Urinary Tract Infections

Question 1

Micturition

Answer 1

urination

Question 2

Dysuria

Answer 2

pain on urination

Question 3

Bacteriuria

Answer 3

presence of bacteria in urine

Question 4

Haematuria

Answer 4

presence of blood in urine

Question 5

Pyelonephritis

Answer 5

Kidney infection

Question 6

Cystitis

Answer 6

infection confined to the bladder

Question 7

Urethritis

Answer 7

inflammation of the urethra

Question 8

Protastitis

Answer 8

prostate infection

Question 9

Lower UTI: Signs and symptoms

Answer 9

• Frequency of micturition
• Urgency to urinate
• Dysuria
• Suprapubic pain and tenderness
• Haematuria
• Smelly/cloudy urine

Question 10

Acute Pyelonephritis: Signs and Symptoms

Answer 10

• Loin pain and tenderness
• High fever
• Systematically unwell

Question 11

UTI Predisposing Factors

Answer 11

• Obstruction: calculi, tumours, benign prostate hyperplasia
• Vesicoureteral Reflux (VUR)
• Incomplete bladder emptying (neurogenic, voluntary)
• Diabetes / Sickle Cell Anaemia / Immune Compromise
• Bladder instrumentation / Foreign bodies
• Congenital Structural Abnormalities
• Sexual activity

Question 12

Catheter Associated UTI

Answer 12

• Each additional day of catheterisation increases the risk
• Entry Points for bacteria: urethral meatus and around catheter, junction between catheter and collection tube, connection to drainage bad and reflux from bag to tubing.

Question 13

Urinary Tract Host Defenses

Answer 13

• Urine: osmolality, pH
• Sloughing of epithelial cells
• Urine flow and micturition
• Mucosal inhibitors of bacterial adherence
• Complement activation
• Inflammatory Response
• Immune Responses
• Commensals

Question 14

Common Causes of UTIs

Answer 14

• E.Coli (80% of community-acquired; 40% of hospital acquired).
• Coagulase-Negative Staphylococci (10%;3%)
• Proteus Mirabilis (5%; 11%)
• Candida (5% of hospital acquired)
• Gram positives e.g. staphylococcus epidermis, staphylococcus aureus, enterococcus faecalis (2%; 16%)
• Gram negatives e.g. Klebsiella, Enterobacter, Serratia, Psuedomonas Aeruginosa (3%; 25%)

Question 15

Uropathogenic E.Coli (UPEC)

Answer 15

• Certain serogroups of O and K serotypes
  - O (somatic)
  - K (capsular)
• Virulence Factors
  - Fimbriae (adhesions; type 1 and type P)
  - K antigen
  - Haemolysin

Question 16

Bacterial Response to Adhesion

Answer 16

Iron acquisition machinery activated via siderophores. Stimulates growth and reproduction. Once a monolayer has formed a biofilm may develop. Bacteria with Type 1 fimbriae may become internalised in phagocytes and epithelial cells.

Question 17

E. Coli K-Antigen

Answer 17

Polysaccharide
Forms a micro-capsule
Confers resistance to phagocytosis

Question 18

E.Coli Haemolysin

Answer 18

Cytolytic Exo-protein
Damages tissue membranes in vivo
Causes kidney damage

Question 19

Proteus Mirabilis

Answer 19

• Gram negative
• Facultative Anaerobe
• Bacillus
• Peritrichous flagellae
• Produces urease
• Swarming ability

Question 20

Gram Negative Bacteria

Answer 20

• Escherichia Coli
• Klebsiella sp.
• Proteus Mirabilis
• Enterobacter sp.
• Serratia sp.

Question 21

Gram Positive Bacteria

Answer 21

• Staphylococcus Saprophyticus
• Staphylococcus Epidermidis
• Enterococcus sp.
• Corynebacteria
• Lactobacillus

Question 22

Staphylococcus Saprophyticus

Answer 22

• Gram positive
• Coagulase negative
• Normal microbiota of female perineum and vagina
• Sexual activity increases risk of UTI
• Commonly causes community acquired UTIs
• Symptomatic Cystitis

Question 23

Candidia Albicans

Answer 23

• Diploid fungus (yeast)
• Commensal
• Candidiasis (thrush)
• Important opportunistic pathogen in immunocompromised individuals
• Often associated with antibiotic use

Question 24

Trichomonas Vaginalis

Answer 24

• Protozoan
• Pear shaped flagellate
• T. vaginalis is pathogenic
• Other species are commensal
• Prefers pH ~6
• Trichomoniasis
• Less common in males

Question 25

Schistosoma Haematobium

Answer 25

• Trematode worm
• Schistomiasis (bilharzia)
• Found in contaminated water
• Gains access to host through skin
• Matures in liver
• Eggs travel to and penetrate bladder
• Treatment with Praziquantal

Question 26

UTI Diagnosis

Answer 26

• Clinical Diagnosis - primarily based on signs and systems. Women who present with acute UTI signs and symptoms but are otherwise healthy have an 80% chance of bacteriuria. If dysuria and frequency are also present, probability is increased to over 90% and empirical treatment with antibiotics is indicated without further testing.
• Urine Dipstick - only use for women under 65 with no risk factors for a complicated UTI or children between 3 months and 16 years to help diagnose.
• Urine Culture - Indicated in children, male UTI, immunosuppressed, pregnancy, toxic appearance, underlying medical/urologic disorder, recently hospitalised, recently instrumented, recently on antibiotics, recent treatment failure.

Question 27

Oral antibiotics for Lower UTIs

Answer 27

• Nitrofurantoin
• Trimethoprim
• Ciprofloxacin
• Pivmecillinam
• Amoxicillin/Cephalexin (pregnancy)

Question 28

Oral Antibiotics for Pyelonephritis

Answer 28

• Co-trimoxazole
• Co-amoxiclav
• Ciprofloxacin

Question 29

Treatments for UTIs

Answer 29

• Drink lots of water
• Dont hold it in
• Proanthrocyanidins (cranberry juice)

Question 30

Complications of UTIs

Answer 30

• Recurrent infections
• Permanent kidney damage from an acute or chronic kidney infection
• Pyelonephritis due to an untreated UTI
• Increased risk of pregnant women of delivering low birth weight ir premature infants.
• Urethral narrowing (stricture) in men from recurrent urethritis, previously seen with gonococcal urethritis.
• Sepsis, a potentially life-threatening complication of an infection.