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Flashcards in Renal Microbiology Deck (35):
1

What is the definition of UTI

Presence of microorganisms in the UT that are causing infection

2

What is the definition of LUTI?

Infection confined to the Bladder (Cystitis)

3

What is the definition of UUTI?

Infection confined to the Ureters and Kidneys (Pyelonephritis)

4

Is the urine in the kidneys, ureters and bladder sterile?

True, although it is normal to see bacteria in elderly patients' urine

5

What is meant by Complicated UTI?

UTI complicated by the systemic symptoms/structural abnormality/stones

6

What is Bacteriuria?

Bacteria in the urine.
Common in elderly patients with catheters and does NOT always mean infection.
Determine if patient symptomatic.

7

List host factors for UTI

Genetic background
Underlying disease - structural abnormality/catheterisation
Gender
Age
Geographical Factors

8

Why are host factors important for UTI?

Denotes recurrence possibility

9

List 2 modes of UTI

Ascending
Bloodstream

10

Who is more affected by UTIs, women or men?

Women
Shorter, wider distal urethra closer to the anus means they are more susceptible
Also increased risk with sexual activity and pregnancy

11

List other patient groups predisposed to UTI

Catheterised patients
Patients with structural abnormality
Diabetics on SGLT2 Inhibitors

12

How does UTI occur?

Contamination of the urethra leads to colonisation and subsequent infection

13

What is Ascending UTI?
How does it occur?

Infection that tracks up from the bladder into the UT, often arising from:
Bacteria from bowel
Perineal Skin
Lower End of Urethra

14

What is the biggest cause of UTI?

Coliforms, especially E.coli

Other coliform causes include:
Enterobacter
Klebsiella
Serratia
Proteus

15

What is the biggest gram negative, non-coliform bacterial causes of UTI?

Pseudomonas Aeruginosa

16

What aids E.coli in its ability to cause disease?

Endotoxin
Flagellum
Fimbriae, help it attach on its way up the bladder

17

What is Proteus UTI associated with?

Struvite stones (staghorn calculi)

These are large stones which take the shape of the renal calyx.
Urologists are needed to break them down

18

How can Proteus be identified?

Foul smelling, smells like burnt chocolate

It produces urease to produce urea which increases urinary pH, increasing salt production

Swarming cultures on agar plate

19

List other forms of urine specimen

Clean Catch Urine (used for children)
Bag Urine (babies), susceptible to contamination
Catheter Specimen of Urine, only if patient has symptomatic UTI
Suprapubic Aspiration

20

Why is Pseudomonas Aeruginosa UTI important?

It is resistant to most oral antibiotics
Can only be treated with Quinolones i.e. Ciprofloxacin

21

List other UTI investigations

Urine Microscopy (only for patients with nephrotic differentials e.g. casts)
Urine Culture (< 10^4 colonisation is Negative for infection)

22

List gram positive causes of UTI

Enterococcus faecalis, which is a common bug of hospitalised patients (HAI)
Staphylococcus Saphrophyticus (women of child bearing age)
Staph. Aureus (associated with bacteraemia)

23

List symptoms of UTI

Dysuria
Increased Frequency
Nocturia (establish change)
Haematuria
Fever, Loin Pain or Rigors (UUTI indication)

24

Antibiotics are required in asymptomatic bacteriuria

No
Except for pregnant women as they may present with pyelonephritis or premature pregnancy later on

Pregnant women are screened for asymptomatic bacteriuria on first antenatal visit

25

Why is it important to be careful with antibiotics in catheterisation?

Catheter may become colonised with resistant bacteria

26

How is a urine sample taken?

First pass of urine is more likely to be contaminated so sample is taken from a midstream specimen as this is more useful and therefore, the best sample.

First pass = urine in toilet
Midstream specimen = sample after

27

Why is Gentamicin use limited to 3 days?

Due to risk of nephrotoxicity

28

What is Abacterial Cystitis?

Syndrome consisting of:
Frequency
Nocturia
Dysuria
May be due to early phase of UTI, urethral trauma (Honeymoon Cystitis) or chlamydia/gonorrhoea urethritis

29

How is female LUT treated?

Trimethoprim or nitrofurantoin orally (3 days)

Anti-inflammatory treatment may be as good as antibiotics for some cystitis patients

30

How is UTI treated for an uncatheterised male?

Trimethoprim or nitrofurantoin orally (7 days)

31

How is a Complicated UTI or GP presentation of Pyelonephritis treated?

Co-amoxiclav or co-trimoxazole (14 days)

32

How is a Complicated UTI or Hospital Pyelonephritis treated?

Amoxicillin and Gentamicin IV for 3 days

Co-trimoxazole and gentamicin if penicillin allergy, stepdown as guided by antibiotic sensitivities

33

How is ESBL UTI treated?

Pivmecillinam (oral)
Temocillin (IV)

34

List first line antibiotics for UTI

Gentamicin
Amoxicillin (not always sensitive)
Trimethoprim
Co-trimoxazole (not reliable in bacteraemia)

35

What is the Kass Criteria?

>10^5 organisms/ml = significant =probable UTI
<10^3 organisms/ml = not significant bacteriuria
10^4 organisms/ml = contaminated? infection? Repeat specimen

CAUTION; these criteria ONLY apply to women of childbearing age