[Identification of mycobacteria species using genetic probes]

Using commercially available probes Gen-Probe (Accu-Probe, Epignost, Austria) labelled with acridinium ester, the authors identified 102 cultures of mycobacteria which are the causal agents of classical tuberculosis or cause mycobacterioses which are difficult to control by therapeutic measures. The cultures were isolated from sputum or lymph nodes and cultivated on Löwenstein-Jensen medium. The authors proved a 100% sensitivity of the probe for isolates of M. tuberculosis and M. kansasii. In a group of 36 strains sent as suspect M. avium 33 strains reacted with the probe for the M. avium complex, 28 strains with the M. avium probe and 4 strains with the M. intracellulare. One isolate hybridized only with the probe for the M. avium complex. In one isolate a positive hybridization value was recorded with the M. gordonae probe and in one pigmented strain with the M. kansasii probe. One isolate did not hybridize with any of the probes used. In one instance a mixed culture of M. tuberculosis and M. avium was involved. The results of hybridization were interpreted in RLU values (relative light unit). Isolates above 30,000 RLU were evaluated positively, as recommended by the manufacturer.