ABSTRACT
Implants made of ceramic and metallic elements, which are used in dentistry, may either promote or hinder the colonization and adhesion of bacteria to the surface of the biomaterial to varying degrees. The increased interest in the use of dental implants, especially in patients with chronic systemic diseases such as cystic fibrosis (CF), is caused by an increase in disease complications. In this study, we evaluated the differences in the in vitro biofilm formation on the surface of biomaterials commonly used in dentistry (Ti-6Al-4V, cobalt-chromium alloy (CoCr), and zirconia) by Staphylococcus aureus isolated from patients with CF. We demonstrated that S. aureus adherence and growth depends on the type of material used and its surface topography. Weaker bacterial biofilm formation was observed on zirconia surfaces compared to titanium and cobalt-chromium alloy surfaces. Moreover, scanning electron microscopy showed clear differences in bacterial aggregation, depending on the type of biomaterial used. Over the past several decades, S. aureus strains have developed several mechanisms of resistance, especially in patients on chronic antibiotic treatment such as CF. Therefore, the selection of an appropriate implant biomaterial with limited microorganism adhesion characteristics can affect the occurrence and progression of oral cavity infections, particularly in patients with chronic systemic diseases.
ABSTRACT
According to a debated hypothesis, the biosynthesis from emodin of the medicinally important natural compound hypericin is catalyzed in St John's wort (Hypericum perforatum) by the phenolic oxidative-coupling protein Hyp-1. Recombinant St John's wort Hyp-1 has been overexpressed in Escherichia coli and obtained in single-crystal form. The crystals belong to the orthorhombic system, space group P2(1)2(1)2(1), with unit-cell parameters a = 37.5, b = 76.7, c = 119.8 A, contain two protein molecules in the asymmetric unit and diffract X-rays to 1.73 A resolution.
