2018/2019 - Essay 3 Flashcards
Title
Describe the role of Type 1 pili in colonisation, invasion and persistence of Escherichia coli in the urinary tract
The Role of Type 1 Pili in Colonisation, Invasion, and Persistence of Escherichia coli in the Urinary Tract
Introduction- Paragraph 1
Describe the role of Type 1 pili in colonisation, invasion and persistence of Escherichia coli in the urinary tract
- gram negative
- commonly found gastrointestinal tract of humans and animals
- certain E.coli strains: urinary tract infections (UTIs) - common bacterial infection
- most prevalent bacterial infections in humans
- > affecting millions worldwide each year
- E.coli: colonise, persist in UT
- > how: expression of Type 1 pili - pathogenesis of UTIs
Type 1 pili colonisation
Paragraph 2
Describe the role of Type 1 pili in colonisation, invasion and persistence of Escherichia coli in the urinary tract
Type 1 pili
* hair-like appendages
* outer membrane of E.coli
* composed: polyer of repeating protein subunits: FimA
* > Facilitate attachment of E.coli to uroepithelial cells lining UT
* >Promote bacterial colonisation
* bind to specifc receptors -> uroepithelial cells
* bacterial adherence
* >resist flushing out of UT ( flow of urine)
Type 1 pilli invasion
Paragraph 3
Describe the role of Type 1 pili in colonisation, invasion and persistence of Escherichia coli in the urinary tract
- E.coli ascend within UT
- > bladder/kidney infections
- Conditions conducive to E.coli
- > upregulated expression of Type 1 pili
- > enhance ability to ascend urethra->bladder
- Reaching bladder
- > Type 1 Pilli invade underlying uropithelial cells
- > FimH-mediated binding
- > activates signaling pathways within host cells>endocytosis of bacterium
- Once inside> evade immune system and persists intracellularly
- > contributes to establishment of persistent infections and recurrent UTIs
Type 1 pilli persistance
Paragraph 4
Describe the role of Type 1 pili in colonisation, invasion and persistence of Escherichia coli in the urinary tract
- adhesive properties
- > biofilms on the surface of bladder and kidneys
- Enclosed self produced extracellular matrix -> intracellular bacterial communities (IBCs)
- -> evade host immune defenses and persis in UT
- > long periods of time
- Less susceptible to antibiotics
- Biofilm undergo periodic dispersal
- > Biofilm: reccurent UTIs and chroni infections
- > recolonize new areas of UT
- > Cause re-infection
- > repeated episodes of UTI’s
Conclusion- Paragraph 5
Describe the role of Type 1 pili in colonisation, invasion and persistence of Escherichia coli in the urinary tract
Summary
- Type 1 Pili: critical virulent factor
- key role UTI pathogenesis
- facilitate bacterial attachmet, colonisation, invasion, persistence within UT
- Formation of biofilms: recuurent and chronic onfecions
- Importance: novel therpeutic trategis for prevention and treatment
- target for new antibiotcs
