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Mem. Inst. Oswaldo Cruz ; 115: e200055, 2020. tab, graf
Article in English | LILACS, SES-SP | ID: biblio-1135234


BACKGROUND Tuberculosis (TB) is an infectious disease caused by the bacterium Mycobacterium tuberculosis, and the number of new cases of multidrug resistant TB (MDR-TB), pre extensively drug-resistant TB (pre-XDR-TB) and extensively drug-resistant TB (XDR-TB) has increased considerably worldwide. OBJECTIVES Herein, using 156 M. tuberculosis isolates from 106 patients previously classified as MDR or pre-XDR or XDR isolates, we investigated the genetic mutation profiles associated with phenotypic resistances in patients with MDR-TB, pre-XDR-TB and XDR-TB, treatment outcomes and resistance evolution. METHODS Molecular analyses were performed by partial sequencing of the rpoB, katG, gyrA, gyrB, rrs genes and analysis of the fabG-inhA promoter region. Clinical, epidemiologic and demographic data were obtained from the TB Notification database system of São Paulo (TB-WEB) and the Information System for Special Tuberculosis Treatments (SITE-TB). FINDINGS Drug resistance was attributed to previously known mutations and a novel Asp449Val mutation in gyrB was observed in four isolates from the same patient. Ten patients had more than one isolate evaluated and eight of these patients displayed resistance progression. MAIN CONCLUSIONS The present study is the first to report the frequency of mutations related to second-line drug resistance in MDR-TB, pre-XDR-TB and XDR-TB isolates. The results could lead to the improvement of available technologies for the rapid detection of drug resistant TB.

Humans , Male , Female , Adolescent , Adult , Young Adult , Tuberculosis, Multidrug-Resistant/microbiology , Drug Resistance, Multiple, Bacterial/genetics , Mutation/genetics , Mycobacterium tuberculosis/drug effects , Mycobacterium tuberculosis/genetics , Antitubercular Agents/pharmacology , Socioeconomic Factors , Brazil , Microbial Sensitivity Tests , Extensively Drug-Resistant Tuberculosis/microbiology , Middle Aged , Mycobacterium tuberculosis/isolation & purification
Einstein (Säo Paulo) ; 18: eAO4620, 2020. tab
Article in English | LILACS | ID: biblio-1039737


ABSTRACT Objective To determine the occurrence of anti-tuberculosis drug resistance and its association with sociodemographic and clinical characteristics of patients in a referral hospital. Methods This was a cross-sectional study based on data from patients who had mycobacterial culture identified and defined antimicrobials sensitivity profile (June 2014 to February 2016). The descriptive statistical analysis and Fisher's exact test were used to compare proportions. Results The study included 104 patients who had positive results for Mycobacterium tuberculosis . Bacilloscopy had high positivity (93.3%). A total of 15 patients (14.4%) had resistant strains and six (5.6%) multidrug-resistant. The sociodemographic and clinical characteristics were not related with resistance. Conclusion This study contributed to further the understandings about the tuberculosis patients' profile, the study also served as a tool for development of specific public policies. Patients diagnosed with resistant tuberculosis must be under greater supervision.

RESUMO Objetivo Verificar a ocorrência de resistência a fármacos antituberculose e a associação com características sociodemográficas e clínicas de pacientes de um hospital referência. Métodos Estudo transversal, com dados de pacientes que tiveram a cultura de micobactérias identificada e o respectivo perfil de sensibilidade aos antimicrobianos definido (junho de 2014 a fevereiro de 2016). Foram realizados a análise estatística descritiva e o teste exato de Fisher, para comparação de proporções. Resultados O estudo envolveu 104 pacientes, e todos tiveram resultados para Mycobacterium tuberculosis . A baciloscopia atingiu alta positividade (93,3%), e 15 pacientes (14,4%) apresentaram linhagens resistentes, sendo 6 (5,6%) multirresistentes. As características sociodemográficas e clínicas não foram associadas à resistência. Conclusão A pesquisa permitiu conhecer melhor o perfil dos pacientes com tuberculose e constitui ferramenta para elaboração de políticas públicas específicas. Os pacientes diagnosticados com tuberculose resistente devem ser submetidos à maior supervisão.

Humans , Male , Female , Adolescent , Adult , Aged , Young Adult , Referral and Consultation/statistics & numerical data , Tuberculosis, Multidrug-Resistant/epidemiology , Brazil/epidemiology , Microbial Sensitivity Tests , Demography , Prevalence , Cross-Sectional Studies , Tuberculosis, Multidrug-Resistant/microbiology , Sex Distribution , Age Distribution , Middle Aged , Mycobacterium tuberculosis/isolation & purification
Braz. arch. biol. technol ; 63: e20190179, 2020. tab, graf
Article in English | LILACS | ID: biblio-1132181


Abstract (1) Background: The Commercial Kit SIRE Nitratase® PlastLabor, is a drug susceptibility test kit used to detect Mycobacterium tuberculosis resistance to first-line TB treatment drugs. The present study aimed at evaluating its performance in a multicenter study. (2) Methods: To determine its accuracy, the proportion methods in Lowenstein Jensen medium or the BACTECTMMGITTM960 system was used as a gold standard. (3) Results: The study revealed that the respective accuracies of the kit with 190 M. tuberculosis clinical isolates, using the proportion methods in Lowenstein Jensen medium or BACTECTMMGITTM960 system as a gold standard, were 93.9% and 94.6%, 96.9% and 94.6%, 98.0% and 97.8%, and 98.0% and 98.9%, for streptomycin, isoniazid, rifampicin, and ethambutol, respectively. (4) Conclusion: Thus, the kit can rapidly screen resistance to streptomycin, isoniazid, rifampicin, and ethambutol. Additionally, it does not require sophisticated equipment; hence, it can be easily used in the laboratories of low and middle income countries.

Humans , Tuberculosis, Multidrug-Resistant/microbiology , Antibiotics, Antitubercular/pharmacology , Mycobacterium tuberculosis/isolation & purification , Mycobacterium tuberculosis/drug effects , Microbial Sensitivity Tests , Multicenter Studies as Topic , Sensitivity and Specificity , Tuberculosis, Multidrug-Resistant/drug therapy , Antibiotics, Antitubercular/classification
J. bras. pneumol ; 45(2): e20180128, 2019. tab, graf
Article in English | LILACS | ID: biblio-1002440


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

RESUMO Objetivo: Avaliar o diagnóstico rápido de tuberculose multirresistente, utilizando um teste comercial de sondas em linha (LPA-plus), na rotina de um laboratório de referência de tuberculose. Métodos: O teste LPA-plus foi avaliado prospectivamente em 341 isolados simultaneamente submetidos ao teste de suscetibilidade aos antimicrobianos em meio líquido, pelo sistema automatizado. Resultados: Entre os 303 resultados fenotipicamente válidos, nenhum foi genotipicamente falso suscetível à rifampicina (13/13; 100% de sensibilidade). Dois isolados sensíveis à rifampicina apresentavam mutações no gene rpoB (288/290; especificidade de 99,3%), as quais, no entanto, não são associadas à resistência a rifampicina. O LPA-plus não identificou resistência à isoniazida em três isolados fenotipicamente resistentes (23/26; 88,5% de sensibilidade) e detectou todos os isolados sensíveis à isoniazida (277/277; especificidade de 100%). Entre os 38 (11%) resultados fenotípicos inválidos, o LPA-plus identificou 31 isolados sensíveis à rifampicina e à isoniazida, um resistente à isoniazida e seis como micobactérias não tuberculosas. Conclusões: O LPA-plus mostrou excelente concordância (≥91%) e acurácia (≥99%). Sua implementação pode acelerar o diagnóstico da tuberculose multirresistente, produzir número significativamente maior de resultados válidos do que o teste fenotípico de suscetibilidade aos antimicrobianos e fornecer informações adicionais sobre o nível de resistência aos fármacos.

Humans , Male , Female , Infant , Child, Preschool , Child , Adolescent , Adult , Middle Aged , Aged , Aged, 80 and over , Young Adult , Tuberculosis, Multidrug-Resistant/diagnosis , Molecular Diagnostic Techniques/methods , Phenotype , Rifampin/pharmacology , Time Factors , DNA, Bacterial , Microbial Sensitivity Tests , Prospective Studies , Reproducibility of Results , Sensitivity and Specificity , Tuberculosis, Multidrug-Resistant/microbiology , Nucleic Acid Amplification Techniques/methods , Early Diagnosis , Isoniazid/pharmacology , Mycobacterium tuberculosis/isolation & purification , Mycobacterium tuberculosis/drug effects , Antitubercular Agents/pharmacology
Rev. Soc. Bras. Med. Trop ; 52: e20190257, 2019. tab, graf
Article in English | LILACS | ID: biblio-1057252


Abstract INTRODUCTION Mozambique is one of three countries with high prevalence of tuberculosis (TB), TB/human immunodeficiency virus coinfection, and multidrug-resistant TB. We aimed to describe Mycobacterium tuberculosis spoligotypes circulating among drug resistant (DR) strains from Beira, Mozambique comparing them with genotypes in the country. METHODS: We performed spoligotyping of 79 M. tuberculosis suspected of DR-TB compared all spoligotype patterns published on the international database and PubMed. RESULTS: Both in Beira and Mozambique (n=578), the main clades were Latin-American-Mediterranean, East-African-Indian, Beijing and T, with no extensively DR TB cases. CONCLUSIONS: Beira and Mozambique share the same population genetic structure of M. tuberculosis.

Humans , Genetic Variation/genetics , Tuberculosis, Multidrug-Resistant/microbiology , Mycobacterium tuberculosis/genetics , Phylogeny , Bacterial Typing Techniques , Genotype , Mozambique , Mutation/genetics
Braz. j. infect. dis ; 22(4): 305-310, July-Aug. 2018. tab, graf
Article in English | LILACS | ID: biblio-974220


ABSTRACT Objectives To determine the main predictors of death in multidrug-resistant (MDRTB) patients from Brazil. Design Retrospective cohort study, a survival analysis of patients treated between 2005 and 2012. Results Of 3802 individuals included in study, 64.7% were men, mean age was 39 (1-93) years, and 70.3% had bilateral pulmonary disease. Prevalence of human immunodeficiency virus (HIV) was 8.3%. There were 479 (12.6%) deaths. Median survival time was 1452 days (4 years). Factors associated with increased risk of death were age greater than or equal to 60 years (hazard rate [HR] = 1.6, confidence interval [CI] = 1.15-2.2), HIV co-infection (HR = 1.46; CI = 1.05-1.96), XDR resistance pattern (HR = 1.74, CI = 1.05-2.9), beginning of treatment after failure (HR = 1.72, CI = 1.27-2.32), drug abuse (HR = 1.64, CI = 1.22-2.2), resistance to ethambutol (HR = 1.30, CI = 1.06-1.6) or streptomycin (HR = 1.24, CI = 1.01-1.51). Mainly protective factors were presence of only pulmonary disease (HR = 0.57, CI = 0.35-0.92), moxifloxacin use (HR = 0.44, CI = 0.25-0.80), and levofloxacin use (HR = 0.75; CI = 0.60-0.94). Conclusion A more comprehensive approach is needed to manage MDRTB, addressing early diagnostic, improving adhesion, and comorbidities, mainly HIV infection and drug abuse. The latest generation quinolones have an important effect in improving survival in MDRTB.

Humans , Male , Female , Infant , Child, Preschool , Child , Adolescent , Adult , Middle Aged , Aged , Aged, 80 and over , Young Adult , HIV Infections/microbiology , HIV Infections/epidemiology , Tuberculosis, Multidrug-Resistant/mortality , Brazil/epidemiology , Ofloxacin/therapeutic use , Survival Analysis , Survival Rate/trends , Retrospective Studies , Cohort Studies , Cause of Death , Tuberculosis, Multidrug-Resistant/microbiology , Quinolones/therapeutic use , Educational Status , Coinfection/etiology , Antitubercular Agents/therapeutic use
Rev. Soc. Bras. Med. Trop ; 51(2): 234-236, Mar.-Apr. 2018. graf
Article in English | LILACS | ID: biblio-1041454


Abstract INTRODUCTION The teste rápido molecular para tuberculose (TRM-TB) was introduced in 2014 in Brazil for tuberculosis screening. However, its role in adolescents in Brazil has not been studied. METHODS A descriptive study of adolescents with suspected tuberculosis using National Laboratory software. RESULTS Of 852 (15.4%) suspected cases, 131 were positive by TRM-TB and 2% were resistant to rifampicin. Among TRM-TB-positive cases, 105 (91.4%) were culture-positive. Sixty-four of 96 samples were sensitive to rifampicin by TRM-TB; 11 were resistant to other drugs by drug sensitivity test (DST). CONCLUSIONS Among suspected cases, 16% were diagnosed by TRM-TB, of which 17% were drug-resistant by DST.

Humans , Child , Adolescent , Rifampin/pharmacology , Streptomycin/pharmacology , Tuberculosis, Multidrug-Resistant/diagnosis , Isoniazid/pharmacology , Antibiotics, Antitubercular/pharmacology , Mycobacterium tuberculosis/drug effects , Microbial Sensitivity Tests , Cross-Sectional Studies , Tuberculosis, Multidrug-Resistant/microbiology , Tuberculosis, Multidrug-Resistant/drug therapy , Genotype , Mycobacterium tuberculosis/isolation & purification , Mycobacterium tuberculosis/genetics
Braz. j. microbiol ; 48(4): 785-790, Oct.-Dec. 2017. tab, graf
Article in English | LILACS | ID: biblio-889167


ABSTRACT Early diagnosis of tuberculosis is of major clinical importance. Among 4733 clinical specimens collected from 3363 patients and subjected to Ziehl-Neelsen microscopy, 4109 were inoculated onto Löwenstein-Jensen slants and 3139 in Bactec/9000MB. Polymerase Chain Reaction (PCR) was performed in 3139 specimens, whereas, a genotypic assay was directly applied in 93 Mycobacterium tuberculosis complex PCR-positive for isoniazid and rifampicin resistance detection specimens (GenoType MTBDRplus). Recovered M. tuberculosis isolates (64) as well as, 21 more sent from Regional Hospitals were tested for antimycobacterial resistance with a phenotypic (manual MGIT-SIRE) and a genotypic assay (GenoType MTBDRplus). PCR in the clinical specimens showed excellent specificity (97.4%) and accuracy (96.8%), good sensitivity (70.4%), but low positive predictive value (40.3%). MGIT-SIRE performed to M. tuberculosis did not confer a reliable result in 16 isolates. Of the remaining 69 isolates, 15 were resistant to streptomycin, seven to isoniazid, seven to ethambutol and five to rifampicin. GenoType MTBDRplus correctly detected isoniazid (seven) and rifampicin-resistant M. tuberculosis strains (five), showing an excellent performance overall (100%). Susceptibility results by the molecular assay applied directly to clinical specimens were identical to those obtained from recovered isolates of the corresponding patients. Combining molecular and conventional methods greatly contribute to early diagnosis and accurate susceptibility testing of tuberculosis.

Humans , Culture Techniques/methods , Molecular Diagnostic Techniques/methods , Mycobacterium tuberculosis/isolation & purification , Tuberculosis, Multidrug-Resistant/diagnosis , Tuberculosis, Pulmonary/diagnosis , Antitubercular Agents/pharmacology , Culture Techniques/economics , Drug Resistance, Bacterial , Genotype , Microbial Sensitivity Tests , Molecular Diagnostic Techniques/economics , Mycobacterium tuberculosis/drug effects , Mycobacterium tuberculosis/genetics , Mycobacterium tuberculosis/growth & development , Tuberculosis, Multidrug-Resistant/drug therapy , Tuberculosis, Multidrug-Resistant/microbiology , Tuberculosis, Pulmonary/drug therapy , Tuberculosis, Pulmonary/microbiology
Mem. Inst. Oswaldo Cruz ; 112(11): 769-774, Nov. 2017. tab
Article in English | LILACS | ID: biblio-894852


BACKGROUND The accurate detection of multidrug-resistant tuberculosis (MDR-TB) is critical for the application of appropriate patient treatment and prevention of transmission of drug-resistant Mycobacterium tuberculosis isolates. The goal of this study was to evaluate the correlation between phenotypic and molecular techniques for drug-resistant tuberculosis diagnostics. Molecular techniques used were the line probe assay genotype MTBDRplus and the recently described tuberculosis-spoligo-rifampin-isoniazid typing (TB-SPRINT) bead-based assay. Conventional drug susceptibility testing (DST) was done on a BACTECTM MGIT 960 TB. METHOD We studied 80 M. tuberculosis complex (MTC) clinical isolates from Minas Gerais state, of which conventional DST had classified 60 isolates as MDR and 20 as drug susceptible. FINDINGS Among the 60 MDR-TB isolates with MGIT as a reference, sensitivity, specificity, accuracy, and kappa for rifampicin (RIF) resistance using TB-SPRINT and MTBDRplus, were 96.7% versus 93.3%, 100.0% versus 100.0%, 97.5% versus 95.0% and 0.94 versus 0.88, respectively. Similarly, the sensitivity, specificity, accuracy, and kappa for isoniazid (INH) resistance were 85.0% and 83.3%, 100.0% and 100.0%, 88.8% and 87.5% and 0.74 and 0.71 for both tests, respectively. Finally, the sensitivity, specificity, accuracy, and kappa for MDR-TB were 85.0% and 83.3%, 100.0% and 100.0%, 88.8% and 87.5% and 0.74 and 0.71 for both tests, respectively. MAIN CONCLUSIONS Both methods exhibited a good correlation with the conventional DST. We suggest estimating the cost-effectiveness of MTBDRplus and TB-SPRINT in Brazil.

Humans , Bacteriological Techniques/methods , Tuberculosis, Multidrug-Resistant/diagnosis , Tuberculosis, Multidrug-Resistant/microbiology , Mycobacterium tuberculosis/genetics , Brazil , Reproducibility of Results , Sensitivity and Specificity , Pathology, Molecular , Genotype
Mem. Inst. Oswaldo Cruz ; 112(6): 396-403, June 2017. tab
Article in English | LILACS | ID: biblio-841801


BACKGROUND To cope with the emergence of multidrug-resistant tuberculosis (MDR-TB), new molecular methods that can routinely be used to screen for a wide range of drug resistance related genetic markers in the Mycobacterium tuberculosis genome are urgently needed. OBJECTIVE To evaluate the performance of multiplex ligaton-dependent probe amplification (MLPA) against Genotype® MTBDRplus to detect resistance to isoniazid (INHr) and rifampicin (RIFr). METHOD 96 culture isolates characterised for identification, drug susceptibility testing (DST) and sequencing of rpoB, katG, and inhA genes were evaluated by the MLPA and Genotype®MTBDRplus assays. RESULTS With sequencing as a reference standard, sensitivity (SE) to detect INHr was 92.8% and 85.7%, and specificity (SP) was 100% and 97.5%, for MLPA and Genotype®MTBDRplus, respectively. In relation to RIFr, SE was 87.5% and 100%, and SP was 100% and 98.8%, respectively. Kappa value was identical between Genotype®MTBDRplus and MLPA compared with the standard DST and sequencing for detection of INHr [0.83 (0.75-0.91)] and RIFr [0.93 (0.88-0.98)]. CONCLUSION Compared to Genotype®MTBDRplus, MLPA showed similar sensitivity to detect INH and RIF resistance. The results obtained by the MLPA and Genotype®MTBDRplus assays indicate that both molecular tests can be used for the rapid detection of drug-resistant TB with high accuracy. MLPA has the added value of providing information on the circulating M. tuberculosis lineages.

Humans , DNA, Bacterial/genetics , Tuberculosis, Multidrug-Resistant/microbiology , Drug Resistance, Multiple, Bacterial/drug effects , Drug Resistance, Multiple, Bacterial/genetics , Isoniazid/pharmacology , Antibiotics, Antitubercular/pharmacology , Mycobacterium tuberculosis/drug effects , Mycobacterium tuberculosis/genetics , Drug Resistance , Anti-Bacterial Agents
Mem. Inst. Oswaldo Cruz ; 111(7): 454-459, tab, graf
Article in English | LILACS | ID: lil-787556


In this study we evaluated the crystal violet decolorization assay (CVDA) for detection of minimum inhibitory concentration (MIC) of antituberculosis drugs. 53 isolates were tested in this study and 13 of them were multidrug resistant (MDR) isolates. The antibiotics concentrations were 2-0.06 mg/L for isoniazid (INH) and rifampicin (RIF) and were 16-0.25 mg/L for streptomycin (STM) and ethambutol (EMB). Crystal violet (CV-25 mg/L) was added into the microwells on the seventh day of incubation and incubation was continued until decolorization. Decolorization of CV was the predictor of bacterial growth. Overall agreements for four drugs were detected as 98.1%, and the average time was detected as 9.5 ± 0.89 day after inoculation. One isolate for INH and two isolates for STM were determined resistant in the reference method, but susceptible by the CVDA. One isolate was susceptible to EMB by the reference method, but resistant by the CVDA. All results were concordant for RIF. This study shows that CVDA is a rapid, reliable and suitable for determination of MIC values of Mycobacterium tuberculosis. And it can be used easily especially in countries with limited-sources.

Humans , Antitubercular Agents/pharmacology , Mycobacterium tuberculosis/drug effects , Antitubercular Agents/administration & dosage , Biological Assay , Drug Resistance, Multiple, Bacterial/drug effects , Ethambutol/administration & dosage , Ethambutol/pharmacology , Gentian Violet/chemistry , Indicators and Reagents/chemistry , Isoniazid/administration & dosage , Isoniazid/pharmacology , Microbial Sensitivity Tests/methods , Mycobacterium tuberculosis/growth & development , Rifampin/administration & dosage , Rifampin/pharmacology , Streptomycin/administration & dosage , Streptomycin/pharmacology , Tuberculosis, Multidrug-Resistant/microbiology
Braz. j. infect. dis ; 20(2): 166-172, Mar.-Apr. 2016. tab, graf
Article in English | LILACS | ID: lil-780813


Abstract Multidrug-resistant tuberculosis (MDRTB) is a serious world health problem that limits public actions to control tuberculosis, because the most used anti-tuberculosis first-line drugs fail to stop mycobacterium spread. Consequently, a quick detection through molecular diagnosis is essential to reduce morbidity and medical costs. Despite the availability of several molecular-based commercial-kits to diagnose multidrug-resistant tuberculosis, their diagnostic value might diverge worldwide since Mycobacterium tuberculosis genetic variability differs according to geographic location. Here, we studied the predictive value of four common mycobacterial mutations in strains isolated from endemic areas of Brazil. Mutations were found at the frequency of 41.9% for katG, 25.6% for inhA, and 69.8% for rpoB genes in multidrug-resistant strains. Multimarker analysis revealed that combination of only two mutations (“katG/S315T + rpoB/S531L”) was a better surrogate of multidrug-resistant tuberculosis than single-marker analysis (86% sensitivity vs. 62.8%). Prediction of multidrug-resistant tuberculosis was not improved by adding a third or fourth mutation in the model. Therefore, rather than using diagnostic kits detecting several mutations, we propose a simple dual-marker panel to detect multidrug-resistant tuberculosis, with 86% sensitivity and 100% specificity. In conclusion, this approach (previous genetic study + analysis of only prevalent markers) would considerably decrease the processing costs while retaining diagnostic accuracy.

Humans , Bacterial Proteins/genetics , DNA-Directed RNA Polymerases/genetics , Catalase/genetics , Drug Resistance, Multiple, Bacterial/genetics , Isoniazid/pharmacology , Antitubercular Agents/pharmacology , Rifampin/pharmacology , DNA, Bacterial , Microbial Sensitivity Tests , Genetic Markers , Polymerase Chain Reaction , Predictive Value of Tests , Sensitivity and Specificity , Tuberculosis, Multidrug-Resistant/microbiology , Genotype , Mutation/genetics , Mycobacterium tuberculosis/drug effects , Mycobacterium tuberculosis/genetics
Braz. j. infect. dis ; 20(1): 41-47, Jan.-Feb. 2016. tab, graf
Article in English | LILACS | ID: lil-776468


Abstract Background Fluoroquinolones are the backbone of multidrug resistant tuberculosis treatment regimens. Despite the high burden of multidrug resistant tuberculosis in the country, little is known about drug resistance patterns, prevalence, and predictors of fluoroquinolones resistance among multidrug resistant tuberculosis patients from Pakistan. Objective To evaluate drug resistance patterns, prevalence, and predictors of fluoroquinolones resistance in multidrug resistant tuberculosis patients. Methods This was a cross-sectional study conducted at a programmatic management unit of drug resistant tuberculosis, Lady Reading Hospital Peshawar, Pakistan. Two hundred and forty-three newly diagnosed multidrug resistant tuberculosis patients consecutively enrolled for treatment at study site from January 1, 2012 to July 28, 2013 were included in the study. A standardized data collection form was used to collect patients’ socio-demographic, microbiological, and clinical data. SPSS 16 was used for data analysis. Results High degree of drug resistance (median 5 drugs, range 2–8) was observed. High proportion of patients was resistant to all five first-line anti-tuberculosis drugs (62.6%), and more than half were resistant to second line drugs (55.1%). The majority of the patients were ofloxacin resistant (52.7%). Upon multivariate analysis previous tuberculosis treatment at private (OR = 1.953, p = 0.034) and public private mix (OR = 2.824, p = 0.046) sectors were predictors of ofloxacin resistance. 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.

Adolescent , Adult , Child , Female , Humans , Male , Middle Aged , Young Adult , Antitubercular Agents/pharmacology , Fluoroquinolones/pharmacology , Mycobacterium tuberculosis/drug effects , Tuberculosis, Multidrug-Resistant/microbiology , Cross-Sectional Studies , Microbial Sensitivity Tests , Pakistan , Prevalence
Braz. j. med. biol. res ; 48(8): 759-764, 08/2015. tab, graf
Article in English | LILACS | ID: lil-753059


Resistance to Mycobacterium tuberculosis is a reality worldwide, and its diagnosis continues to be difficult and time consuming. To face this challenge, the World Health Organization has recommended the use of rapid molecular tests. We evaluated the routine use (once a week) of a line probe assay (Genotype MTBDRplus) for early diagnosis of resistance and for assessment of the main related risk factors over 2 years. A total of 170 samples were tested: 15 (8.8%) were resistant, and multidrug resistance was detected in 10 (5.9%). The sensitivity profile took 3 weeks (2 weeks for culture and 1 week for rapid testing). Previous treatment for tuberculosis and the persistence of positive acid-fast smears after 4 months of supervised treatment were the major risk factors observed. The use of molecular tests enabled early diagnosis of drug-resistant bacilli and led to appropriate treatment of the disease. This information has the potential to interrupt the transmission chain of resistant M. tuberculosis.

Humans , Male , Female , Adult , DNA, Bacterial/genetics , Genotyping Techniques/methods , Mycobacterium tuberculosis/genetics , Tuberculosis, Multidrug-Resistant/diagnosis , Antitubercular Agents/pharmacology , Bacteriological Techniques/methods , Brazil , Early Diagnosis , Isoniazid/pharmacology , Microbial Sensitivity Tests , Mycobacterium tuberculosis/drug effects , Rifampin/pharmacology , Risk Factors , Sensitivity and Specificity , Tuberculosis, Multidrug-Resistant/microbiology
Mem. Inst. Oswaldo Cruz ; 110(5): 618-623, Aug. 2015. tab, ilus
Article in English | LILACS | ID: lil-755891


Drug resistance is a global threat and one of the main contributing factors to tuberculosis (TB) outbreaks. The goal of this study was to analyse the molecular profile of multidrug-resistant TB (MDR-TB) in the state of Santa Catarina in southern Brazil. Fifty-three MDR Mycobacterium tuberculosisclinical isolates were analysed by spoligotyping and a partial region of therpoB gene, which is associated with rifampicin resistance (RMP-R), was sequenced. Some isolates were also distinguished by their mycobacterial interspersed repetitive units (MIRU). S531L was the most prevalent mutation found within rpoBin RMP-R isolates (58.5%), followed by S531W (20.8%). Only two MDR isolates showed no mutations withinrpoB. Isolates of the Latin American Mediterranean (LAM) family were the most prevalent (45.3%) found by spoligotyping, followed by Haarlem (9.4%) and T (7.5%) families. SIT106 was found in 26.4% of isolates and all SIT106 isolates typed by MIRU-12 (5 out of 14) belong to MIT251. There was a high correlation between the S531W mutation and the LAM family mainly because all SIT2263 (LAM9) isolates carry this mutation. Among isolates with the S531W mutation in rpoB MIRU demonstrates a cluster formed by four isolates (SIT2263 and MIT163) and very similar profiles were observed between eight of the nine isolates. Better characterisation of TB isolates may lead to new ways in which to control and treat TB in this region of Brazil.


Adult , Female , Humans , Male , Antitubercular Agents/pharmacology , DNA, Bacterial , Drug Resistance, Multiple, Bacterial/genetics , Mutation/genetics , Mycobacterium tuberculosis/drug effects , Tuberculosis, Multidrug-Resistant/microbiology , Bacterial Typing Techniques , Brazil , Bacterial Proteins/genetics , Genotype , Polymorphism, Restriction Fragment Length , Sequence Analysis, DNA
Rev. chil. infectol ; 32(4): 382-386, ago. 2015. tab
Article in Spanish | LILACS | ID: lil-762634


This publication presents the results of the Chilean initial study of resistance to first line anti-tuberculous drugs. The study was carried out between 2011 and 2012 by the National Reference Laboratory of the Institute of Public Health, as part of the Drug Surveillance Resistance in tuberculosis (TB) promoted by the World Health Organization. Methodology: Cross-sectional study performed using cluster sampling, representative of the entire country as recommended by the World Health Organization. Susceptibility testing to isoniazid, rifampicin, streptomycin, ethambutol and pyrazinamide was performed through the proportion method or Wayne's enzymatic method, as appropriate. Results: 594 susceptibility tests were performed, showing an overall level of TB drug resistance of 8.6% and a prevalence of multidrug resistance of 1.3%. Indeed, the study showed a decrease in streptomycin resistance and an increase of isoniazid resistance in both mono-resistance and accumulated resistance compared to previous studies. No cases of mono-resistance to rifampicin were detected. Conclusion: An increased resistance to anti-TB drugs in Chile is observed, which despite being still low, is no less worrisome. Since 2014 the monitoring of drug resistance to TB is universally performed to avoid sub - diagnosis and treat each case according to the susceptibility profile.

Esta publicación presenta los resultados del estudio de resistencia inicial a fármacos anti-tuberculosos de primera línea realizado entre los años 2011 y 2012 en Chile por el Laboratorio de Referencia Nacional del Instituto de Salud Pública, estudio que forma parte de la vigilancia de la fármaco-resistencia en tuberculosis (TBC) promovida por la Organización Mundial de la Salud. Metodología: Estudio transversal realizado mediante un muestreo por conglomerado, representativo de todo el país según recomendaciones de la Organización Mundial de la Salud. Se realizó prueba de susceptibilidad a isoniacida, rifampicina, estreptomicina, etambutol y pirazinamida a través del método de las proporciones o método enzimático de Wayne según corresponda. Resultados: Se realizó test de susceptibilidad a 594 casos de TBC, observándose una resistencia inicial global de 8,6% y una prevalencia de multi-resistencia de 1,3%. Además destaca la caída en la resistencia a estreptomicina y el aumento de la resistencia a isoniacida, tanto en mono-resistencia como en resistencia acumulada para ambos fármacos comparada con los estudios anteriores. No se observaron casos de mono-resistencia a rifampicina. Conclusión. Se observa un aumento de la resistencia a fármacos anti-tuberculosos en Chile la que, a pesar de ser aún baja, no deja de ser preocupante. Desde el año 2014 la vigilancia de fármaco-resistencia para TBC se hace en forma universal, de modo de evitar el sub-diagnóstico y realizar un tratamiento de acuerdo al perfil de susceptibilidad de cada caso.

Humans , Antitubercular Agents/pharmacology , Drug Resistance, Multiple, Bacterial/drug effects , Mycobacterium tuberculosis/drug effects , Tuberculosis, Multidrug-Resistant/microbiology , Chile , Cross-Sectional Studies , Microbial Sensitivity Tests , Mycobacterium tuberculosis/classification , Sputum/microbiology
Article in English | IMSEAR | ID: sea-158400


Background & objectives: Tuberculosis is a major health problem in India, and the emergence of multidrug resistant (MDR) and extensively drug resistant (XDR) strains of Mycobacterium tuberculosis (Mtb) has further complicated the situation. Though several studies characterizing drug sensitive and drug resistant strains are available in literature, almost all studies are done on unrelated strains. Therefore, the objective of this study was to compare the proteomic data of four sequential isolates of Mtb from a single patient who developed MDR-TB during the course of anti-tuberculosis therapy (ATT). Methods: In this study, using two-dimensional (2D) gel electrophoresis and MALDI-TOF mass spectrometry, we compared and analyzed the cell lysate proteins of Mtb sequential clinical isolates from a patient undergoing anti-TB treatment. The mRNA expression levels of selected identified proteins were determined by quantitative real-time polymerase chain reaction (qRT-PCR). Results: The genotypes of all four isolates remained homologous, indicating no re-infection. The initial isolate (before treatment) was sensitive to all first-line drugs, but the consecutive isolates were found to be resistant to isoniazid (INH) and rifampicin (RIF) and developed mutations in the katG, inhA and rpoB. the intensities of 27 protein spots were found to be consistently overexpressed in INH and RIF resistant isolates. The most prominent and overexpressed proteins found during the development of drug resistance were GarA (Rv1827), wag31 (Rv2145c), Rv1437 and Rv2970c. Interpretation & conclusions: This preliminary proteomic study provides an insight about the proteins that are upregulated during drug resistance development. These upregulated proteins, identified here, could prove useful as immunodiagnostic and possibly drug resistant markers in future. However, more studies are required to confirm these findings.

Electrophoresis, Gel, Two-Dimensional , Humans , Male , Mycobacterium tuberculosis/analysis , Mycobacterium tuberculosis/drug effects , Mycobacterium tuberculosis/isolation & purification , Proteomics/methods , Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization , Tuberculosis, Multidrug-Resistant/microbiology , Tuberculosis, Pulmonary/drug therapy , Tuberculosis, Pulmonary/microbiology , Tuberculosis, Pulmonary/mortality
Biomédica (Bogotá) ; 34(supl.1): 108-113, abr. 2014. tab
Article in Spanish | LILACS | ID: lil-712427


Introducción. La vigilancia de la resistencia a medicamentos antituberculosos permite alertar sobre el hallazgo de aislamientos de Mycobacterium tuberculosis multirresistentes y extremadamente resistentes . Objetivo. Determinar los patrones de resistencia de los aislamientos de M. tuberculosis recuperados en Cuba entre los años 2010 y 2011 y demostrar el desempeño del Laboratorio Nacional de Referencia en la ejecución de las pruebas de sensibilidad. Materiales y métodos. Se realizó un estudio prospectivo longitudinal en el que se incluyeron 657 aislamientos de M. tuberculosis recibidos de todo el país. Se empleó el método de la nitrato reductasa para detectar resistencia a isoniacida y rifampicina, y el método de las proporciones para corroborar la resistencia a dichos medicamentos e investigar la sensibilidad a estreptomicina, etambutol, ofloxacina, kanamicina y capreomicina en aislamientos multirresistentes. Como parte del control de calidad externo de las pruebas de sensibilidad, se evaluaron dos paneles de cepas de M. tuberculosis . Resultados. En 95,69 % de los aislamientos recuperados de casos nuevos de tuberculosis y en 72,64 % de los recuperados de casos previamente tratados, se encontró sensibilidad a isoniacida y rifampicina, siendo la multirresistencia de 1,03 y 10,38 %, respectivamente. Se encontraron dos aislamientos extremadamente resistentes. Con la excepción del etambutol y la capreomicina, para todos los medicamentos la eficiencia fue de 100% en el control de calidad externo. Conclusiones. Se confirmó la baja prevalencia de aislamientos de M. tuberculosis multirresistentes en Cuba, resultado avalado por el excelente desempeño demostrado en el control de calidad externo de las pruebas de sensibilidad.

Introduction: Antituberculosis-drug resistance surveillance is very important to identify multidrug-resistant and extensively drug-resistant Mycobacterium tuberculosis isolates. Objective: To determine the prevalence of resistance in M. tuberculosis strains isolated between 2010 and 2011, and to demonstrate the laboratory performance in the external quality control of drug susceptibility testing. Materials and methods: A prospective longitudinal study was carried out to determine antituberculosis-drug resistance in 657 M. tuberculosis isolates obtained throughout the country. The nitrate reductase assay was used to detect resistance to isoniazid and rifampin. The proportion method was performed to confirm resistance to these drugs and to further investigate in multidrug-resistant isolates their susceptibility to streptomycin, ethambutol, ofloxacin, kanamycin and capreomycin. Additionally, as part of external quality control, susceptibility was evaluated in two M. tuberculosis strain panels. Results: In 95.69% of the isolates recovered from new tuberculosis cases, and in 72.64 % of isolates from previously treated patients we found susceptibility to isoniazid and rifampicin; multidrug resistance was 1,03 and 10.38%, respectively. We found two extensively resistant isolates. Except for ethambutol and capreomycin, the efficiency of all other drugs was 100% in the external quality control. Conclusion: The study confirmed the low prevalence of M. tuberculosis multidrug-resistant isolates in Cuba. This result was confirmed by the external quality control of drug susceptibility testing.

Humans , Antitubercular Agents/pharmacology , Drug Resistance, Bacterial , Mycobacterium tuberculosis/drug effects , Tuberculosis/microbiology , Clone Cells/drug effects , Cuba/epidemiology , Drug Resistance, Multiple, Bacterial , Isoniazid/pharmacology , Laboratories/statistics & numerical data , Microbial Sensitivity Tests/methods , Mycobacterium tuberculosis/isolation & purification , Population Surveillance , Prevalence , Prospective Studies , Rifampin/pharmacology , Tuberculosis, Multidrug-Resistant/epidemiology , Tuberculosis, Multidrug-Resistant/microbiology , Tuberculosis/epidemiology
J. bras. pneumol ; 40(2): 155-163, Mar-Apr/2014. tab, graf
Article in English | LILACS | ID: lil-709769


OBJECTIVE: To describe the prevalence of multidrug-resistant tuberculosis (MDR-TB) among tuberculosis patients in a major Brazilian city, evaluated via the Second National Survey on Antituberculosis Drug Resistance, as well as the social, demographic, and clinical characteristics of those patients. METHODS: Clinical samples were collected from tuberculosis patients seen between 2006 to 2007 at three hospitals and five primary health care clinics participating in the survey in the city of Porto Alegre, Brazil. The samples were subjected to drug susceptibility testing. The species of mycobacteria was confirmed using biochemical methods. RESULTS: Of the 299 patients included, 221 (73.9%) were men and 77 (27.3%) had a history of tuberculosis. The mean age was 36 years. Of the 252 patients who underwent HIV testing, 66 (26.2%) tested positive. The prevalence of MDR-TB in the sample as a whole was 4.7% (95% CI: 2.3-7.1), whereas it was 2.2% (95% CI: 0.3-4.2) among the new cases of tuberculosis and 12.0% (95% CI: 4.5-19.5) among the patients with a history of tuberculosis treatment. The multivariate analysis showed that a history of tuberculosis and a longer time to diagnosis were both associated with MDR-TB. CONCLUSIONS: If our results are corroborated by other studies conducted in Brazil, a history of tuberculosis treatment and a longer time to diagnosis could be used as predictors of MDR-TB. .

OBJETIVO: Descrever a prevalência de tuberculose multirresistente (TBMR) em pacientes com tuberculose em uma importante cidade brasileira através do II Inquérito Nacional de Resistência aos Fármacos Antituberculose, assim como as características sociais, demográficas e clínicas desses pacientes. MÉTODOS: De 2006 a 2007, amostras clínicas de pacientes de três hospitais e das cinco unidades básicas de saúde participantes do inquérito realizado em Porto Alegre foram coletadas e submetidas ao teste de sensibilidade aos fármacos. A confirmação das espécies de micobactérias ocorreu por métodos bioquímicos. RESULTADOS: Foram incluídos 299 pacientes. Desses, 221 (73,9%) eram homens e 77 (27,3%) tinham história de tuberculose. A idade média foi de 36 anos. Dos 252 pacientes testados para HIV, 66 (26,2%) estavam infectados. A prevalência da TBMR na amostra geral foi de 4,7% (IC95%: 2,3-7,1); enquanto essa foi de 2,2% (IC95%: 0,3-4,2) nos pacientes virgens de tratamento e de 12,0% (IC 95%: 4,5-19,5) naqueles com história de tratamento antituberculose. A análise multivariada mostrou que história de tuberculose e maior tempo para o diagnóstico associaram-se a TBMR. CONCLUSÕES: Caso esses resultados sejam confirmados em outros estudos no Brasil, a história de tratamento antituberculose e o maior tempo para o diagnóstico poderão ser utilizados como preditores de TBMR. .

Adult , Female , Humans , Male , Antitubercular Agents/therapeutic use , HIV Infections/epidemiology , Mycobacterium tuberculosis/drug effects , Tuberculosis, Multidrug-Resistant/epidemiology , Brazil/epidemiology , Drug Resistance, Bacterial , Mycobacterium tuberculosis/isolation & purification , Population Surveillance , Prevalence , Tuberculosis, Multidrug-Resistant/drug therapy , Tuberculosis, Multidrug-Resistant/microbiology , Urban Population
J. bras. pneumol ; 40(2): 142-147, Mar-Apr/2014. tab, graf
Article in English | LILACS | ID: lil-709771


OBJECTIVE: To determine the drug resistance profile of Mycobacterium tuberculosis in Mozambique. METHODS: We analyzed secondary data from the National Tuberculosis Referral Laboratory, in the city of Maputo, Mozambique, and from the Beira Regional Tuberculosis Referral Laboratory, in the city of Beira, Mozambique. The data were based on culture-positive samples submitted to first-line drug susceptibility testing (DST) between January and December of 2011. We attempted to determine whether the frequency of DST positivity was associated with patient type or provenance. RESULTS: During the study period, 641 strains were isolated in culture and submitted to DST. We found that 374 (58.3%) were resistant to at least one antituberculosis drug and 280 (43.7%) were resistant to multiple antituberculosis drugs. Of the 280 multidrug-resistant tuberculosis cases, 184 (65.7%) were in previously treated patients, most of whom were from southern Mozambique. Two (0.71%) of the cases of multidrug-resistant tuberculosis were confirmed to be cases of extensively drug-resistant tuberculosis. Multidrug-resistant tuberculosis was most common in males, particularly those in the 21-40 year age bracket. CONCLUSIONS: M. tuberculosis resistance to antituberculosis drugs is high in Mozambique, especially in previously treated patients. The frequency of M. tuberculosis strains that were resistant to isoniazid, rifampin, and streptomycin in combination was found to be high, particularly in samples from previously treated patients. .

OBJETIVO: Avaliar o perfil de resistência de Mycobacterium tuberculosis aos tuberculostáticos em Moçambique. MÉTODOS: Foram analisados dados secundários do Laboratório Nacional de Referência da Tuberculose, em Maputo, Moçambique, e do Laboratório Regional de Referência da Tuberculose, na Beira, Moçambique. Os dados foram relativos a amostras positivas à cultura e submetidas ao teste de sensibilidade aos tuberculostáticos de primeira linha durante o período de janeiro a dezembro de 2011. Os resultados do teste de sensibilidade foram analisados, e sua frequência foi comparada com o tipo de paciente e sua proveniência. RESULTADOS: Foram analisadas 641 cepas, isoladas em cultura e submetidas ao teste de sensibilidade. Das 641 cepas, 374 (58,3%) foram resistentes a pelo menos um tuberculostático e 280 (43,7%) revelaram-se multirresistentes. Dos 280 casos de tuberculose multirresistente, 184 (65,7%) eram pacientes com tratamento prévio, a maioria dos quais era oriunda da zona sul do país. Confirmou-se que 2 (0,71%) dos casos de tuberculose multirresistente eram casos de tuberculose extensivamente resistente a drogas. O sexo masculino foi o mais afetado, particularmente na faixa etária de 21 a 40 anos. CONCLUSÕES: A resistência de M. tuberculosis aos tuberculostáticos é elevada em Moçambique, especialmente em indivíduos com tratamento prévio. A resistência de M. tuberculosis à combinação de isoniazida, rifampicina e estreptomicina foi elevada, especialmente em amostras provenientes de indivíduos com tratamento prévio. .

Adolescent , Adult , Child , Child, Preschool , Female , Humans , Infant , Infant, Newborn , Male , Middle Aged , Young Adult , Antitubercular Agents/therapeutic use , Mycobacterium tuberculosis/drug effects , Tuberculosis, Multidrug-Resistant/drug therapy , Tuberculosis/drug therapy , Age Factors , Cross-Sectional Studies , Microbial Sensitivity Tests , Mozambique/epidemiology , Mycobacterium tuberculosis/isolation & purification , Sex Factors , Tuberculosis, Multidrug-Resistant/epidemiology , Tuberculosis, Multidrug-Resistant/microbiology , Tuberculosis/epidemiology