To assess the in vitro activity of ceftobiprole and comparators against a recent collection of Gram-positive and Gram-negative pathogens, in order to detect potential changes in susceptibility patterns, and to evaluate the Etest assay for ceftobiprole susceptibility testing. Contemporary Gram-positive and Gram-negative isolates (excluding extended-spectrum β-lactamase-producing isolates) from across Europe and the Middle East were collected, and their susceptibility to ceftobiprole, vancomycin, teicoplanin, linezolid, ceftazidime and cefepime was assessed using the Etest method. Quality testing [using Etest and broth microdilution (BMD)] was conducted at a central reference laboratory. Some 5041 Gram-positive and 4026 Gram-negative isolates were included. Against Gram-positive isolates overall, ceftobiprole had the lowest MIC50 (0.5 mg/L), compared with 1 mg/L for its comparators (vancomycin, teicoplanin and linezolid). Against methicillin-resistant Staphylococcus aureus, all four agents had a similar MIC90 (2 mg/L), but ceftobiprole had a 4-fold better MIC90 (0.5 mg/L) against methicillin-susceptible strains. Only 38 Gram-positive isolates were confirmed as ceftobiprole resistant. Among Gram-negative strains, 86.9%, 91.7% and 95.2% were susceptible to ceftobiprole, ceftazidime and cefepime, respectively. Pseudomonas aeruginosa was less susceptible to all three antimicrobials than any other Gram-negative pathogen. There was generally good agreement between local Etest results and those obtained at the reference laboratory (for ceftobiprole: 86.8% with Gram-negatives; and 94.7% with Gram-positives), as well as between results obtained by BMD and Etest methods (for ceftobiprole: 98.2% with Gram-negatives; and 98.4% with Gram-positives). Ceftobiprole exhibits in vitro activity against a wide range of Gram-positive and Gram-negative pathogens, including multidrug-resistant strains. No changes in its known susceptibility profile were identified.
Chronic Helicobacter pylori infection is associated with alterations in gastric mucosal cell proliferation. Despite the recognition that bacterial lipopolysaccharide (LPS) is present in biologically active quantities in the gastric mucosa, the mechanisms by which it stimulates cells are largely unknown. We have previously established a gastric enterochromaffin-like (ECL) cell neoplasia model in the African rodent species Mastomys and identified that tumor ECL cell proliferation is associated with polyamine biosynthesis and ornithine decarboxylase (ODC) activity. In addition, we have shown that H. pylori LPS exhibits a specific mitogenic effect on naive ECL cells in vitro. The aim of this study was to evaluate whether H. pylori has a direct effect on tumor ECL cell proliferation in vitro and further to evaluate the possible molecular mechanisms for this effect. ECL cell neoplasia was generated in Mastomys by endogenous hypergastrinemia induced by H(2) blockade (loxtidine 1 g/kg/day) and tumor ECL cells prepared. The DNA synthesis in 24-hour cultured tumor cells was measured by bromodeoxyuridine uptake and ODC activity by (14)CO(2) formation from (14)C-ornithine. The putative LPS receptor, CD14, was evaluated by reverse-transcription polymerase chain reaction. Our results demonstrated: (1) H. pylori LPS (10(-12) to 10(-7) M) stimulated basal DNA synthesis (2.2-fold) with an estimated EC(50) of 10(-10) M; (2) this proliferative response correlated with an increase in ODC activity (1.4-fold, EC(50) approximately 10(-10) M) which could be inhibited by a specific ODC inhibitor, difluoromethyl ornithine, at 10(-9) M; (3) the CD14 receptor was identified in both naive and transformed ECL cells by reverse-transcription polymerase chain reaction, and (4) the effects of LPS were inhibited by blocking the CD14 receptor with its specific monoclonal antibody (1:100). Thus, H. pylori LPS appears to influence tumor ECL cell proliferation by activation of the intracellular polyamine pathway and ODC activity via a CD14 receptor on the ECL cell.
Severe adverse events (AEs) compromise the outcome of direct antiviral agent-based treatment in patients with advanced liver fibrosis due to HCV infection. HEP3002 is an ongoing multinational programme to evaluate safety and efficacy of telaprevir (TVR) plus pegylated-interferon-α (PEG-IFNα) and ribavirin (RBV) in patients with advanced liver fibrosis caused by HCV genotype 1 (HCV-1).
Methods
1782 patients with HCV-1 and bridging fibrosis or compensated cirrhosis were prospectively recruited from 16 countries worldwide, and treated with 12 weeks of TVR plus PEG-IFN/RBV, followed by 12 or 36 weeks of PEG-IFN and RBV (PR) alone dependent on virological response to treatment and previous response type.
Results
1587 patients completed 12 weeks of triple therapy and 4 weeks of PR tail (53% cirrhosis, 22% HCV-1a). By week 12, HCV RNA was undetectable in 85% of naives, 88% of relapsers, 80% of partial responders and 72% of null responders. Overall, 931 patients (59%) developed grade 1–4 anaemia (grade 3/4 in 31%), 630 (40%) dose reduced RBV, 332 (21%) received erythropoietin and 157 (10%) were transfused. Age and female gender were the strongest predictors of anaemia. 64 patients (4%) developed a grade 3/4 rash. Discontinuation of TVR due to AEs was necessary in 193 patients (12%). Seven patients died (0.4%, six had cirrhosis).
Conclusions
In compensated patients with advanced fibrosis due to HCV-1, triple therapy with TVR led to satisfactory rates of safety, tolerability and on-treatment virological response with adequate managements of AEs.
