Micr Su12 05A. Notes - Gram Negative Bacilli 1

Front 1

Name the genera of Gram-Negative aerobic bacilli. (5)

Back 1

1 Pseudomonas, 2 Legionella, 3 Bordetella, 4 Francisella, 5 Brucella

Front 2

Name the genera of gram-negative microaerophilic curved bacteria. (2)

Back 2

6 Campylobacter, 7 Helicobacter

Front 3

Name the gram-negative facultative aerobes (enterobacteriacea) (7)

Back 3

8 Escherichia, 9 Klebsiella, 10 Shigella, 11 Salmonella, 12 Proteus, 13 Yersinia, 14 Serratia.

Front 4

Name the gram-negative facultative aerobes (non-enterobacteriacea) (3)

Back 4

15 Vibrio, 16 Haemophilus, 17 Pasteurella

Front 5

Name the gram-negative ANaerobes

Back 5

18 Bacteroides, 19 Fusobacterium, 20 Prevotella, 21 Porphyromanas

Front 6

Pseudomonas aeruginosa: classification, metabolism, source, special characteristics (2)

Back 6

Gram-negative rod. aerobic ("AERuginosa"). SRC: water, slimy bar soap. SPECS: produces blue-green pigment pyocyanin ("aqua"), grape-like odor. [1 Pseudomonas, 2 Legionella, 3 Bordetella, 4 Francisella, 5 Brucella are aerobic]

Front 7

Pseudomonas aeruginosa: toxins (2)

Back 7

1 endotoxin (fever, shock), 2 exotoxin A (inactivates EF-2)

Front 8

Pseudomonas aeruginosa: treatment

Back 8

aminoglycoside plus extended-spectrum penicillin

Front 9

Pseudomonas aeruginosa: infections (6)

Back 9

Pneumonia (esp. in cystic fibrosis)
Sepsis (black lesions on skin)
External otitis
UTI with long-term catheter use
Drug use - endocarditis, osteomyelitis, arthritis
Osteomyelitis in Diabetics
hot tub folliculitis

Front 10

CLINICAL APPLICATION: A patient with extensive burns develops black lesions which produce blue-green pus, then dies of septicemia. Name the organism.

Back 10

P. aeruginosa

Front 11

CLINICAL APPLICATION: Name the most common infection in cystic fibrosis patients

Back 11

P. aeruginosa

Front 12

pyocyanin, fxn

Back 12

causes oxidative stress

Front 13

Describe the endotoxin of P. aeruginosa.

Back 13

Lipid A component of LPS released from dying cells.

Front 14

Legionella pneumophila: classification, metabolism

Back 14

Gram-negative rod (stains poorly because it is intracellular), aerobic. [1 Pseudomonas, 2 Legionella, 3 Bordetella, 4 Francisella, 5 Brucella are aerobic]

Front 15

Legionella pneumophila: typical infections

Back 15

1 Legionnaires' disease (severe atypical pneumonia, fever), 2 pontiac fever (mild flulike syndrome)

Front 16

Legionella pneumophila: mode of transmission (2)

Back 16

TRANSMIT: 1 aerosol from environment water source (not person to person), 2 found in AIR CONDITIONERS. (Roman legionairres probably breathed aerosolized versions from streams)

Front 17

Legionella pneumophila: detection, treatment

Back 17

DETECT: direct fluorescent antibody for L. pneumoniae in urine. TREAT: erythromycin.

Front 18

Legionella pneumophila: special culture needs, special stains

Back 18

Cultured on charcoal yeast extract agar buffered with cysteine and iron. Stain with silver.

Front 19

First aid mnemonic for legionella?

Back 19

"Think of a French legionnaire
wearing a SILVER helmet
sitting around a charcoal campfire with his iron dagger - he is no sissy (cystiene)"

Front 20

CLINICAL APPLICATION: Bacteria found in air conditioners?

Back 20

Legionella pneumophilia

Front 21

CLINICAL APPLICATION: A patient presents with toxic pneumonia (pneumonia with shock), no sputum, and a negative on Gram stain. What test should you order?

Back 21

direct fluorescent antibody for Legionella.

Front 22

B. pertussis: full name, culture requirements

Back 22

Bordatella pertussis. Regan-Lowe (charcoal, blood, and antibiotics)

Front 23

B. pertussis: infection

Back 23

whooping cough

Front 24

B. pertussis: morphology, metabolism

Back 24

small Gram negative coccoid rod, aerobic. [1 Pseudomonas, 2 Legionella, 3 Bordetella, 4 Francisella, 5 Brucella are aerobic]

Front 25

Pertussis toxin: mechanism of action, structure

Back 25

Pertussis toxin. Overactivates adenylate cyclase by disabling Gi > inc cAMP > impairs phagocytosis > allows microbe to survive. STRUCTURE: A-B. A=active subunit, B=binding subunit.

Front 26

B. pertussis: transmission

Back 26

airborn droplets

Front 27

B. pertussis: virulence factors (2)

Back 27

1 adhesins for attaching to ciliated resp epithelium, 2 pertussis toxin, 3 tracheal cytotoxin (kills epithelial cells).

Front 28

Name the stages of the whooping cough disease. (2)

Back 28

1 catarrhal stage (1 wk): rhinorrhea but no fever, pt is contagious. 2 paroxysmal stage (3 wk): coughing.

Front 29

CLINICAL APPLICATION: What element of the DTaP vaccine immunizes patients against pertussis? How often must patients be reimmunized?

Back 29

inactivated pertussis toxin + pertussis filamentous hemagglutinin. Must be reimmunized at 11 yr old.

Front 30

CLINICAL APPLICATION: A hunter comes down with fever and chills after skinning a wild rabbit. What lab test should be performed?

Back 30

immunofluorescent microscopy for Francisella tularensis.

Front 31

Francisella: important species, morphology, metabolism

Back 31

Francisella tularensis. Facultative intracellular. Aerobic. [Aerobic: 1 Pseudomonas, 2 Legionella, 3 Bordetella, 4 Francisella, 5 Brucella]

Front 32

Francisella: mode of transmission, progression of disease

Back 32

contact with wild animal blood (skinning a rabbit, bitten by a tick) > fever, chills & ulcer > septicemia > caseating granuloma

Front 33

know the list for intracellular and for aerobic

Back 33

xxx

Front 34

CLINICAL APPLICATION: A slaughterhouse worker who drinks unpasteurized milk for breakfast every day develops an undulating fever. Diagnosis?

Back 34

Brucella from cattle, goats, or swine.

Front 35

Brucella: main species and source of each (3), morphology

Back 35

Brucella abortus (cattle), B. melitensis (goat), B. suis (swine). Aerobic. Facultative intracellular.

Front 36

Name the genera of gram-negative microaerophilic curved bacteria. (2)

Back 36

6 Campylobacter (comma shaped), 7 Helicobacter (spiral shaped)

Front 37

"campylo-", def

Back 37

curvy

Front 38

CLINICAL APPLICATION: An entire family comes down with bloody diarrhea after a delicious Thansgiving meal. Later they speculated that it was because Aunt Sue hadn't cooked the turkey thorougly. What culture should be performed to confirm?

Back 38

Culture on Campy or Skirrow media (highly nutritive) at 42 degC for Campylobacter jejuni.

Front 39

What does it mean when microbes are "oxidase positive"?

Back 39

have cytocrome c oxidase, which can be tested

Front 40

Name the oxidase positive bacteria. (7)

Back 40

Vice President C.H.e.Ne.y Mostly Led. Vibrio, Pseudomonas, Campylobacter, Helicobacter, Neisseria, Moraxella, Legionella.

Front 41

C. jejuni: categorization, morphology, metabolism

Back 41

Gram-negative, aerobic. Spiral shaped ("flying seagull wing" appearance).

Front 42

C. jejuni: typical infections (2)

Back 42

1 infectious diarrhea from undercooked poultry or dogs, 2 Guillain-Barre

Front 43

CLINICAL APPLICATION: A patient presents with severe LUQ abdominal pain that is relieved by eating in the middle of the night. What diagnostic test should be performed to confirm the diagnosis?

Back 43

test for breath that is urease positive. H. pylori.

Front 44

Helicobacter pylori

Back 44

Gram-negative rod. Aerobic. Actually prefers an alkaline environment, so it tunnels to the mucosa.

Front 45

Helicobacter pylori: typical infection,

Back 45

INFECTION: 1 gastritis, 2 duodenal ulcers. TREAT: proton pump inhibitor + clarithromycin + amoxicillin or metronidazole.

Front 46

Helicobacter pylori: outcome risks (3)

Back 46

peptic ulcer, gastric adenocarcinoma, lymphoma

Front 47

Helicobacter pylori: diagnostic test

Back 47

test for breath that is urease positive

Front 48

Helicobacter pylori: virulence factors

Back 48

1 mucinase, 2 uses type IV secretion system to inject 3 cag into epithelial cells and trigger apoptosis, 4 vacuolating agent also causes apoptosis

Front 49

Helicobacter pylori: transmission

Back 49

fecal-oral

Front 50

Name the gram-negative facultative aerobes (non-enterobacteriacea) (3)

Back 50

15 Vibrio, 16 Haemophilus, 17 Pasteurella

Front 51

Name the clinically relevant species of Vibrio. (3)

Back 51

V. cholerae, V. parahaemolyticus, V. vulnificus.

Front 52

V. cholera: full name, morphology, growth media, source.

Back 52

Vibrio cholera. Comma shaped. Grows in TCBS alkaline media. Found in developing countries.

Front 53

V. cholera: toxins, mechanism of toxin, typical infection, treatment, toxin special characteristics

Back 53

TOXINS: 1 cholera toxin, 2 toxin coregulated pili. Cholera toxin activates Gs subunit > inc cAMP. Produces profuse rice-water diarrhea. Treat with oral rehydration. Bacterial toxin is encoded in a lysogenic phage.

Front 54

Describe the mechanism by which activation of Gs leads to watery diarrhea.

Back 54

Gs activation > increased adenylate cyclase > inc cAMP levels > ions and water efflux into lumen

Front 55

Name the toxins whos genes are encoded in a lysogenic phage (ie. specialized transduction lysogeny). (5)

Back 55

1 ShigA-like toxin, 2 Botulinum toxin (certain strains), 3 Cholera toxin, 4 Diphtheria toxin, 5 Erythrogenic toxin of strep pyogenes (ABCDE)

Front 56

Cholera epidemics inc coastal areas are associated with what natural phenomenon?

Back 56

Plankton booms.

Front 57

CLINICAL APPLICATION: Liz gets sick from eating shrimp in Ecuador. Probable infection?

Back 57

V. parahaemolyticus

Front 58

V. parahaemolyticus: typical infections, metabolism, classification

Back 58

Explosive, watery, possibly bloody diarrhea, vomiting, fever. gram-negative facultative anaerobe.

Front 59

CLINICAL APPLICATION: A man gets sick after shucking contaminated oysters. Probable infection?

Back 59

V. vulnificus.

Front 60

V. vulnificus: typical infections, metabolism, classification

Back 60

Gastroenteritis. gram-negative facultative anaerobe.

Front 61

CLINICAL APPLICATION: A patient injests raw oysters and develops gastroenteritis. The internist responsible for the pt care notices on the admit note that the patient is taking iron supplements. What is the main clinical concern?

Back 61

V. vulnificas grows especially well in patients with iron overload conditions, so it may cause septicemia and death in addition to gastroenteritis.

Front 62

CLINICAL APPLICATION: A child is admitted in the ED for fever and dysphagia. The child develops stridor and goes into respiratory arrest. While intubating the child, the anesthesiologist notes that the child has a cherry-red epiglottis. This is most likely due to what organism?

Back 62

H. influenzae

Front 63

Name the three clinically relevant species of Haemophilus.

Back 63

H. influenzae, H. aegypticus, H. ducreyi.

Front 64

H. influenzae: typical infections (4). Name the type.

Back 64

HaEMOPhilus
Epiglottitis (Hib)
Meningitis (Hib)
Otitis media (Hia)
Pneumonia (Hia)

Front 65

H. influenzae: full name, morphology, transmission. Which type is virulent?

Back 65

Haemophilus influenzae. Gram-negative facultative anaerobe. Small coccobacillary rod, can be capsulated (type B, aka "Hib"; virulent) nor non-capsulated (type A; normal flora). Aerosol transmission.

Front 66

H. influenzae: virulence factors (2)

Back 66

capsular type B, IgA protease.

Front 67

H. influenzae: treatment (2)

Back 67

treat meningitis with ceftriaxone. For close contact, give rifampin prophylaxis.

Front 68

H. influenzae: culture medium. Describe the "satellite phenomenon"

Back 68

Chocolate agar with factors V (NAD+) and X (hematin). "Satellite phenomenon": Can also be grown with S. aureus, which provides factor V.

Front 69

Name the components of the H. influenze vaccine. Age of administration?

Back 69

Contains type B capsular polysaccharide conjugated to diphtheria toxoid or other protein. Given between 2 and 18 mo.

Front 70

H. ducreyi, typical infection

Back 70

Chancroid lesion; painful genital ulcer, inguinal adenopathy (so painful, you "do cry")

Front 71

REVIEW: Name the most common cause of meningitis in newborns.

Back 71

N. meningitidis. H. influenzae used to be more common, but high vaccination rates changed that.

Front 72

H. aegypticus, typical infection

Back 72

pink eye

Front 73

CLINICAL APPLICATION: A person is bitten by a cat and develops cellulitis. Diagnosis?

Back 73

infection of Pasteurella multocida. Transmitted by dog, pig, and cat bites. ("many pastoral species")

Front 74

Pasteurella multicida:

Back 74

gram negative facultative aerobe

Front 75

Name the gram-negative ANaerobes

Back 75

18 Bacteroides, 19 Fusobacterium, 20 Prevotella, 21 Porphyromanas

Front 76

Name the typical locations where gram-negative anaerobes are found.

Back 76

chronic otitis media, sinusitis, aspiration pneumonia, decubitus ulcers, diabetic infections

Front 77

CLINICAL APPLICATION: What is the organism most commonly involved in appendicitis?

Back 77

B. fragiles

Front 78

Bacteroides fragiles: classification, metabolism, source, typical infection

Back 78

Gram negative bacilli. Anaerobic (but aerotolerant, so not that "fragile"). Found in the gut. Can also cause lung abscesses.

Front 79

Bacteroides fragiles: virulence factors (3)

Back 79

1 antiphagocytic capsule (helps with abscess formation), 2 modifed (less toxic) endotoxin, 3 beta-lactamase

Front 80

CLINICAL APPLICATION: A patient presents with air-fluid levels on CXR. Name the possible organisms. (4)

Back 80

Lung abscess due to S. aureus or anaerobes (Bacteroides, Fusobacterioum, Peptostreptococcus).

Front 81

CLINICAL APPLICATION: A patient presents with sloughing gingivitis and a "trenchmouth" smell. Diagnosis?

Back 81

Vincent's angina, aka acute necrotizing ulcerative gingivitis; associated with Fusobacterium (anaerobe of the oral and GI tract)

Front 82

Fusobacterium: classification, morphology, source, virulence factor, infection

Back 82

Gram negative bacilli with pointy ends (spindle shaped). Anaerobic. Found in oral and GI tract. Virulence factor is potent LPS. INFECTIONS: intestinal abscesses, Vincent's angina

Front 83

CLINICAL APPLICATION: A patient presents with a respiratory tract infection. When cultured, the colony turns black. What is the appropriate line of treatment for the infection?

Back 83

Prevotella or Porphyromonas. Infection requires debridement as well as antibiotics.

Front 84

Prevotella or Porphyromonas: source, distinguishing characteristic, typical infections (3)

Back 84

SRC: oral and genital tracts. CHAR: produce melanin, so colonies are black. INFECTIONS: ora, respiratory, genitourinary tract infections.