Supplementary Material for: Genetic and Phenotypic Characteristics of <b><i>Staphylococcus aureus</i></b> Isolates from Cystic Fibrosis Patients in Austria

<b><i>Background:</i></b> Cystic fibrosis (CF) is the most common life-limiting inherited disease in Caucasian populations. While pathological changes can be seen in various organs, morbidity and mortality are mainly related to the respiratory tract, with patients suffering from chronic bronchopulmonary infections with characteristic pathogens including <i>Staphylococcus aureus.</i><b><i>Objectives:</i></b> To date, there is only very limited data on the genetic and phenotypic characteristics of <i>S. aureus </i>in CF patients. Therefore, in our study, we characterized 58 <i>S. aureus </i>isolates collected from CF patients in Austria by <i>spa </i>typing, DNA microarray profiling, as well as antimicrobial susceptibility testing in order to determine common genomic and antimicrobial resistance features. The tested strain collection exhibited high genomic diversity. <b><i>Results:</i></b> The 58 isolates were assigned to 16 clonal complexes and 48 <i>spa </i>types and differed greatly regarding their virulence and resistance gene profiles. The predominant clonal complexes were MLST CC30 (22%), CC15 (16%), CC45 (14%), and CC5 (12%), complexes that are highly prevalent worldwide among <i>S. aureus</i> strains isolated from humans colonized or infected with <i>S. aureus.</i> DNA microarray profiles showed a wide variety of genes encoding antimicrobial resistance and virulence factors such as various leukocidins, haemolysins, enterotoxins, exfoliative toxins, toxic shock syndrome toxin, as well as genes involved in adhesion and immune evasion. <b><i>Conclusions:</i></b> While a large number of strains exhibited resistance to one or several antimicrobial agents, methicillin-resistant <i>S. aureus</i> was found at a low prevalence of 3% (n = 2) only. The two methicillin-resistant <i>S. aureus</i> isolates were assigned to CC152/t355 (SCC<i>mec</i>V) and CC5/t001 (SCC<i>mec</i>I). This is the first study to genetically characterize <i>S. aureus</i> isolates in CF patients in Austria.