Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Mega Step 1 Deck > Enteric Pathogens II > Flashcards

Enteric Pathogens II Flashcards

1
Q

general properties of enterobacterials (enterobacteriaceae)

A

*gram NEG rods
*facultative anaerobes
*OXIDASE NEGATIVE
*CATALASE POSITIVE

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

oxidase status of enterobacteriaceae

A

oxidase NEGATIVE

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

catalase status of enterobacteriaceae

A

catalase POSITIVE

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

common virulence factors associated with enterobacteriaceae

A

-endotoxin (LPS/lipid A)
-capsule
-T3SS
-sequester iron
-resistance to serum killing
-antimicrobial resistance
-antigenic phase variation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

what are the lactose POSITIVE enterobacteriaceae (ferment lactose)

A

-klebsiella
-enterobacter
-E. coli

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

what are the lactose NEGATIVE enterobacteriaceae (do NOT ferment lactose)

A

-salmonella
-shigella

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

E. coli - physiology, structure, virulence

A

*gram neg, facultative anaerobic rods
*oxidase NEG
*lactose fermenter (pink on Mac agar)
*LPS with outer O polysaccharide and lipid A

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

E. coli - epidemiology

A

*most common aerobic, gram negative rods in the GI tract
*most extra-intestinal infections (UTI, pneumonia) are ENDOgenous
*most strains causing gastroenteritis are EXOgenous

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

uropathogenic E. coli (UPEC)

A

*causes > 80% of UTIs
adherence virulence factor:
-P fimbriae binds to Gal-Gal**
-SFA on S fimbriae
-AFA

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

variety of diarrheagenic E. coli

A

-enterotoxigenic (ETEC)
-enteropathogenic (EPEC)
-enteroinvasive (EIEC)
-enteroaggregative (EAEC)
-enterohemorrhagic (EHEC) / shiga toxin producing (STEC)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

enterotoxigenic E. coli (ETEC)

A

**most common cause of TRAVELER’S DIARRHEA worldwide
*s/s:
-profuse watery diarrhea
-abdominal cramps
-nausea
-low grade fever
-lasts 3-5 days

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

ETEC pathophysiology

A

*adhesins adhere to intestine (does not invade)
-colonization factor antigens (CFA/1, CFA/II, CFA/III)**
*toxins enhance intestinal secretion of chloride and decreased absorption
-heat labile toxin (LT-I and LT-II)**
-heat stable toxin (STa and STb)**

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

enteroaggregative E. coli (EAEC) pathophysiology

A

*adhesins: aggregative adherence fimbria (AAF/I, AAF/II, AAF/III)
toxins: SHET-1 (enteroaggregative heat stable toxin)
*forms biofilms on intestine
*“stack of bricks”

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

enteropathogenic E. coli (EPEC)

A

attaching and effacing:
-bundle forming pili (BFP) & intimin “ruffle” the cell wall causing leakage

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

enterohemorrhagic E. coli (EHEC) / shiga toxin producing (STEC)

A

*capable of producing Shiga toxin (a cytotoxic exotoxin)
*attaching and effacing
*BLOOD DIARRHEA
*NO fever
-associated with hemolytic uremic syndrome (HUS)
*serotype O157:H7

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

enteroinvasive E. coli

A

*closely related to Shigella
*causes diseases similar to shigellosis
*watery diarrhea; may or not progress to bloody diarrhea
*FEVER

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

salmonella infections

A

*gastroenteritis
*enteric fever
*bacteremia & endovascular infection
*sickle cell + osteomyelitis = salmonella
*ASYMPTOMATIC CHRONIC CARRIER STATE (typhoid Mary)

18
Q

salmonella pathogenesis

A

*enters through GI tract
*attaches to mucosa and invades M cells in Peyer patches
*pathogenicity island I - T3SS & Ssps (salmonella-secreted invasion proteins)
*pathogenicity island II - block lysosome movement & another T3SS

19
Q

salmonella exposure

A

*food/water: poultry, eggs, milk
*pets: turtles, snakes, lizard

20
Q

salmonella - gastroenteritis

A

*watery diarrhea
*fever, abdominal cramps
*resolves over 3-10 dyas
*chronic carriers 4-5 weeks

21
Q

salmonella - enteric fever

A

*typhoid fever (Salmonella typhi)
*systemic illness:
-fever
-headache
-ROSE SPOTS
-constipation > diarrhea

22
Q

shigella - infectious dose

A

VERY LOW ID50 (don’t need a lot of organisms to cause infection)

23
Q

shigella dysenteriae 1 (Sd1) - important features

A

*illness due to Sd1 is the most severe
*resistance to antimicrobials
*produce Shiga toxin!

24
Q

shigella s/s

A

*biphasic illness (sick, better, sick again)
*cramps
*voluminous watery diarrhea, then dysentery
*treat ALL patients

25
Q

shigella pathogenesis

A

*entry via M cells in Peyer patches
*T3SS secretes proteins and induce membrane ruffling
*escape to cytoplasm, following lysis of vacuole membrane
*multiplies in the cell
*uses actin for locomotion (push it from behind)

26
Q

complications of shigella

A

*reactive arthritis
*“sausage digit” or monoarticular arthritis
*HLA-B27 genetic predisposition for more severe disease

27
Q

yersinia - common characteristic

A

use T3SS to resist phagocytic killing

28
Q

yersinia pestis - 2 forms of infection

A

*plague-causing
1) urban plague (rats = reservoir)
2) sylvatic plague (squirrels, rabbits, etc = reservoir)

29
Q

yersinia pestis - bubonic plague presentation

A

*typical presentation
-high fever
-painful bubo (inflammatory swelling of lymph nodes)
-bacteriema

30
Q

yersinia pestis - pneumonic plague

A

-high fever and malaise
*pulmonary signs develop quickly
*worse than bubonic

31
Q

yersinia pestis - morphology

A

gram neg organism w/ SAFETY PIN appearance

32
Q

klebsiella pneumoniae

A

*prominent capsule
*“Currant Jelly” sputum (necrotic destruction of alveolar spaces)
*also causes UTI’s or wound infections

33
Q

klebsiella granulomatis

A

*cause of donovanosis (granuloma inguinale)
*ulceroglandular STI

34
Q

KPC = Klebsiella pneumoniae carbapenamase

A

*most significant antimicrobial resistance mechanism in the US currently
*resistance to our most powerful, broad-spectrum antibiotics

35
Q

proteus mirabilis

A

*produces a lot of UREASE
*urease raises pH and causes “staghorn calculi”
*mostly infects the urinary tract

36
Q

listeria monocytogenes

A

*gram POSITIVE COCCOBACILLI
*contaminated food products (raw milk and cheese, processed meats
*CAN spread transplacentally from mother to neonate
*NOT enterobacterialis

37
Q

listeria monocytogenes - virulence factors

A

*cell attachment factors = internalins
*hemolysins = listeriolysin O & 2 phospholipase C enzymes
*ActA (facilitates actin-directed motility)

38
Q

listeria monocytogenes & at risk populations

A

*always draw blood cultures on a pregnant woman (3rd trimester) presenting with fever
*can cause meningitis in babies & older adults

39
Q

listeria monocytogenes diagnosis

A

*lots of lymphocytes in CSF

40
Q

listeria monocytogenes treatment

A

*penicillin/ampicillin
*TMP/SMX in penicillin allergies

Mega Step 1 Deck (56 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions