The saePQRS system of Staphylococcus aureus controls the expression of major virulence factors and encodes a histidine kinase (SaeS), a response regulator (SaeR), a membrane protein (SaeQ), and a lipoprotein (SaeP). The widely used strain Newman is characterized by a single amino acid change in the sensory domain of SaeS (Pro18 in strain Newman [SaeS P ], compared with Leu18 in other strains [SaeS L ]). SaeS P determines activation of the class I sae target genes (coa, fnbA, eap, sib, efb, fib, sae), which are highly expressed in strain Newman. In contrast, class II target genes (hla, hlb, cap) are not sensitive to the SaeS polymorphism. The SaeS L allele (saeS L ) is dominant over the SaeS P allele, as shown by single-copy integration of saePQRS L in strain Newman, which results in severe repression of class I target genes. The differential effect on target gene expression is explained by different requirements for SaeR phosphorylation. From an analysis of saeS deletion strains and strains with mutated SaeR phosphorylation sites, we concluded that a high level of SaeR phosphorylation is required for activation of class I target genes. However, a low level of SaeR phosphorylation, which can occur independent of SaeS, is sufficient to activate class II target genes. Using inducible saeRS constructs, we showed that the expression of both types of target genes is independent of the saeRS dosage and that the typical growth phase-dependent gene expression pattern is not driven by SaeRS.The human pathogen Staphylococcus aureus can cause a wide range of diseases. The versatility of this organism is due to its capacity to produce accessory molecules that mediate specific interactions with the host cells. Most of these factors are tightly regulated by global regulatory loci, such as agr, rot, sigB, and sae, which act as an interactive regulatory network to ensure that there is coordinated temporal expression of virulence factors. Within the network, the sae system appears to be a central downstream regulator. Mutations in sae do not affect the transcription of agr, sigB, sarA, or rot (18,22,35). However, at least in some strains, agr activates sae transcription, while sigB and rot repress sae transcription (17,19,21,35,44 (18,33,36,44,46,48,52).The sae locus consists of four open reading frames (ORFs), and the products of two of these ORFs (saeR and saeS) show strong sequence homology to bacterial two-component regulators composed of a histidine kinase (HK), SaeS, and a response regulator (RR), SaeR. Two additional ORFs, ORF3 (saeQ) and ORF4 (saeP), which are located upstream of saeRS, are likely to be important for the function of the sae operon (1,17,48). saeP encodes a putative lipoprotein, and saeQ encodes a membrane protein with four membrane-spanning stretches. Four overlapping sae-specific transcripts (T1 to T4) have been detected; the T1 message (3.1 kb) initiates upstream of saeP, T2 (2.4 kb) initiates upstream of saeQ, and T3 (2.0 kb) initiates upstream of saeR. T4 (0.7 kb) represents a monocistronic mRNA encom...

No abstract

No abstract

To achieve a complete remission of cutaneous and ocular rosacea, a long-term anti-inflammatory treatment of at least 6 months is necessary. The relapse rates seem to be lower than in adults especially in the patients treated with erythromycin.

No abstract

BackgroundPeriprosthetic fractures after total knee arthroplasty (TKA) are an increasing problem and challenging to treat. The tibial side is commonly less affected than the femoral side wherefore few studies and case reports are available. The aim of this study was to analyze the outcome of periprosthetic tibial fractures and compare our data with current literature.MethodsAll periprosthetic tibial TKA fractures that were treated at our Level 1 Trauma Center between 2011 and 2015 were included and analyzed consecutively. The Felix classification was used to assess the fracture type and evaluation included the radiological and clinical outcome (Knee Society Score/KSS, Oxford Knee Score/OKS).ResultsFrom a total of 50 periprosthetic TKA fractures, 9 cases (7 female, 2 male; 2 cruciate retaining, 7 constrained TKAs) involving the tibial side were identified. The mean age in this group was 77 (65–85) years with a follow-up rate of 67% after a mean of 22 (0–36) months. The Felix classification showed type IB (n = 1), type IIB (n = 2), type IIIA (n = 4) and type IIIB (n = 2) and surgical intervention included ORIF (n = 6), revision arthroplasty (n = 1), arthrodesis (n = 1) and amputation (n = 1). The rate of adverse events and revision was 55.6% including impaired wound healing, infection and re-fracture respectively peri-implant fracture. Main revision surgery included soft tissue surgery, arthrodesis, amputation and re-osteosynthesis. The clinical outcome showed a mean OKS of 29 (19–39) points and a functional/knee KSS of 53 (40–70)/41 (17–72) points. Radiological analyses showed 4 cases of malalignment after reduction and plate fixation.ConclusionsPeriprosthetic tibial fractures predominantly affect elderly patients with a reduced bone quality and reveal a high complication rate. Careful operative planning with individual solutions respecting the individual patient condition is crucial. If ORIF with a plate is considered, restoration of the correct alignment and careful soft tissue management including minimal invasive procedures seem important factors for the postoperative outcome.

The plate osteosynthesis of the anterior pelvic ring via the minimally invasive variant of the modified Stoppa-approach is feasible with existing standard laparoscopic instruments.

Refractures of long bones after implant removal are a rare but serious complication, which in most cases make a reoperation necessary. We analysed our own cases and reviewed the scarce literature on this subject. As a result we found that it is possible to reduce this complication by performing thorough preoperative preparation, observing an adequate interim time between initial osteosynthesis and hardware removal, cautiously exposing the weakened bone to force for a certain time period after implant removal and taking the character of the fracture healing into consideration. It is not possible to entirely eradicate this complication because a lot of patients demand the implant removal even though it is known that demineralisation and residual screw holes both induce a reduction of energy-absorbing capacity and therefore predispose the patient to refracture. In some cases the surgeon should recommend that the implants remain in situ.