GI- Upper Flashcards Preview

Micro > GI- Upper > Flashcards

Flashcards in GI- Upper Deck (148):
1

What breaks down breast milk for digestion

Bifidobacterium

2

What is needed to digest formula

Lactobacilli

3

Normal flora of the mouth

Strtococcus
Neisseria
Actinomyces
Veillonella
Lactobacillus
Yeast

4

What kind of bacteria is found in stomach

Sterile
Streptococcus
Staphylococcus
Lactobacillus

5

What predisposes you to H pylori

Gastritis
Peptic ulcers

6

Do you find bacteria in the small intestine

No

7

Bacteria in duodenum

Aerobic streptococci
Staphylococci
Lactobacilli
Yeast

8

What bacteria do you find at LI

Anaerobic

9

Which part of the Digestive system has the most amt of bacteria

LI 10^10-10^12

10

What is Allogenic

Factors outside the ecosystem affecting the microbrial composition of GI flora

Diet
Age
Georgraphic location
Antibiotics
Surgery

11

How does diet change flora of GI

Vegetarians have lower bacteroides, higher enterococci

12

How does antibiotics change flora of GI

Makes you susceptible to c. difficile

13

What is autogenic

Factors affecting GI from within the ecosystem
Environment
Activities of microorganisms

14

At risk groups of lower GI infections

CHildren <5
Elderly
Immunocompromised

15

Food hazards

Microbial contamination
Naturally occurring toxicants
Environment contaminants
Nutritional problems
Pesticides
Food additives

16

What are the routinely screened bacteria from stool samples

Campylobacter
Salmonella
Shigella
STECs (if stool is bloody)

17

What is the highest contamination for GI infections

Norwalk virus

18

What is food poisoning

Toxin in food- short incubation period
Toxemia
C. Botulinum
S. Aureus
B. Cereus

19

What is food associated infections

Consumption of food containing organism
Longer incubation period since organisms need to colonize first

20

Enteritis

Inflammation of intestinal mucosa

21

Gastro enteritis

Inflammation of stomach and intestinal linings

22

Colitis

Inflammation of LI

23

Enterocolitis

Inflammation of small and large intestine

24

Dysentery

Inflammation of GI tract and blood and pus in faeces

25

Acute Diarrhea

Resolves in 2 weeks
Infectious agents

26

Chronic diarrhea

Persistent
Lasts longer than 4 weeks
Need to know what meds taken
Possible syndrome
Parasite

27

What is the cause of non inflammatory gastroenteritis

Food poisoning

28

What are the infectious causes of gastroenteritis

S. Aureus
B. Cereus
C. Botulinum
Wild mushroom
Ciguatera
Scrombroid
Shellfish

29

What are the sx of food borne infections

Non inflammatory diarrhea
Inflammatory diarrhea

30

What the the pathogens of inflammatory diarrhea

Shigella
EIEC
Salmonella
Campylobactor
V. Vulnificus
V. Parahaemolyticus
Yersinia
STEC
C. Difficile

31

What are the pathogens of non inflammatory diarrhea

ETEC
EPEC
V. Cholerae
C. Perfringens
B. Cereus
Rotavirus
Norovirus
Adenovirus
Astrovirus
C.difficile

32

Which pathogen is not food borne

c difficile

33

General sx of toxemia

Rapid onset
No fever/faecal leukocytes
Affects CNS and sometimes CNS and Intestines

34

Characteristics of S. Aureus

Aerobic
Coagulase/catalase +
Heat stable enterotoxin production

35

Is S. aureus found naturally in humans

yes

36

What are the toxins released by s. aureus

Exotoxins (8)
A&D typically implicated

37

What are the sx from s. aureus

Neurological (Vomiting)
Enteric (Diarrhea)
Self limiting recovery 24-48 hours

38

Is adenylate cyclase stimulated by s. aureus

No

39

Foods at risk for s. aureus

Meat
Bakery foods
Dairy produce
Fruit
Veg
Salad

40

What causes the spread of s. aureus

poor food handling

41

When is highest incidence of s aureus

summer
Winter holiday periods

42

S. aureus confirmation test

Coagulase test

43

Bacillus cereus characteristics

Gram +
Rods
Aerobic
Spore former
Emetic toxin and enterotoxin

44

How does bacillus cereus spread

Air

45

How does b. cereus look under blood agar

Wrinkly

46

Baby sx to botulism

constipation
Lethargy
Suck/gag reflex diminish
Head control lost
Infant becomes flaccid

47

Tx for botulism

Antitoxin hepatavalent
Baby- immune globulin

48

Mushroom toxin characteristics

Short acting- wild mushrooms
Long acting- uncultivated mushrooms (amantia toxin)

49

Mycotoxigenic fungi characteristics

Aflatoxin
Contamination of nuts
Causes: acute necrosis, cirrhosis, carcinoma of liver

50

Ciguatera poisoning characteristics

Caribbean tropical fish
Large predatory reef fish
Acute GI sx- Watery diarrhea
Neurological sx- paresthesia, temp reversal

51

Scromboid poisoning

Non allergic histamine
Tuna mahi mahi bluefin
metallic taste

52

Shell fish poisoning

Brevetoxin

53

Paralytic shellfish poisoning

Dinoflagellate algae
Saxitoxin
Muscular in coordination

54

What does ecoli activate via its toxins

Heat Labile (LT)- adenylate cyclase
Heat stable (ST)- gunylate cyclase

55

Action of E coli toxin

B binding subunit adheres to GM1 receptor of epithillia cells. Allows for subunit A entrance. Entry of A activates G proteins of adenylate cyclase... hyper secretion of electrolytes and water

56

What is a way to contract c. perfringens

Not well cooked pig
Papua new guinea

57

WHat type of c perfringens is food borne

Type A

58

What is the toxin from c. perfringens called?

CPE

59

WHat are the parasitic causes of diarrhea

Cryptosporidium
Cyclospora
Entamoeba
Giardia

60

CHaracteristics of Rotavirus

11 segments
ds RNA

61

What are the important serotypes of rotavirus

G1-G4

62

Epidemiology of rotavirus

ages 4-5
Asia, africa, latin america
Developed countries- winter
Less developed countries- summer

63

What causes rotavirus

unsafe water

64

When are kids asymptomatic from rota virus

5 years and older
6months and younger

65

Pathogenesis of rotavirus

Fecal oral
Replication on epithelial cells of SMALL intestine
peaks in 8 days

66

Histopath of rotavirus

Shortening and blunting of villi

67

Clinical sx of rota

Sudden watery diarrhea

68

Complications from rota

Extreme dehydration (more severe than cholera)

69

Detection of rota

Latex agglutination
EIA

70

Sapovirus is mostly seen in this population (norovirus)

Elderly
in Winter

71

What is the main sx of sapovirus (norovirus)

vomiting

72

Transmission of noro virus

fecal oral
Spares large intestine (no faecal leukocytes)

73

How long does noro last

24-60 hours

74

Best way to detect noro in stool

RT-qPCR

75

Adenovirus characteristics

Icosahedral
ds DNA
40/41 serotype, Group F

76

Target of adenovirus in GI

Small intestine

77

Epi of adeno

Children less than 5
Diarrhea w/ w.o vomiting

78

Astrovirus characteristics

non enveloped
star shaped
Scotland
+ RNA

79

Hepatitis A transmission

Fecal oral
Non enveloped
ss + RNA

80

Hep E

Non enveloped
icoshedral
Endemic in India

81

Inflammation Diarhea overview

Food associated invasion of intestines
Sx- bloody diarrhea
Toxin: enterotoxin/ cytotoxin

82

Shigella groups

A-D
A is the most severe

83

What are the virulence factors for Shigella

Endotoxin (O toxin)
Exotoxin: Neurotoxin causes coma meningismus
NAD glycohydrolase (destroys NAD in cells- cell death)

84

Main sx of shigellosis sonnei

Watery diarrhea

85

Main sx of shigellosis flexneri

Stool mucus

86

Shigella pathogenesis

Invades distal ileum and colon through specialized epithelial cells (M cells) that overlie mucosal lymphoid follicles → escapes endocytic vesicle → replicates intracellularly, spreads cell-to-cell

87

Action of shiga toxin

cytotoxin- inhibit protein synthesis
Enterotoxin: produces diarrhea
Exotoxin: inhibit sugar aa absorption in SI
Neurotoxin effects

88

Epi shigella sonnei

Children <5

89

Epi shigella flexneri

Homosexuals

90

Transmission of shigella

Food
Fingers
Flies
Feces

91

Diagnosis of shigella

MacConkey agar
S-S agar
Stool is watery to bloody

92

General characteristics of shigella

Gram -
No fermentation lactose
No utilization of citric acid
No H2S production
No gas from glucose

93

Which shigella produces H2S

Shigella flexneri

94

Which is more infective shiga and enteroinvasive

Enteroinvasive Ecoli only 10 organisms needed for infection

95

Enteroinvasive E coli pathogenesis

Invasion in LI
Enters via endocytosis
Inhibits protein synthesis
Dead wbc, rbcs, mucosal cells in stool

96

3 types of clinical sx of salmonella

Gastroenteritis (s. typhimurium, s. enteritidis, s. newport)
Septicemia (s. cholerasuis)
Enteric Typhoid fever

97

Review chart in ipad for Salmonella (bookmarked)
Enteroinvasive vs septic vs typhoid

book mark

98

Where does Salmonella replicate

pyers patches

99

Where does salmonella infect

Columnar epithelial cells of the small intestine

100

What is most at risk for carrying enterocolitis

poultry

101

Highest incidence of salmonella

Serotype enteritidis

102

What besides food carries salmonella

reptiles

103

Enteric fever characteristics

Only found in travelers from asia mexico india
S. typhi

104

What is one weird fruit that carries salmonella typhi

Mamey fruit pulp

105

Diagnosis of salmonella

Macconkey agar

106

General characteristics of salmonella

Motile
Gram - rod
No fermentation lactose
H2S production
Gas from glucose
serotype

107

Clinical diagnosis of salmonella

Hx of travel
Rose colored spots on abdomen
Examine blood for absece of eosinophils
Positive widal reaction

108

Characteristics of campylobacter

Gram -
non sporing
microaerophilic
Does not ferment CH2O
Catalase +

109

Epi of campylobacter compared to h pylori

Campylobacter- Spike in summer
H pylori same level each season

110

What is the #1 food borne disease

Campylobacter

111

Pathogenesis of campylobacter

Invasion
Toxin: Endo/entero (watery diarrhea)
Cytotoxin: Verotoxin similar to shiga

112

Clinical sx of campylobacter

sx after 3-5 days of ingestion
Profuse diarrhea sometimes Green
Fever
Prostration

113

Campylobacter lab

Culture: Spreading, grey color
Catalase/oxidase definitive diagnosis
Microscopy: gram- (presumptive diagnosis)

114

Characteristics of yersinia

Psychrotroph- facultative psychrophile
common in children < 7

115

What is the toxin released by yersinia

ST enterotoxin
Increases cGMP

116

How long does yersinia last

14-21 days

117

What is a complication related to yersinia

Reactive arthritis
Induced polyclonal T cell stimulation (toxin)

118

Lab diagnosis of yersinia

MacConkey look for pinpoints
Specialized media for yersinia

119

General characterisitc of non cholera vibrio

Not agglutinated
Halophilic organisms
Coastal waters

120

Vibrio parahaemolyticus

Eat raw seafood
look out for sushi
Watery diarrhea

121

Vibrio vulnificus

Diarrhea
INfection of cuts
Skin lesions

122

Diagnosis of non vibrios

Screen stool for oxidase
TCBS agar
Sucrose: differentiating agent
Sucrose - : v. parahaemolyticus, v. vulnificus

123

Pathogenesis of EAEC

1. Initial adherence to intestinal mucosa (fimbriae)
2. enhanced mucus production- biofilm
3. cytotoxin production - damage to intestinal cells

124

Prognosis of EHEC

Life threatening
Haemorrhagic colitis
Uremic syndrome: renal failure

125

Toxin for EHEC

Phage encoded cytotoxin verotoxin
VT1: biochem structure similar to shiga toxin
VT2: B toxin bound to receptor allows for subunit A into cell. Activates 28 rna

126

Pathogenesis of EHEC

No invasion
Attaches via fimbrae

127

Diagnosis of e coli

Pink colonies on mac conkey agar
Sortibol macconkey agar
ETEC
ELISA
DNA probe

128

What are the antibiotics associated with C diff

ampicillin
Cephalosporins
clindamycin
Amoxicillin

129

Toxins in C diff

Toxin A: Enterotoxin
Toxin B: cytotoxin

130

Clinical sx of c diff

Varies
watery diarrhea
non bloody
hyposlcumineia, leukocytosis

131

Diagnosis of c diff

presence of pseudomembrane

132

Tx of c diff

Discontinue antibiotics
Tx w/ vancomycin, metronidazole

133

Gastric cancer w. H. Pylori seen with

Low acid production
Pan gastritis

134

Peptic ulcer w. h. pylori seen with

high acid production
antral predominant gastritis

135

What allows for h. pylori to survive at low pH

Urease

136

Virulence factor for H. pylori

cagPAI
VacA cytoxin

137

Non invasive tests for h pylori

Breath (rapid presumptive)
Serology (definitive)

138

Invasive tests for h pylori

Urease (rapid presumptive)
Culture (definitive)
Histo (definitive)

139

Tx for h pylori

Triple/quadruple therapy

140

Gastrointestinal abscess pathogenesis general

Reduced O2 tension/ oxidation reduction potential
Impaired blood supply
Provides anaerobic environment

141

Common cause of peritonitis

Primary: e coli, tb, n. gonorrhoeae, c. thrachomatis
secondary: Spillage of bacteria from GI into peritoneal cavity

142

Common cause of diverticulitis

bacteroides
Ecoli enterococci

143

Common cause of pancreatic absces

e coli
Klebsiella
Enterobacter
enterococci
streptococci

144

Diagnosis of abscess

location of pain
WBC count
imagining

145

Treatment of abscess

improve vascular perfusion
eliminate source of infection
Aspirate infected exudate
Treat complications

146

Anaerobes are resistant to what

penicillins
cephalosporins
Amino glycosides

147

Non toxic b. fargils promotes what

Mucosal health

148

Toxic b fragilis causes what

inflammatory diarrhea coloniziation
Toxins 1-3