Lipoarabinomannan, and its related glycolipids, induce divergent and opposing immune responses to Mycobacterium tuberculosis depending on structural diversity and experimental variations.

Exposure to Mycobacterium tuberculosis (Mtb) may lead to active or latent tuberculosis, or clearance of Mtb, depending essentially on the quality of the host's immune response. This response is initiated through the interaction of Mtb cell wall surface components, mostly glycolipids, with cells of the innate immune system, particularly macrophages (Mφs) and dendritic cells (DCs). The way Mφs and DC alter their cytokine secretome, activate or inhibit different microbicidal mechanisms and present antigens and consequently trigger the T cell-mediated immune response impacts the host immune response against Mtb.

A sensitive urinary lipoarabinomannan test for tuberculosis.

We have previously developed a diagnostic test for tuberculosis based on detection of mycobacterial lipoarabinomannan (LAM) in urine. The method depended on a laborious concentration step. We have now developed an easy to perform test based on a magnetic immunoassay platform, utilizing high avidity monoclonal antibodies for the detection of LAM in urine.

Divergent effects of mycobacterial cell wall glycolipids on maturation and function of human monocyte-derived dendritic cells.

Background: Mycobacterium tuberculosis (Mtb) is able to evade the immune defenses and may persist for years, decades and even lifelong in the infected host. Mtb cell wall components may contribute to such persistence by modulating several pivotal types of immune cells. Dendritic cells (DCs) are the most potent antigen-presenting cells and hence play a crucial role in the initial immune response to infections by connecting the innate with the adaptive immune system.

Molecular evidence of Plesiomonas shigelloides as a possible zoonotic agent.

The most frequently used method for establishing epidemiological relationships between Plesiomonas shigelloides strains is O:H serotyping. However, a number of strains are not serotypeable and isolates from diverse sources can display the same serovar. Moreover, since the zoonotic nature of Plesiomonas has been suggested and this hypothesis is based on the identical serovars found in animals and humans, we intend to use four DNA-based techniques: random amplified polymorphic DNA-PCR, enterobacterial repetitive intergenic consensus-PCR, repetitive extragenic palindromic-PCR, and pulsed field gel electrophoresis in order to screen 24 strains belonging to nine O:H serovars isolated from humans, animals, and the environment.

Towards new tuberculosis vaccines.

According to WHO, about one third of the world's population is infected with bacteria of the Mycobacterium tuberculosis complex. Currently there is globally 9.15 million recorded cases of overt tuberculosis (TB) annually and due to lack of adequate diagnostics presumably a large but unknown number of non-recorded cases.

Epidemiology of Mycobacterium bovis infection in wild boar (Sus scrofa) from Portugal.

Tuberculosis has been diagnosed in wild boar (Sus scrofa) in several European countries during the last decade; however, almost no information has been reported to date for Portugal. This study aimed to investigate tuberculosis in wild boar in Portugal through characterization of Mycobacterium bovis infection and identification of disease risk factors. Tissue samples were obtained from hunted wild boar during the 2005 and 2006 hunting seasons.

Mycobacterial glycoconjugates as vaccine candidates against tuberculosis.

There is an urgent need for an efficient vaccine against tuberculosis. Here, we explore the potential role of carbohydrate antigens as part of a new tuberculosis vaccine. Emphasis is placed on carbohydrate-protein conjugate vaccines, using the arabinomannan portion of lipoarabinomannan, a major structural surface component of Mycobacterium tuberculosis covalently conjugated to (mycobacterial) protein antigens.

Pathogen specific carbohydrate antigen microarrays: a chip for detection of Salmonella O-antigen specific antibodies.

A Salmonella O-antigen microarray was developed by covalent coupling of oligosaccharide antigens specific for serogroups Salmonella enterica sv. Paratyphi (group A), Typhimurium (group B) and Enteritidis (group D). Antibodies were correctly detected in sera from patients with culture verified salmonellosis.

Should a new tuberculosis vaccine be administered intranasally?

Most of the world's population is vaccinated with the only available vaccine against tuberculosis (TB), the Bacillus Calmette-Guérin (BCG) vaccine that was developed almost a century ago. Despite the wide coverage of the BCG vaccine, there are great variations in protective efficacy among different study populations. BCG vaccination protects against childhood forms of TB, but this immunity wanes with age, resulting in none, or insufficient, protection against adult pulmonary TB (PTB).

Evaluation of vaccines in the EU TB Vaccine Cluster using a guinea pig aerosol infection model of tuberculosis.

The TB Vaccine Cluster project funded by the EU Fifth Framework programme aims to provide novel vaccines against tuberculosis that are suitable for evaluation in humans. This paper describes the studies of the protective efficacy of vaccines in a guinea pig aerosol-infection model of primary tuberculosis. The objective was to conduct comparative evaluations of vaccines that had previously demonstrated efficacy in other animal models.

Genetic characterization of the Guinea-Bissau family of Mycobacterium tuberculosis complex strains.

In a previous study of Mycobacterium tuberculosis complex isolates from Guinea-Bissau in West Africa, we identified a unique group of strains, designated here as the Guinea-Bissau family of strains, which, although genotypically closely related, phenotypically demonstrated a considerable heterogeneity. We conducted here a detailed genotypic analysis of a subset (n = 35) of these isolates. Based on the data obtained, and by comparison of known corresponding genes in mycobacteria outside the M.

Serotypes and anti-microbial susceptibility of Plesiomonas shigelloides isolates from humans, animals and aquatic environments in different countries.

A total of 73 strains of Plesiomonas shigelloides isolated from humans (24 strains) animals (21 strains) and aquatic environment (28 strains) were determined for their O:H serotype and susceptibility to 18 anti-microbial substances and to the vibriostatic agent O/129. Of all strains, 86.3% were typeable by the O and 94.

Mycobacterium tuberculosis arabinomannan-protein conjugates protect against tuberculosis.

Lipoarabinomannan (LAM) is a major structural surface component of mycobacteria. Arabinomannan (AM) oligosaccharides derived from LAM of Mycobacterium tuberculosis H37Rv were isolated and covalently conjugated to tetanus toxoid (TT) or to short-term culture filtrate proteins (antigen 85B (Ag85B) or a 75kDa protein) from M. tuberculosis strain Harlingen.

Clinical and radiological features in relation to urinary excretion of lipoarabinomannan in Ethiopian tuberculosis patients.

We have previously reported on the diagnostic potential of urinary lipoarabinomannan (LAM) detection in active tuberculosis (TB). In this study, we identified clinical and radiological parameters that were significantly associated with urine LAM positivity in a clinical sample of 931 patients attending a TB control center in Addis Ababa, Ethiopa. These parameters were attributed weights and used in a diagnostic score (DS) system.

Circulating antibodies to lipoarabinomannan in relation to sputum microscopy, clinical features and urinary anti-lipoarabinomannan detection in pulmonary tuberculosis.

An enzyme-linked immunosorbent assay (ELISA)-based investigation of anti-lipoarabinomannan (LAM) antibody levels in the sera of patients with acid-fast bacilli (AFB)-positive pulmonary tuberculosis (PTB), AFB-negative PTB and non-TB respiratory tract symptoms was conducted. The anti-LAM results were further evaluated using urine LAM detection and a clinical diagnostic score (DS) system as references. Using sputum AFB as a reference, positive anti-LAM was found in 66.