endocarditis sonication

Optimal antimicrobial treatment of infective endocarditis requires identification and susceptibility patterns of pathogens. Sonication of explanted heart valves could increase the identification and culture of pathogens, as shown in prosthetic joint and pacemaker/ICD infections. We tested 26 explanted heart valves from 20 patients with active definite endocarditis for added diagnostic value of sonication to the standard microbiological workup in a prospective diagnostic proof of concept study. Two sonication protocols (broth enrichment vs...

Streptococcus sanguinis is a commensal and early colonizer of oral cavity as well as an opportunistic pathogen of infectious endocarditis. Extracting the soluble proteome of this bacterium provides deep insights about the physiological dynamic changes under different growth and stress conditions, thus defining "proteomic signatures" as targets for therapeutic intervention. In this protocol, we describe an experimentally verified approach to extract maximal cytoplasmic proteins from Streptococcus sanguinis SK36 strain...

BACKGROUND: Trichoderma species are saprophytic filamentous fungi producing localized and invasive infections that are cause of morbidity and mortality, especially in immunocompromised patients, causing up to 53% mortality. Non-immunocompromised patients, undergoing continuous ambulatory peritoneal dialysis, are other targets of this fungus. Current molecular diagnostic tools, based on the barcode marker ITS, fail to discriminate these fungi at the species level, further increasing the difficulty associated with these infections and their generally poor prognosis...

OBJECTIVES: The clinical utility of sonication as an adjunctive diagnostic tool for the microbial diagnosis of cardiac implantable device-associated infections (CIDAIs) was investigated. METHODS: The implants of 83 subjects were investigated, 15 with a CIDAI and 68 without a clinical infection. Clinical data were analyzed prospectively and sonication fluid cultures (83 patients, 100%) and traditional cultures (31 patients, 37.4%) were performed RESULTS: Generator pocket infection and device-related endocarditis were found in 13 (86...

BACKGROUND: The number of patients with cardiovascular implantable electronic devices (CIEDs) is increasing. The purpose of this study was to compare three methods (sonication, swab cultures, and blood cultures) to detect bacteria in infections of CIEDs. METHODS: Patients with pocket infection of CIEDs and/or CIED-associated infective endocarditis were prospectively included. Generators and leads were sonicated together. Swab cultures of the generator pocket and blood cultures were performed...

Corynebacterium striatum is a commensal of human skin and has been recently recognized as an emerging pathogen. A case of nosocomial pacemaker lead endocarditis due to a multidrug-resistant C. striatum strain is described, highlighting the role of sonication as a diagnostic tool in cardiac device infections.

To study the role of platelet microbicidal activity in host defense against infective endocarditis (IE) due to viridans streptococci (VS), the susceptibility to platelet releasate of blood and oral VS isolates from patients with and without IE was compared. The influence of neutralization of platelet microbicidal activity was studied in 2 experimental IE models. Resistance to platelet releasate was more prevalent among VS from blood of patients with IE than from blood of bacteremic patients without IE and among oral VS isolates...

BACKGROUND AND AIM OF THE STUDY: Prosthetic valve endocarditis (PVE) is a serious complication of heart valve replacement. The use of silver-coated polyester fabric in sewing cuff fabrication is intended to reduce the incidence of PVE. In this study, three pathogenic strains of Staphylococcus epidermidis (two PVE and one peripheral vasculature pathogen) were used to evaluate infection of silver-coated and uncoated fabric. METHODS: Fabric was inoculated by preincubation for 30 min in bacterial suspensions containing 10(4), 10(5), 10(6), 10(7) or 10(8) CFU/ml, and implanted subdermally in mice for up to seven days...

Capnocytophaga, one of the genera of oral bacteria, has been implicated in the pathogenesis of several diseases, including endocarditis, septicaemia and disorders of the oral cavity such as abscesses and periodontal disease. This study examined sonic extracts (SE) of Capnocytophaga strains for their ability to alter lymphocyte function. The SE of tested Capnocytophaga caused dose-dependent suppression of spleen cells in response to mitogen. This suppressive effect was heat-labile and sensitive to the proteolytic enzyme pronase E...

A modified rat model of endocarditis with catheterization for 2 days was established in female Lewis rats using different inocula of Enterococcus faecalis (strain no. EF 19) in order to measure IgG antibodies in serum during the course of infection. Increasing the inocula intravenously resulted in an increase in the CFU/g vegetation and the CFU/g spleen, the ID50 being about 10 CFU/ml and the ID90 about 1x10(2) CFU/ml. The lowest bacterial inoculum infecting 100% of the rats was 3x10(3) CFU/ml, and for further investigations we used this inoculum size...

Two hundred microbiology laboratories in the UK took part in two separate experimental external quality assessment distributions related to the serum bactericidal test (SBT). In the first, Staphylococcus aureus NCTC 6571 (vancomycin MIC 1 mg/L), was tested against a human serum containing vancomycin 38 mg/L plus gentamicin 0.5 mg/L. In the second, Streptococcus oralis PAJ 112/4183 (penicillin MBC < or = 0.03 mg/L) and Streptococcus sanguis PAJ 107/4184 (penicillin MBC = 128 mg/L) were tested against human serum containing penicillin 15 mg/L...

Antibody responses against teichoic acids and other antigens from Staphylococcus aureus in 23 patients with septicemia and 8 patients with endocarditis caused by S. aureus were investigated. Both methods used--solid-phase radioimmunoassay (SPRIA) and crossed immunoelectrophoresis (CIE)--detected significantly higher titres in the endocarditis group. The SPRIA method utilized a sonicated extract of S. aureus, strain Wood 46 for the quantitation of antibodies. In CIE precipitating anti-teichoic acid antibodies were measured...

Ampicillin resistance among strains of Hemophilus is usually due to production of beta-lactamase. This paper reports the isolation of a strain of H. parainfluenzae resistant to ampicillin with no detectable beta-lactamase or amidase activity. The organism, isolated from the blood of a patient who had aortic valve endocarditis, gave a zone diameter consistent with ampicillin sensitivity when tested by disc diffusion in Mueller-Hinton agar supplemented with 1% IsoVitaleX and 1% hemoglobin. Broth dilution testing in Levinthal medium, however, revealed the following minimal inhibitory cencentrations: ampicillin, 32 micrograms/ml; penicillin, 256 micrograms/ml; methicillin, 128 micrograms/ml; carbenicillin, 128 micrograms/ml; and cephalothin and chloramphenicol, 1...

We studied penicillin-binding protein (PBP) profiles of two Pseudomonas aeruginosa strains stably derepressed for constitutive, type Id beta-lactamase overproduction. Substantial levels of beta-lactamase were found to be strongly associated with isolated inner membranes of these two strains, as well as from a plasmid-encoded, TEM-2 beta-lactamase-producing control strain of P. aeruginosa. The inner membrane-associated beta-lactamase resulted in significant decreases in the intensity on autoradiographs of PBPs labelled with 35S-penicillin, yielding spurious PBP profiles for these strains...

Antibodies against the adherence protein of Mycoplasma pneumoniae are regularly found in patients with M. pneumoniae infection. Therefore, this 168-kilodalton (kDa) protein was used as an antigen in a dot-ELISA for serological diagnosis of M. pneumoniae disease. M. pneumoniae proteins were separated by preparative sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), gels were stained with Coomassie Blue, and the 168-kDa protein band was cut out and eluted using a special electroelution device...

The use of counterimmunoelectrophoresis (CIE) for detection of serum antibodies to staphylococcal teichoic acids was evaluated against teichoic acids prepared by sonic treatment or lysostaphin extraction of Staphylococcus aureus (Lafferty strain). Of 54 patient sera from suspected cases of staphylococcal endocarditis, osteomyelitis, or septicemia, 33 (61.1%) were positive by CIE analysis; however, 128 of 291 sera (44.0%) from normal adult donors were also positive. Selected CIE-positive sera from patient and control groups were titered by Ouchterlony gel diffusion...