Lecture 8: Urinary tract Infections

Question 1

List some signs and symtoms of UTIs

Answer 1

• frequency
• urgency
• dysuria
• hesitancy
• bad slee, cloudy, hematuria in urine
• pylonephritis - flank pain (kidney)

Question 2

who gets community aquired UTIS

Answer 2

young women , UPEC

Question 3

Who gets hospital squired UTIs

Answer 3

device retlaed, UPEC + others, drug resistance

Question 4

What tests are used to detect UTIs

Answer 4

disptick test
- nitrates present
leukocyte esterase
- positive, presence of WBC

Question 5

What are the major pathogens for UTIs

Answer 5

Escherichia coli (gram -ve)
Proteis mirabilis
Klebsiella

CA and HA

Question 6

how would one culture UTI bacteria

Answer 6

1. CLED agar
   - cyteine lactose electrolyte deficient
2. Enumeration

Question 7

Explain how CLED works

Answer 7

• Cytseine: requirement for UPEC (uropathogenic e coli)
  
  • Lactose – ferment lactose, color change form blue to yellow
    – pseudomonas, protoeus mirabilis (lactose -ve)
    – klebsiella (lactose +ve)
  • Electrolyte deficient – proteus does swarming, wont grow on colonies but in circles/waves

Question 8

Explain how enumeration works

Answer 8

• 10^8 CFU = infection
• <10^4 CFU/mL = urethral or vaginal contamination
• 10^4 or 10^5 CFU/ml = evaluation with clinical information

Question 9

explain what swarming is

Answer 9

• proteus mirabilis
• revents accurate enumeration of bacteria

Question 10

What is the source of UTIs

Answer 10

• faecal origin
• CA: females - “proximity effect”, shorter urethra, older men- stasis due to enlarged prostate
• HA: catheters

Question 11

Who is at risk of getting UTIs

Answer 11

• sexually active women aged 20-40
• women with previous UTIs
• AB or other treatment that disrupts normal vaginal flora
• Catheters
• undrlying disease leading to stasis

Question 12

Virulence factors associated with UPEC

Answer 12

• pili for attachment
• iron acquisition
• Lipid A for inflammation
• Toxins for cell death

Question 13

How does UPEC colonise the bladder and kidney respectively

Answer 13

• Pili - important for adherence, prevent from being washed away
• Type 1 (fim) common to all enetrobacteriacaea
• bind to mannose residues in glycoproteins
• imprtant for bladder colonisation
• Type P pili
• bind to globiose
• important for colonisation of the kidney

Question 14

What are the two infection types that occur in the ascending route?

Answer 14

cystitis - bladder
pyelonephritis - kidneys

Question 15

what is the term used for the descending route of infection

Answer 15

haematogenous infection

Question 16

When is it a good idea to provide patients with ABs

Answer 16

> 10^8 UPC/ml - significant bacteruria (bacteria in urine)

Question 17

What are the ABs used for UTIs

Answer 17

1. Amoxil
2. Trimethoprim (folic acid sythesis), Ciprofloxacin (DNA synthesis) –> both non penicillin antibiotics

Question 18

What are ESBLs

Answer 18

Extended spectrum beta lactamase
- resistant to many beta lactams
- penicillin, cephalosporins, carbapenemms
- encoded by plasminds in gram negative bacterial species

Question 19

How are ESBLs treated?

Answer 19

polymyxin B or E
- disrupts membranes, cationic polypeptide antibiotic

Question 20

For most pathogens which is the most effective infection control procedure in a hospital?

Answer 20

Hand hygiene