A5090366607- Antimicrobial Resistance in Staphylococcus
- Infective Endocarditis Diagnosis and Management
- Streptococcal Infections and Treatments
- Antibiotics Pharmacokinetics and Efficacy
- Bacterial Identification and Susceptibility Testing
- Antibiotic Resistance in Bacteria
- Bacterial biofilms and quorum sensing
- Bacteriophages and microbial interactions
- Clostridium difficile and Clostridium perfringens research
- Pneumonia and Respiratory Infections
- Biochemical and Structural Characterization
- Reproductive tract infections research
- Antifungal resistance and susceptibility
- Microbial infections and disease research
- Bacterial Genetics and Biotechnology
- Microbial Metabolism and Applications
- Pharmaceutical and Antibiotic Environmental Impacts
- Genomics and Phylogenetic Studies
- Infections and bacterial resistance
- Antimicrobial Peptides and Activities
- Cervical Cancer and HPV Research
- Biosensors and Analytical Detection
- Probiotics and Fermented Foods
- Orthopedic Infections and Treatments
- RNA and protein synthesis mechanisms
University of Lausanne
2012-2024
University Hospital of Lausanne
1995-2005
Hôpital Orthopédique de la Suisse Romande
2002
Hôpital l'Archet
1992-1993
The pathogenic role of staphylococcal coagulase and clumping factor was investigated in the rat model endocarditis. coagulase-producing factor-producing parent strain Staphylococcus aureus Newman a series mutants defective either coagulase, factor, or both were tested for their ability (i) to attach vitro fibrinogen platelet-fibrin clots (ii) produce endocarditis rats with catheter-induced aortic vegetations. In vitro, factor-defective up 100 times less able than wild type also significantly...
Increasing antibiotic resistance warrants therapeutic alternatives. Here we investigated the efficacy of bacteriophage-therapy (phage) alone or combined with antibiotics against experimental endocarditis (EE) due to Pseudomonas aeruginosa, an archetype difficult-to-treat infection. In vitro fibrin clots and rats aortic EE were treated antipseudomonas phage cocktail ciprofloxacin. Phage pharmacology, efficacy, determined. vitro, single-dose therapy killed 7 log colony-forming units (CFUs)/g...
Summary The azole antifungal fluconazole possesses only fungistatic activity in Candida albicans and, therefore, this human pathogen is tolerant to agent. However, tolerance can be inhibited when C. exposed combined with the immunosuppressive drug cyclosporin A, which known inhibit calcineurin yeast. A mutant lacking both alleles of a gene encoding subunit ( CNA ) lost viability presence fluconazole, thus making essential for tolerance. Consistent observation, was modulated by calcium ions...
The expression of Staphylococcus aureus adhesins in Lactococcus lactis identified clumping factor A (ClfA) and fibronectin-binding protein (FnBPA) as critical for valve colonization rats with experimental endocarditis. This study further analyzed their role disease evolution. Infected animals were followed 3 d. ClfA-positive lactococci successfully colonized damaged valves, but spontaneously eradicated over 48 h. In contrast, FnBPA-positive progressively increased bacterial titers...
ABSTRACT The growth phase-dependent activity profile of the alternate transcription factor ς B and its effects on expression sar agr were examined in three different Staphylococcus aureus strains by Northern blot analyses use reporter gene fusion experiments. Significant was detectable only clinical isolates MSSA1112 Newman, carrying wild-type rsbU allele, but not NCTC8325 derivative BB255, which is defective . peaked late exponential phase diminished towards stationary when bacteria grown...
ABSTRACT We describe 3 patients with left-sided staphylococcal endocarditis (1 methicillin-susceptible Staphylococcus aureus [MSSA] prosthetic aortic valve and 2 methicillin-resistant S. [MRSA] native-valve endocarditis) who were successfully treated high-dose intravenous daptomycin (10 mg/kg/day) plus fosfomycin (2 g every 6 h) for weeks. This combination was tested in vitro against 7 MSSA, 5 MRSA, intermediately glycopeptide-resistant isolates proved to be synergistic 11 (79%) strains...
The recent rise of multidrug-resistant Gram-negative bacteria represents a serious threat to public health and makes the search for novel effective alternatives antibiotics compelling need. Bacteriophage (Phage) lysins are enzymes that hydrolyze cell wall represent promising alternative tackle this ever-increasing problem. Despite their use is believed be restricted Gram-positive bacteria, findings have shown they can also used against bacteria. By using phage genome-based screening...
ABSTRACT Cpl-1, a pneumococcal phage lytic enzyme, was tested in rats with experimental endocarditis due to Streptococcus pneumoniae WB4. High-dose regimen Cpl-1 eliminated pneumococci from blood within 30 min and decreased bacterial titers vegetations (>4 log 10 CFU/g) 2 h. Rapid lysis induced by treatment increased cytokine secretion noticeably.
Recent observations demonstrated that fluconazole plus cyclosporine (Cy) synergistically killed Candida albicans in vitro. This combination was tested rats with C. experimental endocarditis. The MICs of and Cy for the test organism were 0.25 >10 mg/liter, respectively. Rats treated 5 days either Cy, amphotericin B, fluconazole, or fluconazole-Cy. Although used at high doses, peak concentrations serum (up to 4.5 mg/liter) compatible high-dose therapy humans. On other hand, greater than...
Abstract Background Abiotrophia and Granulicatella species, previously referred to as nutritionally variant streptococci (NVS), are significant causative agents of endocarditis bacteraemia. In this study, we reviewed the clinical manifestations infections due A. defectiva species that occurred at our institution between 1998 2004. Methods The analysis included all strains NVS were isolated from blood cultures or vascular graft specimens. All identified by 16S rRNA sequence analysis....
ABSTRACT Staphylococcus aureus experimental endocarditis relies on sequential fibrinogen binding (for valve colonization) and fibronectin endothelial invasion) conferred by peptidoglycan-attached adhesins. Fibronectin-binding protein A (FnBPA) reconciles these two properties—as well as elastin binding—and promotes itself. Here we attempted to delineate the minimal subdomain of FnBPA responsible for binding, cell invasion, in vivo endocarditis. large library truncated constructs was expressed...
Background. Streptococcus gallolyticus is a causative agent of infective endocarditis associated with colon cancer. Genome sequence strain UCN34 revealed the existence 3 pilus loci (pil1, pil2, and pil3). Pili are long filamentous structures playing key role as adhesive organelles in many pathogens. The pil1 locus encodes 2 LPXTG proteins (Gallo2178 Gallo2179) 1 sortase C (Gallo2177). Gallo2179 displaying functional collagen-binding domain was referred to adhesin, whereas Gallo2178...
ABSTRACT Transient high-grade bacteremia following invasive procedures carries a risk of infective endocarditis (IE). This is supported by experimental endocarditis. On the other hand, case-control studies showed that IE could be caused cumulative exposure to low-grade occurring during daily activities. However, no demonstration this latter possibility exists. study investigated infectivity in animals continuous compared brief bacteremia. Rats with aortic vegetations were inoculated...
Background. Infective endocarditis (IE) mostly occurs after spontaneous low-grade bacteremia. Thus, IE cannot be prevented by circumstantial antibiotic prophylaxis. Platelet activation following bacterial-fibrinogen interaction or thrombin-mediated fibrinogen-fibrin polymerization is a critical step in vegetation formation. We tested the efficacy of antiplatelet and antithrombin to prevent experimental IE. Methods. A rat model prolonged bacteremia mimicking smoldering humans was used....
The present study aimed to fill the knowledge gap between implications of intracellular and extracellular antibiotic resistance mechanisms may inflict on inactivation pathways photo-Fenton process under mild conditions. It was thus designed as a cross-comparison effect homogeneous heterogeneous (near-neutral pH, [Fe]=1 mg/L, [H2O2]=10 mg/L) seven strains Staphylococcus aureus exhibiting different resistance, or susceptibility. Additionally, variations in tolerance (MIC test) relative changes...
ABSTRACT The therapeutic efficacy of BAL9141 (formerly Ro 63-9141), a novel cephalosporin with broad in vitro activity that also has against methicillin-resistant Staphylococcus aureus (MRSA), was investigated rats experimental endocarditis. test organisms were homogeneously S. strain COL transformed the penicillinase-encoding plasmid pI524 (COL Bla+) and methicillin-resistant, penicillinase-producing isolate P8-Hom, selected by serial exposure parent P8 to methicillin. MICs for these (2...
ABSTRACT Animal models of infective endocarditis (IE) induced by high-grade bacteremia revealed the pathogenic roles Staphylococcus aureus surface adhesins and platelet aggregation in infection process. In humans, however, S. IE possibly occurs through repeated bouts low-grade from a colonized site or intravenous device. Here we used rat model continuous to explore further contributions virulence factors initiation IE. Rats with aortic vegetations were inoculated infusion (0.0017 ml/min over...
In this study, silver/copper (Ag/Cu)-coated catheters were investigated for their efficacy in preventing methicillin-resistant Staphylococcus aureus (MRSA) infection vitro and vivo Ag Cu sputtered (67/33% atomic ratio) on polyurethane by direct-current magnetron sputtering. vitro, Ag/Cu-coated uncoated immersed phosphate-buffered saline (PBS) or rat plasma exposed to MRSA ATCC 43300 at 10(4) 10(8) CFU/ml. vivo, placed the jugular vein of rats. Directly after, (10(7) CFU/ml) was inoculated...