Introduction: GeneXpert MTB/RIF is a fully-automated diagnostic molecular test which simultaneously detects tuberculosis (TB) and rifampicin (RIF) drug resistance. The purpose of this study is to evaluate the performance of the GeneXpert MTB/RIF test for the detection of Mycobacterium tuberculosis complex (MTBC) in lymph node specimens and to show the place of Mycobacterium bovis as a major cause of TB lymphadenitis. Material and methods: This study was conducted simultaneously in the National Reference Laboratory for Mycobacteria of Ariana and the Central Laboratory of Sfax, from January to December 2013. In total, 174 lymph node specimens were processed simultaneously for Ziehl–Neelsen, auramine and immuno-histochemical staining. Conventional culture on both Lowenstein–Jensen and liquid medium (Bactec MGIT 960 BD system) and the new molecular-based GeneXpert MTB/RIF assay system were performed. Positive cultures were confirmed using molecular identification (Genotype MTBC Hain Lifescience). Results: Among the 174 samples tested, the GeneXpert detected the DNA of MTBC in 134 samples (77%). Standard bacteriological assays, including AFB microscopy and culture, were positive, respectively, in 41 (23.6%) and 79 (45.4%) specimens. M. bovis was isolated in 76% of positive cultures. GeneXpert sensitivity and specificity results were assessed according to smear and culture results, clinical and histological findings. The sensitivity and specificity of the Xpert assay were 87.5% (126/144) and 73.3%, respectively. Conclusion: The implementation of the GeneXpert MTB/RIF assay may dramatically improve the rapid diagnosis of lymph node TB.

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Objective/background: Many studies have suggested that sputum smear conversion after 2 months of antituberculosis treatment is an important determinant of treatment success and can be a predictor for relapse. The objective of this study is to determine the factors that influence sputum smear conversion after 2 months of treatment among pulmonary tuberculosis patients receiving treatment in the Institute of Respiratory Medicine in Kuala Lumpur, Malaysia. Methods: A total of 75 cases and 75 controls were interviewed, and their medical records were retrieved in order to extract the information needed. All analyses were conducted using SPSS version 17, and binary logistic regression analysis was used to determine the predictors of sputum smear nonconversion. Results: Results showed that the following factors were associated with sputum smear positivity after 2 months of intensive treatment: diabetes mellitus (p = .013, odds ratio [OR] = 2.59, 95% confidence interval [CI] 1.27–5.33), underweight body mass index (p = .025, OR = 1.67, 95% CI 0.80–3.49), nonadherent to tuberculosis treatment (p = .024, OR = 2.85, 95% CI 1.21–6.74), and previous history of tuberculosis (p = .043, OR = 2.53, 95% CI 1.09–5.83). Multivariable analysis identified diabetes mellitus (p = .003, OR = 4.01, 95% CI 1.61–9.96) as being independently associated with the risk of persistent sputum smear positivity after 2 months of intensive treatment. Conclusion: Based on the findings, identification of these factors is valuable in strengthening the management and treatment of tuberculosis in Malaysia in the future. This study emphasizes the importance of diabetes screening and integration of diabetic controls among tuberculosis patients in achieving better treatment outcome.

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Reactivation of Mycobacterium tuberculosis can occur in patients with latent tuberculosis (TB) with risk factors including chronic disease (i.e., malignancy). We herein describe the case of an immigrant from Hong Kong with lung cancer and no known TB disease who presents with reactivation of TB in the setting of chemotherapy and radiation therapy.

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Objective/background: The aim of this study is to determine the rate of hookworm infection among patients with pulmonary tuberculosis (TB) and to find out if there is a relation between hookworm infection and the therapeutic failure of pulmonary TB. Methods: We carried out a prospective, hospital-based study. The study included 231 naıve patients with pulmonary TB, consecutively. Patients were evaluated at the 4th month of therapy for persistence of Mycobacterium tuberculosis infection. All patients had clinical evaluation, laboratory investigations (including sputum culture and stool microscopic examination), and imaging studies (abdominal ultrasonography and chest radiography). Results: The study population mean age was 42.7±13.9 years old with 26.8% of them 40 years old or more. Out of 231 patients, 133 (57.6%) were men. Therapeutic failure rate of pulmonary TB was 29.4%. Hookworm infection was diagnosed among 16.5% of patients and 27.7% had diabetes mellitus (DM). Using multivariate analysis, it was found that age of 40 years or more (odds ratio [OR] 8.4; 95% confidence interval [CI] 1.7–41.3; p = .009), hookworm infection (OR 7.6; 95% CI 1.2–49.9; p = .034), and DM (OR 5.9; 1.2–28; p = .027) were independently associated with therapeutic failure of pulmonary TB among the study population with pulmonary TB. Conclusion: In conclusion, the rate of therapeutic failure of pulmonary TB is high. Besides older age and DM, hookworm infection can reduce the therapeutic response of pulmonary TB. Screening for and control of DM and hookworm infection among patients with pulmonary TB may improve their therapeutic response.

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Objective/background: The diagnosis of leprosy has been a challenge due to the low sensibility of the conventional methods and the impossibility of culturing the causative organism. In this study, four methods for Mycobacterium leprae nucleic-acid extraction from Ziehl–Neelsen-stained slides (ZNS slides) were compared: Phenol/chloroform, Chelex 100 resin, and two commercial kits (Wizard Genomic DNA Purification Kit and QIAamp DNA Mini Kit). Methods: DNA was extracted from four groups of slides: a high-codification-slide group (bacteriological index [BI]≥4), a low-codification-slide group (BI = 1), a negative-slide group (BI = 0), and a negative-control-slide group (BI = 0). Quality DNA was evidenced by the amplification of specific repetitive element present in M. leprae genomic DNA (RLEP) using a nested polymerase chain reaction. Results: This is the first report comparing four different extraction methods for obtaining M. leprae DNA from ZNS slides in Cuban patients, and applied in molecular diagnosis. Good-quality DNA and positive amplification were detected in the high-codification-slide group with the four methods, while from the low-codification-slide group only the QIAGEN and phenol–chloroform methods obtained amplification of M. leprae. In the negative-slide group, only the QIAGEN method was able to obtain DNA with sufficient quality for positive amplification of the RLEP region. No amplification was observed in the negative-control-slide group by any method. Patients with ZNS negative slides can still transmit the infection, and molecular methods can help identify and treat them, interrupting the chain of transmission and preventing the onset of disabilities. Conclusion: The ZNS slides can be sent easily to reference laboratories for later molecular analysis that can be useful not only to improve the diagnosis, but also for the application of other molecular techniques.

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Tuberculosis is a major public health problem in developing countries. Flexor tenosynovitis of the fingers constitutes an exceptional tuberculosis localization (Gabl et al., 1997; Senda et al., 2011) ^[1],[2]. Unusual presentations, such as tuberculous tenosynovitis, often go undetected and are associated with a diagnostic and therapeutic delay, especially when bacteriological research proves to be negative. Here, we report a case of tuberculous flexor tenosynovitis of the hand.

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Objective/Background: Isoniazid (INH) is one of the effective antituberculosis (TB) drugs used for TB treatment. However, most of the drug-resistant Mycobacterium tuberculosis (MTB) clinical strains are resistant to INH, a first-line antituberculous drug. Certain metabolic enzymes such as adenosylhomocysteinase (Rv3248c), universal stress protein (Rv2623), nicotinamide adenine dinucleotide (reduced)-dependent enoyl-acyl carrier protein reductase (Rv1484), oxidoreductase (Rv2971), dihydrofolate reductase (Rv2763c), pyrroline-5-carboxylate dehydrogenase (Rv1187) have been identified to bind INH–nicotinamide adenine dinucleotide (INH–NAD) and INH–nicotinamide adenine dinucleotide phosphate adducts coupled to Sepharose resin. These enzymes are reported to be involved in many important biochemical processes of MTB, including cysteine and methionine metabolism, mycobacterial growth regulation, mycolic acid biosynthesis, detoxification of toxic metabolites, folate biosynthesis, etc. The truncated INH–nicotinamide adenine dinucleotide (oxidized) adduct, 4-isonicotinoylnicotinamide, isolated from urine samples of human TB patients treated with INH therapy is proposed to have antimycobacterial activity. Methods: To understand the mechanism of interaction of the truncated INH–NAD adduct, binding energy studies were carried out on the aforementioned six enzymes with known three-dimensional structures using AutoDock4.2. Results: In silico docking analysis of these MTB enzymes with the truncated INH–NAD adduct showed favorable binding interactions with docking energies ranging from −5.29 to −7.07kcal/mol. Conclusion: Thus, in silico docking study revealed that the INH–NAD adduct, which is generated in vivo after INH activation, may undergo spontaneous hydrolysis to form the truncated INH–NAD adduct and further binds and inhibits multiple enzymes of MTB, in addition to InhA, confirming that INH is an effective anti-TB drug acting at multiple enzymes. Further analysis of amino acid residues in the active site of INH–NAD-binding proteins showed the probable presence of catalytic triad in four enzymes possibly involved in INH binding to the enzyme.

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Objective/background: The latest incidence of tuberculosis (TB) (per 100,000 people) in Cameroon was 243.00 as of 2011. Over the past 21 years, the value for this indicator has fluctuated between 112.00 in 1990 and 320.00 in 2003. Worldwide, this incidence has also increased, bringing back TB as a reemerging disease. On the same note, resistance to anti-TB drugs has increased, urging the search for new molecules. Methods: This study was carried out to evaluate the antimycobacterial activity of six medicinal plants on the virulent strain, H37Rv, using the microplate alamarBlue assay. Mycobacterium tuberculosis (H37Rv strain) was incubated with decreased concentrations of six plant extracts, ranging from 250 μg/mL to 31.25 μg/mL. After 7days of incubation at 37 °C, the effects of these plant extracts on the viability of the mycobacteria were evaluated. For each plant extract, the minimal inhibitory concentration was determined. Results: The results showed that the compounds MBC1, MBC24, MBC68, MBC81, MBC117, and MBC118 were the best candidates with minimal inhibitory concentrations of 31.25, 62.5, 125, 62.5, and 125 μg/mL, respectively. Conclusion: These results confirm and validate the traditional use of these plants to treat respiratory diseases, which could be good sources and alternatives of plant metabolites for anti-TB-drug development.

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An extra-pulmonary tuberculosis (EPTB) infection rate of 30% in Saudi Arabia remains above the global rate. A variable rate of infection in each province has been reported and the involvement of most organs has been cited. Nationwide collective data on the current trends of infection are scarce and the factors behind the increased rate of EPTB are perplexing. This review endeavors to shed light into the epidemiology of EPTB, various types of infections sites, geographical differences in the infection rate, known risk factors, and challenges in the diagnosis and management of EPTB in Saudi Arabia.

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Objective/Background: MicroRNAs (miRNAs) play an important role in diseases development. Therefore, human miRNAs may be able to inhibit the survival of Mycobacterium tuberculosis (Mtb) in the human host by targeting critical genes of the pathogen. Mutations within miRNAs can alter their target selection, thereby preventing them from inhibiting Mtb genes, thus increasing host susceptibility to the disease. Methods: This study was undertaken to investigate the genetic association of pulmonary tuberculosis (TB) with six human miRNAs genes, namely, hsa-miR-370, hsa-miR-520d, hsa-miR-154, hsa-miR-497, hsa-miR-758, and hsa-miR-593, which have been predicted to interact with Mtb genes. The objective of the study was to determine the possible sequence variation of selected miRNA genes that are potentially associated with the inhibition of critical Mtb genes in TB patients. Results: The study did not show differences in the sequences compared with healthy individuals without antecedents of TB. Conclusion: This result could have been influenced by the sample size and the selection of miRNA genes, which need to be addressed in future studies.

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Research objective: Morphological study of tissue necrosis stages in experimental organ-preserving tuberculosis pharmacotherapy using Quercetin and Polyvinylpyrrolidone (QP). Background and methods: 32 laboratory mice of C57BL/6JLacSto strain were used in the experiment. The animals were divided into five groups, six to seven mice in each: group 1- Mycobacterium tuberculosis (MBT) uninfected mice; group 2- MBT infected mice; group 3- MBT infected and treated with antituberculosis preparation (ATP); group 4- MBT infected and QP treated; group 5- MBT infected and treated with ATP and QP. The mice were infected through caudal vein injection with MTB H37Rv strain. The preparation QP, which belongs to the capillary-stabilizing-remedy group, was used for the research. The ATP were izoniazid and streptomycin. Results: QP produced a strict delineation of caseous necrosis from the unaffected parts of the connective tissue with fibrosis in the center and a large number of Langerhans cells, which was not observed in the control groups without QP. The combination of QP and ATP had more pronounced effects. In MBT-infected mice, where QP was not used, unlike the group where QP was used, adipose dystrophy of hepatocytes was observed. Thus, the hepatoprotective effect of QP against TB can be suggested. Conclusion: QP produces a clear delineation of caseous necrosis from an uninfected tissue by connective-tissue formation, and by forming fibrotic tissue in the center of epithelioid cells that prevents further TB dissemination by enhancing TB pharmacotherapy.

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Objective/Background: Tuberculosis (TB) infection is still a major public health burden in Indonesia. TB cases in Indonesia constitute 35% of all the TB cases detected worldwide and the prevalence of TB drug resistance in this country is approximately 3%. The aim of this study was to evaluate the resistance of Mycobacterium tuberculosis to first-line TB drugs among isolates from clinical specimens from a hospital in an urban area. Methods: This laboratory-based study was conducted in Tangerang District, Indonesia, from January 2011 to December 2014. Sputum and other clinical specimens were obtained from patients with pulmonary and extrapulmonary TB. The specimens were stained with Ziehl–Neelsen, inoculated on Löwenstein–Jensen media for 6–8 weeks, and tested for sensitivity against first-line TB drugs [isoniazid (INH), rifampicin (RIF), ethambutol (EMB), and streptomycin (SM)]. Results: All TB patients in this study lived in urban areas with male preponderance. Of the 127 M. tuberculosis isolates collected, 22% showed resistance to first-line TB drugs. Among these resistant isolates, 20.5% showed resistance to at least one of the first-line TB drugs and 0.8% showed multidrug resistance (MDR). Resistance to EMB, INH, RIF, and SM was seen in 6.3% 6.3%, 4.7%, and 1.6% of isolates, respectively. Polyresistance to EMB and INH, EMB and RIF, and EMB, INH, and RIF was seen in 0.8% of the isolates, respectively. Conclusion: Our study confirms that drug resistance, including MDR, observed against all first-line TB drugs was a real threat in the management of TB infection in Indonesia. The resistance pattern identified in this study could assist clinicians in providing appropriate treatment regimen to TB patients and improve their clinical outcome.

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There is an urgent need for a rapid and reliable test to detect actively multiplying Mycobacterium tuberculosis directly from clinical specimens for an early initiation of the appropriate antituberculous treatment. This study was aimed at the optimization and application of nested reverse transcriptase–PCR (nRT–PCR) targeting the messenger RNA of the icl₂, hspx, and rRNAP1 genes directly from sputum specimens, and their evaluation against the culture by the BACTEC MicroMGIT mycobacterial culture system. 203 Sputum samples from clinically suspected tuberculosis patients and 30 control specimens (clinically proven viral or bacterial infections other than tuberculosis) were included in this study. The mycobacterial culture was performed by the BACTEC MicroMGIT system following the manufacturer's instructions. The primers for nRT–PCRs targeting icl₂, hspx, and rRNAP1 genes were indigenously designed using the Primer-BLAST software, and optimized for sensitivity and specificity. The icl₂, hspx, and rRNAP1 genes were able to pick up 63.9%, 67.2%, and 58.75%, respectively, of culture-negative sputum specimens collected from clinically suspected tuberculosis patients. However, three (1.4%) were negative for nRT–PCR, but M. tuberculosis culture positive. All the 30 controls were negative for culture by the BACTEC MicroMGIT method and all three nRT–PCR. The novel nRT–PCRs targeting icl₂, hspx, and rRNAP1 genes developed in this study are rapid and reliable diagnostic tools to detect viable M. tuberculosis directly from sputum specimens. However, further study by including a larger number of sputum specimens needs to be carried out to ascertain the diagnostic utility of the novel nRT–PCRs optimized in the study.

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Objective/background: Molecular typing tools, including spoligotyping, are currently widely used in the monitoring and study of the dynamics of tuberculosis epidemics. Methods: A study of the molecular profile of a sample of 129 Myobacterium tuberculosis strains isolated during 2011 was carried out in the National Reference Laboratory for Tuberculosis and Mycobacteria at the Pasteur Institute of Algeria. This sample was selected at random from a set of 350 strains isolated from tuberculosis patients from central and eastern areas of the country. Results: Genotypic analysis helped to clarify the frequencies of the different genotypes in the current study population: H family, 29%; LAM family, 26%; T family, 25%; S family, 5%, and other genomic families, including orphan strains, 15%. Conclusion: The study of strains isolated between January and December 2011 has allowed insight into the frequency of different genomic families and the importance of existing clusters in the population of central and eastern Algeria.

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Tuberculosis (TB) is one of the oldest threats to public health. TB is caused by the pathogen Mycobacterium tuberculosis (MTB). The Sigma factors are essential for the survival of MTB. The Sigma factor Sigma F (SigF) regulates genes expression under stress conditions. The SigF binds to RNA polymerase and forms a holoenzyme, which initiates the transcription of various genes. The Usfx, an anti-SigF protein, binds to SigF and alters the transcription initiation and gene expression. In the present work, virtual screening studies are taken up to identify the interactions between SigF and small molecular inhibitors which can inhibit the formation of holoenzyme. The studies reveal that ARG 104 and ARG 224 amino acid residues of SigF protein are forming important binding interactions with the ligands. The in silico ADME properties for the ligand data set are calculated to check the druggability of the molecules.

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Introduction: There has been an increase in the number of tuberculosis (TB) cases worldwide, but TB of the skin remains rare. Case presentation: A case of 7-year-old girl with multiple ulcerating nodules who presented with four ulcers in the skin of the left elbow. The patient was unresponsive to broad-spectrum antibiotics treatment initially. Because of poor clinical response to conventional therapy, TB was suspected. Although tuberculin skin test was negative, positive QuantiFERON TB Gold test and clinical picture strongly indicated TB. Clinical diagnosis was confirmed by positive culture for Mycobacterium tuberculosis. Conclusion: A high index of clinical suspicion is necessary to suspect TB of the skin. Positive culture remains the gold standard for diagnosis.

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