Summary
The aim. To determine the resistance to antimicrobials of Staphylococcus aureus strains isolated from clinical samples and to identify prevailing resistance genes.
Material and methods. The study in Vilnius Clinical Hospital was carried out from March 2017 to April 2018. S. aureus strains were isolated from clinical specimens. Antibiotic susceptibility testing was performed according to the European Committee on Antimicrobial Susceptibility guidelines. S. aureus strains resistant to tetracycline and erythromycin had a multiplex PCR performed to detect resistance genes.
Results. 364 S. aureus strains iso lated from clinical specimens were analyzed. 67.6% strains were isolated from the skin and soft tissues, 12.9% – from blood, 14.3% – from the lower respiratory tract, etc. All 364 isolates were found to be susceptible to rifampicin and vancomycin. 22.3% of the isolated strains were susceptible to all tested antimicrobials. Antimicrobial resistance testing revealed that the highest resistance was to penicillin (73.9%). Resistance to erythromycin and tetracycline was 9.9% and 6.3%, respectively. Less than 4% S. aureus strains tested were resitant to fusidic acid and cefoxitin. four of methicillin resistant strains were isolated from the blood, eight – from skin and soft tissues. 87% of tetracycline resistant S. aureus strains harbored tetK gene, ermC gene was detected in 72.2%, ermA – in 19.5% of erythromycin resistant S. aureus strains.
Conclusions. S. aureus resistance rate to antimicrobials was the highest to penicillin. All tested strains were susceptible to rifampicin and vancomycin. 3.6% of the strains were methicillin-resistant S. aureus. tetK gene was predominant among S. aureus strains resistant to tetracycline and ermC gene was predominant among erythromycin resistant strains.
