Analyse der Mikroevolution von Staphylococcus aureus bei hospitalisierten Patienten

BMBF PTJ-BIO/0313801Bim Rahmen der BMBF-Fördermaßnahme "Kompetenznetz Genomforschung an pathogenen Bakterien – PathoGenoMik-Plus
C. von Eiff, K. Becker, G. Peters
As a classical opportunistic pathogen, the bacterial species Staphylococcus aureus interacts in a usually neutral manner with its human host. However, when translocated from its primary nasal habitat, S. aureus has a large pathogenic potential to cause a broad range of superficial to deep and systemic infections as well as toxin-mediated syndromes. The anterior nares (vestibulum nasi) have been shown to be the main reservoirs for S. aureus. Approximately 20 percent of healthy people almost always carry this pathogen. A large proportion of the human population (ca. 60 percent) harbours S. aureus intermittently, and the colonizing strains change with varying frequency. Carriage of S. aureus in the nose appears to play a key part in the pathogenesis of infections due to this pathogen. While nasal carriage has been shown to be a source of subsequent S. aureus infections, only few data are available on the microevolution and genetic plasticity of nasal carriage strains in the biotope of a hospital environment. Consequently, the principal object of our project will be to analyze longitudinally - under hospitalization of its host - the microevolution and genetic plasticity of S. aureus strains including isolates with normal and small-colony variant (SCV) phenotype. For this purpose, the putative adaptation of persistently colonizing S. aureus strains recovered from patients prior, during, and post hospitalization or the replacement by competing strains of this pathogen will be studied with respect to the possession, acquisition and expression of virulence factors and resistance markers, also applying the modern tools of the "omic" era.

Staphylococcal phenotypes: Normal and small colony variant (SCV) phenotype