A case of voluntary intoxication with efavirenz and lamivudine.
Explore the source record for details and available documents.
Adolescent↗
Biomedical subjects
Christoph A Fux
Publications and source records attributed to Christoph A Fux.
Reversible encephalopathy complicating post-streptococcal glomerulonephritis.
We describe a 15-year-old boy with acute transient encephalopathy complicating poststreptococcal glomerulonephritis. Based on advanced magnetic resonance imaging, cerebral alterations were related to cerebrovascular autoregulatory dysfunction (ie, a vasogenic edema) and vasculitis was excluded. These insights into the pathophysiology improve patient management and argue against the therapeutic immunosuppression postulated by some authors.
Adolescent↗
Mansonella perstans causing symptomatic hypereosinophilia in a missionary family.
Mansonella perstans is rarely pathogenic. The rare reports of symptomatic cases, however, include severe complications. Three cases of symptomatic hypereosinophilia with multi-organ involvement are described in a missionary family returning from tropical Africa. Pathogenicity may be related to the induction of hypereosinophilia rather than direct host-parasite interactions.
Adolescent↗
Dynamics of hemodialysis catheter colonization by coagulase-negative staphylococci.
OBJECTIVES: Catheter colonization is a necessary but poorly characterized step in the pathogenesis of catheter-related infections. Colonization dynamics of central venous hemodialysis catheters were studied with emphasis on coagulase-negative staphylococci (CoNS) and their population genetics, antibiotic resistance, and biofilm formation. The homogeneity of CoNS colony morphotypes was evaluated. DESIGN: Prospective, longitudinal study during 1,158 catheter-days with microbiological analysis of skin swabs, weekly catheter blood and brush samples, and catheter tips. SETTING: Hemodialysis unit of a university hospital. PATIENTS: Twenty-six patients with 24 non-tunneled and 5 tunneled catheters. RESULTS: Nineteen (65.5%) of the catheters became colonized, 17 by CoNS. CoNS colonization of the inner lumen was observed in 17.2% of the catheters and was first detectable after 3 weeks. Colonization of the outer surface occurred in 44.8% of the catheters within a minimum of 2 weeks. PFGE of 53 CoNS revealed 10 clones and 20 unique isolates. Isolates from clones were more frequent in catheter blood and brush cultures than were unique isolates (41% vs 15%), were resistant to more antibiotics (median, 7 vs 2), and tended to more often carry the icaA gene (64.1% vs 40%). Four (23.5%) of the catheters showed colonization with a mixture of CoNS based on PFGE. The time from catheter insertion to such mixed CoNS colonization was longer than that for colonization with one CoNS PFGE pattern only (42 vs 25 days). CONCLUSIONS: Colonization of hemodialysis catheters is dominated by multidrug-resistant, icaA-positive CoNS clones. Mixed CoNS colonization occurs, but is delayed, suggesting a process of sequential superinfection.
Adult↗
Prevention of staphylococcal biofilm-associated infections by the quorum sensing inhibitor RIP.
Staphylococcus aureus and Staphylococcus epidermidis associated with implantable medical devices, are often difficult to treat with conventional antimicrobials. Formation of a biofilm and subsequent production of toxins are two distinct mechanisms considered important in foreign body infections. Staphylococcal virulence is caused by a complex regulatory process, which involves cell-to-cell communication through the release and response to chemical signals in a process known as quorum sensing. We explored the possibility of preventing infections by interfering with biofilm formation and toxin production using the quorum sensing inhibitor ribonucleic-acid-III-inhibiting peptide. In our studies ribonucleic-acid-III-inhibiting peptide prevented graft-associated infections caused by all species of staphylococci tested so far, including methicillin resistant S. aureus and S. epidermidis. Ribonucleic-acid-III-inhibiting peptide also enhances the effects of antibiotics and cationic peptides in the clearance of normally recalcitrant biofilm infections. Ribonucleic-acid-III-inhibiting peptide is nontoxic, highly stable, and no resistant strains have been found so far, suggesting that ribonucleic-acid-III-inhibiting peptide may be used to coat medical devices or used systemically to prevent infections. When the target of ribonucleic-acid-III activating protein activity is disrupted, biofilm formation is reduced under flow and static conditions and genes important for toxin production or biofilm formation are down-regulated. These in vitro data help explain why ribonucleic-acid-III-inhibiting peptide seems to be effective in preventing staphylococcal infections.
Animals↗
Viscoelasticity of Staphylococcus aureus biofilms in response to fluid shear allows resistance to detachment and facilitates rolling migration.
Staphylococcus aureus is a leading cause of catheter-related bloodstream infections and endocarditis. Both involve (i) biofilm formation, (ii) exposure to fluid shear, and (iii) high rates of dissemination. We found that viscoelasticity allowed S. aureus biofilms to resist detachment due to increased fluid shear by deformation, while remaining attached to a surface. Further, we report that S. aureus microcolonies moved downstream by rolling along the lumen walls of a glass flow cell, driven by the flow of the overlying fluid. The rolling appeared to be controlled by viscoelastic tethers. This tethered rolling may be important for the surface colonization of medical devices by nonmotile bacteria.
Biofilms↗
Bacterial biofilms: a diagnostic and therapeutic challenge.
Bacteria have traditionally been regarded as individual organisms growing in homogeneous planktonic populations. However, bacteria in natural environments usually form communities of surface-adherent organisms embedded in an extracellular matrix, called biofilms. Current antimicrobial strategies often fail to control bacteria in the biofilm mode of growth. Treatment failure is particularly frequent in association with intracorporeal or transcutaneous medical devices and compromised host immunity. The rising prevalence of these risk factors over the last decades has paralleled the increase in biofilm infections. This review discusses the shortcomings of current therapies against biofilms both in theory and with clinical examples. Biofilm characteristics are described with a focus on new diagnostic and therapeutic targets.
Arthroplasty, Replacement, Hip↗