Staphylococcus aureus carriage state in healthy adult population and phenotypic and genotypic properties of isolated strains

Introduction
At present, infections induced by staphylococci, especially methicillin-resistant Staphylococcus aureus (MRSA) are one of key therapeutic and epidemiological problems.

Aim
The assessment of Staphylococcus aureus carrier state occurrence among a healthy adult population as well as determination of phenotypic and genotypic properties of the isolated strains.

Material and methods
The study included 100 healthy individuals. Material for bacteriological evaluation was collected from the posterior pharyngeal wall and tonsils, nasal vestibule and the skin of anterior nares using a sterile swab. The isolates identified as Staphylococcus aureus were analysed further, towards slime-forming capacity and the presence of genes mecA and nuc.

Results
The analysis included 300 samples obtained from the posterior vault of the pharynx and tonsils, nasal vestibule and the skin of nares. Pharyngeal and vestibular S. aureus carriage was determined in 20% of the examined adults, whereas in 11 people with recognized positive throat colonization, the concurrent presence of golden staph was detected in the vestibule of the nose and on the skin, in the nose region. Identification process indicated the occurrence of strains defective in clumping factor synthesis (5% of isolates) and lack of the coa gene (11% of examined isolates). The PCR technique used to screen for the presence of the mec gene, did not confirm it in any of the strains under study. All the isolates had the gene encoding the thermostable nuclease nuc.

Conclusions
S. aureus is a pervasive pathogen in community settings with constantly changing trends.