Browsing tag: biofilm

Zakażenia w ortopedii związane ze stosowaniem biomateriałów

Orthopedic surgery infections related to the use of biomaterials
J. Nowicka, M. Bartoszewicz

1. Wstęp. 2. Zakażenia związane z wytwarzaniem biofilmu. 3. Czynniki ryzyka powikłań infekcyjnych związane ze stosowaniem biomateriałów. 3.1. Czynniki związane z pacjentem. 3.2. Czynniki związane z zabiegiem operacyjnym. 4. Podział zakażeń wokół implantów. 5. Najczęstsze czynniki etiologiczne zakażeń związanych ze stosowaniem biomateriału. 5.1. Staphylococcus aureus, Staphylococcus epidermidis i inne CNS. 5.2. Pseudomonas aeruginosa. 5.3. Propionibacterium acnes. 5.4. Streptococcus pyogenes. 5.5 Candida albicans. 6. Rozpoznanie infekcji związanych ze stosowaniem biomateriałów. 7. Profilaktyka antybiotykowa okołooperacyjna. 8. Podsumowanie

Abstract: In spite of recent advances in diagnostics and therapy, muscoskeletal infections still remain a huge problem. Etiological agents of infections associated with the use of biomaterials on orthopedic and surgical orthopedic wards are often the microbes included in the patient’s own flora and these commonly found in hospitals. The present paper discusses the risk factors and most common etiological agents of these types of infections.

1. Introduction. 2. Infections associated with biofilm formation. 3. Risk factors for complications following biomaterial-related infections. 3.1. Patient-related factors. 3.2. Surgical procedure-related factors. 4. Infections classified with regard to implants. 5. The most common etiological agents of infections associated with the use of biomaterial. 5.1. Staphylococcus aureus, Staphylococcus epidermidis and other CNS. 5.2. Pseudomonas aeruginosa. 5.3. Propionibacterium acnes. 5.4. Streptococcus pyogenes. 5.5 Candida albicans. 6. Detection of biomaterial-associated infections. 7. Perioperative antibiotic prophylaxis. 8. Summary

Mechanizmy oporności Acinetobacter baumannii na związki przeciwbakteryjne

Acinetobacter baumannii: mechanisms of resistance to antibacterial agents
A. Namysłowska, A. E. Laudy, S. Tyski

1. Wstęp. 2. Oporność na antybiotyki β-laktamowe. 2.1. Enzymy CHDL. 2.2. Enzymy MBL. 2.3. Karbapenemazy należące do klasy A wg Amblera. 2.4. Nabyte enzymy ESβL hamowane przez inhibitory β-laktamaz. 2.5. Enzymy AmpC. 3. Oporność na antybiotyki inne niż β-laktamy. 3.1. Oporność na chinolony i fluorochinolony. 3.2. Oporność na aminoglikozydy. 3.3. Oporność na kolistynę. 4. Aktywne usuwanie antybiotyków z komórki bakteryjnej przy udziale pomp błonowych – mechanizm efflux. 4.1. System pomp RND. 4.2. Inne systemy pomp błonowych. 5. Kanały błonowe – pory. 6. Biofilm i zjawisko quorum sensing. 7. Podsumowanie

Abstract: Acinetobacter baumannii has become one of the most dangerous Gram-negative bacterial species, causing numerous infections over the last 20 years. A. baumannii is responsible for nosocomial ventilator-associated pneumonia (VAP), urinary tract infections, meningitidis and bacteremia. Its remarkable ability to acquire resistance determinants against multiple antibiotics of different classes and to tolerate harsh environments resulted in the dissemination of multi-drug-resistant (MDR) strains. Diverse mechanisms of resistance limit therapeutic options and make the infections difficult to treat. The described resistance mechanisms include: production of β-lactamases, i.e. enzymes modifying structure of antibiotics, activity of efflux pumps, loss of membrane porins and formation of biofilm.

1. Introduction. 2. Resistance to β-lactams. 2.1. CHDLs. 2.2. MBLs. 2.3. Ambler class A carbapenemases. 2.4. Acquired ESβLs inhibited by clavulanic acid. 2.5. AmpC enzymes. 3. Resistance to antibiotics other than β-lactams. 3.1. Resistance to quinolones and fluoroquinolones. 3.2. Resistance to aminoglycosides. 3.3. Resistance to colistin. 4. Efflux systems. 4.1. RND efflux system. 4.2. Other efflux systems. 5. Outer membrane porins. 6. Biofilm and quorum sensing process. 7. Summary

Nowoczesne metody zwalczania biofilmu bakteryjnego

Novel methods of bacterial biofilm elimination
M. Maciejewska, M. Bauer, M. Dawgul

1. Wstęp. 2. Etapy powstawania biofilmu, a oporność na antybiotyki. 3. Strategie zapobiegania tworzenia się biofilmu. 3.1. Celowanie w początkową fazę rozwoju biofilmu. 3.1.1. Związki niskocząsteczkowe (Small Molecules). 3.1.2. Ingerencja w quorum sensing. 3.1.3. Przeciwciała. 3.1.4. Biofilm drobnoustrojów niepatogennych. 3.2. Modyfikacja biomateriałów w celu zwiększenia ich odporności na adhezję drobnoustrojów. 3.2.1. Materiały antyadhezyjne. 3.2.2. Powłoki bakteriobójcze/bakteriostatyczne. 4. Metody eradykacji biofilmu. 4.1. Fizyczne metody eradykacji biofilmu. 4.2. Biologiczne metody eradykacji biofilmu. 4.3. Chemiczne metody eradykacji biofilmu. 5. Peptydy przeciwdrobnoustrojowe. 6. Podsumowanie

Abstract: Bacterial biofilm is defined as a sessile, tridimensional microbial community composed of bacteria immersed in a polysaccharide matrix. The structures can grow on human tissues or medical devices resulting in biofilm related infections, which are very often impossible to treat with the commonly used antibiotics. Due to their resistance to the conventional antimicrobial therapy, efficient methods of treatment as well as prophylaxis need to be developed.
Biofilm formation can be reduced by inhibiting the process of adhesion and by interfering with quorum sensing system. Very promising is also the application of appropriate antibodies or use of non-pathogenic bacterial strains. Another approach focuses on the surface modifications in order to obtain the resistance to microbial colonization.
Disruption of mature structures can be achieved by several physical, chemical and biological methods. The novel approaches, which are currently being under intensive investigation, include: phage therapy, matrix targeting enzymes, photodynamic therapy and antimicrobial peptides. The above-mentioned strategies are described in the presented work with a special focus on antimicrobial peptides as the potential tool for prophylaxis as well as elimination of mature biofilms.

1. Introduction. 2. Stages of biofilm formation and the resistance to antibiotics. 3. Strategies of prevention of biofilm formation. 3.1. Targeting the initial phase of biofilm formation. 3.1.1. Small Molecules. 3.1.2. Interference in quorum sensing. 3.1.3. Antibodies. 3.1.4. Biofilm of non-pathogenic microorganisms. 3.2. Modification of biomaterials for increased resistance to microbial adhesion. 3.2.1. Anti-adhesive materials. 3.2.2. Bacteriostatic/bactericidal coatings. 4. Methods for biofilm eradication. 4.1. Physical methods for biofilm eradication. 4.2. Biological methods for biofilm eradication. 4.3. Chemical methods for biofilm eradication. 5. Antimicrobial peptides. 6. Conclusions

Amyloidy, białka powszechne wśród drobnoustrojów

Amyloids, common proteins among microorganisms
B.K. Pawłowska, B.M. Sobieszczańska

1. Wprowadzenie. 2. Amyloidy bakteryjne. 2.1. Fimbrie spiralne. 2.1.1. Synteza fimbrii spiralnych. 2.1.2. Regulacja ekspresji operonu csg. 2.1.3. Udział fimbrii spiralnych w wirulencji bakterii. 2.1.4. Rola fimbrii spiralnych w patogenezie zakażeń człowieka. 2.2. Inne amyloidy bakteryjne. 2.3. Amyloidy grzybicze. 3. Podsumowanie

Abstract: Historically, the term amyloid was used strictly with reference to human neurodegenerative diseases. Nowadays, it is known that many proteins have the potential to conformational changes into β-sheet structures with tendency to form insoluble amyloid fibrils. Moreover, amyloid proteins are widespread among microorganisms. Bacteria and fungi produce functional amyloids which exhibit all characteristics of amyloid proteins, but in contrast to a numerous group of human toxic amyloids, they play important physiological functions in microorganisms. There is growing evidence that functional amyloids are important in bacterial adhesion and invasion. Furthermore, amyloids make biofilms thicker, rougher, and more resistant to drying out. The increasing interest in better understanding of the nature of these unusual microbial proteins and their role in pathogenesis are likely to contribute to the effective treatment or prevention of infectious diseases in humans.

1. Introduction. 2. Bacterial amyloids. 2.1. Curli fibers. 2.1.1. Curli biogenesis. 2.1.2. Regulation of csg operon. 2.1.3. Participation of curli in bacterial virulence. 2.1.4. Role of curli in pathogenesis. 2.2. Other bacterial amyloids. 2.3. Fungal amyloids. 3. Recapitulation