UTI infections

Question 1

Consequnces

Answer 1

Societal and individual costs – health care costs (GP, ED and hospital), time missed from work

Frequent recurrences
Uncontrolled infection / sepsis
Renal damage in young children
Preterm birth
Recurrent courses of AB contribute to antimicrobial resistance and risk of CDI (Clostridium difficile infection)

Question 2

Uncomplicated Upper UTI

Answer 2

Acute pyelonephritis

Question 3

Uncomplicated Lower UTI

Answer 3

Cystitis

Urethritis, prostatitis, epididymo-orchitis

Question 4

Uncomplicated definition

Answer 4

no anatomical or neurological abnormalities of the urinary tract

Question 5

Host factors - Lower UTI

Answer 5

Catheterisation / instrumentation
Diabetes

Obstruction: prostatic hypertrophy, urethral valves or stricture

Poor bladder emptying: neuropathic, bladder diverticula

Sexual intercourse: female- vaginal or anal; male – insertive anal

Vesico-enteric fistula

Question 6

Host factors - Upper UTI

Answer 6

May follow on from lower UTI

Vesico-ureteric reflux
Obstruction (eg calculus, stricture)

Question 7

Pathogenesis

Answer 7

Contamination of the periurethral area with a uropathogen from the gut
Colonisation of the urethra and migration to the bladder
Colonisation and invasion of the bladder, mediated by pili and adhesins
Neutrophil infiltration

Bacterial multiplication and immune system subversion

Biofilm formation

Epithelial damage by bacterial toxins and proteases

Colonisation of the kidneys

Host tissue damage by bacterial toxins

Bacteremia

Question 8

Adherence

Answer 8

In the bladder, uropathogenic Escherichia coli (UPEC) expression of type 1 pili is essential for colonization, invasion and persistence.

P-pili confer tropism to the kidney

UPEC are highly adhesive so are proficient in retrograde ureteral ascent

Question 9

Invasion

Answer 9

Type 1 pilus binds to host cell.

This induces actin rearrangement within the host cell and causes uptake of the bacteria.

Inside the cell, the bacteria is protected from many antibiotics and host defences.

Question 10

Evasion

Answer 10

UPEC escapes into the cytoplasm, where it multiplies up into intracellular bacterial communities (IBC).
Hemolysin A forms pores in the host cell which promotes host cell lysis, releasing iron and other nutrients.
Plus: siderophores, filaments, exfoliation, block apoptosis

Question 11

Antibiotic treatment

Answer 11

Empiric tx so need to consider:
	target organisms
	route of admin
	target site
	side effects
	resistance

Question 12

Only use catheter for

Answer 12

Measurement of urine output in acutely unwell
Mx of acute retention or obstruction
Selected surgical procedures

Question 13

Catheter use alterations

Answer 13

Aseptic insertion
Closed drainage system
Remove promptly when no longer indicated