Lecture 12 Flashcards Preview

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Flashcards in Lecture 12 Deck (23)
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1
Q

What is the major cause of Hospital Acquired urinary tract infections?

A

Catheters

2
Q

What are the causes of community acquired urinary tract infections?

A

Prostate problems in males and the proximity effect in females

3
Q

What is the proximity effect?

A

Females have a higher incidence rates of UTIs than males as the urethra is closer to faecal origin

4
Q

What is the major pathogen causing urinary tract infections?

A

Escherichia Coli

5
Q

What are the risk factors for a urinary tract infection?

A

Sexually active women, Previous infection, Underlying disease leading to stasis of urine

6
Q

What are the key virulence factors of E.Coli?

A

Pili, Iron acquisition, Lipid A, Toxins for cell death, Intracellular bacterial comunity (strands), Quiescent intracellular reservoir

7
Q

What are the pili of E.Coli used for?

A

P-Pili are used to adhere to the kidney,
Type 1 pili are used to adhere to the bladder,
both types of pili help the microorgansim avoid getting washed away

8
Q

What is the shape of E.Coli?

A

E.coli is a gram negative rod

9
Q

What is cystisis?

A

A relatively less serious condition, but may progress up the urinary tract to cause the more serious pyelonephritis

10
Q

What is pyelonephritis?

A

Inflammation of the kidneys

11
Q

How can E.Coli be diagnosed?

A

Dipstick test, Cysteine-Lactose-Electrolyte deficient agar

12
Q

How does the dipstick test work?

A

Tests for nitrites, Leukocyte esterase, pH, Red blood cells, Protien and glucose levels

13
Q

What can be learned from the cysteine lactose electrolyte deficient agar?

A

As E.Coli is a lactose fermenter it will appear yellow, BUT Klebsiella also turns positive

14
Q

What microorganisms that cause urinary tract infections test negative for the CLED agar?

A

Pseudomonas, Proteus

15
Q

What is the purpose of the ImViC test?

A

To distinguish between E.Coli and Klebsiella

16
Q

What does the ImViC test use?

A
Indole (break down of tryptophan)
Methyl Red (fermentation of glucose)
Vogues Proskauer (Butenyl glycol production from glucose)
Citrate
17
Q

What are the ImViC test results for E.Coli?

A

Positive for Indole and methyl Red, negative for Vogues Proskauer and Citrate
(Pink, Red Light Brown, Green)

18
Q

What are the ImViC test results for Klebsiella?

A

Negative for Indole and methyl red, positive for Vogues Proskauer and Citrate
(Pale with yellow upper layer, yellow, brown precipitate, blue)

19
Q

What are the treatment options for E.Coli that do not involve antibiotics?

A

Fluids and pain relief, good hygiene practices may need to be reinforced, cranberry juice, and yoghurt can help promote the growth of good bacteria to crowd out the infection while mannose tablets may inhibit the pathogen in some cases

20
Q

When should antibiotics be considered with urinary tract infections?

A

If the disease is prolonged or progresses to more severe symptoms
This can also be identified by enumeration of more than 10^8CFU/L

21
Q

What antibiotics can be used against E.Coli?

A

Amoxicillin (Penecillin Based), Trimethoprim (Inhibits folic acid synthesis), Ciprofloxacin (inhibits DNA replication)

22
Q

What is ESBL E.Coli?

A

E.Coli that have resistance to all penicillin based antibiotics due to a beta lactamase enzyme

23
Q

How can ESBL E.Coli be treated?

A

Use of polymyxin B or E or cationic polypeptide antibiotic used as a last resort as these antibiotics can be damaging but maybe the only thing that works