RESUMO
Granulysin is a human polypeptide produced by cytolytic cells active against a broad range of microbes. Three peptides covering the regions 25-50 (Gr-1 and Gr-2) and 39-62 (Gr-3) of granulysin were synthesized, and their in vitro activity against Mycobacterium tuberculosis was evaluated. The most active peptide was Gr-1C, containing a disulphide bridge, with Minimal Inhibitory Concentration value of 10.1 microM. In concentrations of up to 50 microM, Gr-1 and Gr2 didn't exceed 30% of hemolysis.
Assuntos
Antígenos de Diferenciação de Linfócitos T/química , Antígenos de Diferenciação de Linfócitos T/farmacologia , Peptídeos Catiônicos Antimicrobianos/química , Peptídeos Catiônicos Antimicrobianos/farmacologia , Mycobacterium tuberculosis/efeitos dos fármacos , Fragmentos de Peptídeos/química , Fragmentos de Peptídeos/farmacologia , Sequência de Aminoácidos , Contagem de Colônia Microbiana , Eritrócitos/efeitos dos fármacos , Hemólise , Humanos , Testes de Sensibilidade Microbiana , Dados de Sequência Molecular , Fragmentos de Peptídeos/síntese químicaRESUMO
The human immunodeficiency virus (HIV) epidemic has altered the epidemiological profile of tuberculosis in both industrialized and developing countries. Serious diseases caused by mycobacteria other than Mycobacterium tuberculosis, mostly belonging to the M. avium-intracellulare complex (MAC), have become very common in association with severe immunosuppression. The increase in mycobacterial disease complexity has stimulated the development of more rapid and efficient methods for diagnosis. In the present study, we investigated and assessed the suitability of a gas-liquid chromatography technique for diagnosis of clinically important mycobacteria in Argentina. An identification scheme was developed from the results obtained in a previous study where we characterized the cellular fatty acids and the mycolic acid cleavage products from most frequent species in Argentina. Of 183 isolates tested, 69% were correctly identified to species level and 5% were incorrectly classified. If we only take into account the isolates that could be identified, 93% were correctly identified. Although all of the isolates of M. tuberculosis were correctly identified, four isolates of MAC incorrectly matched by M. tuberculosis. Gas chromatography provides a rapid technique of highly predictive value for mycobacteria identification; it could be used in reference laboratories as a rapid presumptive identification until the biochemical tests are completed.