Tuberculosis Research Today is a free monthly online journal that collates and summarizes the latest research about Tuberculosis, including details on symptoms, causes, treatment, pulmonary, mycobacterium. | ||||||
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Relationship between Mycobacterium tuberculosis genotype and the clinical phenotype of pulmonary and meningeal tuberculosis.Thwaites G, Caws M, Chau TT, D'Sa A, Lan NT, Huyen MN, Gagneux S, Anh PT, Tho DQ, Torok E, Nhu NT, Duyen NT, Duy PM, Richenberg J, Simmons C, Hien TT, Farrar J Centre for Molecular Microbiology and Infection, Imperial College, Exhibition Rd., South Kensington, London, United Kingdom. guy.thwaites@btinternet.com We used large sequence polymorphisms to determine the genotypes of 397 isolates of Mycobacterium tuberculosis from human immunodeficiency virus-uninfected Vietnamese adults with pulmonary (n = 235) or meningeal (n = 162) tuberculosis. We compared the pretreatment radiographic appearances of pulmonary tuberculosis and the presentation, response to treatment, and outcome of tuberculous meningitis between the genotypes. Multivariate analysis identified variables independently associated with genotype and outcome. A higher proportion of adults with pulmonary tuberculosis caused by the Euro-American genotype had consolidation on chest X-ray than was the case with disease caused by other genotypes (P = 0.006). Multivariate analysis revealed that meningitis caused by the East Asian/Beijing genotype was independently associated with a shorter duration of illness before presentation and fewer cerebrospinal fluid (CSF) leukocytes. Older age, fewer CSF leukocytes, and the presence of hemiplegia (but not strain lineage) were independently associated with death or severe disability, although the East Asian/Beijing genotype was strongly associated with drug-resistant tuberculosis. The genotype of M. tuberculosis influenced the presenting features of pulmonary and meningeal tuberculosis. The association between the East Asian/Beijing lineage and disease progression and CSF leukocyte count suggests the lineage may alter the presentation of meningitis by influencing the intracerebral inflammatory response. In addition, increased drug resistance among bacteria of the East Asian/Beijing lineage might influence the response to treatment. This study suggests the genetic diversity of M. tuberculosis has important clinical consequences. Published 4 April 2008 in J Clin Microbiol, 46(4): 1363-8. Articles on Tuberculosis published 4 April 2008: Spread of a low-fitness drug-resistant Mycobacterium tuberculosis strain in a setting of high human immunodeficiency virus prevalence. J Clin Microbiol, 46(4): 1514-6. The fitness cost associated with the evolution of resistance to rifampin in Mycobacterium tuberculosis may be different in clinical isolates compared to in vitro-generated mutants. An atypical Beijing strain (attenuated phenotype) demonstrated the ability to spread despite acquiring resistance to rifampin. Transmission was linked to human immunodeficiency virus coinfection (P = 0.029), raising concern for the spread of drug resistance in vulnerable populations. [Abstract] [Full-text] Validation of the BrockTB stat-pak assay for detection of tuberculosis in Eurasian badgers (Meles meles) and influence of disease severity on diagnostic accuracy. J Clin Microbiol, 46(4): 1498-500. A lateral-flow immunoassay (BrockTB Stat-Pak) for detecting tuberculosis in Eurasian badgers was 49% sensitive and 93% specific against culture for M. bovis (n = 1,464) at necropsy. However, the sensitivity was significantly higher (66 to 78%) in animals with more severe tuberculosis, indicating that the BrockTB Stat-Pak may be useful for the detection of badgers with the greatest risk of transmitting disease. [Abstract] [Full-text] Application of sensitive and specific molecular methods to uncover global dissemination of the major RDRio Sublineage of the Latin American-Mediterranean Mycobacterium tuberculosis spoligotype family. J Clin Microbiol, 46(4): 1259-67. The Latin American-Mediterranean (LAM) family of Mycobacterium tuberculosis is believed to be the cause of approximately 15% of tuberculosis cases worldwide. Previously, we defined a prevalent sublineage of the LAM family in Brazil by a single characteristic genomic deletion designated RD(Rio). Using the Brazilian strains, we pinpoint an Ag85C(103) single nucleotide polymorphism (SNP) (screened by restriction fragment length polymorphism [RFLP] analysis) that correctly identified all LAM family ... [Abstract] [Full-text] Three-year population-based evaluation of standardized mycobacterial interspersed repetitive-unit-variable-number tandem-repeat typing of Mycobacterium tuberculosis. J Clin Microbiol, 46(4): 1398-406. Standardized mycobacterial interspersed repetitive-unit-variable-number tandem repeat (MIRU-VNTR) typing based on 15 and 24 loci recently has been proposed for Mycobacterium tuberculosis genotyping. So far, this optimized system has been assessed in a single, 1-year population-based study performed in Germany (M. C. Oelemann, R. Diel, V. Vatin, W. Haas, S. Rusch-Gerdes, C. Locht, S. Niemann, and P. Supply, J. Clin. Microbiol. 45:691-697, 2007). Here, we evaluated these optimized formats in a ... [Abstract] [Full-text] Articles on Tuberculosis published 28 March 2008: The influence of host and bacterial genotype on the development of disseminated disease with Mycobacterium tuberculosis. PLoS Pathog, 4(3): e1000034. The factors that govern the development of tuberculosis disease are incompletely understood. We hypothesized that some strains of Mycobacterium tuberculosis (M. tuberculosis) are more capable of causing disseminated disease than others and may be associated with polymorphisms in host genes responsible for the innate immune response to infection. We compared the host and bacterial genotype in 187 Vietnamese adults with tuberculous meningitis (TBM) and 237 Vietnamese adults with uncomplicated ... [Abstract] [Full-text] Articles on Tuberculosis published 26 March 2008: Age-period-cohort analysis of tuberculosis notifications in Hong Kong from 1961 to 2005. Thorax, 63(4): 312-6. BACKGROUND: Despite its wealth, excellent vital indices and robust health care infrastructure, Hong Kong has a relatively high incidence of tuberculosis (TB) (85.4 per 100 000). Hong Kong residents have also experienced a very rapid and recent epidemiological transition; the population largely originated from migration by southern Chinese in the mid 20th century. Given the potentially long latency period of TB infection, an investigation was undertaken to determine the extent to which TB ... [Abstract] [Full-text] The clinical impact of nucleic acid amplification tests on the diagnosis and management of tuberculosis in a British hospital. Thorax, 63(4): 317-21. BACKGROUND: Nucleic acid amplification tests (NAAT) based on PCR provide rapid identification of Mycobacterium tuberculosis and the detection of rifampicin resistance. Indications for their use in clinical samples are now included in British tuberculosis guidelines. METHODS: A retrospective audit of patients with suspected mycobacterial infection in a Liverpool hospital between 2002 and 2006. Documentation of the impact of NAAT usage in acid fast bacillus (AFB) microscopy positive samples on ... [Abstract] [Full-text] Articles on Tuberculosis published 25 March 2008: Immune reconstitution and "unmasking" of tuberculosis during antiretroviral therapy. Am J Respir Crit Care Med, 177(7): 680-5. Tuberculosis (TB) is the most common opportunistic disease in HIV-infected patients during the initial months of antiretroviral therapy (ART) and presents a great challenge to ART programs in resource-limited settings. The mechanisms underlying development of TB in this period are complex. Some cases may represent progression of undiagnosed subclinical disease present before starting ART, emphasizing the importance of careful screening strategies for TB. It has been suggested that progression ... [Abstract] [Full-text] © 2004-2008 Tuberculosis Research Today. All Rights Reserved. |
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