| Abstract [eng] |
Master’s Thesis by Eglė Galminaitė, supervisor – Agnė Kirkliauskienė, PhD. Vilnius University, Faculty of Medicine, Institute of Biomedical Sciences, Department of Physiology, Biochemistry, Microbiology and Laboratory Medicine. Topic of the thesis. Mupirocin resistance in community-acquired and nosocomial Staphylococcus aureus strains. Aim of the research. To determine mupirocin resistance and the presence of genes encoding resistance to this antimicrobial agent in community-acquired and nosocomial Staphylococcus aureus strains. Objectives of the research: 1. To determine high- and low-level mupirocin resistance in community-acquired S. aureus strains; 2. To determine high- and low-level mupirocin resistance in nosocomial S. aureus strains; 3. To determine the prevalence of genes encoding resistance to mupirocin among community-circulating and clinical S. aureus strains; 4. To compare the resistance of community-acquired and nosocomial S. aureus strains to mupirocin and to another antibacterial agent used for eradication. Methods. The study investigated S. aureus strains isolated in 2018–2019 from clinical samples of hospitalised patients and from both nasal and throat swabs of community respondents. Mupirocin resistance of the isolates was determined by disc diffusion and gradient methods. Real-time polymerase chain reaction was used to detect genes encoding mupirocin resistance in all S. aureus isolates. For comparative antimicrobial resistance analysis, disc diffusion method was applied to determine the resistance of the tested S. aureus strains to another antimicrobial agent, fusidic acid. Results. The analysis included 408 phenotypically different S. aureus strains (216 clinical and 192 community-circulating). No high- and/or low level mupirocin-resistant isolates were detected among either the community-circulating or the nosocomial S. aureus strains. Genes encoding mupirocin resistance were also not detected in the tested S. aureus strains. Resistance to fusidic acid in community and clinical S. aureus strains was 2.1% and 5.1% respectively. Conclusions: 1. S. aureus strains circulating in the community did not show high- and/or low level of resistance to mupirocin; 2. No high- and/or low level of resistance to mupirocin was detected in clinical S. aureus strains; 3. The mupA and mupB genes encoding mupirocin resistance have not been detected in community-circulating and clinical strains of S. aureus; 4. When comparing resistance to mupirocin and fusidic acid between community-acquired and nosocomial strains of S. aureus, only resistance to fusidic acid was found in both groups. The nosocomial strains of S. aureus are more resistant to this antimicrobial agent. Keywords. Community-acquired, nosocomial, Staphylococcus aureus, strains, resistance, mupirocin. |
