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Z MD1 Renal block > microbiology > Flashcards

Flashcards in microbiology Deck (42)
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0

what population is most likely to get UTIs

women

1

what is the average number of UTIs for a sexually active women

1 every 2 years

2

what is pyelonephritis

infection of the kidney and renal pelvis

3

what is sterile pyuria

pus in the urine without bacterial growth

4

what is it called when you have bacteria in the urine but no clinical symptoms

asymptomatic bacteriuria

5

where abouts in the urinary system should be sterile

everything above the lower sphincter of the bladder

6

what is the most likely cause of UTIs

E. coli

7

what are the main causes of UTI

E. coli
Proteus species
Staph saprophyticus
others

8

how do bacteria get to the urinary tract

- most ascending
- occasionally via the blood

9

which bacteria causing UTIs get there via the blood

Staph aureus --> kidney abscess
Salmonella typhi
TB

10

which bacteria causing UTIs are associated with Shistasoma

Salmonella Typhi

11

what are our innate defenses against UTIs

- transitional epithelium resists colonisation by most types of bacteria
- epithelium relatively resistant to bacterial invasion
- some bacteria dont like growing in urine
- constant flushing out of the bladder --> regular bladder emptying

12

what normal host factors predispose us to getting UTIs

- short urethra in girls/women
- sexual intercourse
- colonisation of the distal urethra
- no circumcision (for infant boys only)

13

what abnormal host factors predispose us to getting UTIs

- incomplete bladder emptying (structural abnormality or functional abnormality)
- catheterisation

14

what is vesico-ureteric reflux

when the last part of the ureter is not closed off by contraction of the bladder and therefore reflux of urine goes up the ureter with urination

15

what are PAP pilli associated with

pyelonephritis

16

which adhesins of bacteria make it more likely to get UTIs

- type 1 fimbriae - stick to particular sugar residues on our membranes
- PAP pilli of E. coli
- flagella - able to swim up the ureters

17

what microbial bacterial factors make them more likely to cause UTIs

- adhesins
- polysaccharide capsule
- intracellular bacterial communities
- biofilm formation
- haemolysin
- siderophores
- urease

18

which bacteria associated with UTIs have a polysaccharide capusle

E. coli and Klebsiella

19

what is the advantage of a bacteria having siderophores

sucks iron of transferrin - bacteria will use this for growth

20

how does urease help with bacterial UTI

assists growth and promotes formation of struvite stones

21

where do bacteria with type 1 pilli tend to infect in the urinary system

bladder

22

what are the types of urine samples

- Midstream urine
- catheter/nephrostomy sample
- bag sample (for infants)
- suprapubic aspirate

23

why dont you want the first part of the urine for testing for UTIs

because the first part of the urine will be contaminated with the commensals of the lower urinary tract - so will misdiagnose bacteria in the upper urinary tract if you use this

24

what is the use of a bag sample for detecting UTI

can rule out UTIs - if there are no bacteria in it
if there are any bacteria - useless

25

use of suprapubic aspirate

if there is any bacteria in the aspirate --> significant (should be sterile where you are taking the sample)

26

how do you collect a sample from a catheter bag

never collect it from the bag! - get it from a needle into the tube when fresh urine is being passed

27

what do you look for in the examination of urine under the microscope

WBC
RBC
epithelial cells
casts
crystals
microorganisms

28

what is the normal level of RBC in the urine

<10^4

29

what is the normal and abnormal ranges for WBC in the urine

normal - less than 10^4
abnormal - more than 10^5