Mycobacterium tuberculosis progresses through two phases of latent infection in humans.

Little is known about the physiology of latent Mycobacterium tuberculosis infection. We studied the mutational rates of 24 index tuberculosis (TB) cases and their latently infected household contacts who developed active TB up to 5.25 years later, as an indication of bacterial physiological state and possible generation times during latent TB infection in humans.

Risk factors associated with cluster size of Mycobacterium tuberculosis (Mtb) of different RFLP lineages in Brazil.

Background: Tuberculosis (TB) transmission is influenced by patient-related risk, environment and bacteriological factors. We determined the risk factors associated with cluster size of IS6110 RFLP based genotypes of Mycobacterium tuberculosis (Mtb) isolates from Vitoria, Espirito Santo, Brazil.

Methods: Cross-sectional study of new TB cases identified in the metropolitan area of Vitoria, Brazil between 2000 and 2010.

Strains of Mycobacterium tuberculosis transmitting infection in Brazilian households and those associated with community transmission of tuberculosis.

Molecular epidemiologic studies have shown that the dynamics of tuberculosis transmission varies geographically. We sought to determine which strains of Mycobacterium tuberculosis (MTB) were infecting household contacts (HHC), and which were causing clusters of tuberculosis (TB) disease in Vitoria-ES, Brazil. A total of 741 households contacts (445 TST +) and 139 index cases were characterized according to the proportion of contacts in each household that had a tuberculin skin test positive: low (LT) (≤40% TST+), high (HT) (≥70% TST+) and (40-70% TST+) intermediate (IT) transmission.

Mycobacterial Hsp65 antigen upregulates the cellular immune response of healthy individuals compared with tuberculosis patients.

Previously we showed that 65-kDa Mycobacterium leprae heat shock protein (Hsp65) is a target for the development of a tuberculosis vaccine. Here we evaluated peripheral blood mononuclear cells (PBMC) from healthy individuals or tuberculosis patients stimulated with two forms of Hsp65 antigen, recombinant DNA that encodes Hsp65 (DNA-HSP65) or recombinant Hsp65 protein (rHsp65) in attempting to mimic a prophylactic or therapeutic study in vitro, respectively. Proliferation and cytokine-producing CD4 or CD8 cell were assessed by flow cytometry.

Genotypic and Spatial Analysis of Mycobacterium tuberculosis Transmission in a High-Incidence Urban Setting.

Background: Genotyping Mycobacterium tuberculosis isolates allows study of dynamics of tuberculosis transmission, while geoprocessing allows spatial analysis of clinical and epidemiological data. Here, genotyping data and spatial analysis were combined to characterize tuberculosis transmission in Vitória, Brazil, to identify distinct neighborhoods and risk factors associated with recent tuberculosis transmission.

Methods: From 2003 to 2007, 503 isolates were genotyped by IS6110 restriction fragment length polymorphism (RFLP) and spoligotyping.

Extrapulmonary tuberculosis: Mycobacterium tuberculosis strains and host risk factors in a large urban setting in Brazil.

Background: Factors related to the development of extrapulmonary forms of tuberculosis (EPTB) are still poorly understood, particularly in high-endemic countries like Brazil. The objective of the paper is to determine host and Mycobacterium tuberculosis (MTB) strain-related factors associated with the development of EPTB in Espírito Santo state, Brazil.

Methods And Findings: We conducted a retrospective laboratory-based surveillance study of new tuberculosis (TB) cases diagnosed in Espírito Santo state, Brazil between 1998 and 2007.

Mycobacterium tuberculosis DNA fingerprint clusters and its relationship with RD(Rio) genotype in Brazil.

Mycobacterium tuberculosis (Mtb) strains designated as RD(Rio) are responsible for a large cluster of new cases of tuberculosis (TB) in Rio de Janeiro. They were previously shown to be associated with severe manifestations of TB. Here, we used three genotyping methods (IS6110 RFLP, spoligotyping, and multiplex PCR) to characterize RD(Rio) and non-RD(Rio) strains from the metropolitan area of Vitória, State of Espirito Santo in southeast Brazil to determine strain diversity and transmission patterns.

In vitro activity of amphotericin B cochleates against Leishmania chagasi.

Cochleate delivery vehicles are a novel lipid-based system with potential for delivery of amphotericin B (AmB). In this study, the efficacy of cochleates was evaluated by examining the in vitro activity of AmB cochleates (CAMB) against Leishmania chagasi in a macrophage model of infection. We demonstrate that CAMB is nontoxic to macrophages at concentrations as high as 2.

Saline nebulization before gastric lavage in the diagnosis of pulmonary tuberculosis in children and adolescents.

The main objective is to assess whether nebulization before gastric lavage (GL) improves its sensitivity for the diagnosis of childhood tuberculosis (TB). Children and adolescents suspected of pulmonary TB were randomly assigned (1 : 2) to nebulization with hypertonic saline 30 min before GL (Neb group; n = 36) or GL without prior nebulization (controls; n = 68). The proportion of positive GL smears was greater in Neb group than in the control group; however, no statistical significance was observed (36.

Use of in-house PCR for identification of Mycobacterium tuberculosis in BACTEC broth cultures of respiratory specimens.

We evaluated the ability of a PCR assay to identify Mycobacterium tuberculosis complex (MTBC) from positive BACTEC 12B broth cultures. A total of 107 sputum samples were processed and inoculated into Ogawa slants and BACTEC 12B vials. At a growth index (GI) > or=30, 1.

[Accuracy of inpatient and outpatient gastric lavage in the diagnosis of pulmonary tuberculosis in children].

Objective: To compare gastric lavage (GL) performed in inpatients with GL performed in outpatients in terms of its accuracy in diagnosing pulmonary tuberculosis (TB) in children.

Methods: A prospective study was carried out in the state of Espírito Santo, Brazil, from 1999 to 2003. A total of 230 children suspected of having TB (103 inpatients and 127 outpatients) were selected to undergo GL.

Cavitary disease and quantitative sputum bacillary load in cases of pulmonary tuberculosis.

We examined sputum bacterial loads in adults with newly diagnosed tuberculosis using quantitative culture and time-until-positive (DTP) culture in BACTEC 460. Patients with cavitary disease had higher CFU levels than those without cavities and shorter DTPs. Within radiographic strata of moderately and far advanced tuberculosis, higher CFU counts were associated with cavitary disease.

Evaluation of a commercial test based on ligase chain reaction for direct detection of Mycobacterium tuberculosis in respiratory specimens.

A ligase chain reaction DNA amplification method for direct detection of Mycobacterium tuberculosis (Abbott LCx MTB) in respiratory specimens was evaluated. Results from LCx MTB Assay were compared with those from acid fast bacilli smear, culture, and final clinical diagnosis for each patient. A total of 297 respiratory specimens (sputum and bronchial lavage) from 193 patients were tested.