Phänotypische Differenzierung von Mykobakterien mit Hilfe eines miniaturisierten, automatisierten, enzymatischen Testsystems

摘要

The aim of this study was to evaluate whether a commercially produced test-system, originally designed to differentiate gram-positive bacteria (rapid identification system for gram positive organisms, RPO-system, Merlin comp.) is as well suitable for the differentiation of mycobacteria. The system allows to perform rapid and easy biochemical tests of bacterial strains. The standardised method allowed us to perform 44 tests on enzymatic activity within about 36 hours. Our special interest was to find out which of the enzymatic and fermentative tests are useful for the differentiation of mycobacteria. Therefore we examined, if these tests would allow to identify mycobacterial taxa clearly distinguished on the level of species and subtypes on a molecular basis. 439 strains of 133 different taxa (62 species) were examined providing an average of three strains per taxon. 17 of the 44 biochemical tests proved to be useless. These were mainly tests of fermentation of different sugars, which showed almost uniformly no reaction. 12 of the examined tests allowed a certain degree of differentiation between genetically and chemotaxonomically defined taxa and subgroups. Nevertheless the specificity of the identification was not satisfying. We therefore conclude that the present set of 12 tests could form a basis for a test- system for the rapid identification of mycobacteria. For a sufficient specificity the set would need to be supplemented by further enzymatic tests yet to be developed.