[Biological diagnosis of tuberculosis]

Today, the diagnosis tests for tuberculosis are based on: the observation of acid-fast-bacilli after Ziehl-Neelsen staining or fluorescent microscopy, the growth of a culture, the study of drug sensibility, the observation of granulomatous tissue lesions and caseous necrosis. Use of radioactive liquid culture media (Bactec) or not, has shortened the time required for obtaining the result, but it remains too long and, so far, polymerase chain reaction has not answered the challenge. However molecular techniques have been applied with success to the identification of mycobacterial strains (DNA fingerprinting) and to rapid detection of antimicrobial resistance caused by mutation of the target genes. Progress of the molecular tests could lead to desoxyribonucleic microarrays, which would be able to revolutionize the microbiological diagnostic tests.