Biofilm formation capacities in some staphylococcus aureus strains and the effects of some factors on the biofilm capacities

Biofilms are complex microbial ecosystems formed by one or more microorganism species that adhere to living or non-living surfaces and become organized within a protective matrix composed of extracellular polymeric substances (EPS). In bacteria such as Staphylococcus aureus, a clinically significant pathogen, biofilm formation is considered an important virulence mechanism that enhances tolerance to environmental stresses and contributes to the development of single or multiple resistance to antibiotics. The biofilm development process is significantly influenced by various environmental factors such as temperature, water activity (related to salt concentration), pH, and the presence of nutrients like glucose. This thesis aimed to investigate the biofilm formation potential of a total of four S. aureus strains, comprising two methicillin-resistant (MRSA) and two methicillin-susceptible (MSSA) strains, exhibiting different antibiotic susceptibility profiles, and to determine how this potential is modulated by the key environmental factors: temperature, pH, and NaCl concentration. In the initial phase of the study, the optimal glucose concentration supporting biofilm formation was determined for the four selected strains. In the subsequent phase, the biofilm formation capacities of these strains were quantitatively assessed under varying conditions of temperature, pH, and NaCl concentration to determine the optimum levels for each factor. This research is important for understanding how S. aureus adapts to environmental conditions through biofilm formation and for utilizing this knowledge to develop potential control strategies.