L18: UTI

Question 1

3 things that are a UTI

Answer 1

Pyelonephritis (kidneys and ureters)
Urethritis
Cystitis

Question 2

In whom are UTIs most common?

Answer 2

Female adults

Question 3

What causes UTIs in children?

Answer 3

Poor hygiene

Partial blockage

Question 4

Signs of upper UTI (pyelonephritis)

Answer 4

HIGHER FEVER >101 F
Flank pain
Shaking, chills
N/V

Question 5

Signs of UTI in a newborn

Answer 5

Fever or hypothermia
Poor feeding
Jaundice

Question 6

Signs of UTI in an infant

Answer 6

V/D

Poor feeding

Question 7

Signs of UTI in children

Answer 7

Irritability
Eating poorly
*Unexplained fever*
Loss of bowel control/loose stools
Change in urination patterns

Question 8

URI-cult CLED/EMB

Answer 8

paddles used to make a presumptive identification of the pathogen

Question 9

EMB

Answer 9

contains bile salts that kill G+

Selective for G-

Question 10

CLED

Answer 10

allows growth of both G+ and G-

determines ability to ferment lactose

Question 11

Hallmark UTI pathogens

Answer 11

are G- and ferment lactose

Question 12

Why are CFU used in diagnosis of UTI?

Answer 12

Many of the pathogens are normal flora, so we need a threshold to indicate overgrowth/infection

Question 13

Who usually gets urine cultures?

Answer 13

Men and children

Question 14

A positive urine culture is

Answer 14

5 x 10^4 CFU

Question 15

A positive urine microscopy is

Answer 15

2-5+ WBCs
15 bacteria
per high powered field in centrifuged urine sample

Question 16

What else to do for a UTI in men?

Answer 16

prostate exam

Question 17

Who gets imaging (US/CT/fluoroscope)?

Answer 17

Children
Adults with recurrent infections
Blood in urine

Question 18

Why do we image children?

Answer 18

50% of infants with UTI have an anatomic abnormality

Question 19

Most common causative agent of UTI

Answer 19

E Coli

Question 20

How do you get a candida UTI?

Answer 20

catheterization

Question 21

What can an adenovirus UTI cause? (rare causative agent)

Answer 21

Hemorrhagic cystitis

Question 22

E coli morphology

Answer 22

G-

Flagellated

Question 23

E coli associated with meningitis

Answer 23

Encapsulated K1 stains

Question 24

Why would you get meningitis from E coli?

Answer 24

It’s rare: following neurosurgical trauma

Question 25

Which E coli strain causes UTIs?

Answer 25

UPEC: Uropathogenic E coli

Question 26

UPEC virulence factors

Answer 26

P fimbriae (Pili) Dr adhesions alpha and beta hemolysins +- K (capsular) antigen (biofilms)

Question 27

Dr adhesions

Answer 27

UPEC binds to uroepithelial cells and erythrocytes. form complex structures surrounding bacteria

Question 28

Why does UPEC cause blood in urine?

Answer 28

alpha and beta hemolysins

Question 29

when are UPEC more likely to produce K (capsular) antigen?

Answer 29

Upper UTI Chronic UTI Cause biofilms

Question 30

2 Proteus species

Answer 30

P mirabilis | P vulgaris

Question 31

Proteus which infects the immunocompromised

Answer 31

Proteus vulgaris

Question 32

Proteus which is community acquired

Answer 32

Proteus mirabilis

Question 33

"Swarming" on agar

Answer 33

proteus species

Question 34

when don't proteus swarm

Answer 34

CLED test inhibits it so you can actually count colonies

Question 35

Proteus usually are found in

Answer 35

``` normal flora (intestin) long term care facilities hospitals ```

Question 36

Proteus virulence factors

Answer 36

fimbriae promote attachment to uroepithelial cells | induce apoptosis

Question 37

If proteus spreads

Answer 37

sepsis

Question 38

Urease

Answer 38

proteus | makes urine alkaline by hydrolyzing urea to ammonia

Question 39

Increased pH, as caused by urease from proteus

Answer 39

formation of struvite stones (magnesium ammonium phosphate)

Question 40

proteus gram stain

Answer 40

G-

Question 41

Staph saprophyticus characteristics

Answer 41

``` G+ Coagulase negative Novobiocin resistant Lactosamine (adhesin) Not that virulent, normal flora, ```

Question 42

Second leading cause of UTI

Answer 42

Staph saprophyticus

Question 43

Staph saprophyticus usually infects

Answer 43

Female 17-27, sexually active

Question 44

Honeymoon cystitis

Answer 44

Staph saprophyticus

Question 45

Why is Staph saprophyticus difficult to diagnose?

Answer 45

Low bacterial numbers, less than 10^5

Question 46

No exotoxins

Answer 46

Staph saprophyticus

Question 47

Group B strep (GBS) aka

Answer 47

Strep agalactiae

Question 48

Gray-white colonies with a narrow zone of beta hemolysis

Answer 48

Strep agalactiae (group B strep)

Question 49

where is Strep agalactiae (group B strep) normally found?

Answer 49

Vagina GI tract Upper respiratory tract Makes prevention difficult

Question 50

If a mother has Strep agalactiae (group B strep) colonizaiton of her vagina, will her neonate get it?

Answer 50

50% will | but only 1-2% actually get infected

Question 51

So who gets Strep agalactiae (group B strep)

Answer 51

Immunodeficient

Question 52

Strep agalactiae (group B strep) virulence factors

Answer 52

Capsular polysaccharide Hyaluronidase Collaginase Hemolysin

Question 53

CAMP factor

Answer 53

test for Strep agalactiae (group B strep) | Accentuation of hemolysis due to interaction with staph beta-lysin (s aureus?)

Question 54

Presumptive tests for diagnosis of Strep agalactiae (group B strep)

Answer 54

DNA probe | group CHO identification is insensitive