Abstract: Prosthetic valve and pacemaker lead endocarditis by Staphylococcus lugdunensis remain very rare, while the former is associated with an ominous prognosis. Two cases involving a prosthetic aortic valve and a pacemaker lead, respectively, are reported. Despite disease severity and delayed diagnosis, patients recovered fully with combined antimicrobial and surgical treatment.
Abstract: Antibiotic resistance has been associated with the use of antibiotics. The dispensing of antimicrobials without prescription is a potential source of inappropriate antibiotic use. In our study, antibiotics were requested without prescription from pharmacies in the metropolitan area of Athens in Greece in 2008. Twenty-one collaborators visited 174 pharmacies and asked for either amoxicillin/clavulanate acid or ciprofloxacin without providing a prescription or any other justification for the request. In Greece additional restrictions for fluoroquinolone prescriptions were implemented in 2003 after which a separate specific prescription form needs to be filled in by the prescriber, justifying the choice of any fluoroquinolone. Amoxicillin/clavulanate acid was dispensed in all cases. Furthermore, despite the regulation restricting the prescription of ciprofloxacin, this drug was dispensed by 53% of the pharmacies. It appears that the implementation of measures to restrict the use of certain antibiotics (e.g. ciprofloxacin that was studied in our case) was effective in reducing, although not eliminating, inappropriate dispensing. Overall, dispensing of antimicrobials without prescription is a widespread practice in the studied area and is contributing to the overuse of antibiotics.
Abstract: 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.
Abstract: A synthetic crystallic semihydrate form of calcium sulfate, Stimulan, was evaluated as a biodegradable carrier for the daily in vitro elution of daptomycin. Daptomycin and Stimulan were admixed at a ratio of 95:5. Elution lasted for 28 days. Eluted concentrations peaked on days 1 and 11, when the mean values were 1,320.1 and 949.2 microg/ml, respectively. The lowest eluted concentration was detected on day 28. These results support the application of the system described in experimental models of osteomyelitis.
Abstract: Clinical experience of prolonged use of linezolid in patients with bone infections is accumulating. However more efficacy and safety data are required. this is a case-control study of patients who received linezolid for difficult-to-treat, intolerant or resistant-to-other-antibiotics bone infections. Linezolid was administered i.v. or orally in 34 patients. Results concerning efficacy and safety were compared to a group of well-matched controls. The clinical arrest rate was 74% in the linezolid group and 68% in the control group (p=NS). treatment was discontinued in 14 (44%) patients of the linezolid group and in 2 (6%) patients of the control group due to adverse events. In the linezolid group 11 (33%) patients developed anemia and 3 (9%) developed thrombocytopenia that led to discontinuation of treatment. Linezolid is effective in a substantial proportion of patients, but the incidence of hematologic adverse events makes close follow-up and laboratory monitoring mandatory.
Abstract: Coagulase-negative staphylococci (CNS) are important causes of infective endocarditis (IE), but their microbiological profiles are poorly described. We performed DNA target sequencing and susceptibility testing for 91 patients with definite CNS IE who were identified from the International Collaboration on Endocarditis-Microbiology, a large, multicenter, multinational consortium. A hierarchy of gene sequences demonstrated great genetic diversity within CNS from patients with definite endocarditis that represented diverse geographic regions. In particular, rpoB sequence data demonstrated unique genetic signatures with the potential to serve as an important tool for global surveillance.
Abstract: Identification of viridans group streptococci (VGS) to the species level is difficult because VGS exchange genetic material. We performed multilocus DNA target sequencing to assess phylogenetic concordance of VGS for a well-defined clinical syndrome. The hierarchy of sequence data was often discordant, underscoring the importance of establishing biological relevance for finer phylogenetic distinctions.
Abstract: A total of 10420 Gram-positive cocci (including staphylococci, enterococci and various groups of streptococci) collected from clinically significant specimens in ten Greek hospitals during 2006--2007 were tested for their susceptibility to daptomycin. The minimum inhibitory concentration (MIC) was determined by the broth microdilution method. Daptomycin demonstrated very high activity against Enterococcus faecalis (MIC at which 50% of the isolates were inhibited (MIC50) = 1mg/L and MIC at which 90% of the isolates were inhibited (MIC90) = 1.36 mg/L), Enterococcus faecium (MIC50 = 1.36 mg/L and MIC90 = 1.90 mg/L), Streptococcus pyogenes (MIC50 = 0.12 mg/L and MIC90 = 0.50mg/L), Streptococcus agalactiae (MIC50 = 0.09 mg/L and MIC90 = 0.12 mg/L), Streptococcus pneumoniae (MIC50 = 0.24 mg/L and MIC90 = 0.5 mg/L) and viridans group streptococci (MIC50 = 0.50 mg/L and MIC90 = 0.89 mg/L). Resistance to linezolid and vancomycin for enterococci and to penicillin for streptococci appears to be independent of reduced susceptibility to daptomycin. On the other hand, daptomycin was also active against meticillin-resistant Staphylococcus aureus (MIC50 = 0.44 mg/L and MIC90 = 0.78 mg/L) and meticillin-resistant coagulase-negative staphylococci (MIC50 = 0.24 mg/L and MIC90 = 0.44 mg/L); however, 0.9% of the staphylococci tested had an MIC > 1mg/L, which is the Clinical and Laboratory Standards Institute breakpoint proposed for susceptibility. For all tested organism groups, resistance to daptomycin was not associated with glycopeptide resistance.
Abstract: The pharmacokinetic profiles of fusidic acid and cefepime in heart tissues were assessed in 30 patients undergoing elective valve replacement and cardiopulmonary bypass. Single doses of 1 g of fusidic acid and 2 g of cefepime were administered intravenously to two groups of 15 and 15 patients respectively upon initiation of anesthesia. Samples of serum, heart valves, myocardium, pericardium, mediastinal fat and sternum were collected within <1 hour, 1-2 h and 2-4 h after the end of drug infusion. Drug concentrations were estimated by a microbiological assay. It was found that concentrations of fusidic acid in all specimens were 20-fold higher than the MIC90s of methicillin-resistant Staphylococcus aureus and Staphylococcus epidermidis, being at such levels throughout all period of sampling. Cefepime concentrations in heart valves collected 1-2 h after drug infusion were higher than the MIC90s of multidrug-resistant Enterobacteriaceae. It is concluded that both fusidic acid and cefepime penetrated heart tissues adequately; however only fusidic acid could also accumulate in the mediastinum. These data suggest that both antibiotics may be a good alternative for prophylaxis in open heart surgery.
Abstract: Current epidemiological trends of infective endocarditis (IE) in Greece were investigated via a prospective cohort study of all cases of IE that fulfilled the Duke criteria during 2000-2004 in 14 tertiary and six general hospitals in the metropolitan area of Athens. Demographics, clinical data and outcome were compared for nosocomial IE (NIE) and community-acquired IE (CIE). NIE accounted for 42 (21.5%) and CIE for 153 (78.5%) of 195 cases. Intravenous drug use was associated exclusively with CIE, while co-morbidities (cardiovascular disease, diabetes mellitus, chronic renal failure requiring haemodialysis and malignancies) were more frequent in the NIE group (p <0.05). Prosthetic valve endocarditis (PVE) predominated in the NIE group (p 0.006), and >50% of NIE cases had a history of vascular intervention. Coagulase-negative staphylococci and enterococci were more frequent in cases of NIE than in cases of CIE (26.2% vs. 5.2%, p <0.01, and 30.9% vs. 16.3%, p 0.05, respectively). Enterococci accounted for 19.5% of total IE cases and were the leading cause of NIE. Staphylococcus aureus IE was hospital-acquired in only 11.9% of cases. In-hospital mortality was higher for NIE than for CIE (39.5% vs. 18.6%, p 0.02). Cardiac failure (New York Heart Association grade III-IV; OR 13.3, 95% CI 4.9-36.1, p <0.001) and prosthetic valve endocarditis (OR 3.7, 95% CI 1.3-10.6, p 0.01) were the most important predictors of mortality.
Abstract: Multidrug-resistant infections present a serious clinical and therapeutical problem. Colistin is an old-used polymyxin with rather poor pharmacokinetic profile and a remarkable nephrotoxicity. However, the emergence of multidrug-resistant bacteria has recently led to the increased use of colistin as a potentially available therapy. This article presents a 75-year-old diabetic woman with an early onset total knee arthroplasty infection by a multidrug-resistant Pseudomonas aeruginosa bacterial isolate that was managed successfully with surgical removal of the knee prosthesis, antibiotic impregnated cement and intravenous administration of colistin for 6 weeks, and second stage revision knee surgery. Two years later, laboratory and imaging studies showed no evidence of recurrence of infection.
Abstract: The in vitro activities of tigecycline and selected antimicrobials were evaluated against a variety of multiple-drug-resistant clinical isolates, including extended-spectrum beta-lactamase- and/or metallo-beta-lactamase-producing gram-negative strains, colistin-resistant strains, vancomycin- and/or linezolid-resistant enterococci, and methicillin-resistant Staphylococcus aureus (MRSA). Tigecycline showed excellent activity against a collection of difficult-to-treat pathogens currently encountered in the hospital setting.
Abstract: Complications of long-term linezolid administration include anemia and thrombocytopenia. A recent report has suggested that pyridoxine may prevent myelosuppression. Pyridoxine was administered to 24 patients with bone infections who were being treated with linezolid. Thrombocytopenia occurred in 11 patients (45.8%), and anemia occurred in 6 (25%). We concluded that treatment wtih pyridoxine is unlikely to benefit patients who have been receiving linezolid for >2 weeks.
Abstract: A unique case of septic arthritis caused by Salmonella enteritidis in a patient receiving infliximab for rheumatoid arthritis is presented. Antimicrobial chemotherapy with surgical intervention was necessary for eradication of the infection. Physicians should be aware of rare manifestations of Salmonella infections associated with infliximab use, especially in endemic areas.
