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Flashcards in Bacteria Deck (195):
1

What kind of bacteria is Staph aureus?

Gram + cocci in clusters
Catalase + (Strep is Catalase (-))
Coagulase + (converts fibrinogen to fibrin; compared to other Staph)
Beta hemolytic
Ferments mannitol (turns agar yellow)

2

What is the main virulence factor of Staph aureus? What is it's function?

Protein A; it is part of the cell wall and binds FC portion of antibody; inhibits phagocytosis and complement activation

3

What part of the body is normally colonized with Staph aureus?

Nares (opening of nose)

4

Inflammatory diseases caused by Staph aureus (5)

1. Pneumonia - patchy infiltrate on X-ray; secondary post viral super infection most often
2. Joint problems - septic arthritis
3. Skin infections - cellulitis, boils, abscesses
4. Acute bacterial endocarditis - IV drug user (Right sided heart infection - tricuspid) (rapid onset, acute)
5. Osteomyelitis - Most common cause

5

Toxin mediated diseases caused by Staph aureus

1. Scalded skin syndrome - mediated by exfoliative toxin
2. Toxic shock syndrome - super antigen; from foreign package being left in too long
3. Food poisoning - Rapid onset from preformed toxin (1-8 hours); vomiting; from meats and cream based foods (mayonnaise)
4. MRSA - Alters PBP's to get away from Methicillin; treatment is Vancomycin or Nafcillin

6

What should you use to treat MRSA?

Vancomycin
Nafcillin

7

What kind of bacteria is Staph epidermidis? (5)

Gram + cocci
Catalase +
Coagulase -
Urease +
Novobiocin sensitive (opposite of Staph saprophyticus)

8

What kind of bacteria is Staph saprophyticus? (5)

Gram + cocci
Catalase +
Urease +
Coagulase -
Novobiocin resistant (opposite of Staph epidermidis

9

What does Staph epidermidis classically infect?

1. Artificial joints and catheters; covers everywhere
2. Endocarditis for artificial heart valves - most common cause of artificial valves

10

What do you treat Staph epidermidis endocarditis? Why?

Vancomycin; it is resistant to many ABx

11

Why is Staph epidermidis so good at infecting plastic/foreign surfaces?

Can produce adherent biofilms

12

What disease does Staph saprophyticus cause?

UTI in sexually active females - SECOND most common cause behind E. coli

13

What does Staph epidermidis contaminate?

Blood cultures; component of normal skin flora

14

What kind of bacteria is Strep pyogenes?

Gram positive cocci in chains/pairs (Group A)
Catalase -
Beta hemolytic
Bacitracin sensitive

15

What kind of bacteria is Strep agalactiae?

Gram positive cocci in chains (Group B)
Catalase -
Beta hemolytic
Bacitracin RESISTANT

16

Pyogenic diseases that Strep pyogenes causes (2)

1. Pharyngitis - strep throat
2. Impetigo - honey crusted
3. Cellulitis
4. Erysipelas - most common cause of

17

Toxigenic diseases that Strep pyogenes causes (2)

1. Scarlet fever - strawberry tongue, pharyngitis, rash that spares face
2. Toxic shock like syndrome - super antigen - SpeA, SpeC
3. Necrotizing fasciitis - SpeB

18

Immunologic diseases that Strep pyogenes causes (2)

1. Rheumatic fever
2. Post-Strep Glomerulonephritis

19

Impetigo more commonly precedes __________ than ________.

Impetigo more commonly precedes glomerulonephritis than pharyngitis.

20

How do you detect Strep pyogenes infection?

ASO titer

21

Treating S. pyogenes with Penicillin can prevent which complications?

Penicillin can prevent Acute Rheumatic Fever
It CANNOT prevent Acute Glomerulonephritis

22

Signs of Post-Strep Glomerulonephritis

Type III hypersensitivity
Coca cola colored urine and facial puffiness 2 weeks after Strep infection

23

What is responsible for Acute Rheumatic Fever after Strep infection?

M protein - it interferes with opsonization and is similar to antigen on cardiac myocytes (Strong humoral response created against it)

24

What does Streptokinase do? What bacteria has it?

Strep pyogenes; it converts plasminogen to plasmin

25

What kind of capsule does Strep pyogenes have?

Hyaluronic acid capsule (not immunogenic)

26

Defining characteristics of Strep agalctiae

Gram + cocci
Group B strep
Beta hemolytic
Bacitracin RESISTANT
Polysaccharide capsule
CAMP test positive

27

What is the significance of CAMP factor?
What bacteria produces CAMP factor?

Enlarges the area of hemolysis formed by S. aureus
Strep agalactiae

28

Diseases in Strep agalactiae

Neonatal meningitis + sepsis + pneumonia

29

Why do you need to screen pregnant women for Strep agalactiae? When do you screen them? How do you treat if infected?

It colonizes vagina and there is no vaccine so babies passing through vaginal canal can become infected
Screen at 35-37 weeks; treat with intrapartum penicillin prophylaxis

30

#1 cause of meningitis in neonates

Strep agalactiae (other causes are Listeria and K1 E. coli)

31

Alpha hemolytic strep

Strep pneumoniae
Strep viridans

32

Strep pneumo characteristics

Polysaccharide capsule
Optochin sensitive
Lancet shaped diplococci
Bile soluble
IgA protease

33

Strep pneumo is the most common cause of:

1. Meningitis
2. Otitis media
3. Pneumonia
4. Sinusitis

34

What is treatment of choice for outpatient CAP?

Azithromycin

35

What is pneumococcus associated with in sickle cell disease and splenectomy patients?

Rusty sputum and sepsis

36

What accounts for Strep pneumo resistance?

Polysaccharide capsule

37

Treatment for Strep pneumo

Macrolide (Erythromycin)
3rd gen. Cephalosporin (Ceftriaxone)

38

Vaccines for Strep pneumo

Adults - 23 talent polysaccharide; T cell independent (only IgM)
Children - 7 talent conjugation; more robust T cell response (IgG)

39

Strep viridans characteristics

No capsule
Optochin resistant
Bile resistant

40

What diseases do viridans Strep cause?

Dental caries (mutans)
subacute bacterial endocarditis (sanguinis)

41

Makes dextrans, which bind to fibrin-platelet aggregates on damaged heart valves

Viridans strep

42

Group D Strep

Enterococci (E. faecalis and E. faecium)

43

What are enterococci found?

Normal colonic flora

44

What diseases do enterococci cause?

UTI
Biliary tract infections
Subacute endocarditis (following GI/GU procedures)

45

Which enterococci species is more common?

E. faecalis

46

Which enterococci species is more dangerous?

E. faecium (bile resistant)

47

Why are nosocomial enterococci infections dangerous?

They are resistant to everything
Vancomycin-resistant enterococci

48

How do you treat Vancomycin-resistant enterococci?

Linezolid
Tigecycline

49

Which bacteria is associated with colon cancer?

Strep Bovis (group D strep)
-Can also cause bacteremia and subacute endocarditis

50

What kind of toxin does Corynebacterium diphtheriae cause diphtheria with?

Via exotoxin encoded by B-prophage --> inhibits protein synthesis via ADP-ribosylation of EF-2

51

Pseudomembranous pharyngitis (gray-white membrane) with lymphadenoapthy, myocarditis and arrhythmias

Corynebacterium diptheriae

52

How is Corynebacterium transmitted?

By respiratory droplets

53

Gram positive rods with metachromatic granules and + Elek test for toxin

Corynebacterium diptheriae

54

ABCDEFG of Corynebacterium

ADP ribosylation
B-prophage
Corynebacterium
Diphtheriae
Elongation Factor 2
Granules

55

Black colonies on cystine-tellurite agar (plated on Loeffler's medium)

Corynebacterium diphtheriae

56

Bacterial spores; cause which disease?
a. Bacillus anthracis
b. Bacillus cereus
c. Clostridium botulinum
d. Clostridium difficile
e. Clostidium perfringens
f. Clostridium tetani
g. Coxiella burnetii

a. Anthrax
b. Food poisoning
c. Botulism
d. Antibiotic-associated colitis
e. Gas gangrene
f. Tetanus
g. Q fever

57

How does Bordetella pertussis toxin work?

It ADP ribosylates Gi (inactivates it) and causes over activation of adenylate cyclase that elevates cAMP production and increases secretions and mucus production --> makes it more difficult to clear bacteria

58

Black eschar

Bacillus anthracis (cutaneous)

59

What kind of bacteria is Bacillus anthracis?

Gram positive rods in CHAINS
Obligate AEROBE

60

What kind of capsule does Bacillus anthracis have?

polypeptide capsule (contains D-glutamate) - ONLY BACTERIUM with this

61

Bacillus anthracis toxins

1. Edema factor: adenylate cyclase causes increased cAMP and fluid enters extracellular space --> inhibits host defenses and phagocytosis
2. Lethal factor: Exotoxin that cleaves MAP kinase (normally controls cell growth) and causes tissue necrosis

62

a. What does edema factor do?
b. What bacteria is it associated with?

a. It activates adenylate cyclase to cause increased cAMP and fluid enters the extracellular space --> inhibits host defenses and phagocytosis
b. Bacillus anthracis

63

a. What does lethal factor do?
b. What bacteria is it associated with?

a. Exotoxin that cleaves MAP kinase and causes tissue necrosis

64

What diseases does Bacillus anthracis cause?

a. Cutaneous anthrax - painless papule --> black eschar
b. Pulmonary anthrax - Wool sorter disease

65

What is presentation of cutaneous anthrax?

Painless papule surrounded by vesicles --> ulcer with black eschar 5 f

66

What is presentation of cutaneous anthrax?

Painless papule surrounded by vesicles --> ulcer with black eschar (can uncommonly progress to bacteremia and death)

67

What is presentation of pulmonary anthrax? How do you get it?

Inhalation of spores -->

68

What is presentation of pulmonary anthrax? How do you get it?

Inhalation of spores --> flu like symptoms that rapidly progress to fever, pulmonary hemorrhage, mediastinitis and shock

69

How do you treat pulmonary anthrax (wool sorter's disease)?

Fluoroquinolones

70

How do you treat pulmonary anthrax (wool sorter's disease)?

Fluoroquinolones

71

How do you treat pulmonary anthrax (wool sorter's disease)?

Fluoroquinolones

72

Characteristics of Clostridia bacteria

Gram positive, spore forming, obligate anaerobic bacilli

73

Characteristics of Clostridia bacteria

Gram positive, spore forming, obligate anaerobic bacilli

74

Who is at risk for Listeria infection?

Infants
Pregnant women
Immunocompromised
Elderly

75

Who is at risk for Listeria infection?

Infants
Pregnant women
Immunocompromised
Elderly

76

Branching, filamentous gram positive rods with SULFUR GRANULES

Actinomyces israelii

77

Reheated rice syndrome

Bacillus cereus

78

Food poisoning caused by spores that survive cooking rice/pasta

Bacillus cereus

79

a. What types of food poisoning does Bacillus cereus cause and how long is the incubation period?

1. Emetic type - Nausea and vomiting within 1-5 hours
b. Diarrheal type causes watery, non-bloody diarrhea and GI pain within 8-18 hours

80

Function of tetanus toxin

Protease that cleaves SNARE proteins for neurotransmitters; blocks release of inhibitory neurotransmitters, GABA and glycine (from Renshaw cells in spinal cord)

81

Tetanus toxin presentation

Spastic paralysis, trismus (lock jaw), risus sardonicus (raised eyebrows and open grin)

82

Tetanus toxin presentation

Spastic paralysis, trismus (lock jaw), risus sardonicus (raised eyebrows and open grin)

83

What kind of vaccine is the tetanus vaccine?

Toxoid vaccine (toxin conjugated to protein)

84

Clostridium botulinum toxin?

Produces a preformed, heat-labile toxin that inhibits Ach release at the neuromuscular junction (flaccid paralysis)

85

How is C. botulinum transmitted? In adults? In Kids?

Adults - ingestion of preformed toxin
Babies - ingestion of spores in honey

86

C. botulinum presentation

Adults - Descending paralysis, Mydriasis/muscle weakness
Kids - floppy baby syndrome

87

Why can C. botulinum spores cause disease in babies?

Babies lack enteric flora so spores can germinate after they are ingested

88

Why can C. botulinum spores cause disease in babies?

Babies lack enteric flora so spores can germinate after they are ingested

89

Spore forming bacteria

Clostridium species
Bacillus species
Coxiella burnetii

90

C. difficile toxins

ExoA: enterotoxin that binds to brush border of gut and causes inflammation, cell death and watery diarrhea
ExoB: cytotoxin that causes cytoskeletal disruption via actin depolymerization --> pseudomembranous colitis --> diarrhea

91

C. difficile toxins

ExoA: enterotoxin that binds to brush border of gut and causes inflammation, cell death and watery diarrhea
ExoB: cytotoxin that causes cytoskeletal disruption via actin depolymerization --> pseudomembranous colitis --> diarrhea

92

Antibiotics that commonly cause C. difficile enterocolitis

Clindamycin
Ampicillin

93

How is C. difficile diagnosed?

Detection of one or both toxins in stool by PCR

94

C. difficile treatment

Metronidazole
ORAL Vancomycin
Fidaxomicin - recurrent cases
Fecal microbiota transplant

95

C. difficile treatment

Metronidazole
ORAL Vancomycin
Fidaxomicin - recurrent cases
Fecal microbiota transplant

96

Motor cycle accidents and deep penetrating wounds from military combat

Clostridium perfringens

97

C. perfringens toxin

Alpha toxin (lecithinase - a phospholipase) --> causes damage to cell membranes --> myonecrosis

98

Causes gas gangrene and double zone of hemolysis

Clostridium perfringens

99

Treatment for C. perfringens

IV penicillin G

100

Diseases caused by C. perfringens

1. Gas gangrene (crackling and crepitus)
2. Hemolysis (double zone)
3. Food poisoning - late onset diarrhea (from ingestion of spores and spores germinate in gut, producing toxin)

101

Diseases caused by C. perfringens

1. Gas gangrene (crackling and crepitus)
2. Hemolysis (double zone)
3. Food poisoning - late onset diarrhea (from ingestion of spores and spores germinate in gut, producing toxin)

102

Cells that are susceptible to Corynebacterium toxin

Heart (myocarditis, HF)
Brain tissue (neurologic toxicity)

103

Cells that are susceptible to Corynebacterium toxin

Heart (myocarditis, HF)
Brain tissue (neurologic toxicity)

104

What kind of bacteria is Listeria monocytogenes?

Gram positive rod
BETA HEMOLYTIC
Facultative intracellular

105

Beta hemolytic gram positive rod

Listeria monocytogenes

106

How is Listeria acquired?

Ingestion of unpasteurized dairy products or cold deli meats
Via transplacental transmission or vaginal transmission during birth

107

What kind of bacteria is Listeria monocytogenes?

Gram positive rod
BETA HEMOLYTIC
Facultative intracellular
MOTILE (tumbling extracellularly)
Catalase positive
Can survive in near freezing temps (refrigerator)

108

What kind of bacteria is Listeria monocytogenes?

Gram positive rod
BETA HEMOLYTIC
Facultative intracellular
MOTILE (tumbling extracellularly)
Catalase positive
Can survive in near freezing temps (refrigerator)

109

How does Listeria move intracellularly and extracellularly?

Forms "rocket tails" via actin polymerization that allow intracellular movement and cell to cell spread
Characteristic tumbling motility

110

Diseases that Listeria can cause

Amnionitis
Septicemia
Spontaneous abortion in pregnant women
Granulomatous infantiseptica
Neonatal meningitis
Meningitis in immunocompromised patients
Mild gastroenteritis in healthy

111

Gram positive rod causing spontaneous abortion in pregnant women

Listeria monocytogenes

112

Treatment for Listeria infection

In healthy - self limited
In infants, immunocompromised, elderly - Ampicillin for meningitis

113

Treatment for Listeria infection

In healthy - self limited
In infants, immunocompromised, elderly - Ampicillin for meningitis

114

Gram negative diplococci that ferments maltose

Neisseria meningitidis

115

Gram negative rods that ferment lactose (Pink on MacConkey agar)

Fast - Klebsiella, E. coli, Enterobacter
Slow - Serratia, Citrobacter

116

Gram negative diplococci that does NOT ferment maltose

Neisseria gonorrhoeae

117

Gram negative "Coccoid" rods

Haemophilus influenzae (requires factor V and X)
Pasteurella
Brucella
Bordetella pertussis

118

Gram negative Oxidase Positive comma shaped bacteria

Campylobacter
Vibrio cholerae
Helicobacter pylori

119

Gram negative oxidase positive, comma shaped bacteria that grows at 42 degrees celsius

Campylobacter jejuni

120

Gram negative oxidase positive, comma shaped bacteria that grows in alkaline media

Vibrio cholerar

121

Gram negative oxidase positive comma shaped bacteria that produces urease

Helicobacter pylori

122

Gram negative rod, NON lactose fermenting, Oxidase positive

Pseudomonas

123

What is Waterhouse-Friderichsen syndrome?

Adrenal hemorrhage caused by Neisseria meningitidis

124

What is Waterhouse-Friderichsen syndrome?

Adrenal hemorrhage caused by Neisseria meningitidis

125

What is Waterhouse-Friderichsen syndrome?

Adrenal hemorrhage caused by Neisseria meningitidis

126

Which Neisseria species has a capsule and ferments maltose?

Meningococci

127

a. Transmission of N. meningococci
b. Transmission of N. gonococci

a. respiratory and oral secretions
b. sexually or perinatally transmitted

128

a. diseases of meningococci
b. diseases of gonococci

a. meningococcemia, meningitis, Waterhouse-Friderischsen syndrome
b. Gonorrhea, septic arthritis, neonatal conjunctivitis, PID, Fitz-Hugh-Curtis syndrome (liver capsule)

129

Prophylaxis of N. meningococci infectedclose contacts

Rifampin, Ciprofloxacin or Ceftriaxone

130

Treatment for N. meningococci

Ceftriaxone or Penicillin G

131

Treatment for N. gonococci

Ceftriaxone + (Azithroycin or Doxycycline) for possible chlamydial confection

132

Treatment for N. gonococci

Ceftriaxone + (Azithroycin or Doxycycline) for possible chlamydial co-infection

133

Small gram negative coccobacillary rod transmitted by aerosols

Haemophilus influenzae

134

What does H. influenzae require for growth on chocolate agar?

Factors V (NAD+) and X (hematin) (can also be grown with S. aureus that provides factor V through hemolysis of RBCs)

135

Diseases caused by H. influenzae

Epiglottitis
Meningitis
Otitis media
Pneumonia

136

Treatment of H. influenzae mucosal infections

Amoxicillin +/- Clavulanate

137

Treatment of H. flu meningitis

Ceftriaxone

138

Prophylaxis in close contacts of H. flu meningitis patients

Rifampin

139

Prophylaxis in close contacts of H. flu meningitis patients

Rifampin

140

Rose spots on abdomen

Salmonella typhi

141

Associated with Guillain Barre syndrome

Campylobacter jejuni

142

Associated with Guillain Barre syndrome

Campylobacter jejuni

143

Food poisoning due to exotoxin

Staph aureus and Bacillus cereus

144

Food poisoning due to exotoxin

Staph aureus and Bacillus cereus

145

Most common causes of UTIs

E. coli (80%)
Staph saprophyticus
Klebsiella pneumoniae
Serratia marcescens

146

Most common causes of UTIs

E. coli (80%)
Staph saprophyticus
Klebsiella pneumoniae
Proteus

147

Most common causes of UTIs

E. coli (80%)
Staph saprophyticus
Klebsiella pneumoniae
Proteus

148

4 A's of KlebsiellA

Aspiration pneumonia
Abscess in lungs and liver
Alcoholics
Di-A-betics

149

Diseases that Klebsiella causes:
4 A's of KlebsiellA

Aspiration pneumonia
Abscess in lungs and liver
Alcoholics
Di-A-betics
UTI's

150

Diseases that Klebsiella causes:
4 A's of KlebsiellA

Aspiration pneumonia
Abscess in lungs and liver
Alcoholics
Di-A-betics
UTI's

151

Most common bacteria in a patient with strive kidney stones

Proteus

152

Most common bacteria in a patient with strive kidney stones

Proteus

153

a. animal urine
b. rat urine

a. Leptospira interrogans
b. Hantavirus

154

a. animal urine
b. rat urine

a. Leptospira interrogans
b. Hantavirus

155

Cat scratch fever

Bartonella spp.

156

Lyme disease bug and source

Borrelia burgdorferi, Ixodes tick

157

Undulant fever bug and source

Brucella and unpasteurized dairy

158

Psittacosis bug, source

Chlamydophila psittaci, parrots/birds

159

Q fever bug, source

Coxiella burnetii, aerosols of cattle/sheep amniotic fluid

160

Ehrlichiosis bug, source

Ehrliche chaffeensis, Lone star tick (ambylomma)

161

Tularemia (lymphadenopathy and site specific ulcer, granuloma formation) bug and source

Francisella tularensis, ticks and rabbits

162

Leptospirosis bug and source

Leptospira spp. and animal urine

163

Leprosy bug and source

Mycobacterium leprae, armadillo

164

Cellulitis and osteomyelitis bug and source

Pasteurella multocida, animal bites

165

Rocky Mountain spotted fever bug and source

Rickettsia rickettsii, dermacenter dog tick

166

Tularemia (lymphadenopathy and site specific ulcer, granuloma formation) bug and source

Francisella tularensis, ticks and rabbits (think rabbit hunter)

167

Rocky Mountain spotted fever bug and source

Rickettsia rickettsii, dermacenter dog tick

168

Standard treatment for T. pallidum

Penicillin

169

Cellulitis from dog or cat bite

Pasteurella multocida

170

Non-painful, indurated, ulcerated genital lesion

Chancre of primary syphilis

171

Moist, smooth, flat white genital lesion

Condylomata late of secondary syphilis

172

Large bull's eye rash

Erythema migrants due to Lyme disease

173

R's of Rifampin

RNA polymerase inhibitor
Ramps up microsomal cytochrome P450
Red/orange body fluids
Rapid resistance is used alone

174

Prophylaxis for MAC when CD4 counts

Azithromycin

175

Prophylaxis for MAC when CD4 counts

Azithromycin

176

S/E of Ethambutol

Optic neuropathy

177

Ethambutol mechanism

Blocks arabinosyltransferase causing decreased carbohydrate polymerization

178

a. What is a Ghon complex?
b. What is a Ghon focus?

a. Calcified lung scar (ghon focus) + hilar lymphadenopathy
b. Calcified lung scar
-Seen in Primary TB

179

Ethambutol mechanism

Blocks arabinosyltransferase causing decreased carbohydrate polymerization of mycobacterium cell wall

180

a. What is a Ghon complex?
b. What is a Ghon focus?

a. Calcified lung scar (ghon focus) + hilar lymphadenopathy
b. Calcified lung scar
-Seen in Primary TB

181

What can be given with Isoniazid to prevent neurotoxicity?

Pyridoxine (Vitamin B6)

182

What can be given with Isoniazid to prevent neurotoxicity?

Pyridoxine (Vitamin B6)

183

Calcified granuloma in lung + hilar lymphadenopathy

Ghon complex (TB)

184

Calcified granuloma in lung + hilar lymphadenopathy

Ghon complex (TB)

185

Back pain, fever, night sweats, weight loss

Potts disease (TB)

186

Back pain, fever, night sweats, weight loss

Potts disease (TB)

187

How are all Rickettsial diseases treated?

Doxycycline

188

Mycoplasma pneumoniae cell membrane consists of:

Sterols
NO CELL WALL = NO GRAM STAIN

189

Mycoplasma pneumoniae cell membrane consists of:

Sterols
NO CELL WALL = NO GRAM STAIN

190

Fishy discharge, clue cells, bacterial overgrowth

Gardnerella vaginalis

191

Starts with rash on palms and soles, fever, spread by ticks

Rocky Mountain Spotted Fever

192

Starts with rash on palms and soles, fever, spread by ticks

Rocky Mountain Spotted Fever

193

Fever, spread by ticks, starts with central rash and spreads outward

Rickettsia prowazeki and typhi

194

Fever, spread by ticks, starts with central rash and spreads outward

Rickettsia prowazeki and typhi

195

Treatment for bacterial vaginosis

Metronidazole