microbiology

Question 0

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

Answer 0

1 every 2 years

Question 1

what population is most likely to get UTIs

Answer 1

women

Question 2

what is pyelonephritis

Answer 2

infection of the kidney and renal pelvis

Question 3

what is sterile pyuria

Answer 3

pus in the urine without bacterial growth

Question 4

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

Answer 4

asymptomatic bacteriuria

Question 5

where abouts in the urinary system should be sterile

Answer 5

everything above the lower sphincter of the bladder

Question 6

what is the most likely cause of UTIs

Answer 6

E. coli

Question 7

what are the main causes of UTI

Answer 7

E. coli
Proteus species
Staph saprophyticus
others

Question 8

how do bacteria get to the urinary tract

Answer 8

• most ascending

- occasionally via the blood

Question 9

which bacteria causing UTIs get there via the blood

Answer 9

Staph aureus –> kidney abscess
Salmonella typhi
TB

Question 10

which bacteria causing UTIs are associated with Shistasoma

Answer 10

Salmonella Typhi

Question 11

what are our innate defenses against UTIs

Answer 11

• 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

Question 12

what normal host factors predispose us to getting UTIs

Answer 12

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

Question 13

what abnormal host factors predispose us to getting UTIs

Answer 13

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

Question 14

what is vesico-ureteric reflux

Answer 14

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

Question 15

what are PAP pilli associated with

Answer 15

pyelonephritis

Question 16

which adhesins of bacteria make it more likely to get UTIs

Answer 16

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

Question 17

what microbial bacterial factors make them more likely to cause UTIs

Answer 17

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

Question 18

which bacteria associated with UTIs have a polysaccharide capusle

Answer 18

E. coli and Klebsiella

Question 19

what is the advantage of a bacteria having siderophores

Answer 19

sucks iron of transferrin - bacteria will use this for growth

Question 20

how does urease help with bacterial UTI

Answer 20

assists growth and promotes formation of struvite stones

Question 21

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

Answer 21

bladder

Question 22

what are the types of urine samples

Answer 22

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

Question 23

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

Answer 23

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

Question 24

what is the use of a bag sample for detecting UTI

Answer 24

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

Question 25

use of suprapubic aspirate

Answer 25

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

Question 26

how do you collect a sample from a catheter bag

Answer 26

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

Question 27

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

Answer 27

``` WBC RBC epithelial cells casts crystals microorganisms ```

Question 28

what is the normal level of RBC in the urine

Answer 28

<10^4

Question 29

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

Answer 29

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

Question 30

what does it mean if you have epithelial cells in the urine

Answer 30

suggests poorly gained specimen - using sample from the beginning of the stream

Question 31

what is the cut off for abnormal number of bacteria in a sample collected from a catheter

Answer 31

>10^2

Question 32

what are the normal and abnormal counts for bacteria in the urine

Answer 32

normal - <10^3 | abnormal - more than 10^5

Question 33

how long do you have to get a urine sample to the lab

Answer 33

<1 hour | or keep it at 4 degrees for up to 18 hours

Question 34

which parts of the urine dipstick are useful for detecting UTIs

Answer 34

leukocytes and nitrites

Question 35

what are the causes of sterile pyuria

Answer 35

non-infectious conditions eg tumour partial treatment difficult to grow bacteria - eg. TB

Question 36

what is the Tx for uncomplicated cystitis

Answer 36

- alkalinise urine (check pH first) - cephalexin or co-amoxyclav or trimethoprim - if <2 years, check for UT abnormality

Question 37

what is the Tx for pyelonephritis

Answer 37

- cephalexin or co-amoxyclav or trimethoprim for 10 days - check for UT abnormality - if severe sepsis, use ampi/amoxycillin and gentamycin

Question 38

when is the only time that asymptomatic bacteriuria is a problem

Answer 38

during pregnancy

Question 39

how do you treat asymptomatic bacteriuria during pregnancy

Answer 39

cephalexin/co-amoxyclav or other

Question 40

urease in which bacteria? | What does it do?

Answer 40

proteus uses it to make struvite stones (ammonia)

Question 41

what kind of bacteria is proteus

Answer 41

gram negative rose