Résumé:
Actinomycetes are Gram-stain-positive. Ubiquitous, they live as saprophyte in the soil.
Although they are rarely encountered in clinical practice, they have great potential and
cause serious human infections.
Forty-two strains of aerobic actinomycetes (except mycobacteria) were isolated from
3682 clinical specimens patients from Benbadis Hospital of Constantine. The diversity
and identification of some representative isolates were determined by a polyphasic
approach (phenotypic, genotypic and phylogenetic informations).
Phylogenetic analysis of the isolates allowed to classify them in the phylum of
Actinobacteria, to the families of Nocadiopsaceae, Pseudonocardiaceae,
Micromonosporaceae, Tsukamurellaceae, and Thermomonosporaceae. They are
affiliated to seven different genera, Nocardiopsis (53.33%), Pseudonocardia (13.33%),
Murinocardiopsis (6.66%), Tsukamurella (6.66%), Actinomadura (6.66),
Micromonospora (6.66) et Saccharopolyspora (6.66%).
Approach by proteomics analysis of mass spectrometry MALDI-TOF has been
validated and optimized for the identification and classification of bacteria of the genus
Tsukamurella. Through the MLST method and the amplification of four genes (lepA,
rpoA, rpo B and ftsZ) and the technique of mass spectrometry we were able to conclude
that isolate 1534 is probably a new species of Tsukamurella. Furthermore, sequencing
of the complete genome of this isolate was done by two sequencing techniques, the
shotgun method and 3-kb paired-end.
