In 2012, Uganda introduced the use of GeneXpert MTB/RIF (Cepheid, Sunnyvale CA), a sensitive, automated, real-time polymerase chain reaction-based platform for tuberculosis (TB) diagnosis, for programmatic use among children, adults with presumptive human immunodeficiency virus (HIV)-associated TB, and symptomatic persons at risk for rifampicin (RIF)-resistant TB. The effect of using the platform's Xpert MTB/RIF assay on TB care and control was assessed using routinely collected programmatic data; in addition, a retrospective review of district quarterly summaries using abstracted TB register data from purposively selected facilities in the capital city of Kampala was conducted. Case notification rates were calculated and nonparametric statistical methods were used for analysis.
View Article and Find Full Text PDFBackground: Individuals infected with Mycobacterium tuberculosis (Mtb) may develop symptoms and signs of disease (tuberculosis disease) or may have no clinical evidence of disease (latent tuberculosis infection [LTBI]). Tuberculosis disease is a leading cause of infectious disease morbidity and mortality worldwide, yet many questions related to its diagnosis remain.
Methods: A task force supported by the American Thoracic Society, Centers for Disease Control and Prevention, and Infectious Diseases Society of America searched, selected, and synthesized relevant evidence.
Background: Individuals infected with Mycobacterium tuberculosis (Mtb) may develop symptoms and signs of disease (tuberculosis disease) or may have no clinical evidence of disease (latent tuberculosis infection [LTBI]). Tuberculosis disease is a leading cause of infectious disease morbidity and mortality worldwide, yet many questions related to its diagnosis remain.
Methods: A task force supported by the American Thoracic Society, Centers for Disease Control and Prevention, and Infectious Diseases Society of America searched, selected, and synthesized relevant evidence.
Int J Tuberc Lung Dis
June 2015
We implemented a quality management system (QMS) and documented our improvements in a tuberculosis (TB) laboratory in Kisumu, Kenya. After implementation of the QMS, a sustained reduction in culture contamination rates for solid (from 15.4% to 5.
View Article and Find Full Text PDFTo accelerate the fight against tuberculosis, major diagnostic challenges need to be addressed urgently. Post-2015 targets are unlikely to be met without the use of novel diagnostics that are more accurate and can be used closer to where patients first seek care in affordable diagnostic algorithms. This article describes the efforts by the stakeholder community that led to the identification of the high-priority diagnostic needs in tuberculosis.
View Article and Find Full Text PDFTuberculosis (TB) is a major public health concern worldwide with over 2 billion people currently infected. The rise of strains of Mycobacterium tuberculosis (Mtb) that are resistant to some or all first and second line antibiotics, including multidrug-resistant (MDR), extensively drug resistant (XDR) and totally drug resistant (TDR) strains, is of particular concern and new anti-TB drugs are urgently needed. Curcumin, a natural product used in traditional medicine in India, exhibits anti-microbial activity that includes Mtb, however it is relatively unstable and suffers from poor bioavailability.
View Article and Find Full Text PDFThe lack of capacity to provide laboratory confirmation of a diagnosis of tuberculosis disease (TB) is contributing to enormous gaps in the ability to find, treat and follow TB patients. WHO estimates that globally only about 57% of the notified new cases of pulmonary TB in 2012 and about 19% of rifampicin-resistant TB cases were laboratory confirmed. The Cepheid Xpert(®) MTB/RIF assay has been credited with revolutionizing laboratory testing to aid in the diagnosis of TB and rifampicin-resistant TB.
View Article and Find Full Text PDFXpert MTB/RIF is a major advance for TB diagnostics, especially for multidrug-resistant (MDR) TB and HIV-associated TB. But implementation concerns including cost, technical support requirements, and challenging demands of providing second-line TB drugs for diagnosed MDR-TB cases call for gradual, careful introduction based on country circumstances.
View Article and Find Full Text PDFSince the discovery of streptomycin's bactericidal activity against Mycobacterium tuberculosis, aminoglycosides have been utilized to treat tuberculosis (TB). Today, the aminoglycosides kanamycin and amikacin are used to treat multidrug-resistant (MDR) TB, and resistance to any of the second-line injectable antibiotics, including kanamycin, amikacin, or capreomycin, is a defining characteristic of extensively drug-resistant (XDR) TB. Resistance to kanamycin and streptomycin is thought to be due to the acquisition of unlinked chromosomal mutations.
View Article and Find Full Text PDFThe lengthy course of treatment with currently used antimycobacterial drugs and the resulting emergence of drug-resistant strains have intensified the need for alternative therapies against Mycobacterium tuberculosis (Mtb), the etiologic agent of tuberculosis. We show that Mtb and Mycobacterium marinum use ABL and related tyrosine kinases for entry and intracellular survival in macrophages. In mice, the ABL family tyrosine kinase inhibitor, imatinib (Gleevec), when administered prophylactically or therapeutically, reduced both the number of granulomatous lesions and bacterial load in infected organs and was also effective against a rifampicin-resistant strain.
View Article and Find Full Text PDFBackground: The identification of Mycobacterium tuberculosis vaccines that elicit a protective immune response in the lungs is important for the development of an effective vaccine against tuberculosis.
Methods And Principal Findings: In this study, a comparison of intranasal (i.n.
Comparative genomic sequencing is shedding new light on bacterial identification, taxonomy and phylogeny. An in silico assessment of a core gene set necessary for cellular functioning was made to determine a consensus set of genes that would be useful for the identification, taxonomy and phylogeny of the species belonging to the subclass Actinobacteridae which contained two orders Actinomycetales and Bifidobacteriales. The subclass Actinobacteridae comprised about 85% of the actinobacteria families.
View Article and Find Full Text PDFWe investigated the in vitro production of the antimicrobial peptide hepcidin by cells of the innate immune system that harbor Mycobacterium tuberculosis. Stimulation of mouse lung macrophages with M. tuberculosis or IFN-γ + M.
View Article and Find Full Text PDFThe emergence of multidrug-resistant (MDR) tuberculosis (TB) highlights the urgent need to understand the mechanisms of resistance to the drugs used to treat this disease. The aminoglycosides kanamycin and amikacin are important bactericidal drugs used to treat MDR TB, and resistance to one or both of these drugs is a defining characteristic of extensively drug-resistant TB. We identified mutations in the -10 and -35 promoter region of the eis gene, which encodes a previously uncharacterized aminoglycoside acetyltransferase.
View Article and Find Full Text PDFEthambutol resistance in clinical Mycobacterium tuberculosis isolates is associated primarily with missense mutations in the embB gene. However, recent reports have described the presence of embB mutations, especially those at embB codon 306, in isolates susceptible to ethambutol. To clarify the role of embB mutations in ethambutol resistance, we sequenced the ethambutol resistance-determining region in spontaneous ethambutol-resistant mutants.
View Article and Find Full Text PDFDNA-DNA hybridization (DDH), the gold standard for bacterial species delineation, is a laborious method and the alternative, average nucleotide identity (ANI), a genomic sequence-derived parameter, is not applicable to non-sequenced species. A universal cut-off value to delineate bacterial species does not exist, yet a DDH value <70 % and ANI <95+/-0.5 % have proved useful in selected examples.
View Article and Find Full Text PDFEURASIP J Bioinform Syst Biol
June 2010
Sequencing the complete genome of Mycobacterium tuberculosis H37Rv is a major milestone in the genome project and it sheds new light in our fight with tuberculosis. The genome contains around 4000 genes (protein-coding sequences) in the original genome annotation. A subsequent reannotation of the genome has added 80 more genes.
View Article and Find Full Text PDFMost multidrug-resistant (MDR) Mycobacterium tuberculosis isolates in Russia belong to the Beijing or Latino-American and Mediterranean (LAM) spoligotype families. The objective of this study was to investigate possible associations between genotype and the frequencies of mutations that confer drug resistance in a population that has two large families of circulating strains. Spoligotyping, IS6110 restriction fragment length polymorphism typing, and sequencing of the katG and rpoB genes, were performed for 217 consecutive MDR M.
View Article and Find Full Text PDFTuberculosis caused by Mycobacterium tuberculosis continues to be one of the major public health problems in the world. The eventual control of this disease will require the development of a safe and effective vaccine. One of the approaches receiving a great deal of attention recently is subunit vaccination.
View Article and Find Full Text PDFThe Rv3083-Rv3089 operon of Mycobacterium tuberculosis has been shown to be induced 17-33-fold when tubercle bacilli were exposed in vitro to acidic conditions which may mimic those that the bacilli encounter early during the infection and it is induced during growth in macrophages. To understand the role of this operon in intracellular survival, we constructed a knockout of the operon in the M. tuberculosis H37Rv strain.
View Article and Find Full Text PDFTuberculosis (Edinb)
January 2007
The availability of the complete sequence of Mycobacterium tuberculosis genome coupled with microarray technology has enabled a high-throughput approach to the pharmacogenomics of this organism. Isoniazid (INH) is a first-line drug for the treatment of tuberculosis and the microarray approach has generated new insight into the action of INH on a drug-susceptible strain. It has also shown that INH does not induce any significant change in gene expression when applied to a catalase-negative INH-resistant strain, which is expected because catalase activity is required to convert the prodrug INH to its active form.
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