UTI

Question 1

what are the main structures of the urinary system?

Answer 1

• kidneys
• nephrons
• ureters
• bladder
• urethra

Question 2

function of kidneys?

Answer 2

remove waste from the blood and excrete it in urine

Question 3

function of nephrons?

Answer 3

the functional unit of the kidneys
- filter the blood to form urine

Question 4

function of ureters?

Answer 4

carry urine to the urinary bladder

Question 5

function of urinary bladder?

Answer 5

stores urine until it can be eliminated

Question 6

function of urethra?

Answer 6

urine is excreted via the urethra

Question 7

difference between male and female urinary/reproductive systems?

Answer 7

females have distinct urinary and reproductive systems, male urinary and reproductive systems share some components

Question 8

microbiome of the urinary system? (flora)

Answer 8

urethra supports colonization by some microorganisms
- include lactobacillus and staphylococcus
- other urinary organs are sterile

Question 9

microorganisms in the urethra can…

Answer 9

move up to infect the kidneys

Question 10

bacterial urinary tract infection signs and symptoms?

Answer 10

• frequent, urgent, painful urination
• urine may be cloudy with foul odor

Question 11

pathogens and virulence factors of UTIs?

Answer 11

• enteric (come from intestinal tract) bacteria are the most common cause
• escherichia coli causes most cases
  virulence factors include flagella and attachment fimbriae

Question 12

what is the cause of most UTIs (pathogenesis)?

Answer 12

often results when fecal bacteria are introduced into urethra
- more common in females

Question 13

diagnosis, treatment, and prevention (epidemiology) for UTIs?

Answer 13

• diagnosis is based on urine sample
• treated with antimicrobial drugs (if any at all bc they can resolve on their own)
• prevented by limiting contamination by fecal microbes

Question 14

why does insertion of a urinary catheter increase the likelihood of cystitis (inflammation of bladder)?

Answer 14

catheters can be colonized by bacteria on the skin, so if the catheter is inserted for too long it can provide the bacteria with easy access thus resulting in infection

Question 15

prevalence of UTIs?

Answer 15

• one of the most common reasons for visiting a primary care physician
• up to 50% of women have at least one UTI by age 30
  
  • incidence typically decreases w age
• abt 25% of women will experience a second episode within 6 months of their first UTI (recurrent)

Question 16

bacteriuria means?

Answer 16

the presence of bacteria in urine
- does not necessarily imply infection

Question 17

what is asymptomatic bacteriuria?

Answer 17

presence of bacteria in urinary tract in the absence of symptoms
- not necessary to treat UNLESS pregnant female or patients undergoing procedures on urinary tract

Question 18

what are the seven normal mechanisms that maintain sterility of urine?

Answer 18

• adequate urine volume
• free-flow from kidneys through urinary meatus
• complete bladder emptying
• normal acidity of urine
• peristaltic activity of ureters
• increased intra-vesicular pressure preventing reflux
• in males, antibacterial effect of zinc in prostatic fluid

Question 19

classification of UTIs are based on what three things?

Answer 19

• location
• condition of the urinary tract or the patient (complicated/uncomplicated)
• based on evolution (acute, chronic, recurring)

Question 20

what are the two locations for classification of UTIs?

Answer 20

upper: pyelonephritis
lower: cystitis and urethritis

Question 21

what is cystitis?

Answer 21

UTI presumed to be confined in the bladder
- acute lower UTI

Question 22

what are the main symptoms of cystitis?

Answer 22

• dysuria (pain, burning, itching, stinging)*
• urinary frequency*
• urinary urgency*
• supra-pubic pain
• hematuria (blood in urine)
• nocturia (waking up to pee)
• bladder tenesmus (feeling of have to pee but can’t)
• absence of vulvar or vaginal discharge or irritation

Question 23

what are the three differential diagnosis

Answer 23

1. acute urethritis (caused by UTI)
   - chlamydia trachomatis
   - neisseria gonorrhoeae
2. vulvitis (caused by yeast)
   - contact dermatitis, allergic
   - candida albicans, HSV infection
3. vaginitis/bacterial vaginosis

Question 24

what is pyelonephritis?

Answer 24

clinical diagnosis which implies more invasive infection (not confined to bladder)
- ex. inflammation of the kidney and renal pelvis along w evidence of UTI

Question 25

common symptoms of pyelonephritis?

Answer 25

fever, flank (back/ribs/pelvis) pain, nausea, chills, malaise headache

Question 26

what is prostatitis?

Answer 26

inflammation/infection of the prostate gland - may present as acute or chronic

Question 27

what is intrarenal abscess / perinephric abscess?

Answer 27

collection of pus in the kidney or in the soft tissue surrounding the kidney - rare

Question 28

uncomplicated UTI?

Answer 28

patients w normal genitourinary tract - usually non-pregnant premenopausal women of childbearing age

Question 29

complicated UTIs?

Answer 29

structural or functional abnormality of the genitourinary tract - pregnant people, elderly, men, children - chronic symptoms, comorbid illness or immuno-compromised - upper tract disease (pyelonephritis)

Question 30

complicated infections?

Answer 30

underlying abnormality that predisposes patient to UTI or makes UTI more difficult to treat effectively

Question 31

recurrent infection: relapse?

Answer 31

- recurrence of infection by same organism after discontinuation of treatment due to resistance or underlying issue

Question 32

recurrent infection: re-infection ?

Answer 32

recurrence of infection of infection by a different organism after discontinuation of treatment - due to resistance or underlying issue or repeating infective behaviour

Question 33

UTIs are usually due to...

Answer 33

patients own intestinal flora - ascending route of infection - organisms enter the urinary tract retrograde fashion via the urethra

Question 34

what are the six biggest risk factors for UTIs?

Answer 34

1. age 2. female: shorter urethra, etc. 3. male: prostatic hypertrophy, anal intercourse 4. urinary tract obstruction: tumour or calculi 5. impaired bladder innervation 6. hematogenous spread (through blood)

Question 35

why are females more at risk for UTIs?

Answer 35

shorter urethra, sexual intercourse, contraceptives that alter normal bacteria flora, pregnancy

Question 36

majority of UTIs are due to a single pathogen called:

Answer 36

- the enterobacterales are responsible for 90% of all UTIS escherichia coli - most commonly isolated pathogen, about 70% in all UTIs

Question 37

characteristics of e coli that causes UTI?

Answer 37

gram negative bacilli - facultatively anaerobic - common intestinal flora

Question 38

what is a major virulence factor for e coli?

Answer 38

adherence bc they can stay stuck and not get washed out from urine - uropathogenic e coli are the best at adhering and infecting, they have P fimbria that bind

Question 39

what are the three classical UTI uro-pathogens?

Answer 39

proteus morganella providencia - urease producing organisms, highly motile, fimbria for attachment

Question 40

what uro-pathogen is typically associated with younger sexually active females?

Answer 40

staphylococcus saprophyticus - 1-5% of cystitis

Question 41

what is the most common organisms of UTIs for younger, sexually active females?

Answer 41

e coli

Question 42

what is nosocomial UTI?

Answer 42

catheter associated - e coli still most common cause

Question 43

diagnosis of UTI: rapid in-office lab testing, what is being detected?

Answer 43

primarily interested in detection of nitrites and leukocytes - nitrite presence is reasonably sensitive for gram-negative bacteria (specific) , leukocytes is sensitive combined detection of nitrites and leukocytes is highly sensitive and specific when combined with clinical findings

Question 44

urine culture on quantitative culture: significant bacteriuria defined as?

Answer 44

10^5 bacteria/mL or 10^8/L - needs to be this high or not considered UTI bc could be regular flora

Question 45

what is the problem with using collection bags for specimen collection?

Answer 45

often contaminated by other bacteria

Question 46

what are two ways to collect urine using a catheter?

Answer 46

1. indwelling catheters - urine obtained by inserting needle into catheter or through diaphragm 2. suprapubic aspiration / straight catheter - invasive - specimen obtained directly from bladder

Question 47

specimen transport details?

Answer 47

sent to an processed by lab as quickly as possible - needs to be refrigerated if not received quickly - urine needs to be received and refrigerated within 24 hours or will be rejected unless transported in a boric acid tube

Question 48

what is empiric therapy?

Answer 48

- based on most probable pathogens - lower vs upper tract infection - local rates of resistance - acute vs relapse patients are becoming more resistant to oral first line agents

Question 49

what are the typical treatments for uncomplicated cystitis?

Answer 49

1. nitrofurantoin (interfere w dna rna or protein synthesis) 2. fosfomycin (interfere with cell wall) 3. TMP/SMX ( >25% resistance, interferes w folic acid) second line 1. doxycycline (target ribosome) 2. ciprofloxacin/levofloxacin (target dna gyrase to stop dna replication)

Question 50

what are typical treatments for pyelonephritis? (more complicated)

Answer 50

1. b-lactam + aminoglycoside (targets cell wall) 2. ciprofloxacin / levofloxacin