Search

Purpose. To investigate the clinical, phenotypic and genotypic characteristics of Staphylococcus aureus strains causing osteoarticular infections in a large paediatric series. Methodology. Medical records of children who were hospitalized with the diagnosis of community-associated S. aureus (CA-SA) osteomyelitis and/or septic arthritis in the two major tertiary paediatric hospitals of Athens during an 8-year period (2007–2015) were reviewed, and S. aureus isolates were analysed regarding antimicrobial resistance, detection of pathogenicity genes and genotyping using SCCmec, agr typing, PFGE and MLST. Results. During the study period, 123 children with CA-SA osteoarticular infections were identified, and methicillin-resistant S. aureus (MRSA) accounted for 44 of these (35.8 %). Children with MRSA infection had a significantly higher admission rate to the ICU (5.7 vs 0 %, P=0.04) and longer duration of hospitalization (21.6 vs 16.7 days, P=0.04). Sixty-eight isolates [42 (methicillin-sensitive S. aureus) MSSA and 26 MRSA] were available for molecular analysis. All MRSA strains were mecA-positive and most carried the SCCmec IV cassette (23/26, 88 %) and belonged to the PFGE type C (24/26, 92.3 %), agr type 3 (24/26, 92.3 %) and the MLST ST80 clone (24/26, 92.3 %). In contrast, MSSA strains showed polyclonality by PFGE and agr typing. Regarding pathogenicity genes, MRSA vs MSSA isolates showed higher detection rates of PVL (96.2 vs 4.8 %, P

We hypothesized that a factor may circulate in serum early during sepsis, modulating apoptosis of monocytes and lymphocytes. Serum was collected from 20 healthy volunteers and from 48 patients with severe sepsis/shock within 12 h from signs of the first failing organ. PBMCs were isolated from 20 healthy volunteers and incubated with collected sera. Apoptosis and expression of CD95 were determined by flow cytometry; experiments were run in the presence of caspase-8 and caspase-9 inhibitors and of CaCl2. Activity of caspase-3 was determined in cell lysates by a chromogenic kinetic assay. Incubation with serum of patients induced apoptosis of CD4 lymphocytes and inhibited apoptosis of CD14 monocytes. This was attenuated after diluting serum or mixing with healthy serum. Activity of caspase-3 was consistent with these findings. Induced apoptosis of CD4 lymphocytes was greater among nonsurvivors, and it was inhibited in the presence of caspase inhibitors. Inhibitors did not modify the effect of patients' serum on apoptosis of CD14 monocytes. CaCl2 reversed the inhibitory effect on apoptosis of CD14 moncytes. The above findings support the hypothesis for the existence of an early circulating factor in severe sepsis/shock, modulating apoptosis of CD4 lymphocytes and of CD14 monocytes by interaction with the two apoptotic pathways.

Background A previous randomized study showed that clarithromycin decreases the risk of death due to ventilator-associated pneumonia and shortens the time until infection resolution. The efficacy of clarithromycin was tested in a larger population with sepsis. Methods Six hundred patients with systemic inflammatory response syndrome due to acute pyelonephritis, acute intra-abdominal infections or primary Gram-negative bacteraemia were enrolled in a double-blind, randomized, multicentre trial. Clarithromycin (1 g) was administered intravenously once daily for 4 days consecutively in 302 patients; another 298 patients were treated with placebo. Mortality was the primary outcome; resolution of infection and hospitalization costs were the secondary outcomes. Results The groups were well matched for demographics, disease severity, microbiology and appropriateness of the administered antimicrobials. Overall 28 day mortality was 17.1% (51 deaths) in the placebo arm and 18.5% (56 deaths) in the clarithromycin arm (P = 0.671). Nineteen out of 26 placebo-treated patients with septic shock and multiple organ dysfunctions died (73.1%) compared with 15 out of 28 clarithromycin-treated patients (53.6%, P = 0.020). The median time until resolution of infection was 5 days in both arms. In the subgroup with severe sepsis/shock, this was 10 days in the placebo arm and 6 days in the clarithromycin arm (P = 0.037). The cost of hospitalization was lower after treatment with clarithromycin (P = 0.044). Serious adverse events were observed in 1.3% and 0.7% of placebo- and clarithromycin-treated patients, respectively (P = 0.502). Conclusions Intravenous clarithromycin did not affect overall mortality; however, administration shortened the time to resolution of infection and decreased the hospitalization costs.

Introduction Although major changes of the immune system have been described in sepsis, it has never been studied whether these may differ in relation to the type of underlying infection or not. This was studied for the first time. Methods The statuses of the innate and adaptive immune systems were prospectively compared in 505 patients. Whole blood was sampled within less than 24 hours of advent of sepsis; white blood cells were stained with monoclonal antibodies and analyzed though a flow cytometer. Results Expression of HLA-DR was significantly decreased among patients with severe sepsis/shock due to acute pyelonephritis and intraabdominal infections compared with sepsis. The rate of apoptosis of natural killer (NK) cells differed significantly among patients with severe sepsis/shock due to ventilator-associated pneumonia (VAP) and hospital-acquired pneumonia (HAP) compared with sepsis. The rate of apoptosis of NKT cells differed significantly among patients with severe sepsis/shock due to acute pyelonephritis, primary bacteremia and VAP/HAP compared with sepsis. Regarding adaptive immunity, absolute counts of CD4-lymphocytes were significantly decreased among patients with severe sepsis/shock due to community-acquired pneumonia (CAP) and intraabdominal infections compared with sepsis. Absolute counts of B-lymphocytes were significantly decreased among patients with severe sepsis/shock due to CAP compared with sepsis. Conclusions Major differences of the early statuses of the innate and adaptive immune systems exist between sepsis and severe sepsis/shock in relation to the underlying type of infection. These results may have a major impact on therapeutics.

AIM: To investigate the role of gastric mucosa at the secretion of sTREM-1 in peptic ulcer. METHODS: Seventy two patients were enrolled; 35 with duodenal, 21 with gastric ulcer and 16 with chronic gastritis. Patients were endoscoped and gastric juice was aspirated. Patients with duodenal and gastric ulcer underwent a second endoscopy post-treatment. Biopsies were incubated in the absence/presence of endotoxins or gastric juice. Supernatants were collected and sTREM-1 and TNFα were measured by enzyme immunoabsorbent assays. Scoring of gastritis was performed before and after treatment according to updated Sydney score. RESULTS: Patients with duodenal and gastric ulcer and those with chronic gastritis had similar scores of gastritis. sTREM-1 was higher in supernatants of tissue samples of H pylori-positive than of H pylori-negative patients with gastric ulcer. Median (± SE) sTREM-1 was found increased in supernatants of patients with gastric ulcer before treatment (203.21 ± 88.91 pg/1000 cells) compared to supernatants either from the same patients post-treatment (8.23 ± 5.79 pg/1000 cells) or from patients with chronic gastritis (6.21 ± 0.71 pg/1000 cells) (P < 0.001 and < 0.001, respectively). Similar differences for sTREM-1 were recorded among LPS-stimulated tissue samples of patients (P = 0.001). Similar differences were not found for TNFα. Positive correlations were found between sTREM-1 of supernatants from patients with both duodenal and gastric ulcer before treatment and the degree of infiltration of neutrophils and monocytes. CONCLUSION: sTREM-1 secreted by the gastric mucosa is an independent mechanism connected to the pathogenesis of peptic ulcer. sTREM-1 was released at the presence of H pylori from the inflamed gastric mucosa in the field of gastric ulcer.

Introduction Our aim was to define early changes of lymphocytes and of NK cells in severe sepsis and to correlate them with serum levels of soluble triggering receptor expressed on myeloid cells-1 (sTREM-1). Methods Blood was sampled from 49 patients with proven highly suspected infection by Gram-negative pathogens, within 12 hours of the advent of severe sepsis, and was also sampled from six healthy volunteers. White blood cells were targeted with monoclonal antibodies and were analyzed by flow cytometry. The concentrations of sTREM-1 were estimated by ELISA. Results The presence of CD3/CD4 cells was significantly lower (P 20% survived longer compared with those patients with NK cells ≤20% (P = 0.041), and patients with sTREM-1 concentrations >180 pg/ml survived longer compared with those patients with sTREM-1 concentrations ≤180 pg/ml (P = 0.042). A negative correlation was found between the percentages of ANNEXIN-V/CD4/CD3positive cells and of CD3/CD4 cells (rs = -0.305, P = 0.049), and a positive correlation was found between the serum sTREM-1 concentration and the percentage of NK cells (rs = +0.395, P = 0.014). NK cells isolated from two healthy volunteers released sTREM-1 upon triggering with endotoxins. Conclusion Early severe sepsis is characterized by CD4lymphopenia and increased NK cells, providing a survival benefit for the septic patient at percentages >20%. The survival benefit resulting from elevated NK cells might be connected to elevated serum levels of sTREM-1.