Browsing tag: adhezja

Model patogenezy enteropatogennych szczepów Escherichia coli – kluczowa rola adhezji

Model of enteropathogenic Escherichia coli pathogenesis – a key role of adherence
B. K. Pawłowska, B. M. Sobieszczańska

1. Wprowadzenie. 2. Wyspa patogenności LEE. 2.1. Adhezja EPEC. 2.1.1. Fimbrie BFP. 2.1.2. Fimbrie typu 1. 2.1.3. Fimbrie powszechne E. coli. 2.1.4. Rzęski. 3. System sekrecji typu III. 3.1. Białka efektorowe EPEC. 3.2. Intimina. 3.3. Tir. 3.4. Destrukcja połączeń międzykomórkowych. 3.5. Zdolność inwazji i unikanie fagocytozy. 4. Wpływ EPEC na apoptozę komórek gospodarza. 5. Inne systemy sekrecji. 6. Typowe i atypowe EPEC. 7. Podsumowanie

Abstract: Escherichia coli is a highly diverse and one of the best characterized bacterial genus. The species comprises many commensal strains, colonizing human and animal intestines, as well as pathogenic strains, which can cause gastrointestinal infections. Enteropathogenic E. coli (EPEC) group strains is the pathotype of diarrheagenic E. coli, which is associated with infant diarrhea. The hallmark of EPEC infections is their ability to produce attaching and effacing (A/E) lesions as a result of intimate bacterial adherence to enterocytes and the translocation of bacterial proteins through type III secretion system. The multifunctional and interdependent properties of the effectors contribute to the host cell disruption. The consequences of EPEC infection are: the reorganization of the host cell cytoskeleton underneath adherent bacteria, inhibition of nutrient and water transport, mitochondrial dysfunctions, weak intestinal inflammation, epithelial barrier function disruption and severe watery diarrhea. Despite the recent knowledge development, the mechanism of EPEC diarrhea is still ambiguous. Due to the absence of a proper animal model, further studies should be conducted in volunteers or at least in primates to determine the underlying mechanisms.

1. Introduction. 2. Pathogenicity island LEE. 2.1. Adherence. 2.1.1. BFP pili. 2.1.2. Type 1 pili. 2.1.3. E. coli common pili. 2.1.4. Flagella. 3. Type III system of secretion. 3.1. Effector proteins of EPEC. 3.2. Intimin. 3.3. Tir. 3.4. Disruption of tight junctions. 3.5. Invasion ability and avoidance of phagocytosis. 4. Impact of EPEC on host cell apoptosis. 5. Other secretion systems. 6. Typical and atypical EPEC. 7. Summary

Czynniki warunkujące zdolności adhezyjne bakterii z rodzaju Lactobacillus

Factors determing the adhesive capacity of Lactobacillus bacteria
A. Paliwoda, A. Nowak

1. Wstęp. 2. Etapy adhezji bakterii Lactobacillus do nabłonka jelitowego. 3. Czynniki uczestniczące w adhezji. 3.1. Czynniki białkowe. 3.2. Czynniki niebiałkowe. 3.3 Czynniki środowiskowe. 3.4. Tworzenie agregatów oraz oddziaływania hydrofobowe. 4. Podsumowanie

Abstract: The ability of Lactobacillus to adhere to the intestinal epithelium is one of the most important criterion in the selection of probiotic strains. Adherence allows microorganisms to survive and temporarily colonize the digestive system, which is necessary to induce beneficial effects on the host. Adhesion is a very complex, multistep process and, although there are many proposed theories, the exact mechanism is still not fully understood. A crucial role in the formation of the adhesive interactions plays the bacterial cell wall and its components, such as exopolisaccharydes, lipoteichoic acids and various proteins e.g. S-layer proteins.

1. Introduction. 2. Stages of Lactobacillus adhesion to intestinal epithelium 3. Adhesion factors. 3.1. Protein factors 3.2. Non-protein factors. 3.3. Environmental factors. 3.4. Aggregation and hydrophobic interactions. 4. Summary