Chapter 14 Flashcards Preview

Mechanisms of Microbial Disease > Chapter 14 > Flashcards

Flashcards in Chapter 14 Deck (36):
1

Who is at risk for bacterial urinary tract infections?

Women (pregnancy and sexual activity increases risk)
Elderly (improper emptying of bladder)
Patients with comorbid conditions (diabetes), spinal cord injuries (improper emptying of bladder), catheters, genitaurinal tract abnormalities (tumor, stone)

2

What are the two different routes for pathogens to cause a UTI?

Ascending route up the urinary tract from the outside. E. coli
Heamatogenous from the blood to the kidney

3

What is bacteriuria?

The presence of bacteria in the urine (normally sterile), can be symptomatic (cloudy) or asymptomatic (only found by screening in lab)

4

When is treatment recommended fro asymptomatic bacteriuria (ASB)?

During pregnancy and prostate resection

5

What is the proper procedure when taking a urine sample?

Pee a little bit. Stop. Then pee in the cup to avoid getting skin contamination or tract flushing.

6

What are the two subtypes of a recurrent UTI?

Relapse is when you become infected by the same organism and same strain.
Reinfection is a 2nd subsequent infection from a different organism.

7

What does it mean to have an uncomplicated UTI?

Occuring in healthy, non-pregnant females
Readily treated with antibiotics

8

What does it mean to have a complicated UTI?

Occurring in either gender but is more difficult to treat due to underlying diseases, kidney stones, UT abnormalities or indwelling urinary catheters

9

What are some contributing factors to UTIs?

Length of urethra, sexual activity (females), uncircumcised male infants, blockage and catheterization (each day risk goes up 10%, allows bacteria to avoid urine, biofilm is more resistant)

10

What is urethritis? What are the symptoms?

Infection of the urethra
Symptoms are dysuria (burning pain on passing urine) and frequency

11

What is cystitis? What are the signs and symptoms?

Bladder infection, lower UTI
Symptoms: Dysuria, frequency, urgency, pain over bladder area
Signs: Bloody, cloudy urine and bad odour

12

What is acute urethral syndrome?

Same symptoms as cystitis but less CFU/ml
Pyuria (8 leukocytes/mm3 of uncentrifuged urine)

13

What is polynephritis? What are the two subtypes?
What are the symptoms?

The infection of the kidney and renal pelvis (acute and subclinical)
Fever, lower UTI symptoms

14

What is prostatitis?

Infection involving the prostate

15

What is cervicitis?

Inflammation of the cervix

16

What is the epidemiology of UTIs in pediatrics?

High morbidity
More likely to develop impaired renal function, hypertension, end-stage renal disease and complications during pregnancy as an adult

17

What is the epidemiology of UTIs in geriatrics?

Incidence in both men and women increases but more common in men (prostate enlargement, poorer bladder emptying)

18

What are the microbial virulence factors for pathogens in UTIs?

Adherence (bacterial adhesins), calculi formation, toxin and enzyme production (hemolysins, lipopolysaccharides), capsular polysaccharide, biofilms

19

How does the urinary tract prevent infection?

Flushing action of urinary flow, growth inhibitory properties of urine (low pH, osmolarity, high urea, organic acid concentrations), mucopolysaccharides, preventing reflux

20

How does the normal microflora of the urethra change with growing up?
Newborn to pre-pubertal

Newborns: Sterile
1-3 days: Staph aureus, enterococci, diptheroids
3 days-weeks: Lactobacillus acidophilius
Pre-pubertal: Micrococci, streptococci, coliforms, diphtheroids

21

What does the normal microflora of the urethra look like in pregnancy and post menopausal?

Similar to prepubertal microflora
Micrococci, streptococci, coliforms, diphtheroids

22

What does the normal microflora of the urethra look like in adulthood?

L. acidophilus, staph epidermidis, streptococci (alpha, non-hemolytic), E.coli, diphtheroids, yeasts

23

What are the gram negative bacilli that cause UTIs?

Enterobacteriaceae
Fecal E.coli (uncomplicated)
MDR Enterobacteriaceae (hospital acquired)

24

How does duration of hospitalization and catheterization change the likely causative agents of a UTI?

Increased pseudomonas, proteus, klebsiella, acinetobacter and enterobacter
Decreased E. coli

25

What are the gram positive cocci that cause UTIs?

Enterococci (older men, UT manipulation, instrumentation)
Staph saprophyticus (symptomatic sexually active women

26

What are the gram positive bacilli that cause UTIs?

Diphtheroids, mycobacteria, Listeria monocytogenes
Bacillus (most likely contamination if in sample)

27

What are the fungi that cause UTIs?

Candiduria in hospitalized patients

28

What are the causative agents of cystitis?

E.coli, Klebsiella spp, other enterobacteriaceae, enterococci, CoNS

29

What are the causative agents of acute polynephritis?

Enterobacteriaceae, staphylococcus aureus

30

What are the causative agents of subclinical polynephritis?

CoNS, Candida spp, Mycobacterium spp, Mycoplasma hominis
Must be treated in pregnancy, young children, instrumentation, elderly and diabetics

31

How can a UTI be diagnosed?

From a midstream urine sample or right from bladder (avoids contamination, used to find anaerobic) and then microscopic examination

32

How can you tell if bacteria in urine is from infection or colonization when collected midstream?

1000 CFU/ml is infection

33

What could change the results of a urine sample?

If collected right from bladder, should have 0 CFU/ml
If on antibiotics, finding some CFU, could be a sign of resistant organisms
Drinking lots of water prior could dilute sample

34

How should a urine sample be stored?

Cultured within 1 hour of collection and stored at 4 degree for not more than 18 hours

35

How do we treat uncomplicated UTI (cystitis)?

May resolve spontaneously within 4 weeks
Antibiotics to reduce symptoms and ensure complete eradication, followup at end
Drink lots of fluids to facilitate flushing

36

How do we treat complicated UTI (pyelonephritis)?

Systemic IV treatment until symptoms subside with oral therapy afterwards
Should be >10 days to sterilize the kidney