Bacteria Flashcards
1
Q
What kind of bacteria is Staph aureus?
A
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
Q
What is the main virulence factor of Staph aureus? What is it’s function?
A
Protein A; it is part of the cell wall and binds FC portion of antibody; inhibits phagocytosis and complement activation
3
Q
What part of the body is normally colonized with Staph aureus?
A
Nares (opening of nose)
4
Q
Inflammatory diseases caused by Staph aureus (5)
A
- Pneumonia - patchy infiltrate on X-ray; secondary post viral super infection most often
- Joint problems - septic arthritis
- Skin infections - cellulitis, boils, abscesses
- Acute bacterial endocarditis - IV drug user (Right sided heart infection - tricuspid) (rapid onset, acute)
- Osteomyelitis - Most common cause
5
Q
Toxin mediated diseases caused by Staph aureus
A
- Scalded skin syndrome - mediated by exfoliative toxin
- Toxic shock syndrome - super antigen; from foreign package being left in too long
- Food poisoning - Rapid onset from preformed toxin (1-8 hours); vomiting; from meats and cream based foods (mayonnaise)
- MRSA - Alters PBP’s to get away from Methicillin; treatment is Vancomycin or Nafcillin
6
Q
What should you use to treat MRSA?
A
Vancomycin
Nafcillin
7
Q
What kind of bacteria is Staph epidermidis? (5)
A
Gram + cocci Catalase + Coagulase - Urease + Novobiocin sensitive (opposite of Staph saprophyticus)
8
Q
What kind of bacteria is Staph saprophyticus? (5)
A
Gram + cocci Catalase + Urease + Coagulase - Novobiocin resistant (opposite of Staph epidermidis
9
Q
What does Staph epidermidis classically infect?
A
- Artificial joints and catheters; covers everywhere
2. Endocarditis for artificial heart valves - most common cause of artificial valves
10
Q
What do you treat Staph epidermidis endocarditis? Why?
A
Vancomycin; it is resistant to many ABx
11
Q
Why is Staph epidermidis so good at infecting plastic/foreign surfaces?
A
Can produce adherent biofilms
12
Q
What disease does Staph saprophyticus cause?
A
UTI in sexually active females - SECOND most common cause behind E. coli
13
Q
What does Staph epidermidis contaminate?
A
Blood cultures; component of normal skin flora
14
Q
What kind of bacteria is Strep pyogenes?
A
Gram positive cocci in chains/pairs (Group A)
Catalase -
Beta hemolytic
Bacitracin sensitive
15
Q
What kind of bacteria is Strep agalactiae?
A
Gram positive cocci in chains (Group B)
Catalase -
Beta hemolytic
Bacitracin RESISTANT
16
Q
Pyogenic diseases that Strep pyogenes causes (2)
A
- Pharyngitis - strep throat
- Impetigo - honey crusted
- Cellulitis
- Erysipelas - most common cause of
17
Q
Toxigenic diseases that Strep pyogenes causes (2)
A
- Scarlet fever - strawberry tongue, pharyngitis, rash that spares face
- Toxic shock like syndrome - super antigen - SpeA, SpeC
- Necrotizing fasciitis - SpeB
18
Q
Immunologic diseases that Strep pyogenes causes (2)
A
- Rheumatic fever
2. Post-Strep Glomerulonephritis
19
Q
Impetigo more commonly precedes __________ than ________.
A
Impetigo more commonly precedes glomerulonephritis than pharyngitis.
20
Q
How do you detect Strep pyogenes infection?
A
ASO titer
21
Q
Treating S. pyogenes with Penicillin can prevent which complications?
A
Penicillin can prevent Acute Rheumatic Fever
It CANNOT prevent Acute Glomerulonephritis
22
Q
Signs of Post-Strep Glomerulonephritis
A
Type III hypersensitivity
Coca cola colored urine and facial puffiness 2 weeks after Strep infection
23
Q
What is responsible for Acute Rheumatic Fever after Strep infection?
A
M protein - it interferes with opsonization and is similar to antigen on cardiac myocytes (Strong humoral response created against it)
24
Q
What does Streptokinase do? What bacteria has it?
A
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
