genotyping techniques, including 24-locus mycobacterial interspersed repetitive-unit–variable-number tandem-repeat (MIRU-VNTR) typing, verification of the loci TbD1, RD9, pks15/1, RDRio, and fbpC, the insertion of IS6110 at a site specific to the M. tuberculosis Latin American Mediterranean (LAM) lineage, and whole-genome sequencing. The combined analysis of these markers revealed that the isolates are in fact M. tuberculosis and more specifically belong to the LAM genotype. Most of these isolates (n = 8) were shown to be multidrug resistant (MDR), which prompted us to perform partial sequencing of the rpoA, rpoB, rpoC, katG, and inhA genes. Seven isolates (77.8%) carried the S315T mutation in katG, and one of these (11%) also presented the C(−17)T single-nucleotide polymorphism (SNP) in inhA. Interestingly, six of the MDR isolates also presented an undescribed insertion of 12 nucleotides (CCA GAA CAA CCC) in codon 516 of rpoB. No putative compensatory mutation was found in either rpoA or rpoC. This is the first report of an M. tuberculosis LAM family strain with a convergent M. pinnipedii spoligotype. These spoligotypes are observed in genotype databases at a modest frequency, highlighting that care must be taken when identifying isolates in the M. tuberculosis complex on the basis of single genetic markers.

  17. Primary drug-resistant tuberculosis in Hanoi, Viet Nam: present status and risk factors.

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    Nguyen Thi Le Hang

    Full Text Available INTRODUCTION: Resistance of Mycobacterium tuberculosis (MTB to anti-tuberculosis (TB drugs presents a serious challenge to TB control worldwide. We investigated the status of drug resistance, including multidrug-resistant (MDR TB, and possible risk factors among newly diagnosed TB patients in Hanoi, the capital of Viet Nam. METHODS: Clinical and epidemiological information was collected from 506 newly diagnosed patients with sputum smear- and culture-positive TB, and 489 (96.6% MTB isolates were subjected to conventional drug susceptibility testing, spoligotyping, and 15-locus variable numbers of tandem repeats typing. Adjusted odds ratios (aORs were calculated to analyze the risk factors for primary drug resistance. RESULTS: Of 489 isolates, 298 (60.9% were sensitive to all drugs tested. Resistance to isoniazid, rifampicin, streptomycin, ethambutol, and MDR accounted for 28.2%, 4.9%, 28.2%, 2.9%, and 4.5%, respectively. Of 24 isolates with rifampicin resistance, 22 (91.7% were MDR and also resistant to streptomycin, except one case. Factors associated with isoniazid resistance included living in old urban areas, presence of the Beijing genotype, and clustered strains [aOR = 2.23, 95% confidence interval (CI 1.15-4.35; 1.91, 1.18-3.10; and 1.69, 1.06-2.69, respectively. The Beijing genotype was also associated with streptomycin resistance (aOR = 2.10, 95% CI 1.29-3.40. Human immunodeficiency virus (HIV coinfection was associated with rifampicin resistance and MDR (aOR = 5.42, 95% CI 2.07-14.14; 6.23, 2.34-16.58, respectively. CONCLUSION: Isoniazid and streptomycin resistance was observed in more than a quarter of TB patients without treatment history in Hanoi. Transmission of isoniazid-resistant TB among younger people should be carefully monitored in urban areas, where Beijing strains and HIV coinfection are prevalent. Choosing an optimal treatment regimen on the basis of the results of drug susceptibility tests and monitoring of treatment

  18. Mutations inside rifampicin-resistance determining region of rpoB gene associated with rifampicin-resistance in Mycobacterium tuberculosis.

    Science.gov (United States)

    Zaw, Myo T; Emran, Nor A; Lin, Zaw

    2018-04-26

    Rifampicin (RIF) plays a pivotal role in the treatment of tuberculosis due to its bactericidal effects. Because the action of RIF is on rpoB gene encoding RNA polymerase β subunit, 95% of RIF resistant mutations are present in rpoB gene. The majority of the mutations in rpoB gene are found within an 81bp RIF-resistance determining region (RRDR). Literatures on RIF resistant mutations published between 2010 and 2016 were thoroughly reviewed. The most commonly mutated codons in RRDR of rpoB gene are 531, 526 and 516. The possibilities of absence of mutation in RRDR of rpoB gene in MDR-TB isolates in few studies was due to existence of other rare rpoB mutations outside RRDR or different mechanism of rifampicin resistance. Molecular methods which can identify extensive mutations associated with multiple anti-tuberculous drugs are in urgent need so that the research on drug resistant mutations should be extended. Copyright © 2018 The Authors. Published by Elsevier Ltd.. All rights reserved.

  19. A population-based study of first and second-line drug-resistant tuberculosis in a high-burden area of the Mexico/United States border

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    Pola Becerril-Montes

    2013-04-01

    Full Text Available The resistance of 139 Mycobacterium tuberculosis (MTB isolates from the city of Monterrey, Northeast Mexico, to first and second-line anti-TB drugs was analysed. A total of 73 isolates were susceptible and 66 were resistant to anti-TB drugs. Monoresistance to streptomycin, isoniazid (INH and ethambutol was observed in 29 cases. Resistance to INH was found in 52 cases and in 29 cases INH resistance was combined with resistance to two or three drugs. A total of 24 isolates were multidrug-resistant (MDR resistant to at least INH and rifampicin and 11 MDR cases were resistant to five drugs. The proportion of MDR-TB among new TB cases in our target population was 0.72% (1/139 cases. The proportion of MDR-TB among previously treated cases was 25.18% (35/139 cases. The 13 polyresistant and 24 MDR isolates were assayed against the following seven second-line drugs: amikacin (AMK, kanamycin (KAN, capreomycin (CAP, clofazimine (CLF, ethionamide (ETH, ofloxacin (OFL and cycloserine (CLS. Resistance to CLF, OFL or CLS was not observed. Resistance was detected to ETH (10.80% and to AMK (2.70%, KAN (2.70% and CAP (2.70%. One isolate of MDR with primary resistance was also resistant to three second-line drugs. Monterrey has a high prevalence of MDR-TB among previously treated cases and extensively drug-resistant-MTB strains may soon appear.

  20. Drug susceptibility testing of Mycobacterium Avium subsp. Avium isolates from naturally infected domestic pigeons to avian tuberculosis

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    Kaveh Parvandar

    2016-01-01

    Conclusion: We suggest drug susceptibility testing for more nontuberculous mycobateria, particularly M. avium complex isolated from infected birds and humans, as well as molecular basics of drug sensitivity in order to detect resistance genes of pathogenic M. avium subsp. avium.

  1. Enhancement of antibiotic activity by efflux inhibitors against multidrug resistant Mycobacterium tuberculosis clinical isolates from Brazil

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    Tatiane eCoelho

    2015-04-01

    Full Text Available Drug resistant tuberculosis continues to increase and new approaches for its treatment are necessary. The identification of M. tuberculosis clinical isolates presenting efflux as part of their resistant phenotype has a major impact in tuberculosis treatment. In this work, we used a checkerboard procedure combined with the tetrazolium microplate-based assay (TEMA to study single combinations between antituberculosis drugs and efflux inhibitors (EIs against multidrug resistant M. tuberculosis clinical isolates using the fully susceptible strain H37Rv as reference. Efflux activity was studied on a real-time basis by a fluorometric method that uses ethidium bromide as efflux substrate. Quantification of efflux pump genes mRNA transcriptional levels were performed by RT-qPCR. The fractional inhibitory concentrations (FIC indicated synergistic activity for the interactions between isoniazid, rifampicin, amikacin, ofloxacin, and ethidium bromide plus the EIs verapamil, thioridazine and chlorpromazine. The FICs ranged from 0.25, indicating a four-fold reduction on the MICs, to 0.015, 64-fold reduction. The detection of active efflux by real-time fluorometry showed that all strains presented intrinsic efflux activity that contributes to the overall resistance which can be inhibited in the presence of the EIs. The quantification of the mRNA levels of the most important efflux pump genes on these strains shows that they are intrinsically predisposed to expel toxic compounds as the exposure to subinhibitory concentrations of antibiotics were not necessary to increase the pump mRNA levels when compared with the non-exposed counterpart. The results obtained in this study confirm that the intrinsic efflux activity contributes to the overall resistance in multidrug resistant clinical isolates of M. tuberculosis and that the inhibition of efflux pumps by the EIs can enhance the clinical effect of antibiotics that are their substrates.

  2. Mycobacterium saopaulense sp. nov., a rapidly growing mycobacterium closely related to members of the Mycobacterium chelonae--Mycobacterium abscessus group.

    Science.gov (United States)

    Nogueira, Christiane Lourenço; Whipps, Christopher M; Matsumoto, Cristianne Kayoko; Chimara, Erica; Droz, Sara; Tortoli, Enrico; de Freitas, Denise; Cnockaert, Margo; Palomino, Juan Carlos; Martin, Anandi; Vandamme, Peter; Leão, Sylvia Cardoso

    2015-12-01

    Five isolates of non-pigmented, rapidly growing mycobacteria were isolated from three patients and,in an earlier study, from zebrafish. Phenotypic and molecular tests confirmed that these isolates belong to the Mycobacterium chelonae-Mycobacterium abscessus group, but they could not be confidently assigned to any known species of this group. Phenotypic analysis and biochemical tests were not helpful for distinguishing these isolates from other members of the M. chelonae–M.abscessus group. The isolates presented higher drug resistance in comparison with other members of the group, showing susceptibility only to clarithromycin. The five isolates showed a unique PCR restriction analysis pattern of the hsp65 gene, 100 % similarity in 16S rRNA gene and hsp65 sequences and 1-2 nt differences in rpoB and internal transcribed spacer (ITS) sequences.Phylogenetic analysis of a concatenated dataset including 16S rRNA gene, hsp65, and rpoB sequences from type strains of more closely related species placed the five isolates together, as a distinct lineage from previously described species, suggesting a sister relationship to a group consisting of M. chelonae, Mycobacterium salmoniphilum, Mycobacterium franklinii and Mycobacterium immunogenum. DNA–DNA hybridization values .70 % confirmed that the five isolates belong to the same species, while values ,70 % between one of the isolates and the type strains of M. chelonae and M. abscessus confirmed that the isolates belong to a distinct species. The polyphasic characterization of these isolates, supported by DNA–DNA hybridization results,demonstrated that they share characteristics with M. chelonae–M. abscessus members, butconstitute a different species, for which the name Mycobacterium saopaulense sp. nov. is proposed. The type strain is EPM10906T (5CCUG 66554T5LMG 28586T5INCQS 0733T).

  3. Rapid detection of drug resistance and mutational patterns of extensively drug-resistant strains by a novel GenoType® MTBDRsl assay

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    A K Singh

    2013-01-01

    Full Text Available Background: The emergence of extensively drug-resistant tuberculosis (XDR-TB is a major concern in the India. The burden of XDR-TB is increasing due to inadequate monitoring, lack of proper diagnosis, and treatment. The GenoType ® Mycobacterium tuberculosis drug resistance second line (MTBDRsl assay is a novel line probe assay used for the rapid detection of mutational patterns conferring resistance to XDR-TB. Aim: The aim of this study was to study the rapid detection of drug resistance and mutational patterns of the XDR-TB by a novel GenoType ® MTBDRsl assay. Materials and Methods: We evaluated 98 multidrug-resistant (MDR M. tuberculosis isolates for second line drugs susceptibility testing by 1% proportion method (BacT/ALERT 3D system and GenoType ® MTBDRsl assay for rapid detection of conferring drug resistance to XDR-TB. Results: A total of seven (17.4% were identified as XDR-TB by using standard phenotypic method. The concordance between phenotypic and GenoType ® MTBDRsl assay was 91.7-100% for different antibiotics. The sensitivity and specificity of the MTBDRsl assay were 100% and 100% for aminoglycosides; 100% and 100% for fluoroquinolones; 91.7% and 100% for ethambutol. The most frequent mutations and patterns were gyrA MUT1 (A90V in seven (41.2% and gyrA + WT1-3 + MUT1 in four (23.5%; rrs MUT1 (A1401G in 11 (64.7%, and rrs WT1-2 + MUT1 in eight (47.1%; and embB MUT1B (M306V in 11 (64.7% strains. Conclusions: These data suggest that the GenoType ® MTBDRsl assay is rapid, novel test for detection of resistance to second line anti-tubercular drugs. This assay provides additional information about the frequency and mutational patterns responsible for XDR-TB resistance.

  4. Strong In Vitro Activities of Two New Rifabutin Analogs against Multidrug-Resistant Mycobacterium tuberculosis ▿ †

    Science.gov (United States)

    García, Ana-Belén; Palacios, Juan J.; Ruiz, María-Jesús; Barluenga, José; Aznar, Fernando; Cabal, María-Paz; García, José María; Díaz, Natalia

    2010-01-01

    Two new rifabutin analogs, RFA-1 and RFA-2, show high in vitro antimycobacterial activities against Mycobacterium tuberculosis. MIC values of RFA-1 and RFA-2 were ≤0.02 μg/ml against rifamycin-susceptible strains and 0.5 μg/ml against a wide selection of multidrug-resistant strains, compared to ≥50 μg/ml for rifampin and 10 μg/ml for rifabutin. Molecular dynamic studies indicate that the compounds may exert tighter binding to mutants of RNA polymerase that have adapted to the rifamycins. PMID:20855731

  5. Direct sequencing for rapid detection of multidrug resistant Mycobacterium tuberculosis strains in Morocco.

    Science.gov (United States)

    Zakham, Fathiah; Chaoui, Imane; Echchaoui, Amina Hadbae; Chetioui, Fouad; Elmessaoudi, My Driss; Ennaji, My Mustapha; Abid, Mohammed; Mzibri, Mohammed El

    2013-01-01

    Tuberculosis (TB) is a major public health problem with high mortality and morbidity rates, especially in low-income countries. Disturbingly, the emergence of multidrug resistant (MDR) and extensively drug resistant (XDR) TB cases has worsened the situation, raising concerns of a future epidemic of virtually untreatable TB. Indeed, the rapid diagnosis of MDR TB is a critical issue for TB management. This study is an attempt to establish a rapid diagnosis of MDR TB by sequencing the target fragments of the rpoB gene which linked to resistance against rifampicin and the katG gene and inhA promoter region, which are associated with resistance to isoniazid. For this purpose, 133 sputum samples of TB patients from Morocco were enrolled in this study. One hundred samples were collected from new cases, and the remaining 33 were from previously treated patients (drug relapse or failure, chronic cases) and did not respond to anti-TB drugs after a sufficient duration of treatment. All samples were subjected to rpoB, katG and pinhA mutation analysis by polymerase chain reaction and DNA sequencing. Molecular analysis showed that seven strains were isoniazid-monoresistant and 17 were rifampicin-monoresistant. MDR TB strains were identified in nine cases (6.8%). Among them, eight were traditionally diagnosed as critical cases, comprising four chronic and four drug-relapse cases. The last strain was isolated from a new case. The most recorded mutation in the rpoB gene was the substitution TCG > TTG at codon 531 (Ser531 Leu), accounting for 46.15%. Significantly, the only mutation found in the katG gene was at codon 315 (AGC to ACC) with a Ser315Thr amino acid change. Only one sample harbored mutation in the inhA promoter region and was a point mutation at the -15p position (C > T). The polymerase chain reaction sequencing approach is an accurate and rapid method for detection of drug-resistant TB in clinical specimens, and could be of great interest in the management of TB in

  6. Managing a case of extensively drug-resistant (XDR) pulmonary tuberculosis in Singapore.

    Science.gov (United States)

    Phua, Chee Kiang; Chee, Cynthia B E; Chua, Angeline P G; Gan, Suay Hong; Ahmed, Aneez D B; Wang, Yee Tang

    2011-03-01

    Extensively drug-resistant tuberculosis (XDR-TB) is an emerging global health risk. We present the first case report of XDR-TB in Singapore. A 41-year-old Indonesian lady with previously treated pulmonary tuberculosis presented with chronic cough. Her sputum was strongly acid-fast bacilli positive and grew Mycobacterium tuberculosis complex resistant to first and second-line TB medications. She received 5 months of intensive multidrug treatment without sputum smear conversion. She then underwent resection of the diseased lung. The total cost incurred amounted to over S$100,000. She achieved sputum smear/culture conversion post-surgery, but will require further medical therapy for at least 18 months. XDRTB is poorly responsive to therapy and extremely expensive to manage. Its prevention by strict compliance to therapy is paramount.

  7. MIRU-VNTR typing of drug-resistant tuberculosis isolates in Greece.

    Science.gov (United States)

    Rovina, Nikoletta; Karabela, Simona; Constantoulakis, Pantelis; Michou, Vassiliki; Konstantinou, Konstantinos; Sgountzos, Vassileios; Roussos, Charis; Poulakis, Nikolaos

    2011-08-01

    The increasing immigration rate in Greece from countries with a high prevalence of Mycobacterium tuberculosis (MTB) and multidrug-resistant tuberculosis (MDR-TB) may have an impact οn the number of MDR-TB cases in Greece. The aim of this study was to genotypically characterize the MTB isolates from patients with pulmonary drug-resistant tuberculosis (DR-TB) in Greece, and to determine whether there is any association between the prevalent genotypes and drug resistance. Fifty-three drug-resistant MTB strains isolated from culture specimens of clinical material from native Greeks and immigrant patients with pulmonary tuberculosis were genotyped using the mycobacterial interspersed repetitive units-variable number of tandem repeats (MIRU-VNTR) method. The phylogenetically distinct groups of isolates identified were: the Beijing (34%), the LAM (11%), the Haarlem (24.5%), the Uganda I (9.4%), the Ural (3.8%), the Delhi/CAS (9.4%) and the Cameroon (3.8%) families. Greek patients were more likely to have monoresistant and polyresistant TB with the most prevalent isolates belonging to the Haarlem family. Among foreign-born patients with MDR-TB, the most prevalent genotypes belonged to the Beijing family. MIRU-VNTR rapidly obtained clinically useful genotyping data, by characterizing clonal MTB heterogeneity in the isolated strains. Our results underline the need for more effective antituberculosis control programs in order to control the expansion of DR-TB in Greece.

  8. Prediction of resistance development against drug combinations by collateral responses to component drugs

    DEFF Research Database (Denmark)

    Munck, Christian; Gumpert, Heidi; Nilsson Wallin, Annika

    2014-01-01

    the genomes of all evolved E. coli lineages, we identified the mutational events that drive the differences in drug resistance levels and found that the degree of resistance development against drug combinations can be understood in terms of collateral sensitivity and resistance that occurred during...... adaptation to the component drugs. Then, using engineered E. coli strains, we confirmed that drug resistance mutations that imposed collateral sensitivity were suppressed in a drug pair growth environment. These results provide a framework for rationally selecting drug combinations that limit resistance......Resistance arises quickly during chemotherapeutic selection and is particularly problematic during long-term treatment regimens such as those for tuberculosis, HIV infections, or cancer. Although drug combination therapy reduces the evolution of drug resistance, drug pairs vary in their ability...

  9. qPCR-High resolution melt analysis for drug susceptibility testing of Mycobacterium leprae directly from clinical specimens of leprosy patients.

    Science.gov (United States)

    Araujo, Sergio; Goulart, Luiz Ricardo; Truman, Richard W; Goulart, Isabela Maria B; Vissa, Varalakshmi; Li, Wei; Matsuoka, Masanori; Suffys, Philip; Fontes, Amanda B; Rosa, Patricia S; Scollard, David M; Williams, Diana L

    2017-06-01

    Real-Time PCR-High Resolution Melting (qPCR-HRM) analysis has been recently described for rapid drug susceptibility testing (DST) of Mycobacterium leprae. The purpose of the current study was to further evaluate the validity, reliability, and accuracy of this assay for M. leprae DST in clinical specimens. The specificity and sensitivity for determining the presence and susceptibility of M. leprae to dapsone based on the folP1 drug resistance determining region (DRDR), rifampin (rpoB DRDR) and ofloxacin (gyrA DRDR) was evaluated using 211 clinical specimens from leprosy patients, including 156 multibacillary (MB) and 55 paucibacillary (PB) cases. When comparing the results of qPCR-HRM DST and PCR/direct DNA sequencing, 100% concordance was obtained. The effects of in-house phenol/chloroform extraction versus column-based DNA purification protocols, and that of storage and fixation protocols of specimens for qPCR-HRM DST, were also evaluated. qPCR-HRM results for all DRDR gene assays (folP1, rpoB, and gyrA) were obtained from both MB (154/156; 98.7%) and PB (35/55; 63.3%) patients. All PCR negative specimens were from patients with low numbers of bacilli enumerated by an M. leprae-specific qPCR. We observed that frozen and formalin-fixed paraffin embedded (FFPE) tissues or archival Fite's stained slides were suitable for HRM analysis. Among 20 mycobacterial and other skin bacterial species tested, only M. lepromatosis, highly related to M. leprae, generated amplicons in the qPCR-HRM DST assay for folP1 and rpoB DRDR targets. Both DNA purification protocols tested were efficient in recovering DNA suitable for HRM analysis. However, 3% of clinical specimens purified using the phenol/chloroform DNA purification protocol gave false drug resistant data. DNA obtained from freshly frozen (n = 172), formalin-fixed paraffin embedded (FFPE) tissues (n = 36) or archival Fite's stained slides (n = 3) were suitable for qPCR-HRM DST analysis. The HRM-based assay was also able to

  10. Trends of Mycobacterium bovis Isolation and First-Line Anti-tuberculosis Drug Susceptibility Profile: A Fifteen-Year Laboratory-Based Surveillance.

    Science.gov (United States)

    Bobadilla-del Valle, Miriam; Torres-González, Pedro; Cervera-Hernández, Miguel Enrique; Martínez-Gamboa, Areli; Crabtree-Ramirez, Brenda; Chávez-Mazari, Bárbara; Ortiz-Conchi, Narciso; Rodríguez-Cruz, Luis; Cervantes-Sánchez, Axel; Gudiño-Enríquez, Tomasa; Cinta-Severo, Carmen; Sifuentes-Osornio, José; Ponce de León, Alfredo

    2015-09-01

    Mycobacterium tuberculosis causes the majority of tuberculosis (TB) cases in humans; however, in developing countries, human TB caused by M. bovis may be frequent but undetected. Human TB caused by M. bovis is considered a zoonosis; transmission is mainly through consumption of unpasteurized dairy products, and it is less frequently attributed to animal-to-human or human-to-human contact. We describe the trends of M. bovis isolation from human samples and first-line drug susceptibility during a 15-year period in a referral laboratory located in a tertiary care hospital in Mexico City. Data on mycobacterial isolates from human clinical samples were retrieved from the laboratory's database for the 2000-2014 period. Susceptibility to first-line drugs: rifampin, isoniazid, streptomycin (STR) and ethambutol was determined. We identified 1,165 isolates, 73.7% were M. tuberculosis and 26.2%, M. bovis. Among pulmonary samples, 16.6% were M. bovis. The proportion of M. bovis isolates significantly increased from 7.8% in 2000 to 28.4% in 2014 (X(2)trend, ptuberculosis isolates (10.9% vs.3.4%, ptuberculosis, respectively (p = 0.637). A rising trend of primary STR monoresistance was observed for both species (3.4% in 2000-2004 vs. 7.6% in 2010-2014; p = 0.02). There is a high prevalence and a rising trend of M. bovis isolates in our region. The proportion of pulmonary M. bovis isolates is higher than in previous reports. Additionally, we report high rates of primary anti-tuberculosis resistance and secondary MDR in both M. tuberculosis and M. bovis. This is one of the largest reports on drug susceptibility of M. bovis from human samples and shows a significant proportion of first-line anti-tuberculosis drug resistance.

  11. Trends of Mycobacterium bovis Isolation and First-Line Anti-tuberculosis Drug Susceptibility Profile: A Fifteen-Year Laboratory-Based Surveillance

    Science.gov (United States)

    Bobadilla-del Valle, Miriam; Torres-González, Pedro; Cervera-Hernández, Miguel Enrique; Martínez-Gamboa, Areli; Crabtree-Ramirez, Brenda; Chávez-Mazari, Bárbara; Ortiz-Conchi, Narciso; Rodríguez-Cruz, Luis; Cervantes-Sánchez, Axel; Gudiño-Enríquez, Tomasa; Cinta-Severo, Carmen; Sifuentes-Osornio, José; Ponce de León, Alfredo

    2015-01-01

    Background Mycobacterium tuberculosis causes the majority of tuberculosis (TB) cases in humans; however, in developing countries, human TB caused by M. bovis may be frequent but undetected. Human TB caused by M. bovis is considered a zoonosis; transmission is mainly through consumption of unpasteurized dairy products, and it is less frequently attributed to animal-to-human or human-to-human contact. We describe the trends of M. bovis isolation from human samples and first-line drug susceptibility during a 15-year period in a referral laboratory located in a tertiary care hospital in Mexico City. Methodology/Principal Findings Data on mycobacterial isolates from human clinical samples were retrieved from the laboratory’s database for the 2000–2014 period. Susceptibility to first-line drugs: rifampin, isoniazid, streptomycin (STR) and ethambutol was determined. We identified 1,165 isolates, 73.7% were M. tuberculosis and 26.2%, M. bovis. Among pulmonary samples, 16.6% were M. bovis. The proportion of M. bovis isolates significantly increased from 7.8% in 2000 to 28.4% in 2014 (X 2 trend, ptuberculosis isolates (10.9% vs.3.4%, ptuberculosis, respectively (p = 0.637). A rising trend of primary STR monoresistance was observed for both species (3.4% in 2000–2004 vs. 7.6% in 2010–2014; p = 0.02). Conclusions/Significance There is a high prevalence and a rising trend of M. bovis isolates in our region. The proportion of pulmonary M. bovis isolates is higher than in previous reports. Additionally, we report high rates of primary anti-tuberculosis resistance and secondary MDR in both M. tuberculosis and M. bovis. This is one of the largest reports on drug susceptibility of M. bovis from human samples and shows a significant proportion of first-line anti-tuberculosis drug resistance. PMID:26421930

  12. Multi-drug-resistant tuberculosis in HIV positive patients in Eastern Europe.

    Science.gov (United States)

    Post, Frank A; Grint, Daniel; Werlinrud, Anne Marie; Panteleev, Alexander; Riekstina, Vieja; Malashenkov, Evgeniy A; Skrahina, Alena; Duiculescu, Dan; Podlekareva, Daria; Karpov, Igor; Bondarenko, Vasiliy; Chentsova, Nelly; Lundgren, Jens; Mocroft, Amanda; Kirk, Ole; Miro, Jose M

    2014-03-01

    Observational data from Eastern Europe on the management and outcome of multi-drug-resistant tuberculosis (MDR TB) in HIV positive populations remain sparse in the English-language literature. We compared clinical characteristics and outcomes of 55 patients who were diagnosed with HIV and MDR TB in Eastern Europe between 2004 and 2006 to 89 patients whose Mycobacterium tuberculosis isolates were susceptible to isoniazid and rifampicin. Patients with HIV and MDR TB were young and predominantly male with high rates of intravenous drug use, imprisonment and hepatitis C co-infection. Eighty-four per cent of patients with MDR TB had no history of previous TB drug exposure suggesting that the majority of MDR TB resulted from transmission of drug-resistant M. tuberculosis. The use of non-standardized tuberculosis treatment was common, and the use of antiretroviral therapy infrequent. Compared to those with susceptible tuberculosis, patients with MDR TB were less likely to achieve cure or complete tuberculosis treatment (21.8% vs. 62.9%, p < 0.0001), and they were more likely to die (65.5% vs. 27.0%, p < 0.0001). Our study documents suboptimal management and poor outcomes in HIV positive patients with MDR TB. Implementation of WHO guidelines, rapid TB diagnostics and TB drug susceptibility testing for all patients remain a priority in this region. Copyright © 2013 The British Infection Association. Published by Elsevier Ltd. All rights reserved.

  13. Lysosomes as mediators of drug resistance in cancer.

    Science.gov (United States)

    Zhitomirsky, Benny; Assaraf, Yehuda G

    2016-01-01

    Drug resistance remains a leading cause of chemotherapeutic treatment failure and cancer-related mortality. While some mechanisms of anticancer drug resistance have been well characterized, multiple mechanisms remain elusive. In this respect, passive ion trapping-based lysosomal sequestration of multiple hydrophobic weak-base chemotherapeutic agents was found to reduce the accessibility of these drugs to their target sites, resulting in a markedly reduced cytotoxic effect and drug resistance. Recently we have demonstrated that lysosomal sequestration of hydrophobic weak base drugs triggers TFEB-mediated lysosomal biogenesis resulting in an enlarged lysosomal compartment, capable of enhanced drug sequestration. This study further showed that cancer cells with an increased number of drug-accumulating lysosomes are more resistant to lysosome-sequestered drugs, suggesting a model of drug-induced lysosome-mediated chemoresistance. In addition to passive drug sequestration of hydrophobic weak base chemotherapeutics, other mechanisms of lysosome-mediated drug resistance have also been reported; these include active lysosomal drug sequestration mediated by ATP-driven transporters from the ABC superfamily, and a role for lysosomal copper transporters in cancer resistance to platinum-based chemotherapeutics. Furthermore, lysosomal exocytosis was suggested as a mechanism to facilitate the clearance of chemotherapeutics which highly accumulated in lysosomes, thus providing an additional line of resistance, supplementing the organelle entrapment of chemotherapeutics away from their target sites. Along with these mechanisms of lysosome-mediated drug resistance, several approaches were recently developed for the overcoming of drug resistance or exploiting lysosomal drug sequestration, including lysosomal photodestruction and drug-induced lysosomal membrane permeabilization. In this review we explore the current literature addressing the role of lysosomes in mediating cancer drug

  14. Predicted levels of HIV drug resistance

    DEFF Research Database (Denmark)

    Cambiano, Valentina; Bertagnolio, Silvia; Jordan, Michael R

    2014-01-01

    -term effects. METHODS: The previously validated HIV Synthesis model was calibrated to South Africa. Resistance was modeled at the level of single mutations, transmission potential, persistence, and effect on drug activity. RESULTS: We estimate 652 000 people (90% uncertainty range: 543 000-744 000) are living...... are maintained, in 20 years' time HIV incidence is projected to have declined by 22% (95% confidence interval, CI -23 to -21%), and the number of people carrying NNRTI resistance to be 2.9-fold higher. If enhancements in diagnosis and retention in care occur, and ART is initiated at CD4 cell count less than 500......  cells/μl, HIV incidence is projected to decline by 36% (95% CI: -37 to -36%) and the number of people with NNRTI resistance to be 4.1-fold higher than currently. Prevalence of people with viral load more than 500  copies/ml carrying NRMV is not projected to differ markedly according to future ART...

  15. Young Women's Experiences of Resisting Invitations to Use Illicit Drugs

    Science.gov (United States)

    Koehn, Corinne V.; O'Neill, Linda K.

    2011-01-01

    Ten young women were interviewed regarding their experiences of resisting invitations to use illicit drugs. Hermeneutic phenomenology was used to gather and analyze information. One key theme was the motivations that inspired women to refuse drug offers. Young women resisted drug invitations because of their desires to be authentic, protect their…

  16. Prevalence of drug resistant tuberculosis in Arsi Zone, Ethiopia ...

    African Journals Online (AJOL)

    Background: Wide spread of occurrence of multi-drug resistance tuberculosis is becoming a major challenge to effective tuberculosis control. Thus, it is imperative to monitor the sensitivity of anti-TB drugs regularly. Objective: To determine the prevalence resistance to anti-TB drugs in a well established control program area ...

  17. GEAR: A database of Genomic Elements Associated with drug Resistance

    Science.gov (United States)

    Wang, Yin-Ying; Chen, Wei-Hua; Xiao, Pei-Pei; Xie, Wen-Bin; Luo, Qibin; Bork, Peer; Zhao, Xing-Ming

    2017-01-01

    Drug resistance is becoming a serious problem that leads to the failure of standard treatments, which is generally developed because of genetic mutations of certain molecules. Here, we present GEAR (A database of Genomic Elements Associated with drug Resistance) that aims to provide comprehensive information about genomic elements (including genes, single-nucleotide polymorphisms and microRNAs) that are responsible for drug resistance. Right now, GEAR contains 1631 associations between 201 human drugs and 758 genes, 106 associations between 29 human drugs and 66 miRNAs, and 44 associations between 17 human drugs and 22 SNPs. These relationships are firstly extracted from primary literature with text mining and then manually curated. The drug resistome deposited in GEAR provides insights into the genetic factors underlying drug resistance. In addition, new indications and potential drug combinations can be identified based on the resistome. The GEAR database can be freely accessed through http://gear.comp-sysbio.org. PMID:28294141

  18. Methyltransferase Erm(37) Slips on rRNA to Confer Atypical Resistance in Mycobacterium tuberculosis

    Czech Academy of Sciences Publication Activity Database

    Madsen, Ch. T.; Jakobsen, L.; Buriánková, Karolína; Doucet-Populaire, F.; Perdonet, J. L.; Douthwaite, S.

    2005-01-01

    Roč. 280, č. 47 (2005), s. 38942-38947 ISSN 0021-9258 R&D Projects: GA ČR GA310/03/0292 Institutional research plan: CEZ:AV0Z50200510 Keywords : methyltransferase erm * mycobacterium tuberculosis * rRNA Subject RIV: EE - Microbiology, Virology Impact factor: 5.854, year: 2005

  19. Mycobacterium bovis and Other Uncommon Members of the Mycobacterium tuberculosis Complex.

    Science.gov (United States)

    Esteban, Jaime; Muñoz-Egea, Maria-Carmen

    2016-12-01

    Since its discovery by Theobald Smith, Mycobacterium bovis has been a human pathogen closely related to animal disease. At present, M. bovis tuberculosis is still a problem of importance in many countries and is considered the main cause of zoonotic tuberculosis throughout the world. Recent development of molecular epidemiological tools has helped us to improve our knowledge about transmission patterns of this organism, which causes a disease indistinguishable from that caused by Mycobacterium tuberculosis. Diagnosis and treatment of this mycobacterium are similar to those for conventional tuberculosis, with the important exceptions of constitutive resistance to pyrazinamide and the fact that multidrug-resistant and extremely drug-resistant M. bovis strains have been described. Among other members of this complex, Mycobacterium africanum is the cause of many cases of tuberculosis in West Africa and can be found in other areas mainly in association with immigration. M. bovis BCG is the currently available vaccine for tuberculosis, but it can cause disease in some patients. Other members of the M. tuberculosis complex are mainly animal pathogens with only exceptional cases of human disease, and there are even some strains, like "Mycobacterium canettii," which is a rare human pathogen that could have an important role in the knowledge of the evolution of tuberculosis in the history.

  20. A Structural View on Medicinal Chemistry Strategies against Drug Resistance.

    Science.gov (United States)

    Agnello, Stefano; Brand, Michael; Chellat, Mathieu F; Gazzola, Silvia; Riedl, Rainer

    2018-05-30

    The natural phenomenon of drug resistance represents a generic impairment that hampers the benefits of drugs in all major clinical indications. Antibacterials and antifungals are affected as well as compounds for the treatment of cancer, viral infections or parasitic diseases. Despite the very diverse set of biological targets and organisms involved in the development of drug resistance, underlying molecular processes have been identified to understand the emergence of resistance and to overcome this detrimental mechanism. Detailed structural information of the root causes for drug resistance is nowadays frequently available to design next generation drugs anticipated to suffer less from resistance. This knowledge-based approach is a prerequisite in the fight against the inevitable occurrence of drug resistance to secure the achievements of medicinal chemistry in the future. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. Simple strategy to assess linezolid exposure in patients with multi-drug-resistant and extensively-drug-resistant tuberculosis

    NARCIS (Netherlands)

    Kamp, Jasper; Bolhuis, Mathieu S.; Tiberi, Simon; Akkerman, Onno W.; Centis, Rosella; de lange, Wiel C.; Kosterink, Jos G.; van der Werf, Tjip S.; Migliori, Giovanni B.; Alffenaar, Jan-Willem C.

    Linezolid is used increasingly for the treatment of multi-drug-resistant (MDR) and extensively-drug-resistant (XDR) tuberculosis (TB). However, linezolid can cause severe adverse events, such as peripheral and optical neuropathy or thrombocytopenia related to higher drug exposure. This study aimed

  2. Multi-drug resistance and molecular pattern of erythromycin and ...

    African Journals Online (AJOL)

    The appearance and dissemination of penicillin resistant and macrolide resistant Streptococcus pneumoniae strains has caused increasing concern worldwide. The aim of this study was to survey drug resistance and genetic characteristics of macrolide and penicillin resistance in S. pneumoniae. This is a cross-sectional ...

  3. Simple, direct drug susceptibility testing technique for diagnosis of drug-resistant tuberculosis in resource-poor settings.

    Science.gov (United States)

    Kim, C-K; Joo, Y-T; Lee, E P; Park, Y K; Kim, H-J; Kim, S J

    2013-09-01

    The Korean Institute of Tuberculosis, Seoul, Republic of Korea. To develop a simple, direct drug susceptibility testing (DST) technique using Kudoh-modified Ogawa (KMO) medium. The critical concentrations of isoniazid (INH), rifampicin (RMP), kanamycin (KM) and ofloxacin (OFX) for KMO medium were calibrated by comparing the minimal inhibitory concentrations (MICs) against clinical isolates of Mycobacterium tuberculosis on KMO with those on Löwenstein-Jensen (LJ). The performance of the direct KMO DST technique was evaluated on 186 smear-positive sputum specimens and compared with indirect LJ DST. Agreement of MICs on direct vs. indirect DST was high for INH, RMP and OFX. KM MICs on KMO were ∼10 g/ml higher than those on LJ. The critical concentrations of INH, RMP, OFX and KM for KMO were therefore set at 0.2, 40.0, 2.0, and 40.0 g/ml. The evaluation of direct DST of smear-positive sputum specimens showed 100% agreement with indirect LJ DST for INH and RMP. However, the respective susceptible and resistant predictive values were 98.8% and 100% for OFX, and 100% and 80% for KM. Direct DST using KMO is useful, with clear advantages of a shorter turnaround time, procedural simplicity and low cost compared to indirect DST. It may be most indicated in resource-poor settings for programmatic management of drug-resistant tuberculosis.

  4. Beyond multidrug-resistant tuberculosis in Europe: a TBNET study

    NARCIS (Netherlands)

    Günther, G.; van Leth, F.; Altet, N.; Dedicoat, M.; Duarte, R.; Gualano, G.; Kunst, H.; Muylle, I.; Spinu, V.; Tiberi, S.; Viiklepp, P.; Lange, C.; Alexandru, S.; Cernenco, I.; Ciobanu, A.; Donica, A.; Cayla, J.; Fina, L.; Galvao, M. L. de Souza; Maldonado, J.; Avsar, K.; Bang, D.; Andersen, A. B.; Barbuta, R.; Dubceac, V.; Bothamley, G.; Crudu, V.; Davilovits, M.; Atunes, A.; de Lange, W.; Leimane, V.; Rusmane, L.; de Lorenzo, S.; Cuppen, F.; de Guchtenaire, I.; Magis-Escurra, C.; McLaughlin, A.-M.; Meesters, R.; te Pas, M.; Prins, B.; Mütterlein, R.; Kotrbova, J.; Polcová, V.; Vasakova, M.; Pontali, E.; Rumetshofer, R.; Rowhani, M.; Skrahina, A.; Avchinko, V.; Katovich, D.

    2015-01-01

    The emergence of drug-resistant tuberculosis (TB) is a challenge to TB control in Europe. We evaluated second-line drug susceptibility testing in Mycobacterium tuberculosis isolates from patients with multidrug-resistant, pre-extensively drug-resistant (pre-XDR-TB) and XDR-TB at 23 TBNET sites in 16

  5. Trends of Mycobacterium bovis Isolation and First-Line Anti-tuberculosis Drug Susceptibility Profile: A Fifteen-Year Laboratory-Based Surveillance.

    Directory of Open Access Journals (Sweden)

    Miriam Bobadilla-del Valle

    2015-09-01

    Full Text Available Mycobacterium tuberculosis causes the majority of tuberculosis (TB cases in humans; however, in developing countries, human TB caused by M. bovis may be frequent but undetected. Human TB caused by M. bovis is considered a zoonosis; transmission is mainly through consumption of unpasteurized dairy products, and it is less frequently attributed to animal-to-human or human-to-human contact. We describe the trends of M. bovis isolation from human samples and first-line drug susceptibility during a 15-year period in a referral laboratory located in a tertiary care hospital in Mexico City.Data on mycobacterial isolates from human clinical samples were retrieved from the laboratory's database for the 2000-2014 period. Susceptibility to first-line drugs: rifampin, isoniazid, streptomycin (STR and ethambutol was determined. We identified 1,165 isolates, 73.7% were M. tuberculosis and 26.2%, M. bovis. Among pulmonary samples, 16.6% were M. bovis. The proportion of M. bovis isolates significantly increased from 7.8% in 2000 to 28.4% in 2014 (X(2trend, p<0.001. Primary STR resistance was higher among M. bovis compared with M. tuberculosis isolates (10.9% vs.3.4%, p<0.001. Secondary multidrug resistance (MDR rates were 38.5% and 34.4% for M. bovis and M. tuberculosis, respectively (p = 0.637. A rising trend of primary STR monoresistance was observed for both species (3.4% in 2000-2004 vs. 7.6% in 2010-2014; p = 0.02.There is a high prevalence and a rising trend of M. bovis isolates in our region. The proportion of pulmonary M. bovis isolates is higher than in previous reports. Additionally, we report high rates of primary anti-tuberculosis resistance and secondary MDR in both M. tuberculosis and M. bovis. This is one of the largest reports on drug susceptibility of M. bovis from human samples and shows a significant proportion of first-line anti-tuberculosis drug resistance.

  6. New Real-Time PCR Assays for Detection of Inducible and Acquired Clarithromycin Resistance in the Mycobacterium abscessus Group.

    Science.gov (United States)

    Shallom, Shamira J; Moura, Natalia S; Olivier, Kenneth N; Sampaio, Elizabeth P; Holland, Steven M; Zelazny, Adrian M

    2015-11-01

    Members of the Mycobacterium abscessus group (MAG) cause lung, soft tissue, and disseminated infections. The oral macrolides clarithromycin and azithromycin are commonly used for treatment. MAG can display clarithromycin resistance through the inducible erm(41) gene or via acquired mutations in the rrl (23S rRNA) gene. Strains harboring a truncation or a T28C substitution in erm(41) lose the inducible resistance trait. Phenotypic detection of clarithromycin resistance requires extended incubation (14 days), highlighting the need for faster methods to detect resistance. Two real-time PCR-based assays were developed to assess inducible and acquired clarithromycin resistance and tested on a total of 90 clinical and reference strains. A SYBR green assay was designed to distinguish between a full-length and truncated erm(41) gene by temperature shift in melting curve analysis. Single nucleotide polymorphism (SNP) allele discrimination assays were developed to distinguish T or C at position 28 of erm(41) and 23S rRNA rrl gene mutations at position 2058 and/or 2059. Truncated and full-size erm(41) genes were detected in 21/90 and 69/90 strains, respectively, with 64/69 displaying T at nucleotide position 28 and 5/69 containing C at that position. Fifteen isolates showed rrl mutations conferring clarithromycin resistance, including A2058G (11 isolates), A2058C (3 isolates), and A2059G (1 isolate). Targeted sequencing and phenotypic assessment of resistance concurred with molecular assay results. Interestingly, we also noted cooccurring strains harboring an active erm(41), inactive erm(41), and/or acquired mutational resistance, as well as slowly growing MAG strains and also strains displaying an inducible resistance phenotype within 5 days, long before the recommended 14-day extended incubation. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  7. Molecular cloning and cold shock induced overexpression of the DNA encoding phor sensor domain from Mycobacterium tuberculosis as a target molecule for novel anti-tubercular drugs

    Science.gov (United States)

    Langi, Gladys Emmanuella Putri; Moeis, Maelita R.; Ihsanawati, Giri-Rachman, Ernawati Arifin

    2014-03-01

    Mycobacterium tuberculosis (Mtb), the sole cause of Tuberculosis (TB), is still a major global problem. The discovery of new anti-tubercular drugs is needed to face the increasing TB cases, especially to prevent the increase of cases with resistant Mtb. A potential novel drug target is the Mtb PhoR sensor domain protein which is the histidine kinase extracellular domain for receiving environmental signals. This protein is the initial part of the two-component system PhoR-PhoP regulating 114 genes related to the virulence of Mtb. In this study, the gene encoding PhoR sensor domain (SensPhoR) was subcloned from pGEM-T SensPhoR from the previous study (Suwanto, 2012) to pColdII. The construct pColdII SensPhoR was confirmed through restriction analysis and sequencing. Using the construct, SensPhoR was overexpressed at 15°C using Escherichia coli BL21 (DE3). Low temperature was chosen because according to the solubility prediction program of recombinant proteins from The University of Oklahama, the PhoR sensor domain has a chance of 79.8% to be expressed as insoluble proteins in Escherichia coli's (E. coli) cytoplasm. This prediction is also supported by other similar programs: PROSO and PROSO II. The SDS PAGE result indicated that the PhoR sensor domain recombinant protein was overexpressed. For future studies, this protein will be purified and used for structure analysis which can be used to find potential drugs through rational drug design.

  8. High rates of ofloxacin resistance in Mycobacterium tuberculosis among both new and previously treated patients in Tamil Nadu, South India.

    Science.gov (United States)

    Selvakumar, N; Kumar, Vanaja; Balaji, S; Prabuseenivasan, S; Radhakrishnan, R; Sekar, Gomathi; Chandrasekaran, V; Kannan, T; Thomas, Aleyamma; Arunagiri, S; Dewan, Puneet; Swaminathan, Soumya

    2015-01-01

    Periodic drug resistance surveillance provides useful information on trends of drug resistance and effectiveness of tuberculosis (TB) control measures. The present study determines the prevalence of drug resistance among new sputum smear positive (NSP) and previously treated (PT) pulmonary TB patients, diagnosed at public sector designated microscopy centers (DMCs) in the state of Tamil Nadu, India. In this single-stage cluster-sampling prevalence survey, 70 of 700 DMCs were randomly selected using a probability-proportional to size method. A cluster size of 24 for NSP and a varying size of 0 to 99 for PT cases were fixed for each selected DMC. Culture and drug susceptibility testing was done on Lowenstein-Jensen medium using the economic variant of proportion sensitivity test for isoniazid (INH), rifampicin (RMP), ofloxacin (OFX) and kanamycin (KAN). Human Immunodeficiency Virus (HIV) status was collected from patient records. From June 2011 to August 2012, 1524 NSP and 901 PT patients were enrolled. Any RMP resistance and any INH resistance were observed in 2.6% and 15.1%, and in 10.4% and 30% respectively in NSP and PT cases. Among PT patients, multi drug resistant TB (MDR-TB) was highest in the treatment failure (35%) group, followed by relapse (13%) and treatment after default (10%) groups. Extensively drug resistant TB (XDRTB) was seen in 4.3% of MDR-TB cases. Any OFX resistance was seen in 10.4% of NSP, 13.9% of PT and 29% of PT MDR-TB patients. The HIV status of the patient had no impact on drug resistance levels. RMP resistance was present in 2.6% of new and 15.1% of previously treated patients in Tamil Nadu. Rates of OFX resistance were high among NSP and PT patients, especially among those with MDR-TB, a matter of concern for development of new treatment regimens for TB.

  9. High prevalence of multidrug-resistant tuberculosis among patients with rifampicin resistance using GeneXpert Mycobacterium tuberculosis/rifampicin in Ghana

    NARCIS (Netherlands)

    Boakye-Appiah, Justice K; Steinmetz, Alexis R; Pupulampu, Peter; Ofori-Yirenkyi, Stephen; Tetteh, Ishmael; Frimpong, Michael; Oppong, Patrick; Opare-Sem, Ohene; Norman, Betty R; Stienstra, Ymkje; van der Werf, Tjip S; Wansbrough-Jones, Mark; Bonsu, Frank; Obeng-Baah, Joseph; Phillips, Richard O

    2016-01-01

    OBJECTIVE/BACKGROUND: Drug-resistant strains of tuberculosis (TB) represent a major threat to global TB control. In low- and middle-income countries, resource constraints make it difficult to identify and monitor cases of resistance using drug susceptibility testing and culture. Molecular assays

  10. Effect of radiation decontamination on drug-resistant bacteria

    International Nuclear Information System (INIS)

    Ito, Hitoshi

    2006-01-01

    More than 80% of food poisoning bacteria such as Salmonella are reported as antibiotic-resistant to at least one type antibiotic, and more than 50% as resistant to two or more. For the decontamination of food poisoning bacteria in foods, radiation resistibility on drug-resistant bacteria were investigated compared with drug-sensitive bacteria. Possibility on induction of drug-resistant mutation by radiation treatment was also investigated. For these studies, type strains of Escherichia coli S2, Salmonella enteritidis YK-2 and Staphylococcus aureus H12 were used to induce drug-resistant strains with penicillin G. From the study of radiation sensitivity on the drug-resistant strain induced from E. coli S2, D 10 value was obtained to be 0.20 kGy compared with 0.25 kGy at parent strain. On S. enteritidis YK-2, D 10 value was obtained to be 0.14 kGy at drug-resistant strain compared with 0.16 kGy at parent strain. D 10 value was also obtained to be 0.15 kGy at drug-resistant strain compared with 0.21 kGy at parent strain of St. aureus H12. Many isolates of E. coli 157:H7 or other type of E. coli from meats such as beef were resistant to penicillin G, and looked to be no relationship on radiation resistivities between drug-resistant strains and sensitive strains. On the study of radiation sensitivity on E. coli S2 at plate agars containing antibiotics, higher survival fractions were obtained at higher doses compared with normal plate agar. The reason of higher survival fractions at higher doses on plate agar containing antibiotics should be recovery of high rate of injured cells by the relay of cell division, and drug-resistant strains by mutation are hardly induced by irradiation. (author)

  11. Distribution of red blood cell antigens in drug-resistant and drug ...

    African Journals Online (AJOL)

    sofo

    Frequency distribution of ABO, Rh-Hr, MN, Kell blood group system antigens were studied in 277 TB patients (151-drug-sensitive and 126 drug-resistant) of pulmonary tuberculosis to know whether there was any association between them, and also between drug resistance and sensitiveness. They were compared with 485 ...

  12. Multi-drug resistant tuberculosis in Tanzania: Initial description of ...

    African Journals Online (AJOL)

    Background: Drug resistant Tuberculosis is well documented worldwide and is associated with increasing morbidity and mortality complicating Tuberculosis control with increasing costs of managing the disease. Broad. Objective: To describe clinical and laboratory characteristics of multi-drug resistant Tuberculosis ...

  13. Drug-resistance in chronic tuberculosis cases in Southern Nigeria ...

    African Journals Online (AJOL)

    Nigeria has a high burden of tuberculosis but the drug resistant situationwas previously unknown. This report evaluates the firstline drug resistance and associated factors among chronic tuberculosis cases from the tuberculosis control programme in South south and South east zones ofNigeria. Descriptive study of chronic ...

  14. Tuberculosis drug resistance in the Western Cape | Weyer | South ...

    African Journals Online (AJOL)

    Objectives: Drug resistance is a serious problem in the treatment of tuberculosis and a threat to successful tuberculosis control programmes. Local health workers have expressed concern that the increasing tuberculosis epidemic in the Western Cape is partly attributable to drug resistance. The aim of this study was to ...

  15. Multi drug resistant tuberculosis: a challenge in the management of ...

    African Journals Online (AJOL)

    Multi drug resistant tuberculosis (MDR-TB) will not usually respond to short course chemotherapy. Unless the individual infected with this bug is treated appropriately, they can continue spreading resistant strains in the community and further fuel the tuberculosis epidemic. Diagnosis requires drug sensitivity testing and the ...

  16. One-tube loop-mediated isothermal amplification combined with restriction endonuclease digestion and ELISA for colorimetric detection of resistance to isoniazid, ethambutol and streptomycin in Mycobacterium tuberculosis isolates.

    Science.gov (United States)

    Lee, Mei-Feng; Chen, Yen-Hsu; Hsu, Hui-Jine; Peng, Chien-Fang

    2010-10-01

    In this study, we designed a simple and rapid colorimetric detection method, a one-tube loop-mediated isothermal amplification (LAMP)-PCR-hybridization-restriction endonuclease-ELISA [one-tube LAMP-PCR-HY-RE-ELISA] system, to detect resistance to isoniazid, ethambutol and streptomycin in strains of Mycobacterium tuberculosis isolated from clinical specimens. The clinical performance of this method for detecting isoniazid-resistant, ethambutol-resistant and streptomycin-resistant isolates of M. tuberculosis showed 98.9%, 94.3% and 93.8%, respectively. This assay is rapid and convenient that can be performed within one working day. One-tube LAMP-PCR-HY-RE-ELISA system was designed based on hot spot point mutations in target drug-resistant genes, using LAMP-PCR, hybridization, digestion with restriction endonuclease and colorimetric method of ELISA. In this study, LAMP assay was used to amplify DNA from drug-resistant M. tuberculosis, and ELISA was used for colorimetrical determination. This assay will be a useful tool for rapid diagnosis of mutant codons in strains of M. tuberculosis for isoniazid at katG 315 and katG 463, ethambutol at embB 306 and embB 497, and streptomycin at rpsL 43. Crown Copyright © 2010. Published by Elsevier B.V. All rights reserved.

  17. Drug resistance in leishmaniasis: current drug-delivery systems and future perspectives.

    Science.gov (United States)

    Yasinzai, Masoom; Khan, Momin; Nadhman, Akhtar; Shahnaz, Gul

    2013-10-01

    Leishmaniasis is a complex of diseases with numerous clinical manifestations for instance harshness from skin lesions to severe disfigurement and chronic systemic infection in the liver and spleen. So far, the most classical leishmaniasis therapy, despite its documented toxicities, remains pentavalent antimonial compounds. The arvailable therapeutic modalities for leishmaniasis are overwhelmed with resistance to leishmaniasis therapy. Mechanisms of classical drug resistance are often related with the lower drug uptake, increased efflux, the faster drug metabolism, drug target modifications and over-expression of drug transporters. The high prevalence of leishmaniasis and the appearance of resistance to classical drugs reveal the demand to develop and explore novel, less toxic, low cost and more promising therapeutic modalities. The review describes the mechanisms of classical drug resistance and potential drug targets in Leishmania infection. Moreover, current drug-delivery systems and future perspectives towards Leishmaniasis treatment are also covered.

  18. Mechanisms of antibiotic resistance in Mycobacterium tuberculosis, validation of methods BACTECTM MGIT 960 and AnyplexM TII MTB / MDR / XDR Detection for detection of antibiotic resistance to first and second line in Mycobacterium tuberculosis strains

    International Nuclear Information System (INIS)

    Centeno Urena, Yadel

    2014-01-01

    A literature review is developed of drug-resistant TB in the world and in Costa Rica. The mechanisms of resistance to antibiotics are studied of the bacterium that causes tuberculosis; drug resistance to first-line and second-line, treatment regimen according to the World Health Organization and edge detection methods available in the market. The agreement between the results is studied by the phenotypic detection system of resistance of M. tuberculosis BACTEC MGIT960 and PCR, in real-time of commercial kit Anyplex II MTB/MDR/XDR, for genotypic identification of M. tuberculosis and related mutations to resistance with the referring results to thirty strains provided by the Pan American Health Organization, allowing a significant shortening in the time of obtaining reliable results. The results obtained have allowed to suggest a possible implementation at the Centro Nacional de Referencia en Micobacteriologia (CNRM), to perform antibiotic susceptibility testing and genotypic testing of multidrug cases respectively. The study results have allowed the implementation of the technology of genotypic detection of M. tuberculosis in the CNRM, obtaining for the first time in Costa Rica, information about genes of M. tuberculosis related to the generation of resistance to the major drugs of Primary treatment scheme as well as testing of resistance to second-line drug for resistant strains referred to the Centro Nacional de Referencia en Micobacteriologia in 2013. (author) [es

  19. Population-level genomics identifies the emergence and global spread of a human transmissible multidrug-resistant nontuberculous mycobacterium

    Science.gov (United States)

    Rodriguez-Rincon, Daniela; Everall, Isobel; Brown, Karen P; Moreno, Pablo; Verma, Deepshikha; Hill, Emily; Drijkoningen, Judith; Gilligan, Peter; Esther, Charles R; Noone, Peadar G; Giddings, Olivia; Bell, Scott C.; Thomson, Rachel; Wainwright, Claire E.; Coulter, Chris; Pandey, Sushil; Wood, Michelle E; Stockwell, Rebecca E; Ramsay, Kay A; Sherrard, Laura J; Kidd, Timothy J; Jabbour, Nassib; Johnson, Graham R; Knibbs, Luke D; Morawska, Lidia; Sly, Peter D; Jones, Andrew; Bilton, Diana; Laurenson, Ian; Ruddy, Michael; Bourke, Stephen; Bowler, Ian CJW; Chapman, Stephen J; Clayton, Andrew; Cullen, Mairi; Daniels, Thomas; Dempsey, Owen; Denton, Miles; Desai, Maya; Drew, Richard J; Edenborough, Frank; Evans, Jason; Folb, Jonathan; Humphrey, Helen; Isalska, Barbara; Jensen-Fangel, Søren; Jönsson, Bodil; Jones, Andrew M.; Katzenstein, Terese L; Lillebaek, Troels; MacGregor, Gordon; Mayell, Sarah; Millar, Michael; Modha, Deborah; Nash, Edward F; O’Brien, Christopher; O’Brien, Deirdre; Ohri, Chandra; Pao, Caroline S; Peckham, Daniel; Perrin, Felicity; Perry, Audrey; Pressler, Tania; Prtak, Laura; Qvist, Tavs; Robb, Ali; Rodgers, Helen; Schaffer, Kirsten; Shafi, Nadia; van Ingen, Jakko; Walshaw, Martin; Watson, Danie; West, Noreen; Whitehouse, Joanna; Haworth, Charles S; Harris, Simon R; Ordway, Diane; Parkhill, Julian; Floto, R. Andres

    2016-01-01

    Lung infections with Mycobacterium abscessus, a species of multidrug resistant nontuberculous mycobacteria, are emerging as an important global threat to individuals with cystic fibrosis (CF) where they accelerate inflammatory lung damage leading to increased morbidity and mortality. Previously, M. abscessus was thought to be independently acquired by susceptible individuals from the environment. However, using whole genome analysis of a global collection of clinical isolates, we show that the majority of M. abscessus infections are acquired through transmission, potentially via fomites and aerosols, of recently emerged dominant circulating clones that have spread globally. We demonstrate that these clones are associated with worse clinical outcomes, show increased virulence in cell-based and mouse infection models, and thus represent an urgent international infection challenge. PMID:27846606

  20. Structure and Inhibitor Specificity of L,D-Transpeptidase (LdtMt2) from Mycobacterium tuberculosis and Antibiotic Resistance: Calcium Binding Promotes Dimer Formation.

    Science.gov (United States)

    Gokulan, Kuppan; Khare, Sangeeta; Cerniglia, Carl E; Foley, Steven L; Varughese, Kottayil I

    2018-03-09

    The final step of peptidoglycan (PG) synthesis in all bacteria is the formation of cross-linkage between PG-stems. The cross-linking between amino acids in different PG chains gives the peptidoglycan cell wall a 3-dimensional structure and adds strength and rigidity to it. There are two distinct types of cross-linkages in bacterial cell walls. D,D-transpeptidase (D,D-TPs) generate the classical 4➔3 cross-linkages and the L,D-transpeptidase (L,D-TPs) generate the 3➔3 non-classical peptide cross-linkages. The present study is aimed at understanding the nature of drug resistance associated with L,D-TP and gaining insights for designing novel antibiotics against multi-drug resistant bacteria. Penicillin and cephalosporin classes of β-lactams cannot inhibit L,D-TP function; however, carbapenems inactivate its function. We analyzed the structure of L,D-TP of Mycobacterium tuberculosis in the apo form and in complex with meropenem and imipenem. The periplasmic region of L,D-TP folds into three domains. The catalytic residues are situated in the C-terminal domain. The acylation reaction occurs between carbapenem antibiotics and the catalytic Cys-354 forming a covalent complex. This adduct formation mimics the acylation of L,D-TP with the donor PG-stem. A novel aspect of this study is that in the crystal structures of the apo and the carbapenem complexes, the N-terminal domain has a muropeptide unit non-covalently bound to it. Another interesting observation is that the calcium complex crystallized as a dimer through head and tail interactions between the monomers.

  1. Early antiretroviral therapy and potent second-line drugs could decrease HIV incidence of drug resistance.

    Science.gov (United States)

    Shen, Mingwang; Xiao, Yanni; Rong, Libin; Meyers, Lauren Ancel; Bellan, Steven E

    2017-06-28

    Early initiation of antiretroviral therapy (ART) reduces the risk of drug-sensitive HIV transmission but may increase the transmission of drug-resistant HIV. We used a mathematical model to estimate the long-term population-level benefits of ART and determine the scenarios under which earlier ART (treatment at 1 year post-infection, on average) could decrease simultaneously both total and drug-resistant HIV incidence (new infections). We constructed an infection-age-structured mathematical model that tracked the transmission rates over the course of infection and modelled the patients' life expectancy as a function of ART initiation timing. We fitted this model to the annual AIDS incidence and death data directly, and to resistance data and demographic data indirectly among men who have sex with men (MSM) in San Francisco. Using counterfactual scenarios, we assessed the impact on total and drug-resistant HIV incidence of ART initiation timing, frequency of acquired drug resistance, and second-line drug effectiveness (defined as the combination of resistance monitoring, biomedical drug efficacy and adherence). Earlier ART initiation could decrease the number of both total and drug-resistant HIV incidence when second-line drug effectiveness is sufficiently high (greater than 80%), but increase the proportion of new infections that are drug resistant. Thus, resistance may paradoxically appear to be increasing while actually decreasing. © 2017 The Author(s).

  2. Quantifying the Determinants of Evolutionary Dynamics Leading to Drug Resistance.

    Directory of Open Access Journals (Sweden)

    Guillaume Chevereau

    Full Text Available The emergence of drug resistant pathogens is a serious public health problem. It is a long-standing goal to predict rates of resistance evolution and design optimal treatment strategies accordingly. To this end, it is crucial to reveal the underlying causes of drug-specific differences in the evolutionary dynamics leading to resistance. However, it remains largely unknown why the rates of resistance evolution via spontaneous mutations and the diversity of mutational paths vary substantially between drugs. Here we comprehensively quantify the distribution of fitness effects (DFE of mutations, a key determinant of evolutionary dynamics, in the presence of eight antibiotics representing the main modes of action. Using precise high-throughput fitness measurements for genome-wide Escherichia coli gene deletion strains, we find that the width of the DFE varies dramatically between antibiotics and, contrary to conventional wisdom, for some drugs the DFE width is lower than in the absence of stress. We show that this previously underappreciated divergence in DFE width among antibiotics is largely caused by their distinct drug-specific dose-response characteristics. Unlike the DFE, the magnitude of the changes in tolerated drug concentration resulting from genome-wide mutations is similar for most drugs but exceptionally small for the antibiotic nitrofurantoin, i.e., mutations generally have considerably smaller resistance effects for nitrofurantoin than for other drugs. A population genetics model predicts that resistance evolution for drugs with this property is severely limited and confined to reproducible mutational paths. We tested this prediction in laboratory evolution experiments using the "morbidostat", a device for evolving bacteria in well-controlled drug environments. Nitrofurantoin resistance indeed evolved extremely slowly via reproducible mutations-an almost paradoxical behavior since this drug causes DNA damage and increases the mutation

  3. Correlates between Models of Virulence for Mycobacterium tuberculosis among Isolates of the Central Asian Lineage: a Case for Lysozyme Resistance Testing?

    Science.gov (United States)

    Casali, Nicola; Clark, Simon O.; Hooper, Richard; Williams, Ann; Velji, Preya; Gonzalo, Ximena

    2015-01-01

    Virulence factors (VFs) contribute to the emergence of new human Mycobacterium tuberculosis strains, are lineage dependent, and are relevant to the development of M. tuberculosis drugs/vaccines. VFs were sought within M. tuberculosis lineage 3, which has the Central Asian (CAS) spoligotype. Three isolates were selected from clusters previously identified as dominant in London, United Kingdom. Strain-associated virulence was studied in guinea pig, monocyte-derived macrophage, and lysozyme resistance assays. Whole-genome sequencing, single nucleotide polymorphism (SNP) analysis, and a literature review contributed to the identification of SNPs of interest. The animal model revealed borderline differences in strain-associated pathogenicity. Ex vivo, isolate C72 exhibited statistically significant differences in intracellular growth relative to C6 and C14. SNP candidates inducing lower fitness levels included 123 unique nonsynonymous SNPs, including three located in genes (lysX, caeA, and ponA2) previously identified as VFs in the laboratory-adapted reference strain H37Rv and shown to confer lysozyme resistance. C72 growth was most affected by lysozyme in vitro. A BLAST search revealed that all three SNPs of interest (C35F, P76Q, and P780R) also occurred in Tiruvallur, India, and in Uganda. Unlike C72, however, no single isolate identified through BLAST carried all three SNPs simultaneously. CAS isolates representative of three medium-sized human clusters demonstrated differential outcomes in models commonly used to estimate strain-associated virulence, supporting the idea that virulence varies within, not just across, M. tuberculosis lineages. Three VF SNPs of interest were identified in two additional locations worldwide, which suggested independent selection and supported a role for these SNPs in virulence. The relevance of lysozyme resistance to strain virulence remains to be established. PMID:25776753

  4. Shigella Antimicrobial Drug Resistance Mechanisms, 2004-2014.

    Science.gov (United States)

    Nüesch-Inderbinen, Magdalena; Heini, Nicole; Zurfluh, Katrin; Althaus, Denise; Hächler, Herbert; Stephan, Roger

    2016-06-01

    To determine antimicrobial drug resistance mechanisms of Shigella spp., we analyzed 344 isolates collected in Switzerland during 2004-2014. Overall, 78.5% of isolates were multidrug resistant; 10.5% were ciprofloxacin resistant; and 2% harbored mph(A), a plasmid-mediated gene that confers reduced susceptibility to azithromycin, a last-resort antimicrobial agent for shigellosis.

  5. Cancer stem cells and drug resistance: the potential of nanomedicine

    Science.gov (United States)

    Vinogradov, Serguei; Wei, Xin

    2012-01-01

    Properties of the small group of cancer cells called tumor-initiating or cancer stem cells (CSCs) involved in drug resistance, metastasis and relapse of cancers can significantly affect tumor therapy. Importantly, tumor drug resistance seems to be closely related to many intrinsic or acquired properties of CSCs, such as quiescence, specific morphology, DNA repair ability and overexpression of antiapoptotic proteins, drug efflux transporters and detoxifying enzymes. The specific microenvironment (niche) and hypoxic stability provide additional protection against anticancer therapy for CSCs. Thus, CSC-focused therapy is destined to form the core of any effective anticancer strategy. Nanomedicine has great potential in the development of CSC-targeting drugs, controlled drug delivery and release, and the design of novel gene-specific drugs and diagnostic modalities. This review is focused on tumor drug resistance-related properties of CSCs and describes current nanomedicine approaches, which could form the basis of novel combination therapies for eliminating metastatic and CSCs. PMID:22471722

  6. Enhanced Transmission of Drug-Resistant Parasites to Mosquitoes following Drug Treatment in Rodent Malaria

    OpenAIRE

    Bell, Andrew S.; Huijben, Silvie; Paaijmans, Krijn P.; Sim, Derek G.; Chan, Brian H. K.; Nelson, William A.; Read, Andrew F.

    2012-01-01

    The evolution of drug resistant Plasmodium parasites is a major challenge to effective malaria control. In theory, competitive interactions between sensitive parasites and resistant parasites within infections are a major determinant of the rate at which parasite evolution undermines drug efficacy. Competitive suppression of resistant parasites in untreated hosts slows the spread of resistance; competitive release following treatment enhances it. Here we report that for the murine model Plasm...

  7. A rapid culture system uninfluenced by an inoculum effect increases reliability and convenience for drug susceptibility testing of Mycobacterium tuberculosis.

    Science.gov (United States)

    Jung, Yong-Gyun; Kim, Hyejin; Lee, Sangyeop; Kim, Suyeoun; Jo, EunJi; Kim, Eun-Geun; Choi, Jungil; Kim, Hyun Jung; Yoo, Jungheon; Lee, Hye-Jeong; Kim, Haeun; Jung, Hyunju; Ryoo, Sungweon; Kwon, Sunghoon

    2018-06-05

    The Disc Agarose Channel (DAC) system utilizes microfluidics and imaging technologies and is fully automated and capable of tracking single cell growth to produce Mycobacterium tuberculosis (MTB) drug susceptibility testing (DST) results within 3~7 days. In particular, this system can be easily used to perform DSTs without the fastidious preparation of the inoculum of MTB cells. Inoculum effect is one of the major problems that causes DST errors. The DAC system was not influenced by the inoculum effect and produced reliable DST results. In this system, the minimum inhibitory concentration (MIC) values of the first-line drugs were consistent regardless of inoculum sizes ranging from ~10 3 to ~10 8 CFU/mL. The consistent MIC results enabled us to determine the critical concentrations for 12 anti-tuberculosis drugs. Based on the determined critical concentrations, further DSTs were performed with 254 MTB clinical isolates without measuring an inoculum size. There were high agreement rates (96.3%) between the DAC system and the absolute concentration method using Löwenstein-Jensen medium. According to these results, the DAC system is the first DST system that is not affected by the inoculum effect. It can thus increase reliability and convenience for DST of MTB. We expect that this system will be a potential substitute for conventional DST systems.

  8. Drug-resistant gram-negative uropathogens: A review.

    Science.gov (United States)

    Khoshnood, Saeed; Heidary, Mohsen; Mirnejad, Reza; Bahramian, Aghil; Sedighi, Mansour; Mirzaei, Habibollah

    2017-10-01

    Urinary tract infection(UTI) caused by Gram-negative bacteria is the second most common infectious presentation in community medical practice. Approximately 150 million people are diagnosed with UTI each year worldwide. Drug resistance in Gram-negative uropathogens is a major global concern which can lead to poor clinical outcomes including treatment failure, development of bacteremia, requirement for intravenous therapy, hospitalization, and extended length of hospital stay. The mechanisms of drug resistance in these bacteria are important due to they are often not identified by routine susceptibility tests and have an exceptional potential for outbreaks. Treatment of UTIs depends on the access to effective drugs, which is now threatened by antibiotic resistant Gram-negative uropathogens. Although several effective antibiotics with activity against highly resistant Gram-negatives are available, there is not a unique antibiotic with activity against the high variety of resistance. Therefore, antimicrobial susceptibility tests, correlation between clinicians and laboratories, development of more rapid diagnostic methods, and continuous monitoring of drug resistance are urgent priorities. In this review, we will discuss about the current global status of drug-resistant Gram-negative uropathogens and their mechanisms of drug resistance to provide new insights into their treatment options. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  9. Fitness of Leishmania donovani parasites resistant to drug combinations.

    Directory of Open Access Journals (Sweden)

    Raquel García-Hernández

    2015-04-01

    Full Text Available Drug resistance represents one of the main problems for the use of chemotherapy to treat leishmaniasis. Additionally, it could provide some advantages to Leishmania parasites, such as a higher capacity to survive in stress conditions. In this work, in mixed populations of Leishmania donovani parasites, we have analyzed whether experimentally resistant lines to one or two combined anti-leishmanial drugs better support the stress conditions than a susceptible line expressing luciferase (Luc line. In the absence of stress, none of the Leishmania lines showed growth advantage relative to the other when mixed at a 1:1 parasite ratio. However, when promastigotes from resistant lines and the Luc line were mixed and exposed to different stresses, we observed that the resistant lines are more tolerant of different stress conditions: nutrient starvation and heat shock-pH stress. Further to this, we observed that intracellular amastigotes from resistant lines present a higher capacity to survive inside the macrophages than those of the control line. These results suggest that resistant parasites acquire an overall fitness increase and that resistance to drug combinations presents significant differences in their fitness capacity versus single-drug resistant parasites, particularly in intracellular amastigotes. These results contribute to the assessment of the possible impact of drug resistance on leishmaniasis control programs.

  10. Importance of confirming data on the in vivo efficacy of novel antibacterial drug regimens against various strains of Mycobacterium tuberculosis.

    Science.gov (United States)

    De Groote, Mary A; Gruppo, Veronica; Woolhiser, Lisa K; Orme, Ian M; Gilliland, Janet C; Lenaerts, Anne J

    2012-02-01

    In preclinical testing of antituberculosis drugs, laboratory-adapted strains of Mycobacterium tuberculosis are usually used both for in vitro and in vivo studies. However, it is unknown whether the heterogeneity of M. tuberculosis stocks used by various laboratories can result in different outcomes in tests of antituberculosis drug regimens in animal infection models. In head-to-head studies, we investigated whether bactericidal efficacy results in BALB/c mice infected by inhalation with the laboratory-adapted strains H37Rv and Erdman differ from each other and from those obtained with clinical tuberculosis strains. Treatment of mice consisted of dual and triple drug combinations of isoniazid (H), rifampin (R), and pyrazinamide (Z). The results showed that not all strains gave the same in vivo efficacy results for the drug combinations tested. Moreover, the ranking of HRZ and RZ efficacy results was not the same for the two H37Rv strains evaluated. The magnitude of this strain difference also varied between experiments, emphasizing the risk of drawing firm conclusions for human trials based on single animal studies. The results also confirmed that the antagonism seen within the standard HRZ regimen by some investigators appears to be an M. tuberculosis strain-specific phenomenon. In conclusion, the specific identity of M. tuberculosis strain used was found to be an important variable that can change the apparent outcome of in vivo efficacy studies in mice. We highly recommend confirmation of efficacy results in late preclinical testing against a different M. tuberculosis strain than the one used in the initial mouse efficacy study, thereby increasing confidence to advance potent drug regimens to clinical trials.

  11. Multifaceted remodeling by vitamin C boosts sensitivity of Mycobacterium tuberculosis subpopulations to combination treatment by anti-tubercular drugs.

    Science.gov (United States)

    Sikri, Kriti; Duggal, Priyanka; Kumar, Chanchal; Batra, Sakshi Dhingra; Vashist, Atul; Bhaskar, Ashima; Tripathi, Kritika; Sethi, Tavpritesh; Singh, Amit; Tyagi, Jaya Sivaswami

    2018-05-01

    Bacterial dormancy is a major impediment to the eradication of tuberculosis (TB), because currently used drugs primarily target actively replicating bacteria. Therefore, decoding of the critical survival pathways in dormant tubercle bacilli is a research priority to formulate new approaches for killing these bacteria. Employing a network-based gene expression analysis approach, we demonstrate that redox active vitamin C (vit C) triggers a multifaceted and robust adaptation response in Mycobacterium tuberculosis (Mtb) involving ~ 67% of the genome. Vit C-adapted bacteria display well-described features of dormancy, including growth stasis and progression to a viable but non-culturable (VBNC) state, loss of acid-fastness and reduction in length, dissipation of reductive stress through triglyceride (TAG) accumulation, protective response to oxidative stress, and tolerance to first line TB drugs. VBNC bacteria are reactivatable upon removal of vit C and they recover drug susceptibility properties. Vit C synergizes with pyrazinamide, a unique TB drug with sterilizing activity, to kill dormant and replicating bacteria, negating any tolerance to rifampicin and isoniazid in combination treatment in both in-vitro and intracellular infection models. Finally, the vit C multi-stress redox models described here also offer a unique opportunity for concurrent screening of compounds/combinations active against heterogeneous subpopulations of Mtb. These findings suggest a novel strategy of vit C adjunctive therapy by modulating bacterial physiology for enhanced efficacy of combination chemotherapy with existing drugs, and also possible synergies to guide new therapeutic combinations towards accelerating TB treatment. Copyright © 2018 The Authors. Published by Elsevier B.V. All rights reserved.

  12. Conspicuous multidrug-resistant Mycobacterium tuberculosis cluster strains do not trespass country borders in Latin America and Spain.

    Science.gov (United States)

    Ritacco, Viviana; Iglesias, María-José; Ferrazoli, Lucilaine; Monteserin, Johana; Dalla Costa, Elis R; Cebollada, Alberto; Morcillo, Nora; Robledo, Jaime; de Waard, Jacobus H; Araya, Pamela; Aristimuño, Liselotte; Díaz, Raúl; Gavin, Patricia; Imperiale, Belen; Simonsen, Vera; Zapata, Elsa M; Jiménez, María S; Rossetti, Maria L; Martin, Carlos; Barrera, Lucía; Samper, Sofia

    2012-06-01

    Multidrug-resistant Mycobacterium tuberculosis strain diversity in Ibero-America was examined by comparing extant genotype collections in national or state tuberculosis networks. To this end, genotypes from over 1000 patients with multidrug-resistant tuberculosis diagnosed from 2004 through 2008 in Argentina, Brazil, Chile, Colombia, Venezuela and Spain were compared in a database constructed ad hoc. Most of the 116 clusters identified by IS6110 restriction fragment length polymorphism were small and restricted to individual countries. The three largest clusters, of 116, 49 and 25 patients, were found in Argentina and corresponded to previously documented locally-epidemic strains. Only 13 small clusters involved more than one country, altogether accounting for 41 patients, of whom 13 were, in turn, immigrants from Latin American countries different from those participating in the study (Peru, Ecuador and Bolivia). Most of these international clusters belonged either to the emerging RD(Rio) LAM lineage or to the Haarlem family of M. tuberculosis and four were further split by country when analyzed with spoligotyping and rifampin resistance-conferring mutations, suggesting that they did not represent ongoing transnational transmission events. The Beijing genotype accounted for 1.3% and 10.2% of patients with multidrug-resistant tuberculosis in Latin America and Spain, respectively, including one international cluster of two cases. In brief, Euro-American genotypes were widely predominant among multidrug-resistant M. tuberculosis strains in Ibero-America, reflecting closely their predominance in the general M. tuberculosis population in the region, and no evidence was found of acknowledged outbreak strains trespassing country borders. Copyright © 2011 Elsevier B.V. All rights reserved.

  13. A multiple genome analysis of Mycobacterium tuberculosis reveals specific novel genes and mutations associated with pyrazinamide resistance

    KAUST Repository

    Sheen, Patricia

    2017-10-11

    Tuberculosis (TB) is a major global health problem and drug resistance compromises the efforts to control this disease. Pyrazinamide (PZA) is an important drug used in both first and second line treatment regimes. However, its complete mechanism of action and resistance remains unclear.We genotyped and sequenced the complete genomes of 68 M. tuberculosis strains isolated from unrelated TB patients in Peru. No clustering pattern of the strains was verified based on spoligotyping. We analyzed the association between PZA resistance with non-synonymous mutations and specific genes. We found mutations in pncA and novel genes significantly associated with PZA resistance in strains without pncA mutations. These included genes related to transportation of metal ions, pH regulation and immune system evasion.These results suggest potential alternate mechanisms of PZA resistance that have not been found in other populations, supporting that the antibacterial activity of PZA may hit multiple targets.

  14. A multiple genome analysis of Mycobacterium tuberculosis reveals specific novel genes and mutations associated with pyrazinamide resistance

    KAUST Repository

    Sheen, Patricia; Requena, David; Gushiken, Eduardo; Gilman, Robert H.; Antiparra, Ricardo; Lucero, Bryan; Lizá rraga, Pilar; Cieza, Basilio; Roncal, Elisa; Grandjean, Louis; Pain, Arnab; McNerney, Ruth; Clark, Taane G.; Moore, David; Zimic, Mirko

    2017-01-01

    Tuberculosis (TB) is a major global health problem and drug resistance compromises the efforts to control this disease. Pyrazinamide (PZA) is an important drug used in both first and second line treatment regimes. However, its complete mechanism of action and resistance remains unclear.We genotyped and sequenced the complete genomes of 68 M. tuberculosis strains isolated from unrelated TB patients in Peru. No clustering pattern of the strains was verified based on spoligotyping. We analyzed the association between PZA resistance with non-synonymous mutations and specific genes. We found mutations in pncA and novel genes significantly associated with PZA resistance in strains without pncA mutations. These included genes related to transportation of metal ions, pH regulation and immune system evasion.These results suggest potential alternate mechanisms of PZA resistance that have not been found in other populations, supporting that the antibacterial activity of PZA may hit multiple targets.

  15. DNA origami as a carrier for circumvention of drug resistance.

    Science.gov (United States)

    Jiang, Qiao; Song, Chen; Nangreave, Jeanette; Liu, Xiaowei; Lin, Lin; Qiu, Dengli; Wang, Zhen-Gang; Zou, Guozhang; Liang, Xingjie; Yan, Hao; Ding, Baoquan

    2012-08-15

    Although a multitude of promising anti-cancer drugs have been developed over the past 50 years, effective delivery of the drugs to diseased cells remains a challenge. Recently, nanoparticles have been used as drug delivery vehicles due to their high delivery efficiencies and the possibility to circumvent cellular drug resistance. However, the lack of biocompatibility and inability to engineer spatially addressable surfaces for multi-functional activity remains an obstacle to their widespread use. Here we present a novel drug carrier system based on self-assembled, spatially addressable DNA origami nanostructures that confronts these limitations. Doxorubicin, a well-known anti-cancer drug, was non-covalently attached to DNA origami nanostructures through intercalation. A high level of drug loading efficiency was achieved, and the complex exhibited prominent cytotoxicity not only to regular human breast adenocarcinoma cancer cells (MCF 7), but more importantly to doxorubicin-resistant cancer cells, inducing a remarkable reversal of phenotype resistance. With the DNA origami drug delivery vehicles, the cellular internalization of doxorubicin was increased, which contributed to the significant enhancement of cell-killing activity to doxorubicin-resistant MCF 7 cells. Presumably, the activity of doxorubicin-loaded DNA origami inhibits lysosomal acidification, resulting in cellular redistribution of the drug to action sites. Our results suggest that DNA origami has immense potential as an efficient, biocompatible drug carrier and delivery vehicle in the treatment of cancer.

  16. Drug-resistant tuberculosis in HIV-infected patients in a national referral hospital, Phnom Penh, Cambodia.

    Science.gov (United States)

    Walls, Genevieve; Bulifon, Sophie; Breysse, Serge; Daneth, Thol; Bonnet, Maryline; Hurtado, Northan; Molfino, Lucas

    2015-01-01

    There are no recent data on the prevalence of drug-resistant tuberculosis (DR TB) in Cambodia. We aim to describe TB drug resistance amongst adults with pulmonary and extra-pulmonary TB and human immunodeficiency virus (HIV) co-infection in a national referral hospital in Phnom Penh, Cambodia. Between 22 November 2007 and 30 November 2009, clinical specimens from HIV-infected patients suspected of having TB underwent routine microscopy, Mycobacterium tuberculosis culture, and drug susceptibility testing. Laboratory and clinical data were collected for patients with positive M. tuberculosis cultures. M. tuberculosis was cultured from 236 HIV-infected patients. Resistance to any first-line TB drug occurred in 34.7% of patients; 8.1% had multidrug resistant tuberculosis (MDR TB). The proportion of MDR TB amongst new patients and previously treated patients was 3.7 and 28.9%, respectively (pCambodia may be higher than previously recognised, particularly amongst HIV-infected patients. Additional prevalence studies are needed. This study also illustrates the feasibility and utility of analysis of non-respiratory specimens in the diagnosis of TB, even in low-resource settings, and suggests that extra-pulmonary specimens should be included in TB diagnostic algorithms.

  17. Transmission pattern of drug-resistant tuberculosis and its implication for tuberculosis control in eastern rural China.

    Directory of Open Access Journals (Sweden)

    Yi Hu

    Full Text Available OBJECTIVE: Transmission patterns of drug-resistant Mycobacterium tuberculosis (MTB may be influenced by differences in socio-demographics, local tuberculosis (TB endemicity and efficaciousness of TB control programs. This study aimed to investigate the impact of DOTS on the transmission of drug-resistant TB in eastern rural China. METHODS: We conducted a cross-sectional study of all patients diagnosed with drug-resistant TB over a one-year period in two rural Chinese counties with varying lengths of DOTS implementation. Counties included Deqing, with over 11 years' DOTS implementation and Guanyun, where DOTS was introduced 1 year prior to start of this study. We combined demographic, clinical and epidemiologic information with IS6110-based restricted fragment length polymorphism (RFLP and Spoligotyping analysis of MTB isolates. In addition, we conducted DNA sequencing of resistance determining regions to first-line anti-tuberculosis agents. RESULTS: Of the 223 drug-resistant isolates, 73(32.7% isolates were identified with clustered IS6110RFLP patterns. The clustering proportion among total drug-resistant TB was higher in Guanyun than Deqing (26/101.vs.47/122; p,0.04, but not significantly different among the 53 multidrug-resistant isolates (10/18.vs.24/35; p,0.35. Patients with cavitary had increased risk of clustering in both counties. In Guanyun, patients with positive smear test or previous treatment history had a higher clustering proportion. Beijing genotype and isolates resistant to isoniazid and/or rifampicin were more likely to be clustered. Of the 73 patients with clustered drug-resistant isolates, 71.2% lived in the same or neighboring villages. Epidemiological link (household and social contact was confirmed in 12.3% of the clustered isolates. CONCLUSION: Transmission of drug-resistant TB in eastern rural China is characterized by small clusters and limited geographic spread. Our observations highlight the need for supplementing DOTS

  18. Lung Tissue Concentrations of Pyrazinamide among Patients with Drug-Resistant Pulmonary Tuberculosis

    Science.gov (United States)

    Heinrichs, M. Tobias; Nikolaishvili, Ketino; Sabulua, Irina; Bablishvili, Nino; Gogishvili, Shota; Avaliani, Zaza; Tukvadze, Nestani; Little, Brent; Bernheim, Adam; Read, Timothy D.; Guarner, Jeannette; Derendorf, Hartmut; Peloquin, Charles A.; Blumberg, Henry M.; Vashakidze, Sergo

    2017-01-01

    ABSTRACT Improved knowledge regarding the tissue penetration of antituberculosis drugs may help optimize drug management. Patients with drug-resistant pulmonary tuberculosis undergoing adjunctive surgery were enrolled. Serial serum samples were collected, and microdialysis was performed using ex vivo lung tissue to measure pyrazinamide concentrations. Among 10 patients, the median pyrazinamide dose was 24.7 mg/kg of body weight. Imaging revealed predominant lung lesions as cavitary (n = 6 patients), mass-like (n = 3 patients), or consolidative (n = 1 patient). On histopathology examination, all tissue samples had necrosis; eight had a pH of ≤5.5. Tissue samples from two patients were positive for Mycobacterium tuberculosis by culture (pH 5.5 and 7.2). All 10 patients had maximal serum pyrazinamide concentrations within the recommended range of 20 to 60 μg/ml. The median lung tissue free pyrazinamide concentration was 20.96 μg/ml. The median tissue-to-serum pyrazinamide concentration ratio was 0.77 (range, 0.54 to 0.93). There was a significant inverse correlation between tissue pyrazinamide concentrations and the amounts of necrosis (R = −0.66, P = 0.04) and acid-fast bacilli (R = −0.75, P = 0.01) identified by histopathology. We found good penetration of pyrazinamide into lung tissue among patients with pulmonary tuberculosis with a variety of radiological lesion types. Our tissue pH results revealed that most lesions had a pH conducive to pyrazinamide activity. The tissue penetration of pyrazinamide highlights its importance in both drug-susceptible and drug-resistant antituberculosis treatment regimens. PMID:28373198

  19. Lung Tissue Concentrations of Pyrazinamide among Patients with Drug-Resistant Pulmonary Tuberculosis.

    Science.gov (United States)

    Kempker, Russell R; Heinrichs, M Tobias; Nikolaishvili, Ketino; Sabulua, Irina; Bablishvili, Nino; Gogishvili, Shota; Avaliani, Zaza; Tukvadze, Nestani; Little, Brent; Bernheim, Adam; Read, Timothy D; Guarner, Jeannette; Derendorf, Hartmut; Peloquin, Charles A; Blumberg, Henry M; Vashakidze, Sergo

    2017-06-01

    Improved knowledge regarding the tissue penetration of antituberculosis drugs may help optimize drug management. Patients with drug-resistant pulmonary tuberculosis undergoing adjunctive surgery were enrolled. Serial serum samples were collected, and microdialysis was performed using ex vivo lung tissue to measure pyrazinamide concentrations. Among 10 patients, the median pyrazinamide dose was 24.7 mg/kg of body weight. Imaging revealed predominant lung lesions as cavitary ( n = 6 patients), mass-like ( n = 3 patients), or consolidative ( n = 1 patient). On histopathology examination, all tissue samples had necrosis; eight had a pH of ≤5.5. Tissue samples from two patients were positive for Mycobacterium tuberculosis by culture (pH 5.5 and 7.2). All 10 patients had maximal serum pyrazinamide concentrations within the recommended range of 20 to 60 μg/ml. The median lung tissue free pyrazinamide concentration was 20.96 μg/ml. The median tissue-to-serum pyrazinamide concentration ratio was 0.77 (range, 0.54 to 0.93). There was a significant inverse correlation between tissue pyrazinamide concentrations and the amounts of necrosis ( R = -0.66, P = 0.04) and acid-fast bacilli ( R = -0.75, P = 0.01) identified by histopathology. We found good penetration of pyrazinamide into lung tissue among patients with pulmonary tuberculosis with a variety of radiological lesion types. Our tissue pH results revealed that most lesions had a pH conducive to pyrazinamide activity. The tissue penetration of pyrazinamide highlights its importance in both drug-susceptible and drug-resistant antituberculosis treatment regimens. Copyright © 2017 American Society for Microbiology.

  20. First Report in China on the Identification and Drug Sensitivity of Mycobacterium elephantis Isolated from the Milk of a Cow with Mastitis.

    Science.gov (United States)

    Ji, Ling Yun; Xu, Dong Lei; Yin, Shu Peng; Liu, Hai Can; Li, Gui Lian; Jiang, Yi; Wei, Jian Hao; Zeng, Hao; Lou, Yong Liang; Lyu, Jian Xin; Wan, Kang Lin

    2017-07-01

    In this study, milk from a cow with mastitis was analyzed to determine the presence of mycobacterial infection. Milk quality and security problems pertaining to the safe consumption of dairy products were also discussed in this study. Milk was preprocessed with 4% NaOH. Then, mycobacteria were isolated from the milk sample on L-J medium. The isolate was identified using multiple loci Polymerase Chain Reaction (PCR) and multi-locus sequence analysis with 16S rRNA, sodA, hsp65, and ITS genes. The drug sensitivity of the isolate to 27 antibiotics was tested through alamar blue assay. Smooth, moist, pale yellow colonies appeared on the L-J medium within a week after inoculation. Based on the results of multiple loci PCR analysis, the isolate was preliminarily identified as non-tuberculous mycobacteria. The 16S rRNA, SodA, hsp65, and ITS gene sequences of the isolate exhibited 99%, 99%, 99%, and 100% similarities, respectively, with those of the published reference strains of Mycobacterium elephantis (M. elephantis). The drug sensitivity results showed that the strain is resistant to isoniazid, p-aminosalicylic acid, and trimesulf but is sensitive to ofloxacin, rifampicin, amikacin, capreomycin, moxifloxacin, kanamycin, levofloxacin, cycloserine, ethambutol, streptomycin, tobramycin, rifabutin, ciprofloxacin, linezolid, cefoxitin, clarithromycin, and minocycline. To the best of our knowledge, this study is initially to report the isolation of M. elephantis from the milk of a cow with mastitis in China. Copyright © 2017 The Editorial Board of Biomedical and Environmental Sciences. Published by China CDC. All rights reserved.

  1. Mathematical modeling and computational prediction of cancer drug resistance.

    Science.gov (United States)

    Sun, Xiaoqiang; Hu, Bin

    2017-06-23

    Diverse forms of resistance to anticancer drugs can lead to the failure of chemotherapy. Drug resistance is one of the most intractable issues for successfully treating cancer in current clinical practice. Effective clinical approaches that could counter drug resistance by restoring the sensitivity of tumors to the targeted agents are urgently needed. As numerous experimental results on resistance mechanisms have been obtained and a mass of high-throughput data has been accumulated, mathematical modeling and computational predictions using systematic and quantitative approaches have become increasingly important, as they can potentially provide deeper insights into resistance mechanisms, generate novel hypotheses or suggest promising treatment strategies for future testing. In this review, we first briefly summarize the current progress of experimentally revealed resistance mechanisms of targeted therapy, including genetic mechanisms, epigenetic mechanisms, posttranslational mechanisms, cellular mechanisms, microenvironmental mechanisms and pharmacokinetic mechanisms. Subsequently, we list several currently available databases and Web-based tools related to drug sensitivity and resistance. Then, we focus primarily on introducing some state-of-the-art computational methods used in drug resistance studies, including mechanism-based mathematical modeling approaches (e.g. molecular dynamics simulation, kinetic model of molecular networks, ordinary differential equation model of cellular dynamics, stochastic model, partial differential equation model, agent-based model, pharmacokinetic-pharmacodynamic model, etc.) and data-driven prediction methods (e.g. omics data-based conventional screening approach for node biomarkers, static network approach for edge biomarkers and module biomarkers, dynamic network approach for dynamic network biomarkers and dynamic module network biomarkers, etc.). Finally, we discuss several further questions and future directions for the use of

  2. Drug-Resistant Bacteria: On the Edge of a Crisis | NIH MedlinePlus the Magazine

    Science.gov (United States)

    ... drug-resistant bacteria research program. Why are certain bacteria becoming more resistant to drugs? There is a ... a national, even global crisis of drug-resistant bacteria. Why is that? The more we see this ...

  3. Antimicrobial resistance determinant microarray for analysis of multi-drug resistant isolates

    Science.gov (United States)

    Taitt, Chris Rowe; Leski, Tomasz; Stenger, David; Vora, Gary J.; House, Brent; Nicklasson, Matilda; Pimentel, Guillermo; Zurawski, Daniel V.; Kirkup, Benjamin C.; Craft, David; Waterman, Paige E.; Lesho, Emil P.; Bangurae, Umaru; Ansumana, Rashid

    2012-06-01

    The prevalence of multidrug-resistant infections in personnel wounded in Iraq and Afghanistan has made it challenging for physicians to choose effective therapeutics in a timely fashion. To address the challenge of identifying the potential for drug resistance, we have developed the Antimicrobial Resistance Determinant Microarray (ARDM) to provide DNAbased analysis for over 250 resistance genes covering 12 classes of antibiotics. Over 70 drug-resistant bacteria from different geographic regions have been analyzed on ARDM, with significant differences in patterns of resistance identified: genes for resistance to sulfonamides, trimethoprim, chloramphenicol, rifampin, and macrolide-lincosamidesulfonamide drugs were more frequently identified in isolates from sources in Iraq/Afghanistan. Of particular concern was the presence of genes responsible for resistance to many of the last-resort antibiotics used to treat war traumaassociated infections.

  4. Molecular chess? Hallmarks of anti-cancer drug resistance.

    Science.gov (United States)

    Cree, Ian A; Charlton, Peter

    2017-01-05

    The development of resistance is a problem shared by both classical chemotherapy and targeted therapy. Patients may respond well at first, but relapse is inevitable for many cancer patients, despite many improvements in drugs and their use over the last 40 years. Resistance to anti-cancer drugs can be acquired by several mechanisms within neoplastic cells, defined as (1) alteration of drug targets, (2) expression of drug pumps, (3) expression of detoxification mechanisms, (4) reduced susceptibility to apoptosis, (5) increased ability to repair DNA damage, and (6) altered proliferation. It is clear, however, that changes in stroma and tumour microenvironment, and local immunity can also contribute to the development of resistance. Cancer cells can and do use several of these mechanisms at one time, and there is considerable heterogeneity between tumours, necessitating an individualised approach to cancer treatment. As tumours are heterogeneous, positive selection of a drug-resistant population could help drive resistance, although acquired resistance cannot simply be viewed as overgrowth of a resistant cancer cell population. The development of such resistance mechanisms can be predicted from pre-existing genomic and proteomic profiles, and there are increasingly sophisticated methods to measure and then tackle these mechanisms in patients. The oncologist is now required to be at least one step ahead of the cancer, a process that can be likened to 'molecular chess'. Thus, as well as an increasing role for predictive biomarkers to clinically stratify patients, it is becoming clear that personalised strategies are required to obtain best results.

  5. Mycobacterium tuberculosis thymidylate synthase gene thyX is essential and potentially bifunctional, while thyA deletion confers resistance to p-aminosalicylic acid.

    Science.gov (United States)

    Fivian-Hughes, Amanda S; Houghton, Joanna; Davis, Elaine O

    2012-02-01

    Thymidylate synthase (TS) enzymes catalyse the biosynthesis of deoxythymidine monophosphate (dTMP or thymidylate), and so are important for DNA replication and repair. Two different types of TS proteins have been described (ThyA and ThyX), which have different enzymic mechanisms and unrelated structures. Mycobacteria are unusual as they encode both thyA and thyX, and the biological significance of this is not yet understood. Mycobacterium tuberculosis ThyX is thought to be essential and a potential drug target. We therefore analysed M. tuberculosis thyA and thyX expression levels, their essentiality and roles in pathogenesis. We show that both thyA and thyX are expressed in vitro, and that this expression significantly increased within murine macrophages. Under all conditions tested, thyA expression exceeded that of thyX. Mutational studies show that M. tuberculosis thyX is essential, confirming that the enzyme is a plausible drug target. The requirement for M. tuberculosis thyX in the presence of thyA implies that the essential function of ThyX is something other than dTM synthesis [corrected].We successfully deleted thyA from the M. tuberculosis genome, and this deletion conferred an in vitro growth defect that was not observed in vivo. Presumably ThyX performs TS activity within M. tuberculosis ΔthyA at a sufficient rate in vivo for normal growth, but the rate in vitro is less than optimal. We also demonstrate that thyA deletion confers M. tuberculosis p-aminosalicylic acid resistance, and show by complementation studies that ThyA T202A and V261G appear to be functional and non-functional, respectively.

  6. Aggressive chemotherapy and the selection of drug resistant pathogens.

    Directory of Open Access Journals (Sweden)

    Silvie Huijben

    2013-09-01

    Full Text Available Drug resistant pathogens are one of the key public health challenges of the 21st century. There is a widespread belief that resistance is best managed by using drugs to rapidly eliminate target pathogens from patients so as to minimize the probability that pathogens acquire resistance de novo. Yet strong drug pressure imposes intense selection in favor of resistance through alleviation of competition with wild-type populations. Aggressive chemotherapy thus generates opposing evolutionary forces which together determine the rate of drug resistance emergence. Identifying treatment regimens which best retard resistance evolution while maximizing health gains and minimizing disease transmission requires empirical analysis of resistance evolution in vivo in conjunction with measures of clinical outcomes and infectiousness. Using rodent malaria in laboratory mice, we found that less aggressive chemotherapeutic regimens substantially reduced the probability of onward transmission of resistance (by >150-fold, without compromising health outcomes. Our experiments suggest that there may be cases where resistance evolution can be managed more effectively with treatment regimens other than those which reduce pathogen burdens as fast as possible.

  7. mtct regimen choice, drug resistance and the treatment of hiv

    African Journals Online (AJOL)

    risk of transmission is highest during labour and delivery, ... will have a major impact on controlling perinatally acquired HIV infection. ... could result in the development of drug resistance with potential .... dosing, pharmacokinetics and safety.

  8. Life cycle synchronization is a viral drug resistance mechanism.

    Directory of Open Access Journals (Sweden)

    Iulia A Neagu

    2018-02-01

    Full Text Available Viral infections are one of the major causes of death worldwide, with HIV infection alone resulting in over 1.2 million casualties per year. Antiviral drugs are now being administered for a variety of viral infections, including HIV, hepatitis B and C, and influenza. These therapies target a specific phase of the virus's life cycle, yet their ultimate success depends on a variety of factors, such as adherence to a prescribed regimen and the emergence of viral drug resistance. The epidemiology and evolution of drug resistance have been extensively characterized, and it is generally assumed that drug resistance arises from mutations that alter the virus's susceptibility to the direct action of the drug. In this paper, we consider the possibility that a virus population can evolve towards synchronizing its life cycle with the pattern of drug therapy. The periodicity of the drug treatment could then allow for a virus strain whose life cycle length is a multiple of the dosing interval to replicate only when the concentration of the drug is lowest. This process, referred to as "drug tolerance by synchronization", could allow the virus population to maximize its overall fitness without having to alter drug binding or complete its life cycle in the drug's presence. We use mathematical models and stochastic simulations to show that life cycle synchronization can indeed be a mechanism of viral drug tolerance. We show that this effect is more likely to occur when the variability in both viral life cycle and drug dose timing are low. More generally, we find that in the presence of periodic drug levels, time-averaged calculations of viral fitness do not accurately predict drug levels needed to eradicate infection, even if there is no synchronization. We derive an analytical expression for viral fitness that is sufficient to explain the drug-pattern-dependent survival of strains with any life cycle length. We discuss the implications of these findings for

  9. Drug resistance in the sexually transmitted protozoan Trichomonas vaginalis

    Institute of Scientific and Technical Information of China (English)

    REBECCA L DUNNE; LINDA A DUNN; PETER UPCROFT; PETER J O'DONOGHUE; JACQUELINE A UPCROFT

    2003-01-01

    Trichomoniasis is the most common, sexually transmitted infection. It is caused by the flagellated protozoan parasite Trichomonas vaginalis. Symptoms include vaginitis and infections have been associated with preterm delivery, low birth weight and increased infant mortality, as well as predisposing to HIV/AIDS and cervical cancer. Trichomoniasis has the highest prevalence and incidence of any sexually transmitted infection. The 5-nitroimidazole drugs, of which metronidazole is the most prescribed, are the only approved,effective drugs to treat trichomoniasis. Resistance against metronidazole is frequently reported and crossresistance among the family of 5-nitroimidazole drugs is common, leaving no alternative for treatment, with some cases remaining unresolved. The mechanism of metronidazole resistance in T. vaginalis from treatment failures is not well understood, unlike resistance which is developed in the laboratory under increasing metronidazole pressure. In the latter situation, hydrogenosomal function which is involved in activation of the prodrug, metronidazole, is down-regulated. Reversion to sensitivity is incomplete after removal of drug pressure in the highly resistant parasites while clinically resistant strains, so far analysed, maintain their resistance levels in the absence of drug pressure. Although anaerobic resistance has been regarded as a laboratory induced phenomenon, it clearly has been demonstrated in clinical isolates. Pursuit of both approaches will allow dissection of the underlying mechanisms. Many alternative drugs and treatments have been tested in vivo in cases of refractory trichomoniasis, as well as in vitro with some successes including the broad spectrum anti-parasitic drug nitazoxanide. Drug resistance incidence in T. vaginalis appears to be on the increase and improved surveillance of treatment failures is urged.

  10. Identifying clinically relevant drug resistance genes in drug-induced resistant cancer cell lines and post-chemotherapy tissues.

    Science.gov (United States)

    Tong, Mengsha; Zheng, Weicheng; Lu, Xingrong; Ao, Lu; Li, Xiangyu; Guan, Qingzhou; Cai, Hao; Li, Mengyao; Yan, Haidan; Guo, You; Chi, Pan; Guo, Zheng

    2015-12-01

    Until recently, few molecular signatures of drug resistance identified in drug-induced resistant cancer cell models can be translated into clinical practice. Here, we defined differentially expressed genes (DEGs) between pre-chemotherapy colorectal cancer (CRC) tissue samples of non-responders and responders for 5-fluorouracil and oxaliplatin-based therapy as clinically relevant drug resistance genes (CRG5-FU/L-OHP). Taking CRG5-FU/L-OHP as reference, we evaluated the clinical relevance of several types of genes derived from HCT116 CRC cells with resistance to 5-fluorouracil and oxaliplatin, respectively. The results revealed that DEGs between parental and resistant cells, when both were treated with the corresponding drug for a certain time, were significantly consistent with the CRG5-FU/L-OHP as well as the DEGs between the post-chemotherapy CRC specimens of responders and non-responders. This study suggests a novel strategy to extract clinically relevant drug resistance genes from both drug-induced resistant cell models and post-chemotherapy cancer tissue specimens.

  11. Association between embB mutations and ethambutol resistance in Mycobacterium tuberculosis isolates from Cuba and the Dominican Republic: reproducible patterns and problems Asociación entre las mutaciones en embB y la resistencia a etambutol en aislamientos de Mycobacterium tuberculosis de Cuba y República Dominicana: patrones y problemas reproducibles

    Directory of Open Access Journals (Sweden)

    Elba Guerrero

    2013-03-01

    Full Text Available The relation of ethambutol resistance to embB mutations remains unclear, and there are no reports on ethambutol resistance from the Caribbean. We examined the sequence of embB in 57 distinct Multi-Drug Resistant (MDR and non-MDR strains of Mycobacterium tuberculosis, mostly from Cuba and the Dominican Republic. embB306 codon mutations were found exclusively in MDR-TB, but in both ethambutol sensitive and resistant strains. Valine substitutions predominated in ethambutol resistant strains, while isoleucine replacements were more common in sensitive strains. Three ethambutol resistant MDR strains without embB306 substitutions had replacements in embB406 or embB497, but these were also found in ethambutol sensitive MDR strains. The results confirm previous findings that amino acid substitutions in EmbB306, EmbB406 and EmbB497 are found only in MDR-TB strains but in both phenotypically resistant and sensitive strains. One ethambutol resistant non-MDR strain did not have any embB mutation suggesting that other undefined mutations can also confer ethambutol resistance.La relación entre resistencia a etambutol y mutaciones en embB no se ha establecido claramente y no existen comunicaciones sobre la resistencia a etambutol en cepas provenientes de países Caribeños. Se evaluó la secuencia del gen embB en 57 cepas de Mycobacterium tuberculosis multi-drogo resistentes (MDR y no-MDR, la mayoría aislada en Cuba y República Dominicana. Se encontraron mutaciones en el codón embB306 exclusivamente en cepas MDR, tanto en cepas sensibles como resistentes a etambutol. Tres cepas MDR resistentes a etambutol, sin sustituciones en embB306, tenían mutaciones en los codones embB406 o embB497, pero estos cambios se encontraron también en cepas sensibles. Los resultados confirman otros estudios, mostrando que sustituciones aminoacídicas en EmbB306, EmbB406 y EmbB497 se encuentran exclusivamente en cepas MDR, tanto resistentes como sensibles a etambutol

  12. Evaluation of genotype MTBDRplus assay for rapid detection of isoniazid and rifampicin resistance in Mycobacterium tuberculosis clinical isolates from Pakistan

    Directory of Open Access Journals (Sweden)

    Hasnain Javed

    2016-01-01

    Conclusions: As evidenced in this study, the major concern with the GenoType MTBDRplus assay were false negative results. In comparison to conventional drug susceptibility testing, the assay was unable to detect 30 (30/100; 30% strains resistant to INH and 23 (23/100; 23% strains resistant to RMP. The GenoType MTBDRplus failed to identify 38 MDR (38/100; 38% strains. Resistance in those strains probably originate from mutations in other codons and/or genes than those covered by the test. For detecting INH and RMP resistance in TB cases, especially in high TB incidence countries, such as Pakistan, molecular approaches should still be a complement rather than areplacement to conventional drug susceptibility testing.

  13. Molecular basis of antifungal drug resistance in yeasts

    DEFF Research Database (Denmark)

    Morio, Florent; Jensen, Rasmus Hare; Le Pape, Patrice

    2017-01-01

    Besides inherent differences in in vitro susceptibilities, clinically-relevant yeast species may acquire resistance upon exposure to most antifungal drugs used in the clinic. In recent years, major fundamental research studies have been conducted to improve our understanding of the molecular basis...... of antifungal resistance. This topic is of major interest as antifungal resistance in yeast is clearly evolving and is correlated with clinical failure. This minireview is an overview of the most recent findings about key molecular mechanisms evolving in human pathogenic yeasts, particularly Candida spp......., in the context of antifungal drug resistance. Also included are the methods currently available for in vitro antifungal susceptibility testing and for molecular detection of mutations associated with resistance. Finally, the genetic drivers of antifungal resistance are discussed in light of the spectra...

  14. Competitive release of drug resistance following drug treatment of mixed Plasmodium chabaudi infections.

    Science.gov (United States)

    de Roode, Jacobus C; Culleton, Richard; Bell, Andrew S; Read, Andrew F

    2004-09-14

    Malaria infections are often genetically diverse, potentially leading to competition between co-infecting strains. Such competition is of key importance in the spread of drug resistance. The effects of drug treatment on within-host competition were studied using the rodent malaria Plasmodium chabaudi. Mice were infected simultaneously with a drug-resistant and a drug-sensitive clone and were then either drug-treated or left untreated. Transmission was assessed by feeding mice to Anopheles stephensi mosquitoes. In the absence of drugs, the sensitive clone competitively suppressed the resistant clone; this resulted in lower asexual parasite densities and also reduced transmission to the mosquito vector. Drug treatment, however, allowed the resistant clone to fill the ecological space emptied by the removal of the sensitive clone, allowing it to transmit as well as it would have done in the absence of competition. These results show that under drug pressure, resistant strains can have two advantages: (1) they survive better than sensitive strains and (2) they can exploit the opportunities presented by the removal of their competitors. When mixed infections are common, such effects could increase the spread of drug resistance.

  15. Plasmid Conjugation in E. coli and Drug Resistance | Igwe ...

    African Journals Online (AJOL)

    This study aimed at determining the antibiotics susceptibility pattern of E. coli isolates claimed to be multidrug resistance using disc diffusion method. It also determined the presence of transferable resistance plasmids through conjugation and evaluated the medical significance of plasmid encoding E. coli and drug ...

  16. Antiretroviral drug resistance: A guide for the southern African clinician

    African Journals Online (AJOL)

    Both private and public sector see a bewildering clinical array of patients taking failing antiretroviral (ARV) regimens. We intend this article to provide a practical guide to help clinicians understand and manage ARV drug resistance in an African context. ARV resistance is a rapidly evolving field, requiring expertise in dealing ...

  17. Options for modulation of drug resistance in ovarian cancer

    NARCIS (Netherlands)

    Arts, HJG; Van der Zee, AGJ; De Jong, S; De Vries, EGE

    2000-01-01

    The objective of this paper is to present an update of mechanisms responsible for drug resistance in ovarian cancer and the possible therapeutic options to modulate this resistance using literature review with emphasis on data acquired in studies comprising ovarian tumor samples. The classic

  18. Characterization of drug resistant Enterobacter species isolated from ...

    African Journals Online (AJOL)

    Enterobacter species are emerging clinical pathogens and they play important roles in the dissemination of drug resistant traits within the food chain due to their intrinsic abilities for resistance to commonly used antibiotics such as cephalosporins. Two Enterobacter cloacae and one Enterobacter hormaechei characterized in ...

  19. Public health impact of isoniazid-resistant Mycobacterium tuberculosis strains with a mutation at amino-acid position 315 of katG: a decade of experience in The Netherlands

    NARCIS (Netherlands)

    van Doorn, H. R.; de Haas, P. E. W.; Kremer, K.; Vandenbroucke-Grauls, C. M. J. E.; Borgdorff, M. W.; van Soolingen, D.

    2006-01-01

    A previous limited study demonstrated that Mycobacterium tuberculosis isolates with a mutation at amino-acid position 315 of katG (Delta315) exhibited high-level resistance to isoniazid and were more frequently resistant to streptomycin. In the present study, isoniazid-resistant M. tuberculosis

  20. Drug Resistant Hypertension - No SIMPLE Way Out

    OpenAIRE

    Janusz Skrzypecki; Marcin Ufnal

    2015-01-01

    Hypertension poses growing challenge for health policy-makers and doctors worldwide. Recently published results of Symplicity-III trial (HTN-3), the first blinded, randomized, multicenter study on the efficacy of renal denervation for the treatment of resistant hypertension did not show a significant reduction of BP in patients with resistant hypertension 6 months after renal-artery denervation, as compared with controls. In this paper we review clinical and experimental studies on renal dene...

  1. Multi drug resistance and β-lactamase production by Klebsiella ...

    African Journals Online (AJOL)

    SERVER

    2007-08-06

    Aug 6, 2007 ... *Corresponding author. E-mail: gnsimha123@rediffmail.com. (Rice, 1999). plasmid that can be easily spread from one organisms to another (Sirot, 1995) these enzymes are capable of inactivating a variety of β-lactam drugs (Rice,. 1999). The ESBL producing organisms often show multi- drug resistant as ...

  2. Towards an understanding of drug resistance in malaria

    DEFF Research Database (Denmark)

    Lemcke, T; Christensen, I T; Jørgensen, Flemming Steen

    1999-01-01

    and structural differences. Based on this analysis the molecular consequences of point mutations known to be involved in drug resistance were discussed. The significance of the most important point mutation causing resistance, S108N, could be explained by the model, whereas the point mutations associated...... with enhanced resistance, N51I and C59R, seem to have a more indirect effect on inhibitor binding....

  3. A luciferase-based assay for rapid assessment of drug activity against Mycobacterium tuberculosis including monitoring of macrophage viability.

    Science.gov (United States)

    Larsson, Marie C; Lerm, Maria; Ängeby, Kristian; Nordvall, Michaela; Juréen, Pontus; Schön, Thomas

    2014-11-01

    The intracellular (IC) effect of drugs against Mycobacterium tuberculosis (Mtb) is not well established but increasingly important to consider when combining current and future multidrug regimens into the best possible treatment strategies. For this purpose, we developed an IC model based on a genetically modified Mtb H37Rv strain, expressing the Vibrio harvei luciferase (H37Rv-lux) infecting the human macrophage like cell line THP-1. Cells were infected at a low multiplicity of infection (1:1) and subsequently exposed to isoniazid (INH), ethambutol (EMB), amikacin (AMI) or levofloxacin (LEV) for 5days in a 96-well format. Cell viability was evaluated by Calcein AM and was maintained throughout the experiment. The number of viable H37Rv-lux was determined by luminescence and verified by a colony forming unit analysis. The results were compared to the effects of the same drugs in broth cultures. AMI, EMB and LEV were significantly less effective intracellularly (MIC90: >4mg/L, 8mg/L and 2mg/L, respectively) compared to extracellularly (MIC90: 0.5mg/L for AMI and EMB; 0.25mg/L for LEV). The reverse was the case for INH (IC: 0.064mg/L vs EC: 0.25mg/L). In conclusion, this luciferase based method, in which monitoring of cell viability is included, has the potential to become a useful tool while evaluating the intracellular effects of anti-mycobacterial drugs. Copyright © 2014 Elsevier B.V. All rights reserved.

  4. Research Highlights: Helping Adolescents Resist Drugs

    National Research Council Canada - National Science Library

    2000-01-01

    Project ALERT departs boldly from prevention models of the 196Os and 197Os, which emphasized informing adolescents about the long-term consequences of drug use or building their decisionmaking skills...

  5. A study on Prevalence of Drug Resistance in Drug Default ...

    African Journals Online (AJOL)

    ), and particularly multidrug-resistant TB (MDR-TB), has become a significant public health problem in a number of countries and an obstacle to effective global TB control. Method: This is a prospective randomized cross sectional study to ...

  6. High proportion of modern genotypes of M. tuberculosis and their affinity with drug resistance in northern region of India.

    Science.gov (United States)

    Dhatwalia, Sunil Kumar; Yadav, Rakesh; Behera, Digambar; Kaur, Harsimran; Kumar, Manoj; Sethi, Sunil

    2017-09-01

    Comparative genomics on the basis of TbD1 deletion has differentiated the members of Mycobacterium tuberculosis complex (MTC) in two major genogroups. They exhibit differential distribution and virulence potential. The present study was carried out to see the proportion of these genogroups and their association with drug resistance. The drug resistance pattern of 205 culture positive cases of M. tuberculosis and their relation with TbD1 deletion was analysed from the tertiary care centre. Overall proportion of genotypes (TbD1- and Tbd1+) and their association with drug resistance was also observed from the various studies from India. Our study reports that 85.4% of the isolates of M. tuberculosis were modern genotypes (TbD1-) and rest of 14.6% were ancient genotypes (TbD1+). 37 cases were of multiple drug resistant-TB (MDR-TB), 35 of them belongs to modern genogrop and rest of (2) were in ancient genogroup (p=0.12). Overall pooled estimate of proportion of modern genotype is 75.5% (CI 95%, 73.03-77.87) and 24.55% (CI 95%, 22.13-26.97) for ancient genotypes from the studies carried out in India. Modern genotypes were more rarely drug sensitive phenotypes with a relative risk (RR) of 0.89 (CI 95%, 0.74-1.07) while MDR cases were more in this group with an odds ratio (OR) of 2.27 (CI 95%, 0-1.07). This study demonstrates a higher proportion of modern genotypes in our region/India; which are more likely to be associated with drug resistance. Future, epidemiological/in vitro studies are required to ascertain the relationship between genotypes and their virulence potential. Copyright © 2017 International Society for Chemotherapy of Infection and Cancer. Published by Elsevier Ltd. All rights reserved.

  7. Challenges of drug resistance in the management of pancreatic cancer.

    LENUS (Irish Health Repository)

    Sheikh, Rizwan

    2012-02-01

    The current treatment of choice for metastatic pancreatic cancer involves single-agent gemcitabine or a combination of gemcitabine with capecitabine or erlotinib (a tyrosine kinase inhibitor). Only 25–30% of patients respond to this treatment and patients who do respond initially ultimately exhibit disease progression. Median survival for pancreatic cancer patients has reached a plateau due to inherent and acquired resistance to these agents. Key molecular factors implicated in this resistance include: deficiencies in drug uptake, alteration of drug targets, activation of DNA repair pathways, resistance to apoptosis and the contribution of the tumor microenvironment. Moreover, for newer agents including tyrosine kinase inhibitors, overexpression of signaling proteins, mutations in kinase domains, activation of alternative pathways, mutations of genes downstream of the target and\\/or amplification of the target represent key challenges for treatment efficacy. Here we will review the contribution of known mechanisms and markers of resistance to key pancreatic cancer drug treatments.

  8. Comparing and Validating Machine Learning Models for Mycobacterium tuberculosis Drug Discovery.

    Science.gov (United States)

    Lane, Thomas; Russo, Daniel P; Zorn, Kimberley M; Clark, Alex M; Korotcov, Alexandru; Tkachenko, Valery; Reynolds, Robert C; Perryman, Alexander L; Freundlich, Joel S; Ekins, Sean

    2018-04-26

    Tuberculosis is a global health dilemma. In 2016, the WHO reported 10.4 million incidences and 1.7 million deaths. The need to develop new treatments for those infected with Mycobacterium tuberculosis ( Mtb) has led to many large-scale phenotypic screens and many thousands of new active compounds identified in vitro. However, with limited funding, efforts to discover new active molecules against Mtb needs to be more efficient. Several computational machine learning approaches have been shown to have good enrichment and hit rates. We have curated small molecule Mtb data and developed new models with a total of 18,886 molecules with activity cutoffs of 10 μM, 1 μM, and 100 nM. These data sets were used to evaluate different machine learning methods (including deep learning) and metrics and to generate predictions for additional molecules published in 2017. One Mtb model, a combined in vitro and in vivo data Bayesian model at a 100 nM activity yielded the following metrics for 5-fold cross validation: accuracy = 0.88, precision = 0.22, recall = 0.91, specificity = 0.88, kappa = 0.31, and MCC = 0.41. We have also curated an evaluation set ( n = 153 compounds) published in 2017, and when used to test our model, it showed the comparable statistics (accuracy = 0.83, precision = 0.27, recall = 1.00, specificity = 0.81, kappa = 0.36, and MCC = 0.47). We have also compared these models with additional machine learning algorithms showing Bayesian machine learning models constructed with literature Mtb data generated by different laboratories generally were equivalent to or outperformed deep neural networks with external test sets. Finally, we have also compared our training and test sets to show they were suitably diverse and different in order to represent useful evaluation sets. Such Mtb machine learning models could help prioritize compounds for testing in vitro and in vivo.

  9. Drug Resistant Hypertension - No SIMPLE Way Out

    Directory of Open Access Journals (Sweden)

    Janusz Skrzypecki

    2015-02-01

    Full Text Available Hypertension poses growing challenge for health policy-makers and doctors worldwide. Recently published results of Symplicity-III trial (HTN-3, the first blinded, randomized, multicenter study on the efficacy of renal denervation for the treatment of resistant hypertension did not show a significant reduction of BP in patients with resistant hypertension 6 months after renal-artery denervation, as compared with controls. In this paper we review clinical and experimental studies on renal denervation. In order to identify causes of inconsistent results in renal denervation studies we look at basic science support for renal denervation and at designs of clinical trials.

  10. Functional miRNAs in breast cancer drug resistance

    Directory of Open Access Journals (Sweden)

    Hu WZ

    2018-03-01

    Full Text Available Weizi Hu,1–3,* Chunli Tan,1–3,* Yunjie He,4 Guangqin Zhang,2 Yong Xu,3,5 Jinhai Tang1 1Department of General Surgery, The First Affiliated Hospital of Nanjing Medical University, 2School of Basic Medicine and Clinical Pharmacy, China Pharmaceutical University, 3Nanjing Medical University Affiliated Cancer Hospital, 4The First Clinical School of Nanjing Medical University, 5Jiangsu Key Lab of Cancer Biomarkers, Prevention and Treatment, Nanjing Medical University, Nanjing, People’s Republic of China *These authors contributed equally to this work Abstract: Owing to improved early surveillance and advanced therapy strategies, the current death rate due to breast cancer has decreased; nevertheless, drug resistance and relapse remain obstacles on the path to successful systematic treatment. Multiple mechanisms responsible for drug resistance have been elucidated, and miRNAs seem to play a major part in almost every aspect of cancer progression, including tumorigenesis, metastasis, and drug resistance. In recent years, exosomes have emerged as novel modes of intercellular signaling vehicles, initiating cell–cell communication through their fusion with target cell membranes, delivering functional molecules including miRNAs and proteins. This review particularly focuses on enumerating functional miRNAs involved in breast cancer drug resistance as well as their targets and related mechanisms. Subsequently, we discuss the prospects and challenges of miRNA function in drug resistance and highlight valuable approaches for the investigation of the role of exosomal miRNAs in breast cancer progression and drug resistance. Keywords: microRNA, exosome, breast cancer, drug resistance

  11. Role of Bacterioferritin & Ferritin in M. tuberculosis Pathogenesis and Drug Resistance: A Future Perspective by Interactomic Approach

    Directory of Open Access Journals (Sweden)

    Divakar Sharma

    2017-06-01

    Full Text Available Tuberculosis is caused by Mycobacterium tuberculosis, one of the most successful and deadliest human pathogen. Aminoglycosides resistance leads to emergence of extremely drug resistant strains of M. tuberculosis. Iron is crucial for the biological functions of the cells. Iron assimilation, storage and their utilization is not only involved in pathogenesis but also in emergence of drug resistance strains. We previously reported that iron storing proteins (bacterioferritin and ferritin were found to be overexpressed in aminoglycosides resistant isolates. In this study we performed the STRING analysis of bacterioferritin & ferritin proteins and predicted their interactive partners [ferrochelatase (hemH, Rv1877 (hypothetical protein/probable conserved integral membrane protein, uroporphyrinogen decarboxylase (hemE trigger factor (tig, transcriptional regulatory protein (MT3948, hypothetical protein (MT1928, glnA3 (glutamine synthetase, molecular chaperone GroEL (groEL1 & hsp65, and hypothetical protein (MT3947]. We suggested that interactive partners of bacterioferritin and ferritin are directly or indirectly involved in M. tuberculosis growth, homeostasis, iron assimilation, virulence, resistance, and stresses.

  12. Bacterial subversion of cAMP signalling inhibits cathelicidin expression, which is required for innate resistance to Mycobacterium tuberculosis

    Science.gov (United States)

    Gupta, Shashank; Winglee, Kathryn; Gallo, Richard; Bishai, William R

    2017-01-01

    Antimicrobial peptides such as cathelicidins are an important component of innate immune defence against inhaled microorganisms and have demonstrated antimicrobial activity against Mycobacterium tuberculosis with in vitro models. Despite this, little is known about the regulation and expression of cathelicidin during tuberculosis in vivo. We sought to determine whether the cathelicidin-related antimicrobial peptide (Cramp) gene, the murine functional homologue of the human cathelicidin gene (CAMP or LL-37), is required for regulating protective immunity during M. tuberculosis infection in vivo. We used Cramp−/− mice in a validated model of pulmonary tuberculosis and conducted cell-based assays with macrophages from these mice. We evaluated the in vivo susceptibility of Cramp−/− mice to infection and further dissected various pro-inflammatory immune responses against M. tuberculosis. We observed increased susceptibility of Cramp−/− mice to M. tuberculosis compared to wild type mice. Macrophages from Cramp−/− mice were unable to control M. tuberculosis growth in an in vitro infection model, were deficient in intracellular calcium influx and were defective in stimulating T-cells. Additionally, CD4 and CD8 T-cells from Cramp−/− mice produced less IFNβ upon stimulation. Furthermore, bacterial-derived cyclic-AMP modulated cathelicidin expression in macrophages. Our results demonstrate that cathelicidin is required for innate resistance to M. tuberculosis in a relevant animal model and is a key mediator in regulating the levels of pro-inflammatory cytokines by calcium and cyclic nucleotides. PMID:28097645

  13. Quantification of Markers of Antimalarial Drug Resistance ...

    African Journals Online (AJOL)

    MALISA DR

    2012-08-28

    Aug 28, 2012 ... vivo method for the detection of resistance, and has the potential to guide public health policy in a timely manner. .... signal such that the greater the intensity the greater the parasite .... was carried out by light box illumination, while the phophoimager ..... weakness of underestimation of SNPs/haplotypes.

  14. Insulin resistance induced by antiretroviral drugs: Current ...

    African Journals Online (AJOL)

    Treatment with highly active antiretroviral therapy (HAART) has improved the prognosis of patients with AIDS, but it has also increased the incidence of various metabolic disorders, in particular insulin resistance accompanied by dyslipidaemia, hyperglycaemia and lipodystrophy. This is often accompanied by frank type 2 ...

  15. Drug efflux proteins in multidrug resistant bacteria

    NARCIS (Netherlands)

    vanVeen, HW; Konings, WN

    Bacteria contain an array of transport proteins in their cytoplasmic membrane. Many of these proteins play an important role in conferring resistance to toxic compounds. The multidrug efflux systems encountered in prokaryotic cells are very similar to those observed in eukaryotic cells. Therefore, a

  16. Developing artemisinin based drug combinations for the treatment of drug resistant falciparum malaria: A review

    Directory of Open Access Journals (Sweden)

    Olliaro P

    2004-01-01

    Full Text Available The emergence and spread of drug resistant malaria represents a considerable challenge to controlling malaria. To date, malaria control has relied heavily on a comparatively small number of chemically related drugs, belonging to either the quinoline or the antifolate groups. Only recently have the artemisinin derivatives been used but mostly in south east Asia. Experience has shown that resistance eventually curtails the life-span of antimalarial drugs. Controlling resistance is key to ensuring that the investment put into developing new antimalarial drugs is not wasted. Current efforts focus on research into new compounds with novel mechanisms of action, and on measures to prevent or delay resistance when drugs are introduced. Drug discovery and development are long, risky and costly ventures. Antimalarial drug development has traditionally been slow but now various private and public institutions are at work to discover and develop new compounds. Today, the antimalarial development pipeline is looking reasonably healthy. Most development relies on the quinoline, antifolate and artemisinin compounds. There is a pressing need to have effective, easy to use, affordable drugs that will last a long time. Drug combinations that have independent modes of action are seen as a way of enhancing efficacy while ensuring mutual protection against resistance. Most research work has focused on the use of artesunate combined with currently used standard drugs, namely, mefloquine, amodiaquine, sulfadoxine/pyrimethamine, and chloroquine. There is clear evidence that combinations improve efficacy without increasing toxicity. However, the absolute cure rates that are achieved by combinations vary widely and depend on the level of resistance of the standard drug. From these studies, further work is underway to produce fixed dose combinations that will be packaged in blister packs. This review will summarise current antimalarial drug developments and outline recent

  17. Identification of novel Mycobacterium tuberculosis dihydrofolate reductase inhibitors through rational drug design

    Directory of Open Access Journals (Sweden)

    Mymoona Akhter

    2016-01-01

    Conclusion: Structure based drug design can be used as an effective tool for the design of new cheiocal entity. Number of novel agents have been identified as antitubercular agents whose mechanism of action needs to be ascertained.

  18. Establishing Drug Resistance in Microorganisms by Mass Spectrometry

    Science.gov (United States)

    Demirev, Plamen A.; Hagan, Nathan S.; Antoine, Miquel D.; Lin, Jeffrey S.; Feldman, Andrew B.

    2013-08-01

    A rapid method to determine drug resistance in bacteria based on mass spectrometry is presented. In it, a mass spectrum of an intact microorganism grown in drug-containing stable isotope-labeled media is compared with a mass spectrum of the intact microorganism grown in non-labeled media without the drug present. Drug resistance is determined by predicting characteristic mass shifts of one or more microorganism biomarkers using bioinformatics algorithms. Observing such characteristic mass shifts indicates that the microorganism is viable even in the presence of the drug, thus incorporating the isotopic label into characteristic biomarker molecules. The performance of the method is illustrated on the example of intact E. coli, grown in control (unlabeled) and 13C-labeled media, and analyzed by MALDI TOF MS. Algorithms for data analysis are presented as well.

  19. Antifolate drug resistance: Novel mutations and haplotype ...

    Indian Academy of Sciences (India)

    N P Sarmah

    2017-09-27

    Sep 27, 2017 ... distribution in dhps and dhfr from Northeast India ... The findings of this study strongly discourage the use SP as a partner drug in ACT. ... led to critical hindrances in controlling of Plasmodium fal- ciparum (Pf) malaria in this part of India. ..... alignment editor and analysis programme for Windows95/98/. NT.

  20. Profiling evolutionary landscapes underlying drug resistance

    DEFF Research Database (Denmark)

    Hickman, Rachel

    bacterial communities i.e. biofilms or dormant metabolic states. Antibiotic drugs are currently our best medicine to treat (against) bacterial pathogens due to antibiotics unique properties of being small molecules that are soluble and act systemically. These qualities allow for many modern medical...

  1. Efflux Pump-mediated Drug Resistance in Burkholderia

    Directory of Open Access Journals (Sweden)

    Nicole L Podnecky

    2015-04-01

    Full Text Available Several members of the genus Burkholderia are prominent pathogens. Infections caused by these bacteria are difficult to treat because of significant antibiotic resistance. Virtually all Burkholderia species are also resistant to polymyxin, prohibiting use of drugs like colistin that are available for treatment of infections caused by most other drug resistant Gram-negative bacteria. Despite clinical significance and antibiotic resistance of Burkholderia species, characterization of efflux pumps lags behind other non-enteric Gram-negative pathogens such as Acinetobacter baumannii and Pseudomonas aeruginosa. Although efflux pumps have been described in several Burkholderia species, they have been best studied in B. cenocepacia and B. pseudomallei. As in other non-enteric Gram-negatives, efflux pumps of the resistance nodulation cell division (RND family are the clinically most significant efflux systems in these two species. Several efflux pumps were described in B. cenocepacia, which when expressed confer resistance to clinically significant antibiotics, including aminoglycosides, chloramphenicol, fluoroquinolones, and tetracyclines. Three RND pumps have been characterized in B. pseudomallei, two of which confer either intrinsic or acquired resistance to aminoglycosides, macrolides, chloramphenicol, fluoroquinolones, tetracyclines, trimethoprim, and in some instances trimethoprim+sulfamethoxazole. Several strains of the host-adapted B. mallei, a clone of B. pseudomallei, lack AmrAB-OprA and are therefore aminoglycoside and macrolide susceptible. B. thailandensis is closely related to B. pseudomallei, but non-pathogenic to humans. Its pump repertoire and ensuing drug resistance profile parallels that of B. pseudomallei. An efflux pump in B. vietnamiensis plays a significant role in acquired aminoglycoside resistance. Summarily, efflux pumps are significant players in Burkholderia drug resistance.

  2. Resistance patterns, prevalence, and predictors of fluoroquinolones resistance in multidrug resistant tuberculosis patients

    Directory of Open Access Journals (Sweden)

    Nafees Ahmad

    2016-01-01

    Conclusion: The high degree of drug resistance observed, particularly to fluoroquinolones, is alarming. We recommend the adoption of more restrictive policies to control non-prescription sale of fluoroquinolones, its rational use by physicians, and training doctors in both private and public–private mix sectors to prevent further increase in fluoroquinolones resistant Mycobacterium tuberculosis strains.

  3. Use of GenoType® MTBDRplus assay to assess drug resistance and mutation patterns of multidrug-resistant tuberculosis isolates in northern India

    Directory of Open Access Journals (Sweden)

    A K Maurya

    2013-01-01

    Full Text Available Purpose: The emergence and spread of multidrug-resistant tuberculosis (MDR-TB is a major public health problem. The diagnosis of MDR-TB is of paramount importance in establishing appropriate clinical management and infection control measures. The aim of this study was to evaluate drug resistance and mutational patterns in clinical isolates MDR-TB by GenoType® MTBDRplus assay. Material and Methods: A total of 350 non-repeated sputum specimens were collected from highly suspected drug-resistant pulmonary tuberculosis (PTB cases; which were processed by microscopy, culture, differentiation and first line drug susceptibility testing (DST using BacT/ALERT 3D system. Results: Among a total of 125 mycobacterium tuberculosis complex (MTBC strains, readable results were obtained from 120 (96% strains by GenoType® MTBDRplus assay. Only 45 MDR-TB isolates were analysed for the performance, frequency and mutational patterns by GenoType® MTBDRplus assay. The sensitivity of the GenoType® MDRTBplus assay for detecting individual resistance to rifampicin (RIF, isoniazid (INH and multidrug resistance was found to be 95.8%, 96.3% and 97.7%, respectively. Mutation in codon S531L of the rpoB gene and codon S315T1 of katG genes were dominated in MDR-TB strains, respectively (P < 0.05. Conclusions: The GenoType® MTBDRplus assay is highly sensitive with short turnaround times and a rapid test for the detection of the most common mutations conferring resistance in MDR-TB strains that can readily be included in a routine laboratory workflow.

  4. Radiometric assessment of the sensitivity to antituberculotics of Mycobacterium avium-intracellulare and Mycobacterium xenopi

    International Nuclear Information System (INIS)

    Kubin, M.; Lindholm-Levy, P.; Heifets, L. B.

    1994-01-01

    The macrodilution radiometric method using Middlebrook's 7H12 liquid medium enriched with 14 C-palmitic acid, where the growth activity is monitored by measuring liberated 14 CO 2 , was applied to 25 strains of the Mycobacterium avium complex and to 20 strains of Mycobacterium xenopi to determine the minimal inhibitory concentrations of the following chemotherapeutical agents: ciprofloxacine, clofazimine, rifampin, cycloserine, kanamycin, etionamide, ethambutol, and amikacin. In the case of the M. avium complex, slightly or completely resistant strains were found for the majority of drugs. The sensitive strain proportion was highest with clofazimine and amikacin. The M. xenopis strains exhibited generally lower minimal inhibitory concentrations than the avian mycobacteria for all drugs except for cycloserine and ethambutol. The radiometric method using the BACTEC system was found suitable for the determination of the sensitivity of mycobacteria to chemotherapeutic agents: the results are obtained rapidly, within 8 days following inoculation, and the minimal inhibitory concentrations can be evaluated quantitatively. 1 tab., 8 refs

  5. Perfil de sensibilidade e fatores de risco associados à resistência do Mycobacterium tuberculosis, em centro de referência de doenças infecto-contagiosas de Minas Gerais Multidrug-resistant Mycobacterium tuberculosis at a referral center for infectious diseases in the state of Minas Gerais, Brazil: sensitivity profile and related risk factors

    Directory of Open Access Journals (Sweden)

    Márcia Beatriz de Souza

    2006-10-01

    Full Text Available OBJETIVO: Estudar os fatores determinantes da multirresistência do Mycobacterium tuberculosis às drogas tuberculostáticas em centro de referência de doenças infecto-contagiosas do Estado de Minas Gerais, Hospital Eduardo de Menezes. MÉTODOS: Estudo tipo caso-controle, retrospectivo, realizado de setembro de 2000 a janeiro de 2004. Nesse período, 473 culturas com crescimento de M. tuberculosis relativas a 313 pacientes foram analisadas quanto ao perfil de sensibilidade, no Laboratório Central de Minas Gerais. Foram selecionados os casos multirresistentes definidos como resistência a pelo menos rifampicina e isoniazida, depois de pareados com o grupo controle de pacientes com tuberculose sensível a todas as drogas na razão de 1:3. A associação dos dados demográficos e clínicos foi feita por análise estatística uni e multivariada. RESULTADOS: Durante o período de estudo, doze casos de tuberculose multirresistente foram identificados (3,83%. Na análise univariada, a tuberculose multirresistente foi mais comum no sexo masculino, em pacientes com baciloscopia de escarro positiva, pacientes com cavitações maiores que 4 cm de diâmetro e pacientes com um ou mais tratamentos prévios para tuberculose (p = 0,10. Após a análise multivariada somente o tratamento anterior para tuberculose permaneceu estatisticamente significativo (p = 0,0374, com odds ratio de 14,36 (1,96 - 176,46. CONCLUSÃO: O fator de risco que se mostrou independentemente associado ao desenvolvimento de tuberculose multirresistente neste estudo foi a presença de um ou mais tratamentos prévios para tuberculose.OBJECTIVE: To assess the determining factors for Mycobacterium tuberculosis multidrug resistance at a referral center for infectious diseases in the state of Minas Gerais, Brazil. METHODS: A retrospective case-control study was conducted using data collected from September of 2000 to January of 2004. During this period, 473 cultures presenting growth of M

  6. Nanoparticles: Alternatives Against Drug-Resistant Pathogenic Microbes

    Directory of Open Access Journals (Sweden)

    Gudepalya Renukaiah Rudramurthy

    2016-06-01

    Full Text Available Antimicrobial substances may be synthetic, semisynthetic, or of natural origin (i.e., from plants and animals. Antimicrobials are considered “miracle drugs” and can determine if an infected patient/animal recovers or dies. However, the misuse of antimicrobials has led to the development of multi-drug-resistant bacteria, which is one of the greatest challenges for healthcare practitioners and is a significant global threat. The major concern with the development of antimicrobial resistance is the spread of resistant organisms. The replacement of conventional antimicrobials by new technology to counteract antimicrobial resistance is ongoing. Nanotechnology-driven innovations provide hope for patients and practitioners in overcoming the problem of drug resistance. Nanomaterials have tremendous potential in both the medical and veterinary fields. Several nanostructures comprising metallic particles have been developed to counteract microbial pathogens. The effectiveness of nanoparticles (NPs depends on the interaction between the microorganism and the NPs. The development of effective nanomaterials requires in-depth knowledge of the physicochemical properties of NPs and the biological aspects of microorganisms. However, the risks associated with using NPs in healthcare need to be addressed. The present review highlights the antimicrobial effects of various nanomaterials and their potential advantages, drawbacks, or side effects. In addition, this comprehensive information may be useful in the discovery of broad-spectrum antimicrobial drugs for use against multi-drug-resistant microbial pathogens in the near future.

  7. Drug-resistant tuberculosis in HIV-infected patients in a national referral hospital, Phnom Penh, Cambodia

    Directory of Open Access Journals (Sweden)

    Genevieve Walls

    2015-01-01

    Full Text Available Background and objective: There are no recent data on the prevalence of drug-resistant tuberculosis (DR TB in Cambodia. We aim to describe TB drug resistance amongst adults with pulmonary and extra-pulmonary TB and human immunodeficiency virus (HIV co-infection in a national referral hospital in Phnom Penh, Cambodia. Design: Between 22 November 2007 and 30 November 2009, clinical specimens from HIV-infected patients suspected of having TB underwent routine microscopy, Mycobacterium tuberculosis culture, and drug susceptibility testing. Laboratory and clinical data were collected for patients with positive M. tuberculosis cultures. Results: M. tuberculosis was cultured from 236 HIV-infected patients. Resistance to any first-line TB drug occurred in 34.7% of patients; 8.1% had multidrug resistant tuberculosis (MDR TB. The proportion of MDR TB amongst new patients and previously treated patients was 3.7 and 28.9%, respectively (p<0.001. The diagnosis of MDR TB was made after death in 15.8% of patients; in total 26.3% of patients with MDR TB died. The diagnosis of TB was established by culture of extra-pulmonary specimens in 23.6% of cases. Conclusions: There is significant resistance to first-line TB drugs amongst new and previously treated TB–HIV co-infected patients in Phnom Penh. These data suggest that the prevalence of DR TB in Cambodia may be higher than previously recognised, particularly amongst HIV-infected patients. Additional prevalence studies are needed. This study also illustrates the feasibility and utility of analysis of non-respiratory specimens in the diagnosis of TB, even in low-resource settings, and suggests that extra-pulmonary specimens should be included in TB diagnostic algorithms.

  8. Mycobacterial diversity causing multi- and extensively drug-resistant tuberculosis in Djibouti, Horn of Africa.

    Science.gov (United States)

    Millán-Lou, M I; Ollé-Goig, J E; Tortola, M T; Martin, C; Samper, S

    2016-02-01

    On detecting a high prevalence of multidrug-resistant tuberculosis (TB) in Djibouti, 32 Mycobacterium tuberculosis isolates of patients hospitalised in the TB referral centre of the capital were genotyped. A high variety of M. tuberculosis lineages, including lineage 1, Indo-Oceanic, lineage 2, East-Asian, lineage 3, East-African Indian and lineage 4, Euro-American, were detected.

  9. Characterization of mutations causing rifampicin and isoniazid resistance of Mycobacterium tuberculosis in Syria.

    Science.gov (United States)

    Madania, Ammar; Habous, Maya; Zarzour, Hana; Ghoury, Ifad; Hebbo, Barea

    2012-01-01

    In order to characterize mutations causing rifampicin and isoniazid resistance of M. tuberculosis in Syria, 69 rifampicin resistant (Rif(r)) and 72 isoniazid resistant (Inh(r)) isolates were screened for point mutations in hot spots of the rpoB, katG and inhA genes by DNA sequencing and real time PCR. Of 69 Rif(r) isolates, 62 (90%) had mutations in the rifampin resistance determining region (RRDR) of the rpoB gene, with codons 531 (61%), 526 (13%), and 516 (8.7%) being the most commonly mutated. We found two new mutations (Asp516Thr and Ser531Gly) described for the first time in the rpoB-RRDR in association with rifampicin resistance. Only one mutation (Ile572Phe) was found outside the rpoB-RRDR. Of 72 Inh(r) strains, 30 (41.6%) had a mutation in katGcodon315 (with Ser315Thr being the predominant alteration), and 23 (32%) harbored the inhA(-15C-->T) mutation. While the general pattern of rpoB-RRDR and katG mutations reflected those found worldwide, the prevalence of the inhA(-15C-->T mutation was above the value found in most other countries, emphasizing the great importance of testing the inhA(-15C-->T) mutation for prediction of isoniazid resistance in Syria. Sensitivity of a rapid test using real time PCR and 3'-Minor groove binder (MGB) probes in detecting Rif(r) and Inh(r) isolates was 90% and 69.4%, respectively. This demonstrates that a small set of MGB-probes can be used in real time PCR in order to detect most mutations causing resistance to rifampicin and isoniazid.

  10. MenA Is a Promising Drug Target for Developing Novel Lead Molecules to Combat Mycobacterium tuberculosis

    OpenAIRE

    Kurosu, Michio; Crick, Dean C.

    2009-01-01

    Potent inhibitors of MenA (1,4-dihydroxy-2-naphtoate prenyltrasferase) in Mycobacterium tuberculosis are identified, and are also effective in inhibiting growth of Mycobacterium tuberculosis at low concentrations. The MenA inhibitors possess common chemical structural features of ((alkylamino)alkoxyphenyl)(phenyl)methanones. Significantly, the MenA inhibitors can be synthesized in a few steps with high overall yields. The representative MenA inhibitors are highly effective in killing nonrepli...

  11. An investigation of classification algorithms for predicting HIV drug resistance without genotype resistance testing

    CSIR Research Space (South Africa)

    Brandt, P

    2014-01-01

    Full Text Available is limited in low-resource settings. In this paper we investigate machine learning techniques for drug resistance prediction from routine treatment and laboratory data to help clinicians select patients for confirmatory genotype testing. The techniques...

  12. Spread of anti-malarial drug resistance: Mathematical model with implications for ACT drug policies

    Directory of Open Access Journals (Sweden)

    Dondorp Arjen M

    2008-11-01

    Full Text Available Abstract Background Most malaria-endemic countries are implementing a change in anti-malarial drug policy to artemisinin-based combination therapy (ACT. The impact of different drug choices and implementation strategies is uncertain. Data from many epidemiological studies in different levels of malaria endemicity and in areas with the highest prevalence of drug resistance like borders of Thailand are certainly valuable. Formulating an appropriate dynamic data-driven model is a powerful predictive tool for exploring the impact of these strategies quantitatively. Methods A comprehensive model was constructed incorporating important epidemiological and biological factors of human, mosquito, parasite and treatment. The iterative process of developing the model, identifying data needed, and parameterization has been taken to strongly link the model to the empirical evidence. The model provides quantitative measures of outcomes, such as malaria prevalence/incidence and treatment failure, and illustrates the spread of resistance in low and high transmission settings. The model was used to evaluate different anti-malarial policy options focusing on ACT deployment. Results The model predicts robustly that in low transmission settings drug resistance spreads faster than in high transmission settings, and treatment failure is the main force driving the spread of drug resistance. In low transmission settings, ACT slows the spread of drug resistance to a partner drug, especially at high coverage rates. This effect decreases exponentially with increasing delay in deploying the ACT and decreasing rates of coverage. In the high transmission settings, however, drug resistance is driven by the proportion of the human population with a residual drug level, which gives resistant parasites some survival advantage. The spread of drug resistance could be slowed down by controlling presumptive drug use and avoiding the use of combination therapies containing drugs with

  13. Trade-offs with stability modulate innate and mutationally acquired drug-resistance in bacterial dihydrofolate reductase enzymes.

    Science.gov (United States)

    Matange, Nishad; Bodkhe, Swapnil; Patel, Maitri; Shah, Pooja

    2018-06-05

    Structural stability is a major constraint on the evolution of protein sequences. However, under strong directional selection, mutations that confer novel phenotypes but compromise structural stability of proteins may be permissible. During the evolution of antibiotic resistance, mutations that confer drug resistance often have pleiotropic effects on the structure and function of antibiotic-target proteins, usually essential metabolic enzymes. In this study, we show that trimethoprim-resistant alleles of dihydrofolate reductase from Escherichia coli (EcDHFR) harbouring the Trp30Gly, Trp30Arg or Trp30Cys mutations are significantly less stable than the wild type making them prone to aggregation and proteolysis. This destabilization is associated with lower expression level resulting in a fitness cost and negative epistasis with other TMP-resistant mutations in EcDHFR. Using structure-based mutational analysis we show that perturbation of critical stabilizing hydrophobic interactions in wild type EcDHFR enzyme explains the phenotypes of Trp30 mutants. Surprisingly, though crucial for the stability of EcDHFR, significant sequence variation is found at this site among bacterial DHFRs. Mutational and computational analyses in EcDHFR as well as in DHFR enzymes from Staphylococcus aureus and Mycobacterium tuberculosis demonstrate that natural variation at this site and its interacting hydrophobic residues, modulates TMP-resistance in other bacterial DHFRs as well, and may explain the different susceptibilities of bacterial pathogens to trimethoprim. Our study demonstrates that trade-offs between structural stability and function can influence innate drug resistance as well as the potential for mutationally acquired drug resistance of an enzyme. ©2018 The Author(s).

  14. mTOR Signaling Confers Resistance to Targeted Cancer Drugs.

    Science.gov (United States)

    Guri, Yakir; Hall, Michael N

    2016-11-01

    Cancer is a complex disease and a leading cause of death worldwide. Extensive research over decades has led to the development of therapies that target cancer-specific signaling pathways. However, the clinical benefits of such drugs are at best transient due to tumors displaying intrinsic or adaptive resistance. The underlying compensatory pathways that allow cancer cells to circumvent a drug blockade are poorly understood. We review here recent studies suggesting that mammalian TOR (mTOR) signaling is a major compensatory pathway conferring resistance to many cancer drugs. mTOR-mediated resistance can be cell-autonomous or non-cell-autonomous. These findings suggest that mTOR signaling should be monitored routinely in tumors and that an mTOR inhibitor should be considered as a co-therapy. Copyright © 2016 Elsevier Inc. All rights reserved.

  15. The value of microscopic-observation drug susceptibility assay in the diagnosis of tuberculosis and detection of multidrug resistance.

    Science.gov (United States)

    Sertel Şelale, Denİz; Uzun, Meltem

    2018-01-01

    Inexpensive, rapid, and reliable tests for detecting the presence and drug susceptibility of Mycobacterium tuberculosis complex (MTBC) are urgently needed to control the transmission of tuberculosis. In this study, we aimed to assess the accuracy and speed of the microscopic-observation drug susceptibility (MODS) assay in the identification of MTBC and detection of multidrug resistance. Sputum samples from patients suspected to have tuberculosis were simultaneously tested with MODS and conventional culture [Löwenstein-Jensen (LJ) culture, BACTEC MGIT™ 960 (MGIT) system], and drug susceptibility testing (MGIT system) methods. A total of 331 sputum samples were analyzed. Sensitivity and specificity of MODS assay for detection of MTBC strains were 96% and 98.8%, respectively. MODS assay detected multidrug resistant MTBC isolates with 92.3% sensitivity and 96.6% specificity. Median time to culture positivity was similar for MGIT (8 days) and MODS culture (8 days), but was significantly longer with LJ culture (20 days) (p tuberculosis and detection of multidrug resistance. © 2017 APMIS. Published by John Wiley & Sons Ltd.

  16. Prevalence of genotypic HIV-1 drug resistance in Thailand, 2002

    Directory of Open Access Journals (Sweden)

    Watitpun Chotip

    2003-03-01

    Full Text Available Abstract Background The prices of reverse transcriptase (RT inhibitors in Thailand have been reduced since December 1, 2001. It is expected that reduction in the price of these inhibitors may influence the drug resistance mutation pattern of HIV-1 among infected people. This study reports the frequency of HIV-1 genetic mutation associated with drug resistance in antiretroviral-treated patients from Thailand. Methods Genotypic resistance testing was performed on samples collected in 2002 from 88 HIV-1 infected individuals. Automated DNA sequencing was used to genotype the HIV-1 polymerase gene isolated from patients' plasma. Results Resistance to protease inhibitors, nucleoside and non-nucleoside reverse transcriptase inhibitors were found in 10 (12%, 42 (48% and 19 (21% patients, respectively. The most common drug resistance mutations in the protease gene were at codon 82 (8%, 90 (7% and 54 (6%, whereas resistant mutations at codon 215 (45%, 67 (40%, 41 (38% and 184 (27% were commonly found in the RT gene. This finding indicates that genotypic resistance to nucleoside reverse transcriptase inhibitors was prevalent in 2002. The frequency of resistant mutations corresponding to non-nucleoside reverse transcriptase inhibitors was three times higher-, while resistant mutation corresponding to protease inhibitors was two times lower than those frequencies determined in 2001. Conclusion This study shows that the frequencies of RT inhibitor resistance mutations have been increased after the reduction in the price of RT inhibitors since December 2001. We believe that this was an important factor that influenced the mutation patterns of HIV-1 protease and RT genes in Thailand.

  17. Enhanced transmission of drug-resistant parasites to mosquitoes following drug treatment in rodent malaria.

    Directory of Open Access Journals (Sweden)

    Andrew S Bell

    Full Text Available The evolution of drug resistant Plasmodium parasites is a major challenge to effective malaria control. In theory, competitive interactions between sensitive parasites and resistant parasites within infections are a major determinant of the rate at which parasite evolution undermines drug efficacy. Competitive suppression of resistant parasites in untreated hosts slows the spread of resistance; competitive release following treatment enhances it. Here we report that for the murine model Plasmodium chabaudi, co-infection with drug-sensitive parasites can prevent the transmission of initially rare resistant parasites to mosquitoes. Removal of drug-sensitive parasites following chemotherapy enabled resistant parasites to transmit to mosquitoes as successfully as sensitive parasites in the absence of treatment. We also show that the genetic composition of gametocyte populations in host venous blood accurately reflects the genetic composition of gametocytes taken up by mosquitoes. Our data demonstrate that, at least for this mouse model, aggressive chemotherapy leads to very effective transmission of highly resistant parasites that are present in an infection, the very parasites which undermine the long term efficacy of front-line drugs.

  18. Negligible risk of inducing resistance in Mycobacterium tuberculosis with single-dose rifampicin as post-exposure prophylaxis for leprosy.

    Science.gov (United States)

    Mieras, Liesbeth; Anthony, Richard; van Brakel, Wim; Bratschi, Martin W; van den Broek, Jacques; Cambau, Emmanuelle; Cavaliero, Arielle; Kasang, Christa; Perera, Geethal; Reichman, Lee; Richardus, Jan Hendrik; Saunderson, Paul; Steinmann, Peter; Yew, Wing Wai

    2016-06-08

    Post-exposure prophylaxis (PEP) for leprosy is administered as one single dose of rifampicin (SDR) to the contacts of newly diagnosed leprosy patients. SDR reduces the risk of developing leprosy among contacts by around 60 % in the first 2-3 years after receiving SDR. In countries where SDR is currently being implemented under routine programme conditions in defined areas, questions were raised by health authorities and professional bodies about the possible risk of inducing rifampicin resistance among the M. tuberculosis strains circulating in these areas. This issue has not been addressed in scientific literature to date. To produce an authoritative consensus statement about the risk that SDR would induce rifampicin-resistant tuberculosis, a meeting was convened with tuberculosis (TB) and leprosy experts. The experts carefully reviewed and discussed the available evidence regarding the mechanisms and risk factors for the development of (multi) drug-resistance in M. tuberculosis with a view to the special situation of the use of SDR as PEP for leprosy. They concluded that SDR given to contacts of leprosy patients, in the absence of symptoms of active TB, poses a negligible risk of generating resistance in M. tuberculosis in individuals and at the population level. Thus, the benefits of SDR prophylaxis in reducing the risk of developing leprosy in contacts of new leprosy patients far outweigh the risks of generating drug resistance in M. tuberculosis.

  19. Prevalence and molecular characterization of pyrazinamide resistance among multidrug-resistant Mycobacterium tuberculosis isolates from Southern China.

    Science.gov (United States)

    Pang, Yu; Zhu, Damian; Zheng, Huiwen; Shen, Jing; Hu, Yan; Liu, Jie; Zhao, Yanlin

    2017-11-06

    Pyrazinamide (PZA) plays a unique role in the treatment for multidrug-resistant tuberculosis (MDR-TB) in both first- and second-line regimens. The aim of this study was to investigate the prevalence and molecular characterization of PZA resistance among MDR-TB isolates collected in Chongqing municipality. A total of 133 MDR-TB isolates were collected from the smear-positive tuberculosis patients who were registered at local TB dispensaries of Chongqing. PZA susceptibility testing was determined with a Bactec MGIT 960 system. In addition, the genes conferring for PZA resistance were screened by DNA sequencing. Of these 133 MDR-TB isolates, 83 (62.4%) were determined as PZA-resistant by MGIT 960. In addition, streptomycin- (83.1% vs. 56.0%, P < 0.01), ofloxacin- (51.8% vs. 18.0%, P < 0.01), kanamycin- (22.9% vs. 2.0%, P < 0.01), amikacin- (18.1% vs. 2.0%, P = 0.01), capromycin-resistance (12.0% vs. 2.0%, P = 0.05), were more frequently observed among PZA-resistant isolates compared with PZA-susceptible isolates. Sequence analysis revealed that 73 out of 83 (88.0%) MDR strains harbored a mutation located in the pncA gene, including 55 (75.3%, 55/73) of single nucleotide substitutions and 18 (24.7%, 18/73) of frameshift mutation, while no genetic mutation associated with PZA resistance was found in the rpsA gene. The pncA expression of strains harboring substitution from A to G at position -11 in the promoter region of pncA was significantly lower than that of H37Rv (P < 0.01). In conclusion, our data have demonstrated that the analysis of the pncA gene rather than rpsA gene provides rapid and accurate information regarding PZA susceptibility for MDR-TB isolates in Chongqing. In addition, loss of pncA expression caused by promoter mutation confers PZA resistance in MDR-TB isolates.

  20. Dynamic optical tweezers based assay for monitoring early drug resistance

    International Nuclear Information System (INIS)

    Wu, Xiaojing; Zhu, Siwei; Feng, Jie; Zhang, Yuquan; Min, Changjun; Yuan, X-C

    2013-01-01

    In this letter, a dynamic optical tweezers based assay is proposed and investigated for monitoring early drug resistance with Pemetrexed-resistant non-small cell lung cancer (NSCLC) cell lines. The validity and stability of the method are verified experimentally in terms of the physical parameters of the optical tweezers system. The results demonstrate that the proposed technique is more convenient and faster than traditional techniques when the capability of detecting small variations of the response of cells to a drug is maintained. (letter)

  1. Evaluation of the efficacy of valproic acid and suberoylanilide hydroxamic acid (vorinostat in enhancing the effects of first-line tuberculosis drugs against intracellular Mycobacterium tuberculosis

    Directory of Open Access Journals (Sweden)

    Martin Rao

    2018-04-01

    Full Text Available Background: New tuberculosis (TB drug treatment regimens are urgently needed. This study evaluated the potential of the histone deacetylase inhibitors (HDIs valproic acid (VPA and suberoylanilide hydroxamic acid (SAHA to enhance the effects of first-line anti-TB drugs against intracellular Mycobacterium tuberculosis. Methods: M. tuberculosis H37Rv cultures were exposed to VPA or SAHA over 6 days, in the presence or absence of isoniazid (INH and rifampicin (RIF. The efficacy of VPA and SAHA against intracellular M. tuberculosis with and without INH or RIF was tested by treating infected macrophages. Bactericidal activity was assessed by counting mycobacterial colony-forming units (CFU. Results: VPA treatment exhibited superior bactericidal activity to SAHA (2-log CFU reduction, while both HDIs moderately improved the activity of RIF against extracellular M. tuberculosis. The bactericidal effect of VPA against intracellular M. tuberculosis was greater than that of SAHA (1-log CFU reduction and equalled that of INH (1.5-log CFU reduction. INH/RIF and VPA/SAHA combination treatment inhibited intracellular M. tuberculosis survival in a shorter time span than monotherapy (3 days vs. 6 days. Conclusions: VPA and SAHA have adjunctive potential to World Health Organization-recommended TB treatment regimens. Clinical evaluation of the two drugs with regard to reducing the treatment duration and improving treatment outcomes in TB is warranted. Keywords: Mycobacterium tuberculosis, Adjunct host-directed therapy, Tuberculosis, Histone deacetylase inhibitors, Repurposed drugs

  2. Multi drug resistance to cancer chemotherapy: Genes involved and blockers

    International Nuclear Information System (INIS)

    Sayed-Ahmed, Mohamed M.

    2007-01-01

    During the last three decades, important and considerable research efforts had been performed to investigate the mechanism through which cancer cells overcome the cytotoxic effects of a variety of chemotherapeutic drugs. Most of the previously published work has been focused on the resistance of tumor cells to those anticancer drugs of natural source. Multidrug resistance (MDR) is a cellular cross-resistance to a broad spectrum of natural products used in cancer chemotherapy and is believed to be the major cause of the therapeutic failures of the drugs belonging to different naturally obtained or semisynthetic groups including vinca alkaloids, taxans, epipodophyllotoxins and certain antibiotics. This phenomenon results from overexpression of four MDR genes and their corresponding proteins that act as membrane-bound ATP consuming pumps. These proteins mediate the efflux of many structurally and functionally unrelated anticancer drugs of natural source. MDR may be intrinsic or acquired following exposure to chemotherapy. The existence of intrinsically resistant tumor cell clone before and following chemotherapeutic treatment has been associated with a worse final outcome because of increased incidence of distant metasis. In view of irreplaceability of natural product anticancer drugs as effective chemotherapeutic agents, and in view of MDR as a major obstacle to successful chemotherapy, this review is aimed to highlight the genes involved in MDR, classical MDR blockers and gene therapy approaches to overcome MDR. (author)

  3. "A'ole" Drugs! Cultural Practices and Drug Resistance of Rural Hawai'ian Youths

    Science.gov (United States)

    Po'A-Kekuawela, Ka'Ohinani; Okamoto, Scott K.; Nebre, La Risa H.; Helm, Susana; Chin, Coralee I. H.

    2009-01-01

    This qualitative study examined how Native Hawai'ian youths from rural communities utilized cultural practices to promote drug resistance and/or abstinence. Forty-seven students from five different middle schools participated in gender-specific focus groups that focused on the cultural and environmental contexts of drug use for Native Hawai'ian…

  4. Hepatitis C Virus and Antiviral Drug Resistance.

    Science.gov (United States)

    Kim, Seungtaek; Han, Kwang-Hyub; Ahn, Sang Hoon

    2016-11-15

    Since its discovery in 1989, hepatitis C virus (HCV) has been intensively investigated to understand its biology and develop effective antiviral therapies. The efforts of the previous 25 years have resulted in a better understanding of the virus, and this was facilitated by the development of in vitro cell culture systems for HCV replication. Antiviral treatments and sustained virological responses have also improved from the early interferon monotherapy to the current all-oral regimens using direct-acting antivirals. However, antiviral resistance has become a critical issue in the treatment of chronic hepatitis C, similar to other chronic viral infections, and retreatment options following treatment failure have become important questions. Despite the clinical challenges in the management of chronic hepatitis C, substantial progress has been made in understanding HCV, which may facilitate the investigation of other closely related flaviviruses and lead to the development of antiviral agents against these human pathogens.

  5. Epigenetic Modulation of the Biophysical Properties of Drug-Resistant Cell Lipids to Restore Drug Transport and Endocytic Functions

    OpenAIRE

    Vijayaraghavalu, Sivakumar; Peetla, Chiranjeevi; Lu, Shan; Labhasetwar, Vinod

    2012-01-01

    In our recent studies exploring the biophysical characteristics of resistant cell lipids, and the role they play in drug transport, we demonstrated the difference of drug-resistant breast cancer cells from drug-sensitive cells in lipid composition and biophysical properties, suggesting that cancer cells acquire a drug-resistant phenotype through the alteration of lipid synthesis to inhibit intracellular drug transport to protect from cytotoxic effect. In cancer cells, epigenetic changes (e.g....

  6. High prevalence of multidrug-resistant tuberculosis among patients with rifampicin resistance using GeneXpert Mycobacterium tuberculosis/rifampicin in Ghana

    Directory of Open Access Journals (Sweden)

    Justice K Boakye-Appiah

    2016-01-01

    Conclusion: These findings call for a scale-up of TB control in Ghana and provide evidence that the expansion of GeneXpert may be an optimal means to improve case finding and guide treatment of drug-resistant TB in this setting.

  7. Effect and Safety of Shihogyejitang for Drug Resistant Childhood Epilepsy

    Directory of Open Access Journals (Sweden)

    Jinsoo Lee

    2016-01-01

    Full Text Available Objective. Herbal medicine has been widely used to treat drug resistant epilepsy. Shihogyejitang (SGT has been commonly used to treat epilepsy. We investigated the effect and safety of SGT in children with drug resistant epilepsy. Design. We reviewed medical records of 54 patients with epilepsy, who failed to respond to at least two antiepileptic drugs and have been treated with SGT between April 2006 and June 2014 at the Department of Pediatric Neurology, I-Tomato Hospital, Korea. Effect was measured by the response rate, seizure-free rate, and retention rate at six months. We also checked adverse events, change in antiepileptic drugs use, and the variables related to the outcome. Results. Intent-to-treat analysis showed that, after six months, 44.4% showed a >50% seizure reduction, 24.1% including seizure-free, respectively, and 53.7% remained on SGT. Two adverse events were reported, mild skin rash and fever. Focal seizure type presented significantly more positive responses when compared with other seizure types at six months (p=0.0284, Fisher’s exact test. Conclusion. SGT is an effective treatment with excellent tolerability for drug resistant epilepsy patients. Our data provide evidence that SGT may be used as alternative treatment option when antiepileptic drug does not work in epilepsy children.

  8. Mycobacterium tuberculosis: nepřekonatelný nepřítel

    Czech Academy of Sciences Publication Activity Database

    Machová, Iva; Pichová, Iva

    2014-01-01

    Roč. 24, č. 4 (2014), s. 98-100 ISSN 1210-1737 R&D Projects: GA MŠk LO1302; GA MŠk(CZ) 7E11070 EU Projects: European Commission(XE) 241587 - SYSTEMTB Institutional support: RVO:61388963 Keywords : Mycobacterium tuberculosis * tuberculosis * latent infection * resistance * metabolism * drugs Subject RIV: CE - Biochemistry

  9. Tuberculosis relapse in Vietnam is significantly associated with Mycobacterium tuberculosis Beijing genotype infections

    NARCIS (Netherlands)

    Huyen, Mai N. T.; Buu, Tran N.; Tiemersma, Edine; Lan, Nguyen T. N.; Dung, Nguyen H.; Kremer, Kristin; Soolingen, Dick V.; Cobelens, Frank G. J.

    2013-01-01

    In Vietnam, the Mycobacterium tuberculosis Beijing genotype is associated with multi-drug resistance and is emerging. A possible explanation for this genotype's success is an increased rate of relapse. In a prospective cohort study, isolates from patients with smear-positive tuberculosis were

  10. THE ANTI-TB DRUG SENSITIVITY OF MYCOBACTERIUM TUBERCULOSIS FROM CEREBROSPINAL FLUID AND BONE TISSUE BIOPSY SPECIMENS OF PATIENTS SUSPECTED TUBERCULOUS MENINGITIS AND SPINAL TB IN DR SOETOMO HOSPITAL INDONESIA

    Directory of Open Access Journals (Sweden)

    Ni Made Mertaniasih

    2014-09-01

    Full Text Available Tuberculous meningitis (TBM is an infection of meningens which potentially life threatening with significant morbidity and mortality. Spinal TB has the same problem with TBM, infection in bone and joint, the delayed diagnosis worsens the prognosis. The rapid and accurate diagnosis plus promt adequate treatment is essential for the good outcome. The aim of this research is to study the first line drug sensitivity of Mycobacterium tuberculosis isolated from specimens of cerebrospinal fluid from suspected tuberculous meningitis patients and bone tissue biopsy from suspected spinal TB patients. The method of this research is TB Laboratory examination in Department of Clinical Microbiology – Dr. Soetomo General Hospital, Indonesia, using the gold standard liquid culture method MGIT 960 System (Becton Dickinson and solid culture method with Lowenstein-Jensen medium. The specimens CSF from 50 TBM patients at January 2013 until May 2014. Positive isolate detection of Mycobacterium tuberculosis complex were 11 isolates (22%, which sensitivity 100% (11/11 isolates to Rifampin (R, Pyrazinamide (Z, Ethambutol (E, and Streptomycin (S; one isolate resistant to Isoniazid, sensitivity to Isoniazid 90,90% (10/11; and received 21 specimens of bone tissue biopsy which positive 5 isolates (23%, all isolates sensitive 100% (5/5 isolates to Rifampin and Pyrazinamide, and 1 isolates resistant to Isoniazid, Ethambutol, and Streptomycin, in which sensitivity 80% (4/5 isolates to Isoniazid, Ethambutol, and Streptomycin. The conclusion of this research is positivity detection 22% of CSF specimens, and 23% of bone tissue biopsy were low. All isolates sensitive 100% to Rifampin and Pyrazinamide, and 80-90% sensitive to Isoniazid.

  11. Influence of multidrug resistance and drug transport proteins on chemotherapy drug metabolism.

    Science.gov (United States)

    Joyce, Helena; McCann, Andrew; Clynes, Martin; Larkin, Annemarie

    2015-05-01

    Chemotherapy involving the use of anticancer drugs remains an important strategy in the overall management of patients with metastatic cancer. Acquisition of multidrug resistance remains a major impediment to successful chemotherapy. Drug transporters in cell membranes and intracellular drug metabolizing enzymes contribute to the resistance phenotype and determine the pharmacokinetics of anticancer drugs in the body. ATP-binding cassette (ABC) transporters mediate the transport of endogenous metabolites and xenobiotics including cytotoxic drugs out of cells. Solute carrier (SLC) transporters mediate the influx of cytotoxic drugs into cells. This review focuses on the substrate interaction of these transporters, on their biology and what role they play together with drug metabolizing enzymes in eliminating therapeutic drugs from cells. The majority of anticancer drugs are substrates for the ABC transporter and SLC transporter families. Together, these proteins have the ability to control the influx and the efflux of structurally unrelated chemotherapeutic drugs, thereby modulating the intracellular drug concentration. These interactions have important clinical implications for chemotherapy because ultimately they determine therapeutic efficacy, disease progression/relapse and the success or failure of patient treatment.

  12. Mecanismos de acción y de resistencia a rifampicina e isoniacida en Mycobacterium tuberculosis: nueva información sobre viejos conocidos Mechanisms of action of and resistance to rifampicin and isoniazid in Mycobacterium tuberculosis: new information on old friends

    Directory of Open Access Journals (Sweden)

    A. I. De la Iglesia

    2006-04-01

    Full Text Available La tuberculosis constituye todavía una de la causas más frecuentes de mortalidad en el mundo. A pesar de la implementación de tratamientos con cuatro drogas antituberculosas, la aparición de cepas resistentes y multirresistentes ha comprometido la eficacia de los mismos. Dos de las drogas en uso, la rifampicina y la isoniacida, recibieron gran atención por su importancia terapéutica, incluso se han identificado los genes involucrados en los mecanismos de resistencia y los que codifican para sus blancos moleculares. La rifampicina es un inhibidor de la subunidad beta de la ARN polimerasa de procariotas, incluido Mycobacterium tuberculosis. La resistencia a esta droga está principalmente mediada por mutaciones agrupadas en una región del gen rpoB. Una pequeña fracción de cepas resistentes no mostró mutaciones en rpoB, lo que sugiere la existencia de otros mecanismos de resistencia, posiblemente eflujo de la droga. La isoniacida es una prodroga que se activa por la catalasa-peroxidasa KatG. Mutaciones en katG son las más comúnmente identificadas en cepas clínicas de M. tuberculosis resistentes a isoniacida, confiriendo altos niveles de resistencia. Sin embargo, el blanco molecular de acción para la isoniacida es la InhA, una enoil-ACP reductasa involucrada en la vía de síntesis de los ácidos micólicos. Otras mutaciones involucradas en la resistencia a la isoniacida afectan al gen ndh, que codifica para la NADH deshidrogenasa.Human tuberculosis is still one of the most frequent causes of death worldwide. Despite the implementation of therapeutic regimes combining four drugs, the rise of resistant and multidrug-resistant Mycobacterium tuberculosis strains has compromised their efficacy. Two of the most effective anti-tubercular drugs in use, rifampicin and isoniazid, have been closely studied due to their therapeutic importance. These studies have led to the identification of the genes involved in resistance mechanisms and of those

  13. Emerging drug -resistance and guidelines for treatment of malaria

    International Nuclear Information System (INIS)

    Khan, M.A.; Smego Jr, R.A.; Razi, S.T.; Beg, M.A.

    2004-01-01

    The increasing prevalence of multi-resistant Plasmodium falciparum malaria worldwide is a serious public health threat to the global control of malaria, especially in poor countries like Pakistan. In many countries chloroquine-resistance is a huge problem, accounting for more than 90% of malaria cases. In Pakistan, resistance to chloroquine is on the rise and reported in up to 16- 62% of Plasmodium falciparum. Four to 25% of Plasmodium falciparum also reported to be resistant to sulfadoxine-pyrimethamine and several cases of delayed parasite clearance have been observed in patients with Plasmodium falciparum malaria treated with quinine. In this article we have introduced the concept of artemisinin- based combination therapy (ACT) and emphasize the use of empiric combination therapy for all patients with Plasmodium falciparum malaria to prevent development of drug resistance and to obtain additive and synergistic killing of parasite. (author)

  14. Pattern of secondary acquired drug resistance to antituberculosis drug in Mumbai, India--1991-1995.

    Science.gov (United States)

    Chowgule, R V; Deodhar, L

    1998-01-01

    A retrospective observational study was conducted to find out whether secondary acquired drug resistance to isoniazid and ethambutol is high and to rifamycin and pyrazinamide is low, as is commonly believed in India. There were 2033 patients, whose sputum samples (6099) were reviewed from a specimen registry of the microbiology laboratory for the years 1991 to 1995. Of these, 521 (25.6%) patients [335 males and 186 females; age ranged from 11 to 75 years] had sputum positive culture and sensitivity for acid-fast bacilli (AFB). The drug resistance patterns in our study were: isoniazid (H) 15%, rifamycin (R) 66.8%, pyrazinamide (Z) 72.2%, ethambutol (E) 8.4%, streptomycin (S) 53.6%, cycloserine (C) 39.2% kanamycin (K) 25.1% and ethionamide (Eth) 65.3%. The resistance to streptomycin showed a significant fall over a year while there was a rise in resistance to cycloserine and kanamycin which is significant. The rate of secondary acquired resistance of isoniazid and ethambutol was low, and the rate of secondary acquired resistance to rifamycin and pyrazinamide was high, which is contarary to the common belief regarding these drugs in India. This implies that isoniazid is still a valuable drug in the treatment of multidrug resistance in India.

  15. Investigation of Susceptibility of Mycobacterium tuberculosis Complex Strains Isolated from Clinical Samples Against the First and Second-Line Anti-tuberculosis Drugs by the Sensititre MycoTB Plate Method

    Directory of Open Access Journals (Sweden)

    Figen KAYSERİLİ ORHAN

    2018-03-01

    Full Text Available Introduction: Phenotypic methods for drug susceptibility testing of Mycobacterium tuberculosis complex (MTC to second-line drugs are not yet standardized. The Sensititre MycoTB Plate is a microtiter plate containing lyophilized antibiotics and configured for determination of MIC to first and second-line anti-tuberculosis drugs. The purpose of this study is to detect the susceptibility rates of MTC strains isolated from patients’ specimens for first and second-line anti-tuberculosis drugs. Materials and Methods: This study included 50 MTC strains isolated from various clinical specimens. Out of the 50 strains, 38 were isolated from sputum, three from cerebrospinal fluid, three from bronchoalveolar lavage, and six from other samples in this study. The susceptibility of strains to anti-tuberculosis drugs were determined by the Sensititre MycoTB Plate Method. Thawed isolates were subcultured, and dilutions were inoculated into MycoTB wells. The results were read at days 7, 14 and 21. Results: At the end of study, out of 50 MTC isolates, 7 (14% showed resistance to Isoniazid (INH, 5 (10% to streptomycin (SM, 4 (8% to ethambutol (EMB, 4 (8% to ethionamide (ETH, 3 (6% to rifampicin (RIF, 3 (6% to rifabutin (RFB, 2 (4% to kanamycin (KAN, 2 (4% to ofloxacin (OFL, 2 (4% to P-aminosalicyclic acid (PAS, 1 (2% to moxiflocacin (MOX, and 1 (2% to cycloserine (CYC. All strains were found sensitive to amikacin while 2 strains (4% were identified as multidrug-resistant tuberculosis (MDR-TB. Thirty-five strains (70% were sensitive to all drugs. Extensively drug resistant tuberculosis (XDR-TB was not determined in this study. Conclusion: This is the first study that tests second line anti-tuberculosis drugs in our location and provides us valuable data regarding MDR-TB and XDR-TB rates. The Sensititre MycoTB Plate Method is a fast, reliable and practical method and can be used to determine the susceptibility of first and second-line anti-tuberculosis drugs.

  16. Molecular detection of multi drug resistant tuberculosis (mdr-tb) in mdr-tb patients' attendant in north western pakistan

    International Nuclear Information System (INIS)

    Shah, T.; Hayat, A.; Shah, Z.; Hayat, A.; Khan, S.B.

    2017-01-01

    Objective: To determine the drugs susceptibility pattern of mycobacterium tuberculosis (M.TB) in multi-drug resistant tuberculosis (MDR-TB) patients' attendants in North Western, Pakistan. Study Design: Cross sectional study. Place and Duration of Study: This study was conducted at Peshawar Tuberculosis Research Laboratory (PTRL), Provincial TB Control Program Hayatabad Medical Complex Peshawar, (KP) from August 2013 to March 2014. Material and Methods: A cross sectional study in which four hundred and eighty sputum samples from MDR-TB patients' attendants were processed for the detection of M.TB through Ziehl-Neelsen staining, Lowenstein-Jensen, BACTEC MGIT-960 culture and line probe assay. Results: Out of 480 samples, 06 (2.1%) were found positive for M.TB through Ziehl-Neelsen staining while 10 (2.8%) were positive through LJ and BACTEC MGIT-960 culture. The 10 positive samples were further subjected to drugs susceptibility testing and line probes assay test to find out rifampicin, isoniazid, streptomycin and ethambutol resistant and it was found that 6 M.TB isolates were resistant while 4 were sensitive to rifampicin and isoniazid. Among the 6 resistant M.TB strains, 4 showed mutation in rpoB gene at 531, 516 and 526 codons. Conclusion: Majority of MDR-TB patients' attendants had drug-resistant tuberculosis and the rate of drug susceptible TB was low. (author)

  17. Drug Targets and Mechanisms of Resistance in the Anaerobic Protozoa

    Science.gov (United States)

    Upcroft, Peter; Upcroft, Jacqueline A.

    2001-01-01

    The anaerobic protozoa Giardia duodenalis, Trichomonas vaginalis, and Entamoeba histolytica infect up to a billion people each year. G. duodenalis and E. histolytica are primarily pathogens of the intestinal tract, although E. histolytica can form abscesses and invade other organs, where it can be fatal if left untreated. T. vaginalis infection is a sexually transmitted infection causing vaginitis and acute inflammatory disease of the genital mucosa. T. vaginalis has also been reported in the urinary tract, fallopian tubes, and pelvis and can cause pneumonia, bronchitis, and oral lesions. Respiratory infections can be acquired perinatally. T. vaginalis infections have been associated with preterm delivery, low birth weight, and increased mortality as well as predisposing to human immunodeficiency virus infection, AIDS, and cervical cancer. All three organisms lack mitochondria and are susceptible to the nitroimidazole metronidazole because of similar low-redox-potential anaerobic metabolic pathways. Resistance to metronidazole and other drugs has been observed clinically and in the laboratory. Laboratory studies have identified the enzyme that activates metronidazole, pyruvate:ferredoxin oxidoreductase, to its nitroso form and distinct mechanisms of decreasing drug susceptibility that are induced in each organism. Although the nitroimidazoles have been the drug family of choice for treating the anaerobic protozoa, G. duodenalis is less susceptible to other antiparasitic drugs, such as furazolidone, albendazole, and quinacrine. Resistance has been demonstrated for each agent, and the mechanism of resistance has been investigated. Metronidazole resistance in T. vaginalis is well documented, and the principal mechanisms have been defined. Bypass metabolism, such as alternative oxidoreductases, have been discovered in both organisms. Aerobic versus anaerobic resistance in T. vaginalis is discussed. Mechanisms of metronidazole resistance in E. histolytica have recently

  18. Diversity of Urinary Tract Pathogens and Drug Resistant Isolates of ...

    African Journals Online (AJOL)

    Purpose: This paper was mainly aimed to investigate drug resistance of the various urinary tract infection (UTI) pathogens from patients of different gender and age groups of Pakistanis. Method: For these purposes, urine samples of 109 patients were analyzed. Samples were screened on CLED agar. Antimicrobial ...

  19. National anti-tuberculosis drug resistance study in Tanzania

    NARCIS (Netherlands)

    Chonde, T. M.; Basra, D.; Mfinanga, S. G. M.; Range, N.; Lwilla, F.; Shirima, R. P.; van Deun, A.; Zignol, M.; Cobelens, F. G.; Egwaga, S. M.; van Leth, F.

    2010-01-01

    OBJECTIVE: To assess the prevalence of anti-tuberculosis drug resistance in a national representative sample of tuberculosis (TB) patients in Tanzania according to recommended methodology. DESIGN: Cluster survey, with 40 clusters sampled proportional to size, of notified TB patients from all

  20. Drug-resistant post-neurosurgical nosocomial Acinetobacter ...

    African Journals Online (AJOL)

    Drug-resistant post-neurosurgical nosocomial Acinetobacter baumannii meningitis in two Iranian hospitals. ... Vol 11, No 17 (2012) >. Log in or Register to get access to full text downloads. ... Acinetobacter baumannii may cause meningitis and ventriculitis, particularly after head trauma and/or neurosurgery. The rate of ...

  1. Elucidating the Interdependence of Drug Resistance from Combinations of Mutations.

    Science.gov (United States)

    Ragland, Debra A; Whitfield, Troy W; Lee, Sook-Kyung; Swanstrom, Ronald; Zeldovich, Konstantin B; Kurt-Yilmaz, Nese; Schiffer, Celia A

    2017-11-14

    HIV-1 protease is responsible for the cleavage of 12 nonhomologous sites within the Gag and Gag-Pro-Pol polyproteins in the viral genome. Under the selective pressure of protease inhibition, the virus evolves mutations within (primary) and outside of (secondary) the active site, allowing the protease to process substrates while simultaneously countering inhibition. The primary protease mutations impede inhibitor binding directly, while the secondary mutations are considered accessory mutations that compensate for a loss in fitness. However, the role of secondary mutations in conferring drug resistance remains a largely unresolved topic. We have shown previously that mutations distal to the active site are able to perturb binding of darunavir (DRV) via the protein's internal hydrogen-bonding network. In this study, we show that mutations distal to the active site, regardless of context, can play an interdependent role in drug resistance. Applying eigenvalue decomposition to collections of hydrogen bonding and van der Waals interactions from a series of molecular dynamics simulations of 15 diverse HIV-1 protease variants, we identify sites in the protease where amino acid substitutions lead to perturbations in nonbonded interactions with DRV and/or the hydrogen-bonding network of the protease itself. While primary mutations are known to drive resistance in HIV-1 protease, these findings delineate the significant contributions of accessory mutations to resistance. Identifying the variable positions in the protease that have the greatest impact on drug resistance may aid in future structure-based design of inhibitors.

  2. [Description of Mycobacterium tuberculosis mutations conferring resistance to rifampicin and isoniazid detected by GenoType® MTBDRplus V.2 in Colombia].

    Science.gov (United States)

    Llerena, Claudia; Medina, Raquel

    2017-01-24

    The GenoType®MTBDRplusV.2 assay is a molecular technique endorsed by the World Health Organization and the Pan American Health Organization that allows for the identification of the Mycobacterium tuberculosis complex and the detection of mutations in the rpoβ gene for rifampicin resistance, and katG and inhA genes for isoniazid resistance. Due to the genetic variability in the circulating strains around the world, the national tuberculosis control programs should assess the performance of these new diagnostic technologies and their use under program conditions as rapid tests. To describe the mutations identified by the GenoType®MTBDRplusV.2 assay in pulmonary samples and Mycobacterium tuberculosis isolates in the Laboratorio Nacional de Referencia of the Instituto Nacional de Salud in 2014. We conducted a retrospective, descriptive study to detect the expression of inhA, KatG and rpoβ genes, responsible for resistence against isoniazid and rifampicin using the GenoType® MTBDRplus V.2 assay in 837 samples and isolates from tuberculosis cases. Several mutations in the rpoβ gene were identified. Ser531Leu was the most frequent (36.6%) followed by Asp516Val (21.6%), while Ser315Thr1 was the most frequent mutation in the katG gene (91.9%). We were able to identify different mutations present in MDR-TB strains in the country, with frequencies similar to those reported in other countries in the South American region.

  3. Mechanisms of antifungal drug resistance in Candida dubliniensis.

    LENUS (Irish Health Repository)

    Coleman, David C

    2010-06-01

    Candida dubliniensis was first described in 1995 and is the most closely related species to the predominant human fungal pathogen Candida albicans. C. dubliniensis is significantly less prevalent and less pathogenic than C. albicans and is primarily associated with infections in HIV-infected individuals and other immunocompromised cohorts. The population structure of C. dubliniensis consists of three well-defined major clades and is significantly less diverse than C. albicans. The majority of C. dubliniensis isolates are susceptible to antifungal drugs commonly used to treat Candida infections. To date only two major patterns of antifungal drug resistance have been identified and the molecular mechanisms of these are very similar to the resistance mechanisms that have been described previously in C. albicans. However, significant differences are evident in the predominant antifungal drug mechanisms employed by C. dubliniensis, differences that reflect its more clonal nature, its lower prevalence and characteristics of its genome, the complete sequence of which has only recently been determined.

  4. Xpert MTB/RIF Ultra for detection of Mycobacterium tuberculosis and rifampicin resistance: a prospective multicentre diagnostic accuracy study.

    Science.gov (United States)

    Dorman, Susan E; Schumacher, Samuel G; Alland, David; Nabeta, Pamela; Armstrong, Derek T; King, Bonnie; Hall, Sandra L; Chakravorty, Soumitesh; Cirillo, Daniela M; Tukvadze, Nestani; Bablishvili, Nino; Stevens, Wendy; Scott, Lesley; Rodrigues, Camilla; Kazi, Mubin I; Joloba, Moses; Nakiyingi, Lydia; Nicol, Mark P; Ghebrekristos, Yonas; Anyango, Irene; Murithi, Wilfred; Dietze, Reynaldo; Lyrio Peres, Renata; Skrahina, Alena; Auchynka, Vera; Chopra, Kamal Kishore; Hanif, Mahmud; Liu, Xin; Yuan, Xing; Boehme, Catharina C; Ellner, Jerrold J; Denkinger, Claudia M

    2018-01-01

    The Xpert MTB/RIF assay is an automated molecular test that has improved the detection of tuberculosis and rifampicin resistance, but its sensitivity is inadequate in patients with paucibacillary disease or HIV. Xpert MTB/RIF Ultra (Xpert Ultra) was developed to overcome this limitation. We compared the diagnostic performance of Xpert Ultra with that of Xpert for detection of tuberculosis and rifampicin resistance. In this prospective, multicentre, diagnostic accuracy study, we recruited adults with pulmonary tuberculosis symptoms presenting at primary health-care centres and hospitals in eight countries (South Africa, Uganda, Kenya, India, China, Georgia, Belarus, and Brazil). Participants were allocated to the case detection group if no drugs had been taken for tuberculosis in the past 6 months or to the multidrug-resistance risk group if drugs for tuberculosis had been taken in the past 6 months, but drug resistance was suspected. Demographic information, medical history, chest imaging results, and HIV test results were recorded at enrolment, and each participant gave at least three sputum specimen on 2 separate days. Xpert and Xpert Ultra diagnostic performance in the same sputum specimen was compared with culture tests and drug susceptibility testing as reference standards. The primary objectives were to estimate and compare the sensitivity of Xpert Ultra test with that of Xpert for detection of smear-negative tuberculosis and rifampicin resistance and to estimate and compare Xpert Ultra and Xpert specificities for detection of rifampicin resistance. Study participants in the case detection group were included in all analyses, whereas participants in the multidrug-resistance risk group were only included in analyses of rifampicin-resistance detection. Between Feb 18, and Dec 24, 2016, we enrolled 2368 participants for sputum sampling. 248 participants were excluded from the analysis, and 1753 participants were distributed to the case detection group (n=1439

  5. Evaluation of a u.s. Public health laboratory service for the molecular detection of drug resistant tuberculosis.

    Science.gov (United States)

    Yakrus, Mitchell A; Metchock, Beverly; Starks, Angela M

    2015-01-01

    Crucial to interrupting the spread of tuberculosis (TB) is prompt implementation of effective treatment regimens. We evaluated satisfaction, comfort with interpretation, and use of molecular results from a public health service provided by the Centers for Disease Control and Prevention (CDC) for the molecular detection of drug resistant Mycobacterium tuberculosis complex (MTBC). An electronic survey instrument was used to collect information anonymously from U.S. Public Health Laboratories (PHL) that submitted at least one isolate of MTBC to CDC from September 2009 through February 2011. Over 97% of those responding expressed satisfaction with the turnaround time for receiving results. Twenty-six PHL (74%) reported molecular results to healthcare providers in less than two business days. When comparing the molecular results from CDC with their own phenotypic drug susceptibility testing, 50% of PHL observed discordance. No respondents found the molecular results difficult to interpret and 82% were comfortably discussing them with TB program officials and healthcare providers. Survey results indicate PHL were satisfied with CDC's ability to rapidly provide interpretable molecular results for isolates of MTBC submitted for determination of drug resistance. To develop educational materials and strategies for service improvement, reasons for discordant results and areas of confusion need to be identified.

  6. Evaluation of a U.S. Public Health Laboratory Service for the Molecular Detection of Drug Resistant Tuberculosis

    Directory of Open Access Journals (Sweden)

    Mitchell A. Yakrus

    2015-01-01

    Full Text Available Crucial to interrupting the spread of tuberculosis (TB is prompt implementation of effective treatment regimens. We evaluated satisfaction, comfort with interpretation, and use of molecular results from a public health service provided by the Centers for Disease Control and Prevention (CDC for the molecular detection of drug resistant Mycobacterium tuberculosis complex (MTBC. An electronic survey instrument was used to collect information anonymously from U.S. Public Health Laboratories (PHL that submitted at least one isolate of MTBC to CDC from September 2009 through February 2011. Over 97% of those responding expressed satisfaction with the turnaround time for receiving results. Twenty-six PHL (74% reported molecular results to healthcare providers in less than two business days. When comparing the molecular results from CDC with their own phenotypic drug susceptibility testing, 50% of PHL observed discordance. No respondents found the molecular results difficult to interpret and 82% were comfortably discussing them with TB program officials and healthcare providers. Survey results indicate PHL were satisfied with CDC’s ability to rapidly provide interpretable molecular results for isolates of MTBC submitted for determination of drug resistance. To develop educational materials and strategies for service improvement, reasons for discordant results and areas of confusion need to be identified.

  7. Genetic sequencing for surveillance of drug resistance in tuberculosis in highly endemic countries: a multi-country population-based surveillance study.

    Science.gov (United States)

    Zignol, Matteo; Cabibbe, Andrea Maurizio; Dean, Anna S; Glaziou, Philippe; Alikhanova, Natavan; Ama, Cecilia; Andres, Sönke; Barbova, Anna; Borbe-Reyes, Angeli; Chin, Daniel P; Cirillo, Daniela Maria; Colvin, Charlotte; Dadu, Andrei; Dreyer, Andries; Driesen, Michèle; Gilpin, Christopher; Hasan, Rumina; Hasan, Zahra; Hoffner, Sven; Hussain, Alamdar; Ismail, Nazir; Kamal, S M Mostofa; Khanzada, Faisal Masood; Kimerling, Michael; Kohl, Thomas Andreas; Mansjö, Mikael; Miotto, Paolo; Mukadi, Ya Diul; Mvusi, Lindiwe; Niemann, Stefan; Omar, Shaheed V; Rigouts, Leen; Schito, Marco; Sela, Ivita; Seyfaddinova, Mehriban; Skenders, Girts; Skrahina, Alena; Tahseen, Sabira; Wells, William A; Zhurilo, Alexander; Weyer, Karin; Floyd, Katherine; Raviglione, Mario C

    2018-03-21

    In many countries, regular monitoring of the emergence of resistance to anti-tuberculosis drugs is hampered by the limitations of phenotypic testing for drug susceptibility. We therefore evaluated the use of genetic sequencing for surveillance of drug resistance in tuberculosis. Population-level surveys were done in hospitals and clinics in seven countries (Azerbaijan, Bangladesh, Belarus, Pakistan, Philippines, South Africa, and Ukraine) to evaluate the use of genetic sequencing to estimate the resistance of Mycobacterium tuberculosis isolates to rifampicin, isoniazid, ofloxacin, moxifloxacin, pyrazinamide, kanamycin, amikacin, and capreomycin. For each drug, we assessed the accuracy of genetic sequencing by a comparison of the adjusted prevalence of resistance, measured by genetic sequencing, with the true prevalence of resistance, determined by phenotypic testing. Isolates were taken from 7094 patients with tuberculosis who were enrolled in the study between November, 2009, and May, 2014. In all tuberculosis cases, the overall pooled sensitivity values for predicting resistance by genetic sequencing were 91% (95% CI 87-94) for rpoB (rifampicin resistance), 86% (74-93) for katG, inhA, and fabG promoter combined (isoniazid resistance), 54% (39-68) for pncA (pyrazinamide resistance), 85% (77-91) for gyrA and gyrB combined (ofloxacin resistance), and 88% (81-92) for gyrA and gyrB combined (moxifloxacin resistance). For nearly all drugs and in most settings, there was a large overlap in the estimated prevalence of drug resistance by genetic sequencing and the estimated prevalence by phenotypic testing. Genetic sequencing can be a valuable tool for surveillance of drug resistance, providing new opportunities to monitor drug resistance in tuberculosis in resource-poor countries. Before its widespread adoption for surveillance purposes, there is a need to standardise DNA extraction methods, recording and reporting nomenclature, and data interpretation. Bill & Melinda

  8. Evaluation of polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) analysis for the detection of the rpoB mutations associated with resistance to rifampicin in Mycobacterium tuberculosis

    International Nuclear Information System (INIS)

    Lee, H.; Cho, S.-N.; Bang, H.-E.; Kim, S.-C.; Victor, T.C.; Jordaan, A.; Suffys, P.N.; Gomes, H.M.; Singh, U.; Suresh, V.N.; Khan, B.K.

    2003-01-01

    Resistance of Mycobacterium tuberculosis to rifampicin (RIF) has been associated with mutations of the rpoB gene, which encodes for the RNA polymerase B subunit. Based on this information, polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) has been suggested as a sensitive and rapid screening test for the detection of RIF-resistant M. tuberculosis from clinical isolates. PCR-SSCP analyses with radioisotopes and without radioisotopes were employed to detect mutations of the rpoB gene associated with resistance to RIF in four laboratories, and results were compared with those of sequence analysis and the conventional proportion method of drug susceptibility test between laboratories. Radioisotopic PCR-SSCP showed an excellent correlation with sequence analysis of the 157 bp region of the rpoB gene by identifying correctly all 32 isolates analyzed in this study, with a high resolution of the banding patterns obtained. In a separate study, non-radioisotopic PCR-SSCP also gave a good correlation with sequence analysis in 22 isolates, but two (9.1%) isolates were classified as resistant by PCR-SSCP despite wild type sequences. When PCR-SSCP was compared with the results obtained using the proportion method, sensitivity of 44% to 85% were obtained in the 4 laboratories that participated in this study. Possible reasons for discordant results are discussed. It has been concluded that despite discordant results, which were sometimes observed, depending on the experimental conditions, PCR-SSCP appears to be an effective and promising method for the rapid detection of RIF-resistant M. tuberculosis, a marker of multidrug resistant tuberculosis. (author)

  9. Epigenetic modulation of the biophysical properties of drug-resistant cell lipids to restore drug transport and endocytic functions.

    Science.gov (United States)

    Vijayaraghavalu, Sivakumar; Peetla, Chiranjeevi; Lu, Shan; Labhasetwar, Vinod

    2012-09-04

    In our recent studies exploring the biophysical characteristics of resistant cell lipids, and the role they play in drug transport, we demonstrated the difference of drug-resistant breast cancer cells from drug-sensitive cells in lipid composition and biophysical properties, suggesting that cancer cells acquire a drug-resistant phenotype through the alteration of lipid synthesis to inhibit intracellular drug transport to protect from cytotoxic effect. In cancer cells, epigenetic changes (e.g., DNA hypermethylation) are essential to maintain this drug-resistant phenotype. Thus, altered lipid synthesis may be linked to epigenetic mechanisms of drug resistance. We hypothesize that reversing DNA hypermethylation in resistant cells with an epigenetic drug could alter lipid synthesis, changing the cell membrane's biophysical properties to facilitate drug delivery to overcome drug resistance. Herein we show that treating drug-resistant breast cancer cells (MCF-7/ADR) with the epigenetic drug 5-aza-2'-deoxycytidine (decitabine) significantly alters cell lipid composition and biophysical properties, causing the resistant cells to acquire biophysical characteristics similar to those of sensitive cell (MCF-7) lipids. Following decitabine treatment, resistant cells demonstrated increased sphingomyelinase activity, resulting in a decreased sphingomyelin level that influenced lipid domain structures, increased membrane fluidity, and reduced P-glycoprotein expression. Changes in the biophysical characteristics of resistant cell lipids facilitated doxorubicin transport and restored endocytic function for drug delivery with a lipid-encapsulated form of doxorubicin, enhancing the drug efficacy. In conclusion, we have established a new mechanism for efficacy of an epigenetic drug, mediated through changes in lipid composition and biophysical properties, in reversing cancer drug resistance.

  10. Modeling HIV-1 drug resistance as episodic directional selection.

    Science.gov (United States)

    Murrell, Ben; de Oliveira, Tulio; Seebregts, Chris; Kosakovsky Pond, Sergei L; Scheffler, Konrad

    2012-01-01

    The evolution of substitutions conferring drug resistance to HIV-1 is both episodic, occurring when patients are on antiretroviral therapy, and strongly directional, with site-specific resistant residues increasing in frequency over time. While methods exist to detect episodic diversifying selection and continuous directional selection, no evolutionary model combining these two properties has been proposed. We present two models of episodic directional selection (MEDS and EDEPS) which allow the a priori specification of lineages expected to have undergone directional selection. The models infer the sites and target residues that were likely subject to directional selection, using either codon or protein sequences. Compared to its null model of episodic diversifying selection, MEDS provides a superior fit to most sites known to be involved in drug resistance, and neither one test for episodic diversifying selection nor another for constant directional selection are able to detect as many true positives as MEDS and EDEPS while maintaining acceptable levels of false positives. This suggests that episodic directional selection is a better description of the process driving the evolution of drug resistance.

  11. Modeling HIV-1 drug resistance as episodic directional selection.

    Directory of Open Access Journals (Sweden)

    Ben Murrell

    Full Text Available The evolution of substitutions conferring drug resistance to HIV-1 is both episodic, occurring when patients are on antiretroviral therapy, and strongly directional, with site-specific resistant residues increasing in frequency over time. While methods exist to detect episodic diversifying selection and continuous directional selection, no evolutionary model combining these two properties has been proposed. We present two models of episodic directional selection (MEDS and EDEPS which allow the a priori specification of lineages expected to have undergone directional selection. The models infer the sites and target residues that were likely subject to directional selection, using either codon or protein sequences. Compared to its null model of episodic diversifying selection, MEDS provides a superior fit to most sites known to be involved in drug resistance, and neither one test for episodic diversifying selection nor another for constant directional selection are able to detect as many true positives as MEDS and EDEPS while maintaining acceptable levels of false positives. This suggests that episodic directional selection is a better description of the process driving the evolution of drug resistance.

  12. Molecular Basis for Drug Resistance in HIV-1 Protease

    Directory of Open Access Journals (Sweden)

    Celia A. Schiffer

    2010-11-01

    Full Text Available HIV-1 protease is one of the major antiviral targets in the treatment of patients infected with HIV-1. The nine FDA approved HIV-1 protease inhibitors were developed with extensive use of structure-based drug design, thus the atomic details of how the inhibitors bind are well characterized. From this structural understanding the molecular basis for drug resistance in HIV-1 protease can be elucidated. Selected mutations in response to therapy and diversity between clades in HIV-1 protease have altered the shape of the active site, potentially altered the dynamics and even altered the sequence of the cleavage sites in the Gag polyprotein. All of these interdependent changes act in synergy to confer drug resistance while simultaneously maintaining the fitness of the virus. New strategies, such as incorporation of the substrate envelope constraint to design robust inhibitors that incorporate details of HIV-1 protease’s function and decrease the probability of drug resistance, are necessary to continue to effectively target this key protein in HIV-1 life cycle.

  13. The diarylquinoline TMC207 for multidrug-resistant tuberculosis

    NARCIS (Netherlands)

    Diacon, Andreas H.; Pym, Alexander; Grobusch, Martin; Patientia, Ramonde; Rustomjee, Roxana; Page-Shipp, Liesl; Pistorius, Christoffel; Krause, Rene; Bogoshi, Mampedi; Churchyard, Gavin; Venter, Amour; Allen, Jenny; Palomino, Juan Carlos; de Marez, Tine; van Heeswijk, Rolf P. G.; Lounis, Nacer; Meyvisch, Paul; Verbeeck, Johan; Parys, Wim; de Beule, Karel; Andries, Koen; Mc Neeley, David F.

    2009-01-01

    BACKGROUND: The diarylquinoline TMC207 offers a new mechanism of antituberculosis action by inhibiting mycobacterial ATP synthase. TMC207 potently inhibits drug-sensitive and drug-resistant Mycobacterium tuberculosis in vitro and shows bactericidal activity in patients who have drug-susceptible

  14. Neurological autoantibodies in drug-resistant epilepsy of unknown cause.

    Science.gov (United States)

    Tecellioglu, Mehmet; Kamisli, Ozden; Kamisli, Suat; Yucel, Fatma Ebru; Ozcan, Cemal

    2018-03-09

    Autoimmune epilepsy is a rarely diagnosed condition. Recognition of the underlying autoimmune condition is important, as these patients can be resistant to antiepileptic drugs. To determine the autoimmune and oncological antibodies in adult drug-resistant epilepsy of unknown cause and identify the clinical, radiological, and EEG findings associated with these antibodies according to data in the literature. Eighty-two patients with drug-resistant epilepsy of unknown cause were prospectively identified. Clinical features were recorded. The levels of anti-voltage-gated potassium channel complex (anti-VGKCc), anti-thyroid peroxidase (anti-TPO), anti-nuclear antibody (ANA), anti-glutamic acid decarboxylase (anti-GAD), anti-phospholipid IgG and IgM, anti-cardiolipin IgG and IgM, and onconeural antibodies were determined. Serum antibody positivity suggesting the potential role of autoimmunity in the aetiology was present in 17 patients with resistant epilepsy (22.0%). Multiple antibodies were found in two patients (2.6%). One of these patients (1.3%) had anti-VGKCc and ANA, whereas another (1.3%) had anti-VGKCc and anti-TPO. A single antibody was present in 15 patients (19.5%). Of the 77 patients finally included in the study, 4 had anti-TPO (5.2%), 1 had anti-GAD (1.3%), 4 had anti-VGKCc (5.2%) 8 had ANA (10.3%), and 2 had onconeural antibodies (2.6%) (1 patient had anti-Yo and 1 had anti-MA2/TA). The other antibodies investigated were not detected. EEG abnormality (focal), focal seizure incidence, and frequent seizures were more common in antibody-positive patients. Autoimmune factors may be aetiologically relevant in patients with drug-resistant epilepsy of unknown cause, especially if focal seizures are present together with focal EEG abnormality and frequent seizures.

  15. Evaluation of rapid MTT tube method for detection of drug susceptibility of mycobacterium tuberculosis to rifampicin and isoniazid

    Directory of Open Access Journals (Sweden)

    Raut U

    2008-01-01

    Full Text Available Purpose: To evaluate MTT method for detection of drug resistance to rifampicin and isoniazid in M.tuberculosis . This method utilises the ability of viable mycobacterial cells to reduce MTT( 3-4,5-dimethylthiazol-2-yl-2, 5-diphenyl tetrazolium bromide. Methods: The method was standardised with known resistant and sensitive strains of M.tuberculosis and was then extended to 50 clinical isolates. An inoculum of 10 7 cfu/mL was prepared in Middlebrook 7H9 medium supplemented with oleic acid, albumin, dextrose and catalase. For each drug three tubes were used, one with INH(0.2μg/mL or RIF(1μg/mL, another as inoculum control and third as blank control. These were incubated at 37°C for four and seven days respectively for RIF and INH after which MTT assay was performed. Results were read visually and by colorimeter at 570 nm. Relative optical density unit (RODU of 0.2 was taken as cut off. Results were compared with drug sensitivity obtained by proportion method using LJ medium. Results: For rifampicin, concordance with proportion method was 90% by visual and 94% by RODU. Sensitivity and specificity was 86.8% and 100% respectively by visual method and 95.2% and 87.5% respectively by RODU. For Isoniazid, concordance was 94% and sensitivity and specificity was 94.7 and 91.7% respectively by both visual and RODU. Conclusions: MTT assay proved to be rapid and cheap method for performing drug sensitivity of M.tuberculosis

  16. Drug resistance following irradiation of RIF-1 tumors: Influence of the interval between irradiation and drug treatment

    International Nuclear Information System (INIS)

    Hopwood, L.E.; Davies, B.M.; Moulder, J.E.

    1990-01-01

    RIF-1 tumors contain a small number of cells (1 to 100 per 10(6) cells) that are resistant to 5-fluorouracil, methotrexate, or adriamycin. The frequency of drug-resistant cells among individual untreated tumors is highly variable. Radiation, delivered in vivo at doses of 3 to 12 Gy, increases the frequency of methotrexate- and 5-fluorouracil-resistant cells, but not the frequency of adriamycin-resistant cells. The magnitude of induction of 5-fluorouracil and methotrexate resistance shows a complex dependence on the radiation dose and on the interval between irradiation and assessment of drug resistance. For a dose of 3 Gy, induced 5-fluorouracil and methotrexate resistance is seen only after an interval of 5 to 7 days, whereas for a dose of 12 Gy, high levels of induced resistance are observed 1 to 3 days after irradiation. The maximum absolute risk for induction of resistance is 4 per 10(4) cells per Gy for methotrexate, and 3 per 10(6) cells per Gy for 5-fluorouracil. These results indicate that tumor hypoxia may play a role in the increased levels of drug resistance seen after irradiation, and that both genetic and environmental factors may influence radiation-induction of drug resistance. These studies provide essential data for models of the development of tumor drug resistance, and imply that some of the drug resistance seen when chemotherapy follows radiotherapy may be caused by radiation-induced drug resistance

  17. Drug resistance patterns of acinetobacter baumannii in makkah, saudi arabia

    International Nuclear Information System (INIS)

    Khan, M.A.; Ashshi, A.M.; Mahomed, M.F.

    2012-01-01

    Background: Acinetobacter baumannii causes infections of respiratory, urinary tract, blood stream and surgical sites. Its clinical significance has increased due to its rapidly developing resistance to major groups of antibiotics used for its treatment. There is limited data available on antimicrobial susceptibility of A. baumannii from Saudi Arabia. Objectives: To determine the patterns of drug resistance of Acinetobacter baumannii and predisposing factors for its acquisition.Subjects and Methods: In this descriptive study, 72 hospitalized patients infected with A baumannii were studied. The clinical and demographic data of the patients were collected using a predesigned questionnaire. Isolation and identification of A.baumannii from all clinical specimens were done using standard microbiological methods. Antibiotic susce ptibility testing was performed by disk diffusion method recommended by Clinical Laboratory Standards Institute. Results: Majority of the isolates (61.1%) were from respiratory tract infections. A.baumannii isolates showed high drug resistance to piperacil lin (93.1%), aztreonam (80.5%), ticarcillin, ampicillin, and tetracycline (76.4%, each) and cefotaxime (75%). Only amikacin showed low rate of resistance compared to other antibiotics (40.3%). About 36% patients had some underlying diseases with diabetes mellitus (11%) being the predominant underlying disease. Conclusions: High antimicrobial resistance to commonly used antibiotics was seen against A.baumannii isolates. Only amikacin was most effective against it. (author)

  18. The Use of Genomics in Microbiology: From Vaccines to Drug Resistance

    KAUST Repository

    Hill-Cawthorne, Grant A.

    2015-05-01

    develop a more targeted public health approach to tuberculosis, in particular how antimycobacterial drug resistance evolves within a population and how not all clades of Mycobacterium tuberculosis should be treated the same. Whole genome sequencing clearly has a lot to offer the fields of microbiology and communicable disease control. The next step is in translating its use into public health policy and ensuring that global approaches are unified to best benefit the populations served.

  19. Personalized Cancer Medicine: Molecular Diagnostics, Predictive biomarkers, and Drug Resistance

    Science.gov (United States)

    Gonzalez de Castro, D; Clarke, P A; Al-Lazikani, B; Workman, P

    2013-01-01

    The progressive elucidation of the molecular pathogenesis of cancer has fueled the rational development of targeted drugs for patient populations stratified by genetic characteristics. Here we discuss general challenges relating to molecular diagnostics and describe predictive biomarkers for personalized cancer medicine. We also highlight resistance mechanisms for epidermal growth factor receptor (EGFR) kinase inhibitors in lung cancer. We envisage a future requiring the use of longitudinal genome sequencing and other omics technologies alongside combinatorial treatment to overcome cellular and molecular heterogeneity and prevent resistance caused by clonal evolution. PMID:23361103

  20. Drug membrane interaction and the importance for drug transport, distribution, accumulation, efficacy and resistance.

    Science.gov (United States)

    Seydel, J K; Coats, E A; Cordes, H P; Wiese, M

    1994-10-01

    Some aspects of drug membrane interaction and its influence on drug transport, accumulation, efficacy and resistance have been discussed. The interactions manifest themselves macroscopically in changes in the physical and thermodynamic properties of "pure membranes" or bilayers. As various amounts of foreign molecules enter the membrane, in particular the main gel to liquid crystalline phase transition can be dramatically changed. This may change permeability, cell-fusion, cell resistance and may also lead to changes in conformation of the embedded receptor proteins. Furthermore, specific interactions with lipids may lead to drug accumulation in membranes and thus to much larger concentrations at the active site than present in the surrounding water phase. The lipid environment may also lead to changes in the preferred conformation of drug molecules. These events are directly related to drug efficacy. The determination of essential molecular criteria for the interaction could be used to design new and more selective therapeutics. This excursion in some aspects of drug membrane interaction underlines the importance of lipids and their interaction with drug molecules for our understanding of drug action, but this is not really a new thought but has been formulated in 1884 by THUDICUM: "Phospholipids are the centre, life and chemical soul of all bioplasm whatsoever, that of plants as well as of animals".