[Recommendations for tuberculosis screening before and during treatment with tumour necrosis factor inhibitors].

Patients with an autoimmune disease, such as rheumatoid arthritis, ankylosing spondylitis, psoriatic arthritis, Crohn's disease, ulcerative colitis, uveitis or psoriasis, and treated with the anti-tumour necrosis factor (TNF) alpha inhibitors are at high risk of developing various infections including tuberculosis (TB). Serious infections are the result of the patients' immunocompromised status that is caused by the primary disease itself, as well as by previous immunosuppressive therapy. In order to decrease the risk of developing TB, prior to the introduction of the anti-TNF alpha therapy, all patients should undergo screening for TB.

Elements of signal transduction in Mycobacterium tuberculosis: in vitro phosphorylation and in vivo expression of the response regulator MtrA.

A putative two-component system, mtrA-mtrB, was isolated from M. tuberculosis H37Rv by using phoB from Pseudomonas aeruginosa as a hybridization probe. The predicted gene product of mtrA displayed high similarity with typical response regulators, including AfsQ1, PhoB, PhoP, and OmpR.

Mycobacterium tuberculosis is a natural mutant with an inactivated oxidative-stress regulatory gene: implications for sensitivity to isoniazid.

The systems participating in detoxification of reactive oxygen intermediates in Mycobacterium tuberculosis are believed to play a dual role in the biology of this highly adapted human pathogen: (i) they may contribute to the survival of this bacterium in the host; and (ii) alterations in the gene encoding catalase/peroxidase have been linked to this organism's resistance to the front-line antituberculosis drug isoniazid. These relationships prompted us to extend investigations of the oxidative-stress-response systems in M. tuberculosis by analysing the alkyl hydroperoxide reductase gene ahpC and its putative regulator oxyR.

Gene expression in mycobacteria: transcriptional fusions based on xylE and analysis of the promoter region of the response regulator mtrA from Mycobacterium tuberculosis.

Understanding promoter regulation and signal-transduction systems in pathogenic mycobacteria is critical for uncovering the processes that govern interactions of these bacteria with the human host. In order to develop additional genetic tools for analysis of mycobacterial promoters, the xyIE gene from Pseudomonas was tested as a transcriptional fusion reporter in fast- and slow-growing mycobacteria. Initially, its utility was demonstrated by expression behind the hsp60 promoter in Mycobacterium smegmatis and Mycobacterium bovis BCG.

Conversion to mucoidy in Pseudomonas aeruginosa.

Chronic respiratory complications in cystic fibrosis, compounded by recurring infections with mucoid Pseudomonas aeruginosa and the associated inflammation, are the primary cause of high mortality in this inheritable disease. Since the conversion of P. aeruginosa into the exopolysaccharide alginate overproducing strains plays a critical role in the establishment of chronic infection, studies are directed towards understanding the processes underlying this phenomenon.