Staphylococcus aureus is a facultative pathogen that can encode numerous antibiotic resistance and immune evasion genes and can cause severe infections. Reduced susceptibility to last resort antibiotics such as vancomycin and daptomycin is often associated with mutations in walRK, an essential two-component regulatory system (TCS). This study focuses on the WalK accessory membrane proteins YycH and YycI and their influence on WalRK phosphorylation. Depletion of YycH and YycI by antisense RNA caused an impaired autolysis, indicating a positive regulatory function on WalK as has been previously described. Phosphorylation assays with full-length recombinant proteins in phospholipid liposomes showed that YycH and YycI stimulate WalK activity and that both regulatory proteins are needed for full activation of the WalK kinase. This was validated in vivo through examining the phosphorylation status of WalR using Phos-tag SDS-PAGE with a yycHI deletion mutant exhibiting reduced levels of phosphorylated WalR. In the yycHI knockdown strain, muropeptide composition of the cell wall was not affected, however, the wall teichoic acid content was increased. In conclusion, a direct modulation of WalRK phosphorylation activity by the accessory proteins YycH and YycI is reported both in vitro and in vivo. Taken together, our results show that YycH and YycI are important in the direct regulation of WalRK-dependent cell wall metabolism.

Thyroid eye disease (TED) is a potentially sight-threatening and cosmetically disfiguring condition arising in 25-50% of patients with Graves' hyperthyroidism. CIRTED is the first study to evaluate the long-term role of radiotherapy and prolonged immunosuppression with azathioprine in treating TED, one aim of which was to validate the use of the English version of GO-QOL in an UK population with TED. In a three stage design over a 48 week period, the GO-QOL was tested and compared to a general measure of quality of life (WHOQOL-Bref). In stage 1 utilising a standard 14 day test-retest design both GO-QOL subscales achieved Cronbach's alphas demonstrating excellent validity and internal reliability (Visual Function 0.929 and 0.931; Appearance 0.888 and 0.906). In stage 2, Repeated Measures ANOVA demonstrated longitudinal validity, with both subscales of the GO-QOL showing significant change over time (Visual Function, η = 0.114, p < .001; Appearance, η = 0.069, p < .002). In stage 3 the GO-QOL showed discriminant validity at the week 48 time point, with the visual function subscale being able to detect changes in groups identified by clinicians (using BCCOM ratings of improvement or deterioration), while both subscales could detect group differences when based on participants' subjective ratings of TED noticeability and severity. The results of this project provide support for the English translation of the GO-QOL as an outcome measure for patients with moderately severe active Graves' orbitopathy/TED.

Infections with methicillin-resistant Staphylococcus aureus are commonly treated with vancomycin. This antibiotic inhibits cell wall biosynthesis by binding to the cell wall building block lipid II.

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