To investigate the ability of the bacteriophage Sb-1 to treat and prevent implant-associated infections due to methicillin-resistant Staphylococcus aureus (MRSA) in The stability of Sb-1 in Aim
Method
Virulent bacteriophages are known to be an effective therapy against various human bacterial infections. The aims of the study are to evaluate i) the killing activity of an antistaphylococcal phage lysate (ASPL), available in the Czech Republic for topical application, against The susceptibility of 25 MRSA and 18 methicillin-sensitive Sa (MSSA) strains to the ASPL was evaluated by spot assay. In addition, susceptibility of four laboratory MRSA strains, including ATCC 43300, ATCC 33591, Mu3 (MRSA/hetero vancomycin intermediate resistant Sa) and Mu50 (MRSA/vancomycin-resistant Sa) was also tested. The activity of ASPL against planktonic and biofilm-embedded MRSA ATCC 43300 was evaluated in real-time by isothermal microcalorimetry. The minimum heat inhibitory concentrations (MHIC) was defined as the lowest antimicrobial concentration leading to the lack of heat flow production after 24h for both planktonic and biofilm-embedded cells. The viability of bacterial cells was assessed by plating and colony counting. The minimum bactericidal concentration (MBC) was defined as the lowest antimicrobial concentration leading the reduction of 3 log CFU compared to the untreated control.Aim
Method
Phage therapy has attracted attention as a promising alternative treatment option for biofilm infections. To establish a successful phage therapy, a comprehensive stock of different phages covering a broad bacterial spectrum is crucial. We screened human and environmental sources for presence of lytic phages against selected bacteria. Saliva collected from 10 volunteers and 500 ml of sewage water were screened for the presence of lytic phages active against 20 clinical strains of Aim
Methods
Matrilin-3 is a member of the recently described matrilin family of extracellular matrix proteins containing von Willebrand factor A-like domains. The matrilin-3 subunit can form homotetramers as well as hetero-oligomers together with subunits of matrilin-1 (cartilage matrix protein). It has a restricted tissue distribution and is strongly expressed in growing skeletal tissues. Detailed information on expression and distribution of extracellular matrix proteins is important to understand cartilage function in health and in disease like osteoarthritis.
Matrilin-3 expression was analysed on decalcified normal cartilage/bone sections (N = 5) and decalcified cartilage/ bone sections with minor (N= 10), moderate (N = 10), and severe osteoarthritic lesions (N = 10). Osteoarthritic changes were classified histomorphologically, using the grading system of Mankin. Matrilin-3 expression was investigated by immunohistochemistry, in situ hybridization, Western blot analysis, and quantitative PCR. For immunohistochemistry, a polyclonal antibody against matrilin-3 was used. For Western blot analysis, cartilage extracts were obtained from normal and osteoarthritic samples, partially purified, and separated in SDS poly-acrylamide gelelectrophoreses. After blotting onto nitro-cellulose, matrilin-3 was visualized by incubation with the polyclonal anti-matrilin-3 antibody and chemiluminescence detection. Matrilin-3 -mRNA expression was determined by in situ hybridization using a digoxigenin-labeled anti-sense probe.
Our results indicate that matrilin-3 is a mandatory component of mature articular cartilage with its expression being restricted to chondrocytes from the tangential zone and the upper middle cartilage zone. Osteoarthritic cartilage samples with only moderate morphological osteoarthritic destructions have elevated levels of matrilin-3 mRNA. In parallel, we found an increased deposition of matrilin-3 protein in the cartilage matrix. Matrilin-3 staining was diffusely distributed in the cartilage matrix, with no cellular staining being detectable. In cartilage samples with minor osteoarthritic lesions, matrilin-3 deposition was restricted to the middle zone and to the upper deep zone. A strong correlation was found between enhanced matrilin-3 gene and protein expression and the extent of tissue damage. Sections with severe osteoarthritic destruction showed the highest amount of matrilin-3 mRNA, strong signals in in situ hybridization, and prominent protein deposition in the middle and deep cartilage zone.
We conclude that matrilin-3 is an integral component of human articular cartilage matrix and that the enhanced expression of matrilin-3 in osteoarthritis may be a cellular response to the modified microenvironment in the disease.
