Evgeni Research Flashcards

What are the defining characteristics of the H30R variant of E. Coli ST131?

• Fluoroquinolone resistance

• Produces Extended Spectrum Beta-lactamases

  • Notably Carbapenemases

What are some of the factors that allow the H30R subclone to be effective in colonization?

• FimH

• Fluoroquinolone resistance

• iron uptake systems

• protectins

In Park et al. 2024, what bacterial genus was positively associated with E.Coli ST131?

Collinsella

In Park et al. 2024, what bacterial genus was negatively associated with E.Coli ST131

Alistipes

How does 16S Amplicon sequencing identify species?

By amplifying the V3-V4 hypervariable region of the 16S rRNA, it can distinguish species by sequence

How would one isolate ST131 E. Coli from a fecal sample?

1. Culture on agar plate with Ciprofloxacin → remove any species not flourquinolone resistant

2. Lactose positive

3. Indole Positive

4. Citrate Negative

What are the potential factors causing a complicated UTI infection?

Compromised urinary tract or host defense system.

• Urinary Obstruction

• Urinary retention

• Immunosuppression

• Renal Failure

• Renal Transplantation

• Presence of a foreign body

What are the two types of uncomplicated UTIs

Cystitis (lower) and Pyelonephritis (upper)

Walk through the infection process of a UTI, ending with bacteraemia

1. Contamination of a uropathogen from the gut

2. Colonization of the Urethra

3. Colonization of the bladder - mention role of adhesins (accompanied with buildup of fibrinogens)

4. Neutrophil infiltration

5. bacterial multiplication and immune subversion

6. Biofilm formation

7. Epithelial damage by toxins and proteases

8. Ascension to kidneys

9. Colonization of kidneys

10. tissue damage by toxins

11. Bacteraemia

What are the adherence mechanisms/proteins for UPEC?

• F1C pili

• P pili

• S pili

• Type 1 pili

• Dr adhesins

What toxins are produced by UPEC?

• HlyA

  • CNF1

What is the mechanism of invasion by UPEC using CNF1 and HlyA?

Draw it out!

What are the primary risk factors for complicated UTIs?

• prolonged catheterization

• female

• age

• diabetes

What are the three layers of the bladder epithelium?

• umbrella cells

• intermediate cells

• basal cells

What is the role of a siderophore? What siderophores are produced by UPEC?

Binding iron for uptake

• aerobactin

• yersiniabactin